Publications
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Camera, Andrea; Islam, Tawhidul; Parvan, Reza; Pischke, Søren Erik; Silva, Gustavo Jose Justo Da & Stensløkken, Kåre-Olav
(2025).
Prognostic and diagnostic biomarkers in liver transplantation: A systematic review and meta-analysis.
Liver transplantation.
ISSN 1527-6465.
31(12),
p. 1499–1510.
doi:
10.1097/LVT.0000000000000666.
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Liver transplantation (LT) is a therapeutic option for patients suffering from end-stage liver disease. Recent research has probed the prognostic significance of biomarkers to predict graft function and mortality post-transplant, yet few candidates are recommended in clinical practice. We employed a pipeline that integrates meta-analysis (PRISMA 2020), followed by Kaplan–Meier (KM)-based individual patient data (IPD) analysis, aiming to identify potential novel prognostic biomarker panels for LT recipients. Ovid Medline, Embase, and Cochrane databases were searched. Twenty-one prognostic and 8 diagnostic studies were eligible, pooling 34,922 patients. Single biomarkers sampled at an early stage (≤15 d after LT) were significantly associated with graft-related outcomes (HR/OR 0.95 [0.94–0.97]) but did not predict mortality (HR/OR 1.00 [0.97–1.04]) or composite outcomes (HR/OR 1.02 [0.98–1.07]). Biomarkers in combination (GGT/bilirubin ratio, ALT+AST or ALT+AST+bilirubin+INR) predicted composite outcomes (graft failure or mortality, aHR/aOR 4.37 [2.65–7.21]). Biomarkers assessed at late stage (>15) did not show association with mortality (HR/OR 1.02 [1.00–1.04]) or composite outcomes (HR/OR 1.00 [0.99–1.01]). KM-based IPD analysis showed that coagulation factor V combined with ALT predicted graft survival (HR 2.12 [1.44–3.12]), and coagulation factor V+insulin-like growth factor 1 stratified the risk of patient survival (HR 2.97 [1.79–4.91]). Therefore, we were able to compare various scoring systems in predicting graft-related outcomes and mortality following LT. Additionally, we identified novel combinations of biomarkers that exhibited prognostic value for LT patients. Finally, we demonstrate that combined analytical tools for assessing large clinical datasets effectively evaluate multi-modal markers for risk stratification of early and late outcomes for LT.
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Boer, Eline de; Strandmoe, Anne-Lise; Sokolova, Marina; Michelsen, Trond Melbye; Quach, Huy Quang & Chaban, Viktoriia
[Show all 12 contributors for this article]
(2025).
Extracellular mitochondrial DNA activates complement and is associated with complement activation in patients with out-of-hospital cardiac arrest.
Scientific Reports.
15(1).
doi:
10.1038/s41598-025-24705-1.
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Abstract Synthetic analogues of mitochondrial DNA (mtDNA) have been reported as potent complement system activators. This study investigated the impact of endogenous mtDNA on complement activation. mtDNA and nuclear DNA (nDNA) were extracted from human placental tissue and complement activation was determined using ELISA. When incubated in lepirudin-anticoagulated human blood and plasma, increasing concentrations of mtDNA, but not nDNA, resulted in dose- and time-dependent increases in C3bc, C3bBbP and soluble C5b-9 (sC5b-9). In a clinical context, mtDNA, nDNA, and complement levels of 55 resuscitated out-of-hospital cardiac arrest (OHCA) patients were determined using qPCR and ELISA. C3bc and sC5b-9 correlated significantly with mtDNA and nDNA in OHCA patients. We conclude that mtDNA, but not nDNA, triggers in vitro complement activation, which holds significance in a clinical context in OHCA patients. This novel mode of human complement activation might explain pathophysiological mechanisms of sterile inflammation and could be relevant for innovative therapeutic strategies.
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Wiger, Christine Wagle; Ranheim, Trine; Arnesen, Henriette; Vaage, Ingvar Jarle; Pischke, Soeren & Yndestad, Arne
[Show all 8 contributors for this article]
(2025).
TLR4 Inhibition Attenuated LPS-Induced Proinflammatory Signaling and Cytokine Release in Mouse Hearts and Cardiomyocytes.
Immunity,Inflammation and Disease.
13(1).
doi:
10.1002/iid3.70133.
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Background
Sepsis is associated with myocardial injury and early mortality. The innate immune receptor Toll-like receptor 4 (TLR4) can recognize pathogen-associated-molecular-patterns (PAMPs) and damage-associated molecular patterns (DAMPs); the latter are released during tissue injury. We hypothesized that TLR4 inhibition reduces proinflammatory signaling and cytokine release in: (1) LPS or Escherichia coli-treated isolated mouse heart; (2) LPS-treated mouse primary adult cardiomyocytes; and (3) the isolated heart during ischemia–reperfusion.
Methods
Isolated C57BL/6N male mouse hearts were perfused for 120 min, with either LPS, E. coli, with and without CLI-095 (TLR4 inhibitor). Primary adult mouse cardiomyocytes were treated with LPS or LPS + CLI-095. Isolated hearts, exposed to 35 min of global ischemia, were treated with either vehicle or CLI-095 during reperfusion. Infarct size was quantified by triphenyltetrazolium staining. Cytokine expression was analyzed with ELISA, western blot analysis, and qPCR.
Results
In isolated hearts, E. coli increased the expression of proinflammatory cytokines (IL-6 and CXCL2), which was not attenuated with TLR4 inhibition. TLR4 inhibition reduced expression (p = 0.004) and release of IL-6 (p < 0.0001) in LPS-exposed isolated hearts. LPS activated the nuclear-factor κ-light-chain-enhancer of activated B cells signaling pathway (NF-κB) in primary adult cardiomyocytes. Moreover, TLR4 inhibition reduced LPS-induced mRNA expression and release of IL-6 in primary adult cardiomyocytes. Isolated hearts treated with CLI-095 during reperfusion after ischemia (induced DAMPs release) showed reduced infarct size (39 ± 17% to 26 ± 8%, p = 0.034) and decreased IL-6 release (p = 0.006).
Conclusion
Inhibition of TLR4 reduced proinflammatory signaling and cytokine release in LPS-treated and ischemia–reperfused isolated mouse hearts and in primary adult murine cardiomyocytes.
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Scott, Mark Adam; Fagernes, Cathrine Elisabeth; Nilsson, Göran Erik & Stensløkken, Kåre-Olav
(2024).
Maintained mitochondrial integrity without oxygen in the anoxia-tolerant crucian carp.
Journal of Experimental Biology.
ISSN 0022-0949.
227(20).
doi:
10.1242/jeb.247409.
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Very few vertebrates survive without oxygen (anoxia) for more than a few minutes. Crucian carp (Carassius carassius) are one example, surviving months of anoxia at low temperatures, and we hypothesised that they maintain mitochondrial membrane potential and function. Isolated crucian carp cardiomyocytes indeed maintained mitochondrial membrane potential after blocking complex IV of the electron transport system with cyanide, while those of anoxia-intolerant trout depolarised. When complexes I–III were inhibited, crucian carp mitochondria depolarised, indicating that these complexes need to function during anoxia. Mitochondrial membrane potential depended on reversal of ATP synthase in chemical anoxia, as blocking with cyanide combined with oligomycin to inhibit ATP synthase led to depolarisation. ATP synthase activity was reduced in the heart after 1 week of anoxia in crucian carp, together with a downregulation of ATP synthase subunit gene expression. However, the morphology of cardiac mitochondria was not affected by 1 week of anoxia, even with a large increase in mitofusin 2 mRNA expression. Cardiac citrate synthase activity was not affected by anoxia, while cytochrome c oxidase activity was increased. We show how mitochondria respond to anoxia. A mechanistic understanding of how mitochondrial function can be maintained in anoxia may provide new perspectives to reduce mitochondrial damage in anoxia-sensitive organisms.
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Torp, May-Kristin; Stensløkken, Kåre-Olav & Vaage, Ingvar Jarle
(2024).
When Our Best Friend Becomes Our Worst Enemy: The Mitochondrion in Trauma, Surgery, and Critical Illness.
Journal of Intensive Care Medicine.
ISSN 0885-0666.
doi:
10.1177/08850666241237715.
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Zabirnyk, Arsenii; Evensen, Daria; Kvitting, John-Peder; Kaljusto, Mari-Liis; Stensløkken, Kåre-Olav & Vaage, Ingvar Jarle
(2024).
Hyperglycemia-simulating environment attenuated experimentally induced calcification in cultured human aortic valve interstitial cells.
Scandinavian Cardiovascular Journal.
ISSN 1401-7431.
58(1).
doi:
10.1080/14017431.2024.2353070.
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Objectives: The role of diabetes mellitus as a risk factor for the development of calcific aortic valve disease has not been fully clarified. Aortic valve interstitial cells (VICs) have been suggested to be crucial for calcification of the valve. Induced calcification in cultured VICs is a good in vitro model for aortic valve calcification. The purpose of this study was to investigate whether increased glucose levels increase experimentally induced calcification in cultured human VICs. Design: VICs were isolated from explanted calcified aortic valves after valve replacement. Osteogenic medium induced calcification of cultured VICs at different glucose levels (5, 15, and 25 mM). Calcium deposits were visualized using Alizarin Red staining and measured spectrophotometrically. Results: The higher the glucose concentration, the lower the level of calcification. High glucose (25 mM) reduced calcification by 52% compared with calcification at a physiological (5 mM) glucose concentration (correlation and regression analysis: r = −0.55, p = .025 with increased concentration of glucose). Conclusions: In vitro hyperglycemia-like conditions attenuated calcification in VICs. High glucose levels may trigger a series of events that secondarily stimulate calcification of VICs in vivo.
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2024).
Differential production of mitochondrial reactive oxygen species between mouse (Mus musculus) and crucian carp (Carassius carassius).
Acta Physiologica.
ISSN 1748-1708.
240(12).
doi:
10.1111/apha.14244.
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Aim In most vertebrates, oxygen deprivation and subsequent re-oxygenation are associated with mitochondrial impairment and excess production of reactive oxygen species (ROS) like hydrogen peroxide (H2O2). This in turn triggers a cascade of cell-damaging events in a temperature-dependent manner. The crucian carp (Carassius carassius) is one of few vertebrates that survives months without oxygen at cold temperatures and overcomes oxidative damage during re-oxygenation periods. Mitochondria of this anoxia-tolerant species therefore serve as an excellent model in translational research to study adaptation and resilience to low oxygen conditions and thermal variability. Methods Here, we used high-resolution respirometry on isolated mitochondria from hearts of crucian carp and the anoxia-intolerant mouse (Mus musculus), at 37 and 8°C; two temperatures relevant for transplantation medicine (i.e., graft preservation and subsequent rewarming). Results We find: (1) a striking difference in H2O2 release between the two species at 37°C despite comparable mitochondrial efficiency and capacity, (2) a massive H2O2 release after inhibition of complex V in mouse at 37°C that is absent in crucian carp, and prevented in mouse by incubation at 8°C or uncoupling with a protonophore at 37°C, and (3) indications that differences in mitochondrial complex I and II capacity and thermal sensitivity influence the release of mitochondrial H2O2 relative to respiration. Conclusion Our findings provide comparative insights into a spectrum of mitochondrial adaptations in vertebrates and the importance of thermal variability. Furthermore, the species- and temperature-related changes associated with mitochondria highlighted in this study may help identify mitochondria-based targets for translational medicine.
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Sánchez-Pérez, Patricia; Mata, Ana; Torp, May-Kristin; López-Bernardo, Elia; Heiestad, Christina Mathisen & Aronsen, Jan Magnus
[Show all 14 contributors for this article]
(2023).
Energy substrate metabolism, mitochondrial structure and oxidative stress after cardiac ischemia-reperfusion in mice lacking UCP3.
Free Radical Biology & Medicine.
ISSN 0891-5849.
205,
p. 244–261.
doi:
10.1016/j.freeradbiomed.2023.05.014.
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Myocardial ischemia-reperfusion (IR) injury may result in cardiomyocyte dysfunction. Mitochondria play a critical role in cardiomyocyte recovery after IR injury. The mitochondrial uncoupling protein 3 (UCP3) has been proposed to reduce mitochondrial reactive oxygen species (ROS) production and to facilitate fatty acid oxidation. As both mechanisms might be protective following IR injury, we investigated functional, mitochondrial structural, and metabolic cardiac remodeling in wild-type mice and in mice lacking UCP3 (UCP3–KO) after IR. Results showed that infarct size in isolated perfused hearts subjected to IR ex vivo was larger in adult and old UCP3–KO mice than in equivalent wild-type mice, and was accompanied by higher levels of creatine kinase in the effluent and by more pronounced mitochondrial structural changes. The greater myocardial damage in UCP3–KO hearts was confirmed in vivo after coronary artery occlusion followed by reperfusion. S1QEL, a suppressor of superoxide generation from site IQ in complex I, limited infarct size in UCP3–KO hearts, pointing to exacerbated superoxide production as a possible cause of the damage. Metabolomics analysis of isolated perfused hearts confirmed the reported accumulation of succinate, xanthine and hypoxanthine during ischemia, and a shift to anaerobic glucose utilization, which all recovered upon reoxygenation. The metabolic response to ischemia and IR was similar in UCP3–KO and wild-type hearts, being lipid and energy metabolism the most affected pathways. Fatty acid oxidation and complex I (but not complex II) activity were equally impaired after IR. Overall, our results indicate that UCP3 deficiency promotes enhanced superoxide generation and mitochondrial structural changes that increase the vulnerability of the myocardium to IR injury.
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Schauber, Stefan & Stensløkken, Kåre-Olav
(2023).
No knowledge gap in human physiology after remote teaching for second year medical students throughout the Covid-19 pandemic.
BMC Medical Education.
23(1).
doi:
10.1186/s12909-023-04959-x.
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The COVID-19 pandemic had a disruptive effect on higher education. A critical question is whether these changes affected students’ learning outcomes. Knowledge gaps have consequences for future learning and may—in health professionals' education—also pose a threat to patient safety. Current research has shortcomings and does not allow for clear-cut interpretation. Our context is instruction in human physiology in an undergraduate medical program from high stakes end of term examinations. The sequence of imposed measures to slow the COVID-19 pandemic created a natural experiment, allowing for comparisons in performance during in-person versus remote instruction. In a two-factorial design, mode of instruction (in-person vs. remote) and mode of assessment (in-person vs. remote) were analyzed using both basic (non-parametric statistics, T-tests) and advanced statistical methods (linear mixed-effects model; resampling techniques). Test results from a total of N = 1095 s-year medical students were included in the study. We did not find empirical evidence of knowledge gaps; rather, students received comparable or higher scores during remote teaching. We interpret these findings as empirical evidence that both students and teachers adapted to pandemic disruption in a way that did not lead to knowledge gaps. We conclude that highly motivated students had no reduction in academic achievement. Moreover, we have developed an accessible digital exam system for secure, fair, and effective assessments which is sufficiently defensible for making pass/fail decisions.
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Torp, May-Kristin; Vaage, Ingvar Jarle & Stensløkken, Kåre-Olav
(2023).
Mitochondria-derived damage-associated molecular patterns and inflammation in the ischemic-reperfused heart.
Acta Physiologica.
ISSN 1748-1708.
237(3).
doi:
10.1111/apha.13920.
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Cardiac cell death after myocardial infarction release endogenous structures termed damage-associated molecular patterns (DAMPs) that trigger the innate immune system and initiate a sterile inflammation in the myocardium. Cardiomyocytes are energy demanding cells and 30% of their volume are mitochondria. Mitochondria are evolutionary endosymbionts originating from bacteria containing molecular patterns similar to bacteria, termed mitochondrial DAMPs (mDAMPs). Consequently, mitochondrial debris may be particularly immunogenic and damaging. However, the role of mDAMPs in myocardial infarction is not clarified. Identifying the most harmful mDAMPs and inhibiting their early inflammatory signaling may reduce infarct size and the risk of developing post-infarct heart failure. The focus of this review is the role of mDAMPs in the immediate pro-inflammatory phase after myocardial infarction before arrival of immune cells in the myocardium. We discuss different mDAMPs, their role in physiology and present knowledge regarding their role in the inflammatory response of acute myocardial infarction.
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Semenova, Daria; Zabirnyk, Arsenii; Lobov, Arseniy; Boyarskaya, Nadezda; Kachanova, Olga & Uspensky, Vladimir
[Show all 16 contributors for this article]
(2022).
Multi-omics of in vitro aortic valve calcification.
Frontiers in Cardiovascular Medicine.
9.
doi:
10.3389/fcvm.2022.1043165.
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Heart valve calcification is an active cellular and molecular process that partly remains unknown. Osteogenic differentiation of valve interstitial cells (VIC) is a central mechanism in calcific aortic valve disease (CAVD). Studying mechanisms in CAVD progression is clearly needed. In this study, we compared molecular mechanisms of osteogenic differentiation of human VIC isolated from healthy donors or patients with CAVD by RNA-seq transcriptomics in early timepoint (48 h) and by shotgun proteomics at later timepoint (10th day). Bioinformatic analysis revealed genes and pathways involved in the regulation of VIC osteogenic differentiation. We found a high amount of stage-specific differentially expressed genes and good accordance between transcriptomic and proteomic data. Functional annotation of differentially expressed proteins revealed that osteogenic differentiation of VIC involved many signaling cascades such as: PI3K-Akt, MAPK, Ras, TNF signaling pathways. Wnt, FoxO, and HIF-1 signaling pathways were modulated only at the early timepoint and thus probably involved in the commitment of VIC to osteogenic differentiation. We also observed a significant shift of some metabolic pathways in the early stage of VIC osteogenic differentiation. Lentiviral overexpression of one of the most upregulated genes (ZBTB16, PLZF) increased calcification of VIC after osteogenic stimulation. Analysis with qPCR and shotgun proteomics suggested a proosteogenic role of ZBTB16 in the early stages of osteogenic differentiation.
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Melsom, Helene Støle; Heiestad, Christina Mathisen; Eftestøl, Einar; Torp, May-Kristin; Gundersen, Kristian & Bjørnebekk, Astrid
[Show all 9 contributors for this article]
(2022).
Reduced arterial elasticity after anabolic–androgenic steroid use in young adult males and mice.
Scientific Reports.
12(1).
doi:
10.1038/s41598-022-14065-5.
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Abstract High-doses of anabolic–androgenic steroids (AAS) is efficient for building muscle mass, but pose a risk of cardiovascular side effects. Little is known of the effect of AAS on vasculature, but previous findings suggest unfavorable alterations in vessel walls and vasoreactivity. Here, long-term effect of AAS on vascular function and morphology were examined in male weightlifters, and in a mimicking animal model. Arterial elasticity and morphology were tested with ultrasound, pulse wave velocity (PWV) and carotid intima media thickness (cIMT) in 56 current male AAS users, and 67 non-exposed weightlifting controls (WLC). Female mice were treated with testosterone for 14 days and echocardiography were applied to evaluate vascular function and morphology. Male AAS users had higher PWV (p = 0.044), reduced carotid artery compliance (p = 0.0005), and increased cIMT (p = 0.041) compared to WLC. Similar functional changes were found in the ascending aorta of mice after 7- (p = 0.043) and 14 days (p = 0.001) of testosterone treatment. This animal model can be used to map molecular mechanisms responsible for complications related to AAS misuse. Considering the age-independent stiffening of major arteries and the predictive power of an increase in PWV and cIMT, the long-term users of AAS are at increased risk of severe cardiovascular events.
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Torp, May-Kristin; Ranheim, Trine; Schjalm, Camilla; Hjorth, Marit; Heiestad, Christina Mathisen & Dalen, Knut Tomas
[Show all 13 contributors for this article]
(2022).
Intracellular Complement Component 3 Attenuated Ischemia-Reperfusion Injury in the Isolated Buffer-Perfused Mouse Heart and Is Associated With Improved Metabolic Homeostasis.
Frontiers in Immunology.
13.
doi:
10.3389/fimmu.2022.870811.
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The innate immune system is rapidly activated during myocardial infarction and blockade of extracellular complement system reduces infarct size. Intracellular complement, however, appears to be closely linked to metabolic pathways and its role in ischemia-reperfusion injury is unknown and may be different from complement activation in the circulation. The purpose of the present study was to investigate the role of intracellular complement in isolated, retrogradely buffer-perfused hearts and cardiac cells from adult male wild type mice (WT) and from adult male mice with knockout of complement component 3 (C3KO). Main findings: (i) Intracellular C3 protein was expressed in isolated cardiomyocytes and in whole hearts, (ii) after ischemia-reperfusion injury, C3KO hearts had larger infarct size (32 ± 9% in C3KO vs. 22 ± 7% in WT; p=0.008) and impaired post-ischemic relaxation compared to WT hearts, (iii) C3KO cardiomyocytes had lower basal oxidative respiration compared to WT cardiomyocytes, (iv) blocking mTOR decreased Akt phosphorylation in WT, but not in C3KO cardiomyocytes, (v) after ischemia, WT hearts had higher levels of ATP, but lower levels of both reduced and oxidized nicotinamide adenine dinucleotide (NADH and NAD+, respectively) compared to C3KO hearts. Conclusion: intracellular C3 protected the heart against ischemia-reperfusion injury, possibly due to its role in metabolic pathways important for energy production and cell survival.
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Bogdanova, Mariia; Zabirnyk, Arsenii; Malashicheva, Anna; Semenova, Daria; Kvitting, John-Peder & Kaljusto, Mari-Liis
[Show all 12 contributors for this article]
(2022).
Models and Techniques to Study Aortic Valve Calcification in Vitro, ex Vivo and in Vivo. An Overview.
Frontiers in Pharmacology.
13.
doi:
10.3389/fphar.2022.835825.
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Aortic valve stenosis secondary to aortic valve calcification is the most common valve disease in the Western world. Calcification is a result of pathological proliferation and osteogenic differentiation of resident valve interstitial cells. To develop non-surgical treatments, the molecular and cellular mechanisms of pathological calcification must be revealed. In the current overview, we present methods for evaluation of calcification in different ex vivo , in vitro and in vivo situations including imaging in patients. The latter include echocardiography, scanning with computed tomography and magnetic resonance imaging. Particular emphasis is on translational studies of calcific aortic valve stenosis with a special focus on cell culture using human primary cell cultures. Such models are widely used and suitable for screening of drugs against calcification. Animal models are presented, but there is no animal model that faithfully mimics human calcific aortic valve disease. A model of experimentally induced calcification in whole porcine aortic valve leaflets ex vivo is also included. Finally, miscellaneous methods and aspects of aortic valve calcification, such as, for instance, biomarkers are presented.
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Baysa, Anton; Maghazachi, Azzam; Sand, Kristin Larsen; Campesan, Marika; Zaglia, Tania & Mongillo, Marco
[Show all 13 contributors for this article]
(2022).
Toll-like receptor 9 signaling after myocardial infarction: Role of p66ShcA adaptor protein.
Biochemical and Biophysical Research Communications - BBRC.
ISSN 0006-291X.
644,
p. 70–78.
doi:
10.1016/j.bbrc.2022.12.085.
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During myocardial infarction, cellular debris is released, causing a sterile inflammation via pattern recognition receptors. These reactions amplify damage and promotes secondary heart failure. The pattern recognition receptor, Toll-like receptor 9 (TLR9) detects immunogenic fragments of endogenous DNA, inducing inflammation by NFκB. The p66ShcA adaptor protein plays an important role in both ischemic myocardial damage and immune responses. We hypothesized that p66ShcA adaptor protein promotes DNA-sensing signaling via the TLR9 pathway after myocardial infarction. TLR9 protein expression increased in cardiac tissue from patients with end-stage heart failure due to ischemic heart disease. Myocardial ischemia in mice in vivo induced gene expression of key TLR9 pathway proteins (MyD88 and Unc93b1). In this model, a functional link between TLR9 and p66ShcA was revealed as; (i) ischemia-induced upregulation of TLR9 protein was abrogated in myocardium of p66ShcA knockout mice; (ii) when p66ShcA was overexpressed in NFkB reporter cells stably expressing TLR9, NFkB-activation increased during stimulation with the TLR9 agonist CpG B; (iii) in cardiac fibroblasts, p66ShcA overexpression caused TLR9 upregulation. Co-immunoprecipitation showed that ShcA proteins and TLR9 may be found in the same protein complex, which was dissipated upon TLR9 stimulation in vivo. A proximity assay confirmed the co-localization of TLR9 and ShcA proteins. The systemic immune response after myocardial ischemia was dampened in p66ShcA knockout mice as interleukin-4, -17 and −22 expression in mononuclear cells isolated from spleens was reduced. In conclusion, p66ShcA adaptor may be an interaction partner and a regulator of the TLR9 pathway post-infarction.
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Shah, Mohammed; He, Zhenhe; Rauf, Ali; Kalkhoran, Siavash Beikoghli; Heiestad, Christina Mathisen & Stensløkken, Kåre-Olav
[Show all 11 contributors for this article]
(2022).
Extracellular histones are a target in myocardial ischaemia-reperfusion injury.
Cardiovascular Research (CVR).
ISSN 0008-6363.
118(4),
p. 1115–1125.
doi:
10.1093/cvr/cvab139.
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Abstract Aims Acute myocardial infarction causes lethal cardiomyocyte injury during ischaemia and reperfusion (I/R). Histones have been described as important Danger Associated Molecular Proteins (DAMPs) in sepsis. The objective of this study was to establish whether extracellular histone release contributes to myocardial infarction. Methods and results Isolated, perfused rat hearts were subject to I/R. Nucleosomes and histone-H4 release was detected early during reperfusion. Sodium-β-O-Methyl cellobioside sulfate (mCBS), a newly developed histone-neutralizing compound, significantly reduced infarct size whilst also reducing the detectable levels of histones. Histones were directly toxic to primary adult rat cardiomyocytes in vitro. This was prevented by mCBS or HIPe, a recently described, histone-H4 neutralizing peptide, but not by an inhibitor of TLR4, a receptor previously reported to be involved in DAMP-mediated cytotoxicity. Furthermore, TLR4-reporter HEK293 cells revealed that cytotoxicity of histone H4 was independent of TLR4 and NF-κB. In an in vivo rat model of I/R, HIPe significantly reduced infarct size. Conclusion Histones released from the myocardium are cytotoxic to cardiomyocytes, via a TLR4-independent mechanism. The targeting of extracellular histones provides a novel opportunity to limit cardiomyocyte death during I/R injury of the myocardium.
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Tombolesi, Niki; Altara, Raffaele; Silva, Gustavo Jose Justo; Tannous, Cynthia; Zouein, Fouad A. & Stensløkken, Kåre-Olav
[Show all 11 contributors for this article]
(2022).
Early cardiac-chamber-specific fingerprints in heart failure with preserved ejection fraction detected by FTIR and Raman spectroscopic techniques.
Scientific Reports.
12(1).
doi:
10.1038/s41598-022-07390-2.
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Abstract The pathophysiology of heart failure with preserved ejection fraction (HFpEF) is a matter of investigation and its diagnosis remains challenging. Although the mechanisms that are responsible for the development of HFpEF are not fully understood, it is well known that nearly 80% of patients with HFpEF have concomitant hypertension. We investigated whether early biochemical alterations were detectable during HFpEF progression in salt-induced hypertensive rats, using Fourier-transformed infrared (FTIR) and Raman spectroscopic techniques as a new diagnostic approach. Greater protein content and, specifically, greater collagen deposition were observed in the left atrium and right ventricle of hypertensive rats, together with altered metabolism of myocytes. Additionally, Raman spectra indicated a conformational change, or different degree of phosphorylation/methylation, in tyrosine-rich proteins. A correlation was found between tyrosine content and cardiac fibrosis of both right and left ventricles. Microcalcifications were detected in the left and right atria of control animals, with a progressive augmentation from six to 22 weeks. A further increase occurred in the left ventricle and right atrium of 22-week salt-fed animals, and a positive correlation was shown between the mineral deposits and the cardiac size of the left ventricle. Overall, FTIR and Raman techniques proved to be sensitive to early biochemical changes in HFpEF and preceded clinical humoral and imaging markers.
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Li, Yuchuan; Torp, May-Kristin; Norheim, Frode; Khanal, Prabhat; Kimmel, Alan R. & Stensløkken, Kåre-Olav
[Show all 8 contributors for this article]
(2020).
Isolated Plin5-deficient cardiomyocytes store less lipid droplets than normal, but without increased sensitivity to hypoxia.
Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids.
ISSN 1388-1981.
1866(4).
doi:
10.1016/j.bbalip.2020.158873.
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Plin5 is abundantly expressed in the heart where it binds to lipid droplets (LDs) and facilitates physical interaction between LDs and mitochondria. We isolated cardiomyocytes from adult Plin5+/+ and Plin5-/- mice to study the role of Plin5 for fatty acid uptake, LD accumulation, fatty acid oxidation, and tolerance to hypoxia. Cardiomyocytes isolated from Plin5-/- mice cultured with oleic acid stored less LDs than Plin5+/+, but comparable levels to Plin5+/+ cardiomyocytes when adipose triglyceride lipase activity was inhibited. The ability to oxidize fatty acids into CO2 was similar between Plin5+/+ and Plin5-/- cardiomyocytes, but Plin5-/- cardiomyocytes had a transient increase in intracellular fatty acid oxidation intermediates. After pre-incubation with oleic acids, Plin5-/- cardiomyocytes retained a higher content of glycogen and showed improved tolerance to hypoxia compared to Plin5+/+. In isolated, perfused hearts, deletion of Plin5 had no important effect on ventricular pressures or infarct size after ischemia. Old Plin5-/- mice had reduced levels of cardiac triacylglycerides, increased heart weight, and apart from modest elevated expression of mRNAs for beta myosin heavy chain Myh7 and the fatty acid transporter Cd36, other genes involved in fatty acid oxidation, glycogen metabolism and glucose utilization were essentially unchanged by removal of Plin5. Plin5 seems to facilitate cardiac LD storage primarily by repressing adipose triglyceride lipase activity without altering cardiac fatty acid oxidation capacity. Expression of Plin5 and cardiac LD content of isolated cardiomyocytes has little importance for tolerance to acute hypoxia and ischemia, which contrasts the protective role for Plin5 in mouse models during myocardial ischemia.
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Zabirnyk, Arsenii; Perez, Maria del Mar; Blasco, Marc; Stensløkken, Kåre-Olav; Ferrer, Miguel D. & Salcedo, Carolina
[Show all 7 contributors for this article]
(2020).
A Novel Ex Vivo Model of Aortic Valve Calcification. A Preliminary Report.
Frontiers in Pharmacology.
11.
doi:
10.3389/fphar.2020.568764.
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Background: No pharmacological treatment exists to prevent or stop the calcification process of aortic valves causing aortic stenosis. The aim of this study was to develop a robust model of induced calcification in whole aortic valve leaflets which could be suitable for studies of the basic mechanisms and for testing potentially inhibitory drugs. Methods: Pig hearts were obtained from a commercial abattoir. The aortic valve leaflets were dissected free and randomized between experimental groups. Whole leaflets were cultured in individual wells. Two growth media were used for cultivation: standard growth medium and an antimyofibroblastic growth medium. The latter was employed to inhibit contraction of the leaflet into a ball-like structure. Calcification was induced in the growth medium by supplementation with an osteogenic medium. Leaflets were cultivated for four weeks and medium was changed every third day. To block calcification, the inhibitor SNF472 (a formulation of the hexasodium salt of myo-inositol hexaphosphate hexasodium salt) was used at concentrations between 1 and 100 µM. After cultivation for four weeks the leaflets were snap frozen in liquid nitrogen and kept at −80 °C until blind assessment of the calcium amount in leaflets by inductively coupled plasma optical emission spectroscopy. For statistical analysis, a Kruskal–Wallis test with Dunn’s post-test was applied. Results: Osteodifferentiation with calcium accumulation was in principle absent when standard medium was used. However, when the antimyofibroblastic medium was used, a strong calcium accumulation was induced ( p = 0.006 compared to controls), and this was blocked in a dose-dependent manner by the calcification inhibitor SNF472 ( p = 0.008), with an EC 50 of 3.3 µM. Conclusion: A model of experimentally induced calcification in cultured whole leaflets from porcine aortic valves was developed. This model can be useful for studying the basic mechanisms of valve calcification and to test pharmacological approaches to inhibit calcification.
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Davidson, Sean M.; Adameová, Adriana; Barile, Lucio; Cabrera-Fuentes, Hector Alejandro; Lazou, Antigone & Pagliaro, Pasquale
[Show all 8 contributors for this article]
(2020).
Mitochondrial and mitochondrial-independent pathways of myocardial cell death during ischaemia and reperfusion injury.
Journal of Cellular and Molecular Medicine.
ISSN 1582-1838.
24(7),
p. 3795–3806.
doi:
10.1111/jcmm.15127.
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Acute myocardial infarction causes lethal injury to cardiomyocytes during both ischaemia and reperfusion (IR). It is important to define the precise mechanisms by which they die in order to develop strategies to protect the heart from IR injury. Necrosis is known to play a major role in myocardial IR injury. There is also evidence for significant myocardial death by other pathways such as apoptosis, although this has been challenged. Mitochondria play a central role in both of these pathways of cell death, as either a causal mechanism is the case of mitochondrial permeability transition leading to necrosis, or as part of the signalling pathway in mitochondrial cytochrome c release and apoptosis. Autophagy may impact this process by removing dysfunctional proteins or even entire mitochondria through a process called mitophagy. More recently, roles for other programmed mechanisms of cell death such as necroptosis and pyroptosis have been described, and inhibitors of these pathways have been shown to be cardioprotective. In this review, we discuss both mitochondrial and mitochondrial‐independent pathways of the major modes of cell death, their role in IR injury and their potential to be targeted as part of a cardioprotective strategy. This article is part of a special Issue entitled ‘Mitochondria as targets of acute cardioprotection’ and emerged as part of the discussions of the European Union (EU)‐CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225.
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Torp, May-Kristin; Yang, Kuan; Ranheim, Trine; Lauritzen, Knut Husø; Alfsnes, Katrine & Vinge, Leif Erik
[Show all 10 contributors for this article]
(2019).
Mammalian target of rapamycin (mTOR) and the proteasome attenuates IL-1β expression in primary mouse cardiac fibroblasts.
Frontiers in Immunology.
10.
doi:
10.3389/fimmu.2019.01285.
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Background: IL-1β is a highly potent pro-inflammatory cytokine and its secretion is tightly regulated. Inactive pro-IL-1β is transcribed in response to innate immune receptors activating NFκB. If tissue damage occurs, danger signals released from necrotic cells, such as ATP, can activate NLRP3-inflammasomes (multiprotein complexes consisting of NLRP3, ASC, and active caspase-1) which cleaves and activates pro-IL-1β. NLRP3 activation also depends on NEK7 and mitochondrial ROS-production. Thus, IL-1β secretion may be regulated at the level of each involved component. We have previously shown that NLRP3-dependent IL-1β release can be induced in cardiac fibroblasts by pro-inflammatory stimuli. However, anti-inflammatory mechanisms targeting IL-1β release in cardiac cells have not been investigated. mTOR is a key regulator of protein metabolism, including autophagy and proteasome activity. In this study we explored whether autophagy or proteasomal degradation are regulators of NLRP3 inflammasome activation and IL-1β release from cardiac fibroblasts. Methods and Results: Serum starvation selectively reduced LPS/ATP-induced IL-1β secretion from cardiac fibroblasts. However, no other inflammasome components, nor mitochondrial mass, were affected. The mTOR inhibitor rapamycin restored pro-IL-1β protein levels as well as LPS/ATP-induced IL-1β release from serum starved cells. However, neither serum starvation nor rapamycin induced autophagy in cardiac fibroblasts. Conversely, chloroquine and bafilomycin A (inhibitors of autophagy) and betulinic acid (a proteasome activator) effectively reduced LPS-induced pro-IL-1β protein levels. Key findings were reinvestigated in human monocyte-derived macrophages. Conclusion: In cardiac fibroblasts, mTOR inhibition selectively favors pro-IL-1β synthesis while proteasomal degradation and not autophagy is the major catabolic anti-inflammatory mechanism for degradation of this cytokine.
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Zabirnyk, Arsenii; Ferrer, Miguel David; Bogdanova, Mariia; Perez, MM; Salcedo, C & Kaljusto, Mari-Liis
[Show all 10 contributors for this article]
(2019).
SNF472, a novel anti-crystallization agent, inhibits induced calcification in an in vitro model of human aortic valve calcification.
Vascular pharmacology.
ISSN 1537-1891.
p. 1–7.
doi:
10.1016/j.vph.2019.106583.
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The purpose of the present study was to investigate whether SNF472, the hexasodium salt of myo-inositol hexaphosphate (IP6 or phytate): 1. Inhibits induced calcification in cultured aortic valve interstitial cells (VIC) as an in vitro model of aortic valve stenosis and 2. Whether inhibition is different in VIC obtained from healthy and calcified aortic valves. VIC from healthy (n = 5) and calcified (n = 7) human aortic valves were seeded in basic growth medium, osteogenic differentiation medium alone, or in osteogenic medium with SNF472 (3, 10, and 30 μM) and cultivated for 3 weeks. Calcification was quantified spectrophotometrically after Alizarin Red staining. In VIC from calcified valves, a complete inhibition of calcification was observed with SNF472 concentrations of 10 and 30 μM (p < .01), significantly stronger than in VIC from healthy valves. When SNF472 was added to VIC after 1 week in osteogenic medium, 30 and 100 μM SNF472 inhibited the progression of ongoing calcification by 81 and 100% (p < .01), respectively. The same concentrations of SNF472 given after 2 weeks reduced calcification by 35 and 40% respectively (not significant). SNF472 inhibited both the formation and the progression of calcification with the strongest effect in VIC from calcified valves.
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Mariero, Lars Henrik; Torp, May-Kristin; Heiestad, Christina Mathisen; Baysa, Anton; Li, Yuchuan & Valen, Guro
[Show all 8 contributors for this article]
(2019).
Inhibiting nucleolin reduces inflammation induced by mitochondrial DNA in cardiomyocytes exposed to hypoxia and reoxygenation.
British Journal of Pharmacology.
ISSN 0007-1188.
176(22),
p. 4360–4372.
doi:
10.1111/bph.14830.
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Background and purpose Cellular debris causes sterile inflammation after myocardial infarction. Mitochondria constitute about 30 percent of the human heart. Mitochondrial DNA (mtDNA) is a damage‐associated‐molecular‐pattern that induce injurious sterile inflammation. Little is known about mtDNA's inflammatory signalling pathways in cardiomyocytes and how mtDNA is internalized to associate with its putative receptor, toll‐like receptor 9 (TLR9). Experimental Approach We hypothesized that mtDNA can be internalized in cardiomyocytes and induce an inflammatory response. Adult mouse cardiomyocytes were exposed to hypoxia‐reoxygenation and extracellular DNA. Microscale thermophoresis was used to demonstrate binding between nucleolin and DNA. Key results Expression of the pro‐inflammatory cytokines IL‐1β and TNFα were upregulated by mtDNA, but not by nuclear DNA (nDNA), in cardiomyocytes exposed to hypoxia‐reoxygenation. Blocking the RNA/DNA binding protein nucleolin with midkine reduced expression of IL‐1β/TNFα and the nucleolin inhibitor AS1411 reduced interleukin‐6 release in adult mouse cardiomyocytes. mtDNA bound 10‐fold stronger than nDNA to nucleolin. In HEK293‐NF‐κB reporter cells, mtDNA induced NF‐κB activity in normoxia, while CpG‐DNA and hypoxia‐reoxygenation, synergistically induced TLR9‐dependent NF‐κB activity. Protein expression of nucleolin was found in the plasma membrane of cardiomyocytes and inhibition of nucleolin with midkine inhibited cellular uptake of CpG‐DNA. Inhibition of endocytosis did not reduce CpG‐DNA uptake in cardiomyocytes. Conclusion and implications mtDNA, but not nDNA, induce an inflammatory response in mouse cardiomyocytes during hypoxia‐reoxygenation. In cardiomyocytes, nucleolin is expressed on the membrane and blocking nucleolin reduce inflammation. Nucleolin might be a therapeutic target to prevent uptake of immunogenic DNA and reduce inflammation.
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Bogdanova, Mariia; Zabirnyk, Arsenii; Malashicheva, Anna; Zihlavnikova, Katarina; Karlsen, Tommy Aleksander & Kaljusto, Mari-Liis
[Show all 13 contributors for this article]
(2019).
Interstitial cells in calcified aortic valves have reduced differentiation potential and stem cell-like properties.
Scientific Reports.
9:12934,
p. 1–13.
doi:
10.1038/s41598-019-49016-0.
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Valve interstitial cells (VICs) are crucial in the development of calcific aortic valve disease. The purpose of the present investigation was to compare the phenotype, differentiation potential and stem cell-like properties of cells from calcified and healthy aortic valves. VICs were isolated from human healthy and calcified aortic valves. Calcification was induced with osteogenic medium. Unlike VICs from healthy valves, VICs from calcified valves cultured without osteogenic medium stained positively for calcium deposits with Alizarin Red confirming their calcific phenotype. Stimulation of VICs from calcified valves with osteogenic medium increased calcification (p = 0.02), but not significantly different from healthy VICs. When stimulated with myofibroblastic medium, VICs from calcified valves had lower expression of myofibroblastic markers, measured by flow cytometry and RT-qPCR, compared to healthy VICs. Contraction of collagen gel (a measure of myofibroblastic activity) was attenuated in cells from calcified valves (p = 0.04). Moreover, VICs from calcified valves, unlike cells from healthy valves had lower potential to differentiate into adipogenic pathway and lower expression of stem cell-associated markers CD106 (p = 0.04) and aldehyde dehydrogenase (p = 0.04). In conclusion, VICs from calcified aortic have reduced multipotency compared to cells from healthy valves, which should be considered when investigating possible medical treatments of aortic valve calcification.
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Bogdanova, Mariia; Kostina, Aleksandra; Zihlavnikova, Katarina; Zabirnyk, Arsenii; Malashicheva, Anna & Stensløkken, Kåre-Olav
[Show all 12 contributors for this article]
(2018).
Inflammation and Mechanical Stress Stimulate Osteogenic Differentiation of Human Aortic Valve Interstitial Cells.
Frontiers in Physiology.
9.
doi:
10.3389/fphys.2018.01635.
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Background: Aortic valve calcification is an active proliferative process, where interstitial cells of the valve transform into either myofibroblasts or osteoblast-like cells causing valve deformation, thickening of cusps and finally stenosis. This process may be triggered by several factors including inflammation, mechanical stress or interaction of cells with certain components of extracellular matrix. The matrix is different on the two sides of the valve leaflets. We hypothesize that inflammation and mechanical stress stimulate osteogenic differentiation of human aortic valve interstitial cells (VICs) and this may depend on the side of the leaflet. Methods: Interstitial cells isolated from healthy and calcified human aortic valves were cultured on collagen or elastin coated plates with flexible bottoms, simulating the matrix on the aortic and ventricular side of the valve leaflets, respectively. The cells were subjected to 10% stretch at 1 Hz (FlexCell bioreactor) or treated with 0.1 μg/ml lipopolysaccharide, or both during 24 h. Gene expression of myofibroblast- and osteoblast-specific genes was analyzed by qPCR. VICs cultured in presence of osteogenic medium together with lipopolysaccharide, 10% stretch or both for 14 days were stained for calcification using Alizarin Red. Results: Treatment with lipopolysaccharide increased expression of osteogenic gene bone morphogenetic protein 2 (BMP2) (5-fold increase from control; p = 0.02) and decreased expression of mRNA of myofibroblastic markers: α-smooth muscle actin (ACTA2) (50% reduction from control; p = 0.0006) and calponin (CNN1) (80% reduction from control; p = 0.0001) when cells from calcified valves were cultured on collagen, but not on elastin. Mechanical stretch of VICs cultured on collagen augmented the effect of lipopolysaccharide. Expression of periostin (POSTN) was inhibited in cells from calcified donors after treatment with lipopolysaccharide on collagen (70% reduction from control, p = 0.001), but not on elastin. Lipopolysaccharide and stretch both enhanced the pro-calcific effect of osteogenic medium, further increasing the effect when combined for cells cultured on collagen, but not on elastin. Conclusion: Inflammation and mechanical stress trigger expression of osteogenic genes in VICs in a side-specific manner, while inhibiting the myofibroblastic pathway. Stretch and lipopolysaccharide synergistically increase calcification.
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Fagernes, Cathrine Elisabeth; Stensløkken, Kåre-Olav; Kjendseth, Åsmund Røhr; Berenbrink, Michael; Ellefsen, Stian & Nilsson, Göran Erik
(2017).
Extreme anoxia tolerance in
crucian carp and goldfish through
neofunctionalization of duplicated
genes creating a new ethanol-
producing pyruvate decarboxylase
pathway.
Scientific Reports.
doi:
10.1038/s41598-017-07385-4.
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Without oxygen, most vertebrates die within minutes as they cannot meet cellular energy demands with anaerobic metabolism. However, fish of the genus Carassius (crucian carp and goldfish) have evolved a specialized metabolic system that allows them to survive prolonged periods without oxygen by producing ethanol as their metabolic end-product. Here we show that this has been made possible by the evolution of a pyruvate decarboxylase, analogous to that in brewer’s yeast and the first described in vertebrates, in addition to a specialized alcohol dehydrogenase. Whole-genome duplication events have provided additional gene copies of the pyruvate dehydrogenase multienzyme complex that have evolved into a pyruvate decarboxylase, while other copies retained the essential function of the parent enzymes. We reveal the key molecular substitution in duplicated pyruvate dehydrogenase genes that underpins one of the most extreme hypoxic survival strategies among vertebrates and that is highly deleterious in humans.
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Rutkovskiy, Arkady; Malashicheva, Anna; Sullivan, Gareth; Bogdanova, Mariia; Kostareva, Anna & Stensløkken, Kåre-Olav
[Show all 8 contributors for this article]
(2017).
Valve interstitial cells: The key to understanding the pathophysiology of heart valve calcification.
Journal of the American Heart Association (JAHA).
6(9),
p. 1–24.
doi:
10.1161/JAHA.117.006339.
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Aortic valve stenosis due to calcification of the valve leaflets is the most common valve disease in the developed world. It is the third leading cause of cardiovascular disease.1 Risk factors include male gender, smoking, diabetes mellitus, hypertension, high levels of circulating lipids, and metabolic syndrome.2 Calcification was earlier believed to be a passive degenerative process, but it is now recognized as an active disease process driven by the cells native to the aortic valve.3, 4 The only option for treatment is heart surgery with implantation of a valve prosthesis. The heart valve prostheses are either mechanical, requiring life‐long anticoagulation treatment, or based on biological material, which will degenerate and calcify after 10 to 15 years. Implantation of heart valve prostheses has been characterized as “replacing one disease with another.” Understanding the cellular and molecular processes behind valve calcification may possibly lead to nonsurgical treatment.
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Lefevre, Sjannie; Stecyk, Jonathan Anthony William; Torp, May-Kristin; Løvold, Lisa Yuen; Sørensen, Christina & Johansen, Ida Beitnes
[Show all 10 contributors for this article]
(2017).
Re-oxygenation after anoxia induces brain cell death and memory loss in the anoxia-tolerant crucian carp.
Journal of Experimental Biology.
ISSN 0022-0949.
220(21),
p. 3883–3895.
doi:
10.1242/jeb.165118.
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Crucian carp (Carassius carassius) survive without oxygen for several months, but it is unknown whether they are able to protect themselves from cell death normally caused by the absence, and particularly return, of oxygen. Here, we quantified cell death in brain tissue from crucian carp exposed to anoxia and re-oxygenation using the terminal deoxy-nucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, and cell proliferation by immunohistochemical staining for proliferating cell nuclear antigen (PCNA) as well as PCNA mRNA expression. We also measured mRNA and protein expression of the apoptosis executer protease caspase 3, in laboratory fish exposed to anoxia and re-oxygenation and fish exposed to seasonal anoxia and re-oxygenation in their natural habitat over the year. Finally, a behavioural experiment was used to assess the ability to learn and remember how to navigate in a maze to find food, before and after exposure to anoxia and re-oxygenation. The number of TUNEL-positive cells in the telencephalon increased after 1 day of re-oxygenation following 7 days of anoxia, indicating increased cell death. However, there were no consistent changes in whole-brain expression of caspase 3 in either laboratory-exposed or naturally exposed fish, indicating that cell death might occur via caspase-independent pathways or necrosis. Re-oxygenated crucian carp appeared to have lost the memory of how to navigate in a maze (learnt prior to anoxia exposure), while the ability to learn remained intact. PCNA mRNA was elevated after re-oxygenation, indicating increased neurogenesis. We conclude that anoxia tolerance involves not only protection from damage but also repair after re-oxygenation.
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Bliksøen, Marte; Rutkovskiy, Arkady; Vaage, Ingvar Jarle & Stensløkken, Kåre-Olav
(2017).
Mode of perfusion influences infarct size, coronary flow and stress kinases in the isolated mouse heart.
Acta Physiologica.
ISSN 1748-1708.
220(1),
p. 36–46.
doi:
10.1111/apha.12773.
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Aim: The isolated, retrogradely perfused heart (modified Langendorff
model) is a widely used method in experimental heart research. The presence
of an intraventricular balloon is necessary to get functional measurements.
We have previously shown that the balloon induces
phosphorylation of some suggested cardioprotective mitogen-activated protein
kinases (MAPK): P38-MAPK, ERK 1/2 and JNK. We hypothesized
that the balloon could influence cardioprotection, protect against ischaemia
reperfusion injury and interfere with coronary flow.
Methods and Results: Isolated mouse hearts were perfused for 5, 10, 20,
40 and 60 min with a balloon in the left ventricle. We found a wavelike
phosphorylation of all MAPK while AKT displayed a gradual dephosphorylation
when compared to non-perfused hearts. Hearts were subjected to
20 min of stabilization with or without the balloon, followed by 35 min of
ischaemia and 120 min of reperfusion. Although the MAPK were phosphorylated,
the infarcts were larger in the balloon group. When the balloon
was present during the entire protocol, compared to removal at the end of
ischaemia, the infarct size was also larger, especially in the endocardial
layer. The balloon reduced post-ischaemic endocardial coronary flow,
despite a higher average flow, indicating a hyperperfused epicard. Blocking
the balloon-induced ERK 1/2 phosphorylation during stabilization did not
affect infarct size. The effect of post-conditioning was influenced by the
balloon, showing reduced infarct size when the balloon was present.
Conclusion: The balloon used for pressure measurements may contributes
to cell death possibly by reducing endocardial coronary flow.
Keywords coronary flow, kinases, Langendorff, perfusion, post-conditioning,
pre-conditioning.
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Nilsson, Göran Erik; Vaage, Ingvar Jarle & Stensløkken, Kåre-Olav
(2015).
Oxygen- and temperature-dependent expression of survival protein kinases in crucian carp (carassius carassius) heart and brain.
American Journal of Physiology. Regulatory Integrative and Comparative Physiology.
ISSN 0363-6119.
308(1),
p. R50–R61.
doi:
10.1152/ajpregu.00094.2014.
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Stensløkken, Kåre-Olav; Ellefsen, Stian; Vasieva, Olga; Fang, Youhan; Farrell, Anthony P. & Olohan, Lisa
[Show all 9 contributors for this article]
(2014).
Life without Oxygen: Gene Regulatory Responses of the Crucian Carp (Carassius carassius) Heart Subjected to Chronic Anoxia.
PLOS ONE.
9(11).
doi:
10.1371/journal.pone.0109978.
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Crucian carp are unusual among vertebrates in surviving extended periods in the complete absence of molecular oxygen. During this time cardiac output is maintained though these mechanisms are not well understood. Using a high-density cDNA microarray, we have defined the genome-wide gene expression responses of cardiac tissue after exposing the fish at two temperatures (8 and 13uC) to one and seven days of anoxia, followed by seven days after restoration to normoxia. At 8uC, using a false discovery rate of 5%, neither anoxia nor re-oxygenation elicited appreciable changes in gene expression. By contrast, at 13uC, 777 unique genes responded strongly. Up-regulated genes included those involved in protein turnover, the pentose phosphate pathway and cell morphogenesis while down-regulated gene categories included RNA splicing and transcription. Most genes were affected between one and seven days of anoxia, indicating gene regulation over the medium term but with few early response genes. Re-oxygenation for 7 days was sufficient to completely reverse these responses. Glycolysis displayed more complex responses with anoxia up-regulated transcripts for the key regulatory enzymes, hexokinase and phosphofructokinase, but with down-regulation of most of the non-regulatory genes. This complex pattern of responses in genomic transcription patterns indicates divergent cardiac responses to anoxia, with the transcriptionally driven reprogramming of cardiac function seen at 13uC being largely completed at 8uC.
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Mariero, Lars Henrik; Rutkovskiy, Arkady; Stensløkken, Kåre-Olav & Vaage, Ingvar Jarle
(2012).
Hyperoxia during early reperfusion does not increase ischemia-reperfusion injury.
European Journal of Cardio-Thoracic Surgery.
ISSN 1010-7940.
41(1),
p. 149–153.
doi:
10.1016/j.ejcts.2011.04.022.
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Rutkovskiy, Arkady; Mariero, Lars Henrik; Nygård, Ståle; Stensløkken, Kåre-Olav; Valen, Guro & Vaage, Ingvar Jarle
(2012).
Transient hyperosmolality modulates expression of cardiac aquaporins.
Biochemical and Biophysical Research Communications - BBRC.
ISSN 0006-291X.
425(1),
p. 70–75.
doi:
10.1016/j.bbrc.2012.07.052.
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Stensløkken, Kåre-Olav; Ellefsen, Stian; Larsen, Helene Kile; Vaage, Ingvar Jarle & Nilsson, Göran Erik
(2010).
Expression of heat shock proteins in anoxic crucian carp (Carassius carassius): support for cold as a preparatory cue for anoxia.
American Journal of Physiology. Regulatory Integrative and Comparative Physiology.
ISSN 0363-6119.
298(6),
p. R1499–R1508.
doi:
10.1152/ajpregu.00675.2009.
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Kaljusto, Mari-Liis; Rutkovskiy, Arkady; Stensløkken, Kåre-Olav & Vaage, Ingvar Jarle
(2010).
Postconditioning in mouse hearts is inhibited by blocking the reverse mode of the sodium - calcium exchanger.
Interactive Cardiovascular and Thoracic Surgery.
ISSN 1569-9293.
10,
p. 743–748.
doi:
10.1510/icvts.2009.217083.
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Stensløkken, Kåre-Olav; Rutkovskiy, Arkady; Kaljusto, Mari-Liis; Hafstad, Anne Dragøy; Larsen, Terje Steinar & Vaage, Ingvar Jarle
(2009).
Inadvertent phosphorylation of survival kinases in isolated perfused hearts: a word of caution.
Basic Research in Cardiology.
ISSN 0300-8428.
104,
p. 412–423.
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Ellefsen, Stian; Stensløkken, Kåre-Olav; Fagernes, Cathrine; Kristensen, Tom A. & Nilsson, Göran E.
(2009).
Expression of genes involved in GABAergic neurotransmission in anoxic crucian carp (Carassius carassius) brain.
Physiological Genomics.
ISSN 1094-8341.
p. 61–68.
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Ellefsen, Stian; Stensløkken, Kåre-Olav; Fagernes, Cathrine Elisabeth; Kristensen, Tom & Nilsson, Gøran Erik
(2009).
Expression of genes involved in GABAergic neurotransmission in anoxic crucian carp brain (Carassius carassius).
Physiological Genomics.
ISSN 1094-8341.
36(2),
p. 61–68.
doi:
10.1152/physiolgenomics.90301.2008.
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Stensløkken, Kåre-Olav; Ellefsen, Stian; Stecyk, Jonathan Anthony William; Dahl, Mai Britt; Nilsson, Gøran Erik & Vaage, Jarle
(2008).
Differential regulation of AMP-activated kinase and AKT kinase in response to oxygen availability in crucian carp (Carassius carassius).
American Journal of Physiology. Regulatory Integrative and Comparative Physiology.
ISSN 0363-6119.
295(6),
p. R1803–R1814.
doi:
10.1152/ajpregu.90590.2008.
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Bliksøen, Marte; Kaljusto, Mari-Liis; Vaage, Ingvar Jarle & Stensløkken, Kåre-Olav
(2008).
Effects of hydrogen sulphide on ischaemia-reperfusion injury and ischaemic preconditioning in the isolated, perfused rat heart.
European Journal of Cardio-Thoracic Surgery.
ISSN 1010-7940.
34,
p. 344–349.
doi:
10.1016/j.ejcts.2008.03.017.
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Ellefsen, Stian; Sandvik, Guro Katrine; Larsen, Helene Kile; Stensløkken, Kåre-Olav; Hov, Dag Are Steenhoff & Kristensen, Tom
[Show all 7 contributors for this article]
(2008).
Expression of genes involved in excitatory neurotransmission in anoxic crucian carp (Carassius carassius) brain.
Physiological Genomics.
ISSN 1094-8341.
35,
p. 5–17.
Full text in Research Archive
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Ellefsen, Stian; Sandvik, Guro K.; Larsen, Helene K.; Stensløkken, Kåre-Olav; Hov, Dag Are S. & Kristensen, Tom A.
[Show all 7 contributors for this article]
(2008).
Expression of genes involved in excitatory neurotransmission in anoxic crucian carp (Carassius carassius) brain.
Physiological Genomics.
ISSN 1094-8341.
p. 5–17.
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Stensløkken, Kåre-Olav; Ellefsen, Stian; Stecyk, Jonathan A. W.; Dahl, Mai Brit; Nilsson, Göran E. & Vaage, Jarle
(2008).
Differential regulation of AMP-activated kinase and AKT kinase in response to oxygen availability in crucian carp (Carassius carassius).
American Journal of Physiology. Regulatory Integrative and Comparative Physiology.
ISSN 0363-6119.
p. 1803–1814.
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Stecyk, Jonathan AW; Stensløkken, Kåre-Olav; Nilsson, Gøran Erik & Farell, Anthony P
(2007).
Adenosine does not save the heart of anoxia-tolerant vertebrates during prolonged oxygen deprivation.
Comparative Biochemistry and Physiology A.
ISSN 1095-6433.
147,
p. 961–973.
doi:
10.1016/j.cbpa.2007.03.002.
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Stensløkken, Kåre-Olav; Sundin, Lena & Nilsson, Gøran Erik
(2006).
Endothelin receptors in teleost fishes: cardiovascular effects and branchial distribution.
American Journal of Physiology. Regulatory Integrative and Comparative Physiology.
ISSN 0363-6119.
290.
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Stecyk, Jonathan A. W.; Stensløkken, Kåre-Olav; Farrell, Anthony P. & Nilsson, Gøran Erik
(2004).
Maintained cardiac pumping in anoxic crucian carp.
Science.
ISSN 0036-8075.
306,
p. 77–77.
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Stensløkken, Kåre-Olav; Sundin, Lena; Renshaw, Gillian M. C. & Nilsson, Gøran Erik
(2004).
Adenosinergic and cholinergic control mechanisms during hypoxia in the epaulette shark (Hemiscyllium ocellatum), with emphasis on branchial circulation.
Journal of Experimental Biology.
ISSN 0022-0949.
207,
p. 4451–4461.
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Stensløkken, Kåre-Olav; Sundin, Lena & Nilsson, Gøran Erik
(2002).
Cardiovascular effects of prostaglandin F2a and prostaglandin E2 in Atlantic cod (Gadus morhua).
Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology.
ISSN 0174-1578.
172,
p. 363–369.
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Stensløkken, Kåre-Olav; Sundin, Lena & Nilsson, Gøran Erik
(1999).
Cardiovascular and gill microcirculatory effects of endothelin-1 in Atlantic cod: evidence for pillar cell contraction.
Journal of Experimental Biology.
ISSN 0022-0949.
202,
p. 1151–1157.
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Endothelin-1 (ET-1) has been shown to cause a considerable increase in the vascular resistance of fish gills. In trout, recent evidence suggest that this is the result of pillar cell contraction in the gill lamellae. Using epi-illumination microscopy to observe the gill lamellae of anaesthetised Atlantic cod (Gadus morhua), we here show that ET-1 (100 ng kg-1, injected into the ventral aorta) causes an enlargement of the pillar cell diameter, consistent with pillar cell contraction, and a shift of intralamellar blood flow from the lamellar sheet to the outer marginal channels. Simultaneously, there was an increase in ventral aortic blood pressure, a fall in cardiac output, an increase in gill vascular resistance, and a fall in the oxygen tension of venous blood. All these effects were blocked by the ETA/ETB receptor antagonist bosentan (5 mg kg-1). Pillar cell contraction is likely to be a mechanism for matching the functional respiratory surface area with the momentary respiratory needs
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Gerber, Lucie Claire Lola; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2023).
Comparison of Cardiac Mitochondrial Function of an Anoxia Tolerant and Intolerant Vertebrate.
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2022).
Improving organ preservation: Another lesson from the champion of anoxia tolerance, the crucian carp (C. carassius).
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Stensløkken, Kåre-Olav & Lefevre, Sjannie
(2022).
Mitochondrial Functions in the Anoxia Tolerant Crucian Carp.
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2022).
Improving organ preservation: Another lesson from the champion of anoxia tolerance, the crucian carp (C. carassius).
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Gerber, Lucie; Helle-Valle, Tellef; Resseguier, Julien Alain Andre; Torp, May-Kristin; Dahl, Helge Andre & Nilsson, Göran Erik
[Show all 8 contributors for this article]
(2022).
Prolyl Hydroxylase Domains in the Anoxia Tolerant Crucian Carp (c. carassius): Insights into the Regulation of the HIF Response to Anoxia-Reoxygenation.
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Gerber, Lucie; Helle-Valle, Tellef; Resseguier, Julien Alain Andre; Torp, May-Kristin; Dahl, Helge Andre & Nilsson, Göran Erik
[Show all 8 contributors for this article]
(2022).
Prolyl Hydroxylase Domains in the Anoxia Tolerant Crucian Carp (c. carassius): Insights into the Regulation of the HIF Response to Anoxia-Reoxygenation.
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Ytrehus, Kirsti; Larsen, Terje; Christensen, Geir Arve; Stensløkken, Kåre-Olav & Levy, Finn Olav
(2015).
In memory of Guro Valen (1960-2014).
Journal of Molecular and Cellular Cardiology.
ISSN 0022-2828.
79,
p. 254–255.
doi:
10.1016/j.yjmcc.2014.11.026.
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Røsjø, Helge; Stridsberg, M.; Florholmen, Geir; Stensløkken, Kåre-Olav; Sjaastad, Ivar & Husberg, Cathrine
[Show all 10 contributors for this article]
(2010).
Secretoneurin is a novel peptide increased in the myocardium and circulation in heart failure with cardioprotective properties.
European Heart Journal.
ISSN 0195-668X.
31,
p. 314–314.
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Ellefsen, Stian & Stensløkken, Kåre-Olav
(2010).
Gene-family profiling : a normalization-free real-time RT-PCR approach with increased physiological resolution.
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Mariero, Lars Henrik; Rutkovskiy, Arkady; Stensløkken, Kåre-Olav & Vaage, Ingvar Jarle
(2010).
May hyperoxic ventilation during early reperfusion increase infarct size?
Cardiovascular Research (CVR).
ISSN 0008-6363.
87,
p. S134–S134.
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Bliksoen, M; Rutkovskiy, Arkady; Mariero, Lars Henrik; Vaage, Ingvar Jarle & Stensløkken, Kåre-Olav
(2010).
Phosphorylation of survival kinases is not a guarantee for protection of ischemia-reperfusion injury in the isolated, perfused mouse heart.
Cardiovascular Research (CVR).
ISSN 0008-6363.
87,
p. S85–S85.
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Rutkovskiy, Arkady; Mariero, Lars Henrik; Stensløkken, Kåre-Olav; Valen, Guro & Vaage, Ingvar Jarle
(2010).
Osmotic pressure regulates expression levels of cardiac aquaporins 1 and 4.
Cardiovascular Research (CVR).
ISSN 0008-6363.
87,
p. S104–S104.
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Stecyk, Jonathan A. W.; Stensløkken, Kåre-Olav; Farrell, Anthony & Nilsson, Gøran Erik
(2005).
The beat goes on: The heart of anoxic crucian carp.
The FASEB Journal.
ISSN 0892-6638.
19(4),
p. A213–A214.
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Stensløkken, Kåre-Olav; Sundin, Lena; Renshaw, Gillian M. C. & Nilsson, Gøran Erik
(2003).
Effects of hypoxia and acetylcholine on branchial circulation in epaulette shark (Hemiscyllium ocellatum).
Comparative Biochemistry and Physiology A.
ISSN 1095-6433.
134,
p. S21–S21.
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Published
Nov. 4, 2010 2:49 PM
- Last modified
Mar. 23, 2011 9:34 PM
