Critical Roles of Calpastatin in Ischemia/Reperfusion Injury in Aged Livers

Ischemia/reperfusion (I/R) injury unavoidably occurs during hepatic resection and transplantation. Aged livers poorly tolerate I/R during surgical treatment. Although livers have a powerful endogenous inhibitor of calpains, calpastatin (CAST), I/R activates calpains, leading to impaired autophagy, mitochondrial dysfunction, and hepatocyte death. It is unknown how I/R in aged livers affects CAST. Human and mouse liver biopsies at different ages were collected during in vivo I/R. Hepatocytes were isolated from 3-month- (young) and 26-month-old (aged) mice, and challenged with short in vitro simulated I/R. Cell death, protein expression, autophagy, and mitochondrial permeability transition (MPT) between the two age groups were compared. Adenoviral vector was used to overexpress CAST. Significant cell death was observed only in reperfused aged hepatocytes. Before the commencement of ischemia, CAST expression in aged human and mouse livers and mouse hepatocytes was markedly greater than that in young counterparts. However, reperfusion substantially decreased CAST in aged human and mouse livers. In hepatocytes, reperfusion rapidly depleted aged cells of CAST, cleaved autophagy-related protein 5 (ATG5), and induced defective autophagy and MPT onset, all of which were blocked by CAST overexpression. Furthermore, mitochondrial morphology was shifted toward an elongated shape with CAST overexpression. In conclusion, CAST in aged livers is intrinsically short-lived and lost after short I/R. CAST depletion contributes to age-dependent liver injury after I/R.

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Targeted disruption of PDE3B, but not PDE3A, protects murine heart from ischemia/reperfusion injury

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1416230112 ◽

2015 ◽

Vol 112 (17) ◽

pp. E2253-E2262 ◽

Cited By ~ 43

Author(s):

Youn Wook Chung ◽

Claudia Lagranha ◽

Yong Chen ◽

Junhui Sun ◽

Guang Tong ◽

...

Keyword(s):

Connexin 43 ◽

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Permeability Transition Pore ◽

Permeability Transition ◽

Mouse Heart ◽

Targeted Disruption

Although inhibition of cyclic nucleotide phosphodiesterase type 3 (PDE3) has been reported to protect rodent heart against ischemia/reperfusion (I/R) injury, neither the specific PDE3 isoform involved nor the underlying mechanisms have been identified. Targeted disruption of PDE3 subfamily B (PDE3B), but not of PDE3 subfamily A (PDE3A), protected mouse heart from I/R injury in vivo and in vitro, with reduced infarct size and improved cardiac function. The cardioprotective effect in PDE3B−/− heart was reversed by blocking cAMP-dependent PKA and by paxilline, an inhibitor of mitochondrial calcium-activated K channels, the opening of which is potentiated by cAMP/PKA signaling. Compared with WT mitochondria, PDE3B−/− mitochondria were enriched in antiapoptotic Bcl-2, produced less reactive oxygen species, and more frequently contacted transverse tubules where PDE3B was localized with caveolin-3. Moreover, a PDE3B−/− mitochondrial fraction containing connexin-43 and caveolin-3 was more resistant to Ca2+-induced opening of the mitochondrial permeability transition pore. Proteomics analyses indicated that PDE3B−/− heart mitochondria fractions were enriched in buoyant ischemia-induced caveolin-3–enriched fractions (ICEFs) containing cardioprotective proteins. Accumulation of proteins into ICEFs was PKA dependent and was achieved by ischemic preconditioning or treatment of WT heart with the PDE3 inhibitor cilostamide. Taken together, these findings indicate that PDE3B deletion confers cardioprotective effects because of cAMP/PKA-induced preconditioning, which is associated with the accumulation of proteins with cardioprotective function in ICEFs. To our knowledge, our study is the first to define a role for PDE3B in cardioprotection against I/R injury and suggests PDE3B as a target for cardiovascular therapies.

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The cyclophilin inhibitor NIM-811 increases muscle cell survival with hypoxia in vitro and improves gait performance following ischemia–reperfusion in vivo

Scientific Reports ◽

10.1038/s41598-021-85753-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Khairat Bahgat Youssef El Baradie ◽

Mohammad B. Khan ◽

Bharati Mendhe ◽

Jennifer Waller ◽

Frederick O’Brien ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Survival ◽

Reperfusion Injury ◽

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Permeability Transition ◽

Mitochondrial Permeability

AbstractAcute ischemia–reperfusion injury in skeletal muscle is a significant clinical concern in the trauma setting. The mitochondrial permeability transition inhibitor NIM-811 has previously been shown to reduce ischemic injury in the liver and kidney. The effects of this treatment on skeletal muscle are, however, not well understood. We first used an in vitro model of muscle cell ischemia in which primary human skeletal myoblasts were exposed to hypoxic conditions (1% O2 and 5% CO2) for 6 h. Cells were treated with NIM-811 (0–20 µM). MTS assay was used to quantify cell survival and LDH assay to quantify cytotoxicity 2 h after treatment. Results indicate that NIM-811 treatment of ischemic myotubes significantly increased cell survival and decreased LDH in a dose-dependent manner. We then examined NIM-811 effects in vivo using orthodontic rubber bands (ORBs) for 90 min of single hindlimb ischemia. Mice received vehicle or NIM-811 (10 mg/kg BW) 10 min before reperfusion and 3 h later. Ischemia and reperfusion were monitored using laser speckle imaging. In vivo data demonstrate that mice treated with NIM-811 showed increased gait speed and improved Tarlov scores compared to vehicle-treated mice. The ischemic limbs of female mice treated with NIM-811 showed significantly lower levels of MCP-1, IL-23, IL-6, and IL-1α compared to limbs of vehicle-treated mice. Similarly, male mice treated with NIM-811 showed significantly lower levels of MCP-1 and IL-1a. These findings are clinically relevant as MCP-1, IL-23, IL-6, and IL-1α are all pro-inflammatory factors that are thought to contribute directly to tissue damage after ischemic injury. Results from the in vitro and in vivo experiments suggest that NIM-811 and possibly other mitochondrial permeability transition inhibitors may be effective for improving skeletal muscle salvage and survival after ischemia–reperfusion injury.

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Acute Induction of Translocon-Mediated Ca2+ Leak Protects Cardiomyocytes Against Ischemia/Reperfusion Injury

Cells ◽

10.3390/cells9051319 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1319

Author(s):

Ribal Al-Mawla ◽

Mallory Ducrozet ◽

Nolwenn Tessier ◽

Lucille Païta ◽

Bruno Pillot ◽

...

Keyword(s):

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Permeability Transition Pore ◽

Permeability Transition ◽

New Paradigm ◽

Leak Channel

During myocardial infarction, dysregulation of Ca2+ homeostasis between the reticulum, mitochondria, and cytosol occurs in cardiomyocytes and leads to cell death. Ca2+ leak channels are thought to be key regulators of the reticular Ca2+ homeostasis and cell survival. The present study aimed to determine whether a particular reticular Ca2+ leak channel, the translocon, also known as translocation channel, could be a relevant target against ischemia/reperfusion-mediated heart injury. To achieve this objective, we first used an intramyocardial adenoviral strategy to express biosensors in order to assess Ca2+ variations in freshly isolated adult mouse cardiomyocytes to show that translocon is a functional reticular Ca2+ leak channel. Interestingly, translocon activation by puromycin mobilized a ryanodine receptor (RyR)-independent reticular Ca2+ pool and did not affect the excitation–concentration coupling. Second, puromycin pretreatment decreased mitochondrial Ca2+ content and slowed down the mitochondrial permeability transition pore (mPTP) opening and the rate of cytosolic Ca2+ increase during hypoxia. Finally, this translocon pre-activation also protected cardiomyocytes after in vitro hypoxia reoxygenation and reduced infarct size in mice submitted to in vivo ischemia-reperfusion. Altogether, our report emphasizes the role of translocon in cardioprotection and highlights a new paradigm in cardioprotection by functionally uncoupling the RyR-dependent Ca2+ stores and translocon-dependent Ca2+ stores.

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LncRNA PVT1 Mediated by ZFP36L2 Regulates Myocardial Ischemia/Reperfusion Injury and Attenuates Mitochondrial Fusion and Fission via Activating miR-21-5p/MARCH5 Axis

10.21203/rs.3.rs-108063/v1 ◽

2020 ◽

Author(s):

Weifeng Huang ◽

Qin Tan ◽

Yong Guo ◽

Yongmei Cao ◽

Jiawei Shang ◽

...

Keyword(s):

Zinc Finger Protein ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Mitochondrial Fission ◽

Tumor Biology ◽

Luciferase Reporter ◽

Mitochondrial Morphology ◽

Mrna Levels

Abstract BackgroundAmong several leading cardiovascular disorders, ischemia-reperfusion (I/R) injury causes severe manifestations including acute heart failure, inflammation, and systemic dysfunction. Recently, there has been increasing evidence suggesting that alterations in mitochondrial morphology play a role in the prognoses of cardiac disorders. Long non-coding RNAs (lncRNAs) form major regulatory networks to modify gene transcription and translation. While several roles of lncRNAs have been explored in cancer and tumor biology, their implications on mitochondrial morphology and functions remain to be elucidated. MethodsThe functional roles of ZFP36L2 and lncRNA PVT1 were determined by a series of cardiomyocyte hypoxia/ reoxygenation (H/R) in vitro and myocardial I/R injury in vivo experiments. Quantitative Reverse transcription-polymerase chain reaction (qRT-PCR) and western blot analysis were used to detect the mRNA levels of ZFP36L2 and mitochondrial fission and fusion markers in the myocardial tissues and cardiomyocyte. Cardiac function was determined by immunohistochemistry, H&E, Masson’s staining and echocardiogram. Ultrastructural analysis of mitochondrial fission was performed using transmission electron microscopy (TEM). The mechanistic model of PVT1 with ZFP36L2 and miR-21-5p with MARCH5 was detected by subcellular fraction, RNA pull down, FISH, and luciferase reporter assays.ResultsIn this study, we report a novel regulatory axis involving lncRNA PVT1, microRNA miR-21-5p, and E3 ubiquitin ligase MARCH5, which alters mitochondrial morphology during myocardial I/R injury. Using an in vivo I/R injury mouse model and in vitro cardiomyocyte H/R model, we observed that zinc finger protein ZFP36L2 directly associated with PVT1 and altered mitochondrial fission and fusion. PVT1 also interacted with miR-21-5p and suppressed its expression and activity. Furthermore, we identified MARCH5 as a modifier of miR-21-5p, and expression of MARCH5 and its effect on mitochondrial fission and fusion were directly proportional to PVT1 expression during H/R injury. ConclusionsOur findings demonstrated that manipulation of PVT1-miR-21-5p-MARCH5-mediated mitochondrial fission and fusion via ZFP36L2 may be a novel therapeutic approach to regulate myocardial I/R injury.

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Up-regulation of MicroRNA-21 Mediates Isoflurane-induced Protection of Cardiomyocytes

Anesthesiology ◽

10.1097/aln.0000000000000567 ◽

2015 ◽

Vol 122 (4) ◽

pp. 795-805 ◽

Cited By ~ 29

Author(s):

Jessica M. Olson ◽

Yasheng Yan ◽

Xiaowen Bai ◽

Zhi-Dong Ge ◽

Mingyu Liang ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Messenger Rna ◽

Functional Role ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Cell Death Protein

Abstract Background: Anesthetic cardioprotection reduces myocardial infarct size after ischemia–reperfusion injury. Currently, the role of microRNA in this process remains unknown. MicroRNAs are short, noncoding nucleotide sequences that negatively regulate gene expression through degradation or suppression of messenger RNA. In this study, the authors uncovered the functional role of microRNA-21 (miR-21) up-regulation after anesthetic exposure. Methods: MicroRNA and messenger RNA expression changes were analyzed by quantitative real-time polymerase chain reaction in cardiomyocytes after exposure to isoflurane. Lactate dehydrogenase release assay and propidium iodide staining were conducted after inhibition of miR-21. miR-21 target expression was analyzed by Western blot. The functional role of miR-21 was confirmed in vivo in both wild-type and miR-21 knockout mice. Results: Isoflurane induces an acute up-regulation of miR-21 in both in vivo and in vitro rat models (n = 6, 247.8 ± 27.5% and 258.5 ± 9.0%), which mediates protection to cardiomyocytes through down-regulation of programmed cell death protein 4 messenger RNA (n = 3, 82.0 ± 4.9% of control group). This protective effect was confirmed by knockdown of miR-21 and programmed cell death protein 4 in vitro. In addition, the protective effect of isoflurane was abolished in miR-21 knockout mice in vivo, with no significant decrease in infarct size compared with nonexposed controls (n = 8, 62.3 ± 4.6% and 56.2 ± 3.2%). Conclusions: The authors demonstrate for the first time that isoflurane mediates protection of cardiomyocytes against oxidative stress via an miR-21/programmed cell death protein 4 pathway. These results reveal a novel mechanism by which the damage done by ischemia/reperfusion injury may be decreased.

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Cell death during ischemia: relationship to mitochondrial depolarization and ROS generation

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00708.2002 ◽

2003 ◽

Vol 284 (2) ◽

pp. H549-H558 ◽

Cited By ~ 131

Author(s):

Jacques Levraut ◽

Hirotaro Iwase ◽

Z.-H. Shao ◽

Terry L. Vanden Hoek ◽

Paul T. Schumacker

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Permeability Transition ◽

Ros Generation ◽

Ischemia And Reperfusion ◽

Mitochondrial Depolarization ◽

Sytox Green ◽

Transport Chain

Ischemia-reperfusion injury induces cell death, but the responsible mechanisms are not understood. This study examined mitochondrial depolarization and cell death during ischemia and reperfusion. Contracting cardiomyocytes were subjected to 60-min ischemia followed by 3-h reperfusion. Mitochondrial membrane potential (ΔΨm) was assessed with tetramethylrhodamine methyl ester. During ischemia, ΔΨm decreased to 24 ± 5.5% of baseline, but no recovery was evident during reperfusion. Cell death assessed by Sytox Green was minimal during ischemia but averaged 66 ± 7% after 3-h reperfusion. Cyclosporin A, an inhibitor of mitochondrial permeability transition, was not protective. However, pharmacological antioxidants attenuated the fall in ΔΨm during ischemia and cell death after reperfusion and decreased lipid peroxidation as assessed with C11-BODIPY. Cell death was also attenuated when residual O2 was scavenged from the perfusate, creating anoxic ischemia. These results suggested that reactive oxygen species (ROS) were important for the decrease in ΔΨm during ischemia. Finally, 143B-ρ0 osteosarcoma cells lacking a mitochondrial electron transport chain failed to demonstrate a depletion of ΔΨm during ischemia and were significantly protected against cell death during reperfusion. Collectively, these studies identify a central role for mitochondrial ROS generation during ischemia in the mitochondrial depolarization and subsequent cell death induced by ischemia and reperfusion in this model.

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ZFP36L2 regulates myocardial ischemia/reperfusion injury and attenuates mitochondrial fusion and fission by LncRNA PVT1

Cell Death and Disease ◽

10.1038/s41419-021-03876-5 ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Fang Wu ◽

Weifeng Huang ◽

Qin Tan ◽

Yong Guo ◽

Yongmei Cao ◽

...

Keyword(s):

Zinc Finger Protein ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Mitochondrial Fission ◽

Tumor Biology ◽

Luciferase Reporter ◽

Pcr Analysis ◽

Mitochondrial Morphology

AbstractAmong several leading cardiovascular disorders, ischemia–reperfusion (I/R) injury causes severe manifestations including acute heart failure and systemic dysfunction. Recently, there has been increasing evidence suggesting that alterations in mitochondrial morphology and dysfunction also play an important role in the prognosis of cardiac disorders. Long non-coding RNAs (lncRNAs) form major regulatory networks altering gene transcription and translation. While the role of lncRNAs has been extensively studied in cancer and tumor biology, their implications on mitochondrial morphology and functions remain to be elucidated. In this study, the functional roles of Zinc finger protein 36-like 2 (ZFP36L2) and lncRNA PVT1 were determined in cardiomyocytes under hypoxia/reoxygenation (H/R) injury in vitro and myocardial I/R injury in vivo. Western blot and qRT-PCR analysis were used to assess the levels of ZFP36L2, mitochondrial fission and fusion markers in the myocardial tissues and cardiomyocytes. Cardiac function was determined by immunohistochemistry, H&E staining, and echocardiogram. Ultrastructural analysis of mitochondrial fission was performed using transmission electron microscopy. The mechanistic model consisting of PVT1 with ZFP36L2 and microRNA miR-21-5p with E3 ubiquitin ligase MARCH5 was assessed by subcellular fraction, RNA pull down, FISH, and luciferase reporter assays. These results identified a novel regulatory axis involving PVT1, miR-21-5p, and MARCH5 that alters mitochondrial morphology and function during myocardial I/R injury. Using an in vivo I/R injury mouse model and in vitro cardiomyocytes H/R model, we demonstrated that ZFP36L2 directly associates with PVT1 and alters mitochondrial fission and fusion. PVT1 also interactes with miR-21-5p and suppresses its expression and activity. Furthermore, we identified MARCH5 as a modifier of miR-21-5p, and its effect on mitochondrial fission and fusion are directly proportional to PVT1 expression during H/R injury. Our findings show that manipulation of PVT1-miR-21-5p-MARCH5-mediated mitochondrial fission and fusion via ZFP36L2 may be a novel therapeutic approach to regulate myocardial I/R injury.

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Inhibition of Neuronal Necroptosis Mediated by RIPK1 Provides Neuroprotective Effects on Hypoxia and Ischemia In Vitro and In Vivo

International Journal of Molecular Sciences ◽

10.3390/ijms23020735 ◽

2022 ◽

Vol 23 (2) ◽

pp. 735

Author(s):

Elena V. Mitroshina ◽

Maria M. Loginova ◽

Roman S. Yarkov ◽

Mark D. Urazov ◽

Maria O. Novozhilova ◽

...

Keyword(s):

Cell Death ◽

Ischemia Reperfusion Injury ◽

Pathological Condition ◽

Ischemia Reperfusion ◽

Laboratory Animals ◽

Bioelectrical Activity ◽

Electrode Arrays ◽

Ischemic Brain

Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.

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Mitochondrial bioenergetics and cardiolipin alterations in myocardial ischemia-reperfusion injury: implications for pharmacological cardioprotection

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00028.2018 ◽

2018 ◽

Vol 315 (5) ◽

pp. H1341-H1352 ◽

Cited By ~ 15

Author(s):

Giuseppe Paradies ◽

Valeria Paradies ◽

Francesca Maria Ruggiero ◽

Giuseppe Petrosillo

Keyword(s):

Myocardial Ischemia ◽

Mitochondrial Dysfunction ◽

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Mitochondrial Dynamics ◽

Ischemia Reperfusion ◽

Permeability Transition Pore ◽

Permeability Transition ◽

Mitochondrial Morphology ◽

Myocardial Ischemia Reperfusion

Mitochondrial dysfunction plays a central role in myocardial ischemia-reperfusion (I/R) injury. Increased reactive oxygen species production, impaired electron transport chain activity, aberrant mitochondrial dynamics, Ca2+ overload, and opening of the mitochondrial permeability transition pore have been proposed as major contributory factors to mitochondrial dysfunction during myocardial I/R injury. Cardiolipin (CL), a mitochondria-specific phospholipid, plays a pivotal role in multiple mitochondrial bioenergetic processes, including respiration and energy conversion, in mitochondrial morphology and dynamics as well as in several steps of the apoptotic process. Changes in CL levels, species composition, and degree of oxidation may have deleterious consequences for mitochondrial function with important implications in a variety of pathophysiological conditions, including myocardial I/R injury. In this review, we focus on the role played by CL alterations in mitochondrial dysfunction in myocardial I/R injury. Pharmacological strategies to prevent myocardial injury during I/R targeting mitochondrial CL are also examined.

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