scholarly journals Mitochondrial Metabolism behind Region-Specific Resistance to Ischemia-Reperfusion Injury in Gerbil Hippocampus. Role of PKCβII and Phosphate-Activated Glutaminase

2021 ◽  
Vol 22 (16) ◽  
pp. 8504
Author(s):  
Małgorzata Beręsewicz-Haller ◽  
Olga Krupska ◽  
Paweł Bochomulski ◽  
Danuta Dudzik ◽  
Anita Chęcińska ◽  
...  

Ischemic episodes are a leading cause of death worldwide with limited therapeutic interventions. The current study explored mitochondrial phosphate-activated glutaminase (GLS1) activity modulation by PKCβII through GC-MS untargeted metabolomics approach. Mitochondria were used to elucidate the endogenous resistance of hippocampal CA2-4 and dentate gyrus (DG) to transient ischemia and reperfusion in a model of ischemic episode in gerbils. In the present investigation, male gerbils were subjected to bilateral carotids occlusion for 5 min followed by reperfusion (IR). Gerbils were randomly divided into three groups as vehicle-treated sham control, vehicle-treated IR and PKCβII specific inhibitor peptide βIIV5-3-treated IR. Vehicle or βIIV5-3 (3 mg/kg, i.v.) were administered at the moment of reperfusion. The gerbils hippocampal tissue were isolated at various time of reperfusion and cell lysates or mitochondria were isolated from CA1 and CA2-4,DG hippocampal regions. Recombinant proteins PKCβII and GLS1 were used in in vitro phosphorylation reaction and organotypic hippocampal cultures (OHC) transiently exposed to NMDA (25 μM) to evaluate the inhibition of GLS1 on neuronal viability. PKCβII co-precipitates with GAC (GLS1 isoform) in CA2-4,DG mitochondria and phosphorylates GLS1 in vitro. Cell death was dose dependently increased when GLS1 was inhibited by BPTA while inhibition of mitochondrial pyruvate carrier (MPC) attenuated cell death in NMDA-challenged OHC. Fumarate and malate were increased after IR 1h in CA2-4,DG and this was reversed by βIIV5-3 what correlated with GLS1 activity increases and earlier showed elevation of neuronal death (Krupska et al., 2017). The present study illustrates that CA2-4,DG resistance to ischemic episode at least partially rely on glutamine and glutamate utilization in mitochondria as a source of carbon to tricarboxylic acid cycle. This phenomenon depends on modulation of GLS1 activity by PKCβII and remodeling of MPC: all these do not occur in ischemia-vulnerable CA1.

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sergiy M Nadtochiy ◽  
Paul S Brookes

Introduction: The adult heart utilizes mostly fat for energy production, with adaptation to different fuels (“metabolic plasticity”) being a hallmark of the healthy heart. However, metabolic maladaptation is known to occur in heart failure. As such, the ability of the heart to metabolize specific substrates could impact the outcome of pathological insults, such as ischemia-reperfusion (IR) injury. The aim of this study was to develop a system whereby adult mouse cardiomyocytes (AMC) subjected to IR injury could be supplied with different fuels, and metabolism measured in real-time. Methods: AMC were divided in 3 groups, supplied either with glucose (GLU, 5mM), palmitate/fat free BSA (FAT, 100µM) or GLU+FAT. A previously developed method for in-vitro IR injury using a Seahorse XF24 [1], was adopted for ACM. IR comprised 60 min. ischemia and 60 min. reperfusion, and additional metabolic parameters were measured separately using mitochondrial inhibitors and uncouplers [2]. Oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were simultaneously measured during the IR protocol, followed by a cell death assay. Results: FAT cells showed higher baseline OCR and lower ECAR rates compare to GLU cells, although uncoupled OCR was lower in FAT group, suggesting a lower metabolic reserve capacity for cells respiring on fat. Upon IR, the drop in pH was significantly greater in GLU compare to FAT, indicating faster lactate production. During reperfusion, both OCR and ECAR recovered to pre-ischemic levels in GLU cells but failed to do so in FAT cells. Post-IR cell death was significantly higher in FAT vs. GLU. Surprisingly, GLU+FAT (modeling a “physiologic” substrate mix) replicated the same metabolic profile and cell death as GLU. Conclusions: (i) AMC had better recovery from IR injury using glucose as fuel. (ii) Lower cell viability in FAT (vs. GLU) correlated with smaller metabolic reserve capacity and with a smaller pH drop during ischemia. This is consistent with a known protective role for acidification during IR injury. (iii) Mixed substrates (GLU+FAT) gave a similar response to glucose alone, suggesting that fat may not be toxic, rather glucose is protective, in IR injury. [1] Circ Res. (2012), 110. 948-57. [2] J Vis Exp. (2010), 46. pii: 2511.


2015 ◽  
Vol 122 (4) ◽  
pp. 795-805 ◽  
Author(s):  
Jessica M. Olson ◽  
Yasheng Yan ◽  
Xiaowen Bai ◽  
Zhi-Dong Ge ◽  
Mingyu Liang ◽  
...  

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.


2022 ◽  
Vol 23 (2) ◽  
pp. 735
Author(s):  
Elena V. Mitroshina ◽  
Maria M. Loginova ◽  
Roman S. Yarkov ◽  
Mark D. Urazov ◽  
Maria O. Novozhilova ◽  
...  

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.


2018 ◽  
Vol 9 (1) ◽  
pp. 17-32 ◽  
Author(s):  
Eakkapote Prompunt ◽  
Nitirut Nernpermpisooth ◽  
Jantira Sanit ◽  
Sarawut Kumphune

AbstractOne of the major causes of cardiac cell death during myocardial ischemia is the oversecretion of protease enzymes surrounding the ischemic tissue. Therefore, inhibition of the protease activity could be an alternative strategy for preventing the expansion of the injured area. In the present study, we investigated the effects of Secretory Leukocyte Protease Inhibitor (SLPI), by means of overexpression and treatment of recombinant human SLPI (rhSLPI) in an in vitro model. Rat cardiac myoblast (H9c2) cells overexpressing rhSLPI were generated by gene delivery using pCMV2-SLPI-HA plasmid. The rhSLPI-H9c2 cells, mock transfected cells, and wild-type (WT) control were subjected to simulated ischemia/reperfusion (sI/R). Moreover, the treatment of rhSLPI in H9c2 cells was also performed under sI/R conditions. The results showed that overexpression of rhSLPI in H9c2 cells significantly reduced sI/R-induced cell death and injury, intracellular ROS level, and increased Akt phosphorylation, when compared to WT and mock transfection (p <0.05). Treatment of rhSLPI prior to sI/R reduced cardiac cell death and injury, and intra-cellular ROS level. In addition, 400 ng/ml rhSLPI treatment, prior to sI, significantly inhibited p38 MAPK phosphorylation and rhSLPI at 400–1000 ng/ml could increase Akt phosphorylation.


2020 ◽  
Vol 21 (10) ◽  
pp. 3583
Author(s):  
Yu Ah Hong ◽  
So Young Jung ◽  
Keum Jin Yang ◽  
Dai Sig Im ◽  
Kyung Hwan Jeong ◽  
...  

Cilastatin is a specific inhibitor of renal dehydrodipeptidase-1. We investigated whether cilastatin preconditioning attenuates renal ischemia-reperfusion (IR) injury via hypoxia inducible factor-1α (HIF-1α) activation. Human proximal tubular cell line (HK-2) was exposed to ischemia, and male C57BL/6 mice were subjected to bilateral kidney ischemia and reperfusion. The effects of cilastatin preconditioning were investigated both in vitro and in vivo. In HK-2 cells, cilastatin upregulated HIF-1α expression in a time- and dose-dependent manner. Cilastatin enhanced HIF-1α translation via the phosphorylation of Akt and mTOR was followed by the upregulation of erythropoietin (EPO) and vascular endothelial growth factor (VEGF). Cilastatin did not affect the expressions of PHD and VHL. However, HIF-1α ubiquitination was significantly decreased after cilastatin treatment. Cilastatin prevented the IR-induced cell death. These cilastatin effects were reversed by co-treatment of HIF-1α inhibitor or HIF-1α small interfering RNA. Similarly, HIF-1α expression and its upstream and downstream signaling were significantly enhanced in cilastatin-treated kidney. In mouse kidney with IR injury, cilastatin treatment decreased HIF-1α ubiquitination independent of PHD and VHL expression. Serum creatinine level and tubular necrosis, and apoptosis were reduced in cilastatin-treated kidney with IR injury, and co-treatment of cilastatin with an HIF-1α inhibitor reversed these effects. Thus, cilastatin preconditioning attenuated renal IR injury via HIF-1α activation.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1863
Author(s):  
Joseph Flores-Toro ◽  
Sung-Kook Chun ◽  
Jun-Kyu Shin ◽  
Joan Campbell ◽  
Melissa Lichtenberger ◽  
...  

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.


2001 ◽  
Vol 94 (6) ◽  
pp. 1082-1088 ◽  
Author(s):  
Bradley C. McPherson ◽  
Zhenhai Yao

Background Morphine reduces myocardial ischemia-reperfusion injury in vivo and in vitro. The authors tried to determine the role of opioid delta1 receptors, oxygen radicals, and adenosine triphosphate-sensitive potassium (KATP) channels in mediating this effect. Methods Chick cardiomyocytes were studied in a flow-through chamber while pH, flow rate, oxygen, and carbon dioxide tension were controlled. Cell viability was quantified by nuclear stain propidium iodide, and oxygen radicals were quantified using molecular probe 2',7'-dichlorofluorescin diacetate. Results Morphine (1 microM) or the selective delta-opioid receptor agonist BW373U86 (10 pM) given for 10 min before 1 h of ischemia and 3 h of reoxygenation reduced cell death (31 +/- 5%, n = 6, and 28 +/- 5%, n = 6 [P &lt; 0.05], respectively, 53 +/- 6%, n = 6, in controls) and generated oxygen radicals before ischemia (724 +/- 53, n = 8, and 742 +/- 75, n = 8 [P &lt; 0.05], respectively, vs. 384 +/- 42, n = 6, in controls, arbitrary units). The protection of morphine was abolished by naloxone, or the selective delta1-opioid receptor antagonist 7-benzylidenenaltrexone. Reduction in cell death and increase in oxygen radicals with BW373U86 were blocked by the selective mitochondrial KATP channel antagonist 5-hydroxydecanoate or diethyldithiocarbamic acid (1,000 microM), which inhibited conversion of O2- to H2O2. The increase in oxygen radicals was abolished by the mitochondrial electron transport inhibitor myxothiazoL Reduction in cell death was associated with attenuated oxidant stress at reperfusion. Conclusion Stimulation of delta1-opioid receptors generates oxygen radicals via mitochondrial KATP channels. This signaling pathway attenuates oxidant stress and cell death in cardiomyocytes.


2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Ying Xiong ◽  
Yun Xia ◽  
Jiangtao Deng ◽  
Xuetao Yan ◽  
Jianjuan Ke ◽  
...  

Direct peritoneal resuscitation with pyruvate (Pyr-PDS) has emerged as an interesting candidate to alleviate injury in diverse organs, while the potential mechanism has yet to be fully elucidated. To explore the effect of autophagy in the spinal cord ischemia-reperfusion (SCIR) injury and the underlying mechanism, we established a model of SCIR in vivo and in vitro. In vivo, male SD rats underwent aortic occlusion for 60 min and then followed by intraperitoneally infused with 20 mL of pyruvate or normal saline for 30 min, and the spinal cords were removed for analysis after 48 h of reperfusion. The functional and morphological results showed that Pyr-PDS alleviated SCIR injury; meanwhile, the expression of autophagy-related genes and transmission electron microscopy displayed autophagy was activated by SCIR injury, and Pyr-PDS treatment could further upregulate the degree of autophagy which plays a protective part in the SCIR injury, while there is no significant difference after treatment with saline. In addition, SCIR injury inhibited expression of PHD2, which results to activate its downstream HIF-1α/BNIP3 pathway to promote autophagy. In the Pyr-PDS, the results revealed PHD2 was further inhibited compared to the SCIR group, which could further activate the HIF-1α/BNIP3 signaling pathway. Additionally, oxygen-glucose deprivation and reoxygenation were applied to SH-SY5Y cells to mimic anoxic conditions in vitro, and the expression of autophagy-related genes, PHD2, and its downstream HIF-1α/BNIP3 pathway showed the same trend as the results in vivo. Besides, IOX2, a specific inhibitor of PHD2 was also treated to SH-SY5Y cells during reoxygenation, in which the result is as same as the pyruvate group. Then, we observed the expression of autophagy-related genes and the HIF-1α signal pathway in the process of reoxygenation; the results showed that as the reoxygenation goes, the expression of the HIF-1α signal pathway and degree of autophagy came to decrease gradually, while treated with pyruvate could maintain autophagy high and stable through keeping PHD2 at a lower level during reoxygenation, and the latter was observed downregulated during reoxygenation process from 0 to 24 hours in a time-effect way. The above results indicated that direct peritoneal resuscitation with pyruvate showed effective protection to ischemia-reperfusion of the spinal cord through activating autophagy via acting on PHD2 and its downstream HIF-1α/BNIP3 pathway.


2015 ◽  
Vol 36 (5) ◽  
pp. 2072-2082 ◽  
Author(s):  
Peng Zhang ◽  
Yong Lu ◽  
Dong Yu ◽  
Dadong Zhang ◽  
Wei Hu

Background: Tumor necrosis factor receptor-associated protein 1 (TRAP1), an essential mitochondrial chaperone is induced in rat hearts following ischemia/reperfusion (I/R), but its role in myocardial I/R injury is unclear. The present study examined the function of TRAP1 in cardiomyocyte hypoxia/reoxygenation injury in vitro and myocardial I/R injury in vivo. Methods: HL-1 cardiomyocytes transfected with TRAP1 or vector were subjected to simulated I/R (SI/R) in vitro. Cell death and mitochondrial function were assessed. Wild type (WT) and TRAP1 knockout (TRAP1 KO) mice were subjected to cardiac I/R in vivo. The infarct size and myocardial apoptosis were determined. WT and TRAP1 KO cardiomyocytes were subjected to SI/R in vitro. Mitochondrial function was assessed. Results: TRAP1 overexpression protects HL-1 cardiomyocytes from SI/R-induced cell death in vitro. The reduced cell death was associated with decreased ROS generation, better-preserved mitochondrial ETC complex activity, membrane potential, and ATP production, as well as delayed mPTP opening. Loss of TRAP1 aggravates SI/R-induced mitochondrial damage in cardiomyocytes in vitro and myocardial I/R injury and apoptosis in vivo. Conclusion: The results of the present study show that TRAP1 provides cardioprotection against myocardial I/R by ameliorating mitochondrial dysfunction.


2021 ◽  
Vol 8 ◽  
Author(s):  
John Henderson ◽  
Praveen K. Dubey ◽  
Mallikarjun Patil ◽  
Sarojini Singh ◽  
Shubham Dubey ◽  
...  

Doxorubicin (DOX, an anthracycline) is a widely used chemotherapy agent against various forms of cancer; however, it is also known to induce dose-dependent cardiotoxicity leading to adverse complications. Investigating the underlying molecular mechanisms and strategies to limit DOX-induced cardiotoxicity might have potential clinical implications. Our previous study has shown that expression of microRNA-377 (miR-377) increases in cardiomyocytes (CMs) after cardiac ischemia-reperfusion injury in mice, but its specific role in DOX-induced cardiotoxicity has not been elucidated. In the present study, we investigated the effect of anti-miR-377 on DOX-induced cardiac cell death, remodeling, and dysfunction. We evaluated the role of miR-377 in CM apoptosis, its target analysis by RNA sequencing, and we tested the effect of AAV9-anti-miR-377 on DOX-induced cardiotoxicity and mortality. DOX administration in mice increases miR-377 expression in the myocardium. miR-377 inhibition in cardiomyocyte cell line protects against DOX-induced cell death and oxidative stress. Furthermore, RNA sequencing and Gene Ontology (GO) analysis revealed alterations in a number of cell death/survival genes. Intriguingly, we observed accelerated mortality and enhanced myocardial remodeling in the mice pretreated with AAV9-anti-miR-377 followed by DOX administration as compared to the AAV9-scrambled-control-pretreated mice. Taken together, our data suggest that in vitro miR-377 inhibition protects against DOX-induced cardiomyocyte cell death. On the contrary, in vivo administration of AAV9-anti-miR-377 increases mortality in DOX-treated mice.


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