scholarly journals Inactivation of TOPK Caused by Hyperglycemia Blocks Diabetic Heart Sensitivity to Sevoflurane Postconditioning by Impairing the PTEN/PI3K/Akt Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Sumin Gao ◽  
Rong Wang ◽  
Siwei Dong ◽  
Jing Wu ◽  
Bartłomiej Perek ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
High Glucose ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
Cardioprotective Effect ◽  
Diabetic Heart ◽  
H9c2 Cells ◽  
Sevoflurane Postconditioning ◽  
And Oxidative Stress

The cardioprotective effect of sevoflurane postconditioning (SPostC) is lost in diabetes that is associated with cardiac phosphatase and tensin homologue on chromosome 10 (PTEN) activation and phosphoinositide 3-kinase (PI3K)/Akt inactivation. T-LAK cell-originated protein kinase (TOPK), a mitogen-activated protein kinase- (MAPKK-) like serine/threonine kinase, has been shown to inactivate PTEN (phosphorylated status), which in turn activates the PI3K/Akt signaling (phosphorylated status). However, the functions of TOPK and molecular mechanism underlying SPostC cardioprotection in nondiabetes but not in diabetes remain unknown. We presumed that SPostC exerts cardioprotective effects by activating PTEN/PI3K/Akt through TOPK in nondiabetes and that impairment of TOPK/PTEN/Akt blocks diabetic heart sensitivity to SPostC. We found that in the nondiabetic C57BL/6 mice, SPostC significantly attenuated postischemic infarct size, oxidative stress, and myocardial apoptosis that was accompanied with enhanced p-TOPK, p-PTEN, and p-Akt. These beneficial effects of SPostC were abolished by either TOPK kinase inhibitor HI-TOPK-032 or PI3K/Akt inhibitor LY294002. Similarly, SPostC remarkably attenuated hypoxia/reoxygenation-induced cardiomyocyte damage and oxidative stress accompanied with increased p-TOPK, p-PTEN, and p-Akt in H9c2 cells exposed to normal glucose, which were canceled by either TOPK inhibition or Akt inhibition. However, either in streptozotocin-induced diabetic mice or in H9c2 cells exposed to high glucose, the cardioprotective effect of SPostC was canceled, accompanied by increased oxidative stress, decreased TOPK phosphorylation, and impaired PTEN/PI3K/Akt signaling. In addition, TOPK overexpression restored posthypoxic p-PTEN and p-Akt and decreased cell death and oxidative stress in H9c2 cells exposed to high glucose, which was blocked by PI3K/Akt inhibition. In summary, SPostC prevented myocardial ischemia/reperfusion injury possibly through TOPK-mediated PTEN/PI3K/Akt activation and impaired activation of this signaling pathway may be responsible for the loss of SPostC cardioprotection by SPostC in diabetes.

scholarly journals Hyperglycemia Aggravates Hepatic Ischemia Reperfusion Injury by Inducing Chronic Oxidative Stress and Inflammation

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Yihan Zhang ◽  
Dongdong Yuan ◽  
Weifeng Yao ◽  
Qianqian Zhu ◽  
Yue Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Glucose ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Diabetic Rats ◽  
Nuclear Factor ◽  
Hepatic Ischemia ◽  
Chronic Oxidative Stress ◽  
Hepatic Ischemia Reperfusion ◽  
And Oxidative Stress

Aim. To investigate whether hyperglycemia will aggravate hepatic ischemia reperfusion injury (HIRI) and the underlying mechanisms.Methods. Control and streptozotocin-induced diabetic Sprague-Dawley rats were subjected to partial hepatic ischemia reperfusion. Liver histology, transferase, inflammatory cytokines, and oxidative stress were assessed accordingly. Similarly, BRL-3A hepatocytes were subjected to hypoxia/reoxygenation (H/R) after high (25 mM) or low (5.5 mM) glucose culture. Cell viability, reactive oxygen species (ROS), and activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) were determined.Results. Compared with control, diabetic rats presented more severe hepatic injury and increased hepatic inflammatory cytokines and oxidative stress. HIRI in diabetic rats could be ameliorated by pretreatment of N-acetyl-L-cysteine (NAC) or apocynin. Excessive ROS generation and consequent Nrf2 and NF-κB translocation were determined after high glucose exposure. NF-κB translocation and its downstream cytokines were further increased in high glucose cultured group after H/R. While proper regulation of Nrf2 to its downstream antioxidases was observed in low glucose cultured group, no further induction of Nrf2 pathway by H/R after high glucose culture was identified.Conclusion. Hyperglycemia aggravates HIRI, which might be attributed to chronic oxidative stress and inflammation and potential malfunction of antioxidative system.

Dapagliflozin activates AMPK to attenuate cardiac dysfunction and oxidative stress under hypoxia/reoxygenation-caused damage

2020 ◽  
Author(s):  
Kun-Ling Tsai ◽  
Pei-Ling Hsieh ◽  
Wan-Ching Chou ◽  
Hui-Ching Cheng ◽  
Yu-Ting Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Cardiac Dysfunction ◽  
Ischemia Reperfusion ◽  
Terminal Deoxynucleotidyl Transferase ◽  
H9c2 Cells ◽  
Glucose Medium ◽  
Sprague Dawley ◽  
Mitochondrial Dna Copy Number ◽  
Hypoxia Reoxygenation

Abstract Background: Emerging evidence demonstrated Dapagliflozin (DAPA), an inhibitor of type II sodium-glucose cotransporter-2, prevented various cardiovascular events. However, the detailed mechanisms underlying its cardioprotective properties remained largely unknown. In the present study, we sought to investigate the effects of DAPA on the cardiac ischemia/reperfusion (I/R) injury and study the mechanisms of DAPA-provided cardioprotection.Methods: For in intro studies, cardiac myoblast H9c2 cells were exposed to hypoxia with no-glucose medium for 1 hr than followed a reoxygenation with high-glucose medium for 4 hr. DAPA was treated before hypoxia/reoxygenation (H/R) exposure. For in vivo investigations, I/R was instigated in Sprague-Dawley (SD) rats using ligation of the left anterior descending coronary artery (LAD). DAPA was given daily by gavage for 5 days before I/R induction.Results: Results from in vitro experiments showed that DAPA induced the phosphorylation of adenosine 5'-monophosphate activated protein kinase (AMPK), resulting in the downregulation of phosphorylated protein kinase C (PKC) in the cardiac myoblast H9c2 cells following H/R condition. We demonstrated that DAPA treatment diminished the H/R-elicited oxidative stress via the AMPK/ PKC/ NADPH oxidase (Nox) pathway. In addition, DAPA prevented the H/R-induced abnormality of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) expression, mitochondrial membrane potential, and mitochondrial DNA copy number through AMPK/ PKC/ Nox signaling. Besides, DAPA reversed the apoptosis-associated changes, including H/R-suppressed Bcl-2 and H/R-induced expression of phosphorylated p53, Bax cytochrome c, and activated caspase 3 via AMPK/ PKC/ Nox/ PGC-1α signaling. Furthermore, we demonstrated that DAPA improved the I/R-induced cardiac dysfunction by echocardiography and abrogated the I/R-elicited apoptotic cells by terminal deoxynucleotidyl transferase dUTP nick end labeling assay in the myocardium of rats. Also, the administration of DAPA mitigated the production of two myocardial infarction markers, creatine phosphokinase isoenzymes and lactate dehydrogenase.Conclusion: In conclusion, our data suggested that DAPA treatment holds the potential to ameliorate the I/R-elicited oxidative stress and the following cardiac apoptosis via AMPK/ PKC/ Nox/ PGC-1α signaling, which attenuates the cardiac dysfunction caused by I/R injury.

scholarly journals Diabetes impairs the protective effects of sevoflurane postconditioning in myocardium subjected to ischemia/reperfusion injury in rats: important role of Drp1

2020 ◽  
Author(s):  
Jing Yu ◽  
Jiandong He ◽  
Wenqu Yang ◽  
Xiang Wang ◽  
Gaoxiang Shi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Myocardial Infarct Size ◽  
Diabetic Myocardium ◽  
Sevoflurane Postconditioning ◽  
And Oxidative Stress

Abstract Background Sevoflurane postconditioning (SevP) is an effective way in relieving myocardial ischemia/reperfusion (IR) injury, which doesn’t work well in diabetic myocardium unfortunately. Prior studies have noted the importance of increasing oxidative stress in diabetic tissues. Noteworthily, mitochondrial fission mediated by dynamin-related protein 1 (Drp1) is an upstream pathway of reactive oxygen production. Whether Drp1 dependent mitochondrial fission is associated with the ineffectiveness of SevP in diabetic myocardium remains unknown. The aim of this study was to explore the important role of Drp1 in diabetic myocardium and investigate whether Drp1 inhibition could restore the cardioprotective effect of SevP. Methods In the first part, adult male Sprague-Dawley(SD) rats were divided into 6 groups. Rats in diabetic groups were fed with high-fat and high-sugar for 8 weeks, and then received a injection of streptozotocin (35 mg/kg) intraperitoneally. Myocardial IR was induced by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion༎SevP was applied by continuous inhalation of 2.5% sevoflurane 1 min before reperfusion, which lasted for 10 min. In the second part, mdivi-1 was used to investigate whether Drp1 inhibition could restore the cardioprotective effects of SevP in diabetic myocardium against I/R injury. The myocardial infarct size, pathology, mitochondrial ultrastructure, cardiomyocyte apoptosis, total SOD activity, MDA content, and Drp1 expression were detected. Results The diabetic myocardium displayed severer injury with greater infarct size and apoptosis. Up-regulated Drp1 expression concomitant with increased mitochondrial fission and oxidative stress were observed in diabetic myocardium subjected to I/R. The deteriorated changes were alleviated in normal but not in diabetic rats. Importantly, mdivi-1 administration significantly suppressed mitochondrial fission and oxidative stress, and the beneficial effects of SevP were restored by mdivi-1. Conclusions The present study indicates a crucial role of Drp1 dependent mitochondrial fission in diabetic myocardium subjected to IR. Drp1 inhibition may be effective in restoring the effect of SevP in reducing diabetic myocardial IR injury.

scholarly journals Diabetes impairs the protective effects of sevoflurane postconditioning in the myocardium subjected to ischemia/ reperfusion injury in rats: important role of Drp1

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Yu ◽  
Jiandong He ◽  
Wenqu Yang ◽  
Xiang Wang ◽  
Gaoxiang Shi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Cardioprotective Effect ◽  
Myocardial Infarct Size ◽  
Apoptosis Index ◽  
Diabetic Myocardium ◽  
Sevoflurane Postconditioning

Abstract Background Sevoflurane postconditioning (SevP) effectively relieves myocardial ischemia/reperfusion (I/R) injury but performs poorly in the diabetic myocardium. Previous studies have revealed the important role of increased oxidative stress in diabetic tissues. Notably, mitochondrial fission mediated by dynamin-related protein 1 (Drp1) is an upstream pathway of reactive oxygen production. Whether the ineffectiveness of SevP in the diabetic myocardium is related to Drp1-dependent mitochondrial fission remains unknown. This study aimed to explore the important role of Drp1 in the diabetic myocardium and investigate whether Drp1 inhibition could restore the cardioprotective effect of SevP. Methods In the first part of the study, adult male Sprague-Dawley rats were divided into 6 groups. Rats in the diabetic groups were fed with high-fat and high-sugar diets for 8 weeks and injected intraperitoneally with streptozotocin (35 mg/kg). Myocardial I/R was induced by 30 min of occlusion of the left anterior descending branch of the coronary artery followed by 120 min of reperfusion. SevP was applied by continuous inhalation of 2.5 % sevoflurane 1 min before reperfusion, which lasted for 10 min. In the second part of the study, we applied mdivi-1 to investigate whether Drp1 inhibition could restore the cardioprotective effect of SevP in the diabetic myocardium. The myocardial infarct size, mitochondrial ultrastructure, apoptosis index, SOD activity, MDA content, and Drp1 expression were detected. Results TTC staining and TUNEL results showed that the myocardial infarct size and apoptosis index were increased in the diabetic myocardium. However, SevP significantly alleviated myocardial I/R injury in the normal myocardium but not in the diabetic myocardium. Additionally, we found an elevation in Drp1 expression, accompanied by more severe fission-induced structural damage and oxidative stress in the diabetic myocardium. Interestingly, we discovered that the beneficial effect of SevP was restored by mdivi-1, which significantly suppressed mitochondrial fission and oxidative stress. Conclusions Our study demonstrates the crucial role of mitochondrial fission dependent on Drp1 in the diabetic myocardium subjected to I/R, and strongly indicates that Drp1 inhibition may restore the cardioprotective effect of SevP in diabetic rats.

scholarly journals Short-Term Pretreatment of Naringin Isolated from Citrus Wilsonii Tanaka Attenuates Rat Myocardial Ischemia/Reperfusion Injury

2021 ◽  
Author(s):  
Liping Cheng ◽  
Hangxiu Liu ◽  
Xuefei Li ◽  
Wenting Liu ◽  
Lili Zhao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Response ◽  
Aqueous Extract ◽  
Ischemia Reperfusion ◽  
Cardioprotective Effect ◽  
High Yield ◽  
Short Term ◽  
Myocardial Apoptosis ◽  
Freeze Dried ◽  
And Oxidative Stress

Abstract Pretreatment or treatment with anti-apoptotic, anti-inflammatory, or anti-oxidative approaches could be critical for reducing the occurrence of myocardial I/R injury. Naringin, a natural flavonoid, plays important roles in inflammation-related diseases. Immature dry fruits of Citrus wilsonii Tanaka (Xiang Yuan) are rich in naringin that can be used as traditional Chinese medicine to treat inflammation-related symptoms. However, its roles in cardioprotective role remain unclear. This study aimed to isolate naringin from Citrus wilsonii Tanaka fruit and test their cardioprotective effect. The dry fruits of Citrus wilsonii Tanaka were extracted with boiling water and then supernatants were freeze-dried to yiled aqueous extract (ZQAE). The extract was chemoprofiled using UPLC-MS/MS to stand for major constituents, then subjected to different chromatographic separation steps and naringin was isolated in a high yield. The cardioprotective effect of the aqueous extract of ZQAE and naringin were investigated in a myocardial I/R rat model and to elucidate the mechanism underlying its cardioprotective effect. Naringin was successfully isolated from ZQAE powder by recrystallization in a very high yield. Our results indicated that 5-day ZQAE and naringin pretreatment both promoted histopathological changes and reduced myocardial enzymes induced by I/R. Moreover, the 50mg/kg and 100mg/kg ZQAE doses pretreatment presented a striking decreased the infarct size as well as myocardial enzyme levels but also inhibited myocardial apoptosis, the inflammatory response and oxidative stress. The cardioprotective effect of 5mg/kg dose of naringin pretreatment is comparable with that of 5mg/kg drug ditiazem pretreatment. Additionally, Naringin pretreatment exhibited striking decreases in the apoptosis index and downregulation of cleaved-Caspase3 protein expression. Meanwhile, naringin downregulated HMGB1 expression and upregulated SIRT1 expression in the myocardium. These findings suggest that short-term pretreatment with ZQAE and naringin both protect against myocardial I/R injury by suppressing myocardial apoptosis, the inflammatory response and oxidative stress. The cardioprotective effect of naringin involves SIRT1 activation and may interact with HMGB1 and inhibit the release of HMGB1.

scholarly journals Nerol protects against hypoxia/reoxygenation-induced apoptotic injury by activating PI3K/AKT signaling in cardiomyocytes

STEMedicine ◽  
2021 ◽  
Vol 2 (6) ◽  
pp. e87
Author(s):  
Jin Cheng ◽  
Qing Zou ◽  
Yugang Xue
Keyword(s):  
Protein Kinase ◽  
Western Blot ◽  
Cell Viability ◽  
Signaling Pathway ◽  
Akt Signaling ◽  
Cardioprotective Effect ◽  
H9c2 Cells ◽  
Akt Signaling Pathway ◽  
Ldh Release ◽  
Hypoxia Reoxygenation

Background: Nerol was reported as a natural anti-oxidant product and its protective effects against cardiovascular diseases have been documented. Our current study was designed to explore the cardioprotective effect of Nerol on hypoxia/reoxygenation (H/R)-induced production of reactive oxygen species (ROS) and cell apoptosis in H9c2 cells. The potential molecular mechanisms were further investigated. Methods: The cells were treated with 2.5 or 5 µM Nerol before or after H/R. Lactate dehydrogenase (LDH) release, cell viability, oxidative stress markers, and apoptotic proteins were assessed by cell counting kit-8, LDH release assay, commercial kits, and Western blot, respectively. To explore the underlying mechanism, the phosphorylation of p85 and p38, regulatory subunits of phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinase (MAPK), was evaluated by Western blot. To further confirm that the PI3K/AKT signaling pathway participated in the cardiomyocyte protection, H9c2 cells were treated with 5 µM Nerol in the presence or absence of 5 µM BEZ235 or LY294002 followed by H/R treatment. Results: H/R remarkably induced apoptosis, LDH release and ROS production. The cell viability was suppressed via inhibiting the PI3K/AKT signaling pathway activation. By contrast, pretreatment with Nerol can neutralize these effects by activating the PI3K/AKT signaling pathway. With the addition of BEZ235 or LY294002, the inhibitory effects of Nerol were abolished. Conclusion: Nerol provided promising cardioprotective effect against H/R-induced injuries in H9c2 cells by activating the PI3K/AKT pathway.

Effects of Off-Pump Versus On-Pump Coronary Artery Bypass Grafting: Apoptosis, Inflammation, and Oxidative Stress

2014 ◽  
Vol 17 (5) ◽  
pp. 271 ◽  
Author(s):  
Murat Bicer ◽  
Tunay Senturk ◽  
Murat Yanar ◽  
Ahmet Tutuncu ◽  
Arzu Yilmaztepe Oral ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ischemia Reperfusion ◽  
Artery Bypass ◽  
Bypass Grafting ◽  
Artery Bypass Grafting ◽  
Cabg Surgery ◽  
Off Pump ◽  
Pump Cabg ◽  
Hs Crp ◽  
And Oxidative Stress

<strong>Background</strong>: It has been suggested that off-pump coronary<br />artery bypass grafting (CABG) surgery reduces myocardial<br />ischemia-reperfusion injury, postoperative systemic<br />inflammatory response, and oxidative stress. The aim of this<br />study was to measure serum malondialdehyde (MDA), highsensitivity<br />C-reactive protein (hs-CRP), M30, and M65 levels<br />and to investigate the relationship between M30 levels and<br />oxidative stress and inflammation in patients undergoing onand<br />off-pump CABG surgery.<br /><strong>Methods</strong>: Fifty patients were randomly assigned to onpump<br />or off-pump CABG surgery (25 patients off-pump and<br />25 on-pump CABG surgery), and blood samples were collected<br />prior to surgery, and 30 minutes, 60 minutes, 6 hours,<br />and 24 hours after CABG surgery.<br /><strong>Results</strong>: Compared to the on-pump group, serum MDA<br />levels at 30 minutes, 60 minutes, 6 hours, and 24 hours after<br />the CABG surgery were significantly lower in the off-pump<br />group (P = .001, P = .001, P = .001, and P = .001, respectively).<br />Serum M30 levels were found to be elevated in both groups,<br />returning to baseline at 24 hours. When compared to baseline,<br />the hs-CRP level reached its peak at 24 hours at 13.28 ±<br />5.32 mg/dL in the on-pump group, and 15.44 ± 4.02 mg/dL<br />in the off-pump group.<br /><strong>Conclusion</strong>: CABG surgery is associated with an increase<br />in inflammatory markers and serum M30 levels, indicating<br />epithelial/endothelial apoptosis in the early period.

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