scholarly journals Targeting Dynamin 2 as a Novel Pathway to Inhibit Cardiomyocyte Apoptosis Following Oxidative Stress

2016 ◽  
Vol 39 (6) ◽  
pp. 2121-2134 ◽  
Author(s):  
Danchen Gao ◽  
Jian Yang ◽  
Yutao Wu ◽  
Qiwen Wang ◽  
Qiaoling Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Mitochondrial Morphology ◽  
Ros Production ◽  
Protective Effects ◽  
Mitochondrial Fragmentation ◽  
Induced Apoptosis ◽  
Dynamin 2

Background/Aims: Inhibition of Drp-1-mediated mitochondrial fission limits reactive oxygen species (ROS) production and apoptosis in cardiomyocytes subjected to ischemia/reperfusion injury. It remains unknown if Dynamin 2 inhibition results in similar protective effects. Here we studied the role of Dynamin 2 in cardiomyocyte oxidative stress-induced apoptosis and ROS production. Methods: The effect of lentiviral shRNA (lv5-shRNA) mediated Dynamin 2 knockdown on apopotosis, mitochondria, and ROS production were studied in neonatal mouse cardiomycytes, which were further treated with either selective Drp1 inhibitor mdivi-1 or the Dynamin 2/Drp1 inhibitor Dynasore. Apoptosis was evaluated by flow cytometry. Mitochondrial morphology and transmembrane potential (ΔΨm) were studied by confocal microscopy, and ROS production was detected by dichlorofluorescein diacetate. Results: Inhibition of Drp1 and Dynamin 2 protected against mitochondrial fragmentation, maintained ΔΨm, attenuated cellular ROS production and limited apoptosis. Moreover, Lv5-shRNA mediated knockdown of Dynamin 2 alleviated mitochondrial fragmentation, and reduced both ROS production and oxidative stress-induced apoptosis. The protective effects of Dynamin 2 knockdown were enhanced by Dynasore, indicating an added benefit. Conclusions: Oxidative stress-induced apoptosis and ROS production are attenuated by not only Drp1 inhibition but also Dynamin 2 inhibition, implicating Dynamin 2 as a mediator of oxidative stress in cardiomyocytes.

scholarly journals Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Anthony R. Anzell ◽  
Garrett M. Fogo ◽  
Zoya Gurm ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Conditional Knockout ◽  
Mitochondrial Morphology ◽  
Primary Neurons ◽  
Mitochondrial Fragmentation

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.

scholarly journals Lingonberry anthocyanins protect cardiac cells from oxidative-stress-induced apoptosis

2017 ◽  
Vol 95 (8) ◽  
pp. 904-910 ◽  
Author(s):  
Cara K. Isaak ◽  
Jay C. Petkau ◽  
Heather Blewett ◽  
Karmin O ◽  
Yaw L. Siow
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cardiac Cells ◽  
Control Group ◽  
Protective Effects ◽  
H9c2 Cells ◽  
Induced Apoptosis ◽  
Hoechst Staining

Lingonberry grown in northern Manitoba, Canada, contains exceptionally high levels of anthocyanins and other polyphenols. Previous studies from our lab have shown that lingonberry anthocyanins can protect H9c2 cells from ischemia–reperfusion injury and anthocyanin-rich diets have been shown to be associated with decreased cardiovascular disease and mortality. Oxidative stress can impair function and trigger apoptosis in cardiomyocytes. This study investigated the protective effects of physiologically relevant doses of lingonberry extracts and pure anthocyanins against hydrogen-peroxide-induced cell death. Apoptosis and necrosis were detected in H9c2 cells after hydrogen peroxide treatment via flow cytometry using FLICA 660 caspase 3/7 combined with YO-PRO-1 and then confirmed with Hoechst staining and fluorescence microscopy. Each of the 3 major anthocyanins found in lingonberry (cyanidin-3-galactoside, cyanidin-3-glucoside, and cyanidin-3-arabinoside) was protective against hydrogen-peroxide-induced apoptosis in H9c2 cells at 10 ng·mL−1 (20 nmol·L−1) and restored the number of viable cells to match the control group. A combination of the 3 anthocyanins was also protective and a lingonberry extract tested at 3 concentrations produced a dose-dependent protective effect. Lingonberry anthocyanins protected cardiac cells from oxidative-stress-induced apoptosis and may have cardioprotective effects as a dietary modification.

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

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.

scholarly journals Ischemic Postconditioning Alleviates Intestinal Ischemia-Reperfusion Injury by Enhancing Autophagy and Suppressing Oxidative Stress through the Akt/GSK-3β/Nrf2 Pathway in Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Rong Chen ◽  
Yun-yan Zhang ◽  
Jia-nan Lan ◽  
Hui-min Liu ◽  
Wei Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intestinal Ischemia ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Ischemic Postconditioning ◽  
Intestinal Barrier Function ◽  
Protective Effects ◽  
Nrf2 Pathway ◽  
Intestinal Ischemia Reperfusion

Aims. Ischemic postconditioning (IPO) has a strong protective effect against intestinal ischemia-reperfusion (IIR) injury that is partly related to autophagy. However, the precise mechanisms involved are unknown. Methods. C57BL/6J mice were subjected to unilateral IIR with or without IPO. After 45 min ischemia and 120 min reperfusion, intestinal tissues and blood were collected for examination. HE staining and Chiu’s score were used to evaluate pathologic injury. We test markers of intestinal barrier function and oxidative stress. Finally, we used WB to detect the expression of key proteins of autophagy and the Akt/GSK-3β/Nrf2 pathway. Results. IPO significantly attenuated IIR injury. Expression levels of LC3 II/I, Beclin-1, and p62 were altered during IIR, indicating that IPO enhanced autophagy. IPO also activated Akt, inhibited GSK-3β, induced Nrf2 nuclear translocation, and upregulated HO-1 and NQO1 expression, thus providing protective effects against IIR injury by suppressing oxidative stress. Consistently, the beneficial effects of IPO were abolished by pretreatment with 3-methyladenine, SC66, and brusatol, potent inhibitors of autophagy, Akt, and Nrf2, respectively. Conclusion. Our study indicates that IPO can ameliorate IIR injury by evoking autophagy, activating Akt, inactivating GSK-3β, and activating Nrf2. These findings may provide novel insights for the alleviation of IIR injury.

scholarly journals Cabbage (Brassica oleracea var. capitata) Protects against H2O2-Induced Oxidative Stress by Preventing Mitochondrial Dysfunction in H9c2 Cardiomyoblasts

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Dong Kwon Yang
Keyword(s):  
Oxidative Stress ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitogen Activated Protein Kinase ◽  
Ros Production ◽  
Hepatic Diseases ◽  
Mitochondrial Functions ◽  
Wide Range ◽  
H9c2 Cardiomyoblasts ◽  
Cabbage Extract

Oxidative stress plays an important role in the progression of cardiac diseases, including ischemia/reperfusion injury, myocardial infarction, and heart failure. Growing evidence indicates that cabbage has various pharmacological properties against a wide range of diseases, such as cardiovascular diseases, hepatic diseases, and cancer. However, little is known about its effects on oxidative stress in cardiomyocytes or the underlying mechanisms. Therefore, the present study examined the effects of cabbage extract on oxidative stress in H9c2 cardiomyoblasts. Cell viability, reactive oxygen species (ROS) production, apoptosis, mitochondrial functions, and expression levels of mitogen-activated protein kinase (MAPK) proteins were analyzed to elucidate the antioxidant effects of this extract. Cabbage extract protected against H2O2-induced cell death and did not elicit any cytotoxic effects. In addition, cabbage extract suppressed ROS production and increased expression of antioxidant proteins (SOD-1, catalase, and GPx). Cabbage extract also inhibited apoptotic responses and activation of MAPK proteins (ERK1/2, JNK, and p-38) in oxidative stress-exposed H9c2 cells. Notably, cabbage extract preserved mitochondrial functions upon oxidative stress. These findings reveal that cabbage extract protects against oxidative stress and suggest that it can be used as an alternative therapeutic strategy to prevent the oxidative stress in the heart.

scholarly journals SS-31 Protects Liver from Ischemia-Reperfusion Injury via Modulating Macrophage Polarization

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Longcheng Shang ◽  
Haozhen Ren ◽  
Shuai Wang ◽  
Hanyi Liu ◽  
Anyin Hu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Liver Injury ◽  
Reperfusion Injury ◽  
Liver Damage ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Protective Effects ◽  
Inflammation Response ◽  
Stat3 Signaling

Ischemia-reperfusion injury (IRI) is a common complication in liver surgeries. It is a focus to discover effective treatments to reduce ischemia-reperfusion injury. Previous studies show that oxidative stress and inflammation response contribute to the liver damage during IRI. SS-31 is an innovated mitochondrial-targeted antioxidant peptide shown to scavenge reactive oxygen species and decrease oxidative stress, but the protective effects of SS-31 against hepatic IRI are not well understood. The aim of our study is to investigate whether SS-31 could protect the liver from damages induced by IRI and understand the protective mechanism. The results showed that SS-31 treatment can significantly attenuate liver injury during IRI, proved by HE staining, serum ALT/AST, and TUNEL staining which can assess the degree of liver damage. Meanwhile, we find that oxidative stress and inflammation were significantly suppressed after SS-31 administration. Furthermore, the mechanism revealed that SS-31 can directly decrease ROS production and regulate STAT1/STAT3 signaling in macrophages, thus inhibiting macrophage M1 polarization. The proinflammation cytokines are then significantly reduced, which suppress inflammation response in the liver. Taken together, our study discovered that SS-31 can regulate macrophage polarization through ROS scavenging and STAT1/STAT3 signaling to ameliorate liver injury; the protective effects against hepatic IRI suggest that SS-31 may be an appropriate treatment for liver IRI in the clinic.

Sign in / Sign up

Export Citation Format

Share Document