scholarly journals Suppression of microRNA-135b-5p protects against myocardial ischemia/reperfusion injury by activating JAK2/STAT3 signaling pathway in mice during sevoflurane anesthesia

2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Xiao-Juan Xie ◽  
Dong-Mei Fan ◽  
Kai Xi ◽  
Ya-Wei Chen ◽  
Peng-Wei Qi ◽  
...  

The study aims to explore the effects of miR-135b-5p on myocardial ischemia/reperfusion (I/R) injuries by regulating Janus protein tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription (STAT) signaling pathway by mediating inhalation anesthesia with sevoflurane. A sum of 120 healthy Wistar male mice was assigned into six groups. Left ventricular ejection fraction (LVEF) and left ventricular shortening fraction (LVSF) were detected. Cardiomyocyte apoptosis was determined by terminal dexynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) assay. MiR-135b-5p expression, mRNA and protein expression of p-STAT3, p-JAK2, STAT3, JAK2, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein B (Bax) were detected by quantitative real-time PCR (qRT-PCR) and Western blotting. Target relationship between miR-135b-5p and JAK2 was confirmed by dual-luciferase reporter assay. The other five groups exhibited increased cardiomyocyte necrosis, apoptosis, miR-135b-5p and Bax expression, mRNA expression of JAK2 and STAT3, and protein expression of p-STAT3 and p-JAK2 compared with the sham group, but showed decreased LVEF, LVFS, and Bcl-2 expression. Compared with the model and AG490 + Sevo groups, the Sevo, inhibitor + Sevo and inhibitor + AG490 + Sevo groups displayed reduced cardiomyocyte necrosis, apoptosis, miR-135b-5p and Bax expression, but displayed elevated mRNA expression of JAK2 and STAT3, protein expression of p-STAT3 and p-JAK2, LVEF, LVFS and Bcl-2 expression. Compared with the Sevo and inhibitor + AG490 + Sevo groups, the AG490 + Sevo group showed decreased LVEF, LVFS, Bcl-2 expression, mRNA expressions of JAK2 and STAT3, and protein expressions of p-STAT3 and p-JAK2, but increased cardiomyocyte necrosis, apoptosis, and Bax expressions. MiR-135b-5p negatively targetted JAK2. Inhibition of miR-135b-5p can protect against myocardial I/R injury by activating JAK2/STAT3 signaling pathway through mediation of inhalation anesthesia with sevoflurane.

2021 ◽  
Vol 11 (1) ◽  
pp. 89-98
Author(s):  
Jianxian Xiong ◽  
Dongmin Yu ◽  
Wentong Li ◽  
Xiaowei Wang

Background: Rhein is a kind of lipophilic anthraquinone widely existing in herbal medicine. Here we aim to investigate whether Rhein can reduce the degree of myocardial ischemia/reperfusion injury and inhibit the development of oxidative stress, and elucidate the molecular mechanism of Rhein in protecting myocardial cells. Methods: The anti-oxidation and anti-apoptosis effects of Rhein were studied by using the primary myocardial cells of ischemia/reperfusion rat as the model of myocardial injury. Cell viability was detected by MTT, The level of LDH and CK-MB released by cardiomyocytes was measured by Colorimetric assay. The ROS was observed under microscope and the level of catalase and glutathione peroxidase were detected by enzymatic methods. The JAK2/STAT3 signaling pathway mediated by Rhein was observed by Western blot. Results: Compared with that of the SIR group, cell viability in the SIR and Rhein co-treatment groups increased significantly (P < 0.001), the release of LDH and CK-MB decreased, the positive rate of ROS in cardiomyocytes decreased, and the concentration of catalase and glutathione peroxidase increased significantly (P < 0.001). Besides, Rhein can activate JAK2/STAT3 signaling pathway. JAK2 siRNA can inhibit the JAK2/STAT3 signaling mediated by Rhein. The addition of Rhein can significantly increase the activity of mitochondrial superoxide dismutase (SOD) and reduce the MDA, which indicates that the oxidative damage of mitochondria induced by Rhein was significantly weakened. The mitochondrial functional changes induced by Rhein can be reversed by JAK2 siRNA. Conclusion: Our study shows that Rhein can reduce ROS in cardiomyocytes by JAK2/STAT3 signaling pathway activation, and effectively inhibit the apoptosis of cardiomyocytes, thus having a direct protective effect on cardiomyocytes under SIR.


Author(s):  
Zi-Long Wang ◽  
Xiao-Chen Sun ◽  
Rong Luo ◽  
Dong-Ye Li ◽  
Hao-Chen Xuan

IntroductionTo explore serum norepinephrine (NE) concentration and β3-adrenoceptor (β3AR) protein expression at different times during myocardial ischemia/reperfusion (I/R) and examine the role of β3AR in I/R.Material and methods28 Sprague-Dawley (SD) rats were randomly divided into one sham group and six I/R groups. The rats in the I/R groups were subjected to ischemia for 45 minutes. After reperfusion, the serum NE concentration and the β3AR protein expression in the myocardial tissue of the left ventricular injury region were detected. Another 18 SD rats were randomly divided into a sham group, I/R groups, and I/R + BRL37344 group.ResultsCompared with the sham group, the serum NE concentration of rats in the I/R groups significantly increased at 6 hours (P < 0.001). The serum NE concentration and myocardial β3AR protein expression were both highest at 72 hours. Compared with the sham group, the expressions of the pro-apoptotic proteins Bax and cleaved caspase-3 after I/R were significantly increased (P < 0.01, P < 0.001, respectively), and the expression of anti-apoptotic protein Bcl-2 was significantly decreased (P < 0.01). Compared with I/R groups, the expressions of Bax and cleaved caspase-3 in the I/R + BRL37344 group were significantly decreased (P < 0.05, P < 0.01, respectively).ConclusionsWith the prolongation of myocardial I/R in rats, serum NE concentration and β3AR protein expression showed a significant increase trend and reached a peak at 72 hours. Specific β3AR agonist BRL37344 can reduce myocardial I/R injury in vivo in rats, alleviate apoptosis, reduce infarct size, and improve cardiac function.


2018 ◽  
Vol 47 (3) ◽  
pp. 1193-1206 ◽  
Author(s):  
Yunyang Lu ◽  
Yingda Feng ◽  
Dan Liu ◽  
Zhiran Zhang ◽  
Kai Gao ◽  
...  

Background/Aims: Myocardial ischemia/reperfusion (MI/R) injury is a leading factor responsible for damage in myocardial infarction, resulting in additional injury to cardiac tissues involved in oxidative stress, inflammation, and apoptosis. Thymoquinone (TQ), the main constituent of Nigella sativa L. seeds, has been reported to possess various biological activities. However, few reports regarding myocardial protection are available at present. Therefore, this study was conducted aiming to investigate the protective effect of TQ against MI/R injury and to clarify its potential mechanism. Methods: MI/R injury models of isolated rat hearts and neonatal rat cardiomyocytes were established. The Langendorff isolated perfused heart system, triphenyltetrazolium chloride staining, gene transfection, TransLaser scanning confocal microscopy, and western blotting were employed to evaluate the cardioprotection effect of TQ against MI/R injury. Results: Compared with the MI/R group, TQ treatment could remarkably improve left ventricular function, decrease myocardial infarct size and production of lactate dehydrogenase (LDH), and attenuate mitochondrial oxidative damage by elevating superoxide dismutase (SOD) activity and reducing production of hydrogen peroxide (H2O2) and malonaldehyde (MDA). Moreover, the cardioprotective effect of TQ was accompanied by up-regulated expression of SIRT1 and inhibition of p53 acetylation. Additionally, TQ treatment could also enhance mitochondrial function and reduce the number of apoptotic cardiomyocytes. Nonetheless, the cardioprotective effect of TQ could be mitigated by SIRT1 inhibitor sirtinol and SIRT1 siRNA, respectively, which was achieved through inhibition of the SIRT1 signaling pathway. Conclusions: The findings in this study demonstrate that TQ is efficient in attenuating MI/R injury through activation of the SIRT1 signaling pathway, which can thus reduce mitochondrial oxidative stress damage and cardiomyocyte apoptosis.


Author(s):  
Tao Liang ◽  
Xiao-Yong Hu ◽  
Yong-Hui Li ◽  
Bin-Qiang Tian ◽  
Zuo-Wei Li ◽  
...  

MicroRNA-21 (miRNA-21), a kind of short, noncoding RNAs, functioned as a tumor marker and was upregulated in renal cell carcinoma (RCC). However, the underlying mechanisms of miRNA-21 in RCC were uncertain. Therefore, the effects and mechanisms of miRNA-21 on the proliferation, differentiation, and apoptosis of cultured human RCC cells were further investigated in this study. After slicing miRNA-21 in RCC cells, the viability, mRNA expression of C/EBPα and PPARγ, caspase 3 activity, and protein expression of mTOR, STAT3, and pSTAT3 were determined. It was found that knockdown of miRNA-21 downregulated the optical density (OD) value of cells, inhibited mRNA expression of PPARγ and C/EBPα, and enhanced activity of caspase 3. Furthermore, protein expression of pSTAT3 was also decreased in the absence of miRNA-21. Notably, miRNA-21-changed proliferation, differentiation, and apoptosis of human RCC cells were partially regulated following the block of the mTOR-STAT3 signaling pathway by the mTOR inhibitor (XL388). It was indicated that miRNA-21 promoted proliferation and differentiation and decreased apoptosis of human RCC cells through the activation of the mTOR-STAT3 signaling pathway.


2018 ◽  
pp. 563-570 ◽  
Author(s):  
X. DONG ◽  
X. YAN ◽  
W. ZHANG ◽  
S. TANG

Adiponectin (APN), an adipose tissue-excreted adipokine, plays protective roles in metabolic and cardiovascular diseases. In this study, the effects and mechanisms of APN on biological functions of rat vascular endothelial progenitor cells (VEPCs) were investigated in vitro. After administrating APN in rat VEPCs, the proliferation was measured by methyl thiazolyl tetrazolium (MTT) method, the apoptotic rate was test by Flow cytometry assay, mRNA expression of B-cell lymphoma-2 (Bcl-2) and vascular endothelial growth factor (VEGF) was determined by real-time reverse transcriptase polymerase chain reaction (RT-PCR), and protein expression of mechanistic target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3) and phospho-STAT3 (pSTAT3) was analyzed by Western blot. It was suggested that APN promoted the optical density (OD) value of VEPCs, enhanced mRNA expression of Bcl-2 and VEGF, and inhibited cell apoptotic rate. Furthermore, protein expression of pSTAT3 was also increased in the presence of APN. Moreover, APN changed-proliferation, apoptosis and VEGF expression of VEPCs were partially suppressed after blocking the mTOR-STAT3 signaling pathway by the mTOR inhibitor XL388. It was indicated that APN promoted biological functions of VEPCs through targeting the mTOR-STAT3 signaling pathway.


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