scholarly journals SRC-3 Knockout Attenuates Myocardial Injury Induced by Chronic Intermittent Hypoxia in Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wanyu Wang ◽  
Hongbo Gu ◽  
Weihua Li ◽  
Yihua Lin ◽  
Xiangyang Yao ◽  
...  

This study investigated the effects of chronic intermittent hypoxia (CIH), a model of sleep apnea syndrome (SAS), on cardiac function. SRC-3 was extremely lowly expressed in the adult mouse heart tissue, while SRC-3 was highly expressed in the adult mouse heart tissue after CIH, suggesting that SRC-3 is involved in CIH model. We further studied the role of SRC-3 in CIH-induced myocardial injury in mice. Twenty-four healthy Balb/c male mice ( n = 16 , wild type; n = 8 , SRC-3 knockout (SRC3-KO)) were randomly divided into three groups: air control (Ctrl), CIH, and CIH+SRC3-KO. Mice were exposed to CIH for 12 weeks. qRT-PCR was used to evaluate cardiac expression of the following genes: 11HSD1, 11HSD2, GR, MR, COX-2, OPN, NOX2, HIF-1-α, IL-1β, IL-6, iNOS, TNF-α, PC-1, and TGF-β. Enzymatic levels of SOD, CAT, MDA, NOS, and NO in the mouse hearts were determined using commercially available kits. Immunohistochemistry (IHC) was used to evaluate NF-κB expression in cardiac tissues. A transmission electron microscope (TEM) was used to evaluate myocardial ultrastructure. TUNEL staining was used to assess myocardial cell apoptosis. CIH induced cardiac damage, which was ameliorated in the SRC-3 KO mice. CIH significantly increased the heart-to-body weight ratio, expression of all aforementioned genes except 11HSD1, GR, and MR, and increased the levels of MDA, NOS, NO, and NF-κB, which were attenuated in the SRC-3 KO mice. The CIH group had the lowest SOD and CAT levels, which were partially recovered in the CIH+SRC3-KO group. 11HSD2 gene expression was elevated in both the CIH and CIH+SRC3-KO groups compared to the Ctrl group. The CIH group had severe myocardial cell apoptosis and mitochondrial dysfunction, which were alleviated in the CIH+SRC3-KO group. CIH causes cardiac damage through inducing oxidative stress and inflammation. Knockout of SRC-3 ameliorates CIH-induced cardiac damage through antagonizing CIH-triggered molecular changes in cardiac tissue.

2021 ◽  
Vol 12 ◽  
Author(s):  
Li-Fei Luo ◽  
Lu-Yun Qin ◽  
Jian-Xin Wang ◽  
Peng Guan ◽  
Na Wang ◽  
...  

Astragaloside IV (ASIV) is the main active component of Astragalus, and can ameliorate cardiomyocyte hypertrophy, apoptosis and fibrosis. In this experiment, we studied how ASIV reduces the cardiotoxicity caused by adriamycin and protects the heart. To this end, rats were randomly divided into the control, ADR, ADR + ASIV and ASIV groups (n = 6). Echocardiography was used to observe cardiac function, HE staining was used to observe myocardial injury, TUNEL staining was used to observe myocardial cell apoptosis, and immunofluorescence and Western blotting was used to observe relevant proteins expression. Experiments have shown that adriamycin can damage heart function in rats, and increase the cell apoptosis index, autophagy level and oxidative stress level. Further results showed that ADR can inhibit the PI3K/Akt pathway. ASIV treatment can significantly improve the cardiac function of rats treated with ADR and regulate autophagy, oxidative stress and apoptosis. Our findings indicate that ASIV may reduce the heart damage caused by adriamycin by activating the PI3K/Akt pathway.


2020 ◽  
Vol 38 (6) ◽  
pp. 710-720 ◽  
Author(s):  
Shan Jiang ◽  
Guangyu Jiao ◽  
Yunqiu Chen ◽  
Mingxin Han ◽  
Xinzhuo Wang ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Thomas Gille ◽  
Morgane Didier ◽  
Cécile Rotenberg ◽  
Eva Delbrel ◽  
Dominique Marchant ◽  
...  

Background. Severe obstructive sleep apnea (OSA) with chronic intermittent hypoxia (IH) is common in idiopathic pulmonary fibrosis (IPF). Here, we evaluated the impact of IH on bleomycin- (BLM-) induced pulmonary fibrosis in mice. Methods. C57BL/6J mice received intratracheal BLM or saline and were exposed to IH (40 cycles/hour; FiO2 nadir: 6%; 8 hours/day) or intermittent air (IA). In the four experimental groups, we evaluated (i) survival; (ii) alveolar inflammation, pulmonary edema, lung oxidative stress, and antioxidant enzymes; (iii) lung cell apoptosis; and (iv) pulmonary fibrosis. Results. Survival at day 21 was lower in the BLM-IH group (p<0.05). Pulmonary fibrosis was more severe at day 21 in BLM-IH mice, as assessed by lung collagen content (p=0.02) and histology. At day 4, BLM-IH mice developed a more severe neutrophilic alveolitis, (p<0.001). Lung oxidative stress was observed, and superoxide dismutase and glutathione peroxidase expression was decreased in BLM-IH mice (p<0.05 versus BLM-IA group). At day 8, pulmonary edema was observed and lung cell apoptosis was increased in the BLM-IH group. Conclusion. These results show that exposure to chronic IH increases mortality, lung inflammation, and lung fibrosis in BLM-treated mice. This study raises the question of the worsening impact of severe OSA in IPF patients.


2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Qixue Wang ◽  
Yue Wang ◽  
Jiner Zhang ◽  
Shuo Pan ◽  
Shaofeng Liu

Background. Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) often have cardiac insufficiency mainly due to hypoxia/reperfusion injury caused by chronic intermittent hypoxia (CIH). Inflammation and oxidative stress are involved in the cardiovascular events of OSAHS patients. Studies have found that myofibrillation regulator-1 (MR-1) participates in the pathological process of OSAHS-induced myocardial injury, but the specific mechanism is still unclear. Methods. We used a CIH-induced rat model to simulate the process of OSAHS disease. Indices of myocardial injury, inflammation, and oxidative stress were detected using quantitative PCR and enzyme-linked immunosorbent assay (ELISA). After administration of adenoassociated viral vector (AAV) encoding silencing RNA against MR-1, we examined expression of the classic antioxidant stress pathway protein NF-E2-related factor 2 (Nrf2) using western blotting. Results. We found that levels of serum inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 were increased, and we further observed disturbance of the oxidative stress system, in which the content of reactive oxygen species (ROS), superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) was enhanced in CIH-induced rats. Subsequently, we detected that expression of Nrf2 and heme oxygenase-1 (HO-1) was slightly increased, while the expression of Kelch-like ECH-associated protein 1 (Keap-1) was significantly increased in the CIH model. Interestingly, after administration of silencing MR-1 AAV, the elevated levels of inflammatory factors were reduced, and the disordered oxidative stress system was corrected. Additionally, the expression of Nrf2 and HO-1 was distinctly increased, but the high expression of Keap-1 was decreased. Conclusions. Our research results demonstrate that silencing MR-1 rescued the myocardium the injury from inflammatory and oxidative stress in CIH-induced rats by administration of the Nrf2 signaling pathway.


2007 ◽  
Vol 102 (5) ◽  
pp. 1806-1814 ◽  
Author(s):  
Ah-Mee Park ◽  
Yuichiro J. Suzuki

Obstructive sleep apnea is associated with increased risk for cardiovascular diseases. As obstructive sleep apnea is characterized by episodic cycles of hypoxia and normoxia during sleep, we investigated effects of intermittent hypoxia (IH) on ischemia-reperfusion-induced myocardial injury. C57BL/6 mice were subjected to IH (2 min 6% O2 and 2 min 21% O2) for 8 h/day for 1, 2, or 4 wk; isolated hearts were then subjected to ischemia-reperfusion. IH for 1 or 2 wk significantly enhanced ischemia-reperfusion-induced myocardial injury. However, enhanced cardiac damage was not seen in mice treated with 4 wk of IH, suggesting that the heart has adapted to chronic IH. Ischemia-reperfusion-induced lipid peroxidation and protein carbonylation were enhanced with 2 wk of IH, while, with 4 wk, oxidative stress was normalized to levels in animals without IH. H2O2 scavenging activity in adapted hearts was higher after ischemia-reperfusion, suggesting the increased antioxidant capacity. This might be due to the involvement of thioredoxin, as the expression level of this protein was increased, while levels of other antioxidant enzymes were unchanged. In the heart from mice treated with 2 wk of IH, ischemia-reperfusion was found to decrease thioredoxin. Ischemia-reperfusion injury can also be enhanced when thioredoxin reductase was inhibited in control hearts. These results demonstrate that IH changes the susceptibility of the heart to oxidative stress in part via alteration of thioredoxin.


2021 ◽  
Author(s):  
MiaoShang Su ◽  
Yifan He ◽  
Sichen Xue ◽  
Jueke Yu ◽  
Xikai Ren ◽  
...  

To investigate whether butyric acid could alleviate chronic intermittent hypoxia (CIH)-induced lipid formation in human preadipocytes-subcutaneous (HPA-s) through accumulation of human antigen R (HuR) and inactivation of AMP-activated protein kinase (AMPK) pathway, human preadipocytes-subcutaneous (HPA-s) were obtained and divided into 3 groups: CIH group: cells were cultured in a three-gas incubator (10% O2); Butyric acid group: 10 mmol/L butyric acid added into cell culture medium. HuR-siRNA was futher transfected into CIH group for verification the function of HuR. Oil red O was implemented for observation of lipid droplets within cells. CCK8 assay was used for detecting cell viability. TUNEL assay as well as flow cytometry analysis was employed for determining cell apoptosis. Western blotting was used for measurement of protein expression levels. RT-qPCR analysis was used for detecting mRNA expression. CIH treatment increased adipocytes proliferation, while butyric acid inhibited cell proliferation and promoted cell apoptosis. The treatment of butyric acid in CIH group downregulated expression of inflammatory factors and increase cell apoptotic rate. Butyric acid treatment increased HuR expression in both cytoplasm and nucleus and decreased the level of p-AMPK and p-ACC, while transfection of AMPK activator or HuR-siRNA would downregulate HuR expression. Moreover, butyric acid alleviated CIH-induced cell proliferation, lipid formation and inflammatory status and promoted cell apoptosis through regulating related genes including p21, PPARγ, C/EBPa, IL-1β, IL-6, TLR4, caspase-8 and caspase-3. In conclusion, butyric acid could alleviate CIH-induced inflammation, cell proliferation and lipid formation through accumulation of HuR and inactivation of AMPK pathway.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Hongwei Zhao ◽  
Xiaobei Zhang ◽  
Ying Zheng ◽  
Yuan Li ◽  
Xiaokun Wang ◽  
...  

We aimed to evaluate the cardioprotective effect and mechanism of propofol in anthracycline-induced cardiomyocyte apoptosis. We selected the rat myocardial cell line, H9c2, and primary cardiomyocytes for in vitro study. The cardiomyocytes were treated with vehicle, Adriamycin® (ADM), propofol, or a combination of ADM and propofol. The proportion of apoptotic cells and the expression of miR-181a were detected by flow cytometry and real-time PCR, respectively. Luciferase assays were performed to explore the direct target gene of miR-181a. In vivo assay, rats were randomly divided into different treatment groups. The apoptosis index was determined by TUNEL staining, and the expression of miR-181a and STAT3 in heart tissue was detected. The antiproliferative effect of ADM alone was significantly greater than that of ADM plus propofol. A significantly greater decrease in the proportion of apoptotic cells and in miR-181a expression was observed in the combination treatment group compared with that in the ADM groups in vitro and in vivo. The loss-of-function of miR-181a in H9c2 of ADM treatment resulted in increased Bcl-2 and decreased Bax. MiR-181a suppressed Bcl-2 expression through direct targeting of the Bcl-2 transcript. Propofol reduced anthracycline-induced apoptosis in cardiomyocytes via targeting miR-181a/Bcl-2, and a negative correlation between miR-181a and Bcl-2 was observed.


2020 ◽  
Vol 11 ◽  
pp. 204062232092210 ◽  
Author(s):  
Sophie Moulin ◽  
Claire Arnaud ◽  
Sophie Bouyon ◽  
Jean-Louis Pépin ◽  
Diane Godin-Ribuot ◽  
...  

Background: Chronic intermittent hypoxia (IH), the hallmark feature of obstructive sleep apnoea syndrome, contributes to infarct size enhancement after myocardial ischemia–reperfusion (I/R). Curcumin (Curc), the natural pigment of Curcuma longa, has been demonstrated to be beneficial in the context of myocardial injury. In this study, we assessed the effects of Curc on the maladaptive cardiac response to IH, and particularly on IH-induced hypoxia inducible factor-1 (HIF-1) expression, oxidative stress, inflammation, endoplasmic reticulum (ER) stress and apoptosis. Methods: Swiss/SV129 mice were exposed to normoxia or IH (21–5% FiO2, 60 s cycles, 8 h per day, for 21 days) and treated orally with Curc (100 mg kg−1 day−1, oral gavage) or its vehicle. Mice were then either euthanised for heart sampling in order to perform biochemical and histological analysis, or subjected to an in vivo ischemia-reperfusion protocol in order to measure infarct size. Results: IH increased nuclear HIF-1α expression and superoxide anion (O2.–) production as well as nuclear factor kappa B (NF-kB) p65, glucose-regulated protein (Grp78) and C/EBP homologous protein (CHOP) expression. IH also induced apoptosis and increased infarct size after I/R . The IH-induced HIF-1 activation, oxidative stress, inflammation, ER stress and apoptosis were abolished by chronic Curc treatment. Curc also significantly decreased infarct size only in mice exposed to IH. Conclusion: Curc prevents IH-induced myocardial cell death signalling. Curc might be used as a combined therapy with continuous positive airway pressure in sleep apnoea patients with high cardiovascular risk.


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