Exogenous hydrogen sulfide protects against high glucose‑induced apoptosis and oxidative stress by inhibiting the STAT3/HIF‑1α pathway in H9c2 cardiomyocytes

Abstract

Hydrogen sulfide (H2S), an endogenous gasotransmitter, possesses multiple physiological and pharmacological properties including anti-apoptotic, anti-oxidative stress and cardiac protective activities in diabetic cardiomyopathy. An increasing body of evidence has suggested that signal transducer and activator of transcription 3 (STAT3) has beneficial effects in the heart. However, the effect of diabetes on the phosphorylation or activation of cardiac STAT3 appears to be controversial. The present study was designed to investigate the precise function of the STAT3/hypoxia-inducible factor-1α (HIF-1α) signaling pathway in high glucose (HG)-induced H9c2 cardiomyocyte injury and the function of the STAT3/HIF-1α pathway in the cardioprotective action of H2S. The results revealed that GYY4137 pretreatment substantially ameliorated the HG-induced decrease in cell viability and the increase in lactate dehydrogenase (LDH) release in H9c2 cells. Additionally, HG treatment resulted in the upregulation of the phosphorylated (p)-STAT3/STAT3 ratio and HIF-1α protein expression in H9c2 cells, indicating that the activation of the STAT3/HIF-1α pathway was induced by HG. STAT3/HIF-1α pathway inhibition induced by transfection with STAT3 small interfering (si)-RNA attenuated the HG-induced downregulation of cell viability and the upregulation of LDH release. Furthermore, STAT3 siRNA transfection and GYY4137 pretreatment combined attenuated HG-induced apoptosis as illustrated by the decrease in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, caspase-3 activity, apoptosis ratio and BCL2 associated X, apoptosis regulator/BCL2 apoptosis regulator ratio in H9c2 cells. In addition, STAT3 siRNA transfection and GYY4137 blocked HG-induced oxidative stress as evidenced by the decrease in reactive oxygen species generation, malondialdehyde content and NADPH oxidase 2 expression, and the increase in superoxide dismutase activity and glutathione level. Notably, GYY4137 pretreatment was revealed to reduce the p-STAT3/STAT3 ratio and HIF-1α protein expression, resulting in the inhibition of the STAT3/HIF-1α signaling pathway in HG-treated H9c2 cells. Altogether, the present results demonstrated that H2S mitigates HG-induced H9c2 cell damage, and reduces apoptosis and oxidative stress by suppressing the STAT3/HIF-1α signaling pathway.

The Potential of Hydrogen Sulfide Donors in Treating Cardiovascular Diseases

“…Despite the positive results observed following the treatment of various CVDs models with H 2 S donors, the outcome mainly depends on the characteristics of the donor, cell type, and concentration used. For example, treatment with the fast-releasing donor NaHS has been reported to elevate HIF-α levels, while the slow-releasing donor GYY4137 decreases the levels [ 78 , 81 , 105 ]. Similarly, treatment with NaHS has been shown to sulfurate and increase the activities of c-jun/AP-1 in macrophages [ 124 ], while inhibition of the JNK pathway has been reported in cardiomyocytes and epithelial cells A549 [ 104 , 125 ].…”

“…In smoke-induced left ventricular dysfunction rat models, treatment with NaHS suppresses the elevated pro-apoptotic activities by activating the PI3K/AKT and deactivating the c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) pathways [ 104 ]. In addition, it has been shown that treatment with GYY4137 can markedly prevent glucose-induced damage in H9c2 cells by reducing apoptosis via the inhibition of the STAT-3/HIF-α signaling cascade [ 105 ]. Collectively, the above evidence indicates that apoptosis-induced progression of myocardial dysfunction can be attenuated with the elevation of H 2 S levels.…”

“…Similarly, pre-treatment with NaHS has been shown to prevent neonatal mouse cardiomyocyte damage induced by H 2 O 2 through the alleviation of LDL-induced ROS increase and upregulation of sirtuin (SIRT)-1 expression [ 111 ]. Besides, treatment of H9c2 with GYY4137 also suppresses glucose-induced oxidative stress by decreasing the levels of malondialdehyde, ROS, and NADPH oxidase 2, as well as increasing that of superoxide dismutase (SOD) through STAT-3/HIF-α inactivation [ 105 ]. Strangely, under hypoxic conditions, the elevation of HIF-α has been reported following supplementation of H 2 S using the fast-releasing donor NaHS [ 78 , 81 ]; however, the slow-releasing donor GYY4137 exhibits the opposite effect, suggesting that the nature of the donor might influence the downstream effect on HIF-α.…”

Hydrogen Sulfide Plays an Important Role in Diabetic Cardiomyopathy

“…H 2 S can act as a signal molecule immediately after it is released, and it can also be stored as bound endosulfan, which can release H 2 S. At physiological pH, nearly two-thirds of H 2 S is in the form of hydrogen sulfide anion (HS–) (Guo et al, 2016 ). H 2 S plays important roles in many physiological processes, including vasodilation, blood pressure reduction (Greaney et al, 2017 ; Jin et al, 2017 ), anti-apoptosis (Li et al, 2019b ), anti-inflammation (Zhao et al, 2019 ), anti-oxidative stress (Tocmo and Parkin, 2019 ), cell survival/death, cell differentiation, cell proliferation/hypertrophy, mitochondrial bioenergetics/biogenesis, and endoplasmic reticulum stress (ERS) ( Figure 1 ) (Zhang D. et al, 2017 ). Recent studies have shown that H 2 S ameliorates diabetic complications including endothelial dysfunction (Li et al, 2019a ), nephropathy (Karmin and Siow, 2018 ), retinopathy (Wang P. et al, 2019 ), and cardiovascular diseases (Citi et al, 2018 ).…”

Hydrogen Sulfide and Carnosine: Modulation of Oxidative Stress and Inflammation in Kidney and Brain Axis

“…In addition, recent studies demonstrated that H 2 S, in the form of a NaHS donor, may reduce high glucose-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2/ARE pathway and may exert anti-apoptotic effects in diabetic myocardium by inhibiting c-Jun N-terminal kinase (JNK) and p38 MAPK pathways and activating PI3K/Akt signaling in vitro and in vivo [ 266 ]. Nevertheless, other recent studies showed that slow-releasing H 2 S donor, GYY4137, induces cardioprotection against myocardial ischemia and reperfusion injury by attenuating oxidative stress and apoptosis via activation of the PHLPP-1/Akt/Nrf2 pathway in mice [ 267 ], inhibition of the STAT3/HIF-1α signaling pathway [ 268 ], and activation of the AMPK (5′AMP-activated protein kinase)/mTOR signal pathway in high glucose-induced H9c2 cardiomyocyte damage [ 269 ]. Moreover, the GYY4137 donor exerts anti-inflammatory effects by suppression of the NF-kB and MAPK signaling pathway in Coxsackie virus B3-infected rat cardiomyocytes [ 270 ] as well as attenuating the development of diabetic cardiomyopathy via FoxO1 signaling pathway in vitro and in vivo [ 271 ].…”