Hydrogen sulfide alleviates hypothyroidism-induced myocardial fibrosis in rats through stimulating autophagy and inhibiting TGF-ß1/Smad2 pathway.

Hypothyroidism alone can lead to myocardial fibrosis and result in heart failure, but traditional hormone replacement therapy does not improve the fibrotic situation. Hydrogen sulfide (H2S), a new gas signaling molecule, possesses anti-inflammatory, antioxidant, and anti-fibrotic capabilities. Whether H2S could improve hypothyroidism-induced myocardial fibrosis are not yet studied. In our study, H2S could decrease collagen deposition in the myocardial tissue of rats caused by hypothyroidism. Furthermore, in hypothyroidism-induced rats, we found that H2S could enhance cystathionine-gamma-lyase (CSE), not cystathionine ß-synthase (CBS), protein expressions. Finally, we noticed that H2S could elevate autophagy levels and inhibit the transforming growth factor-ß1 (TGF-ß1) signal transduction pathway. In conclusion, our experiments not only suggest that H2S could alleviate hypothyroidism-induced myocardial fibrosis by activating autophagy and suppressing TGF-ß1/SMAD family member 2 (Smad 2) signal transduction pathway, but also show that it can be used as a complementary treatment to conventional hormone therapy.

H2S attenuates the myocardial fibrosis in diabetic rats through modulating PKC-ERK1/2MAPK signaling pathway.

OBJECTIVETo investigate the roles and underlying mechanism of exogenous H2S (hydrogen sulfide) in attenuating the myocardial fibrosis in diabetic rats. METHODS: A total of 40 SD rats were randomly divided into 4 groups: control group, STZ group, STZ + H2S group and H2S group. To build the DM rat model , the rats in the STZ group and STZ + H2S group were injected streptozotocin (STZ) intraperitoneally, While the rats in the STZ + H2S group and the H2S group received sodium hydrosulfide (NaHS), which provides exogenous H2S. Eight weeks later, the myocardial tissues of rats were used to detecting the collagen deposition through Masson staining, as well as some protein expressions related to myocardial fibrosis and signaling pathway by western blotting. RESULTS: Comparing to control group, the collagen deposition of myocardial matrix remarkably increased in the STZ group, and almost all the proteins that are relative to myocardial fibrosis, inflammatory and signaling pathway show an overexpression, except for PPARG and NF-κBp65. When Compared with the STZ group, the collagen deposition was obviously attenuated in STZ + H2S group, as well as the protein expressions above-mentioned, While PPARG was up-regulated. CONCLUSION: The myocardial fibrosis in DM rats can be attenuated effectively by exogenous H2S, and the underlying mechanism is likely to regulating PKC-ERK1/2MAPK signaling pathway, improving the MMPs/TIMPs expression dysregulation and inhibiting inflammatory reaction.

Gefitinib-coated balloon inhibits the excessive hyperplasia of intima after vascular injuries through PI3K/AKT pathway.

OBJECTIVE: To explore the effect of gefitinib-coated balloon suppressive action on the excessive hyperplasia of intima after balloon injury of common carotid artery in rats and on the PI3K/AKT signal pathway. METHODS: MTT method and the expression of Bcl-2 and Caspase-3 proteins were detected in vitro; Adult SD rats were randomly split into 5 groups, namely sham group, model group, low-dosage gefitinib-coated balloon group, high-dosage gefitinib-coated balloon group, and paclitaxel-coated balloon group. The intimal proliferation of arteries, PCNA, P-AKT and PI3K protein expression, the cell apoptosis, expression of MMP9, TGFß and IL6 mRNA were measured by hematoxylin and eosin (H&E) staining, immunohistochemistry, TUNEL staining, and RT-qPCR. RESULTS: At the same time and concentration, Gefitinib suppressed the proliferation of smooth muscle cell more significantly than paclitaxel. Bcl-2 and Caspase-3 in vascular smooth muscle and endothelial cells (VSMC, EC) were significantly down-regulated and up-regulated after the cells were treated with gefitinib and paclitaxel. In gefitinib- and paclitaxel-coated balloon groups, significant up-regulations were found in the area of lumen. Furthermore, the expression of PCNA suggested that all coated balloons could suppress the excessive proliferation of smooth muscle cells in the hyperplastic intima compared with the control group. In gefitinib- and paclitaxel-coated balloon group, the expression of PI3K/AKT was significantly down-regulated. The use of drug-coated balloons mitigated the cell apoptosis in TUNEL. The expressions of MMP9, TGFß and IL6 mRNA in the model group were obviously up-regulated; and they were obviously down-regulated in the high-dose gefitinib-coated balloon group compared with the model group. CONCLUSIONS: Gefitinib-coated balloons were able to suppress the excessive proliferation in the common carotid arterial intima of rats more effectively than the paclitaxel-coated ones. The underlying mechanism may cover the PI3K/AKT signal pathway.

Hydrogen sulfide ameliorates rat myocardial fibrosis induced by thyroxine through PI3K/AKT signaling pathway.

This study aims to investigate the role and regulatory mechanism of the Hydrogen sulfide (H2S) in amelioration of rat myocardial fibrosis induced by thyroxine through interfering the autophagy via regulating the activity of PI3K/AKT1 signaling pathway and the expression of relative miRNA. 40 adult male SD rats were randomly divided into 4 groups (n = 10): the control group, the thyroxine model group (TH group), the model group with H2S intervention (TH + H2S group) and the normal group with H2S intervention (H2S group). Pathological changes were observed via H&E staining and Masson staining, Expressions of MMPs/TIMPs, PI3K/AKT, autophagy-related proteins in myocardial tissues were detected via Western blotting, and the expressions of miR-21, miR-34a, miR-214 and miR-221 were detected via RT-qPCR. Compared with the control group, in the TH group, myocardial fibrosis was more significant, the expressions of proteins in PI3K/AKT and autophagy-related proteins were significantly decreased, as well as the expression of miR-221; while the expressions of miR-21, miR-34a and miR-214 were significantly elevated. By contrast, all above-mentioned changes were obviously reversed with H2S treatment, which demonstrated the positive function of H2S in amelioration of rat myocardial fibrosis induced by thyroxine. The mechanism of such amelioration may be correlated with autophagy activated by the upregulation of expression of PI3K/AKT signaling pathway and downregulation of expressions of miR-21, miR-34a and miR-214.

Gaseous signalling molecule SO2 via Hippo­MST pathway to improve myocardial fibrosis of diabetic rats.

Recent studies have indicated the existence of an endogenous sulfur dioxide (SO2)­generating system in the cardiovascular system. The present study aimed to discuss the function and regulatory mechanism of gaseous signal molecule SO2 in inhibiting apoptosis and endoplasmic reticulum stress (ERS) via the Hippo­MST signaling pathway to improve myocardial fibrosis of diabetic rats. A total of 40 male Sprague­Dawley rats were randomly divided into four groups (10 rats per group): Normal control group (control group), diabetic rats group [streptozotocin (STZ) group], SO2 intervention group (STZ+SO2 group) and diabetes mellitus rats treated with L­Aspartic acid ß­hydroxamate (HDX) group (HDX group). Diabetic rats models were established by intra­peritoneal injection of STZ (40 mg/kg) Following model establishment, intra­peritoneal injection of Na2SO3/NaHSO3 solution (0.54 mmol/kg) was administered in the STZ+SO2 group, and HDX solution (25 mg/kg/week) was administered in the HDX group. A total of 4 weeks later, echocardiography was performed to evaluate rats' cardiac function; Masson staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and transmission electron microscopy examinations were performed to observe myocardial morphological changes. ELISA was employed to determine the SO2 content. Western blot analysis was performed to detect the expression of proteins associated with apoptosis, ERS and the Hippo­MST signalling pathway. Compared with the control group, the STZ group and HDX group had a disordered arrangement of myocardial cells with apparent myocardial fibrosis, and echocardiography indicated that the cardiac function was lowered, there was an obvious increase of apoptosis in myocardial tissue, the expression levels of apoptosis­associated protein B­cell lymphoma associated protein X, caspase­3 and caspase­9 were upregulated, and Bcl­2 expression was downregulated. The expression of ERS and Hippo­MST pathway­associated proteins, including CHOP, GRP94, MST1 and MST2, were significantly upregulated. By contrast, these above­mentioned changes were reversed by SO2 treatment. Compared with STZ group, the HDX group had a further increase of myocardial fibrosis and apoptosis, while there were no statistically significant differences in the expression of Bax/Bcl­2, caspase­3, caspase­9 and ERS and Hippo­MST pathway­associated proteins. The results of the present study demonstrated that the gaseous signal molecule SO2 can effectively improve the myocardial fibrosis of diabetic rats, and its mechanism may be associated with reduced apoptosis and ERS by downregulated Hippo­MST pathway.

Hydrogen sulfide alleviates myocardial fibrosis in mice with alcoholic cardiomyopathy by downregulating autophagy.

Myocardial fibrosis is one of the most important pathological features of alcoholic cardiomyopathy (ACM). Hydrogen sulfide (H2S) exerts protective effects in various types of cardiovascular disease, which has been demonstrated by many previous studies. However, there is a lack of adequate research on the effect of H2S on myocardial fibrosis in ACM. The present study aimed to investigate the etiopathogenic role of H2S in myocardial fibrosis induced by chronic alcohol intake. An ACM mouse model was induced by consumption of 4% ethanol solution in drinking water for 12 weeks. Sodium hydrosulfide (NaHS) was used as a donor to provide exogenous H2S. Twelve weeks later, mice were sacrificed to calculate the heart to body weight ratio. The degree of myocardial collagen deposition was evaluated by Masson's and Van Gieson's staining, the expression level of collagen â…  was measured by immunohistochemistry and autophagosomes were observed by transmission electron microscopy. In addition, the expression levels of autophagy­associated proteins and fibrosis-associated proteins were detected by western blotting, and the expression levels of miR-21 and miR-211 were detected by reverse transcription-quantitative polymerase chain reaction. The outcomes of the study revealed that chronic alcohol intake results in myocardial fibrosis, enhanced myocardial collagen deposition and increased expression levels of collagen I, autophagy, autophagy-associated proteins (Beclin 1, Atg3 and Atg7) and fibrosis-associated proteins (MMP8, MMP13, MMP14, MMP17 and TGF-ß1), as well as miR-21 and miR-221. These results were markedly reversed following treatment with H2S. The present study confirmed that H2S relieves myocardial fibrosis in mice with ACM, and the underlying mechanism may involve the downregulation of autophagy and miR-21 and miR-211 expression levels.

[Effect of Shexiang Baoxin Pills on isoprenaline-induced myocardial cell hypertrophy and Cx43 expression].

OBJECTIVE: To observe the effects of Shexiang Baoxin Pill (SBP) on isoprenaline (Iso)-induced changes in myocardial cell volume, shape, and connexin 43 (Cx43) expression.
 Methods: H9C2 myocardial cells were randomly divided into a control group, a Iso group and a Iso+SBP group. After 72 h of culture, the average surface area of H9C2 cells was measured under phase contrast microscope. Bicinchoninic acid (BCA) protein assay was carried out to determine the concentration of proteins. The survival rate of myocardial cells was measured by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, and the Cx43 expression was detected by Western blot.
 Results: The mean surface area and Cx43 concentration in Iso-treated myocardial cells were increased under the phase contrast microscope (P<0.05). Compared with the Iso group, the mean surface area was decreased, and the Cx43 concentration was reduced in the Iso+SBP group (both P<0.05). Compared with the control group, the Cx43 expression was obviously down-regulated in the H9C2 cells of the Iso group (P<0.05); while compared with the Iso group, the Cx43 expression was obviously up-regulated in the Iso+SBP group (P<0.05).
 Conclusion: Shexiang Baoxin Pills can prevent Iso-induced myocardial hypertrophy and down-regulate Cx43 expression.