Capsaicin ameliorates intermittent high glucose-mediated endothelial senescence via the TRPV1/SIRT1 pathway.

BACKGROUND: Patients with diabetes have accelerated vascular aging when compared with healthy individuals. Hyperglycemia, especially intermittent high glucose (IHG), is the main cause of vascular endothelial senescence. Capsaicin, a major component of chili pepper is thought to contribute to cardiovascular protection by spicy food. OBJECTIVE: To investigate the pathway related with the effects of capsaicin on endothelial cell senescence induced by IHG. METHODS: HUVECs were exposed to IHG (5 mM or 33 mM glucose, alternating every 12 hours for 3 days) and treated with capsaicin at 0.3, 1 and 3 µM. To determine endothelial cell senescence, we examined the senescence-related ß-galactosidase staining, cell cycle arrest, cell viability, as well as production of reactive oxygen species (ROS). To evaluate the involvement of TRPV1/[Ca2+]i/CaMKII/AMPK/SIRT1 pathway in anti- senescence effects of capsaicin, HUVECs were treated with CAPZ (a TRPV1 antagonist), BAPTA-AM (an intracellular calcium chelator), KN62 (a CaMKII antagonist), compound C (an AMPK inhibitor), or EX527 (a SIRT1 inhibitor). To knockdown TRPV1, HUVECs were transfected with shRNA lentivirus targeting TRPV1. The levels of SIRT1, p21, TRPV1, AMPK and phospho-AMPK were evaluated by western blotting. RESULTS: IHG suppressed the levels of SIRT1 and enhanced endothelial senescence. Capsaicin upregulated SIRT1 expression and downregulated the senescence marker, p21, thereby protecting endothelial cells from IHG-induced senescence as indicated by relieved G0/G1 phase arrest, improved cell viabilities, and reduced counts of senescent cells and ROS production. Pre-treatment with CAPZ, BAPTA-AM, KN62 or compound C abrogated the anti-senescence effects of capsaicin. Capsaicin restored AMPK phosphorylation and IHG-inhibited TRPV1 expression. Moreover, TRPV1 silencing suppressed SIRT1 expression and abolished the anti-senescence effects of capsaicin. CONCLUSION: Capsaicin elevates SIRT1 levels through TRPV1/[Ca2+]i/CaMKII/AMPK pathway and suppresses IHG-mediated endothelial cell senescence. This study provides initial evidence that capsaicin is a potential candidate for the prevention of vascular aging in diabetes.

Integrating network pharmacology and experimental evidence to decipher the cardioprotective mechanism of Yiqihuoxue decoction in rats after myocardial infarction.

ETHNOPHARMACOLOGICAL RELEVANCE: "Qi deficiency and blood stasis" syndrome is one of the most common syndromes treated with Traditional Chinese Medicine among ischemic heart disease (IHD) patients in clinic. As a Chinese herbal formula with the function of tonifying Qi and activating blood, Yiqihuoxue Decoction (YQHX) has been frequently proven to be effective in the clinical treatment of IHD. AIM OF THE STUDY: The cardioprotective mechanisms of YQHX in treating ischemic heart disease were investigated, with emphasis on the key targets and pathways. MATERIALS AND METHODS: In the present study, the potential targets of compounds identified in YQHX were predicted using PharmMapper, Symmap, and STITCH databases, and a "herb-compound-target" network was constructed using Cytoscape. Subsequently, the GO and KEGG functional enrichment analyses were analyzed using the DAVID database. Furthermore, a protein-protein interaction network was constructed using STRING to obtain the key target information. Besides, we used a myocardial ischemia rat model to investigate the cardioprotective effects of YQHX. Transmission electron microscopy and Western blotting were used to observe apoptotic bodies and confirm protein expressions of key candidate targets, respectively. RESULTS: Network pharmacology showed that a total of 141 potential targets were obtained from these databases. The functional analysis results revealed that the targets of YQHX were largely associated with apoptosis, and the PI3K-AKT and MAPK pathways might represent key functional pathways. The hub genes of network include ALB, TP53, AKT1, TNF, VEGFA, EGFR, MAPK1, CASP3, JUN, FN1, MMP9, and MAPK8. In vivo, YQHX significantly improved cardiac function and suppressed apoptosis in ischemic rat myocardium. Furthermore, YQHX could significantly upregulate Nrf2 and HO-1 expression, and inhibit JNK phosphorylation. CONCLUSIONS: Based on network pharmacology and experimental evidence, this study proves that the cardioprotective effects and mechanisms of YQHX depend on multi-component, multi-target, and multi-pathway. In particular, YQHX exerts anti-apoptotic effects potentially by regulating the Nrf2/HO-1 and JNK-MAPK pathways.

Protective effect of Yi-Qi-Huo-Xue Decoction against ischemic heart disease by regulating cardiac lipid metabolism.

Yi-Qi-Huo-Xue Decoction (YQHX) is the recombination of Dang-Gui-Bu-Xue Decoction (DBD), which is one of the well-known traditional Chinese Medicine (TCM) prescription, and has long been shown to have significant protective effects against myocardial ischemic injury. In previous studies, we found that YQHX could regulate lipid and glucose metabolism, promote angiogenesis, attenuate inflammatory response, and ameliorate left ventricular function in myocardial ischemia rat models. However, the underlying mechanism of how YQHX involves in lipid metabolism remains unclear so far. In this study, the underlying mechanism of YQHX in lipid metabolism disorders was elucidated in a myocardial ischemia rat model and a hypoxia-induced H9c2 cell injury model. YQHX (8.2 g·kg-1) and positive-control drug trimetazidine (10 mg·kg-1) were administered daily on the second day after left anterior descending (LAD) operation. At 7 days and 28 days after surgery, changes of cardiac morphology, structure, and function were evaluated by H&E staining and echocardiography, respectively. The plasma lipid levels and mitochondrial ATP content were also evaluated. Western blot and RT-PCR were used to determine the protein and mRNA expressions of AMPK, PGC-1α, CPT-1α, and PPARα. YQHX improved cardiac function and ameliorated lipid metabolism disorders. Furthermore, YQHX increased the expression of p-AMPK, PGC-1α, and CPT-1α without changing PPARα in ischemic rat myocardium. In vitro, YQHX activated the protein and mRNA expression of PGC-1α, CPT-1α, and PPARα in hypoxia-induced H9c2 cells injury, whereas AMPK inhibitor Compound c blocked the effects of YQHX. Taken together, the results suggest that YQHX reduces lipid metabolism disorders in myocardial ischemia via the AMPK-dependent signaling pathway.

Can respiratory muscle training therapy effectively manage obstructive sleep apnea syndrome after stroke?: A protocol of systematic review and meta-analysis.

BACKGROUND: This study will explore the effectiveness and safety of respiratory muscle training therapy (RMTT) for the treatment of patients with obstructive sleep apnea syndrome (OSAS) after stroke. METHODS: In this study, we will systematically and comprehensively search Cochrane Library, PubMed, EMBASE, WANGFANG, VIP, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure for relevant literature from their inception to March 1, 2020 without any limitations to language and publication status. We will consider any randomized controlled trials focusing on the effectiveness and safety of RMTT for the treatment of patients with OSAS after stroke. The study quality will be checked using Cochrane risk of bias tool, and statistical analysis will be performed utilizing RevMan 5.3 software. RESULTS: This study will summarize and synthesize the current evidence of RMTT for the treatment of patients with OSAS following stroke. CONCLUSION: The findings of this study will assess the present evidence for the benefits and harms of RMTT for treating OSAS after stroke, and will inform clinical practice and future research. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42020170355.

[Time-phase changed character of cardiac muscle cell apoptosis and proliferation induced by angiotensin II and influences of TCM herbs for supplementing qi and activating blood circulation on it].

OBJECTIVE: To observe the dynamic change of apoptosis and proliferation of cardiac muscle cells (CMC) after being induced by Angiotensin II (Ang I), and the effect of TCM herbs for supplementing qi and/ or activating blood circulation on it. METHODS: The cultured CMC of SD suckling rat were treated by Ang II, and the amplitude, rhythm and frequency of cell pulsation, the protein content, area size and apoptosis of cells at various phases as well as the influence of TCM herbs afterwards were determined by image pattern analysis system, flow cytometry and biochemical assay. RESULTS: In the model group, cell pulsation showed quickened frequency from the 24th to 48th hr after Ang II treatment with the highest amplitude at the 24th hr; the cell area enlarged at the 24th hr, the enlargement became evident at the 48hr. Cell content of protein increased at the 24th hr, which reached to its peak at the 48th hr; an increasing trend of cell number was shown from the 12th to 48th hr; cell apoptosis started to appear at the 24th hr, it increased gradually from the 48th to 72th hr, and reached to the peak at the 72th hr (P < 0.05 or P < 0.01). All the Chinese herbs, both for supplementing qi and/or activating blood circulation, especially when they were used in combination, showed favourable preventive and therapeutic effect on CMC (P < 0.05 or P < 0.01), either at the early phase (24-48th hrs) mainly manifesting hypertrophy and proliferation or the late phase (48-96th hrs) mainly manifesting apoptosis. CONCLUSION: There exist characterized phasic windows of CMC after being treated by Ang II, the window of hypertrophy-proliferation phase and the window of cell apoptosis phase. When CMC were mainly in hypertrophic manner, myocardial hypertrophy may appear. Cell apoptosis may be one of the mechanisms for turning myocardial hypertrophy to heart failure, and it could be improved by Chinese herbs for supplementing qi and/or activating blood circulation.