Acacetin Protects Myocardial Cells against Hypoxia-Reoxygenation Injury through Activation of Autophagy.

Ischemic heart disease is a leading cause of mortality and morbidity worldwide. We previously demonstrated that acacetin protects against myocardial ischemia reperfusion injury in rats, although the underlying mechanism remains to be elucidated. In the present study, we investigated the effects of acacetin on autophagy during hypoxia/reoxygenation (H/R) injury by exposing H9c2 myocardial cells to H/R with or without acacetin pretreatment during hypoxia. Our results show that acacetin significantly increased cell viability in a dose-dependent manner, enhanced antioxidant capacity, and suppressed protein apoptosis of rat cardiomyocytes H9c2 cells following H/R injury. In addition, lentiviral infection of H9c2 cardiomyocytes revealed that acacetin pretreatment significantly enhanced the fluorescence intensity of autophagy proteins Beclin 1, LC3-II, and p62. These results indicate that acacetin protected H9c2 cardiomyocytes from H/R damage by enhancing autophagy. Moreover, we found that application of acacetin increased activation of the PI3K/Akt signaling pathway, whereas cotreatment with the PI3K inhibitor LY294002 reversed the inhibition of apoptosis and autophagy induced by acacetin. In conclusion, acacetin mitigated H/R injury by promoting autophagy through activating the PI3K/Akt/mTOR signaling pathway.

Clinical evaluation of a rapid colloidal gold immunochromatography assay for SARS-Cov-2 IgM/IgG.

BACKGROUND: Since December 2019, there had been an outbreak of COVID-19 in Wuhan, China. At present, diagnosis COVID-19 were based on real-time RT-PCR, which have to be performed in biosafe laboratory and is unsatisfactory for suspect case screening. Therefore, there is an urgent need for rapid diagnostic test for COVID-19. OBJECTIVE: To evaluate the diagnostic performance and clinical utility of the colloidal gold immunochromatography assay for SARS-Cov-2 specific IgM/IgG anti-body detection in suspected COVID-19 cases. METHODS: In the prospective cohort, 150 patients with fever or respiratory symptoms were enrolled in Taizhou Public Health Medical Center, Taizhou Hospital, Zhejiang province, China, between January 20 to February 2, 2020. All patients were tested by the colloidal gold immunochromatography assay for COVID-19. At least two samples of each patient were collected for RT-PCR assay analysis, and the PCR results were performed as the reference standard of diagnosis. Meanwhile 26 heathy blood donor were recruited. The sensitivity and specificity of the immunochromatography assay test were evaluated. Subgroup analysis were performed with respect to age, sex, period from symptom onset and clinical severity. RESULTS: The immunochromatography assay test had 69 positive result in the 97 PCR-positive cases, achieving sensitivity 71.1% [95% CI 0.609-0.797], and had 2 positive result in the 53 PCR-negative cases, achieving specificity 96.2% [95% CI 0.859-0.993]. In 26 healthy donor blood samples, the immunochromatography assay had 0 positive result. In subgroup analysis, the sensitivity was significantly higher in patients with symptoms more than 14 days 95.2% [95% CI 0.741-0.998] and patients with severe clinical condition 86.0% [95% CI 0.640-0.970]. CONCLUSIONS: The colloidal gold immunochromatography assay for SARS-Cov-2 specific IgM/IgG anti-body had 71.1% sensitivity and 96.2% specificity in this population, showing the potential for a useful rapid diagnosis test for COVID-19. Further investigations should be done to evaluate this assay in variety of clinical settings and populations.

Evidence That ADAM17 Mediates the Protective Action of CGRP against Angiotensin II-Induced Inflammation in Vascular Smooth Muscle Cells.

Calcitonin gene-related peptide (CGRP) has a potent protective action on the cardiovascular system; however, little is known about the role of CGRP in angiotensin II- (Ang II-) induced inflammation of vascular smooth muscle cells (VSMCs). This study is aimed at determining the anti-inflammatory effect of CGRP in Ang II-treated VSMCs and whether a disintegrin and metalloproteinase 17 (ADAM17) modulates this protective action. Small interference RNA (siRNA) and inhibitors of CGRP, epidermal growth factor receptor (EGFR), and extracellular signal-regulated kinase 1/2 (ERK1/2) were adopted to investigate their effect on Ang II-induced inflammation in VSMCs. Here, we found that CGRP could inhibit inflammation and decrease ADAM17 expression and activation of EGFR and ERK1/2 in VSMCs stimulated with Ang II. Results of siRNA demonstrated that ADAM17 siRNA attenuated Ang II-induced inflammation and up-regulation of activities of EGFR and ERK1/2 in VSMCs. Furthermore, the EGFR-ERK1/2 pathway promoted Ang II-induced VSMC inflammation. In summary, these findings identify the anti-inflammatory effect of CGRP in VSMCs stimulated by Ang II and suggest that ADAM17 is involved in the protective effect of CGRP against Ang II-induced inflammation via the EGFR-ERK1/2 pathway in VSMCs.

Involvement of CGRP-RCP in the caveolin-1/ERK1/2 signal pathway in the static pressure-induced proliferation of vascular smooth muscle cells.

Previous study suggested that the receptor component protein (RCP), one of the components of calcitonin gene-related peptide (CGRP) receptor, plays a multiple role in the cellular signal transduction. The study was designed to investigate whether or not the RCP involved in the regulation of caveolin-1/extracellular signal-regulated kinases-1 and -2 (ERK1/2) signal pathway in the vascular smooth muscle cells (VSMCs) proliferation induced by static pressure. Mouse-derived VSMCs line A10 (A10 VSMCs) was served as project in this experiment. Results showed that the A10 VSMCs viability and proliferating cell nuclear antigen (PCNA) expression which were increased by static pressure were inhibited by pretreatment of CGRP. In like manner, the expressions of the decreased-caveolin-1 and the increased-phosphorylated ERK1/2 (p-ERK1/2) induced by static pressure were significantly reversed by pretreatment of CGRP, respectively. Meanwhile, the expression of RCP was up-regulated by the static pressure. Silence of RCP gene with the small interrupt RNA (siRNA) not only significantly increased A10 VSMC proliferation but also increased the expression of p-ERK1/2 in response to static pressure. When treatment of A10 VSMCs with 120-mmHg static pressure for different time, however, the protein band of caveolin-1 and RCP was the least at time point of 10 min, but the p-ERK1/2 expression was the most maximum. In conclusion, RCP maybe involved in the static pressure-induced A10 VSMCs proliferation by regulation of caveolin-1/ERK1/2 signal pathway.

PDGF Promotes the Warburg Effect in Pulmonary Arterial Smooth Muscle Cells via Activation of the PI3K/AKT/mTOR/HIF-1α Signaling Pathway.

BACKGROUND/AIMS: The enhanced proliferation of pulmonary arterial smooth muscle cells (PASMCs) is a central pathological component in pulmonary arterial hypertension (PAH). Both the Warburg effect and platelet-derived growth factor (PDGF) are involved in the proliferation of PASMCs. However, the mechanism underlying the crosstalk between the Warburg effect and PDGF during PASMC proliferation is still unknown. We hypothesized that PDGF promotes the Warburg effect via activating the phosphatidylinositol 3-kinase (PI3K) signaling pathway and hypoxia-inducible factor 1-α (HIF-1α) in proliferative PASMCs. METHODS: PASMCs were derived from pulmonary arteries of SD rats; cell viability, the presence of metabolites, and metabolic enzyme activities assay were determined by MTT assays, kit assays and western blot analysis, respectively. RESULTS: PDGF promoted PASMC proliferation in a dose- and time-dependent manner, accompanied by an enhanced Warburg effect. Treatment with PDGFR antagonists, Warburg effect inhibitor and PDK1 inhibitor significantly inhibited PI3K signaling activation, HIF-1α expression and PASMC proliferation induced by PDGF, respectively. Furthermore, treatment with PI3K signaling pathway inhibitors remarkably suppressed PDGF-induced PASMC proliferation and the Warburg effect. CONCLUSION: microplate reader (Biotek, Winooski The Warburg effect plays a critical role in PDGF-induced PASMC proliferation and is mediated by activation of the PI3K signaling pathway and HIF-1α.

The Warburg effect: A new story in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a rare yet fatal condition that is characterized by a continuous and notable elevation of pulmonary arterial pressure (PAP), resulting in right heart failure and death. Pulmonary arterial remodelling does not result from abnormal proliferation of pulmonary arterial vascular smooth muscle cells (PASMCs) but from pulmonary arterial endothelial cell (PAEC) dysfunction. However, the pathological mechanism of these two types of vascular cells in pulmonary artery remodelling is unclear. The Warburg effect describes aerobic glycolysis wherein cells commonly reprogram their energy metabolism to preferentially utilize glycolysis over oxidative phosphorylation for ATP production. Recent research has demonstrated that the Warburg effect plays a significant role in the development of PAH, which involves the abnormal proliferation of PASMCs and endothelial dysfunction. This review attempts to illustrate the functions of the Warburg effect in PAH, which may provide a new therapeutic target for PAH treatment.