Transient receptor potential melastatin 7 (TRPM7) contributes to H2O2-induced cardiac fibrosis via mediating Ca(2+) influx and extracellular signal-regulated kinase 1/2 (ERK1/2) activation in cardiac fibroblasts.

Transient receptor potential melastatin 7 (TRPM7), a Ca(2+)-nonselective cation channel, plays a key role in the pathophysiological response of multiple cell types. However, the role of TRPM7 channels in hydrogen peroxide (H2O2)-induced cardiac fibrosis remains unclear. This study aimed to explore whether TRPM7 channels are involved in H2O2-induced cardiac fibrosis and the underlying mechanisms. Our results showed that 2-aminoethoxydiphenylborate (2-APB), which is commonly used to block TRPM7 channels, inhibited H2O2-induced cardiac fibrosis via attenuating the overexpression of important fibrogenic biomarkers and growth factors in cardiac fibroblasts, including collagen type I (Col I), fibronectin (FN), smooth muscle α-actin (α-SMA), connective tissue growth factor (CTGF), and transforming growth factor-ß1 (TGF-ß1). In addition, 2-APB also decreased H2O2-mediated elevation of the concentration of intracellular Ca(2+) ([Ca(2+)]i). Meanwhile, silencing TRPM7 channels by shRNA interference also impaired the increased [Ca(2+)]i and upregulation of Col I, FN, α-SMA, CTGF, and TGF-ß1 induced by H2O2. Furthermore, we found that H2O2-mediated activation of extracellular signal-regulated kinase 1/2 (ERK1/2) decreased in TRPM7-shRNA cells and Ca(2+)-free culture media. These results demonstrated that TRPM7 channels contributed to H2O2-induced cardiac fibrosis and suggested that this contribution may be through mediating Ca(2+) influx and phosphorylation of ERK1/2.

(E)-1-(4-ethoxyphenyl)-3-(4-nitrophenyl)-prop-2-en-1-one suppresses LPS-induced inflammatory response through inhibition of NF-κB signaling pathway.

Flavonoids are a class of compounds that exist in nature with the structure of 2-phenyl-chromone. In Chinese traditional medicine, herbal drugs containing flavonoids are widely used for the treatment of inflammation, cardiovascular disease, tumor and so on. In this study, we investigated the anti-inflammatory effect and related mechanisms of a novel synthetic flavonoid, (E)-1-(4-ethoxyphenyl)-3-(4-nitrophenyl)-prop-2-en-1-one (ETH) in lipopolysaccharide (LPS) stimulated macrophages. Our results showed that ETH inhibited LPS-induced TNF-α and IL-6 release in a dose-dependent manner, and decreased TNF-α, IL-1ß, IL-6 and iNOS mRNA production. LPS-induced expression of cyclooxygenase-2 (COX-2) was also significantly attenuated by ETH. Pretreatment with ETH reduced the I-κBα phosphorylation, p65 nuclear translocation as well as NF-κB-dependent transcriptional activity. In addition, ETH exhibited a significant protection against LPS-induced inflammatory mortality in mice. Taken together, these findings suggest that ETH can inhibit LPS-induced inflammation via suppressing NF-κB signaling pathway, indicating that ETH may be a potential anti-inflammatory agent.