Diosgenin improves post-myocardial infarction cardiac function via HAND2-induced angiogenesis.

While diosgenin has been demonstrated effective in various cardiovascular diseases, its specific impact on treating heart attacks remains unclear. Our research revealed that diosgenin significantly improved cardiac function in a myocardial infarction (MI) mouse model, reducing cardiac fibrosis and cell apoptosis while promoting angiogenesis. Mechanistically, diosgenin upregulated the Hand2 expression, promoting the proliferation and migration of endothelial cells under hypoxic conditions. Acting as a transcription factor, HAND2 activated the angiogenesis-related gene Aggf1. Conversely, silencing Hand2 inhibited the diosgenin-induced migration of hypoxic endothelial cells and angiogenesis. In summary, these findings provide new insights into the protective role of diosgenin in MI, validating its effect on angiogenic activity and providing a theoretical basis for clinical treatment strategies.

Dual roles of demethylation in cancer treatment and cardio-function recovery.

There are no effective therapeutic targets or strategies that simultaneously inhibit tumour growth and promote cardiac function recovery. Here, we analyzed targets for cancer treatments and cardiac repair, with demethylation emerging as a common factor in these candidate lists. As DNA methyltransferase 1 (DNMT1) majorly responds to methylation, a natural compound library is screened, identifying dioscin as a novel agent targeted at DNMT1, widely used for heart diseases. Dioscin was found to reduce DNMT activities and inhibits growth in breast cancer cells. Combined with analyses of RNA-seq and MeDIP-seq, the promoters of antioxidant genes were demethylated after dioscin, recruiting NRF2 and elevating their expression. In Nrf2 knockout mice, the cardiac protection role of dioscin was blocked by Nrf2-loss. Furthermore, in tumour-bearing mice with hypertrophy, dioscin was observed to inhibit tumour growth and alleviate cardiac injury simultaneously. This study is the first to identify dioscin as a novel demethylation agent with dual functions of anti-cancer and cardio-protection.

Attenuated macrophage activation mediated by microRNA-183 knockdown through targeting NR4A2.

Atherosclerosis is considered a chronic inflammatory disease, and macrophages function as important mediators in the development of atherogenesis. MicroRNA (miR)-183 is a small non-coding RNA that acts as a novel tumor suppressor and has recently been proposed to affect cardiac hypertrophy. However, the exact role and underlying mechanism of miR-183 in macrophage activation remain unknown. In the present study, miR-183 showed upregulated expression in atheromatous plaques and in bone marrow-derived macrophages (BMDMs) subjected to stimulation with oxidized low-density lipoproteins. Using a miR-183 loss-of-function strategy, it was demonstrated that miR-183 knockdown significantly increased resolving M2 macrophage marker expression but decreased proinflammatory M1 macrophage marker expression, as well as attenuated NF-κB activation. Moreover, decreased foam-cell formation accompanied by upregulation of genes involved in cholesterol efflux and downregulation of genes implicated in cholesterol influx was found in BMDMs transfected with a miR-183 inhibitor. Mechanistically, macrophage activation mediated by miR-183 silencing was partially attributed to direct upregulation of NR4A2 expression in BMDMs. Thus, the present study suggests that neutralizing miR-183 may be a potential therapeutic strategy for the treatment of atherosclerosis.