Aging impairs the functions of human mesenchymal stem cells (MSCs), thereby severely reducing their beneficial effects on myocardial infarction (MI). MicroRNAs (miRNAs) play crucial roles in regulating the senescence of MSCs; however, the underlying mechanisms remain unclear. Here, we investigated the significance of miR‐155‐5p in regulating MSC senescence and whether inhibition of miR‐155‐5p could rejuvenate aged MSCs (AMSCs) to enhance their therapeutic efficacy for MI. Young MSCs (YMSCs) and AMSCs were isolated from young and aged donors, respectively. The cellular senescence of MSCs was evaluated by senescence‐associated β‐galactosidase (SA‐β‐gal) staining. Compared with YMSCs, AMSCs exhibited increased cellular senescence as evidenced by increased SA‐β‐gal activity and decreased proliferative capacity and paracrine effects. The expression of miR‐155‐5p was much higher in both serum and MSCs from aged donors than young donors. Upregulation of miR‐155‐5p in YMSCs led to increased cellular senescence, whereas downregulation of miR‐155‐5p decreased AMSC senescence. Mechanistically, miR‐155‐5p inhibited mitochondrial fission and increased mitochondrial fusion in MSCs via the AMPK signaling pathway, thereby resulting in cellular senescence by repressing the expression of Cab39. These effects were partially reversed by treatment with AMPK activator or mitofusin2‐specific siRNA (Mfn2‐siRNA). By enhancing angiogenesis and promoting cell survival, transplantation of anti‐miR‐155‐5p‐AMSCs led to improved cardiac function in an aged mouse model of MI compared with transplantation of AMSCs. In summary, our study shows that miR‐155‐5p mediates MSC senescence by regulating the Cab39/AMPK signaling pathway and miR‐155‐5p is a novel target to rejuvenate AMSCs and enhance their cardioprotective effects.

Cardiovascular diseases (CVDs) remain a global health concern, prompting ongoing research into novel contributors to their pathogenesis. Due to the proximity of the coronary arteries and the myocardium in epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT), these tissues have emerged as key areas of interest for their potential influence on cardiac function and vascular health. This review synthesizes current research on the physiological and biological characteristics of EAT and PAT, exploring their composition and clinical measurement approaches. The roles of EAT and PAT in coronary artery disease (CAD), atrial fibrillation, and heart failure are discussed, and the contributions of EAT and PAT to these cardiovascular conditions are highlighted alongside their potential as therapeutic targets.

In the elderly population, coronary heart disease (CHD) often coexists with hypertension. However, excessive blood pressure reduction can paradoxically increase the incidence of adverse events. Understanding the molecular mechanisms underlying hypertension and CHD in aged populations is crucial for developing targeted therapies and improving clinical outcomes. In this study, we constructed myocardial infarction (MI) and transverse aortic constriction (TAC) modelsY in aged mice to simulate the disease states of CHD and hypertension, respectively. Using integrated proteomic and phosphoproteomic analyses, we investigated the molecular signatures associated with MI and TAC in these models. Our aim was to identify key molecules involved in these conditions and to understand their unique and shared characteristics. Through our comprehensive proteomic and phosphoproteomic analysis, we identified a total of 1583 proteins and 232 phosphorylated proteins. We observed significant upregulation of heart disease markers such as Myh7, Xirp2, and Acta1, indicating the successful establishment of the MI and TAC models. The overlapped differentially expressed proteins (DEPs) and differentially phosphorylated proteins (DPPs) in MI and TAC were involved in heart failure‐related processes including cardiac muscle contraction and hypertrophic cardiomyopathy, further supporting the validity of the models. Among the DEPs, Ppme1 was upregulated in the TAC model but downregulated in the MI model, while Sec31a and Gm56451 displayed the opposite expression patterns. Among the DPPs, Ablim1 and Atp2a2 were found to be significantly upregulated in the TAC model, whereas their expression was markedly reduced in the MI model. In addition, five other DPPs, including REV_Q3TAY5, Cbx3, PITPNB, Eif4b, and A0A1Y7VP73, were elevated in the MI model but decreased in the TAC model. In conclusion, these findings suggest that MI and TAC not only share certain molecular features but also retain their unique characteristics, providing potential biomarkers and therapeutic targets.