Cationic microbubbles loading shFOXO4/SDF1 rejuvenate the aged heart and alleviate myocardial ischemia-reperfusion injury in the elderly.

Aging is a significant risk factor for cardiovascular diseases, with ischemic heart disease (IHD) being the leading cause of cardiovascular-related mortality. Inhibition of FOXO4, which selectively eliminates senescent cells, offers protective effects on the aging myocardium. However, the removal of senescent cells may lead to a reduction in tissue cell density, thereby exacerbating tissue space formation and perivascular fibrosis. Therefore, selectively eliminating senescent cells in the aging heart, while simultaneously replenishing therapeutic bone marrow-derived mesenchymal stem cells (BMSCs), holds substantial therapeutic potential for synergistically combating cardiac aging. This study proposes a promising cardiac rejuvenation strategy using ultrasound-targeted microbubble destruction (UTMD)-mediated delivery of shFOXO4/SDF1 to eliminate cellular senescence and enhance BMSC homing. Transcriptomic analysis identified FOXO4 as a pivotal transcription factor in cardiac aging, with FOXO4 protein predominantly expressed in cardiac fibroblasts (CFs) and vascular endothelial cells in the myocardium of aged rats. Knockdown of FOXO4 in aging CFs reversed cellular senescence, and co-culturing these rejuvenated CFs with BMSCs further enhanced the reversal of senescence and bolstered resistance to oxidative stress. The use of UTMD for delivering shFOXO4/SDF1 in dual-gene therapy significantly enhanced BMSC homing, ameliorating cardiac aging, oxidative stress, and inflammation. In an ischemia-reperfusion injury (MIRI) model, pretreatment with shFOXO4/SDF1 effectively reduced cardiomyocyte apoptosis, promoted neovascularization, reduced infarct size, and improved cardiac function. The combined removal of senescent cells and enhanced BMSC homing synergistically ameliorated cardiac aging and improved post-MIRI prognosis in aging hearts. These findings provide novel insights and potential therapeutic strategies for addressing cardiac aging and age-related heart diseases.