Caloric restriction (CR) is a well-established dietary intervention known to extend healthy lifespan and exert positive effects on aging-related diseases, including cardiovascular conditions. Sirtuins, a family of nicotinamide adenine dinucleotide (NAD +)-dependent histone deacetylases, have emerged as key regulators of cellular metabolism, stress responses, and the aging process, serving as energy status sensors in response to CR. However, the mechanism through which CR regulates Sirtuin function to ameliorate cardiovascular disease remains unclear. This review not only provided an overview of recent research investigating the interplay between Sirtuins and CR, specifically focusing on their potential implications for cardiovascular health, but also provided a comprehensive summary of the benefits of CR for the cardiovascular system mediated directly via Sirtuins. CR has also been shown to have considerable impact on specific metabolic organs, leading to the production of small molecules that enter systemic circulation and subsequently regulate Sirtuin activity within the cardiovascular system. The direct and indirect effects of CR offer a potential mechanism for Sirtuin modulation and subsequent cardiovascular protection. Understanding the interplay between CR and Sirtuins will provide new insights for the development of interventions to prevent and treat cardiovascular diseases.

BACKGROUNDTherapeutic angiogenesis has been shown to promote blood vessel growth and improve tissue perfusion. Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis. However, it has side effects that limit its therapeutic utility in vivo, especially at high concentrations. This study aimed to investigate whether an intramuscular injection of a genetically engineered zinc finger VEGF-activating transcription factor modulates the endothelial progenitor cells (EPC) and promotes therapeutic angiogenesis in a hindlimb ischemia model with type 1 diabetes.

METHODSAlloxan (intravenous injection) was used to induce type I diabetes in C57BL/6 mice (n = 58). The ischemic limb received ZFP-VEGF (125 µg ZFP-VEGF plasmid in 1% poloxamer) or placebo (1% poloxamer) intramuscularly. Mice were sacrificed 3, 5, 10, or 20 days post-injection. Limb blood flow was monitored using laser Doppler perfusion imaging. VEGF mRNA and protein expression were examined using real-time PCR and ELISA, respectively. Capillary density, proliferation, and apoptosis were examined using immunohistochemistry techniques. Flow cytometry was used to detect the EPC population in bone marrow. Two-tailed Student's paired t test and repeated-measures analysis of variance were used for statistical analysis.

RESULTSZFP-VEGF increased VEGF mRNA and protein expression at 3 and 10 days post-injection, and increased EPC in bone marrow at day 5 and 20 post-injection compared with controls (P < 0.05). ZFP-VEGF treatment resulted in better perfusion recovery, a higher capillary density and proliferation, and less apoptosis compared with controls (P < 0.05).

CONCLUSIONSIntramuscular ZFP-VEGF injection promotes therapeutic angiogenesis in an ischemic hindlimb model with type 1 diabetes. This might be due to the effects of VEGF on cell survival and EPC recruitment.

Animals ; Diabetes Mellitus, Type 1 ; metabolism ; Endothelial Progenitor Cells ; metabolism ; Flow Cytometry ; Hindlimb ; pathology ; Ischemia ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Vascular Endothelial Growth Factor A ; genetics ; metabolism