Targeting Perilipin 2 alleviates vascular aging through regulation of lipid droplet-mitochondria tethering and fatty acid oxidation

Background Lipid droplet (LD) accumulation due to lipometabolic disturbances has been implicated in accelerating vascular aging; however, the underlying mechanisms remain poorly understood. Perilipin 2 (PLIN2), a key LD-associated protein, plays a pivotal role in lipid metabolism and cellular senescence. Despite its significance, the specific role of PLIN2 in vascular aging is yet to be elucidated. Betulinic acid (BA), a natural pentacyclic triterpenoid derived from birch bark, has demonstrated potential anti-aging properties, but its effects on vascular aging remain unexplored. Purpose This study investigates whether PLIN2 modulates vascular aging by regulating LD-mitochondria tethering and β-oxidation, and explores the therapeutic potential of BA in this context. Methods Primary mouse aortic smooth muscle cells (MASMCs) were treated with oleic acid (OA) to induce senescence, followed by BA intervention or targeted modulation of PLIN2 expression via plasmid overexpression and shRNA silencing. LD formation was assessed using BODIPY and Oil Red O staining. Mitochondrial function was evaluated using JC-1 and DHE probes. Fatty acid β-oxidation was quantified via ¹⁴C-palmitate assay and acylcarnitine profiling. RNA sequencing was performed to identify downstream targets of PLIN2. In vivo, high-fat diet (HFD)-fed mice were treated with BA, and vascular aging was assessed through carotid artery pulse wave velocity (PWV) and en face Oil Red O staining. Results RNA sequencing revealed that PLIN2 and its downstream targets, CPT1A and FABP4, were significantly upregulated in OA-induced senescent MASMCs. This upregulation enhanced LD-mitochondria tethering and β-oxidation, thereby promoting vascular aging. In contrast, BA, a potential PLIN2 antagonist, attenuated these effects by suppressing PLIN2 expression. In vivo, BA treatment reduced vascular aging markers in HFD-fed mice, as evidenced by improved PWV and reduced lipid accumulation. Conclusions This study demonstrates that targeting PLIN2 alleviates vascular aging by modulating LD-mitochondria tethering and β-oxidation. BA, as a potential PLIN2 antagonist, effectively mitigates lipometabolic disturbance-induced vascular aging. These findings underscore PLIN2 as a promising therapeutic target for vascular aging and associated cardiovascular diseases.