Lumican is Both a Novel Risk Factor and Potential Plasma Biomarker for Vascular Aging, Capable of Promoting VSMCs Senescence through Interacting with Integrin α2β1.

Vascular aging, a common pathogenesis of senile chronic diseases, significantly increases morbidity and mortality in older adults; its intricate cellular and molecular mechanisms necessitate further investigation. Lumican (LUM) and integrin α2β1(ITGα2β1) are profibrotic extracellular matrix proteins and vital cell regulatory receptors, respectively. However, their roles in vascular aging remain unclear. This study sought to elucidate the connection between LUM and vascular aging as well as the biological mechanism of LUM/ITGα2β1 in this process. Using an enzyme-linked immunosorbent assay, we discovered that plasma LUM was elevated in vascular aging individuals and was positively correlated with brachial-ankle pulse wave velocity. Additionally, immunohistochemical and western blot analyses confirmed LUM upregulation in arteries of older adults and aged mice, as well as in senescent vascular smooth cells (VSMCs). Wild-type and LUM semiknockout (Lum-/+) mice, along with primary VSMCs extracted from these mice, were exposed to angiotensin II (Ang II) to induce stress-induced senescence model. LUM semiknockout mitigated Ang Ⅱ-induced arteriosclerosis, hypertension, vascular aging and remodeling in mice. Both in vitro and in vivo studies revealed that LUM deficiency suppressed p53, p21, collagen 1 and collagen 3 upregulation and synthetic phenotype formation in VSMCs stimulated by Ang Ⅱ. Treating VSMCs with a ITGα2β1 antagonist reversed the aforementioned changes triggered by LUM proteins. Briefly, LUM functions as a potential marker and risk factor for vascular aging and promotes pathological changes by affecting ITGα2β1 in VSMCs. This study introduces a novel molecular target for the early diagnosis and treatment of vascular aging and age-related vascular diseases.