LAUSR

In adipogenesis, perivascular adipose tissue (PVAT) preadipocytes turn into adipocytes. In non-PVAT preadipocytes, mechanical forces affect the commitment and lipogenic stages of adipogenesis. The mechanism may involve PIEZO1, a mechanosensor, that boosts differentiation of progenitor cells towards osteogenic and fibroblastic lineages. Since hypertension causes changes in the vascular forces that could affect adipogenesis in PVAT, our objective was to evaluate PIEZO1 expression patterns in PVAT and the effects of PIEZO1 activation on the adipogenic potential of preadipocytes. We hypothesize that PIEZO1 activation limits the adipogenic potential of PVAT preadipocytes. PVAT from the thoracic aorta (APVAT) was collected from male Sprague Dawley rats at 10 weeks of age (n=5). Preadipocytes were obtained by Liberase digestion followed by serial passage of adherent cells. Preadipocyte progenitors, CD34+PDGFRα+, were harvested by magnetic-activated sorting. PIEZO1 expression was assessed by RT-qPCR and immunofluorescence (IF). Preadipocytes were induced to differentiate for 14 d in standard media (CON) or in the presence of PIEZO1 agonist Yoda (10μM) and inhibitor Dooku (5μM) during days 0-2 (commitment), 3-14 (lipogenesis), and 0-14 (overall adipogenesis). Adipogenesis was evaluated with IncuCyte Live-Cell system using the triglyceride stain Bodipy 493503. Triglyceride content is reported as Bodipy Intensity/Adipocyte Count. Piezo1 RNA was expressed in adipocytes and the stromal vascular fraction of APVAT. PIEZO1 IF signal was detected in SVF and preadipocyte. Triglyceride was reduced by Yoda (62 ± 14.3) and Dooku (49.3 ± 14) during 0-2 d compared to CON (312.5 ± 165.6). Neither Yoda nor Dooku for 12 d affected triglyceride accumulation compared to CON. In contrast, the lipid content of Yoda (77.7 ± 21.3) and Dooku (48.9 ± 15.2) treated cells during 14 d was reduced vs CON (312.5 ± 165.6). The expression of PIEZO1 in all PVAT fractions suggests mechanosensitivity. PIEZO1 activation during adipogenesis commitment impaired adipocyte maturation. These data provide evidence for the capacity of mechanosensory expressed in PVAT preadipocytes to modulate adipogenesis, underpinning the deleterious impact of hypertension on PVAT function.