Lipofilling is a widely used technique in plastic and reconstructive surgery, but its long-term success is often limited by unpredictable fat graft resorption. Optimizing the adipogenic environment th Show more
Lipofilling is a widely used technique in plastic and reconstructive surgery, but its long-term success is often limited by unpredictable fat graft resorption. Optimizing the adipogenic environment through bioactive factors may enhance graft survival and volume retention. This study investigates the adipogenic potential of Hypoxia Preconditioned Serum (HPS) and Platelet-rich Plasma (PRP), in comparison to normal serum (NS). Cytokine profiles of HPS, PRP, and NS from 10 donors were analyzed. Human preadipocytes (n = 3) were cultured with low (10%) and high (40%) concentrations of these secretomes. Proliferation, cytotoxicity (LDH assay), lipid droplet formation (Oil Red O staining), and gene expression (qPCR) of adipogenic markers (PPARgamma, C/EBPalpha, FABP4, Adiponectin, LPL) were assessed after 2 and 4 days. HPS contained significantly higher levels of Adiponectin, IGF-1, bFGF, VEGF-A, and PDGF-BB compared with PRP and NS, while Leptin was lower in HPS and PRP than in NS. All conditions increased proliferation on day 4, with the highest cell counts in NS-40%. No treatment-related cytotoxicity was observed. HPS-40% induced the strongest adipogenic differentiation, evidenced by increased lipid droplet formation and upregulation of all measured adipogenic genes by day 4. These findings suggest that HPS enhance the proliferation, survival, and differentiation of preadipocytes. Validation in Show less
Blood vessel tubulogenesis requires the formation of stable cell-to-cell contacts and the establishment of apicobasal polarity of vascular endothelial cells. Cell polarity is regulated by highly conse Show more
Blood vessel tubulogenesis requires the formation of stable cell-to-cell contacts and the establishment of apicobasal polarity of vascular endothelial cells. Cell polarity is regulated by highly conserved cell polarity protein complexes such as the Par3-aPKC-Par6 complex and the CRB3-Pals1-PATJ complex, which are expressed by many different cell types and regulate various aspects of cell polarity. Here we describe a functional interaction of VE-cadherin with the cell polarity protein Pals1. Pals1 directly interacts with VE-cadherin through a membrane-proximal motif in the cytoplasmic domain of VE-cadherin. VE-cadherin clusters Pals1 at cell-cell junctions. Mutating the Pals1-binding motif in VE-cadherin abrogates the ability of VE-cadherin to regulate apicobasal polarity and vascular lumen formation. In a similar way, deletion of the Par3-binding motif at the C-terminus of VE-cadherin impairs apicobasal polarity and vascular lumen formation. Our findings indicate that the biological activity of VE-cadherin in regulating endothelial polarity and vascular lumen formation is mediated through its interaction with the two cell polarity proteins Pals1 and Par3. Show less