Abstract: Objective To study the effect and mechanism of CD44 in endothelial cell proliferation and adhesion. Methods The pcDNA3.1 vectors were constructed to upregulate the CD44 gene of Human umbilical vein endothelial cells (HUVEC); Akt siRNA and PECAM1 siRNA were used to knockdown the gene of Akt and PECAM1, respectively. Cell proliferation was measured by MTT assay, cell adhesion rate was measured by cell counting, PECAM1 mRNA levels were detected by RT-PCR, and Western blot was used to determine the protein levels of Ki67, PECAM1 and Akt phosphorylation. Results CD44 promoted HUVEC proliferation, increased Ki67 expression and promoted Akt phosphorylation (all P<0.05); while, Akt siRNA decreased the CD44-induced cell proliferation (P<0.05). Moreover, CD44 promote HUVEC adhesion (P<0.05), and increased the mRNA and protein levels of PECAM1 (all P<0.05); moreover, PECAM1 siRNA impaired CD44-induced cell adhesion. Conclusion CD44 promotes the proliferation of HUVEC cells by activating the Akt signaling pathway; CD44 promotes cell adhesion by increasing the mRNA and protein levels of PECAM1.

Key words: CD44, Vascular endothelial cells, cell proliferation, cell adhesion