Department of Molecular Biology Laboratory, Shanghai No. 6 People’s Hospital Affiliated Shanghai Jiaotong University, Shanghai 200233, People’s Republic of China.
Exp Biol Med (Maywood). 2011 Jan;236(1):84-90. doi: 10.1258/ebm.2010.010206.
Oligosaccharides of hyaluronan (o-HA) can induce angiogenesis and the growth and tube formation of vascular endothelial cells (ECs) in particular. As the major o-HA receptor, CD44 has been implicated in EC function, but its role in mediating o-HA-induced EC proliferation and tube formation remains unclear. In this study, we investigated the role of CD44 in o-HA-induced proliferation and tube formation of human umbilical vein endothelial cells (HUVECs) and explored the molecular mechanisms underlying the angiogenesis process. A CD44 siRNA was delivered into HUVECs by electroporation and o-HA-induced proliferation and tube formation capacity of CD44-silenced or control HUVECs were assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) and Matrigel assays. Furthermore, the changes in Src, focal adhesion kinase (FAK) and extracellular signal-regulated kinase1 and 2 (ERK1/2) phosphorylation, as well as the expression of c-jun and c-fos were examined by Western blot and realtime-polymerase chain reaction assays. Our results demonstrated that 10 μg/mL o-HA obviously induced the proliferation and tube formation in HUVECs, and stimulated the phosphorylation of Src, FAK and ERK1/2 and upregulation of c-jun and c-fos, which could be inhibited by CD44 silencing. Altogether our data suggest that CD44 functions to initiate tyrosine phosphorylation of Src, FAK and ERK1/2, and upregulates the expression of c-jun and c-fos, thus mediating o-HA-induced proliferation and tube formation in HUVECs.
透明质酸（HA）的寡糖可以诱导血管内皮细胞（EC）的血管生成以及生长和管形成。作为主要的 HA 受体，CD44 已被牵连到 EC 功能中，但其在介导 o-HA 诱导的 EC 增殖和管形成中的作用仍不清楚。在这项研究中，我们研究了 CD44 在 o-HA 诱导的人脐静脉内皮细胞（HUVEC）增殖和管形成中的作用，并探讨了血管生成过程的分子机制。通过电穿孔将 CD44 siRNA 递送至 HUVEC 中，并通过甲基噻唑基二苯基四唑溴盐（MTT）和 Matrigel 测定评估 CD44 沉默或对照 HUVEC 中 o-HA 诱导的增殖和管形成能力。此外，通过 Western blot 和实时聚合酶链反应测定检查Src、粘着斑激酶（FAK）和细胞外信号调节激酶 1 和 2（ERK1/2）磷酸化以及 c-jun 和 c-fos 表达的变化。我们的结果表明，10 μg/mL o-HA 明显诱导 HUVEC 增殖和管形成，并刺激 Src、FAK 和 ERK1/2 的磷酸化以及 c-jun 和 c-fos 的上调，这可以通过 CD44 沉默来抑制。总的来说，我们的数据表明 CD44 作用于启动 Src、FAK 和 ERK1/2 的酪氨酸磷酸化，并上调 c-jun 和 c-fos 的表达，从而介导 o-HA 诱导的 HUVEC 增殖和管形成。
