The Mechanisms Of C1ql1 And C1ql4 On Proangiogenesis

In our previous study,we found that recombinat globular domain of C1ql1 and C1ql4(g C1ql1 and g C1ql4)could promote capillary-like tube formation and migration of rat cardiac microvascular enthelial cells(CMECs),and phosphprylation of ERK1/2 was activated during these processes.For further confirming the function of C1ql1 and C1ql4 on angiogenesis,human umbilical vein endothelium cells(HUVECs)and chick yolk-sac membrane were used as two angiogenic assay models in this study.U0126,the specific inhibitor of ERK1/2 upstream MEK,was used to study the effect of ERK1/2 signal pathway on g C1ql1 and g C1ql4 induced angiogenesis.Moreover,the downsteam genes involved in g C1ql1 and g C1ql4 induced angiogenesis were analyzed by microarray and quantitative realtime PCR(q PCR).Hypoxia is a common cause of vascular endothelial injury pathological factor.A variety of cardiovascular diseases is caused by endothelial dysfunction.The improvement of vascular endothelial dysfunction induced by hypoxia injury has important significance to prevent cardiovascular disease.In the present study,the effect of g C1ql1 on cardiac microvascular endothelial injury was analyzed by flow cytometry and CCK8 cell activity assay.In vitro angiogenesis assayed by capillary-like tube formation on Matrigel and cell migration assay by wound healing showed that recombinants of the globular domain of g C1ql1 and g C1ql4 promoted the migration and capillary tube formation of HUVECs in a dose-dependent manner.g C1ql1 and g C1ql4 exposure caused a stimulatory response of angiogenesis in vivo in chick yolk-sac membrane(YSM).Western blot analyses showed that stimulation of HUVECs and CMECs by g C1ql1 and g C1ql4 led to activation of extracellular signal-regulated kinase 1/2(ERK1/2).MEK inhibitor,U0126,blocked the g C1ql1 and g C1ql4-induced capillary tube formation and cell migration.g C1ql1 and g C1ql4 unregulated the genes expression of VEGF,GDF15,PGDF,NOS2,CYP7B1,and ENGL3 in CMECs analyzed by microarray and q PCR.Flow cytometry analyses showed pretreatment CMECs with g C1ql1 protein attenuated the apoptosis effect induced by hypoxia,while CCK8 cell activity assay confirmed that pretreat with CMECs with g C1ql1 protein inhibited the CMECs injury inducd by hypoxia,indicating that g C1ql1 may possess the protective effect on hypoxia-induced CMECs injury.