The Expression And Function Of Caveolin-1in Human Myometrium And Uterine Leiomyoma

Objective:To examine the protein and mRNA levels of caveolin-1(Cav-1), which inhibits proliferation of vascular smooth muscle cells(VSMCs), in uterine leiomyoma, matched myometrium and two kinds of primary cultured cells, and to explore the role of Cav-1in the occurrence of uterine leiomyoma.Methods:Collect24pairs of human uterine leiomyoma tissues and their matched myometrial tissues for primary cell culture. To detect the expression of Cav-1in two tissues by immunofluorescence.To detect Cav-1and ERa intracellular by immunoprecipitation. Western Blotting and Real-time PCR (RT-PCR) was used for the detection of Cav-1, Cav-2, Cav-3protein and mRNA levels in uterine leiomyoma, uterine myometrium tissues and two kinds of primary cultured cells:human leiomyoma smooth muscle cells (HL-SMCs) and human myometrium smooth muscle cells (HM-SMCs). WST-1asssay was used to analyse the effects of E2on the proliferation of the HM-SMCs and HL-SMCs.Results:1. Both Cav-1and Cav-2were expressed in human uterine smooth muscle and uterine leiomyoma, but significantly down-regulated in uterine leiomyoma tissue while the immunoreactivity of Cav-3was not detected in either myometrium or leiomyoma tissues.2. Cav-1protein and mRNA level were significantly lower in human leiomyoma smooth muscle cells compared to human myometrium smooth muscle cells.3. Cav-1co-localized with ERa intracellular.4. The Cav-1protein and mRNA amount decreased in human leiomyoma smooth muscle cells, but increased in cultured HM-SMCs after treatment with estrogen for24hours.5. E2promoted human leiomyoma smooth muscle cells prolifetion but inhibited the proliferation of human myometrium smooth muscle cells.6. E2treatment stimulated the expression of only Cav-1in myometrium which could be blocked by ICI182780, but not leiomyoma, SMCs, while it had no effect on the expression of Cav-2in HM-SMCs and HL-SMCs.Conclusions:The protein and mRNA of Cav-1were lower in uterine leiomyoma tissue and primary cultured human leiomyoma smooth muscle cells. Cav-2protein and mRNA levels were lower in uterine leimyoma tissue. Cav-1co-localized with ERa intracellular. E2decreased Cav-1protein and mRNA levels of HL-SMCs, thus promoting the proliferation of them, but E2increased Cav-1protein and mRNA of HM-SMCs, consequently inhibiting their proliferation. Also the increased expression of Cav-1stimulated by E2could be blocked by ICI182780. The different effects of E2on the two kinds of cells may have some relationship with the occurrence of human uterine leiomyma.