Dalrymple A, Slater D M, Beech D, Poston L, Tribe R M
Parturition Research Group, Maternal and Fetal Research Unit, Department of Women's Health, 10th Floor North Wing, Guy's School of Medicine, St Thomas' Hospital Campus, Lambeth Palace Road, London SE1 7EH, UK.
Mol Hum Reprod. 2002 Oct;8(10):946-51. doi: 10.1093/molehr/8.10.946.
The mechanisms underlying the switch from uterine quiescence to contractile activity in labour are not clearly understood. Increasing evidence suggests that pathways of myometrial calcium homeostasis, including store-operated calcium entry (SOCE), may play an important role. The molecular basis of the membrane-associated calcium channels contributing to SOCE in pregnant human myometrium is not known, but they are likely to be hetero- or homo-oligomeric assemblies of transient receptor potential channel (TrpC) proteins, encoded by the mammalian homologues of Drosophila Trp genes. This study has therefore determined Trp gene expression and also TrpC protein expression and localization in term pregnant human myometrial tissue and primary cultured human myometrial smooth muscle (HMSM) cells. RT-PCR amplified fragments of Trp1, Trp3, Trp4, Trp6 and Trp7. PCR products were 100% homologous to published human sequences. Western blot analysis detected TrpC1, TrpC3, TrpC4 and TrpC6 proteins, which were of expected size. Immunolocalization revealed TrpC1, TrpC3, TrpC4 and TrpC6 protein expression in myometrial tissue and HMSM cells. TrpC protein immunostaining in HMSM cells was distributed in a distinct reticular fashion. TrpC proteins may be candidate proteins forming SOCE channels in term pregnant human myometrium.
分娩过程中子宫从静止状态转变为收缩活动的潜在机制尚未完全明确。越来越多的证据表明，子宫肌层钙稳态途径，包括储存式钙内流（SOCE），可能起重要作用。在妊娠人类子宫肌层中，参与SOCE的膜相关钙通道的分子基础尚不清楚，但它们可能是由果蝇Trp基因的哺乳动物同源物编码的瞬时受体电位通道（TrpC）蛋白的异源或同源寡聚体组合。因此，本研究确定了足月妊娠人类子宫肌层组织和原代培养的人类子宫肌层平滑肌（HMSM）细胞中Trp基因的表达以及TrpC蛋白的表达和定位。RT-PCR扩增出Trp1、Trp3、Trp4、Trp6和Trp7的片段。PCR产物与已发表的人类序列100%同源。蛋白质印迹分析检测到预期大小的TrpC1、TrpC3、TrpC4和TrpC6蛋白。免疫定位显示子宫肌层组织和HMSM细胞中有TrpC1、TrpC3、TrpC4和TrpC6蛋白表达。HMSM细胞中的TrpC蛋白免疫染色呈独特的网状分布。TrpC蛋白可能是足月妊娠人类子宫肌层中形成SOCE通道的候选蛋白。
