■Mirabegron可用于治疗膀胱过度活动症(OAB)。然而,症状改善和对膀胱平滑肌细胞的长期影响的潜在机制尚不确定.膀胱平滑肌的收缩性和生长有助于OAB,依赖于平滑肌的表型,以及毒蕈碱受体的表达。这里,我们检查了长时间暴露于米拉贝隆(20-48小时)的表型标记,毒蕈碱受体表达,和人膀胱平滑肌细胞(hBSMC)中的表型依赖性功能。
■收缩标志物的表达(钙蛋白,MYH11)和增殖(MYH10,波形蛋白)表型,增殖(Ki-67),并通过RT-PCR评估毒蕈碱受体。扩散,生存能力,EdU检查了培养的hBSMC中的肌动蛋白组织和收缩,CCK-8,鬼笔环肽染色和基质收缩测定。
■Calponin-1mRNA随着100nM和150nM米拉贝隆施用20小时而降低(对照的0.56-0.6倍)。减少对β3-AR拮抗剂L-748,337(0.34-0.55倍,100-150nM,20h).40小时后,在存在L-748,337的情况下发生下降,但没有L-748,337的情况下发生下降。MYH11mRNA随150nM米拉贝隆(40小时,1.9倍)。用L-748,337部分保存,但在暴露于米拉贝隆20小时后未观察到。波形蛋白mRNA在20小时后用150nM米拉贝隆减少,但不是在40小时后,有和没有L-748,337(0.71-0.63倍)。MYH10mRNA表达不受米拉贝隆的影响。暴露于150nM米拉贝隆20小时后,Ki-67mRNA增加,但没有L-748,337,40小时后没有,但不是L-748,337.增殖速率和肌动蛋白组织在50-150nMmirabegron(24小时,48小时)。米拉贝隆暴露20小时后,生存能力显着增加,从40小时后的趋势来看,对L-748,337完全敏感.M2mRNA减少20小时米拉贝隆,对L-748,337有抗性。卡巴胆碱(3µM)增强hBSMC的时间依赖性收缩,在晚期(24小时)被米拉贝隆(150nM)抑制,但不是在收缩的早期阶段。结论:Mirabegron在hBSMC中诱导动态表型改变和M2下调,与时移的抗收缩作用平行。表型转变可能与mirabegron改善OAB的储存症状有关。
UNASSIGNED: Mirabegron is available for treatment of overactive bladder (OAB). However, mechanisms underlying symptom improvements and long-term effects on bladder smooth muscle cells are uncertain. Contractility and growth of bladder smooth muscle contribute to OAB, and depend on smooth muscle phenotypes, and on muscarinic receptor expression. Here, we examined prolonged exposure to mirabegron (20-48 h) on phenotype markers, muscarinic receptor expression, and phenotype-dependent functions in human bladder smooth muscle cells (hBSMC).
UNASSIGNED: Expression of markers for contractile (calponin, MYH11) and proliferative (MYH10, vimentin) phenotypes, proliferation (Ki-67), and of muscarinic receptors were assessed by RT-PCR. Proliferation, viability, actin organization and contractions in cultured hBSMC were examined by EdU, CCK-8, phalloidin staining and matrix contraction assays.
UNASSIGNED: Calponin-1 mRNA decreased with 100 nM and 150 nM mirabegron applied for 20 h (0.56-0.6 fold of controls). Decreases were resistant to the β3-AR antagonist L-748,337 (0.34-0.55 fold, 100-150 nM, 20 h). After 40 h, decreases occured in the presence of L-748,337, but not without L-748,337. MYH11 mRNA increased with 150 nM mirabegron (40 h, 1.9 fold). This was partly preserved with L-748,337, but not observed after 20 h mirabegron exposure. Vimentin mRNA reduced with 150 nM mirabegron after 20 h, but not after 40 h, with and without L-748,337 (0.71-0.63 fold). MYH10 mRNA expression remained unaffected by mirabegron. Exposure to 150 nM mirabegron increased Ki-67 mRNA after 20 h in the presence of, but not without L-748,337, and after 40 h without, but not with L-748,337. Proliferation rates and actin organization were stable with 50-150 nM mirabegron (24 h, 48 h). Viability increased significantly after mirabegron exposure for 20 h, and by trend after 40 h, which was fully sensitive to L-748,337. M2 mRNA was reduced by 20 h mirabegron, which was resistant to L-748,337. Carbachol (3 µM) enhanced time-dependent contractions of hBSMC, which was inhibited by mirabegron (150 nM) in late phases (24 h), but not in early phases of contractions. Conclusion: Mirabegron induces dynamic phenotype alterations and M2 downregulation in hBSMC, which is paralleled by time-shifted anticontractile effects. Phenotype transitions may be involved in improvements of storage symptoms in OAB by mirabegron.