Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Canada.
Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Canada.
J Pediatr Urol. 2019 May;15(3):254.e1-254.e10. doi: 10.1016/j.jpurol.2019.03.003. Epub 2019 Mar 12.
Partial bladder outlet obstruction (pBOO) is characterized by an initial inflammatory response that progresses to smooth muscle hypertrophy and fibrosis. Current treatment modalities carry high risk of morbidity. Mesenchymal stem cells (MSCs) are undifferentiated adult cells with reparative, immunomodulatory, and anti-inflammatory capacities. The ability of MSCs to inhibit inflammatory and profibrotic pathways in bladder cells has been recently reported.
This study aimed to investigate the therapeutic effects of MSCs on pBOO-induced inflammatory, profibrotic signaling pathways and end-organ physiology.
Twenty Sprague Dawley rats were randomly assigned to 5 groups: unobstructed controls, pBOO for 2 and 4 weeks, pBOO+MSCs for 2 and 4 weeks. Partial bladder outlet obstruction was surgically induced followed by intravenous injection of MSCs. Endpoint urodynamics was performed, and bladder tissue harvested for analysis. Reverse transcription real time polymerase chain reaction (RT-PCR) and immunohistochemistry were performed to study gene and protein expression of major inflammatory and profibrotic markers.
Partial bladder outlet obstruction resulted in an upregulation of transforming growth factor beta (TGFβ1), mothers against decapentaplegic homolog 2/3 (SMAD2/3), hypoxia inducible factor 1 alpha (HIF1α), hypoxia inducible factor 3 alpha (HIF3α), vascular endothelial growth factor (VEGF), tumor necrosis factor (TNFα), mechanistic target of rapamycin (mTOR), p70 ribosomal S6 protein kinase (p70 S6K), collagen 1 (COL1), and collagen 3 (COL3) expression in a time-dependent manner. This was coupled with a downregulation of interleukin (IL)-10 expression. Increase of bladder fibrosis was directly related to the duration of pBOO and associated with high urine storage pressure. Injected MSCs were identified in the bladder 4 weeks after therapy. The immunomodulatory effect of MSCs(defined by reduced TNFα and increased IL-10 and VEGF) was most predominant 2 weeks after therapy. Significant downregulation of profibrotic genes occurred 4 weeks after therapy. End filling pressure, hypertrophy, and fibrosis were significantly reduced after MSC therapy (P < 0.05).
Mesenchymal stem cell therapy led to a profound systematic improvement of the obstructed bladder. This included an initial anti-inflammatory response and a subsequent antifibrotic reaction. Essentially, both phases were associated with a reduction of urine storage pressure. The intravenously injected MSCs were tracked in the bladder. However, their presence in non-target organs such as the lungs, spleen, and liver was not tracked.
Partial bladder outlet obstruction induced significant upregulation of hypoxic, inflammatory, and profibrotic markers. Mesenchymal stem cell therapy potently inhibited these pathways and improved bladder function.
部分膀胱出口梗阻（pBOO）的特征是最初的炎症反应，进展为平滑肌肥大和纤维化。目前的治疗方法具有很高的发病率风险。间充质干细胞（MSCs）是未分化的成体细胞，具有修复、免疫调节和抗炎能力。最近有报道称 MSCs 能够抑制膀胱细胞中的炎症和促纤维化途径。
本研究旨在探讨 MSCs 对 pBOO 诱导的炎症、促纤维化信号通路和终末器官生理学的治疗作用。
20 只 Sprague Dawley 大鼠随机分为 5 组：未梗阻对照组、pBOO 2 周和 4 周组、pBOO+MSCs 2 周和 4 周组。通过手术诱导部分膀胱出口梗阻，然后静脉注射 MSCs。进行终点尿动力学检查，并采集膀胱组织进行分析。采用逆转录实时聚合酶链反应（RT-PCR）和免疫组织化学方法研究主要炎症和促纤维化标志物的基因和蛋白表达。
部分膀胱出口梗阻导致转化生长因子β（TGFβ1）、母亲抗 decapentaplegic 同源物 2/3（SMAD2/3）、缺氧诱导因子 1α（HIF1α）、缺氧诱导因子 3α（HIF3α）、血管内皮生长因子（VEGF）、肿瘤坏死因子（TNFα）、雷帕霉素靶蛋白（mTOR）、p70 核糖体 S6 蛋白激酶（p70 S6K）、胶原 1（COL1）和胶原 3（COL3）的表达呈时间依赖性上调。这与白细胞介素（IL）-10 表达的下调有关。膀胱纤维化的增加与 pBOO 的持续时间直接相关，并与高储尿压力有关。治疗后 4 周可在膀胱中识别出注射的 MSCs。治疗后 2 周，MSCs 的免疫调节作用（通过降低 TNFα和增加 IL-10 和 VEGF 来定义）最为明显。治疗后 4 周，促纤维化基因显著下调。MSC 治疗后充盈末期压力、肥大和纤维化显著降低（P<0.05）。
间充质干细胞治疗导致梗阻膀胱的系统改善。这包括最初的抗炎反应和随后的抗纤维化反应。基本上，这两个阶段都与储尿压力的降低有关。静脉注射的 MSCs 在膀胱中被追踪到。然而，它们在非目标器官（如肺、脾和肝）中的存在并未被追踪到。
部分膀胱出口梗阻诱导了显著的缺氧、炎症和促纤维化标志物的上调。间充质干细胞治疗强烈抑制这些途径并改善膀胱功能。
