⼈類臍帶間質幹細胞衍⽣外泌體於甲基⼄⼆醛誘導之腹膜纖維化的預防效用

Abstract

腹膜透析是⼀種針對末期腎病患者的成熟腎臟替代療法。然⽽，長期接受腹膜透析的患者由於暴露於葡萄糖降解產物，常會出現腹膜結構與功能的變化，進⽽導致腹膜纖維化。腹膜纖維化最終會引起腹膜超過濾能⼒的喪失，但迄今尚無有效或令⼈滿意的治療⽅法。在本研究中，我們旨在探討⼈源臍帶間質幹細胞衍⽣外泌體對甲基⼄⼆醛誘導的腹膜纖維化的治療效果。我們通過切向流過濾和超速離⼼結合蔗糖沉降從臍帶間質幹細胞培養的條件培養基中分離外泌體。隨後，利用西⽅默點法偵測外泌體標記以及奈米粒⼦追蹤以及穿透式電⼦顯微鏡確認外泌體表徵。利用脂質染劑標記外泌體，我們確認了分泌膠原蛋白的腹膜細胞可以攝取間質幹細胞外泌體。在動物實驗中，我們利用甲基⼄⼆醛誘導小鼠腹膜纖維化藉以評估間質幹細胞外泌體的劑量依賴性效果。結果顯示，每週三次給予 25微克外泌體能夠保護腹膜滲透性，減少腹腔器官粘連的嚴重程度，緩解間皮下層增厚，維持間皮層的完整性，並減少分泌膠原蛋白的細胞。然⽽，給予 50 微克外泌體的組別卻未觀察到相同的預防效果。我們再藉由對外泌體的蛋白質組學分析發現其具有免疫調節、⾎管⽣成調節、組織再⽣、抗氧化應激和促進吞噬作用的攻能。此外，在 25 微克外泌體組中觀察到間皮下層巨噬細胞的徵募，這表明其治療效果可能來自於促進凋亡小體的清除。本研究表明，⼈源臍帶間質幹細胞外泌體是⼀種具有潛⼒的腹膜纖維化治療⽅法。

Peritoneal dialysis is an established renal replacement therapy for patients with end-stage renal disease. Patients who experience long-term peritoneal dialysis exposed to glucose degradation products often develop morphologic and functional changes to the peritoneal membrane, which often result in peritoneal fibrosis. Peritoneal fibrosis eventually leads to peritoneal ultrafiltration capacity loss, but there hasn’t been an effective or satisfactory therapy to date. In our study, we intended to investigate the preventive effect of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (HuMSC-EVs) on methylglyoxal-induced peritoneal fibrosis. We applied tangential flow filtration and ultracentrifugation processes with a sucrose cushion to isolate HuMSC-EVs from HuMSC cultured conditioned media. HuMSC-EVs are further characterized by western blot for EV markers, nanoparticle tracking analysis, and transmission electron microscopy. By labeling EVs with lipid dye, we confirmed collagen secreting-peritoneal cells can intake HuMSC-EVs. In vivo evaluation of the dose-dependent effects of HuMSC-EVs using methylglyoxal-induced peritoneal fibrosis mouse model was conducted, and we observed that giving 25 ug of HuMSC-EVs thrice per week was able to preserve peritoneal permeability, decrease the severity of abdominal organ adhesions, alleviate thickening of the submesothelial layer, maintain the integrity of the mesothelial layer, and decrease the presence of collagen secreting cells. Surprisingly, the same preventive effects were not detected in mice giving 50 ug of HuMSC-EVs. Proteomic analysis from HuMSC-EVs revealed their functions on immune modulation, angiogenesis modulation, tissue regeneration, oxidative stress protection and phagocytosis enhancement capabilities. Furthermore, submesothelial recruitment of macrophages was also observed in the 25 ug EV group, suggesting therapeutic effects could come from enhancing apoptotic body clearance. This study demonstrated HuMSC-EVs as a promising preventive approach for peritoneal fibrosis.