Bian Zhixiang, Wang Xiangxiang, Su Xiaoxuan, Yang Ming, Zhu Rui, Chen Shunjie
Department of Nephrology, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, PR China.
Department of Nephrology, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, PR China.
Transl Res. 2025 Jul;281:14-30. doi: 10.1016/j.trsl.2025.05.002. Epub 2025 May 20.
This study explored the molecular mechanism of adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) improving post-sepsis-associated acute kidney injury (S-AKI) tubular epithelial cell (TEC) apoptosis by modulating ADAM17/MerTK-mediated macrophage efferocytosis.
The S-AKI mouse model was established by caecal ligation and puncture and intravenously injected with ADSC-EVs. Mouse kidney macrophages were cultured with LPS, cultured with EVs while transfecting with oe-ADAM17 or si-MerTK, then incubated with Jurkat cells. Mouse serum urea and creatinine, and KIM-1, efferocytosis- and apoptosis-related protein, inflammatory factor, cytokine, and soluble MerTK (sMerTK) levels were determined using colorimetric assay, immunohistochemistry, Western blot, and ELISA. Renal tubular injury, TEC apoptosis, macrophage efferocytosis, and M1/M2 polarization levels were assessed via HE staining, TUNEL staining, immunofluorescence, and flow cytometry, respectively. In vivo validation experiments were conducted.
S-AKI mice displayed elevated levels of serum urea, creatinine, KIM-1, pro-inflammatory factors, pro-apoptotic proteins and ADAM17 protein, decreased anti-apoptotic protein and MerTK protein levels, and diminished M2 polarization. ADSC-EVs down-regulated ADAM17 and sMerTK, and increased cell membrane MerTK, macrophage recognition of apoptotic cells and efferocytosis, and M2 polarization in renal tissues of S-AKI mice and LPS-induced mouse renal macrophages, indicating that ADSC-EVs regulated ADAM17/MerTK-mediated macrophage efferocytosis and promoted M2 polarization. MerTK silencing partially reversed ADSC-EVs-regulated LPS-induced mouse renal macrophage efferocytosis and M2 polarization. In vivo, ADAM17 upregulation partly averted ADSC-EVs-regulated post-S-AKI TEC apoptosis in mouse renal tissues.
ADSC-EVs down-regulated sMerTK level and up-regulated macrophage membrane MerTK protein level by modulating ADAM17 to promote macrophage efferocytosis and ameliorate post-S-AKI TEC apoptosis and inflammation.
本研究探讨脂肪来源干细胞衍生的细胞外囊泡（ADSC-EVs）通过调节ADAM17/MerTK介导的巨噬细胞胞葬作用改善脓毒症相关急性肾损伤（S-AKI）后肾小管上皮细胞（TEC）凋亡的分子机制。
通过盲肠结扎和穿刺建立S-AKI小鼠模型，并静脉注射ADSC-EVs。用脂多糖培养小鼠肾脏巨噬细胞，在转染oe-ADAM17或si-MerTK的同时用细胞外囊泡培养，然后与Jurkat细胞共孵育。采用比色法、免疫组织化学、蛋白质免疫印迹法和酶联免疫吸附测定法测定小鼠血清尿素、肌酐以及KIM-1、胞葬作用和凋亡相关蛋白、炎症因子、细胞因子和可溶性MerTK（sMerTK）水平。分别通过苏木精-伊红染色、TUNEL染色、免疫荧光和流式细胞术评估肾小管损伤、TEC凋亡、巨噬细胞胞葬作用和M1/M2极化水平。进行体内验证实验。
S-AKI小鼠血清尿素、肌酐、KIM-1、促炎因子、促凋亡蛋白和ADAM17蛋白水平升高，抗凋亡蛋白和MerTK蛋白水平降低，M2极化减弱。ADSC-EVs下调了S-AKI小鼠肾组织和脂多糖诱导的小鼠肾巨噬细胞中的ADAM17和sMerTK，并增加了细胞膜MerTK、巨噬细胞对凋亡细胞的识别和胞葬作用以及M2极化，表明ADSC-EVs调节ADAM17/MerTK介导的巨噬细胞胞葬作用并促进M2极化。MerTK沉默部分逆转了ADSC-EVs调节的脂多糖诱导的小鼠肾巨噬细胞胞葬作用和M2极化。在体内，ADAM17上调部分避免了ADSC-EVs调节的小鼠肾组织中S-AKI后TEC凋亡。
ADSC-EVs通过调节ADAM17下调sMerTK水平并上调巨噬细胞膜MerTK蛋白水平，以促进巨噬细胞胞葬作用，改善S-AKI后TEC凋亡和炎症。
