1. uPAR isoform 2 forms a dimer and induces severe kidney disease in mice
- Author
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Wei, Changli, Li, Jing, Adair, Brian D., Zhu, Ke, Cai, Jian, Merchant, Michael, Samelko, Beata, Liao, Zhongji, Koh, Kwi Hye, Tardi, Nicholas J., Dande, Ranadheer R., Liu, Shuangxin, Ma, Jianchao, Dibartolo, Salvatore, Hagele, Stefan, Peev, Vasil, Hayek, Salim S., Cimbaluk, David J., Tracy, Melissa, Klein, Jon, Sever, Sanja, Shattil, Sanford J., Arnaout, M. Amin, and Reiser, Jochen
- Subjects
Laboratory rats -- Research -- Health aspects ,Medical research ,Fibrinolytic agents -- Research ,Kidney diseases -- Risk factors ,Gene expression -- Research ,Genes ,Chronic kidney failure ,Genetic engineering ,Microscopy ,Proteinuria ,Protein binding ,Animal genetic engineering ,Electron microscopy ,Integrins ,Health care industry - Abstract
Soluble urokinase plasminogen activator receptor (suPAR) is an immune-derived circulating signaling molecule that has been implicated in chronic kidney disease, such as focal segmental glomerulosclerosis (FSGS). Typically, native uPAR (isoform 1) translates to a 3-domain protein capable of binding and activating integrins, yet the function of additional isoforms generated by alternative splicing is unknown. Here, we characterized mouse uPAR isoform 2 (msuPAR2), encoding domain I and nearly one-half of domain II, as a dimer in solution, as revealed by 3D electron microscopy structural analysis. In vivo, msuPAR2 transgenic mice exhibited signs of severe renal disease characteristic of FSGS with proteinuria, loss of kidney function, and glomerulosclerosis. Sequencing of the glomerular RNAs from msuPAR2-Tg mice revealed a differentially expressed gene signature that includes upregulation of the suPAR receptor Itgb3, encoding [[beta].sub.3] integrin. Crossing msuPAR2- transgenic mice with 3 different integrin [[beta].sub.3] deficiency models rescued msuPAR2-mediated kidney function. Further analyses indicated a central role for [[beta].sub.3] integrin and c-Src in msuPAR2 signaling and in human FSGS kidney biopsies. Administration of Src inhibitors reduced proteinuria in msuPAR2-transgenic mice. In conclusion, msuPAR2 may play an important role in certain forms of scarring kidney disease., Introduction Urokinase receptor or urokinase plasminogen activator receptor (uPAR) is a glycosylphosphatidylinisotol-anchored (GPI-anchored) protein that acts as a receptor for prourokinase and facilitates the generation of activated plasmin. Removal of [...]
- Published
- 2019
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