| First Author | Fukusumi Y | Year | 2021 |
| Journal | Am J Pathol | Volume | 191 |
| Issue | 7 | Pages | 1209-1226 |
| PubMed ID | 33887216 | Mgi Jnum | J:308521 |
| Mgi Id | MGI:6729803 | Doi | 10.1016/j.ajpath.2021.04.004 |
| Citation | Fukusumi Y, et al. (2021) Nephrin-Ephrin-B1-Na(+)/H(+) Exchanger Regulatory Factor 2-Ezrin-Actin Axis Is Critical in Podocyte Injury. Am J Pathol 191(7):1209-1226 |
| abstractText | Ephrin-B1 is one of the critical components of the slit diaphragm of kidney glomerular podocyte. However, the precise function of ephrin-B1 is unclear. To clarify the function of ephrin-B1, ephrin-B1-associated molecules were studied. RNA-sequencing analysis suggested that Na(+)/H(+) exchanger regulatory factor 2 (NHERF2), a scaffolding protein, is associated with ephrin-B1. NHERF2 was expressed at the apical area and the slit diaphragm, and interacted with the nephrin-ephrin-B1 complex at the slit diaphragm. The nephrin-ephrin-B1-NHERF2 complex interacted with ezrin bound to F-actin. NHERF2 bound ephrin-B1 via its first postsynaptic density protein-95/disks large/zonula occludens-1 domain, and podocalyxin via its second postsynaptic density protein-95/disks large/zonula occludens-1 domain. Both in vitro analyses with human embryonic kidney 293 cells and in vivo study with rat nephrotic model showed that stimulaiton of the slit diaphragm, phosphorylation of nephrin and ephrin-B1, and dephosphorylation of NHERF2 and ezrin, disrupted the linkages of ephrin-B1-NHERF2 and NHERF2-ezrin. It is conceivable that the linkage of nephrin-ephrin-B1-NHERF2-ezrin-actin is a novel critical axis in the podocytes. Ephrin-B1 phosphorylation also disrupted the linkage of an apical transmembrane protein, podocalyxin, with NHERF2-ezrin-actin. The phosphorylation of ephrin-B1 and the consequent dephosphorylation of NHERF2 are critical initiation events leading to podocyte injury. |
