Mutations in six nephrosis genes delineate a pathogenic pathway amenable to treatment.

Mutations in six nephrosis genes delineate a pathogenic pathway amenable to treatment.

Nature communications (2018-05-19)

Shazia Ashraf, Hiroki Kudo, Jia Rao, Atsuo Kikuchi, Eugen Widmeier, Jennifer A Lawson, Weizhen Tan, Tobias Hermle, Jillian K Warejko, Shirlee Shril, Merlin Airik, Tilman Jobst-Schwan, Svjetlana Lovric, Daniela A Braun, Heon Yung Gee, David Schapiro, Amar J Majmundar, Carolin E Sadowski, Werner L Pabst, Ankana Daga, Amelie T van der Ven, Johanna M Schmidt, Boon Chuan Low, Anjali Bansal Gupta, Brajendra K Tripathi, Jenny Wong, Kirk Campbell, Kay Metcalfe, Denny Schanze, Tetsuya Niihori, Hiroshi Kaito, Kandai Nozu, Hiroyasu Tsukaguchi, Ryojiro Tanaka, Kiyoshi Hamahira, Yasuko Kobayashi, Takumi Takizawa, Ryo Funayama, Keiko Nakayama, Yoko Aoki, Naonori Kumagai, Kazumoto Iijima, Henry Fehrenbach, Jameela A Kari, Sherif El Desoky, Sawsan Jalalah, Radovan Bogdanovic, Nataša Stajić, Hildegard Zappel, Assel Rakhmetova, Sharon-Rose Wassmer, Therese Jungraithmayr, Juergen Strehlau, Aravind Selvin Kumar, Arvind Bagga, Neveen A Soliman, Shrikant M Mane, Lewis Kaufman, Douglas R Lowy, Mohamad A Jairajpuri, Richard P Lifton, York Pei, Martin Zenker, Shigeo Kure, Friedhelm Hildebrandt

PMID29773874

ABSTRACT

No efficient treatment exists for nephrotic syndrome (NS), a frequent cause of chronic kidney disease. Here we show mutations in six different genes (MAGI2, TNS2, DLC1, CDK20, ITSN1, ITSN2) as causing NS in 17 families with partially treatment-sensitive NS (pTSNS). These proteins interact and we delineate their roles in Rho-like small GTPase (RLSG) activity, and demonstrate deficiency for mutants of pTSNS patients. We find that CDK20 regulates DLC1. Knockdown of MAGI2, DLC1, or CDK20 in cultured podocytes reduces migration rate. Treatment with dexamethasone abolishes RhoA activation by knockdown of DLC1 or CDK20 indicating that steroid treatment in patients with pTSNS and mutations in these genes is mediated by this RLSG module. Furthermore, we discover ITSN1 and ITSN2 as podocytic guanine nucleotide exchange factors for Cdc42. We generate Itsn2-L knockout mice that recapitulate the mild NS phenotype. We, thus, define a functional network of RhoA regulation, thereby revealing potential therapeutic targets.

MATERIALS

Product Number

Brand

Product Description

HPA034659

Sigma-Aldrich

Anti-TNS2 antibody produced in rabbit, Prestige Antibodies^® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution

F3165

Sigma-Aldrich

Monoclonal ANTI-FLAG^® M2 antibody produced in mouse, clone M2, purified immunoglobulin (Purified IgG1 subclass), buffered aqueous solution (10 mM sodium phosphate, 150 mM NaCl, pH 7.4, containing 0.02% sodium azide)