Journal article
Human Kidney Disease-causing INF2 Mutations Perturb Rho/Dia Signaling in the Glomerulus
EBioMedicine, Vol.1(2-3), pp.107-115
12/01/2014
DOI: 10.1016/j.ebiom.2014.11.009
PMCID: PMC4457406
PMID: 26086034
Abstract
Mutations in Inverted Formin 2 (INF2), a diaphanous formin family protein that regulates actin cytoskeleton dynamics, cause focal segmental glomerulosclerosis (FSGS) and Charcot-Marie-Tooth Disease (CMT) in humans. In addition to directly remodeling actin filaments in vitro, we have shown that INF2 regulates intracellular actin dynamics and actin dependent cellular behavior by opposing Rhoa/Dia signaling. As a step towards a better understanding of the human kidney disease, we wanted to explore the relevance of these findings to the in vivo situation. We used dose dependent knockdown of INF2 to first define an in vivo model and establish an overt glomerular phenotype in zebrafish. This simple assay was validated by rescue with wild type INF2 confirming the specificity of the findings. The edema, podocyte dysfunction, and an altered glomerular filtration barrier observed in the zebrafish pronephros correlate with mistrafficking of glomerular slit diaphragm proteins, defective slit-diaphragm signaling, and disinhibited diaphanous formin (mDia) activity. In contrast to wild-type human INF2, INF2 mutants associated with kidney disease fail to rescue the zINF2 morphant phenotype. Of particular interest, this INF2 knockdown phenotype is also rescued by loss of either RhoA or Dia2. This simple assay allows the demonstration that INF2 functions, at least in part, to modulate Dia-mediated Rho signaling, and that disease causing mutations specifically impair this regulatory function. These data support a model in which disease-associated diaphanous inhibitory domain (DID) mutants in INF2 interfere with its binding to and inhibition of Dia, leading to uncontrolled Rho/Dia signaling and perturbed actin dynamics. Methods to fine tune Rho signaling in the glomerulus may lead to new approaches to therapy in humans. (C) 2014 The Authors. Published by Elsevier B.V.
Details
- Title: Subtitle
- Human Kidney Disease-causing INF2 Mutations Perturb Rho/Dia Signaling in the Glomerulus
- Creators
- Hua Sun - University of IowaKhaldoun I. Al-Romaih - Harvard UniversityCalum A MacRae - Harvard Medical SchoolMartin R. Pollak - Beth Israel Deaconess Medical Center
- Resource Type
- Journal article
- Publication Details
- EBioMedicine, Vol.1(2-3), pp.107-115
- DOI
- 10.1016/j.ebiom.2014.11.009
- PMID
- 26086034
- PMCID
- PMC4457406
- NLM abbreviation
- EBioMedicine
- ISSN
- 2352-3964
- eISSN
- 2352-3964
- Publisher
- Elsevier
- Number of pages
- 9
- Grant note
- R01DK088826 / NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK) HL109264; DK088826 / NIH; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA
- Language
- English
- Date published
- 12/01/2014
- Academic Unit
- Nephrology, Dialysis and Transplantation; Stead Family Department of Pediatrics
- Record Identifier
- 9984384745902771
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