INF2 formin variants linked to human inherited kidney disease reprogram the transcriptome, causing mitotic chaos and cell death

Mutations in the human INF2 gene cause autosomal dominant focal segmental glomerulosclerosis (FSGS)—a condition characterized by podocyte loss, scarring, and subsequent kidney degeneration. To understand INF2-linked pathogenicity, we examined the efect of pathogenic INF2 on renal epithelial cell lin...

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Bibliographic Details
Authors: Labat-de-Hoz, Leticia, Fernández-Martín, Laura, Alonso, Miguel Angel, Correas Hornero, María Isabel
Format: article
Publication Date:2024
Country:España
Institution:Universidad Autónoma de Madrid
Repository:Biblos-e Archivo. Repositorio Institucional de la UAM
Language:English
OAI Identifier:oai:repositorio.uam.es:10486/716701
Online Access:http://hdl.handle.net/10486/716701
https://dx.doi.org/10.1007/s00018-024-05323-y
Access Level:Open access
Keyword:Focal segmental glomerulosclerosis
formins
charcot-Marie-tooth disease
actin
polarized epithelial cells
podocytes
multinucleation
mitotic catastrophe
Biología y Biomedicina / Biología
Description
Summary:Mutations in the human INF2 gene cause autosomal dominant focal segmental glomerulosclerosis (FSGS)—a condition characterized by podocyte loss, scarring, and subsequent kidney degeneration. To understand INF2-linked pathogenicity, we examined the efect of pathogenic INF2 on renal epithelial cell lines and human primary podocytes. Our study revealed an increased incidence of mitotic cells with surplus microtubule-organizing centers fostering multipolar spindle assembly, leading to nuclear abnormalities, particularly multi-micronucleation. The levels of expression of exogenous pathogenic INF2 were similar to those of endogenous INF2. The aberrant nuclear phenotypes were observed regardless of the expression method used (retrovirus infection or plasmid transfection) or the promoter (LTR or CMV) used, and were absent with exogenous wild type INF2 expression. This indicates that the efect of pathogenic INF2 is not due to overexpression or experimental cell manipulation, but instead to the intrinsic properties of pathogenic INF2. Inactivation of the INF2 catalytic domain prevented aberrant nuclei formation. Pathogenic INF2 triggered the translocation of the transcriptional cofactor MRTF into the nucleus. RNA sequencing revealed a profound alteration in the transcriptome that could be primarily attributed to the sustained activation of the MRTF-SRF transcriptional complex. Cells eventually underwent mitotic catastrophe and death. Reducing MRTF-SRF activation mitigated multi-micronucleation, reducing the extent of cell death. Our results, if validated in animal models, could provide insights into the mechanism driving glomerular degeneration in INF2-linked FSGS and may suggest potential therapeutic strategies for impeding FSGS progression