ORCID Profile
0000-0002-6752-9633
Current Organisation
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 04-09-2015
DOI: 10.1111/BPH.13249
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 27-09-2022
Abstract: Missense variants of NPHS2 that cause mistrafficking of the encoded protein, PODOCIN, have been associated with steroid-resistant nephrotic syndrome. However, most studies have overexpressed such variants in 2D nonpodocyte cells. This study describes the generation and characterization of human kidney organoids representing an allelic series of homozygous NPHS2 missense variants. The strategy revealed a previously unappreciated reduction in variant PODOCIN protein, variant-specific subcellular localization, and specific effects on NEPHRIN association. All variants showed apoptosis in the absence of endoplasmic reticulum stress. Engineering endogenous NPHS2 variants to model in 3D human organoids provides a more accurate view of the pathobiology and a toolkit to screen compounds for reduction of variant protein degradation and mistrafficking. NPHS2 variants are the most common cause of steroid-resistant nephrotic syndrome in children month old. Missense NPHS2 variants were reported to cause mistrafficking of the encoded protein, PODOCIN, but this conclusion was on the basis of overexpression in some nonpodocyte cell lines. We generated a series of human induced pluripotent stem cell (iPSC) lines bearing pathogenic missense variants of NPHS2 , encoding the protein changes p.G92C, p.P118L, p.R138Q, p.R168H, and p.R291W, and control lines. iPSC lines were also generated from a patient with steroid-resistant nephrotic syndrome (p.R168H homozygote) and a healthy heterozygous parent. All lines were differentiated into kidney organoids. Immunofluorescence assessed PODOCIN expression and subcellular localization. Podocytes were transcriptionally profiled and PODOCIN-NEPHRIN interaction interrogated. All variant lines revealed reduced levels of PODOCIN protein in the absence of reduced transcription. Although wild-type PODOCIN localized to the membrane, distinct variant proteins displayed unique patterns of subcellular protein trafficking, some unreported. P118L and R138Q were preferentially retained in the endoplasmic reticulum (ER) R168H and R291W accumulated in the Golgi. Podocyte profiling demonstrated minimal disease-associated transcriptional change. All variants displayed podocyte-specific apoptosis, which was not linked to ER stress. NEPHRIN-PODOCIN colocalization elucidated the variant-specific effect on NEPHRIN association and hence NEPHRIN trafficking. Specific variants of endogenous NPHS2 result in distinct subcellular PODOCIN localization within organoid podocytes. Understanding the effect of each variant on protein levels and localization and the effect on NEPHRIN provides additional insight into the pathobiology of NPHS2 variants. This article contains a podcast at edirect.mp3/edia odcast/JASN/2023_01_05_JASN2022060707.mp3
Publisher: Public Library of Science (PLoS)
Date: 02-01-2018
Publisher: Public Library of Science (PLoS)
Date: 23-11-2015
Publisher: MDPI AG
Date: 15-01-2022
Abstract: Zika virus (ZIKV) is a pathogenic neurotropic virus that infects the central nervous system (CNS) and results in various neurological complications. Astrocytes are the dominant CNS cell producer of the antiviral cytokine IFN-β, however little is known about the factors involved in their ability to mediate viral infection control. Recent studies have displayed differential responses in astrocytes to ZIKV infection, and this study sought to elucidate astrocyte cell-specific responses to ZIKV using a variety of cell models infected with either the African (MR766) or Asian (PRVABC59) ZIKV strains. Expression levels of pro-inflammatory (TNF-α and IL-1β) and inflammatory (IL-8) cytokines following viral infection were low and mostly comparable within the ZIKV-resistant and ZIKV-susceptible astrocyte models, with better control of proinflammatory cytokines displayed in resistant astrocyte cells, synchronising with the viral infection level at specific timepoints. Astrocyte cell lines displaying ZIKV-resistance also demonstrated early upregulation of multiple antiviral genes compared with susceptible astrocytes. Interestingly, pre-stimulation of ZIKV-susceptible astrocytes with either poly(I:C) or poly(dA:dT) showed efficient protection against ZIKV compared with pre-stimulation with either recombinant IFN-β or IFN-λ, perhaps indicating that a more erse antiviral gene expression is necessary for astrocyte control of ZIKV, and this is driven in part through interferon-independent mechanisms.
Publisher: Elsevier BV
Date: 06-2015
Location: Australia
No related grants have been discovered for Mithun Das.