Project description:The gene WFS1 encodes a protein with unknown function although its functional deficiency causes different neuropsychiatric and neuroendocrine syndromes. In the present study, we aimed to find the functional networks influenced by the time-dependent silencing of WFS1 in HEK cells. We performed whole genome gene expression profiling (Human Gene 1.0 ST Arrays) in HEK cells 24, 48, 72 and 96 hours after transfection with three different WFS1 siRNAs. In order to verify silencing we performed quantitative RT-PCR and western blot analysis. Analysis was conducted in two ways. First we analyzed the overall effect of the siRNA treatment on the gene expression profile. As a next step we performed time-course analysis separately for different siRNAs and combined for all siRNAs. Quantitative RT-PCR and western blot confirmed clear silencing of WFS1 gene expression after 48 hours. Eleven genes had an FDR value less than 10% and most of them were genes related to the mitochondrial dysfunction and apoptosis. Time-course analysis confirmed significant correlation between WFS1 silencing and changes in the expression profiles of several genes. The pathways that were influenced significantly by WFS1 silencing were related to mitochondrial damage and neurodegenerative diseases. Our findings suggest the role of WSF1 gene in cell survival and its involvement in the degenerative diseases. 54 samples; whole genome gene expression profiling (Human Gene 1.0 ST Arrays) in HEK cells 24, 48, 72 and 96 hours after transfection with three different WFS1 siRNAs.
Project description:The gene WFS1 encodes a protein with unknown function although its functional deficiency causes different neuropsychiatric and neuroendocrine syndromes. In the present study, we aimed to find the functional networks influenced by the time-dependent silencing of WFS1 in HEK cells. We performed whole genome gene expression profiling (Human Gene 1.0 ST Arrays) in HEK cells 24, 48, 72 and 96 hours after transfection with three different WFS1 siRNAs. In order to verify silencing we performed quantitative RT-PCR and western blot analysis. Analysis was conducted in two ways. First we analyzed the overall effect of the siRNA treatment on the gene expression profile. As a next step we performed time-course analysis separately for different siRNAs and combined for all siRNAs. Quantitative RT-PCR and western blot confirmed clear silencing of WFS1 gene expression after 48 hours. Eleven genes had an FDR value less than 10% and most of them were genes related to the mitochondrial dysfunction and apoptosis. Time-course analysis confirmed significant correlation between WFS1 silencing and changes in the expression profiles of several genes. The pathways that were influenced significantly by WFS1 silencing were related to mitochondrial damage and neurodegenerative diseases. Our findings suggest the role of WSF1 gene in cell survival and its involvement in the degenerative diseases.
Project description:WFS1 pull-down in HEK293 cells transfected with WFS1 expression plasmid. Precipitated proteins were separates into 13 fractions by SDS-PAGE, digested with trypsin and analyzed by LC-MS/MS. Samples P1-13 = pull-down with anti-WFS rabbit polyclonal (Cell Signaling Technologies #8749S), samples N14-26 = negative control (rabbit IgG).
Mitochondrial dysfunction involving mitochondria-associated ER membrane (MAM) dysregulation is implicated in the pathogenesis of late-onset neurodegenerative
diseases, but understanding is limited for rare early-onset conditions. Loss of the MAMresident
protein WFS1 causes Wolfram syndrome (WS), a rare early-onset
neurodegenerative disease that has been linked to mitochondrial abnormalities. Here
we demonstrated mitochondrial dysfunction in human induced pluripotent stem cellderived
neuronal cells of WS patients. VDAC1 was identified to interact with WFS1,
whereas loss of this interaction in WS cells could compromise mitochondrial function.
Restoring WFS1 levels in WS cells reinstated WFS1-VDAC1 interaction, which
correlated with increase in MAMs and mitochondrial network that could positively affect
mitochondrial function. Genetic rescue by WFS1 overexpression or pharmacological
agents modulating mitochondrial function improved the viability and bioenergetics of
WS neurons. Our data implicate a role of WFS1 in regulating mitochondrial
functionality and highlight a therapeutic intervention for WS and related rare diseases
with mitochondrial defects.
Project description:Aim of present study was to describe the changes induced deletion of the Wfs1 gene in the temporal lobe of mice. Mutant mice were backcrossed to two different genomic backgrounds in order to exclude confounding foreign genomic background influence. Samples from temporal lobes were analyzed by using Affymetrix Genechips, expression profiles were functionally annotated by using GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 +/- 1.6 g) than their wild-type counterparts (31.0 +/- 0.6 g, p < 0.0001). Interestingly, genechip analysis identified growth hormone transcripts up-regulated and functional analysis found appropriate pathways activated. Moreover, we found significant increase in the level of IGF1 in the plasma of wfs1 mutant mice. Taken together, wfs1 mutation induces growth retardation whereas the growth hormone pathway is activated. Further studies are needed to describe biochemical and molecular details of the growth hormone axis in the wfs1 mutant mice. 37 samples, two genotypes (wild type and mutant), in two different genetic background (C57B6 and 129S6)
Project description:Wolfram syndrome is a rare genetic disorder largely caused by pathogenic variants in the WFS1 gene and manifested by diabetes mellitus, optic nerve atrophy, and progressive neurodegeneration. Recent genetic and clinical findings have revealed Wolfram syndrome as a spectrum disorder. Therefore, a genotype-phenotype correlation analysis is needed for diagnosis and therapeutic development. Here, we focus on the WFS1 c.1672C>T, p.R558C variant which is highly prevalent in the Ashkenazi-Jewish population. Clinical investigation indicates that subjects carrying the homozygous WFS1 c.1672C>T, p.R558C variant show mild forms of Wolfram syndrome phenotypes. Expression of WFS1 p.R558C is more stable compared to the other known recessive pathogenic variants associated with Wolfram syndrome. Human induced pluripotent stem cell (iPSC)-derived islets (SC-islets) homozygous for WFS1 c.1672C>T variant recapitulate genotype-related Wolfram syndrome phenotypes. Enhancing residual WFS1 function by a combination treatment of chemical chaperones mitigates detrimental effects caused by the WFS1 c.1672C>T, p.R558C variant and increases insulin secretion in SC-islets. Thus, the WFS1 c.1672C>T, p.R558C variant causes a mild form of Wolfram syndrome phenotypes, which can be remitted with a combination treatment of chemical chaperones. We demonstrate that our patient iPSC-derived disease model provides a valuable platform for further genotype-phenotype analysis and therapeutic development for Wolfram syndrome.
Project description:Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. WFS1 encodes an endoplasmic reticulum resident transmembrane protein. The Wfs1-null mice exhibit progressive insulin deficiency and diabetes. The aim of the present study was to describe the insulin secretion and transcriptome of pancreatic islets in WFS1-deficient mice. WFS1-deficient (Wfs1KO) mice had considerably less pancreatic islets than heterozygous (Wfs1HZ) or wild-type (WT) mice. Wfs1KO pancreatic islets secreted less insulin after stimulation with 2 and 10 mM glucose and with tolbutamide solution compared to WT and Wfs1HZ islets, but not after stimulation with 20 mM glucose. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. After stimulation with 2 mM glucose solution the proinsulin/insulin ratio in Wfs1KO was significantly higher than that of WT and Wfs1HZ. RNA-seq from pancreatic islets found melastatin-related transient receptor potential subfamily member 5 protein gene (Trpm5) to be downregulated in WFS1-deficient mice. Functional annotation of RNA sequencing results showed that WFS1 deficiency influenced significantly the pathways related to tissue morphology, endocrine system development and function, molecular transport network. These findings suggest an interactive role of WFS1 and TRPM5 in insulin secretion. 12 samples: three genotypes, 4 individuals in each genotype
Project description:The difficulty associated with generating induced pluripotent stem cells (iPSC) from patients with chromosomal instability syndromes suggests the cellular DNA damage response poses a barrier to reprogramming. Here we demonstrate that fibroblasts from patients with ataxia-telangiectasia (A-T) can be reprogrammed to bona-fide iPSC, albeit at a reduced efficiency. A-T iPSC display defective radiation-induced signaling, radiosensitivity and cell cycle checkpoint defects. Bioinformatic analysis of gene expression in the A-T iPSC identifies abnormalities in DNA damage signaling pathways as well as changes in mitochondrial and pentose phosphate pathways. A-T iPSC can be differentiated into functional neurons and thus represent a suitable model system to investigate A-T associated neurodegeneration. Collectively our data show that iPSC can be generated from a chromosomal instability syndrome and that these cells can be used to discover early developmental consequences of ATM deficiency, such as altered mitochondrial function, that may be relevant to A-T pathogenesis and amenable to therapeutic intervention. Three different cell types: fibroblasts, human embyronic stem cells, and induced pluripotent stem cells with heterozygote, homozygote A-T compared to normal samples.
Project description:Aim of present study was to describe the changes induced deletion of the Wfs1 gene in the temporal lobe of mice. Mutant mice were backcrossed to two different genomic backgrounds in order to exclude confounding foreign genomic background influence. Samples from temporal lobes were analyzed by using Affymetrix Genechips, expression profiles were functionally annotated by using GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 ± 1.6 g) than their wild-type counterparts (31.0 ± 0.6g, p < 0.0001). Interestingly, genechip analysis identified growth hormone transcripts up-regulated and functional analysis found appropriate pathways activated. Moreover, we found significant increase in the level of IGF1 in the plasma of wfs1 mutant mice. Taken together, wfs1 mutation induces growth retardation whereas the growth hormone pathway is activated. Further studies are needed to describe biochemical and molecular details of the growth hormone axis in the wfs1 mutant mice.
Project description:Mitochondrial dysfunction is a common feature in neurodegeneration and aging. We identify mitochondrial dysfunction in xeroderma pigmentosum group A (XPA), a nucleotide excision DNA repair disorder with severe neurodegeneration, in silico and in vivo. XPA deficient cells show defective mitophagy with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD+-SIRT1-PGC-1α axis triggered by hyperactivation of the DNA damage sensor PARP1. This phenotype is rescued by PARP1 inhibition or by supplementation with NAD+ precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration. Our findings reveal a novel nuclear-mitochondrial cross-talk that is critical for the maintenance of mitochondrial health.
Project description:Mitochondrial dysfunction is a common feature in neurodegeneration and aging. We identify mitochondrial dysfunction in xeroderma pigmentosum group A (XPA), a nucleotide excision DNA repair disorder with severe neurodegeneration, in silico and in vivo. XPA deficient cells show defective mitophagy with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD+-SIRT1-PGC-1α axis triggered by hyperactivation of the DNA damage sensor PARP1. This phenotype is rescued by PARP1 inhibition or by supplementation with NAD+ precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration. Our findings reveal a novel nuclear-mitochondrial cross-talk that is critical for the maintenance of mitochondrial health.