Project description:Differential gene expression in CHCHD10 G58R mouse hearts treated with nontargeting or OMA1-targeting antisense oligomers (ASOs) provided by Ionis Pharmaceuticals (Carlsbad, CA) This experiment used the Clariom_S_Mouse Microarray from Affymetrix to analyze the effect of acute OMA1 KD on gene expression in CHCHD10 G58R mouse hearts.
Project description:Differential gene expression in CHCHD10 mutants with OMA1 present or knocked out This experiment used the Clariom_S_Mouse Microarray from Affymetrix to analyze the effect of CHCHD10 mutations on gene expression, and the effect of congenital OMA1 KO on gene expression in these CHCHD10 mutants.
Project description:Mutations in CHCHD10, coding for a mitochondrial intermembrane space protein, are a rare cause of autosomal dominant amyotrophic lateral sclerosis (ALS). Mutation-specific toxic gain of function or haploinsuffuciency models have been proposed to explain pathogenicity. To decipher the metabolic dysfunction associated with the haploinsufficient p.R15L variant we conducted a TMT labelling experiment. Fibroblasts with the CHCHD10 p.R15L variant (hereafter referred to as ‘patient’), were compared to the same cells expressing wild-type CHCHD10 cDNA (hereafter called ‘rescue’) under nutrient stress, in which galactose was substituted for glucose.
Project description:Mutations in CHCHD10, a mitochondrial protein with undefined functions, are associated with autosomal dominant mitochondrial diseases. Chchd10 knock-in mice harboring a heterozygous S55L mutation (equivalent to human pathogenic S59L) develop a fatal mitochondrial cardiomyopathy caused by CHCHD10 aggregation and proteotoxic mitochondrial integrated stress response (mtISR). In mutant hearts, mtISR is accompanied by a metabolic rewiring characterized by increased reliance on glycolysis rather than fatty acid oxidation. To counteract this metabolic rewiring, heterozygous S55L mice were subjected to chronic high fat diet (HFD) to decrease insulin sensitivity and glucose uptake and enhance fatty acid utilization in the heart. HFD ameliorated the ventricular dysfunction of mutant hearts and significantly extended the survival of mutant female mice affected by severe pregnancy-induced cardiomyopathy. Gene expression profiles confirmed that HFD increased fatty acid utilization and ameliorated cardiomyopathy markers. Importantly, HFD also decreased accumulation of aggregated CHCHD10 in the S55L heart, suggesting activation of quality control mechanisms. Overall, our findings indicate that metabolic therapy can be effective in mitochondrial cardiomyopathies associated with proteotoxic stress.
Project description:Mitochondrial dysfunction causes devastating disorders, including mitochondrial myopathy. Here, we identified that diverse mitochondrial myopathy models elicit a protective mitochondrial integrated stress response (mt-ISR), mediated by OMA1-DELE1 signaling. The response was similar following disruptions in mtDNA maintenance, from knockout of Tfam, and mitochondrial protein unfolding, from disease-causing mutations in CHCHD10 (G58R and S59L). The preponderance of the response was directed at upregulating pathways for aminoacyl-tRNA biosynthesis, the intermediates for protein synthesis, and was similar in heart and skeletal muscle but more limited in brown adipose challenged with cold stress. Strikingly, models with early DELE1 mt-ISR activation failed to grow and survive to adulthood in the absence of Dele1, accounting for some but not all of OMA1’s protection. Notably, the DELE1 mt-ISR did not slow net protein synthesis in stressed striated muscle, but instead prevented loss of translation-associated proteostasis in muscle fibers. Together our findings identify that the DELE1 mt-ISR mediates a stereotyped response to diverse forms of mitochondrial stress and is particularly critical for maintaining growth and survival in early-onset mitochondrial myopathy. This experiment used the Clariom_S_Mouse Microarray from Affymetrix/Applied Biosystems to analyze the effect of knocking down OMA1 by ASO in CHCHD10 G58R mouse model of mitochondrial myopathy/cardiomyopathy.
Project description:Transcriptional mitochondrial stress response to CHCHD10 G58R protein misfolding in mouse heart, gastrocnemius, and tibalis anterior muscle the presence and absence of the DELE1 mitochondrial integrated stress responses
Project description:Artificial microRNA mutants of Toc75 were generated in Arabidopsis. Shotgun proteomics was with Col-0 and two independent knockdown lines.
Project description:The goal of this study was to analyze the molecular changes that occur over the time course of disease in a mutant CHCHD10-related mouse model of primary mitochondrial cardiomyopathy.