Project description:We identified a non-synonymous mutation in Oas2 (I405N), a sensor of viral double-stranded RNA, from an ENU-mutagenesis screen designed to discover new genes involved in mammary development. The mutation caused post-partum failure of lactation in healthy mice with otherwise normally developed mammary glands, characterized by greatly reduced milk protein synthesis coupled with epithelial cell death, inhibition of proliferation and a robust interferon response. Expression of mutant but not wild type Oas2 in cultured HC-11 or T47D mammary cells recapitulated the phenotypic and transcriptional effects observed in the mouse. The mutation activates the OAS2 pathway, demonstrated by a 100-fold increase in RNase L activity, and its effects were dependent on expression of RNase L and IRF7, proximal and distal pathway members. This is the first report of a viral recognition pathway regulating lactation.
Project description:We identified a non-synonymous mutation in Oas2 (I405N), a sensor of viral double-stranded RNA, from an ENU-mutagenesis screen designed to discover new genes involved in mammary development. The mutation caused post-partum failure of lactation in healthy mice with otherwise normally developed mammary glands, characterized by greatly reduced milk protein synthesis coupled with epithelial cell death, inhibition of proliferation and a robust interferon response. Expression of mutant but not wild type Oas2 in cultured HC-11 or T47D mammary cells recapitulated the phenotypic and transcriptional effects observed in the mouse. The mutation activates the OAS2 pathway, demonstrated by a 100-fold increase in RNase L activity, and its effects were dependent on expression of RNase L and IRF7, proximal and distal pathway members. This is the first report of a viral recognition pathway regulating lactation.
Project description:Oligoadenylate synthase 1 (OAS1) is a type-1 interferon-inducible, intracellular double-stranded RNA (dsRNA) sensor that generates 2'-5'-oligoadenylate (2-5A) to activate RNaseL as a means of antiviral defense. We report four de novo heterozygous OAS1 variants in five patients. Variant OAS1 proteins show dsRNA-independent gain-of-function 2-5A synthetase activity that results in RNaseL-mediated RNA-cleavage, transcriptomic downregulation, and functional impairment and/or apoptosis of monocytes, iPSC-derived macrophages, and B-cells. This leads to a polymorphic syndrome of monocyte, macrophage, and B-cell deficiency characterized by autoinflammation, pulmonary alveolar proteinosis, and hypogammaglobulinemia. RNase-L-inhibition in vitro mitigates, and hematopoietic cell transplantation in vivo corrects the autoinflammatory and immunodeficiency phenotype.
Project description:To determine transcriptome changes in adult spinal cord induced by the GarsC201R mutation. How mutations in broadly expressed housekeeping genes lead to neurodegeneration in specific cell types remains unclear. Mutations in ubiquitously expressed tRNA synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth disease. Genetic evidence in mouse and Drosophila models suggests a neomorphic gain-of-function mechanism. Here, we use in vivo, cell-type-specific transcriptional and translational profiling of affected peripheral neurons to show that mutant tRNA synthetases impair translation and activate the integrated stress response (ISR) through the sensor kinase, GCN2. The chronic activation of the ISR contributes to the pathophysiology, and genetic deletion of Gcn2 alleviates the peripheral neuropathy. The activation of GCN2 by tRNA synthetase mutations indicates their neomorphic activity is still related to translation and suggests inhibiting GCN2 or the ISR as a therapeutic strategy.
Project description:To determine transcriptome changes in adult spinal cord induced by the YarsE196K mutation. How mutations in broadly expressed housekeeping genes lead to neurodegeneration in specific cell types remains unclear. Mutations in ubiquitously expressed tRNA synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth disease. Genetic evidence in mouse and Drosophila models suggests a neomorphic gain-of-function mechanism. Here, we use in vivo, cell-type-specific transcriptional and translational profiling of affected peripheral neurons to show that mutant tRNA synthetases impair translation and activate the integrated stress response (ISR) through the sensor kinase, GCN2. The chronic activation of the ISR contributes to the pathophysiology, and genetic deletion of Gcn2 alleviates the peripheral neuropathy. The activation of GCN2 by tRNA synthetase mutations indicates their neomorphic activity is still related to translation and suggests inhibiting GCN2 or the ISR as a therapeutic strategy.
Project description:To determine transcriptome changes in spinal cord induced by the GarsdelETAQ mutation. How mutations in broadly expressed housekeeping genes lead to neurodegeneration in specific cell types remains unclear. Mutations in ubiquitously expressed tRNA synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth disease. Genetic evidence in mouse and Drosophila models suggests a neomorphic gain-of-function mechanism. Here, we use in vivo, cell-type-specific transcriptional and translational profiling of affected peripheral neurons to show that mutant tRNA synthetases impair translation and activate the integrated stress response (ISR) through the sensor kinase, GCN2. The chronic activation of the ISR contributes to the pathophysiology, and genetic deletion of Gcn2 alleviates the peripheral neuropathy. The activation of GCN2 by tRNA synthetase mutations indicates their neomorphic activity is still related to translation and suggests inhibiting GCN2 or the ISR as a therapeutic strategy.
Project description:To determine transcriptome changes in pre-disease onset motor neurons induced by the GarsC201R mutation. How mutations in broadly expressed housekeeping genes lead to neurodegeneration in specific cell types remains unclear. Mutations in ubiquitously expressed tRNA synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth disease. Genetic evidence in mouse and Drosophila models suggests a neomorphic gain-of-function mechanism. Here, we use in vivo, cell-type-specific transcriptional and translational profiling of affected peripheral neurons to show that mutant tRNA synthetases impair translation and activate the integrated stress response (ISR) through the sensor kinase, GCN2. The chronic activation of the ISR contributes to the pathophysiology, and genetic deletion of Gcn2 alleviates the peripheral neuropathy. The activation of GCN2 by tRNA synthetase mutations indicates their neomorphic activity is still related to translation and suggests inhibiting GCN2 or the ISR as a therapeutic strategy.
Project description:To determine transcriptome changes in pre-disease onset spinal cord induced by the GarsP278KY mutation. How mutations in broadly expressed housekeeping genes lead to neurodegeneration in specific cell types remains unclear. Mutations in ubiquitously expressed tRNA synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth disease. Genetic evidence in mouse and Drosophila models suggests a neomorphic gain-of-function mechanism. Here, we use in vivo, cell-type-specific transcriptional and translational profiling of affected peripheral neurons to show that mutant tRNA synthetases impair translation and activate the integrated stress response (ISR) through the sensor kinase, GCN2. The chronic activation of the ISR contributes to the pathophysiology, and genetic deletion of Gcn2 alleviates the peripheral neuropathy. The activation of GCN2 by tRNA synthetase mutations indicates their neomorphic activity is still related to translation and suggests inhibiting GCN2 or the ISR as a therapeutic strategy.