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:Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited cardiac disease characterized by fibro-fatty replacement of the myocardium that causes heart failure and sudden cardiac death. The most aggressive subtype of ARVC is ARVC type 5 (ARVC5), caused by a p.S358L mutation in TMEM43. The function and localization of TMEM43 and the mechanism by which the p.S358L mutation causes the disease, are unknown.
