Search bioRxiv⌕ Search

Biology subjects

Menissy, S.

Publications and source records attributed to Menissy, S..

2 recordsLinked to original sources
bioRxiv2020

Innate immune signaling and sex differences contribute to neurocognitive impairment, neuroinflammation, and mitochondrial rewiring in a mouse model of Gulf War illness

Gulf War Illness (GWI) is a chronic, multi-symptom disorder affecting approximately 30 percent of the nearly 700,000 veterans of the 1991 Persian Gulf War. Recent studies have revealed that GWI-related chemical (GWIC) exposure promotes immune activation and metabolic rewiring, which correlate with neurocognitive impairments and other symptoms of GWI. However, the molecular mechanisms and signaling pathways linking GWIC to inflammation, metabolic alterations, and neurological symptoms remain unclear. Mitochondrial dysfunction has been documented in veterans with GWI and rodent models, and because mitochondria are key immune regulators, we hypothesized that alterations to mitochondria-immune crosstalk could contribute to the development of GWI-related symptoms. Here we show that acute exposure of murine macrophages to GWIC alters mitochondrial respiration and potentiates innate immune signaling and inflammatory cytokine secretion. Using an established mouse model of GWI, we report that neurobehavioral changes, neuroinflammation, and mitochondrial protein rewiring are attenuated in mice lacking the cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) and NOD-, LRR- or pyrin domain-containing protein 3 (NLRP3) innate immune pathways. Finally, we report sex differences in response to GWIC, with female mice showing more pronounced cognitive impairment, neuroinflammation, and mitochondrial protein alterations in the brain compared to male mice. Our results provide novel information on sex differences in this model and suggest that STING and NLRP3 are key mediators of the cognitive impairment, inflammation, and mitochondrial dysfunction observed in GWI.

neuroscience↗
bioRxiv2020

Loss of mitochondrial protease CLPP activates type I interferon responses through the mtDNA-cGAS-STING signaling axis

Caseinolytic mitochondrial matrix peptidase proteolytic subunit, CLPP, is a serine protease that degrades damaged or misfolded mitochondrial proteins. CLPP null mice exhibit growth retardation, deafness, and sterility, resembling human Perrault syndrome (PS), but also display immune system alterations. However, the molecular mechanisms and signaling pathways underlying immunological changes in CLPP null mice remain unclear. Here we report the steady state activation of type I interferon (IFN-I) signaling and antiviral gene expression in CLPP deficient cells and tissues. Depletion of the cyclic GMP-AMP (cGAS)-Stimulator of Interferon Genes (STING) DNA sensing pathway ablates heightened IFN-I responses and abrogates the broad viral resistance phenotype of CLPP null cells. Moreover, we report that CLPP deficiency leads to mitochondrial DNA (mtDNA) instability and packaging alterations. Pharmacological and genetic approaches to deplete mtDNA or inhibit cytosolic release markedly reduce antiviral gene expression, implicating mtDNA stress as the driver of IFN-I signaling in CLPP null mice. Our work places the cGAS-STING-IFN-I innate immune pathway downstream of CLPP and may have implications for understanding myriad human diseases involving CLPP dysregulation.

immunology↗