Biology subjects

Bryant, J. D.

Publications and source records attributed to Bryant, J. D..

4 recordsLinked to original sources

bioRxiv2025

Activation of the cGAS-STING pathway contributes to cancer-related fatigue in a murine model of head and neck cancer

Cancer-related inflammation and metabolic alterations extend beyond the tumor microenvironment, exerting systemic effects that disrupt energy homeostasis and contribute to reduced physical function and chronic fatigue. The cGAS-STING pathway has emerged as a key regulator of innate immunity and inflammation; however, its role in cancer-associated fatigue remains poorly understood. In this study, we investigated the contribution of cGAS- STING-mediated inflammation to cancer- and/or its treatment-induced fatigue using a mouse model of human papillomavirus-related head and neck cancer. Wheel running activity, along with inflammatory and metabolic changes in tumor and liver tissues, were assessed following chemoradiotherapy and pharmacological inhibition of STING in tumor-bearing and tumor-free control mice. The results revealed that tumor growth and chemoradiotherapy activated the cGAS-STING pathway, together with an upregulation of proinflammatory mediators and alterations of mitochondrial and metabolic gene expression in the liver. To inhibit STING activation, mice were administered H-151, a specific STING antagonist. This intervention attenuated hepatic inflammatory signatures and mitigated tumor and/or chemoradiotherapy-associated behavioral fatigue measured by decreased voluntary wheel running. These findings implicate for the first time the cGAS-STING signaling pathway and metabolic homeostasis in cancer- and cancer therapy-related fatigue.

cancer biology↗

bioRxiv2022

ZBP1 sequesters cGAS in the cytoplasm and sustains type I interferon responses to mitochondrial DNA

Mitochondrial DNA (mtDNA) is a potent agonist of the innate immune system; however, the exact immunostimulatory features of mtDNA and the kinetics of mtDNA detection by cytosolic nucleic acid sensors remain poorly defined. Here, we show that mitochondrial genome instability leads to Z-form mtDNA accumulation. Z-DNA Binding Protein 1 (ZBP1) stabilizes Z-form mtDNA and nucleates a cytosolic complex containing cGAS, RIPK1, and RIPK3 to sustain STAT1 phosphorylation and type I interferon (IFN-I) signaling. Increased mitochondrial Z-DNA, ZBP1 expression, and IFN-I responses are observed in cardiomyocytes after exposure to Doxorubicin, a first-line chemotherapeutic agent that induces frequent cardiotoxicity in cancer patients. Strikingly, mice lacking ZBP1 or IFN-I signaling are protected from Doxorubicin-induced cardiotoxicity. Our findings reveal ZBP1 as a cooperative partner for cGAS that sustains IFN-I responses to mitochondrial genome instability and highlight ZBP1 as a potential target in heart failure and other disorders where mtDNA stress contributes to interferon-related pathology.

immunology↗

bioRxiv2020

Type I interferon potentiates metabolic dysfunction, inflammation, and accelerated aging in mtDNA mutator mice

Mitochondrial dysfunction is a key driver of inflammatory responses in human disease. However, it remains unclear whether alterations in mitochondria-innate immune crosstalk contribute to the pathobiology of mitochondrial disorders and aging. Using the polymerase gamma (POLG) mutator model of mitochondrial DNA (mtDNA) instability, we report that aberrant activation of the type I interferon (IFN-I) innate immune axis potentiates immunometabolic dysfunction, reduces healthspan, and accelerates aging in mutator mice. Mechanistically, elevated IFN-I signaling suppresses activation of nuclear factor erythroid 2-related factor 2 (Nrf2), which increases oxidative stress, enhances pro-inflammatory cytokine responses, and accelerates metabolic dysfunction. Ablation of IFN-I signaling attenuates hyper-inflammatory phenotypes by restoring Nrf2 activity and reducing aerobic glycolysis, which combine to lessen cardiovascular and myeloid dysfunction in aged mutator mice. These findings further advance our knowledge of how mitochondrial dysfunction shapes innate immune responses and provide a framework for understanding mitochondria-driven immunopathology in POLG-related diseases and aging.

immunology↗

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↗