Biology subjects

Suarez, Y.

Publications and source records attributed to Suarez, Y..

2 recordsLinked to original sources

bioRxiv2020

Ketogenesis restrains aging-induced exacerbation of COVID in a mouse model

Increasing age is the strongest predictor of risk of COVID-19 severity. Unregulated cytokine storm together with impaired immunometabolic response leads to highest mortality in elderly infected with SARS-CoV-2. To investigate how aging compromises defense against COVID-19, we developed a model of natural murine beta coronavirus (mCoV) infection with mouse hepatitis virus strain MHV-A59 (mCoV-A59) that recapitulated majority of clinical hallmarks of COVID-19. Aged mCoV-A59-infected mice have increased mortality and higher systemic inflammation in the heart, adipose tissue and hypothalamus, including neutrophilia and loss of {gamma}{delta} T cells in lungs. Ketogenic diet increases beta-hydroxybutyrate, expands tissue protective {gamma}{delta} T cells, deactivates the inflammasome and decreases pathogenic monocytes in lungs of infected aged mice. These data underscore the value of mCoV-A59 model to test mechanism and establishes harnessing of the ketogenic immunometabolic checkpoint as a potential treatment against COVID-19 in the elderly. Highlights - Natural MHV-A59 mouse coronavirus infection mimics COVID-19 in elderly. - Aged infected mice have systemic inflammation and inflammasome activation - Murine beta coronavirus (mCoV) infection results in loss of pulmonary {gamma}{delta} T cells. - Ketones protect aged mice from infection by reducing inflammation. eTOC BlurbElderly have the greatest risk of death from COVID-19. Here, Ryu et al report an aging mouse model of coronavirus infection that recapitulates clinical hallmarks of COVID-19 seen in elderly. The increased severity of infection in aged animals involved increased inflammasome activation and loss of {gamma}{delta} T cells that was corrected by ketogenic diet.

immunology↗

bioRxiv2020

Liver-specific suppression of ANGPTL4 improves obesity-associated diabetes and mitigates atherosclerosis in mice

ABSTRACTAngiopoietin-like 4 (ANGPTL4) is a major regulator of lipoprotein lipase (LPL) activity, which is responsible for maintaining optimal levels of circulating triacylglycerol (TAG) for distribution to different tissues including the adipose tissues (ATs), heart, muscle and liver. Dysregulation of trafficking and portioning of fatty acids (FA) can promote ectopic lipid accumulation in metabolic tissues such as the liver, ultimately leading to systemic metabolic dysfunction. To investigate how ANGPTL4 regulates hepatic lipid and glucose metabolism, we generated liver-specific ANGPTL4 knockout mice (LKO). Using metabolic turnover studies, we demonstrate that hepatic ANGPTL4 deficiency facilitates catabolism of TAG-rich lipoprotein (TRL) remnants in the liver via increased hepatic lipase (HL) activity, which results in a significant reduction in circulating TAG and cholesterol levels. Deletion of hepatocyte ANGPTL4 protects against diet-induce obesity, glucose intolerance, liver steatosis, and atherogenesis. Mechanistically, we demonstrate that absence of ANGPTL4 in hepatocytes promotes FA uptake which results in increased FA oxidation, ROS production, and AMPK activation. Finally, we demonstrate the utility of a targeted pharmacologic therapy that specifically inhibits ANGPTL4 in the liver and protects against diet-induced obesity, dyslipidemia, glucose intolerance, and liver damage without causing any of the deleterious effects previously observed with neutralizing antibodies.Competing Interest StatementThe authors have declared no competing interest.View Full Text

physiology↗