“Locked down outside”: Perception of hazard and health resources in COVID-19 epidemic context among homeless people

International audienceWhile social inequality is widely recognised as being a risk factor for COVID-19 infection or serious forms of the disease, many questions still remain concerning the perception of hazard and protective measures by the most vulnerable populations. This mixed-methods study aimed (1) to describe the self-perceived health and protective measures linked to COVID-19 of homeless people in one of the largest and poorest cities in France, and (2) to assess which skills and resources they used to address the COVID-19 pandemic. The quantitative survey addressed these questions among a sample of 995 homeless people living either on the streets, in homeless shelters or in squats/slums, whereas the qualitative survey was constructed from 14 homeless interviewees. Both data collections were carried out between June and July 2020. Results showed that COVID-19 infection was clearly perceived by homeless people as a risk, but the experience of being homeless placed this risk among several others. Different practices of protection were observed according to the type of living place. Lockdown of the general population severely impacted the survival systems of the populations furthest from housing, with alarming rates of people without access to water or food. 77% of homeless participants reported that they encountered significant financial difficulties. All interviewees were particularly attentive to their health, with awareness and even a familiarity with the risks of infectious diseases long before the pandemic. Using a capability framework, our study showed a predominant lack of external health-related resources for homeless people, while internal health-related resources were more developed than expected. None of the places and lifestyles studied was favourable to health: collective shelters due to a greater restriction of people's choices, slums and street life due to a greater lack of basic resources

Regulation of skeletal muscle lipolysis and oxidative metabolism by the co-lipase CGI-58.

International audienceWe investigated here the specific role of CGI-58 in the regulation of energy metabolism in skeletal muscle. We first examined CGI-58 protein expression in various muscle types in mice, and next modulated CGI-58 expression during overexpression and knockdown studies in human primary myotubes and evaluated the consequences on oxidative metabolism. We observed a preferential expression of CGI-58 in oxidative muscles in mice consistent with triacylglycerol hydrolase activity. We next showed by pulse-chase that CGI-58 overexpression increased by more than 2-fold the rate of triacylglycerol (TAG) hydrolysis, as well as TAG-derived fatty acid (FA) release and oxidation. Oppositely, CGI-58 silencing reduced TAG hydrolysis and TAG-derived FA release and oxidation (-77%, P < 0.001), whereas it increased glucose oxidation and glycogen synthesis. Interestingly, modulations of CGI-58 expression and FA release are reflected by changes in pyruvate dehydrogenase kinase 4 gene expression. This regulation involves the activation of the peroxisome proliferator activating receptor-δ (PPARδ) by lipolysis products. Altogether, these data reveal that CGI-58 plays a limiting role in the control of oxidative metabolism by modulating FA availability and the expression of PPARδ-target genes, and highlight an important metabolic function of CGI-58 in skeletal muscle