Publications by authors named "Avelino De Leon"

Obesity affects nearly one billion globally and can lead to life-threatening sequelae. Consequently, there is an urgent need for novel therapeutics. We have previously shown that laminin, alpha 4 () knockout in mice leads to resistance to adipose tissue accumulation; however, the relationship between and obesity in humans has not been established.

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Objective: There is increasing evidence that immune cell interactions in adipose tissue contribute to the development of metabolic dysfunction. Pro-inflammatory cytokines have been shown to mediate insulin resistance, and the presence of macrophages is a salient feature in the development of obesity. The present study aimed to evaluate adipocyte size and macrophage activation in women before and 3 months after laparoscopic vertical sleeve gastrectomy (VSG).

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Epidemiological evidence correlates low serum vitamin A (retinol) levels with increased susceptibility to active tuberculosis (TB); however, retinol is biologically inactive and must be converted into its bioactive form, all- retinoic acid (ATRA). Given that ATRA triggers a Niemann-Pick type C2 (NPC2)-dependent antimicrobial response against , we investigated the mechanism by which the immune system converts retinol into ATRA at the site of infection. We demonstrate that granulocyte-macrophage colony-stimulating factor (GM-CSF)-derived dendritic cells (DCs), but not macrophages, express enzymes in the vitamin A metabolic pathway, including aldehyde dehydrogenase 1 family, member a2 (ALDH1A2) and short-chain dehydrogenase/reductase family, member 9 (DHRS9), enzymes capable of the two-step conversion of retinol into ATRA, which is subsequently released from the cell.

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A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the mechanism is unclear. In this study, we demonstrate that vitamin A-triggered antimicrobial activity against M. tuberculosis requires expression of NPC2.

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