A TRAIL-TL1A Paracrine Network Involving Adipocytes, Macrophages, and Lymphocytes Induces Adipose Tissue Dysfunction Downstream of E2F1 in Human Obesity
DIABETES
Authors: Maixner, Nitzan; Pecht, Tal; Haim, Yulia; Chalifa-Caspi, Vered; Goldstein, Nir; Tarnovscki, Tania; Liberty, Idit F.; Kirshtein, Boris; Golan, Rachel; Berner, Omer; Monsonego, Alon; Bashan, Nava; Blueher, Matthias; Rudich, Assaf
Abstract
Elevated expression of E2F1 in adipocyte fraction of human visceral adipose tissue (hVAT) associates with a poor cardiometabolic profile. We hypothesized that beyond directly activating autophagy and MAP3K5 (ASK)-MAP kinase signaling, E2F1 governs a distinct transcriptome that contributes to adipose tissue and metabolic dysfunction in obesity. We performed RNA sequencing of hVAT samples from age-, sex-, and BMI-matched patients, all obese, whose visceral E2F1 protein expression was either high (E2F1(high)) or low (E2F1(low)). Tumor necrosis factor superfamily (TNFSF) members, includingTRAIL(TNFSF10),TL1A(TNFSF15), and their receptors, were enriched in E2F1(high). WhileTRAILwas equally expressed in adipocytes and stromal vascular fraction (SVF),TL1Awas mainly expressed in SVF, and TRAIL-inducedTL1Awas attributed to CD4(+)and CD8(+)subclasses of hVAT T cells. In human adipocytes, TL1A enhanced basal and impaired insulin-inhibitable lipolysis and altered adipokine secretion, and in human macrophages it induced foam cell biogenesis and M1 polarization. Two independent human cohorts confirmed associations between TL1A and TRAIL expression in hVAT and higher leptin and IL6 serum concentrations, diabetes status, and hVAT-macrophage lipid content. Jointly, we propose an intra-adipose tissue E2F1-associated TNFSF paracrine loop engaging lymphocytes, macrophages, and adipocytes, ultimately contributing to adipose tissue dysfunction in obesity.
Assessment of HIV-1 integration in tissues and subsets across infection stages
JCI INSIGHT
Authors: Wu, Vincent H.; Nobles, Christopher L.; Kuri-Cervantes, Leticia; McCormick, Kevin; Everett, John K.; Nguyen, Son; Estrada, Perla M. del Rio; Gonzalez-Navarro, Mauricio; Avila-Rios, Santiago; Reyes-Teran, Gustavo; Bushman, Frederic D.; Betts, Michael R.
Abstract
The integration of HIV DNA into the host genome contributes to lifelong infection in most individuals. Few studies have examined integration in lymphoid tissue, where HIV predominantly persists before and after antiretroviral treatment (ART). Of particular interest is whether integration site distributions differ between infection stages with paired blood and tissue comparisons. Here, we profiled HIV integration site distributions in sorted memory, tissue-resident, and/or follicular helper CD4(+) T cell subsets from paired blood and lymphoid tissue samples from acute, chronic, and ART-treated individuals. We observed minor differences in the frequency of nonintronic and nondistal intergenic sites, varying with tissue and residency phenotypes during ART. Genomic and epigenetic annotations were generally similar. Clonal expansion of cells marked by identical integration sites was detected, with increased detection in chronic and ART-treated individuals. However, overlap between or within CD4(+) T cell subsets or tissue compartments was only observed in 8 unique sites of the 3540 sites studied. Together, these findings suggest that shared integration sites between blood and tissue may, depending on the tissue site, be the exception rather than the rule and indicate that additional studies are necessary to fully understand the heterogeneity of tissue-sequestered HIV reservoirs.