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Organic Chemicals
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
Careful study of diet-induced obesity has identified chronic leukocyte-mediated low-grade inflammation within professional metabolic tissues as the characteristic pathophysiology of metabolic syndrome.423,427 This focus on obesity, however, has limited our understanding of leukocyte activation to the role in promoting metabolic disease. Nonetheless, leukocytes are normally present in metabolic tissues, where they perform nonredundant, supportive functions.438 In lean WAT, for example, eosinophil-derived IL-4 drives the production of IL-10 and other mediators by macrophages. This phenotype is critical for the maintenance of both adipocyte insulin sensitivity (IL-10 directly potentiates insulin signaling in adipocytes428) and the general anti-inflammatory timbre of the WAT microenvironment (both directly and through support of adipose tissue resident Treg cells).427 Congruent with these observations, disruption of IL-4 production or signaling in adipose tissue macrophages results in adipocyte dysfunction, insulin resistance, and metabolic disease.429,435,439–441 In contrast, augmentation of IL-4 signaling blunts the deleterious effects of high-fat-diet challenge.435,467
The effects of ambient particulate matter on human adipose tissue
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Lior Hassan, Tal Pecht, Nir Goldstein, Yulia Haim, Itai Kloog, Shaked Yarza, Batia Sarov, Victor Novack
Paired approximately 5 g samples of OM and SC adipose were obtained from study participants during abdominal surgery. All biopsies were extracted from surgical incisions performed during the planned surgery, and no additional incisions were made beyond the standard clinical care. All samples were immediately delivered to the lab. Adipose samples were processed and analyzed for various cellular, histological, and expression markers. Overall, 25 cellular markers were measured in the OM and SC adipose tissue (Table 1). The expression levels of molecules involved in stress responses included the inflammatory (NFkB), insulin, mitogen-activated protein kinase (MAPK) signaling; as well as activation of the autophagy pathway, cell cycle regulators, immune cells, adipocyte size chemokines, and growth factors as determined by western-blot (protein) and real-time PCR (mRNA) analyses. Adipose tissue samples used for biomarker measurements were frozen immediately after surgery, except for the tissues that were used to measure the autophagy protein levels which were handled as previously described (Kovsan et al. 2011), and the autophagy mRNA measurements which required the freezing of the adipose tissue samples in liquid nitrogen. Processing of adipose tissue samples and flow-cytometry analyses for cellular analysis and identification of adipose tissue macrophages were performed as previously described (Shapiro et al. 2013). The number of immune cells in adipose tissue and size of adipocytes were determined after appropriate histological staining on formaldehyde fixed biopsies. Immune cells were identified by a certified pathologist from the Pathology Unit in SUMC. The size of the adipocytes was determined using Fiji image processing software (see Appendix 1 for detailed lab methods).