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Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells., Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (OExo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for the stimulation of HepG2 cells in vitro. After 24 h of incubation, the protein levels of TNF-α, IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit., Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with the control group (P=0.039 and P<0.001 respectively), while significant differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found among the three groups in terms of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001)., Conclusion: These findings suggest that plasma circulating exosomes have probably antiinflammatory properties independent of body mass index and may decrease the secretion of inflammatory cytokines in the liver. However, further in vitro and in vivo investigations are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Obesity is associated with breast cancer aggressiveness and drug resistance. Although the underlying mechanisms are unknown, recent studies indicated that exosomes have a principal contributory role in obesity-associated metabolic complications. Hence, we investigated whether obesity can mediate breast cancer progression and resistance to tamoxifen by plasma-derived-exosomes from obese women or not. Plasma exosomes isolated from five normal-weight (N-Exo) and five obese women (O-Exo) were characterized for size, zeta potential, and CD63 expression. After the treatment of MCF-7 cells with N-Exo and O-Exo, cell proliferation, migration, invasion as well as levels of MMP-9 and MMP-2 were evaluated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, wound healing, transwell, and zymography methods, respectively. For evaluating resistance to tamoxifen, the cell viability, apoptosis, and the p53 protein were evaluated using the MTT assay, flow cytometry, and western blot methods, respectively. Cell proliferation, migration, and invasion were significantly increased in the cells treated with O-Exo than untreated cells (p = .001, p = .018, p = .034, respectively). Levels of MMP-2 and MMP-9 were remarkably increased in the cells treated with O-Exo in comparison with ones treated with N-Exo (p = .040, p = .043, respectively). As for resistance to tamoxifen, O-Exo had significantly the greater anti-apoptotic effects in comparison with the N-Exo group (p = .013). Besides, p53 levels were significantly decreased in the cells treated with O-Exo than ones treated with N-Exo (p = .045). The cell viability was significantly more in cells treated with O-Exo in comparison with the cells only treated with tamoxifen (p = .040). Our findings demonstrated that circulating exosomes derived from obese women could lead to tumorigenesis and tamoxifen resistance in breast cancer cells. However, more studies are needed to establish this notion., (© 2020 International Union of Biochemistry and Molecular Biology.)