Alterations in MHC‐II expression in gonadal adipose tissue CD14+ cells related to prolonged commercial sweetener intake

Abstract

Obesity is currently a major public health issue. In order to reduce its incidence, non‐nutritive sweeteners have been widely implemented by the food and beverages industries; therefore, these products are frequently consumed by humans. However, it has long been debated whether or not these compounds actually contribute to development of obesity or help to promote low grade, constant inflammation seen in the adipose tissue of obese people.Activated macrophages are one of the main cell populations found in obese adipose tissue, where they contribute to the pro‐inflammatory phenotype by secreting pro‐inflammatory cytokines and presenting antigens, events that will lead to insulin resistance if left untreated.To elucidate the possible relationship between sweetener consumption and macrophage‐dependent inflammation in vivo, the present study quantified leukocyte recruitment and changes in MHC‐II expression on CD14+ cells isolated from gonadal adipose tissue from mice supplemented with commercial non‐nutritive sweeteners (sucralose or steviol glucosides). 8‐ week‐old BALB/c mice, male and female (6 animals per group/sex), were supplemented with commercial sweeteners in their drinking water for 6 weeks. A control group without supplementation was also included. Gonadal adipose tissue was subsequently obtained to isolate leukocytes and identify the frequencies of CD45+ and CD14+ cells expressing MHC‐II by flow cytometry.Our results show a significantly increased frequency of CD45+ cells in female animals supplemented with both sucralose (66.1 ± 3.4%) and steviol glycosides (63.8 ± 5.0%), compared to controls (41.5 ± 1.5%). In contrast, an increased leukocyte frequency was observed only in the steviol glycosides group in males (67.1 ± 3.4% vs. 47.3 ± 5.0%). For the CD14+marker, our data indicate once more a significantly higher frequency of CD14+ cells in females from both the sucralose and steviol glycosides groups (22.2 ± 3.3% and 20.1 ± 4.2% respectively), compared to controls (6.8 ± 1.6%). No differences were found among male groups. Regarding MHC‐II expression, our results show no differences in the frequency of MHC‐II+ cells among groups in either female or male mice. Nevertheless, mean fluorescence intensity (MFI) analyses demonstrate a significant increase in MHC‐II expression in CD14+ cells from females in both the sucralose and steviol glycosides groups (826,477.6 ± 197,543 and 1,200,615.7 ± 246,660, arbitrary units), compared to controls (458,036.2 ± 191,989), with the same effect being observed in male groups (1,018,015 ± 156,297.5 and 1,126,581 ± 183,204.7, respectively, vs. 537,065.5 ± 29,445.5).Our results suggest that chronic consumption of non‐caloric sweeteners may have an effect on leukocyte recruitment to the adipose tissue and in the expression of MHC‐II by macrophages, particularly in female animals, which may have important implications for the role of these cells in the modulation of adipose tissue homeostasis.Support or Funding InformationConsejo Mexiquense de Ciencia y TecnologíaThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.