Analysis of the percentages of monocyte subsets and ILC2s, their relationships with metabolic variables and response to hypocaloric restriction in obesity

PLoS One. 2020 Feb 19;15(2):e0228637. doi: 10.1371/journal.pone.0228637. eCollection 2020.

Abstract

Purpose: Obesity results from excess energy intake over expenditure and is characterized by chronic low-grade inflammation involving circulating monocytes (Mo) and group 2 innate lymphoid cells (ILC2s) imbalance. We analyzed circulating Mo subsets and ILC2s percentages and β2-adrenergic receptor (β2AR) expression in lean and obese subjects, and the possible effect of hypocaloric restriction on these innate immune cells.

Methods: In 139 individuals aged 45 to 57 years, classified in 74 lean individuals (>18.9kg/m2 BMI <24.9kg/m2) and 65 with obesity (n = 65), we collected fasting blood samples to detect Mo subsets, ILC2s number, and β2AR expression by flow cytometry. Lipids, insulin, leptin, and acylated-ghrelin concentrations were quantified. Resting energy expenditure (REE) was estimated by indirect calorimetry. These measurements were repeated in obese subjects after 7-weeks of hypocaloric restriction.

Results: Non-classical monocytes (NCM) and β2AR expression on intermediate Mo (IM) were increased in obese individuals (p<0.001, in both cases), whereas the percent of ILC2s was decreased (p<0.0001). Stepwise regression analysis showed significantly negative associations of ILC2s with caloric intake, β2AR expression on IM with REE, but a positive relationship between NCM and HOMA-IR. Caloric restriction allowed a significant diminution of NCM and the β2AR expression on IM, as well as, an increase in the percent of classical Mo (CM), and ILC2s. ΔREE was related to ΔCD16+/CD16- ratio.

Conclusions: These findings show that in obesity occur changes in NCM, ILC2s and β2AR expression, which contribute to the low-grade inflammation linked to obesity and might revert with caloric restriction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Caloric Restriction*
  • Female
  • Ghrelin / blood
  • Humans
  • Insulin / blood
  • Leptin / blood
  • Lipids / blood
  • Lymphocyte Subsets
  • Male
  • Middle Aged
  • Monocytes / cytology
  • Monocytes / metabolism*
  • Obesity / blood
  • Obesity / diet therapy*
  • Obesity / metabolism
  • Receptors, Adrenergic, beta-2 / metabolism

Substances

  • Ghrelin
  • Insulin
  • Leptin
  • Lipids
  • Receptors, Adrenergic, beta-2

Grant support

This work was supported by the grant CB2014-242065M from Consejo Nacional de Ciencia y Tecnología (CONACYT, México, to Juan M. Malacara). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.