Original article
Increased levels of chemerin and its receptor, chemokine-like receptor-1, in obesity are related to inflammation: tumor necrosis factor-α stimulates mRNA levels of chemerin in visceral adipocytes from obese patients

https://doi.org/10.1016/j.soard.2011.11.001Get rights and content

Abstract

Background

Chemerin is a novel adipokine that regulates adipocyte development and metabolic function and glucose metabolism. Our aim was to determine the effect of chemerin and its receptor, chemokine-like receptor-1, in obesity-associated low-grade chronic inflammation, exploring its circulating and gene expression levels in obesity and the effect of weight loss and to analyze the effect of the stimulation with tumor necrosis factor-α in human visceral adipocytes at a University hospital.

Methods

We included 52 women (16 lean and 36 obese) in the present study. The plasma concentrations of chemerin and the expression levels of chemerin and its receptor in visceral adipose tissue were analyzed. The chemerin concentrations were also measured before and after weight loss achieved by Roux-en-Y gastric bypass (n = 26).

Results

The circulating concentrations and visceral adipose tissue expression of chemerin were increased in obese patients (P < .01) and were associated with well-established markers of inflammation (P < .001). Gene expression levels of chemokine-like receptor-1 followed the same trend and were upregulated (P < .05) in human obesity. Elevated chemerin levels in obese patients did not change after Roux-en-Y gastric bypass weight loss. Tumor necrosis factor-α treatment significantly enhanced (P < .05) the mRNA levels of chemerin in human visceral adipocytes, but the gene expression levels of chemokine-like receptor-1 were not affected.

Conclusion

The increased levels of chemerin in obesity and its positive association with inflammation suggest a role for this chemoattractant protein in the changes that take place in visceral adipose tissue in the presence of energy surplus, establishing a link between inflammation and the greater risk of the development of metabolic disease.

Section snippets

Methods

For a detailed description of the research design and methods of the present study, see the Supplemental Methods section.

Circulating levels of chemerin are increased in human obesity: effect of weight loss

The biochemical and hormonal characteristics of the subjects included in the present study are listed in Table 1. The obese patients had a significantly greater (P < .001) BMI, BF, waist circumference, and WHR compared with the lean volunteers. The obese patients exhibited lower insulin sensitivity than the lean participants as evidenced by the higher homeostatic model of assessment (P = .002) and lower quantitative insulin sensitivity check index (P < .001). Circulating concentrations of

Discussion

Despite the growing understanding of adipose biology, the precise role of the players involved in energy homeostasis and the regulation of obesity-related co-morbidities still needs to be disentangled [21]. Compelling evidence points to the fact that excess VAT accumulation dysregulates the adipokine secretion profile. Chemerin is an adipokine reportedly involved in a large number of cellular functions, such as the immune and inflammatory responses, adipocyte metabolism, or energy homeostasis.

Conclusion

The increased levels of chemerin in human obesity might represent a link between obesity-associated changes in adipose tissue and a greater risk of metabolic diseases. Furthermore, chemerin displaying a role as a chemoattractant protein, together with its receptor CMKLR1, might influence the cross-talk between adipocytes and macrophages pivotal for controlling the initiation and progression of inflammation in the obese state or in situations in which the adequate threshold between the fat mass

Disclosures

The authors have no commercial associations that might be a conflict of interest in relation to this article.

Acknowledgment

We gratefully acknowledge the valuable collaboration of all the members of the Multidisciplinary Obesity Team, Clínica Universidad de Navarra, Pamplona, Spain. CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN) is an initiative of the Instituto de Salud Carlos III, Spain.

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  • Cited by (0)

    Supported by FIS PI09/02330 from the Spanish Instituto de Salud Carlos III, by the Department of Health (20/2005 and 3/2006) of the Gobierno de Navarra of Spain and by PIUNA (2009–2011) of the University of Navarra.

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