[The influence of obesity on the gene expression of adiponectin and its receptor in subcutaneous adipose tissue]

III. interní klinika 1. lékarské fakulty UK a VFN Praha.
Vnitr̆ní lékar̆ství 11/2007; 53(11):1190-7.
Source: PubMed


The objective of the study was to measure the concentration of adiponectin in plasma, its mRNA expression and the expression of the adiponectin receptors AdipoR1 and AdipoR2 in subcutaneous adpipose tissue (ST) of women with various levels of fat in their organism. A further objective of the study was to determine to what extent the stated parameters correlate with obesity as defined by BMI (body mass index) and how it can be affected by a very low calorie diet (VLCD).
The sample of 70 women was divided into groups by BMI: patients with class 3 obesity (BMI > 40 kg.m(-2), n = 25), patients with class 1 and 2 obesity (BMI 30-40 kg.m(-2), n = 15), overweight patients (BMI 25-30 kg.m(-2), n = 10) and a normal healthy control group (BMI 20-25 kg.m(-2), n = 20). In the case of 14 women with class 3 obesity, the parameters were measured before and after a three-week diet with an energy content of 2200 kJ (550 kcal)/day (VLCD).
Plasma concentrations of adiponectin were measured using an ELISA kit (LINCO Research, USA). Subcutaneous adipose tissue was taken using biopsy. RNA was isolated using a MagNA Pure Compact RNA Isolation Kit (Tissue) (Roche, SRN). The gene expression of adiponectin, AdipoR1 and AdipoR2 was determined using the real-time PCR (RT-PCR) method on a ABI Real-Time PCR 7500 instrument (Applied Biosystems, USA) with TaqMan Gene Expression Assays hydrolisation probes. beta-2-mikroglobulin (beta2M) was used as an endogenous control, to which the data was normalised.
The circulatory concentration of adiponectin, its mRNA expression and the mRNA expression of AdipoR1 in ST correlate negatively with BMI (r = -0.524, p < 0.001; r = -0.460, p < 0 001; p = -0.354, p = 0.004). The expression of AdipoR2 in ST did not correlate with BMI. The VLCD reduced weight by 9% but did not affect the plasma concentration of adiponectin or the rate of its expression, or the expression of AdipoR1 and AdipoR2.
Our results show that not only the circulatory concentration of adiponectin but also its mRNA expression and the expression of AdipoR1 in ST are significantly lower in obese women compared to a control group and may contribute to the development of metabolic complications in obesity.

4 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Obesity is a multisystem disorder associated with cardiovascular and metabolic complications. According to recent studies, it is characterized as a condition of low-grade inflammation with altered adipose tissue function and secretion of various adipokines. One of the strategies in obesity treatment is dietary intervention (DI) that could modulate cytokine levels in a favourable way. The aim of this review was to summarize the results of studies performed in the last 13 years investigating DI programmes accompanied with weight loss in relation to profile of adipokines at different level (adipose tissue mRNA, adipose tissue secretion and circulating level) and identify whether modulations of adipokines are implicated in the positive effects of DIs. The overall finding is that DIs leading to 5-10% weight loss modulate production of certain adipokines and generally induce improvement of clinical parameters, e.g. insulin sensitivity, but the amelioration of obesity complications is not coherent with the pattern of adipokine regulation, except maybe for leptin. Global analysis of the adipose tissue secretome and measurement of panels of adipokines may prove more informative than studies on individual molecules.
    No preview · Article · Jun 2010 · Obesity Reviews
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Adipokines play key roles in the regulation of bone growth, obesity, diabetes mellitus type 2, and HIV infection. As a newly discovered hormone in the adipokine family, the precise role of apelin on articular cartilage metabolism is not yet clear. The aim of this study was to evaluate the role of apelin on articular cartilage. In vitro, we examined the effects of apelin on normal chondrocyte proliferation and gene expression of metalloproteinases (MMPs) and interleukin-1beta (IL-1beta). In vivo, by intra-articular injection with apelin, we examined MMP-3, -9, collagen II and IL-1beta at both gene and protein levels. Furthermore, we measured the messenger RNA (mRNA) expression of ADAMTS-4 and -5 (a disintegrin and metalloproteinase with thrombospondin motifs 4 and 5) and the proteoglycan content in articular cartilage. Apelin stimulated the proliferation of chondrocytes and significantly increased mRNA levels of MMP-1, -3, -9 and IL-1beta in vitro. Intra-articular injection with apelin in vivo up-regulated the expression of MMP-3, -9, and IL-1beta as well as decreased the level of collagen II. Additionally, after treatment with apelin, mRNA levels of ADAMTS-4 and -5 markedly increased and depletion of proteoglycan in articular cartilage was found by histological assessment. These findings suggest that apelin plays a catabolic role in cartilage metabolism and is a risk factor in the pathophysiology of osteoarthritis.
    Preview · Article · Sep 2010 · International Journal of Molecular Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Adipose tissue had been traditionally considered a passive energy storage site without direct influence on energy homeostasis regulation. This view has been principally changed during early nineties by the discovery of hormonal production of adipose tissue. At present, the list of hormonally active substances of adipose tissue includes more than one hundred factors with paracrine or endocrine activity that play an important role in metabolic, food intake a inflammatory regulations and many other processes. Only minority of adipose tissue-derived hormones is produced exclusively in fat. Most of these factors is primarily put out by other tissues and organs. Adipose tissue-derived hormones are produced not only by adipocytes but also by preadipocytes, immunocompetent and endothelial cells and other cell types residing in fat. This paper summarizes current knowledge about endocrine function of adipose tissue with special respect to its changes in obesity. It also describes its possible role in the ethiopathogenesis of insulin resistance, atherosclerosis and other obesity-related pathologies.
    No preview · Article · Oct 2010 · Vnitr̆ní lékar̆ství