Regulation of the Expression of Adiponectin, Resistin and GLUT4 in Omental Adipose Tissue of Baboon
Year: 2003
Type: dissertation
Abstract: The purpose of this research was to identify the chromosomal regions influencing the \nmRNA expression of the hormones resistin and adiponectin, and the glucose transporter \n4 (GLUT4) in omental adipose tissue of baboons. These baboon genes were cloned \nusing a two-step reverse transcription- polymerase chain reaction (RT-PCR) technique. \nReal- time, quantitative RT-PCR assays were developed and standardized for \nmeasurement of mRNA levels of each gene. Total RNA was isolated from 460 samples \nof adipose tissue from adult pedigreed baboons, and used for the quantification of \nadiponectin, resistin and GLUT4 mRNA. Quantitative genetic analyses were conducted \nusing the mRNA abundance of each gene as a quantitative phenotype applying the \nvariance decomposition approach. Heritabilities were calculated for resistin (h2 \n = 0.23, p \n= 0.005), adiponectin (h2 = 0.23, p = 0.001) and GLUT4 (h2 = 0.24, p = 0.001). Genome \nscan analyses were conducted to locate the chromosomal regions influencing the \nexpression of the studied genes. The identified regions and corresponding LOD scores \nare: 19p13 (LOD score = 3.8) for resistin, 6q13 (LOD score =1.6) for adiponectin mRNA \nand same location (LOD score =1.0) for adiponectin protein, and 10q24-26 (LOD score = \n1.4) for GLUT4 mRNA. A parallel study in 120 baboons indicated a relationship between \nbody weight and indicators for insulin sensitivity, and an association between \nadiponectin levels and insulin resistance (HOMA-IR index) in baboons. No correlation \nbetween the analyzed phenotypes and resistin expression in monocytes was found. The \nrelationships between mRNA expression in adipose tissue of resistin, adiponectin and \nGLUT4 and circulating levels of selected cytokines (TNFa, IL-6 and IL-1b) and \nphenotypes associated to insulin resistance were investigated in a sub-sample of \nunrelated baboons (n=40). Resistin expression in adipose tissue was related to insulin \nsensitivity, adiponectin mRNA was inversely associated with cytokines in plasma, and \nGLUT4 abundance and the HOMA-IR index were correlated. Collectively, these results \nrevealed novel findings on the genetic component of the endocrine function of adipose \ntissue, and confirmed the value of the baboon as a model for the genetic study of \nobesity-related conditions.
Author: M. Elizabeth Tejero
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2127856879