Decorin is a secreted protein associated with obesity and type 2 diabetes

• Published in: International Journal of Obesity Vol. 32; no. 7; pp. 1113 - 1121
• Main Authors: Bolton, K, Segal, D, McMillan, J, Jowett, J, Heilbronn, L, Abberton, K, Zimmet, P, Chisholm, D, Collier, G, Walder, K
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2008; Nature Publishing; Nature Publishing Group
• Subjects: Abdominal Fat; Abdominal Fat - metabolism; Adipose tissue; Adipose Tissue - metabolism; Adult; Aged; analysis; animal models; animal proteins; Animals; Biological and medical sciences; blood; blood chemistry; Body fat; Decorin; Diabetes; Diabetes Mellitus, Type 2; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - metabolism; Diabetes. Impaired glucose tolerance; Diagnosis; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Epidemiology; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Extracellular Matrix Proteins; Extracellular Matrix Proteins - analysis; Extracellular Matrix Proteins - blood; Extracellular Matrix Proteins - genetics; fasting; Female; Gene Expression; genetics; Gerbillinae; Glucose; Glucose Intolerance; glucose tolerance; Glycoproteins; Health Promotion and Disease Prevention; Homeostasis; Human subjects; Humans; Immunohistochemistry; Insulin; Insulin resistance; Internal Medicine; Liver; Male; Mauritius; Medical research; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Metabolic syndrome; metabolism; methods; Middle Aged; Models, Animal; Musculoskeletal system; noninsulin-dependent diabetes mellitus; Obesity; Obesity - metabolism; original-article; Overweight; Pathophysiology; Physiological aspects; Plasma; polymerase chain reaction; Properties; protein secretion; protein synthesis; Proteins; Proteoglycans; Proteoglycans - analysis; Proteoglycans - blood; Proteoglycans - genetics; Psammomys obesus; Public Health; Regression Analysis; Reverse Transcriptase Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction - methods; Risk factors; RNA, Messenger; RNA, Messenger - metabolism; subcutaneous fat; Subcutaneous Fat - metabolism; tissue culture; Tissue Distribution; Type 2 diabetes; visceral fat; Waist-Hip Ratio; waist-to-hip ratio; Mauritius; Australia; United States > US; Victoria Australia; adipose tissue; decorin; Endocrinopathy; Type 2 diabetes; Human; Proteoglycan; Obesity; Decorin; Adipose tissue; Nutrition; Nutrition disorder; Metabolic diseases; Association; Secretory protein; Psammomys obesus; Nutritional status
• ISSN: 0307-0565; 1476-5497; 1476-5497
• DOI: 10.1038/ijo.2008.41

Objective: To characterize the expression of the small leucine-rich glycoprotein decorin in adipose tissue. Design: Real-time PCR was used to measure decorin gene expression in adipose tissue from normal glucose tolerant (NGT), impaired glucose tolerant and type 2 diabetic (T2D) Psammomys obesus. Adipose tissue was fractionated to determine which cells were responsible for decorin expression. The location of decorin protein expression in adipose tissue was determined using immunohistochemistry. Real-time PCR was used to measure decorin mRNA levels in human adipose tissue from 16 insulin-sensitive, 16 insulin-resistant and 6 T2D human subjects. Circulating plasma decorin concentrations were measured by enzyme-linked immunosorbent assay in 145 NGT and 141 T2D human individuals from a large-scale epidemiological study in Mauritius. Results: Decorin mRNA was found to be highly expressed in adipose tissue, and decorin gene expression was significantly higher in visceral than that in subcutaneous adipose tissue depots in both P. obesus and human subjects (P=0.002 and P=0.001, respectively). Decorin mRNA was predominantly expressed by stromal/vascular cells of adipose tissue, and decorin protein in adipose tissue was primarily detected adjacent to blood vessels. Circulating plasma decorin levels in humans were elevated by 12% in T2D (P=0.049) compared to NGT subjects. There was a significant independent correlation between plasma decorin levels and waist-to-hip ratio (WHR, P=0.024). In male subjects, plasma decorin levels were significantly correlated with WHR (P=0.006), and fasting and 2-h glucose levels in an oral glucose tolerance test (P=0.027 and P=0.001, respectively). Conclusions: Decorin expression in adipose tissue was markedly upregulated in the obese state and may therefore play a role in adipose tissue homeostasis or in pathophysiology associated with obesity.