Omentin-1 Human ELISA

Summary

Omentin (intelectin-1, intestinal lactoferin receptor, endothelian lectin HL-1, galactofurano­sebinding lectin) is newly identified secretory protein that is highly and selectively expressed in visceral adipose tissue relative to subcutaneous adipose tissue (adipokine). The mature omentin is secretory glycoprotein consisting of 295 amino acids and 1-linked oligosacharides, and its basic structural unit is a 120-kDa homotrimer in which 40-kDa polipeptides are bridged by disulfide bonds. Omentin has been identified in other tissue at lower expression levels such are Paneth cells, endothelial cells, and visceral adipose stromal-vascular cells. A homolog of omentin has been identified that shares 83% amino acid identity with omentin and was referred to as omentin 2. The two omentin genes, omentin 1 and omentin 2, are localized adjacent to each other in chromosomal region, which has been previously linked to type 2 diabetes in several populations. To determine the impact of obesity-dependent insulin resistance on the regulation of two omentin isoforms, gene expression and plasma levels were measured in lean, overweight, and obese subjects. Omentin-1 was shown to be the major circulating isoform in human plasma. Lean subjects had significantly higher omentin-1 plasma levels than obese and overweight subjects. In addition, higher plasma omentin-1 levels were detected in women compared with men. Plasma omentin-1 levels were inversely correlated with BMI, waist circumference, leptin levels, and insulin resistance as measured by homeostasis model assessment and positively correlated with adiponectin and HDL levels. In summary, decreased omentin-1 levels are associated with increasing obesity and insulin resistance. An independent experiment reported that the addition of recombinant omentin-1 in vitro did not affect basal glucose uptake but did enhance insulin-stimulated glucose uptake in both subcutaneous and omental human adipocytes. Omentin-1 increased Akt phosphorylation in the absence and presence of insulin and may regulate insulin action. A recent study of women with the polycystic ovary syndrome (PCOS) found significantly reduced omentin-1 mRNA expression and protein levels in adipose tissue in overweight PCOS women. In addition, significantly lower plasma omentin-1 levels were detected in these women.

Features

• It is intended for research use only.
• The total assay time is less than 3.5 hours.
• The kit measures omentin-1 in serum and plasma (EDTA, citrate, heparin).
• Assay format is 96 wells.
• Quality Controls are human serum based. No animal sera are used.
• Standard is recombinant protein based.
• Components of the kit are provided ready to use, concentrated or lyophilized.

Research topic

Diabetology - Autoimmunity, Energy metabolism and body weight regulation, Reproduction

Assay format

Sandwich ELISA, Biotin-labelled antibody

Applications

Serum

Sample requirements

6 ul

Calibration Curve

Calibration range

2 to 64 ng/ml

Limit of detection

0.5 ng/ml

Cross-Reactivity

Goat, Monkey, Pig, Sheep

References to summary

• Buchler C, Scholmerich J, Furst A, Neumeier M, Herfarth H, Schaffler A. Genomic structure of human omentin, a new adipocytokine expressed in omental adipose tissue. Biochim Biophys Acta. 2005 Dec 30;1732 (1-3):96-102
• Gong DW, McLenithan JC, Lee MJ, Fried SK, Shuldiner AR, Hansen BC, Hu H, Wu HB, Pray J, Yang RZ. Identification of omentin as a novel depot-specific adipokine in human adipose tissue: possible role in modulating insulin action. Am J Physiol Endocrinol Metab. 2006 Jun;290 (6):E1253-61
• McLenithan JC, Pollin TI, Shuldiner AR, Gong DW, Fried SK, Kligman M, Schwartz A, Patil S, Ndubuizu K, Pray J, Yu DZ, Glynn NM, Lee MJ, Yang RZ, de Souza Batista CM. Omentin plasma levels and gene expression are decreased in obesity. Diabetes. 2007 Jun;56 (6):1655-61
• Tan BK, Adya R, Farhatullah S, Lewandowski KC, O'Hare P, Lehnert H, Randeva HS. Omentin-1, a novel adipokine, is decreased in overweight insulin-resistant women with polycystic ovary syndrome: ex vivo and in vivo regulation of omentin-1 by insulin and glucose. Diabetes. 2008 Apr;57 (4):801-8
• Buechler C, Schaffler A, Weigert J, Neumeier M, Wurm S. Plasma levels of leptin, omentin, collagenous repeat-containing sequence of 26-kDa protein (CORS-26) and adiponectin before and after oral glucose uptake in slim adults. Cardiovasc Diabetol. 2007;6:7

By research topic:

• Diabetology - Autoimmunity
• Energy metabolism and body weight regulation
• Reproduction

By molecule:

• Omentin-1

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