Vaspin Human ELISA

Summary

Visceral adipose tissue – derived serpin A12 (vaspin), also named OL-64, an adipocytokine, is structurally a member of the serine protease family. Serpins are the most diverse family of protease inhibitors. Their typical structural feature is the core domain composed from 3 beta-sheets and 9 alpha-helixes. The inhibitory activity of vaspin has not been described up to now, but its reactive site loop is typical for this proteinase family. Human Vaspin protein is composed of 395 amino acids and has a molecular weight of approximately 45.2 kDa and predicted pI 9.26. The cDNA was first isolated from white adipose tissue of Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Vaspin mRNA expression is specific for visceral adipose tissues and it is also found circulating in the serum. The level of serum vaspin increased with age up to the peak of obesity, body weight and insulin resistance in OLETF rats and decreases with worsening of diabetes. Vaspin expression is missing in the diabetes-resistant lean rats, LETO, in comparison to OLEFT rats, animal model of metabolic syndrome. Expression was also absent in the subdermal, brown fatty tissue and other non-adipose tissues in OLEFT rats. These findings lead to the conclusion that the target tissue for insulin sensitising effect of vaspin is white adipose tissue. In humans, elevated serum concentration of vaspin is associated with obesity and impaired insulin sensitivity. In patients with type 2 diabetes the correlation between increased vaspin levels and BMI and decreased insulin sensitivity has not been observed. Vaspin expression decreased when diabetes worsened and its levels normalised when insulin or pioglitazone was administered. Gender differences in vaspin serum levels have been found in separate studies by two different authors. The low levels of vaspin in serum seem to be typical for lean subjects and athletes with long-term physical training. On the other hand, serum vaspin concentration increased in overweight people after they lost weight because of increased exercise. This paradox has been explained by the fact that serum vaspin level is differentially regulated in the non-active resting state and after exercise.

Features

• It is intended for research use only
• The total assay time is less than 3.5 hours
• The kit measures vaspin in serum and plasma (EDTA, heparin)
• Assay format is 96 wells
• Standard is recombinant protein based
• Quality Controls are human serum 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

Plasma-EDTA, Plasma-Heparin, Serum

Sample requirements

80 µl/well

Storage/Shipping

Store the complete kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Calibration Curve

Calibration range

0.031 to 2 ng/ml

Limit of detection

0.01 ng/ml

Cross-Reactivity

References to summary

• Bluher M, Stumvoll M, Fasshauer M, Oberbach A, Ruschke K, Song ES, Park JW, Lee N, Kratzsch J, Kloting N, Youn BS. Serum vaspin concentrations in human obesity and type 2 diabetes. Diabetes. 2008 Feb;57 (2):372-7
• Bluher M, Stumvoll M, Schon MR, Fasshauer M, Kovacs P, Kralisch S, Berndt J, Kloting N. Vaspin gene expression in human adipose tissue: association with obesity and type 2 diabetes. Biochem Biophys Res Commun. 2006 Jan 6;339 (1):430-6
• Kanwar YS, Makino H, Akagi S, Hiramatsu R, Matsuki Y, Watanabe E, Futami J, Hourai S, Shikata K, Nakatsuka A, Yasuhara A, Okada T, Hashimoto I, Seida A, Baba M, Zhang H, Eguchi J, Wada J, Hida K. Visceral adipose tissue-derived serine protease inhibitor: a unique insulin-sensitizing adipocytokine in obesity. Proc Natl Acad Sci U S A. 2005 Jul 26;102 (30):10610-5
• Lehnert H, Kennedy CR, Keay SD, Adya R, Farhatullah S, Chen J, Heutling D, Tan BK, Randeva HS. Metformin decreases the adipokine vaspin in overweight women with polycystic ovary syndrome concomitant with improvement in insulin sensitivity and a decrease in insulin resistance. Diabetes. 2008 Jun;57 (6):1501-7
• Stumvoll M, Bluher M, Kratzsch J, Lossner U, Bachmann A, Ziegelmeier M, Seeger J, Fasshauer M. Serum levels of the adipokine vaspin in relation to metabolic and renal parameters. J Clin Endocrinol Metab. 2008 Jan;93 (1):247-51
• Takahashi T, Kanda T, Sumino H, Yamakawa J, Moriya J, Chen R, Li Q. A novel adipocytokine, visceral adipose tissue-derived serine protease inhibitor (vaspin), and obesity. J Int Med Res. 2008 Jul-Aug;36 (4):625-9
• Wada J. Vaspin: a novel serpin with insulin-sensitizing effects. Expert Opin Investig Drugs. 2008 Mar;17 (3):327-33

By research topic:

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

By molecule:

• Vaspin

Registration form