Fibroblast Growth Factor-19 Human ELISA

Research topic

Energy metabolism and body weight regulation

Features

• It is intended for research use only
• The total assay time is less than 3.5 hours
• The kit measures FGF-19 in serum and plasma (EDTA, citrate, heparin)
• Assay format – 96 wells
• Standard and Quality Controls are recombinant protein based
• Components of the kit are provided ready to use, concentrated or lyophilized

Storage/Shipping

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

Summary

Fibroblast growth factors (FGFs) are a large family of small (17–26 kDa) polypeptide growth factors found in organisms ranging from nematodes to humans. The FGF family has at least 22 members in vertebrates and share 13–71% amino acid identity. The initial characterization of these proteins focused on their ability to stimulate fibroblast proliferation. During embryonic development, FGFs have diverse roles in regulating cell proliferation, migration and differentiation. In the adult organism, FGFs are homeostatic factors and function in tissue repair and response to injury. FGF signaling is mediated through one of four FGF receptors (FGFR1-FGFR4), a complex family of transmembrane receptor tyrosine kinases. FGFR5 has also been described, but lacks the kinase domain and signaling capability. FGFs have a high affinity for heparin sulfate proteoglycans and require heparin sulfate to activate FGF receptors. Although multiple FGFs interact with each of the four FGFRs, a novel fibroblast growth factor FGF-19 exhibits exclusive binding to only one of FGF receptors (FGFR4). The normal function of FGF-19 has not been resolved, although its role in inner ear development has been suggested. It has been also found that hepatocyte expression of FGF-19 is induced by the transcription factor, farnesoid X receptor (FXR). FXR is a key regulator of cholesterol metabolism through suppression of the catabolic enzyme cyp7a, the first and rate-limiting step in the biosynthesis of bile acids (BA). A recent study found that, in humans, circulating FGF-19 has a diurnal rhythm controlled by the transintestinal BA flux, and that FGF-19 modulates hepatic BA synthesis. Through its systemic effects, circulating FGF-19 may also mediate other known BA-dependent effects on lipid and carbohydrate metabolism. In transgenic mice expressing human FGF-19, researchers found a significant increased metabolic rate as well as decreased body weight and adiposity. Additionally, resistance to both diet-induced obesity and insulin desensitization were found. Similar responses have been observed when recombinant FGF-19 was injected into the mice. However, it has been shown too, that FGF-19 transgenic mice develop hepatic adrenocarcinomas with age, and recombinant FGF-19 treated mice exhibit proliferation of hepatocytes.

Areas of investigation: Cholesterol metabolism, Metabolic syndrome

Assay format

Sandwich ELISA, Biotin-labelled antibody

Sample requirements

50 µl/well

Applications

Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Calibration Curve

Calibration range

30 to 960 ng/ml

Limit of detection

Limit of detection (LOD) (defined as concentration of analyte giving absorbance higher than mean absorbance of blank plus three standard deviations of the absorbance of blank: Ablank + 3×SDblank) is calculated from the real human FGF-19 values in wells and is: 4.8 pg/ml.

Intra-assay (Within-Run, n=8)

CV = 6.0 %

Inter-assay (Run-to-Run, n=6)

CV = 7.5 %

Spiking Recovery

90.6 %

Dilution Linearity

96.3 %

Cross-Reactivity

horse, monkey, pig

Find out more on biovendor.com

• Fibroblast growth factor 19 in BioVendor News

References to this product

• Dostalova I, Kavalkova P, Haluzikova D, Lacinova Z, Mraz M, Papezova H, Haluzik M. Plasma concentrations of fibroblast growth factors 19 and 21 in patients with anorexia nervosa. J Clin Endocrinol Metab. 2008 Jun 17;

References to summary

• Shih DM, Kast-Woelbern HR, Wong J, Xia Y-R, Edwards PA and Lusis AJ: A role for FXR and human FGF-19 in the repression of paraoxonas1 gene expression by bile acids.Journal of Lipid Research 47, 384–392 (2006)
• Lundasen T, Galman C, Angelin B. and Rudling M: Circulating intestinal fibroblast growth factor 19 has a pronounced diurnal variation and modulates hepatic bile acid synthesis in man.Journal of Internal Medicine 260, 530–536 (2006)
• Kurose H, Okamoto M, Shimizu M, Bito T, Marcelle C, Noji S and Ohuchi H: FGF-19-FGFR4 signaling elaborates lends induction with the FGF8-L-Maf cascade in the chick embryo.Develop. Growth Differ. 47, 213–223 (2005)
• Fu L, John LM, Adams SH, Yu XX, Tomlinson E, Renz M, Williams PM, Soriano R, Corpuz R, Moffat B, Vandlen R, Simmons L, Foster J, Stephan JP, Tsai SP, Stewart TA: Fibroblast growth factor 19 increases metabolic rate and reverses dietary and leptin-deficient diabetes.Endo­crinology 145, 2594–2603 (2004)
• Strack AM and Myers RW: Modulation of metabolic syndrome by fibroblast growth factor 19 (FGF-19)? Endocrinology 145, 2591–2593 (2004), Review
• Holt JA, Luo G, Billin AN, Bisi J, McNeill YY, Kozarsky KF, Donahee M, Wang DY, Mansfield TA, Kliewer SA, Goodwin B and Jones SA: Definition of a novel growth factor-dependent signal cascade for the suppression of bile acid biosynthesis.Genes and Development 17, 1581–1591 (2003)
• Tomlinson E, Fu L, John L, Hultgren B, Huang X, Renz M, Stephan JP, Tsai SP, Powell-Braxton L, French D and Stewart TA: Transgenic mice expressing human fibroblast grwth factor-19 display increased metabolic rate and decreased adiposity.Endo­crinology 143, 1741–1747 (2002)
• Ornitz DM and Itoh N: Fibroblast growth factors.Genome Biology 2(3), 3005.1–3005.12 (2001), Review