Acute phase reaction and acute phase proteins

A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations.

Connective tissue growth factor reacts as an IL-6/STAT3-regulated hepatic negative acute phase protein

AIM:To investigate the mechanisms involved in a possible modulator role of interleukin(IL) -6 signalling on CYR61-CTGF-NOV(CCN) 2/connective tissue growth factor(CTGF) expression in hepatocytes(PC) and to look for a relation between serum concentrations of these two parameters in patients with acute inflammation. METHODS:Expression of CCN2/CTGF,p-STAT3,p-Smad 3/1 and p-Smad2 was examined in primary freshly isolated rat or cryo-preserved human PC exposed to various stimuli by Western blotting,electrophoretic mobility shift assay(EMSA) ,reporter-gene-assays and reversetranscriptase polymerase chain reaction. RESULTS:IL-6 strongly down-regulated CCN2/CTGF protein and mRNA expression in PC,enhanceable by extracellular presence of the soluble IL-6 receptor gp80,and supported by an inverse relation between IL-6 and CCN2/CTGF concentrations in patients'sera.The inhi-bition of TGFβ1 driven CCN2/CTGF expression by IL-6 did not involve a modulation of Smad2(and Smad1/3) signalling.However,the STAT3 SH2 domain binding peptide,a selective inhibitor of STAT3 DNA binding activity,counteracted the inhibitory effect of IL-6 on CCN2/CTGF expression much more pronounced than pyrrolidine-dithiocarbamate,an inhibitor primarily of STAT3 phosphorylation.An EMSA confirmed STAT3 binding to the proposed proximal STAT binding site in the CCN2/CTGF promoter. CONCLUSION:CCN2/CTGF is identified as a hepatocellular negative acute phase protein which is downregulated by IL-6 via the STAT3 pathway through interaction on the DNA binding level.