Inhibition by deacetylase inhibitors of IL-1-dependent induction of haptoglobin involves CCAAT/Enhancer-binding protein isoforms in intestinal epithelial cells.

Intestinal epithelial cells participate in an acute phase response (APR) by responding to cytokines and by expressing acute phase protein genes. We hypothesized that butyrate, a fermentation product of the bacterial intestinal flora with deacetylase activity, affects the APR in intestinal epithelial cells. Sodium butyrate (NaBu) and Trichostatin A (TSA) induced alkaline phosphatase activity and histone H4 acetylation in IEC-6 rat intestinal epithelial cells treated with or without interleukin-1beta (IL-1). In contrast, both NaBu and TSA attenuated the IL-1-dependent induction of the acute phase protein gene haptoglobin, as well as C/EBPbeta and C/EBPdelta transcription factors mRNAs. Gel shift and supershift assays showed a strong decrease in the IL-1-induced C/EBPbeta and C/EBPdelta containing complexes binding to the HaptoA C/EBP DNA-binding site of the haptoglobin promoter, by NaBu and TSA. Furthermore, site-specific mutation of the HaptoA site abolished the NaBu- and TSA-dependent inhibition of haptoglobin, as determined by transient transfection assays. These results suggest that deacetylase inhibitors may regulate the IL-1 dependent induction of haptoglobin by down-regulating C/EBP isoforms, and that C/EBPs represent a target for the action of butyrate in the control of the APR of intestinal epithelial cells.

Attenuation of haptoglobin gene expression by TGFbeta requires the MAP kinase pathway.

In addition to important roles in the regulation of cell growth and cell restitution, both pro- and anti-inflammatory effects have been ascribed to TGFbeta in intestinal epithelial cells. However, the mechanisms involved in TGFbeta-dependent anti-inflammatory activities remain to be determined. In the rat intestinal epithelial cell line IEC-6, TGFbeta attenuated the glucocorticoid-dependent increases in mRNA levels of the acute phase protein gene haptoglobin, and of C/EBP isoforms beta and delta. Supershift assays demonstrated a TGFbeta-mediated decrease in the binding of C/EBP isoforms beta and delta to the haptoA and haptoC C/EBP DNA-binding sites from the haptoglobin promoter. Mutations of both HaptoA and HaptoC sites abolished the glucocorticoid-dependent activation and the TGFbeta-mediated attenuation of the haptoglobin promoter, as assessed by transient transfection assays. TGFbeta induced p42/p44 MAP kinase activities. Treatment with the MEK 1/2 inhibitor PD 98059 abolished TGFbeta attenuation. These results suggest that C/EBP isoforms are involved both in the glucocorticoid-dependent induction and in the TGFbeta-mediated attenuation of haptoglobin expression. Furthermore, p42/p44 MAP kinases may function in a TGFbeta-dependent signaling pathway leading to attenuation of haptoglobin expression.

Outbreak of Salmonella give in the province of Quebec.

Salmonellosis due to Salmonella Give involving cows, a goat, and an ostrich over a 6-month period was investigated. Cases were found in 4 different regions. Antimicrobial susceptibility patterns, phagetyping, and pulsed-field gel electrophoresis analyses confirmed that all isolates belonged to the same clone. A common source of infection was suspected.

Aspects épizootiologiques des affections respiratoires porcines qui sévirent au Québec, de septembre 1980 à février 1981.

EPIZOOTIOLOGICAL ASPECTS OF PORCINE RESPIRATORY DISEASES WHICH WERE ENCOUNTERED IN QUEBEC FROM SEPTEMBER 1980 UNTIL FEBRUARY 1981: In the spring of 1981, a questionnaire was mailed to pig farmers of Quebec, in order to determine the epizootiological factors susceptible to account for the deaths which had occurred during the period extending from September 1980 until February 1981. The mortality rate was estimated at 4.5% for that period. It proved to be higher on the farms where hogs were fattened only (5.9%), compared to those where they were raised and fattened (3.4%) and for those where the hogs were owned (6.8%) compared to those where they were fattened by contract (4.3%). During that six month period, severe mortality problems (>/= 4%) were experienced by approximately 32% of the hog producers in Quebec, mainly by those who were fattening hogs. The mortality rate was found to be proportional to the size of the herds; it proved to be definitely higher when the pigs had been bought at auction sales or from livestock dealers and even higher when the pigs had been simultaneously obtained from both sources. The results of this investigation and the importance of some epizootiological factors are discussed. The economical loss for the Province was estimated at $15 120 000 for the 126 000 pigs which died during that six month period.

Serological survey of leptospiral antibodies in swine in Quebec.

The prevalence of reactors to different serovars of Leptospira interrogans was determined in 117 swine premises in Quebec. A total of 926 sera were tested, using the microscopic agglutination method, against six leptospiral serovars: pomona, icterohaemorrhagiae, grippotyphosa, hardjo, canicola and ballum. Of the sera tested, 30 (3.2%) reacted to one of the three following serovars: pomona (2%), icterohaemorrhagiae (1.1%) and ballum (0.1%).