Influence of pathogenic bacteria species present in the postpartum bovine uterus on proteome profiles

In the first 2–3 weeks after parturition >90% of dairy cows will have some form of uterine infection. Uterine contamination with pathogens, such as Trueperella (formerly Arcanobacterium) pyogenes increases the risk of developing more severe endometritis, which can reduce conception rates. In this study, we compared the uterine proteome of cows infected with Trueperella pyogenes with that of uninfected cows, using 2D gel electrophoresis, and identified annexins A1 and A2 (ANXA1 and ANXA2), apolipoprotein A-1, calprotectin (S100A9), cathelicidin, enolase 1 (ENO1), peptidoglycan recognition protein 1 (PGLYRP1), phosphoglycerate mutase 1 (PGAM1), serine dehydratase (SDS) and serine protease inhibitors (SERPIN) B1, B3 and B4 proteins as differing in abundance in endometritis. Subsequently, levels of ten of these proteins were monitored in uterine samples collected from a herd of lactating, dairy cows at 15 and 42 days post-partum (DPP). The levels were compared with the cytology scores of the samples and the bacterial species isolated from the uterus. Cathelicidin, PGLYRP1, SERPINB1 and S100A9 levels at 15DPP showed strong positive correlations (r = 0.78, 0.80, 0.79, and 0.68 respectively; P < 0.001) with % of polymorphonuclear neutrophils (PMN). When compared with other bacterial pathogens identified, Streptococcus agalactiae and Truperella pyogenes induced increased expression of the indicator proteins, suggesting that these organisms may adversely affect the subsequent ability of the cow to conceive. Interestingly, there was no difference in the proportion of cows pregnant at 6 and 17 weeks after start of mating between the cows with high or low %PMN.

Serpin B1 protects colonic epithelial cell via blockage of neutrophil elastase activity and its expression is enhanced in patients with ulcerative colitis

Serpin B1 is a monocyte neutrophil elastase (NE) inhibitor and is one of the most efficient inhibitors of NE. In the present study, we investigated the role of serpin B1 in the pathogenesis of ulcerative colitis by using clinical samples and an experimental model. The colonic expression of serpin B1 was determined by real-time polymerase chain reaction (PCR), Western blot analysis, and immunohistological studies in both normal and inflamed mucosa from patients with ulcerative colitis. Serpin B1 mRNA expression was determined by real-time PCR in the mouse dextran sodium sulfate (DSS)-induced colitis model. Young adult mouse colonic epithelial (YAMC) cells were used to determine the role of serpin B1. Serpin B1 gene transfected YAMC cells were treated with H2O2 to measure cell viability. The expression of NE was determined in YAMC cells treated with H2O2. NE-silenced YAMC cells were also treated with H2O2 and then measured for viability. Upregulated expression of serpin B1 in colonic mucosa was confirmed from patients with active ulcerative colitis. Immunohistochemical studies showed that serpin B1 expression was localized not only in inflammatory infiltration cells but also in epithelial cells. Serpin B1 mRNA expression was also increased in colonic mucosa of mouse DSS-induced colitis. Serpin B1-transfected YAMC cells were resistant against the treatment of H2O2. H2O2 treatment significantly induced NE in YAMC cells, and NE-silenced YAMC cells were also resistant against the treatment of H2O2. These results suggest that serpin B1 may be a novel marker of active ulcerative colitis and may play an important role in the pathogenesis of inflammatory bowel disease.

Characterization of proteins associating with 5’ terminus of PGHS-1 mRNA

Induction of Prostaglandin Endoperoxide H Synthase-1 (PGHS-1) gene has been previously documented in a few studies during events such as development and cellular differentiation. However, molecular mechanisms governing the regulation of PGHS-1 gene expression and contributing to changes in protein levels are poorly understood. Using the MEG-01 cell model of PGHS-1 gene induction, our laboratory has previously demonstrated that the 5’UTR and the first two exons of PGHS-1 mRNA had a significant impact on decreasing the translational efficiency of a reporter gene and suggested that the presence of a secondary structure is required for conservation of this activity. This 5’end of PGHS-1 mRNA sequence has also been shown to associate with nucleolin protein. In the current study, we set to investigate the protein composition of the mRNP (messenger ribonucleoprotein) associating with the 5’end of PGHS-1 mRNA and to identify its protein members. RNA/protein binding assays coupled with LC-MS analysis identified serpin B1 and NF45 (nuclear factor 45) proteins as potential members of PGHS-1 mRNP complex. Immunoprecipitation experiments using MEG-01 protein extracts validated mass spectrometry data and confirmed binding of nucleolin, serpin B1, NF45 and NF90. The RNA fraction was extracted from immunoprecipitated mRNP complexes and association of RNA binding proteins, serpin B1, NF45 and NF90, to PGHS-1 mRNA target sequence was confirmed by RT-PCR. Together these data suggest that serpin B1, NF45 and NF90 associate with PGHS-1 mRNA and can potentially participate in the formation a single or a number of PGHS-1 ribonucleoprotein complexes, through nucleolin that possibly serves as a docking base for other protein complex members.