Variation in the expression of Hsp27, αB-crystallin mRNA and protein in heart and liver of pigs exposed to different transport times

Meat quality traits and the expression of tenderness-related genes in the loins of young goats at different ages

Goat meat is considered healthy because of its low fat content, but it is often rather tough. Tenderness is the most important attribute of quality during meat consumption and there is scarce information about the expression of genes involved in the meat tenderization process in goats. The aim of this trial was to assess certain meat quality traits and the expression, at the messenger RNA (mRNA) and protein levels, of specific genes involved in the tenderization process of the longissimus lumborum (LL) in young male goats (Capra hircus) at different ages. Samples of LL were collected at slaughter from 32 Alpine goats that were divided into three categories: 9 suckling kids (Sk) at 5.4±0.15 weeks of age, 16 chevons (Ch) at 17.1±0.55 weeks of age and 7 post-puberal goats (Pu) at 34.3±2.5 weeks of age. Animal and carcass variables (live weight gain, live weight, carcass weight and fat deposits) and quality traits of meat (lipid content, ultimate pH, color parameters, cooking loss and shear force) were determined. The mRNA abundances of calpain-1 (Capn1), calpain-2 (Capn2), calpastatin (Cast), caspase 3 (Casp3), caspase 9 (Casp9), αB-crystallin (Cryab), heat shock protein 27 (Hsp27), heat shock protein 40 (Hsp40) and heat shock protein 70 (Hsp70) were detected by quantitative PCR. Capn1, Cast, Cryab and Hsp27 protein expression was investigated by ELISA. The Sk group had the leanest carcasses. The meat of the Pu group was the darkest (P<0.05) and the toughest (P<0.05). The redness of meat increased with the age of the goats. The Sk group showed lower mRNA abundances for the Capn2/Cast ratio, Casp3, Cryab, Hsp27, Hsp40 and Hsp70 than the Pu group (P<0.05). Intermediate values were found for the Ch group. Similar results were highlighted for the protein expression of Cryab and Hsp27. The experiment acknowledged a differentiation of the experimental groups based on performance, carcass and meat characteristics, and the genes considered. Moreover, Sk and Pu groups, characterized by a different tenderness of their meat, were clearly discriminated by a different expression of the Hsp.

HSP90 gene expression induced by aspirin is associated with damage remission in a chicken myocardial cell culture exposed to heat stress

To understand the potential protection of heat shock protein 90 (HSP90) induced by aspirin against heat stress damage in chicken myocardial cells, enzyme activities related to stress damage, cytopathological changes, the expression and distribution of HSP90, and HSP90 mRNA levels in the myocardial cells exposed to heat stress (42°C) for different durations with or without aspirin administration (1 mg/ml, 2 h prior) in vitro were investigated. Significant increase of enzyme levels in the supernatant of heat-stressed myocardial cells and cellular lesions characterised by acute degeneration, karyopyknosis and karyorrhexis were observed, compared to non-treated cells. However, the lesions of cells treated with aspirin were milder, characterised by earlier recovery of enzyme levels to the control levels and no obvious heat stress-related cellular necrosis. Stronger positive signals in the cytoplasm and longer retention of HSP90 signal in nuclei were observed in aspirin-treated myocardial cells than those of only heat-stressed cells. HSP90 level in the aspirin-treated myocardial cells was 11.1-fold higher than that in non-treated cells, and remained at a high level at the early stage of heat stress, whereas it was just 4.1-fold higher in only heat-stressed cells and returned rapidly to a low level. Overexpression of HSP90 mRNA in aspirin-treated cells was observed throughout the experiment, whereas HSP90 mRNA decreased significantly only in heat-stressed cells. The early higher HSP90 expression induced by aspirin during heat stress was accompanied by decreased heat stress damage, suggesting that aspirin might play an important role in preventing myocardial cells from heat stress damage in vitro.

The association of Hsp90 expression induced by aspirin with anti-stress damage in chicken myocardial cells

The protective effect of aspirin during exposure to heat stress in broiler chickens was investigated. We assayed pathological damage, expression and distribution of Hsp90 protein and hsp90 mRNA expression in chicken heart tissues after oral administration of aspirin following exposure to high temperature for varying times. Heat stress induced increases in plasma aspartate aminotransferase, creatine kinase and lactate dehydrogenase activities while causing severe heart damage, which was characterized by granular and vacuolar degeneration, nuclear shrinkage and even myocardium fragmentation in cardiac muscle fibers. After aspirin administration, myocardial cells showed fewer pathological lesions than broilers treated with heat alone. A high positive Hsp90 signal was always detected in the nuclei of myocardial cells from broilers treated with aspirin, while in myocardial cells treated with heat alone, Hsp90 in the nuclei decreased, as did that in the cytoplasm. Aspirin induced rapid and significant synthesis of Hsp90 before and at the initial phase of heat stress, and significant expression of hsp90 mRNA was stimulated throughout the experiment when compared with cells exposed to heat stress alone. Thus, specific pre-induction of Hsp90 in cardiovascular tissue was useful for resisting heat stress damage because it produced stable damage-related enzymes and fewer pathologic changes.

Early changes in microbial colonization selectively modulate intestinal enzymes, but not inducible heat shock proteins in young adult Swine

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but also exert site- and sometimes diet-specific long-term effects on key components of intestinal homeostasis.

Localization and expression of Hsp27 and αB-crystallin in rat primary myocardial cells during heat stress in vitro

Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for investigating the distribution and expression of Hsp27 and αB-crystallin. After exposure to heat stress at 42°C for different durations, the activities of enzymes expressed during cell damage increased in the supernatant of the heat-stressed myocardial cells from 10 min, and the pathological lesions were characterized by karyopyknosis and acute degeneration. Thus, cell damage was induced at the onset of heat stress. Immunofluorescence analysis showed stronger positive signals for both Hsp27 and αB-crystallin from 10 min to 240 min of exposure compared to the control cells. According to the Western blotting results, during the 480 min of heat stress, no significant variation was found in Hsp27 and αB-crystallin expression; however, significant differences were found in the induction of their corresponding mRNAs. The expression of these small heat shock proteins (sHsps) was probably delayed or overtaxed due to the rapid consumption of sHsps in myocardial cells at the onset of heat stress. Our findings indicate that Hsp27 and αB-crystallin do play a role in the response of cardiac cells to heat stress, but the details of their function remain to be investigated.