Mastitis increases growth factor messenger ribonucleic acid in bovine mammary glands.
Multiparous Holstein cows were infected in two quarters by intramammary infusion with Streptococcus agalactiae and slaughtered approximately 36 h later. Mammary tissue was removed from the infected quarters, uninfected contralateral quarters, and from pair-slaughtered uninfected controls; the tissue was frozen in liquid nitrogen. The RNA was extracted, and Northern blot analysis was performed for a variety of growth factors, stress-induced genes, milk protein genes, and control genes. Infection increased levels of mRNA coding for heat shock proteins 89 alpha, 89 beta, 70, 60, and 27. Simultaneously, concentrations of alpha-lactalbumin and casein mRNA decreased; alpha-lactalbumin mRNA showed a greater decline. The mRNA for several growth factors, including acidic fibroblast growth factor, basic fibroblast growth factor, epidermal growth factor, transforming growth factor-alpha, IGF-I, and IGF-II, were also increased as was the apoptosis marker, testosterone-repressed prostate mucin-2. Concentrations of mRNA for controls, beta-actin, and glyceraldehyde-3-phosphate dehydrogenase were unaffected. These results indicate that mastitis induces changes in the levels of mRNA encoding for a variety of peptide growth factors. Such changes in growth factors could be important in a variety of processes that occur during infection, such as protection against injury or tissue repair and recovery processes.
Sheffield
L G
LG
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
D000818:Animals; D002364:Caseins / Q000235:genetics; D002417:Cattle; D004815:Epidermal Growth Factor / Q000235:genetics; D005260:Female; D016220:Fibroblast Growth Factor 1 / Q000235:genetics; D016222:Fibroblast Growth Factor 2 / Q000235:genetics; D006133:Growth Substances / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D007768:Lactalbumin / Q000235:genetics; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008414:Mastitis, Bovine / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D016211:Transforming Growth Factor alpha / Q000235:genetics
D002364:Caseins; D006133:Growth Substances; D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D007768:Lactalbumin