Mastitis Increases Growth Factor Messenger Ribonucleic Acid in Bovine Mammary Glands

Abstract

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.

Intramammary administration of platelet concentrate as an unconventional therapy in bovine mastitis: First clinical application

“…Particularly in the case of chronic mastitis, these findings suggest a possible role of growth factors in tissue protection or repair processes, or both (Sheffield, 1997). It is known, for example, that the action of TGF-α promotes tissue repair, mammary epithelial proliferation, and morphogenesis of the mammary gland (Derynck, 1992).…”

“…Indeed, infection of bovine udders induces a variety of changes in gene expression, including a decrease in α-LA and casein mRNA and, on the contrary, an increase in mRNA of several growth factors, including acidic fibroblast growth factor, basic fibroblast growth factor, epidermal growth factor, transforming growth factor (TGF) α, IGF-I, and IGF-II. These results suggest a possible role of peptide growth factors in tissue protection or repair processes (Sheffield, 1997). For this reason, a different approach for the treatment of mastitis might be to stimulate the regeneration of glandular tissue, providing a supraphysiological concentration of growth factors through the use of platelet concentrate (PC) as an alternative therapy.…”

Application of disease-associated differentially expressed genes – Mining for functional candidate genes for mastitis resistance in cattle

“…Inflammation of cows with Streptococcus agalactiae significantly increased the levels of mRNA coding for several growth factors [30]. Genes involved in cellular proliferation also represent putative candidate genes that might potentially affect both the resistance and etiology of disease.…”

“…In one of the first studies it was shown that the infection of multiparous Holstein cows with Streptococcus agalactiae significantly increased levels of mRNA coding for heat shock proteins, several growth factors, and the apoptosis marker testosterone-repressed prostate mucine-2 [30].…”

Escherichia coli induces apoptosis and proliferation of mammary cells

“…6 During Streptococcus agalactiae (S. agalactiae)-induced mastitis, the increased expression of an apoptosis marker, TRPM-2, has been reported. 7 Furthermore, Staphylococcus aureus (S. aureus), one of the major contagious pathogens leading to bovine mastitis, induced apoptosis of a bovine mammary epithelial cell line. 8 These studies suggest that mammary epithelial cells die via apoptosis during bovine mastitis induced by Gram-positive pathogens.…”