Comparisons Of Characteristics And Functions Of Mammary Stromal Fibroblasts Derived From Normal And Clinical Mastitic Bovine Mammary Tissue

Mastitis is a common disease of dairy cows, which is the mammary gland inflammation caused the change of body’s metabolism and physiological state or the damage of mammary gland and infected by the pathogenic microorganism,and the mastitis takes severe harm to the dairy industry. Except for the mammary epithelial cells,mammary stromal fibroblast(MSF) is also one of the most crucial components the mammary tissue, and play an important role in normal development and disease process of mammary gland. In order to find out whether if the MSF participates in the inflammation process of dairy cow mammary gland, normal MSF(N-MSF) and inflammation related MSF(In-MSF) were isolated from mammary tissues obtained from cows introduced to the slaughterhouse due to problems of clinical mastitis or fractured legs during the lactation. We used microscope, CCK-8 kit, flow cytometery of AnnexinV/PI double staining, Real-time PCR, ELISA to compare the morphology, cell proliferation, apoptosis and inflammatory gene expression of these two types of fibroblasts. It was found that In-MSF had no obvious difference to the N-MSF in morphology and apoptosis. The cell proliferation rate of In-MSF was higher than N-MSF(P<0.05). Real-time PCR results showed that the mRNA expression of TNF-a, IL6, and IL8 in In-MSF was higher than N-MSF(P<0.05). Furthermore, the protein level of TNF-a, IL6 and IL8 secreted by In-MSF was higher than N-MSF(P<0.01, P<0.05). The results of this research suggest that the biological characteristics of mammary stromal fibroblasts are changed after the mammary gland is infected, and these changes may be involved in the occurrence and development of the mastitis. These findings will provide new methods to diagnosis, treatment and prevention for bovine mastitis.