220 Exploring the use of mesenchymal stem cells for treatment of mastitis and metritis in cattle

Abstract

The present study was carried out to isolate mesenchymal stem cells (MSCs) from adipose tissue of cattle (Bos indicus), characterise them, and apply them for the treatment of mastitis and metritis in the cow. Cattle MSCs were isolated from adipose tissue near the loin region of cow. Isolated adipose tissue was subjected to enzymatic digestion using 2% collagenase with agitation at regular intervals. The cells obtained after digestion were resuspended in cell culture flasks containing growth enriched medium and cultured under standard culture conditions. Alkaline phosphatase staining was used as one of the parameters to confirm cultured putative MSCs. Bovine Ad-MSCs were further characterised using real time-PCR by amplification of MSC-specific markers: CD73, CD90, and CD105 as positive markers and CD34, CD45, and CD79a as negative markers. Immunocytochemistry showed the presence of CD73, CD90, and CD105 on the cell surface. Three groups-control (C), local (L), and intravenous (IV)-with 6 cows suffering from mastitis were taken in each group and subjected to MSC transplantation through local and intravenous routes. Control group animals were subjected to antibiotic treatment only. Similarly, another three groups were taken with 6 cows in each group suffering from metritis. Post-transplantation wound healing, tissue repair, and reduction in inflammation were monitored for 26 days, at different time intervals; that is, after Days 1, 3, 7, and 15. Blood samples were also collected from animals at the same time intervals for real time-PCR. A similar examination was also done in metritis groups along with the analysis of the reduction in turbidity of cervical fluid at the abovementioned time intervals. Real time-PCR was performed to determine relative expression of genes for proliferative factors, anti-inflammatory cytokines, and antimicrobial peptides on cells isolated from blood collected at different time intervals. Gene expression in the local group of mastitis subjected to MSC injection was significantly higher than that of the IV and control group. The somatic cell count declined in both local and IV groups compared with the control group. Whereas the expression of the same genes in the IV group of metritis was significantly higher than that of the local and control groups of cows. The turbidity of cervical fluid and mucus was reduced in the IV group compared with the local group. In conclusion, we demonstrated the healing potential of MSCs in a cow model via MSC injection. Promising results were obtained in curing mastitis in both local and IV groups, whereas healing in the case of metritis was significantly higher in the IV group compared with both the control and local groups of cows. The study indicates the potential use of MSc for treatment of mastitis and metritis in cattle through wound healing and decreasing microbial infection.