| Mastitis is one of the most common diseases industry,which is mammary inflammation caused by changes in body metabolism and physiological status,mammary damage and exposure to infectious or environmental pathogenic micro-organisms.As the most important functional unit of breast tissue,mammary epithelial cells(MAC-T)' inflammatory response and function maintenance in the inflammatory state determine the occurrence and development of mastitis.lncRNAH19(H19),as the latest discovered non-coding RNA,is widely involved in the physiological and pathological activities of animal organisms.The effect of H19 on cell proliferation has been observed in various cell types,and increasing H19 expression was also found in the bovine mammary epithelial cells in the lipopolysaccharide(LPS)-induced inflammatory response process.However,the roles of H19 in the inflammatory response and underlying function of bovine mammary epithelial cells is not clear.In the present study,we found that stable expression of H19 significantly promoted cell proliferation and ?-casein expression in MAC-T cells.In addition,we observed that stably expressing H19 in MAC-T cells significantly enhanced the expression levels of tight junction-related proteins to reduce staphylococcus aureus adherence.Finally,we demonstrated that H19 promoted LPS-induced activation of the NF-?B pathway,and then promoted the expression of TNF-?,IL-6,CCL2,CCL5 and other inflammatory factors.These results indicated that H19 played an important role in the inhibition of bacterial infection and functional recovery of breast tissue.Finally,we used a luciferase gene reporter assay to detect the specific initiation sequence of LPS in the 4.679-kb sequence upstream of the H19 gene.As a result,no effector promoter to LPS was found within the examined sequence regions.Further studies are intended to determine the mechanism,in which LPS regulates the expression of H19 in MAC-T cells. |
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