Objective      To determine the role of miR-144-overexpressed lentivirus in the pathological process of synovial tissue in arthritis mouse model and its possible mechanism.       Methods      Type Ⅱ collagen-induced arthritis (CIA) mouse models were obtained by injecting the emulsion of type II collagen into subcutaneous tail base of BALB/c mice. Then miRNA-144 overexpression lentivirus was injected into the tail vein. The expression and distribution of cadherin-11 and TNF-α in the synovial tissue of model mice were detected through immunofluorescence staining a

nd the pathological characteristics were studied with HE staining.       Results      The mouse model exhibited similar characteristics as the pathological processes of synovial tissue in rheumatoid arthritis. Compared with saline and dummy vector lentivirus-treated groups

the inflammation of the synovial tissue was significantly reduced in the miRNA-144 overexpression lentivirus-treated group

whose TNF-α expression and cadherin-11 protein expression were also significantly lower (P0.05

P

0.05).       Conclusion      The increase of miRNA-144 content reduces the inflammation of synovial tissue in the CIA mouse models

and down-regulates the expression of TNF-α which may result from miRNA-144-induced cadherin-11inhibition.