The Study Of The Dexamethasone On Proliferation And Expression Of Aggrecan Of Rabbit Nucleus Pulposus Cells In Vitro

In this study we investigated the roles of dexamethasone on proliferation and proliferative cell nuclear antigen expression in cultured rabbit nucleus pulposus (NP) cells. Firstly, the nucleus pulposus cells were collected from spine of rabbit bacterially, then the dexamethasone of different concentration was added into culture medium, the final concentration was as following:0.001μmol/L-100μmol/L, the timing of treatment was 24h to 120h. The MTT assay was used to detect the proliferative effect of dexamethasone on cultured nucleus pulposus cells. The proliferative cell nucleus antigen (PCNA) was detected by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and Western blot assay. The expression of Aggrecan was detected by RT-PCR and western blot assay. then the dexamethasone of different concentration was added into culture medium, the final concentration was as following:0.001μmol/L-10μmol/L, the timing of treatment was 48h. The Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) assay was used to detect the expression of Aggrecan in culture nucleus pulposus cells treated by dexamethasone. The MTT assay indicated that 1-100μmol/L of dexamethasone could improve the proliferation of cultured nucleus pulposus cell, and the maximum effect occurred in 0.1μmol/L of dexamethasone. In time dependence assay, we detected the time of 24 to 120 hours, the maximum effect was occurred at 48 hours. In detection of expression of PCNA by RT-PCR and Western blot, we found that 1-0.1μmol/L of dexamethasone could increase the expression of PCNA in cultured nucleus pulposus cells, with the increase of dexamethasone the expression of PCNA also increased. In the detection of Aggrecan by RT-PCR, we found that 1-1000nmol/L of dexamethasone treated for 48 hours could increase the expression of aggrecan, and the maximum was occurred at 100nmol/L of dexamethasone. From above results, we can make a conclusion that, dexamethasone could improve the proliferation of cultured rabbit nucleus pulposus cells, and increase the expression of proliferative cell nuclear antigen in nucleus pulposus cells, and increase the expression of Aggrecan in nucleus pulposus cells.