Impact Of Resolvin D1 On The Inflammatory Response Of Rats Temporomandibular Joint Condylar Chondrocyte Stimulated By IL-1β

Objective: Temporomandibular joint osteoarthritis,characterized by cartilage degeneration,is one of the common inflammatory diseases in oral and maxillofacial region.Resolvin D1(Rv D1)has obvious effects of anti-inflammation and stimulating tissue repair.This study mainly explored the regulatory effect of Rv D1 on the inflammatory and cartilage metabolic factors of rat temporomandibular joint condylar chondrocyte stmulated by IL-1β and its mechanism.Methods:(1)Temporomandibular joint condyle chondrocytes(MCCs)are extracted from 6-week-old male SD rats and characterized by immunofluorescence staining of Col2 and Col1 and toluidine blue staining.(2)The inflammation response of MCCs induced by rat IL-1β recombinant protein.q RT-PCR was used to detect the expression of genes related to inflammation and cartilage metabolism in MCCs,and then choose the action time and concentration of IL-1β.(3)According to the different dosing methods of Rv D1,the experiments were divided into three groups,namely pretreatment group,treatment group 1 and treatment group 2.q RT-PCR was used to detect the expression of inflammation-related,cartilage catabolism-related and anabolism-related genes.(4)Western blot and immunofluorescence staining were used to measure the expressions of PI3K-AKT and NF-κB pathway-related proteins and explore the regulatory effect of Rv D1 on MCCs stimulated by IL-1β and its possible mechanism.Results:(1)Positive Col2 immunofluorescence and positive toluidine blue staining indicated that the cells had chondrocyte characteristics,which proved that the extracted cells were MCCs.And MCCs were polygonal and short spindle-shaped.(2)CCK8 results show that 0-100 ng/m L IL-1β has no toxic effect on MCCs.The results of q RT-PCR show that 10 ng/m L IL-1β up-regulated the expression of inflammation-related genes and cartilage catabolism-related genes,and down-regulated the expression of cartilage anabolism-related genes.(3)In the treatment group,Rv D1 could be down-regulated the expression of inflammation-related and cartilage catabolism-related genes,but the effects on anabolism-related genes aren’t obvious,and these effects can be exhibited in the treatment group 1 at low concentrations of Rv D1,and the treatment group 2 only exert effects at high concentrations.In the pretreatment group,Rv D1 could hardly reverse the effects of IL-1β.(4)The results of western blot and immunofluorescence staining showed that: IL-1β promotes the phosphorylation of NF-κB p65 and its translocation into the nucleus,while Rv D1 has a regulatory effect on the NF-κB pathway,which can be affected by the inhibition of this pathway.It indicates that Rv D1 plays a protective role in chondrocytes by inhibiting the NF-κB pathway,and delays the degeneration process of cartilage tissue.And IL-1β can promote the expression of AKT and the phosphorylation of PI3 K,and activate the PI3K-AKT signaling pathway.Rv D1 has a certain inhibitory effect on this pathway,thus affecting the process of inflammation and cartilage catabolism.Conclusions:(1)Treatment group 1 and 2 have a better regression effect on inflammatory response of temporomandibular joint condyle chondrocyte than pretreatment group.(2)Rv D1 can inhibite the effects of IL-1β on inflammatory and cartilage catabolism-related factors in MCCs,and this effect may be related to PI3K-AKT and NF-κB pathways.