The Effect Of Immune Tolerance Induced By β₂ Adrenalin Receptor Signal Transduction On Mesenteric Lymph Node Lymphocytes In Rats With Collagen-induced Arthritis And The Effect Of Chicken Type II Collagen

OBJECTIVE According to the changes of paw swelling, histological morphological of mesenteric lymph nodes (MLNs) and synovium of collagen-induced arthritis (CIA) rats, to study the effect of CCâ…¡on the CIA rats. we designed the beta2-adrenergic receptor (β₂-AR) of MLNLs to investeigate the mechanisms of MLNLs proliferation and the effects of CCâ…¡on the expression ofβ₂-AR, GRK2, GRK3, G_αs andβ-arrestin1, 2 and the desensitization of MLNLs in CIA rats and the effects of G protein-AC-cAMP transmembrane signal transduction on the proliferation of MLNLs in CIA rats.METHODS The model of CIA rats were induced by injection of CCâ…¡emulsion. CCâ…¡(10, 20, 40μg·kg^-1·d^-1, ig, d14-d21) was administrated intragastricly to CIA rats. Secondary paw swelling of CIA rats was measured by volume meter. Histopathological change of MLNs and synovium were observed by light microscope. The expression ofβ₂-AR, GRK2, GRK3 andβ-arrestin1, 2 was measured by western blot and immunohistochemistry analysis, respectively. Fractionating Membrane and Cytoplasm,β₂-AR, GRK2, G_αs and beta-arrestin1, 2 distribution was measured by western blot in cytoplasm and membrane fractions. The expression change of cAMP was investigated by radioimmunoassay.RESULTS(1)CCâ…¡relieves joints swelling,changes inflammation of MLNs and synovium in CIA ratsInflammatory reaction occurred on d26 after immunization. There was a marked secondary inflammatory response in the models, which accompanied with paw swelling, pain, polyarthritis, decrease of body weight, and the development of inflammatory lesions. Compared with the normal rats, in CIA rats, the histological morphological examination of rats knee joints showed hyperplastic synovium, synovial lining hyperplasia, inflammatory cells infiltration. The MLNs of CIA represented that lymphatic follicle was hyperplastic and the number of inflammatory cells. It was found that CCâ…¡(10, 20, 40μg·kg^-1·d^-1, ig, d14-d21) significantly suppressed secondary hind paw swelling and polyarthritis index, as well as improved arthritic status histological of MLNs and synovium in CIA rats.(2)CCâ…¡decreasing the proliferation of MLNLs and up-regulating the level of cAMP CCâ…¡(10, 20, 40μg·kg^-1·d^-1, ig, d14-d21)inhibited the highered proliferation of MLNLs, and up-regulated the level of cAMP of MLNLs in CIA rats. The results suggested that one of characteristic effects of CCâ…¡on exerting therapy rats CIA is inhibiting the proliferation of MLNLs and up-regulating the level of cAMP.(3)Enhancing desensitization, and recovering the balance of the expression of GRK2/β-arrestin1, 2 proteins and recovering G protein-AC-cAMP signal transduction of MLNLs in CIA rats was one of the most important mechanisms of up-regulating the level of cAMP, inhibiting the proliferation of the lymphocytesCCâ…¡(10, 20, 40μg·kg^-1·d^-1, ig, d14-d21) increased total protein expressions ofβ₂-AR, GRK2 and GRK3 and decreased that ofβ-arrestin1, 2 of MLNLs in CIA rats. CCâ…¡further increased plasmatic protein expressions of GRK2, G_αs and decreased that ofβ-arrestin1, 2,β₂-AR and increased membrane protein expressions ofβ₂-AR, GRK2, G_αs and decreased that ofβ-arrestin1, 2 of MLNLs in CIA rats. The results suggested that CCâ…¡Enhancedβ₂-AR desensitization, recovered the balance of the expression of GRK2/β-arrestin1, 2 proteins and recovered G protein-AC-cAMP signal transduction and induced immune tolerance of MLNLs in CIA rats.CONCLUSIONS(1)CCâ…¡suppressed secondary hind paw swelling and improved arthritic status histological of mesenteric lymph node in CIA rats. CCâ…¡inhibited the highered proliferation of MLNLs, and up-regulated the level of cAMP of MLNLs in CIA rats. The result suggested that CCâ…¡might regulate the G protein-AC-cAMP transmembrane signal transduction to regulate the level of cAMP and to inhibit the proliferation of MLNLs in CIA rats.(2)CCâ…¡significantly increased the expression levels ofβ₂-AR and GRK2 protein, decreased the elevated expression level ofβ-arrestin1, 2 protein, enhancedβ₂-AR desensitization, and regulated the balance of GRK2/β-arrestin1, 2 in MLNLs in CIA rats. Enhancingβ₂-AR desensitization, and regulating the balance of expression of GRK2/β-arrestin1, 2 proteins from MLNLs in CIA rats is one of the most important mechanisms of CCâ…¡up-regulating the level of the cAMP and inhibiting proliferation of the lymphocytes.