[Effect of heat-reinforcing needling on the inflammation and necrotizing apoptosis of synovial cells in synovial tissues of knee joint in rabbits with cold syndrome rheumatoid arthritis].

OBJECTIVE: To observe the effect of heat-reinforcing needling (HRN) on inflammatory factors and necrotizing apoptosis of synovial cells in synovial tissues of knee joint in rabbits with cold syndrome rheumatoid arthritis (RA), so as to explore its underlying mechanisms in treating RA. METHODS: By using the random number table method, 40 New Zealand rabbits were randomly divided into normal, model, antagonist(AG), twist-reinforceing needling (TRN) and HRN groups, with 8 rabbits in each group. The model of cold syndrome RA was established by ovalbumin induction combined with Freund's complete adjuvant injection and cryogenic freezing method. In the AG group, the antagonist TAK-632 (25 mg/kg) was administered intragastrically, once every 2 days, for a total of 7 times. Rabbits of TRN and HRN groups were treated with corresponding acupuncture techniques on bilateral "Zusanli" (ST36) for 30 min, once a day for 14 days. After intervention, the changes of knee skin temperature and circumference were measured. Color Doppler ultrasound was used to observe the joint cavity effusion, synovial thickness and internal blood flow signal. The histomorphological changes of synovial tissues were observed after HE staining. ELISA was used to detect the contents of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 in serum. Transmission electron microscope was used to observe the ultrastructure, necrosis and apoptosis of synovial cells. Western blot was used to detect the protein expressions of receptor-interacting protein kinase1 (RIPK1), RIPK3, mixed lineage kinase domain-like protein (MLKL), and phosphorylation （p）-MLKL in synovial tissues. RESULTS: Compared with the normal group, the synovial was diffusely hyperplasia, joint cavity effusion and abnormal blood flow signal were obvious, inflammatory cells were clustered, arranged closely and disordered in the model group. The findings of transmission electron microscopy showed disruption of cell membrane integrity, swollen or ruptured mitochondria, obviously ruptured nucleus, condensed and pyknotic chromatin and nucleolus in the model group. Also, the skin temperature of the knee joint was significantly decreased (P<0.01), while the circumference of the knee joint, the contents of TNF-α, IL-1ß and IL-6 in serum, the protein expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues were significantly increased (P<0.01) in the model group. Compared with the model group, synovial tissue hyperplasia, joint cavity effusion, abnormal blood flow signals, synovial cell proliferation, inflammatory cell infiltration, disruption of cell membrane integrity, cell swelling, cell rupture, and nuclear pyknosis were reduced to different degrees in the AG, TRN and HRN groups. Additionally, the skin temperature of the knee joint was increased (P<0.01, P<0.05), while the circumference of the knee joint, the contents of TNF-α, IL-1ß and IL-6 in serum, the expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues were decreased (P<0.01, P<0.05) in the AG, TRN and HRN groups. The effects of HRN and AG were notably superior to that of TRN in up-regulating skin temperature of the knee joint, and down-regulating the circumference of the knee joint, the contents of TNF-α, IL-1ß and IL-6 in serum, the expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues (P<0.01, P<0.05). CONCLUSION: HRN can reduce synovial inflammation of knee joint in rabbits with cold syndrome RA, which may be related to its function in inhibiting the necrotizing apoptosis of synovial cells.

[Effects of heat-reinforcing needling on synovial inflammation and miR-155/TLR4/NF-κB signaling axis in rheumatoid arthritis rabbits with cold syndrome].

OBJECTIVE: To observe the effects of heat-reinforcing needling on synovial inflammation and microRNA-155 (miR-155)/Toll-like receptor 4 (TLR4)/nuclear transcription factor-κB (NF-κB) signaling axis, so as to investigate its anti-inflammatory mechanism in rabbits with cold syndrome of rheumatoid arthritis (RA). METHODS: A total of 36 rabbits were randomly divided into normal, model, agonist, inhibitor, heat-reinforcing needling (HRN) and agonist+heat-reinforcing needling (A+HRN) groups, with 6 rabbits in each group. The RA with cold syndrome model was induced by injecting ovalbumin dry powder and Freund's complete adjuvant combined with cold freezing. Rabbits in agonist group were intraperitoneally injected with miR-155 agomir 4.5 OD; rabbits in the inhibitor group were intraperitoneally injected with miR-155 antagomir 6.1 OD; rabbits in HRN group received heat-reinforcing needling at bilateral "Zusanli" (ST36) for 30 min；rabbits in A+HRN group received the same treatment as agonist group, and 30 min later, received the same treatment as the HRN group; rabbits in the normal and model groups were grasped and fixed in the same way, all groups received continuous treatment once a day for 7 d. After modeling, the knee joints of rabbits were examined by ultrasound, the pain threshold and the circumference were determined. After the interventions, the pain threshold and knee circumference were measured; the pathological morphology of synovial tissue of the knee joints were observed by HE staining; the mRNA levels of miR-155 and suppressor of cytokine signaling protein 1 (SOCS1), the expression levels of SOCS1, TLR4, NF-κB p65, interleukin (IL)-1ß and IL-17A proteins in synovial tissue of knee joints were detected by real-time PCR and Western blot respectively. RESULTS: Compared with the normal group, the pain threshold was significantly decreased (P<0.05), and the knee circumference was significantly increased (P<0.05); the synovial tissue of knee joints showed significant hyperplasia, abundant blood flow signal, joint cavity effusion and obvious inflammatory invasion, the pathological score was significantly increased (P<0.05), the expressions of miR-155 mRNA and IL-1ß, IL-17A, TLR4, NF-κB p65 proteins were significantly increased (P<0.05), the expressions of SOCS1 mRNA and protein were significantly decreased (P<0.05) in the model group. Compared with model group, the pain threshold was significantly increased (P<0.05), the circumference of knee joint was significantly decreased (P<0.05); in synovial tissue, the pathological score was decreased (P<0.05), the expression levels of miR-155 mRNA and IL-1ß, IL-17A, TLR4, NF-κB p65 proteins were significantly decreased (P<0.05), and the expressions of SOCS1 mRNA and protein were significantly increased (P<0.05) in inhibitor group and HRN group, while the above changes in agonist group were reversed (P<0.05). Compared with the agonist group, the pain threshold was significantly increased (P<0.05), the knee circumference was significantly decreased (P<0.05), the synovial pathological score was significantly decreased (P<0.05), the expressions of miR-155 mRNA and IL-1ß, IL-17A, TLR4, NF-κB proteins in synovial tissue were significantly decreased (P<0.05), and the expression levels of SOCS1 mRNA and protein were significantly increased (P<0.05) in A+HRN group. CONCLUSION: The heat-reinforcing needling can increase the pain threshold, reduce the knee circumference and inhibit the inflammatory response in rabbits with RA cold syndrome. The possible mechanism is related to the regulation of miR-155/TLR4/NF-κB signaling axis.

[Effect of heat-reinforcing needling on expression of serum inflammatory factors and autophagy of knee joint synovial tissue in rheumatoid arthritis rabbits with cold syndrome].

OBJECTIVE: To observe the effect of heat-reinforcing needling on the expression of serum inflammatory factors and autophagy of knee synovial tissue in rheumatoid arthritis (RA) rabbits with cold syndrome, so as to explore its mechanism of anti-inflammatory in the treatment of RA. METHODS: Fifty rabbits were randomly divided into normal, model, heat-reinforcing needling, inhibitor and agonist groups (n=10 rabbits in each group). The model of RA with cold syndrome was established by Freund's adjuvant and ovalbumin mixed solution injection combined with freezing and wind-cold dampness method. Heat-reinforcing needling was applied at "Zusanli" (ST36) for 30 min, once a day for 14 days. Rabbits of the inhibitor and agonist groups were given intraperitoneally injected with autophagy inhibitor 3-methyladenine (3-MA) or autophagy agonist rapamycin, once every 2 days for 7 days. The knee circumference and skin temperature of the rabbits in each group were measured. Color doppler ultrasonography was applied to examine the synovial membrane, joint effusion and blood flow signals in the knee joints of the rabbits in each group. Serum tumor necrosis factor (TNF) -α, interleukin (IL)-1ß, IL-6 and C-creactive protein (CRP) were detected by ELISA. Transmission electron microscopy was applied to observe the ultrastructure and autophagosomes of synovial cells. The protein expressions of autophagy-related protein Atg5, serine/threonine protein kinase-dysregulated 51-like kinase 1 (ULK1), microtubule-associated protein light chain 3B (LC3B), and Beclin-1 were detected by Western blot. Fluorescence quantitative PCR was used to detect the mRNA expressions of NOD-like receptor 3 (NLRP3) and nuclear factor-κB (NF-κB). RESULTS: Compared with the normal group, the circumference of the knee joint was increased (P<0.01), the skin temperature was decreased (P<0.01), the knee joint synovium was thickened and the blood flow signal was abundant, the contents of serum TNF-α, IL-1ß, IL-6, and CRP were increased (P<0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3BⅡ/LC3BⅠof synovial tissue were significantly decreased (P<0.01), the mRNA expressions of NLRP3 and NF-κB were increased (P<0.01) in the model group. In comparison with the model and inhibitor groups, the circumference of the knee joint was decreased (P<0.01), whlie the skin temperature was increased (P<0.01), the synovial membrane became thinner and the blood flow signal was wea-kened, the contents of TNF-α, IL-1ß, IL-6 and CRP were decreased (P<0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3B Ⅱ/LC3B Ⅰ were increased (P<0.01), and the mRNA expressions of NLRP3 and NF-κB were decreased (P<0.01) in the heat-reinforcing needling and agonist groups. CONCLUSION: Heat-reinforcing needling can alleviate the inflammatory response of the knee joint synovium in RA rabbits with cold syndrome, which may be related to its function in enhancing the autophagy activity of synovial cells and inhibiting the synthesis and release of inflammatory factors TNF-α, IL-1ß, IL-6 and CRP.