RESUMEN
Objective: To explore the possible mechanism of Duhuo Jisheng Tang in relieving knee osteoarthritis based on protein kinase R-like endoplasmic reticulum kinase (PERK)/immunoglobulin-binding protein (Bip) signaling pathway.Method: A model of knee osteoarthritis was established by cold stimulation.Rats were randomly divided into blank group,model group,celecoxib group (0.021 g·kg-1),low,medium and high-dose Duhuo Jisheng Tang groups (8.37,16.72,33.48 g·kg-1).Blank group and model group were given equal volume of physiological saline.The changes of knee joint diameter were recorded.The pathological changes of rat articular cartilage were observed by hematoxylin-eosin (HE) staining.The expressions of tumor necrosis factor-alpha (TNF-α),interleukin-1β(IL-1β) and hyaluronic acid (HA) in serum were detected by enzyme-linked immunosorbent assay (ELISA).The mRNA and protein expression levels of PERK,Bip and cysteinyl as parates pecific protein-9(Caspase-9) in cartilage were detected by Real-time PCR and Western blot.Result: The knee joint redn ess and the joint diameter of celecoxib group and high-dose Duhuo Jisheng Tang group were improved,and the joint diameter was reduced significantly (Pα,IL-1β and HA were increased in model group (PPPα,IL-1β and HA in serum of celecoxib group and high-dose Duhuo Jisheng Tang group were decreased (PPPPConclusion: Duhuo Jisheng Tang can alleviate the symptoms of knee osteoarthritis model rats,and its mechanism may be related to the regulation of PERK/Bip signaling pathway in rat cartilage.
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AIM: To investigate the role of mild heat stress towards the immunological function of splenic macrophages and significance of BiP protein expression. METHODS: Primary cultured splenic macrophages were prepared and placed in 41 ℃ thermostat for thermal stress and restored to 37 ℃ after an hour. Heat stressed macrophages were separated into groups at time points of 0 min, 30 min, 60 min, 120 min and 180 min, and their BiP mRNA and BiP protein expressions were detected. At the same time, the phagocytic function, cytotoxicity and chemotaxis of the macrophages were detected. RESULTS: After heat stress, the expressions of BiP mRNA and BiP protein in splenic macrophages remarkably increased, and reached to peak after 30-60 min, still remained higher than control group after 120 min and restored to normal level after 180 min. At the same time, mild heat stress enhanced the phagocytotic, cytotoxicity and chemotactic activities of splenic macrophages, and reached to peak after 60 min then gradually decreased. CONCLUSION: The expression of BiP protein is enhanced after mild heat stress, synchronous changes happen both in BiP protein expression and cellular function. There is close relation between BiP protein expression and increased functions of splenic macrophages induced by mild heat stress.