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OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) and "Feishu" (BL 13) on pulmonary function, inflammatory reaction and expression of macrophage migration inhibitory factor (MIF) and its receptor complex CD 74-CD 44, etc. in rats with chronic obstructive pulmonary disease (COPD), so as to explore its mechanism underlying improvement of COPD. METHODS: Thirty male SD rats were randomly divided into normal, model and EA groups (n＝10 in each group). The COPD model was established by intratracheal infusion of Lipopolysaccharide (LPS, 1 mg/mL) and forced smoke-inhaling. EA was applied to bilateral ST 36 and BL 13 for 30 min, once daily for 7 days. The rat's lung function (forced vital capacity [FVC], forced expiratory capacity ratio ([FEV 0.1/FVC] and [FEV 0.3/FVC]) was detected under anesthesia. Pathological changes of the lung tissue were detected by H．E. staining, and the contents of MIF, tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1 β) and IL-8 in serum, bronchoalveolar lavage fluid (BALF) and lung tissue were assayed by ELISA. The immunoactivity of CD 74 and CD 44 was detected by immunohistochemistry, and the expression levels of MIF, CD 74, CD 44 and p 38 MAPK mRNAs and proteins were examined by quantitative RT-PCR and Western blot, respectively. RESULTS: Compared with the normal group, the FVC, FEV 0.1, FEV 0.3, FEV 0.1/FVC and FEV 0.3/FVC levels were significantly decreased in the model group (P<0.01). After EA treatment, the FVC, FEV 0.1, FEV 0.3, FEV 0.1/FVC and FEV 0.3/FVC were significantly increased (P<0.01, P<0.05), suggesting an improvement of the pulmonary function after EA. H．E. staining showed that the severity of modeling induced alveolar expansion and inflammatory cell infiltration in the lung tissue was relatively milder in the EA group relevant to the model group. The contents of MIF, TNF-α， IL-1 β and IL-8 in the serum, BALF and lung tissues were significantly higher in the model group than in the normal group (P<0.01), and significantly down-regulated in the EA group relevant to the model group (P<0.01). The expression levels of MIF, CD 74, CD 44 and p 38 MAPK mRNAs and proteins and the immunoactivity levels of CD 74, CD 44 in the lung tissue were obviously higher in the model group than those in the normal group (P<0.01), and considerably lower in the EA group than those in the model group (P<0.01). There was a positive correlation between p 38 MAPK and MIF in mRNA and protein expression levels (P<0.01). CONCLUSION: EA intervention can improve the pulmonary function in COPD rats, which may be related to its effects in inhibiting inflammatory reaction, and MIF/CD 74-CD 44/p 38 MAPK signaling pathway.
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PURPOSE: CD74 (cluster of differentiation 74) is a type II transmembrane protein that associates with MHC-II (major histocompatibility complex-II) molecules and binds with the macrophage migration inhibitory factor (MIF), which is known to be associated with tumorigenesis. The purpose of this study was to examine the relationship between CD74 with MIF and the role of CD74 in osteosarcoma tumorigenesis. MATERIALS AND METHODS: A correlation between CD74 with MIF was examined using immunohistochemistry (IHC) of tissues from patients with osteosarcoma (n=45). The mRNA expression of CD74 from patient-derived primary cells of osteosarcoma (n=22) was examined by a real-time polymerase chain reaction. The role of CD74 and in cisplatin-resistance of osteosarcoma was examined using WST-1 and colony forming assay. RESULTS: Of the 45 patients, 25 patients (55.6%) had a high level of expression in both CD74 and MIF by IHC. High level of MIF expression was observed in 40 patients (88.9%). We detected that mRNA expression of CD74 was higher in cells of all osteosarcoma patients (n=22) examined than in the control cells (hFOb 1.19). After cisplatin treatment, the inhibition of cell proliferation and suppression of colony formation were reduced in osteosarcoma cells expressing CD74. Interestingly, the effect of inhibiting anchorage independent growth was activated after cisplatin treatment in the cells with very high expression CD74 mRNA. CONCLUSION: This study suggests that the level of CD74 expression correlates with that of MIF expression. Moreover, CD74 might have a role in cisplatin resistance of osteosarcoma.