[Protective effects of dexamethasone combined with valsartan on chronic obstructive pulmonary disease in mice and its mechanism].

Objective: To investigate the possible protective effects of combined dexamethasone and valsartan against cigarette induced chronic obstructive pulmonary disease (COPD) in mice. Methods: Forty C57BL/6 mice were randomly divided into control group, COPD group, dexamethasone treated group, valsartan treated group and dexamethasone + valsartan combined treatment group, with 8 mice in each group. Mice in COPD group were exposed to cigarette for 8 weeks. On the basis of cigarette exposure, mice in dexamethasone treated group were intraperitoneally injected with dexamethasone (2 mg / kg) before cigarette exposure for 5-8 weeks. Mice in valsartan treated group were intraperitoneally injected with valsartan (30 mg/kg) before cigarette exposure for 1-8 weeks. Dexamethasone (2 mg/kg) and valsartan (30 mg/kg) were injected intraperitoneally into mice in the dexamethasone + valsartan combined treatment group. After 8 weeks, the lung tissues and bronchoalveolar lavage fluid (BALF) of mice in each group were collected. The pathological score of lung tissue was evaluated. The activities of superoxide dismutase(SOD) and matrix metalloproteinase-9 (MMP-9), and the contents of malondialdehyde (MDA), intracellular adhesion molecule-1 (ICAM-1), C-reactive protein (CRP) and nitric oxide (NO) in BALF were determined. Results: Compared with the control group, COPD mice had emphysema and alveolar congestion, the levels of MDA, ICAM-1, MMP-9, CRP and lymphocytes in BALF were increased, while the levels of SOD, macrophages and NO were decreased (all P＜0.05). Compared with COPD group, there was no significant improvement in emphysema and alveolar congestion, the levels of SOD and NO in BALF were increased, and the levels of MDA, lymphocytes and macrophages were decreased in dexamethasone or valsartan group (all P＜0.05). Compared with dexamethasone or valsartan group, the dexamethasone + valsartan combined treatment was more effective in preventing pulmonary emphysema and alveolar congestion caused by cigarette smoke. The levels of MDA, ICAM-1, MMP-9, CRP and lymphocyte in BALF were decreased, while the levels of SOD, macrophage and NO were increased (all P＜0.05). Conclusion: Compared with dexamethasone or valsartan, dexamethasone combined with valsartan has a more effective protective effect in COPD mice by inhibiting oxidative stress and inflammation.

Genetic diversity and identification of Chinese-grown pecan using ISSR and SSR markers.

Pecan is an important horticultural nut crop originally from North America and now widely cultivated in China for its high ecological, ornamental and economic value. Currently, there are over one hundred cultivars grown in China, including introduced American cultivars and Chinese seedling breeding cultivars. Molecular markers were used to assess the genetic diversity of these cultivars and to identify the pedigrees of fine pecan plants with good characteristics and no cultivar-related data. A total of 77 samples grown in China were studied, including 14 introduced cultivars, 12 domestic seedling breeding cultivars, and 49 fine pecan plants with no cultivar data, together with Carya cathayensis and Juglans nigra. A total of 77 ISSR and 19 SSR primers were prescreened; 10 ISSR and eight SSR primers were selected, yielding a total of 94 amplified bands (100% polymorphic) in the range of 140-1,950 bp for the ISSR and 70 amplified bands (100% polymorphic) in the range of 50-350 bp for SSR markers. Genetic diversity analyses indicated Chinese-grown pecan cultivars and fine plants had significant diversity at the DNA level. The dengrograms constructed with ISSR, SSR or combined data were very similar, but showed very weak grouping association with morphological characters. However, the progeny were always grouped with the parents. The great diversity found among the Chinese cultivars and the interesting germplasm of the fine pecan plants analyzed in this study are very useful for increasing the diversity of the pecan gene pool. All 77 accessions in this study could be separated based on the ISSR and SSR fingerprints produced by one or more primers. The results of our study also showed that ISSR and SSR techniques were both suitable for genetic diversity analyses and the identification of pecan resources.

[Protective effects of exogenous vitamin D on nerve injury in mice with cerebral ischemia/reperfusion].

OBJECTIVE: To investigate the effects of 1,25-dihydroxyvitamin D3 (1,25-VitD3) supplementation on cerebral injury after ischemia/reperfusion (I/R) in mice with middle cerebral artery occlusion (MCAO). METHODS: Male C57BL6 mice were randomly divided into Sham group, Vehicle group and 1,25-VitD3 group, with 10 mice in each group. Vehicle group and 1,25-VitD3 group were given MCAO for 1 hour, and then killed after reperfusion for 24 hours. Mice in 1,25-VitD3 group were treated with 1,25-VitD3 at the dose of 100 ng/(kg·d) by injected intraperitoneally for 5 days before MCAO operation. Cerebral ischemic penumbra areas of each group were collected for TTC staining, RT-PCR, TTC staining and immunohistochemistry assay. The function defect of mice was evaluated by using neurological function score. RESULTS: Compared with the sham group, the volume of cerebral infarction in Vehicle group was increased significantly, and the expressions of IL-6, IL-1beta and Gp91phox in brain tissues were increased significantly (P＜0.05); compared with Vehicle group, supplementation of 1,25-VitD3 reduced the volume of cerebral infarction by about 50% in I/R mice (P＜0.05), and the expressions of IL-6, IL-1beta and Gp91phox in brain tissues of 1,25-VitD3 group were decreased significantly (P＜0.05). The expression of Foxp3, a T-regulatory cell marker, was significantly increased in the brain of mice (P＜0.05), while the expression of Rorc, a transcription factor, was significantly decreased (P＜0.05), suggesting that Th17/gamma Delta T-cell response was reduced and the number of neutrophils in the brain injury site of mice was significantly reduced (P＜0.05). CONCLUSION: Vitamin D could alleviate the development of cerebral infarction after arterial occlusion (MCAO) reperfusion, and its mechanism may be through regulating the inflammatory response in mouse brain I/R.