Circulating ghrelin was negatively correlated with pulmonary arterial pressure in atrial septal defect patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ghrelin was found to attenuate the magnitude of pulmonary arterial hypertension and pulmonary vascular remodeling in rats. The objective of this study was to explore the fasting plasma ghrelin level and the relationships between ghrelin and pulmonary arterial pressure (PAP) in atrial septal defect (ASD) patients with pulmonary arterial hypertension (PAH).</p><p><b>METHODS</b>Fasting plasma ghrelin, obestatin, and insulin levels were measured by enzyme linked immunosorbent assay (ELISA) method in ASD patients with or without PAH according to the manufacturer's instructions. Insulin resistance was calculated by the homeostasis model of assessment for insulin resistance (HOMA-IR) approach, calculated as fasting insulin (microunits/ml)× fasting blood glucose (mmol/L)/22.5. Comparisons between the parameters of patients with PAH and those of patients with normal PAP were performed with an unpaired Student's t test. The relationships between ghrelin and various clinical parameters were examined by bivariate correlations and multiple regression analysis.</p><p><b>RESULTS</b>We found that the fasting plasma ghrelin level and the ratio of ghrelin to obestatin were significantly lower in the PAH group compared with the control group ((582.4±12.8) pg/ml vs. (1045.2±95.5) pg/ml, P < 0.05 and 30.5±4.9 vs. 70.0±9.7, P < 0.01). The fasting plasma obestatin level was higher in the PAH group compared with the control group, but the difference between them was not significant ((23.2±3.1) pg/ml vs. (16.3±1.6) pg/ml, P > 0.05). In a multiple regression model analysis, only mean PAP was an independent predictor of ghrelin and the ratio of ghrelin to obestatin (standardized coefficient = -0.737, P < 0.001 and standardized coefficient = -0.588, P = 0.006, respectively).</p><p><b>CONCLUSION</b>Ghrelin is negatively correlated with mean PAP and this suggests that circulating ghrelin might predict the severity of pulmonary hypertension in ASD patients with PAH.</p>

Preparation of anti-P21-activated kinase 5 polyclonal antibody and its application in dental germ cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone PAK5-N terminal sequence for expression in E. coli to prepare its polyclonal antibody, and examine the role of PAK5 in dental germ cells.</p><p><b>METHODS</b>Based on human PAK5 cDNA sequence, PCR primers were designed to amplify PAK5-N terminal sequence. The PCR product was cloned into the expression vector pGEX-4T-1 EcoRI/XhoI sites, and the recombinant plasmids were identified by agarose gel electrophoresis followed by DNA sequence analysis. The recombinant plasmids were transformed into E. coli BL21 and the expression of GST-fusion protein was induced by IPTG. Glutathione-Sepharose beads were used to purify GST-fusion PAK5-N-terminal fragment. Anti-PAK5 polyclonal antibody was obtained in immunizing rabbits with purified GST-PAK5 N-terminal fusion protein, and the antibodies were purified by protein A beads and used for detection of PAK5 expression in dental germ cells.</p><p><b>RESULTS AND CONCLUSIONS</b>We successfully cloned PAK5-N terminal gene fragment, and achieved protein expression, purification and production of PAK5-NT polyclonal antibody. The results of Western blotting indicated that PAK5 can be highly expressed in the dental germ cells, suggesting that PAK5 may play an important role in biological function of dental germ cells.</p>

Colocalization of 11beta-hydroxysteroid dehydrogenase type I and glucocorticoid receptor and its significance in rat hippocampus / 生理学报

This paper was designed to observe the colocalization of 11beta-HSD1 and GR, and its significance in the rat hippocampus. Immunocytochemical dual-staining showed that not only 11beta-HSD1 but also GR immunoreactive substances were present in the cultured rat hippocampal neurons. Moreover, they were colocalized in the same hippocampal neuron. Synthetic glucocorticoid dexamethasone (DEX) up-regulated the protein expression and activity of 11beta-HSD1 in the cultured hippocampal neurons, as determined by Western blot and thin layer chromatography (TLC) respectively. The transfection of PC12 cells with the plasmid containing promoter sequence of 11beta-HSD1 gene and the reporter gene of CAT enzyme was conducted. DEX up-regulated the reporter gene expression in the system described above. The up-regulation of 11beta-HSD1 and reporter gene expression induced by DEX were both blocked by GR antagonist RU38486. Our study suggests that the colocalization of 11beta-HSD1 and GR in the hippocampus may be implicated in the up-regulation of 11beta-HSD1 expression by glucocorticoids combining to its promoter region, which in turn produces more biologically active glucocorticoids necessary for the binding of low affinity of GR.