In order to investigate the effect of nuclear factor-kappa B (NF-κB) on vascular endothelial growth factor (VEGF) mRNA expression of human pulmonary artery smooth muscle cells (HPASMCs) in hypoxia, the cultured HPASMCsin vitro were stimulated with pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB. The NF-κB p65 nuclei positive expression was detected by immunocytochemical technique. The IκBα protein expression was measured by Western blot. RT-PCR was used to detect the VEGF mRNA expression of HPASMCs. The results showed that no significant change was observed in the NF-κB p65 nuclei positive expression of HPASMCs during 6 h−24 h in normoxia, but the levels of NF-κB p65 nuclei positive expression of cultured HPASMCs were significantly increased in hypoxia groups as compared with those in all normoxia groups (P<0.05). The IκBα protein expression of cultured HPASMCs showed no significant change during 6 h−24 h in normoxia, but significantly decreased in hypoxia as comapred with that in normoxia groups (P<0.05). PDTC (1 to 100 μmol/L) could inhibit the VEGF mRNA expression of HPASMCs in a concentration-dependent manner in hypoxia. In conclusion, NF-κB can be partly translocation activated from cytoplasm into nuclei in the cultured HPASMCs under hypoxia. The inhibition of NF-κB activation can decrease the VEGF mRNA expression. It is suggested that the activation of NF-κB is involved in the VEGF mRNA expression of HPASMCs under hypoxia.
This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagle dog plasma. Pharmacokinetic findings were compared among three preparation (lovastatin sustained-release tablet, Tp; sustained-release capsule, Tj and conventional capsule). Our results showed that the pharmacokinetic parameters in 6 dogs after single-dose oral administration of three perparations were calculated. Tmax, Cmax and MRT revealed significant difference (P<0.05). Relative bioavailability was 111.5±16.9% (Tp) and 110.4%±9.6% (T1). The pharmacokinetic parameters in the 6 dogs after multiple-dose oral administration of three perparations, Tmax, Cmax MRT and DF had significant difference (P<0.05); Cav, Cmin and AUC0–24h displayed no significant difference (P>0.05). It is concluded that the lovastatin sustained-release tablet and sustained-release capsule are able to maintain a sustained-release for 24 h.
The integral mature peptide gene of human growth differentiation factor-5 (GDF-5) was cloned to provide the essential foundation for study on the biological characteristics of GDF-5 at gene and protein levels. Two primers were chemosynthesized according to the hGDF-5 sequence reported in Genbank. The hDGF-5 gene was gained by TR-PCR methods from the total RNA extracted from human fetus cartilage tissue, and was cloned into vector pMD18-T. The sequence of recombinant plasmid pMD18-T-hGDF-5 was analyzed by sequence analysis. DNA agarose gel electrophoresis showed that the product of TR-PCR was about 380bp, and double enzyme digestion of the recombinant plasmid corresponded with it. The result of sequence assay was in agreement with the reported hGDF-5 sequence in Genbank. Our results showed that the integral mature peptide gene of human GDF-5 was cloned successfully from human fetal cartilage tissue, and totally identified with the sequence of human GDF-5 in Genbank.
To investigate the effect of lithium on cell cycle progression of airway epithelial cells, primary pig tracheobronchial epithelial cells were incubated with lithium chloride (LiCl) at different concentrations (0, 5 mmol/L, and 10 mmol/L) and time (12 h, 16 h and 24 h). After the treatment, cells were counted, cell cycle profile was measured by BrdU labeling and flow cytometry, and expression of cyclin D1 and cyclin B1 were detected by Western blotting. The results showed that after 24h of 10mmol/L but not 5mmol/L LiCl treatment, proliferation of cells was slowed down as manifested by delayed confluence and cell number accumulation (P<0.05). Lithium did not change the percentage of cells in S phase (P>0.05), but 24 h incubation with 10 mmol/L LiCl induced a G2/M cell cycle arrest. Furthermore, 10mmol/L LiCl elevated cyclin D1 expression after 12h treatment, while expression of cyclin B1 increased more significantly after 24h incubation. These data demonstrate that lithium inhibits proliferation of pig airway epithelial cells by inhibiting cell cycle progression, and suggest that lithium-sensitive molecule(s) such as glycogen synthase kinase 3 may have a role in the regulation of growth of airway epithelial cells.
The effects of retinoic acid on the β-catenin/TCF pathway in cultured porcine tracheo-bronchial epithelial cells (TBEC) were investigated. After TBEC were treated with retinoic acid at various concentrations, mRNA and protein changes of β-catenin in cytoplasm, nucleus and whole cell of the TBEC were observed by immunocytochemical stain, RT-PCR and Western blotting. And the changes of the target gene cyclinD1 of β-catenin/TCF pathway were also observed. It was found that there was no significant difference in β-cat mRNA level after retinoic acid treatment. However, the expression of β-catenin in the whole cell and cytoplasm was elevated with the increase of retinoic acid concentration (P<0.01). The nuclear protein β-catenin and target gene cyclinD1 of β-catenin/TCF pathway was decreased (P<0.05). It was indicated that retinoic acid could increase β-catenin level of the whole cell protein and decreased nuclear β-catenin, downregulating β-cat/TCF signaling activity and reducing target gene cyclinD1 protein level. As a result, retinoic acid can downregulate β-catenin/TCF pathway in porcine tracheobronchial epithelial cell, suggesting that retinoic acid can inhibit the proliferation and accelerate differentiation of tracheobronchial epithelial cells.