Effect of astaxanthin on expression of type Ⅰ and type Ⅲ collagen in cardiac fibroblasts and its mechanism based on TGF-β1/Smad3 signaling pathway / 中国药理学通报

Aim To observe the effects of astaxanthin ( ASTX) on the expression of collegeⅠ( ColⅠ) and type Ⅲcollagen ( Col Ⅲ) of cardiac fibroblasts( CFs) which caused by transforming growth factor β1 ( TGF-β1) and to explore its mechanism of action. Methods CFs were induced by TGF-β1 , and then pretreated with different concentrations of ASTX ( 0 , 5 , 10 , 20 , 40, 80, 160 μmol·L-1) for 24 h. MTT assay was used to determine the activity of CFs. The activation of ROS in CFs cells was detected by DCFH-DA kit. Smad3 gene was silenced by siRNA technique, and re-al-time PCR was used to detect the expression of ColⅠ, Col Ⅲ mRNA before and after Smad3 silencing. Western blot was used to detect the expression of ColⅠ, Col Ⅲ and Smad3 protein levels before and after Smad3 silencing. Results ASTX had no obvious cyto-toxicity in the range of 0 ～20 μmol · L-1 , and could significantly reduce ROS production induced by TGF-β1 in CFs (P<0.05). In addition, ASTX significant-ly inhibited the expression of ColⅠand ColⅢmRNA and protein ( P<0.01 ) of TGF-β1-induced CFs in a concentration-dependent manner. Also, ASTX could significantly down-regulate phosphorylation of Smad3 in TGF-β1-induced CFs ( P <0.01 ) . The expression of Col Ⅰ and Col Ⅲ mRNA and protein was also signifi-cantly down-regulated by Smad3 gene silencing ( P <0.01 ) . Conclusions ASTX can effectively inhibit the expression of Col Ⅰ, Col Ⅲ mRNA and protein of TGF-β1-induced CFs, and the possible mechanism may involve the down-regulation of Smad3 phosphoryla-tion.

Relative analysis of OPN and its related signal molecules in hepatocellular carcinoma / 中华肝脏病杂志

Osteopontin (OPN) has close relationship with metastasis in hepatocellular carcinoma but its downstream signal pathways have not been well defined in hepatocellular carcinoma. The object of this study is to identify the associated signal pathways in human HCC tissues. The expressions of OPN, intergrin aV, CD44v6, P-FAK, FAK, P-Src, Src, P-ERK and P-AKT were assayed using TMA analysis. The relationship of OPN with P-ERK, P-Src and P-AKT were explored and the role in HCC metastasis was analysed. The expression levels of OPN, intergrin aV, CD44v6, P-FAK, P-Src, Src, P-ERK and P-AKT in HCC tissue were significantly higher than that in normal tissue (P value is less than 0.05). No significant difference was found between the expression levels of FAK in HCC tissue and normal tissue (P value is more than 0.05). OPN expression was significantly associated with Integrin av (P value is less than 0.01), CD44V6 (P value is less than 0.01) and P-ERK (P value is less than 0.05) but not with P-Src, P-FAK and P-AKT (P value is more than 0.05). The expressions of P-FAK (P value is less than 0.05), P-Src (P value is less than 0.01) and P-AKT (P value is less than 0.05) were significantly associated with Integrin av and the P-FAK expression was also significantly associated with CD44V6 (P value is less than 0.01). OPN promotes HCC metastasis though Integrin av/CD44V6/MAPK pathway in human HCC.

Reconstruction of an intracellular transduction system based on HIV-1 TAT protein transduction domain / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the reasons for the low intracellular transduction efficiency of a previously constructed His-TAT-Flag recombinant protein and establish a more efficient transduction system.</p><p><b>METHODS</b>The Flag tag of pET14b-His- Tat-Flag vector was deleted with PCR mutant kit, and enhanced green fluorescent protein (EGFP) coding sequence was inserted into the new pET14b-His-TAT recombinant vector. Enzyme digestion and DNA sequencing were performed for identification of pET14b-His-TAT-EGFP vector, which was then transformed into E. coli BL21(DE(3)). After IPTG induction, the recombinant protein of His-TAT-EGFP was isolated and analyzed with SDS-PAGE. Purified His-TAT-EGFP recombinant protein was added to ECV304 cells and the fluorescence was observed to evaluate the transduction efficiency.</p><p><b>RESULTS</b>pET14b-His-TAT vector and pET14b-His-TAT- EGFP vector were successfully constructed, which was identified with enzyme digestion and DNA sequencing. His-TAT-EGFP fusion protein was expressed and purified successfully and showed cellular transduction activity.</p><p><b>CONCLUSION</b>The prokaryotic expression vector has been successfully constructed by modifying pET14b-His-TAT-Flag, and the expressed and purified recombinant protein of His-TAT-EGFP possesses high efficiency of intracellular transduction activity.</p>

Construction and functional study of a cell penetrating peptide-based expression vector for targeted delivery of proteins into the cell nuclei / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct an cell penetrating peptide-based expression vector capable of targeted delivery of proteins into the cell nuclei and study its function of protein transduction.</p><p><b>METHODS</b>The fusion protein expression vector pET14b-HC(L)NE (pET14-b-His-CPP-Linker-NLS-EGFP) incorporating cell penetrating peptide (CPP), nuclear localization signal(NLS), linker and enhanced green fluorescent protein (EGFP) was constructed based on His-tagged pET14b-HE (pET14b-His-EGFP) by site-directed mutagenesis PCR method. After identification by enzyme digestion and DNA sequencing, the recombinant plasmid was transformed into BL21(DE(3)) strain. The HC(L)NE fusion protein was expressed following IPTG induction and purified with Ni(2+)-NTA affinity chromatography. After dialysis and filtration, the HC(L)NE fusion protein was added into cultured eukaryotic cells. The protein transduction in the living cells was observed under fluorescence microscope and analyzed by Western blotting.</p><p><b>RESULTS</b>Enzyme digestion and DNA sequencing confirmed successful construction of the pET14b-HC(L)NE vector, and the fusion protein efficiently expressed in E. coli. Protein transduction experiments in eukaryotic cells revealed that the fusion protein could rapidly penetrate the cell membrane and reach the cell nucleus, and this internalization was time- and concentration-dependent.</p><p><b>CONCLUSION</b>The cell penetrating peptide-based expression vector for targeted protein delivery to the cell nucleus has been successfully constructed, and a transport system that can delivery exogenous proteins or polypeptides into the cytoplasm and cell nucleus is established, which provides an economical and efficient means for functional study of the proteins and polypeptide in cells and targeted drug delivery.</p>