Anti-oxidative protective effect and mechanism of klotho on ischemic brain injury / 药学学报

Present study was designed to investigate the effects and underlying antioxidant mechanism of klotho overexpression through an intracerebroventricular injection of a lentiviral vector that encoded murine klotho (LV-KL) on cerebral ischemia injury. Four weeks after the injection of lentivirus into the lateral ventricle of C57Balc/6J mice, a mouse model of global cerebral ischemia-reperfusion was established by bilateral common carotid artery occlusion (2VO). Klotho overexpression significantly improved neurobehavioral deficits and increased the number of survival neurons in the hippocampal CA1 and caudate putamen subregions. The overexpression also decreased malondialdehyde (MDA) content in brain, while mitochondrial manganese- superoxide dismutase (Mn-SOD) and catalase (CAT) expression in brain were increased. Moreover, klotho overexpression decreased Akt and forkhead box class O1 phosphorylation. These findings suggest that klotho may compensate for its aging-related decline to provide a promising therapeutic approach for the acute ischemic stroke during aging.

Effects of Different Stimulators on Proliferation of Peripheral Blood Lymphocyte Subsets / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of different stimultors (PHA, PMA and IL-2) and culture systems (PBMC and whole blood) on the proliferation of human peripheral blood lymphocyte subsets, so as to provide the experimental basis for selecting the appropriate system according to the experimental purposes.@*METHODS@#A total of 10 ml serum samples were collected from healthy volunteers (n=6). The 300 μl whole blood was directly used to detect lymphocyte subsets by flow cytometry. The 400 μl whole blood were inoculated respectively with 3 different stimulators at 37℃ and 5% CO2 for 60 h; Three different stimulators were also added to the PBMC which were isolated from 2 ml whole blood. Then the proliferation ability of lymphocyte subsets was analyzed by flow cytometry.@*RESULTS@#After the PBMC were stimulated with PHA, CD4CD8CD3 lymphocytes were the most subset; The proportion of CD3CD4 T lymphocytes and CD3CD19 B lymphocytes decreased after being stimulated by PMA (P<0.01, P<0.05); the lymphocyte subset ratio had no significant change after being stimulated by IL-2. After the whole blood system was stimulated with PHA, the CD4/CD8 T lymphoblasts were main subsets, the counts of B lymphocytes and NK cells were reduced; after being stimulated with PMA, the number of CD8CD3 T lymphoblast and CD4CD8T lymphocytes increased, the B/NK cells were not distinguished with the surface markers; after the whole blood system was stimulated with IL-2, the proportion of NK cells significantly increased (P<0.05).@*CONCLUSION@#Lymphocyte proliferation stimulated by PMA is the fastest, while the effect of IL-2 on the lymphocyte subset proportion stimulated by IL-2 is the minimal. After being stimulated by PHA the division cycles of lymphocyte are the most.

Isolation and characterization of antimicrobial peptides from healthy male urine

A complex of low-molecular cationic peptides, extracted from human urine by a combination membrane ultrafiltration and weak cation exchange chromatography, was characterized in this study. It provides a simpler solution for the development of novel antimicrobial peptides from biological liquid waste

nm23-H1-siRNA enhances the chemosensitivity to liposome-encapsulated paclitaxel in lung adenocarcinoma cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the chemosensitivity of lung adenocarcinoma cell line A549 cells to liposome-encapsulated paclitaxel after treatment by nm23-H1-small interference RNA (nm23-H1-siRNA) in vitro.</p><p><b>METHODS</b>The A549 cells were divided into two groups: non-transfected group and nm23-H1-siRNA-transfected group. Western blot analysis was used to detect the expression of nm23-H1. MTT and flow cytometry were used to determine the cell mortality rate, apoptosis rate and cell cycle after liposome-encapsulated paclitaxel treatment in both groups.</p><p><b>RESULTS</b>The expression of nm23-H1 in A549 cells was significantly decreased after transfection with nm23-H1-siRNA. After treatment for 48 hours with liposome-encapsulated paclitaxel, the cell mortality rate was increased with the increasing concentration of liposome-encapsulated paclitaxel in both groups, but increased higher in the nm23-H1-siRNA-transfected group. When the concentration of liposome-encapsulated paclitaxel was above 5 µg/ml, the cell mortality rate was significantly higher than that in the non-transfected group (P < 0.05). The proportion of apoptotic cells also increased in the nm23-H1-siRNA-transfected group, compared with that of the non-transfected group (t = 3.812, P < 0.05), while the proportion of cells at S and G(2)/M phase decreased after transfection with nm23-H1-siRNA (S phase:t = 8.356, P < 0.05; G(2)/M phase:t = 7.256, P < 0.05).</p><p><b>CONCLUSIONS</b>Nm23-H1 is related with the chemoresistance to liposome-encapsulated paclitaxel in lung adenocarcinoma cell line A549 cells. Inhibition of the expression of nm23-H1 by nm23-H1-siRNA can improve the in vitro chemosensitivity of A549 cells to liposome-encapsulated paclitaxel.</p>

Cloning, soluble expression and mutant activity analysis of lactate dehydrogenase gene from Plasmodium falciparum / 生物工程学报

To establish a platform for high throughput screening and in vitro evaluating novel metabolic enzyme-targeted inhibitors towards anti-malarial drugs, a lactate dehydrogenase gene of Plasmodium falciparum (PfLDH) was amplified from the Hainan isolate FCC1/HN. The fusion expression vectors, pGEX-2TK and pET-29a( + ), were utilized to introduce the PfLDH gene into strains of Escherichia coli, BL21 and BL21 (DE3), for over-expression. Consequently, the enzymatic activity of PfLDH was successfully detected in the suspension of lytic bacteria. The PfLDH gene cloned in pGEX-2TK was mainly expressed as inclusion bodies, while the same gene cloned in pET-29a( + ) was nearly expressed in a soluble form of PfLDH, demonstrating the latter vehicle might be more suitable for the large-scale preparation of recombinant PfLDH. Furthermore, according to the electrophoregram of SDS-PAGE and the sequencing data, a series of truncated PfLDH sequences generated randomly from gene amplification were screened and cloned, from which four pre-matured genes with a terminator mutation, PfLDH-delta271, -delta236, -delta167 and -delta53 coding for 45, 80, 149 and 263 amino acid residues, were individually recovered. Through the gene expression and enzymatic activity measurement, the effect of pre-matured terminator mutation on the activity of PfLDH was evaluated, which should pave the way for probing the relationship between structure and function of PfLDH.