Isolation, structural identification of secondary metabolites from Pseudomonas aeruginosa HBD-12 with antibacterial and antitumor activities / 生物工程学报

To screen strains with antibacterial and antitumor activity, pregnenolone was used as the sole carbon source for screening bacteria from soil. Based on bacteriostatic activity assay, Pseudomonas aeruginosa HBD-12 was found to be effectively inhibiting the growth of Escherichia coli, Bacillus thuringiensis, Penicillium digitatum and Penicillium italicum, and its fermentation broth was separated and purified using column chromatography. Then, structure of the obtained monomeric compounds was analyzed by spectrum analysis, and their antitumor activity was measured using HTRF kinase detection kit. The isolated monomeric compounds 1-hydroxy-9,10-phenanthroline and 3-hydroxy-9,10-dihydrophenanthroline had significant antitumor activity. At 20 μg/mL, 1-hydroxy-9,10-phenanthroline and 3-hydroxy-9,10-dihydrophenanthroline inhibited 78.39±2.29% and 60.34±8.35% Aurora kinase A, respectively. Therefore, the secondary metabolites of Pseudomonas aeruginosa HBD-12 have the potential to develop antibacterial and antitumor drugs.

Effect of electroacupuncture at different time on circadian rhythm and SCN epigenetic modification in mice with hepatocellular carcinoma / 中国针灸

<p><b>OBJECTIVE</b>To observe the effects of electroacupuncture (EA) on the circadian rhythm and suprachiasmatic nucleus (SCN) epigenetic modification in mice with hepatocellular carcinoma (HCC), and to explore the epigenetics mechanism of EA on circadian rhythm in patients with HCC.</p><p><b>METHODS</b>According to six zeitbeger time (ZT) of ZT0 (7:00), ZT4 (11:00), ZT8 (15:00), ZT12 (19:00), ZT16 (23:00) and ZT20 (3:00), a total of 108 eligible male C57BL/6J mice were divided into a blank group, a model group and an EA group at each ZT, 6 mice each group. Injection of H22 cancer cell suspension was used to establish the HCC model. After 11 days, EA (2 Hz/15 Hz, 0.2 mA) for 10 days was applied at "Ganshu" (BL 18) and "Zhiyang" (GV 9) in the EA group at each ZT, once a day, 15 min a time; the rats in the blank group and model group were treated with immobilization at the same time and under the same conditions. ClockLab (ACT-500) software was used to record the activity rhythm of mice. After 10 days intervention, MATLAB (R2007b) was used to export the circadian rhythm of mice, and the amplitude and peak phase of the mice were analyzed. The high-throughput epigenetics PCRarray array was applied to detect epigenetics-related gene expression in SCN.</p><p><b>RESULTS</b>(1) After modeling, compared with the blank group, the amplitude of activity was decreased and peak phase was delayed in the model group and EA group at each ZT (all <0.05), but the difference of rhythm parameters between the model group and EA group was not significant (all > 0.05). (2) After intervention, compared with the model group, the amplitude of activity in the EA group at ZT 8 was increased and peak phase was advanced (both <0.05); the difference of the activity amplitude and peak phase between the EA group and model group at ZT0, ZT4, ZT12, ZT16 and ZT20 was not significant (all >0.05); compared with the ZT0, ZT4, ZT12, ZT16 and ZT20, the amplitude of activity in the EA group at ZT 8 was increased and peak phase was advanced (all <0.05). (3) The results of epigenetic PCRarray array showed that after intervention at ZT 8, compared with the blank group, the expression of 48 epigenetic-related genes in SCN of HCC mice was up-regulated; compared with the model group, the relative expression of 49 epigenetic-related genes in the SCN was down-regulated in the EA group; there were 23 epigenetic-related genes differentially expressed among the three groups.</p><p><b>CONCLUSION</b>EA has benign regulation on circadian rhythm of HCC mice, and achieves the best efficacy at ZT 8. EA at ZT 8 could down-regulate the overexpression of epigenetic-related genes.</p>

HMGB1/SREBP-1 mediated IFN-gamma-induced lipid deposition in mouse mesangial cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the possible mechanism of lipid deposition induced by interferon-gamma (IFN-gamma).</p><p><b>METHODS</b>The mouse mesangial cells (MMC) were randomly divided into control group, stimulation group, stimulation + control vector group (sh-HMGB1) and stimulation+ specific sh-vector group (sh-SREBP-1). RT-PCR was used to detect the expression of HMGB1, SREBP-1 and fatty acid synthetase (FAS) mRNA; the protein expression was determined by Western blot.</p><p><b>RESULTS</b>The Oil Red O staining revealed that the mouse mesangial cells showed significant lipid droplet in IFN-gamma group. IFN-gamma up-regulated the expression of HMGB1, SREBP-1, FAS mRNA and protein time-dependently; Transfection of MMC with HMGB1 siRNA resulted in the suppression of SREBP-1, FAS protein levels induced by IFN-gamma, following with decrease of lipid deposition. Stimulation with HMGB1 markedly induced expression of SREBP-1, FAS expression and peaked at 8 h, decreased at 12 h compared with that at 8 h. Sh-SREBP-1 decreased the lipid deposition induced by HMGB1 in MMC.</p><p><b>CONCLUSION</b>IFN-gamma might induce lipid deposition in mouse mesangial cells partly by up-regulating the expression of HMGB1/SREBP-1/FAS.</p>

Prevention of central pontine myelinolysis in rats by early treatment with dexamethasone / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To explore the effect and mechanism of dexamethasone (DEX) in the prevention of central pontine myelinolysis (CPM) in rats.</p><p><b>METHODS</b>Hyponatremia was induced in rat by subcutaneous injection of Vasopressin Tannate and intraperitoneal injection of 2.5% dextrose in water for 3 d, the rats of Group A received a bolus of 1 mol/L NaCl (2 ml/kg) and DEX (5 mg/kg) simultaneously at the 4th day; the rats of Group B were treated with DEX after 24 h of the injection of 1 mol/L NaCl; the rats in Group C received a bolus of 1 mol/L NaCl and saline simultaneously; Group D was the control group. The demyelinative lesions were evaluated by myelin staining. The Evans blue (EB) contents of brain were detected to evaluate the blood-brain-barrier permeability after rapid correction of hyponatremia. The expression of inducible nitric oxide synthase (iNOS) in brains was evaluated by Western blotting.</p><p><b>RESULT</b>CPM was induced successfully in rats. The EB contents of Group A, B and C had no significant difference at 0 h after injection of hypertonic saline compared with Group D. The EB contents of Group C began to increase significantly at 6 h after injection of hypertonic saline, peaked at 24 h; the expression of iNOS in brains began to increase after 3 h after the rapid correction of hyponatremia. The rate of morbidity in Group C was 66.7%. The demyelinative lesions were rarely seen in Group A, the EB contents of brain decreased significantly compared with Group C at the same time point (P<0.05), the iNOS expression was also inhibited. DEX could not prevent the attack of CPM at Group B, the rate of morbidity (75%) had no significant difference compared with Group C (P>0.05).</p><p><b>CONCLUSION</b>Early treatment with DEX can protect blood-brain-barrier and inhibit the expression of iNOS to prevent the attack of CPM.</p>

Antitumor effect of immunizations with fusions of dendritic and hepatocellular carcinoma cells in mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of immunization with fusions of dendritic cells and H22 cells on tumor-bearing mice and their possible mechanisms.</p><p><b>METHODS</b>Fusion cells of DC and H22 cells were prepared with polyethylene glycol (PEG). Expression of MHC and costimulatory molecules by dendritomas were determined by FACs. To study the antitumor immune preventative and therapeutic effects, fusions were subcutaneously injected into tumor-bearing mice. The cytotoxic T lymphocyte (CTL) activity was determined by LDH method, the expression of TNF-a and IFN-g in tumors were assayed by RT-PCR.</p><p><b>RESULTS</b>The data showed that the hybridomas of DC and H22 cells acquired both DC and H22 cell phenotypes. Immunization of BALB/C mice with DC/H22 fusions induced potent CTL activity (mean CTL activity=0.624+/-0.024, compared with DC + H22, DC, H22 groups, F = 65.46) and a protective immunity against a high dose of H22 tumor challenge. After treatment with hybridomas, the survival time of tumor-bearing mice was greatly extended (x2=18.45). The expression levels of TNF-a and IFN-g mRNA were remarkably increased (TNF-a, F = 47.84; IFN-g, F = 37.23).</p><p><b>CONCLUSIONS</b>The hybridomas of DC and H22 cells could induce effective antitumor immune responses and may have a useful potential in prevention and management of the recurrences and metastases of HCC.</p>

Association of single nucleotide polymorphism in glucagon-like peptide-1 receptor gene with type 2 diabetes in Shanghai / 中华内分泌代谢杂志

Objective To study the association of glucagon like peptide 1 receptor (GLP1R) gene polymorphism with type 2 diabetes in Han population in Shanghai. Methods In the study, 360 type 2 diabetic patients and 313 normal control subjects were enrolled. Diabetic patients were further subdivided into insulin treated non obese patients (BMI28, 192 subjects). A single nucleotide polymorphism (SNP) rs 2268657 was genotyped in all the subjects enrolled in the study using allele specific real time PCR and its association with type 2 diabetes was examined. Results The frequencies of AA,AG, GG genotype incontrol group were0.086,0.447, 0.466 respectively, 0.155, 0.375, 0.470 in non obese diabetic patient group respectively, and 0.109, 0.500, 0.391 in obese diabetic patient group respectively. There was significant difference of the frequency of genotype AA between control group and non obese diabetic patient group (OR=1.939, P