1.Investigations on biological functions of heat shock transcription factor 1 (HSF1) using a gene knock out mouse model
Xianzhong XIAO ; Guangwen CHEN ; Jialu YOU ; J.benjamin IVOR
Chinese Journal of Pathophysiology 2001;17(8):793-
HSF1 is the major heat shock transcription factor that binds heat shock element (HSE) in the promoter of heat shock proteins (HSPs) and controls rapid HSP induction in cells subjected to various stresses such as elevated temperature, chemicals, or exposure to toxins. Although at least four members of the vertebrate HSF have been cloned, details of their individual physiological roles remain relatively obscure. To clarify the exact in vivo functions of HSF1 and assess whether HSF1 exhibits redundant or unique roles, we have created homozygous Hsf1-/- mice using standard gene targeting techniques and isolated Hsf1-/- embryonic fibroblasts. Here we demonstrate that heat shock response (HSR) was not attainable in Hsf1-/- embryonic fibroblasts, and this response was required for thermotolerance and protection against heat-induced apoptosis, and that homozygous Hsf1-/- mice, which survived to adulthood according to genetic background, exhibited multiple phenotypes including: (1) placental defects that reduced embryonic viability after late midgestation (day 13.5); (2) growth retardation; (3) female infertility caused by preimplantation lethality, and (4) increased mortality (+/+ vs -/-, P<0.05) and exaggerated production of proinflammatory cytokine, TNF α (+/- vs -/-, P<0.05) after endotoxin challenge. Interestingly, although Hsf1-/- mice exhibited placental defects and embryonic death, basal HSP expression is not appreciably altered during embryonic development by the HSF1 null mutation, suggesting this factor might be involved in regulating some non-HSP genes or signaling pathways which may be important for development. Taken together, our results established direct causal effects for the HSF1 transactivator in regulating diverse physiological and pathophysiological conditions such as developnent, growth, reproduction, apoptosis and sepsis. The present work also provided a useful mammalian model for further investigating the implications of Hsf1 and its target genes (HSPs and other possible non-HSP genes) in various physiological and pathophysiological processes.
2.Surface display of phytase on Saccharomyces cerevisiae for efficient bioethanol production from corn starch.
Yan XIAO ; Xianzhong CHEN ; Wei SHEN ; Haiquan YANG ; You FAN
Chinese Journal of Biotechnology 2015;31(12):1700-1710
Production of bioethanol using starch as raw material has become a very prominent technology. However, phytate in the raw material not only decreases ethanol production efficiency, but also increases phosphorus discharge. In this study, to decrease phytate content in an ethanol fermentationprocess, Saccharomyces cerevisiae was engineered forheterologous expression of phytase on the cell surface. The phy gene encoding phytase gene was fused with the C-terminal-half region of α-agglutinin and then inserted downstream of the secretion signal gene, to produce a yeast surface-display expression vector pMGK-AG-phy, which was then transformed into S. cerevisiae. The recombinant yeast strain, PHY, successfully displayed phytase on the surface of cells producing 6.4 U/g wet cells and its properties were further characterized. The growthrate and ethanol production of the PHY strain were faster than the parent S. cerevisiae strain in the fermentation medium by simultaneous saccharification and fermentation. Moreover, the phytate concentration decreased by 91% in dry vinasse compared to the control. In summary, we constructed recombinant S. cerevisiae strain displaying phytase on the cell surface, which could effectively reduce the content of phytate, improve the utilization value of vinasse and reduce the discharge of phosphorus. The strain reported here represents a useful novel engineering platform for developing an environment-friendly system for bioethanol production from a corn substrate.
6-Phytase
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metabolism
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Biofuels
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Ethanol
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chemistry
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Fermentation
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Industrial Microbiology
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Saccharomyces cerevisiae
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metabolism
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Starch
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chemistry
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Zea mays
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chemistry
4.The expression and significance of human macrophage metalloelastase in both gastric cancer cell lines and gastric cancer tissues
Hong ZHANG ; You-Ming LI ; Chun-Xiao CHEN ;
Chinese Journal of Digestion 1996;0(05):-
Objective To investigate the expression of human macrophage metalloelastase(HME) both in gastric cancer cell lines and gastric cancer tissues,and to find the role of HME in gastric carcino genesis.Methods Fifty eight patients who were operated in our hospital during April to Aug.2003 were enrolled.The samples taken from cancer,paracancer or normal tissues of these patients and cancer cell lines(MGC-803,SGC-7901,AGS)were detected for HME protein and HME mRNA expressions by Western blot and immunohistochemistry,RT-PCR and fluorescence quantitative PCR,respectively. Results Both HME mRNA and HME protein expressions were found in all three gastric cancer cell lines.The expressions of HME mRNA and HME protein in gastric cancer tissues was increased signifi- cantly compared with that in normal tissues(P0.05).Conclusions The increased HME expression in gastric cancer tissures compared with normal tissue indicate that HME may be a potential tumor marker for gastric cancer.
6.Isolation and Identification of Osmotolerant Yeast from "Swollen Can" Soy Sauce
You-Sheng OUYANY ; Xiao-Bao XIE ; Jiao-Di CHEN ; Hua XUE ; Yi-Ben CHEN ;
Microbiology 1992;0(04):-
Three osmotolerant yeasts were isolated from three batches of "swollen can" soy sauce produced by a Guangdong condiment plant. These strains grew faster in the media containing 50%~60% glucose or 15% NaCl than in common yeast media. The three yeasts were identified as Pichia etchellsii by using morphological characteristics, physiological and biochemical tests.
7.Pharmacokinetics of oleanolic acid liposomes in rats
Hongxuan CHEN ; Jiangxiu NIU ; Yanyu XIAO ; Zhipeng CHEN ; Ping HE ; Guoye YOU
Chinese Traditional Patent Medicine 1992;0(04):-
AIM: To study the pharmacokinetics of oleanolic acid liposomes in rats.METHODS: Oleanolic acid liposomes were prepared by ethanol injection-sonication;The pharmaceutical properties including morphology,encapsulation efficiency,particle size,zeta potential were determined.Rats were injected with oleanolic acid lipo-somes and oleanolic acid solution via the tail,respectively.The plasma concentrations of sample in rats were assayed by RP-HPLC.The pharmacokinetic parameters were computered by 3P97 program package.RESULTS: Oleanolic acid liposomes showed almost spherical,the mean diametre was(206.4 ? 4.7) nm.The encapsulation efficiency of oleanolic acid liposomes could be more than 90% based on orthogonal design,and no haemolyticus existed.The plasma concentration-time curves of the oleanolic acid liposomes conformed to a two-compartment model.T1/2? of oleanolic acid liposomes was(33.59 ? 12.53) min,AUC was(240.13 ? 23.62)(?g/mL.min),obviously higher than that of the control preparation.CONCLUSION: The oleanolic acid liposomes with high entrapment efficiency and even size has a good pharmacokinetic parameters by comparison with non-liposomes.
8.Effect of different pressure oxygen pre-breathe in diving decompression sickness of rats.
Fang-fang WANG ; Yi-qun FANG ; Pu YOU ; Xiao-chen BAO ; Jun MA ; Shi ZHANG
Chinese Journal of Applied Physiology 2015;31(5):401-404
OBJECTIVETo investigate the effect of different pressure oxygen pre-breathing in preventing decompression sickness of rats.
METHODSForty male SD rats were randomly divided into 4 groups: decompression sickness (DCS) group and three oxygen pre-breathing groups with 1 ATA, 2 ATA and 3 ATA pressure respectively. The rats of DCS group were placed in the hyperbaric chamber and the chamber was compressed evenly within 3 minutes to depths of 7 absolute atmosphere(ATA) and held at the designated depth for 60 min, then decompressed (3 min) at constant speed to the surface pressure. After that, the rats were taken out for further detection. While the rats of oxygen pretreatment groups pre-breathed different pressure oxygen for 20 min before entering into chamber. The mortality and behavioral of rats were observed with 30 min post decompression. The dry/wet ratio of the lung, protein levels in the bronchoalveolar lavage fluid (BALF), and the inflammatory cytokine tumor necrosis factor (TNF-alpha) expression were also tested.
RESULTSCompared with that of the DCS group, the mortality and morbidity of oxygen pre-breathe groups didn't change obviously. But the total BALF protein level and the inflammatory cytokine TNF-alpha expression of 1 ATA oxygen pre-breathe group were obviously decreased, while the dry/wet ratio of lung as obviously increased instead (P < 0.05).
CONCLUSIONAlthough preoxygenation can' t obviously change the mortality and mobidity of rats, normal pressure oxygen pre-breathing can mitigate the protein infiltration in BALF and the expression of inflammatory cytokine in lung tissue.
Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Decompression Sickness ; Diving ; Lung ; pathology ; Oxygen ; physiology ; Pressure ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism
9.Expression and clinical significance of amplified in breast cancer 1 and epithelial cadherin in ovarian carcinoma tissues
Xiao WU ; Yanjie YOU ; Chaoqun HONG ; Jiongyu CHEN ; Yixuan ZHUANG ; Mingyao WU
Chinese Journal of Postgraduates of Medicine 2012;35(15):1-5
ObjectiveTo examine the expressions of amplified in breast cancer 1(AIB1) and epithelial cadherin (E-cadherin) in ovarian carcinoma (OC) tissues,and determine the correlation between the expression and clinical pathological features.MethodsThe expression of AIB 1,E-cadherin,estrogen receptor (ER),progesterone receptor (PR) and Ki-67 in tissues of 50OCs and 13 normal ovarians tissues were detected by immunohistochemistry(IHC) EnVision two step process analysis.ResultsPositive expression of AIB1 in OC tissues[68%(34/50) ] was obviously higher than that in normal ovarian tissues [8% (1/13)] (P <0.01).Down-regulation of E-cadherin expression was 60% (30/50).The positive expression of AIB1 was significantly higher in stage Ⅲ and Ⅳ than in stage Ⅰand Ⅱ according to International Federation of Gynecology and Obstetrics (FIGO) stage (P =0.036),in lymph node metastasis group than in none lymph node metastasis group ( P =0.027 ),in stage G3 than in stage G1 and G2 according to Silverberg stage (P =0.003),and in serous adenocarcinoma group than in non-serous adenocarcinoma group (P=0.049);positive rates of ER and Ki-67 were higher than negative rates of ER(P=0.000) and Ki-67 (P =0.009) respectively.Down-regulation of E-cadherin expression was higher in FIGO stage Ⅲ and Ⅳ than in stage Ⅰ and Ⅱ (P =0.044),in serous adenocarcinoma group than in non- serous adenocarcinoma group ( P =0.022) ; positive rates of ER and Ki-67 were higher than negative rates of ER ( P =0.02 1 ) and Ki-67 (P=0.035) respectively.The expression of AIB1 was negatively correlated with E-cadherin expressioh (P =0.026).ConclusionsThe expressions of AIB1 and E-cadherin in OC tissues is closely related to clinical stage.Therefore,AIB1 and E-cadherin may be important moleculars involved in the progression of OC.
10.Effectiveness of idarubicin-intensified myeloablastive conditioning regimen in allogeneic peripheral blood stem cell transplantation in 12 patients with myelodysplastic syndromes
Yin XIAO ; Yong YOU ; Zhichao CHEN ; Linghui XIA ; Mei HONG ; Ping ZOU
Chinese Journal of Organ Transplantation 2010;31(2):75-78
Objective To analyze the outcome of idarubicin-intensified myeloablastive conditioning regimen in allogeneic peripheral blood stem cell transplantation (allo-PBSCT) in patients with myelodysplastic syndromes (MDS). Methods From August 2004 to July 2009, 12 patients with MDS were treated with alIo-PBSCT following the idarubicin-intensified conditioning regimen. The conditioning regimen was idarubicin (15 mg/m~2), continuous intravenous infusion for 20 h, days-12 to-10; busulfan (0.8 mg/kg), intravenous infusion every 6 h, days-6 to-4; cyclophosphamide (1.8 g/m~2), intravenous infusion every 6 h, days-3 to-2; cyclosporine A combined with short-term methotrexate was used for the prophylaxes of acute graft versus host disease (aGVHD). Results All twelve patients achieved Trilineage engraftment, and were well tolerated to this regimen. Eight patients survived, and the overall survival was 66.7%, disease-free survival (DFS) 58.3%. Two patients relapsed. OS for neither WHO subgroups nor IPSS subgroups had statistically significant difference. Conclusion Allo-PBSCT with idarubicin-inteusified conditioning regimen is an effective treatment with reduction of the relapse rate for MDS patients.