Yan Teng

Xi'an Jiaotong University, Xi’an, Shaanxi Sheng, China

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Publications (8)4.71 Total impact

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    ABSTRACT: To study the protective effect of recombinant adenovirus-mediated human cytosolic glutathione peroxidase (hCGPx) gene transfection on vascular endothelial cells ECV304 from oxidative damage. pGEM-T Easy Vector containing hCGPx cDNA and recombinant adenovirus shuttle plasmid pACCMV-pLpA were used to construct the shuttle plasmid pACCMV-hCGPx for cotransfection of 293 cells with pJM17, thereby to obtain the recombinant adenovirus AdCMV-hCGPx. Cultured ECV304 cells were transfected with AdCMV-hCGPx for 24, 48 and 72 h, respectively, with the cells transfected with the empty vector serving as control, and hCGPx gene expression was then examined in the transfected cells. The transfected cell viability and apoptotic cell ratio were evaluated after treatment of the cells with H(2)O(2). The expression ratio of hCGPx gene was significantly higher in the AdCMV-hCGPx-transfected cells than in those with empty vector transfection (P<0.01). The hCGPx gene-transfected cells showed significantly higher viability and significantly lower apoptotic ratio than the control cells following challenge with H(2)O(2)-induced oxidative damage. hCGPx gene transfer mediated by recombinant adenovirus protects the vascular endothelial cells from oxidative damage in vitro, possibly due to the antioxidative and apoptosis-inhibiting effect of hCGPx.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 10/2006; 26(10):1417-20.
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    ABSTRACT: To investigate the feasibility and benefits of co-culture of cryopreserved islets with small intestinal submucosa (SIS). Purified rat islets cryopreserved for one month were divided into SIS group and control group, and after culture in standard islet culture media RPMI1640 for 1 week, the morphology and function of the islets were assessed. The SIS protects the fragile islets from damage by cryopreservation, and increased the recovery from (60.6-/+3.3)% to (91.7-/+1.8) % (P<0.05). Compared with the control group, incubation of the islets of the SIS group in high-glucose (16.7 mmol/L) solution resulted in significantly enhanced insulin secretion (23.7-/+1.6 vs 12.5-/+1.1 mU/L, P<0.05). When the islets were incubated in high-glucose solution containing theophylline, the calculated stimulation index of SIS group was about 3-fold higher than that of the control group. Co-culture of cryopreserved rat islets with SIS can increase the recovery of islet cells and improve their function.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 09/2006; 26(8):1121-3.
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    ABSTRACT: To study the protective effect of human renal tubular epithelial cells (HK-2 cells) from hypoxia-reoxygenation damage by transfection of recombinant adenovirus-mediated human cytosolic glutathione peroxidase(hCGPx) gene. Recombinant pGEM-T vector containing hCGPx cDNA and pACCMV-pLpA adenovirus shuttle plasmid was constructed. Then the shuttle plasmid pACCMV-hCGPx and pJM17 were co-transfected into 293 cells and recombinant adenovirus AdCMV-hCGPx was obtained. Cultured HK-2 cells were transfected with AdCMV-hCGPx or vacant recombinant adenovirus (control). The expression ratio of transfected hCGPx gene were studied. Cell viability, the percentage of apoptosis and death were evaluated after hypoxia-reoxygenation damage. The expression ratio of hCGPx gene was higher in the AdCMV-hCGPx transfected cells than that in the control group (P<0.01). After hypoxia-reoxygenation damage, the viability of hCGPx gene transfected cells was significantly higher than that of control and the percentage of apoptosis and death of hCGPx transfected cells was significantly lower than that of control. The transfection of hCGPx mediated by recombinant adenovirus could protect renal tubular epithelial cells from hypoxia-reoxygenation damage in vitro.
    Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 08/2006; 22(4):472-4.
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    ABSTRACT: To investigate the role of alginate-polylysine-alginate (APA) microcapsules in protecting rat islet cells in cryopreservation. Purified rat islet cells microencapsulated with APA and free islet cells were cryopreserved for one month and then thawed for culture in RPMI 1640 overnight. The morphology of the cells was observed and their function assessed by stimulated insulin release test. APA microcapsulation protected the fragile islets from freezing damage by increasing the recovery rate of the cells from 68.6%+/-2.9% to 94.7%+/-1.4% (P<0.05). After incubation with high glucose (16.7 mmol/L) solution, the insulin release from the encapsulated cells after cryopreservation significantly increased in comparison with that of the nonencapsulated cells (22.6+/-1.8 mU/L vs 11.7+/-1.5 mU/L, P<0.05). In high glucose solution containing theophylline, the calculated stimulation index of the encapsulated cells was about 3 times that of the nonencapsulated cells. APA microencapsulation may significantly increase the post-thaw recovery and improve the function for cryopreserved rat islets.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 02/2006; 26(1):46-8.
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    ABSTRACT: To evaluate the recovery and function of isolated rat pancreatic islets during in vitro culture with small intestinal submucosa (SIS). Pancreatic islets were isolated from Wistar rats by standard surgical procurement followed by intraductal collagenase distension, mechanical dissociation and Euroficoll purification. Purified islets were cultured in plates coated with multilayer SIS (SIS-treated group) or without multilayer SIS (standard cultured group) for 7 and 14 d in standard islet culture media of RPMI 1640. After isolation and culture, islets from both experimental groups were stained with dithizone and counted. Recovery of islets was determined by the ratio of counts after the culture to the yield of islets immediately following islet isolation. Viability of islets after the culture was assessed by the glucose challenge test with low (2.7 mmol/L) and high glucose (16.7 mmol/L) solution supplemented with 50 mmol/L 3-isobutyl-1-methylxanthine (IBMX) solution. Apoptosis of islet cells after the culture was measured by relative quantification of histone-complexed DNA fragments using ELISA. After 7 or 14 d of in vitro tissue culture, the recovery of islets in SIS-treated group was significantly higher than that cultured in plates without SIS coating. The recovery of islets in SIS-treated group was about twice more than that of in the control group. In SIS-treated group, there was no significant difference in the recovery of islets between short- and long-term periods of culture (95.8+/-1.0% vs 90.8+/-1.5%, P>0.05). When incubated with high glucose (16.7 mmol/L) solution, insulin secretion in SIS-treated group showed a higher increase than that in control group after 14 d of culture (20.7+/-1.1 mU/L vs 11.8+/-1.1 mU/L, P<0.05). When islets were placed in high glucose solution containing IBMX, stimulated insulin secretion was higher in SIS-treated group than in control group. Calculated stimulation index of SIS-treated group was about 23 times of control group. In addition, the stimulation index of SIS-treated group remained constant regardless of short- and long-term periods of culture (9.5+/-0.2 vs 10.2+/-1.2, P>0.05). Much less apoptosis of islet cells occurred in SIS-treated group than in control group after the culture. Co-culture of isolated rat islets with native sheet-like SIS might build an extracellular matrix for islets and provide possible biotrophic and growth factors that promote the recovery and subsequent function of islets.
    World Journal of Gastroenterology 12/2005; 11(46):7378-83. · 2.55 Impact Factor
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    ABSTRACT: Globally, 180 million people suffer from diabetes mellitus. Islet transplantation is believed to be an almost ideal therapy for insulin-dependent patients. How to maintain the viability and the function of isolated human islets is a challenge in clinical practice. Sertoli cells are considered 'nurse cells' in the seminiferous tubules and have been used in cell graft protocols for neurodegenerative diseases and diabetes in many studies. Many researchers have used immature murine testes as the primarily source of Sertoli cells in islet transplantation because they are easily purified. Mature human Sertoli cells have been seldom investigated. In the present study, we developed a method for the isolation and culture of Sertoli cells derived from adult human testes, and investigated their effects on the function of allogeneic islets when they were cultured together in vitro. Adult Sertoli cells were prepared successfully by two-step enzyme digestion with trypsin, collagenase and hyaluronidase. They were identified by morphological characteristics and their activity was determined by MTT colorimetry over a 28-day culture time in vitro. A glucose-stimulated insulin secretion test was performed to detect the effects of Sertoli cells on allogeneic islets' function when they were co-cultured for 21 days in vitro. In cultured cells, mature human Sertoli cells accounted for more than 90% of total cells. The activity of Sertoli cells reached 95% and they remained highly cytoactive for a long time in vitro (P > 0.05). Compared with the islets cultured alone, the co-cultured islets with allogeneic Sertoli cells maintained higher sensitivity to glucose stimulation for the duration of the experiment (P < 0.01). A method of isolation and culture of Sertoli cells from adult testes has been established. Sertoli cells could enhance allogeneic islets' function when they were co-cultured in vitro. They could be a helper cell in islet transplantation.
    Chinese medical journal 11/2005; 118(22):1857-62. · 0.90 Impact Factor
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    ABSTRACT: The ability to maintain isolated human islet preparation in tissue culture has recently been adopted by most islet transplant centers to improve the safety and practicality of islet transplantation. However, maintaining islet viability and recovery remains a challenge in clinical setting. Extracellular matrix (ECM) is one of the most important components of islet microenvironment. The reconstruction of the cell-matrix relationship seems to be effective in improving the loss of differentiated islet structure and function. Small intestinal submucosa (SIS), a naturally occurring ECM, has been investigated to be able to promote wound healing, tissue remodeling, and cell growth. The purpose of this study was to evaluate the recovery and function of isolated rat pancreatic islets after in vitro culture with SIS. Pancreatic islets were isolated from Wistar rats by using standard surgical procurement followed by intraductal collagenase distension, mechanical dissociation, and EuroFicoll purification. Groups of purified islets were cultured in plates which were coated with multilayer SIS (SIS-treated group) or without (standard cultured group) for 7 days and 14 days in standard islet culture conditions of RPMI 1640 tissue culture media in humidified atmosphere containing 95% air and 5% CO2 at 37 degree centigrade. The mean recovery of islets after the culture period was determined by sizing duplicate counts of a known volume and their viability was assessed by static incubation with low glucose (2.7 mmol), high glucose (16.7 mmol) and high glucose solution supplemented with 50 mum 3-isobutyl-1-methylxanthine (IBMX) solution. After 7 days and 14 days of in vitro tissue culture, the SIS-treated group showed a significantly higher recovery compared with those cultured under standard conditions. The recovery in the SIS-treated group was about two times of the control group cultured in standard conditions after 14 days culture. In the SIS-treated group, there was no statistically difference between the short and long periods of culture(95.8+/-1.0% vs. 90.8+/-1.5%, P>0.05). During incubation in high glucose (16.7 mmol) solution, there was a 2-3 fold increase in insulin secretion from both groups,but the SIS-treated group showed a higher increase than the standard cultured group after 14-day culture (20.7+/-1.1 mU/L vs. 11.8+/-1.1 mU/L, P<0.05). When islets were placed in the high glucose solution supplemented with IBMX, the stimulated insulin response in the SIS-treated group was higher than that in the standard cultured group in spite of the duration of the culture. The stimulation index of the SIS-treated group was about 2-3 times of the standard cultured group. In addition, after a long period of culture, the stimulation index of the SIS-treated group was statistically equivalent with that of the short period of culture (9.5+/-0.2 vs. 10.2+/-1.2, P>0.05). The co-culture of isolated rat islets with native sheet-like SIS can provide an excellent extracellular matrix, possible biotrophic and growth factors that promote the recovery and subsequent function of islets after in vitro tissue culture. In view of results of this study and rapid degradation of SIS in vitro, future studies will investigate the extended duration of culture and the effect of SIS on islets in vitro.
    Hepatobiliary & pancreatic diseases international: HBPD INT 11/2005; 4(4):524-9. · 1.26 Impact Factor
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    ABSTRACT: To set up a method of isolation and culture of Sertoli cells from adult testis and to investigate their immune privilege mechanism. Adult testis Sertoli cells were prepared successfully by digestion with trypsin, collagenase, hyaluronidase and DNase, and then the expression of Fas-L and TGF-beta1 was examined by SABC staining. The Sertoli cells were cocultured with adult splenocytes to detect the inhibitory effect of Sertoli cells on splenocyte proliferation by MTT colorimetry. In cultured cells, Sertoli cells accounted for more than 80% of total cells. The activity of Sertoli cells reached 90%. Sertoli cells expressed Fas-L and TGF-beta1 and could inhibit the proliferation of cocultured splenocytes in vitro. A method of isolation and culture of Sertoli cells from adult testis has been established. The immune privilege mechanism of Sertoli cells may be related to the expression of Fas-L and TGF-beta1.
    Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 10/2005; 21(5):643-5, 649.