AIM:To assess the prevalence of human papilloma virus(HPV) in esophageal squamous cell carcinoma(ESCC) in the south-eastern region of Poland.METHODS:The study population consisted of 56 ESCC patients and 35 controls.T...AIM:To assess the prevalence of human papilloma virus(HPV) in esophageal squamous cell carcinoma(ESCC) in the south-eastern region of Poland.METHODS:The study population consisted of 56 ESCC patients and 35 controls.The controls were patients referred to our department due to other nonesophageal and non-oncological disorders with no gross or microscopic esophageal pathology as confirmed by endoscopy and histopathology.In the ESCC patients,samples were taken from normal mucosa(56 mucosa samples) and from the tumor(56 tumor samples).Tissue samples from the controls were taken from normal mucosa of the middle esophagus(35 control samples).Quantitative determination of DNA was carried out using a spectrophotometric method.Genomic DNA was isolated using the QIAamp DNA Midi Kit.HPV infection was identified following PCR amplification of the HPV gene sequence,using primers MY09 and MY11 complementary to the genome sequence of at least 33 types of HPV.The sequencing results were computationally analyzed using the basic local alignment search tool database.RESULTS:In tumor samples,HPV DNA was identified in 28 of 56 patients(50%).High risk HPV phenotypes(16 or/and 18) were found in 5 of 56 patients(8.9%),low risk in 19 of 56 patients(33.9%) and other types of HPV(37,81,97,CP6108) in 4 of 56 patients(7.1%).In mucosa samples,HPV DNA was isolated in 21 of 56 patients(37.5%).High risk HPV DNA was confirmed in 3 of 56 patients(5.3%),low risk HPV DNA in 12 of 56 patients(21.4%),and other types of HPV in 6 of 56 patients(10.7%).In control samples,HPV DNA was identified in 4 of 35 patients(11.4%) with no high risk HPV.The occurrence of HPV in ESCC patients was significantly higher than in the controls [28 of 56(50%) vs 4 of 35(11.4%),P < 0.001].In esophageal cancer patients,both in tumor and mucosa samples,the predominant HPV phenotypes were low risk HPV,isolated 4 times more frequently than high risk phenotypes [19 of 56(33.9%) vs 5 of 56(8.9%),P < 0.001].A higher prevalence of HPV was identified in female patients(71.4% vs 46.9%展开更多
The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established hu...The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.展开更多
The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a new...The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid （RA） was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin （STZ）-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.展开更多
To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell’s replication activity and the donor’s age factor, and t...To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell’s replication activity and the donor’s age factor, and to assess the stem cells as a new source for tissue engineering. hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: <20 years old, 21―40 years old, 41―60 years old and >61 years old groups). The protein markers (CD29, CD34, CD44, CD45, CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell, and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro. The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula “ log2T D = t logN t ? logN 0” was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the <20 years old group was lower than that of the >61 years old group (statistical analysis of variance (ANOVA), P=0.002, P<0.05). These find- ings suggested that a higher level of hADAS cells replication activity was found in the younger dona- tors, and they represent novel and valuable seed cells for studies of tissue engineering.展开更多
AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluor...AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein （pEGFP） transfer into human umbilical vein endothelial cells （HUVECs）. METHODS： HUVECs with fluorescein isothiocyanatedextran （FD500） and HUVECs with pEGFP were exposed to continuous wave （1.9 MHz, 80.0 mW/cm^2） for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS： The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone （24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001）. Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue （16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001）. No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue （94.1% ± 2.3% vs 91.1% ± 4.1% ）. CONCLUSION： The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.展开更多
Background Human umbilical cord blood contains an abundance of immature stem/progenitor cells, which may participate in the repair of hearts that have been damaged by myocardial infarction （MI）. This study aimed to ...Background Human umbilical cord blood contains an abundance of immature stem/progenitor cells, which may participate in the repair of hearts that have been damaged by myocardial infarction （MI）. This study aimed to evaluate the effects of human umbilical cord blood mononuclear cells （hUCBC） transplantation on cardiac function and left ventricular remodeling in rat model of MI. Methods Forty-five male Wistar rats were randomized into three groups： MI or control group （n=15）, MI plus cell transplantation （n=15）, and sham group （n=15）. Acute myocardial infarction （AMI） was established by ligating the left anterior descending artery, thereafter, hUCBC were implanted into the marginal area of infarcted myocardium. In MI/control group, DMEM was injected instead of hUCBC following the same protocol. Left ventricular function assessment was carded out by echocardiography and invasive hemodynamic measurements one month post MI. All rats were sacrificed for histological and immunochemical examinations.Results The transplanted hUCBC survived and engaged in the process of myocardial repair in the host heart. Echocardiography demonstrated that left ventricular function improved significantly in the rats that underwent cell transplantation. Hemodynamic studies found a significantly decreased left ventricular end-diastolic pressure （LVEDP） [（21.08±8.10） mmHg vs （30.82±9.59） mmHg, P〈0.05], increase in ＋dp/dtmax [（4.29± 1.27） mmHg/ms vs （3.24±0.75） mmHg/ms, P〈0.05）, and increase in -dp/dtmax [（3.71 ±0.79） mmHg/ms vs （3.00± 0.49） mmHg/ms, P〈0.05] among MI group with hUCBC transplantation when compared with MI/control group. Masson＇s trichrome staining revealed that the collagen density in the left ventricle was significantly lower in rats of transplantation group than that in the MI control groups [（6.33±2.69）% vs （11.10±3.75）%, P〈 0.01]. Based on immunostaining of α-actin, the numbers of microvessels were significantly （P〈0.01） increased at展开更多
Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation sy...Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation system in mouse is very different from that of humans.Whether BMAL1 plays a role in regulating human heart function remains unclear.Here we generated a BMAL1 knockout human embryonic stem cell(hESC)model and further derived human BMAL1 deficient cardiomy-ocytes.We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility,cal-cium dysregulation,and disorganized myofilaments.In addition,mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes,which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomy-ocyte function.We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression.BMAL1 knockout directly reduced BNIP3 protein level,causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function.Our data indicated that the core circadian gene S/VMLf is critical for normal mitochondria activities and cardiac function.Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.展开更多
AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated w...AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated with hepatic progenitor cells. METHODS： EpCAM ＋ve cells were isolated using magnetic cell sorting （MACS） from human fetuses （n = 10） at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein （AFP）, CD29 （integrin ~1）, CD49f （integrin c^6） and CD90 （Thy 1） was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ （A, B, C） and class Ⅱ （DR） expression was studied by flow cytometry only. RESULTS： FACS analysis indicated that EpCAM ＋ve cells were positive for CD29, CD49f, CD90, CD34, HLA class I, albumin and AFP but negative for HLA class Ⅱ （DR） and CD45. RT PCR showed that EpCAM ＋ve cells expressed liver epithelial markers （CK18）, biliary specific marker （CK19） and hepatic markers （albumin, AFP）. On immunocytochemical staining, EpCAM ＋ve cells were shown positive signals for CK18 and albumin. CONCLUSION： Our study suggests that these EpCAM ＋ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.展开更多
BACKGROUND Premature ovarian failure(POF)affects many adult women less than 40 years of age and leads to infertility.According to previous reports,various tissue-specific stem cells can restore ovarian function and fo...BACKGROUND Premature ovarian failure(POF)affects many adult women less than 40 years of age and leads to infertility.According to previous reports,various tissue-specific stem cells can restore ovarian function and folliculogenesis in mice with chemotherapy-induced POF.Human embryonic stem cells(ES)provide an alternative source for mesenchymal stem cells(MSCs)because of their similarities in phenotype and immunomodulatory and anti-inflammatory characteristics.Embryonic stem cell-derived mesenchymal stem cells(ES-MSCs)are attractive candidates for regenerative medicine because of their high proliferation and lack of barriers for harvesting tissue-specific MSCs.However,possible therapeutic effects and underlying mechanisms of transplanted ES-MSCs on cyclophosphamide and busulfan-induced mouse ovarian damage have not been evaluated.AIM To evaluate ES-MSCs vs bone marrow-derived mesenchymal stem cells(BMMSCs)in restoring ovarian function in a mouse model of chemotherapy-induced premature ovarian failure.METHODS Female mice received intraperitoneal injections of different doses of cyclophosphamide and busulfan to induce POF.Either human ES-MSCs or BMMSCs were transplanted into these mice.Ten days after the mice were injected with cyclophosphamide and busulfan and 4 wk after transplantation of the ESMSCs and/or BM-MSCs,we evaluated body weight,estrous cyclicity,folliclestimulating hormone and estradiol hormone concentrations and follicle count were used to evaluate the POF model and cell transplantation.Moreover,terminal deoxynucleotidyl transferase mediated 2-deoxyuridine 5-triphosphate nick end labeling,real-time PCR,Western blot analysis and immunohistochemistry and mating was used to evaluate cell transplantation.Enzyme-linked immunosorbent assay was used to analyze vascular endothelial growth factor,insulin-like growth factor 2 and hepatocyte growth factor levels in ES-MSC condition medium in order to investigate the mechanisms that underlie their function.RESULTS The human ES-MSCs significantly restored hormone s展开更多
AIM： To look for the evidence of human papilloma virus （HPV） infection in esophageal squamous cell carcinomas （ESCC） and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of ...AIM： To look for the evidence of human papilloma virus （HPV） infection in esophageal squamous cell carcinomas （ESCC） and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of esophageal carcinomas in Henan emigrants. METHODS： Papilloma virus （PV） and HPV were determined by UltrasensiveTM S-P immunohistochemistry （IHC） and in situ hybridization （ISH） in esophageal carcinoma tissues （82 cases） and the normal mucosa （40 cases）. RESULTS： IHC revealed that the positive rate of PV was 75.0%, 68.18% and 72.5% respectively while the HPV （16/18-E6） positive rate was 45.0%, 36.36%, 37.5%, respectively in esophageal carcinoma tissue specimens from Henan emigrants,the local citizens and patients in Hubei Cancer Hospital. The PV and HPV （16/18-E6） were negative in all normal esophageal mucosa specimens. No correlation was found between HPV in esophageal squamous cell carcinoma tissues and in grade 1-3 esophageal squamous cell carcinoma cells. In situ hybridization showed that the HPV （16/18） DNA positive rate was 30.0%, 31.8%, 25.0%, respectively in the 3 groups of samples. No positive hybridization signal was found in 40 normal esophageal mucosa specimens. The positive rate of HPV （16/18） DNA in the esophageal carcinoma specimens was significantly higher than that in normal mucosa specimens （P〈0.05）. The positive rate was not different among the 3 groups of esophageal carcinoma tissue specimens （P〉0.05）.CONCLUSION： HPV infection is high in esophageal carcinoma of Henan emigrants, local residents and patients in Hubei Cancer Hospital. HPV is closely related with esophageal squarnous cell carcinoma. HPV infection may play an important role in esophageal squarnous cell carcinoma.展开更多
AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h ...AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h incubation, cytotoxicity and apoptosis evaluations were determined by MTT and DNA fragmentation assay, respectively. After treatment with SWE, mitochondrial membrane potential (MMP) was determined by measuring the retention of the dye 3,3'-dihexyloxacarbocyanine (DiOC6(3)) and the protein expression including cytochrome C and poly-(ADPribose) polymerase (PARP) were measured by Western blotting. Caspase-3 and -9 enzyme activities were measured using specific fluorescence dyes such as Ac-DEVD-AFC and Ac-LEHD-AFC. RESULTS: We found that treatment with SWE induced apoptosis as confirmed by discontinuous DNA fragmentation in cultured human hepatoma HepG2 cells. Our investigation also showed that SWE-induced apoptosis of HepG2 cells were associated with intracellular events including disruption of MMP, increased translocation of cytochrome C from mitochondria to cytosol, activation of caspase-3, and PARP. Pre-treatment of N-acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), a caspase-3 specific inhibitor, or cyclosporin A (CsA), an inhibitor of MMP disruption, completely abolished SWE-induced DNA fragmentation. CONCLUSION: These results suggest that SWE possibly causes mitochondrial damage, leading to cytochrome C release into cytosol and activation of caspases resulting in PARP cleavage and execution of apoptotic cell death in HepG2 cells. These results further suggest that Scorpio may be a valuable agent of therapeutic intervention of human hepatomas.展开更多
AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 l...AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.展开更多
基金Supported by Medical University of Lublin,Scientific Research Grant
文摘AIM:To assess the prevalence of human papilloma virus(HPV) in esophageal squamous cell carcinoma(ESCC) in the south-eastern region of Poland.METHODS:The study population consisted of 56 ESCC patients and 35 controls.The controls were patients referred to our department due to other nonesophageal and non-oncological disorders with no gross or microscopic esophageal pathology as confirmed by endoscopy and histopathology.In the ESCC patients,samples were taken from normal mucosa(56 mucosa samples) and from the tumor(56 tumor samples).Tissue samples from the controls were taken from normal mucosa of the middle esophagus(35 control samples).Quantitative determination of DNA was carried out using a spectrophotometric method.Genomic DNA was isolated using the QIAamp DNA Midi Kit.HPV infection was identified following PCR amplification of the HPV gene sequence,using primers MY09 and MY11 complementary to the genome sequence of at least 33 types of HPV.The sequencing results were computationally analyzed using the basic local alignment search tool database.RESULTS:In tumor samples,HPV DNA was identified in 28 of 56 patients(50%).High risk HPV phenotypes(16 or/and 18) were found in 5 of 56 patients(8.9%),low risk in 19 of 56 patients(33.9%) and other types of HPV(37,81,97,CP6108) in 4 of 56 patients(7.1%).In mucosa samples,HPV DNA was isolated in 21 of 56 patients(37.5%).High risk HPV DNA was confirmed in 3 of 56 patients(5.3%),low risk HPV DNA in 12 of 56 patients(21.4%),and other types of HPV in 6 of 56 patients(10.7%).In control samples,HPV DNA was identified in 4 of 35 patients(11.4%) with no high risk HPV.The occurrence of HPV in ESCC patients was significantly higher than in the controls [28 of 56(50%) vs 4 of 35(11.4%),P < 0.001].In esophageal cancer patients,both in tumor and mucosa samples,the predominant HPV phenotypes were low risk HPV,isolated 4 times more frequently than high risk phenotypes [19 of 56(33.9%) vs 5 of 56(8.9%),P < 0.001].A higher prevalence of HPV was identified in female patients(71.4% vs 46.9%
基金This work was supported in part by National Natural Science Foundation of China(No.30170413)the Foundation for Jing Yuan FANG of National Excellent Doctoral Dissertation of China(No.199946)the Foundation of Shanghai Education Committee(Shuguang Plan,No.02SG45).
文摘The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.
基金This research was supported by the Ministry of Science and Technology Grant （2001CB510106）；Science and Technology Plan of Beijing Municipal Government （H020220050290）；National Natural Science Foundation of China Awards for 0utstanding Young Scientists （30125022）；for Creative Research Groups （30421004）；Bill ＆ Melinda Gates Foundation Grant （37871） to H Deng.
文摘The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid （RA） was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin （STZ）-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.
基金the Science and Technical Research Funds of Guangdong Province, China (Grant Nos. 2004B34001004 and04009423)
文摘To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell’s replication activity and the donor’s age factor, and to assess the stem cells as a new source for tissue engineering. hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: <20 years old, 21―40 years old, 41―60 years old and >61 years old groups). The protein markers (CD29, CD34, CD44, CD45, CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell, and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro. The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula “ log2T D = t logN t ? logN 0” was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the <20 years old group was lower than that of the >61 years old group (statistical analysis of variance (ANOVA), P=0.002, P<0.05). These find- ings suggested that a higher level of hADAS cells replication activity was found in the younger dona- tors, and they represent novel and valuable seed cells for studies of tissue engineering.
基金Supported by grants from the Nationl Natural Scientific Foundation of China, No.30300082, 30470467, and Scientific Foundation Committee of Guangdong Province, China, No.04009360
文摘AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein （pEGFP） transfer into human umbilical vein endothelial cells （HUVECs）. METHODS： HUVECs with fluorescein isothiocyanatedextran （FD500） and HUVECs with pEGFP were exposed to continuous wave （1.9 MHz, 80.0 mW/cm^2） for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS： The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone （24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001）. Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue （16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001）. No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue （94.1% ± 2.3% vs 91.1% ± 4.1% ）. CONCLUSION： The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.
基金This study was supported by the Research Fund of the Department of Guangdong Science and Technology （No. 2003C30603） and Natural Science Foundation of Guangdong （No. 5001680）.
文摘Background Human umbilical cord blood contains an abundance of immature stem/progenitor cells, which may participate in the repair of hearts that have been damaged by myocardial infarction （MI）. This study aimed to evaluate the effects of human umbilical cord blood mononuclear cells （hUCBC） transplantation on cardiac function and left ventricular remodeling in rat model of MI. Methods Forty-five male Wistar rats were randomized into three groups： MI or control group （n=15）, MI plus cell transplantation （n=15）, and sham group （n=15）. Acute myocardial infarction （AMI） was established by ligating the left anterior descending artery, thereafter, hUCBC were implanted into the marginal area of infarcted myocardium. In MI/control group, DMEM was injected instead of hUCBC following the same protocol. Left ventricular function assessment was carded out by echocardiography and invasive hemodynamic measurements one month post MI. All rats were sacrificed for histological and immunochemical examinations.Results The transplanted hUCBC survived and engaged in the process of myocardial repair in the host heart. Echocardiography demonstrated that left ventricular function improved significantly in the rats that underwent cell transplantation. Hemodynamic studies found a significantly decreased left ventricular end-diastolic pressure （LVEDP） [（21.08±8.10） mmHg vs （30.82±9.59） mmHg, P〈0.05], increase in ＋dp/dtmax [（4.29± 1.27） mmHg/ms vs （3.24±0.75） mmHg/ms, P〈0.05）, and increase in -dp/dtmax [（3.71 ±0.79） mmHg/ms vs （3.00± 0.49） mmHg/ms, P〈0.05] among MI group with hUCBC transplantation when compared with MI/control group. Masson＇s trichrome staining revealed that the collagen density in the left ventricle was significantly lower in rats of transplantation group than that in the MI control groups [（6.33±2.69）% vs （11.10±3.75）%, P〈 0.01]. Based on immunostaining of α-actin, the numbers of microvessels were significantly （P〈0.01） increased at
基金This work was supported by the National Natural Science Foundation of China(NSFC No.81322003,No.31571527,N.S.No.31501098,Q.L.,No.81500241,C.X.,No.81870600,C.L.,No-81570771 and 31871189,RZ.Q.)+1 种基金the Science and Technology Commission of Shanghai Municipality(No.17XD1400300,No.17JC1400200)the National Key R&D Program of China 2018YFC2000202,and the Haiju program of National Children’s Medical Center EK1125180102.We apologize to people whose work was relevant to but not cited in this study due to limited space。
文摘Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation system in mouse is very different from that of humans.Whether BMAL1 plays a role in regulating human heart function remains unclear.Here we generated a BMAL1 knockout human embryonic stem cell(hESC)model and further derived human BMAL1 deficient cardiomy-ocytes.We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility,cal-cium dysregulation,and disorganized myofilaments.In addition,mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes,which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomy-ocyte function.We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression.BMAL1 knockout directly reduced BNIP3 protein level,causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function.Our data indicated that the core circadian gene S/VMLf is critical for normal mitochondria activities and cardiac function.Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.
基金Council of Scientific and Industrial Research Network Grant CMM002ICMR Grant (GAP 0215)
文摘AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated with hepatic progenitor cells. METHODS： EpCAM ＋ve cells were isolated using magnetic cell sorting （MACS） from human fetuses （n = 10） at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein （AFP）, CD29 （integrin ~1）, CD49f （integrin c^6） and CD90 （Thy 1） was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ （A, B, C） and class Ⅱ （DR） expression was studied by flow cytometry only. RESULTS： FACS analysis indicated that EpCAM ＋ve cells were positive for CD29, CD49f, CD90, CD34, HLA class I, albumin and AFP but negative for HLA class Ⅱ （DR） and CD45. RT PCR showed that EpCAM ＋ve cells expressed liver epithelial markers （CK18）, biliary specific marker （CK19） and hepatic markers （albumin, AFP）. On immunocytochemical staining, EpCAM ＋ve cells were shown positive signals for CK18 and albumin. CONCLUSION： Our study suggests that these EpCAM ＋ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.
文摘BACKGROUND Premature ovarian failure(POF)affects many adult women less than 40 years of age and leads to infertility.According to previous reports,various tissue-specific stem cells can restore ovarian function and folliculogenesis in mice with chemotherapy-induced POF.Human embryonic stem cells(ES)provide an alternative source for mesenchymal stem cells(MSCs)because of their similarities in phenotype and immunomodulatory and anti-inflammatory characteristics.Embryonic stem cell-derived mesenchymal stem cells(ES-MSCs)are attractive candidates for regenerative medicine because of their high proliferation and lack of barriers for harvesting tissue-specific MSCs.However,possible therapeutic effects and underlying mechanisms of transplanted ES-MSCs on cyclophosphamide and busulfan-induced mouse ovarian damage have not been evaluated.AIM To evaluate ES-MSCs vs bone marrow-derived mesenchymal stem cells(BMMSCs)in restoring ovarian function in a mouse model of chemotherapy-induced premature ovarian failure.METHODS Female mice received intraperitoneal injections of different doses of cyclophosphamide and busulfan to induce POF.Either human ES-MSCs or BMMSCs were transplanted into these mice.Ten days after the mice were injected with cyclophosphamide and busulfan and 4 wk after transplantation of the ESMSCs and/or BM-MSCs,we evaluated body weight,estrous cyclicity,folliclestimulating hormone and estradiol hormone concentrations and follicle count were used to evaluate the POF model and cell transplantation.Moreover,terminal deoxynucleotidyl transferase mediated 2-deoxyuridine 5-triphosphate nick end labeling,real-time PCR,Western blot analysis and immunohistochemistry and mating was used to evaluate cell transplantation.Enzyme-linked immunosorbent assay was used to analyze vascular endothelial growth factor,insulin-like growth factor 2 and hepatocyte growth factor levels in ES-MSC condition medium in order to investigate the mechanisms that underlie their function.RESULTS The human ES-MSCs significantly restored hormone s
基金Supported by Key Technology R&D Program of Hubei Province, No.2004AA304B08
文摘AIM： To look for the evidence of human papilloma virus （HPV） infection in esophageal squamous cell carcinomas （ESCC） and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of esophageal carcinomas in Henan emigrants. METHODS： Papilloma virus （PV） and HPV were determined by UltrasensiveTM S-P immunohistochemistry （IHC） and in situ hybridization （ISH） in esophageal carcinoma tissues （82 cases） and the normal mucosa （40 cases）. RESULTS： IHC revealed that the positive rate of PV was 75.0%, 68.18% and 72.5% respectively while the HPV （16/18-E6） positive rate was 45.0%, 36.36%, 37.5%, respectively in esophageal carcinoma tissue specimens from Henan emigrants,the local citizens and patients in Hubei Cancer Hospital. The PV and HPV （16/18-E6） were negative in all normal esophageal mucosa specimens. No correlation was found between HPV in esophageal squamous cell carcinoma tissues and in grade 1-3 esophageal squamous cell carcinoma cells. In situ hybridization showed that the HPV （16/18） DNA positive rate was 30.0%, 31.8%, 25.0%, respectively in the 3 groups of samples. No positive hybridization signal was found in 40 normal esophageal mucosa specimens. The positive rate of HPV （16/18） DNA in the esophageal carcinoma specimens was significantly higher than that in normal mucosa specimens （P〈0.05）. The positive rate was not different among the 3 groups of esophageal carcinoma tissue specimens （P〉0.05）.CONCLUSION： HPV infection is high in esophageal carcinoma of Henan emigrants, local residents and patients in Hubei Cancer Hospital. HPV is closely related with esophageal squarnous cell carcinoma. HPV infection may play an important role in esophageal squarnous cell carcinoma.
文摘AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h incubation, cytotoxicity and apoptosis evaluations were determined by MTT and DNA fragmentation assay, respectively. After treatment with SWE, mitochondrial membrane potential (MMP) was determined by measuring the retention of the dye 3,3'-dihexyloxacarbocyanine (DiOC6(3)) and the protein expression including cytochrome C and poly-(ADPribose) polymerase (PARP) were measured by Western blotting. Caspase-3 and -9 enzyme activities were measured using specific fluorescence dyes such as Ac-DEVD-AFC and Ac-LEHD-AFC. RESULTS: We found that treatment with SWE induced apoptosis as confirmed by discontinuous DNA fragmentation in cultured human hepatoma HepG2 cells. Our investigation also showed that SWE-induced apoptosis of HepG2 cells were associated with intracellular events including disruption of MMP, increased translocation of cytochrome C from mitochondria to cytosol, activation of caspase-3, and PARP. Pre-treatment of N-acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), a caspase-3 specific inhibitor, or cyclosporin A (CsA), an inhibitor of MMP disruption, completely abolished SWE-induced DNA fragmentation. CONCLUSION: These results suggest that SWE possibly causes mitochondrial damage, leading to cytochrome C release into cytosol and activation of caspases resulting in PARP cleavage and execution of apoptotic cell death in HepG2 cells. These results further suggest that Scorpio may be a valuable agent of therapeutic intervention of human hepatomas.
文摘AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.
