SIRT1 inhibits apoptosis of human lens epithelial cells through suppressing endoplasmic reticulum stress in vitro and in vivo

AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing endoplasmic reticulum(ER)stress.METHODS:HLECs(SRA01/04)were treated with varying concentrations of tunicamycin(TM)for 24h,and the expression of SIRT1 and C/EBP homologous protein(CHOP)was assessed using real-time quantitative polymerase chain reaction(RT-PCR),Western blotting,and immunofluorescence.Cell morphology and proliferation was evaluated using an inverted microscope and cell counting kit-8(CCK-8)assay,respectively.In the SRA01/04 cell apoptosis model,which underwent siRNA transfection for SIRT1 knockdown and SRT1720 treatment for its activation,the expression levels of SIRT1,CHOP,glucose regulated protein 78(GRP78),and activating transcription factor 4(ATF4)were examined.The potential reversal of SIRT1 knockdown effects by 4-phenyl butyric acid(4-PBA;an ER stress inhibitor)was investigated.In vivo,age-related cataract(ARC)rat models were induced by sodium selenite injection,and the protective role of SIRT1,activated by SRT1720 intraperitoneal injections,was evaluated through morphology observation,hematoxylin and eosin(H&E)staining,Western blotting,and RT-PCR.RESULTS:SIRT1 expression was downregulated in TMinduced SRA01/04 cells.Besides,in SRA01/04 cells,both cell apoptosis and CHOP expression increased with the rising doses of TM.ER stress was stimulated by TM,as evidenced by the increased GRP78 and ATF4 in the SRA01/04 cell apoptosis model.Inhibition of SIRT1 by siRNA knockdown increased ER stress activation,whereas SRT1720 treatment had opposite results.4-PBA partly reverse the adverse effect of SIRT1 knockdown on apoptosis.In vivo,SRT1720 attenuated the lens opacification and weakened the ER stress activation in ARC rat models.CONCLUSION:SIRT1 plays a protective role against TM-induced apoptosis in HLECs and slows the progression of cataract in rats by inhibiting ER stress.These findings suggest a novel strategy for cataract treatment focused on targeting ER stress,highlighting the therapeutic potential of SIRT1 modulation in ARC development.

Parthenolide protects human lens epithelial cells from oxidative stress-induced apoptosis via inhibition of activation of caspase-3 and caspase-9

The apoptosis of lens epithehal cells has been proposed as the common basis of cataract formation, with oxidative stress as the major cause. This study was performed to investigate the protective effect of the herbal constituent parthenolide against oxidative stress-induced apoptosis of human lens epithelial （HLE） cells and the possible molecular mechanisms involved. HLE cells （SRA01-04） were incubated with 50 μM H2O2 in the absence or presence of different doses of parthenolide （10, 20 and 50 μM）. To study apoptosis, the cells were assessed by morphologic examination and Annexin V-propidium iodide double staining flow cytometry; to investigate the underlying molecular mechanisms, the expression of caspase-3 and caspase-9 were assayed by Western blot and quantitative RT-PCR, and the activities of caspase-3 and caspase-9 were measured by a Chemicon caspase colorimetric activity assay kit. Stimulated with H202 for 18 h, a high fraction of riLE cells underwent apoptosis, while in the presence ofparthenolide of different concentrations, dose-dependent blocking of HLE cell apoptosis was observed. The expression of caspase-3 and caspase-9 induced by H202 in HLE cells was significantly reduced by parthenolide both at the protein and mRNA levels, and the activation ofcaspase-3 and caspase-9 was also suppressed by parthenolide in a dose-dependent manner. In conclusion, parthenolide prevents HLE cells from oxidative stress-induced apoptosis through inhibition of the activation ofcaspase-3 and caspase-9, suggesting a potential protective effect against cataract formation.

Quercetin exerts anti-inflammatory effects via inhibiting tumor necrosis factor-α-induced matrix metalloproteinase-9 expression in normal human gastric epithelial cells

BACKGROUND Gastric injury is the most common digestive system disease worldwide and involves inflammation,which can lead to gastric ulcer or gastric cancer(GC).Matrix metallopeptidase-9[MMP-9(gelatinase-B)]plays an important role in inflammation and GC progression.Quercetin and quercetin-rich diets represent potential food supplements and a source of medications for treating gastric injury given their anti-inflammatory activities.However,the effects and mechanisms of action of quercetin on human chronic gastritis and whether quercetin can relieve symptoms remain unclear.AIM To assess whether tumor necrosis factor-α(TNF-α)-induced MMP-9 expression mediates the anti-inflammatory effects of quercetin in normal human gastric mucosal epithelial cells.METHODS The normal human gastric mucosa epithelial cell line GES-1 was used to establish a normal human gastric epithelial cell model of TNF-α-induced MMP-9 protein overexpression to evaluate the antiinflammatory effects of quercetin.The cell counting Kit-8 assay was used to evaluate the effects of varying quercetin doses on cell viability in the normal GES-1 cell line.Cell migration was measured using Transwell assay.The expression of proto-oncogene tyrosine-protein kinase Src(cSrc),phospho(p)-c-Src,extracellular-signal-regulated kinase 2(ERK2),p-ERK1/2,c-Fos,p-c-Fos,nuclear factor kappa B(NF-κB/p65),and p-p65 and the effects of their inhibitors were examined using Western blot analysis and measurement of luciferase activity.p65 expression was detected by immunofluorescence.MMP-9 m RNA and protein levels were measured by quantitative reverse transcription polymerase chain reaction(q RT–PCR)and gelatin zymography,respectively.RESULTS q RT-PCR and gelatin zymography showed that TNF-αinduced MMP-9 m RNA and protein expression in a dose-and time-dependent manner.These effects were reduced by the pretreatment of GES-1 cells with quercetin or a TNF-αantagonist(TNFR inhibitor)in a dose-and timedependent manner.Quercetin and TNF-αantagonists decreased the TNF-α-induced phosphorylation of c-Src,ERK1/2,c-Fos,and p65 in a dose-and time-dependent manner.Quercetin,TNF-αantagonist,PP1,U0126,and tanshinone IIA(TSIIA)reduced TNF-α-induced c-Fos phosphorylation and AP-1–Luciferase(Luc)activity in a dose-and time-dependent manner.Pretreatment with quercetin,TNF-αantagonist,PP1,U0126,or Bay 11-7082 reduced TNF-α-induced p65 phosphorylation and translocation and p65–Luc activity in a dose-and timedependent manner.TNF-αsignificantly increased GES-1 cell migration,and these results were reduced by pretreatment with quercetin or a TNF-αantagonist.CONCLUSION Quercetin significantly downregulates TNF-α-induced MMP-9 expression in GES-1 cells via the TNFR-c-Src–ERK1/2 and c-Fos or NF-κB pathways.

MicroRNA-34a promoting apoptosis of human lens epithelial cells through down-regulation of B-cell lymphoma-2 and silent information regulator

AIM： To investigate the role of micro RNA-34a（mi R-34a） in the induction of apoptosis of human lens epithelial（HLE-B3） cells. METHODS： The apoptosis of HLE-B3 cells was detected by Annexin V-PE apoptosis detection kit after the treatment with 200 μmol/L H2O2 for 24h and lentiviral mi R-34 a vector transfection. The expression of mi R-34 a in the cells was quantified by quantitative real time polymerase chain reaction（q RT-PCR） in response to H2O2 exposure and the vector transfection. The effects of overexpression of mi R-34 a on the expression of B-cell lymphoma-2（Bcl-2） and silent information regulator 1（SIRT1） was determined by q RT-PCR and Western blot. RESULTS： The expression of mi R-34 a was up-regulated by the treatment of H2O2 in HLE-B3 cells. The increased expression of mi R-34 a is accompanied with the cell apoptosis. Consistence with the H2O2 exposure,ectopic overexpression of mi R-34 a in HLE-B3 cells promoted cells apoptosis. Importantly the anti-apoptosis factors Bcl-2 and SIRT1 were reduced significantly by up-regulation of mi R-34 a in HLE-B3 cells.CONCLUSION： Mi R-34 a promotes the apoptosis of HLE-B3 cells by down-regulating Bcl-2 and SIRT1,suggesting that mi R-34 a may involve in the pathogenesis of cataract formation and targeting mi R-34 a may be a potentially therapeutic approach for treatment of cataract.

Monoamine alterations and rotational asymmetry in a rat model of Parkinson's disease following lateral ventricle transplantation of human amniotic epithelial cells

BACKGROUND： Human amniotic epithelial cells （HAECs） can differentiate into neurons, astrocytes and oligodendrocytes. They biologically secrete many active neurotrophins and have the capacity to metabolize dopamine enzymes. These features underlie a theoretical basis for the treatment of Parkinson＇s disease （PD）. OBJECTIVE： To investigate the survival and differentiation of transplanted HAECs in the lateral ventricle of PD model rats, and to explore its effect on circling behavior, as well as levels of dopamine （DA）, the metabolite homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, and Shanghai Celstar Institute of Biotechnology from May 2007 to December 2008. MATERIALS： HAECs were derived from the placental chorion following caesarean delivery at the Shanghai International Matemal and Child Health Hospital. 6-hydroxydopamine （6-OHDA）, and mouse anti-human Vimentin monoclonal antibody were purchased from Sigma, USA; mouse anti-human nestin and tyrosine hydroxylase （TH） monoclonal antibodies were purchased from Chemicon, USA. METHODS： A total of 114 healthy, adult, Sprague Dawley rats were randomly assigned to two groups： PD model [n = 90, stereotactic microinjection of 2 μL 6-OHDA （3.5 μg/uL） into the striatum] and control （n = 24, no treatment）. The 51 successful PD model rats were randomly divided into 3 subgroups （n = 17）： HAEC, PBS, and model. The HAEC and PBS groups were respectively injected with 10 μL PBS solution containing 1 × 10^5/mL HAECs or 10 pL PBS into the lateral ventricle. The model group was not treated. MAIN OUTCOME MEASURES： TH protein expression in the striatum was evaluated by immunohistochemistry 5 weeks after HAEC transplantation. At 10 weeks, HAEC survival in the lateral ventricle was investigated by immunofluorescent staining; differentiation of HAECs in the lateral and third ventricles was examined by TH immunohistochemistry; concentrations of DA, homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum, as well as DA concentration in the cerebrospinal fluid, were measured with high-performance liquid chromatography-electrochemical detection. Circling behavior of PD model rats was consecutively observed for 10 weeks following intraperitoneal injection of amphetamine 1 week after successful model establishment. RESULTS： tn the HAEC group, the number of TH-positive cells significantly increased in the striatum, and circling behavior significantly decreased, compared with the PBS and model groups （P 〈 0.01）. In addition, monoamine concentrations in the striatum, as well as DA concentrations in the cerebrospinal fluid, significantly increased, compared with the PBS group （P 〈 0.05-0.01）. Moreover, a large number of nestin-, vimentin-, and TH-positive cells were observed in the lateral and third ventricles following HAEC injection.CONCLUSION： HAECs survived for 10 weeks with no overgrowth following transplantation into the lateral ventricle of PD model rats. Moreover, the cells differentiated into dopaminergic neurons, which increased DA secretion. HAEC transplantation improved cycling behavior in PD model rats.

In vitro inhibition of proliferation,migration and epithelial-mesenchymal transition of human lens epithelial cells by fasudil

AIM： To study the potential role of fasudil as a treatment for posterior capsular opacification（PCO） of the human crystalline lens.METHODS： Human lens epithelial cells（HLECs; line SRA01/04） was exposed to transforming growth factor-β2（TGF-β2） to induce the process of epithelial-mesenchymal transition（EMT）. Fasudil was applied to the cell samples. Its effect on overall HLECs proliferation and migration was studied, as was its influence on EMT induction by TGF-β2 using cell migration assay, MTT colorimetric assay and Western blot assay.RESULTS： Fasudil inhibited the proliferation of SRA01/04. Its effect was time-and concentration-dependent. The migration of SRA01/04 cells was significantly reduced 24-72 h after fasudil treatment, and the half maximal inhibitory concentration（IC50） was 22.37 μmol/mL at 72 h. Reversal of the elongated, fibroblast-like shape changes induced by TGF-β2 in SRA01/04 cells was observed. Fasudil up-regulated the expression of Connexin43 protein and down-regulated the expression of α-SMA protein compared with the cells treated with TGF-β2. Furthermore, when exposed to fasudil, the phosphorylation of Rhoassociated protein kinase（Rock） and myosin light chain（MLC） could not be activated in the cell preparations.CONCLUSION： Fasudil suppresses the proliferation and migration of SRA01/04 cells, and inhibits the process of EMT induced by TGF-β2. These results suggest that fasudil may serve as a therapeutic agent for PCO.

Effects of Sodium Salicylate on the Expression of HSP27 Protein during Oxidative Stress in Tissue-cultured Human Lens Epithelial Cells

The effects of sodium salicylate on the expression of heat shock protein 27 （HSP27） during oxidative stress in tissue-cultured human lens epithelial cells were investigated. Cultured human lens epithelial cells （HLB-3） were divided into 3 groups： control group （group A）, oxidation injury group （group B） and sodium salicylate group （group C）. Apoptosis of human lens epithelial cells cultured in vitro was induced in the presence of 150 μmol/L H2O2. Cells viability and the expression of HSP27 were analyzed. Viability of the cells was measured by methyl thiazole tetrazolium （MTT） chromatometry. The expression of HSP27 in HLB-3 cells was detected by using immunohistochemistry and image analysis system, Sodium salicylate could induce the expression of HSP27, and the cells viability in group C was significantly higher than in group B （0.2667±0.01414 vs 0.2150±0.01080, P=0.012〈0.05）. The average gray value of HSP27 in group B was less than that in group C （P=0.000〈0.05）. The increased expression of HSP27 by sodium salicylate might play an important role in the protection of hydrogen peroxide-induced injury of human lens epithelial cells, suggesting that sodium salicylate could suppress, at least in part, the apoptosis of human lens epithelial cells.

Effects of Rapamycin on Expression of Bcl-2 and Bax in Human Lens Epithelial Cells and Cell Cycle in Rats

The effects of rapamycin on the expression of Bcl-2 and Bax protein in in vitro cultured human lens epithelial cells（LECs） and cell cycle were investigated in order to provide the theoretical basis for the development of new inhibitory drugs for clinical prevention and treatment of after-cataract.The cultured LECs of second and third passages were collected and treated with rapamycin.The LECs were transferred into 96-well culture plates and divided into 6 groups,and each group was set to have 8 duplicate wells.In the negative control group,the LECs were given culture medium only,and in the blank control group,only culture medium was given.In the four rapamycin-treated groups,different concentrations（20,40,60 and 80 ng/mL） of rapamycin were given.After treatment for 24,48 and 72 h,the absorbance（A） values in each well were determined by MTT assay.The cell cycles of all groups were detected by using flow cytometry.Real-time fluorescent quantitative polymerase chain reaction（RFQ-PCR） and Western blot were used to detect the mRNA and protein expression of Bcl-2 and Bax respectively.MTT assay showed that rapamycin could inhibit proliferation of LECs in a time-and dose-dependent manner.Flow cytometry revealed that rapamycin could block the conversion of LECs from G1 phase to S phase,resulting in the increase of cells in G1 phase and the decrease of the cells in S phase.RFQ-PCR indicated that rapamycin could down-regulate the expression of Bcl-2 mRNA,but up-regulate the expression of Bax mRNA,suggesting it could induce apoptosis of LECs.Western blot demonstrated that rapamycin could suppress the expression of Bcl-2 protein,but promote the expression of Bax protein.It is concluded that rapamycin could inhibit proliferation of LECs probably not only by blocking the progression of cell cycle,but also by promoting the induction of apoptosis.

Alterations of FHIT Gene and P16 Gene in Nickel Transformed Human Bronchial Epithelial Cells

Objective To study the alterations of FHIT gene and P16 gene in malignant transformed human bronchial epithelial cells induced by crystalline nickel sulfide using an immortal human bronchial epithelial cell line, and to explore the molecular mechanism of nickel carcinogenesis. Methods 16HBE cells were treated 6 times with different concentrations of NiS in vitro, and the degree of malignant transformation was determined by assaying the anchorage-independent growth and tumorigenicity. Malignant transformed cells and tumorigenic cells were examined for alterations of FHIT gene and P16 gene using RT-PCR, DNA sequencing, silver staining PCR-SSCP and Western blotting. Results NiS-treated cells exhibited overlapping growth. Compared wkh that of negative control cells, soft agar colony formation efficiency of NiS-treated cells showed significant increases （P〈0.01） and dose-dependent effects. NiS-treated cells could form tumors in nude mice, and a squamous cell carcinoma was confirmed by histopathological examination. No mutation of exon 2 and exons 2-3, no abnormal expression in pl6 gene and mutation of FHIT exons 5-8 and exons 1-4 or exons 5-9 were observed in transformed cells and tumorigenic cells. However, aberrant transcripts or loss of expression of the FHIT gene and Fhit protein was observed in transformed cells and tumorigenic cells. One of the aberrant transcripts in the FHIT gene was confirmed to have a deletion of exon 6, exon 7, exon 8, and an insertion of a 36 bp sequence replacing exon 6-8. Conclusions The FHIT gene rather than the P16 gene, plays a definite role in nickel carcinogenesis. Alterations of the FHIT gene induced by crystalline NiS may be a molecular event associated with carcinogen, chromosome fragile site instability and cell malignant transformation. FHIT may be an important target gene activated by nickel and other exotic carcinogens.

Transplantation of human amniotic epithelial cells repairs brachial plexus injury:pathological and biomechanical analyses

A brachial plexus injury model was established in rabbits by stretching the C6 nerve root. Imme- diately after the stretching, a suspension of human amniotic epithelial cells was injected into the injured brachial plexus. The results of tensile mechanical testing of the brachial plexus showed that the tensile elastic limit strain, elastic limit stress, maximum stress, and maximum strain of the injured brachial plexuses were significantly increased at 24 weeks after the injection. The treatment clearly improved the pathological morphology of the injured brachial plexus nerve, as seen by hematoxylin eosin staining, and the functions of the rabbit forepaw were restored. These data indicate that the injection of human amniotic epithelial cells contributed to the repair of brachial plexus injury, and that this technique may transform into current clinical treatment strategies.

Human amniotic epithelial cells express specific markers of nerve cells and migrate along the nerve fibers in the corpus callosum

Human amniotic epithelial cells were isolated from a piece of fresh amnion. Using immunocytochemical methods, we investigated the expression of neuronal phenotypes （microtubule-associated protein-2, glial fibrillary acidic protein and nestin） in human amniotic epithelial cells. The conditioned medium of human amniotic epithelial cells promoted the growth and proliferation of rat glial cells cultured in vitro, and this effect was dose-dependent. Human amniotic epithelial cells were further transplanted into the corpus striatum of healthy adult rats and the grafted cells could integrate with the host and migrate 1 2 mm along the nerve fibers in corpus callosum. Our experimental findings indicate that human amniotic epithelial cells may be a new kind of seed cells for use in neurograft.

Effect of peroxisome proliferator-activated receptor-gamma ligand on inflammation of human gallbladder epithelial cells

AIM： To investigate the effect of peroxisome proliferatoractivated receptor gamma （PPAR-γ） and its ligand, ciglitazone, on inflammatory regulation of human gallbladder epithelial cells （HGBECs） and to assess the effect of human epithelial growth factor （hEGF） on growth of HGBECs. METHODS： HGBECs were cultured in media containing hEGF or in hEGF-free media. HGBECs were divided into normal control group, inflammatory control group and ciglitazone group （test group）. Inflammatory control group and ciglitazone group were treated with 5 μg/L of human interleukin-1β（hIL-1β） to make inflammatory model of HGBECs. The ciglitazone group was treated with various concentrations of ciglitazone, a potent ligand of PPAR-y. Subsequently, interleukin-8 （IL-8）, IL-6, and tumor necrosis factor-α （TNF-α） concentrations in all groups were measured. The data were analyzed statistically. RESULTS： HGBECs were cultured in medium successfully. The longevity of HGBECs in groups containing hEGF was longer than that in hEGF-free groups. So was the number of HGBECs. The longest survival time of HGBEC was 25 d. The inflammatory model of HGBECs was obtained by treating with hIL-1β. The concentrations of IL-6 and IL-8 in ciglitazone group were lower than those in inflammatory conlyol group （P〈0.05）. The secretion of IL-6 in inflammatory control group was higher （350.31±37.05 μg/L） than that in normal control group （50.0±0.00 μg/L, P〈0.001）. Compared to normal control group, IL-8 concentration in inflammatory control was higher （P〈0.05）. CONCLUSION： hEGF improves the growth of HGBECs in vitro. Ciglitazone inhibits the inflammation of HGBECs in vitro and has potential therapeutic effect on cholecystitis in vivo.

In vitro reconstruction and characterization of tissue-engineered human corneal epithelium with seeder cells from an untransfected human corneal epithelial cell line

AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were reconstructed in vitro with seeder cells from an untransfected HCEP cell line, and scaffold carriers of denuded amniotic membrane (dAM) in air-liquid interface culture for 3, 5, 7 and 9 days, respectively. The specimens were examined with hematoxylin-eosin (HE) staining of paraffin-section, immunocytochemical staining, scanning and transmission electron microscopy. RESULTS: During in vitro reconstruction of TE-HCEP, HCEP cells formed a 3-4, 6-7 and 8-10 layers of an HCEP-like structure on dAMs in air-liquid interface culture for 3, 5 and 7 days, respectively. But the cells deceased to 5-6 layers and the structure of straified epithelium became loose at day 9. And the cells maintained positive expression of marker proteins (keratin 3 and keratin 12), cell-junction proteins (zonula occludens-1, E-cadherin, connexin 43 and integrin beta 1) and membrane transport protein of Na+-K+ ATPase. The HCEP cells in TE-HCEP were rich in microvilli on apical surface and established numerous cell-cell and cell-dAM junctions at day 5. CONCLUSION: The morphology and structure of the reconstructed TE-HCEP were similar to those of HCEP in vivo. The HCEP cells in the reconstructed TE-HCEP maintained the properties of HCEP cells, including abilities of forming intercellular and cell-extracellular matrix junctions and abilities of performing membrane transportation. The untransfected HCEP cells and dAMs could promisingly be used in reconstruction HCEP equivalent for clinical corneal epithelium transplantation.

Effects of transforming growth factor β2 and connective tissue growth factor on induction of epithelial mesenchymal transition and extracellular matrix synthesis in human lens epithelial cells

AIM:To Investigate the effects of transforming growth factorβ2(TGF-β2)and connective tissue growth factor(CTGF)on transdifferentiation of human lens epithelial cells(HLECs)cultured in vitro and synthesis of extracellular matrix(ECM).METHODS:HLECs were treated with TGF-β2(0,0.5,1.0,5,10μg/L)and CTGF(0,15,30,60,100μg/L)for different times(0,24,48,72h)in vitro and the expression ofα-smooth muscle actin(α-SMA),the main component of the extracellular matrix typeⅠcollagen(Col-1)and fibronectin(Fn)were measured by using real-time polymerase chain reaction(PCR)and western-blot.RESULTS:TGF-β2 and CTGF significantly increased expression ofα-SMA mRNA and protein(P【0.05,P【0.001),Fn mRNA and protein(P【0.001),Col-1 mRNA and protein(P【0.001).TGF-β2 could induce HLECs expression of CTGF mRNA and protein in dosedependent manner(P【0.05,P【0.001).TGF-β2 and CTGF could induce HLECs to expressα-SMA,Fn and Col-1 in time-dependent manner.Each time of TGF-β2and CTGF induced HELCs expression ofα-SMA,Fn,Col-1 mRNA and protein was significant increase compared with control(P【0.05,P【0.001).CONCLUSION:TGF-β2 and CTGF could induce HLECs epithelial mesenchymal transition and ECM synthesis.

Helicobacter pylori damages human gallbladder epithelial cells in vitro

AIM: To study the mechanism by which Helicobacter pylori (H pylori) damages human gallbladder epithelial cells (HGBEC). METHODS: H pylori isolated from gallbladder were cultured in a liquid medium. Different concentration supernatants and sonicated extracts of H pylori cells were then added to HGBEC in a primary culture. The morphological changes in HGBEC as well as changes in the levels of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and glutamyltransferase (GGT) were measured.RESULTS: According to the culture curve of HGBEC, it was convenient to study the changes in HGBEC by adding H pylori sonicated extracts and H pylori culture supernatants. Both H pylori sonicated extracts and H pylori culture supernatants had a significant influence on HGBEC morphology, i.e. HGBEC grew more slowly, their viability decreased and their detachment increased. Furthermore, HGBEC ruptured and died. The levels of ALP (33.84 ± 6.00 vs 27.01 ± 4.67, P < 0.05), LDH (168.37 ± 20.84 vs 55.51 ± 17.17, P < 0.01) and GGT (42.01 ± 6.18 vs 25.34 ± 4.33, P < 0.01) significantly increased in the HGBEC culture supernatant in a time-and concentration-dependent. The damage to HGBEC in H pylori culture liquid was more significant than that in H pylori sonicated extracts. CONCLUSION: H pylori induces no obvious damage to HGBEC.

A panel of monoclonal antibodies against the prion protein proves that there is no prion protein in human pancreatic ductal epithelial cells

Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay(ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells(HPDC).

Possible Role of DNA Polymerase beta in Protecting Human Bronchial Epithelial Cells Against Cytotoxicity of Hydroquinone

Objective To explore the toxicological mechanism of hydroquinone in human bronchial epithelial cells and to investigate whether DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone. Methods DNA polymerase beta knock-down cell line was established via RNA interference as an experimental group. Normal human bronchial epithelial cells and cells transfected with the empty vector of pEGFP-C1 were used as controls. Cells were treated with different concentrations of hydroquinone （ranged from 10 μmol/L to 120 μmol/L） for 4 hours. MTT assay and Comet assay [single-cell gel electrophoresis （SCGE）] were performed respectively to detect the toxicity of hydroquinone. Results assay showed that DNA polymerase beta knock-down cells treated with different concentrations of hydroquinone had a lower absorbance value at 490 nm than the control cells in a dose-dependant manner. Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in DNA polymerase beta knock-down cell line than in control cells and there was no significant difference in the two control groups. Conclusions Hydroquinone has significant toxicity to human bronchial epithelial cells and causes DNA damage. DNA polymerase beta knock-down cell line appears more sensitive to hydroquinone than the control cells. The results suggest that DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

Alterative Expression and Sequence of Human Elongation Factor-1δ during Malignant Transformation of Human Bronchial Epithelial Cells Induced by Cadmium Chloride

Objective To study the alternative expression and sequence of human elongation factor-1δ （human EF-1δ p31） during malignant transformation of human bronchial epithelial cells induced by cadmium chloride （CdCl2） and its possible mechanism. Methods Total RNA was isolated at different stages of transformed human bronchial epithelial cells （16HBE） induced by CdCl2 at a concentration of 5.0 μM. Special primers and probe for human EF-1δ p31 were designed and expression of human EF-18 mRNA from different cell lines was detected with fluorescent quantitative PCR technique. EF-18 cDNA from different cell lines was purified and cloned into pMD 18-T vector followed by confirming and sequencing analysis. Results The expressions of human EF-1δ p31 at different stages of 16HBE cells transformed by CdCl2 was elevated （P〈0.01 or P〈0.05）. Compared with their corresponding non-transformed ceils, the overexpression level of EF-15 p31 was averagely increased 2.9 folds in Cd-pretransformed cells, 4.3 folds in Cd-transformed ceils and 7.2 folds in Cd-tumorigenic cells. No change was found in the sequence of overexpressed EF-1δ p31 at different stages of 16HBE cells transformed by CdCl2. Conclusion Overexpression of human EF-1δ p31 is positively correlated with malignant transformation of 16HBE cells induced by CdCl2, but is not correlated with DNA mutations.

Effects of lentiviral RNA interference-mediated downregulation of integrin-linked kinase on biological behaviors of human lens epithelial cells

AIM：To investigate the effects of lentivirus（LV）mediated integrin-linked kinase（ILK）RNA interference（RNAi）on biological behaviors of human lens epithelial cells（LECs）.·METHODS：Human cataract LECs and immortalized human LEC line,human lens epithelial（HLE）B-3 cells were transfected by lentiviral vector expressing ILKspecific short hairpin RNA（sh RNA）and then stimulated by transforming growth factor-β（TGF-β）,the silencing of ILK gene and protein was identified by reverse transcription-polymerase chain reaction（RT-PCR）and Western blot methods;biological behaviors including cell cycle and apoptosis,cell morphology,α-smooth muscle actin（SMA）stress fiber formation and cell migration were examined.·RESULTS：Remarkable decreases of ILK protein expression were detected in LECs carrying lentiviral ILK-sh RNA vector;flow cytometry revealed arresting of cell cycle progression through the G1/S transition and higher apoptosis rate in ILK-RNAi-LV transfected cells.Lessα-SMA stress fiber formation and migration was observed in ILK-RNAi-LV transfected LECs.·CONCLUSION：The present study demonstrated that ILK was an important regulator for LECs proliferation and migration.LV mediated ILK RNAi is an effective way todecrease ILK-regulated cell growth by arresting cell cycle progression and increasing cell apoptosis,as well as,to prevent cell migration by inhibiting TGF-βinducedα-SMA stress fiber formation.Thus,LV mediated ILK RNAi might be useful to prevent posterior capsular opacification.

Transcriptional Factor Snail Mediates Epithelial-Mesenchymal Transition in Human Bronchial Epithelial Cells Induced by Silica

Epithelial-mesenchymal transition （EMT） plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells （BECs）; however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTr assay, western blot, electrophoretic mobility shift assay （EMSA）, and small interfering RNA （siRNA） transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI silica-induced expression siRNA upregulated the siRNA inhibited the of Snail. Moreover, SNAI expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker a-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.