954 resultados para human amnion epithelial cell transplantation


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Although mutations in intermediate filament proteins cause many human disorders, the detailed pathogenic mechanisms and the way these mutations affect cell metabolism are unclear. In this study, selected keratin mutations were analysed for their effect on the epidermal stress response. Expression profiles of two keratin-mutant cell lines from epidermolysis bullosa simplex patients (one severe and one mild) were compared to a control keratinocyte line before and after challenge with hypo-osmotic shock, a common physiological stress that transiently distorts cell shape. Fewer changes in gene expression were found in cells with the severely disruptive mutation (55 genes altered) than with the mild mutation (174 genes) or the wild type cells (261 genes) possibly due to stress response pre-activation in these cells. We identified 16 immediate-early genes contributing to a general cell response to hypo-osmotic shock, and 20 genes with an altered expression pattern in the mutant keratin lines only. A number of dual-specificity phosphatases (MKP-1, MKP-2, MKP-3, MKP-5 and hVH3) are differentially regulated in these cells, and their downstream targets p-ERK and p-p38 are significantly up-regulated in the mutant keratin lines. Our findings strengthen the case for the expression of mutant keratin proteins inducing physiological stress, and this intrinsic stress may affect the cell responses to secondary stresses in patients' skin.

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Epidemiological studies have shown that ingestion of isoflavone-rich soy products is associated with a reduced risk for the development of breast cancer. In the present study, we investigated the hypothesis that genistein modulates the expression of glutathione S-transferases (GSTs) in human breast cells, thus conferring protection towards genotoxic carcinogens which are GST substrates. Our approach was to use human mammary cell lines MCF-10A and MCF-7 as models for non-neoplastic and neoplastic epithelial breast cells, respectively. MCF-10A cells expressed hGSTA1/2, hGSTA4-4, hGSTM1-1 and hGSTP1-1 proteins, but not hGSTM2-2. In contrast, MCF-7 cells only marginally expressed hGSTA1/2, hGSTA4-4 and hGSTM1-1. Concordant to the protein expression, the hGSTA4 and hGSTP1 mRNA expression was higher in the non-neoplastic cell line. Exposure to genistein significantly increased hGSTP1 mRNA (2.3-fold), hGSTP1-1 protein levels (3.1-fold), GST catalytic activity (4.7-fold) and intracellular glutathione concentrations (1.4-fold) in MCF-10A cells, whereas no effects were observed on GST expression or glutathione concentrations in MCF-7 cells. Preincubation of MCF-10A cells with genistein decreased the extent of DNA damage by 4-hydroxy-2-nonenal (150 mu M) and benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (50 mu M), compounds readily detoxified by hGSTA4-4 and hGSTP1-1. In conclusion, genistein pretreatment protects non-neoplastic mammary cells from certain carcinogens that are detoxified by GSTs, suggesting that dietary-mediated induction of GSTs may be a mechanism contributing to prevention against genotoxic injury in the aetiology of breast cancer.

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Corneal tissue engineering has improved dramatically over recent years. It is now possible to apply these technological advancements to the development of superior in vitro ocular surface models to reduce animal testing. We aim to show the effect different substrates can have on the viability of expanded corneal epithelial cells and that those which more accurately mimic the stromal surface provide the most protection against toxic assault. Compressed collagen gel as a substrate for the expansion of a human epithelial cell line was compared against two well-known substrates for modeling the ocular surface (polycarbonate membrane and conventional collagen gel). Cells were expanded over 10 days at which point cell stratification, cell number and expression of junctional proteins were assessed by electron microscopy, immunohistochemistry and RT-PCR. The effect of increasing concentrations of sodium lauryl sulphate on epithelial cell viability was quantified by MTT assay. Results showed improvement in terms of stratification, cell number and tight junction expression in human epithelial cells expanded upon either the polycarbonate membrane or compressed collagen gel when compared to a the use of a conventional collagen gel. However, cell viability was significantly higher in cells expanded upon the compressed collagen gel. We conclude that the more naturalistic composition and mechanical properties of compressed collagen gels produces a more robust corneal model.

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Independent studies have demonstrated that flagella are associated with the invasive process of Salmonella enterica serotypes, and aflagellate derivatives of Salmonella enterica serotype Enteritidis are attenuated in murine and avian models of infection. One widely held view is that the motility afforded by flagella, probably aided by chemotactic responses, mediates the initial interaction between bacterium and host cell. The adherence and invasion properties of two S. Enteritidis wild-type strains and isogenic aflagellate mutants were assessed on HEp-2 and Div-1 cells that are of human and avian epithelial origin, respectively. Both aflagellate derivatives showed a significant reduction of invasion compared with wild type over the three hours of the assays. Complementation of the defective fliC allele recovered partially the wild-type phenotype. Examination of the bacterium-host cell interaction by electron and confocal microscopy approaches showed that wild-type bacteria induced ruffle formation and significant cytoskeletal rearrangements on HEp-2 cells within 5 minutes of contact. The aflagellate derivatives induced fewer ruffles than wild type. Ruffle formation on the Div-1 cell line was less pronounced than for HEp-2 cells for wild-type S. Enteritidis. Collectively, these data support the hypothesis that flagella play an active role in the early events of the invasive process.

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A framework for understanding the complexity of cancer development was established by Hanahan and Weinberg in their definition of the hallmarks of cancer. In this review, we consider the evidence that parabens can enable development in human breast epithelial cells of 4/6 of the basic hallmarks, 1/2 of the emerging hallmarks and 1/2 of the enabling characteristics. Hallmark 1: parabens have been measured as present in 99% of human breast tissue samples, possess oestrogenic activity and can stimulate sustained proliferation of human breast cancer cells at concentrations measurable in the breast. Hallmark 2: parabens can inhibit the suppression of breast cancer cell growth by hydroxytamoxifen, and through binding to the oestrogen-related receptor gamma (ERR) may prevent its deactivation by growth inhibitors. Hallmark 3: in the 10nM to 1M range, parabens give a dose-dependent evasion of apoptosis in high-risk donor breast epithelial cells. Hallmark 4: long-term exposure (>20weeks) to parabens leads to increased migratory and invasive activity in human breast cancer cells, properties which are linked to the metastatic process. Emerging hallmark: methylparaben has been shown in human breast epithelial cells to increase mTOR, a key regulator of energy metabolism. Enabling characteristic: parabens can cause DNA damage at high concentrations in the short term but more work is needed to investigate long-term low-doses of mixtures. The ability of parabens to enable multiple cancer hallmarks in human breast epithelial cells provides grounds for regulatory review of the implications of the presence of parabens in human breast tissue.

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Cancer and many chronic inflammatory diseases are associated with increased amounts of reactive oxygen species (ROS). The potential cellular and tissue damage created by ROS has significant impact on many disease and cancer states and natural therapeutics are becoming essential in regulating altered redox states. We have shown recently that iron content is a critical determinant in the antitumour activity of bovine milk lactoferrin (bLF). We found that 100% iron-saturated bLF (Fe-bLF) acts as a potent natural adjuvant and fortifying agent for augmenting cancer chemotherapy and thus has a broad utility in the treatment of cancer. Furthermore, we also studied the effects of iron saturated bLF's ability as an antioxidant in the human epithelial colon cancer cell line HT29, giving insights into the potential of bLF in its different states. Thus, metal saturated bLF could be implemented as anti-cancer neutraceutical. In this regard, we have recently been able to prepare a selenium (Se) saturated form of bLF, being up to 98% saturated. Therefore, the objectives of this study were to determine how oxidative stress induced by hydrogen peroxide (H2O2) alters antioxidant enzyme activity within HT29 epithelial colon cancer cells, and observe changes in this activity by treatments with different antioxidants ascorbic acid (AA), Apo (iron free)-bLF and selenium (Se)-bLF. The states of all antioxidant enzymes (glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-s-transferase (GsT), catalase and superoxide dismutase (SOD)) demonstrated high levels within untreated HT29 cells compared to the majority of other treatments being used, even prior to H2O2 exposure. All enzymes showed significant alterations in activity when cells were treated with antioxidants AA, Apo-bLF or Se-bLF, with and/or without H2O2 exposure. Obvious indications that the Se content of the bLF potentially interacted with the glutathione (GSH)/GPx/GR/GsT associated redox system could be observed immediately, showing capability of Se-bLF being highly beneficial in helping to maintain a balance between the oxidant/antioxidant systems within cells and tissues, especially in selenium deficient systems. In conclusion, the antioxidative defence activity of Se-bLf, investigated in this study for the first time, shows dynamic adaptations that may allow for essential protection from the imbalanced oxidative conditions. Because of its lack of toxicity and the availability of both selenium and bLF in whole milk, Se-bLF offers a promise for a prospective natural dietary supplement, in addition to being an immune system enhancement, or a potential chemopreventive agent for cancers.

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Purpose. To report the development of a new apparatus for non-invasive collection of human corneal epithelial cells.

Methods. Previous methods of non-invasive, irrigative corneal cell collection resulted in low cell yields limiting potential analysis. A new ocular surface cell collection apparatus (OSCCA) was designed to collect more epithelial cells from direct irrigation of the corneal surface to allow for clinical comparisons. Forty-five samples were obtained (unilateral or bilateral over seven visits) from five human participants. Cell yield, size, phenotype, and corneal staining (prior and post eye wash) were examined.

Results. On average 364 ± 230 epithelial cells were collected from the cornea per eye. Epithelial cell sizes ranged from 8.21 to 51.69 μm in diameter, and 67.30 to 2098.85 μm2 area. The proportion of corneal specific cells collected per sample was 75 ± 14% as determined by positive K3 expression with AE5. On average, 77 ± 0.2% of epithelial cells harvested were nucleated, the remainder were non-nucleated ghost cells. Corneal staining was reduced in the OSCCA-washed vs. contralateral non-washed eyes (p = 0.02).

Conclusions. The OSCCA allows collection of human corneal epithelial cells with significantly higher yields, and greater specificity than previously reported. Reduced corneal staining observed post eye-wash demonstrated the safety of the technique, and its ability to remove cells directly from the corneal surface. The OSCCA could provide an objective non-invasive method of investigating pathological changes, effects of topical therapeutics, and impact of contact lenses and care-solutions of the cells of the ocular surface.

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Epithelial cell adhesion molecule (EpCAM) is overexpressed in most solid cancers and is an ideal antigen for clinical applications in cancer diagnosis, prognosis, imaging, and therapy. Currently, most of the EpCAM-based diagnostic, prognostic, and therapeutic strategies rely on the anti-EpCAM antibody. However, the use of EpCAM antibody is restricted due to its large size and instability. In this study, we have successfully identified DNA aptamers that selectively bind human recombinant EpCAM protein. The aptamers can specifically recognize a number of live human cancer cells derived from breast, colorectal, and gastric cancers that express EpCAM but not bind to EpCAM-negative cells. Among the aptamer sequences identified, a hairpin-structured sequence SYL3 was optimized in length, resulting in aptamer sequence SYL3C. The Kd values of the SYL3C aptamer against breast cancer cell line MDA-MB-231 and gastric cancer cell line Kato III were found to be 38±9 and 67±8 nM, respectively, which are better than that of the full-length SYL3 aptamer. Flow cytometry analysis results indicated that the SYL3C aptamer was able to recognize target cancer cells from mixed cells in cell media. When used to capture cancer cells, up to 63% cancer cell capture efficiency was achieved with about 80% purity. With the advantages of small size, easy synthesis, good stability, high binding affinity, and selectivity, the DNA aptamers reported here against cancer biomarker EpCAM will facilitate the development of novel targeted cancer therapy, cancer cell imaging, and circulating tumor cell detection.

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Rotavirus replication occurs in vivo in intestinal epithelial cells. Cell lines fully permissive to rotavirus include kidney epithelial (MA104), colonic (Caco-2) and hepatic (HepG2) types. Previously, it has been shown that cellular integrins α2β1, α4β1 and αXβ2 are involved in rotavirus cell entry. As receptor usage is a major determinant of virus tropism, the levels of cell surface expression of these integrins have now been investigated by flow cytometry on cell lines of human (Caco-2, HepG2, RD, K562) and monkey (MA104, COS-7) origin in relation to cellular susceptibility to infection with monkey and human rotaviruses. Cells supporting any replication of human rotaviruses (RD, HepG2, Caco-2, COS-7 and MA104) expressed α2β1 and (when tested) αXβ2, whereas the non-permissive K562 cells did not express α2β1, α4β1 or αXβ2. Only RD cells expressed α4β1. Although SA11 grew to higher titres in RD, HepG2, Caco-2, COS-7 and MA104 cells, this virus still replicated at a low level in K562 cells. In all cell lines tested, SA11 replicated to higher titres than did human strains, consistent with the ability of SA11 to use sialic acids as alternative receptors. Levels of cell surface α2 integrin correlated with levels of rotavirus growth. The α2 integrin relative linear median fluorescence intensity on K562, RD, COS-7, MA104 and Caco-2 cells correlated linearly with the titre of SA11 produced in these cells at 20 h after infection at a multiplicity of 0·1, and the data best fitted a sigmoidal dose–response curve (r2=1·00, P=0·005). Thus, growth of rotaviruses in these cell lines correlates with their surface expression of α2β1 integrin and is consistent with their expression of αXβ2 and α4β1 integrins.

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Adequate amounts of copper in milk are critical for normal neonatal development, however the mechanisms regulating copper supply to milk have not been clearly defined. PMC42-LA cell cultures representative of resting, lactating and suckled mammary epithelia were used to investigate the regulation of the copper uptake protein, CTR1. Both the degree of mammary epithelial differentiation (functionality) and extracellular copper concentration greatly impacted upon CTR1 expression and its plasma membrane association. In all three models (resting, lactating and suckling) there was an inverse correlation between extracellular copper concentration and the level of CTR1. Cell surface biotinylation studies demonstrated that as extracellular copper concentration increased membrane associated CTR1 was reduced. There was a significant increase in CTR1 expression (total and membrane associated) in the suckled gland model in comparison to the resting gland model, across all copper concentrations investigated (0-50 μM). Regulation of CTR1 expression was entirely post-translational, as quantitative real-time PCR analyses showed no change to CTR1 mRNA between all models and culture conditions. X-ray fluorescence microscopy on the differentiated PMC42-LA models revealed that organoid structures distinctively accumulated copper. Furthermore, as PMC42-LA cell cultures became progressively more specialised, successively more copper accumulated in organoids (resting

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OBJETIVO: Avaliar a eficácia da mitomicina C (MMC) na prevenção da recorrência quando previamente utilizada no transplante autólogo de conjuntiva (TAC). A avaliação da proliferação celular epitelial pelo antígeno Ki-67 e a cariometria do núcleo dos fibroblastos foram usados como auxiliares na avaliação do tratamento. MÉTODOS: Vinte e nove pacientes com pterígio recidivado foram divididos em três grupos: Grupo (G) 1-TAC e colírio placebo (PLA); G2-TAC, MMC 0,015% subconjuntival e PLA; G3-TAC e colírio de MMC 0,02%. A imuno-histoquímica foi realizada no tecido excisado para o antígeno Ki-67, como a cariometria dos núcleos dos fibroblastos (divididos em lado nasal e temporal). A cariometria dos núcleos dos fibroblastos foi avaliada de acordo com os seguintes parâmetros: volume (Vl) e área (Ar) em pelos menos 50 células por paciente. RESULTADOS: A porcentagem das células epiteliais positivas para o antígeno Ki-67 no lado nasal e temporal após o tratamento dos três grupos estudados foi: nasal (3,30% G1, 4,49% G2 e 3,38% G3) e temporal (3,30% G1, 4,46% G2 e 4,14% G3) não mostrando diferença significativa. A cariometria do núcleo dos fibroblastos foi: Vl nasal (792,1 µ3 G1, 605,1 µ3 G2, e 549,9 µ3 G3) e a Ar (100,58 µ2 G1, 83,13 µ2 G2, e 78,41 µ2 G3). Os três grupos mostraram uma diferença significativa p=0,039 e p=0,035, respectivamente do Vl e da Ar no lado nasal. Após seis meses de tratamento, os três grupos apresentaram a seguinte taxa de recidiva: 22,22% G1, 18,18%, G2 e 33,33% G3 respectivamente. CONCLUSÃO: O uso da MMC não interferiu nas células epiteliais positivas para o antígeno Ki-67 no pterígio recidivado, mas acarretou diminuição do volume e área dos núcleos dos fibroblastos no lado nasal do pterígio. As células epiteliais positivas para o antígeno Ki-67 parecem não ter relação com a recidiva do pterígio após seis meses da cirurgia. Outros estudos devem ser realizados para avaliar o papel da proliferação das células epiteliais na recorrência do pterígio.

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Investigation of the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia patients is essential to predict prognosis and survival. In 20 patients treated at the Bone Marrow Transplantation Unit of São José do Rio Preto (São Paulo, Brazil), we used fluorescence in situ hybridization (FISH) to investigate the frequency of cells with BCR/ABL rearrangement at diagnosis and at distinct intervals after allo-HSCT until complete cytogenetic remission (CCR). We investigated the disease-free survival, overall survival in 3 years and transplant-related mortality rates, too. Bone marrow samples were collected at 1, 2, 3, 4, 6, 12, and 24 months after transplantation and additional intervals as necessary. Success rate of the FISH analyses was 100%. CCR was achieved in 75% of the patients, within on average of 3.9 months; 45% patients showed CCR within 60 days after HSCT. After 3 years of the allo-HSCT, overall survival rate was 60%, disease-free survival was 50% and the transplant-related mortality rate was 40%. The study demonstrated that the BCR-ABL FISH assay is useful for follow-up of chronic myeloid leukemia patients after HSCT and that the clinical outcome parameters in our patient cohort were similar to those described for other bone marrow transplantation units. ©FUNPEC-RP.

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Abstract Background The thymus is a central lymphoid organ, in which bone marrow-derived T cell precursors undergo a complex process of maturation. Developing thymocytes interact with thymic microenvironment in a defined spatial order. A component of thymic microenvironment, the thymic epithelial cells, is crucial for the maturation of T-lymphocytes through cell-cell contact, cell matrix interactions and secretory of cytokines/chemokines. There is evidence that extracellular matrix molecules play a fundamental role in guiding differentiating thymocytes in both cortical and medullary regions of the thymic lobules. The interaction between the integrin α5β1 (CD49e/CD29; VLA-5) and fibronectin is relevant for thymocyte adhesion and migration within the thymic tissue. Our previous results have shown that adhesion of thymocytes to cultured TEC line is enhanced in the presence of fibronectin, and can be blocked with anti-VLA-5 antibody. Results Herein, we studied the role of CD49e expressed by the human thymic epithelium. For this purpose we knocked down the CD49e by means of RNA interference. This procedure resulted in the modulation of more than 100 genes, some of them coding for other proteins also involved in adhesion of thymocytes; others related to signaling pathways triggered after integrin activation, or even involved in the control of F-actin stress fiber formation. Functionally, we demonstrated that disruption of VLA-5 in human TEC by CD49e-siRNA-induced gene knockdown decreased the ability of TEC to promote thymocyte adhesion. Such a decrease comprised all CD4/CD8-defined thymocyte subsets. Conclusion Conceptually, our findings unravel the complexity of gene regulation, as regards key genes involved in the heterocellular cell adhesion between developing thymocytes and the major component of the thymic microenvironment, an interaction that is a mandatory event for proper intrathymic T cell differentiation.

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Background Up-regulation of S100A7 (Psoriasin), a small calcium-binding protein, is associated with the development of several types of carcinomas, but its function and possibility to serve as a diagnostic or prognostic marker have not been fully defined. In order to prepare antibodies to the protein for immunohistochemical studies we produced the recombinant S100A7 protein in E. coli. mRNA extracted from human tracheal tumor tissue which was amplified by RT-PCR to provide the region coding for the S100A7 gene. The amplified fragment was cloned in the vector pCR2.1-TOPO and sub-cloned in the expression vector pAE. The protein rS100A7 (His-tag) was expressed in E. coli BL21::DE3, purified by affinity chromatography on an Ni-NTA column, recovered in the 2.0 to 3.5 mg/mL range in culture medium, and used to produce a rabbit polyclonal antibody anti-rS100A7 protein. The profile of this polyclonal antibody was evaluated in a tissue microarray. Results The rS100A7 (His-tag) protein was homogeneous by SDS-PAGE and mass spectrometry and was used to produce an anti-recombinant S100A7 (His-tag) rabbit serum (polyclonal antibody anti-rS100A7). The molecular weight of rS100A7 (His-tag) protein determined by linear MALDI-TOF-MS was 12,655.91 Da. The theoretical mass calculated for the nonapeptide attached to the amino terminus is 12,653.26 Da (delta 2.65 Da). Immunostaining with the polyclonal anti-rS100A7 protein generated showed reactivity with little or no background staining in head and neck squamous cell carcinoma cells, detecting S100A7 both in nucleus and cytoplasm. Lower levels of S100A7 were detected in non-neoplastic tissue. Conclusions The polyclonal anti-rS100A7 antibody generated here yielded a good signal-to-noise contrast and should be useful for immunohistochemical detection of S100A7 protein. Its potential use for other epithelial lesions besides human larynx squamous cell carcinoma and non-neoplastic larynx should be explored in future.

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Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33 % of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15 % of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6 % of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57 % and 50 % of patients, respectively, with probing depth and clinical attachment level ≥6 mm, no correlation was found with age, sex, bleeding on probing or the presence of supragingival biofilm. The prevalence of these pathogens in epithelial cells is correlated with the state of periodontal disease.