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Mesenchymal Transition (mesenchymal + transition)
Selected AbstractsAlcohol Stimulates Activation of Snail, Epidermal Growth Factor Receptor Signaling, and Biomarkers of Epithelial,Mesenchymal Transition in Colon and Breast Cancer CellsALCOHOLISM, Issue 1 2010Christopher B. Forsyth Background:, Alcohol consumption is associated with the risk of progressive cancers including colon and breast cancer. The mechanisms for the alcohol-induced aggressive behavior of these epithelial cancer cells have not been fully identified. Epithelial,mesenchymal transition (EMT) is a developmental program recently shown to play a role in cancer progression and metastases. We hypothesized that alcohol might promote cancer progression by inducing EMT in cancer cells and tested this hypothesis by assessing alcohol-stimulated changes in phenotypic markers of EMT as well as the EMT transcription factor Snail and its related cell signaling. Methods:, Colon and breast cancer cell lines and a normal intestinal epithelial cell line were tested as well as colonic mucosal biopsy samples from alcoholic subjects. Cells were treated with alcohol and assessed for EMT-related changes using immunofluorescent microscopy, western blotting, reporter assays, RT-PCR, and knockdown of Snail with siRNA. Results:, We show alcohol upregulated the signature EMT phenotypic marker vimentin as well as matrix metalloprotease (MMP)-2, MMP-7, and MMP-9 and cell migration in colon and breast cancer cells,all characteristics of EMT. Alcohol also stimulated nuclear localization of Snail phosphorylated at Ser246, transcription from a Snail reporter plasmid, and Snail mRNA expression by RT-PCR. Snail siRNA knockdown prevented alcohol-stimulated vimentin expression. In vivo, Snail expression was significantly elevated in colonic mucosal biopsies from alcoholics. Also, we found alcohol stimulated activation of epidermal growth factor receptor (EGFR) signaling and an EGFR inhibitor blocked alcohol-induced cell migration and Snail mRNA expression. Conclusions:, Collectively, our data support a novel mechanism for alcohol promoting cancer progression through stimulating the EMT program in cancer cells via an EGFR-Snail mediated pathway. This study reveals new pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers. [source] Inflammation and Epithelial to Mesenchymal Transition in Lung Transplant Recipients: Role in Dysregulated Epithelial Wound RepairAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010L. A. Borthwick Epithelial to mesenchymal transition (EMT) has been implicated in the pathogenesis of obliterative bronchiolitis (OB) after lung transplant. Although TNF-, accentuates TGF-,1 driven EMT in primary human bronchial epithelial cells (PBECs), we hypothesized that other acute pro-inflammatory cytokines elevated in the airways of patients with OB may also accentuate EMT and contribute to dysregulated epithelial wound repair. PBECs from lung transplant recipients were stimulated with TGF-,1 ± IL-1,, IL-8, TNF-, or activated macrophages in co-culture and EMT assessed. The quality and rate of wound closure in a standardized model of lung epithelial injury was assessed in response to above stimuli. Co-treatment with TGF-,1 + TNF-, or IL-1, significantly accentuates phenotypic and some functional features of EMT compared to TGF-,1 alone. Co-treatment with TGF-,1 + TNF-, or IL-1, accelerates epithelial wound closure however the quality of repair is highly dysregulated. Co-treatment with TGF-,1 + IL-8 has no significant effect on EMT or the speed or quality of wound healing. Activated macrophages dramatically accentuate TGF-,1-driven EMT and cause dysregulated wound repair. Crosstalk between macrophage-derived acute inflammation in the airway and elevated TGF-,1 may favor dysregulated airway epithelial repair and fibrosis in the lung allograft via EMT. [source] Posttransplant Bronchiolitis Obliterans Syndrome Is Associated with Bronchial Epithelial to Mesenchymal TransitionAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009S. Hodge Bronchiolitis obliterans syndrome (BOS) compromises lung transplant outcomes and is characterised by airway epithelial damage and fibrosis. The process whereby the normal epithelial configuration is replaced by fibroblastic scar tissue is poorly understood, but recent studies have implicated epithelial mesenchymal transition (EMT). The primary aim of this study was to assess the utility of flow cytometry in detecting and quantifying EMT in bronchial epithelial cells. Large airway brushings were obtained at 33 bronchoscopies in 16 BOS-free and 6 BOS grade 1,3 patients at 2,120 months posttransplant. Flow cytometry was used to assess expression of the mesenchymal markers ,SMA, S100A4 and ED-A FN and HLA-DR. TGF ,1 and HGF were measured in Bronchoalveolar lavage (BAL). Expression of all three mesenchymal markers was increased in BOS, as was HLA-DR. BAL HGF, but not TGF ,1 was increased in BOS. Longitudinal investigation of one patient revealed a 100% increase in EMT markers concurrent with a 6-fold increase in BAL TGF ,1 and the diagnosis of BOS at 17 months posttransplant. Flow cytometric evaluation of bronchial epithelium may provide a novel and rapid means to assess lung allografts at risk of BOS. [source] Epithelial to Mesenchymal Transition During Late Deterioration of Human Kidney Transplants: The Role of Tubular Cells in FibrogenesisAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2005Attapong Vongwiwatana The hallmark of failing renal transplants is tubular atrophy and interstitial fibrosis (TA/IF). Injury to tubular epithelial cells (TEC) could contribute to fibrogenesis via epithelial,mesenchymal transition (EMT). We examined the features of EMT in renal transplants that developed TA/IF. Biopsies from 10 allograft kidneys with impaired function and TA/IF and 10 biopsies from transplants with stable function were compared to their implantation biopsies. Relative to implantation biopsies, TEC in TA/IF kidneys showed loss of epithelial markers (E-cadherin, cytokeratin) with altered distribution. Some TEC also showed new cytoplasmic expression of mesenchymal markers vimentin, S100A4, and alpha smooth muscle actin (,-SMA) and collagen synthesis marker heat shock protein (HSP-47), both in deteriorating and atrophic tubules. Double immunostaining showed coexpression of cytokeratin and vimentin, S100A4 and HSP-47, indicating intermediate stages of EMT in TA/IF. These changes were absent or much less in transplants with stable function. EMT features in the TA/IF group correlated with serum creatinine (vimentin, S100A4, HSP-47), history of T-cell-mediated rejection (cytokeratin, S100A4) and proteinuria (cytokeratin). These findings support a model in which the TEC damage induces loss of epithelial features and expression of fibroblast features, as a common pathway of deterioration by either immunologic or nonimmunologic processes. [source] Homocysteine inhibits cardiac neural crest cell formation and morphogenesis in vivoDEVELOPMENTAL DYNAMICS, Issue 1 2004Brent J. Tierney Abstract Elevated homocysteine increases the risk of neurocristopathies. Here, we determined whether elevating homocysteine altered the proliferation or number of chick neural crest cells that form between the midotic and third somite in vivo. Homocysteine increased the number of neural tube cells but decreased neural crest cell number. However, the sum total of cells was not different from controls. In controls, the 5-bromo-2,-deoxyuridine-labeling index was higher in newly formed neural crest cells than in their progenitors, paralleling reports showing these progenitors must pass the restriction point before undergoing epithelial,mesenchymal transition. Homocysteine decreased the labeling index of newly formed neural crest cells, suggesting that it inhibited cell cycle progression of neural crest progenitors or the S-phase entry of newly formed neural crest cells. Homocysteine also inhibited neural crest dispersal and decreased the distance they migrated from the neural tube. These results show neural crest morphogenesis is directly altered by elevated homocysteine in vivo. Developmental Dynamics 229:63,73, 2004. © 2003 Wiley-Liss, Inc. [source] Bile duct proliferation in Jag1/fringe heterozygous mice identifies candidate modifiers of the alagille syndrome hepatic phenotype,HEPATOLOGY, Issue 6 2008Matthew J. Ryan Alagille syndrome (AGS) is a heterogeneous developmental disorder associated with bile duct paucity and various organ anomalies. The syndrome is caused by mutations in JAG1, which encodes a ligand in the Notch signaling pathway, in the majority of cases and mutations in the NOTCH2 receptor gene in less than 1% of patients. Although a wide array of JAG1 mutations have been identified in the AGS population, these mutational variants have not accounted for the wide phenotypic variability observed in patients with this syndrome. The Fringe genes encode glycosyltransferases, which modify Notch and alter ligand-receptor affinity. In this study, we analyzed double heterozygous mouse models to examine the Fringe genes as potential modifiers of the Notch-mediated hepatic phenotype observed in AGS. We generated mice that were haploinsufficient for both Jag1 and one of three paralogous Fringe genes: Lunatic (Lfng), Radical (Rfng), and Manic (Mfng). Adult Jag1+/,Lfng+/, and Jag1+/,Rfng+/, mouse livers exhibited widespread bile duct proliferation beginning at 5 weeks of age and persisting up to 1 year. The Jag1+/,Mfng+/, livers showed a subtle, yet significant increase in bile duct numbers and bile duct to portal tract ratios. These abnormalities were not observed in the newborn period. Despite the portal tract expansion by bile ducts, fibrosis was not increased and epithelial to mesenchymal transition was not shown in the affected portal tracts. Conclusion: Mice heterozygous for mutations in Jag1 and the Fringe genes display striking bile duct proliferation, which is not apparent at birth. These findings suggest that the Fringe genes may regulate postnatal bile duct growth and remodeling, and serve as candidate modifiers of the hepatic phenotype in AGS. (HEPATOLOGY 2008;48:1989,1997.) [source] Immunophenotypic features of MELF pattern invasion in endometrial adenocarcinoma: evidence for epithelial,mesenchymal transitionHISTOPATHOLOGY, Issue 1 2009Colin J R Stewart Aims:, Endometrial endometrioid adenocarcinomas (EEC) may show a distinctive morphological alteration characterized by the presence of microcystic, elongated and fragmented (,MELF') glands. These changes share features of epithelial,mesenchymal transition (EMT) in carcinomas arising at other sites. The aim was to compare the immunophenotypic profile of MELF-type epithelium with conventional glandular areas of EEC. Methods and results:, Twenty-one EEC were stained immunohistochemically for cytokeratin (CK) AE1/AE3, CK7, vimentin, oestrogen receptor, progesterone receptor and E-cadherin. Conventional tumour glands usually showed preserved membranous E-cadherin immunoreactivity with peripheral accentuation of vimentin and hormone receptor expression. MELF-type invasion was characterized by strong CK7 expression, sometimes in contrast to adjacent unstained tumour glands. MELF areas were usually negative for hormone receptors and showed reduced E-cadherin expression. Conclusions:, The expression of hormone receptors and intermediate filaments shows specific distribution patterns within EEC. MELF pattern invasion shows an altered immunophenotype compared with conventional glandular tumour areas. These findings suggest that MELF-type invasion represents a specific tumour alteration, and the reduction in hormone receptor and E-cadherin expression would be consistent with EMT. Immunohistochemical studies of EEC should consider micro anatomical variations in immunoreactivity, since these may be relevant to tumour invasion and progression. [source] Upregulation of myosin Va by Snail is involved in cancer cell migration and metastasisINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Linxiang Lan Abstract Cell migration, which involves acto-myosin dynamics, cell adhesion, membrane trafficking and signal transduction, is a prerequisite for cancer cell metastasis. Here, we report that an actin-dependent molecular motor, unconventional myosin Va, is involved in this process and implicated in cancer metastasis. The mRNA expression of myosin Va is increased in a number of highly metastatic cancer cell lines and metastatic colorectal cancer tissues. Suppressing the expression of myosin Va by lentivirus-based RNA interference in highly metastatic cancer cells impeded their migration and metastasis capabilities both in vitro and in vivo. In addition, the levels of myosin Va in cancer cell lines are positively correlated with the expression of Snail, a transcriptional repressor that triggers epithelial,mesenchymal transition. Repression or overexpression of Snail in cancer cells caused reduced or elevated levels of myosin Va, respectively. Furthermore, Snail can bind to an E-box of the myosin Va promoter and induce its activity, which indicates that Snail might act as a transcriptional activator. These data demonstrate an essential role of myosin Va in cancer cell migration and metastasis, and suggest a novel target for Snail in its regulation of cancer progression. [source] Nicotine induces cell proliferation, invasion and epithelial-mesenchymal transition in a variety of human cancer cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 1 2009Piyali Dasgupta Abstract Cigarette smoking is strongly correlated with the onset of nonsmall cell lung cancer (NSCLC). Nicotine, an active component of cigarettes, has been found to induce proliferation of lung cancer cell lines. In addition, nicotine can induce angiogenesis and confer resistance to apoptosis. All these events are mediated through the nicotinic acetylcholine receptors (nAChRs) on lung cancer cells. In this study, we demonstrate that nicotine can promote anchorage-independent growth in NSCLCs. In addition, nicotine also induces morphological changes characteristic of a migratory, invasive phenotype in NSCLCs on collagen gel. These morphological changes were similar to those induced by the promigratory growth factor VEGF. The proinvasive effects of nicotine were mediated by ,7-nAChRs on NSCLCs. RT-PCR analysis showed that the ,7-nAChRs were also expressed on human breast cancer and pancreatic cancer cell lines. Nicotine was found to promote proliferation and invasion in human breast cancer. The proinvasive effects of nicotine were mediated via a nAChR, Src and calcium-dependent signaling pathway in breast cancer cells. In a similar fashion, nicotine could also induce proliferation and invasion of Aspc1 pancreatic cancer cells. Most importantly, nicotine could induce changes in gene expression consistent with epithelial to mesenchymal transition (EMT), characterized by reduction of epithelial markers like E-cadherin expression, ZO-1 staining and concomitant increase in levels of mesenchymal proteins like vimentin and fibronectin in human breast and lung cancer cells. Therefore, it is probable that the ability of nicotine to induce invasion and EMT may contribute to the progression of breast and lung cancers. © 2008 Wiley-Liss, Inc. [source] Periostin, secreted from stromal cells, has biphasic effect on cell migration and correlates with the epithelial to mesenchymal transition of human pancreatic cancer cellsINTERNATIONAL JOURNAL OF CANCER, Issue 12 2008Atsushi Kanno Abstract Periostin is a secretory protein that has been suggested to function as a cell adhesion molecule and promote the invasiveness or growth rate of tumors. However, little is known about the association of its expression and epithelial to mesenchymal transition (EMT), which is considered to play a crucial role in cancer cell metastasis. Thus, the authors investigated whether periostin could be involved in the process of EMT and the role of this gene in pancreatic cancer development. The expression of periostin was observed mainly in stromal cells but very little in cancer cells by immunohistochemistry and real-time RT-PCR. In vitro, pancreatic stellate cells (PSCs) exhibited a much higher basal expression of periostin compared with cancer cells. Periostin secreted in the supernatant from 293T cells that expressed periostin (approximately 150 ng/ml) inhibited the migration of pancreatic cancer cells. Coculture assay revealed that periostin expression in PSC was induced by pancreatic cancer cells. To assess the direct role of periostin in pancreatic cancer cells, the authors generated pancreatic cancer cell lines that stably express periostin. The induced expression of periostin (to 150 ng/ml) altered the morphology of cancer cells, changing them from mesenchymal to epithelial phenotypes with the induction of epithelial markers and a reduction of mesenchymal markers, and showed reduced cell migration in vitro and formed smaller tumors as well as suppressed metastasis in vivo. On the other hand, high concentration of recombinant periostin (1 ,g/ml) promoted cell migration with AKT activation. The findings suggest that periostin has biphasic effect on the development of pancreatic cancer. © 2008 Wiley-Liss, Inc. [source] Changing the pathogenetic roadmap of liver fibrosis?JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7pt1 2008Where did it start; where will it go? Abstract The pathophysiology of liver injury has attracted the interest of experimentalists and clinicians over many centuries. With the discovery of liver-specific pericytes , formerly called fat-storing cells, Ito-cells, lipocytes, and currently designated as hepatic stellate cells (HSC) , the insight into the cellular and molecular pathobiology of liver fibrosis has evolved and the pivotal role of HSC as a precursor cell-type for extracellular matrix,producing myofibroblasts has been established. Although activation and transdifferentiation of HSC to myofibroblasts is still regarded as the pathogenetic key mechanism of fibrogenesis, recent studies point to a prominent heterogeneity of the origin of myofibroblasts. Currently, the generation of matrix-synthesizing fibroblasts by epithelial,mesenchymal transition, by influx of bone marrow,derived fibrocytes into damaged liver tissue, and by differentiation of circulating monocytes to fibroblasts after homing in the injured liver are discussed as important complementary mechanisms to enlarge the pool of (myo-)fibroblasts in the fibrosing liver. Among the molecular mediators, transforming growth factor-beta (TGF-,) plays a central role, which is controlled by the bone-morphogenetic protein (BMP)-7, an important antagonist of TGF-, action. The newly discovered pathways supplement the linear concept of HSC activation to myofibroblasts, point to fibrosis as a systemic response involving extrahepatic organs and reactions, add further evidence to a more or less uniform concept of organ fibrosis in general (e.g. liver, lung, kidney), and offer innovative approaches for the development of non-invasive biomarkers and antifibrotic trials. [source] Blocking Wnt/LRP5 signaling by a soluble receptor modulates the epithelial to mesenchymal transition and suppresses met and metalloproteinases in osteosarcoma Saos-2 cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2007Yi Guo Abstract We previously reported the Wnt receptor low-density lipoprotein receptor-related protein 5 (LRP5) was frequently expressed in osteosarcoma (OS) tissue and correlated with metastasis and a lower disease-free survival. Subsequent in vitro analysis revealed that dominant-negative, soluble LRP5 (sLRP5) can reduce in vitro cellular invasion. In the current study, we examined the molecular mechanisms of blocking canonical Wnt signaling by sLRP5 in Saos-2 osteosarcoma cells. Transfection of sLRP5 caused a marked up-regulation of E-cadherin in this cell line. This increase in E-cadherin, seen primarily at the cell,cell contact borders, was associated with down-regulation of Slug and Twist, transcriptional repressors which mediate cancer invasion and metastasis. In contrast, N-cadherin, a mesenchymal marker, was reduced by sLRP5. In addition, blocking Wnt signaling by sLRP5 modulated other epithelial and mesenchymal markers (keratin 8 and 18, fibronectin), suggesting a reversal of epithelial,mesenchymal transition (EMT) seen during cancer progression. SLRP5 also reduced the expression of matrix metalloproteinase (MMP) 2 and 14, consistent with a decrease in invasive capacity. SLRP5 transfection decreased both Met expression and hepatocyte growth factor (HGF)-induced cell motility. Taken together, these results support a role for Wnt/LRP5 signaling in invasiveness of a subset of OS cells. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:964,971, 2007 [source] Alcohol Stimulates Activation of Snail, Epidermal Growth Factor Receptor Signaling, and Biomarkers of Epithelial,Mesenchymal Transition in Colon and Breast Cancer CellsALCOHOLISM, Issue 1 2010Christopher B. Forsyth Background:, Alcohol consumption is associated with the risk of progressive cancers including colon and breast cancer. The mechanisms for the alcohol-induced aggressive behavior of these epithelial cancer cells have not been fully identified. Epithelial,mesenchymal transition (EMT) is a developmental program recently shown to play a role in cancer progression and metastases. We hypothesized that alcohol might promote cancer progression by inducing EMT in cancer cells and tested this hypothesis by assessing alcohol-stimulated changes in phenotypic markers of EMT as well as the EMT transcription factor Snail and its related cell signaling. Methods:, Colon and breast cancer cell lines and a normal intestinal epithelial cell line were tested as well as colonic mucosal biopsy samples from alcoholic subjects. Cells were treated with alcohol and assessed for EMT-related changes using immunofluorescent microscopy, western blotting, reporter assays, RT-PCR, and knockdown of Snail with siRNA. Results:, We show alcohol upregulated the signature EMT phenotypic marker vimentin as well as matrix metalloprotease (MMP)-2, MMP-7, and MMP-9 and cell migration in colon and breast cancer cells,all characteristics of EMT. Alcohol also stimulated nuclear localization of Snail phosphorylated at Ser246, transcription from a Snail reporter plasmid, and Snail mRNA expression by RT-PCR. Snail siRNA knockdown prevented alcohol-stimulated vimentin expression. In vivo, Snail expression was significantly elevated in colonic mucosal biopsies from alcoholics. Also, we found alcohol stimulated activation of epidermal growth factor receptor (EGFR) signaling and an EGFR inhibitor blocked alcohol-induced cell migration and Snail mRNA expression. Conclusions:, Collectively, our data support a novel mechanism for alcohol promoting cancer progression through stimulating the EMT program in cancer cells via an EGFR-Snail mediated pathway. This study reveals new pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers. [source] Low Ki-67 proliferation index is an indicator of poor prognosis in gastric cancerJOURNAL OF SURGICAL ONCOLOGY, Issue 3 2010Hee Eun Lee MD Abstract Background and Objectives We designed this study to assess the biologic significance of Ki-67 proliferation index (PI) in gastric cancer. Methods Gastric cancer tissue from 245 patients were immunostained for Ki-67. Ki-67 PI was defined as the percentage of tumor cells positive for Ki-67. In addition, we have previously evaluated the expressions of nine epithelial mesenchymal transition (EMT)-related proteins. The relationship between Ki-67 PI and clinicopathologic parameters, patient survival, and EMT data were sought. Results Low Ki-67 PI was correlated with poorly differentiated histology (P,=,0.034), an advanced T stage (P,<,0.001), and lymph node metastasis (P,=,0.011). Also, the low PI group was found to have a significantly worse prognosis than the high PI group (P,=,0.003, log-rank test). Multivariate analysis revealed that Ki-67 PI remained as an independent prognostic factor (hazard ratio (95% CI),=,0.670 (0.450,0.999)). Furthermore, greater expressional changes of EMT-related proteins were found to be significantly associated with low Ki-67 PI (P,=,0.025). Conclusions These findings suggest that Ki-67 PI is an effective tool for predicting survival in gastric cancer. In addition, we found that an invasive property presented as EMT-related protein expressional changes was inversely correlated with a proliferative activity in gastric cancer. J. Surg. Oncol. 2010;102:201,206. © 2010 Wiley-Liss, Inc. [source] Expression of Snail1 in the vimentin-expressing squamous cell carcinoma mimicking atypical fibroxanthoma: possible involvement of an epithelial,mesenchymal transitionJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 11 2010M Nakamura No abstract is available for this article. [source] Spindle cell squamous cell carcinoma showing epithelial,mesenchymal transitionJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2 2009H Iwata [source] Epithelial to mesenchymal transition in primary sclerosing cholangitisLIVER INTERNATIONAL, Issue 8 2008John A. Kirby [source] Transforming growth factor-, induces epithelial to mesenchymal transition by down-regulation of claudin-1 expression and the fence function in adult rat hepatocytesLIVER INTERNATIONAL, Issue 4 2008Takashi Kojima Abstract Background/Aims: Transforming growth factor-, (TGF-,) initiates and maintains epithelial,mesenchymal transition (EMT), which causes disassembly of tight junctions and loss of epithelial cell polarity. In mature hepatocytes during EMT induced by TGF-,, changes in the expression of tight junction proteins and the fence function indicated that epithelial cell polarity remains unclear. Methods: In the present study, using primary cultures of adult rat hepatocytes at day 10 after plating, in which epithelial cell polarity is well maintained by tight junctions, we examined the effects of 0.01,20 ng/ml TGF-, on the expression of the integral tight junction proteins, claudin-1, -2 and occludin, as well as the fence function. Results: In adult rat hepatocytes, TGF-, induced EMT, which was indicated as upregulation of Smad-interacting protein-1 (SIP1) and Snail and down-regulation of E-cadherin. Down-regulation of claudin-1 and upregulation of occludin were observed beginning from a low dose of TGF-,, whereas upregulation of claudin-2 was observed at a high dose of TGF-,. Furthermore, treatment with TGF-, caused disruption of the fence function, which was closely associated with the expression of claudin-1 via p38 mitogen-activated protein kinase (MAPK), phosphoinositide-3 kinase and protein kinase C but not MAPK signalling pathways. Conclusion: These results suggest that in mature hepatocytes in vitro, TGF-, induces EMT by down-regulation of claudin-1 and the fence function via distinct signalling pathways. [source] Urinary proteins from patients with nephrotic syndrome alters the signalling proteins regulating epithelial,mesenchymal transitionNEPHROLOGY, Issue 1 2010QIONG WEN ABSTRACT: Aim: Proteinuria plays an important role in the progression of tubulointerstitial fibrosis, but the mechanism for the differential renal damage induced by proteinuria is unknown. This study examined the effects of urinary proteins from patients with idiopathic minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) on several epithelial,mesenchymal transition (EMT)-related marker proteins in cultured proximal tubular HK-2 cells. Methods: Urinary proteins from MCD and FSGS patients were extracted by ultrafiltration and incubated with HK-2 cells; the expression of the cytokeratin-18, ,-smooth muscle actin (,-SMA) and vimentin were assessed. p38 and extracellular regulated kinase (ERK) activation were measured by western blotting, and SB203580 (a p38 inhibitor) and PD98059 (an ERK1/2 inhibitor) were used to inhibit their activation. Results: It was observed that urinary proteins from FSGS patients more significantly induced the expression of ,-SMA and vimentin and reduced cytokeratin-18 expression than those from MCD patients in HK-2 cells. Both ERK1/2 and p38 were activated by urinary proteins from MCD or FSGS patients. Pretreatment of the cells with SB203580 or PD98059 abolished the effect of urinary proteins from FSGS patients on the expression of ,-SMA, vimentin and cytokeratin-18, while only SB203580 elicited this effect when cells were treated with urinary proteins from MCD patients. Conclusion: The urinary proteins from MCD and FSGS patients induced significant changes of EMT-related proteins through activation of distinct mitogen-activated protein kinase-related signalling pathways. Quality of proteinuria may play an important role in determining the severity and progression of tubular injury associated with different kidney diseases. [source] Aldosterone induces collagen synthesis via activation of extracellular signal-regulated kinase 1 and 2 in renal proximal tubulesNEPHROLOGY, Issue 8 2008GUOSHUANG XU SUMMARY: Aim: Aldosterone plays a crucial role in renal fibrosis by inducing mesangial cell proliferation and promoting collagen synthesis in renal fibroblasts. However, renal proximal tubule involvement in aldosterone-induced collagen synthesis has not yet been identified. The aim of this study was to examine the potential role of aldosterone in collagen expression and its possible mineralocorticoid receptor (MR)-dependent pathway, mediated by activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) in cultured human renal proximal tubular epithelial (HKC) cells. Methods: After HKC cells were stimulated by aldosterone with different concentrations for various time and periods, the gene expression and protein synthesis of collagen I, II, III and IV were measured by real-time polymerase chain reaction and western blot, respectively. ERK1/2 activation, ,-smooth muscle actin (,-SMA), and E-cadherin were also detected by western blot. Results: Aldosterone can increase ERK1/2 phosphorylation of human renal proximal tubular epithelial cells in a time- and dose-dependent manner. Although aldosterone had no effect on collagen I and II expression, it increased expression of ,-SMA and collagen III and IV and decreased that of E-cadherin in HKC cells after 48 h. These effects could be prevented by a ERK pathway inhibitor, U0126, or by a selective MR antagonist, spironolactone. Conclusion: The results suggest that aldosterone plays a pivotal role in tubulointerstitial fibrosis by promoting tubular epithelial,mesenchymal transition and collagen synthesis in proximal tubular cells. The process is MR-dependent, and mediated by ERK1/2 mitogen-activated protein kinase pathway. [source] Pathological airway remodelling in inflammationTHE CLINICAL RESPIRATORY JOURNAL, Issue 2010Gunilla Westergren-Thorsson Abstract Introduction:, Airway remodelling refers to a wide pattern of patophysiological mechanisms involving smooth muscle cell hyperplasia, increase of activated fibroblasts and myofibroblasts with deposition of extracellular matrix. In asthma, it includes alterations of the epithelial cell layer with goblet cell hyperplasia, thickening of basement membranes, peri-bronchial and peri-broncheolar fibrosis. Moreover, airway remodelling occurs not only in asthma but also in several pulmonary disorders such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and systemic sclerosis. Asthma treatment with inhaled corticosteroids does not fully prevent airway remodelling and thus have restricted influence on the natural course of the disease. Objectives:, This review highlights the role of different fibroblast phenotypes and potential origins of these cells in airway remodelling. Results:, During inflammatory conditions, such as asthma, fibroblasts can differentiate into an active, more contractile phenotype termed myofibroblast, with expression of stress fibres and alpha-smooth muscle actin. The origin of myofibroblasts has lately been debated, and three sources have been identified: recruitment and differentiation of resident tissue fibroblasts; fibrocytes , circulating progenitor cells; and epithelial,mesenchymal transition. Conclusion:, It is clear that airway mesenchymal cells, including fibroblasts/myofibroblasts, are more dynamic in terms of differentiation and origin than has previously been recognised. Considering that these cells are key players in the remodelling process, it is of utmost importance to characterise specific markers for the various fibroblast phenotypes and to explore factors that drive the differentiation to develop future diagnostic and therapeutic tools for asthma patients. Please cite this paper as: Westergren-Thorsson G, Larsen K, Nihlberg K, Andersson-Sjöland A, Hallgren O, Marko-Varga G and Bjermer L. Pathological airway remodelling in inflammation. Clin Respir J 2010; 4 (Suppl. 1): 1,8. [source] REVIEW ARTICLE: RCAS1, MT, and Vimentin as Potential Markers of Tumor Microenvironment RemodelingAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2010Magdalena Dutsch-Wicherek Citation Dutsch-Wicherek M. RCAS1, MT, and vimentin as potential markers of tumor microenvironment remodeling. Am J Reprod Immunol 2010; 63: 181,188 A tumor stimulates the remodeling of its microenvironment for its own survival. To protect its own growth and induce angiogenesis, the tumor changes the structure of extracellular matrix and the function of existing cells; it thus chemo-attracts immune system cells altering their function. In our study, we discuss the potential markers of tumor microenvironment remodeling. For instance, RCAS1 is a protein responsible for tumor escape from host immunologic surveillance that additionally seems to be involved in the remodeling of the microenvironment. Another protein, metallothionein, which is both anti-apoptotic and pro-proliferative, is also responsible for modulating the response of immune system cells. Most likely, the expression of this protein by the fibroblasts of tumor microenvironment is related to the remodeled phenotype of these cells because of the tumor influence on cancer-associated fibroblasts. Lastly, vimentin is a protein that would appear to be the marker for the mesenchymal transition of cells from the epithelial phenotype. These cells seem to acquire the mesenchymal phenotype to migrate so that they can facilitate the development of metastases. Interestingly, the expression of vimentin has also been observed in the tumor microenvironment as well and may serve as a marker of a remodeled stroma in the process of facilitating tumor spread. [source] Inflammation and Epithelial to Mesenchymal Transition in Lung Transplant Recipients: Role in Dysregulated Epithelial Wound RepairAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010L. A. Borthwick Epithelial to mesenchymal transition (EMT) has been implicated in the pathogenesis of obliterative bronchiolitis (OB) after lung transplant. Although TNF-, accentuates TGF-,1 driven EMT in primary human bronchial epithelial cells (PBECs), we hypothesized that other acute pro-inflammatory cytokines elevated in the airways of patients with OB may also accentuate EMT and contribute to dysregulated epithelial wound repair. PBECs from lung transplant recipients were stimulated with TGF-,1 ± IL-1,, IL-8, TNF-, or activated macrophages in co-culture and EMT assessed. The quality and rate of wound closure in a standardized model of lung epithelial injury was assessed in response to above stimuli. Co-treatment with TGF-,1 + TNF-, or IL-1, significantly accentuates phenotypic and some functional features of EMT compared to TGF-,1 alone. Co-treatment with TGF-,1 + TNF-, or IL-1, accelerates epithelial wound closure however the quality of repair is highly dysregulated. Co-treatment with TGF-,1 + IL-8 has no significant effect on EMT or the speed or quality of wound healing. Activated macrophages dramatically accentuate TGF-,1-driven EMT and cause dysregulated wound repair. Crosstalk between macrophage-derived acute inflammation in the airway and elevated TGF-,1 may favor dysregulated airway epithelial repair and fibrosis in the lung allograft via EMT. [source] Anti-thrombin Therapy During Warm Ischemia and Cold Preservation Prevents Chronic Kidney Graft Fibrosis in a DCD ModelAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010F. Favreau Ischemia reperfusion injury (IRI) is pivotal for renal fibrosis development via peritubular capillaries injury. Coagulation represents a key mechanism involved in this process. Melagatran® (M), a thrombin inhibitor, was evaluated in an autotransplanted kidney model, using Large White pigs. To mimic deceased after cardiac death donor conditions, kidneys underwent warm ischemia (WI) for 60 min before cold preservation for 24 h in University of Wisconsin solution. Treatment with M before WI and/or in the preservation solution drastically improved survival at 3 months, reduced renal dysfunction related to a critical reduction in interstitial fibrosis, measured by Sirius Red staining. Tissue analysis revealed reduced expression of transforming growth factor-, (TGF-,) and activation level of its effectors phospho-Smad3, Smad4 and connective tissue growth factor (CTGF) after M treatment. Fibrinolysis activation was also observed, evidenced by downregulation of PAI-1 protein and gene expression. In addition, M reduced S100A4 expression and vimentin staining, which are markers for epithelial mesenchymal transition, a major pathway to chronic kidney fibrosis. Finally, expression of oxidative stress markers Nox2 and iNOS was reduced. We conclude that inhibition of thrombin is an effective therapy against IRI that reduces chronic graft fibrosis, with a significantly positive effect on survival. [source] Posttransplant Bronchiolitis Obliterans Syndrome Is Associated with Bronchial Epithelial to Mesenchymal TransitionAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009S. Hodge Bronchiolitis obliterans syndrome (BOS) compromises lung transplant outcomes and is characterised by airway epithelial damage and fibrosis. The process whereby the normal epithelial configuration is replaced by fibroblastic scar tissue is poorly understood, but recent studies have implicated epithelial mesenchymal transition (EMT). The primary aim of this study was to assess the utility of flow cytometry in detecting and quantifying EMT in bronchial epithelial cells. Large airway brushings were obtained at 33 bronchoscopies in 16 BOS-free and 6 BOS grade 1,3 patients at 2,120 months posttransplant. Flow cytometry was used to assess expression of the mesenchymal markers ,SMA, S100A4 and ED-A FN and HLA-DR. TGF ,1 and HGF were measured in Bronchoalveolar lavage (BAL). Expression of all three mesenchymal markers was increased in BOS, as was HLA-DR. BAL HGF, but not TGF ,1 was increased in BOS. Longitudinal investigation of one patient revealed a 100% increase in EMT markers concurrent with a 6-fold increase in BAL TGF ,1 and the diagnosis of BOS at 17 months posttransplant. Flow cytometric evaluation of bronchial epithelium may provide a novel and rapid means to assess lung allografts at risk of BOS. [source] Renal Allografts with IF/TA Display Distinct Expression Profiles of Metzincins and Related GenesAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2009S. Rödder Chronic renal allograft injury is often reflected by interstitial fibrosis (IF) and tubular atrophy (TA) without evidence of specific etiology. In most instances, IF/TA remains an irreversible disorder, representing a major cause of long-term allograft loss. As members of the protease family metzincins and functionally related genes are involved in fibrotic and sclerotic processes of the extracellular matrix (ECM), we hypothesized their deregulation in IF/TA. Gene expression and protein level analyses using allograft biopsies with and without Banff'05 classified IF/TA illustrated their deregulation. Expression profiles of these genes differentiated IF/TA from Banff'05 classified Normal biopsies in three independent microarray studies and demonstrated histological progression of IF/TA I to III. Significant upregulation of matrix metalloprotease-7 (MMP-7) and thrombospondin-2 (THBS-2) in IF/TA biopsies and sera was revealed in two independent patient sets. Furthermore, elevated THBS-2, osteopontin (SPP1) and ,-catenin may play regulatory roles on MMP. Our findings further suggest that deregulated ECM remodeling and possibly epithelial to mesenchymal transition (EMT) are implicated in IF/TA of kidney transplants, and that metzincins and related genes play an important role in these processes. Profiling of these genes may be used to complement IF/TA diagnosis and to disclose IF/TA progression in kidney transplant recipients. [source] Epithelial to Mesenchymal Transition During Late Deterioration of Human Kidney Transplants: The Role of Tubular Cells in FibrogenesisAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2005Attapong Vongwiwatana The hallmark of failing renal transplants is tubular atrophy and interstitial fibrosis (TA/IF). Injury to tubular epithelial cells (TEC) could contribute to fibrogenesis via epithelial,mesenchymal transition (EMT). We examined the features of EMT in renal transplants that developed TA/IF. Biopsies from 10 allograft kidneys with impaired function and TA/IF and 10 biopsies from transplants with stable function were compared to their implantation biopsies. Relative to implantation biopsies, TEC in TA/IF kidneys showed loss of epithelial markers (E-cadherin, cytokeratin) with altered distribution. Some TEC also showed new cytoplasmic expression of mesenchymal markers vimentin, S100A4, and alpha smooth muscle actin (,-SMA) and collagen synthesis marker heat shock protein (HSP-47), both in deteriorating and atrophic tubules. Double immunostaining showed coexpression of cytokeratin and vimentin, S100A4 and HSP-47, indicating intermediate stages of EMT in TA/IF. These changes were absent or much less in transplants with stable function. EMT features in the TA/IF group correlated with serum creatinine (vimentin, S100A4, HSP-47), history of T-cell-mediated rejection (cytokeratin, S100A4) and proteinuria (cytokeratin). These findings support a model in which the TEC damage induces loss of epithelial features and expression of fibroblast features, as a common pathway of deterioration by either immunologic or nonimmunologic processes. [source] Epithelial,mesenchymal transition in cancer development and its clinical significanceCANCER SCIENCE, Issue 2 2010Masaaki Iwatsuki The epithelial,mesenchymal transition (EMT) plays a critical role in embryonic development. EMT is also involved in cancer progression and metastasis and it is probable that a common molecular mechanism is shared by these processes. Cancer cells undergoing EMT can acquire invasive properties and enter the surrounding stroma, resulting in the creation of a favorable microenvironment for cancer progression and metastasis. Furthermore, the acquisition of EMT features has been associated with chemoresistance which could give rise to recurrence and metastasis after standard chemotherapeutic treatment. Thus, EMT could be closely involved in carcinogenesis, invasion, metastasis, recurrence, and chemoresistance. Research into EMT and its role in cancer pathogenesis has progressed rapidly and it is now hypothesized that novel concepts such as cancer stem cells and microRNA could be involved in EMT. However, the involvement of EMT varies greatly among cancer types, and much remains to be learned. In this review, we present recent findings regarding the involvement of EMT in cancer progression and metastasis and provide a perspective from clinical and translational viewpoints. (Cancer Sci 2009) [source] Hereditary diffuse gastric cancer: A manifestation of lost cell polarityCANCER SCIENCE, Issue 7 2009Bostjan Humar Hereditary diffuse gastric cancer is a cancer syndrome caused by germline mutations in the gene for the cell adhesion protein E-cadherin (CDH1). E-cadherin plays a central role in the maintenance of cell polarity and its loss during tumorigenesis is associated with poorly differentiated cancers and a poor prognosis. Hereditary diffuse gastric cancer is dominated by diffuse-type gastric adenocarcinoma, often with signet ring cell morphology. Large numbers of stage T1a signet ring cell carcinomas exist in the stomachs of CDH1 mutation carriers from a young age, and these foci sometimes show enrichment to the transition zone between the body and antrum. Generally these signet ring cell carcinomas are hypoproliferative, lack Wnt pathway activation, and are relatively indolent. However, a small proportion of the T1a foci contain cells that are poorly differentiated, display mesenchymal features, and express activated c-Src and its downstream targets. These same features are observed in more advanced stages of hereditary diffuse gastric cancer progression, suggesting that an epithelial,mesenchymal transition is required for tumor invasion beyond the muscularis mucosae. Hereditary diffuse gastric cancer initiation requires somatic down-regulation of the second CDH1 allele, which in most cases is caused by DNA promoter hypermethylation. Subsequent to CDH1 down-regulation, lost polarity in gastric stem or progenitor cells would be predicted to interfere with mitotic spindle orientation and the segregation of cell fate determinants. We predict that this disruption of cell division results in daughter cells being deposited in the lamina propria where their population expands and partially differentiates, resulting in the formation of foci of signet ring cells. (Cancer Sci 2009; 100: 1151,1157) [source] Signaling networks guiding epithelial,mesenchymal transitions during embryogenesis and cancer progressionCANCER SCIENCE, Issue 10 2007Aristidis Moustakas Epithelial,mesenchymal transition (EMT) describes the differentiation switch between polarized epithelial cells and contractile and motile mesenchymal cells, and facilitates cell movements and generation of new tissue types during embryogenesis. Many secreted polypeptides are implicated in the EMT process and their corresponding intracellular transduction pathways form highly interconnected networks. Transforming growth factor-,, Wnt, Notch and growth factors acting through tyrosine kinase receptors induce EMT and often act in a sequential manner. Such growth factors orchestrate the concerted regulation of an elaborate gene program and a complex protein network, needed for establishment of new mesenchymal phenotypes after disassembly of the main elements of epithelial architecture, such as desmosomes, as well as tight, adherens and gap junctions. EMT of tumor cells occurs during cancer progression and possibly generates cell types of the tumor stroma, such as cancer-associated myofibroblasts. EMT contributes to new tumor cell properties required for invasiveness and vascular intravasation during metastasis. Here we present some of the current mechanisms that mediate the process of EMT and discuss their relevance to cancer progression. (Cancer Sci 2007; 98: 1512,1520) [source] | |||||||||||||||||||||||||