Expression Of TGF-beta Receptors Research Articles

Abstract P1007: Cardiac Fibroblast BAG3 Controls TGFBR2 Signaling And Contributes To Engineered Cardiac Tissue Function.

Introduction: Mutations in BAG3 result in dilated cardiomyopathy with cardiac fibrosis. Currently, the role of BAG3 in non-myocyte cell types is not known. We tested the hypothesis that BAG3 controls cardiac fibroblast (CF) function and that the loss of fibroblast-specific BAG3 is deleterious, using cells and engineered cardiac tissues (ECT) derived from pluripotent stem cells (iPSC). Methods: Isogenic iPSCs containing homozygous knockout (KO) of BAG3 were differentiated into CFs. Mass spectrometry measured the effect of BAG3 loss on CF proteome. EdU staining and flow cytometry were used to assess CF proliferation. Transforming growth factor beta (TGF) signaling pathway activity was measured using a luciferase reporter and Western blotting. Affinity purification mass spectrometry (AP-MS) identified high-confidence interactors of BAG3 in CFs. To assess the role of fibroblast-specific BAG3 in cardiac function, conditional KO ECTs were generated using wild-type cardiomyocytes mixed with either wild-type CFs or KO CFs. ECTs were functionally assessed using video microscopy and immunofluorescence. The effects of CF BAG3 loss on tissue gene expression are under study by single nuclear RNA sequencing. Results: Analysis of proteomics data revealed enrichment of TGF and proliferation pathways in KO cells. KO-CFs had increased proliferation measured by EdU staining and increased SMAD luciferase reporter activity. Western blotting showed that KO CFs have higher expression of TGF beta receptor 2 (TGFBR2) and activation of canonical TGF signaling. AP-MS identified TGFBR2 as an interacting partner of BAG3, suggesting BAG3 mediated TGFBR2 turnover. In ECT, the loss of CF BAG3 caused a reduction in cardiac tissue contractile force (50% reduction, n = 10-12 tissues per group). Immunofluorescence revealed significantly increased tissue fibrosis in CF-KO cardiac tissues quantified by vimentin staining. Conclusions: BAG3 loss results in increased TGFBR2 signaling and proliferation in cardiac fibroblasts. Conditional KO ECTs demonstrate that CF BAG3 affects tissue function. These data suggest that fibrosis related to BAG3 pathology may be a result of a primary deficiency in CFs rather than a secondary response to cardiomyocyte death.

CircFAM120B Blocks the Development of Colorectal Cancer by Activating TGF-Beta Receptor II Expression via Targeting miR-645.

Circular RNAs (circRNAs) are implicated in various human cancers, including colorectal cancer (CRC). The objective of this study was to investigate the function and regulatory mechanism of a novel circRNA, circFAM120B, in CRC development. The expression of circFAM120B, miR-645 and TGF-beta receptor II (TGFBR2) mRNA was detected by quantitative real-time polymerase chain reaction. Cellular biological functions, including cell proliferation, migration/invasion, and glycolysis metabolism, were assessed using CCK-8 assay, colony formation assay, transwell assay, and glycolysis stress test, respectively. Glycolysis progression was also monitored by lactate production and glucose consumption. The expression of glycolysis-related markers and TGFBR2 at the protein level was detected by western blot. The interaction between miR-645 and circFAM120B or TGFBR2 was predicted by bioinformatics analysis and verified by pull-down assay, dual-luciferase reporter assay and RIP assay. In vivo animal experiments were performed to further explore the function of circFAM120B. The expression of circFAM120B was decreased in CRC tissues and cells. CircFAM120B overexpression blocked CRC cell proliferation, migration/invasion, and glycolysis metabolism. MiR-645 was a target of circFAM120B, and miR-645 restoration reversed the effects of circFAM120B overexpression. In addition, TGFBR2 was a target of miR-645, and miR-645 inhibition-suppressed CRC cell proliferation, migration/invasion and glycolysis were restored by TGFBR2 knockdown. Moreover, circFAM120B activated the expression of TGFBR2 by targeting miR-645. TGFBR2 also blocked tumor growth in vivo by targeting the miR-645/TGFBR2 axis. CircFAM120B inhibited CRC progression partly by mediating the miR-645/TGFBR2 network, which explained the potential mechanism of circFAM120B function in CRC.

Expression of TGF-beta receptor 1 and Smads in the tissues of primary spontaneous pneumothorax.

Primary spontaneous pneumothorax (PSP) is a common disease which is often caused by the rupture of bullae in the lungs. The underlying pathogenesis of PSP remains unclear. Some molecules may be involved in the development of PSP potentially. The aim of this study was to investigate the expression of TGF-beta receptor 1 (TβR1), Smad2, Smad3 and Smad4 in the resected bullae of patients with PSP. From May 2015 to May 2016, 34 patients with PSP underwent video-assisted thoracoscopic surgery (VATS) bullectomy. Immunohistochemistry was performed to identify the expression of TβR1, Smad2, Smad3 and Smad4 in the resected pulmonary bullae tissues. The levels of these cytokines were calculated by immunoreactivity scoring system (IRS). Ten patients without pneumothorax associated disease were selected as the control group. The analysis showed that the expression levels of TβR1, Smad2 and Smad4 were significantly higher in bullae tissues of patients with PSP than that in normal lung tissues (P=0.012, 0.031, 0.000 respectively). There was no significant difference between the expression level of Smad3 in bullae tissue of PSP patients and that in normal lung tissues of the control group (P=0.140). However, the absolute quantity of Smad3 expression in PSP bullae tissues was (4.2529±1.7193), scored by the IRS, which is higher than that in the control lung tissues (3.2600±2.2132). Also, the expression of TβR1, Smad2, Smad3 and Smad4 were not showed correlation with the clinical characteristics of PSP patients, such as age, sex, body mass index (BMI), recurrence and side of pneumothorax. TβR1, Smad2 and Smad4 highly expressed in bullae tissues of PSP patients. Our findings suggested that TβR1, Smad2 and Smad4 may be related to the development of PSP bullae.

Abstract MP03: Intracerebroventricular Administration Of Autologous Bone Marrow-derived Cells Attenuate Inflammation And Increase In AT1 Receptor In The Brain Of Angiotensin II Initiated Hypertensive Rats

Objectives: Bone marrow-derived cells (BMCs) include mesenchymal stem cells (MSC) play critical role in repairing damaged tissue and anti-inflammation. We reported that intracerebroventricular (icv) administration of autologous BMCs attenuate slow pressor Ang II initiated hypertension via attenuating Ang II mediated sympathetic activation in rats. However, mechanisms of this observation have not been elucidated. We hypothesized that BMCs in the brain would attenuate inflammation and modulate overactive renin angiotensin system (RAS) in the brain of Ang II initiated hypertensive rats. Therefore we examined characteristics of BMCs prepared with identical cultural condition to previous experiment and examined expression of inflammation related cytokines and RAS component in the brain of Ang II initiated hypertensive rats. Methods: Aspirated bone marrow cells underwent red blood cell lysis protocol were seeded in an individual dish in Dulbecco Modified Eagle Media with 10% fetal bovine serum. Floating cells were removed and plastic adherent cells were allowed to glow for 3 weeks at passage 3. The number of BMCs proliferated more than 10 6 were used for immunocytochemical, flowcytometric, BrdU uptake, and Western blot analysis. TGF-beta, IL-10 and AT1 receptor protein expression were examined in brains of Ang II initiated hypertensive rats. Results: Cultured BMCs expressed CD29, a marker of mesenchymal stem cell. Flowcytometric analysis revealed that 38% of BMCs were CD29+ CD34-. Endothelial cell (EC) proliferation assay exhibited 52% higher BrdU uptake with conditioned media from BMCs than the media from ECs. Expression of angiotensin converting enzyme (ACE) was 87% lower in BMCs than in ECs, whereas ACE2 expression was 142% higher in BMCs. Furthermore, Ang II infusion significantly increased expression of TGF-beta and AT1 receptor in the brain by 146% and 135% respectively and icv administration of BMCs attenuated the increases of both expressions (39%, 59% respectively). Ang II infusion with or without BMCs icv did not affect to IL-10 expression in the brain. Conclusion: BMCs in the brain may have protective role against Ang II induced sympathetic activation via attenuation of brain inflammation and increase in AT1 receptors.

Abstract 3103: Overexpression of homeoprotein six1 activates non-canonical TGF-beta signaling to induce epithelial-mesenchymal transition in human papillomavirus type 16-immortalized human keratinocytes.

Abstract Inappropriate expression of embryonic genes, particularly homeodomain transcription factors, contributes to tumorigenesis and tumor progression. The overexpression of Six1, a member of the Six family of homeodomain transcription factors, has been found in various human cancers, and is associated with increased tumor progression and metastasis. Previous studies in our laboratory discovered that the expression of Six1 mRNA and protein increased during in vitro progression of human papillomavirus type 16 (HPV16)-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. However, the precise mechanisms of how Six1 promotes tumor onset at early and late stages of HPV16-mediated transformation remain unknown. In this study, we found that HKc/HPV16 and HKc/DR overexpressing Six1 exhibited a more mesenchymal phenotype compared to vector controls, as characterized by a fibroblastic morphology, and increased migration and invasion. We utilized Whole Human Genome Microarrays (4x44K from Agilent Technologies) to explore the gene expression changes associated with Six1 overexpression in HKc/HPV16 and HKc/DR. We found that overexpression of Six1 down-regulated epithelial-related genes (ex., E-cadherin and occludin) and up-regulated mesenchymal-related genes (ex., N-cadherin, vimentin, and snail), which strongly suggests that Six1 overexpression induces epithelial-mesenchymal transition (EMT). Gene expression changes determined by microarray analysis were confirmed by real time PCR and western blotting. Increased expression of TGF-beta receptors in response to overexpression of Six1 in HKc/DR did not lead to increased Smad-dependent signaling but did activate the Mitogen-activated protein kinase (MAPK) pathway, suggesting that MAPK non-Smad TGF-β signaling may be involved in Six1-mediated EMT. In conclusion, our study demonstrates that Six1 overexpression induces EMT, possibly by activation of the MAPK non-canonical (non-Smad) TGF-β pathway, during HPV16-mediated transformation of human keratinocytes. Citation Format: Hanwen Xu, Lucia Pirisi, Kim E. Creek. Overexpression of homeoprotein six1 activates non-canonical TGF-beta signaling to induce epithelial-mesenchymal transition in human papillomavirus type 16-immortalized human keratinocytes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3103. doi:10.1158/1538-7445.AM2013-3103

Blocking the Class I Histone Deacetylase Ameliorates Renal Fibrosis and Inhibits Renal Fibroblast Activation via Modulating TGF-Beta and EGFR Signaling

BackgroundHistone deacetylase (HDAC) inhibitors are promising anti-fibrosis drugs; however, nonselective inhibition of class I and class II HDACs does not allow a detailed elucidation of the individual HDAC functions in renal fibrosis. In this study, we investigated the effect of MS-275, a selective class I HDAC inhibitor, on the development of renal fibrosis in a murine model of unilateral ureteral obstruction (UUO) and activation of cultured renal interstitial fibroblasts.Methods/FindingsThe UUO model was established by ligation of the left ureter and the contralateral kidney was used as a control. At seven days after UUO injury, kidney developed fibrosis as indicated by deposition of collagen fibrils and increased expression of collagen I, fibronectin and alpha-smooth muscle actin (alpha-SMA). Administration of MS-275 inhibited all these fibrotic responses and suppressed UUO-induced production of transforming growth factor-beta1 (TGF-beta), increased expression of TGF-beta receptor I, and phosphorylation of Smad-3. MS-275 was also effective in suppressing phosphorylation and expression of epidermal growth factor receptor (EGFR) and its downstream signaling molecule, signal transducer and activator of transcription-3. Moreover, class I HDAC inhibition reduced the number of renal tubular cells arrested in the G2/M phase of the cell cycle, a cellular event associated with TGF-beta1overproduction. In cultured renal interstitial fibroblasts, MS-275 treatment inhibited TGF-beta induced phosphorylation of Smad-3, differentiation of renal fibroblasts to myofibroblasts and proliferation of myofibroblasts.Conclusions and SignificanceThese results demonstrate that class I HDACs are critically involved in renal fibrogenesis and renal fibroblast activation through modulating TGF-beta and EGFR signaling and suggest that blockade of class I HDAC may be a useful treatment for renal fibrosis.

Protection of Bone Marrow-Derived CD45(superscript +)/CD34(superscript -)/lin(superscript -) Stromal Cells with Immunosuppressant Activity against Ischemia/Reperfusion Injury in Rats

Non-hematopoietic CD45+ precursor cells are not known to differentiate into cardiomyocytes. We found that CD45+/CD34-/lin- stromal cells isolated from mouse bone marrow (BMSCs) potentially differentiated into cardiomyocyte-like cells in vitro. Therefore, we hypothesized that the CD45+/CD34-/ lin- BMSCs might protect rat hearts against ischemia/reperfusion (IR) injury following xeno-transplantation. In the present study, BMSCs were isolated by immunoselection and their cellular phenotype and biochemical properties were characterized. The immunological inertness of BMSCs was examined by the allogeneic and xenogeneic mixed lymphocyte reaction (MLR). The potential role of BMSCs for cardioprotection was evaluated by intravenous introduction of 1 x 10(6) cells into rat IR hearts, induced by left coronary ligation for 45 min and released for 72 h. Changes in cardiac contractility and the degree of myocardial injury were assessed. Our findings indicated that BMSCs expressed the muscle-cell marker alpha-actinin after 5-azacytidine treatment. CD45+/CD34-/lin- stromal cells were characterized as mesenchymal progenitor cells based on the expression of Sca-1 and Rex-1. The MLR assay revealed an immunosuppression of BMSCs on mouse and rat lymphocytes. After xeno-transplantation, the BMSCs engrafted into the infarct area and attenuated IR injury. However, increases in intracardial TGF-beta and IFN-gamma contents of IR hearts were not affected by BMSC treatment. Interestingly, ex vivo evidence indicated that CXCR4, SDF-1 and TGFbeta-1 receptors were up-regulated after the cells were exposed to tissue extracts prepared from rat post-IR hearts. In addition, IFN-gamma treatment also markedly increased Sca-1 expression in BMSCs. Mechanistically, these results indicated that CXCR4/SDF-1 and TGF-beta signals potentially enhanced the interaction of BMSCs with the damaged myocardium, and increased IFN-gamma in post-ischemic hearts might cause BMSC to behave more like stem cells in cardioprotection. These data show that CD45+/CD34-/lin- BMSCs possess cardioprotective capacity. Evidently, the accurate production of soluble factors TGF-beta and IFN-gamma in parallel with increased expression of both TGF-beta and Sca-1 receptors may favor BMSCs to achieve a more efficient protective capacity.

Unbalanced helper T cell function in Behcet's disease

Behcet's disease (BD) is a multisystem inflammatory disease that is characterized by recurrent attacks of uveitis, oral apthous ulcers, genital ulcers, and erythema nodosum. The etiology and pathogenesis of BD are largely unknown. We have presented evidence that supports a role of excessive Th1 cell activity in BD. Recently, it has been suggested that Th17 cells are associated with several autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease, all of which are considered to be Th1 diseases. Therefore, it is interesting to study the role of Th17-related cytokines and Th17-associated signaling molecules in BD. Major Th17-related cytokines were not detected in peripheral blood mononuclear cells (PBMCs) and in skin lesions of BD patients. Expression of TGF-beta receptor and Smad2 mRNA was significantly higher in BD patients compared with the levels in normal controls. Interleukin (IL)-23 receptor, ROR-C, and Foxp3 are key transcription factors expressed by Th17 cells and regulatory T cells, respectively, and their expression was decreased in BD. These findings suggest that T cell function may be unbalanced in BD.

Transforming growth factor β2 is negatively regulated by endogenous retinoic acid during early heart morphogenesis

Vitamin A-deficient (VAD) quail embryos lack the vitamin A-active form, retinoic acid (RA) and are characterized by a phenotype that includes a grossly abnormal cardiovascular system that can be rescued by RA. Here we report that the transforming growth factor, TGFbeta2 is involved in RA-regulated cardiovascular development. In VAD embryos TGFbeta2 mRNA and protein expression are greatly elevated. The expression of TGFbeta receptor II is also elevated in VAD embryos but is normalized by treatment with TGFbeta2-specific antisense oligonucleotides (AS). Administration of this AS or an antibody specific for TGFbeta2 to VAD embryos normalizes posterior heart development and vascularization, while the administration of exogenous active TGFbeta2 protein to normal quail embryos mimics the excessive TGFbeta2 status of VAD embryos and induces VAD cardiovascular phenotype. In VAD embryos pSmad2/3 and pErk1 are not activated, while pErk2 and pcRaf are elevated and pSmad1/5/8 is diminished. We conclude that in the early avian embryo TGFbeta2 has a major role in the retinoic acid-regulated posterior heart morphogenesis for which it does not use Smad2/3 pathways, but may use other signaling pathways. Importantly, we conclude that retinoic acid is a critical negative physiological regulator of the magnitude of TGFbeta2 signals during vertebrate heart formation.

1195 PSA-INDUCED OSTEOBLASTIC DIFFERENTIATION IN SAOS-2 CELLS: ROLE OF WIF-1 AND TGF-BETA

You have accessJournal of UrologyProstate Cancer: Basic Research VI1 Apr 20101195 PSA-INDUCED OSTEOBLASTIC DIFFERENTIATION IN SAOS-2 CELLS: ROLE OF WIF-1 AND TGF-BETA Nagalakshmi Nadiminty, Wei Lou, and Allen Gao Nagalakshmi NadimintyNagalakshmi Nadiminty More articles by this author , Wei LouWei Lou More articles by this author , and Allen GaoAllen Gao More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.696AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The high prevalence of osteoblastic bone metastases in prostate cancer likely involves the production of osteoblast-stimulating factors by prostate cancer cells. The identity of the factors responsible for the homing of circulating prostate cancer cells to the bone remains unknown. Prostate specific antigen (PSA) is a serine protease produced by prostate cancer cells and is an important serological marker for prostate cancer. In this study, we examined the involvement of Wnt inhibitory factor 1 (Wif-1) and Transforming growth factor beta (TGF-beta) in osteoblastic differentiation induced by PSA in SaOS-2 human osteosarcoma cells. METHODS Microarray analysis of RNAs from Saos-2 cells stably expressing PSA and vector controls was performed and the results were validated by northern blotting. The potential role of Wif-1 and TGF-β in osteoblatic differentiation induced by PSA was examined by alkaline phosphatase assays, luciferase assays and northern analysis. RESULTS PSA was found to induce bone remodeling in SaOS-2 cells as evidenced by increases in alkaline phosphatase activity, mineral deposition and osteogenic gene expression. Saos-2 cells expressing PSA exhibited markedly upregulated expression of markers of osteoblastic differentiation like collagen type 1, osteocalcin, Runx-2, alkaline phosphatase and bone sialoprotein compared to parental Saos-2 cells and vector controls. Treatment of SaOS cells with exogenous enzymatically active PSA produced similar results, suggesting that osteoblastic differentiation may be regulated by PSA. Among the genes found to be regulated by PSA expression, TGF-beta and Wif-1 were examined further. PSA enhanced the expression and activation of TGF-beta as shown by higher levels of TGF-beta-responsive reporter activity and increase in expression of TGF-beta receptors I and II. Overexpression of Wif-1 in SaOS-2 cells enhanced osteogenic gene expression, while inhibition of Wif-1 expression in PSA-expressing cells resulted in reduction of alkaline phosphatase activity, a marker of osteoblastic differentiation. CONCLUSIONS PSA-induced bone remodeling was mediated by enhanced expression of several markers of osteoblastic differentiation and modulation of TGF-beta and the Wnt/beta-catenin pathways. These results suggest that PSA produced by metastatic prostate cancer cells may participate in bone remodeling in favor of development of osteoblastic metastases. These findings provide a molecular basis for understanding the high prevalence of osteoblastic bone metastases in prostate cancer. Sacramento, CA© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e463 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nagalakshmi Nadiminty More articles by this author Wei Lou More articles by this author Allen Gao More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

IL-18 Downregulates Collagen Production in Human Dermal Fibroblasts via the ERK Pathway

Excessive accumulation of collagen contributes to the fibrotic process. Several experimental studies have shown that IFN-gamma is effective in preventing fibrogenesis. IL-18, originally identified as an IFN-gamma-inducing factor, is a key mediator of inflammation and host defense responses. In this study, we investigated the regulatory effect of IL-18 on the expression of type I and III collagen genes in dermal fibroblasts. The exposure of human dermal fibroblasts (HDFs) to IL-18 resulted in a reduction of collagen gene expression and production. Also, IL-18 inhibited the fibrogenic cytokine transforming growth factor (TGF)-beta-induced collagen gene expression. Next, to determine the molecular mechanism involved in this regulation, we showed that IL-18-regulated collagen expression was blocked by small interfering RNA (siRNA)-mediated Ets-1 knockdown. Furthermore, we showed that IL-18 induced phosphorylation of extracellular signal-regulated kinase (ERK) within 10 minutes and that the ERK inhibitor PD98059 blocked the inhibitory effect of IL-18. IL-18 also inhibited the production of collagen in systemic sclerosis (SSc) dermal fibroblasts. Our data indicate that IL-18 downregulates collagen production in HDF directly via Ets-1 and the ERK pathway, suggesting that IL-18 may exert antifibrotic activities in dermal fibroblasts.

Changes in expression, and/or mutations in TGF-β receptors (TGF-β RI and TGF-β RII) and Smad 4 in human ovarian tumors

Loss of sensitivity to transforming growth factor beta (TGF-beta) signaling typically occurs in human ovarian cancer cells, but there is paucity of information regarding this in human ovarian tumors. Thus the association of inactivating mutations and/or variations in expression levels of TGF-beta signaling components with human ovarian tumors was evaluated. Forty human ovarian tissue samples were analyzed for mutations and/or variations in the expression of transforming growth factor beta signaling components. Mutation studies were done through reverse transcription (RT) PCR, single strand conformation polymorphism analysis and automated DNA sequencing. Expression studies were carried out by semi quantitative RT PCR and western blotting. DNA binding ability of Smad complexes and expression of downstream targets were also analyzed. The six alanine repeat containing variant of TGF-beta RI was seen in 27% of the tumor cases studied, in addition to the 45 bp nucleotide deletions in exon 1 of the receptor in two ovarian tumor samples. A deletion in the polyadenine tract of exon 3 of TGF-beta RII was seen in 22% of the tumor samples. We also report a loss or decrease in the expression of Smad 4 protein in tumor samples with a concurrent loss or reduced DNA binding ability of the Smad complex and deregulated expression of p21 and c-Myc. Our results suggest that mutations and/or alterations in expression of TGF-beta receptors and loss of Smad 4 are frequent in human ovarian cancers and may potentially explain the frequent loss of TGF-beta responsiveness that typically occurs in human ovarian cancer.

TGF‐beta1 and TGFBR1 are Expressed in Ameloblasts and Promote MMP20 Expression

Transforming growth factor-beta (TGF-beta) signaling exerts a wide spectrum of biological functions. To investigate TGF-beta signaling in amelogenesis, we initially assessed the expression of TGF-beta1 and TGF-beta receptor 1 (TGFBR1) in developing teeth by immunohistochemistry. Both TGF-beta1 and TGFBR1 were strongly expressed in secreting ameloblasts. Next, we studied the effects of TGF-beta signaling on the expression of MMP20 and KLK4 mRNA using ameloblast-lineage cells (ALC) in vitro. Our RT-PCR study showed that TGF-beta1, TGFBR1, and enamel matrix proteases (MMP20 and KLK4) were expressed in ALC. Following TGF-beta1 treatment, the expression of MMP20 mRNA, but not KLK4 mRNA, was significantly upregulated. To further confirm the TGF-beta signaling involvement in the MMP20 expression, we constructed the activated TGFBR1 vector and transfected the construct into ALC. The activated TGFBR1 notably promoted MMP20 expression, but had no obvious effects on the KLK4 mRNA expression. Our studies strongly suggest that TGF-beta signaling involved in amelogenesis is partially mediated by regulating the expression of MMP20 mRNA.

Hydrogen peroxide-induced cellular apoptosis is mediated by TGF-β2 signaling pathway in cultured human lens epithelial cells

The objective of this study was to investigate the signaling characteristics of transforming growth factor-beta2 (TGF-beta2) and the Smads (Caenorhabditis elegans, Sma; Drosophila mothers against dpp, Mad) signal pathway of cellular apoptosis induced by hydrogen peroxide with human lens epithelial cells (HLECs). HLECs were starved for 24 h before exposure to 0.1 mumol/ml of hydrogen peroxide in the presence and in the absence of 0.01 mug/ml of AF-302-NA, a monoclonal anti-TGF-beta2 neutralization antibody. Non-stimulated cells served as controls. Cell apoptosis was examined by in situ immunocytochemistry using terminal deoxynucleotidyl transferase dUTP-mediated biotin nick end labeling (TUNEL) and by flow cytometry (FCM) using Annexin V-FITC apoptosis detection. Gene expression was assessed using the reverse transcription-polymerase chain reaction (RT-PCR). Smad-4 localization was observed by immunocytochemistry. Hydrogen peroxide induced the accumulation of Smad-4 in the nucleus of HLECs, and upregulated the expression of TGF-beta receptors (TbetaRs) mRNA in HLECs, as well as upregulated the expression of the apoptotic gene bax, which leads HLECs to apoptosis. AF-302-NA decreased cellular apoptosis induced by hydrogen peroxide in HLECs and inhibited the translocation of Smad-4 from the cytoplasm to the cell nucleus. Moreover, AF-302-NA upregulated the expression of TbetaRs mRNA and downregulated the expression of bax mRNA in HLECs incubated with hydrogen peroxide. Our study demonstrated that the TGF-beta2 signal pathway participated in the apoptotic signal transfer and might be an initiator of cellular apoptosis of HLECs after incubation with hydrogen peroxide. Interruption of the TGF-beta2 signal pathway could partially protect HLECs from apoptosis induced by incubation with hydrogen peroxide.

Radiation-Induced Activation of TGF-β Signaling Pathways in Relation to Vascular Damage in Mouse Kidneys

The purpose of this study was to investigate the long-term effects of radiation-induced alterations in TGF-beta signaling pathways with respect to the development of vascular damage in the irradiated kidney. Total RNA was isolated from mouse kidneys at 1-30 weeks after irradiation, and quantitative real-time PCR analyses were performed for TGF-beta receptors (ALK1, ALK5, endoglin), downstream mediators (Smad7, CTGF), and downstream targets (PAI-1 and Id-1). Expression of endoglin and Smad7 protein as well as nucleo-cytoplasmic distribution of phospho Smad 2/3 and phospho Smad 1/5 was analyzed by immunohistochemistry. Radiation caused a rapid and persistent increase in expression of TGF-beta receptors and mediators from 1-30 weeks after treatment. Expression of Id-1, a downstream target of endothelial cell specific receptor ALK1, was transiently increased (1-10 weeks after irradiation) but returned to control levels at later times. Expression of PAI-1, a downstream target of ALK5, increased progressively from 10-30 weeks after irradiation. These results show that radiation activated TGF-beta signaling pathways in the kidney and shifted the balance in favor of ALK5 signaling, which generally inhibits endothelial cell proliferation and migration. We hypothesize that prolonged activation of ALK5 signaling and relative suppression of ALK1 signaling may provide an explanation for the telangiectatic phenotype observed in irradiated kidneys.

Imbalanced expression of the type I TGF-beta receptors ALK-1 and ALK-5 in pulmonary fibrosis

Einleitung: Idiopathic pulmonary fibrosis (IPF) is a devastating disease with no effective treatment options. The lungs of IPF patients are characterized by alveolar epithelial cell injury, an accumulation of activated (myo)fibroblasts, and excessive deposition of extracellular matrix, especially collagens. This is, to a great extend, due to enhanced TGF-beta activity. In this study, we hypothesized that IPF is characterized by distinct alterations in the expression and activity of TGF-beta receptors (TbR) and its intracellular mediators, smads.

Downregulation of SMAD2, 4 and 6 mRNA and TGFβ Receptor I mRNA in Lesional and Non-lesional Psoriatic Skin

Transforming growth factor beta (TGFbeta) has been suggested to be an effective inhibitor of the increased keratinocyte proliferation in psoriasis. Three TGFbeta isoforms are described (TGFbeta1, 2 and 3), signalling via a heteromeric receptor complex of TGFbetaRI and TGFbetaRII. Receptor binding activates SMAD2, 3 and 4, which translocate into the nucleus and regulate TGFbeta-responsive genes. SMAD6 and 7 proteins represent a negative feedback loop inhibiting the TGFbeta-SMAD signalling path-way. As TGFbeta1 overexpression inhibits keratinocyte proliferation, the aim of this study was to investigate with real-time RT-PCR the expression of TGFbeta1, 2 and 3, TGFbetaRI and TGFbetaRII and SMAD2, 3, 4, 6 and 7 in lesional and non-lesional psoriatic skin from 13 patients with chronic plaque-type psoriasis as compared to skin from 10 healthy subjects . The study data demonstrate significantly downregulated TGFbetaRI and SMAD2, 4 and 6 mRNA expression in lesional and non-lesional psoriatic skin. SMAD7 mRNA expression was significantly decreased in lesional psoriatic skin compared with both non-lesional psoriatic skin and healthy skin. A significant TGFbeta3 and TGFbetaRII mRNA upregulation exclusively in non-lesional psoriatic skin but no significant difference in the expression of TGFbeta1 and 2 was found. The results of this study suggest that the expression of TGFbeta isoforms, receptors and SMADs may be involved in the increased proliferation of keratinocytes in psoriatic skin.

Basic fibroblast growth factor: A potential new therapeutic tool for the treatment of hypertrophic and keloid scars

Numerous tissue niches in the human body, such as skin, are now recognized to harbour adult stem cells. In this study, we analyze multipotent human dermis-derived progenitor cell populations, isolated and propagated from mechanically and enzymatically processed adult scalp skin. The populations encompass Nestin-positive and -negative cells, which may serve as a convenient and abundant source for various therapeutic applications in regenerative medicine. Here, we show that these cultures exhibit a strong tendency to differentiate into mesodermal derivatives, particularly myofibroblasts, when maintained in media containing serum. Since undesired and excessive myofibroblast formation is a frequent postsurgical complication, we sought culture conditions that would prevent myofibroblast formation. In particular, we analyzed the effect of growth factors, such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and platelet-derived growth factor AB (PDGF AB). Our results demonstrate that bFGF is a potent inhibitor of mesodermal differentiation, whereas PDFG AB favours myofibroblast formation and up-regulates expression of TGFbeta receptors I and II. This interesting discovery may help in the prevention and treatment of tissue fibrosis and in particular in the eradication of hypertrophic and keloid scars.

Fibromuscular differentiation in deeply infiltrating endometriosis is a reaction of resident fibroblasts to the presence of ectopic endometrium

In this study, we characterized the fibromuscular (FM) tissue, typical of deeply infiltrating endometriosis, investigated which cells are responsible for the FM reaction and evaluated whether transforming growth factor-beta (TGF-beta) signaling is involved in this process. FM differentiation and TGF-beta signaling were assessed in deeply infiltrating endometriosis lesions (n = 20) and a nude mouse model of endometriosis 1, 2, 3 and 4 weeks post-transplantation. The FM reaction was evaluated by immunohistochemistry using different markers of FM and smooth muscle cell differentiation (vimentin, desmin, alpha-smooth muscle actin, smooth muscle myosin heavy chain). TGF-beta signaling was assessed by immunostaining for its receptors and phosphorylated Smad. Deeply infiltrating endometriosis lesions contain myofibroblast-like cells that express multiple markers of FM differentiation. Expression of TGF-beta receptors and phospho-Smad was more pronounced in the endometrial component of the lesions than in the FM component. In the nude mouse model, alpha-smooth muscle actin expression was observed in murine fibroblasts surrounding the lesion, but not in human endometrial stroma. FM differentiation in deeply infiltrating endometriosis is the result of a reaction of the local environment to the presence of ectopic endometrium. It shares characteristics with pathological wound healing, but cannot be explained by TGF-beta signaling alone.

S1700 Smurf2 Activity in T Lymphocytes Protects Mice from Experimental Colon Cancer

Introduction: TGF-beta is a pleiotropic cytokine with wide ranging effects in proliferation, differentiation, immune suppression and apoptosis. Recent work from our group has shown that TGF-beta signalling in T cells is protective in a mouse model of colitis associated cancer. Smad ubiquitin regulating factors (Smurf) are ubiquitin ligases that are involved in the regulation of TGF-beta signalling. The aim of this study was to determine the function of Smurf2 expression in T-cells on the pathogenesis of experimental colitis associated colon cancer. Methodology: We could isolate a known splice variant of Smurf2 lacking an Exon in the C2-domain. To analyse whether this form has a regulatory role in colon associated cancer we generated a transgenic mouse strain that overexpresses Smurf2 in T-cells. Smurf2 expression were analysed by qPCR. Wild type (WT) and Transgenic (TG) mice were treated once with the mutagenic agent Azoxymethan (AOM) followed by three cycles of Dextran Sodiumsulfate (DSS). After each cycle, the inflammation of the gut and the tumor growth and size of every mouse were monitored by colonoscopy. Results: Smurf2 expression was upregulated by TGF-beta stimulation in T-cells and Smurf2 was markedly upregulated in tumor infiltrating CD4+ lymphocytes in AOM/DSS treated mice. Whereas WT mice suffered from severe colitis resulting in colon tumors beginning at day 35, Smurf2 transgenic mice had less colitis and were significantly protected from tumor development. Interestingly, Tlymphocytes overexpressing Smurf2 showed an upregulation of Smurf2 target genes including the TGFbRII and an activation of Smad3 as compared towild-type T-lymphocytes, whichwere previously described as typical Smurf2 targets for degradation. In addition the transfection of Smurf2 and a CAGA-Luc Plasmid into Cos-cells for Smad3-Promotor studies yielded the same effect as shown by an upregulation of the Smad3 activity. Conclusion: Although, WTSmurf has been described as a negative regulator of the TGF-beta signalling pathway, our data show surprisingly that a Smurf2 splice variant upregulates the TGF-beta receptor expression and increases TGF-beta signalling effects. Due to immunosuppressive effects on T-cells Smurf2 has beneficial effects on mucosal inflammation and colon tumor development. These findings are probably due to autoubiquitination of WTSmurf2 via the splice variant of Smurf2. Smurf2 thus emerges as an attractive target for modulation of chronic intestinal inflammation and colitis associated carcinogenesis.