BACKGROUNDMesenchymal stem cells (MSCs) are bone marrow stem cells which play an important role in tissue repair. The treatment with MSCs will be likely to aggravate the degree of fibrosis. The Wnt/β-catenin signaling pathway is involved in developmental and physiological processes, such as fibrosis. Dickkopfs (DKKs) are considered as an antagonist to block Wnt/β-catenin signaling pathway by binding the receptor of receptor-related protein (LRP5/6). DKK1 was chosen in attempt to inhibit fibrosis of MSCs by lowering activity of Wnt/β-catenin signaling pathway.

METHODSStable MSCs were randomly divided into four groups: MSCs control, MSCs + transforming growth factor-β (TGF-β), MSCs + DKK1, and MSCs + TGF-β + DKK1. Flow cytometry was used to identify MSCs. Cell viability was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide test. Immunofluorescence was used to detect protein expression in the Wnt/β-catenin signaling pathways. Western blotting analysis was employed to test expression of fibroblast surface markers and, finally, real-time reverse transcription polymerase chain reaction was employed to test mRNA expression of fibroblast surface markers and Wnt/β-catenin signaling proteins.

RESULTSCultivated MSCs were found to conform to the characteristics of standard MSCs: expression of cluster of differentiation (CD) 73, 90, and 105, not expression of 34, 45, and 79. We found that DKK1 could maintain the normal cell morphology of MSCs. Western blotting analysis showed that fibroblast surface markers were expressed in high quantities in the group MSCs + TGF-&beta;. However, the expression was lower in the MSCs + TGF-&beta; + DKK1. Immunofluorescence showed high expression of all Wnt/&beta;-catnin molecules in the MSCs + TGF-&beta; group but expressed in lower quantities in MSCs + TGF-&beta; + DKK1 group. Finally, mRNA expression of fibroblast markers vimentin, α-smooth muscle actin and Wnt/&beta;-catenin signaling proteins &beta;-catenin, T-cell factor, and glycogen synthase kinase-3&beta; was significantly increased in MSCs + TGF-&beta; group compared to control (P < 0.05). Expression of the same fibroblast markers and Wnt/&beta;-catenin was decreased to regular quantities in the MSCs + TGF-&beta; + DKK1 group.

CONCLUSIONSDKK1, Wnt/&beta;-catenin inhibitors, blocks the Wnt/&beta;-catenin signaling pathway to inhibit the process of MSCs fibrosis. It might provide some new ways for clinical treatment of certain diseases.

Animals ; Cell Differentiation ; physiology ; Cells, Cultured ; Female ; Fibroblasts ; cytology ; metabolism ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; Rats ; Transforming Growth Factor beta ; genetics ; metabolism

Using forward and reverse genetics and global gene expression analyses, we explored the crosstalk between the IκB kinase β (IKKβ) and the transforming growth factor β (TGFβ) signaling pathways. We show that in vitro ablation of Ikkβ in fibroblasts led to progressive ROS accumulation and TGFβ activation, and ultimately accelerated cell migration, fibroblast-myofibroblast transformation and senescence. Mechanistically, the basal IKKβ activity was required for anti-oxidant gene expression and redox homeostasis. Lacking this activity, IKKβ-null cells showed ROS accumulation and activation of stress-sensitive transcription factor AP-1/c-Jun. AP-1/c-Jun activation led to up-regulation of the Tgfβ2 promoter, which in turn further potentiated intracellular ROS through the induction of NADPH oxidase (NOX). These data suggest that by blocking the autocrine amplification of a ROS-TGFβ loop IKKβ plays a crucial role in the prevention of fibroblast-myofibroblast transformation and senescence.
Adenoviridae ; genetics ; Animals ; Autocrine Communication ; physiology ; Cell Line ; Cell Movement ; Cellular Senescence ; Genetic Vectors ; genetics ; metabolism ; I-kappa B Kinase ; deficiency ; genetics ; metabolism ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Mice ; Myofibroblasts ; cytology ; metabolism ; NADPH Oxidases ; metabolism ; Oxidative Stress ; Promoter Regions, Genetic ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; Superoxide Dismutase ; genetics ; metabolism ; Transcription Factor AP-1 ; metabolism ; Transforming Growth Factor beta ; genetics ; metabolism ; Up-Regulation

OBJECTIVEThe purpose of the present study was to observe the changes in CD4+CD25+Nrp1+Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved.

METHODSICR mice and mouse lymphoma cell line (EL-4 cells) was used. The expressions of CD4, CD25, Nrp1, calcineurin and PKC-α were detected by flow cytometry. The expressions of TGF-&beta;1, IL-10, PKA and cAMP were estimated with ELISA.

RESULTSAt 12 h after irradiation, the expression of Nrp1 increased significantly in 4.0 Gy group, compared with sham-irradiation group (P<0.05) in the spleen and thymus, respectively, when ICR mice received whole-body irradiation (WBI). Meanwhile the synthesis of Interleukin 10 (IL-10) and transforming growth factor-&beta;1 (TGF-&beta;1) increased significantly after high dose irradiation (HDR) (> or = 1.0 Gy). In addition, the expression of cAMP and PKA protein increased, while PKC-α, calcineurin decreased at 12h in thymus cells after 4.0 Gy X-irradiation. While TGF-&beta;1 was clearly inhibited when the PLC-PIP2 signal pathway was stimulated or the cAMP-PKA signal pathway was blocked after 4.0 Gy X-irradiation, this did not limit the up-regulation of CD4+CD25+Nrp1+Treg cells after ionizing radiation.

CONCLUSIONThese results indicated that HDR might induce CD4+CD25+Nrp1+Treg cells production and stimulate TGF-&beta;1 secretion by regulating signal molecules in mice.

Animals ; Calcineurin ; genetics ; metabolism ; Cyclic AMP ; metabolism ; Dose-Response Relationship, Radiation ; Female ; Gene Expression Regulation ; radiation effects ; Immunosuppression ; Interleukin-10 ; genetics ; metabolism ; Lymphocyte Subsets ; physiology ; Male ; Mice ; Neuropilin-1 ; genetics ; metabolism ; Phosphoinositide Phospholipase C ; genetics ; metabolism ; Protein Kinases ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta ; genetics ; metabolism ; Whole-Body Irradiation ; adverse effects

BACKGROUNDDecorin is a small leucine-rich proteoglycan and it plays an important role in regulation of cell growth and migration in various tumor cell lines. Decorin was found down-regulated in non-small cell lung cancer tissue and may be involved in regulation of lung cancer development.

METHODSIn this study, lentivirus-mediated RNA interference and over expression were employed to change the expression levels of decorin in lung cancer A549 cells. We tested the cell cycle of A549 cells and the expression of transforming growth factor (TGF)-&beta;, cyclin D1, epidermal growth factor receptor (EGFR), P53, and P21.

RESULTSWe found that up-regulation of decorin could inhibit proliferation, block cell cycle at G1 and decrease invasive activity of A549 cells. Moreover, we also show that up-regulation of decorin induced significant decreases of TGF-&beta;1, cyclin D1 expression, phosphorylation of EGFR, and increases of P53 and P21 expression. Opposite results were observed in A549 cells with down-regulation of decorin.

CONCLUSIONOur results suggest that decorin is a key regulator involved in proliferation and migration of A549 cells.

Cell Cycle ; genetics ; physiology ; Cell Movement ; genetics ; physiology ; Cell Proliferation ; Cyclin D1 ; genetics ; metabolism ; Decorin ; genetics ; metabolism ; Humans ; Receptor, Epidermal Growth Factor ; genetics ; metabolism ; Transforming Growth Factor beta ; genetics ; metabolism ; Tumor Cells, Cultured

BACKGROUNDHaze or corneal subepithelial fibrosis is one of the common complications after refractive surgery procedures, such as photorefractive keratectomy (PRK), laser epithelial keratomileusis, and epipolis laser in situ keratomileusis, which would result in refractive regression, decreased visual quality, and corneal opacification. Haze directly resulted from corneal fibrosis mediated by transforming growth factor &beta; (TGF&beta;). Smad7, an inhibitory Smad, can inhibit TGF&beta; signal transduction. Recently, the effects of Smad7 on the inhibition of fibrosis in several organs have been studied, while little is known about the effects on cornea after PRK. This study was aimed to determine the effects of lentiviral-mediated Smad7 gene expression on corneal fibrosis in rats after PRK.

METHODSFour different experimental groups were established using right eyes of Sprague-Dawley rats. Thirty-two eyes underwent de-epithelialization only and served as a sham operation group (group 1). Ninety-six eyes underwent PRK operation and were further divided into group 2 (the PRK group) without lentivector administration, group 3 (the Lv-blank group) with control lentiviral vector without Smad7 administration, and group 4 (the Lv-Smad7 group) with Smad7 expressing lentiviral vector Smad7 administration. At 1 day, 1 week, 1 month, and 3 months after PRK, the transfection efficiency was determined by measuring the fluorescence signal as well as Smad7 protein and mRNA levels. Corneas were further processed for immunoblotting to assess the phosphorylation of Smad2 as a downstream event of TGF&beta;/Smad signaling. The expression of fibrotic markers, such as α-smooth muscle actin (α-SMA), Type III collagen (collagen III), and cell cycle-related marker Ki67, was measured by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTSLentivirus-mediated exogenous Smad7 gene expression in rat corneal tissue resulted in reduced activation of TGF&beta;/Smad signaling caused by downregulation of phosphorylation of Smad2. Smad7 also downregulated the expression of TGF&beta;2. Markers of cell proliferation and fibrosis, including Ki67, α-SMA, and collagen III, were inhibited by Smad7 up to 3 months after PRK operation.

CONCLUSIONSmad7 gene transfer inhibits fibrogenic responses of cornea in rats after PRK.

Actins ; genetics ; Animals ; Collagen Type III ; genetics ; Cornea ; pathology ; Fibrosis ; Genetic Therapy ; Ki-67 Antigen ; genetics ; Lentivirus ; genetics ; Photorefractive Keratectomy ; adverse effects ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Smad7 Protein ; genetics ; physiology ; Transforming Growth Factor beta ; physiology

OBJECTIVETo examine the single nucleotide polymorphism (SNP) (rs1495592) in transforming growth factor-beta receptor 2 (TGFBR2) gene in children, and to investigate its association with Kawasaki disease (KD) and coronary artery lesions (CALs).

METHODSThirty-five KD patients, 14 of whom had CALs (CAL subgroup), were selected as the case group, and 25 healthy age-matched children were selected as the control group. The SNP (rs1495592) in TGFBR2 gene was studied by gene sequencing. The association of SNP (rs1495592) with KD and (CALs) was analyzed based on the sequencing results.

RESULTSThere were no significant differences in genotype frequency distribution (χ(2)=0.566, P=0.452) and allele frequency distribution (χ(2)=0.216, P=0.642) between the two groups. Genotypes in the CAL subgroup included CC (21.4%) and CT+TT (78.6%), while genotypes in the non-CAL subgroup included CC (61.9%) and CT+TT (38.1%). There was significant difference in genotype frequency distribution between the two groups (χ(2)=5.546, P=0.019), but without significant difference in allele frequency distribution (χ(2)=3.673, P=0.055).

CONCLUSIONSThe SNP (rs1495592) in TGFBR2 gene may not be associated with development of KD in children, but it is associated with CALs in children with KD.

Coronary Artery Disease ; genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Infant ; Male ; Mucocutaneous Lymph Node Syndrome ; genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Protein-Serine-Threonine Kinases ; genetics ; Receptors, Transforming Growth Factor beta ; genetics ; Signal Transduction ; Transforming Growth Factor beta ; physiology

BACKGROUNDSmad4 is found mutated in many cancers. It acts as a tumor suppressor in the regulation of TGF-&beta; signaling pathway. The objective of this work was to study the expression of Smad4 in intrahepatic cholangiocarcinoma (ICC) and its relationship with the biological behavior and prognosis of the disease.

METHODSForty-nine paraffin-embedded ICC specimens and nine normal liver tissues were analyzed by immunohistochemical methods using Smad4 monoclonal antibodies. The expression of Smad4 was compared with the clinical pathological characteristics of the patients.

RESULTSThe expression of Smad4 was 100% positive in normal liver tissues, which was higher than that in the ICC (44.9%). Negative labeling of the Smad4 protein was found in 26.1% (6/23) of well-differentiated ICCs and 61.5% (16/26) of poorly to moderately differentiated ICCs, and 34.3% (12/35) and 71.4% (10/14) showed negative Smad4 labeling (P = 0.018) of ICC at pathological Tumor Node Metastasis (pTNM) stage I-II and pTNM stage III-IV separately. Furthermore, 72% (8/11) of lymph node metastatic ICCs and 73.3% (11/15) of intrahepatic metastatic ICCs showed negative labeling of the Smad4 protein. The loss of Smad4 expression in those metastatic ICCs was significantly more severe compared with non-metastatic ICCs (P = 0.000).

CONCLUSIONSThe expression of Smad4 was associated with the histological grade, clinical stage, and metastasis of ICC (P < 0.05). The detection of Smad4 may be helpful in determining the degree of malignancy and prognosis of ICC.

Adult ; Aged ; Bile Duct Neoplasms ; Bile Ducts, Intrahepatic ; Cholangiocarcinoma ; chemistry ; pathology ; Female ; Humans ; Liver Neoplasms ; chemistry ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; Signal Transduction ; physiology ; Smad4 Protein ; analysis ; genetics ; physiology ; Transforming Growth Factor beta ; physiology

OBJECTIVETo determine the expression level of Smad ubiquitination regulatory factor 1 (SMURF1) gene in hepatocellular carcinoma, and to explore its role in liver cancer.

METHODSWith non-neoplastic adjacent normal tissues as controls, real-time PCR and Western blotting were used for measuring the expression of SMURF1 mRNA and protein in 89 samples of hepatocellular carcinoma. Correlations between SMURF1 expression and clinical features were explored. Following transfection of SMURF1--specific small interference RNA(siRNA), the apoptosis and proliferation of hepatic cancer cells Hep G2 were detected using flow cytometry and MTT assays .

RESULTSThe expression of SMURF1 mRNA and protein were significantly higher in hepatocellular cancer tissues compared with the paired normal tissues (P< 0.05). The expression of SMURF1 however did not correlate with any clinical features (P> 0.05). Transfection of SMURF1-specific siRNA can promote the apoptosis whilst inhibit the proliferation of Hep G2 cells.

CONCLUSIONThe expression of SMURF1 is enhanced in hepatocellular carcinoma, which may have played a role in the disease through affecting apoptosis and proliferation of hepatic cancer cells.

Female ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; Male ; RNA, Messenger ; analysis ; Transforming Growth Factor beta ; physiology ; Ubiquitin-Protein Ligases ; genetics ; physiology

OBJECTIVETo study the protective effect of oxymatrine (OMT) on myocardial fibrosis induced by acute myocardial infarction in rats and its effect on TGF-beta-Smads signal pathway.

METHODArteria coronaria ligation-induced acute myocardial infarction model was established in rats. The survived rats were randomly allotted into the model group, 50, 25, 12.5 mg x kg(-1) OMT groups, the 50 mg x kg(-1) captopril group, and the Sham-operated group which was treated as the model group without the arteria coranaria ligation. After 8 weeks of ligation, myocardial fibrosis was detected by HE and Masson staining, and the RT-PCR method were used to detect the expression of mRNA of TGF-beta-Smads signal system.

RESULTThe histopathological examination showed decrease in cardiocytes, deposition of extra-cellular matrix, and increase of collagen contents after 8 weeks of ligation. RT-PCR results showed that mRNA expressions of TGF-beta1, TbetaR1, Smad2, Smad3 and Smad4 significantly increased, but mRNA expression of Smad7 is remarkable lower than the sham-operated group. Treatment with OMT for 8 weeks could remarkably inhibit myocardial fibrosis, decrease mRNA expressions of TGF-beta1, TbetaR1, Smad2, Smad3, and Smad4, and increase mRNA expressions of Smad7.

CONCLUSIONOMT has the inhibitory effect on the experimental myocardial fibrosis induced by AMI in rats. Its mechanism may be closely related to TGF-beta-Smads signal system.

Acute Disease ; Alkaloids ; therapeutic use ; Animals ; Fibrosis ; Male ; Myocardial Infarction ; complications ; Myocardium ; pathology ; Quinolizines ; therapeutic use ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology ; Smad Proteins ; genetics ; physiology ; Transforming Growth Factor beta ; genetics ; physiology

TGF&beta;/smad pathway is recognized as an important signal pathway to promote the pathogenesis of atherosclerosis (AS). Peroxisome proliferator-activated receptor γ (PPARγ) activation is considered to be important in modulating AS. Herein, we investigated the regulation of PPARγ on c-Ski, the repressor of TGF&beta;/smad pathway, in rat AS model and cultured vascular smooth muscle cells (VSMCs). c-Ski mRNA and protein expression were detected by real-time PCR and Western blot, respectively, in vivo and in vitro with treatment of PPARγ agonist rosiglitazone and antagonist GW9662. The proliferation and collagen secretion of VSMCs after c-Ski transfection were investigated. The underlying mechanism was further investigated by online program NUBIScan and luciferase reporter gene analysis. Results showed that both mRNA and protein expressions of c-Ski in the AS lesions was down-regulated in vivo, while in cultured VSMCs, c-Ski transfection significantly suppressed the proliferation and collagen secretion of rat VSMCs. Rosiglitazone significantly up-regulated mRNA and protein levels of c-Ski in VSMCs, which could be blocked by GW9662. Online NUBIScan analysis suggested possible PPARγ binding sites in the promoter region of c-Ski. In addition, luciferase activity of c-Ski reporter gene was also increased obviously in the presence of rosiglitazone. These results indicate that c-Ski is one of the newly found target genes of PPARγ and thus involved in the anti-AS effect of PPARγ.
Anilides ; pharmacology ; Animals ; Atherosclerosis ; physiopathology ; Cells, Cultured ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; PPAR gamma ; agonists ; antagonists & inhibitors ; physiology ; Proto-Oncogene Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Repressor Proteins ; genetics ; metabolism ; Signal Transduction ; Smad Proteins ; metabolism ; Thiazolidinediones ; pharmacology ; Transforming Growth Factor beta ; metabolism ; Up-Regulation