Rebalancing TGF-ß/Smad7 signaling via Compound kushen injection in hepatic stellate cells protects against liver fibrosis and hepatocarcinogenesis.

BACKGROUND: Liver fibrosis and fibrosis-related hepatocarcinogenesis are a rising cause for morbidity and death worldwide. Although transforming growth factor-ß (TGF-ß) is a critical mediator of chronic liver fibrosis, targeting TGF-ß isoforms and receptors lead to unacceptable side effect. This study was designed to explore the antifibrotic effect of Compound kushen injection (CKI), an approved traditional Chinese medicine formula, via a therapeutic strategy of rebalancing TGF-ß/Smad7 signaling. METHODS: A meta-analysis was performed to evaluate CKI intervention on viral hepatitis-induced fibrosis or cirrhosis in clinical randomized controlled trials (RCTs). Mice were given carbon tetrachloride (CCl4 ) injection or methionine-choline deficient (MCD) diet to induce liver fibrosis, followed by CKI treatment. We examined the expression of TGF-ß/Smad signaling and typical fibrosis-related genes in hepatic stellate cells (HSCs) and fibrotic liver tissues by qRT-PCR, Western blotting, RNA-seq, immunofluorescence, and immunohistochemistry. RESULTS: Based on meta-analysis results, CKI improved the liver function and relieved liver fibrosis among patients. In our preclinical studies by using two mouse models, CKI treatment demonstrated promising antifibrotic effects and postponed hepatocarcinogenesis with improved liver function and histopathologic features. Mechanistically, we found that CKI inhibited HSCs activation by stabilizing the interaction of Smad7/TGF-ßR1 to rebalance Smad2/Smad3 signaling, and subsequently decreased the extracellular matrix formation. Importantly, Smad7 depletion abolished the antifibrotic effect of CKI in vivo and in vitro. Moreover, matrine, oxymatrine, sophocarpine, and oxysophocarpine were identified as material basis responsible for the antifibrosis effect of CKI. CONCLUSIONS: Our results unveil the approach of CKI in rebalancing TGF-ß/Smad7 signaling in HSCs to protect against hepatic fibrosis and hepatocarcinogenesis in both preclinical and clinical studies. Our study suggests that CKI can be a candidate for treatment of hepatic fibrosis and related oncogenesis.

RS4651 suppresses lung fibroblast activation via the TGF-ß1/SMAD signalling pathway.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease resulting in respiratory failure with no efficient treatment options. We investigated the protective effect of RS4651 on pulmonary fibrosis in mice and the mechanism. METHODS: Intratracheal injection of bleomycin (BLM) was used to induce pulmonary fibrosis in mice. RS4561 was administered intraperitoneally at different doses. Histopathological changes were observed. The level of alpha-smooth muscle actin (α-SMA) were also tested. In vitro, the proliferation and migratory effects of RS4651 treatment on MRC-5 cells pre-treated with transforming growth factor (TGF-ß1) were examined. RNA-sequencing was used to detect differentially expressed target genes. Then, the expression of α-SMA, pSMAD2 and SMAD7 were analysed during RS4651 treatment of MRC-5 cells with or without silencing by SMAD7 siRNA. RESULTS: Histopathological staining results showed decreased collagen deposition in RS4651 administered mice. Additionally, a lower level of α-SMA was also observed compared to the BLM group. The results of in vitro studies confirmed that RS4651 can inhibit the proliferation and migration, as well as α-SMA and pSMAD2 expression in MRC-5 cells treated with TGF-ß1. RNA-sequencing data identified the target gene SMAD7. We found that RS4651 could upregulate SMAD7 expression and inhibit the proliferation and migration of MRC-5 cells via SMAD7, and RS4651 inhibition of α-SMA and pSMAD2 expression was blocked in SMAD7-siRNA MRC-5 cells. In vivo studies further confirmed that RS4651 could upregulate SMAD7 expression in BLM-induced lung fibrosis in mice. CONCLUSIONS: Our data suggest that RS4651 alleviates BLM-induced pulmonary fibrosis in mice by inhibiting the TGF-ß1/SMAD signalling pathway.

Involvement of Smad7 in Inflammatory Diseases of the Gut and Colon Cancer.

In physiological conditions, the human intestinal mucosa is massively infiltrated with various subsets of immune cells, the activity of which is tightly regulated by several counter-regulatory factors. One of these factors is transforming growth factor-ß1 (TGF-ß1), a cytokine produced by multiple cell types and targeting virtually all the intestinal mucosal cells. Binding of TGF-ß1 to its receptors triggers Smad2/3 signaling, thus culminating in the attenuation/suppression of immune-inflammatory responses. In patients with Crohn's disease and patients with ulcerative colitis, the major human inflammatory bowel diseases (IBD), and in mice with IBD-like colitis, there is defective TGF-ß1/Smad signaling due to high levels of the intracellular inhibitor Smad7. Pharmacological inhibition of Smad7 restores TGF-ß1 function, thereby reducing inflammatory pathways in patients with IBD and colitic mice. On the other hand, transgenic over-expression of Smad7 in T cells exacerbates colitis in various mouse models of IBD. Smad7 is also over-expressed in other inflammatory disorders of the gut, such as refractory celiac disease, necrotizing enterocolitis and cytomegalovirus-induced colitis, even though evidence is still scarce and mainly descriptive. Furthermore, Smad7 has been involved in colon carcinogenesis through complex and heterogeneous mechanisms, and Smad7 polymorphisms could influence cancer prognosis. In this article, we review the data about the expression and role of Smad7 in intestinal inflammation and cancer.

Superparamagnetic iron oxide (SPIO) nanoparticles labeled endothelial progenitor cells (EPCs) administration inhibited heterotopic ossification in rats.

Heterotopic ossification (HO) is a painful disease characterized by unwanted bone ectopic formation outside of the skeleton after injury. SPIO nanoparticles therapy has been widely used in diverse orthopedic diseases. However, the effect of SPIO nanoparticles on heterotopic ossification remains unknown. Here, we prepared the SPIO nanoparticles carrying mothers against decapentaplegic homolog 7 (SMAD7) and evaluated their mechanism function to HO in a rat model. The results revealed that SPIO nanoparticles containing SMAD7 treatment lead to a decrease in epithelial-mesenchymal transition (EMT) relevant protein expression in vitro. Moreover, SPIO nanoparticles labeled EPCs transplantation effectively prevented heterotopic ossification and inhibited endothelial-mesenchymal transition (EndMT) in HO rats. In addition, SPIO nanoparticles labeled EPCs transplantation suppressed osteogenic and adipogenic differentiation of embryonic fibroblasts (EFs) in HO rats. Our results demonstrated that administration of SPIO nanoparticles labeled EPCs could inhibit heterotopic ossification in rats, which might be a potential therapy method for a medical intervention to treat HO in clinic.

Combination of Ginsenoside Rg1 and Astragaloside IV reduces oxidative stress and inhibits TGF-ß1/Smads signaling cascade on renal fibrosis in rats with diabetic nephropathy.

INTRODUCTION: Anti-oxidative stress and inhibition of TGF-ß1/Smads signaling cascade are essential therapeutic strategies for diabetic nephropathy (DN). In this study, we aimed to explore the effect of combination of Ginsenoside Rg1 and Astragaloside IV on oxidative stress and TGF-ß1/Smads signaling in DN rats. MATERIALS AND METHODS: Wistar rats were divided into five groups: N group, M group (streptozotocin [STZ], intraperitoneally), G group (STZ rats with Ginsenoside Rg1, intragastrically [ig]), A group (STZ rats with Astragaloside IV, ig) and C group (STZ rats with Ginsenoside Rg1 and Astragaloside IV, ig). The levels of methane dicarboxylic aldehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-PX), total anti-oxidative capacity (T-AOC), blood urea nitrogen (BUN), ß2-microglobulin (ß2-MG), serum creatinine (SCr) and urinary creatinine (UCr) were detected in all the groups. The left kidneys of the rats were harvested to detect the expression of TGF-ß1, Smad2/3, Smad7 and CTGF by immunohistochemical staining, while the right kidneys were used to detect the mRNA expression of TGF-ß1, Smad7 and CTGF by real-time PCR. RESULTS: Rats in G group, A group and C group had lower level of MDA but higher levels of CAT, GSH-PX and T-AOC compared with rats in M group. Rats in C group showed the best anti-oxidative stress level. G group, A group and C group treatments significantly decreased the levels of BUN, SCr, ß2-MG and UCr. In addition, C group treatment showed the best kidney protective effect. G group, A group and C group treatments significantly diminish ED both factor and mRNA overexpression of TGF-ß1 and CTGF but increase Smad7 expression in kidney tissue. CONCLUSION: The combination of Ginsenoside Rg1 and Astragaloside IV may potentially protect against DN by reducing oxidative stress and inhibiting TGF-ß1/Smads signaling cascade.

miR-27b Suppresses Endothelial Cell Proliferation and Migration by Targeting Smad7 in Kawasaki Disease.

BACKGROUND/AIMS: Increasing evidence indicates that microRNAs (miRNAs) play important roles in Kawasaki disease (KD). Our previous study demonstrated that hsa-miR-27b-3p (miR-27b) was up-regulated in KD serum. However, the specific role of miR-27b in KD remains unclear. We aimed to investigate that miR-27b could be a biomarker and therapeutic target for KD treatment. As well, the specific mechanism of miR-27b effecting endothelial cell functions was studied. METHODS: The expression of miR-27b and Smad7 was measured by qRT-PCR. Gain-of-function strategy was used to observe the effect of miR-27b on human umbilical vein endothelial cells (HUVECs) proliferation and migration. Bioinformatics analyses were applied to predict miR-27b targets and then we verified Smad7 by a luciferase reporter assay. Western blot was performed to detect the protein expression of Smad7, PCNA, MMP9, MMP12 and TGF-ß-related genes. RESULTS: We confirmed that miR-27b was shown to be dramatically up-regulated in KD serum and KD serum-treated HUVECs and that elevated expression of miR-27b suppressed the proliferation and migration of HUVECs. Furthermore, our results verified that miR-27b mediated cell functions by affecting the TGF-ß via targeting Smad7 in HUVECs. CONCLUSION: These results suggested that up-regulated miR-27b had a protective role in HUVECs proliferation and migration via targeting Smad7 and affecting TGF-ß pathway. Therefore, miR-27b represented a potential biomarker for KD and may serve as a promising therapeutic target for KD treatment.

Chemokines and Chemokine Receptors as Therapeutic Targets in Inflammatory Bowel Disease; Pitfalls and Promise.

The principal targets for anti-chemokine therapy in inflammatory bowel disease (IBD) have been the receptors CCR9 and CXCR3 and their respective ligands CCL25 and CXCL10. More recently CCR6 and its ligand CCL20 have also received attention, the expression of the latter in enterocytes being manipulated through Smad7 signalling. These pathways, selected based on their fundamental role in regulating mucosal immunity, have led to the development of several therapeutic candidates that have been tested in early phase clinical trials with variable clinical efficacy. In this article, we appraise the status of chemokine-directed therapy in IBD, review recent developments, and nominate future areas for therapeutic focus.

Oligonucleotide-Based Therapies for Inflammatory Bowel Disease.

The growing understanding of the immunopathogenesis of inflammatory bowel diseases (IBDs) has contributed to the identification of new targets whose expression/activity can be modulated for therapeutic purposes. Several approaches have been employed to develop selective pharmaceutical compounds; among these, antisense oligonucleotides (ASOs) or synthetic oligonucleotides represent a valid option for inhibiting or enhancing, respectively, the expression/function of molecules that have been implicated in the control of IBD-related inflammation. In this context, data have been accumulated for the following compounds: alicaforsen, an ASO targeting intercellular adhesion molecule-1, a transmembrane glycoprotein that regulates rolling and adhesion of leukocytes to inflamed intestine; DIMS0150 and BL-7040, two oligonucleotides that enhance Toll-like receptor-9 activity; Mongersen, an ASO that inhibits Smad7, thereby restoring transforming growth factor-ß1/Smad-associated signaling; STNM01, a double-stranded RNA oligonucleotide silencing carbohydrate sulfotransferase, an enzyme involved in fibrogenic processes, and hgd40, a specific DNAzyme inhibiting expression of the transcription factor GATA3. In this article, we review the rationale and the available data relative to the use of these agents in IBD. Although pre-clinical and phase II trials in IBD support the use of oligonucleotide-based therapies for treating the pathogenic process occurring in the gut of patients with these disorders, further work is needed to establish whether and which patients can benefit from specific ASOs and identify biomarkers that could help optimize treatment.

MiR-378 and BMP-Smad can influence the proliferation of sheep myoblast.

MicroRNA (miRNA) is a sort of endogenous ~20-25 nt non-coding RNAs, and it can regulate a variety of biological events. We found the miR-378 may involve in regulating the muscle development of sheep during our previous research. However, the molecular mechanism of miR-378 regulating myoblast proliferation is still unclear. In this research, we predicted that BMP2 (Bone morphogenetic protein 2) was the target gene of miR-378 and the BMP-Smad signal pathway that BMP2 participated in playing an important role in the muscle development. Therefore, we tried to determine whether miR-378 influence myoblast proliferation of sheep through the BMP-Smad signal pathway. The results indicated that inhibit BMP-Smad signal pathway by interfering Smad4 to promote proliferation of sheep myoblasts; promote BMP-Smad signal pathway by interfering Smad7 to inhibit proliferation of sheep myoblasts; over-expression miR-378 promotes BMP-Smad signal pathway and myoblast proliferation in sheep; interfering miR-378 inhibits BMP-Smad signal pathway and myoblast proliferation in sheep. However, when both of which functioned at the myoblast, miR-378 could not fully depend on BMP-Smad signal pathway to regulate myoblast proliferation. In sum, both miR-378 and BMP-Smad can influence the proliferation of myoblast, but miR-378 does not target the 3' UTR of sheep BMP2.

YAP/TAZ regulates TGF-ß/Smad3 signaling by induction of Smad7 via AP-1 in human skin dermal fibroblasts.

BACKGROUND: Transcription factors YAP and TAZ function as the primary mediators of the Hippo pathway. Yet, crosstalk of YAP and TAZ with other signaling pathways remains relatively unexplored. We have explored the impact of YAP and TAZ levels on the TGF-ß/Smad signaling pathway in human skin dermal fibroblasts. METHODS: YAP and TAZ levels in dermal fibroblasts were reduced in dermal fibroblasts by siRNA-mediated knockdown. The effects of YAP and TAZ reduction on TGF-ß/Smad signaling were examined by quantitative real-time PCR, Western analysis, and immunostaining. Luciferase reporter assays and electrophoretic mobility shift assays were conducted to investigate the transcription factor DNA-binding and transcriptional activities. RESULTS: Knockdown of both YAP and TAZ (YAP/TAZ), but not either separately, impaired TGF-ß1-induced Smad3 phosphorylation and Smad3 transcriptional activity, thereby inhibiting the expression of TGF-ß target genes. This reduction by reduced levels of YAP/TAZ results from induction of inhibitory Smad7, which inhibits Smad3 phosphorylation and activity by TGF-ß1. Conversely, prevention of Smad7 induction restores Smad3 phosphorylation and Smad3 transcriptional activity in fibroblasts that have reduced YAP/TAZ. In agreement with these findings, inhibition of YAP/TAZ transcriptional activity, similar to the reduction of YAP/TAZ levels, also significantly induced Smad7 and impaired TGF-ß/Smad signaling. Further investigations revealed that reduced levels of YAP/TAZ led to induction of activator protein-1 (AP-1) activity, Activated AP-1 bound to DNA sequences in the Smad7 gene promoter, and deletion of these AP-1 binding sequences substantially reduced Smad7 promoter reporter activity. CONCLUSION: YAP/TAZ functions in concert with transcription factor AP-1 and Smad7 to regulate TGF-ß signaling, in human dermal fibroblasts. Reduction of YAP/TAZ levels leads to activation of AP-1 activity, which induces Smad7. Smad7 suppresses the TGF-ß pathway.

The Expanding Therapeutic Armamentarium for Inflammatory Bowel Disease: How to Choose the Right Drug[s] for Our Patients?

The therapeutic landscape for inflammatory bowel disease [IBD] is rapidly evolving. Two new biologic drugs, vedolizumab and ustekinumab, have recently entered the marketplace, the first biosimilars have been introduced, and several other agents are at an advanced stage of clinical development. In parallel, therapeutic goals have shifted from symptom control towards mucosal healing and prevention of bowel damage. In the coming years, gastroenterologists will be faced with unprecedented choices when selecting the best treatment for their patients with IBD. In this article, we review existing data on the mechanisms of action, efficacy, and safety of recently approved and late-stage pipeline therapies, and use this information to speculate on the positioning of these drugs, alone or in combination, in therapeutic algorithms for Crohn's disease and ulcerative colitis.

Celastrol improves self-renewal and differentiation of human tendon-derived stem cells by suppressing Smad7 through hypoxia.

BACKGROUND: We aimed to evaluate the potential enhancing effect of celastrol on the stemness of human tendon-derived stem cells (hTSCs) in vitro and the underlying molecular mechanisms. METHODS: The capability of hTSC self-renewal was assessed by cell proliferation and colony formation as determined with the CCK-8 kit. Adipogenesis, chondrogenesis, and osteogenesis were determined by Oil Red O, Alcian Blue, and Alizarin Red staining, respectively. The relative mRNA levels of Sox9, PPARγ, Runx2, Smad7, and HIF1α were determined by real-time polymerase chain reaction (PCR). The levels of Smad7 and HIF1α protein were measured by immunoblotting. The chromatin immunoprecipitation (ChIP) assay was used to assess the direct binding of HIF1α to the Smad7 promoter. Suppression of Smad7 induced by hypoxia was examined using the luciferase reporter assay. RESULTS: We found that treatment with celastrol resulted in improvement in both the multi-differentiation potential and self-renewal capability of hTSCs. Celastrol elicited hypoxia and subsequently suppressed the expression of Smad7 through direct association with the hypoxia response element consensus sequence. Further, we demonstrated that both Smad7 and HIF1α were involved in the beneficial effects of celastrol on the differentiation and self-renewal of hTSCs. CONCLUSIONS: We demonstrated the positive effect of celastrol on the stemness of hTSCs and elucidated the essential role of the HIF1α-Smad7 pathway in this process.

Downregulated MicroRNA-195 in the Bicuspid Aortic Valve Promotes Calcification of Valve Interstitial Cells via Targeting SMAD7.

BACKGROUND/AIMS: Aortic stenosis caused by leaflet calcification in the bicuspid aortic valve (BAV) is more accelerative than that in the tricuspid aortic valve (TAV). MicroRNA-195 (miR-195) is downregulated more in stenotic than in insufficient BAVs, but its expression in BAVs compared with TAVs is unclear. We aimed to investigate the roles of miR-195 and its calcification-related target SMAD7 in stenotic BAVs compared with those in TAVs. METHODS: Twenty-one stenotic BAV and 29 TAV samples were collected from surgical patients and examined for the expression of miR-195 and SMAD7 by RT-PCR. The samples were also assessed by western blotting and immunohistochemistry for the functional protein alteration associated with calcification. Dual-luciferase assay was performed to determine the putative target of miR-195 before the effects of miR-195 expression on osteogenic progression was demonstrated in cultured porcine valve interstitial cells (VICs). RESULTS: Compared with TAV, the expression of miR-195 was remarkably lower in the BAV leaflet with higher expression of SMAD7, which was then validated as a direct target of miR-195. Their negative correlation was then confirmed in cultured VICs. Under an osteogenic environment, the cellular calcification was promoted in miR-195-repressed VICs expressing higher BMP-2 and Runx2 and higher activity of MMP-2 compared with the controls. Finally, higher MMP-2 and MMP-9 expression and more collagen distribution were observed in BAV than TAV samples. CONCLUSIONS: miR-195 is downregulated more in stenotic BAV than TAV in this study. The downregulation of miR-195 is associated with valvular calcification via targeting SMAD7, which promotes the remodeling of the extracellular matrix.

MiR-21-Mediated Suppression of Smad7 Induces TGFß1 and Can Be Inhibited by Activation of Nrf2 in Alcohol-Treated Lung Fibroblasts.

BACKGROUND: We previously demonstrated that chronic alcohol ingestion augments TGFß1 expression in the lung fibroblast and increases the risk of fibroproliferative disrepair in a mouse model of acute lung injury. The effect of alcohol on TGFß1 is mitigated by treatment with sulforaphane (SFP), which can activate nuclear factor (erythroid-derived 2)-like 2 (Nrf2). However, the mechanisms by which alcohol amplifies, or SFP attenuates, TGFß1 expression in the fibroblast are not known. MicroRNA (miR)-21 has been shown to inhibit Smad7, a TGFß1 signaling inhibitor. In this study, we hypothesized that alcohol augments TGFß1 expression through up-regulation of miR-21, which subsequently inhibits Smad7. METHODS: Primary mouse lung fibroblasts were cultured ± alcohol ± SFP and assessed for gene expression of miR-21, and gene and/or protein expression of Nrf2, Nrf2-regulated antioxidant enzymes, Smad7, STAT3, and TGFß1. NIH 3T3 fibroblasts were transfected with a miR-21 inhibitor and cultured ± alcohol. α-SMA, Smad7, and TGFß1 protein expression were then assessed. In parallel, NIH 3T3 lung fibroblasts were transfected with Nrf2 silencing RNA (siRNA) and cultured ± alcohol ± SFP. Gene expression of miR-21, Nrf2, Smad7, and TGFß1 was assessed. RESULTS: MiR-21 gene expression was increased by 12-fold at 48 hours, and Smad7 gene expression and protein expression were reduced by ~30% in alcohol-treated fibroblasts. In parallel, inhibition of miR-21 attenuated alcohol-mediated decrease in Smad7 and increase in TGFß1 and α-SMA protein expression. Treatment with SFP mitigated the effect of alcohol on miR-21, Smad7 and total and phosphorylated STAT3, and restored Nrf2-regulated antioxidant gene expression. Silencing of Nrf2 prevented the effect of SFP on miR-21, Smad7, and TGFß1 gene expression in alcohol-treated NIH 3T3 fibroblasts. CONCLUSIONS: Alcohol treatment increases TGFß1 in fibroblasts, at least in part, through augmentation of miR-21, which then inhibits Smad7 expression. These effects can be attenuated by activation of Nrf2 with SFP.

Janus Kinase Antagonists and Other Novel Small Molecules for the Treatment of Crohn's Disease.

There is an ongoing, unmet need for effective therapies for Crohn's disease. Treatments for Crohn's disease continue to evolve from the traditional biologics to novel small molecules, with targeted mechanisms directed toward pathways that are dysregulated in Crohn's disease. There are multiple emerging mechanisms of action, including Janus kinase inhibition, Smad7 inhibition, and sphingosine-1-phosphate receptor modulators, that are administered as oral medications, and small molecules represent the next generation of therapies for Crohn's disease.

Mir-21 Promotes Cardiac Fibrosis After Myocardial Infarction Via Targeting Smad7.

BACKGROUND/AIMS: Cardiac fibrosis after myocardial infarction (MI) has been identified as an important factor in the deterioration of heart function. Previous studies have demonstrated that miR-21 plays an important role in various pathophysiological processes in the heart. However, the role of miR-21 in fibrosis regulation after MI remains unclear. METHODS: To induce cardiac infarction, the left anterior descending coronary artery was permanently ligated of mice. First, we explored the expression of miR-21 in the infarcted zone in mice model of MI via RT-qPCR. Next, we examined the effects of TGF-ß1 on miR-21 expression in cardiac fibroblasts (CFs). Then, CFs were infected with miR-21 mimics or miR-21 inhibitors to investigate the effects of miR-21 on the process of CFs activation in vitro. Further, bioinformatics analysis and luciferase reporter assay were performed to identify and validate the target gene of miR-21. At last, in-vivo study was done to confirm MiR-21 regulated myocardial fibrosis after MI in mice. RESULTS: MiR-21 was up-regulated in the infarcted zone after MI in vivo. TGF-ß1 treatment increased miR-21 expression in CFs. Overexpression of miR-21 promoted the effects of TGF-ß1-induced activation of CFs, evidenced by increased expression of Col-1, α-SMA and F-actin, whereas inhibition of miR-21 attenuated the process of fibrosis. Bioinformatics, Western blot analysis and luciferase reporter assay demonstrated that Smad7 is a direct target of miR-21. In addition, in-vivo study revealed that MiR-21 regulated myocardial fibrosis after MI in mice. CONCLUSION: These findings suggested that miR-21 has a critical role in CF activation and cardiac fibrosis after MI through via TGF-ß/Smad7 signaling pathway. Thus, miR-21 promises to be a potential therapy in treatment of cardiac fibrosis after MI.

Branched chain amino acids supplementation modulates TGF-ß1/Smad signaling pathway and interleukins in CCl4 -induced liver fibrosis.

The alterations and low levels of circulating branched chain amino acids (BCAAs), leucine, isoleucine, and valine, are associated with liver diseases. The study was designed to evaluate hepatoprotective effect of BCAAs on CCl4 -induced liver fibrosis and to investigate the molecular mechanisms underlying these effects in rats. In all, 30 male rats were divided into three groups. Control group (n = 10) and CCl4 group (n = 10), where rats were injected with CCl4 (1 mL/kg of 0.5 : 1 v/v injected i.p. twice weekly for 12 weeks). In CCl4 + BCAAs group (n = 10), rats were injected with similar doses of CCl4 and supplemented with a mixture of 600 mg/kg BCAAs (2 : 1 : 1.2 leucine : isoleucine : valine) by oral gavage, three times/week for 12 weeks. Liver fibrosis was assessed by measuring total bilirubin, total protein, alanine aminotransferase, and aspartate aminotransferase, hydroxyproline content, and serum IL-6 and IL-10. Histopathologic studies and α-smooth muscle actin (α-SMA) were detected immunohistochemically in liver. Serum insulin level, blood glucose, liver malodialdehyde concentration (MDA), glutathione peroxidase, and superoxide dismutase (SOD) activities were quantified. TGF-ß1, Smad3, and Smad7 gene expressions were estimated by qRT-PCR. BCAAs suppressed liver fibrosis induced by CCl4 treatment. BCAAs modulated liver indices and downregulated TGF-ß1, Smad3, and Smad7 expressions in hepatocytes. BCAAs enhanced liver antioxidant enzyme activities (P < 0.001), reduced serum levels of TGF-ß1, IL-6, and IL-10 compared to CCL4 group and ameliorated histopathologic changes in rat liver. BCAAs may have a protective role against liver fibrosis via antioxidant and anti-inflammatory mechanisms.

CCL20 Is Negatively Regulated by TGF-ß1 in Intestinal Epithelial Cells and Reduced in Crohn's Disease Patients With a Successful Response to Mongersen, a Smad7 Antisense Oligonucleotide.

BACKGROUND AND AIMS: The chemokine CCL20 is over-produced in epithelium of Crohn's disease [CD] patients and contributes to recruiting immune cells to inflamed gut. Tumour necrosis factor-α [TNF-α] is a powerful inducer of CCL20 in intestinal epithelial cells. In CD, high levels of Smad7 block the activity of transforming growth factor-ß1 [TGF-ß1], a negative regulator of TNF signalling. We investigated whether intestinal epithelial cell-derived CCL20 is negatively regulated by TGF-ß1 and whether Smad7 knock-down reduces CCL20 in CD. METHODS: CCL20 was evaluated in NCM460, a normal colonic epithelial cell line, stimulated with TGF-ß1 and TNF-α, and in Smad7 over-expressing NCM460 cells. CCL20 and Smad7 expression were assessed in sections of CD intestinal specimens by immunochemistry, and in CD colonic explants treated with mongersen, a Smad7 antisense oligonucleotide. CCL20 was examined in serum samples taken from 95 of 166 active CD patients receiving mongersen or placebo for 2 weeks and participating in a phase II, multicentre, double-blind, placebo-controlled study. RESULTS: CCL20 expression was increased by TNF-α, and this effect was inhibited by TGF-ß1 in NCM460 cells, but not in Smad7 over-expressing NCM460 cells. In CD, epithelium CCL20 and Smad7 co-localised, and treatment of CD explants with mongersen reduced CCL20 production. During follow-up, in responders to mongersen, serum CCL20 levels significantly decreased, whereas patients without response/remission to mongersen and placebo patients did not have change in CCL20. CONCLUSIONS: TGF-ß1 reduces intestinal epithelial cell-derived CCL20 production, an effect abrogated by Smad7. CD patients responding to mongersen demonstrated a reduction in serum CCL20.

TMPRSS2:ERG gene fusion variants induce TGF-ß signaling and epithelial to mesenchymal transition in human prostate cancer cells.

TMPRSS2:ERG (T/E) gene fusions are present in approximately 50% of all prostate cancer (PCa) cases. The expression of fusion mRNAs from distinct T/E variants is associated with clinicopathological parameters, while the underlying molecular processes remain unclear. We characterized the molecular mechanisms and functional implications caused by doxycycline (Dox)-inducible overexpression of the frequent T/E III and VI fusion variants in LNCaP cells. Induction of T/E expression resulted in increased cellular migratory and invasive potential, and reduced proliferation and accumulation in G1 phase. T/E overexpressing cells showed epithelial-to-mesenchymal transition (EMT), as demonstrated by upregulation of TGF-ß and WNT pathway genes, mesenchymal markers, and increased phosphorylation of the p38 MAPK. Augmented secretion of TGF-ß1 and -ß2, and T/E-mediated regulation of ALK1, a member of the TGF-ß receptor family, was detected. ALK1 inhibition in T/E overexpressing cells blocked p38 phosphorylation and reduced the expression of the TGF-ß target genes VIM, MMP1, CDH2, and SNAI2. We found a T/E variant VI-specific induction of miR-503 associated with reduced expression of SMAD7 and CDH1. Overexpression of miR-503 led to increased levels of VIM and MMP1. Our findings indicate that TGF-ß signaling is a major determinant of EMT in T/E overexpressing LNCaP cells. We provide evidence that T/E VI-specific transcriptional modulation by miR-503 accounts for differences in the activation of EMT pathway genes, promoting the aggressive phenotype of tumors expressing T/E variant VI. We suggest that ALK1-mediated TGF-ß signaling is a novel oncogenic mechanism in T/E positive PCa.

Inflammatory Bowel Disease: New Therapeutic Options in the Post Anti-TNFα Era.

BACKGROUND: Inflammatory bowel diseases are chronic bowel disorders the causes of which have not been fully elucidated, though they all sharean immunological basis. They have an important impact on both quality of life of the patient and on healthcare services. METHOD: The incorporation of biological agents against tumour necrosis factor (TNF) alpha some 15 years ago represented a revolution in the management of patients with disease that did not respond to conventional treatment, enabling an overall improvement in the quality of life of many of these patients. RESULTS: Nonetheless, these agents are not effective in an appreciable percentage of patients (primary lack of response), can lose their efficacy over time even though they were initially effective (loss of secondary response), and can also be burdened by varied and sometimes severe adverse effects (e.g., infusion reactions, infections, neoplasms). Consequently, basic research over recent years has provided us with promising new pharmacological agents aimed at targets other than TNF alpha (IL12/23, anti-adhesion molecules, Janus kinase inhibitors, anti- Smad7, blockade of sphingosine-1-phosphate receptors). CONCLUSION: This paper reviews some of the key aspects of these new drugs, including their mechanism of action, some incipient pharmacokinetic and metabolic data, their efficacy and their safety. These new agents will take on an important role in the coming years in the management of patients with moderate-to-severe forms of inflammatory bowel disease.