Inhibition of TGF-ß1/Smad3 signaling by compound 5aa: A potential treatment for idiopathic pulmonary fibrosis.

The incidence of idiopathic pulmonary fibrosis (IPF) has been steadily increasing each year, posing significant challenges in its treatment. In this study, we conducted the design and synthesis of 23 new inhibitors that specifically target the TGF-ß1/Smad3 pathway. Initially, we employed a cell model of TGF-ß-induced pulmonary fibrosis, using cell survival rate and HYP expression as indicators to identify the potent ingredient 5aa, which demonstrated significant anti-pulmonary fibrosis activity. Subsequently, we induced mice with bleomycin (BLM) to establish an experimental animal model of pulmonary fibrosis, and evaluated the pharmacodynamics of 5aa in vivo against pulmonary fibrosis. The alterations in HYP and collagen levels in BLM-induced pulmonary fibrosis mice were analyzed using ELISA and immunohistochemistry techniques. The results indicated that compound 5aa effectively suppressed the fibrotic response induced by TGF-ß1, inhibited the expression of the fibrotic marker α-SMA, and hindered the EMT process in NIH3T3 cells. Additionally, oral administration of 5aa demonstrated significant therapeutic effects in a mouse model of IPF, comparable to the established drug Nintedanib. Moreover, compound 5aa exhibited higher bioavailability in vivo compared to Nintedanib. These collective outcomes suggest that 5aa holds promise as a potential inhibitor of TGF-ß1/Smad3 signaling for the treatment of IPF.

Endoplasmic reticulum stress promotes sepsis-induced muscle atrophy via activation of STAT3 and Smad3.

Endoplasmic reticulum (ER) stress is involved in skeletal muscle atrophy in various conditions, but the role of ER stress in sepsis-induced muscle atrophy is not well understood. In this study, we conducted experiments in wild-type (WT) mice and C/EBP homologous protein knockout (CHOP KO) mice to explore the role and mechanism of ER stress in sepsis-induced muscle atrophy. Cecal ligation and puncture (CLP) was used to establish a mouse model of sepsis. In WT mice, the body weight, muscle mass, and cross-sectional area of muscle fibers in CLP group both decreased significantly compared with sham group, which revealed that sepsis-induced dramatic muscle atrophy. Additionally, sepsis activated the ubiquitin-proteasome system (UPS), accompanied by the activation of ER stress. In vitro, inhibition of ER stress suppressed the activity of E3 ubiquitin ligases and alleviated the myotube atrophy. In vivo, CHOP KO also reduced the expression of E3 ubiquitin ligases and UPS-mediated protein degradation, and significantly attenuated sepsis-induced muscle atrophy. Deletion of CHOP also decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and Smad3, and inhibition of STAT3 and Smad3 partly reduced proteolysis caused by ER stress in vitro. These findings confirm that ER stress activates UPS-mediated proteolysis and promotes sepsis-induced muscle atrophy, which is partly achieved by activating STAT3 and Smad3.

ß-Elemene Attenuates Renal Fibrosis in the Unilateral Ureteral Obstruction Model by Inhibition of STAT3 and Smad3 Signaling via Suppressing MyD88 Expression.

Renal fibrosis is a chronic pathological process that seriously endangers human health. However, the current therapeutic options for this disease are extremely limited. Previous studies have shown that signaling factors such as JAK2/STAT3, Smad3, and Myd88 play a regulatory role in renal fibrosis, and ß-elemene is a plant-derived sesquiterpenoid organic compound that has been shown to have anti-inflammatory, anti-cancer, and immunomodulatory effects. In the present study, the anti-fibrotic effect of ß-elemene was demonstrated by in vivo and in vitro experiments. It was shown that ß-elemene inhibited the synthesis of extracellular matrix-related proteins in unilateral ureteral obstruction mice, and TGF-ß stimulated rat interstitial fibroblast cells, including α-smooth muscle actin, vimentin, and connective tissue growth factor, etc. Further experiments showed that ß-elemene reduced the expression levels of the above-mentioned fibrosis-related proteins by blocking the phosphorylation of JAK2/STAT3, Smad3, and the expression or up-regulation of MyD88. Notably, knockdown of MyD88 attenuated the phosphorylation levels of STAT3 and Smad3 in TGF-ß stimulated NRK49F cell, which may be a novel molecular mechanism by which ß-elemene affects renal interstitial fibrosis. In conclusion, this study elucidated the anti-interstitial fibrosis effect of ß-elemene, which provides a new direction for future research and development of drugs related to chronic kidney disease.

Up-regulation of Nrf2/HO-1 and inhibition of TGF-ß1/Smad2/3 signaling axis by daphnetin alleviates transverse aortic constriction-induced cardiac remodeling in mice.

Oxidative damage and accumulation of extracellular matrix (ECM) components play a crucial role in the adverse outcome of cardiac hypertrophy. Evidence suggests that nuclear factor erythroid-derived factor 2 related factor 2 (Nrf2) can modulate oxidative damage and adverse myocardial remodeling. Daphnetin (Daph) is a coumarin obtained from the plant genus Daphne species that exerts anti-oxidative and anti-inflammatory properties. Herein, we investigated the roles of Daph in transverse aortic constriction (TAC)-induced cardiac hypertrophy and fibrosis in mice. TAC-induced alterations in cardiac hypertrophy markers, histopathological changes, and cardiac function were markedly ameliorated by oral administration of Daph in mice. We found that Daph significantly reduced the reactive oxygen species (ROS) generation, increased the nuclear translocation of Nrf2, and consequently, reinstated the protein levels of NAD(P)H quinone dehydrogenase1 (NQO1), heme oxygenase-1 (HO-1), and other antioxidants in the heart. Besides, Daph significantly inhibited the TAC-induced accumulation of ECM components, including α-smooth muscle actin (α-SMA), collagen I, collagen III, and fibronectin, and interfered with the TGF-ß1/Smad2/3 signaling axis. Further studies revealed that TAC-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive nuclei and the protein levels of Bax/Bcl2 ratio and cleaved caspase 3 were substantially decreased by Daph treatment. We further characterized the effect of Daph on angiotensin II (Ang-II)-stimulated H9c2 cardiomyoblast cells and observed that Daph markedly decreased the Ang-II induced increase in cell size, production of ROS, and proteins associated with apoptosis and fibrosis. Mechanistically, Daph alone treatment enhanced the protein levels of Nrf2, NQO1, and HO-1 in H9c2 cells. The inhibition of this axis by Si-Nrf2 transfection abolished the protective effect of Daph in H9c2 cells. Taken together, Daph effectively counteracted the TAC-induced cardiac hypertrophy and fibrosis by improving the Nrf2/HO-1 axis and inhibiting the TGF-ß1/Smad2/3 signaling axis.

miR-154-5p Affects the TGFß1/Smad3 Pathway on the Fibrosis of Diabetic Kidney Disease via Binding E3 Ubiquitin Ligase Smurf1.

AIM: The study is aimed at verifying miR-154-5p and Smurf1 combination in glomerular mesangial cells regulating TGFß1/Smad3 pathway-related protein ubiquitination in the model of diabetic rats renal tissues, primary mesangial cells, and cell lines. METHODS: The diabetic SD rat model and high-glucose-cultured primary mesangial cells and cell lines were established. miR-154-5p mimic and inhibitor, Smurf1 siRNA, and TGF ß 1/Smad3 inhibitor (SB431542) were pretreated to make the TGFß1/Smad3 pathway and ubiquitin changes. Fluorescence in situ hybridization was used for the miR-154-5p renal localization; molecular biological detection was adopted for cell proliferation, renal function, urine protein, and pathway proteins. After bioinformatics predicted binding sites, luciferase and Co-IP were used to detect miRNA and protein binding. RESULTS: miR-154-5p was significantly increased and mainly concentrated in the glomerular of renal cortex in well-established diabetic rat renal tissues. Rno-miR-154-5p combined Rno-Smurf1 3' UTR, while Smurf1 combined Smad3 directly. Meanwhile, miR-154-5p regulates TGFß1/Smad3-mediated cell proliferation via Smurf1 ubiquitination. CONCLUSION: miR-154-5p regulates the TGFß1/Smads pathway through Smurf1 ubiquitination and promotes the fibrosis process of diabetic kidney disease.

Tetrodecadazinone, a novel tetrodecamycin-pyridazinone hybrid with anti-liver fibrosis activity from Streptomyces sp. HU051.

Tetrodecadazinone (1), a novel tetrodecamycin-pyridazinone hybrid possessing a new 1,2-dimethyl-1-(2-methylnonyl)decahydronaphthalene skeleton, and 4-hydroxydihydrotetrodecamycin (2) were separated from a culture of Streptomyces sp. HU051, together with a known compound, dihydrotetrodecamycin (3). Diverse spectroscopic approaches were applied to assign the structures of 1-3, and the structure of 1 was further confirmed by single crystal X-ray diffraction analysis. Compound 1 is the first example of a pyridazinone-containing natural product. Biosynthetically, 1 is proposed to be derived from a Michael addition reaction of a PKS-derived tetrodecamycin and a piperazic-acid-derived pyridazinone. Biological evaluation revealed 1 could reduce the expressions of extracellular matrix proteins (fibronectin and collagen I) and α-smooth muscle actin (α-SMA) in transforming growth factor-ß (TGF-ß1)-activated LX-2 cells. Preliminary mechanism study showed 1 exerted its anti-liver fibrosis effect by regulating TGF-ß1/Smad2/3 signaling pathway.

GRK2 promotes activation of lung fibroblast cells and contributes to pathogenesis of pulmonary fibrosis through increasing Smad3 expression.

Pulmonary fibrosis is a chronic, progressive, and irreversible interstitial lung disease. Transforming growth factor-ß1 (TGF-ß1) plays a major role in lung fibroblast cell differentiation to myofibroblast cells and production of extracellular matrix, which are hallmarks of pulmonary fibrosis. G protein-coupled receptor kinase-2 (GRK2) has been shown to play controversial roles in TGF-ß1-induced signal transduction in different cell types; however, the role of GRK2 in TGF-ß1-induced activation of lung fibroblast cells and development of pulmonary fibrosis has not been revealed. In this study, we found that GRK2 levels were increased in lungs and isolated fibroblast cells in a murine model of pulmonary fibrosis, as well as TGF-ß1-treated lung fibroblasts. GRK2 levels were not changed in lungs in the injury phase of pulmonary fibrosis. Posttreatment with GRK2 inhibitor reduced extracellular matrix (ECM) accumulation in lungs in bleomycin-challenged mice, suggesting that GRK2 activation contributes to the progressive phase of pulmonary fibrosis. Inhibition or downregulation of GRK2 attenuates fibronectin, collagen, and α-smooth muscle actin expression in TGF-ß1-induced lung fibroblast cells or myofibroblast cells isolated from patients with pulmonary fibrosis. Furthermore, we showed that GRK2 regulates Smad3 expression, indicating that inhibition of GRK2 attenuates ECM accumulation through downregulation of Smad3 expression. This study reveals that GRK2 is a therapeutic target in treating pulmonary fibrosis and inhibition of GRK2 dampens pulmonary fibrosis by suppression of Smad3 expression, eventually attenuating TGF-ß1 signal pathway and ECM accumulation.

Artesunate inhibits the development of PVR by suppressing the TGF-ß/Smad signaling pathway.

Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment surgery failure. The epithelial-mesenchymal transition (EMT) induced by transforming growth factor (TGF-ß2) plays an important role in the development of PVR. Artesunate has been widely studied as a treatment for ophthalmic diseases because of its antioxidant, anti-inflammatory, antiapoptotic and antiproliferative properties. The purpose of this study was to investigate the effects of artesunate on the TGF-ß2-induced EMT in ARPE-19 cells and PVR development. We found that artesunate inhibited the proliferation and contraction of ARPE-19 cells after the EMT and the autocrine effects of TGF-ß2 on ARPE-19 cells. Additionally, the levels of Smad3 and p-Smad3 were increased in clinical samples, and artesunate decreased the levels of Smad3 and p-Smad3 in ARPE-19 cells treated with TGF-ß2. Artesunate also inhibited the occurrence and development of PVR in vivo. In summary, artesunate inhibits the occurrence and development of PVR by inhibiting the EMT in ARPE-19 cells.

Glycyrrhizic acid, as an inhibitor of HMGB1, alleviates bleomycin-induced pulmonary toxicity in mice through the MAPK and Smad3 pathways.

AIM: High-mobility group box 1 (HMGB1) protein has been noticed particularly for its pivotal role in several pathologies. However, the relevance between HMGB1 and pathological progress in lung toxicity still remains unclear. In the study, we evaluated the effect of glycyrrhizic acid as an HMGB1 inhibitor on the early inflammation and late fibrosis in bleomycin-induced pulmonary toxicity in mice. METHODS: We established a bleomycin-induced pulmonary toxicity model to detect the relevance between HMGB1 and pathological changes in the early inflammatory and late fibrotic stages. RESULTS: We found that bleomycin-induced increase in inflammatory cytokines interleukin (IL)-ß1, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1, and inflammatory lesions in lung tissue in the early stage of the model. However, markers of fibrosis such as transforming growth factor (TGF)-ß1 and α-smooth muscle actin (α-SMA) were significantly elevated on day 7 after bleomycin instillation. Interestingly, HMGB1 also began to rise on day 7, rather than in the early inflammatory phase. However, early (from day 0 to 14 after bleomycin instillation) or late (from day 14 to 28) intervention with HMGB1 neutralizing antibody or glycyrrhizic acid alleviated inflammation and fibrosis through down-regulating the inflammatory signaling mitogen-activated protein kinase (MAPK) and fibrotic signaling Smad3 pathway. CONCLUSION: Our results suggested that HMGB1 mediates both inflammation and fibrosis in this model. The development of high-potency and low-toxicity HMGB1 inhibitors may be a class of potential drugs for the treatment of pulmonary fibrosis.

Ivermectin inhibits cell proliferation and the expression levels of type I collagen, α­SMA and CCN2 in hypertrophic scar fibroblasts.

A hypertrophic scar (HPS) is characterized by abnormal cell proliferation and the overproduction of extracellular matrix. Currently, the treatment options available for this remain unsatisfactory. Innovative treatments are required to attenuate or prevent hypertrophic scarring and the present study searched for a drug capable of becoming a new preventative and therapeutic strategy. Although the underlying mechanisms have not been fully clarified; it is widely accepted that the TGF­ß1/SMAD3 signaling pathway serves an essential role in HPS formation. In the present study, a compound library consisting of clinically used drugs was screened for their inhibitory activity against the SMAD3 protein. The results indicated that ivermectin was able to suppress the phosphorylation of SMAD3. Therefore, the present study further investigated whether ivermectin exhibited antifibrotic effects on HPS fibroblasts. The results demonstrated that ivermectin inhibited the proliferation of HPS fibroblasts and significantly decreased the production of type I collagen, α­smooth muscle actin and cellular communication network factor 2, as determined by analyzing the mRNA and protein expression levels. In conclusion, the results of the present study suggested that ivermectin may be a promising therapeutic agent for HPS.

Demethyleneberberine promotes apoptosis and suppresses TGF-ß/Smads induced EMT in the colon cancer cells HCT-116.

Colorectal cancer (CRC) is one of the most common malignant tumours in the world. Recent reports have revealed natural products displayed inhibition on colon cancer potential by suppressing transforming growth factor-ß/Smads induced epidermal-mesenchymal transition (EMT). In this article, 12 kinds of natural berberine analogues were screened for their effects on the inhibition of the colon cancer cells, the results showed that demethyleneberberine (DM-BBR) exhibited an interesting and potential effect on inducing the apoptosis of HCT-116 cells with drug concentrations of 6, 12 and 18 µM. Particularly, DM-BBR reversed the EMT process by inhibiting the expression of p-Smad2 and p-Smad3 in the transforming growth factor-ß/Smads signal pathway, up-regulated pro-apoptotic protein cleaved caspase-9, and blocked cell cycle at the S phase and increasing the expression of cyclin proteins P27 and P21. Taken together, these findings suggested that DM-BBR could promote apoptosis and suppress TGF-ß/Smads induced EMT in the colon cancer cells HCT-116.

Identification of an allosteric and Smad3-selective inhibitor of p38αMAPK using a substrate-based approach.

p38α mitogen activated protein kinase (MAPK) plays important roles in multiple cellular functions by phosphorylating a wide variety of substrates, and therefore, p38α MAPK has been considered as an important drug target. In this study, we designed peptide-based inhibitors for p38α MAPK, which can only inhibit the Smad3 phosphorylation specifically, by targeting the KIM binding site of p38α MAPK. Peptide 6 showed a significant inhibitory potency for the Smad3 phosphorylation by p38α MAPK. Peptide 6 showed no ATP dependency, and did not inhibit the phosphorylation of other substrates by p38α MAPK. The discovery of peptide 6 by targeting the KIM binding site likely provide an opportunity for the discovery of a novel class of allosteric and substrate-specific p38α MAPK inhibitors.

Protective effects of total flavonoids from Qu Zhi Qiao (fruit of Citrus paradisi cv. Changshanhuyou) on OVA-induced allergic airway inflammation and remodeling through MAPKs and Smad2/3 signaling pathway.

Allergic asthma is one of the inflammatory diseases, which has become a major public health problem. Qu zhi qiao (QZQ), a dry and immature fruit of Citrus paradisi cv. Changshanhuyou, has various flavonoids with pharmacological properties. However, there is a knowledge gap on the pharmacological properties of QZQ on allergic asthma. Therefore, here, we explored the efficacy and mechanism of total flavonoids from QZQ (TFCH) on allergic asthma. We extracted and purified TFCH and conducted animal experiments using an Ovalbumin (OVA)-induced mice model. Bronchoalveolar lavage fluid and Swiss-Giemsa staining were used to count different inflammatory cells in allergic asthma mice. We conducted histopathology and immunohistochemistry to evaluate the changes in the lungs of allergic asthma mice. Moreover, we used ELISA assays to analyze chemokines and inflammatory cytokines. Furthermore, western blot analyses were conducted to elucidate the mechanism of TFCH on allergic asthma. We established that TFCH has anti-inflammatory effects and inhibits airway remodeling, providing a potential therapeutic strategy for allergic asthma.

TGFB1/INHBA Homodimer/Nodal-SMAD2/3 Signaling Network: A Pivotal Molecular Target in PDAC Treatment.

Pancreatic cancer remains a grueling disease that is projected to become the second-deadliest cancer in the next decade. Standard treatment of pancreatic cancer is chemotherapy, which mainly targets the differentiated population of tumor cells; however, it paradoxically sets the roots of tumor relapse by the selective enrichment of intrinsically chemoresistant pancreatic cancer stem cells that are equipped with an indefinite capacity for self-renewal and differentiation, resulting in tumor regeneration and an overall anemic response to chemotherapy. Crosstalk between pancreatic tumor cells and the surrounding stromal microenvironment is also involved in the development of chemoresistance by creating a supportive niche, which enhances the stemness features and tumorigenicity of pancreatic cancer cells. In addition, the desmoplastic nature of the tumor-associated stroma acts as a physical barrier, which limits the intratumoral delivery of chemotherapeutics. In this review, we mainly focus on the transforming growth factor beta 1 (TGFB1)/inhibin subunit beta A (INHBA) homodimer/Nodal-SMAD2/3 signaling network in pancreatic cancer as a pivotal central node that regulates multiple key mechanisms involved in the development of chemoresistance, including enhancement of the stem cell-like properties and tumorigenicity of pancreatic cancer cells, mediating cooperative interactions between pancreatic cancer cells and the surrounding stroma, as well as regulating the deposition of extracellular matrix proteins within the tumor microenvironment.

Repurposing mesalazine against cardiac fibrosis in vitro.

Cardiovascular diseases are exacerbated and driven by cardiac fibrosis. TGFß induces fibroblast activation and differentiation into myofibroblasts that secrete excessive extracellular matrix proteins leading to stiffening of the heart, concomitant cardiac dysfunction, and arrhythmias. However, effective pharmacotherapy for preventing or reversing cardiac fibrosis is presently unavailable. Therefore, drug repurposing could be a cost- and time-saving approach to discover antifibrotic interventions. The aim of this study was to investigate the antifibrotic potential of mesalazine in a cardiac fibroblast stress model. TGFß was used to induce a profibrotic phenotype in a human cardiac fibroblast cell line. After induction, cells were treated with mesalazine or solvent control. Fibroblast proliferation, key fibrosis protein expression, extracellular collagen deposition, and mechanical properties were subsequently determined. In response to TGFß treatment, fibroblasts underwent a profound phenoconversion towards myofibroblasts, determined by the expression of fibrillary αSMA. Mesalazine reduced differentiation nearly by half and diminished fibroblast proliferation by a third. Additionally, TGFß led to increased cell stiffness and adhesion, which were reversed by mesalazine treatment. Collagen 1 expression and deposition-key drivers of fibrosis-were significantly increased upon TGFß stimulation and reduced to control levels by mesalazine. SMAD2/3 and ERK1/2 phosphorylation, along with reduced nuclear NFκB translocation, were identified as potential modes of action. The current study provides experimental pre-clinical evidence for antifibrotic effects of mesalazine in an in vitro model of cardiac fibrosis. Furthermore, it sheds light on possible mechanisms of action and suggests further investigation in experimental and clinical settings.

Xiaoyaosan decoction alleviated rat liver fibrosis via the TGFß/Smad and Akt/FoxO3 signaling pathways based on network pharmacology analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Liver fibrosis is an outcome of many chronic liver diseases and often results in cirrhosis, liver failure, and even hepatocarcinoma. Xiaoyaosan decoction (XYS) as a classical Traditional Chinese Medicine (TCM) formula is used to liver fibrosis in clinical practice while its mechanism is unclear. AIM OF THE STUDY: The aim of this study was to investigate the anti-fibrosis effect of XYS and to explore the molecular mechanisms by combining network pharmacology and transcriptomic technologies. MATERIALS AND METHODS: The carbon tetrachloride (CCl4)-induced liver fibrosis rat were treated with three doses of XYS. The liver fibrosis and function were evaluated by histopathological examination and serum biochemical detection. The fibrosis related protein a-SMA and collagen I were assessed by Western blot. Different expressed genes (DEGs) between XYS-treated group and model group were analyzed. The herb-component-target network was constructed combined the network pharmacology. The predict targets and pathways were validated by in vitro and in vivo experiments. RESULTS: With XYS treatment, the liver function was significantly improved, and fibrotic changes were alleviated. The a-SMA and collagen I expression levels in the liver were also decreased in XYS-treated rats compared with CCl4 model rats. 108 active components and 42 targets from 8 herbs constituted herb-compound-target network by transcriptomics and network pharmacology analysis. The KEGG pathway and GO enrichment analyses showed that the FoxO, TGFß, AMPK, MAPK, PPAR, and hepatitis B and C pathways were involved in the anti-fibrosis effects of XYS. In the liver tissues, p-FoxO3a and p-Akt expression levels were significantly increased in the CCl4 model group but decreased in the XYS-treated group. The TGFß1/Smad pathway and Akt/FoxO3 pathway were verified in LX2 cells by inhibiting phosphorylation of Smad3 and Akt activity, respectively. CONCLUSIONS: Our findings suggested that XYS markedly alleviated CCl4-induced liver fibrosis in histopathological and serum liver function analyses, and this effect may occur via the TGFß1/Smad and Akt/FoxO signaling pathways.

TGF-ß1 promotes epithelial-to-mesenchymal transition and stemness of prostate cancer cells by inducing PCBP1 degradation and alternative splicing of CD44.

CD44 is a marker of cancer stem cell (CSC) in many types of tumors. Alternative splicing of its 20 exons generates various CD44 isoforms that have different tissue specific expression and functions, including the CD44 standard isoform (CD44s) encoded by the constant exons and the CD44 variant isoforms (CD44v) with variant exon insertions. Switching between the CD44v and CD44s isoforms plays pivotal roles in tumor progression. Here we reported a novel mechanism of CD44 alternative splicing induced by TGF-ß1 and its connection to enhanced epithelial-to-mesenchymal transition (EMT) and stemness in human prostate cancer cells. TGF-ß1 treatment increased the expression of CD44s and N-cadherin while decreased the expression of CD44v and E-cadherin in DU-145 prostate cancer cells. Other EMT markers and cancer stem cell markers were also upregulated after TGF-ß1 treatment. RNAi knockdown of CD44 reversed the phenotype, which could be rescued by overexpressing CD44s but not CD44v, indicating the alternatively spliced isoform CD44s mediated the activity of TGF-ß1 treatment. Mechanistically, TGF-ß1 treatment induced the phosphorylation, poly-ubiquitination, and degradation of PCBP1, a well-characterized RNA binding protein known to regulate CD44 splicing. RNAi knockdown of PCBP1 was able to mimic TGF-ß1 treatment to increase the expression of CD44s, as well as the EMT and cancer stem cell markers. In vitro and in vivo experiments were performed to show that CD44s promoted prostate cancer cell migration, invasion, and tumor initiation. Taken together, we defined a mechanism by which TGF-ß1 induces CD44 alternative splicing and promotes prostate cancer progression.

Inhibition of Smad3 promotes the healing of rotator cuff injury in a rat model.

To investigate the effect of inhibiting transforming growth factor-ß (TGF-ß1)/Smad2/3 signaling on rotator cuff (RC) healing. A bilateral supraspinatus tendon detachment-repair model of Sprague-Dawley (SD) rats was utilized. A total of 120 SD rats were randomly assigned to six groups and each group received the subacromial injection of normal saline, empty vectors, or lentiviral vectors containing small interfering RNA against TGF-ß1, Smad2, Smad3 at the bone-tendon junction. Biomechanical and histological analyses were performed to evaluate bone-tendon junction healing quality at 8 weeks after repair. Histologically, scar healing was found in all surgical groups. Animals with inhibited Smad3 exhibited better bone-tendon junction structures with higher density, parallel orientation, and collagen fiber continuity than other surgical group animals. Immunohistochemistry revealed that the protein expression level of collagen I in animals with inhibited Smad3 was more prominent compared with all other surgical groups. Biomechanically, Animals with inhibited Smad3 showed better results in the maximum load at 4, 6, and 8 weeks after surgery compared with other surgical groups. Besides, C3H10T1/2 (Smad3-) cells increased TT-D6 cell migration and tendon-associated genes expression (scleraxis, tenascin C, collagen I) in coculture system. We conclude that inhibition of Smad3 promotes RC tendon healing in the rat supraspinatus model.

Effect of SIS3 on Extracellular Matrix Remodeling and Repair in a Lipopolysaccharide-Induced ARDS Rat Model.

The remodeling of the extracellular matrix (ECM) in the parenchyma plays an important role in the development of acute respiratory distress syndrome (ARDS), a disease characterized by lung injury. Although it is clear that TGF-ß1 can modulate the expression of the extracellular matrix (ECM) through intracellular signaling molecules such as Smad3, its role as a therapeutic target against ARDS remains unknown. In this study, a rat model was established to mimic ARDS via intratracheal instillation of lipopolysaccharide (LPS). A selective inhibitor of Smad3 (SIS3) was intraperitoneally injected into the disease model, while phosphate-buffered saline (PBS) was used in the control group. Animal tissues were then evaluated using histological analysis, immunohistochemistry, RT-qPCR, ELISA, and western blotting. LPS was found to stimulate the expression of RAGE, TGF-ß1, MMP2, and MMP9 in the rat model. Moreover, treatment with SIS3 was observed to reverse the expression of these molecules. In addition, pretreatment with SIS3 was shown to partially inhibit the phosphorylation of Smad3 and alleviate symptoms including lung injury and pulmonary edema. These findings indicate that SIS3, or the blocking of TGF-ß/Smad3 pathways, could influence remodeling of the ECM and this may serve as a therapeutic strategy against ARDS.

Evogliptin attenuates bleomycin-induced lung fibrosis via inhibiting TGF-ß/Smad signaling in fibroblast.

OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is a pulmonary interstitial fibrosis disease. Excessive activation of fibroblasts in the lung contributes to severe alveoli dysfunction and histological destruction. Evogliptin, a dipeptidyl peptidase IV inhibitor, has been widely used to reduce glucose level in type 2 diabetes, whereas evogliptin treatment to fibrosis process of lung IPF is elusive. The study aimed to investigate the mechanism of evogliptin in transforming growth factor-beta (TGF-ß)-activated lung fibroblasts and evaluate the efficacy of evogliptin in lung fibrosis model. MATERIALS AND METHODS: In lung fibroblast culture, the RNA expression of α-SMA in lung fibroblasts was detected, and α-SMA/COL-1 immunofluorescence co-staining after TGF-ß stimulation and evogliptin administration was displayed. Mechanically, the phosphorylation level of Smad2/3 protein in cells was analyzed using Western blotting, and the scratch assay was used to reflect fibroblast proliferation. Furthermore, bleomycin was employed to induce lung fibrosis in mice, and IHC staining and hematoxylin and eosin (HE) & Masson staining were carried out to examine the extracellular matrix (ECM) expression and tissue fibrosis. RESULTS: The results demonstrated that evogliptin treatment attenuated the activation of fibroblasts and collagen deposition following TGF-ß stimulation. Furthermore, the extracellular matrix expression was descended via evogliptin restraining the TGF-ß/Smad pathway. Besides, it was also found that evogliptin affected the proliferation degree of lung fibroblasts. In vivo, the COL-1 and α-SMA were significantly reduced through evogliptin treatment compared with the bleomycin group, and fibroblasts and collagenous fiber were remarkably decreased. CONCLUSIONS: Evogliptin exerts an anti-fibrosis effect on TGF-ß induced lung fibroblast activation, which restrains ECM formation and decreases cell proliferation level in fibroblasts. Moreover, the fibroblast infiltration and collagen deposition were ameliorated following evogliptin administration. Therefore, evogliptin serves as a potential implication to protect lung fibrosis.