HOXC10 promotes hypertrophic scar fibroblast fibrosis through the regulation of STMN2 and the TGF-ß/Smad signaling pathway.

The pathophysiology of hypertrophic scar (HS) shares similarities with cancer. HOXC10, a gene significantly involved in cancer development, exhibits higher expression levels in HS than in normal skin (NS), suggesting its potential role in HS regulation. And the precise functions and mechanisms by which HOXC10 influences HS require further clarification. Gene and protein expressions were analyzed using raeal-time quantitative polymerase chain reaction (RT-qPCR) and western blot techniques. Cell proliferation and migration were evaluated using EdU proliferation assays, CCK-8 assays, scratch assays, and Transwell assays. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were conducted to investigate the interactions between HOXC10 and STMN2. HOXC10 and STMN2 expression levels were significantly higher in HS tissues compared with NS tissues. Silencing HOXC10 led to decreased activation, proliferation, migration, and fibrosis in hypertrophic scar fibroblasts (HSFs). Our findings also indicate that HOXC10 directly targets STMN2. The promotional effects of HOXC10 knockdown on HSF activation, proliferation, migration, and fibrosis were reversed by STMN2 overexpression. We further demonstrated that HOXC10 regulates HSF activity through the TGF-ß/Smad signaling pathway. HOXC10 induces the activation and fibrosis of HSFs by promoting the transcriptional activation of STMN2 and engaging the TGF-ß/Smad signaling pathway. This study suggests that HOXC10 could be a promising target for developing treatments for HS.

OLFM2 promotes epithelial-mesenchymal transition, migration, and invasion in colorectal cancer through the TGF-ß/Smad signaling pathway.

BACKGROUND: Colorectal cancer (CRC) is an aggressive tumor of the gastrointestinal tract, which is a major public health concern worldwide. Despite numerous studies, the precise mechanism of metastasis behind its progression remains elusive. As a member of the containing olfactomedin domains protein family, olfactomedin 2 (OLFM2) may play a role in tumor metastasis. It is highly expressed in colorectal cancer, and its role in the metastasis of CRC is still unclear. As such, this study seeks to explore the function of OLFM2 on CRC metastasis and its potential mechanisms. METHODS: Real-time fluorescence quantitative PCR and western blotting were used to study the expression of OLFM2 in human CRC and adjacent normal tissues. Knockdown and overexpression OLFM2 cell lines were constructed using siRNA and overexpression plasmids to explore the role of OLFM2 in the migration and invasion of CRC through transwell, and wound healing experiments. Finally, the expression of epithelial-mesenchymal transition (EMT) -related proteins and TGF-ß/Smad signaling pathway-related proteins was investigated using western blotting. RESULTS: In this study, we observed an elevation of OLFM2 expression levels in CRC tissues. To investigate the function of OLFM2, we overexpressed and knocked down OLFM2. We discovered that OLFM2 knockdown inhibited migration and invasion of colon cancer cells. Furthermore, E-cadherin expression increased while N-cadherin and Vimentin expression were opposite. It is no surprise that overexpressing OLFM2 had the opposite effects. We also identified that OLFM2 knockdown resulted in reduced TGF-ßR1 and downstream molecules p-Smad2 and p-Smad3, which are related to the TGF-ß / Smad pathway. In contrast, overexpressing OLFM2 significantly boosted their expression levels. CONCLUSION: The protein OLFM2 has been identified as a crucial determinant in the progression of CRC. Its mechanism of action involves the facilitation of EMT through the TGF-ß/Smad signaling pathway. Given its pivotal role in CRC, OLFM2 has emerged as a promising diagnostic and therapeutic target for the disease. These results indicate the potential of OLFM2 as a valuable biomarker for CRC diagnosis and treatment and highlight the need for further research exploring its clinical significance.

Human umbilical cord mesenchymal stem cells improve uterine incision healing after cesarean delivery in rats by modulating the TGF-ß/Smad signaling pathway.

OBJECTIVE: Although human umbilical cord-derived mesenchymal stem cells (HU-MSCs) have attracted increasing attention because of their pivotal functions in the process of wound healing, the underlying molecular mechanisms have been poorly understood. It has been shown that the TGF-ß/Smad signaling pathway plays an important role in the process of scar formation. The present study focused on exploring whether HU-MSCs improve uterine incision healing after cesarean delivery in rats via the TGF-ß/Smad signaling pathway. STUDY DESIGN: Pregnant rats were randomly assigned to three groups, including the NP group, incision-injected group (HU-MSCs1 group), and tail vein-injected group (HU-MSCs2 group), and 30 days after cesarean section, sampling was carried out to further explore the specific mechanisms from tissue and protein levels. RESULTS: HU-MSCs secretion could inhibit the fibrosis of scar tissue. We observed that the TGF-ß induced expression of TGF-ß1, Smad2, and Smad3 was attenuated upon HU-MSCs treatment in scar tissue, while the decrease in TGF-ß3 expression was enhanced by HU-MSCs. Furthermore, HU-MSCs treatment accelerated wound healing and attenuated collagen deposition in a damaged uterine rat model, leading to the promoting of uterine incision scarring. In addition, the expression of alpha-smooth muscle actin (a-SMA) was enhanced by HU-MSCs treatment. CONCLUSION: HU-MSCs transplantation promotes rat cesarean section uterine incision scar healing by modulating the TGF-ß/Smad signaling pathway.

HIVEP3 as a potential prognostic factor promotes the development of acute myeloid leukemia.

Acute myeloid leukemia (AML) is a common malignancy worldwide. Human immune deficiency virus type 1 enhancer-binding protein 3 (HIVEP3) was verified to play a vital role in types of cancers. However, the functional role of HIVEP3 in AML was rarely reported. In this study, CCK-8, colony formation assay, flow cytometry, and Trans-well chamber experiments were applied for detecting cell proliferation, apoptosis, and invasion in AML cells. The expression of proteins related to TGF-ß/Smad signaling pathway was determined by western blot. Our data showed that the expression level of HIVEP3 was closely related to the risk classification and prognosis of AML patients. Moreover, HIVEP3 was highly expressed in AML patients and cells. Knockdown of HIVEP3 significantly repressed cell proliferation invasion, and enhanced cell apoptosis in HL-60 and THP-1 cells. In addition, HIVEP3 donwreglation could inhibit the TGF-ß/Smad signaling pathway. TGF-ß overexpression could reverse the inhibition effects of HIVEP3 knockdown on AML development and the TGF-ß/Smad signaling pathway. These findings indicated that HIVEP3 contributed to the progression of AML via regulating the TGF-ß/Smad signaling pathway and had a prognostic value for AML.

Congenital mandibular coronoid process hyperplasia and associated diseases.

Coronoid process hyperplasia (CPH) is an oral and maxillofacial surgical disease that can result in restricted jaw movement due to an enlarged and elongated mandibular coronoid process. It is characterized by the painless progressive restriction of unilaterally or bilaterally mouth opening. Clinically, unexplained bilateral CPH is less common and therefore often overlooked or misdiagnosed, and coronoidectomy can be very effective on improving mouth opening. Currently, the exact etiology and mechanism of congenital CPH have not yet been fully understood, but it is generally believed to be genetically related. In this paper, the relationship of the congenital mandibular CPH with the related diseases was examined based on cases collected in our clinic and literature review for the clinical diagnosis and treatment of patients with restricted mouth opening associated with CPH.

[Role of TGF-ß/Smad signaling pathway in diabetic kidney disease and research progress of traditional Chinese medicine intervention].

Diabetic kidney disease is an important microvascular complication of diabetes and the leading cause of end-stage renal disease. Its pathological characteristics mainly include epithelial mesenchymal transition(EMT) in glomerulus, podocyte apoptosis and autophagy, and damage of glomerular filtration barrier. Transforming growth factor-ß(TGF-ß)/Smad signaling pathway is specifically regulated by a variety of mechanisms, and is a classic pathway involved in physiological activities such as apoptosis, proliferation and differentiation. At present, many studies have found that TGF-ß/Smad signaling pathway plays a key role in the pathogenesis of diabetic kidney disease. Traditional Chinese medicine has significant advantages in the treatment of diabetic kidney disease for its multi-component, multi-target and multi-pathway characteristics, and some traditional Chinese medicine extracts, traditional Chinese medicines and traditional Chinese medicine compound prescription improve the renal injury of diabetic kidney disease by regulating TGF-ß/Smad signaling pathway. This study clarified the mechanism of TGF-ß/Smad signaling pathway in diabetic kidney disease by expounding the relationship between the key targets of the pathway and diabetic kidney disease, and summarized the research progress of traditional Chinese medicine in the treatment of diabetic kidney disease by interfering with TGF-ß/Smad signaling pathway in recent years, to provide reference for drug research and clinical treatment of diabetic kidney disease in the future.

Regulation of SMAD Signaling Pathway by miRNAs Associated with Myocardial Fibrosis: In silico Analysis of Target Gene Networks.

Hypertrophic cardiomyopathy (HCM) is a hereditary heart disease caused by mutations in the sarcomere genes, which is accompanied by myocardial fibrosis leading to progressive heart failure and arrhythmias. Recent studies suggest that the HCM development involves dysregulation of gene expression. Among the molecules involved in this process are microRNAs (miRNAs), which are short non-coding RNAs. Typically, one miRNA regulates several target genes post-transcriptionally, hence, it might be difficult to determine the role of a particular miRNA in the disease pathogenesis. In this study, using the PubMed database, we selected 15 miRNAs whose expression is associated with myocardial fibrosis, one of the critical pathological processes in HCM. We then used an earlier developed algorithm to search in silico for the signaling pathways regulated by these miRNAs and found that ten of them participate in the regulation of the TGF-ß/SMAD signaling pathway. At the same time, among the SMAD signaling pathway genes, the target of the most identified miRNAs was the MYC gene, which is involved in the development of fibrosis in some tissues. In our earlier work, we found that the TGF-ß/SMAD pathway is also regulated by a set of other miRNAs associated with the myocardial hypertrophy in HCM. The fact that two sets of miRNAs identified in two independent bioinformatic studies are involved in the regulation of the same signaling pathway indicates that the SMAD signaling cascade is indeed a key element in the regulation of pathological processes in HCM. The obtained data might contribute to understanding pathological processes underlying HCM development.

Golgi scaffold protein PAQR3 as a candidate suppressor of gastric cardia adenocarcinoma via regulating TGF-ß/Smad pathway.

OBJECTIVES: To investigate the function of PAQR3 in gastric cardia adenocarcinoma (GCA) and understand the possible mechanism of PAQR3 in regulating epithelial-mesenchymal transition (EMT). METHODS: We detected PAQR3 protein in 146 GCA tissues and paired normal adjacent tissues (PNTs) specimens using immunohistochemical analysis, and explored its clinical significance. The expression levels of PAQR3 protein in 20 GCA tissues, their paired PNTs, HGC27, SGC7901, and GES-1 cells were analyzed by Western blot. Wild-type PAQR3 was overexpressed in HGC27 cells. The effects of PAQR3 overexpression on the function of HGC27 cells and its underlying mechanisms were then analyzed through a series of cell and molecular biology experiments. RESULTS: PAQR3 was significantly down-regulated in GCA tissues when compared with paired PNTs (p < 0.0001). The expression level of PAQR3 in GCA tissues was significantly negatively correlated with Helicobacter pylori infection (p = 0.000), venous invasion (p = 0.000), invasion depth (p = 0.000), lymph node metastasis (p = 0.022), tumor stage (p = 0.000), and patient survival (p = 0.009). Downregulation of PAQR3 was highly correlated with increased EMT signature and activated TGF-ß/Smad pathway in GCA tissues. Overexpression of PAQR3 in HGC27 cells negatively regulates its cellular functions, such as cell proliferation and migration, and suppresses EMT. Mechanistically, overexpression of PAQR3 significantly down-regulates the protein expression levels of TGF-1, p-Smad2, and p-Smad3 in HGC27 cells. CONCLUSION: PAQR3 was significantly down-regulated in GCA tissues, HGC27, and SGC7901 cells. PAQR3 significantly inhibits the proliferation, migration, and invasion of HGC27 cells. Mechanistically, PAQR3 can inhibit the EMT process in HGC27 cells by regulating TGF-ß/Smad signaling pathway.

The TGF-ß/SMAD Signaling Pathway Prevents Follicular Atresia by Upregulating MORC2.

In mammals, female fertility is determined by the outcome of follicular development (ovulation or atresia). The TGF-ß/SMAD signaling pathway is an important regulator of this outcome. However, the molecular mechanism by which the TGF-ß/SMAD signaling pathway regulates porcine follicular atresia has not been fully elucidated. Microrchidia family CW-type zinc finger 2 (MORC2) is anovel epigenetic regulatory protein widely expressed in plants, nematodes, and mammals. Our previous studies showed that MORC2 is a potential downstream target gene of the TGF-ß/SMAD signaling pathway. However, the role of MORC2 in porcine follicular atresia is unknown. To investigate this, qRT-PCR, western blotting, and TdT-mediated dUTP nick-end labeling were performed. Additionally, the luciferase activity assay was conductedto confirm that the TGF-ß/SMAD signaling pathway regulates MORC2. Our results demonstrate that MORC2 is animportant anti-apoptotic molecule that prevents porcine follicular atresia via a pathway involving mitochondrial apoptosis, not DNA repair. Notably, this studyrevealsthat the TGF-ß/SMAD signaling pathway inhibits porcine granulosa cell apoptosis by up-regulating MORC2. The transcription factor SMAD4 regulated the expression of MORC2 by binding to its promoter. Our results will help to reveal the mechanism underlying porcine follicular atresia and improve the reproductive efficiency of sows.

Investigation of the Antiremodeling Effects of Losartan, Mirabegron and Their Combination on the Development of Doxorubicin-Induced Chronic Cardiotoxicity in a Rat Model.

Despite the effectiveness of doxorubicin (DOXO) as a chemotherapeutic agent, dose-dependent development of chronic cardiotoxicity limits its application. The angiotensin-II receptor blocker losartan is commonly used to treat cardiac remodeling of various etiologies. The beta-3 adrenergic receptor agonist mirabegron was reported to improve chronic heart failure. Here we investigated the effects of losartan, mirabegron and their combination on the development of DOXO-induced chronic cardiotoxicity. Male Wistar rats were divided into five groups: (i) control; (ii) DOXO-only; (iii) losartan-treated DOXO; (iv) mirabegron-treated DOXO; (v) losartan plus mirabegron-treated DOXO groups. The treatments started 5 weeks after DOXO administration. At week 8, echocardiography was performed. At week 9, left ventricles were prepared for histology, qRT-PCR, and Western blot measurements. Losartan improved diastolic but not systolic dysfunction and ameliorated SERCA2a repression in our DOXO-induced cardiotoxicity model. The DOXO-induced overexpression of Il1 and Il6 was markedly decreased by losartan and mirabegron. Mirabegron and the combination treatment improved systolic and diastolic dysfunction and significantly decreased overexpression of Smad2 and Smad3 in our DOXO-induced cardiotoxicity model. Only mirabegron reduced DOXO-induced cardiac fibrosis significantly. Mirabegron and its combination with losartan seem to be promising therapeutic tools against DOXO-induced chronic cardiotoxicity.

MicroRNA-362 negatively and positively regulates SMAD4 expression in TGF-ß/SMAD signaling to suppress cell migration and invasion.

Cell migration and invasion are modulated by epithelial-to-mesenchymal transition (EMT) and the reverse MET process. Despite the detection of microRNA-362 (miR-362, both the miR-362-5p and -3p species) in cancers, none of the identified miR-362 targets is a mesenchymal or epithelial factor to link miR-362 with EMT/MET and metastasis. Focusing on the TGF-ß/SMAD signaling pathway in this work, luciferase assays and western blot data showed that miR-362 targeted and negatively regulated expression of SMAD4 and E-cadherin, but not SNAI1, which is regulated by SMAD4. However, miR-362 knockdown also down-regulated SMAD4 and SNAI1, but up-regulated E-cadherin expression. Wound-healing and transwell assays further showed that miR-362 knockdown suppressed cell migration and invasion, effects which were reversed by over-expressing SMAD4 or SNAI1, or by knocking down E-cadherin in the miR-362 knockdown cells. In orthotopic mice, miR-362 knockdown inhibited metastasis, and displayed the same SMAD4 and E-cadherin expression profiles in the tumors as in the in vitro studies. A scheme is proposed to integrate miR-362 negative regulation via SMAD4, and to explain miR-362 positive regulation of SMAD4 via miR-362 targeting of known SMAD4 suppressors, BRK and DACH1, which would have resulted in SMAD4 depletion and annulment of subsequent involvement in TGF-ß signaling actions. Hence, miR-362 both negatively and positively regulates SMAD4 expression in TGF-ß/SMAD signaling pathway to suppress cell motility and invasiveness and metastasis, and may explain the reported clinical association of anti-miR-362 with suppressed metastasis in various cancers. MiR-362 knockdown in miR-362-positive cancer cells may be used as a therapeutic strategy to suppress metastasis.

Investigation of the Antihypertrophic and Antifibrotic Effects of Losartan in a Rat Model of Radiation-Induced Heart Disease.

Radiation-induced heart disease (RIHD) is a potential late side-effect of thoracic radiotherapy resulting in left ventricular hypertrophy (LVH) and fibrosis due to a complex pathomechanism leading to heart failure. Angiotensin-II receptor blockers (ARBs), including losartan, are frequently used to control heart failure of various etiologies. Preclinical evidence is lacking on the anti-remodeling effects of ARBs in RIHD, while the results of clinical studies are controversial. We aimed at investigating the effects of losartan in a rat model of RIHD. Male Sprague-Dawley rats were studied in three groups: (1) control, (2) radiotherapy (RT) only, (3) RT treated with losartan (per os 10 mg/kg/day), and were followed for 1, 3, or 15 weeks. At 15 weeks post-irradiation, losartan alleviated the echocardiographic and histological signs of LVH and fibrosis and reduced the overexpression of chymase, connective tissue growth factor, and transforming growth factor-beta in the myocardium measured by qPCR; likewise, the level of the SMAD2/3 protein determined by Western blot decreased. In both RT groups, the pro-survival phospho-AKT/AKT and the phospho-ERK1,2/ERK1,2 ratios were increased at week 15. The antiremodeling effects of losartan seem to be associated with the repression of chymase and several elements of the TGF-ß/SMAD signaling pathway in our RIHD model.

FBXO31 modulates activation of hepatic stellate cells and liver fibrogenesis by promoting ubiquitination of Smad7.

Liver fibrosis is a critical pathological process in the early stage of many liver diseases, including hepatic cirrhosis and liver cancer. However, the molecular mechanism is not fully revealed. In this study, we investigated the role of F-box protein 31 (FBXO31) in liver fibrosis. We found FBXO31 upregulated in carbon tetrachloride (CCl4 ) induced liver fibrosis and in activated hepatic stellate cells, induced by transforming growth factor-ß (TGF-ß). The enforced expression of FBXO31 caused enhanced proliferation and increased expression of α-smooth muscle actin (α-SMA) and Col-1 in HSC-T6 cells. Conversely, suppression of FBXO31 resulted in inhibition of proliferation and decreased accumulation of α-SMA and Col-1 in HSC-T6 cells. In addition, upregulation of FBXO31 in HSC-T6 cells decreased accumulation of Smad7, the negative regulator of the TGF-ß/smad signaling pathway, and suppression of the FBXO31 increased accumulation of Smad7. Immunofluorescence staining showed FBXO31 colocalized with Smad7 in HSC-T6 cells and in liver tissues of BALB/c mice treated with CCl4 . Immunoprecipitation demonstrated FBXO31 interacted with Smad7. Moreover, FBXO31 enhanced ubiquitination of Smad7. In conclusion, FBXO31 modulates activation of HSCs and liver fibrogenesis by promoting ubiquitination of Smad7.

TGFß/Smad mediated the polyhexamethyleneguanide areosol-induced irreversible pulmonary fibrosis in subchronic inhalation exposure.

AIM: Polyhexamethylene guanidine (PHMG) is widely used as a disinfectant with broad spectra of bactericidal activity and low oral toxicity. However, inhalation of PHMG can cause pulmonary injury and severe pulmonary fibrosis. The mechanism underlying PHMG aerosol induced pulmonary fibrosis remains unclear. In this study, we aimed to examine the subchronic lung injury and determine potential cytokines involved in PHMG aerosol induced fibrosis. METHODS: C57BL/6N mice were exposed to 1.03 mg/m3 PHMG through aerosol inhalation for 3 weeks, or 3 weeks followed by other 3 weeks recovery. RESULTS: The results indicated that the expression of transforming growth factor-beta1 (TGF-ß1) and extracellular matrix remodeling markers were up-regulated in the PHMG-treated mice and these parameters were aggravated after 3 weeks recovery. Bronchoalveolar lavage fluids (BALFs) analysis showed that the number of total cells was significantly decreased in exposure group. The percentage of macrophages in BALFs decreased significantly whereas the percentage of neutrophils and lymphocytes increased. Extensive collagen deposition was observed in the peribronchiolar and interstitial areas in the PHMG exposed lungs. CONCLUSION: In conclusion, even low-does PHMG aerosol exposure could induce mice pulmonary local inflammation and irreversible fibrosis. In addition, TGF-ß/Smad signaling pathway mediated the extracellular matrix remodeling involved in the development of pulmonary fibrosis.

TGF-ß/SMAD signaling inhibits intermittent cyclic mechanical tension-induced degeneration of endplate chondrocytes by regulating the miR-455-5p/RUNX2 axis.

A mechanical stimulation plays a pivotal role in maintaining normal cartilage function. Our objective was to reveal the mechanism of action of the tension-sensitive molecule miR-455-5p in the degeneration of endplate chondrocytes and to identify whether the transforming growth factor beta (TGF-ß)/SMAD signaling pathway has a regulatory effect on it. The expression profiles of members of the TGF-ß/SMAD pathway, miR-455-5p, and RUNX2 were determined by microRNA microarray analysis, reverse transcription quantitative polymerase chain reaction, luciferase reporter assay, and Western blot analysis. Intermittent cyclic mechanical tension (ICMT) induced the degeneration of endplate chondrocytes without affecting their viability. The tension-sensitive molecule miR-455-5p specifically bound to RUNX2, a gene involved in the degeneration of endplate chondrocytes. Activation of the TGF-ß/SMAD signaling pathway upregulated miR-455-5p expression and thus inhibited RUNX2 levels. Therefore, the TGF-ß/SMAD signaling pathway inhibits the ICMT-induced degeneration of endplate chondrocytes by regulating the miR-455-5p/RUNX2 axis.

HOXC6 gene silencing inhibits epithelial-mesenchymal transition and cell viability through the TGF-ß/smad signaling pathway in cervical carcinoma cells.

BACKGROUND: Homeobox C6 (HOXC6) plays a part in malignant progression of some tumors. However, the expression of HOXC6 and its clinical significance remains unclear in cervical carcinoma (CC). The purpose of this study is to verify the effects of HOXC6 gene silencing on CC through the TGF-ß/smad signaling pathway. METHODS: CC tissues and corresponding paracancerous tissues were collected from CC patients with involvement of a series of HOXC6-siRNA, HA-HOXC6 and the TGF-ß/smad pathway antagonist. HOXC6 expression was analyzed in six CC cell lines (C-33A, HeLa, CaSki, SiHa, ME-180, and HCC-94) by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The mRNA and protein expression of HOXC6, TGF-ß1, TGF-ß RII, smad4, smad7, E-cadherin, N-cadherin, Vimentin, ki-67, proliferating cell nuclear antigen (PCNA), p27, and Cyclin D1 were determined by RT-qPCR and western blot analysis. Cell proliferation, apoptosis and cell cycle were detected by MTT assay and flow cytometry, respectively. RESULTS: Higher positive expression rate of HOXC6 protein was observed in CC tissues and HOXC6 was related to TNM stage, lymphatic metastasis, cancer types, primary lesion diameter, and histological grade of CC. Silencing HOXC6 inhibited epithelial-mesenchymal transition (EMT) (shown as decreased N-cadherin and Vimentin, and increased E-cadherin) through the inactivation of the TGF-ß/smad signaling pathway. HOXC6 gene silencing hindered cell proliferation and accelerated cell apoptosis of CC cells. Furthermore, the effect of HOXC6 silencing was enhanced when the TGF-ß/smad signaling pathway was suppressed. CONCLUSION: The results reveal that HOXC6 gene silencing may inhibit EMT event and cell viability in CC through the inhibition of the activation of TGF-ß/smad signaling pathway.

Quantitative single-molecule study of TGF-ß/Smad signaling.

TGF-ß/Smad signaling pathway triggers diverse cellular responses among different cell types and environmental conditions. Quantitative analysis of protein-protein interactions involved in TGF-ß/Smad signaling is demanded for understanding the molecular mechanism of this signaling pathway. Live-cell single-molecule microcopy with high spatiotemporal resolution is a new tool to monitor key molecular events in a real-time manner. In this review, we mainly presented the recent work on the quantitative characterization of TGF-ß/Smad signaling proteins by single-molecule method, and showed how it enabled us to obtain new insights about this canonical signaling process.

High doses of baicalin induces kidney injury and fibrosis through regulating TGF-ß/Smad signaling pathway.

Baicalin is a major flavonoid compound purified from Scutellariae radix, which has been described as an herb in the Chinese Pharmacopoeia. Previous studies have suggested baicalin possessed extensive anti-inflammatory, anti-cancer, anti-viral properties. However, up to known, there have been no reports of safety and toxicity in the rats following oral administration of baicalin. In this present study, we showed the first evidence that treatment of baicalin (400, 800 and 1600mg/kg/day) induced significantly kidney injury and fibrosis. The collagen synthesis and fibrosis-related protein expression were increased in the kidney of Sprague-Dawley (SD) rats after treatment with high doses of baicalin. We further investigated the potential molecular mechanism of baicalin-mediated renal fibrosis and revealed that baicalin activated the transforming growth factor-ß (TGF-ß)/Smad signaling pathway in a dose-dependent manner. Moreover, we also observed that baicalin induced Smad3 interaction with transcriptional coactivator p300 accompanying with increment of Smad3 acetylation. Our results may contribute to better understanding of the future pharmacological and toxicological studies of Scutellaria baicalensis Georgi and its active compounds on the human disease.

Protective Effects of Berberine on Renal Injury in Streptozotocin (STZ)-Induced Diabetic Mice.

Diabetic nephropathy (DN) is a serious diabetic complication with renal hypertrophy and expansion of extracellular matrices in renal fibrosis. Epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells may be involved in the main mechanism. Berberine (BBR) has been shown to have antifibrotic effects in liver, kidney and lung. However, the mechanism of cytoprotective effects of BBR in DN is still unclear. In this study, we investigated the curative effects of BBR on tubulointerstitial fibrosis in streptozotocin (STZ)-induced diabetic mice and the high glucose (HG)-induced EMT in NRK 52E cells. We found that BBR treatment attenuated renal fibrosis by activating the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in the diabetic kidneys. Further revealed that BBR abrogated HG-induced EMT and oxidative stress in relation not only with the activation of Nrf2 and two Nrf2-targeted antioxidative genes (NQO-1 and HO-1), but also with the suppressing the activation of TGF-ß/Smad signaling pathway. Importantly, knockdown Nrf2 with siRNA not only abolished the BBR-induced expression of HO-1 and NQO-1 but also removed the inhibitory effect of BBR on HG-induced activation of TGF-ß/Smad signaling as well as the anti-fibrosis effects. The data from present study suggest that BBR can ameliorate tubulointerstitial fibrosis in DN by activating Nrf2 pathway and inhibiting TGF-ß/Smad/EMT signaling activity.

Direct contacts with colon cancer cells regulate the differentiation of bone marrow mesenchymal stem cells into tumor associated fibroblasts.

Tumor-stroma interactions are referred to as essential events in tumor progression. There has been growing attention that bone marrow-derived mesenchymal stem cells (BMSCs) can travel to tumor stroma, where they differentiate into tumor-associated fibroblast (TAF)-like cells, a predominant tumor-promoting stromal cell. However, little is definitively known about the contributors for this transition. Here, using an in vitro direct co-culture model of colon cancer cells and BMSCs, we identify that colon cancer cells can induce adjoining BMSCs to exhibit the typical characteristic of TAFs, with increased expression of α-smooth muscle actin (α-SMA). Importantly, the present data also reveals that activated Notch signaling mediates transformation of BMSCs to TAFs through the downstream TGF-ß/Smad signaling pathway.