Exosomes derived from adipose tissue-derived stem cells alleviated H2O2-induced oxidative stress and endothelial-to-mesenchymal transition in human umbilical vein endothelial cells by inhibition of the mir-486-3p/Sirt6/Smad signaling pathway

Hypertrophic scar (HS) is characterized by excessive collagen deposition and myofibroblasts activation. Endothelial-to-mesenchymal transition (EndoMT) and oxidative stress were pivotal in skin fibrosis process. Exosomes derived from adipose tissue-derived stem cells (ADSC-Exo) have the potential to attenuate EndoMT and inhibit fibrosis. The study revealed reactive oxygen species (ROS) levels were increased during EndoMT occurrence of dermal vasculature of HS. The morphology of endothelial cells exposure to H2O2, serving as an in vitro model of oxidative stress damage, transitioned from a cobblestone-like appearance to a spindle-like shape. Additionally, the levels of endothelial markers decreased in H2O2-treated endothelial cell, while the expression of fibrotic markers increased. Furthermore, H2O2 facilitated the accumulation of ROS, inhibited cell proliferation, retarded its migration and suppressed tube formation in endothelial cell. However, ADSC-Exo counteracted the biological effects induced by H2O2. Subsequently, miRNAs sequencing analysis revealed the significance of mir-486-3p in endothelial cell exposed to H2O2 and ADSC-Exo. Mir-486-3p overexpression enhanced the acceleration of EndoMT, its inhibitors represented the attenuation of EndoMT. Meanwhile, the target regulatory relationship was observed between mir-486-3p and Sirt6, whereby Sirt6 exerted its anti-EndoMT effect through Smad2/3 signaling pathway. Besides, our research had successfully demonstrated the impact of ADSC-Exo and mir-486-3p on animal models. These findings of our study collectively elucidated that ADSC-Exo effectively alleviated H2O2-induced ROS and EndoMT by inhibiting the mir-486-3p/Sirt6/Smad axis.

BMP-2 regulates the expression of myosin Va via smad in melan-a melanocyte

Myosin Va (Myo Va) is one of three protein complexes involved in melanosome transport. In this study, we identified BMP-2 as an up-regulator of Myo Va expression using 2-methyl-naphtho[1,2,3-de]quinolin-8-one (MNQO). Our results showed that MNQO reduced the mRNA and protein expression of Myo Va and BMP-2 in melanocytes. Knockdown of BMP-2 by siRNA also affected Myo Va mRNA and protein expression, confirming that MNQO regulates Myo Va through BMP-2. Furthermore, phosphorylation of Smad1/5/8 by BMP2 treatment confirmed that the BMP-2/Smad signaling pathway regulates Myo Va expression in Melan-a melanocytes. Smad-binding elements were found in the Myo Va promoter and phosphorylated Smad1/5/8 bind directly to the Myo Va promoter to activate Myo Va transcription and BMP-2 enhances this binding. These findings provide insight into a new role for BMP-2 in Melan-a melanocytes and a mechanism of regulation of Myo Va expression that may be beneficial in the treatment of albinism or hyperpigmentation disorders.

Recent Advances (2015-2020) in Drug Discovery for Attenuation of Pulmonary Fibrosis and COPD

A condition of scarring of lung tissue due to a wide range of causes (such as environmental pollution, cigarette smoking (CS), lung diseases, some medications, etc.) has been reported as pulmonary fibrosis (PF). This has become a serious problem all over the world due to the lack of efficient drugs for treatment or cure. To date, no drug has been designed that could inhibit fibrosis. However, few medications have been reported to reduce the rate of fibrosis. Meanwhile, ongoing research indicates pulmonary fibrosis can be treated in its initial stages when symptoms are mild. Here, an attempt is made to summarize the recent studies on the effects of various chemical drugs that attenuate PF and increase patients' quality of life. The review is classified based on the nature of the drug molecules, e.g., natural/biomolecule-based, synthetic-molecule-based PF inhibitors, etc. Here, the mechanisms through which the drug molecules attenuate PF are discussed. It is shown that inhibitory molecules can significantly decrease the TGF-β1, profibrotic factors, proteins responsible for inflammation, pro-fibrogenic cytokines, etc., thereby ameliorating the progress of PF. This review may be useful in designing better drugs that could reduce the fibrosis process drastically or even cure the disease to some extent.

Deficiency of HtrA3 Attenuates Bleomycin-Induced Pulmonary Fibrosis Via TGF-β1/Smad Signaling Pathway

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by excessive extracellular matrix deposition. No effective treatments are currently available for IPF. High-temperature requirement A3 (HtrA3) suppresses tumor development by antagonizing transforming growth factor β (TGF-β) signaling; however, little is known about the role of HtrA3 in IPF. This study investigated the role of HtrA3 in IPF and underlying mechanisms.

METHODS

Lung tissues were collected from patients with IPF and mice with bleomycin (BLM)-induced pulmonary fibrosis, and HtrA3 expression was measured in tissue samples. Then, HtrA3 gene knockout mice were treated with BLM to induce pulmonary fibrosis and explore the effects and underlying mechanism of HtrA3 on pulmonary fibrosis.

RESULTS

HtrA3 was up-regulated in the lung tissues of patients with IPF and the pulmonary fibrotic mouse model compared to corresponding control groups. HtrA3 knockout decreased pulmonary fibrosis-related protein expression, alleviated the symptoms of pulmonary fibrosis, and inhibited epithelial-mesenchymal transition (EMT) in BLM-induced lung tissue compared with BLM-induced wild-type mice. The TGF-β1/Smad signaling pathway was activated in fibrotic lung tissue, whereas HtrA3 knockout inhibited this pathway.

CONCLUSION

The expression level of HtrA3 is increased in fibrotic lungs. HtrA3 knockout alleviates the symptoms of pulmonary fibrosis probably via the TGF-β1/Smad signaling pathway. Therefore, HtrA3 inhibition is a potential therapeutic target for pulmonary fibrosis.

Activin a inhibits foam cell formation and up-regulates ABCA1 and ABCG1 expression through Alk4-Smad signaling pathway in RAW 264.7 macrophages

BACKGROUND

Activin A has been reported to play important roles in the pathogenesis of atherosclerosis. The purpose of this study is to investigate the effects of activin A on oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation and explore the underlying molecular mechanisms in murine macrophage-like cell line RAW 264.7.

METHODS

The effects of activin A on Dil-labeled ox-LDL uptake were examined by confocal microscopy and flow cytometry analysis. The mRNA and protein levels of cholesterol receptors were analyzed by RT-qPCR and western blot analysis, respectively. To investigate whether activin receptor-like kinase 4 (Alk4) is required for activin A-mediated cellular effects, cells were pre-treated with SB-431542. The involvement of Smad2, Smad3 and Smad4 was confirmed by transfection with specific small interfering RNAs (siRNAs).

RESULTS

Activin A inhibits ox-ldl-induced foam cell formation and class A scavenger receptors (SR-A) expression, while up-regulates ATP-binding cassette transporter A1 (ABCA1) and ABCG1 expression in RAW 264.7 macrophages. Pre-treatment with SB-431542 abolished activin A-mediated anti-atherogenic effect. Knockdown of Smad2 reversed activin A-induced inhibition of ox-LDL uptake and SR-A expression. However, knockdown of Smad3 or Smad4 did not have such effect. Meanwhile, knockdown of either Smad2, Smad3 or Smad4 reversed the activin A-induced up-regulation of ABCA1 and ABCG1.

CONCLUSIONS

Our study provides novel evidence that activin A may exert anti-atherogenic effects through Alk4-Smad signaling pathway in RAW 264.7 macrophages.

The Smad Dependent TGF-β and BMP Signaling Pathway in Bone Remodeling and Therapies

Bone remodeling is a continuous process that maintains the homeostasis of the skeletal system, and it depends on the homeostasis between bone-forming osteoblasts and bone-absorbing osteoclasts. A large number of studies have confirmed that the Smad signaling pathway is essential for the regulation of osteoblastic and osteoclastic differentiation during skeletal development, bone formation and bone homeostasis, suggesting a close relationship between Smad signaling and bone remodeling. It is known that Smads proteins are pivotal intracellular effectors for the members of the transforming growth factor-β (TGF-β) and bone morphogenetic proteins (BMP), acting as transcription factors. Smad mediates the signal transduction in TGF-β and BMP signaling pathway that affects both osteoblast and osteoclast functions, and therefore plays a critical role in the regulation of bone remodeling. Increasing studies have demonstrated that a number of Smad signaling regulators have potential functions in bone remodeling. Therefore, targeting Smad dependent TGF-β and BMP signaling pathway might be a novel and promising therapeutic strategy against osteoporosis. This article aims to review recent advances in this field, summarizing the influence of Smad on osteoblast and osteoclast function, together with Smad signaling regulators in bone remodeling. This will facilitate the understanding of Smad signaling pathway in bone biology and shed new light on the modulation and potential treatment for osteoporosis.

MiR-497-5p Regulates Osteo/Odontogenic Differentiation of Stem Cells From Apical Papilla via the Smad Signaling Pathway by Targeting Smurf2

Osteo/odontogenic differentiation is a key process of human stem cells from apical papilla (SCAP) in tooth root development. Emerging evidence indicates microRNAs (miRNAs) play diverse roles in osteogenesis. However, their functions in osteo/odontogenic differentiation of SCAP require further elucidation. To investigate the role of miRNA in SCAP osteo/odontogenic differentiation and underlying mechanisms, miRNA microarray analysis was performed to screen differentially expressed miRNAs between control and osteo/odontogenic-induced group. Quantitative real-time PCR (qRT-PCR) and western blot were used to detected osteo/odontogenic differentiation-related markers and possible signaling pathway SCAP-associated genes. Alizarin Red Staining (ARS) were applied to evaluated osteogenic capacity. The results showed that miR-497-5p increased during SCAP osteo/odontogenic differentiation. Overexpression of miR-497-5p enhanced the osteo/odontogenic differentiation of SCAP, whereas downregulation of miR-497-5p elicited the opposite effect, thus suggesting that miR-497-5p is a positive regulator of the osteo/odontogenic differentiation of SCAP. Bioinformatic analysis and dual luciferase reporter assay identified that SMAD specific E3 ubiquitin protein ligase 2 (Smurf2) is a direct target of miR-497-5p. Further study demonstrated that Smurf2 negatively regulates SCAP osteo/odontogenic differentiation, and silencing Smurf2 could block the inhibitory effect of the miR-497-5p inhibitor. Meanwhile, pathway detection manifested that miR-497-5p promotes osteo/odontogenic differentiation via Smad signaling pathway. Collectively, our findings demostrate that miR-497-5p promotes osteo/odontogenic differentiation of SCAP via Smad signaling pathway by targeting Smurf2.

MDM2 promotes epithelial-mesenchymal transition through activation of Smad2/3 signaling pathway in lung adenocarcinoma

Background

Mouse double minute 2 (MDM2) contributes to cancer metastasis and epithelial-mesenchymal transition (EMT). This study aimed to investigate small mothers against decapentaplegic (Smad) signaling in MDM2-mediated EMT in lung adenocarcinoma (LAC).

Materials and methods

Expression patterns of MDM2 in LAC tissues, adjacent tissues, and cell lines (BEAS-2B, PC9, H1975, and A549) were detected. We then overexpressed MDM2 in PC9 cells and knocked it down in H1975 cells. To explore whether MDM2 activates EMT through the Smad2/3 signaling pathway, Smad2 and Smad3 were also silenced by siRNA in H1975 cells. Male BALB/c nude mice were used in in vivo model to validate the effects of MDM2 on LAC cells.

Results

MDM2 was significantly upregulated in LAC tissues compared with adjacent tissues. The expression of MDM2 was relatively higher in PC9 cells and relatively lower in H1975 cells compared with A549 cells. Overexpression of MDM2 significantly increased cell proliferation, migration, and invasion in LAC cells, while inhibiting apoptosis in PC9 cells. On the contrary, silencing of MDM2 significantly inhibited the expression of EMT-related genes N-cadherin and vimentin, while promoting the expression of E-cadherin and β-catenin. In vivo, MDM2 knockdown inhibited tumor growth. In addition, the expression of Smad2/3 was correlated with MDM2 in H1975 cells transfected with Smad2 and Smad3 siRNAs, which inhibited EMT progress.

Conclusion

MDM2 can activate the Smad2/3 signaling pathway, which promotes the proliferation and EMT progress of LAC cells.

[Effects of centellaasiatica granule on the expression of Smad 2/3, Smad 7 and collagen Ⅳ in the mesangial cells stably expressed TGF-β1]

OBJECTIVES

Stably expressed transforming growth factor -beta 1(TGF-β1)MCs were obtained and the effects of centellaasiatica (CA) granule on the expressions of Smad 2/3, Smad 7 and collagen Ⅳ and the level of Smad 2/3 phosphorylation were observed.

METHODS

Lipofectin method was used to transfect TGF-β1 vector into MC, and the stably expressed TGF-β1 cell lines were selected by G418. The cells were divided into three groups. Control group:normal MC + RPMI 1640 + 10% normal rat serum; TGF-β1 group:stably expressed TGF-β1 MC + RPMI 1640 + 10% normal rat serum; CA group:stably expressed TGF-β1 MC + RPMI 1640 + 10% rat serum containing high CA. The experiments were repeated for five times. The contents of TGF-β1 and collagen Ⅳ in the culture medium were detected with ELISA, the expressions of mRNA and protein of TGF-β1, Smad 2/3, Smad 7 and the level of Smad 2/3 phosphorylation were detected by using real time quantitative polymerase chain reaction and Western blot.

RESULTS

The contents of TGF-β1 and collagen Ⅳ in the culture medium of stably-expressed TGF-β1 MC were increased significantly, and the CA could reverse the effects of TGF-β1. The expressions of mRNA and protein of TGF-β1, Smad 2/3 and the level of Smad 2/3 phosphorylation were increased significantly in TGF-β1 transfected MC, and CA could dramatically reduce the expressions of mRNA and protein of TGF-β1, Smad 2/3 and the level of Smad 2/3 phosphorylation. The high expression of TGF-β1 decreased the expression of Smad 7 mRNA and protein, and the CA could antagonize the effect of mRNA expression.

CONCLUSIONS

The MCs stably-expressed TGF-β1 can activate the TGF-β1/Smad signal pathway and increase the expression of collagen Ⅳ. CA can decrease the occurrence of diabetic nephropathy(DN) by reducing the production of collagen Ⅳ through inhibiting the TGF-β1/Smad signal pathway.

Ferulic acid attenuates liver fibrosis and hepatic stellate cell activation via inhibition of TGF-β/Smad signaling pathway

Purpose

Liver fibrosis is a worldwide health issue. Development of effective new drugs for treatment of this disease is of great importance. This study investigated the therapeutic effects of ferulic acid on liver fibrosis in vitro and in vivo.

Materials and methods

Human hepatic stellate cell line (HSC) LX-2 was used for in vitro assays. Transforming growth factor β1 (TGF-β1) was used to induce hepatic fibrosis in LX-2 cells. Western blot was used to detect protein levels of collagen I, fibronectin, α-smooth muscle actin (SMA), p-Smad2, p-Smad3, p-p38, and p-JNK. Gene expression was measured by RT-qPCR. Fluorescence staining was used to determine localization of Smad4. CCl4-induced hepatic fibrosis in SD rats was used as an in vivo model. Histological features were detected by hematoxylin and eosin staining. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hexadecenoic acid (HA), and hydroxyproline (Hyp) were measured by ELISA.

Results

TGF-β1 treatment significantly increased levels of collagen I, fibronectin, α-SMA, p-Smad2, p-Smad3, and Smad4 in LX-2 cells. Ferulic acid improved TGF-β1-induced hepatic fibrosis via regulation of the TGF-β1/Smad pathway. Consistent with in vitro data, CCl4 caused severe hepatic fibrosis in SD rats, as determined by ALT, AST, HA, and Hyp upregulation. Protein levels of p-Smad2 and p-Smad3 in liver tissues were significantly increased following treatment with CCl4. All CCL4-induced changes were markedly attenuated by ferulic acid treatment.

Conclusion

Ferulic acid potently improved hepatic fibrosis via inhibition of the TGF-β1/Smad pathway in vitro and in vivo. These findings provided evidence for potential use of ferulic acid to treat or prevent liver fibrosis.

Genetic polymorphisms in bone morphogenetic protein receptor type IA gene predisposes individuals to ossification of the posterior longitudinal ligament of the cervical spine via the smad signaling pathway

Background

The present study investigated the molecular mechanisms underlying the 4A > C and -349C > T single nucleotide polymorphisms (SNPs) in bone morphogenetic protein receptor type IA (BMPR-IA) gene, which significantly associated with the occurrence and the extent of ossification of the posterior longitudinal ligament (OPLL) in the cervical spine.

Methods

The SNPs in BMPR-IA gene were genotyped, and the association with the occurrence and severity of OPLL were evaluated in 356 OPLL patients and 617 non-OPLL controls. In stably transfected mouse embryonic mesenchymal stem cells (C3H10T1/2), the expression levels of the BMPR-IA gene and Smad4 protein as well as phosphorylated Smad1/5/8 were detected by Western blotting. In addition, the alkaline phosphatase (ALP) and osteocalcin (OC) activity of osteogenesis specificity protein was assessed using the ALP quantitation and osteocalcin radioimmunoassay kit, respectively.

Results

The 4A > C and the -349C > T polymorphisms of BMPR-IA gene were significantly associated with the development of OPLL in the cervical spine. The C allele type in 4A > C polymorphism significantly increases the occurrence and the extent of OPLL. The T allele type in -349C > T polymorphism significantly increases the susceptibility to OPLL, but not the extent of OPLL. The current results further validate our previous observations. The expression levels of BMPR-IA gene were significantly increased in pcDNA3.1/BMPR-IA (mutation type, MT -349C > T; MT 4A > C; MT -349C > T and 4A > C) vector-transfected C3H10T1/2 cells compared to the wild type (WT) vector-transfected cells. The levels of phosphorylated Smad1/5/8 and ALP activity were significantly increased in pcDNA3.1/BMPR-IA (MT -349C > T) vector-transfected C3H10T1/2 cells compared to the WT vector-transfected cells. However, no significant differences were observed in the protein levels of phosphorylated Smad1/5/8 and the ALP activity between MT A/C and WT vector-transfected cells. In addition, no significant differences were observed in the Smad4 protein levels among the experimental groups, as well as in the OC activity between WT vector-transfected and MT C/T, MT A/C, MT C/T and MT A/C vector-transfected cells.

Conclusions

Our results suggest that Smad signaling pathway may play important roles in the pathological process of OPLL induced by SNPs in BMPR-IA gene. These results will help to clarify the molecular mechanisms underlying the SNP and gene susceptibility to OPLL.

Expression and prognostic value of glutamate dehydrogenase in extrahepatic cholangiocarcinoma patients

Glutamate dehydrogenase (GDH) produces a precursor to glutathione, an important molecule in maintaining cellular redox balance and the cancerous characteristics of tumor cells through intracellular signaling pathways. However, the underlying molecular mechanisms linking glutamate dehydrogenase and extrahepatic cholangiocarcinoma have not been elucidated yet. Herein, we examined GDH expression levels and evaluated its potential correlations with prognosis. Meanwhile, the therapeutic value of GDH targeting the Smad pathways in extrahepatic cholangiocarcinoma was explored. Immunohistochemical studies revealed that GDH expression level was correlated to CD34 expression, cellular differentiation, the presence or absence of capsular and vascular invasion, lymph node metastasis, neural invasion and patient age. Kaplan-Meier survival analysis and COX proportional hazards models demonstrated that the prognosis was closely associated with GDH expression, CD34 positivity, nerve infiltration and cell differentiation. GDH silencing significantly reduced the proliferation, migratory potential and invasive capability. We also demonstrated that GDH promoted cell proliferation and metastasis potentially through Smad-mediated induction of TGF-β signaling pathway. Therefore, GDH may be an important prognostic indicator and may provide a new target for novel treatments of extrahepatic cholangiocarcinoma.

Bone mesenchymal stem cell-conditioned medium induces the upregulation of Smad6, which inhibits the BMP-4/Smad1/5/8 signaling pathway

OBJECTIVES

In this study, we aimed to investigate the effect of bone mesenchymal stem cells (BMSCs) conditioned medium on BMP4-induced activation of the Smad signaling pathway during the process of neural stem cells differentiation.

METHODS

We designed four experimental groups: (A) control group, (B) BMP-4 treatment group, (C) BMSC-CM group, and (D) BMSC-CM (BMSC-conditioned medium) combined with BMP-4 group. The expression of microtube-associated protein-2 (MAP-2) detected by immunocytochemical staining and western blot. The expression of glial fibrillary acidic protein (GFAP) and BMP receptors (BMPRII and BMPRIa) was determined by western blot, while SMAD1/5/8 and SMAD6 mRNA expression was detected by quantitative real-time polymerase chain reaction (Q-RT-PCR).

RESULTS

We found that the expression of microtube-associated protein-2 (MAP-2) increased in group B compared to group A. In group C, the expression of GFAP was increased and the expression of MAP-2 was decreased compared to group A. This phenomenon was weaker in group D. We also demonstrated that BMSC-CM could inhibit the activation of BMP signaling by downregulating the expression of BMPRII and BMPRIa proteins. Moreover, BMSC-CM could upregulate the expression of Smad6 mRNA and inhibit the activation of Smad1/5/8 mRNA.

CONCLUSION

These observations suggest that BMSC-CM could neutralize the effect of BMP-4 on the differentiation of NSCs by upregulating the expression of Smad6 and decrease the expression of GFAP by inhibiting the BMP-4-SMAD1/5/8 signaling pathway, conversely increasing the generation of neurons.

Involvement of Ras GTPase-activating protein SH3 domain-binding protein 1 in the epithelial-to-mesenchymal transition-induced metastasis of breast cancer cells via the Smad signaling pathway

In situ models of epithelial-to-mesenchymal transition (EMT)-induced carcinoma develop into metastatic carcinoma, which is associated with drug resistance and disease recurrence in human breast cancer. Ras GTPase-activating protein SH3 domain-binding protein 1 (G3BP1), an essential Ras mediator, has been implicated in cancer development, including cell growth, motility, invasion and apoptosis. Here, we demonstrated that the upregulation of G3BP1 activates the EMT in breast cancer cells. Silencing Smads almost completely blocked this G3BP1-induced EMT, suggesting that this process depends on the Smad signaling pathway. We also found that G3BP1 interacted with the Smad complex. Based on these results, we proposed that G3BP1 might act as a novel co-factor of Smads by regulating their phosphorylation status. Moreover, knockdown of G3BP1 suppressed the mesenchymal phenotype of MDA-MB-231 cells in vitro and suppressed tumor growth and lung metastasis of 4T1 cells in vivo. Our findings identified a novel function of G3BP1 in the progression of breast cancer via activation of the EMT, indicating that G3BP1 might represent a potential therapeutic target for metastatic human breast cancer.

Magnesium modification up-regulates the bioactivity of bone morphogenetic protein-2 upon calcium phosphate cement via enhanced BMP receptor recognition and Smad signaling pathway

Efficient presentation of growth factors is one of the great challenges in tissue engineering. In living systems, bioactive factors exist in soluble as well as in matrix-bound forms, both of which play an integral role in regulating cell behaviors. Herein, effect of magnesium on osteogenic bioactivity of recombinant human bone morphogenetic protein-2 (rhBMP-2) was investigated systematically with a series of Mg modified calcium phosphate cements (xMCPCs, x means the content of magnesium phosphate cement wt%) as matrix model. The results indicated that the MCPC, especially 5MCPC, could promote the rhBMP-2-induced in vitro osteogenic differentiation via Smad signaling of C2C12 cells. Further studies demonstrated that all MCPC substrates exhibited similar rhBMP-2 release rate and preserved comparable conformation and biological activity of the released rhBMP-2. Also, the ionic extracts of MCPC made little difference to the bioactivity of rhBMP-2, either in soluble or in matrix-bound forms. However, with the quartz crystal microbalance (QCM), we observed a noticeable enhancement of rhBMP-2 mass-uptake on 5MCPC as well as a better recognition of the bound rhBMP-2 to BMPR IA and BMPR II. In vivo results demonstrated a better bone regeneration capacity of 5MCPC/rhBMP-2. From the above, our results demonstrated that it was the Mg anchored on the underlying substrates that tailored the way of rhBMP-2 bound on MCPC, and thus facilitated the recognition of BMPRs to stimulate osteogenic differentiation. The study will guide the development of Mg-doped bioactive bone implants for tissue regeneration.

ESC reverses epithelial mesenchymal transition induced by transforming growth factor-β via inhibition of Smad signal pathway in HepG2 liver cancer cells

Background

Epithelial mesenchymal transition (EMT) mediated by TGF-β pays an important role in malignant tumor acquired abilities of migration and invasion. Our previous study showed that the extract of Stellera chamaejasme L. (ESC) was against proliferation of a variety of tumor cells, but there were no studies in the effects of ESC on EMT in tumor cells. In this study, TGF-β was adopted to induce EMT in HepG2 cells and the influence of ESC on EMT was observed.

Methods

MTT assay was used to observe the cell viability. Wound healing assay and transwell assay were used to observe the migration and invasion activities. Western blot and immunofluorescence methods were used to observe the expression of proteins.

Results

We found that HepG2 cells induced by TGF-β showed mesenchymal morphology, down-regulation of epithelial marker E-cadherin and up-regulation of mesenchymal marker Vimentin, indicating that TGF-β could mediate epithelial mesenchymal induction in HepG2 cells. ESC could reverse the mesenchymal morphology and regulate expressions of marker proteins in HepG2 induced by TGF-β and significantly inhibit TGF-β induced HepG2 cell migration and invasion. We further found that ESC could also significantly depress Smad2 phosphorylation and nuclear translocation, and ESC had coordination with SB432542, a specific inhibitor of TβRI kinases.

Conclusions

These results suggested that the ESC could reverse epithelial mesenchymal transition induced by TGF-β via inhibition Smad2 signaling pathway.

Vitamin D analog EB1089 could repair the defective bone marrow-derived mesenchymal stromal cells in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) involves multiple factors, which result in the breakdown of self-tolerance and development of autoimmunity with organ damage. Bone marrow mesenchymal stem cells (BMMSCs) from the patients with SLE showed an impaired proliferative capacity compared with that from normal controls. In this study, we isolated BMMSCs from the patients with SLE and found that Vitamin D analog EB1089 could induce BMMSCs proliferation and mineralization deposition. Furthermore, we found that the expression of p-Smad 1/5/8 was promoted in BMMSCs with EB1089 treatment. In conclusion, our results support the notion that EB1089 promoted proliferation and osteogenic differentiation of BMMSCs by Smad 1/5/8 signaling pathway.

Effects of traditional Chinese medicine Ganyanping on TGFβ1/Smad signaling pathway in carbon tetrachloride-induced hepatic fibrosis of rats

AIM: To study the effects of Ganyanping on the experimental hepatic fibrosis induced by carbon tetrachloride (CCl₄) in rats, and to explore its anti-fibrotic molecular mechanism.

METHODS: Thirty-eight healthy Wistar rats were randomly divided into normal control (N), model control (A), and Ganyanping therapeutic group (B). The rats in group N was treated with normal saline by intragastrical irrigation, and those in group A and B were subcutaneous injected with CCl₄ to establish hepatic fibrosis model. Four weeks later, the animas in group B were treated with Ganyanping (10 L/g) and those in group A were treated with normal saline by intragastrical irrigation at the same time. The histological changes of the liver tissues were examined by pathological examination. The protein expression of transforming growth factor beta 1 (TGFβ₁) and its receptors (TβRⅠ and TβRⅡ) were measured by immunohistochemical technique. The changes of Smad3, Smad7 and Col1a2 mRNA expression were observed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS: The levels of TGFβ₁, TβRT, TβRU, Smad3 and Col1a2 expression were elevated, and that of Smad7 was reduced in the model rats. In comparison with those in group A, the levels of TGFβ₁ and its receptors protein expression in group B were significantly decreased after treatment with Ganyanping (TGFβ₁: 4.18 ± 0.17 vs 4.30 ± 0.16, P < 0.05; TβRⅠ: 4.24 ± 0.10 vs 4.35 ± 0.14, P < 0.05; TβRⅡ: 4.27 ± 0.08 vs 4.37 ± 0.11, P < 0.05). Meanwhile, the levels of Smad3 and Col1a2 mRNA expression were also down-regulated (Smad3: 0.90 ± 0.41 vs 0.93 ± 0.05, P < 0.05; Col1a2: 0.92 ± 0.03 vs 0.95 ± 0.03, P < 0.05). However, the level of Smad7 mRNA expression was significantly up-regulated (0.87 ± 0.03 vs 0.84 ± 0.05, P < 0.05). The pathological changes of liver tissues in group B were also markedly alleviated.

CONCLUSION: Ganyanping has significant inhibitory effects on CCl₄-induced hepatic fibrosis in rats, and its mechanism may be associated with the inhibition of TGFβ₁ and its receptors protein expression, down-regulation of Smad3 mRNA expression and up-regulation of Smad7 mRNA expression.