TMED3 stabilizes SMAD2 by counteracting NEDD4-mediated ubiquitination to promote ovarian cancer

Ovarian cancer is a major cause of death among cancer patients. Recent research has shown that the transmembrane emp24 domain (TMED) protein family plays a role in the progression of various types of cancer. In this study, we investigated the expression of TMED3 in ovarian cancer tumors compared to nontumor tissues using immunohistochemical staining. We found that TMED3 was overexpressed in ovarian cancer tumors, and its high expression was associated with poor disease-free and overall survival. To understand the functional implications of TMED3 overexpression in ovarian cancer, we conducted experiments to knockdown TMED3 using short hairpin RNA (shRNA). We observed that TMED3 knockdown resulted in reduced cell viability and migration, as well as increased cell apoptosis. Additionally, in subcutaneous xenograft models in BALB-c nude mice, TMED3 knockdown inhibited tumor growth. Further investigation revealed that SMAD family member 2 (SMAD2) was a downstream target of TMED3, driving ovarian cancer progression. TMED3 stabilized SMAD2 by inhibiting the E3 ligase NEDD4-mediated ubiquitination of SMAD2. To confirm the importance of SMAD2 in TMED3-mediated ovarian cancer, we performed functional rescue experiments and found that SMAD2 played a critical role in this process. Moreover, we discovered that the PI3K-AKT pathway was involved in the promoting effects of TMED3 overexpression on ovarian cancer cells. Overall, our study identifies TMED3 as a prognostic indicator and tumor promoter in ovarian cancer. Its function is likely mediated through the regulation of the SMAD2 and PI3K-AKT signaling pathway. These findings contribute to our understanding of the molecular mechanisms underlying ovarian cancer progression and provide potential targets for therapeutic intervention.

Protective effect and regulatory mechanism of salidroside on skin inflammation induced by imiquimod in psoriasis mice

Salidroside (SAL) is a glucoside of tyrosol commonly existing in the roots of Rhodiola rosea. This study unveils the protective effect of SAL on skin inflammation in imiquimod (IMQ)-induced psoriasis. The mouse model of psoriasis was established by local application of IMQ, and SAL efficacy was evaluated through PASI scoring, H&E staining, and skin tissue pathology observation. The HaCaT cell model was established by interferon (IFN)-γ induction, followed by MTT assay detection of cell viability, detection of ROS, SOD, MDA, and CAT levels in skin tissues and cells using reagent kits, ELISA detection of inflammatory factors (TNF-α, IL-6, IL-1β), and qRT-PCR detection of psoriasis-related genes (S100a9, Cxcl1, Cxcl2) as well as miR-369-3p and SMAD2 expressions. The binding relationship between miR-369-3p and SMAD2 was validated using dual-luciferase reporter assay. SAL treatment reduced PASI scores and alleviated psoriasis symptoms of IMQ-induced mice, and also augmented the viability and subsided the oxidative stress and inflammation of IFN-γ-treated HaCaT cells. SAL treatment restrained miR-369-3p expression but elevated SMAD2 expression. Mechanistically, miR-369-3p targeted SMAD2 expression. miR-369-3p overexpression or SMAD2 inhibition partially offset the alleviating effect of SAL on psoriasis skin inflammation. In conclusion, SAL alleviates skin inflammation in IMQ-induced psoriasis mice via the miR-369-3p/SMAD2 axis.

Porcine platelet lysates exert the efficacy of chondroregeneration and SMAD2-mediated anti-chondrofibrosis on knee osteoarthritis

BACKGROUND

The lack of self-repairability in cartilage and the formation of fibrocartilage pose significant challenges in treating knee osteoarthritis, and there is still no ideal solution. Autologous platelet lysates have been clinically applied to treat kOA and exert satisfactory cartilage-repair efficacy, but the preparation of human PL brings damage to patients and is hardly standardized.

METHODS

In this study, porcine PL was developed to replace hPL, and its chondroregenerative and anti-chondrofibrosis effects were explored. Enzyme-Linked Immunosorbent Assay was applied to qualify the PL products. In vivo, partial-thickness cartilage defects were created on rats as a kOA model, and the von Frey test, histopathological observation, immunohistochemical analysis, and western blot analysis were conducted. In vitro, CCK-8 assay, real-time PCR analysis, immunofluorescence test, and WB analysis were conducted for the mechanism study of pPL.

RESULTS

The in vivo data showed that pPL significantly repaired the cartilage defect by improving matrix synthesis and also ameliorated the pain response in the kOA model of rats. In addition, pPL exerted an anti-fibrosis effect on cartilage by suppressing the expressions of COL1, COL3, α-SMA, VIMENTIN, SMAD2, p-SMAD2, and CTGF in cartilage. The in vitro data verified these effects and indicated that the SMAD2 pathway mediated the anti-fibrosis mechanism of pPL. Moreover, the comparable effects between pPL and rat PL indicate that there is no immune rejection from pPL.

CONCLUSIONS

This study firstly demonstrated the anti-kOA effects of pPL on both cartilage-repair and anti-chondrofibrosis. It developed pPL as a promising alternative to autologous PL for clinical applications.

Cyclophosphamide activates ferroptosis induced dysfunction of Leydig cells via SMAD2 pathway

Cyclophosphamide (CP) is a widely used chemotherapeutic drug and immunosuppressant in the clinic, and the hypoandrogenism caused by CP is receiving more attention. Some studies found that ferroptosis is a new mechanism of cell death closely related to chemotherapeutic drugs and plays a key role in regulating reproductive injuries. The purpose of this study is to explore ferroptosis' role in testicular Leydig cell dysfunction and molecular mechanisms relating to it. In this study, The level of ferroptosis in the mouse model of testicular Leydig cell dysfunction induced by CP was significantly increased and further affected testosterone synthesis. The ferroptosis inhibitors ferrostatin-1and iron chelator deferoxamine can improve injury induced by CP. The results of immunohistochemistry showed that ferrostatin-1 and deferoxamine could improve the structural disorder of seminiferous tubules and the decrease of the number of Leydig cells in testicular tissue induced by CP. Immunofluorescence and western blot confirmed that ferrostatin-1and deferoxamine could improve the expression of key enzymes in testosterone synthesis. The activation of Smad2 (SMAD family member 2)/Cdkn1a (cyclin-dependent kinase inhibitor 1A) pathway can improve the ferroptosis of Leydig cells induced by CP and protect the function of Leydig cells. By inhibiting the Smad2/Cdkn1a signal pathway, CP can regulate ferroptosis, resulting in testicular Leydig cell dysfunction. In this study, CP-induced hypoandrogenism is explained theoretically and a potential therapeutic strategy is provided.

Urinary extracellular vesicles prevent di-(2-ethylhexyl) phthalate-induced hypospadias by facilitating epithelial-mesenchymal transition via PFN2 delivery

BACKGROUND

Urinary extracellular vesicles (EVs) have gained increasing interest in recent years as a potential source of noninvasive biomarkers of diseases related to urinary organs, but knowledge of the mechanism is still limited. The current study sought to clarify the mechanism of urinary EVs behind di-(2-ethylhexyl) phthalate (DEHP)-induced hypospadias via PFN2 delivery.

METHOD

PFN2 expression in hypospadias was predicted by bioinformatics analysis. Following the induction of a hypospadias rat model using DEHP, rats were injected with EVs and/or underwent alteration of PFN2 and TGF-β1 to assess their effects in vivo. The extracted rat urothelial cells (UECs) were co-cultured with EVs extracted from urine for in vitro experiments.

RESULT

Microarray analysis predicted poor PFN2 expression in hypospadias. Upregulated PFN2 was found in urinary EVs, and restrained epithelial-mesenchymal transition (EMT) was observed in DEHP-exposed rats. Urinary EVs or PFN2 overexpression increased SMAD2, SMAD3, and TGF-β1 protein expression and SMAD2 and SMAD3 phosphorylation in UECs and DEHP-exposed rats. UEC migration, invasion, and EMT were augmented by EV co-culture or upregulation of PFN2. Of note, the silencing of TGF-β1 counterweighed the effect of PFN2. Besides, EV co-culture or overexpression of PFN2 or TGF-β1 elevated the body weight, anal-genital distance (AGD), anal-genital index (AGI), and EMT of DEHP-exposed rats.

CONCLUSION

In summary, urinary EVs activated the SMAD/TGF-β1 pathway to induce EMT via PFN2 delivery, thus protecting against DEHP-induced hypospadias. (1) EMT in epithelial cells inhibits DEHP-induced hypospadias. (2) Urine-derived EVs deliver PFN2 to promote EMT in epithelial cells. (3) PFN2 can activate the SMAD/TGF-β1 signaling axis. (4) Urine-derived EVs can transmit PFN2 to activate the SMAD/TGF-β1 signaling axis, thus promoting EMT and inhibiting the occurrence of hypospadias.

TGF-β phospho antibody array identifies altered SMAD2, PI3K/AKT/SMAD, and RAC signaling contribute to the pathogenesis of myxomatous mitral valve disease

Background

TGFβ signaling appears to contribute to the pathogenesis of myxomatous mitral valve disease (MMVD) in both dogs and humans. However, little is known about the extent of the downstream signaling changes that will then affect cell phenotype and function in both species.

Objective

Identify changes in downstream signals in the TGFβ pathway in canine MMVD and examine the effects of antagonism of one significant signal (SMAD2 was selected).

Materials and methods

Canine cultures of normal quiescent valve interstitial cells (qVICs) and disease-derived activated myofibroblasts (aVICs) (n = 6) were examined for TGFβ signaling protein expression using a commercial antibody array. Significant changes were confirmed, and additional proteins of interest downstream in the TGFβ signaling pathway and markers of cell phenotype were examined (PRAS40, S6K, elF4E IRS-1, αSMA, and VIM), using protein immunoblotting. RT-PCR examined expression of gene markers of VIC activation (ACTA2, TAGLN, and MYH10; encoding the proteins αSMA, SM22, and Smemb, respectively). Attenuation of pSMAD2 in aVICs was examined using a combination of RNA interference technology (siRNA) and the SMAD7 (antagonizes SMAD2) agonist asiaticoside.

Results

The antibody array identified significant changes (P < 0.05) in 19 proteins, of which six were phosphorylated (p). There was increased expression of pSMAD2 and pRAC1 and decreased expression of pmTOR, pERK1/2, and pAKT1. Expression of pPRAS40 and pIRS-1 was increased, as was the mTOR downstream transcription factor pS6K, with increased expression of peIF4E in aVICs, indicating negative feedback control of the PI3K/AKT/mTOR pathway. SMAD2 antagonism by siRNA and the SMAD7 agonist asiaticoside decreased detection of pSMAD by at least 50%, significantly decreased expression of the aVIC gene markers ACTA2, TAGLN, and MYH10, and pαSMA, pAKT2, and pERK1, but had no effect on pS6K, pERK2, or pVIM expression in aVICs. SMAD2 antagonism transitioned diseased aVICs to normal qVICs, while maintaining a mesenchymal phenotype (VIM+) while concurrently affecting non-canonical TGFβ signaling.

Conclusion

MMVD is associated with changes in both the canonical and non-canonical TGFβ signaling pathway. Antagonism of SMAD2 transitions diseased-activated myofibroblasts back to a normal phenotype, providing data that will inform studies on developing novel therapeutics to treat MMVD in dogs and humans.

Activin A/ACVR2A axis inhibits epithelial-to-mesenchymal transition in colon cancer by activating SMAD2

Colorectal cancer is one of the most common malignancies worldwide. Liver metastasis is the major direct cause of colorectal cancer-related deaths. Although radical resection is the most effective treatment for colorectal cancer liver metastasis, several patients are not eligible for surgery. Therefore, there is a need to develop novel treatments based on the understanding of the biological mechanisms underlying liver metastasis in colorectal cancer. This study demonstrated that activin A/ACVR2A inhibits colon cancer cell migration and invasion, as well as suppresses the epithelial-to-mesenchymal transition of mouse colon cancer cells. This finding has been further validated in animal experiments. Mechanistic studies revealed that activin A binds to Smad2 (instead of Smad3) and activates its transcription. Analysis of the paired clinical samples further confirmed that the expression levels of ACVR2A and SMAD2 were the highest in adjacent healthy tissues, followed by primary colon cancer tissues and liver metastasis tissues, suggesting that ACVR2A downregulation may promote colon cancer metastasis. Bioinformatics analysis and clinical studies demonstrated that ACVR2A downregulation was significantly associated with liver metastasis and poor disease-free and progression-free survival of patients with colon cancer. These results suggest that the activin A/ACVR2A axis promotes colon cancer metastasis by selectively activating SMAD2. Thus, targeting ACVR2A is a potential novel therapeutic strategy to prevent colon cancer metastasis.

Impact of SMAD2 and MET Expression on Lymph Node Metastasis of HER2-positive Gastric Cancer Cells

BACKGROUND/AIM

Intra-tumoral heterogeneity, which is frequently found in various types of cancers, has been suggested to play an important role in cancer progression and metastasis. The findings of our previous study suggested that p-SMAD2 and c-MET signaling might play important roles in the progression to lymph node metastasis of HER2-positive gastric cancer. In this study, we confirmed the effect of SMAD2/MET signaling in the progression of HER2-positive gastric cancer in an animal model.

MATERIALS AND METHODS

NCI-N87 cells over-expressing ERBB2, SMAD2, MET were used. To confirm the role of SMAD2 and MET expression on lymph node metastasis of gastric cancer, we orthotopically injected NCI-N87 cells with or without the knockdown of both SMAD2 and MET into the gastric walls of BALBc nude mice.

RESULTS

The number of metastatic lymph nodes was significantly smaller in the knockdown group compared to that in the control group. However, there was no significant difference in gastric tumor size between the two groups.

CONCLUSION

SMAD2 and MET signaling might play important roles specifically in the progression to lymph node metastasis of HER2-positive gastric cancer. c-MET and SMAD2 may be useful targets for preventing lymph node metastasis in patients with HER2-positive gastric cancer.

SMAD2 inhibits pyroptosis of fibroblast-like synoviocytes and secretion of inflammatory factors via the TGF-β pathway in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease. Over-activation of fibroblast-like synoviocytes is responsible for the hyperplasia of synovium and destruction of cartilage and bone and pyroptosis of FLS plays a key role in those pathological processes during RA. This study investigated the detailed mechanisms that SMAD2 regulates the pyroptosis of FLS and secretion of inflammatory factors in rheumatoid arthritis.

METHODS

We collected synovial tissues of RA patients and FLS-RA and cultured FLS for detection of expression of SMAD2. ASC, NLRP3, cleaved-caspase-1, and GSDMD-N were detected by Western blot after overexpression of SMAD2. Besides, flow cytometry, electron microscope, ELISA, HE staining, and Safranin O staining were performed to further demonstrate that SMAD2 can affect the pyroptosis of FLS-RA.

RESULTS

The expression of SMAD2 was down-regulated in synovial tissues of RA patients and FLS-RA. Overexpression of SMAD2 can inhibit the expression of ASC, NLRP3, cleaved-caspase-1, and GSDMD-N. Flow cytometry and electron microscope further demonstrated that SMAD2 attenuated pyroptosis of FLS-RA. In addition, overexpression of SMAD2 also inhibited inflammatory factors such as IL-1β, IL-18, IL-6, and IL-8 secretion and release of LDH. Besides, overexpression of SMAD2 can reverse the decrease of p-SMAD2 and TGF-TGF-β induced by nigericin. In vivo experiments on CIA rats further demonstrated that overexpression of SMAD2 by local intra-articular injection of LV-SMAD2 can effectively alleviate joint redness, swelling, and destruction of cartilage and bones.

CONCLUSION

SMAD2 inhibited FLS-RA pyroptosis by down-regulating of NLRP3 inflammasomes (NLRP3, ASC, and caspase-1 complex) and eased the secretion of inflammatory factors via the TGF-β signaling pathway, thereby improving the symptom of RA. We hope that this study may provide a new research idea for RA and a potential target for the treatment of RA.

Pan-integrin inhibitor GLPG-0187 promotes T-cell killing of mismatch repair-deficient colorectal cancer cells by suppression of SMAD/TGF-β signaling

Colorectal cancer is the third leading cause of cancer-related death and the third most common cause of cancer. As the five-year survival with advanced metastatic colorectal cancer (mCRC) is 14%, new treatment strategies are needed. Immune checkpoint blockade, which takes advantage of an individual's immune system to fight cancer, has an impact in the clinic; however, for CRC, it is only effective and approved for treating mismatch repair (MMR)-deficient cancer. Moreover, long-term outcomes in MMR-deficient mCRC suggest that most patients are not cured and eventually develop therapy resistance. We hypothesized that targeting TGF-β signaling may enhance immune-mediated T-cell killing by MMR-deficient CRC cells. Using GLPG-0187, an inhibitor of multiple integrin receptors and TGF-β, we demonstrate minimal cytotoxicity against MMR-deficient HCT116 or p53null HCT116 human CRC cells. GLPG-0187 promoted significant immune cell killing of the CRC cells by TALL-104 T lymphoblast cells and reduced phosphoSMAD2 in HCT116 p53-null cells either in the absence or presence of exogenous TGF-β. We observed a reduction in CCL20, CXCL5, prolactin, and TRAIL-R3, while GDF-15 was increased in TALL-104 cells treated with a T-cell activating dose of GLPG-0187 (4 µM). Our results suggest that TGF-β signaling inhibition by a general integrin receptor inhibitor may boost T-cell killing of MMR-deficient colorectal cancer cells and suggest that a combination of anti-GDF-15 in combination with TGF-β blockade be further investigated in the treatment of MMR-deficient mCRC. Our results support the development of a novel immune-based therapeutic strategy to treat colorectal cancer by targeting the TGF-β signaling pathway through integrin receptor blockade.

The SMAD2/miR-4256/HDAC5/p16INK4a signaling axis contributes to gastric cancer progression

The dysregulation of exosomal microRNAs (miRNAs) plays a crucial role in the development and progression of cancer. This study investigated the role of a newly identified serum exosomal miRNA miR-4256 in gastric cancer (GC) and the underlying mechanisms. The differentially expressed miRNAs were firstly identified in serum exosomes of GC patients and healthy individuals using next-generation sequencing and bioinformatics. Next, the expression of serum exosomal miR-4256 was analyzed in GC cells and GC tissues, and the role of miR-4256 in GC was investigated by in vitro and in vivo experiments. Then, the effect of miR-4256 on its downstream target genes HDAC5/p16^INK4a was studied in GC cells, and the underlying mechanisms were evaluated using dual luciferase reporter assay and Chromatin Immunoprecipitation (ChIP). Additionally, the role of the miR-4256/HDAC5/p16^INK4a axis in GC was studied using in vitro and in vivo experiments. Finally, the upstream regulators SMAD2/p300 that regulate miR-4256 expression and their role in GC were explored using in vitro experiments. miR-4256 was the most significantly upregulated miRNA and was overexpressed in GC cell lines and GC tissues; in vitro and in vivo results showed that miR-4256 promoted GC growth and progression. Mechanistically, miR-4256 enhanced HDAC5 expression by targeting the promoter of the HDAC5 gene in GC cells, and then restrained the expression of p16^INK4a through the epigenetic modulation of HDAC5 at the p16^INK4a promoter. Furthermore, miR-4256 overexpression was positively regulated by the SMAD2/p300 complex in GC cells. Our data indicate that miR-4256 functions as an oncogene in GC via the SMAD2/miR-4256/HDAC5/p16^INK4a axis, which participates in GC progression and provides novel therapeutic and prognostic biomarkers for GC.

Interaction of C/EBPβ with SMAD2 and SMAD4 genes induces the formation of lipid droplets in bovine myoblasts

As a key component of Transforming growth factor-β (TGF-β) pathway, Smad2 has many crucial roles in a variety of cellular processes, but it cannot bind DNA without complex formation with Smad4. In the present study, the molecular mechanism in the progress of myogenesis underlying transcriptional regulation of SMAD2 and SMAD4 had been clarified. The result showed the inhibition between SMAD2 and SMAD4, which promotes and inhibits bovine myoblast differentiation, respectively. Further, the characterization of promoter region of SMAD2 and SMAD4 was analyzed, and identified C/EBPβ directly bound to the core region of both SMAD2 and SMAD4 genes promoter and stimulated the transcriptional activity. However, C/EBPβ has lower expression in myoblasts which plays vital function in the transcriptional networks controlling adipogenesis, while the overexpression of C/EBPβ gene in myoblasts significantly increased SMAD2 and SMAD4 gene expression, induced the formation of lipid droplet in bovine myoblasts, and promoted the expression of adipogenesis-specific genes. Collectively, our results showed that C/EBPβ may play an important role in the trans-differentiation and dynamic equilibrium of myoblasts into adipocyte cells via promoting an increase in SMAD2 and SMAD4 gene levels. These results will provide an important basis for further understanding of the TGFβ pathway and C/EBPβ gene during myogenic differentiation.

LINC01232 promotes lung squamous cell carcinoma progression through modulating miR-181a-5p/SMAD2 axis

BACKGROUND

LINC01232 has been implicated in the progression of multiple malignancies. Yet, the function of LINC01232 in the carcinogenesis of lung squamous cell carcinoma (LUSC) remains unclear. This study aims to examine the role LINC01232 plays in LUSC progression.

METHODS

mRNA and protein levels were assessed using qRT-PCR and western blot, respectively. Cell proliferation was assessed by CCK-8 and colony formation assays. Cell migration and invasion were evaluated by transwell assay. The interactions between LINC01232, miR-181a-5p, and SMAD2 were assessed using luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays. The subcellular distribution of LINC01232 was examined by cytosolic/nuclear fractionation assay RESULTS: LINC01232 was upregulated in both LUSC tissues and cell lines. Knockdown of LINC01232 impaired cell proliferation, migration and invasion capability in H1229 and A549 cells, a phenotype that could be reversed by miR-181a-5p silencing. In addition, LINC01232 silencing reduced levels of N-cadherin, Vimentin, and Snail in H1229 and A549 cells, but increased the level of E-cadherin, which can be abrogated by miR-181a-5p inhibitors.

CONCLUSIONS

In summary, our study demonstrates that LINC01232 expression increases in LUSC tissues and cell lines and promotes LUSC progression by modulating the miR-181a-5p/SMAD2 signaling, providing new potential drug targets for LUSC treatment.

Increase in transforming growth factor-β didnot affect trombospondin1 in preeclampsia placentas

Objective

The abnormalities of the placental growth process are a theory causing pre-eclampsia. Antiangiogenic factors contributed to it, such as thrombospondin-1 (TSp-1) that could stimulate transforming growth factor-beta (TGF-β), or vice versa. Some research showed that an increase in TGF-β did not always figurized its signaling. Therefore, we conducted a study to examine the TGF-β signaling proteins through its receptors and TSp-1 expression in preeclampsia placentas.

Materials and Methods

This observational study used 33 normal and 33 pre-eclampsia placental storaged samples, for examination of TGF-β and TGF-βR 1 and 2, SMAD2 using ELISA, and SMAD2 and TSp-1 mRNA using the reverse transcription polymerase chain reaction method. Data were analyzed using SPSS version 20.0, normality test by Kolmogorov-Smirnov, and significancy was analyzed using nonparametric Mann-Whitney test, or t-test for parametric, with confidence interval 95%. Spearman correlation was used for non-parametric data, besides the Pearson correlation for parametric data.

Results

Results showed that there were significant differences between preeclampsia and normal placenta in TGF-β, its receptors, SMAD2, and TSp-1 mRNA. Normal-TGF-β=1.19 (0.713-2.051) pg/mg; preeclampsia-TGFB=2.69 (0.906-10.252) pg/mg; p=0.001; normal-TGFBR1=1.025 (0.622-1.402) ng/mg; preeclampsia-TGFBR1=1.223 (0.372-2.553) ng/mg; p=0.004; Normal-TGF-βR2=0.959 (0.644-1.634) pg/mg; preeclampsia-TGFBR2=1.490 (0.775-3.645) pg/mg; p=0.0001; normal-SMAD2=2.087 (1.279-4.300) ng/mg; preeclampsia-SMAD2=3.508 (1.842-22.489) ng/mg; p=0.0001. The SMAD2 mRNA relative expression (Livax) in the normal placenta was=0.71 (0.03-7.25); pre-eclampsia placenta (PE)=0.49 (0.01-40.71); p=0.075, the normal TSp-1 mRNA expression=1.08 (0.09-5.31); PE=0.21 (0.002-24.06); p=0.002. The correlation test showed a strong correlation between TGF-β with TGFBR1 and 2 in the normal placenta, conversely, there was no correlation in the preeclampsia placenta. There was also no correlation between SMAD2 and TSp-1 mRNA in both normal and pre-eclampsia.

Conclusion

TGF-β signaling in the preeclampsia placenta was changed due to the increased of the protein signaling it self without correlation between TGF-β to its receptors and TSp-1 relative expression.

Expression and Polymorphisms of SMAD1, SMAD2 and SMAD3 Genes and Their Association with Litter Size in Tibetan Sheep (Ovis aries)

SMAD1, SMAD2, and SMAD3 are important transcription factors downstream of the TGF-β/SMAD signaling pathway that mediates several physiological processes. In the current study, we used cloning sequencing, RT-qPCR, bioinformatics methods and iMLDR technology to clone the coding region of Tibetan sheep genes, analyze the protein structure and detect the tissue expression characteristics of Tibetan sheep genes, and detect the polymorphisms of 433 Tibetan sheep and analyze their correlation with litter size. The results showed that the ORFs of the SMAD1, SMAD2 and SMAD3 genes were 1398 bp, 1404 bp and 1278 bp, respectively, and encoded 465, 467 and 425 amino acids, respectively. The SMAD1, SMAD2, and SMAD3 proteins were all unstable hydrophilic mixed proteins. SMAD1, SMAD2 and SMAD3 were widely expressed in Tibetan sheep tissues, and all were highly expressed in the uterus, spleen, ovary and lung tissues. Litter sizes of the genotype CC in the SMAD1 gene g.10729C>T locus were significantly higher than that of CT (p < 0.05). In the SMAD3 gene g.21447C>T locus, the genotype TT individuals showed a higher litter size than the CC and CT genotype individuals (p < 0.05). These results preliminarily demonstrated that SMAD1, SMAD2 and SMAD3 were the major candidate genes that affected litter size traits in Tibetan sheep and could be used as a molecular genetic marker for early auxiliary selection for improving reproductive traits during sheep breeding.

Mangiferin promotes the osteogenic differentiation of human periodontal ligament stem cells via TGF‑β/SMAD2 signaling

Mangiferin (MAG) is a polyphenolic compound present in mangoes. This compound suppresses inflammation and decreases bone destruction. This study aimed to determine whether MAG directly promotes proliferation and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). Cell proliferation and osteogenic differentiation experiments were performed in hPDLSCs, and MAG was used as a stimulator during osteogenic induction. Alkaline phosphatase (ALP) activity and Alizarin red staining were analyzed, and the expression of osteogenesis‑associated genes was investigated by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis to determine the effect of MAG on the osteogenic differentiation of hPDLSCs. Galunisertib was used to selectively inhibit TGF‑β/SMAD2 signaling. Western blotting was performed to study the underlying mechanism. Cell Counting Kit‑8 assay showed that MAG did not promote the proliferation of hPDLSCs. MAG (200 µM) significantly promoted ALP activity, mRNA levels of alkaline phosphatase biomineralization associated, collagen type 1, and runt‑related transcription factor‑2, protein levels of SMAD5, alkaline phosphatase and bone morphogenetic protein 2 protein expression and mineralized nodule formation in hPDLSCs. Furthermore, MAG significantly promoted the phosphorylation of SMAD2. Galunisertib inhibited the activation of SMAD2 and partially reversed the MAG‑mediated promotion of hPDLSC osteogenic differentiation. These data indicated that MAG promoted osteogenic differentiation of hPDLSCs potentially through TGF‑β/SMAD2 signaling. Therefore, MAG may help improve periodontal bone loss.

Circ_0002623 promotes bladder cancer progression by regulating the miR-1276/SMAD2 axis

Circular RNAs (circRNAs) are key regulatory factors in the development of multiple cancers. This study is targeted at exploring the effect of circ_0002623 on bladder cancer (BCa) progression and its mechanism. Circ_0002623 was screened out by analyzing the expression profile of circRNAs in BCa tissues. Circ_0002623, miR-1276 and SMAD2 mRNA expression levels in clinical sample tissues and cell lines were detected through quantitative real-time polymerase chain reaction (qRT-PCR). After circ_0002623 was overexpressed or silenced in BCa cells, the cell proliferation, migration and cell cycle were evaluated by CCK-8, BrdU, Transwell assay and flow cytometry. Tumor xenograft model was used to validate the biological function of circ_0002623 in vivo. Bioinformatics analysis and dual-luciferase reporter gene assay were conducted for analyzing and confirming, respectively, the targeted relationship between circ_0002623 and miR-1276, as well as between miR-1276 and SMAD2. The regulatory effects of circ_0002623 and miR-1276 on the expression levels of TGF-β, WNT1 and SMAD2 in BCa cells were detected by Western blot. We reported that, in BCa tissues and cell lines, circ_0002623 was up-regulated, whereas miR-1276 was down-regulated. Circ_0002623 positively regulated BCa cell proliferation, migration and cell cycle progression. Additionally, circ_0002623 could competitively bind with miR-1276 to increase the expression of SMAD2, the target gene of miR-1276. Furthermore, circ_0002623 could regulate the expression of TGF-β and WNT1 via modulating miR-1276 and SMAD2. This study helps to better understand the molecular mechanism underlying BCa progression.

Long non-coding RNA SND1-IT1 accelerates cell proliferation, invasion and migration via regulating miR-132-3p/SMAD2 axis in retinoblastoma

Long noncoding RNAs (lncRNAs) have been identified as prognostic biomarkers and functional regulators in human tumors. In our study, we aim to investigate the roles of lncRNA SND1-IT1 (SND1-IT1) in retinoblastoma (RB). We observed that SND1-IT1 was highly expressed in both RB specimens and cells, and associated with poorer prognosis of RB patients. Functional investigation revealed that downregulation of SND1-IT1 suppressed RB cell proliferation, migration and invasion in vitro and restrained RB tumorigenesis in vivo. MiR-132-3p was predicted to interact with SND1-IT1. RT-qPCR and dual-luciferase reporter assays verified the regulation of miR-132-3p by SND1-IT1 in RB cells. In addition, SND1-IT1 enhanced the expression of SMAD2 by sponging miR-132-3p. Rescue experiments revealed that knockdown of miR-132-3p reversed the inhibiting effects of miR-132-3p knockdown on RB cells. Overall, SND1-IT1 can promote the progression of RB cells through miR-132-3p/SMAD2 axis, suggesting that l SND1-IT1 might be a novel biomarker and potential target for RB.

Circ_0000527 Drives Retinoblastoma Progression by Regulating miR-1236-3p/SMAD2 Pathway

PURPOSE

Circular RNAs (circRNAs) play essential roles in the progression of human tumors, including retinoblastoma (RB). In this study, we aimed to explore the functions and potential mechanisms of circ_0000527 in RB.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot assay and immunohistochemistry (IHC) assay were conducted to determine the levels of circ_0000527, microRNA-1236-3p (miR-1236-3p) and SMAD family member 2 (SMAD2). RNase R assay and actinomycin D assay were conducted to analyze the characteristic of circ_0000527. Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, and colony formation assay were performed for cell proliferation ability. Wound healing assay and transwell assay were applied to assess cell migration and invasion. Tube formation assay was utilized for angiogenesis ability. Flow cytometry analysis was adopted to analyze cell apoptosis. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to analyze the relationships among circ_0000527, miR-1236-3p, and SMAD2. Murine xenograft model assay was conducted for the role of circ_0000527 in vivo.

RESULTS

Circ_0000527 was overexpressed in RB patients and related to advanced TNM stages, optic nerve invasion and choroidal invasion. Circ_0000527 knockdown suppressed cell proliferation, migration, invasion and angiogenesis and promoted apoptosis in RB cells in vitro. Circ_0000527 sponged miR-1236-3p, which directly targeted SMAD2. MiR-1236-3p level was decreased in RB tissues and cells. MiR-1236-3p inhibition reversed circ_0000527 knockdown-mediated effects on RB cell malignant behaviors. Moreover, miR-1236-3p overexpression suppressed RB cell progression, with SMAD2 elevation abrogated the effect. Additionally, circ_0000527 knockdown restrained tumor formation in vivo.

CONCLUSIONS

Circ_0000527/miR-1236-3p/SMAD2 axis played a positive role in the progression of RB.

Plasma Exosomal Mir-423-5p Is Involved in the Occurrence and Development of Bicuspid Aortopathy via TGF-β/SMAD2 Pathway

Objectives: Patients with bicuspid aortic valve (BAV) are at increased risk for ascending aortic dilation (AAD). Our study was aimed at systemically analyzing the expression profile and mechanism of circulating plasma exosomal microRNAs (miRNAs) related to BAV and AAD.

Methods: We isolated plasma exosomes from BAV patients (n=19), BAV patients with AAD (BAVAD, n=26), and healthy tricuspid aortic valve individuals with low cardiovascular risk (TAVnon, n=16). We applied a small RNA sequencing approach to identify the specific plasma exosomal miRNAs associated with BAV (n=8) and BAVAD (n=10) patients compared with healthy TAVnon (n=6) individuals. The candidate differentially expressed (DE) miRNAs were selected and validated by RT-qPCR in the remaining samples. GO and KEGG pathway enrichment analyses were performed to illustrate the functions of target genes. Western blot analysis and luciferase reporter assay were conducted in human aortic vascular smooth muscle cells (VSMCs) to verify the results of target gene prediction in vitro.

Results: The expression levels of three up-regulated (miR-151a-3p, miR-423-5p, and miR-361-3p) and two down-regulated (miR-16-5p and miR-15a-5p) exosomal miRNAs were significantly altered in BAV disease. Additionally, miR-423-5p could be functionally involved in the occurrence and development of BAV and its complication BAVAD by regulating TGF-β signaling. miR-423-5p could target to SMAD2 and decreased the protein levels of SMAD2 and P-SMAD2.

Conclusion: Plasma exosomal miR-423-5p regulated TGF-β signaling by targeting SMAD2, thus exerting functions in the occurrence and development of BAV disease and its complication bicuspid aortopathy.

PCSK9 regulates the NODAL signaling pathway and cellular proliferation in hiPSCs

Proprotein convertase subtilisin kexin type 9 (PCSK9) is a key regulator of low-density lipoprotein (LDL) cholesterol metabolism and the target of lipid-lowering drugs. PCSK9 is mainly expressed in hepatocytes. Here, we show that PCSK9 is highly expressed in undifferentiated human induced pluripotent stem cells (hiPSCs). PCSK9 inhibition in hiPSCs with the use of short hairpin RNA (shRNA), CRISPR/cas9-mediated knockout, or endogenous PCSK9 loss-of-function mutation R104C/V114A unveiled its new role as a potential cell cycle regulator through the NODAL signaling pathway. In fact, PCSK9 inhibition leads to a decrease of SMAD2 phosphorylation and hiPSCs proliferation. Conversely, PCSK9 overexpression stimulates hiPSCs proliferation. PCSK9 can interfere with the NODAL pathway by regulating the expression of its endogenous inhibitor DACT2, which is involved in transforming growth factor (TGF) β-R1 lysosomal degradation. Using different PCSK9 constructs, we show that PCSK9 interacts with DACT2 through its Cys-His-rich domain (CHRD) domain. Altogether these data highlight a new role of PCSK9 in cellular proliferation and development.

SMAD2 and SMAD3 differentially regulate adiposity and the growth of subcutaneous white adipose tissue

Adipose tissue is the primary site of energy storage, playing important roles in health. While adipose research largely focuses on obesity, fat also has other critical functions, producing adipocytokines and contributing to normal nutrient metabolism, which in turn play important roles in satiety and total energy homeostasis. SMAD2/3 proteins are downstream mediators of activin signaling, which regulate critical preadipocyte and mature adipocyte functions. Smad2 global knockout mice exhibit embryonic lethality, whereas global loss of Smad3 protects mice against diet-induced obesity. The direct contributions of Smad2 and Smad3 in adipose tissues, however, are unknown. Here, we sought to determine the primary effects of adipocyte-selective reduction of Smad2 or Smad3 on diet-induced adiposity using Smad2 or Smad3 "floxed" mice intercrossed with Adiponectin-Cre mice. Additionally, we examined visceral and subcutaneous preadipocyte differentiation efficiency in vitro. Almost all wild type subcutaneous preadipocytes differentiated into mature adipocytes. In contrast, visceral preadipocytes differentiated poorly. Exogenous activin A suppressed differentiation of preadipocytes from both depots. Smad2 conditional knockout (Smad2cKO) mice did not exhibit significant effects on weight gain, irrespective of diet, whereas Smad3 conditional knockout (Smad3cKO) male mice displayed a trend of reduced body weight on high-fat diet. On both diets, Smad3cKO mice displayed an adipose depot-selective phenotype, with a significant reduction in subcutaneous fat mass but not visceral fat mass. Our data suggest that Smad3 is an important contributor to the maintenance of subcutaneous white adipose tissue in a sex-selective fashion. These findings have implications for understanding SMAD-mediated, depot selective regulation of adipocyte growth and differentiation.

Knockdown of circSMAD2 inhibits the tumorigenesis of gallbladder cancer through binding with eIF4A3

Background

Gallbladder cancer (GBC) is the seventh most common gastrointestinal cancer worldwide. This study aimed to investigate the function of circSMAD2 in GBC.

Methods

To investigate the function of circSMAD2 in GBC, the level of circSMAD2 in GBC cells was detected by RT-qPCR. CCK-8 assay was performed to investigate the cell viability. Cell apoptosis was tested by flow cytometry. In addition, transwell assay was used to detect the cell migration and invasion. RIP and RNA pull-down were used to explore the relation among circSMAD2, eIF4A3 and SMAD2. Meanwhile, xenograft mice model was established to investigate the function of circSMAD2 in GBC.

Results

The data revealed that circSMAD2 was upregulated in GBC, and circSMAD2 knockdown significantly inhibited the viability of GBC cells. In addition, circSMAD2 siRNA notably induced the apoptosis in GBC cells. The migration and invasion of GBC cells were obviously suppressed in the presence of circSMAD2 siRNA. Meanwhile, circSMAD2 suppressed the binding between eukaryotic translation initiation factor 4A3 (eIF4A3) and SMAD2 through binding with eIF4A3. Knockdown of circSMAD2 notably inhibited the expression of SMAD2 in GBC cells, and SMAD2 overexpression partially reversed the anti-tumor effect of circSMAD2 knockdown. Finally, circSMAD2 siRNA significantly inhibited the tumor growth of GBC in vivo.

Conclusion

Knockdown of circSMAD2 inhibits the tumorigenesis of gallbladder cancer through binding with eIF4A3. Thus, our study provided a new strategy for the treatment of GBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08895-1.

SMAD2 regulates testicular development and testosterone synthesis in Hu sheep

The SMAD protein family plays crucial roles in reproduction as a downstream target genes of the TGFβ signaling pathway. Many studies have focused on the expression change exploration of SMADs during testicular development and investigation of SMAD2 in hormone synthesis regulation. However, little attention has been given to determining the regulatory mechanism of SMADs in sheep testes. In the present study, we first detected SMAD mRNA expression levels in three-month-old (3 M), six-month-old (6 M), nine-month-old (9 M) and two-year-old (2Y) sheep testes. Different SMADs showed various expression patterns. In addition, the subcellular localization of SMAD2 was also analyzed, and Sertoli cells (SCs), Leydig cells (LCs) and spermatogonia presented mainly positive staining. Protein and nucleic acid sequence alignment showed that the SMAD2 gene was extremely homologous between various species. SMAD2 interference RNA was transfected into sheep LCs to examine the cell proliferation and hormone levels. The testosterone level was significantly decreased, and cell proliferation efficiency presented the same trend (P < 0.05). Moreover, SMAD2 downregulation promoted cell apoptosis (P < 0.05) and changed the cell cycle. In total, our results revealed that downregulating the expression of SMAD2 can effectively inhibit testosterone levels by affecting cell proliferation and apoptosis.

Long noncoding RNA ZFAS1 suppresses chondrocytes apoptosis via miR-302d-3p/SMAD2 in osteoarthritis

Osteoarthritis (OA) seriously affects people's quality of life due to joint pain, stiffness, disability, and dyskinesia worldwide. Long noncoding RNA zinc finger antisense 1 (ZFAS1) is downregulated and tightly associated with proliferation, migration, apoptosis, and matrix synthesis of chondrocyte in OA. However, the molecular mechanisms of ZFAS1 in OA remain unknown. The expression correlation between ZFAS1, miR-302d-3p, and SMAD2 in OA tissues was analyzed by Pearson correlation analysis. ZFAS1 was a lower expression, and expedited proliferation and repressed apoptosis of chondrocytes. MiR-302d-3p was a direct target of ZFAS1. MiR-302d-3p hindered proliferation and facilitated apoptosis of chondrocytes. MiR-302d-3p partially reversed the effect of ZFAS1 on proliferation and apoptosis of chondrocytes. SMAD2 was positively regulated by the ZFAS1/miR-302d-3p. MiR-302d-3p-mediated proliferation and apoptosis were partly abrogated by targeting SMAD2. ZFAS1 promoted chondrocytes proliferation and repressed apoptosis possibly by regulating miR-302d-3p/SMAD2 axis, providing a potential target for OA treatment.

Effects of miR‑210‑3p on the erythroid differentiation of K562 cells under hypoxia

GATA binding protein 1 (GATA-1) is one of the most important hematopoietic transcription factors in the production of blood cells, such as platelets, eosinophils, mast cells and erythrocytes. GATA-1 regulates the participation of microRNA (miRNAs/miRs) in erythroid differentiation under normoxia. However, GATA-1 expression and the regulation of miR-210-3p in the context of erythroid differentiation under hypoxia remain unknown. The present study examined the expression levels of GATA-1 and miR-210-3p in the model of erythroid differentiation in K562 cells under hypoxia, and determined the effects of GATA-1, miR-210-3p and SMAD2 on erythroid differentiation through lentivirus transfection experiments. The present study detected increased GATA-1 expression under hypoxia. Moreover, miR-210-3p was identified as a positive regulator of erythroid differentiation, which was upregulated both during erythroid differentiation and in GATA-1 overexpression experiments under hypoxia. Importantly, in the K562 cell model of erythroid differentiation under hypoxia, miR-210-3p was upregulated in a GATA-1-dependent manner. Using a double luciferase reporter assay, miR-210-3p was identified as a downstream target of GATA-1-mediated regulation of erythropoiesis. Gain- or loss-of-function analysis of miR-210-3p identified its importance in erythroid differentiation. Furthermore, it was found that SMAD2 may be a downstream target gene for miR-210-3p. Bioinformatics predictions suggested that SMAD2 mediated miR-210-3p-induced regulation of erythroid differentiation. Collectively, the present study provides novel insights into the miRNA regulation of erythroid differentiation.

miRNAs through β-ARR2/p-ERK1/2 pathway regulate the VSMC proliferation and migration

BACKGROUND

miRNAs are involved in plaque formation of atherosclerosis and vessel restenosis. In this study, we investigated the effects of miR-599, miR-204, and miR-181b on VSMC proliferation, and migration through TGFβ receptor 2 (TGFβR2), β-arrestin 2 (β-ARR2), SMAD2/p-SMAD2, and ERK1/2/p-ERK1/2.

MATERIALS & METHODS

Genes and miRNAs were predicted by bioinformatics tools and were transfected by PEI-miRNAs (miR-599, miR-204, and miR-181b) complexes into VSMCs. The gene and protein expression levels were evaluated by real-time RT-PCR and western blotting techniques, respectively. The VSMC proliferation and migration were studied by MTT and scratch assay, respectively.

RESULTS

The miR-181b and miR-204 downregulated significantly β-ARR2 gene and protein expression levels and p-ERK1/2 values. Moreover, TGFβR2 gene and protein expression levels and p-SMAD2 values were not significantly affected by miR-181b and miR-204. The VSMC proliferation (p = 0.0019, p = 0.0054, respectively) and migration (p < 0.0001, p < 0.0001, respectively) were inhibited by the miR-181b and miR-204. The miR-599 inhibited VSMC proliferation (p = 0.044) and migration (p = 0.0055) but it did not affect significantly the β-ARR2 and TGFβR2 gene and protein expression levels.

CONCLUSION

The results suggested that the inhibitory effects of miR-181b and miR-204 on VSMC proliferation and migration are mediated by the β-ARR2/p-ERK1/2 pathway. Since VSMC proliferation and migration are involved in plaque growth, therefore this pathway can be a therapeutic target for atherosclerosis.

Importance of Potential New Biomarkers in Patient with Serouse Ovarian Cancer

Ovarian cancer remains the gynecological cancer with the highest mortality rate. In our study, we compare a number of proteins from different effector pathways to assess their usefulness in the diagnosis of ovarian cancer. The tissue expression of the tested proteins was assessed by two methods: qRT-PCR and an immunohistochemical analysis. A significantly higher level of mRNA expression was found in the ovarian cancer group for YAP and TEAD4 (p = 0.004 and p = 0.003, respectively). There was no statistical significance in the expression of mRNA for SMAD3, and there was borderline statistical significance for SMAD2 between the groups of ovarian cancer patients and other subgroups of patients with simple cysts and healthy ovarian tissue (p = 0.726 and p = 0.046, respectively). Significantly higher levels of transferrin receptor (CD71), H2A.X, and ADH1A gene expression were found in the ovarian cancer group compared to the control group for YAP, and TEAD4 showed strong nuclear and cytoplasmic staining in ovarian carcinoma and weak staining in non-carcinoma ovarian samples, ADH1A1 showed strong staining in the cytoplasm of carcinoma sections and a weak positive reaction in the non-carcinoma section, H2A.X showed strong positive nuclear staining in carcinoma sections and moderate positive staining in non-carcinoma samples, and CD71 showed moderate positive staining in carcinoma and non-carcinoma samples. YAP, TEAD4, and ADH1A proteins appear to be promising biomarkers in the diagnosis of ovarian cancer.

Interplay between SMAD2 and STAT5A is a critical determinant of IL-17A/IL-17F differential expression

Interleukins (IL)-17A and F are critical cytokines in anti-microbial immunity but also contribute to auto-immune pathologies. Recent evidence suggests that they may be differentially produced by T-helper (Th) cells, but the underlying mechanisms remain unknown. To address this question, we built a regulatory graph integrating all reported upstream regulators of IL-17A and F, completed by ChIP-seq data analyses. The resulting regulatory graph encompasses 82 components and 136 regulatory links. The graph was then supplemented by logical rules calibrated with original flow cytometry data using naive CD4⁺ T cells, in conditions inducing IL-17A or IL-17F. The model displays specific stable states corresponding to virtual phenotypes explaining IL-17A and IL-17F differential regulation across eight cytokine stimulatory conditions. Our model analysis points to the transcription factors NFAT2A, STAT5A and SMAD2 as key regulators of the differential expression of IL-17A and IL-17F, with STAT5A controlling IL-17F expression, and an interplay of NFAT2A, STAT5A and SMAD2 controlling IL-17A expression. We experimentally observed that the production of IL-17A was correlated with an increase of SMAD2 transcription, and the expression of IL-17F correlated with an increase of BLIMP-1 transcription, together with an increase of STAT5A expression (mRNA), as predicted by our model. Interestingly, RORγt presumably plays a more determinant role in IL-17A expression as compared to IL-17F expression. In conclusion, we propose the first mechanistic model accounting for the differential expression of IL-17A and F in Th cells, providing a basis to design novel therapeutic interventions in auto-immune and inflammatory diseases.

Myocardial TGFβ2 Is Required for Atrioventricular Cushion Remodeling and Myocardial Development

Among the three transforming growth factor beta (TGFβ) ligands, TGFβ2 is essential for heart development and is produced by multiple cell types, including myocardium. Heterozygous mutations in TGFB2 in patients of connective tissue disorders result in congenital heart defects and adult valve malformations, including mitral valve prolapse (MVP) with or without regurgitation. Tgfb2 germline knockout fetuses exhibit multiple cardiac defects but the role of myocardial-TGFβ2 in heart development is yet to be elucidated. Here, myocardial Tgfb2 conditional knockout (CKO) embryos were generated by crossing Tgfb2^flox mice with Tgfb2^+/−; cTntCre mice. Tgfb2^flox/− embryos were normal, viable. Cell fate mapping was done using dual-fluorescent mT/mG^+/− mice. Cre-mediated Tgfb2 deletion was assessed by genomic PCR. RNAscope in situ hybridization was used to detect the loss of myocardial Tgfb2 expression. Histological, morphometric, immunohistochemical, and in situ hybridization analyses of CKOs and littermate controls at different stages of heart development (E12.5–E18.5) were used to determine the role of myocardium-derived TGFβ2 in atrioventricular (AV) cushion remodeling and myocardial development. CKOs exhibit a thin ventricular myocardium, AV cushion remodeling defects and developed incomplete AV septation defects. The loss of myocardial Tgfb2 resulted in impaired cushion maturation and dysregulated cell death. Phosphorylated SMAD2, a surrogate for TGFβ signaling, was “paradoxically” increased in both AV cushion mesenchyme and ventricular myocardium in the CKOs. Our results indicate that TGFβ2 produced by cardiomyocytes acting as cells autonomously on myocardium and via paracrine signaling on AV cushions are required for heart development.

SMAD2, SMAD3 and TGF-β GENE expressions in women suffering from urge urinary incontinence and pelvic organ prolapse

We evaluated the changes in the levels of TGF-β and SMAD gene and protein expression in the uterosacral ligament (USL) of patients with concomitant pelvic organ prolapse (POP) and urgency urinary incontinence (UUI) to illuminate the pathophysiology of UUI. The TGF-β pathway is involved in collagen synthesis and degradation. The Transforming Growth Family-β (TGF-β) superfamily has essential intracellular signaling components, such as newly identified SMAD family members. We evaluated the changes in the levels of TGF-β and SMAD gene and protein expression in the USL of patients with concomitant pelvic organ prolapse (POP) and UUI. This study included 10 patients who had been diagnosed with POP and UUI in the study group and 14 asymptomatic women without complaints of POP and UUI in the control group. Biopsy samples were collected from bilateral USL tissues during vaginal or abdominal hysterectomy. Total RNA was extracted from USL tissue and analyzed by qPCR. The protein expression levels were also analyzed with ELISA. In UUI patients, SMAD3 and TGF-ß1 gene expression levels significantly decreased compared to the control patients (p = 0.008 and p = 0.006, respectively). SMAD2 mRNA levels did not differ between the study and control groups (p = 0.139). No differences was found in the levels of SMAD2, SMAD3, and TGF-ß1 protein expression between the two groups. The reduction in the gene and protein expression levels of SMAD3 and TGF-ß1 in women with UUI and lax uterosacral ligaments may indicate a causal link.Clinical trial registration: NCT04525105.

Human Placental NADPH Oxidase Mediates sFlt-1 and PlGF Secretion in Early Pregnancy: Exploration of the TGF-β1/p38 MAPK Pathways

Preeclampsia, a hypertensive disorder occurring during pregnancy, is characterized by excessive oxidative stress and trophoblast dysfunction with dysregulation of soluble Fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) production. Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (Nox) is the major source of placental superoxide in early pregnancy and its activation with the subsequent formation of superoxide has been demonstrated for various agents including Transforming Growth Factor beta-1 (TGF-β1), a well-known p38 MAPK pathway activator. However, the bridge between Nox and sFlt-1 remains unknown. The purpose of this study was to explore the possible signaling pathway of TGF-β1/Nox/p38 induced sFlt-1 production in human chorionic villi (CV). Methods: Human chorionic villi from first trimester placenta (7–9 Gestational Weeks (GW)) were treated with TGF-β1 or preincubated with p38 inhibitor, SB203580. For NADPH oxidase inhibition, CV were treated with diphenyleneiodonium (DPI). The protein levels of phospho-p38, p38, phospho-Mothers Against Decapentaplegic homolog 2 (SMAD2), and SMAD2 were detected by Western blot. The secretion of sFlt-1 and PlGF by chorionic villi were measured with Electrochemiluminescence Immunologic Assays, and NADPH oxidase activity was monitored by lucigenin method. Results: We demonstrate for the first time that NADPH oxidase is involved in sFlt-1 and PlGF secretion in first trimester chorionic villi. Indeed, the inhibition of Nox by DPI decreases sFlt-1, and increases PlGF secretions. We also demonstrate the involvement of p38 MAPK in sFlt-1 secretion and Nox activation as blocking the p38 MAPK phosphorylation decreases both sFlt-1 secretion and superoxide production. Nevertheless, TGF-β1-mediated p38 activation do not seem to be involved in regulation of the first trimester placental angiogenic balance and no crosstalk was found between SMAD2 and p38 MAPK pathways. Conclusions: Thus, the placental NADPH oxidase play a major role in mediating the signal transduction cascade of sFlt-1 production. Furthermore, we highlight for the first time the involvement of p38 activation in first trimester placental Nox activity.

SMAD2 promotes myogenin expression and terminal myogenic differentiation

SMAD2 is a transcription factor, the activity of which is regulated by members of the transforming growth factor β (TGFβ) superfamily. Although activation of SMAD2 and SMAD3 downstream of TGFβ or myostatin signaling is known to inhibit myogenesis, we found that SMAD2 in the absence of TGFβ signaling promotes terminal myogenic differentiation. We found that, during myogenic differentiation, SMAD2 expression is induced. Knockout of SMAD2 expression in primary myoblasts did not affect the efficiency of myogenic differentiation but produced smaller myotubes with reduced expression of the terminal differentiation marker myogenin. Conversely, overexpression of SMAD2 stimulated myogenin expression, and enhanced both differentiation and fusion, and these effects were independent of classical activation by the TGFβ receptor complex. Loss of Smad2 in muscle satellite cells in vivo resulted in decreased muscle fiber caliber and impaired regeneration after acute injury. Taken together, we demonstrate that SMAD2 is an important positive regulator of myogenic differentiation, in part through the regulation of Myog.

Prenatal characterization of a novel inverted SMAD2 duplication by mate pair sequencing in a fetus with dextrocardia

This case report underlines the importance of molecular characterization of genomic duplications and other structural variants in the prenatal setting to guide clinical interpretation, genetic counseling, and perinatal medical care.

Extracorporeal Shock Wave Therapy Promotes Osteogenic Differentiation in a Rabbit Osteoporosis Model

Extracorporeal shock wave therapy (ESWT) has been identified to accelerate bone formation. However, detailed mechanism has not been fully explained. In this study, we found that ESWT promoted osteoblast formation in vitro. Local ESW treatment of femur increased bone formation in vivo. Furthermore, changing the density or frequency of energy, there was no statistical difference in osteogenic differentiation. Therapeutically, local ESW therapy relieved bone loss and increased the number of bone trabecular in a rabbit osteoporosis model and promoted endogenous levels of SMAD2 protein expression. Thus, ESWT may be a potential therapy by promoting osteoblast maturation through TGF-β/SMAD2 pathway.

Characterization and functional analysis of SMAD2 regulation in hair follicle cycle in Angora rabbits

Hair follicle (HF) development is characterized by periodic growth cycles regulated by numerous factors. We previously showed that SMAD2 might be involved in the HF growth cycle in Angora rabbits. However, its extra role in the HF growth and development remains obscure. In this study, we cloned the complete coding sequence (CDS) of the Angora rabbit SMAD2 gene. Within SMAD2 CDS, we identified the open reading frame (ORF) had a length of 1314 bp and encoding 437 amino acids. Bioinformatics analyses revealed that the SMAD2 protein is unstable and hydrophilic, and predominatelylocalizesin the cell nucleus. We identified that SMAD2 expression was elevated in the telogen phase of the during HF cycle. The knockdown and overexpression of SMAD2 could regulate HF growth and development related genes, such as WNT2, FGF2, and LEF1.Furthermore, SMAD2 may upregulate TGF-β signaling pathway-related genes, including TFDP1, E2F4, and RBL1. In conclusion, our results indicate that SMAD2 plays a vital role in HF development by regulating the TGF-β signaling pathway.

Circular RNA hsa_circ_0001829 promotes gastric cancer progression through miR-155-5p/SMAD2 axis

Background

Accumulating evidences have shown that circular RNAs (circRNAs) play important roles in regulating the pathogenesis of cancer. However, the role of circRNAs in gastric cancer (GC) remains largely unclear.

Methods

In this study, we identified a novel upregulated circRNA, hsa_circ_0001829, in chemically induced malignant transformed human gastric epithelial cells using RNA-seq. Subsequent qRT-PCR and ISH assays were performed to detect the expression level of hsa_circ_0001829 in GC cell lines and tissues. Functional roles of hsa_circ_0001829 in GC were then explored by loss- and gain-of- function assays. Bioinformatic prediction and luciferase assay were used to investigate potential mechanisms of hsa_circ_0001829. Finally, the mice xenograft and metastasis models were constructed to assess the function of hsa_circ_0001829 in vivo.

Results

We found that hsa_circ_0001829 was significantly upregulated in GC tissues and cell lines. Loss- and gain-of- function assays showed that hsa_circ_0001829 promotes GC cells proliferation, migration and invasion, and the affected cell cycle progression and apoptosis rates may account for the effect of hsa_circ_0001829 on GC proliferation. In addition, bioinformatic prediction and luciferase assay showed that hsa_circ_0001829 acts as a molecular sponge for miR-155-5p and that SMAD2 was a target gene of miR-155-5p; moreover, hsa_circ_0001829 sponges miR-155-5p to regulate SMAD2 expression and hsa_circ_0001829 promotes GC progression through the miR-155-5p–SMAD2 pathway. Finally, suppression of hsa_circ_0001829 expression inhibited tumor growth and aggressiveness in vivo.

Conclusion

Taken together, our findings firstly demonstrated a novel oncogenic role of hsa_circ_0001829 in GC progression through miR-155-5p–SMAD2 axis, and our study may offer novel biomarkers and therapeutic targets for GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01790-w.

NEAT1/miR-200b-3p/SMAD2 axis promotes progression of melanoma

Melanoma is a skin malignancy with a high mutation frequency of genetic alterations. MicroRNA (miR)-200b-3p is involved in various cancers, while in melanoma its bio-function remains unknown. In this study, we found that miR-200b-3p was down-regulated in melanoma tissues and cell lines compared to benign nevus cells. Overexpression of miR-200b-3p significantly inhibited the proliferation and invasion of melanoma cells. According to bioinformatics analysis and sequencing data, we supposed that SMAD family member 2 (SMAD2) was the target gene and nuclear enriched abundant transcript 1 (NEAT1) was the upstream long non-coding RNA (lncRNA) of miR-200b-3p. These predictions were verified by western blotting and quantitative real-time reverse transcription PCR (RT-qPCR). Luciferase reporter assays revealed that NEAT1 up-regulated SMAD2 by directly sponging miR-200b-3p. In vitro and in vivo, we demonstrated that both NEAT1 and SMAD2 could promote the proliferation and invasion of melanoma cells, and these effects were reversed by up-regulating miR-200b-3p. In addition, NEAT1/miR-200b-3p/SMAD2 axis promoted melanoma progression by activating EMT signaling pathway and immune responses. Taken together, the NEAT1/miR-200b-3p/SMAD2 signaling pathway promotes melanoma via activation of EMT, cell invasion and is related with immune responses, which provides new insights into the molecular mechanisms and therapeutic targets for melanoma.

Tranilast Inhibits Pulmonary Fibrosis by Suppressing TGFβ/SMAD2 Pathway

Purpose

Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of extracellular matrix (ECM) protein in the lungs. Transforming growth factor (TGF) β-induced ECM protein synthesis contributes to the development of IPF. Tranilast, an anti-allergy drug, suppresses TGFβ expression and inhibits interstitial renal fibrosis in animal models. However, the beneficial effects of tranilast or its mechanism as a therapy for pulmonary fibrosis have not been clarified.

Methods

We investigated the in vitro effect of tranilast on ECM production and TGFβ/SMAD2 pathway in TGFβ2-stimulated A549 human alveolar epithelial cells, using quantitative polymerase chain reaction, Western blotting, and immunofluorescence. In vitro observations were validated in the lungs of a murine pulmonary fibrosis model, which we developed by intravenous injection of bleomycin.

Results

Treatment with tranilast suppressed the expression of ECM proteins, such as fibronectin and type IV collagen, and attenuated SMAD2 phosphorylation in TGFβ2-stimulated A549 cells. In addition, based on a wound healing assay in these cells, tranilast significantly inhibited cell motility, with foci formation that comprised of ECM proteins. Histological analyses revealed that the administration of tranilast significantly attenuated lung fibrosis in mice. Furthermore, tranilast treatment significantly reduced levels of TGFβ, collagen, fibronectin, and phosphorylated SMAD2 in pulmonary fibrotic tissues in mice.

Conclusion

These findings suggest that tranilast inhibits pulmonary fibrosis by suppressing TGFβ/SMAD2-mediated ECM protein production, presenting tranilast as a promising and novel anti-fibrotic agent for the treatment of IPF.

Obg-like ATPase 1 inhibited oral carcinoma cell metastasis through TGFβ/SMAD2 axis in vitro

BACKGROUND

The human Obg-like ATPase 1 (OLA1) protein has been reported to play an important role in cancer cell proliferation. The molecular mechanism underlying OLA1 regulated oral metastasis is still unknown. We investigated in this study the regulatory role of OLA1 playing in oral squamous cell metastasis.

RESULTS

A series of in vitro assays were performed in the cells with RNAi-mediated knockdown or overexpression to expound the regulatory function of OLA1 in oral cancer. We found that the endogenous level of OLA1 in a highly metastatic oral squamous cell line was significantly lower than that in low metastatic oral cells as well as in normal oral cells. Escalated expression of OLA1 resulted in a reduced ability of metastasis in highly metastatic cells, and enhanced its sensitivity to the paclitaxel treatment. Further analysis of the EMT markers showed that Snail, Slug, N-cadherin were up-expressed significantly. Meanwhile, E-cadherin was significantly down-regulated in the oral cancer cells with OLA1-knocked down, suggesting that OLA1 inactivated EMT process. Furthermore, we found that OLA1 suppressed oral squamous cell metastasis by suppressing the activity of a TGFβ/SMAD2/EMT pathway.

CONCLUSION

Our data suggests that OLA1 may be developed as a potential target for the treatment of oral cancer metastasis.

MicroRNA-27a inhibits trophoblast cell migration and invasion by targeting SMAD2: Potential role in preeclampsia

Preeclampsia (PE) is a severe idiopathic obstetric complication that occurs worldwide. Insufficient trophoblast invasion is a characteristic of the pathogenesis of PE. MicroRNA-27a (miR-27a) has been reported to be highly expressed in PE placentas. The aim of the present study was to investigate the role and underlying mechanisms of miR-27a in the pathogenesis of PE. The expression level of miR-27a was evaluated in the placenta and serum from patients with PE and healthy pregnant women. Cell Counting Kit-8 and flow cytometry assays were performed to detect human HTR-8/SVneo trophoblast proliferation and apoptosis after miR-27a overexpression or inhibition. In addition, Transwell assays were used to measure cell migration and invasion. A luciferase reporter assay was performed to determine the interaction between miR-27a and SMAD2. The present results suggested that miR-27a expression level was significantly increased in PE placentas and serum. In addition, miR-27a overexpression suppressed cell migratory and invasive abilities, impaired proliferation and promoted apoptosis in human trophoblasts. It was demonstrated that miR-27a may target SMAD and contribute to trophoblast invasion. Collectively, the results of the present study suggested that miR-27a inhibited trophoblast cell migration and invasion by targeting SMAD2, thus presenting a promising therapeutic target for PE.

MicroRNA-148a-3p inhibits progression of hepatocelluar carcimoma by repressing SMAD2 expression in an Ago2 dependent manner

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent common cancer worldwide with high mortality. Transforming growth factor-β (TGF-β) signaling pathway was reported dysregulated during liver cancer formation and progression. As a key component of TGF-β signaling, the role of SMAD2 and its regulatory mechanisms in HCC remain unclear.

Methods

SMAD2 expression in paired HCC specimens were determined by western blot and immunohistochemistry (IHC). quantitative real-time PCR (qRT-PCR) was used to measure mRNA and microRNA (miRNA) expression level. Cell migration, invasion and proliferation ability were evaluated by transwell, CCK8 and EdU assay. In silico websites were used to manifest overall survival rates of HCC patients or to predict miRNAs targeting SMAD2. Dual luciferase reporter assay and anti-Ago2 immunoprecipitation assay were performed to confirm the binding between SMAD2 mRNA and miRNA-148a-3p (miR-148a). Tumorigenesis and lung metastasis mouse model were used to explore the role of miR-148a in vivo. In situ hybridization (ISH) was conducted to determine the expression of miR-148a in liver tissues.

Results

In this study, we found that SMAD2 was highly expressed in HCC and elevated SMAD2 expression predicted shorter overall survival (OS) time for HCC patients. SMAD2 promoted mobility and proliferation of HCC cells in vitro. We further revealed that the expression of miR-148a was negatively correlated with SMAD2 and found that miR-148a repressed SMAD2 expression by downregulating its mRNA through binding with Argonaute 2 (Ago2) in HCC. Transwell, CCK8 and animal experiments exhibited miR-148a inhibited metastasis and proliferation of HCC in vitro and in vivo. Moreover, the phenotype changes caused by miR-148a manipulation were recovered by rescuing SMAD2 expression in HCC cells. ISH assay indicated miR-148a was downregulated in HCC and low expression of miR-148a associated with more aggressive clinic features and poor prognosis.

Conclusion

miR-148a was identified as a repressor of HCC progression by downregulating SMAD2 in an Ago2 dependent manner.

Use of a PTFE Micro-Bioreactor to Promote 3D Cell Rearrangement and Maintain High Plasticity in Epigenetically Erased Fibroblasts

Phenotype definition is driven by epigenetic mechanisms as well as directly influenced by the cell microenvironment and by biophysical signals deriving from the extracellular matrix. The possibility to interact with the epigenetic signature of an adult mature cell, reversing its differentiated state and inducing a short transient high plasticity window, was previously demonstrated. In parallel, in vitro studies have shown that 3D culture systems, mimicking cell native tissue, exert significant effects on cell behavior and functions. Here we report the production of "PTFE micro-bioreactors" for long-term culture of epigenetically derived high plasticity cells. The system promotes 3D cell rearrangement, global DNA demethylation and elevated transcription of pluripotency markers, that is dependent on WW domain containing transcription regulator 1 (TAZ) nuclear accumulation and SMAD family member 2 (SMAD2) co-shuttling. Our findings demonstrate that the use of 3D culture strategies greatly improves the induction and maintenance of a high plasticity state.

SMAD2 rs4940086 heterozygosity increases the risk of cervical cancer development among the women in Bangladesh

SMAD2 is a critical signal transducer molecule in the TGFβ- SMAD pathway which is also known for its tumor suppressor role. Genetic variations in SMAD2 render cells insensitive to its anti-proliferative signals leading to tumor formation. In this study, we demonstrate the impact of single nucleotide polymorphisms (SNPs) of SMAD2 (rs4940086 and rs8085335) on cervical cancer risk development in Bangladeshi population. 132 cervical cancer patients and 98 control volunteers were enrolled in the study and genotyped utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The association between cervical cancer susceptibility and the chosen SNPs were evaluated through multiple logistic regression. SMAD2 rs4940086 heterozygous genotype (T/C) was associated with a 3.89 times higher risk of cervical cancer development (P = 0.001, AOR 3.89, 95% CI 1.777-8.513). The T/C and C/C genotypes in combination also significantly elevated cervical cancer risk (P = 0.035, AOR 1.876, 95% CI 1.047-3.364). Urban cancer patients had a significantly higher chance of carrying the rs4940086 polymorphism as compared to rural cancer patients (P = 0.045, OR 2.59 95% CI 1.02-6.59). SMAD2 rs8085335 heterozygous variant (A/G) demonstrated modest effects in increasing cervical cancer susceptibility (P = 0.594, AOR 1.247, 95% CI 0.554-2.809). Our results suggest that polymorphic variations in SMAD2, particularly rs4940086, can potentially elevate cervical cancer susceptibility in Bangladeshi women.

USP32 promotes tumorigenesis and chemoresistance in gastric carcinoma via upregulation of SMAD2

USP32, a member of the ubiquitin-specific proteases family, has been implicated in the development of breast cancer and small lung cancer. However, its biological functions and clinical significance in gastric cancer (GC) remain unclear. In the present study, we reported that knockdown or depletion of USP32 significantly inhibited GC cell proliferation and migration in vitro and in vivo, indicating that USP32 functions as an oncogene in GC. Importantly, results from immunohistochemical staining in a tissue microarray revealed that USP32 was upregulated in GC tissues compared with paracancerous tissues. Further analyses showed that high expression of USP32 was closely related with high T-staging and poor outcomes of GC patients. Mechanistically, USP32 silencing caused a decrease in the expression of SMAD2, which resulted in the inhibitory effects of GC cells on growth, motility, and chemoresistance to cisplatin. Therefore, our findings strongly suggest the involvement of USP32 in GC progression and provide a potential target for future therapy of GC.

TGFBR2 mediated phosphorylation of BUB1 at Ser-318 is required for transforming growth factor-β signaling

BUB1 (budding uninhibited by benzimidazoles-1) is required for efficient TGF-β signaling, through its role in stabilizing the TGFBR1 and TGFBR2 complex. Here we demonstrate that TGFBR2 phosphorylates BUB1 at Serine-318, which is conserved in primates. S318 phosphorylation abrogates the interaction of BUB1 with TGFBR1 and SMAD2. Using BUB1 truncation domains (1–241, 241–482 and 482–723), we demonstrate that multiple contact points exist between BUB1 and TGF-β signaling components and that these interactions are independent of the BUB1 tetratricopeptide repeat (TPR) domain. Moreover, substitutions in the middle domain (241–482) encompassing S318 reveals that efficient interaction with TGFBR2 occurs only in its dephosphorylated state (241–482 S318A). In contrast, the phospho-mimicking mutant (241–482 S318D) exhibits efficient binding with SMAD2 and its over-expression results in a decrease in TGFBR1-TGFBR2 and TGFBR1-SMAD2 interactions. These findings suggest that TGFBR2 mediated BUB1 phosphorylation at S318 may serve as a switch for the dissociation of the SMAD2-TGFBR complex, and therefore represents a regulatory event for TGF-β signaling. Finally, we provide evidence that the BUB1-TGF-β signaling axis may mediate aggressive phenotypes in a variety of cancers.

MIR22HG acts as a tumor suppressor via TGFβ/SMAD signaling and facilitates immunotherapy in colorectal cancer

Background

Long noncoding RNAs (lncRNAs) are emerging as critical regulatory elements and play fundamental roles in the biology of various cancers. However, we are still lack of knowledge about their expression patterns and functions in human colorectal cancer (CRC).

Methods

Differentially expressed lncRNAs in CRC were identified by bioinformatics screen and the level of MIR22HG in CRC and control tissues were determined by qRT-PCR. Cell viability and migration capacities were examined by MTT and transwell assay. Mouse model was used to examine the function and rational immunotherapy of MIR22HG in vivo.

Results

We systematically investigated the expression pattern of lncRNAs and revealed MIR22HG acts as a tumor suppressor in CRC. The expression of MIR22HG was significantly decreased in CRC, which was mainly driven by copy number deletion. Reduced expression of MIR22HG was significantly associated with poor overall survival. Silencing of MIR22HG promoted cell survival, proliferation and tumor metastasis in vitro and in vivo. Mechanistically, MIR22HG exerts its tumor suppressive activity by competitively interacting with SMAD2 and modulating the activity of TGFβ pathway. Decreased MIR22HG promoted the epithelial-mesenchymal transition in CRC. Importantly, we found that MIR22HG expression is significantly correlated with CD8A and overexpression of MIR22HG triggers T cell infiltration, enhancing the clinical benefits of immunotherapy.

Conclusion

MIR22HG acts as a tumor suppressor in CRC. Our data provide mechanistic insights into the regulation of MIR22HG in TGFβ pathway and facilitates immunotherapy in cancer.

Exploring organ-specific features of fibrogenesis using murine precision-cut tissue slices

Fibrosis is the hallmark of pathologic tissue remodelling in most chronic diseases. Despite advances in our understanding of the mechanisms of fibrosis, it remains uncured. Fibrogenic processes share conserved core cellular and molecular pathways across organs. In this study, we aimed to elucidate shared and organ-specific features of fibrosis using murine precision-cut tissue slices (PCTS) prepared from small intestine, liver and kidneys. PCTS displayed substantial differences in their baseline gene expression profiles: 70% of the extracellular matrix (ECM)-related genes were differentially expressed across the organs. Culture for 48 h induced significant changes in ECM regulation and triggered the onset of fibrogenesis in all PCTS in organ-specific manner. TGFβ signalling was activated during 48 h culture in all PCTS. However, the degree of its involvement varied: both canonical and non-canonical TGFβ pathways were activated in liver and kidney slices, while only canonical, Smad-dependent, cascade was involved in intestinal slices. The treatment with galunisertib blocked the TGFβRI/SMAD2 signalling in all PCTS, but attenuated culture-induced dysregulation of ECM homeostasis and mitigated the onset of fibrogenesis with organ-specificity. In conclusion, regardless the many common features in pathophysiology of organ fibrosis, PCTS displayed diversity in culture-induced responses and in response to the treatment with TGFβRI kinase inhibitor galunisertib, even though it targets a core fibrosis pathway. A clear understanding of the common and organ-specific features of fibrosis is the basis for developing novel antifibrotic therapies.

BMP3 suppresses colon tumorigenesis via ActRIIB/SMAD2-dependent and TAK1/JNK signaling pathways

Background

BMP3 gene is often found hypermethylated and hence inactivated in several types of cancers including colorectal cancer (CRC), indicating that it has a suppressor role in carcinogenesis. Though BMP3 is a reliable biomarker for screening CRC, the molecular mechanism of BMP3 in carcinogenesis remains largely unknown.

Methods

The expression level of BMP3 was examined by immunohistochemistry staining and western blot. Methylation-specific PCR (MSP) and real-time quantitative MSP were used to test the hypermethylation status of BMP3 gene. Analyses of BMP3 function in colon cancer cell proliferation, migration, invasion, and apoptosis were performed using HCT116 and KM12 cells. BMP3 was further knocked down or overexpressed in CRC cells, and the effects on cell growth of xenograft tumors in nude mice were assessed. Co-immunoprecipitation and immunofluorescence staining were used to analyze the association between BMP3 and BMPR2 or BMP3 and ActRIIB. Microarray analysis was performed to identify most differentially expressed genes and pathways regulated by BMP3. The BMP3-regulated SMAD2-dependent signaling pathway and TAK1/JNK signal axes were further investigated by quantitative PCR and western blot.

Results

BMP3 gene was hypermethylated and its expression was downregulated in both CRC tissues and cell lines. Expressing exogenous BMP3 in HCT116 inhibited cell growth, migration, and invasion and increased rate of apoptosis both in vitro and in vivo. However, shRNA-mediated attenuation of endogenous BMP3 in KM12 reversed such inhibitory and apoptotic effects. Furthermore, BMP3 could bind to ActRIIB, an activin type II receptor at the cellular membrane, thereby activating SMAD2-dependent pathway and TAK1/JNK signal axes to regulate downstream targets including caspase-7, p21, and SMAD4 that play crucial roles in cell cycle control and apoptosis.

Conclusions

Our study reveals a previously unknown mechanism of BMP3 tumor suppression in CRC and provides a rationale for future investigation of BMP3 as a potential target for the development of novel therapeutic agents to fight CRC.

SMAD2 overexpression rescues the TGF-β3 null mutant mice cleft palate by increased apoptosis

During palatal development, medial edge epithelium (MEE) disappearance is one of the crucial steps in the process of fusion. The fate of these cells is still debated, and controversies remain. During secondary palate fusion, TGF-β3 signaling mediated in the cell through the SMAD2 protein plays an important role and leads to the disappearance of the midline epithelial seam (MES) and the confluence of the palatal mesenchyme. In mice, TGF-β3 knock-out is lethal and mice are born with a cleft in the secondary palate. This phenotype has been rescued by targeted overexpression of SMAD2 in the medial edge epithelium (MEE). The goal of this research was to understand the mechanism of palatal fusion in the rescue mice.

METHODS

The heads of embryos with four different genotypes (wild-type, K14-SMAD2/TGF-β3^(-/-), K14-SMAD2/TGF-β3^(±), and TGF-β3 null) were collected at embryonic day E14.5, genotyped, fixed and embedded in paraffin. Serial sections were studied for detection of apoptosis and epithelial mesenchymal transition using immunofluorescence.

RESULTS

TGF-β3 null mice developed a cleft in the secondary palate while both mice with K14-SMAD2 overexpression had fusion of the secondary palate. The MEE of both the rescue mice and K14-SMAD2 overexpression had a much higher ratio of apoptotic cells than wild-type mice. The increase in apoptosis was correlated with increased phospho-SMAD2 in the MEE.

CONCLUSION

SMAD2 overexpression rescued the cleft in the secondary palate by increasing apoptosis in the medial edge epithelium.