Astragaloside IV attenuates high glucose-induced human keratinocytes injury via TGF-β/Smad signaling pathway

OBJECTIVES

In this study, we have investigated the effect of Astragaloside IV on keratinocytes' proliferation, migration, oxidative stress, apoptosis, inflammation, and relevant signaling pathway, using human keratinocytes exposed to high glucose.

BACKGROUND

Astragaloside IV is one of the main active ingredients of Astragalus membranaceus (Fisch.) Bunge. Previous studies have found that Astragaloside IV exerts positive effects in various disease models and promotes wound healing.

METHODS

Cell proliferation and migration of keratinocytes, oxidative stress indicators, cell apoptosis rate, inflammatory factors, and key proteins in the TGF-β/Smad signaling pathway were evaluated by molecular biology/biochemical techniques, fluorescence microscope, and flow cytometry.

RESULTS

High glucose inhibited the cell proliferation and migration of keratinocytes, upregulated the levels of MDA, ROS, IL-6, IL-8, and Smad7, and decreased the levels of SOD, IL-10, TGF-β1, p-Smad2, and p-Smad3. Astragaloside IV attenuated the dysfunction of keratinocytes, oxidative stress, cell apoptosis, and inflammation, but activated TGF-β/Smad signaling pathway. Meanwhile, the addition of SB431542 (the inhibitor of TGF-β/Smad signaling pathway) eliminated the impact of Astragaloside IV on high glucose-induced keratinocytes.

CONCLUSIONS

These results strongly suggest that Astragaloside IV may be a potential drug candidate for accelerating diabetic wound healing, by protecting keratinocytes against damages induced by high glucose and TGF-β/Smad pathway is involved in this process at the cellular level.

LncRNAs as epigenetic regulators of epithelial to mesenchymal transition in pancreatic cancer

Pancreatic cancer is the leading cause of cancer-related mortality because of tumor metastasis. Activation of the epithelial-to-mesenchymal transition (EMT) pathway has been confirmed to be an important driver of pancreatic cancer progression from initiation to metastasis. Long noncoding RNAs (lncRNAs) have been reported to exert essential physiological functions in pancreatic cancer progression by regulating the EMT program. In this review, we have summarized the role of EMT-related lncRNAs in human pancreatic cancer and the potential molecular mechanisms by which lncRNAs can be vital epigenetic regulators of epithelial to mesenchymal transition. Specifically, EMT-activating transcription factors (EMT-TFs) regulate EMT via TGF-β/Smad, Wnt/β-catenin, and JAK/STAT pathways. In addition, the interaction between lncRNAs and HIF-1α and m6A RNA methylation also have an impact on tumor metastasis and EMT in pancreatic cancer. This review will provide insights into lncRNAs as promising biomarkers for tumor metastasis and potential therapeutic strategies for pancreatic cancer.

Collagen type X alpha 1 promotes proliferation, invasion and epithelial-mesenchymal transition of cervical cancer through activation of TGF-β/Smad signaling

Background

Collagen type X alpha 1 (COL10A1) belongs to the collagen family and constitutes the main component of the interstitial matrix. COL10A1 was found to be dysregulated in various cancers, and to participate in tumorigenesis. However, the role of COL10A1 in cervical cancer (CC) remains unclear.

Methods

Expression of COL10A1 in CC cells and tissues was detected by western blot and qRT-PCR. CC cells were transfected with pcDNA-COL10A1 or si-COL10A1, and the effect of COL10A1 on cell proliferation of CC was assessed by MTT and colony formation assays. Cell metastasis was detected by wound healing and transwell assays. Western blot was applied to evaluate epithelial-mesenchymal transition.

Results

COL10A1 was significantly elevated in CC tissues and cells (P < 0.001). Over-expression of COL10A1 increased cell viability of CC (P < 0.001), and enhanced the number of colonies (P < 0.001). However, knockdown of COL10A1 reduced the cell proliferation of CC (P < 0.001). Over-expression of COL10A1 also promoted cell migration (P < 0.001) and invasion (P < 0.001) of CC, whereas silencing of COL10A1 suppressed cell metastasis (P < 0.001). Protein level of E-cadherin in CC was reduced (P < 0.05), whereas N-cadherin and vimentin were enhanced by COL10A1 over-expression (P < 0.001). Silencing of COL10A1 reduced the protein level of TGF-β1 (P < 0.01), and down-regulated the phosphorylation of Smad2 and Smad3 in CC (P < 0.001).

Conclusion

Down-regulation of COL10A1 suppressed cell proliferation, metastasis, and epithelial-mesenchymal transition of CC through inactivation of TGF-β/Smad signaling.

Trimetazidine inhibits liver fibrosis and hepatic stellate cell proliferation and blocks transforming growth factor-β (TGFβ)/Smad signaling in vitro and in vivo

Trimetazidine (TMZ) has been used extensively to treat coronary artery disease and to reduce fibrosis. Liver fibrosis is a reversible process. However, the impacts of TMZ on liver fibrosis triggered by CCl₄ and on hepatic stellate cells in liver fibrosis remain to be elaborated. In the current study, the liver fibrosis models were constructed by using CCl₄-induced mice and TGF-β-induced hepatic stellate cells. The involvement of TMZ in liver fibrosis was subsequently investigated. In the CCl₄-induced hepatic fibrosis mouse model, it was shown that the expression levels of alanine aminotransferase and aspartate aminotransferase were reduced after TMZ treatment; the expression levels of the extracellular matrix proteins colla1 and α-SMA were down-regulated; furthermore, the expression levels of TGFβ/Smad signaling proteins were inhibited. In TGF-β-induced hepatic stellate cells, compared to the TGF-β-induced group, cell proliferation and migration were inhibited after TMZ treatment; meanwhile, extracellular matrix protein and TGFβ/Smad signaling protein expression levels followed the same trend as in the hepatic fibrosis model. In conclusion, TMZ could block the TGFβ/Smad signaling in liver fibrosis model, with inhibiting liver fibrosis and hepatic stellate cell proliferation. This may broaden the application sphere of TMZ in liver fibrosis therapy.

Tangshen Formula Improves Diabetes-Associated Myocardial Fibrosis by Inhibiting TGF-β/Smads and Wnt/β-Catenin Pathways

Cardiovascular disease has become the main cause of death among complications of diabetes. Myocardial fibrosis is a crucial pathological change of cardiovascular disease. Tangshen Formula (TSF) shows a good clinical effect in the treatment of diabetic kidney disease (DKD). However, whether TSF alleviates diabetes-associated myocardial fibrosis is still unknown. In the present research, we studied the effect and mechanism of TSF in the treatment of myocardial fibrosis in vivo and in vitro. We found that TSF treatment significantly downregulates myocardial fibrosis-related markers, including collagens I and III, and α-SMA. TSF also protects primary mouse cardiac fibroblast (CF) from transforming growth factor-β1- (TGF-β1-) induced damage. Moreover, TSF decreased the expression levels of TGF-β/Smad-related genes (α-SMA, collagens I and III, TGF-β1, and pSmad2/3), and increased Smad7 gene expression. Finally, TSF decreased the expressions of wnt1, active-β-catenin, FN, and MMP7 to regulate the Wnt/β-catenin pathway. Taken together, TSF seems to attenuate myocardial fibrosis in KKAy mice by inhibiting TGF-β/Smad2/3 and Wnt/β-catenin signaling pathways.

Suppression of latent transforming growth factor-β (TGF-β)-binding protein 1 (LTBP1) inhibits natural killer/ T cell lymphoma progression by inactivating the TGF-β/Smad and p38MAPK pathways

BACKGROUND

Natural killer/T cell lymphoma (NKTCL) is a distinct subtype of Non-Hodgkin's lymphoma with highly aggressive clinical behavior. We aim to investigate the function of Latent transforming growth factor β binding protein 1 (LTBP1) and transforming growth factor beta1 (TGF-β1) and complex molecular pathogenesis of this disease.

METHODS

NKTCL patients and reactive lymph nodes patients were recruited in this study. The expression of LTBP1 and TGF-β1 was examined using qRT-PCR, Western blot, IHC and ELISA analyses in biopsied tissues and serum from participants and NKTCL cell lines. Cell proliferation was determined using CFSE. Cell cycle and apoptosis were evaluated using flow cytometric analyses. The expression of Ki-67, CDK4 and cyclinD1 proteins was measured using Western blot analyses. The roles of LTBP-1/TGF-β1 in EMT program were determined by measuring E-cadherin, N-cadherin and Vimentin using Western blot analyses. The effects of LTBP-1 and TGF-β1 on tumor progression in vivo were determined by animal experiments.

RESULTS

LTBP-1 and TGF-β1 levels were elevated in NKTCL tissues and serum. The expression of LTBP-1 was positively correlated with the expression of TGF-β1 in NKTCL tissues. LTBP-1 was overexpressed in NKTCL cells. Knockdown of LTBP-1 suppressed cell proliferation and cell cycle progression, induced cell apoptosis, and suppressed EMT program in NKTCL cells. These effects of LTBP-1 knockdown were attenuated after TGF-β1 stimulation. Knockdown of LTBP-1 inhibited NKTCL tumor weight and volume in vivo. Also, stimulation of TGF-β1 attenuated the suppressive effects on tumor growth from sh-LTBP-1. Silencing of LTBP-1 lowered cellular TGF-β1, phosphorylated-Smad2, phosphorlyatd-Smad3, and phosphorylated-p38 and the suppressive effects were reversed after stimulation of TGF-β1.

CONCLUSION

Our findings suggested that inhibition of LTBP-1/TGF-β1 suppressed the malignant phenotypes of NKTCL cells and tumor growth via inactivating the canonical TGF-β/Smad signaling and p38^MAPK signaling.

Phytoconstituents and renoprotective effect of Polyalthia longifolia leaves extract on radiation-induced nephritis in rats via TGF-β/smad pathway

Renoprotectors are highly demanded due to environmental nephrotoxic factors. P. longifolia leaves extract alleviating effect was assessed in nephritic-induced rats by whole body shot dose of γ-radiation. Many biomarkers were detected using several assays. Renohistopathological examinations were performed. Moreover, the extract phytoconstituents were identified using spectroscopic analysis. In-vitro anti-inflammatory activity of some compounds was examined using histamine release assay. Post-irradiation treatment with the extract significantly ameliorated all elevated biomarker levels. Creatinine and urea were adjusted, TGF-β/Smad signaling was suppressed causing down-regulation to microRNA-21. Nitric oxide, reactive oxygen species, glutathione and kidney injury molecule-1 were normalized in comparison with the γ-irradiated group. The renohistopathological analysis was consistent with the biochemical study. Phytochemical analysis resulted in the isolation of two diterpenoids (γ-methoxybutenolide clerodane diterpene and 16(R/S)-hydroxycleroda-3,13-dien-16,15-olide-2-one), aporphine alkaloid (anonaine) and flavonol (kaempferol-3-O-rutinoside). The latter two showed moderate anti-histaminic activities. Our results indicated that P. longifolia reduced oxidative stress and nephropathy in rats due to its anti-inflammatory principles.

Rack1 is essential for corticogenesis by preventing p21-dependent senescence in neural stem cells

Normal neurodevelopment relies on intricate signaling pathways that balance neural stem cell (NSC) self-renewal, maturation, and survival. Disruptions lead to neurodevelopmental disorders, including microcephaly. Here, we implicate the inhibition of NSC senescence as a mechanism underlying neurogenesis and corticogenesis. We report that the receptor for activated C kinase (Rack1), a family member of WD40-repeat (WDR) proteins, is highly enriched in NSCs. Deletion of Rack1 in developing cortical progenitors leads to a microcephaly phenotype. Strikingly, the absence of Rack1 decreases neurogenesis and promotes a cellular senescence phenotype in NSCs. Mechanistically, the senescence-related p21 signaling pathway is dramatically activated in Rack1 null NSCs, and removal of p21 significantly rescues the Rack1-knockout phenotype in vivo. Finally, Rack1 directly interacts with Smad3 to suppress the activation of transforming growth factor (TGF)-β/Smad signaling pathway, which plays a critical role in p21-mediated senescence. Our data implicate Rack1-driven inhibition of p21-induced NSC senescence as a critical mechanism behind normal cortical development.

In Vitro and In Vivo Study on the Toxic Effects of Propiconazole Fungicide in the Pathogenesis of Liver Fibrosis

Propiconazole (PCZ) is a hepatotoxic triazole fungicide. There are insufficient data on how PCZ induces liver fibrosis in humans. This study aimed to investigate the effect of PCZ on liver fibrosis and its underlying mechanisms. HepG2 cells and Sprague-Dawley rats were exposed to PCZ at doses of 0-160 μM (3-72 h) and 0.5-50 mg/kg body weight/day (28 days), respectively. PCZ-treated cells activated intracellular oxidative stress via cytochrome P450 and had higher mRNA levels of interleukin-1β, tumor necrosis factor-α, matrix metalloproteinase (MMP)-2, MMP-9, and transforming growth factor-β (TGF-β) than the control. PCZ treatment in cells induced a morphological transition with E-cadherin decrease and vimentin and Snail increase via the oxidative stress and TGF-β/Smad pathways. PCZ administration in rats induced liver fibrosis through pathological changes, epithelial-mesenchymal transition, and collagen deposition. Thus, our data suggest that exposure of PCZ to humans may be a risk factor for the functional integrity of the liver.

ADNP prompts the cisplatin-resistance of bladder cancer via TGF-β-mediated epithelial-mesenchymal transition (EMT) pathway

Activity-dependent neuroprotective protein (ADNP) is vital for embryonic development and brain formation. Besides, the upregulated expression of ADNP enhances tumorigenesis in some human tumors like bladder cancer (BC). However, the potential roles of ADNP in drug resistance and the related mechanisms in BC is unknown. We performed this study to elucidate the influence of ADNP in the chemoresistance of BC and tried to explore the underlying molecular mechanism. The expressions of ADNP in BC from progression and non-progression patient specimens were measured by quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC). In vitro experiments including colony formation, cell counting kit-8 (CCK-8), wound healing, and in vivo tumorigenesis assay were performed to explore the effects of ADNP on chemoresistance of BC. The impacts of ADNP on TGF-β/Smad signaling pathways were explored by western blot. Our results showed that the expression of ADNP mRNA and protein were significantly upregulated in BC tissues of the patients who suffered tumor-progression via RT-PCR and western blot. Cox regression survival analysis revealed that patients with high ADNP expression closely linked to shorter tumor-free survival. ADNP downregulation in BC showed more sensitive to cisplatin in vivo, while ADNP overexpression showed the opposite results. Additionally, we confirmed that ADNP promoted cell migration and EMT, thereby inducing cisplatin resistance, which may be related to TGF-β / Smad signaling pathway.

LINC00174 Facilitates Cell Proliferation, Cell Migration and Tumor Growth of Osteosarcoma via Regulating the TGF-β/SMAD Signaling Pathway and Upregulating SSH2 Expression

Osteosarcoma (OS), a frequent malignant tumor which mainly occurs in the bone. The roles of long noncoding RNAs (lncRNAs) have been revealed in cancers, including OS. LncRNA long intergenic non-protein coding RNA (LINC00174) has been validated as an oncogene in several cancers. However, the role of LINC00174 in OS has not been explored. In our research, loss-of-function assays were conducted to explore the function of LINC00174 in OS cells. Then, we explored the downstream pathway of LINC00174 in OS cells. Bioinformatics, RNA pull-down and RIP experiments investigated the downstream mechanism of LINC00174 in OS cells. Finally, in vivo assays clarified the effect of LINC00174 on tumorigenesis. We found that LINC00174 was upregulated in OS tissues and cells. LINC00174 knockdown repressed OS cell growth. Mechanistically, LINC00174 knockdown suppressed the TGF-β/SMAD pathway. LINC00174 interacted with miR-378a-3p, and slingshot protein phosphatase 2 (SSH2) 3′UTR was targeted by miR-378a-3p in OS cells. Rescue assays showed that SSH2 upregulation or miR-378a-3p inhibition counteracted the inhibitory effect of LINC00174 depletion in OS cell growth. Additionally, LINC00174 depletion suppressed tumor growth in mice. In conclusion, LINC00174 promotes OS cellular malignancy and tumorigenesis via the miR-378a-3p/SSH2 axis and the TGF-β/SMAD pathway, which might provide a novel insight for OS treatment.

The role of MEG3 in the proliferation of palatal mesenchymal cells is related to the TGFβ/Smad pathway in TCDD inducing cleft palate

Cleft palate (CP) is a common birth defect with a high incidence of occurrence in humans. The 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is a highly toxic halogenated aromatic hydrocarbon, with a strong CP effect on mice. Increasing recent evidences have shown that long-noncoding RNAs (lncRNAs) play an important role in several diseases, including CP. However, there is a paucity of studies on the role of lncRNA MEG3 in the occurrence and development of TCDD-induced CP. In this study, the relationship between MEG3 and the proliferation of palatal mesenchymal cells and the underlying molecular mechanism were studied by establishing fetal CP with TCDD (64 μg/kg) in C57BL/6N mice. The results revealed that MEG3 was highly expressed during the critical period of CP formation and that the fetal mesenchymal proliferation was significantly inhibited at certain critical periods in the mice receiving TCDD. In addition, we noted a possibility of a crosstalk between MEG3 and the TGF-β/Smad pathway, such that the inhibition of the TGF-β/Smad pathway was induced by TCDD. Cumulatively, our study suggests that TCDD-induced CP may be caused by MEG3 inhibition of the proliferation of palatal mesenchymal cells involving the TGFβ/Smad pathway, which may provide a novel perspective to understand the pathogenesis of CP.

Ligustroflavone ameliorates CCl4-induced liver fibrosis through down-regulating the TGF-β/Smad signaling pathway

Liver fibrosis is a pathological process characterized by excess deposition of extracellular matrix (ECM) that are mainly derived from activated hepatic stellate cells. Previous studies suggested that ligustroflavone (LF) was an ingredient of Ligustrum lucidum Ait. with activities of anti-inflammation and anti-oxidation. In this study, we investigated whether LF had any effect on liver fibrosis. In our study, we established a mouse model of carbon tetrachloride (CCl₄)-induced liver fibrosis and used TGF-β₁-stimulated human hepatic stellate cell line (LX-2) to explore the effect of LF and associated underlying mechanism. LF was used in vivo with low dose (L-LF, 5 mg·kg^-1, i.p., 3 times each week) and high dose (H-LF, 20 mg·kg^-1, i.p., 3 times each week) and in vitro (25 μmol·L^-1). Histopathological and biochemical assays investigations showed that LF delayed the formation of liver fibrosis; decreased AST, ALT activities and increased Alb activity in serum; decreased MDA level, Hyp content and increased GSH-Px concentration, SOD activity in liver tissues. Moreover, immunohistochemical, immunofluorescent and Western blot results showed that LF reduced the expressions of hepatic stellate cells specific marker proteins, including collagen I and α-SMA in vivo and in vitro. In addition, LF markedly suppressed TGF-β₁-upregulated protein expressions of TβR I, TβR II, P-Smad2, P-Smad3 and Smad4 in LX-2 cells. Taken together, these findings demonstrated LF could decrease histopathological lesions, ameliorate oxidative injury, attenuate CCl₄-induced liver fibrosis, which may be associated with down-regulating the TGF-β/Smad signaling pathway.

Silymarin nanoliposomes attenuate renal injury on diabetic nephropathy rats via co-suppressing TGF-β/Smad and JAK2/STAT3/SOCS1 pathway

AIMS

To investigate the improvement and mechanisms of silymarin on renal injury in mouse podocytes and streptozotocin (STZ)-induced diabetic nephropathy model (DN) rats.

MAIN METHODS

Firstly, the effects of silymarin on the cell viability and cellular injury-related indicators of high-glucose incubated mouse podocytes MPC-5 were assessed by CCK-8 and western blotting (WB) methods, respectively. The STZ-induced diabetic rats with DN were treated with silymarin nanoliposomes at three doses for consecutive 8-week. General metabolic indicators, renal functions and lipid accumulation-related factors were all measured. The renal tissue sections were stained and observed via hematoxylin-eosin (H&E) staining method. Real-time RT-PCR and WB methods were utilized to measure the expression of JAK2/STAT3/SOCS1 and TGF-β/Smad signaling pathway related factors.

KEY FINDINGS

Silymarin significantly improve the high-glucose induced up-regulation of podoxin and nephrin, as well as the expression of inflammatory cytokines IL-6, ICAM-1 and TNF-α, and the cell survival rates were also significantly increased in a dose-dependent manner. Significant improvement on body weight/kidney ratio, renal functions and lipid profiles in renal tissues were observed in STZ-induced diabetic rats after chronic silymarin treatment. The H&E staining exhibited that the pathological damages in renal tissues were obviously improved. Moreover, silymarin nanoliposomes treatment notably suppressed expression levels of inflammation-related proteins as well as IL-6 and ICAM-1, and regulated JAK2/STAT3/SOCS1 and TGF-β/Smad signaling pathway, thereby exhibited protective effects on kidney of DN model rats.

SIGNIFICANCE

Silymarin nanoliposomes ameliorate STZ-induced kidney injury by improving oxidative stress, renal fibrosis, and co-inhibiting JAK2/STAT3/SOCS1 and TGF-β/Smad signaling pathways in diabetic rats.

EMT-Related Markers in Serum Exosomes are Potential Diagnostic Biomarkers for Invasive Pituitary Adenomas

PURPOSE

Assessing the invasiveness of pituitary adenomas (PAs) is critical to making the best surgical and treatment plan. However, it is difficult to determine the invasiveness of pituitary adenomas based on current clinical methods, such as imaging and histological methods. The present article aims to investigate noninvasive methods to discover viable biomarkers for invasive pituitary adenomas and provide a basis for early intervention of pituitary adenomas.

METHODS

E-cadherin, N-cadherin, Epcam, TGF-β, Smad3, and Smad7 were detected in the tissues and exosomes in 10 cases of invasive PAs and 10 cases of noninvasive PAs by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemical analysis.

RESULTS

Compared with that in the noninvasive group, the expression of N-cad in the exosomes of the invasive group was significantly increased, and the expression of E-cad and Epcam was reduced. In the invasive group, the expression levels of TGF-β1 and Smad3 were reduced. These results were consistent across exosomes and groups. In further cell experiments, the EMT ratio in the SIS3 treatment group, and especially in the TGF-β1 plus SIS3 treatment group (P <0.001), was significantly increased, and the EMT ratio was significantly lower when one-half the dose of TGF-β and SIS3.

CONCLUSION

The results indicate that EMT-related biomarkers in serum exosomes can be potentially used for assessing the invasiveness of pituitary adenoma.

Piperlongumine attenuates bile duct ligation-induced liver fibrosis in mice via inhibition of TGF-β1/Smad and EMT pathways

Liver fibrosis (LF) is a progressive liver injury that may result in excessive accumulation of extracellular matrix (ECM). However, transforming growth factor-beta (TGF-β) and epithelial to mesenchymal transition (EMT) play a central role in the progression of LF through the activation of matrix producing hepatic stellate cells (HSCs). Piperlongumine (PL), an alkaloid extracted from Piper longum, has been reported to possess anti-inflammatory and antioxidant activities in various diseases but its hepatoprotective and antifibrotic effects have not been reported yet. Therefore, in the present study, we investigated the protective effect of PL in bile duct ligation (BDL)-induced LF model and explored the molecular mechanisms underlying its antifibrotic effect. BDL group displayed a significant degree of liver damage, oxidative-nitrosative stress, hepatic inflammation and collagen deposition in the liver while these pathological changes were effectively attenuated by treatment with PL. Furthermore, we found that PL treatment greatly inhibited HSCs activation and ECM deposition via downregulation of fibronectin, α-SMA, collagen1a, and collagen3a expression in the fibrotic livers. We further demonstrated that PL administration significantly inhibited TGF-β1/Smad and EMT signaling pathways. Our study demonstrated that PL exerted strong hepatoprotective and antifibrotic activities against BDL-induced LF and might be an effective therapeutic agent for the treatment of LF.

MFAP4 deficiency alleviates renal fibrosis through inhibition of NF-κB and TGF-β/Smad signaling pathways

Renal fibrosis, which is characterized by excessive extracellular matrix (ECM) accumulation in the renal tubulointerstitium, can lead to chronic kidney disease (CKD). The role of microfiber-associated protein 4 (MFAP4), which is an ECM protein that interacts with elastin and collagen, in renal fibrosis has not been investigated. The aim of this study was to examine the role of MFAP4 in the pathogenesis of renal fibrosis and the underlying mechanism using in vivo and in vitro models. The MFAP4^-/- mice were subjected to unilateral ureteral obstruction (UUO) to elucidate the role of MFAP4 in renal fibrosis in vivo. Compared to the wild-type mice, the MFAP4^-/- mice exhibited decreased protein expression of p-p65 and p-IKBα and ECM deposition after UUO. The MFAP4^-/- mice exhibited attenuated nuclear translocation of p65 (the hub subunit of nuclear factor (NF)-κB signaling pathway), suppressed activation of transforming growth factor (TGF)-β/Smad pathways, and downregulated expression of fibronectin, collagen I, and plasminogen activator inhibitor-1. The knockdown of MFAP4 mitigated the TGF-β-induced upregulated expression of fibronectin, collagen I, and plasminogen activator inhibitor-1 in the human proximal tubular epithelial cells (HK-2). Compared to the HK-2 cells transfected with sh-MFAP4, the HK-2 cells co-transfected with sh-MFAP4 and Ad-MFAP4 exhibited severe inflammatory response and increased fibrosis-related proteins expression. Mechanistically, the knockdown of MFAP4 inhibited the activation of NF-κB and TGF-β/Smad signaling pathways and downregulated the expression of fibrosis-related proteins. The findings of this study indicate that MFAP4 is involved in UUO-induced renal fibrosis through regulation of NF-κB and TGF-β/Smad pathways.

The anti-fibrotic effect of human fetal skin-derived stem cell secretome on the liver fibrosis

BACKGROUND

Liver fibrosis resulting from chronic liver injury is one of the major causes of mortality worldwide. Stem cell-secreted secretome has been evaluated for overcoming the limitations of cell-based therapy in hepatic disease, while maintaining its advantages.

METHODS

In this study, we investigated the effect of human fetal skin-derived stem cell (hFSSC) secretome in the treatment of liver fibrosis. To determine the therapeutic potential of the hFSSC secretome in liver fibrosis, we established the CCl₄-induced rat liver fibrosis model and administered hFSSC secretome in vivo. Moreover, we investigated the anti-fibrotic mechanism of hFSSC secretome in hepatic stellate cells (HSCs).

RESULTS

Our results showed that hFSSC secretome effectively reduced collagen content in liver, improved the liver function and promoted liver regeneration. Interestingly, we also found that hFSSC secretome reduced liver fibrosis through suppressing the epithelial-mesenchymal transition (EMT) process. In addition, we found that hFSSC secretome inhibited the TGF-β1, Smad2, Smad3, and Collagen I expression, however, increased the Smad7 expression.

CONCLUSIONS

In conclusions, our results suggest that hFSSC secretome treatment could reduce CCl₄-induced liver fibrosis via regulating the TGF-β/Smad signal pathway.

Treatment of Hypertensive Heart Disease by Targeting Smad3 Signaling in Mice

Transforming growth factor β (TGF-β)/Smad3 signaling plays a central role in chronic heart disease. Here, we report that targeting Smad3 with a Smad3 inhibitor SIS3 in an established mouse model of hypertension significantly improved cardiac dysfunctions by preserving the left ventricle (LV) ejection fraction (LVEF) and LV fractional shortening (LVFS), while reducing the LV mass. In addition, SIS3 treatment also halted the progression of myocardial fibrosis by blocking α-smooth muscle actin-positive (α-SMA⁺) myofibroblasts and collagen matrix accumulation, and inhibited cardiac inflammation by suppressing interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP1), intercellular cell adhesion molecule-1 (ICAM1) expression, and infiltration of CD3⁺ T cells and F4/80⁺ macrophages. Interestingly, treatment with SIS3 did not alter levels of high blood pressure, revealing a blood pressure-independent cardioprotective effect of SIS3. Mechanistically, treatment with SIS3 not only directly inactivated TGF-β/Smad3 signaling but also protected cardiac Smad7 from Smurf2-mediated proteasomal ubiquitin degradation. Because Smad7 functions as an inhibitor for both TGF-β/Smad and nuclear factor κB (NF-κB) signaling, increased cardiac Smad7 could be another mechanism through which SIS3 treatment blocked Smad3-mediated myocardial fibrosis and NF-κB-driven cardiac inflammation. In conclusion, SIS3 is a therapeutic agent for hypertensive heart disease. Results from this study demonstrate that targeting Smad3 signaling with SIS3 may be a novel and effective therapy for chronic heart disease.

Chrysophanol ameliorates renal interstitial fibrosis by inhibiting the TGF-β/Smad signaling pathway

Renal interstitial fibrosis (RIF) is a major pathological feature of chronic kidney disease at middle and end stages. Chrysophanol (CP), 1,8-dihydroxy-3-methyl-9,10-anthraquinone, is an anthraquinone isolated from Rheum palmatum L. with a variety of pharmacological activities including the suppression of RIF. However, the effect of CP on renal fibrosis and its potential mechanism have not been elucidated. We conducted a comprehensive study by determining the expression levels of fibrotic markers and proteins including TGF-β1, α-SMA, and Smad3 related to transforming growth factor-beta/Smad (TGF-β/Smad) pathway in unilateral ureteral obstruction (UUO) mice and TGF-β1-stimulated HK-2 cells with the treatment of CP using western blotting and RT-qPCR analyses. Using small interfering RNA and co-immunoprecipitation, we evaluated the influences of CP on the interactions between Smad3 and Smad7 proteins and also on TGF-β RI and TGF-βR II. We found that CP administration significantly ameliorated UUO-induced kidney damage by reversing abnormal serum and urine biochemical parameters and decreasing the production of fibrotic markers including collagen I, collagen III, fibronectin, and α-SMA. Our results showed that TGF-β1 and phospho-Smad3 (p-Smad3) expression was significantly down-regulated and Smad7 expression was up-regulated by CP in UUO mice compared to the model group; however, the expression of Smad2, Smad4, and TGF-β receptors was not affected. Furthermore, CP modulated these fibrotic markers as well as p-Smad3 and Smad7 in TGF-β1-induced HK-2 cells. The inhibitory effect of CP was markedly reduced in TGF-β1-treated HK-2 cells transfected with Smad3 siRNA. Additionally, co-immunoprecipitation analysis indicated that CP blocked the interaction between Smad3 and TGF-β receptor I to suppress p-Smad3 expression. These findings demonstrated that CP alleviated RIF by inhibiting Smad3 phosphorylation, which provides a molecular basis for a new drug candidate for the treatment of RIF.

Asiaticoside inhibits TGF-β1-induced mesothelial-mesenchymal transition and oxidative stress via the Nrf2/HO-1 signaling pathway in the human peritoneal mesothelial cell line HMrSV5

Background

Peritoneal fibrosis (PF) is a frequent complication caused by peritoneal dialysis (PD). Peritoneal mesothelial cells (PMCs), the first barrier of the peritoneum, play an important role in maintaining structure and function in the peritoneum during PD. Mesothelial-mesenchymal transition (MMT) and oxidative stress of PMCs are two key processes of PF.

Purpose

To elucidate the efficacy and possible mechanism of asiaticoside inhibition of MMT and ROS generation in TGF-β1-induced PF in human peritoneal mesothelial cells (HPMCs).

Methods

MMT and ROS generation of HPMCs were induced by TGF-β1. To explain the anti-MMT and antioxidant role of asiaticoside, varied doses of asiaticoside, oxygen radical scavenger (NAC), TGF-β receptor kinase inhibitor (LY2109761) and Nrf2 inhibitor (ML385) were used separately. Immunoblots were used to detect the expression of signaling associated proteins. DCFH-DA was used to detect the generation of ROS. Transwell migration assay and wound healing assay were used to verify the capacity of asiaticoside to inhibit MMT. Immunofluorescence assay was performed to observe the subcellular translocation of Nrf2 and expression of HO-1.

Results

Asiaticoside inhibited TGF-β1-induced MMT and suppressed Smad signaling in a dose-dependent manner. Migration and invasion activities of HPMCs were decreased by asiaticoside. Asiaticoside decreased TGF-β1-induced ROS, especially in a high dose (150 μM) for 6 h. Furthermore, ML385 partly abolished the inhibitory effect of asiaticoside on MMT, ROS and p-Smad2/3.

Conclusions

Asiaticoside inhibited the TGF-β1-induced MMT and ROS via Nrf2 activation, thus protecting the peritoneal membrane and preventing PF.

Aluminum exposure promotes the metastatic proclivity of human colorectal cancer cells through matrix metalloproteinases and the TGF-β/Smad signaling pathway

Human exposure to aluminum (Al) mainly occurs through food intake. However, influences of Al on the gastrointestinal tract have been rarely reported. In particular, the effect of Al on the metastasis and angiogenesis of colorectal cancer cells has not been studied. Thus, we investigated the effect of Al on the metastatic proclivity using the human colorectal cancer cell line, HT-29. Cells were exposed to 1-16 mM AlCl₃ for 3-72 h. The effects of AlCl₃ on HT-29 cells for migration/invasion/adhesion, and metastasis-associated protein and gene expression were evaluated. AlCl₃ promoted cell migration and invasion, whereas it suppressed cell adhesion. AlCl₃-exposed cells showed decreased E-cadherin and increased vimentin and Snail. AlCl₃ increased transforming growth factor-beta (TGF-β) mRNA expression and Smad2/3 nuclear translocation. AlCl₃-treated cells had a higher mRNA expression of matrix metalloproteinase (MMP)-7 and -9 than the control. Particularly, AlCl₃-treated HT-29 cells promoted the angiogenesis of endothelial cells via increasing the secretion of vascular endothelial growth factor. Taken together, AlCl₃ can promote the metastatic proclivity of colorectal cancer cells through MMP-7, -9, and TGF-β/Smad2/3 pathway. Our data suggest that Al exposure of the gastrointestinal tract may be a risk factor for metastasis initiation in colorectal cancer cells.

TRIM59 inhibits PPM1A through ubiquitination and activates TGF-β/Smad signaling to promote the invasion of ectopic endometrial stromal cells in endometriosis

This study was conducted to define the underlying molecular mechanism of tripartite motif (TRIM) 59-induced invasion of ectopic endometrial stromal cells in endometriosis. Primary endometriosis ectopic endometrial stromal cells and normal endometrial cells were isolated and purified. Western blot was used to detect the expression of TRIM59, protein phosphatase Mg²⁺/Mn²⁺-dependent 1A (PPM1A), smad2/3, and phosphorylated (p)-smad2/3. Lentiviral vector-mediated TRIM59 interference and overexpression were established. Cell Counting Kit-8 assay was used to detect cell proliferation, and the Transwell migration assay was used to detect cell invasion. Matrix metalloproteinase (MMP-2), MMP9, smad2/3, and p-smad2/3 expressions were also detected using Western blot analysis; degradation of PPM1A was verified to be through ubiquitination. We found that TRIM59 expression levels in the endometriosis group was significantly higher compared with the normal group (P < 0.05), whereas the expression levels of PPM1A in the endometriosis group were significantly lower (P < 0.05). Endometriosis did not alter smad2/3 (P > 0.05) expression. However, after activating smad2/3 by phosphorylation, the expression of p-smad2/3 in the endometriosis group was significantly higher compared with the normal group (P < 0.05). The content of PPM1A in the TRIM59 overexpression group was significantly lower than that in the control group (P < 0.001), whereas the content of PPM1A in the siTRIM59 group was significantly higher than that in the control group (P < 0.001). In addition, there were no significant differences in the mRNA levels of PPM1A among the five groups, indicating that TRIM59 affects the expression of PPM1A at the posttranslational level (P < 0.05). Overexpression of TRIM59 significantly promoted the ubiquitination of PPM1A. We conclude that TRIM59 inhibits PPM1A through ubiquitination and activates the transforming growth factor-β/Smad pathway to promote the invasion of ectopic endometrial stromal cells in endometriosis.

TOP2A Promotes Tumorigenesis of High-grade Serous Ovarian Cancer by Regulating the TGF-β/Smad Pathway

Background: High-grade serous ovarian cancer (HGS) is the most aggressive form of ovarian cancer due to its rapid spread, insidious onset, and early dissemination throughout the abdominal cavity. However, the molecular pathogenesis of HGS remains unclear. This study aimed to identify key pathogenic genes and explore the underlying molecular mechanisms of HGS using bioinformatics analysis and biological experiments.

Methods: Two datasets were downloaded from the Gene Expression Omnibus databases to find differentially expressed genes (DEGs) between HGS and normal tissue samples. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were applied to investigate the primary functions of the DEGs. The protein-protein interaction network of the DEGs was constructed, and the interactions of various genes were ranked.

Results: Topoisomerase IIα (TOP2A) was identified as the hub gene associated with survival and mutation. Gene Set Enrichment Analysis and Gene Set Variation Analysis were conducted to predict the potential biological functions of TOP2A. Furthermore, the TOP2A expression level was significantly up-regulated in HGS cell lines, SKOV3 and HEY. Moreover, the proliferation, migration, and invasion capacities of SKOV3 and HEY cells were strongly suppressed after TOP2A knockdown. In addition, the levels of phosphorylated Smad2 and Smad3, the key members of the transforming growth factor-β (TGF-β)/Smad pathway that regulate HGS tumorigenesis, strongly decreased after knockdown of TOP2A.

Conclusions: This study identified that TOP2A was up-regulated in HGS, and it accelerated HGS progression via the TGF-β/Smad pathway. The findings provided a blueprint for TOP2A serving as a therapeutic target and a treatment response prediction biomarker for HGS.

Wu-Mei-Wan ameliorates chronic colitis-associated intestinal fibrosis through inhibiting fibroblast activation

ETHNOPHARMACOLOGICAL RELEVANCE

Wu-Mei-Wan (WMW), a classic traditional Chinese herb medicine, is one of the most important formulations to treat digestive diseases from ancient times to the present. Previous study showed that WMW has satisfactory curative effects on experimental colitis, which motivating the application of WMW on colitis-associated complications.

AIM OF THE STUDY

Intestinal fibrosis is usually considered to be a common complication of inflammatory bowel disease (IBD), particularly Crohn's disease (CD). Currently, no effective preventive measures or medical therapies are available for that. This work was designed to evaluate the effect and related mechanism of WMW on chronic colitis-associated intestinal fibrosis mice model.

MATERIALS AND METHODS

The chronic colitis-associated intestinal fibrosis mice model was established by weekly intrarectal injection of 2,4,6-trinitrobenzene sulfonic acid (TNBS). The mice survival rate, disease activity index (DAI), colon length and histological score were examined to assess the therapeutic effect of WMW. Masson's trichrome staining, hydroxyproline assay, immunohistochemical staining and western blot analysis were used to evaluate fibrosis level. Colon inflammation was determined by ELISA and immunofluorescence staining. Immunofluorescence staining was used to evaluate fibroblasts proliferation and epithelial to mesenchymal transition (EMT), and the expression of key molecules in fibrosis was analyzed by western blot.

RESULTS

Here we showed that WMW alleviates chronic colitis with improved survival rate, DAI, colon length and histological score. WMW inhibited the progression of intestinal fibrosis, decreased the expression of various fibrosis markers, such as α-SMA, collagen I, MMP-9 and fibronectin. In addition, WMW treatment reduced cytokines IL-6 and IFN-γ, and downregulated proinflammatory NF-κBp65 and STAT3 signaling pathways. Importantly, administration of WMW led to the inhibition of colon fibroblast proliferation and EMT, which are important mediators during fibrosis. Several key profibrotic pathways, including TGF-β/Smad and Wnt/β-catenin pathways, were downregulated by WMW treatment.

CONCLUSION

Our work demonstrated that WMW can prevent intestinal fibrosis and the mechanisms involved may be related to the inhibition of colon fibroblasts activation.