Ellagic acid ameliorates renal fibrogenesis by blocking epithelial-to-mesenchymal transition.

Objectives: Ellagic acid (EA), a kind of polyphenol found in numerous fruits and vegetables, has anti-inflammatory, anti-apoptotic, anti-oxidant, and anti-fibrotic effects against a variety of diseases, but its role in mediating renal fibrogenesis remains unknown. Materials and Methods: We used an in vivo mouse unilateral ureteral obstruction (UUO) model and an in vitro model with HK-2 cell lines treated with EA and transforming growth factor ß1 (TGF-ß1). The expression of epithelial-to-mesenchymal transition (EMT)-related proteins of UUO mice was examined using immunohistochemical staining. Liver function and renal function were evaluated using biochemical testing. Western blot analysis was used to determine the proteins related to EMT, and MTT assay was used to determine cell viability. Results: In UUO mice fed EA, both microscopical examination with immunohistochemical staining and western blotting protein analysis showed reduced expression of fibrotic (α-SMA, fibronectin, and collagen I)- and EMT (vimentin and N-cadherin)-related proteins, compared with sham control. In HK-2 cells treated with TGF-ß1, EA decreased motility as well as expression of α-SMA, collagen-I, fibronectin, N-cadherin, and vimentin. Conclusion: EA reduced the progression of the morphological transformations and concomitantly suppressed the expression of fibrotic- and EMT-related proteins in vitro and in vivo. These findings improved our understanding of the role of EA in suppressing renal fibrogenesis and demonstrated the promising role EA may play in the management of chronic kidney disease.

Alpha-mangostin alleviate renal interstitial fibrosis via suppression of TGF-ß1/Smad/ERK signaling axis in vitro and in vivo.

α-mangostin (α-MG), a natural derivative of coumarin, exhibits anti-inflammatory, antioxidant and anti-fibrotic effects. This study aimed to determine the effect of α-MG treatment in mediating the process of renal interstitial fibrosis. We found that α-MG could alleviate tubule-interstitial damage and decrease fibrotic (α-smooth muscle actin [α-SMA], fibronectin, and collagen I), and epithelial-mesenchymal transition (EMT) protein (N-cadherin, Snail, Slug, TGF-ß1 and vimentin) expression in unilateral ureteral obstruction (UUO) mice with chronic kidney disease. α-MG significantly decreased motility as well as inhibited expression of fibrotic- and EMT-related proteins in TGF-ß1-induced HK2 cells. To clarify the molecular mechanisms of α-MG in reducing renal interstitial fibrosis, we used a MEK inhibitor (U0126) or Smad inhibitor (SB431542) cotreatment with α-MG. This is the first study is to demonstrate the antifibrotic effects of α-MG by targeting the TGF-ß1/ERK/Smad-mediated EMT signaling pathway, is even more effective against renal interstitial fibrosis.

Melatonin combined with sorafenib synergistically inhibit the invasive ability through targeting metastasis-associated protein 2 expression in human renal cancer cells.

Objectives: Renal cell carcinoma (RCC) was the most common and lethal urological malignancy with the dismal outcome when distant metastasis. Melatonin was known as a potential oncostatic agent against several types of malignancy and sorafenib had been considered as an agent to treat RCC, but the synergistic effects of melatonin and sorafenib on human RCC have not been elucidated. Materials and Methods: Human renal cancer cell lines (Caki-1 and ACHN) were treated with melatonin combined with sorafenib were detected the cell growth and cell cycle by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and flow cytometry. The ability of cell migration/invasion was performed with in vitro migration and invasion assay. The proteins and mRNA expression of metastasis-associated protein 2 (MTA2) from the RCC cells were measured by quantitative reverse transcription-polymerase chain reaction and western blotting. Clinical significance of MTA2 in RCC tissues was analyzed from The Cancer Genome Atlas database by using TISIDB software. Results: Our results showed that melatonin combined with sorafenib, sorafenib or melatonin-treated alone did not induce the cytotoxic effects or cell cycle arrest in human RCC cells and HK2 cells. Additionally, cotreatment with melatonin and sorafenib synergistically reduced migration and invasion in human Caki-1 and ACHN cells through synergistically suppression of MTA2 expression. Bioinformatics analysis showed that MTA2 expression significantly correlated with overall survival (P < 0.002), tumor grade (P < 0.001) and tumor stage (P < 0.001) in human RCC. Conclusion: Our results demonstrated that concomitantly used melatonin and sorafenib could significantly reduce the abilities of migration and invasion of RCC cells through inhibiting MTA2. We considered that this novel promising combination strategy towards the treatment of RCC, but further studies are warranted.

Blockage of Autophagy Increases Timosaponin AIII-Induced Apoptosis of Glioma Cells In Vitro and In Vivo.

Timosaponin AIII (TSAIII), a saponin isolated from Anemarrhena asphodeloides and used in traditional Chinese medicine, exerts antitumor, anti-inflammatory, anti-angiogenesis, and pro-apoptotic activity on a variety of tumor cells. This study investigated the antitumor effects of TSAIII and the underlying mechanisms in human glioma cells in vitro and in vivo. TSAIII significantly inhibited glioma cell viability in a dose- and time-dependent manner but did not affect the growth of normal astrocytes. We also observed that in both glioma cell lines, TSAIII induces cell death and mitochondrial dysfunction, consistent with observed increases in the protein expression of cleaved-caspase-3, cleaved-caspase-9, cleaved-PARP, cytochrome c, and Mcl-1. TSAIII also activated autophagy, as indicated by increased accumulation of the autophagosome markers p62 and LC3-II and the autolysosome marker LAMP1. LC3 silencing, as well as TSAIII combined with the autophagy inhibitor 3-methyladenine (3MA), increased apoptosis in GBM8401 cells. TSAIII inhibited tumor growth in xenografts and in an orthotopic GBM8401 mice model in vivo. These results demonstrate that TSAIII exhibits antitumor effects and may hold potential as a therapy for glioma.

C-C Motif Chemokine Ligand-17 as a Novel Biomarker and Regulator of Epithelial Mesenchymal Transition in Renal Fibrogenesis.

CCL17, a chemotactic cytokine produced by macrophages, is known to promote inflammatory and fibrotic effects in multiple organs, but its role in mediating renal fibrosis is unclear. In our study cohort of 234 chronic kidney disease (CKD) patients and 65 healthy controls, human cytokine array analysis revealed elevated CCL17 expression in CKD that correlated negatively with renal function. The area under the receiver operating characteristic curve of CCL17 to predict the development of CKD stages 3b-5 was 0.644 (p < 0.001), with the optimal cut-off value of 415.3 ng/mL. In vitro over-expression of CCL17 in HK2 cells had no effect on cell viability, but increased cell motility and the expression of α-SMA, vimentin and collagen I, as shown by western blot analysis. In a unilateral ureteral obstruction (UUO) mouse model, we observed significantly increased interstitial fibrosis and renal tubule dilatation by Masson's Trichrome and H&E staining, and markedly increased expression of CCL17, vimentin, collagen I, and α-SMA by IHC stain, qRTPCR, and western blotting. CCL17 induced renal fibrosis by promoting the epithelial-mesenchymal transition, resulting in ECM accumulation. CCL17 may be a useful biomarker for predicting the development of advanced CKD.

In Vitro and In Vivo Antifibrotic Effects of Fraxetin on Renal Interstitial Fibrosis via the ERK Signaling Pathway.

Fraxetin, a natural derivative of coumarin, is known to have anti-inflammatory, anti-oxidant, and hepatoprotective effects in multiple diseases and in liver fibrosis. Whether fraxetin exerts similar effects against renal fibrosis is unknown. In a Unilateral Ureteral Obstruction (UUO) mouse model of renal fibrosis, fraxetin decreased UUO-induced renal dysfunction with a marked reduction in renal interstitial collagen fibers as detected by Masson's Trichrome staining. Fraxetin treatment also inhibited the expression of α-SMA, Collagen I, Collagen IV, fibronectin, N-cadherin, vimentin, phosphorylated-ERK, and increased the expression of E-cadherin in UUO mice, as shown by immunohistochemical staining and western blot analysis. In vitro studies showed that fraxetin and indoxyl sulfate had no cytotoxic effects on MES13 kidney cells, but that fraxetin significantly decreased IS-induced cell motility and decreased protein expression of α-SMA, N-cadherin, vimentin, and Collagen IV via the ERK-mediated signaling pathway. These findings provide insight into the mechanism underlying fraxetin-induced inhibition of fibrogenesis in renal tissue and suggest that fraxetin treatment may be beneficial for slowing CKD progression.

Overexpression of Lipocalin-2 Inhibits Proliferation and Invasiveness of Human Glioblastoma Multiforme Cells by Activating ERK Targeting Cathepsin D Expression.

Lipocalin-2 (LCN2) exhibits pro- and anti-carcinogenic effects in several cancers, but its role in the progression of glioblastoma multiforme (GBM) remains unclear. This study aims to elucidate the effect of LCN2 in human GBM cell, and the mechanism underlying its effects on GBM malignant progression. We observed that LCN2 expression was significantly lower in GBM than in normal tissues and was associated with poorer GBM patient survival. LCN2-overexpressing GBM cells showed significantly reduced proliferation and migration/invasion abilities. Human protease antibody array analysis showed that the expression of cathepsin D (CTSD) protein and mRNA was lower in LCN2-overexpressing GBM cells than in controls. Higher CTSD expression was observed in GBM tumors than in normal tissues, and higher CTSD expression was associated with poorer overall and disease-free survival. LCN2-overexpressing GBM cells exhibited increased ERK phosphorylation. Treatment of these cells with a MEK inhibitor (U0126) restored CTSD expression, cell migration, and cell invasiveness. In conclusion, LCN2 might be serving as a prognostic marker and promising anti-proliferative and anti-metastatic target for treating GBM.

Endothelial Cell-Specific Molecule 1 Promotes Endothelial to Mesenchymal Transition in Renal Fibrosis.

The endothelial-to-mesenchymal transition (EndoMT) is involved in the complex pathogenesis of renal fibrosis. The soluble proteoglycan endothelial cell-specific molecule 1 (ESM1) is significantly upregulated in many tumor cells and cirrhosis-related disease. The role of ESM1 in renal fibrosis is unknown. This study investigates the role of ESM1 in renal fibrosis, using an in vivo unilateral ureteral obstruction (UUO) mouse model of renal fibrosis and in vitro mouse kidney MES 13 cells overexpressing ESM1. We observed that ESM1 overexpression significantly increased the motility and migration of MES 13 cells, independent of cell viability. In ESM1-overexpressing MES 13 cells, we also observed elevated expression of mesenchymal markers (N-cadherin, vimentin, matrix metallopeptidase 9 (MMP9)) and the fibrosis marker α-smooth muscle actin (α-SMA) and decreased expression of the endothelial marker vascular endothelial cadherin (VE-cadherin) and CD31. In a mouse model of fibrosis induced by unilateral ureter obstruction, we observed time-dependent increases in ESM1, α-SMA, and vimentin expression and renal interstitial collagen fibers in kidney tissue samples. These results suggest that ESM1 may serve as an EndoMT marker of renal fibrosis progression.

Arecoline induces epithelial mesenchymal transition in HK2 cells by upregulating the ERK-mediated signaling pathway.

Arecoline, a component of betel nuts, is a known carcinogen that causes oral cancers among those who chew betel nuts. Betel nut chewing is also associated with an increased risk of chronic kidney disease (CKD), but the role of arecoline in this association is unclear. This in vitro study investigates the effects of arecoline on cultured human kidney (HK2) cells. We observed that arecoline had no effect on cell viability but increased cell migration in a dose-dependent manner. Western blot analysis showed that arecoline treatment caused a dose-dependent decrease in E-cadherin expression and dose-dependent increases in N-cadherin, vimentin, α-SMA, and collagen expression; reverse transcriptase-polymerase chain reaction analysis revealed dose-dependent increases in α-SMA and collagen mRNA. Arecoline treatment upregulated the expression of phosphorylated extracellular signal-regulated kinase through epithelial mesenchymal transition and renal fibrosis in HK2 cells. These findings demonstrate that arecoline plays a role in inducing the epithelial mesenchymal transition and fibrogenesis in renal tubule cells and suggest that arecoline promotes the progression of CKD.

MTA2 as a Potential Biomarker and Its Involvement in Metastatic Progression of Human Renal Cancer by miR-133b Targeting MMP-9.

Metastasis-associated protein 2 (MTA2) was previously known as a requirement to maintain malignant potentials in several human cancers. However, the role of MTA2 in the progression of renal cell carcinoma (RCC) has not yet been delineated. In this study, MTA2 expression was significantly increased in RCC tissues and cell lines. Increased MTA2 expression was significantly associated with tumour grade (p = 0.002) and was an independent prognostic factor for overall survival with a high RCC tumour grade. MTA2 knockdown inhibited the migration, invasion, and in vivo metastasis of RCC cells without effects on cell proliferation. Regarding molecular mechanisms, MTA2 knockdown reduced the activity, protein level, and mRNA expression of matrix metalloproteinase-9 (MMP-9) in RCC cells. Further analyses demonstrated that patients with lower miR-133b expression had poorer survival rates than those with higher expression from The Cancer Genome Atlas database. Moreover, miR-133b modulated the 3'untranslated region (UTR) of MMP-9 promoter activities and subsequently the migratory and invasive abilities of these dysregulated expressions of MTA2 in RCC cells. The inhibition of MTA2 could contribute to human RCC metastasis by regulating the expression of miR-133b targeting MMP-9 expression.