One of the major challenges in gastric cancer (GC) chemotherapy is the phenomenon of multi-drug resistance (MDR). The epithelial-mesenchymal transition (EMT) and its key molecules, transforming growth factor-β (TGFβ) and SMAD2, play a central role in MDR occurrence. Tamoxifen (TAM), a triphenylethylene derivative, can overcome MDR in human gastric cancers. The aim of this study was to investigate the effect of TAM on 5-FU resistance of GC by suppressing the TGFβ1/SMAD2 signaling pathway and EMT. The MKN-45 cell line was subjected to treatment with 5-FU, TAM and a combination of both. The MTT assay was used to investigate the cytotoxic effects of 5-FU and TAM, and the DNA laddering technique was used to assess DNA fragmentation and apoptosis. Real-time RT-PCR examined the change in gene expression in EMT-related genes (SNAI2, VIM, TGFβ1 and SMAD2). The results of the present study indicated that not only TAM treatment significantly decreased the IC50 of 5-FU (P≤0. 05), but also the addition of TAM to 5-FU induced apoptosis in the MKN-45 cell line. Treatment with TAM and 5-FU significantly inhibited TGFβ1 and TGFβ1-induced expression of EMT markers (VIM and SNAI2) in MKN-45 cells (P≤0. 05). The reduction of TGFβ1 targets downstream of the SMAD2 signaling pathway reversed the process of EMT and significantly increased the sensitivity of MKN-45 cells to 5-FU. The results of the present study suggested that reversal of EMT-mediated MDR via the TGFβ1/SMAD signaling pathway using TAM may be a potential new therapeutic strategy to overcome chemoresistance to 5-FU during GC chemotherapy.

Introduction. One of the most significant clinical features of chronic kidney disease is renal interstitial fibrosis (RIF). This study aimed to investigate the role and mechanism of Shenqi Pill (SQP) on RIF. Methods. RIF model was established by conducting unilateral ureteral obstruction (UUO) surgery on rat or stimulating human kidney-2 (HK-2) cell with transforming growth factor β1 (TGFβ1). After modeling, the rats in the SQP low dose group (SQP-L), SQP middle dose group (SQP-M) and SQP high dose group (SQP-H) were treated with SQP at 1. 5, 3 or 6 g/kg/d, and the cells in the TGFβ1+SQP-L/M/H were treated with 2. 5%, 5%, 10% SQP-containing serum. In in vivo assays, serum creatinine (SCr) and blood urea nitrogen (BUN) content were measured, kidney histopathology was evaluated., and α-smooth muscle actin (α‐SMA) expression was detected by immunohistochemistry. Interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) content, inhibitor of kappa B alpha (IKBα) and P65 phosphorylation were assessed. Meanwhile, cell viability, inflammatory cytokines content, α‐SMA expression, IKBα and P65 phosphorylation were detected in vitro experiment. Results. SQP exhibited reno-protective effect by decreasing SCr and BUN content, improving renal interstitial damage, blunting fibronectin (FN) and α‐SMA expression in RIF rats. Similarly, after the treatment with SQP-containing serum, viability and α‐SMA expression were remarkably decreased in TGFβ1-stimulated HK-2 cell. Furthermore, SQP markedly down-regulated IL-1β, IL-6, and TNF-α content, IKBα and RelA (P65) phosphorylation both in vivo and in vitro. Conclusion. SQP has a reno-protective effect against RIF in vivo and in vitro, and the effect is partly linked to nuclear factor-kappa B (NF-κB) pathway related inflammatory response, which indicates that SQP may be a candidate drug for RIF.

Background: Impaired wound healing is one of the complications of diabetes. Carvacrol, a natural substance, shows promising results in diabetic wound healing despite the fact that its therapeutic mechanisms are not fully understood. Objectives: The aim of this study was to investigate the molecular alterations caused by carvacrol intervention in human dermal fibroblasts (HDFs) cultured at a high-glucose condition. Methods: The HDFs were incubated in different glucose concentrations, and cell viability was assessed. In addition, carvacrol cytotoxicity was determined. Then, the HDFs were incubated in 50 mM glucose prior to treatment. After that, the cells were divided into 4 groups: Controls, high-glucose (50 mM), carvacrol-treated (9 µM), and high-glucose carvacrol-treated for 24 h. Cell proliferation and migration were examined. Furthermore, superoxide dismutase (SOD) production, collagen deposition, and RNA levels of TGFβ1, ACTA2, and miR-155 were investigated. Results: The in vitro scratch assay revealed that the fibroblast migration, which was reduced at high-glucose concentration, was reversed due to the carvacrol intervention during 12 h and 24 h (P < 0. 01 and P < 0. 001, respectively). Collagen deposition and SOD synthesis showed an increase in treated cells (P < 0. 001). Both TGFβ1 and ACTA2 mRNA expressions were elevated due to the carvacrol treatment, while the miR-155 level decreased (P < 0. 001). Conclusions: A high level of glucose impaired the cellular function of human dermal fibroblast. Carvacrol reversed the adverse effects of high-glucose stress and promoted wound healing through greater cell migration, collagen deposition, and levels of TGFb1 and ACTA2 gene expression. It showed inhibitory effects against miR-155, which is known for its negative role in diabetic wound healing.

Background: Activated hepatic stellate cells (HSC) through the TGF-β signaling pathway are likely to exacerbate liver fibrosis, which is a later stage of NASH, a condition in which, in addition to HSC activation, the overexpression of extracellular matrix (ECM) proteins, specifically collagen-I α and α-SMA, is expected. MicroRNA-126a, a modulator of HSC activation, influences the phosphorylation of Smad2/3. Objectives: This study aimed to investigate the impact of exosomes on miRNAs implicated in the progression of liver fibrosis by focusing on the role of miR-126a in the HSC-T6 cell line. Methods: In the present study, we investigated the effects of exosomes derived from LPS-stimulated mesenchymal stem cells (MSCs) on the expression of miR-126a and the phosphorylation of Smad3c in the HSC-T6 cell line. First, HSC-T6 cells were cultured in DMEM supplemented with 10% FBS. Next, we isolated exosomes derived from MSCs using the ExoCib kit. Finally, we examined the gene expression levels of collagen-Iα, α-SMA, and miR-126a using real-time PCR. Results: The results showed that treatment with TGFβ1 increased the phosphorylation of p-Smad3c (P < 0.0001), as well as the expression of α-SMA and Collagen-Iα. Conversely, miR-126a expression was down-regulated after treatment with TGFβ1 (P < 0.01). However, exposure to LPS-treated MSC-derived exosomes resulted in a significant decrease in the levels of p-Smad3c phosphorylation (P < 0.001) and the gene expression of α-SMA and Collagen-Iα, accompanied by the up-regulation of miR-126a (P < 0.05). Conclusions: Based on our observations, MSCs-derived exosomes were able to reduce the expression of the genes associated with hepatic fibrosis, such as collagen-Iα and α-SMA. Furthermore, exosomes inhibited Smad3c phosphorylation by increasing miR-126a expression, ultimately hindering the progression of liver fibrosis. Therefore, exosomes should be recognized as a valuable and beneficial therapeutic tool for liver fibrosis.