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Mesenchymal stem cells (MSCs) ameliorate graft-versus-host disease (GVHD)-induced tissue damage by exerting immunosuppressive effects. However, the related mechanism remains unclear. Here, we explored the therapeutic effect and mechanism of action of human placental-derived MSCs (hPMSCs) on GVHD-induced mouse liver tissue damage, which shows association with inflammatory responses, fibrosis accompanied by hepatocyte tight junction protein loss, the upregulation of Bax, and the downregulation of Bcl-2. It was observed in GVHD mice and Th1 cell differentiation system that hPMSCs treatment increased IL-10 levels and decreased TNF-α levels in the Th1 subsets via CD73. Moreover, hPMSCs treatment reduced tight junction proteins loss and inhibited hepatocyte apoptosis in the livers of GVHD mice via CD73. ADO level analysis in GVHD mice and the Th1 cell differentiation system showed that hPMSCs could also upregulate ADO levels via CD73. Moreover, hPMSCs enhanced Nrf2 expression and diminished Fyn expression via the CD73/ADO pathway in Th1, TNF-α+, and IL-10+ cells. These results indicated that hPMSCs promoted and inhibited the secretion of IL-10 and TNF-α, respectively, during Th1 cell differentiation through the CD73/ADO/Fyn/Nrf2 axis signaling pathway, thereby alleviating liver tissue injury in GVHD mice. [ABSTRACT FROM AUTHOR]

Background: Emerging evidence suggests the involvement of caudal-related homoeobox transcription factor 2 (CDX2) in tumorigenesis of various cancers. Although CDX2 functions in cancer invasion and metastasis, fewer studies focus on the role of CDX2 during the induction of epithelial-mesenchymal transition (EMT) in colorectal cancer (CRC).Methods: Immunohistochemical analysis of CDX2 was performed. A series of in vitro and in vivo experiments were conducted to reveal the role of CDX2 in the invasion and metastasis of CRC.Results: CDX2 was downregulated in CRC tissues and reduced CDX2 correlated with poor prognosis. Knockdown of CDX2 promoted colon cancer cell invasion in vitro and facilitated liver metastasis in vivo with inducing EMT phenotypes. Further investigation indicated that CDX2 retarded Akt and GSK-3β phosphorylation, and thereby diminished Snail expression, β-catenin stabilisation and nuclear translocation. The depletion of β-catenin neutralised the regulation of Slug and ZEB1 by CDX2 knockdown. Mechanistically, CDX2 antagonised PI3K/Akt activity in CRC by modulating PTEN expression. CDX2 directly bound to the promoter of PTEN and transactivated its expression.Conclusions: Our study first uncovered that CDX2 inhibits EMT and metastasis of CRC by regulation of Snail expression and β-catenin stabilisation via transactivation of PTEN expression. [ABSTRACT FROM AUTHOR]

Abstract: Recent studies have indicated that the Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway is closely involved in liver fibrosis and other fibrotic diseases. However, whether targeting the AMPK pathway can rescue liver fibrosis and its complications, such as portal hypertension, is unknown. This study aimed to explore the therapeutic value of AICAR (5-aminoimidazole-4-carboxyamide ribonucleoside), an agonist of the AMPK pathway, on liver fibrosis and portal hypertension in bile duct ligation (BDL) rats. In vitro experiments showed that the gene expression levels of TGF-b, a-SMA, and collagen 1 in primary rat hepatic stellate cells (HSCs) were significantly decreased after AICAR treatment. The p-eNOS expression and nitric oxide (NO) production were increased by AICAR administration in sinusoidal endothelial cells (SECs). For in vivo animal studies, AICAR acutely decreased portal pressure in the BDL and CCL4 fibrotic rats, but not in the partial portal vein ligation (PVL) rats, without changes in systemic hemodynamics. It was also observed by using intravital fluorescence microscopy that AICAR led to sinusoidal vasodilation in situ experiment. We propose that the relevant mechanisms may be related to the activation of the AMPK/NO pathway in SECs and that this activation promoted NO production in the liver, thereby promoting hepatic sinusoid microcirculation and decreased intrahepatic resistance. The results were verified using the NO inhibitor L-NAME. Chronic AICAR treatment also showed profound beneficial effects on the BDL model rats. The hemodynamic condition was greatly improved, but the positive effect could be partially blocked by L-NAME. Moreover, AICAR also decreased hepatic fibrogenesis in the BDL rats.Key messages: Acute and chronic use of AICAR could alleviate portal pressure without changing systemic hemodynamics.AICAR induced sinusoidal vasodilation by improving NO bioavailability and ameliorating endothelial dysfunction in vivo and in vitro.AICAR could alleviate liver cirrhosis in the BDL model rats. [ABSTRACT FROM AUTHOR]

Cytochrome P450 55B1 from Chlamydomonas reinhardtii is reported to function as a nitric oxide reductase (NOR). Here, we expressed the cytochrome P450 55B1 gene with an HIS-tag in E scherichia coli using a pET28a vector. The native protein was produced at a level of 1.59 μmol/g of total protein, with approximately 85% of the P450 being soluble. The CYP55B1 protein was characterized spectrally and purified by a HIS-trap column. This procedure allowed recovery of 45% of the expressed protein and CYP55B1 with a specific content of 0.70 μmol/g of the total protein, which showed a single band on a SDS-PAGE and Western blot. The direct electrochemistry of CYP55B1 in dihexadecylphosphate (DHP) film was realized with an electric potential at −0.47 V at the scan rate of 1 V s. We studied the in vitro interaction between P450 55B1 and NO by the fluorescence spectrometric method. The results show that the fluorescence intensity of iron-porphyrin in P450 55B1 changes gradually with the addition of NO. The fluorescence intensity change values against NO concentrations were plotted, and it showed a linear range of NO from 0 to 22.5 μM with a sensitivity of 0.15 μM/AU and a detection limit of 0.15 μM. [ABSTRACT FROM AUTHOR]

Aromatic peroxygenase (APO) from the basidiomycetous mushroom Agrocybe aegerita ( AaeAPO) and microperoxidases (MPs) obtained from cytochrome c exhibit a broad substrate spectrum including hydroxylation of selected aromatic substrates, demethylation and epoxidation by means of hydrogen peroxide. It overlaps with that of cytochrome P450 (P450), making MPs and APOs to alternate recognition elements in biosensors for the detection of typical P450 substrates. Here, we discuss recently developed approaches using microperoxidases and peroxygenases in view of their potential to supplement P450 enzymes as recognition elements in biosensors for aromatic compounds. Starting as early as the 1970s, the direct electron transfer between electrodes and the heme group of heme peptides called microperoxidases has been used as a model of oxidoreductases. These MP-modified electrodes are used as hydrogen peroxide detectors based on the catalytic current generated by electrically contacted microperoxidase molecules. A similar catalytic reaction has been obtained for the electrode-immobilised heme protein AaeAPO. However, up to now, no MP-based sensors for substrates have been described. In this review, we present biosensors which indicate 4-nitrophenol, aniline, naphthalene and p-aminophenol based on the peroxide-dependent substrate conversion by electrode-immobilised MP and AaeAPO. In these enzyme electrodes, the signal is generated by the conversion of all substrates, thus representing in complex media an overall parameter. The performance of these sensors and their further development are discussed in comparison with P450-based electrodes. [ABSTRACT FROM AUTHOR]

Lung cancer is one of the most common malignant tumors in the world. Non-small cell lung cancer (NSCLC) accounts for about 80% of all lung cancers. About 75% of patients are in the middle and advanced stages at the time of discovery, and the 5-year survival rate is very low. The aim of this study was to investigate the role of long non-coding RNA (lncRNA) NORAD in the pathogenesis of NSCLC. We found that lncRNA NORAD was highly expressed in human NSCLC tissues and cell lines. The CCK-8 assay results showed that lncRNA NORAD had no effect on cell proliferation. The Transwell assay and Western blotting results showed that overexpression of lncRNA NORAD promoted the invasion and epithelial-mesenchymal transition (EMT) of NSCLC cells. Then bioinformatics analysis was used to screen for candidate miRNA bound with lncRNA NORAD and the target gene of miRNA in NSCLC. The luciferase reporter gene assay and RNA pull-down assay were used to verify the relationship. We found that miR-363-3p expression was down-regulated, whereas PEAK1 expression was upregulated in NSCLC cells. We performed gain and loss function test of lncRNA NORAD, miR-363-3p and PEAK1, the results showed that while miR-363-3p-mimic inhibited cell invasion and EMT by targeting PEAK1, lncRNA NORAD acted as a sponge of miR-363-3p and promoted cell invasion and EMT by increasing the expression of PEAK1. In addition, p-ERK expression was detected by Western blotting to observe the effects of lncRNA NORAD, miR-363-3p and PEAK1 on activation of the ERK signaling pathway. Taken together, lncRNA NORAD upregulated the expression of PEAK1 through sponging miR-363-3p, and then activated the ERK signaling pathway, thereby promoting the development of NSCLC. [ABSTRACT FROM AUTHOR]