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Diabetic retinopathy (DR) is a serious complication of diabetes mellitus. This study aimed to observe the alleviation of the ethanol extract of Dendrobium chrysotoxum Lindl. (DC), a traditional Chinese herbal medicine, on DR and its engaged mechanism. After DC (30 or 300 mg/kg) was orally administrated, the breakdown of blood retinal barrier (BRB) in streptozotocin- (STZ-) induced diabetic rats was attenuated by DC. Decreased retinal mRNA expression of tight junction proteins (including occludin and claudin-1) in diabetic rats was also reversed by DC. Western blot analysis and retinal immunofluorescence staining results further confirmed that DC reversed the decreased expression of occludin and claudin-1 proteins in diabetic rats. DC reduced the increased retinal mRNA expressions of intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor α (TNFα), interleukin- (IL-) 6, and IL-1β in diabetic rats. In addition, DC alleviated the increased 1 and phosphorylated p65, IκB, and IκB kinase (IKK) in diabetic rats. DC also reduced the increased serum levels of TNFα, interferon-γ (IFN-γ), IL-6, IL-1β, IL-8, IL-12, IL-2, IL-3, and IL-10 in diabetic rats. Therefore, DC can alleviate DR by inhibiting retinal inflammation and preventing the decrease of tight junction proteins, such as occludin and claudin-1. [ABSTRACT FROM AUTHOR]

Stromal cell-derived factor (SDF-1) is a CXC chemokine that selectively activates the CXCR4 chemokine receptor. Fibronectin is an intracellular matrix component that binds integrin and mediates cell-matrix adhesion. Activation of the integrin receptor can occur in two ways: by ligand binding (outside-in signaling), and in response to intracellular events (inside-out signaling). In the current study we showed that SDF-1α inhibited adhesion of T lymphocyte Jurkat cells resulting from binding high concentrations of fibronectin as well as that of THP-1 monocytes. The effect of SDF-1α on fibronectin-mediated adhesion was partly reversed by the CXCR4 receptor antagonist T140. Our results suggest that an SDF-1/ CXCR4 signal pathway modulates fibronectin-mediated lymphocytes adhesion. [ABSTRACT FROM AUTHOR]

Diosbulbin B (DB) is the main hepatotoxic compound in Airpotato yam, which is traditionally used for treating thyroid disease and cancer in China, and its hepatotoxic mechanism still remains unclear. This study aims to investigate its hepatotoxic mechanism by focusing on regulating microRNA (miRNA). DB induced hepatotoxicity both in vivo and in vitro. Results of miRNA chip analysis showed that the expression of eleven miRNAs was up-regulated and twelve miRNAs was down-regulated in livers from DB-treated mice. The altered expression of seven miRNAs was further validated by using real-time polymerase chain reaction (RT-PCR) assay. DB induced G 2 /M arrest in L-02/cytochrome P450 3A4 (CYP3A4) cells in both concentration- and time-dependent manner. A total of eleven predicted target genes was related with cell cycle regulation of those above seven miRNAs, among which the mRNA and protein expression of cyclin-dependent kinase 1 (CDK1) decreased both in vivo and in vitro. Both miR-378a-5p and miR-186-3p have binding sites in the 3'-untranslated region (UTR) of CDK1. With the use of CDK1 3'-UTR luciferase reporter assay, miR-378a-5p and miR-186-3p was found to down-regulate the luciferase activity. The mimics of miR-378a-5p or miR-186-3p reduced CDK1 expression in L-02/CYP3A4 cells, but their inhibitors reversed the decreased CDK1 expression induced by DB. Moreover, overexpression of miR-186-3p inhibitor reversed the G 2 /M cell cycle arrest induced by DB in L-02/CYP3A4 cells. Taken together, our results showed that DB induced hepatotoxicity by inducing G 2 /M cell cycle arrest in hepatocytes via miR-186-3p or miR-378a-5p-mediated the reduced CDK1 expression., (Copyright © 2018. Published by Elsevier Inc.)

MicroRNA (miRNA) has been reported to play important roles in regulating drug-induced liver injury. Ethyl acetate extract isolated from rhizoma Dioscoreae bulbifera (EF) has been reported to induce hepatotoxicity in our previous studies. This study aims to observe the altered liver miRNA profile and its related signalling pathway involved in EF-induced hepatotoxicity. Serum alanine/aspartate aminotransferase assay showed that EF (450 mg/kg)-induced hepatotoxicity in mice. Results of miRNA chip analysis showed that the expression of eight miRNAs was up-regulated and of other nine miRNAs was down-regulated in livers from EF-treated mice. Further, the altered expression of miR-200a-3p, miR-5132-5p and miR-5130 was validated using real-time polymerase chain reaction (PCR) assay. There were total seven predicted target genes of miR-200a-3p, miR-5132-5p and miR-5130. Only one kyoto encyclopedia genes and genomes pathway was annotated using those target genes, which is protein processing in endoplasmic reticulum (ER). Furthermore, liver expression of DnaJ subfamily A member 1, a key gene involved in protein processing in ER based on the altered miRNAs, was increased in EF-treated mice. In conclusion, the results demonstrated that EF altered the expression of liver miRNA profile and its related signalling pathway, which may be involved in EF-induced hepatotoxicity.

Acetaminophen (AP) is widely used as the antipyretic and analgesic drug in clinic, and it can induce serious liver injury in the case of excessive abuse. The present study showed that AP (400 mg/kg) induced obvious liver injury, while in male mice the hepatotoxicity induced by AP was much more serious than in female mice as indicated by the results of alanine aminotransferase (ALT) activity and reduced glutathione (GSH) amount. Further, the enzymatic activity and protein expression of glutamate-cysteine ligase (GCL) and glutathione peroxidase (GPx) were all higher in female mice liver than in male after the administration of AP (200 mg/kg). Meanwhile, AP (10 mM) decreased GCL and GPx activity in isolated mouse hepatocytes in the time-dependent manner, while the inhibitors of GCL and GPx can augment AP induced-cytotoxicity. Taken together, our results demonstrate the gender-related liver injury induced by AP and the important role of GCL and GPx in regulating such hepatotoxicity.