Orientin reverses acetaminophen-induced acute liver failure by inhibiting oxidative stress and mitochondrial dysfunction.

Oxidative stress, as an important pathogenic factor, plays a critical role in acetaminophen (APAP) overdose-induced acute liver failure (ALF). Thus, an antioxidative strategy may be a good way to alleviate APAP-induced liver damage. Previous research has reported that Orientin (Ori) possesses antioxidant, anti-inflammatory and anticancer effects. This study aimed to explore whether Ori can protect against APAP-induced oxidative stress and to elucidate its underlying mechanism. Our results indicated that Ori alleviated APAP-induced hepatic pathological changes by reducing mouse mortality, inhibiting the expression of cytochrome P450 2E1 (CYP2E1), maintaining a normal liver structure, and reducing the levels of serum alanine transaminase (ALT) and serum aspartate aminotransferase (AST). Moreover, Ori protected against APAP-induced oxidative damage by decreasing the formation of malondialdehyde (MDA) and myeloperoxidase (MPO) and increasing the levels of superoxide dismutase (SOD) and the GSH-to-GSSG ratio. Moreover, Ori regulated APAP-induced hepatocyte apoptosis and mitochondrial dysfunction by inhibiting cytochrome c mitochondrial translocation and c-jun N-terminal kinase phosphorylation, promoting Bcl-2 expression and reducing Bax and caspase-3 cleavage. Furthermore, Ori not only obviously promoted Nrf2 nuclear translocation but also activated the antioxidant-related proteins HO-1, GCLC, GCLM and NQO1. Therefore, Ori prevented APAP-induced hepatocyte oxidative damage and mitochondrial dysfunction via Nrf2-mediated and JNK/cytochrome c/caspase-3 signaling pathways.

Salmonella Pathogenicity Island 1 (SPI-1) and Its Complex Regulatory Network.

Salmonella species can infect a diverse range of birds, reptiles, and mammals, including humans. The type III protein secretion system (T3SS) encoded by Salmonella pathogenicity island 1 (SPI-1) delivers effector proteins required for intestinal invasion and the production of enteritis. The T3SS is regarded as the most important virulence factor of Salmonella. SPI-1 encodes transcription factors that regulate the expression of some virulence factors of Salmonella, while other transcription factors encoded outside SPI-1 participate in the expression of SPI-1-encoded genes. SPI-1 genes are responsible for the invasion of host cells, regulation of the host immune response, e.g., the host inflammatory response, immune cell recruitment and apoptosis, and biofilm formation. The regulatory network of SPI-1 is very complex and crucial. Here, we review the function, effectors, and regulation of SPI-1 genes and their contribution to the pathogenicity of Salmonella.

Orientin-mediated Nrf2/HO-1 signal alleviates H2O2-induced oxidative damage via induction of JNK and PI3K/AKT activation.

Oxidative stress is closely associated with the pathogenesis of various diseases. Orientin (Ori), a flavonoid component isolated from natural plants, possesses antioxidant activity. Accordingly, we focused on exploring the potential therapeutic effects of Ori on hydrogen peroxide (H2O2)-induced oxidative impairment in RAW 264.7 cells and the underlying antioxidative mechanisms. Our findings suggested that Ori exposure effectively alleviated H2O2-stimulated cytotoxicity, inhibited reactive oxygen species (ROS) generation, and glutathione (GSH) depletion, which were involved in induction of heme oxygenase-1 (HO-1) by enhancing the nuclear factor-erythroid 2-related factor 2 (Nrf2) translocation, decreasing the Keap1 protein expression, and increasing the antioxidant response element (ARE) activity. However, knockdown of Nrf2 and HO-1 with siRNA mostly abolished the cytoprotective effects against H2O2-induced cell oxidative injury, reduced the expression of Nrf2 and HO-1, respectively. Moreover, Ori exposure significantly induced a c-Jun NH2-terminal kinase (JNK) and phosphatidylinositol 3-kinase (PI3K)/serine/threonine kinase (AKT) phosphorylation, but JNK and PI3K/AKT inhibitors treatment effectively reduced levels of Ori-enhanced Nrf2 nuclear translocation and HO-1 protein expression, and blocked Ori-inhibited cytotoxicity and ROS accumulation triggered by H2O2 respectively. Taken together, Ori might exhibit a protective role against H2O2-stimulated oxidative damage by the induction of HO-1 expression through the activation of the JNK- and PI3K/AKT-Nrf2 signaling pathways.

An immortalized rat pancreatic stellate cell line RP-2 as a new cell model for evaluating pancreatic fibrosis, inflammation and immunity.

BACKGROUND: Pancreatic stellate cells (PSCs) play a critical role in the pathogenesis of pancreatic fibrosis and have emerging functions as progenitor cells, immune cells or intermediaries in pancreatic exocrine secretion. Increasing evidence has shown that desmin as an exclusive cytoskeleton marker of PSC is only expressed in part of these cells. This study was to establish a desmin-positive PSC cell line and evaluate its actions on pancreatic fibrosis, inflammation and immunity. METHODS: The presence of cytoskeletal proteins, integrin α5ß1 or TLR4, was determined by immunocytochemistry while the production of desmin, collagen I, MMP-1, MMP-2, TIMP-2, or CD14 was evaluated by Western blotting. The levels of desmin, collagen I, IL-1 and IL-6 mRNA were determined by real-time quantitative PCR. The secretion of cytokines was detected by ELISA. Cell function was assessed using adhesion, migration, or proliferation assays. RESULTS: A stable activated rat PSC cell line (designated as RP-2) was established by RSV promoter/enhancer-driven SV40 large T antigen expression. RP-2 cells retained typical PSC properties, exhibited a myofibroblast-like phenotype and persistently produced desmin. The cells produced collagen I protein, matrix metalloproteinases and inhibitors thereof. RP-2 cells demonstrated typical PSC functions, including proliferation, adherence, and migration, the latter two of which occurred in response to fibronectin and were mediated by integrin α5ß1. TLR4 and its response genes including proinflammatory cytokines (IL-1, IL-6, TNF-alpha) and chemotactic cytokines (MCP-1, MIP-1α, Rantes) were produced by RP-2 cells and activated by LPS. LPS-induced IL-1 or IL-6 mRNA expression in this cell line was fully blocked with MyD88 inhibitor. CONCLUSION: RP-2 cells provide a novel tool for analyzing the properties and functions of PSCs in the pathogenesis of fibrosis, inflammation and immunity in the pancreas.

Focal autoimmune pancreatitis and chronic sclerosing sialadenitis mimicking pancreatic cancer and neck metastasis.

Type 1 autoimmune pancreatitis (AIP) or chronic sclerosing sialadenitis (Küttner's tumour) is an uncommon disorder that has recently been confirmed as an IgG4-related disease. Here, we describe a rare case of a 53-year-old male patient who primarily presented with pancreatic body mass, left neck mass and several lumps in his lower lip mimicking pancreatic cancer (PC) and neck metastasis. The patient underwent pancreatic body mass and labial gland lumps resection as well as an ultrasound-guided biopsy of the left neck mass. He was diagnosed with IgG4-related focal type of AIP (f-AIP) and Küttner's tumour by immunohistochemistry. The patient responded well to corticosteroid therapy and remains healthy with no signs of recurrence at one year follow-up. The differentiation of f-AIP from PC is very important to avoid unnecessary pancreatic resection.

Clinical significance of connective tissue growth factor in hepatitis B virus-induced hepatic fibrosis.

AIM: To determine the utility of connective tissue growth factor (CCN2/CTGF) for assessing hepatic fibrosis in hepatitis B virus (HBV)-induced chronic liver diseases (CLD-B). METHODS: Enzyme-linked immunosorbent assay was used to measure CCN2 in sera from 107 patients with chronic hepatitis B (CHB) and 39 patients with HBV-induced active liver cirrhosis and 30 healthy individuals. Liver samples from 31 patients with CHB, 8 patients with HBV-induced liver cirrhosis and 8 HBV carriers with normal liver histology were examined for transforming growth factor ß-1 (TGF-ß1) or CCN2 mRNA levels by in situ hybridization, and computer image analysis was performed to measure integrated optimal density (IOD) of CCN2 mRNA-positive cells in liver tissues. Histological inflammation grading and fibrosis staging were evaluated by H and E staining and Van Gieson's method. RESULTS: Serum CCN2 concentrations were, respectively, 4.0- or 4.9-fold higher in patients with CHB or active liver cirrhosis as compared to healthy individuals (P < 0.01). There was good consistency between the levels of CCN2 in sera and CCN2 mRNA expression in liver tissues (r = 0.87, P < 0.01). The levels of CCN2 in sera were increased with the enhancement of histological fibrosis staging in patients with CLD-B (r = 0.85, P < 0.01). Serum CCN2 was a reliable marker for the assessment of liver fibrosis, with areas under the receiver operating characteristic (ROC) curves (AUC) of 0.94 or 0.85 for, respectively, distinguishing normal liver controls from patients with F1 stage liver fibrosis or discriminating between mild and significant fibrosis. CONCLUSION: Detection of serum CCN2 in patients with CLD-B may have clinical significance for assessment of severity of hepatic fibrosis.

Adefovir dipivoxil modulates cytokine expression in Th1/Th2 cells in patients with chronic hepatitis B.

The impact of adefovir dipivoxil (ADV) treatment on the immune system in patients with chronic hepatitis B (CHB) is unknown. The present study was designed to determine the expression of six cytokines, IL-2, IFN-γ, TNF-α, IL-4, IL-6 and IL-10, and their correlation with liver functions and clinical responses to ADV treatment. A total of 22 CHB patients were treated with ADV at a daily oral dose of 10 mg. Six cytokines, as well as AST, ALT and HBV DNA levels in blood samples were quantified prior to and following the treatment. A total of 10 healthy volunteers were enrolled as the control group. The six cytokines in CHB patients were significantly lower than in healthy individuals, and were increased significantly following 4, 12 and 24 weeks of ADV treatment. Although ALT, AST and HBV DNA were reduced following treatment, no correlation was found between these six cytokines and liver function or HBV DNA levels. The levels of the six cytokines in the group of patients with a complete clinical response were significantly higher than those in the group with a partial clinical response. ADV treatment increases the immunity of Th1/Th2 cells in CHB patients, and the increases in cytokines partly reflect the efficacy of the antiviral treatment.