Potential role of HBV DNA-induced CD8high T cell apoptosis in patients with systemic lupus erythematosus and rheumatoid arthritis.

OBJECTIVE: To investigate the potential role of hepatitis B virus (HBV) DNA-induced CD8high T cell apoptosis in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). METHODS: The activity and HBV seropositivity rates of patients with SLE and RA were determined. The proportions of T cell subgroups were detected by fluorescence-activated cell sorting. The apoptosis of T cell subgroups was detected after peripheral blood mononuclear cells were stimulated with HBV DNA. RESULTS: The HBV infection rate was higher in patients with RA than in patients with SLE. Current or previous HBV infection was more common among patients with inactive SLE than among those with active SLE. Conversely, previous or current HBV infection was more common among patients with active RA than among those with inactive RA. CD4-CD8high T cell counts were higher among patients with active SLE than in those with inactive SLE. However, CD4-CD8high T cell counts were lower in patients with active RA patients than in those with inactive RA. HBV DNA increased the apoptosis of CD4-CD8high T cells. CONCLUSION: HBV DNA-induced CD8high T cell apoptosis appears to play different roles in SLE and RA.

Deletion of RNF186 expression suppresses diet-induced hepatic steatosis by regulating insulin activity.

RING finger protein186 (RNF186) is dramatically upregulated in steatotic livers. The physiological role of RNF186 in non-alcoholic fatty liver disease (NAFLD) remains obscure. Here, we found that hepatocyte-specific RNF186 knockout (RNF186 LKO ) mice were protected from HFD-induced obesity. RNF186 ablation in liver suppressed inflammatory responses and ER stress and alleviated insulin tolerance, leading to improved glucose and lipid metabolism under HFD conditions. RNA-seq and western blot analyses revealed a significant downregulation of peroxisome proliferator-activated receptor γ, stearoyl-CoA desaturase 1, and cluster of differentiation 36 in the liver of RNF186 knockout mice consuming HFD. RNF186 deletion in liver results in less weight gain during HFD feeding and is associated with reduced liver fat, inflammation, and improved glucose and insulin tolerance. In contrast, upregulation of RNF186 in C57BL/6J mice livers impaired lipid metabolism and insulin tolerance. The collective results suggest that RNF186 may be a potential regulator of NAFLD in obesity.

Imbalance in the ratio of CpG and polyG contributes to impaired interferon-α expression.

The secretion of interferon-α (IFN-α) is impaired during hepatitis B virus (HBV) infection. DNA sequences purified from distinct viruses, for example, HBV versus members of Herpesviridae, have been shown to differ in their IFN-α signaling properties. The present study found that DNA from HBV inhibited, while DNA from members of Herpesviridae induced, the expression of IFN-α. Furthermore, stimulatory cytosine-phosphate-guanosine (CpG) sequences derived from these DNA viruses could induce the secretion of IFN-α, while inhibitory guanosine-rich oligodeoxynucleoti (polyG) oligonucleotide sequences derived from these DNA viruses could inhibit CpG-induced IFN-α secretion. Using a computational analysis of genomic DNA sequences, the discrimination between the genomes of HBV and those of other DNA viruses that can also cause inflammation of the liver is based on different frequencies of the CpG and polyG motifs. The underrepresentation of stimulatory CpG motifs and overrepresentation of inhibitory polyG motifs were documented in HBV genomes, whereas the DNA from other viral genomes displayed the opposite trend. Moreover, it was demonstrated that HBV could suppress the activation of IFN-α via its own DNA through the high proportion of polyG motifs. To our knowledge, this is the first demonstration of a specific role for polyG motifs in the inhibition of the IFN-α response following DNA virus infection.

Gypsophila elegans isoorientin-2″-O-α-l-arabinopyranosyl ameliorates porcine serum-induced immune liver fibrosis by inhibiting NF-κB signaling pathway and suppressing HSC activation.

The present study was to investigate the inhibitory effect of Gypsophila elegans isoorientin-2″-O-α-l-arabinopyranosyl (GEI) on hepatic stellate cells (HSCs), to reveal the underlying mechanism of GEI against hepatic fibrosis. Our study showed that GEI significantly alleviated liver injury induced by porcine serum (PS) in rats; it notably alleviated collagen accumulation as evidenced by a significant decrease in the levels of collagen biomarkers including hyaluronic acid, laminin, hydroxyproline and procollagen III N-terminal peptide. Moreover, GEI treatment markedly decreased the secretion of inflammatory cytokines by inhibiting the NF-κB pathway and significantly inhibited the generation of excessive extracellular matrix (ECM) components by restoring the balance between matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs). Additionally, the cell experiments in vitro showed that GEI strongly inhibited HSC proliferation, migration and clonogenicity and markedly induced HSC apoptosis. Moreover, GEI caused cell cycle arrest at G2 phase. In conclusion, our study demonstrates that GEI significantly alleviates PS-induced hepatic fibrosis by inhibiting the NF-κB pathway, restoring the balance between MMPs and TIMPs, and suppressing HSC activation.

Loss of Raf kinase inhibitor protein is associated with malignant progression in hepatic fibrosis.

Raf kinase inhibitory protein (RKIP), besides regulating important intracellular signaling cascades, was described to be associated with progression, metastasis and prognosis in several human neoplasms. But its role in hepatic fibrogenesis remains unclear. In the present study, we found that the absence of RKIP expression significantly enhanced the proliferation of HSC-T6 cells. Reduced RKIP expression promoted the activation of HSCs and the accumulation of collagen, as evidenced by the increases in the levels of collagen I and α-smooth muscle actin. Moreover, down-regulating RKIP expression led to severe histopathological changes and collagen accumulation in hepatic tissues of rats with liver fibrosis. Furthermore, the absence of RKIP promoted the activation of ERK/MAPK pathway in vitro and in vivo. Our findings clearly demonstrate an inverse correlation between RKIP level and the degree of the liver injury and fibrosis. Loss of RKIP may be associated with malignant progression in hepatic fibrosis.

[Protective effect of asiatic acid from Potentilla chinensis on alcohol hepatic injury in rats].

To study the protective effect and the mechanism of asiatic acid (AA) from Potentilla chinensis on alcohol hepatic injury in rats. Male Wistar rats were randomly divided into six groups: the normal control group, the AA control group (8 mg · kg(-1) AA), the model group (5.0-9.0 g · kg(-1) alcohol) and high, medium and low-dose AA-treated groups (alcohol + 8, 4, 2 mg · kg(-1) AA). Each group was orally administered with the corresponding drugs once a day for 24 weeks. Approximately 1. 5 hours after the final administration, all rats were killed, and their blood samples and hepatic tissues were collected. The AST and ALT in rat serum and the contents of MPO, TNF-α, IL-1ß, SOD, GSH-Px, GSH-Rd and MDA in hepatic tissues were detected. The expressions of NF-κB, TLR4, CD14, MyD88, TRIF and protein expression in hepatic tissues were measured by western blot. The pathological changes in liver tissues were observed by histological examination. The results showed that compared with the model group, the AA-treated groups showed significant decreases in serum ALT, AST and MDA and increases in the activities of SOD, GSH-Px, GSH-Rd and MPO. Moreover, AA markedly inhibited the expressions of TNF-α, IL-1ß, TLR4, CD14, MyD88 and NF-κB. The histological examination showed alleviated hepatic issue ijury to varying degrees. In short, asiatic acid (AA) from P. chinensis could protect alcohol-induced hepatic injury in rats. Its mechanism may be related to the inhibition of NF-κB inactivation and the reduction of inflammatory response.

Gypsophila elegans isoorientin attenuates CCl4-induced hepatic fibrosis in rats via modulation of NF-κB and TGF-ß1/Smad signaling pathways.

The hepatoprotective effect of Gypsophila elegans isoorientin (GEI) was evaluated using a hepatic fibrosis model induced by CCl4 in rats. The results revealed that GEI significantly prevented CCl4-induced liver injury and fibrosis, as evidenced by the attenuation of histopathological changes, the decrease in serum aminotransferase, and the inhibition of collagen accumulation. GEI strongly inhibited lipid peroxidation and recruited anti-oxidative defense system. Moreover, GEI alleviated pro-inflammatory cytokines such as TNF-α, IL-1ß and IL-6 via inhibiting nuclear factor-κB (NF-κB) activation. In addition, GEI down-regulated the phosphorylation of Smad2/3 and up-regulated the level of hepatic Smad7, thereby inhibiting TGFß1/Smad signaling pathway. In conclusion, our findings indicate that GEI can inhibit CCl4-induced hepatic fibrosis, which may be ascribed to its radical scavenging action, antioxidant activity, and modulation of NF-κB and TGF-ß1/Smad signaling pathways.

Pratensein attenuates Aß-induced cognitive deficits in rats: enhancement of synaptic plasticity and cholinergic function.

An isoflavone was isolated from Trifolium pratense using bioassay-guided screening. The structure of this natural compound was elucidated based on its spectral data, and it was identified as pratensein. The protective effect of pratensein was evaluated using a cognitive impairment model induced by injecting amyloid beta (1-42) (Aß1-42) into the bilateral hippocampus of rats. The results showed that pratensein treatment significantly protected against Aß1-42-induced cognitive impairments, as evidenced by the improvement in learning and memory and the attenuation of neuronal degeneration and apoptosis in hippocampus. Analysis of the potential mechanisms of action showed that pratensein significantly decreased inflammatory indicators such as MDA, NO, nNOS, IL-1ß and TNF-α. Pratensein markedly decreased the content and deposition of ß-amyloid peptide through regulating the expressions of Aß-related genes including APP, BACE1, CatB, NEP and IDE. Moreover, pratensein significantly increased the expressions of synapse plasticity-related proteins, i.e., PSD-95, p-NMDAR1, p-CaMKII, p-PKACß, PKCγ, p-CREB and BDNF. In addition, pratensein significantly decreased the activity of cholinesterase, then subsequently elevated the level of acetylcholine. In summary, our study indicated that pratensein may have a likely protective effect against Alzheimer's disease (AD) via improving synaptic plasticity and increasing cholinesterase activity.

Protective effect of madecassoside against cognitive impairment induced by D-galactose in mice.

This study was designed to investigate the protective effect of madecassoside from Hydrocotyle sibthorpioides against cognitive impairment induced by D-galactose (D-gal) in mice. The result revealed that treatment with madecassoside significantly reversed D-gal-induced learning and memory impairments, as measured by the Morris water-maze test. Studies on the potential mechanisms of this action showed that madecassoside significantly reduced oxidative stress and suppress inflammatory responses via blocking NF-κB and ERK/p38 MAPK pathways. Moreover, madecassoside markedly attenuated the content and deposition of ß-amyloid peptide by inducing a decrease in the expression of amyloid protein precursor, ß-site amyloid cleaving enzyme-1 and cathepsin B and an increase in the levels of neprilysin and insulin-degrading enzyme. Madecassoside significantly increased the expression of synapse plasticity-related proteins in the hippocampus, such as postsynaptic density 95, long-term potentiation, N-methyl-D-aspartic acid receptors, Ca(2+)/calmodulin-dependent protein kinase II, NMDA receptor subunit 1, protein kinase C, protein kinase A, cAMP-response element binding protein, and brain-derived neurotrophic factor. In addition, madecassoside significantly increased the levels of acetylcholine but decreased cholinesterase activity. In conclusion, the protective effect of madecassoside against d-gal-induced cognitive impairment was mainly due to its ability to reduce oxidative damage, improve synaptic plasticity and restore cholinergic function. These findings suggest that madecassoside can be considered as a potential agent for preventing cognitive impairment.

Protective effect of genistein on lipopolysaccharide/D-galactosamine- induced hepatic failure in mice.

This study examined the effect of genistein from Hydrocotyle sibthorpioides on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute hepatic failure. Compared to the model control, genistein treatment significantly protected against LPS/D-GalN-induced liver injury, as evidenced by the decrease in serum alanine and aspartate aminotransferases activities and the attenuation of histopathological changes. Furthermore, genistein alleviated the pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α) and nitric oxide (NO)/inducible nitric oxide synthase (iNOS) by inhibiting nuclear factor-κB (NF- κB) activity. Genistein attenuated the elevated level of caspases-3, while augmented the expression of Bcl-2. In addition, LPS/D-GalN induced significant increase of heme oxygenase (HO), carbon monoxide and bilirubin levels and these alterations were augmented by genistein treatment. In conclusion, the protective effect of genistein on LPS/D-GalN-induced liver damage was mainly due to its ability to block NF-κB signaling pathway for anti-inflammation response, attenuate hepatocellular apoptosis and increase HO level. These findings suggest that genistein can be considered as a potential agent for preventing acute hepatic failure.

Nanoparticles encapsulating hepatitis B virus cytosine-phosphate-guanosine induce therapeutic immunity against HBV infection.

UNLABELLED: Infection with hepatitis B virus (HBV) is the most common cause of liver disease worldwide. However, because the current interferon (IFN)-based treatments have toxic side effects and marginal efficacy, improved antivirals are essential. Here we report that unmethylated cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODNs) from the HBV genome (HBV-CpG) induced robust expression of IFN-α by plasmacytoid dendritic cells (pDCs) in a Toll-like receptor 9 (TLR9)-dependent manner. We also identified inhibitory guanosine-rich ODNs in the HBV genome (HBV-ODN) that are capable of inhibiting HBV-CpG-induced IFN-α production. Furthermore, nanoparticles containing HBV-CpG, termed NP(HBV-CpG), reversed the HBV-ODN-mediated suppression of IFN-α production and also exerted a strong immunostimulatory effect on lymphocytes. Our results suggest that NP(HBV-CpG) can enhance the immune response to hepatitis B surface antigen (HBsAg) and skew this response toward the Th1 pathway in mice immunized with rHBsAg and NP(HBV-CpG). Moreover, NP(HBV-CpG)-based therapy led to the efficient clearance of HBV and induced an anti-HBsAg response in HBV carrier mice. CONCLUSION: Endogenous HBV-CpG ODNs from the HBV genome induce IFN-α production so that nanoparticle-encapsulated HBV-CpG may act as an HBsAg vaccine adjuvant and may also represent a potent therapeutic agent for the treatment of chronic HBV infection.

Isolation and identification of an anti-hepatitis B virus compound from Hydrocotyle sibthorpioides Lam.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydrocotyle sibthorpioides (Apiaceae) have been used as a folk remedy for the treatment of fever, edema, detoxication, throat pain, psoriasis and hepatitis B virus infections in China. The aim of this study is to isolate and identify an anti-HBV compound from this herb. MATERIALS AND METHODS: A compound (saponin) was isolated from the active ethanol extract using bioassay-guided screening. The structure of the saponin was elucidated by spectroscopic methods and compared with published data. The anti-HBV activity of the saponin was evaluated by detecting the levels of HBV antigens, extracellular HBV DNA, nuclear covalent closed circular DNA (cccDNA) and five HBV promoters in HepG2.2.15 cells. In addition, the levels of serum HBsAg/HBeAg, DHBV DNA, ALT/AST and hepatic pathological changes were analyzed in DHBV-infected ducks. RESULTS: The chemical analysis indicated that the saponin isolated from Hydrocotyle sibthorpioides is asiaticoside. The pharmacodynamics experimental studies showed that asiaticoside effectively suppressed the levels of HBsAg/HBeAg, extracellular HBV DNA and intracellular cccDNA in a dose-dependent manner. Furthermore, experiments demonstrated that asiaticoside markedly reduced viral DNA transcription and replication by inhibiting the activities of core, s1, s2, and X gene promoters. In addition, asiaticoside markedly reduced DHBV replication without any obvious signs of toxicity. The levels of serum DHBV DNA, HBsAg/HBeAg were increased 3 days after drug withdrawal, but the levels rebounded slightly in the asiaticoside treatment groups compared with the 3TC treatment group. Moreover, analysis of the serum ALT/AST levels and the liver pathological changes indicated that asiaticoside could alleviate liver damage. CONCLUSIONS: Our results show that asiaticoside could efficiently inhibit HBV replication both in vitro and in vivo, and asiaticoside may be a major bioactive ingredient in Hydrocotyle sibthorpioides.

Antiviral activity of methyl helicterate isolated from Helicteres angustifolia (Sterculiaceae) against hepatitis B virus.

The anti-HBV effect of methyl helicterate (MH), a triterpenoid isolated from the Chinese herb Helicteres angustifolia, was explored both in vitro and in vivo. In the HBV-transfected cell line HepG2.2.15, the secretion of HBsAg/HBeAg, the levels of HBV DNA and cccDNA, and the amount of viral RNA were significantly decreased after treatment with MH for 144h. In addition, MH had no inhibitory effect on the mitochondrial DNA content. In DHBV-infected ducklings, MH significantly reduced the serum DHBV DNA, liver total viral DNA, and cccDNA levels. Furthermore, analysis of the liver pathological changes confirmed the hepatoprotective effect of MH. These results indicate that MH efficiently inhibits HBV replication both in vitro and in vivo and that MH may be a major bioactive ingredient in H. angustifolia.

Asiatic acid from Potentilla chinensis attenuate ethanol-induced hepatic injury via suppression of oxidative stress and Kupffer cell activation.

This study examined the effect of Asiatic acid from Potentilla chinensis (AAPC) on chronic ethanol-induced hepatic injury. Rats underwent intragastric administration of ethanol (5.0­9.0 g/kg) once a day for 12 weeks. A subset of rats were also intragastrically treated with AAPC (2, 4 or 8 mg/kg) once a day. In the end, AAPC treatment significantly protected against ethanol-induced liver injury, as evidenced by the decrease in serum alanine and aspartate aminotransferases levels and the attenuation of histopathological changes in rats. Additionally, AAPC significantly decreased blood alcohol and acetaldehyde concentrations by enhancing alcohol dehydrogenase and aldehyde dehydrogenase activities. Mechanistically, studies showed that AAPC remarkably alleviated the formations of malondialdehyde and myeloperoxidase, restored impaired antioxidants, including superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, and inhibited cytochrome P450 (CYP)2E1 activity. Moreover, the over-expression of cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), the elevated plasma endotoxin level and the up-regulated Toll-like receptor 4 (TLR4), CD14 and myeloid differentiation factor 88 (MyD88) as well as nuclear factor-κB were also suppressed by AAPC in ethanol-intoxicated rats. In conclusion, the protective effect of AAPC on ethanol-induced hepatotoxicity was mainly due to its ability to attenuate oxidative stress and inhibit Kupffer cell activation by decreasing the level of plasma endotoxin and the expression of TLR4, CD14 and MyD88.