NEDDylation has been shown to participate in the DNA damage pathway, but the substrates of neural precursor cell expressed developmentally downregulated 8 (NEDD8) and the roles of NEDDylation involved in the DNA damage response (DDR) are largely unknown. Translesion synthesis (TLS) is a damage-tolerance mechanism, in which RAD18/RAD6-mediated monoubiquitinated proliferating cell nuclear antigen (PCNA) promotes recruitment of polymerase η (polη) to bypass lesions. Here we identify PCNA as a substrate of NEDD8, and show that E3 ligase RAD18-catalyzed PCNA NEDDylation antagonizes its ubiquitination. In addition, NEDP1 acts as the deNEDDylase of PCNA, and NEDP1 deletion enhances PCNA NEDDylation but reduces its ubiquitination. In response to HO stimulation, NEDP1 disassociates from PCNA and RAD18-dependent PCNA NEDDylation increases markedly after its ubiquitination. Impairment of NEDDylation by Ubc12 knockout enhances PCNA ubiquitination and promotes PCNA-polη interaction, while up-regulation of NEDDylation by NEDD8 overexpression or NEDP1 deletion reduces the excessive accumulation of ubiquitinated PCNA, thus inhibits PCNA-polη interaction and blocks polη foci formation. Moreover, Ubc12 knockout decreases cell sensitivity to HO-induced oxidative stress, but NEDP1 deletion aggravates this sensitivity. Collectively, our study elucidates the important role of NEDDylation in the DDR as a modulator of PCNA monoubiquitination and polη recruitment.
DNA Damage ; drug effects ; DNA Repair ; genetics ; DNA Replication ; genetics ; DNA-Binding Proteins ; genetics ; DNA-Directed DNA Polymerase ; genetics ; Endopeptidases ; genetics ; Gene Knockout Techniques ; Humans ; Hydrogen Peroxide ; toxicity ; NEDD8 Protein ; genetics ; Oxidative Stress ; genetics ; Proliferating Cell Nuclear Antigen ; genetics ; Ubiquitin-Conjugating Enzymes ; genetics ; Ubiquitin-Protein Ligases ; genetics ; Ubiquitination ; genetics ; Ultraviolet Rays

Werner syndrome (WS) is a premature aging disorder that mainly affects tissues derived from mesoderm. We have recently developed a novel human WS model using WRN-deficient human mesenchymal stem cells (MSCs). This model recapitulates many phenotypic features of WS. Based on a screen of a number of chemicals, here we found that Vitamin C exerts most efficient rescue for many features in premature aging as shown in WRN-deficient MSCs, including cell growth arrest, increased reactive oxygen species levels, telomere attrition, excessive secretion of inflammatory factors, as well as disorganization of nuclear lamina and heterochromatin. Moreover, Vitamin C restores in vivo viability of MSCs in a mouse model. RNA sequencing analysis indicates that Vitamin C alters the expression of a series of genes involved in chromatin condensation, cell cycle regulation, DNA replication, and DNA damage repair pathways in WRN-deficient MSCs. Our results identify Vitamin C as a rejuvenating factor for WS MSCs, which holds the potential of being applied as a novel type of treatment of WS.
Animals ; Ascorbic Acid ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line ; Cellular Senescence ; drug effects ; DNA Damage ; DNA Repair ; drug effects ; DNA Replication ; drug effects ; Disease Models, Animal ; Heterochromatin ; metabolism ; pathology ; Humans ; Mesenchymal Stem Cells ; metabolism ; pathology ; Mice ; Nuclear Lamina ; metabolism ; pathology ; Reactive Oxygen Species ; metabolism ; Telomere Homeostasis ; drug effects ; Werner Syndrome ; drug therapy ; genetics ; metabolism

To verify the effect of echinacoside on replication and antigen expression of hepatitis B virus (HBV) by using HBV-transfected HepG2. 2. 15 cells as the in vitro model. The ELISA method was used to determine HBeAg and HBsAg levels in cellular supernatants. The effect of echinacoside on HBV replication was studied by using HBV transgenic mice as the in vivo model. First of all, the HBV DNA level in hepatic tissues was quantified with PCR method. Meanwhile, the serum transaminase levels and hepatic pathological changes were also evaluated. Subsequently, HBV transgenic mice were divided into five groups: the control group, the lamivudine group (50 mg · kg(-1)) and echinacoside high, medium and low dose group (50, 25 and 12.5 mg · kg(-1)). The mice were orally administered with drugs once per day for 30 days. At the 31st day, the mice serum was separated to measure HBsAg, HBeAg and HBV DNA. Additionally, the liver HBV DNA level and histopathological change were detected. The results indicated that echinacoside at 50 and 100 mg · L(-1) suppressed significantly HBsAg and HBeAg expressions on the sixth day, with the maximum inhibition ratios of 42.68% and 46.29%; And echinacoside at 100 mg · L(-1) also showed an inhibitory effect on HBV DNA. Besides, echinacoside at 50 mg · kg(-1) inhibited significantly HBsAg and HBeAg expressions of HBV transgenic mice, with the inhibition ratios of 42.82% and 29.12%, and reduced markedly the serum HBV DNA level in HBV transgenic mice. In conclusion, the study suggested that echinacoside has a strong effect against HBV replication and antigen expression.
Animals ; DNA, Viral ; blood ; Female ; Glycosides ; pharmacology ; Hep G2 Cells ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Virus Replication ; drug effects

OBJECTIVETo study the role of tumor necrosis factor-alpha (TNFalpha) in the anti-replication effects of tetracycline (Tet) on hepatitis B virus (HBV).

METHODSThe Tet-dependent regulatory fragment (TO) was PCR amplified from the pcDNA4TM/TO vector, inserted into the pUC118 cloning vector, and verified by sequencing. The counterpart fragment in the pVITRO3 expression vector, which contains two multiple cloning sites (MCSs), was replaced with the confirmed TO to generate a pVITRO3-TO vector. The Tet repressor (TR) gene from the pcDNA6/TR regulatory vector was incorporated into one MCS of pVITRO3-TO and the TNFalpha gene was subsequently incorporated into the other MCS. The resultant vector, pVITRO3-TOTR-TNFalpha, was transiently transfected into HepG2 cells. TNFalpha expression from the vector was induced by exposure to various concentrations of Tet and measured by enzyme-linked immunosorbent assay to determine the appropriate Tet concentration for experimentation. To investigate whether Tet inhibits TNFalpha expression as a mechanism of its anti-replication activity against HBV, the HepG2.2.15 cell line stably transfected with pVITRO3-TOTR-TNFalpha was used as an HBV replication model. Levels of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) were detected by immunoassay. HBV DNA level was detected by fluorescence quantitative PCR.

RESULTSThe TNFalpha expression from the newly constructed pVITRO3-TOTR-TNFalpha vector was Tet-controllable in the eukaryotic cells examined. The optimal concentration of Tet for the experimental system was 1.0 mug/ml. HBsAg and HBeAg expression was down-regulated in the HepG2.2.15 cells stably transfected with the pVITRO3-TO-TR-TNFalpha vector. After incubation with Tet for 1, 3 and 5 days, the inhibition rate of HBsAg was 2%, 1.1% and 0, compared to 14.8%, 11.5% and 28.4% in the non-Tet control group. The corresponding inhibition rates of HBeAg were 50.0%, 26.7% and 47.9%, compared to 0.3%, 1.6% and 0.0%, in the control group. HBV DNA levels in the cells and the cell culture supernatants exposed to Tet were decreased by 70.3% and 79.9%, respectively. TNFalpha inhibited production of HBsAg mRNA.

CONCLUSIONA Tet-dependent regulatory fragment double-expressing TNFalpha single vector system was constructed successfully, achieving controllable TNFalpha expression in both transiently transfected eukaryotic cells and stable cell lines. In this HBV cell model system, Tet-induced overexpression of human TNFalpha inhibited HBV DNA replication and reduced HBsAg and HBeAg expression. Inhibition of HBV transcription may be a key role of TNFalpha against HBV replication.

DNA, Viral ; biosynthesis ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Tetracycline ; pharmacology ; Transfection ; Tumor Necrosis Factor-alpha ; genetics ; Virus Replication

This study sought to investigate the in vivo antiviral effect of amantadine (AM) and biphenyl dimethyl dicarboxylate (DDB) on hepatitis B virus (HBV) in HBV replication mice. HBV replication-competent plasmid was transferred into male BALB/c mice by using hydrodynamics-based in vivo transfection procedure to develop HBV replication mouse model. The model mice were matched by body weigh, age and serum levels of hepatitis B e antigen (HBeAg) and were divided into four groups: AM group, DDB group, AM+DDB group and NS group, with the last one as control, and the mice of each group were administered corresponding agent orally twice a day, in a medication course lasting 3 d. On the third day, the mice were sacrificed 4-6 h after the last oral intake. HBV DNA replication intermediates in liver were analyzed by Southern blot hybridization. The serum hepatitis B surface antigen (HBsAg) and HBeAg were detected by enzyme linked immunosorbent assay (ELISA). Compared to the animals in the control group, HBV DNA replication intermediates in liver and HBsAg and HBeAg in serum from the AM and AM plus DDB group of mice decreased, and there was no difference between these two groups of mice. The levels of HBV DNA intermediate from liver and the serum HBsAg and HBeAg between the control and DDB group, however, were not obviously different. In conclusion, the inhibition effect of AM on HBV was detected, but treatment with DDB for 3 days did not influence the viral replication and expression of HBV in the HBV replication mice.
Amantadine ; pharmacology ; Animals ; Antiviral Agents ; pharmacology ; DNA Replication ; DNA, Viral ; biosynthesis ; Dioxoles ; pharmacology ; Disease Models, Animal ; Hepatitis B ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; drug effects ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; Transfection ; Virus Replication ; drug effects

Betulinic acid is a naturally occurring pentacyclic triterpenoid, which has antiretroviral, antimalarial, and anti-inflammatory properties. The purpose of this study is to investigate the HBV DNA replication inhibition in the mouse model with betulinic acid. Hydrodynamic injection method via the tail vein with the Paywl. 3 plasmid was used to establish the animal mode (n = 15), and the mice were randomly divided into the PBS control group (n = 5), Betulinic acid treatment group (n = 5) and lamivudine control group (n = 5). The day after successful modeling , the mice would have taken Betulinic acid (100 mg x kg(-1)), lamivudine (50 mg x kg(-1)), PBS drugs orally, once daily for 7 days, blood samples were acquired from the orbital venous blood at 3, 5, 7 days after the administering, HBsAg and HBeAg in serum concentration were measured by ELISA and the mice were sacrificed after 7 days, HBV DNA southern detections were used with part of mice livers. The results showed that betulinic acid significantly inhibited the expression of HbsAg in the mice model at the fifth day compared with the control group, and there was no significant differences between the effects of lamivudine and the PBS control group; both the betulinic acid and lamivudine groups had no significant inhibition for the HBeAg expression; the HBV DNA expressions of the liver tissue from the betulinic acid and lamivudine groups were inhibited compared with the control group. Taken together, these results reveal betulinic acid can inhibit the HBsAg expression and replication of the liver HBV DNA in the mouse model.
Acute Disease ; Animals ; Antiviral Agents ; pharmacology ; DNA Replication ; drug effects ; DNA, Viral ; biosynthesis ; Hepatitis B ; blood ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; drug effects ; genetics ; immunology ; physiology ; Male ; Mice ; Plasmids ; genetics ; Triterpenes ; pharmacology ; Virus Replication ; drug effects

This paper is aimed to investigate the inhibitory effects of hepatitis B virus (HBV) preC and C genes-specific antisense locked nucleic acid (LNA) on HBV replication and expression in transgenic mice. The antisense LNA, which was complementary to the preC and C gene region of HBV, was designed, synthesized, and injected into transgenic mice via the tail vein. Serum HBV DNA was tested with real-time PCR, and Serum HBsAg was tested with time-resolved fluorescence immune assay (TRFIA). Then the expression of HBcAg in the liver was detected with immuneohistochemistry. Serum ALB, ALT, BUN and CRea were measured with an antomatic biochemicall analyzer. It was found that 5 days after LNA injection, serum HBV DNA levels in the dual-target group were reduced by 53.72%, and serum HBsAg levels were decreased by 71.57%. These values were significantly higher than those in the control groups (P<0.05) and the expression levels of HBcAg in the liver were significantly lower than those in the control groups (P<0.05). The result also showed that there were no significant differences discovered in serum ALB, ALT, BUN and CR between the experiment groups and the control groups. The present study provides that antisense LNA targeting to both preC and C genes has shown strong inhibition on HBV replication and expression in transgenic mice, and stronger than target at single gene site.
Animals ; Antiviral Agents ; pharmacology ; DNA, Viral ; blood ; Female ; Gene Targeting ; Hepatitis B Core Antigens ; metabolism ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; drug effects ; genetics ; physiology ; Liposomes ; Male ; Mice ; Mice, Transgenic ; Oligonucleotides ; pharmacology ; Oligonucleotides, Antisense ; pharmacology ; Virus Replication ; drug effects

This study is to investigate the mechanism and action characteristics of 6-chloro-3-methyl-4-(2-methyoxycarbonylthiophene-3-sulfonyl)-3, 4-dihydroquinoxa-lin-2-(1 H)-one (XU07011) against HIV-1 replication. XU07011 anti-HIV activity was tested by using VSVG/HIV pseudotype viral system and confirmed by HIV-1 live viruses' infectious assay. Time of addition was used to test HIV-1 reverse transcription process. RNA-dependent DNA polymerase activity and RNase H activity were tested by using enzyme linked immunoabsorbent assay and fluorescence method. Wild type and nine NNRTIs-resistant reverse transcriptase enzymatic models and cell-based pharmacological models were used to evaluate XU07011 bio-characteristics. The results showed that XU07011 inhibited HIV-1 replication with IC50 of (0.057 +/- 0.01) micromol x L(-1) which was comparable to nevirapine [IC50: (0.046 +/- 0.01) micromol x L(-1)]. Mechanism study data indicated that XU07011 blocked HIV-1 reverse transcription process through acting on reverse transcriptase RNA-dependent DNA polymerase with IC 50 of (1.1 +/- 0.3) micromol x L(-1). The compound showed no effect on RNase H activity. XU07011 exhibited better activities comparing with nevirapine on K103N mutated NNRTIs-resistant HIV-1 strains. This study could provide a theoretical basis for novel anti-HIV reagents development.
Anti-HIV Agents ; chemistry ; pharmacology ; Drug Resistance, Viral ; HEK293 Cells ; HIV-1 ; physiology ; Humans ; Inhibitory Concentration 50 ; Molecular Structure ; Nevirapine ; pharmacology ; Quinoxalines ; pharmacology ; RNA-Directed DNA Polymerase ; metabolism ; Ribonuclease H ; metabolism ; Thiophenes ; pharmacology ; Virus Replication ; drug effects

OBJECTIVETo investigate the inhibitory effect of compound cantharides capsules on the proliferation of xenografts of human hepatocellular carcinoma HepG(2215) in mice and their mechanism of action.

METHODSOne hundred healthy Balb/c mice (5-week old, male:female 1:1) were used in this study. Mouse models of human HepG(2215) hepatocarcinoma were established. The tumor-bearing mice were divided into five groups randomly. The control group A received daily intragastric administration of physiologic saline. The intervention groups B1, B2 and B3 were treated with compound cantharides capsule in a dose of 12.5 mg×kg(-1)×d(-1), 25 mg×kg(-1)×d(-1) and 37.5 mg×kg(-1)×d(-1), respectively, for 10 consecutive days. The group C had intraperitoneal injection of cyclophosphamide (25 mg×kg(-1)×d(-1)) for 10 consecutive days. The mice were sacrificed after the completion of administration. The tumors were taken out, the tumor volume was measured, the inhibitory rate of body weight was calculated, and the serum AFP concentration and the level of HBV DNA were determined. The survival of each group mice was analyzed. The levels of mRNA expression of apoptosis-related genes were assayed by quantitative RT-PCR. Apoptosis in the tumor cells was assayed with TUNEL staining. Flow cytometry was used to detect the levels of CD3(+), CD19(+), CD4(+) and CD8(+), and microvessel density (MVD) of the tumors was assessed by immunohistochemistry.

RESULTSAfter completion of the treatment, the inhibition rate of tumor growth of the groups B1, B2 and B3 was 29.8%, 38.7% and 48.1%, respectively, and that of the group C was 52.4%, with a significant difference among the groups (P < 0.05). The median survival time of the groups A, B1, B2, B3 and C was (30.0 ± 3.2) days, (49.0 ± 5.1) days, (50.0 ± 5.2) days, (57.5 ± 6.5) days and (49.0 ± 4.7) days, respectively. The median survival time of the group B3 was significantly longer than that of other groups (P < 0.05). The serum AFP level in the groups A, B1, B2, B3 and C was (492.7 ± 48.5) ng/ml, (281.2 ± 25.6) ng/ml, (194.3 ± 18.7) ng/ml, (170.1 ± 15.8) ng/ml and (138.7 ± 12.5) ng/ml, respectively, indicating that it was significantly inhibited in the group C. The inhibition rate of HBV DNA replication of the groups B1, B2, B3 and C was (46.0 ± 5.1)%, (65.5 ± 6.9)%, (81.3 ± 7.8)% and (19.5 ± 2.1)%, respectively, showing that compound cantharides capsules inhibited HBV DNA replication in a dose-dependent manner. The apoptosis rate of the groups A, B1, B2, B3 and C was (0.27 ± 0.03)%, (7.18 ± 2.12)%, (9.17 ± 2.42)%, (11.27 ± 3.03)% and (5.44 ± 2.45)%, respectively, and that of the group B3 was significantly higher than that of the groups A, B1, B2 and C (P < 0.05). The expression level of bax mRNA was significantly higher than that of the group C (P < 0.05). The drug could significantly decrease the bcl-2 mRNA expression level, more remarkably along with the increasing dose of cantharides, and it was significantly lower than that in the group C (P < 0.05). The levels of CD4(+), CD8(+), CD3(+) and CD19(+) were significantly higher than that in the groups A and C (P < 0.05). The value of MVD of the group B3 was significantly lower that that of groups A and C (P < 0.05).

CONCLUSIONCompound cantharides capsules may inhibit the replication of HBV DNA in HepG(2215) cells, inducing apoptosis in the tumor cells, enhancing the immune function to inhibit the growth of liver cancer cells in mice, and significantly prolong the median survival time of tumor-bearing mice.

Animals ; Antineoplastic Agents ; administration & dosage ; pharmacology ; Antiviral Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cantharidin ; administration & dosage ; pharmacology ; Capsules ; DNA Replication ; DNA, Viral ; Drug Combinations ; Female ; Hep G2 Cells ; Hepatitis B virus ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Microvessels ; pathology ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Tumor Burden ; drug effects ; Virus Replication ; Xenograft Model Antitumor Assays ; alpha-Fetoproteins ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

It has been previously shown that Taraphochlamys affinis possessed anti-hepatitis B virus (HBV) activities. To identify the active ingredients, the total saponins (TSTA) were isolated from T. affinis and the inhibitory effect of TSTA on HBV in the duck HBV model was examined. The results showed that serum levels of DHBV-DNA decreased in all ducks treated with TSTA (1.0 and 2.0 g x kg(-1) x d(-1)) and lamivudine (3TC) (50 mg x kg(-1) x d(-1)) during treatment, but 7 days after the cessation of treatment (p7) with 3TC, the viral replication level returned to the pretreatment baseline. Contrariwise in ducks treated with TSTA, the effect of DHBV DNA inhibition lasted. Compared with model control group,the alanine aminotransferase (ALT), aspartate aminotransferase (AST) and duck hepatitis B surface antigen (DHBsAg) values of 1.0 and 2.0 g x kg(-1) x d(-1)-dose TSTA groups were significantly lower on 7, 14 days after the treatment (d7, d14) and p7, and at p7, the ALT and DHBsAg levels of 2.0 g x kg(-1) x d(-1)-dose TSTA group was significantly lower than that of 3TC group. Furthermore, significant histological improvement was noted in ducklings of TSTA treatment group 7 days after the withdrawal. The study results demonstrate that TSTA possesses potent anti-HBV activity.
Animals ; Antigens, Surface ; blood ; Antiviral Agents ; administration & dosage ; isolation & purification ; pharmacology ; DNA, Viral ; blood ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Hepadnaviridae Infections ; drug therapy ; virology ; Hepatitis B Virus, Duck ; drug effects ; immunology ; Hepatitis, Viral, Animal ; drug therapy ; virology ; Liver ; drug effects ; metabolism ; pathology ; Liver Function Tests ; Saponins ; administration & dosage ; isolation & purification ; pharmacology ; Virus Replication ; drug effects