Protective Effects and Mechanisms of Esculetin against H2O2-Induced Oxidative Stress, Apoptosis, and Pyroptosis in Human Hepatoma HepG2 Cells.

Oxidative stress plays a crucial role in the pathogenesis of many diseases. Esculetin is a natural coumarin compound with good antioxidant and anti-inflammatory properties. However, whether esculetin can protect HepG2 cells through inhibiting H2O2-induced apoptosis and pyroptosis is still ambiguous. Therefore, this study aimed to investigate the protective effects and mechanisms of esculetin against oxidative stress-induced cell damage in HepG2 cells. The results of this study demonstrate that pretreatment with esculetin could significantly improve the decrease in cell viability induced by H2O2 and reduce intracellular ROS levels. Esculetin not only apparently reduced the apoptotic rates and prevented MMP loss, but also markedly decreased cleaved-Caspase-3, cleaved-PARP, pro-apoptotic protein (Bax), and MMP-related protein (Cyt-c) expression, and increased anti-apoptotic protein (Bcl-2) expression in H2O2-induced HepG2 cells. Meanwhile, esculetin also remarkably reduced the level of LDH and decreased the expression of the pyroptosis-related proteins NLRP3, cleaved-Caspase-1, Il-1ß, and GSDMD-N. Furthermore, esculetin pretreatment evidently downregulated the protein expression of p-JNK, p-c-Fos, and p-c-Jun. Additionally, anisomycin, a specific activator of JNK, blocked the protection of esculetin against H2O2-induced HepG2 cells apoptosis and pyroptosis. In conclusion, esculetin can protect HepG2 cells against H2O2-induced oxidative stress, apoptosis, and pyroptosis via inhibiting the JNK signaling pathway. These findings indicate that esculetin has the potential to be used as an antioxidant that improves oxidative stress-related diseases.

The association between statin use and depression in diabetes.

BACKGROUND: Depression is a common mental disorder. Some studies have demonstrated that people with diabetes are more likely to suffer from depression. Statins are an everyday use for diabetes. Trials of statin therapy have had conflicting findings on the potential risk of depression. METHODS: The National Health and Nutrition Examination Survey (NHANES) 2005-2018 was used to collect a representative sample. Weighted multivariate logistic regression models were used to evaluate odds ratios (ORs) and 95 % CIs for having depression symptoms. We performed stratified analyses to compare the effects of statins in subsamples with and without diabetes on depression symptoms. RESULTS: Statin use showed a significant and strong decreasing effect on having depression symptoms in participants with diabetes (aOR (adjusted OR) 0.59, p = 0.014) compared with that in non-diabetics (aOR 0.78, p = 0.128). Diabetic individuals with statin use for >5 years had a lower risk of having depression symptoms (aOR 0.42, p = 0.002) than those with shorter-term statin use (1-5 years, aOR 0.69, p = 0.111; <1 year: aOR 0.83, p = 0.646). Atorvastatin was more effective in decreasing depression symptoms either in diabetes (aOR 0.49, p = 0.018) or in non-diabetes (aOR 0.58, p = 0.033). LIMITATIONS: First, the dosage of statins cannot be obtained from NHANES datasets. Second, after being stratified, the number of participants for several statins was insufficient. Third, recall bias may exist in the survey. CONCLUSIONS: Diabetics with depression symptoms may benefit from long-term statin therapy. Atorvastatin and pravastatin should be recommended for diabetic patients with depression.

Ursolic acid induces apoptosis and pyroptosis in Reh cells by upregulating of the JNK signalling pathway based on network pharmacology and experimental validation.

Objective: To explore the mechanism of ursolic acid (UA) against acute B lymphoblastic leukaemia (B-ALL) based on network pharmacological analysis, molecular docking and experimental verification. Methods: The core targets, functional processes, and biological pathways of UA in B-ALL were predicted by network pharmacology and molecular docking. The efficacy and mechanism of UA against B-ALL were verified through in vitro experiments such as cell viability assays, CCK-8 assays, LDH assays, AO/EB staining, flow cytometry, and Western blot assays. Results: Network pharmacology analysis of the core targets indicated that the effects of UA on B-ALL were related to programmed cell death (apoptosis and pyroptosis). Molecular docking results showed that FOS, CASP8, MAPK8, IL-1ß and JUN were the key targets of UA against B-ALL. The MTS assay showed that UA decreased the viability of Reh cells in a concentration- and time-dependent manner. Cellular and Western blot experiments found that UA induced Reh cell apoptosis and pyroptosis by upregulating the JNK signalling pathway. Conclusions: Our findings demonstrated that UA could induce Reh cell apoptosis and pyroptosis by activating the JNK signalling pathway to exert anti-B-ALL effects. This indicates that UA may become a potential drug for the effective treatment of B-ALL.

HPV16 E7 protein antagonizes TNF-α-induced apoptosis of cervical cancer cells via Daxx/JNK pathway.

Human papillomavirus (HPV) E7 protein as an important viral factor was involved in the progression of cervical cancer by mediating the cellular signaling pathways. Daxx (Death domain-associated protein) can interact with a variety of proteins to affect the viral infection process. However, the interaction and its related function between HPV16 E7 and Daxx have not been adequately investigated. Here, it was found that HPV16 E7 can interact with Daxx in HeLa or C33A cells by co-immunoprecipitation. HPV16 E7 protein treatment can up-regulate Daxx protein expression, while the interference in Daxx expression and the agonists for JNK can both reduce the antagonistic effects of HPV16 E7 on TNF-α-induced apoptosis, suggesting that Daxx/JNK pathway may be involved in the anti-apoptotic activity of HPV16 E7.

Novel use of graphene oxide quantum dots in a pickering emulsion as a Chlamydia trachomatis vaccine adjuvant.

Graphene oxide quantum dots (GOQDs), which are graphene-based nanoparticles, are potential surfactant substitutes for stabilizing Pickering emulsions, due to their high surface area, biodegradability, and reasonable biocompatibility. In the present study, GOQDs stabilized Pickering emulsion (GQPE) was prepared by simple sonication and then used as an adjuvant to enhance immune responses to the Chlamydia trachomatis Pgp3 recombinant vaccine. Immunization of mice showed that GQPE robustly activates adaptive immunity by efficiently stimulating IgG, sIgA, IFN-γ, IL-4, and TNF-α production. Controlled release repository of antigens both in vivo and in vitro prolonged the immune response. In addition, GQPE enhanced dendritic cell recruitment at the injection site, ensuring rapid and efficient innate immunity. Safety assessment revealed that GQPE does not cause liver, kidney, and myocardial damage in mice, suggesting its favorable biocompatibility. This study provides evidence for the use of GOPE as a facile, effective, and safe strategy to enhance the immune response to Pgp3 recombinant vaccines.

HPV Prevalence and Genotype Distribution Among Women From Hengyang District of Hunan Province, China.

Most cervical cancers were closely associated with human papillomavirus (HPV) infections. Therefore, understanding the ecological diversity of HPV prevalence and genotype distribution among various populations in different geographical regions was essential for optimizing HPV vaccination and maximizing the vaccination effects. A total of 12,053 patient data from the three-level hospitals in Hengyang city were retrospectively analyzed. In this study, the HPV prevalence was 10.16% overall, and the multiple-type infection rate was 1.83%. The HR-HPV infection rate was 8.52%. The top six HPV genotypes were as follows in descending order: HPV16, HPV58, HPV52, HPV39, HPV51, and HPV53. The HPV prevalence in the group above 60 years old was the most, and their HR-HPV infection rate corresponded to the most too. The infection rates of HPV and HR-HPV among outpatients were both lower than those among the hospitalized-patients, respectively. Among the hospitalized-patients, the infection rates of HPV and HR-HPV among the 50-60 years group were the most in both. The HR-HPV ratio-in-positive among HPV-positive patients with the histopathologic examination was higher than that among those patients without. Among 52 HPV-positive patients with cervical squamous carcinoma, the ratio-in-positive of HPV16 was 61.54%. This study demonstrated that the HPV prevalence varied with age among women from Hengyang district of Hunan province in China and showed that HPV16, HPV58, HPV52, HPV39, HPV51, and HPV53 genotypes were more popularly distributed in this region, which could provide the experimental basis for Chinese public health measures on cervical cancer prevention.

Dual-signal amplification electrochemical sensing for the sensitive detection of uranyl ion based on gold nanoparticles and hybridization chain reaction-assisted synthesis of silver nanoclusters.

Herein, a dual-signal amplification electrochemical sensing has been proposed for the ultrasensitive detection of uranyl ions (UO22+) by integration of gold nanoparticles (AuNPs) and hybridization chain reaction (HCR)-assisted synthesis of silver nanoclusters (AgNCs). In this sensing platform, AuNPs are used as an ideal signal amplification carrier, aiming at increasing the loads of UO22+-specific DNAzyme on the gold electrode. In the presence of UO22+, UO22+-specific DNAzyme can be activated, leading to the cleavage of substrate strands (S-DNA). Then, HCR is triggered to produce long dsDNA through hybridization the probe with the ssDNA on the electrode surface. As a result, an amplified electrochemical response can be detected by inserting a large amount of AgNCs generated in situ using dsDNA as template. Featured with amplification efficiency, good specificity and high sensitivity, the strategy could quantitatively detect UO22+ down to 6.2 pM with a linear calibration range from 20 pM to 5000 pM. The proposed sensing platform has been also successfully demonstrated the practical application of detecting UO22+, indicating that the developed method has the potential applications and can open up a new avenue for highly sensitive detection of UO22+ in environmental monitoring.

Effects of HPV16 E6 protein on Daxx-induced apoptosis in C33A cells.

AIMS: Daxx is a highly conserved nuclear protein with an important role in transcription, apoptosis and other cell processes. We investigated the role of HPV16 E6 in Daxx-induced apoptosis through their interactions in C33A cells. METHODS: The binding of HPV16 E6 and Daxx was confirmed in C33A cells using co-immunoprecipitation and indirect immunofluorescence assays. Quantitative PCR and western blotting were performed to determine the RNA and protein expressions of Daxx, respectively. Automatic cell count and MTT assays were performed to investigate the proliferation of C33A cells. The apoptosis rate of C33A cells was determined via flow cytometry using Annexin V-FITC/PI staining. The relative activity of caspase-8 was tested using ELISA. RESULTS: HPV16 E6 can bind with Daxx and cause its translocation in C33A cells. The transfected HPV16 E6 can cause a decrease in relative quantification for Daxx in Daxx-overexpressing cells. After Daxx transfection, cell proliferation was found to decrease sharply and cell apoptosis to increase sharply. However, when HPV16 E6 was co-transfected with Daxx, this decrease and increase both became gentle. Similarly, HPV16 E6 made the Daxx-induced increase in caspase-8 activity milder. CONCLUSIONS: HPV16 E6 is involved in inhibiting apoptosis through deregulation of Daxx-induced caspase-8 activities.

Amplified electrochemical determination of UO22+ based on the cleavage of the DNAzyme and DNA-modified gold nanoparticle network structure.

A superior electrochemical biosensor was designed for the determination of UO22+ in aqueous solution by integration of DNAzyme and DNA-modified gold nanoparticle (DNA-AuNP) network structure. Key features of this method include UO22+ inducing the cleavage of the DNAzyme and signal amplification of DNA-AuNP network structure. In this electrochemical method, the DNA-AuNP network structure can be effectively modified on the surface of gold electrode and then employed as an ideal signal amplification unit to generate amplified electrochemical response by inserting a large amount of electrochemically active indicator methylene blue (MB). In the presence of UO22+, the specific sites on DNA-AuNP network structure can be cleaved by UO22+, releasing the DNA-AuNP network structure with detectable reduction of electrochemical response intensity. The electrochemical response intensity is related to the concentration of UO22+. The logarithm of electrochemical response intensity and UO22+ concentration showed a wide linear range of 10~100 pM, and the detection limit reached 8.1 pM (S/N = 3). This method is successfully used for determination of UO22+ in water samples. Graphical abstract Fabricated DNAzyme network structure for enhanced electrical signal. Numerical experiments show that the current signal decreases as the concentration of UO22+ increases. It can be seen that the biosensors could be used to detect UO22+ in aqueous solution effectively.

4-Sulfonylcalix[6]Arene Modified Fe3O4@Aspergillus Niger Biosorbents for Effective Removal of Uranium(VI) from Aqueous Solutions.

A biosorbent, 4-sulfonylcalix[6]arene modified Fe3O4@Aspergillus Niger (MFSC), was successfully prepared through a two-step route for the effective removal of uranium (U(VI)) from aqueous solutions with high selectivity. The structure of MFSC was characterized by FT-IR, SEM, XRD, TGA and VSM, respectively. The impacts of various experimental parameters were investigated in detail. The results indicated that the biosorption of U(VI) on MFSC was mainly attributed to the electrostatic attraction (91% within 8 hours for U(VI)). The adsorption kinetics and adsorption isotherm of U(VI) were found to follow the pseudo second-order model and to be fitted by the Langmuir model, respectively. The thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. The findings herein highlight the MFSC with high ability for removal of U(VI) from aqueous solutions.

Selective Adsorption of Uranium (VI) by Calix[6]arene-Modified Magnetic Graphene Oxide.

Magnetic graphene oxide/calix[6]arene (MGO-C6) composites were prepared and then characterized by Fourier transform infrared spectroscopy, Scanning electron microscope, X-ray diffraction and Thermo gravimetric analyzer, the adsorption of U(VI) by MGO-C6 from aqueous solution was investigated as a function of pH, contact time, initial U(VI) concentration and adsorbent dosage. The maximum adsorption rate of MGO-C6 can reach up to 93.21%, which was highly efficient for the removal of U(VI) under the condition of 1 mg/L initial uranium concentration. In addition, the selective adsorption experiment showed that MGO-C6 had an overall preference for U(VI). Adsorption process of MGO-C6 fitted well with the pseudo-second-order kinetic kinetics and the Langmuir isotherm model. The thermodynamic parameters illustrated that the adsorption process was endothermic and spontaneous. This work demonstrated that MGO-C6 was a promising adsorbent for removal of U(VI) from low concentration uranium-containing wastewater.

Construction and protective immunogenicity of DNA vaccine pNMB0315 against Neisseria meningitidis serogroup B.

Neisseria meningitidis (N. meningitidis) is a major cause of meningitis and sepsis. Capsular polysaccharide­based vaccines against serogroups A, C, Y, and W135 are available; however, the development of a vaccine against N. meningitidis serogroup B (NMB) has been problematic. NMB0315 is an outer membrane protein of NMB that may be a virulence factor for N. meningitidis and a possible target for functional bactericidal antibodies. The present study aimed to develop a potent DNA vaccine against NMB by cloning the NMB0135 gene into the pcDNA3.1(+) vector to construct the recombinant plasmid pcDNA3.1(+)/NMB0315 (designated pNMB0315). pNMB0315 was transfected into eukaryotic COS­7 and RAW264.7 cells to express the recombinant (r)NMB0315 protein. Protective immunogenicity of the DNA vaccine was assessed in an in vivo mouse model. The levels of rNMB0315­specific immunoglobulin G (IgG), IgG1 and IgG2a antibodies in the pNMB0315­immunized group increased dramatically up to week 6 following the initial vaccination, and were significantly higher compared with the levels in the Control groups. The serum concentrations of interleukin­4 and interferon­Î³ were significantly higher in the pNMB0315­immunized group compared with the control groups. Following intraperitoneal challenge with a lethal dose of NMB strain MC58, the survival rate in the pNMB0315 + CpG group was 70% (14 out of 20 mice) at 14 days; by contrast, all mice in the control groups succumbed within 3 days. The serum bactericidal titers of the pNMB0315 + CpG group in vitro reached 1:128 following three immunizations. The results indicated that pNMB0315 may serve as a promising DNA vaccine against NMB.

[Preparation and identification of the polyclonal antibody against ATRX-C2193-2492].

Objective To prepare the polyclonal antibody against human alpha thalassemia/mental retardation syndrome X-linked (ATRX) C-terminal and study the distribution and expression of ATRX protein in human cervical cancer tissues. Methods The antiserum was obtained from the BALB/c mice immunized with 6His-ATRX-C2193-2492 protein and then purified by the saturated ammonium sulfate precipitation and affinity chromatography. The titer of anti-ATRX polyclonal antibody was determined by ELISA. Its specificity was identified by SDS-PAGE analysis and Western blotting. The expression and location of ATRX in human cervical tissues were analyzed by immunohistochemistry. Results The titer of the polyclonal antibody against 6His-ATRX-C2193-2492 protein was about 1:12 800. The antibody could recognize 6His-ATRX-C2193-2492 protein specifically. With the polyclonal antibody, the target protein was found mainly in the nucleus of para-carcinoma tissues, and it was also expressed in the nucleus of cervical cancer tissue cells, but the expression in the latter was obviously lower. Conclusion The polyclonal antibody against 6His-ATRX-C2193-2492 protein has been produced successfully and used to detect ATRX protein in human cervical cancer tissues.

Death domain associated protein (Daxx), a multi-functional protein.

Death domain associated protein (Daxx), a multi-functional protein, plays an important role in transcriptional regulation, cell apoptosis, carcinogenesis, anti-virus infection and so on. However, its regulatory mechanisms for both cell survival and apoptosis remain largely obscure. Our review of recent studies shows that Daxx has many interesting functional dualities and can provide a reference for further research on Daxx.

CD4(+) Foxp3(+) regulatory T-cell number increases in the gastric tissue of C57BL/6 mice infected with Helicobacter pylori.

Helicobacter pylori (H. pylori), one of the most common infections, is associated with various clinical outcomes. In addition to inducing inflammation, immunological clearance of the pathogen is often incomplete. Regulatory T cells (Treg cells) have been recently demonstrated to play an important role in H. pylori infection and the final clinical outcome. The aim of this study was to investigate the number and localization of CD4(+) Foxp3(+) Treg cells in stomachs and spleens of H. pylori-infected mice. The expression levels of Foxp3 as well as anti- and pro-inflammatory cytokines before and after H. pylori triple eradication therapy were examined. We found that the percentages of CD4(+) Foxp3(+) Treg cells out of the lamina propria lymphocytes (LPLs) and spleen lymphocytes in the infection group were higher than the PBS negative control group and the treatment group. H. pylori antigen stimulation was associated with an increased number of Treg cells in vitro. Furthermore, compared with the PBS and treatment groups, a higher mRNA expression level of Foxp3 in the gastric tissue was detected in the infection group. IL-10 and TGF-ß1 contents were increased significantly in the culture supernatant of spleen lymphocyte stimulated with H. pylori antigen. A marked elevation in serum IFN-γ level was observed in H. pylori-infected mice. In addition, gastric tissues of the infection group contained more Foxp3(+) cells. These results indicate that the percentage of CD4(+) Foxp3(+) Treg cells are increased in H. pylori-infected mice, suggesting a role of Treg cells in H. pylori-induced pathologies, even at the early stages of chronic gastritis and gastric tumorigenesis.

Helicobacter pylori induces IL-1ß and IL-18 production in human monocytic cell line through activation of NLRP3 inflammasome via ROS signaling pathway.

This study investigated whether Helicobacter pylori could activate the nucleotide-binding oligomerization domain-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome in human macrophages and the involvement of reactive oxygen species (ROS) in inflammasome activation. Phorbol-12-myristate-13-acetate (PMA)-differentiated human acute monocytic leukemia cell line THP-1 was infected with H. pylori. The levels of pro-inflammatory cytokines interleukin (IL)-1ß and IL-18 in supernatant were measured by ELISA. Intracellular ROS level was analyzed by flow cytometry. Quantitative real-time PCR and western blot analysis were employed to determine the mRNA and protein expression levels of NLRP3 and caspase-1 in THP-1 cells, respectively. Our results showed that H. pylori infection could induce IL-1ß and IL-18 production in PMA-differentiated THP-1 cells in a dose- and time-dependent manner. Moreover, secretion of IL-1ß and IL-18 in THP-1 cells following H. pylori infection was remarkably reduced by NLRP3-specific small interfering RNA treatment. In addition, the intracellular ROS level was elevated by H. pylori infection, which could be eliminated by the ROS scavenger N-acetylcysteine (NAC). Furthermore, NAC treatment could inhibit NLRP3 inflammasome formation and caspase-1 activation and suppress the release of IL-1ß and IL-18 from H. pylori-infected THP-1 cells. These findings provide novel insights into the innate immune response against H. pylori infection, which could potentially be used for the prevention and treatment of H. pylori-related diseases.

Awareness and knowledge about human papillomavirus among high school students in China.

OBJECTIVE: To investigate awareness and knowledge of human papillomavirus (HPV) infection among high school students and to provide a basis for health education on HPV infection for high school students in China. STUDY DESIGN: A questionnaire on HPV awareness and knowledge was administered to 900 high school students in Xiangtan City of Hunan Province in China by layer cluster sampling. A total of 848 anonymous valid questionnaires were received from volunteers who completed the questionnaire correctly. RESULTS: Only 10.1% had heard of HPV, and of those only 18.6% knew that HPV could lead to cervical cancer. Single factor analysis indicated that home address, age, grade, academic achievement, sex history, gender, father's education level and mother's education level were impact factors for HPV knowledge of high school students. Multiple regression analysis showed 4 independent risk factors associated with HPV knowledge: academic achievement, sex history, gender, and mother's education level. The limited knowledge came primarily from television and radio broadcasts (59.3%), the Internet (57.0%), parents (25.6%), medical workers (20.9%), and teachers (18.6%). CONCLUSION: High school students lack HPV knowledge, which is affected by multiple factors. Targeted health education of all sorts must be provided. Both schools and families are responsible for reinforcing HPV education provided to high school students.

Distribution and location of Daxx in cervical epithelial cells with high risk human papillomavirus positive.

AIMS: To provide the basis for further exploring the effect and its mechanism of Death domain associated protein (Daxx) on the progress of cervical carcinoma induced by human papillomavirus (HPV), the distribution and location of Daxx in cervical carcinoma with high risk HPV(HR-HPV) positive was analyzed. METHODS: The samples of normal cervical epithelial cells, cervical intraepithelial neoplasia grade I (CINI), CINII CINIII and cervical cancers were collected. Immunohistochemistry assay was used to analyze the distributions and locations of Daxx in the cervical tissue. Indirect immunoinfluorescence test was utilized to observe the locations of Daxx in Caski cells with HPV16 positive. RESULTS: Under the light microscopy, the brown signals of Daxx distributed in the nuclei of normal cervical epithelial cells; Daxx mainly distributed in nuclear membrane and there were a small amount of Daxx in the nuclei in CINI. Daxx intensively distributed in the cytoplasm and cell membrane in CINII, CINIII and cervical cancer. Under fluorescent microscopy, the distribution and location of Daxx in Caski cells was similarly to that in cervical cells of CINII, CINIII and cervical cancer. CONCLUSION: In the progress of the cervical cancer, Daxx gradually translocates from nucleus into nuclear membrane, cytoplasm and cell membrane. Daxx locates in the cytoplasm and cell membrane in CINII, CINIII and cervical cancer. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/4671548951113870.

[The expressions of NLRP3 inflammasome and its downstream molecules in the mouse model of Helicobacter pylori infection].

OBJECTIVE: To study the expressions of NLRP3 inflammasome and its downstream molecules in the gastric tissues and sera of Helicobacter pylori (H.pylori)-infected C57BL/6 mice, and to preliminary explore the role of NLRP3 inflammasome signalling pathway in the pathogenesis of H.pylori infection. METHODS: C57BL/6 mice were randomly divided into H.pylori infection group and PBS control group, and mice were sacrificed at different time points after H.pylori infection. The mRNA expressions of NLRP3 inflammasome and downstream signalling pathway related molecules in mouse gastric tissues were detected by RT-PCR, and the protein level of caspase-1 was analyzed by Western blotting. The contents of IL-1ß, IL-18 and IL-33 in the sera were measured with ELISA. RESULTS: Chronic inflammatory response was observed in the gastric mucosal tissues of H.pylori-infected mice and it gradually aggravated. Compared with the control mice, the mRNA expressions of NLRP3 inflammasome signalling pathway related molecules and the protein level of caspase-1 increased markedly in the gastric tissues of H.pylori-infected mice. Moreover, the contents of IL-1ß, IL-18 and IL-33 in the sera of H.pylori-infected mice were also significantly elevated. CONCLUSION: NLRP3 inflammasome signalling pathway could be activated by H.pylori infection.

Overexpression of Helicobacter pylori VacA N-terminal fragment induces proinflammatory cytokine expression and apoptosis in human monocytic cell line through activation of NF-κB.

Vacuolating cytotoxin (VacA) is an important virulence factor in the pathogenesis of Helicobacter pylori-related diseases. The aim of this study was to investigate the function of the amino-terminal 476 residue fragment (p52) of VacA and the possible molecular mechanisms responsible for its induction of proinflammatory cytokines secretion and apoptosis. Human acute monocytic leukemia cell line THP-1 was used as an in vitro model to study proinflammatory cytokines secretion and apoptosis induced by transfection of a recombinant plasmid encoding the amino-terminal 476 residue fragment (p52) of VacA. The results showed that VacA p52 overexpression induced the production of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), nitric oxide, and reactive oxygen species in THP-1 cells in a time-dependent manner. VacA p52 overexpression also promoted THP-1 cells apoptosis. In addition, VacA p52 triggered the activation of nuclear factor kappa B (NF-κB), indicating a possible mechanism for its induction of proinflammatory cytokines secretion and cell apoptosis. Our study demonstrated that the induction of cytokines secretion and apoptosis by VacA p52 in THP-1 cells could be mediated through activation of nuclear factor kappa B.