Objective To investigate the antibacterial activity of the antifungal peptide Mt6-21DLeu derived from Musca domestica against Acinetobacter baumannii (AB) and unravel its underlying mechanisms, so as to provide insights into development of novel agents against AB. Methods The minimum inhibitory concentrations (MICs) of Mt6-21DLeu, M. domestica-derived antifungal peptide-1 (MAF-1A), and polymyxin B were determined against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and AB using the broth microdilution assay, and the antibacterial activity of Mt6-21DLeu and polymyxin B was dynamically assessed against AB over 24 hours with time-kill curves. The inhibitory effects of Mt6-21DLeu and polymyxin B on biofilm formation in AB at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and the eradication effects of Mt6-21DLeu and polymyxin B on mature biofilms in AB at concentrations of MIC, 2 × MIC, and 4 × MIC were evaluated using crystal violet staining. Structural changes in the cell membrane of AB were observed 3 hours post-exposure to Mt6-21DLeu at concentrations of MIC and 2 × MIC using scanning electron microscopy, and alterations in the cell membrane permeability of AB were analyzed 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC by means of fluorescence microscopy and propidium iodide (PI) staining. Intracellular reactive oxygen species (ROS) levels in AB were measured 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC using flow cytometry. The survival of Caenorhabditis elegans exposed to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC was monitored for 7 consecutive days, and survival curves were plotted to evaluate the in vivo toxicity of Mt6-21DLeu. In addition, C. elegans infected with AB and treated with Mt6-21DLeu at a concentration of 4 × MIC served as the treatment group, and uninfected C. elegans served as the control group, while infected but untreated C. elegans served as the infection group. The in vivo antibacterial efficacy of Mt6-21DLeu at a concentration of 4 × MIC was evaluated by comparing the survival curves and bacterial load among the three groups. Results The MICs of MAF-1A were all >128 μg/mL against S. aureus, B. subtilis, E. coli, K. pneumoniae, P. aeruginosa, and AB. In contrast, the MICs of Mt6-21DLeu were >128, 32, 8, 8, 16, and 4 μg/mL against these strains, respectively, and the MIC of Mt6-21DLeu against AB was close to that of polymyxin B (2 μg/mL). Time-kill curve analysis showed that both Mt6-21DLeu at concentrations of MIC and 2 × MIC and polymyxin B at a concentration of MIC inhibited AB growth over the 24-hour study period. The biofilm biomass in AB was (52.38 ± 6.92)%, (40.88 ± 9.17)% and (14.77 ± 6.00)% post-exposure with Mt6-21DLeu at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, (61.58 ± 7.35)%, (47.42 ± 5.51)% and (20.85 ± 10.48)% post-treatment with polymyxin B at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and (100.00 ± 15.92)% in the control group (only bacterial suspension), respectively (F = 68.38, P < 0.001), and pairwise comparisons indicated that Mt6-21DLeu and polymyxin B at all concentrations significantly inhibited biofilm formation as compared to the control group (all P values < 0.001). The mature biofilm biomass in AB was (73.44 ± 11.41)%, (72.56 ± 13.08)% and (49.65 ± 9.23)% post-exposure to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC, (84.38 ± 8.60)%, (72.31 ± 9.63)% and (58.85 ± 4.96)% post-treatment with polymyxin B at concentrations of MIC, 2 × MIC, and 4 × MIC, and (100.00 ± 6.36)% in the control group (F = 35.63, P < 0.001), and pairwise comparisons revealed that Mt6-21DLeu at all concentrations significantly eradicated biofilm biomass (all P values < 0.05); however, polymyxin B showed no clear-cut eradication effect at a concentration of MIC (P > 0.05). Scanning electron microscopy revealed pore formation and content leakage in the cell membrane of AB 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC. Fluorescence microscopy showed that the proportions of PI-stained AB were (24.79 ± 11.51)% and (68.44 ± 15.80)% post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC, and (0.96 ± 0.94)% in the phosphate-buffered saline (PBS) treatment group (F = 105.90, P < 0.001), with the highest proportion of PI-stained AB seen post-treatment with Mt6-21DLeu at a concentration of 2 × MIC (P < 0.05). Flow cytometry revealed that the relative intracellular ROS levels in AB were (652.00 ± 141.90), (694.33 ± 14.19), and (974.33 ± 160.02) 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC and 4 × MIC, and (403.67 ± 86.56) in the PBS treatment group, respectively (F = 12.27, P < 0.05), with the highest intracellular ROS level measured following treatment with Mt6-21DLeu at a concentration of 4 × MIC (P < 0.05). Survival curve analysis revealed that Mt6-21DLeu posed no impact on C. elegans survival at concentrations of MIC (χ² = 0.02, P > 0.05), 2 × MIC (χ² = 0.06, P > 0.05) or 4 × MIC (χ² = 0.16, P > 0.05), and there was a significant difference in the survival period of C. elegans among the control group, the infection group, and the treatment group (χ² = 82.66, P < 0.05), with a significantly longer survival period in the treatment group than in the infection group (χ² = 45.00, P < 0.05). In addition, the log-transformed bacterial colony counts in C. elegans were (0.00 ± 0.00), (5.46 ± 0.03), and (3.91 ± 0.47) CFU/mL in the control group, the infection group, and the treatment group, respectively (F = 324.80, P < 0.001), and the log-transformed bacterial colony counts in C. elegans were significantly lower in the treatment group than in the infection group (P < 0.05). Conclusions Mt6-21DLeu exerts potent antibacterial effects through disrupting the cell membrane integrity of AB and promoting intracellular ROS accumulation in AB, and exhibits promising potential for treatment of AB infections both in vivo and in vitro, which may serve as a candidate drug molecule against multidrug-resistant AB infections.

Purpose: C5α receptor 1 (C5ΑR1) is associated with the development of various human cancers. However, whether it is involved in the development of hepatitis B virus (HBV)–related hepatocellular carcinoma (HCC) is poorly understood. We explored the expression, biological role, and associated mechanisms of C5AR1 in HBV-related hepatoma cells. Materials and Methods: The expression of C5ΑR1 mediated by HBV and HBV core protein (HBc) was detected in hepatoma cells. The function of nuclear factor кB (NF-κB) pathway in HBc-induced C5AR1 expression was assessed. The roles of C5ΑR1 in the activation of intracellular signal pathways, the upregulation of inflammatory cytokines, and the growth and migration of hepatoma cells mediated by HBc, were investigated. The effect of C5α in the development of HCC mediated by C5AR1 was also measured. Results: C5ΑR1 expression was increased in HBV-positive hepatoma cells. Dependent on HBc, HBV enhanced the expression of C5ΑR1 at the mRNA and protein levels. Besides, HBc could promote C5ΑR1 expression via the NF-κB pathway. Based on the C5ΑR1, HBc facilitated the activation of JNK and ERK pathways and the expression and secretion of interleukin-6 in hepatoma cells. Furthermore, C5ΑR1 was responsible for enhancing the growth and migration of hepatoma cells mediated by HBc. Except these, C5α could promote the malignant development of HBc-positive HCC via C5AR1. Conclusion We provide new insight into the mechanisms of hepatocarcinogenesis mediated by HBc. C5ΑR1 has a significant role in the functional abnormality of hepatoma cells mediated by HBc, and might be utilized as a potential therapeutic target for HBV-related HCC.

Purpose: C5α receptor 1 (C5ΑR1) is associated with the development of various human cancers. However, whether it is involved in the development of hepatitis B virus (HBV)–related hepatocellular carcinoma (HCC) is poorly understood. We explored the expression, biological role, and associated mechanisms of C5AR1 in HBV-related hepatoma cells. Materials and Methods: The expression of C5ΑR1 mediated by HBV and HBV core protein (HBc) was detected in hepatoma cells. The function of nuclear factor кB (NF-κB) pathway in HBc-induced C5AR1 expression was assessed. The roles of C5ΑR1 in the activation of intracellular signal pathways, the upregulation of inflammatory cytokines, and the growth and migration of hepatoma cells mediated by HBc, were investigated. The effect of C5α in the development of HCC mediated by C5AR1 was also measured. Results: C5ΑR1 expression was increased in HBV-positive hepatoma cells. Dependent on HBc, HBV enhanced the expression of C5ΑR1 at the mRNA and protein levels. Besides, HBc could promote C5ΑR1 expression via the NF-κB pathway. Based on the C5ΑR1, HBc facilitated the activation of JNK and ERK pathways and the expression and secretion of interleukin-6 in hepatoma cells. Furthermore, C5ΑR1 was responsible for enhancing the growth and migration of hepatoma cells mediated by HBc. Except these, C5α could promote the malignant development of HBc-positive HCC via C5AR1. Conclusion We provide new insight into the mechanisms of hepatocarcinogenesis mediated by HBc. C5ΑR1 has a significant role in the functional abnormality of hepatoma cells mediated by HBc, and might be utilized as a potential therapeutic target for HBV-related HCC.

Objective To investigate the role of interleukin-22 (IL-22)-regulated autophagy in hydrogen peroxide (H2 O2 )-induced hepatocarcinoma cell damage. Methods HepG2 cells were transfected with pEGFP-LC3 and then cultured in RPMI 1640 medium free of fetal bovine serum (FBS) or containing 1％ or 10％ FBS. These cells were pretreated with rapamycin or an autophagy inhibitor (3-MA) and then stimulated with recombinat human IL-22 (rhIL-22). GFP-LC3 puncta formation and autophagy signaling ac-tivation were measured. MTT assay was performed to detect cell viability. Results rhIL-22 significantly promoted GFP-LC3 puncta formation and LC3-Ⅱ expression in HepG2 cells treated with different stimulation protocols. The autophagy pathway inhibitor, 3-MA, dramatically suppressed the rhIL-22-activated autophagy signals. rhIL-22 attenuated H2 O2-mediated HepG2 cell death and that could be inhibited by 3-MA. Conclu-sion IL-22 promoted the activation of autophagy signaling pathways and alleviated H2 O2-mediated HepG2 cell damage.

Objective To explore the effects of the down-regulating peroxiredoxin 2 (PRDX2) on invasion, migration and proliferation of human gastric cancer MGC803 cells by using RNA interference. Methods MGC803 cells were divided into 3 groups:blank control group,negative control group and PRDX2 siRNA group. Transwell assay was used to examine the invasive ability change of MGC803 cells after transfection. Scratch test was used to detect the change of MGC803 cells migration ability after transfection. Western blot was used to examine the expression changes of PRDX2, matrix metalloproteinase (MMP)-2 and MMP-9. The proliferation ability of MGC803 cells was assessed by using CCK-8 assay. Results The expressions of PRDX2(0.345±0.006,0.721±0.013,0.720±0.014),MMP-2(0.067±0.012, 0.391±0.015, 0.371± 0.016) and MMP-9 (0.073±0.013, 0.341±0.028, 0.346±0.024) in the PRDX2 siRNA group were lower than those in the blank control group and negative control group (all P < 0.05). The cell invasion, migration and proliferation were inhibited in MGC803 cells (all P < 0.05). Conclusion PRDX2 is overexpressed in MGC803 cells. Down-regulating the expression of PRDX2 could inhibit the invasion, migration and proliferation of MGC803 cells.

Objective To investigate the effects of 14-3-3 phosphorylation (p-14-3-3) induced by C-Jun N-termi-nal kinase (JNK) on ischemic brain injury in rats. Methods Twenty rats were divided into 4 groups:sham operation group, ischemia-reperfusion group, SP600125 group and solvent control group. The rat model of cerebral ischemia was established. The p-14-3-3, the binding of 14-3-3 and Bax and the protein expression of Bax in cytoplasm and mitochondria in hippo-campal CA1 region were detected by immunoprecipitation (IP) and immunoblotting 12-hour after ischemia-reperfusion in four groups. Results Compared with the sham operation group, protein expression levels of p-14-3-3 in cytoplasm and Bax in mitochondria were significantly increased, the binding of 14-3-3 and Bax was significantly decreased in ischemia-re-perfusion group, solvent control group and SP600125 group. The protein expressions of p-14-3-3 and Bax were significantly lower in SP600125 group than those of ischemia-reperfusion group and solvent control group. The binding of 14-3-3 and Bax was significantly higher in SP600125 group than that of ischemia-reperfusion group and solvent control group (P <0.05). Conclusion 14-3-3 phosphorylation induced by JNK plays important effects on ischemic brain injury in rats.

OBJECTIVETo investigate the risk factors for contact dermatitis in pig farm workers.

METHODSThe cross-sectional questionnaire survey and on-site survey were conducted in pig farms raising more than 50 pigs in a county of Fujian Province, China. The study subjects were grouped based on different factors. The incidence rate was compared between groups by statistical analysis.

RESULTSOf 302 subjects, 70 (23.18%) had contact dermatitis. There was a significant difference in the prevalence of contact dermatitis between the subjects in direct contact with commercially available pannage and those in indirect contact (χ(2) = 14.552, P < 0.01). Region, season, farm scale, brand of pannage, and allergic history were not influential factors for contact dermatitis (P > 0.05 for all).

CONCLUSIONDirect contact with commercially available pannage is closely associated with contact dermatitis in pig farm workers.

Adolescent ; Adult ; Aged ; Agriculture ; China ; epidemiology ; Cross-Sectional Studies ; Dermatitis, Contact ; epidemiology ; Dermatitis, Occupational ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Prevalence ; Risk Factors ; Surveys and Questionnaires ; Young Adult

BACKGROUND: Tumor necrosis factor-α (TNF-α) is one of important cytokines to promote the maturation of dendritic cells. Blockage of TNF-α action by binding with soluble tumor necrosis factor receptor 1 (sTNFR1) may arrest dendritic cells in an immature state and induce stable, long-term tolerance. OBJECTIVE: To construct the lentiviral vectors carrying sTNFR1 gene and investigate sTNFR1 expression in immature dendritic cells. METHODS: Total RNA of human peripheral blood mononuclear cells was taken as a template. The sTNFR1 gene fragment was amplified by RT-PCR, subcloned to the lentiviral vectors pXZ208, and ligated to the enhanced green fluorescent protein (eGFP) reporter gene to establish lentiviral vector, called pXZ9-sTNFR1. DNA sequencing was performed for lentiviral vector identification. Lentivirus was prepared by transfection of 293 FT cells with pXZ9-sTNFR1. Viral titer was determined by eGFP expression. C57BL/6 mouse bone marrow-derived dendritic cells were in vitro cultured with low-dose granulocyte-macrophage colony stimulating factors and interleukin 4. On day 5 of culture, immature dendritic cells were transfected with pXZ9-sTNFR1 recombinant lentiviral supernatant, sTNFR1 transcription was detected by RT-PCR, sTNFR1 protein expression by Western blot analysis. Following sTNFR1 gene modification and lipopolysaccharide stimulation, the phenotype characteristics of dendritic cells were observed. RESULTS AND CONCLUSION: Recombinant plasmid pXZ9-sTNFR1 was successfully constructed. Twenty-four hours after 293 FT cell transfection, eGFP expression was observed and viral titer was over 10<'6> U/L. RT-PCR demonstrated that pXZ9-sTNFRl-transfected immature dendritic cells showed sTNFR1 positive expression. Western blot analysis revealed that sTNFR1 protein appeared in the immature dendritic cells and supernatant following 293 FT cell transfection. On day 5 of culture, dendritic cells expressed low level of class Ⅱ major histocompatibility complex (MHC Ⅱ), as well as CD40, CD86, CD80, molecules. However, following lipopolysaccharide stimulation, dendritic cells expressed high level of MHC Ⅱ, as well as CD40, CD80, and CD86, molecules, exhibiting the phenotype characteristics of mature dendritic cells. But after sTNFR modification, the expression level of MHC Ⅱ, as well as CD40, CD80, and CD86, molecules was not altered obviously. Lentiviral vectors carrying sTNFR1 gene and eGFP reporter gene were successfully constructed, and recombinant lentiviral plasmids with high titer were acquired. Following high efficacy of lentiviral gene transfection, immature dendritic cells stably express sTNFR1 mRNA and protein, which prevents immature dendritic cells from activation by exogenous lipopolysaccharide and maintains the immature state.

Objective To study the molecular mechanism of glutamate receptor-6 (GluR6) in the pathogenesis of epilepsy. Methods Seizure model of SD rats was induced by intraperitoneal injection of kainate (KA). Immunoprecipitation and immunoblotting were performed to examine the interactions of GluR6 and MLK3 with PSD95 at various time points after KA injection. The effect of Tat-GluR6-9c on the MLK3 phospharylation induced by kainate was observed with immunoblotting and immunohistochemistry. Results The assembly of GluR6 and MLK3 with PSD95 was induced after KA hippocampal CA3 region, and bagan to decrease one day later. Pretreatment after KA injection in CA3 region (P<0.05). Conclusion KA induces the assembly of the GluR6-PSD95-MLK3 signaling module and subsequently activates MLK3, which ultimately results in brain injury.

Using recombinant TpNs proteins of Treponema pallidum as antigens, ELISAs are proved to be of higher sensitivity and specificity. However, they can be further increased by using multiple TpNs antigens. According to the epitope analysis, we firstly used linking primers PCRs to obtain an artificial fusion gene segment tpE17-47 containing epitopes of both TpN17 and TpN47. Subsequently, we conducted the prokaryotic expression systems of entire tpN17 and tpN47 genes and tpE17-47 fusion gene. SDS-PAGE analysis and BioRad Gel Image Analysis System showed that the recombinant proteins rTpN17, rTpN47 and rTpE17-47 expressed stably, with 36%, 20% and 28% yields of total bacterial protein, respectively. After purified by Ni-NTA affinity chromatography, all the three recombinant proteins could be recognized by T. pallidum antibody positive sera from syphilis patients. The positive rate of rTpE17-47-ELISA for detecting serum specimens in clinically 630 cases with syphilis was 98.6%. This rate was slightly higher than that by Treponema pallidum particle agglutination (TPPA) (97.9%) (P > 0.05), but significantly higher than those by rTpN17-ELISA (83.8%), rTpN47-ELISA (83.3%) and rapid plasma reagin (RPR) (72.1%) (P < 0.01). Furthermore, both ELISAs and TPPA for detecting the serum specimens in 25 cases with SLE, 36 cases with RA and 250 healthy cases were all negative. RPR showed positive in 1 case with SLE, 2 cases with RA and 2 healthy cases. This could be a novel serological screening or diagnostic method of syphilis with advantages of quickness, convenience, safety, sensitivity and specificity.
Amino Acid Sequence ; Antigens, Bacterial ; biosynthesis ; genetics ; Base Sequence ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunodominant Epitopes ; immunology ; Molecular Sequence Data ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Sensitivity and Specificity ; Syphilis ; diagnosis ; microbiology ; Syphilis Serodiagnosis ; methods ; Treponema pallidum ; immunology