Treponema pallidum protein Tp47 induced prostaglandin E2 to inhibit the phagocytosis in human macrophages.

BACKGROUND: During Treponema pallidum (T. pallidum) infection, the host's immune system actively engages in pursuit and elimination of T. pallidum, while T. pallidum skillfully employs various mechanisms to evade immune recognition. Macrophages exhibit incomplete clearance of T. pallidum in vitro and the underlying mechanism of how T. pallidum resists the attack of macrophage remains unclear. OBJECTIVES: To investigate the effect of T. pallidum membrane protein Tp47 on the phagocytosis of macrophages. METHODS: THP-1-derived macrophages were used to investigate the role of Tp47 in the secretion of Prostaglandin E2 (PGE2) in macrophages and the mechanism by which Tp47 induced the production of PGE2, as well as the impact of PGE2 on the macrophage's phagocytosis. RESULTS: Tp47 (1-10 µg/mL) significantly inhibited the phagocytosis of latex beads and T. pallidum in macrophages (p ≤ 0.05). PGE2 production by macrophages could be induced by Tp47, and the phagocytic function of macrophages could be restored using PGE2 antibody. Tp47 produced PGE2 by activating the PERK/NF-κB/COX-2 pathway in macrophages. Inhibitors targeting PERK, NF-κB and COX-2, respectively, reduced the level of PGE2 and restored the phagocytic function of macrophages. CONCLUSION: Tp47-induced PGE2 production via the PERK/NF-κB/COX-2 pathway contributed to macrophage phagocytosis inhibition, which potentially contributes to immune evasion during the T. pallidum infection.

[Research advances on allergen component-resolved diagnosis in respiratory allergic diseases].

Allergen component-resolved diagnosis (CRD) is an emerging molecular diagnostic technology, which can further clarify the protein profile of allergen components in allergic patients, achieve accurate detection of allergens, and have great significance and value for the precise prevention and treatment of allergic diseases. In this article, the CRD technology and its research progress in respiratory allergic diseases are introduced, and the importance of CRD in the evaluation, prevention and treatment of respiratory allergic diseases are discussed.

Mycoplasma Bovis adhesins and their target proteins.

Bovine mycoplasmosis is an important infectious disease of cattle caused by Mycoplasma bovis (M. bovis) which poses a serious threat to the breeding industry. Adhesin is involved in the initial process of M. bovis colonization, which is closely related to the infection, cell invasion, immune escape and virulence of this pathogenic microorganism. For the reason that M. bovis lacks a cell wall, its adhesin is predominantly located on the surface of the cell membrane. The adhesins of M. bovis are usually identified by adhesion and adhesion inhibition analysis, and more than 10 adhesins have been identified so far. These adhesins primarily bind to plasminogen, fibronectin, heparin and amyloid precursor-like protein-2 of host cells. This review aims to concisely summarize the current knowledge regarding the adhesins of M. bovis and their target proteins of the host cell. Additionally, the biological characteristics of the adhesin will be briefly analyzed.

[The mediating role of worker-occupation fit between occupational stress and anxiety symptoms in medical staff].

Objective: To analyze the mediating effect of work-occupation fit between occupational stress and anxiety symptoms in medical staff. Methods: Convenience sampling method was adopted to select participants of one general hospital and three specialized hospitals as respondents for a questionnaire survey in Henan Province from October 2020 to January 2021. A total of 2050 medical staff were investigated, and 1988 valid questionnaires were collected, and the effective rate of the questionnaire was 97.0% (1988/2050) . The "Depression-Anxiety-Stress Scale" and "Worker-Occupation Fit Inventory" were used to evaluate the occupational stress, anxiety symptoms and worker-occupation fit level of medical staff, and the mediation effect of work-occupation fit on the relationship between occupational stress and anxiety symptoms was analyzed using a mediating effect model. Results: The average age of the 1988 medical staff was (32.7±7.8) years old, the positive detection rates of occupational stress and anxiety symptoms were 42.5% (845/1988) and 56.7% (1127/1988) , respectively. Anxiety symptoms of medical staff were positively correlated with occupational stress, negatively correlated with worker-occupation fit (r=0.831, -0.364, P<0.001) , work-occupation fit was negatively correlated with occupational stress (r=-0.259, P<0.001) . The results of the mediation effect analysis showed that occupational stress had a direct effect on anxiety symptoms (ß=0.677, BCa 95%CI: 0.648-0.707) , and worker-occupation fit (ß=0.047, BCa 95%CI: 0.039-0.056) , characteristic fit (ß=0.089, BCa 95%CI: 0.074-0.104) , need-supply fit (ß=0.075, BCa 95%CI: 0.062-0.089) , and ability-demand fit (ß=0.035, BCa 95%CI: 0.026-0.044) mediated the association between occupational stress and anxiety symptoms in medical staff, with the mediating effect as a percentage of 6.5%, 12.3%, 10.3%, and 4.8%, respectively. Conclusion: Worker-occupation fit has a mediating effect between occupational stress and anxiety symptoms in medical staff, but mainly direct effect.

Tp47 promoted the phagocytosis of HMC3 cells though autophagy induced by endoplamic reticlum stress.

BACKGROUND: Central nervous system damage is an essential clinical feature that occurs in the early or late stages of syphilis infection. The abnormal enhancement of microglial phagocytosis can cause damage to the nervous system. However, the contribution of abnormally enhanced microglial phagocytosis to the pathogenesis of Treponema pallidum subsp. pallidum (T. pallidum) infection remains unknown. OBJECTIVES: In this study, we sought to determine the role of recombinant T. pallidum Tp47 in promoting microglia phagocytosis and its associated mechanisms. METHODS: Microglial HMC3 cells were used to investigate the effect of the Tp47 on phagocytosis and the roles of autophagy and endoplasmic reticulum stress in Tp47-induced phagocytosis. RESULTS: HMC3 cells exhibited obvious phagocytosis when stimulated with Tp47. The levels of P62 degradation, Beclin1 expression and the LC3II/LC3I ratio were significantly elevated, and the fusion of autophagosomes and lysosomes was promoted in Tp47-stimulated HMC3 cells. Treatment with the autophagy inhibitors 3-MA and Baf A1 inhibited Tp47-induced phagocytosis. Meanwhile, the endoplasmic reticulum stress markers PERK, IRE1α, GRP78, ATF4 and XBP1s were upregulated in Tp47-stimulated HMC3 cells. In addition, we found that TUDCA could inhibit Tp47-induced expression of IRE1α but not PERK or ATF4. 4-PBA inhibited TP47-induced PERK and ATF4 protein expression but did not inhibit IRE1α expression. Attenuation of endoplasmic reticulum stress by administration of TUDCA and 4-PBA abrogated Tp47-mediated autophagy. CONCLUSIONS: These results suggested that Tp47 activated autophagy through two key pathways associated with endoplasmic reticulum stress, PERK/ATF4 and IRE1/XBP1, to promote phagocytosis in HMC3 cells. These findings provided a basis for the understanding of the pathophysiology of neurological disorders that occur during the course of syphilis.

[The influence of subjective comfort of working environment on occupational stress of railway station workers].

Objective: To explore the influential factors of job stress suffered by workers in railway stations, the level of job stress of were measured and subjective comfort of employees targeting to working environment were reported. Methods: In March 2019, a cluster sampling study was designed to collect the personal characteristics, job characteristics and subjective comfort degree of working environment of 432 employees in Chongqing railway stations. Meanwhile, job stress was assessed using the effort-reward imbalance scale. Chi-square test was used to compare the difference of occupational stress detection rate among different stratified factors such as occupational characteristics. Logistic regression was applied to analyze the influential factors of occupational stress. Results: The detection rate of job stress of workers in the railway stations was 31.02% (134/432) . The detection rate of job stress was higher among the divorced workers in railway stations, those earning less than 5, 000 yuan per month, those with 10-20 years' length of service, those who worked as a conductor and other workers including baggageman, station master on duty and assistant engineer (χ(2)=9.61, 14.76, 23.28, 11.06, P=0.008, 0.002, 0.000, 0.011) . The detection rate of job stress was higher among those whose working environment subjective feelings were uncomfortable, the differences were statistically significant (P<0.001) . The results showed that the occupational stress of the staff in the railway stations was influenced by their subjective feeling of air quality, noise and Space Layout (P<0.05) . The risk factors of occupational stress were air quality, noise and uncomfortable space layout (OR=0.571, 0.068, 0.441, P=0.051, 0.054, 0.007) . Conductor, other (Bellboy, Duty Station Master, assistant engineer) were the risk factors of occupational stress (OR=1.884, 2.703, P=0.065, 0.019) . The employees of station A and station B were the risk factors of occupational stress (OR=4.681, 1.811, P=0.002, 0.067) . Conclusion: The higher detection rate of job stress of workers in the railway stations is correlated with the subjective comfort degree of the working environment of the workers.

[Literature analysis of hot topics on occupational noise-induced hearing loss].

Objective: To analyze the literature of related research reports on occupational hearing loss (ONIHL) , study the characteristics of the subject and determine the research hotspots. Methods: In December 2020, PubMed database was searched by bibliometrics for ONIHL published in PubMed database from January 1971 to December 2020. Bicomb 2.03 software was used to extract the subject. The publication year, publication country, source magazine and subject words were summarized and analyzed. Results: A total of 1 473 papers were included in this study, and the number of papers was 66 from 1971 to 1980, and 628 from 2011 to 2020, an increase of nearly 10 times. The top three countries were the United States, China and Germany, with 31.5% (464/1473) , 11.5% (171/1473) and 6.2% (91/1473) ; The cross-sectional study was the most applied type; The top five words for 2011-2020: Mental Illness, polymorphism, cardiovascular disease, high frequency hearing impairment and standards and regulations. Conclusion: Susceptibility Genes, Psychological Disorders, Cardiovascular Diseases and Risk Assessment are hot areas in ONIHL at present. Researchers should focus on major fields and grasp future trends as a whole.

[Clinical phenotype and gene mutation analysis of 12 patients with hereditary protein C deficiency in different families].

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.

Application of Chlorophyte ChlB Gene and Cyanophyte NIES Gene in the Detection of Drowning-Related Plankton.

ABSTRACT: Objective To construct a polymerase chain reaction-capillary electrophoresis （PCR-CE） detection method using ChlB gene and NIES gene, investigate the method's specificity and sensitivity, and to evaluate its application value in drowning diagnosis. Methods The specific primers ChlB and NIES were designed for the conserved sequence of chlorophyte ChlB gene and cyanophyte NIES gene in GenBank to construct PCR-CE detection method; 50 species of standard DNA samples were amplified; the sensitivity was determined by gradient concentration detection of positive standard samples; 25 actual cadaver lung tissue samples （drowned： 20, natural death： 5） were detected, and the simultaneous detection results of microwave digestion-vacuum filtration-automated scanning electron microscopy （MD-VF-Auto SEM） were simultaneously compared. Results The minimum DNA detection concentration of primers ChlB and NIES was 0.161 ng and 0.109 ng, respectively, which could specifically amplify chlorophyte （Chlorella pyrenoidosa） and cyanophyte ［Microcystis aeruginosa （producing and not producing toxin）］ widespread in water. The product fragments were 156 bp and 182 bp, respectively. The results of non-drowning tissues were negative. Conclusion This method has high sensitivity and specificity. It can be applied to the detection of plankton related to drowning and combined with MD-VF-Auto SEM method, can increase the detection range of plankton related to drowning and improve the evidence power of drowning diagnosis.

Ecdysis triggering hormone is essential for larva-pupa-adult transformation in Leptinotarsa decemlineata.

In Drosophila melanogaster, ecdysis triggering hormone (ETH) is the key factor triggering ecdysis behaviour and promoting trachea clearance. However, whether ETH plays the dual roles in non-dipteran insects is unknown. In this survey, we found that Ldeth mRNA levels were positively correlated with circulating 20-hydroxyecdysone (20E) titers in Leptinotarsa decemlineata. Ingestion of an ecdysteroid agonist halofenozide or 20E stimulated the transcription of Ldeth, whereas RNA interference (RNAi) of ecdysteroidogenesis (LdPTTH or LdSHD) or 20E signalling (LdEcR, LdUSP or LdFTZ-F1) genes inhibited the expression, indicating ETH acts downstream of 20E. RNAi of Ldeth at the final instar stage impaired pupation. More than 80% of the Ldeth-depleted beetles remained as prepupae, completely wrapped in the old larval cuticles. These prepupae became withered, dried and darkened gradually, and finally died in soil. The remaining Ldeth hypomorphs pupated and emerged as abnormal adults, bearing smaller and wrinkle elytrum and hindwing. Moreover, the tracheae in the Ldeth hypomorphs were full of liquid. We accordingly proposed that the failure of trachea clearance disenabled air-swallowing after pupa-adult ecdysis and impacted wing expansion. Our results suggest that ETH plays the dual roles, initiation of ecdysis and motivation of trachea clearance, in a coleopteran.

[Effect of complement C5a on the expression of MCP-1 and NGAL in immune kidney injury of trichloroethylene sensitized mice].

Objective: To explore the possible role of C5a in the pathogenesis of renal injury in TCE- sensitized mice, to analyze the impact of expression of neutrophil gelatinase-associated lipocalin (NGAL) and monocyte chemotactic protein-1 (MCP-1) in the presence or absence of C5a receptor antagonist (C5aRA) pretreatment. Methods: A total of 50 female specific pathogens free(SPF) BALB/c mice were randomly divided into blank control group (n=5) , solvent control group (n=5) , TCE group (n=20) , and TCE+C5aRA group (n= 20) . After one week for adaptive feeding, a mouse model of TCE-induced skin sensitization was established by treating with 50% TCE and 30% TCE in turn. The mice in solvent control group accept same reagents without TCE and the mice in blank control group underwent nothing. In TCE +C5aRA group, except for the TCE solution treatment, mice were intraperitoneally injected with 0.5 mg/kg C5aRA solution at the time of challenge. And the skin erythema and edema reaction were scored 24 h after the last challenge. The mice were divided into sensitization positive group and sensitization negative group according to the scoring result. The mice were aseptically sacrificed 72 h after the last challenge to obtain the kidneys. The structural damage of kidney was observed after histopathological staining. The levels of NGAL and MCP-1 mRNA and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) , respectively. Results: The sensitization rate of mice in TCE group and TCE+C5aRA group was 45.0% (9/20) and 40.0% (8/20) , respectively. No skin lesions was found in the mice of blank control group and solvent control group. The results of histopathological staining showed that the TCE sensitization positive mice showed renal tubular dilatation, vacuolar degeneration of renal tubular epithelial cells, and infiltration of interstitial cells. The pathological damage of the kidney in TCE sensitization positive group was mild, and no inflammatory cell infiltration was seen. The data of qRT-PCR showed that the expression levels of NGAL and MCP-1 mRNA in the TCE sensitization positive group were significantly increased than in solvent control group and TCE sensitization negative group (P<0.05) , while the levels of NGAL and MCP-1 mRNA in TCE+C5aRA sensitization positive group were decreased than TCE sensitization positive group (P <0.05) . The results of IHC showed that the expression levels of NGAL and MCP-1 in TCE protein sensitization positive group were significantly higher than those in solvent control group and TCE sensitization negative group (P<0.05) . After C5aRA pretreatment, the expression levels of NGAL and MCP-1 protein were decreased than the mice in TCE sensitization positive group (P<0.05) . Conclusion: The regulation of C5a on the expression of MCP-1 and NGAL may participate in TCE- induced mice kidney damage, and pharmacological inhibition of C5a seems to be an effective way to protect the kidney injury in TCE-sensitized mice.

Effect of circ MTHFD2 on resistance to pemetrexed in gastric cancer through regulating expression of miR-124.

OBJECTIVE: The aim of this study was to explore the effect of circ MTHFD2 on resistance to pemetrexed (MTA) in gastric cancer by regulating the expression of micro ribonucleic acid (miR)-124. MATERIALS AND METHODS: Human gastric cancer MGC-803 cells were induced by MTA at an increasing concentration. MGC-803/MTA resistant cell model was successfully established after 5 months. The half-maximal inhibitory concentration (IC50) of MTA on the two kinds of cells was detected via cell counting kit-8 (CCK-8) assay. Differentially expressed circular RNAs (circRNAs) were screened using circRNA microarray analysis. Meanwhile, the target miRNAs of circRNAs were predicted using bioinformatics tool and verified via luciferase reporter assay, respectively. In MGC-803 cells, the effects of overexpression and knockdown of circ MTHFD2 on the expression of miR-124 were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Finally, the effects of circ MTHFD2 on the protein expressions of FDZ5 and multidrug resistance gene-1 (MDR-1) were detected via Western blotting. RESULTS: MGC-803/MTA resistant cell lines were successfully constructed via persistent drug exposure to MTA at an increasing concentration for 5 months. Compared with parental cells, MGC-803/MTA resistant cells showed significantly enhanced drug resistance. Subsequently, differentially expressed circRNAs were screened using circRNA microarray analysis. A total of 673 circRNAs were screened out based on Fold Change >3 and adjusted p-value. The results of qRT-PCR showed that the expression levels of all differentially expressed circRNAs were significantly changed when compared with MGC-803/MTA resistant cells. Compared with MGC-803/MTA resistant cells, the drug resistance of cells increased significantly in circ MTHFD2 overexpression group. However, it markedly decreased in circ MTHFD2 knockdown group. According to the results of bioinformatics and luciferase reporter assay, circ MTHFD2 could target bind to miR-124. In MGC-803/MTA cells, miR-124 could remarkably increase the resistance of MGC-803/MTA cells to MTA. Western blotting results revealed that overexpression of circ MTHFD2 significantly increased the protein expressions of FDZ5 and MDR-1. However, miR-124 mimics reversed the inhibitory effect of circ MTHFD2 on FDZ5 and MDR-1. CONCLUSIONS: Circ MTHFD2 directly binds to miR-124 through the molecular sponge effect. This may induce increased protein expression of MDR-1, ultimately enhancing the drug resistance of MGC-803/MTA cells.

Functional characterization of ultraspiracle in Leptinotarsa decemlineata using RNA interference assay.

A heterodimer of ultraspiracle (USP) and ecdysone receptor (EcR) mediates 20-hydroxyecdysone (20E) signalling cascade to regulate insect moulting and metamorphosis. However, at least two questions remain to be addressed in terms of the molecular importance of USP in insect species. First, is USP involved in both regulation of ecdysteroidogenesis and mediation of 20E signalling in non-drosophilid insects, as in Drosophila melanogaster? Second, does USP play any role in larval metamorphosis except as the partner of heterodimeric receptor to activate the downstream 20E signalling genes? In this paper, we found that RNA interference (RNAi) of LdUSP in the final (fourth) instar larvae reduced the messenger RNA levels of four ecdysteroidogenesis genes (Ldspo, Ldphm, Lddib and Ldsad) and 20E titre, and repressed the expression of five 20E signal genes (EcRA, HR3, HR4, E74 and E75) in Leptinotarsa decemlineata. The LdUSP RNAi larvae remained as prepupae, with developing antennae, legs and discs of forewings and hindwings. Dietary supplement with 20E restored the expression of the five 20E signal genes, but only partially alleviated the decreased pupation rate in LdUSP RNAi beetles. Knockdown of LdUSP at the penultimate (third) instar larvae did not affect third-fourth instar moulting. However, silencing LdUSP caused similar but less severe impairments on pupation. Accordingly, we propose that USP is undoubtedly necessary for ecdysteroidogenesis, for mediation of 20E signalling and for initiation of metamorphosis in L. decemlineata.