[Association analysis of famine exposure during early life and risk of hypertension in adulthood]

Objective: To explore the relationship between exposure to famine in early life and the risk of hypertension in adulthood. Methods: The medical data of Yichang Health Management Big Data Center from 2018 to 2019 were analyzed. A retrospective cohort study design was adopted, with hypertension as the study outcome, and different life periods exposed to the Great Famine in China were divided into groups. Multivariate logistic regression model was used to analyze the relationship between famine exposure in early life and hypertension in adulthood. At the same time, the interaction between gender and famine exposure was analyzed. Results: The age of 142 016 subjects was (60. 56±4.43). Among them, men accounted for 46.36% (65 845/142 016) and women accounted for 53.64% (76 171/142 016). There are 42 575(29.98%), 19 644(13.83%), 28 405(20.00%), 28 305(19.93%), 23 087 (19.93%) in non-famine exposure group, fetal famine exposure group, early childhood famine exposure group and late childhood famine exposure group, respectively. The prevalence of hypertension was 17.57% (24 947 cases). Multivariate logistic regression model analysis showed that after adjusting for related confounding factors, compared with non-famine exposure group, the risk of hypertension in fetal, early childhood, middle childhood and late childhood famine exposure group was higher and the OR (95%CI) values were 1.16 (1.11-1.22), 1.27 (1.21-1.33), 1.54 (1.47-1.60) and 1.84 (1.76-1.92), respectively. There was an interaction between sex and famine exposure group (P<0.001). The above association is stronger among women than among men. Conclusion: Famine exposure in early life may increase the risk of hypertension in adulthood, and the risk of women is greater than that of men.

OP0201 DYNAMIC CHANGES IN O-GLCNACYLATION REGULATE OSTEOCLAST DIFFERENTIATION AND BONE LOSS IN ARTHRITIS

Background:

Bone remodeling is a constant process maintained by the balance between osteoclast-triggered bone resorption and osteoblast-mediated bone formation. In inflammatory arthritis, such as rheumatoid arthritis (RA), the pro-inflammatory environment favors osteoclast differentiation and skews the balance towards resorption, leading to progressive bone erosion and bone loss. O-GlcNAcylation is a post-translational modification, which transfers a single N-acetylglucosamine molecule to the serine or threonine of the target protein. The modification is accomplished by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Unlike other glycosylation, O-GlcNAcylation occurs in multiple cellular compartments, including the nucleus. Although O-GlcNAcylation is one of the most common modifications, its role in bone homeostasis is still poorly understood.

Objectives:

We aimed to investigate the role of O-GlcNAcylation in osteoclastogenesis under pro-inflammatory milieus. We also focused on dissecting the signaling pathways affected by O-GlcNAcylation during osteoclast differentiation.

Methods:

We examined the levels of O-GlcNAc during in vitro osteoclastogenesis by western blotting. The levels of O-GlcNAc in tissue from RA patients and experimental arthritis were detected by immunofluorescence. Pharmacological inhibition and genetic knockout were used to manipulate O-GlcNAcylaiton during osteoclastogenesis. RNA sequencing was performed to study O-GlcNAc-mediated pathways.

Results:

We demonstrate the dynamic changes in O-GlcNAcylation during osteoclastogenesis. The elevated O-GlcNAcylation was found in the early differentiation stages, whereas its downregulation was detected in the maturation process. TNFα elaborates the dynamic changes in O-GlcNAcylation, which further intensifies osteoclast differentiation.

Targeting OGT by selective inhibitor and genetic knockout restrain O-GlcNAcylation and hinder the expression of the early differentiation marker Nfatc1. Inhibition of OGA, which forces high levels of O-GlcNAcylation throughout the differentiation, reduces the formation of multinucleated mature osteoclasts. Consistent with our in vitro data, suppressing OGT and OGA both ameliorate bone loss in experimental arthritis. We detected a reduced number of TRAP-expressing precursors and mature osteoclasts in the mice subjected to OGT inhibition. While inhibiting OGA only lowers the number of TRAP+F4/80– mature osteoclasts without affecting the number of TRAP+F4/80+ precursors.

Transcriptome profiling reveals that O-GlcNAcylation regulates several biological processes. Increased O-GlcNAcylation promotes cytokine signaling and oxidative phosphorylation. The downregulation of O-GlcNAcylation is essential for cytoskeleton organization and cell fusion.

Conclusion:

We demonstrate that the dynamic changes of O-GlcNAcylation are essential for osteoclast differentiation. These findings reveal the therapeutic potential of targeting O-GlcNAcylation in pathologic bone resorption.

Disclosure of Interests:

Chih-Wei Chen: None declared, Yi-Nan Li: None declared, Thuong Trinh-Minh: None declared, ZHU Honglin: None declared, Alexandru-Emil Matei: None declared, Xiao Ding: None declared, Cuong Tran Manh: None declared, Xiaohan Xu: None declared, Christoph Liebel: None declared, Ruifang Liang: None declared, Min-Chuan Huang: None declared, Neng-Yu Lin: None declared, Andreas Ramming Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Grant/research support from: Pfizer, Novartis, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg H.W. Distler Shareholder of: 4D Science, Speakers bureau: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Employee of: FibroCure

MiR-21-5p in macrophage-derived extracellular vesicles affects podocyte pyroptosis in diabetic nephropathy by regulating A20

OBJECTIVES

Podocyte pyroptosis, characterized by inflammasome activation, plays an important role in inflammation-mediated diabetic nephropathy (DN). Our study aimed to investigate whether miR-21-5p in macrophage-derived extracellular vesicles (EVs) could affect podocyte injury in DN.

METHODS

EVs were extracted after the treatment of RAW 264.7 (mouse macrophage line) with high glucose (HG). The podocyte pyroptosis was determined using the flow cytometry and the western blot. After the knockdown of miR-21-5p in HG-induced RAW264.7 cells, we injected the extracted EVs into DN model mice.

RESULTS

The level of miR-21-5p was higher in HG-stimulated macrophage-derived EVs than in normal glucose-cultured macrophage-derived EVs. The co-culture of EVs and podocytes promoted reactive oxygen species (ROS) production and activation of inflammatory in MPC5 cells (mouse podocyte line). However, restraint of miR-21-5p in EVs reduced ROS production and inhibit inflammasome activation in MPC5 cells, thereby reducing podocytes injury. Meanwhile, we found that miR-21-5p inhibited the A20 expression through binding with its 3'-untranslated regions in MPC5 cells. Further studies showed that A20 was also involved in the regulation of miR-21-5p of RAW 264.7-derived EVs on MPC5 injury. At the same time, it was also proved in the DN model mice that miR-21-5p in macrophage-derived EVs could regulate podocyte injury.

CONCLUSION

MiR-21-5p in macrophage-derived EVs can regulate pyroptosis-mediated podocyte injury by A20 in DN.

Magnetization Process of Atacamite: A Case of Weakly Coupled S=1/2 Sawtooth Chains

We present a combined experimental and theoretical study of the mineral atacamite Cu_{2}Cl(OH)_{3}. Density-functional theory yields a Hamiltonian describing anisotropic sawtooth chains with weak 3D connections. Experimentally, we fully characterize the antiferromagnetically ordered state. Magnetic order shows a complex evolution with the magnetic field, while, starting at 31.5 T, we observe a plateaulike magnetization at about M_{sat}/2. Based on complementary theoretical approaches, we show that the latter is unrelated to the known magnetization plateau of a sawtooth chain. Instead, we provide evidence that the magnetization process in atacamite is a field-driven canting of a 3D network of weakly coupled sawtooth chains that form giant moments.

[Effects of RNA interference of CTHRC1 on proliferation and apoptosis of thyroid papillary cancer TCP-1 cells in vitro]

OBJECTIVE

To explore the role of CTHRC1 in regulating the proliferation and apoptosis of papillary thyroid cancer cells.

OBJECTIVE

Papillary thyroid cancer TPC-1 cells were transfected with a small interfering RNA (siRNA) targeting CTHRC1, with the cells transfected with a scrambled sequence as the negative control. The changes in cell proliferation and apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry with AV/PI double staining, respectively. The expression of c-caspase-3, c-PARP1 and phosphorylation of ERK1/2 in the cells were examined with Western blotting.

OBJECTIVE

Transfection with the siRNA sequence significantly decreased the mRNA and protein levels of CTHRC1 in TCP-1 cells (P < 0.05). Compared with blank and negative control cells, TCP-1 cells with RNA interference of CTHRC1 showed significantly lowered proliferative activity and enhanced cell apoptosis (P < 0.05) with significantly increased expressions of c-caspase-3 and c-PARP1 and phosphorylation of ERK1/2 (P < 0.05).

OBJECTIVE

RNA interference of CTHRC1 promotes the proliferation and inhibits apoptosis of papillary thyroid cancer cells possibly by activating the ERK1/2 pathway.

Effectiveness and safety of ear acupuncture for allergic rhinitis: A protocol of randomized controlled trial

BACKGROUND

Allergic rhinitis is a global problem. About 10% to 40% of the global population is affected by allergic rhinitis and is on the rise, which has a significant health and economic impact on society. Ear acupuncture is a non-invasive acupuncture therapy, which has been used in the treatment of allergic rhinitis, and some positive results have been reported, but there is not enough evidence to prove its efficacy and safety.

METHODS

This is a single-center, randomized, single-blind, sham-controlled trial. With the approval of the ethics committee of our hospital, participants with allergic rhinitis will be randomly assigned to receive either real or sham ear acupuncture once a week for 8 weeks, followed by 12 weeks of follow-up. Evaluate the patient's nasal symptom score and Standardised Rhinoconjunctivitis Quality of Life Questionnaire score, and monitor adverse events. Finally, the data are analyzed by SPSS 22.0 software.

DISCUSSION

The results of this study will determine the efficacy and safety of ear acupuncture in the treatment of allergic rhinitis and provide a basis for promoting the application of ear acupuncture in the treatment of allergic rhinitis.

TRIAL REGISTRATION

OSF Registration number: DOI 10.17605/OSF.IO/MVEF7.

Mental Component Score (MCS) from Health-Related Quality of Life Predicts Incidence of Dementia in U.S. Males

BACKGROUND

The Medical Outcomes Study Questionnaire Short Form 36 health survey (SF-36) measures health-related quality of life (HRQoL) from the individual's point of view and is an indicator of overall health status.

OBJECTIVE

To examine whether HRQoL shows differential changes over time prior to dementia onset and investigate whether HRQoL predicts incidence of dementia.

DESIGN

Prevention of Alzheimer's Disease (AD) by Vitamin E and Selenium (PREADViSE) trial, which recruited 7,547 non-demented men between 2002 and 2009. A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis.

SETTING

Secondary data analysis of PREADViSE data.

PARTICIPANTS

A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis.

MEASUREMENTS

Two summary T scores were generated for analysis: physical component score (PCS) and mental component score (MCS), each with a mean of 50 (standard deviation of 10); higher scores are better. Linear mixed models (LMM) were applied to determine if mean component scores varied over time or by eventual dementia status. Cox proportional hazards regression was used to determine if the baseline component scores were associated with dementia incidence, adjusting for baseline age, race, APOE-4 carrier status, sleep apnea, and self-reported memory complaint at baseline.

RESULTS

The mean baseline MCS score for participants who later developed dementia (mean± SD: 53.9±9.5) was significantly lower than for those participants who did not develop dementia during the study (mean±SD: 56.4±6.5; p = 0.005). Mean PCS scores at baseline (dementia: 49.3±7.9 vs. non-dementia: 49.8±7.8) were not significantly different (p = 0.5) but LMM analysis showed a significant time effect. For MCS, the indicator for eventual dementia diagnosis was significantly associated with poorer scores after adjusting for baseline age, race, and memory complaint. Adjusted for other baseline risk factors, the Cox model showed that a 10-unit increase in MCS was associated with a 44% decrease in the hazard of a future dementia diagnosis (95% CI: 32%-55%).

CONCLUSION

The SF-36 MCS summary score may serve as a predictor for future dementia and could be prognostic in longitudinal dementia research.

Differentially expressed proteins identified by TMT proteomics analysis in children with verrucous epidermal naevi

BACKGROUND

Verrucous epidermal naevi (VEN) are benign skin tumours, considered keratinocytic epidermal naevi, that appear at birth or early childhood. VEN may display a range of appearances, depending on patient age. Although the number of studies regarding VEN is increasing, the exact mechanism of VEN is still unknown.

OBJECTIVES

The aim of this study was to analyse the changes in the expression of protein factors in lesions of VEN children by TMT labelling-based quantitative proteomics.

METHODS

A total of 8 children with VEN (5 for experiment and 3 for validation) and 8 healthy children (5 for experiment and 3 for validation) presented to the Department of Dermatology, the First Affiliated Hospital of Anhui Medical University, Boao Super Hospital, between January 2019 and November 2019. The lesions and lesion-adjacent tissues from children with VEN and naevus-adjacent normal skin tissues from children with pigmented naevi were defined as the VEN group, VENC group and C group, respectively. We performed a proteomics analysis to screen for differentially expressed proteins in the lesions of these individuals. We further performed Western blotting to validate the relative expression levels of nine targeted proteins in the validation group.

RESULTS

According to the proteomics results, a total of 4970 proteins were identified, and 4770 proteins were quantified. Among these proteins, 586 proteins were up- or downregulated at least 1.3-fold with a P-value < 0.05 (upregulated: 399, downregulated: 187) in lesions between the VEN group and the C group. These proteins played important roles in multiple biological functions, such as cornification, epidermal cell differentiation and neutrophil activation, and formed a complicated protein-protein interaction network. Of the 586 up- or downregulated proteins, nine were selected for further validation. According to Western blotting analysis results, the relative expression levels of Involucrin, NDUFA4, Loricrin, Keratin type II cytoskeletal 6A (Cytokeratin 6A), BRAF, Filaggrin, S100A7 and Desmocollin-3 were significantly upregulated in VEN children and may be associated with skin barrier dysfunction, epidermal cell overgrowth and differentiation, inflammation and immune and oxidative phosphorylation, which are involved in the pathogenesis of VEN.

CONCLUSIONS

According to TMT-based proteomics and Western blotting results, we identified eight noteworthy proteins, Involucrin, NDUFA4, Loricrin, Keratin type II cytoskeletal 6A, BRAF, Filaggrin, S100A7 and Desmocollin-3, that were upregulated in the lesions of VEN children and may be associated with the pathogenesis of VEN. Our findings provide new starting points for identifying precise pathogenic mechanisms or therapeutic targets for VEN.

Chemokine C-C motif ligand 8 in periodontal ligament during orthodontic tooth movement

OBJECTIVES

To investigate the roles of chemokine (C-C motif) ligand 8 (CCL8) in periodontal ligament during orthodontic tooth movement (OTM).

METHODS

Bioinformatics analyzed 100 genes in human periodontal ligament cells that were most upregulated after 48 hours of mechanical stress, and these genes were classified through GO and KEGG databases. Nickel-titanium closed-coil springs were placed between right first molar and incisors to produce 20 cN of orthodontic force in eight-week-old male SD rats for 1 and 2 days, followed by immunohistochemical staining of CCL8. Human periodontal ligament fibroblasts (hPDLFs) were stimulated by 14% cyclic tension force (Flexcell FX-5000 T Tension System) or hypoxia conditions to mimic OTM for 1 and 2 days, then the resulting CCL8 were examined through ELISA. Scratching assay was performed by treating hPDLFs with different concentrations of CCL8 (1 ng/ml, 10 ng/ml, 100 ng/ml). The migration, proliferation, and adhesion abilities of 100 ng/ml CCL8-treated hPDLFs were also examined. qRT-PCR and western blot detected matrix metalloproteinase 3, periostin, and osteoprotegrin expressions of hPDLFs under 100 ng/ml CCL8.

RESULTS

Bioinformatic analysis demonstrated that CCL8 was upregulated after applying mechanical stress for 48 hours. CCL8 secretion showed upregulation after 24 hours of OTM applicationsin vivo and in vitro. CCL8-treated hPDLFs showed significant positive effects on cell proliferation and matrix metalloproteinase 3. It also inhibited periostin and osteoprotegrin expressions.

CONCLUSIONS

CCL8 was upregulated in periodontal ligament during initial stage of OTM. Although CCL8 in human periodontal ligaments showed no significant effects on cell migration ability, it did enhance cell proliferation and osteoclastogenesis.

Public moral motivation during the COVID-19 pandemic: Analysis of posts on Chinese social media

As COVID-19 struck worldwide, we were inspired by behavioral immune system theory and wondered whether there would be changes to public morality brought about by the pandemic. We tracked public reactions through posts on Chinese social media to analyze the dynamics of public moral motivation. Big data analysis shows that the impact of disaster upon moral motivation was context-sensitive. The level of the severity of the disaster played a leading role in variation of moral motivation. We found that disaster increased moral motivation only when the situation was severe, and such augmentation rapidly faded when the disaster was under control and recovery began. The sentiment of news shared during the pandemic played a regulating role, such that positive or encouraging news helped augment moral motivation only when the situation was severe. Finally, we found that the pandemic increased expressions of both agency and communion in a similar way to that of moral motivation.

Development of an immunogenomic landscape for the competing endogenous RNAs network of peri-implantitis

BACKGROUND

Peri-implantitis is an inflammation that occurs around the implant, resulting in varying degrees of inflammatory damage to the soft and hard tissues. The characteristic criterion is the loss of the supporting bone in an inflammatory environment. However, the specific mechanisms and biomarkers involved in peri-implantitis remain to be further studied. Recently, competing endogenous RNAs (ceRNA) and immune microenvironment have been found to play a more important role in the inflammatory process. In our study, we analyzed the expression of immune related microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and message RNAs (mRNAs) in peri-implantitis by analyzing GSE33774 and GSE57631.

METHODS

In this study, we explored the expression profile data of immune-related lncRNAs, miRNAs and mRNAs, and constructed immune-related ceRNA network involved in the pathogenesis of peri-implantitis. In addition, the CIBERSORT was used to evaluate the content of immune cells in normal tissues and peri-implantitis to detect the immune microenvironment of peri-implantitis.

RESULTS

In the analysis, 14 DElncRNAs, 16 DEmiRNAs, and 18 DEmRNAs were used to establish an immune related ceRNA network and the immune infiltration patterns associated with peri-implantitis was discovered. Through the mutual verification of the two datasets, we found that GSK3B and miR-1297 may have important significance in the immune microenvironment and pathogenesis of peri-implantitis and GSK3B was closely related to four types of immune cells, especially with the highest correlation with resting mast cells (P = 0.0003).

CONCLUSIONS

Through immune-related ceRNA network, immune-related genes (IRGs) and immune cell infiltration can further comprehensively understand the pathogenesis of peri-implantitis, which built up an immunogenomic landscape with clinical significance for peri-implantitis.

PINK1 in normal human melanocytes: first identification and its effects on H2 O2 -induced oxidative damage

BACKGROUND

Oxidative stress plays an important role in initiating the destruction of melanocytes, which could be one possible mechanism of vitiligo. PINK1 is an outer membrane protein of mitochondria, which protects many cells from oxidative stress through regulating mitochondrial function. However, the role of PINK1 and its effects on oxidative damage in melanocytes have not been elucidated.

AIM

To investigate the expression and effects of PINK1 on oxidative stress in human melanocytes.

METHODS

Quantitative reverse transcription-PCR and western blot analysis were used to analyse the expression of PINK1 in PIG1 melanocyte and gene downregulation models. Levels of cell viability, cell apoptosis and intracellular reactive oxygen species (ROS), mitochondrial morphology, mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPTP) opening were measured in PIG1 models transfected with PINK1 small interfering RNA with or without hydrogen peroxide (H₂ O₂ ).

RESULTS

We first observed the expression of PINK1 in human PIG1 melanocytes and found that downregulation of PINK1 made melanocytes more sensitive to oxidative stress induced by H₂ O₂ , with more cell apoptosis and increased intracellular ROS. Meanwhile, downregulation of PINK1 caused morphological changes in mitochondria, decreased the MMP and increased MPTP opening.

CONCLUSIONS

Our study found PINK1 plays an essential role in protecting human melanocytes from oxidative stress.

[The value of 3.0T magnetic resonance -diffusion kurtosis imaging in the differential diagnosis of rectal mucinous adenocarcinoma and common adenocarcinoma]

Objective: To investigate the value of 3.0T MRI diffusion kurtosis imaging (DKI) quantitative histogram parameters in the differential diagnosis of rectal mucinous adenocarcinoma (MC) and common adenocarcinoma (AC). Methods: One hundred and ten patients from Department of Radiology, the Second Affiliated Hospital of Soochow University between September 2015 and September 2019 with complete magnetic resonance imaging (MRI) and DKI results confirmed by surgery and pathology were retrospectively analyzed, including 16 patients in MC group and 94 patients in AC group. Two physicians outlined the region of interest (ROI) on the DKI image with b=1 000 s/mm(2), and obtained quantitative DKI parameters, including the diffusion coefficient (D value) and kurtosis coefficient (K value) corrected for non-Gaussian distribution. The apparent diffusion coefficient (ADC) values of quantitative parameters of diffusion-weighted imaging (DWI) were obtained through image registration, and histogram analysis was performed to obtain the mean value, 25th percentile, 50th percentile, 75th percentile, skewness and kurtosis of the above parameters, respectively. The difference between the quantitative histogram parameter analysis results of the rectal MC group and the AC group was evaluated, and the main indicators and multivariate comprehensive analysis indicators was screened, and the effectiveness of quantitative histogram parameters related to histopathological classification in the differential diagnosis of rectal MC and AC was evaluated. Results: There was no significant differences in gender, age, lesion location, T stage or N stage between MC group and AC group (all P>0.05). The multivariate binary logistic stepwise regression screening showed that D50th percentile and K25th percentile are statistically significant indicators (B values were 2 966.166 and -4.550, respectively; Wals values were 9.000 and 15.720, respectively; and P values were 0.003 and <0.001, respectively). The combined area under the curve of the two indictors was 0.85, but there was no statistically significant difference in pairwise comparison using DeLong method (P>0.05). The results of histogram analysis of quantitative parameters measured by the two physicians were consistent, and the inter-group correlation coefficient ranged from 0.880 to 0.981. Conclusions: The quantitative parameter histogram analysis of the DKI double-index model is helpful for the differentiation of rectal MC and AC, in which the D50th percentile and K25th percentile have differential diagnosis significance, and are superior to the ADC value of the single-index model.

[Establishment of a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification assay]

OBJECTIVE

To establish a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification (RAA) assay.

METHODS

The 12S rRNA gene of E. granulosus was selected as the target gene, and the specific primers and fluorescent probes for RAA assay were designed, screened and synthesized to establish a fluorescent RAA assay for detection of E. granulosus. The sensitivity of the fluorescent RAA assay was evaluated using different copy numbers of target gene sequence-contained recombinant plasmids and various concentrations of E. granulosus genomic DNA as templates, and the specificity of the fluorescent RAA assay was evaluated using the genomic DNA from E. granulosus, E. multilocularis, Schistosoma japonicum, S. mansoni, Ancylostoma duodenale, Clonorchis sinensis, Taenia saginata, Spirometra mansoni and Taenia solium as templates.

RESULTS

A fluorescent RAA assay was successfully established for detection of E. granulosus, which achieved specific amplification of E. granulosus genomic DNA within 20 min at 39 ℃. The lowest detection limit of the fluorescent RAA assay was 10 copies/μL of recombinant plasmids and 0.1 ng/μL E. granulosus genomic DNA, which exhibited a high sensitivity, and the fluorescent RAA assay was all negative for the genomic DNA from E. multilocularis, S. japonicum, S. mansoni, A. duodenale, C. sinensis, T. saginata, Spirometra mansoni and T. solium, which exhibited a high specificity. In addition, this fluorescent RAA assay successfully detected genomic DNA from E. granulosus cysts.

CONCLUSIONS

A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of E. granulosus.

[Establishment of a recombinase-aided isothermal amplification assay for nucleic acid detection of Angiostrongylus cantonensis]

OBJECTIVE

To establish a recombinase-aided isothermal amplification (RAA) assay for the nucleic acid detection of Angiostrongylus cantonensis.

METHODS

The internal transcribed spacer-1 (ITS1) gene sequence of A. cantonensis was used as the detection target sequence, and the specific primers and probes were designed and synthesized, followed by screening of the primers and probes with the highest specificity, to establish the basic and fluorescent RAA assay for nucleic acid detection of A. cantonensis. The sensitivity of the fluorescent RAA assay was evaluated by using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the template DNA samples, and the specificity of the fluorescent RAA assay was evaluated by using the genomic DNA from A. cantonensis, Schistosoma mansoni, Ascaris lumbricoides, Clonorchis sinensis, Echinococcus granulosus and Ancylostoma duodenale, as well as Pomacea canaliculata and Biomphalaria straminea snail tissues as the template DNA samples.

RESULTS

A fluorescent RAA assay was successfully established for nucleic acid detection of A. cantonensis, which achieved real-time amplification of the specific DNA fragment of A. cantonensis within 20 min at 37 ℃. By using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the DNA templates, the lowest detection limits of the fluorescent RAA assay were 10 copies/μL of recombinant plasmids and 100 pg/μL of genomic DNA, respectively. The fluorescent RAA assay was negative for detection of the genomic DNA from A. cantonensis, S. mansoni, A. lumbricoides, C. sinensis, E. granulosus, A. duodenale, and P. canaliculata and B. straminea snail tissues.

CONCLUSIONS

A simple, rapid fluorescent RAA assay has been successfully established, which has a high sensitivity and specificity for the nucleic acid detection of A. cantonensis.

[Polarization of human acute monocytic leukemia THP-1 cells-derived macprophages induced by Nippostrongylus brasiliensis proteins in vitro]

OBJECTIVE

To investigate the polarization of human acute monocytic leukemia THP-1 cells-derived macrophages induced by Nippostrongylus brasiliensis proteins in vitro, so as to provide insights into the elucidation of the mechanisms underlying host immune responses to hookworm infections.

METHODS

The in-vitro culture of N. brasiliensis was established and maintained in the laboratory, and the third- (L3) and fifth-stage larvae (L5) were collected under a sterile condition for preparation of L3 and L5 proteins. The in-vitro culture of THP-1 cells was established, stimulated with 500 ng/mL PMA to yield M0 macrophages that were adherent to the plate wall. The LPS + IFN-γ group, IL-4 + IL-13 group, L3 protein group and L5 protein group were given stimulation with 500 ng/mL LPS plus 100 ng/mL IFN-γ, IL-4 and IL-13 (both 100 ng/mL), L3 protein (5 mg/mL) and L5 protein (5 mg/mL), respectively, while the negative control group was given no stimulation. The cell morphology was observed using microscopy, the mRNA expression of M1/M2 macrophages-specific genes was quantified using a quantitative real-time PCR (qPCR) assay, and the surface markers of M1/M2 macrophages were detected using flow cytometry, while the levels of cytokines secreted by M1/M2 macrophages were measured using enzyme-linked immunosorbent assay (ELISA) following stimulations, so as to examine the polarization of THP-1-derived macrophages induced by N. brasiliensis proteins in vitro.

RESULTS

Following stimulation with PMA, THP-1 cells appeared wall-adherent M0 macrophages, and polarized to typical M1 macrophages following stimulation with LPS + IFN-γ, and typical M2 macrophages following stimulation with IL-4 + IL-13, IL-3 protein or L5 protein. There was a significant difference in the proportion of M1 macrophages among the negative control group, the LPS + IFN-γ group, the IL-4 + IL-13 group, the L3 protein group and the L5 protein group (χ² = 3 721.00, P < 0.001), with the highest proportion detected in the LPS + IFN-γ group, and there was also a significant difference in the proportion of M2 macrophages among groups (χ² = 105.43, P < 0.001). There were significant differences among groups in terms of the mRNA expression of CCL2 (F = 191.95, P < 0.001), TNF-α (F = 129.95, P < 0.001), IL-12b (F = 82.89, P < 0.001), PPARγ (F = 11.30, P < 0.001), IL-10 (F = 9.51, P < 0.001) and Mrc1 genes (F = 12.35, P < 0.001). In addition, there were significant differences in the proportion of positive CD86 and CD206 expression among groups (χ² = 24 004.33 and 832.50, P < 0.001). Higher IL-1β and TNF-α levels were measured in the LPS + IFN-γ group than in the IL-4 + IL-13 group, the L3 protein group and the L5 protein group (P < 0.001), and greater TGF-β1 and IL-10 levels were seen in the IL-4 + IL-13 group, the L3 protein group and the L5 protein group than in the negative control group and the LPS + IFN-γ group (P < 0.05).

CONCLUSIONS

Both L3 and L5 proteins of N. brasiliensis may induce the polarization of THP-1-derived macrophages to M2 type in vitro.