Dynamics design of a non-natural transcription factor responding to androst-4-ene-3,17-dione

The production of androst-4-ene-3,17-dione (AD) by the steroidal microbial cell factory requires transcription factors (TFs) to participate in metabolic regulation. However, microbial cell factory lacks effective TFs that can respond to AD in its metabolic pathway. Additionally, finding and obtaining natural TFs that specifically respond to AD is a complex and onerous task. In this study, we devised an artificial TF that responds to AD, termed AdT, based on structure-guided molecular dynamics (MD) simulation. According to MD analysis of the conformational changes of AdT after binding to AD, an LBD in which the N- and C-termini exhibited convergence tendencies was used as a microswitch to guide the assembly of a DNA-binding domain lexA, a linker (GGGGS)2, and a transcription activation domain B42 into an artificial TF. As a proof of design, a AD biosensor was designed and constructed in yeast on the basis of the ligand-binding domain (LBD) of hormone receptor. In addition, the transcription factor activity of AdT was increased by 1.44-fold for its variant F320Y. Overall, we created non-natural TF elements for AD microbial cell factory, and expected that the design TF strategy will be applied to running in parallel to the signaling machinery of the host cell.

Reducing the risk of tooth injury in anterior maxillary interdental osteotomy for cleft lip and palate patients using a surgical navigation technique

The aim of this study was to investigate the clinical feasibility of preventing tooth injury from anterior maxillary interdental osteotomy by using a surgical navigation technique. A retrospective review was conducted on cleft lip and palate patients treated with anterior maxillary osteotomy followed by distraction osteogenesis between August 2019 and May 2022. Patients operated on through image guidance were enrolled in the navigation group, while those who were operated on freehand were enrolled in the freehand group. Tooth injuries were identified on postoperative images. Linear and angular deviations of the osteotomy line were measured. Twelve patients were enrolled in the study, seven in the navigation group and five in the freehand group. Altogether, 24 osteotomy lines and 53 adjacent teeth were evaluated. The dental injury rate was 3% in the navigation group and 27% in the freehand group (P = 0.016). The average linear deviations (mean ± standard deviation) were 0.67 ± 0.30 mm and 2.05 ± 1.33 mm, respectively (P < 0.001), while the average angular deviations were 1.67 ± 0.68° and 11.41 ± 7.46°, respectively (P < 0.001). The results suggest that navigation was able to reduce the tooth injury risk compared with freehand interdental osteotomies in crowded dental arches.

Changes and significance of the fibrinolytic system following two pulmonary thromboembolisms in a rabbit model

In this study, we examined the changes in the fibrinolytic system in a rabbit model of two acute pulmonary thromboembolisms (PTE). Fourteen healthy adult New Zealand white rabbits were divided into three groups: the single PTE group (five rabbits), the double PTE group (five rabbits), and the control group (four rabbits). A rabbit model of acute pulmonary embolism was established, and immunohistochemistry and polymerase chain reaction (PCR) were performed on tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) in plasma, and pulmonary embolism tissue. Plasma results: 1) t-PA levels: one hour following the initial modeling, the levels of t-PA in the modeling groups were significantly lower than those in the control group (P<0.05). In addition, the t-PA levels in the double PTE group were found to be lower after the modeling, as compared to the pre-modeling period (P<0.05). One hour after the second modeling, the double PTE group had lower t-PA levels compared to the control group (P<0.05). However, t-PA rebounded two hours after modeling in the double PTE group. One week after the second modeling, the double PTE group had higher t-PA levels compared to the other two groups (P<0.05). 2) PAI-1 results: one hour after the initial modeling, PAI-1 levels in the two modeling groups were lower compared to the pre-modeling period and control groups (P<0.05). Two hours following modeling, PAI-1 levels in both modeling groups were lower compared to the control group (P<0.05). PAI-1 levels were lower in the double PTE group one and two hours after the second modeling compared to the other two groups and pre-modeling period (P<0.05). 3) The immunohistochemistry results: the expression of PAI-1 decreased in the two modeling groups, while t-PA expression increased compared to the control group. 4) PCR results: t-PA mRNA expression did not differ among the three groups. The PAI-1 mRNA expression was lower in the two PTE groups compared to the control group. We conclude that in the early stages of PTE, the local fibrinolytic activity of the thrombus is increased, which is favorable for thrombolysis. However, as the thrombus persists, the activity of the fibrinolytic system is inhibited, contributing to the development of chronic thromboembolic pulmonary hypertension.

Artificial Space Weathering to Mimic Solar Wind Enhances the Toxicity of Lunar Dust Simulants in Human Lung Cells

During NASA's Apollo missions, inhalation of dust particles from lunar regolith was identified as a potential occupational hazard for astronauts. These fine particles adhered tightly to spacesuits and were unavoidably brought into the living areas of the spacecraft. Apollo astronauts reported that exposure to the dust caused intense respiratory and ocular irritation. This problem is a potential challenge for the Artemis Program, which aims to return humans to the Moon for extended stays in this decade. Since lunar dust is "weathered" by space radiation, solar wind, and the incessant bombardment of micrometeorites, we investigated whether treatment of lunar regolith simulants to mimic space weathering enhanced their toxicity. Two such simulants were employed in this research, Lunar Mare Simulant-1 (LMS-1), and Lunar Highlands Simulant-1 (LHS-1), which were added to cultures of human lung epithelial cells (A549) to simulate lung exposure to the dusts. In addition to pulverization, previously shown to increase dust toxicity sharply, the simulants were exposed to hydrogen gas at high temperature as a proxy for solar wind exposure. This treatment further increased the toxicity of both simulants, as measured by the disruption of mitochondrial function, and damage to DNA both in mitochondria and in the nucleus. By testing the effects of supplementing the cells with an antioxidant (N-acetylcysteine), we showed that a substantial component of this toxicity arises from free radicals. It remains to be determined to what extent the radicals arise from the dust itself, as opposed to their active generation by inflammatory processes in the treated cells.

Phosphatase A1 accessory protein PlaS from Serratia marcescens controls cell membrane permeability, fluidity, hydrophobicity, and fatty acid composition in Escherichia coli BL21

Phospholipase A1 (PlaA) plays a pivotal role in diverse applications within the food and biochemical medical industries. Herein, we investigate the impact of the accessory protein encoded by plaS from Serratia marcescens on PlaA activity in Escherichia coli. Notably, PlaS demonstrates the ability to enhance PlaA activity while concurrently exhibiting inhibitory effects on the growth of E. coli BL21 (DE3). Our study revolves around probing the inhibitory action of PlaS on E. coli BL21 (DE3). PlaS exhibits a propensity to heighten both the permeability of outer and inner cell membranes, leading to concomitant reductions in membrane fluidity and surface hydrophobicity. This phenomenon is validated through scanning electron microscopy (SEM) analysis, which highlights PlaS's capacity to compromise membrane integrity. Moreover, through a comprehensive comparative transcriptomic sequencing approach, we identify four down-regulated genes (galM, ybhC, ldtC, and kdpB) alongside two up-regulated genes (rbsB and degP). These genes are intricately associated with processes such as cell membrane synthesis and modification, energy metabolism, and transmembrane transport. Our investigation unveils the intricate gene-level mechanisms underpinning PlaS-mediated growth inhibition and membrane disruption. Consequently, our findings serve as a significant reference for the elucidation of membrane protein mechanisms, shedding light on potential avenues for future exploration.

Efficient production of α-ketoglutaric acid using an economical double-strain cultivation and catalysis system

The whole-cell catalysis strategy of alpha-ketoglutaric acid (α-KG) production from L-glutamic acid (L-Glu) using recombinant Escherichia coli, in which L-glutamate oxidase (LGox) was over-expressed, has replaced the traditional chemical synthesis strategy. However, large amounts of toxic by-product, H2O2, should be eliminated through co-expressing catalase (Cat), thus severely increasing burden in cells. To efficiently and economically produce α-KG, here, the genes SpLGox (from Streptomyces platensis NTU3304) and SlCat (from Streptomyces lividans TK24) were inserted into the low-dosage-IPTG (Isopropyl β-D-Thiogalactoside) inducible expression system, constructed in our previous work, in E. coli, respectively. Besides, a double-strain catalysis system was established and optimized to produce α-KG, and the productivity of α-KG was increased 97% compared with that through single strain catalysis. Finally, a double-strain cultivation strategy was designed and employed to simplify the scale-up fermentation. Using the optimized whole-cell biocatalyst conditions (pH 7.0, 35 °C), majority of the L-glutamic acid was transformed into α-KG and the titer reached 95.4 g/L after 6 h with the highest productivity at present. Therefore, this strategy may efficiently and cost-effectively produce α-KG, enhancing its potential for industrial applications. KEY POINTS: • SpLGox and SlCat were over-expressed to catalyze L-Glu to α-KG and eliminate by-product H2O2, respectively. • Double-strain cultivation and catalysis system can efficiently and cost-effectively produce α-KG from L-Glu.

The economic burden of coronary heart disease in mainland China

OBJECTIVES

The aim of this study was to systematically evaluate the current economic burden of coronary heart disease (CHD) in mainland China and provide a reference for the formulation of policies to reduce the economic burden of CHD.

STUDY DESIGN

A systematic literature review was conducted of empirical studies on the economic burden of CHD over the past 20 years.

METHODS

PubMed, Web of Science, Embase, China Knowledge Resource Integrated Database and the WANFANG database were comprehensively searched for relevant articles published between 1 January 2000 and 22 December 2021. Content analysis was used to extract the data, and Stata 17.0 software was used for analysis. The median values were used to describe trends.

RESULTS

A total of 35 studies were included in this review. The annual median per-capita hospitalisation expense and the average expense per hospitalisation were $3544.40 ($891.64-$18,371.46) and $5407.34 ($1139.93-$8277.55), respectively. The median ratio on medical consumables expenses, drug expenses, medical examination expenses and treatment expenses were 41.59% (12.40%-63.73%), 26.90% (7.30%-60.00%), 9.45% (1.65%-33.40%) and 10.10% (2.36%-66.00%), respectively. The median per-capita hospitalisation expense in the eastern, central and western regions were $9374.45 ($2056.13-$18,371.46), $4751.5 ($2951.95-$8768.93) and $3251.25 ($891.64-$13,986.38), respectively. The median average expense per hospitalisation in the eastern and central regions were $6177.15 ($1679.15-$8277.55) and $1285.49 ($1239.93-$2197.36), respectively. The median average length of stay in the eastern, central and western regions were 9.3 days, 15.2 days and 16.1 days, respectively.

CONCLUSIONS

The economic burden of CHD is more severe in mainland China than in developed countries, especially in terms of the direct economic burden. In terms of the types of direct medical expenses, a proportion of medical examination expenses, treatment expenses and drug expenses were lowest in the eastern region, but medical consumables expenses were the highest in this region. This study provides guidance for the formulation of policies to reduce the economic burden of CHD in mainland China.

A Multiomics Analysis of the Close Connection between Intratumoral Microbiota and Immune Cell Infiltration in Colorectal Cancer

PURPOSE/OBJECTIVE(S)

The colorectal intratumoral microbiome and its association with the expression of the tumor genome and immune cell infiltration remain poorly characterized. Our study aims to investigate the relationship between intratumoral microbiota with tumor immune infiltration, patient prognosis, and potential downstream signaling pathways.

MATERIALS/METHODS

We collected biopsy samples of tumor tissue and paracancerous tissue from 92 patients with colorectal cancer, and acquired microbiota profiling in these samples using 16s rRNA sequencing. Meanwhile, the immune markers including CD8, FOXP3, CD163, PD-1 and PD-L1 were stained by immunohistochemistry (IHC) to identify the immune infiltration in tumors. Furthermore, we used The Cancer Genome Atlas and The Cancer Microbiome Atlas databases to conduct multiomics analysis on tumor flora and patient survival, tumor gene expression profile and potential downstream pathways.

RESULTS

There was a significant difference in α-diversity (p = 0.00051) and β-diversity (p = 0.004) between tumor and paracancerous tissues. The β-diversity of intratumoral bacterial differed by colorectal cancer tumor stage (early vs. late stage, p = 0.049) and location (left vs. right colon, p = 0.04). Stage-related flora cluster (Porphyromonas, Lachnoclostridium, Bacteroides, Aggregatibacter, and Hungatella) were identified and found to be associated with poor prognosis in colorectal cancer patients (HR = 1.79, p = 0.015). By IHC staining, we found that expression of PD-1 and FOXP3 was significantly reduced at low abundance of stage-related bacterial cluster (p<0.05). Among of them, Hungatella was negatively associated with CD8+T cell infiltration (p<0.05) in tumor. Besides, tumor-location related flora cluster (Bacteroides and Blautia) were identified and found to be associated with good prognosis in colorectal cancer patients (HR = 0.52, p = 0.011). Expression of CD163 was decreased at high abundance of location-related bacterial cluster (p<0.05). Among of them, Blautia was negatively correlated with tumor-associated macrophage infiltration(p<0.05). Furthermore, we found that the stage-related flora cluster was positively connected with the pathway of bile acid metabolism, whereas the location-dependent cluster was negatively correlated with this pathway.

CONCLUSION

We found specific intratumoral bacterial clusters that were related to tumor stage and location, and the clusters were strongly associated with tumor immune infiltration and patient prognosis. Our findings may provide new viewpoint for future research between intratumoral microbiota, metabolism pathway and tumor microenvironment.

Perturbation of Gut Microbiota Modulated the Abscopal Effects of Immunoradiotherapy in Rectal Cancer

PURPOSE/OBJECTIVE(S)

The abscopal effect-the regression of malignancies outside the irradiation zone-can be increased by combining radiotherapy (RT) with immunotherapy. In this study, we aimed to investigate whether the gut microbiota affected the abscopal effect following immunoradiotherapy (iRT) in rectal cancer.

MATERIALS/METHODS

Bilateral MC38 subcutaneous tumors (primary and abscopal tumor) were established in C57/B6 mice with or without oral antibiotic treatment (preadministration of vancomycin, streptomycin, and ampicillin 14 days before therapy). Mice with or without antibiotic therapy were then randomized into eight groups to receive one of four treatments: (1) RT to the primary tumor + anti-PD-1 therapy (iRT), (2) RT to the primary tumor (RT), (3) anti-PD-1 therapy (anti-PD-1), and (4) no treatment. Flow cytometry was used to determine the composition and function of immune cells in the primary and abscopal tumors as well as in the spleen. 16S rRNA sequencing was used to assess the gut microbiome alteration following antibiotic intervention. Multiple bioinformatics were then explored to investigate the impact of specific flora that related to abscopal antitumor effect.

RESULTS

We found that radiation on primary tumors exhibited cytotoxic effect in nonirradiated (abscopal) tumors (p=0.0057, RT vs. untreated group; p=0.0037, iRT vs. anti-PD-1 group). In contrast, abscopal tumors were resistant to the anticancer effects of RT when antibiotics were given (p=0.5374, RT + antibiotics vs. untreated group + antibiotics; p=0.42, iRT + antibiotics vs. anti-PD-1 + antibiotics group). Comparing the RT+antibiotics group to the RT group, we discovered that the number of CD8+CD44+ T cells decreased significantly in both abscopal tumors (p<0.001) and spleens (p=0.0061). In anti-PD-1-treated groups, antibiotics significantly reduced the number of CD8+GranzymeB+ T cells in primary tumors (p=0.0061) and CD4+CD25+ T cells in spleens (p<0.001). In iRT-treated groups, the antibiotic reduced the fraction of CD4+INF-γ+ cells in abscopal tumors (p=0.0134), and increased the number of CD4+PD-1+ T cells in spleens (p<0.001). Moreover, we found that both α- and β-diversity decreased significantly in the gut microbiota after antibiotic treatment (p=0.0079 and p<0.001, respectively). The abundance of g_Alistipes, g_Lactobacillus, g_Lachnospiraceae and g__Lactobacillus fell dramatically in the presence of antibiotics. In addition, functional analyses of Picrust2 and KEGG revealed that antibiotic therapy had the most profound impact on the D-Alanine metabolism pathway (p<0.001).

CONCLUSION

We found that the alteration of the gut microbiome by antibiotics significantly affects the local and systemic antitumoral effect of iRT, our results may provide new insight on how gut modification converts the local anticancer effects of RT into a systemic response that targets metastatic tumors.

PARP Inhibitor Plus Radiotherapy Reshapes IDH1 Mutation Tumor Immune Suppression Microenvironment Potentiating the Efficiency of Immune Checkpoint Inhibitor

PURPOSE/OBJECTIVE(S)

Isocitrate dehydrogenase 1 (IDH1) mutations confer gain-of-function activity by converting α-ketoglutarate (α-KG) to the oncometabolite D-2-hydroxyglutarate (D-2HG). IDH mutant tumors have fewer tumor-infiltrating CD8+ T cells and reduced PD-L1 expression compared with their wild type (WT) counterparts. In addition, 2-HG can directly inhibit the killing and proliferative functions of CD8+ T lymphocytes, and suggesting that 2-HG promotes an immunosuppressive TME. Several studies have shown that 2-HG can inhibit homologous recombination (HR) and weaken the DNA damage response (DDR), making them more sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors and radiotherapy (RT). At the same time, RT and PARP inhibition (PARPi) have been considered to be a new direction to stimulate antitumor immunity. Therefore, our study intends to use RT + PARPi to reverse the immunosuppressive microenvironment caused by IDH1 mutations, thereby promoting the therapeutic effect of immune checkpoint inhibitors.

MATERIALS/METHODS

We compared the immune responses of clinical tissue samples and TCGA data from either IDH1mut or IDH1WT low-grade gliomas. We then established IDH1mut-overexpressing MC38 and GL261 cell lines to determine the antitumor effect of RT + PARPi. Apoptosis and immunogenic death markers were detected by flow cytometry, western blot (WB) and ELISA in these cell lines. Tumor growth and mouse survival curves were observed in both an MC38 subcutaneous and GL261 orthotopic tumor model. Changes in the composition of the immune microenvironment were assessed using flow cytometry. The mechanisms underpinning these compositional shifts were then further interrogated using various techniques, including WB, immunofluorescence, qRT-PCR, CRISPR/Cas9, and CD8+ T cell migration experiments.

RESULTS

We observed that CD8+ T cell infiltration and expression of the chemokines CXCL10 and CCL5 of CD8+ T cells in IDH1mut tumors were significantly downregulated by immunohistochemistry and TCGA analysis. Gene enrichment analysis using the TCGA database found that IDH1 mutations downregulated interferon (IFN)-related signaling pathways. RT + PARPi induces more DNA damage and actives the CGAS-STING pathway compared with monotherapy, leading to more expression of IFN-β, CXCL10 and CCL5 at mRNA and protein level. In the MC38 subcutaneous tumor model, we found that RT + PARPi increased the infiltration of CD8+ T cells while enhancing the killing function of CD8+ T cells. We observed these same effects in the GL261 orthoma model, as well as increased proliferation function of CD8+ T cells. In addition, RT + PARPi increased the expression of PD-L1 and enhanced the therapeutic effect of immune checkpoint inhibitors.

CONCLUSION

RT + PARPi reshapes the IDH1mut tumor immune suppression microenvironment, thereby potentiating the antitumor effect and efficiency of immune checkpoint inhibitor.

[Epidemiological characteristics of imported malaria cases after malaria elimination in Yixing City of Jiangsu Province]

OBJECTIVE

To analyse the epidemiological characteristics of imported malaria cases after malaria elimination in Yixing City, Jiangsu Province, so as to provide reference for malaria prevention and control in grassroots healthcare institutions.

METHODS

All data pertaining to malaria cases reported in Yixing City from 2016 to 2022 were retrieved from Chinese Disease Control and Prevention Information System, and the data pertaining to vector monitoring and human malaria parasite infections from 2016 to 2022 were collected for a descriptive statistical analysis.

RESULTS

A total of 14 imported malaria cases were reported in Yixing City from 2016 to 2022, including 12 cases with Plasmodium falciparum malaria, one case with P. vivax malaria and one case with P. ovale malaria, and all cases acquired infections in Africa and then returned to Yixing City. Malaria cases were reported across 2016 to 2022 except in 2020 and 2021. Malaria cases were predominantly reported during the period between December and February of the next year, and workers were the predominant occupation. The institutions where malaria was initially diagnosed included county-level general hospitals, county-level disease prevention and control institutions and grassroots healthcare centers, and there were 10 cases with definitive diagnosis of malaria on the day of initial diagnosis, with a 64.29% (9/14) correct rate of initial diagnosis. There were 5 cases diagnosed with severe malaria, and the standardized response rate was 100.00% following the "1-3-7" surveillance and response strategy. Of all malaria vectors, only Anopheles sinensis was monitored in Yixing City from 2016 to 2022, and all humans were tested negative for blood smears exceptimportedmalariacases.

CONCLUSIONS

The correct rate of initial malaria diagnosis was not high in healthcare institutions in Yixing City from 2016 to 2022, and there are still multiple challenges for prevention of re-establishment of imported malaria.

An objective, quantitative, dynamic assessment of facial movement symmetry changes after orthognathic surgery

The aim of this study was to generate a quantitative dynamic assessment of facial movement symmetry changes after orthognathic surgery. Twenty-five patients diagnosed with skeletal class III malocclusion with facial asymmetry who underwent bimaxillary surgery were recruited. The patients were asked to perform a maximum smile that was recorded using a three-dimensional facial motion capture system preoperatively (T0), 6 months postoperatively (T1), and 12 months postoperatively (T2). Eleven facial landmarks were selected to analyse the cumulative distance and average speed during smiling. The absolute differences for the paired landmarks between the sides were analysed to reflect the symmetry changes. The results showed that the asymmetry index of the cheilions at T2 was significantly lower than that at T0 (P = 0.004), as was the index of the mid-lateral lower lips (P = 0.006). The mean difference in cheilions was 2.13 ± 1.41 mm at T0, 1.33 ± 1.09 mm at T1, and 1.00 ± 0.98 mm at T2. The facial total mobility at T1 was significantly lower than that at T0 (P < 0.001), while the total mobility at T2 was significantly higher than that at T1 (P = 0.012). The orthognathic surgical correction of facial asymmetry was able to improve the associated asymmetry of facial movements.

Determination of the Anti-Oxidative Stress Mechanism of Isodon suzhouensis Leaves by Employing Bioinformatic and Novel Research Technology

Isodon suzhouensis from Suzhou, China, is a traditional Chinese herb with wide applications in medicine and food. The antioxidant activity against oxidative stress of the leaves of Isodon suzhouensis is a myth since long and is not explored earlier thoroughly. The present study is focused to explore the active components in Isodon suzhouensis leaf extracts responsible for antioxidant effects against oxidative stress and the potential mechanism of this activity. We obtained the chromatograms of Isodon suzhouensis leaf extracts by the high-performance liquid phase (HPLC) for possible detection of antioxidant constituents. Some compounds in Isodon suzhouensis leaf extracts were then further assessed through the luminol luminescence mechanism combined with HPLC analysis as well as with SwissTargetPrediction database that helped to screen out the other constituents. The targets for effects against oxidative stress were then further screened through the GeneCards database, and the PPI network was constructed. The targets were analyzed by GO and KEGG using the David database. The obtained results were then further studied by employing in vitro experimentation and protein expression analyses by Western blotting. It is found that Isodon suzhouensis leaf extracts contain rutin, isoquercetin, glaucocalyxin A, glaucocalyxin B, and other compounds with antioxidant activity. The activity map of the free radical scavenging signals from Isodon suzhouensis showed a strong ability to scavenge free radicals with the highest capacity of glaucocalyxin B followed by isoquercetin succeeding the glaucocalyxin A supervening the rutin. Further network pharmacological analyses and in vitro experimentation showed that Isodon suzhouensis leaf extracts interfere with TNF and the p38 MAPK signaling pathway for antioxidant effects against oxidative stress. Conclusively, it is found that Isodon suzhouensis leaf extracts possess strong antioxidant potential via targeting TNF and p38 MAPK signaling pathways against oxidative stress, providing scientific foundation for further studies on Isodon suzhouensis for the further therapeutic approach.

Point mutation of V252 in neomycin C epimerase enlarges substrate-binding pocket and improves neomycin B accumulation in Streptomyces fradiae

Neomycin, an aminoglycoside antibiotic with broad-spectrum antibacterial resistance, is widely used in pharmaceutical and agricultural fields. However, separation and purification of neomycin B as an active substance from Streptomyces fradiae are complicated. Although NeoN can catalyze conversion of neomycin C to neomycin B, the underlying catalytic mechanism is still unclear. In this study, the genomic information of high-yielding mutant S. fradiae SF-2 was elucidated using whole-genome sequencing. Subsequently, the mechanism of NeoN in catalyzing conversion of neomycin C to neomycin B was resolved based on NeoN-SAM-neomycin C ternary complex. Mutant NeoNV252A showed improved NeoN activity, and the recombinant strain SF-2-NeoNV252A accumulated 16,766.6 U/mL neomycin B, with a decrease in neomycin C ratio from 16.1% to 6.28%, when compared with the parental strain SF-2. In summary, this study analyzed the catalytic mechanism of NeoN, providing significant reference for rational design of NeoN to improve neomycin B production and weaken the proportion of neomycin C.

P12.09.B Extracellular vesicle derived-miR-146a increases melanoma brain metastasis progression via Notch signalling pathway dysregulation

Background

Melanoma has the highest tropism of any cancer to metastasize to the brain, and 40% of late-stage patients develop brain metastasis. Invasion, survival, and progression of tumors is dependent on the support of the surrounding microenvironment; therefore, modulation of neighboring cells is a key factor in metastasis. Extracellular vesicles (EVs) are important in cell-to-cell signalling, shuttling proteins, RNA and DNA to alter the surroundings into a favorable tumor microenvironment. Our aims were to investigate the role of melanoma brain metastasis (MBM) derived EVs in MBM development to find possible contributing mechanisms to cancer progression for eventual therapeutic targeting.

Material and Methods

MBM-EVs isolated via sequential ultracentrifugation were injected into mice as a pre-treatment prior to intracardial injection of MBM cells. EVs were co-cultured with normal human astrocytes (NHA) to investigate phenotypic changes. MiRNA sequencing was performed on EVs collected from MBM cells and compared to NHA and melanocytes to determine a candidate miRNA for targeting. In situ hybridization was utilized to evaluate the level of miRNA in clinical patient MBM samples. Functional in vivo validation was performed by injecting miRNA knockout MBM cells into mice. Sequencing of NHA in the presence or absence of target miRNA mimic was used to determine downstream targets.

Results

Mice primed with EVs had a significant increase in MBM tumor burden, compared to non-primed mice. Co-culture with MBM-EVs resulted in NHA activation in vitro, with increased proliferation, invasion, cytokine production, and upregulation of GFAP. MiR-146a was highly upregulated in MBM EVs, and miR-146a mimics activated NHA. Patient samples had a significant increase in miR-146a expression, compared to healthy brain controls. MiR-146a knockdown in MBM mice models reduced MBM burden and prolonged animal survival. Sequencing of NHA determined NUMB, an inhibitor of the Notch signalling pathway, as a target of miR-146a. Numb and other downstream Notch proteins expression was significantly altered in NHA in the presence of both MBM-EVs and miR-146a.

Conclusion

In conclusion, EVs are important regulators of MBM and establish tumor-supporting reactive astrocytes by delivery of miR-146a. MiR-146a alters Notch signalling in astrocytes via inhibition of the tumor suppressor gene NUMB. Elevated miR-146a levels in patients suggests a potential clinical intervention is possible via miR-146a targeting.

POS1029 EFFECTS OF TREATMENT WITH RISANKIZUMAB ON MINIMAL DISEASE ACTIVITY (MDA) AND DISEASE ACTIVITY IN PSORIATIC ARTHRITIS (DAPSA): AN ANALYSIS OF THE KEEPsAKE-1 AND -2 TRIALS

Background

Risankizumab (RZB) is a monoclonal antibody that specifically inhibits interleukin 23.

Objectives

To evaluate the achievement of Minimal Disease Activity (MDA), its components, and achievement of Disease Activity in PsA Low Disease Activity and Remission (DAPSA LDA+REM, [DAPSA score ≤14]) in patients receiving RZB or placebo (PBO) in the KEEPsAKE 1 and 2 clinical trials.

Methods

KEEPsAKE-1 and -2, double-blind, phase 3 trials, evaluated the efficacy of RZB versus PBO for the treatment of adult patients with active psoriatic arthritis (PsA). Patients were randomized (1:1) to receive subcutaneous RZB 150 mg or PBO at weeks 0, 4, and 16. The open label extension began at Week 24 with all patients receiving RZB 150 mg every 12 weeks thereafter. Achievement of MDA, its components, and achievement of DAPSA LDA+REM are reported using non-responder imputation.

Results

MDA achievement at Week 52 in KEEPsAKE-1 was 37.9% for patients originally randomized to RZB and 27.4% for patients originally randomized to PBO. In KEEPsAKE-2, MDA achievement was 27.2% and 33.8% for patients originally randomized to RZB and PBO, respectively. Achievement of MDA and its components are presented in Figure 1. In KEEPsAKE-1, at Week 52 59.2% of patients originally randomized to RZB and 51.4% of patients originally randomized to PBO achieved DAPSA LDA+REM. At Week 52 in KEEPsAKE-2, DAPSA LDA+REM was achieved by 44.6% of patients originally randomized to RZB and 46.6% of patients originally randomized to PBO (Figure 1).

Conclusion

Patients treated with RZB demonstrate achievement of MDA, its components, and DAPSA LDA+REM at Weeks 24 and 52.

Acknowledgements

AbbVie Inc, participated in the study design; study research; collection, analysis and interpretation of data; and writing, reviewing, and approving of this abstract for submission. AbbVie funded the research for this study and provided writing support for this abstract. Medical writing assistance was provided by Trisha Rettig, Ph.D. of AbbVie

Disclosure of Interests

Joseph F. Merola Consultant of: Amgen, Bristol-Myers Squibb, Abbvie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Sanofi, Regeneron, Sun Pharma, Biogen, Pfizer and Leo Pharma, Iain McInnes Consultant of: AbbVie, Amgen, Astra Zeneca, Compugen, Cabaletta, Evelo, Janssen, Lilly, Novartis, Pfizer, Sanofi, and UCB, Grant/research support from: AbbVie, Amgen, Astra Zeneca, Janssen, Lilly, Novartis, Pfizer, UCB, Arthur Kavanaugh Consultant of: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Grant/research support from: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Peter Nash Speakers bureau: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Consultant of: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Grant/research support from: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Zhenyi Xue Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Vassilis Stakias Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Ann Eldred Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Sandra Ciecinski Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Kevin Douglas Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis and Pfizer

POS1032 RISANKIZUMAB FOR ACTIVE PSORIATIC ARTHRITIS: INTEGRATED SUBGROUP ANALYSIS FROM 2 DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE 3 STUDIES (KEEPsAKE 1 AND KEEPsAKE 2)

Background

Risankizumab (RZB), a monoclonal antibody that specifically inhibits interleukin 23, is being investigated as a treatment for adults with psoriatic arthritis (PsA).

Objectives

We report the proportion of patients with active PsA treated with RZB vs placebo who achieved ≥20% improvement in American College of Rheumatology criteria (ACR20) by baseline demographics and by concomitant or prior medication use subgroups.

Methods

KEEPsAKE 1 (NCT03675308) and KEEPsAKE 2 (NCT03671148) are ongoing, multicenter, randomized, double-blind, placebo-controlled, phase 3 studies. Patients with active PsA with an inadequate response or intolerance to conventional synthetic disease-modifying, anti-rheumatic drug (csDMARD; KEEPsAKE 1 and 2) and/or biologic therapy (KEEPsAKE 2) received RZB 150 mg or placebo (1:1). The primary endpoint was the proportion of patients achieving ≥20% improvement in ACR criteria (ACR20) at week 24.

Results

In KEEPsAKE 1 (RZB, n=483; placebo, n=481) and KEEPsAKE 2 (RZB, n=224; placebo, n=219), baseline demographics and characteristics were generally balanced between treatment groups. In this integrated analysis, a greater proportion of patients receiving RZB vs placebo achieved ACR20 at week 24, regardless of age (<65 years, ≥65 years, ≥65 to <75 years, ≥75 years), sex, body mass index (<25 kg/m2, ≥25 to <30 kg/m2, ≥30 kg/m2), race (White, non-White), PsA duration (≤5 years, >5 to ≤10 years, >10 years), baseline hs-CRP (<3 mg/L, ≥3 mg/L), concomitant csDMARD at baseline (any csDMARD, any methotrexate, none), or prior biologics use (yes, no). The proportion of RZB-treated patients who achieved ACR20 was generally similar across most assessed demographic or prior treatment subgroups. No new safety concerns were observed with RZB.

Conclusion

RZB demonstrates efficacy vs placebo for active PsA as shown by greater proportions of patients achieving ACR20 at week 24, regardless of baseline demographics, concomitant csDMARD use at baseline, or prior biologic use.

Acknowledgements

AbbVie Inc. participated in the study design; study research; collection, analysis, and interpretation of data; funded the research for this study. Medical writing assistance, funded by AbbVie, was provided by Alicia Salinero, PhD, of JB Ashtin.

Disclosure of Interests

Joseph F. Merola Consultant of: Amgen, Bristol-Myers Squibb, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Sanofi, Regeneron, Sun Pharma, Biogen, Pfizer and Leo Pharma, Kristina Callis-Duffin Consultant of: Amgen/Celgene, AbbVie, Boehringer-Ingelheim, Bristol-Myers Squibb, CorEvitas, Janssen, Lilly, Novartis, and Pfizer, Grant/research support from: Amgen/Celgene, AbbVie, Boehringer-Ingelheim, CorEvitas, Lilly, Janssen, Novartis, Pfizer, Byron Padilla Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Zhenyi Xue Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Huzefa Photowala Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Blair Kaplan Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Iain McInnes Consultant of: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers, Celgene, Janssen, Leo, Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers, Celgene, Janssen, Leo, Lilly, Novartis, Pfizer, and UCB

Evaluation of antibiotic combination of Litsea cubeba essential oil on Vibrio parahaemolyticus inhibition mechanism and anti-biofilm ability

Vibrio parahaemolyticus (V. parahaemolyticus) is a common pathogen in seafood. The use of antibiotics is a primary tool to prevent and control V. parahaemolyticus in the aquaculture industry. However, V. parahaemolyticus combats the damage caused by antibiotics by forming biofilms under certain conditions. In this study, we analyzed the antibacterial effect and the characteristics of V. parahaemolyticus by experimentally determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI) values of a combination of the Litsea cubeba essential oil (LCEO) and several commonly used V. parahaemolyticus antibiotics. The bactericidal effect of the essential oil alone and essential oil in combination with the antibiotics were evaluated with time-kill curves. The damage to cell membranes and cell walls were assessed by measuring the content of macromolecules and alkaline phosphatase (AKP) released into the supernatant using V. parahaemolyticus ATCC17802 as the experimental strain. The membrane structure was observed by transmission electron microscopy. The results showed that the MIC value of the LCEO was 1,024 μg/mL, and the LCEO FICI values in combination with tetracycline or oxytetracycline hydrochloride was 0.3125 and 0.75, respectively, indicating synergistic and additive effects. Moreover, LCEO inhibited the growth and promoted the removal of biofilms by reducing the content of hydrophobic and extracellular polysaccharides on the cell surface. This study provides a reference for studying the antibacterial activity of LCEO and the combination of antibiotics to prevent and control the formation of biofilms by V. parahaemolyticus.

[Establishment of artificial neural network model for predicting lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer]

Objective: To establish a neural network model for predicting lymph node metastasis in patients with stage II-III gastric cancer. Methods: Case inclusion criteria: (1) gastric adenocarcinoma diagnosed by pathology as stage II-III (the 8th edition of AJCC staging); (2) no distant metastasis of liver, lung and abdominal cavity in preoperative chest film, abdominal ultrasound and upper abdominal CT; (3) undergoing R0 resection. Case exclusion criteria: (1) receiving preoperative neoadjuvant chemotherapy or radiotherapy; (2) incomplete clinical data; (3) gastric stump cancer.Clinicopathological data of 1231 patients with stage II-III gastric cancer who underwent radical surgery at the Fujian Medical University Union Hospital from January 2010 to August 2014 were retrospectively analyzed. A total of 1035 patients with lymph node metastasis were confirmed after operation, and 196 patients had no lymph node metastasis. According to the postoperative pathologic staging. 416 patients (33.8%) were stage Ⅱ and 815 patients (66.2%) were stage III. Patients were randomly divided into training group (861/1231, 69.9%) and validation group (370/1231, 30.1%) to establish an artificial neural network model (N+-ANN) for the prediction of lymph node metastasis. Firstly, the Logistic univariate analysis method was used to retrospectively analyze the case samples of the training group, screen the variables affecting lymph node metastasis, determine the variable items of the input point of the artificial neural network, and then the multi-layer perceptron (MLP) to train N+-ANN. The input layer of N+-ANN was composed of the variables screened by Logistic univariate analysis. Artificial intelligence analyzed the status of lymph node metastasis according to the input data and compared it with the real value. The accuracy of the model was evaluated by drawing the receiver operating characteristic (ROC) curve and obtaining the area under the curve (AUC). The ability of N+-ANN was evaluated by sensitivity, specificity, positive predictive values, negative predictive values, and AUC values. Results: There were no significant differences in baseline data between the training group and validation group (all P>0.05). Univariate analysis of the training group showed that preoperative platelet to lymphocyte ratio (PLR), preoperative systemic immune inflammation index (SII), tumor size, clinical N (cN) stage were closely related to postoperative lymph node metastasis. The N+-ANN was constructed based on the above variables as the input layer variables. In the training group, the accuracy of N+-ANN for predicting postoperative lymph node metastasis was 88.4% (761/861), the sensitivity was 98.9% (717/725), the specificity was 32.4% (44/136), the positive predictive value was 88.6% (717/809), the negative predictive value was 84.6% (44/52), and the AUC value was 0.748 (95%CI: 0.717-0.776). In the validation group, N+-ANN had a prediction accuracy of 88.4% (327/370) with a sensitivity of 99.7% (309/310), specificity of 30.0% (18/60), positive predictive value of 88.0% (309/351), negative predictive value of 94.7% (18/19), and an AUC of 0.717 (95%CI:0.668-0.763). According to the individualized lymph node metastasis probability output by N+-ANN, the cut-off values of 0-50%, >50%-75%, >75%-90% and >90%-100% were applied and patients were divided into N0 group, N1 group, N2 group and N3 group. The overall prediction accuracy of N+-ANN for pN staging in the training group and the validation group was 53.7% and 54.1% respectively, while the overall prediction accuracy of cN staging for pN staging in the training group and the validation group was 30.1% and 33.2% respectively, indicating that N+-ANN had a better prediction than cN stage. Conclusions: The N+-ANN constructed in this study can accurately predict postoperative lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer. The N+-ANN based on individualized lymph node metastasis probability has better accurate prediction for pN staging as compared to cN staging.

Improved Neomycin Sulfate Potency in Streptomyces fradiae Using Atmospheric and Room Temperature Plasma (ARTP) Mutagenesis and Fermentation Medium Optimization

To improve the screening efficiency of high-yield neomycin sulfate (NM) Streptomyces fradiae strains after mutagenesis, a high-throughput screening method using streptomycin resistance prescreening (8 μg/mL) and a 24-deep well plates/microplate reader (trypan blue spectrophotometry) rescreening strategy was developed. Using this approach, we identified a high-producing NM mutant strain, Sf6-2, via six rounds of atmospheric and room temperature plasma (ARTP) mutagenesis and screening. The mutant displayed a NM potency of 7780 ± 110 U/mL and remarkably stable genetic properties over six generations. Furthermore, the key components (soluble starch, peptone, and (NH₄)₂SO₄) affecting NM potency in fermentation medium were selected using Plackett-Burman and optimized by Box-Behnken designs. Finally, the NM potency of Sf6-2 was increased to 10,849 ± 141 U/mL at the optimal concentration of each factor (73.98 g/L, 9.23 g/L, and 5.99 g/L, respectively), and it exhibited about a 40% and 100% enhancement when compared with before optimization conditions and the wild-type strain, respectively. In this study, we provide a new S. fradiae NM production strategy and generate valuable insights for the breeding and screening of other microorganisms.

Identification of phytochemicals and antioxidant activity of Premna microphylla Turcz. stem through UPLC-LTQ-Orbitrap-MS

Premna microphylla Turcz. is a commonly used traditional Chinese medicine totreatdysentery and appendicitis. Present study is focused to explore antioxidants and other compounds in the Premna microphylla Turcz. stem. Assessment of chemical composition was done with high sensitivity UPLC-LTQ-Orbitrap-MS and for Separation Thermo Hypersil Gold (100 mm × 2.1 mm, 1.9 µm) was used while electrospray ionization (ESI) was used for the mass spectrometry. 18 compounds were identified including Vitexin (1), Schaftoside (2), Vicenin-2 (3), Apigenin-6, 8-di-C-arabinoside (4), Apigenin-7-O-β-d-glucoside (5), Carnosic acid (6), Apigenin-8-C-β-d-xylopyranoside (7), Prostratin (8), Aurantio-obtusin-β-d-glucoside (9), Royleanone (10), 5-hydroxy-7,3',4'-Trimethoxy flavonols (11), 6-Hydroxy-5,6-dehydrosugiol (12), 14-deoxycoleon (13), Arucadiol (14), Obtusinone-B (15), Trehalose (16), Citric acid (17) and Betaine (18). Among these, 6 compounds including (6), (8), (9), (16), (17) and (18) were identified first time within this genus and plant. Study highlights the importance of Premna microphylla Turcz. stem extract for strong therapeutic potential against oxidation-related diseases.

Biochemical and Phylogenetic Characterization of a Novel NADP+-Specific Isocitrate Dehydrogenase From the Marine Microalga Phaeodactylum tricornutum

Isocitrate dehydrogenase (IDH) family of proteins is classified into three subfamilies, namely, types I, II, and III. Although IDHs are widely distributed in bacteria, archaea, and eukaryotes, all type III IDHs reported to date are found only in prokaryotes. Herein, a novel type III IDH subfamily member from the marine microalga Phaeodactylum tricornutum (PtIDH2) was overexpressed, purified, and characterized in detail for the first time. Relatively few eukaryotic genomes encode this type of IDH and PtIDH2 shares the highest homology with marine bacterial monomeric IDHs, suggesting that PtIDH2 originated through a horizontal gene transfer event between a marine alga and a bacterium. Size-exclusion chromatography revealed that the native PtIDH2 is a homotetramer (∼320 kDa) in solution, comprising four monomeric IDH-like subunits (80 kDa each). Enzymatic characterization showed that PtIDH2 is a bivalent metal ion-dependent enzyme and Mn²⁺ is the optimal activator. The recombinant PtIDH2 protein exhibited maximal activity at 35°C and pH 8.0 in the presence of Mn²⁺. Heat-inactivation analysis revealed that PtIDH2 is a cold-adapted enzyme. Kinetic analysis demonstrated that PtIDH2 is a completely NADP⁺-specific IDH with no detectable NAD⁺-associated catalytic activity. The three putative key NADP⁺-binding residues (His604, Arg615, and Arg664) in PtIDH2 were also evaluated by site-directed mutagenesis. The H⁶⁰⁴L/R⁶¹⁵D/R⁶⁶⁴S triple mutant showed a 3.25-fold preference for NAD⁺ over NADP⁺, implying that the coenzyme specificity of PtIDH2 can be converted from NADP⁺ to NAD⁺ through rational engineering approaches. Additionally, the roles of the conserved residues Ala718 and Leu742 in the thermostability of PtIDH2 were also explored by site-directed mutagenesis. We found that the L⁷⁴²F mutant displayed higher thermostability than wild-type PtIDH2. This study expands the phylogeny of the IDH family and provides new insights into the evolution of IDHs.

Effects of oregano essential oil as an antibiotic growth promoter alternative on growth performance, antioxidant status, and intestinal health of broilers

This experiment was conducted to assess the comparative effects of dietary antibiotics and oregano essential oil (OEO) addition on growth performance, antioxidant status and intestinal health of broilers. A total of 384 one-day-old broilers were randomly allocated to 4 treatments with 6 replicates of 16 broilers each. The 4 treatments were: an antibiotic-free control diet (control), control + 20 mg/kg colistin sulfate and 20 mg/kg virginiamycin (antibiotics), control + 200 mg/kg natural oregano essential oil (NOEO), and control + 200 mg/kg synthetic oregano essential oil (SOEO). The experiment lasted for 42 d. Results showed that birds fed with OEO had greater (P < 0.05) average daily gain (ADG) and lower (P < 0.05) feed conversion ratio (FCR) than those fed with control diet during d 1 to 21. Besides, birds fed with NOEO had the greatest (P < 0.05) ADG in the four groups during d 22 to 42. The serum oxidative stress parameters showed that OEO improved (P < 0.05) the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathione reductase (GR) of birds on day 21 and the activity of total antioxidant capacity (T-AOC) of birds on d 42. Relative to control, NOEO increased (P < 0.05) the activity of T-AOC in jejunum and decreased (P < 0.05) the level of malondialdehyde (MDA) in serum and jejunum. Moreover, OEO supplementation increased (P < 0.05) the concentrations of sIgA in duodenum and jejunum, Lactobacillus and total anaerobes in cecum, as well as activities of trypsin, chymotrypsin, lipase and amylase in duodenum, but restrained (P < 0.05) the amount of Escherichia coli. The NOEO supplementation increased (P < 0.05) total anaerobes of broilers on d 42 and the villus height to crypt depth ratio (VH/CD) of ileum. These results suggest that OEO improved antioxidant status and intestinal health of broilers which contributed to the growth performance improvement of broilers. Dietary OEO supplementation can be a promising alternative to antibiotic growth promoters for improving poultry production.

AB0343 THE CHARACTERISTICS OF T CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH ANXIETY BASED ON MACHINE LEARNING

Background:

Systemic lupus erythematosus (SLE) is an autoimmune disease, the immune system of patients to be disordered, especially in T cell subsets1. They were prone to mental diseases, anxiety particularly, which lead to suicide2. The recent study had reported that CD4+ T cells in the peripheral blood played the key role in like anxiety behavior of mice3. Although there showed that the level of serum TNF-α in SLE patients with anxiety was higher than without anxiety4, finding the important special mediators especially in T cell subsets was still necessary for the prevention of anxiety in SLE patients.

Objectives:

In total, 108 SLE patients, which met the diagnostic criteria of the American Society of rheumatology (v1997), were enrolled in this study from Affilliated Hospital of Nantong University, China. Exclusion criteria included other autoimmune diseases and active infection (including hepatitis B or C virus, Epstein-Barr virus, human immunodeficiency virus or Mycobacterium tuberculosis infection).

Methods:

We surveyed the abundance of 74 immune cell subpopulations from 108 SLE patients using flow cytometry, and investigated their differences between patients with and without anxiety (24 versus 84). Moreover, machine learning including Lasso regression, Random forest (RF) and Sparsity partial least squares discriminant analysis (sPLS-DA) was employed to build models and futher selected important features for the classification of SLE patients with anxiety.

Results:

SLE patients with anxiety showed higher body mass index (BMI) and lower quality of life. In their peripheral blood, the proportion of internal cell subsets composition of Th cell and Treg cells changed. By machine learning, we finally found that BMI and PD1-CD28- Treg played important rules to developing lupus anxiety.

Conclusion:

In this study, machine learning was applied to build models to select the most important T cell subset in SLE patients with anxiety. These findings suggested that BMI and imbalance of PD1-CD28- Treg containing effector memory Treg cells and effector Treg cells mostly played important roles in the development of SLE anxiety.

Disclosure of Interests:

None declared

POS0787 BERBERINE MODULATE LUPUS SYNDROME VIA THE REGULATION OF GUT MICROBIOTA IN MRL/LPR MICE

Background:

Intestinal flora disorder and immune abnormalities have been reported in systemic lupus erythematosus (SLE) patients1,2. Berberine (BBR) showed significant effects in regulating the intestinal flora, repairing gut barriers and regulating immune cells3,4. While few reports mentioned the abnormal gut microbiota and metabolites in Chinese SLE patients.

Objectives:

Our investigation tried to illustrate the relationship between gut microbiota, intestinal metabolites and disease activity in Chinese SLE patients. And the effect of BBR to intestinal dysbacteriosis, multiple organ damages and over-activated immune system in MRL/Lpr mice.

Methods:

16S high-throughput (16S rRNA) sequence, qRT-PCR and gas chromatography technology were used to determine the gut microbiota and metabolites in 104 SLE patients from Affiliated Hospital of Nantong University, China. BBR was orally treated to the MRL/Lpr mice in low, medium and high doses. After 6 weeks treatment, mice were sacrificed. Serum, faeces and organs were collected for further studies.

Results:

Chinese SLE patients showed higher abundance of Bacteroidetes and lower abundance of Firmcutes. The results of qRT-PCR showed high Firmcutes/Bacteroidetes (F/B) ratio of SLE patients. The F/B ratio was negative correlated with SLE disease activity index (SLEDA) score. Almost all the tested short-chain fatty acids (SCFAs) found statistically significant results in SLE and LN (lupus nephritis) patients, especially the propanoic acid and butyric. BBR altered the relative abundance of Bacteroides and Verrucomicrobia and the butyric acid content in colon of MRL/Lpr mice. The increase of tight junction protein also indicated the gut barrier was repaired by BBR. Treg and Tfr cells in spleen and mesenteric lymph node (MLN) were increased. These results revealed a positive therapeutic effect of berberine on SLE from gut microbiota to immune status.

Conclusion:

Our study highlights current status of intestinal dysbacteriosis in Chinese patients with SLE and differences in intestinal metabolites among patients with different disease states. The regulation of intestinal flora and the repairment of gut barrier by intestinal metabolites in BBR treated mice seemed to be the factor that directed the immune responses and disease outcomes. The ultimate goal of our study was to determine the beneficial effects of regulating the gut microbiota on the treatment of SLE. The application of berberine is a relatively safe and convenient way. In the coming investigations, we plan to focus on the study of berberine and its metabolites on intestinal function and systemic immunity.

References:

[1]Guo, M. et al. Alteration in gut microbiota is associated with dysregulation of cytokines and glucocorticoid therapy in systemic lupus erythematosus. Gut microbes11, 1758-1773, doi:10.1080/19490976.2020.1768644 (2020).

[2]Mu, Q. et al. Control of lupus nephritis by changes of gut microbiota. Microbiome5, 73, doi:10.1186/s40168-017-0300-8 (2017).

[3]Habtemariam, S. Berberine pharmacology and the gut microbiota: A hidden therapeutic link. Pharmacological research155, 104722, doi:10.1016/j.phrs.2020.104722 (2020).

[4]Cui, H. et al. Berberine Regulates Treg/Th17 Balance to Treat Ulcerative Colitis Through Modulating the Gut Microbiota in the Colon. Frontiers in pharmacology9, 571, doi:10.3389/fphar.2018.00571 (2018).

Figure 1.

Disclosure of Interests:

None declared

POS0761 INVESTIGATION ON THE EFFECT AND MECHANISM OF ABNORMALLY ACTIVATED CD8+ T CELLS FROM BONE MARROW ON HEMATOPOIETIC STEM CELLS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

SLE is an autoimmune disease characterized by the abnormal function of lymphocytes. The impairment of hematopoietic function of bone marrow participates in its pathogenesis, in which T cells play an important role. However, study on bone marrow T cells in SLE patients is very limited.

Objectives:

This study aims to characterize the phenotype and molecular characteristics of abnormally activated CD8+T cells in bone marrow of SLE patients and explore the mechanism of hematopoietic stem cells (HSCs) reduction caused by the abnormally activated CD8+T cells in bone marrow of patients with SLE.

Methods:

A total of 8 SLE patients and 5 age- and sex-matched controls were recruited in our study. Among them, 3 SLE patients and 4 donors were collected bone marrow and peripheral blood samples for Single-cell RNA sequencing (scRNA-seq) and functional studies. BM and peripheral T cell subsets were measured by flow cytometry. Plasma cytokines and secreted immunoglobulins were detected by Luminex. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI). All analyses were performed using R language and Flowjo 9.

Results:

In the present study, SLE patients had increased CD8+T%αβT cells and decreased CD4+T%αβT cells in bone marrow of SLE, compared to healthy controls. A large number of CD38+HLADR+CD8+T cells existed in the bone marrow and peripheral blood of SLE patients. Those patients also showed reduced number of HSCs, and with a downward trend of the numbers of peripheral red blood cells, white blood cells, neutrophils, hemoglobin, and platelets. By scRNA-seq, the CD38+HLADR+CD8+T cells contained high levels of GZMK, GZMA, PRF1, IFNG, and TNF in the bone marrow of SLE patients. the CD38+HLADR+CD8+T cells exhibited significant relationship with HSCs, white blood cells, neutrophils, and platelets.

Conclusion:

These findings demonstrated that the abnormally activated CD8+T cells in bone marrow can reduce the number of HSCs by the expression of killer molecules, which contributes to the impairment of hematopoietic function and the development of SLE. This project focuses on the specific bone marrow T cell subset in SLE. The completement of this project provides information for exploring the mechanism of hematopoiesis involvement.

References:

[1]Anderson E, Shah B, Davidson A, Furie R. Lessons learned from bone marrow failure in systemic lupus erythematosus: Case reports and review of the literature. Semin Arthritis Rheum. 2018;48(1):90-104.

[2]Sun LY, Zhou KX, Feng XB, Zhang HY, Ding XQ, Jin O, Lu LW, Lau CS, Hou YY, Fan LM. Abnormal surface markers expression on bone marrow CD34+cells and correlation with disease activity in patients with systemic lupus erythematosus. Clin Rheumatol. 2007;26(12):2073-2079.

Acknowledgements:

We want to thank Lu Meng, Teng Li, Wei Zhou, and Jiaxin Guo for their assistance with this study.

Disclosure of Interests:

None declared

Micromonospora zhangzhouensis sp. nov., a Novel Actinobacterium Isolated from Mangrove Soil, Exerts a Cytotoxic Activity in vitro

A new bacterial strain, designated HM134^T, was isolated from a sample of soil collected from a Chinese mangrove Avicennia marina forest. Assessed by a polyphasic approach, the taxonomy of strain HM134^T was found to be associated with a range of phylogenetic and chemotaxonomic properties consistent with the genus Micromonospora. Phylogenetic analysis based on the 16s rRNA gene sequence indicated that strain HM134^T formed a distinct lineage with the most closely related species, including M. rifamycinica AM105^T, M. wenchangensis CCTCC AA 2012002^T and M. mangrovi 2803GPT1-18^T. The ANI values between strain HM134^T and the reference strains ranged from 82.6% to 95.2%, which was below the standard criteria for classifying strains as the same species (96.5%). Strain HM134^T and related species shared in silico dDDH similarities values below the recommended 70% cut-off for the delineation of species (range from 25.7–62.6%). The DNA G+C content of strain HM134^T was 73.2 mol%. Analysis of phylogenetic, genomic, phenotypic and chemotaxonomic characteristics revealed that strain HM134^T is considered to represent a novel species of the genus Micromonospora, for which the name M. zhangzhouensis sp. nov. is proposed. The extract of strain HM134^T was demonstrated to exhibit cytotoxic activity against the human cancer cell lines HepG2, HCT-116 and A549. Active substance presented in the fermentation broth of strain HM134^T was isolated by bioassay-guided analysis and purified afterwards. A new derivative of diterpenoid was identified through electrospray ionizing mass spectrometry (MS) and nuclear magnetic resonance (NMR). The compound showed different cytotoxic activities against cancer cells, with the highest cytotoxicity against HCT-116, corresponding to IC₅₀ value of 38.4 μg/mL.

A novel stacked generalization of models for improved TB detection in chest radiographs

Chest x-ray (CXR) analysis is a common part of the protocol for confirming active pulmonary Tuberculosis (TB). However, many TB endemic regions are severely resource constrained in radiological services impairing timely detection and treatment. Computer-aided diagnosis (CADx) tools can supplement decision-making while simultaneously addressing the gap in expert radiological interpretation during mobile field screening. These tools use hand-engineered and/or convolutional neural networks (CNN) computed image features. CNN, a class of deep learning (DL) models, has gained research prominence in visual recognition. It has been shown that Ensemble learning has an inherent advantage of constructing non-linear decision making functions and improve visual recognition. We create a stacking of classifiers with hand-engineered and CNN features toward improving TB detection in CXRs. The results obtained are highly promising and superior to the state-of-the-art.

[Interaction between orally administrated heparin and intestinal microbiota in mice]

The development of orally administrated heparin drugs requires a systematic understanding of the interaction between heparin and gut flora. The in vivo distribution of fluorescein-labeled heparin that is orally administrated by mice was observed using fluorescein microscopy. In addition, the stability of heparin in simulated gastric and intestinal fluids, as well as the in vitro degradation of heparin by gut flora were detected by HPLC. The results show that orally administrated heparin was mainly distributed in the gastrointestinal tract of mice, and exerted structural stability under the condition of simulated gastric and intestinal fluids in vitro. However, heparin could be degraded by intestinal flora cultured in medium containing heparin. In order to further study the effect of orally administrated heparin on intestinal flora in mice, the fecal microbiota 16S rRNA fragment of C57BL/6J mice was tested by the Illumina Mi-Seq high-throughput sequencing technology. Compared with the gut flora of mice that orally administrated by saline, the biodiversity of gut flora in mice with orally administrated heparin was decreased. The difference of microflora structure was not significant at the phylum level, and the relative abundance of Alistipes, Parasutterella and Akkermansia was increased at the genus level, and the relative abundance of Bilophila, Enterorhabdus, Ruminiclostridium, Prevotellaceae_UCG_001, Ruminiclostridium-9, Bacteroides, Lachnoclostridium, Candidatus, Saccharimonas, Intestinimonas and Dubosiella was reduced. These findings indicate that heparin could influence the gut flora of mice. In addition, no obvious toxic and side effects were found in mice that orally administrated heparin, suggesting the safety of orally administrated heparin.

Isolation and Characterization of New 16-Membered Macrolides from the aveA3 Gene Replacement Mutant Strain Streptomyces avermitilis TM24 with Acaricidal and Nematicidal Activities

Polyketides represent an important class of biologically active and structurally diverse compounds found in nature. They are biosynthesized from acyl CoA precursors by polyketide synthases (PKSs). The use of combinatorial biosynthesis to form hybrid PKSs is considered to be an excellent approach for the development of novel polyketides. Here, 10 new 16-membered macrolide compounds were isolated from the broth of the genetically engineered strain Streptomyces avermitilis TM24, in which the PKS gene aveA3 was seamlessly replaced by the milbemycin PKS gene milA3. Their structures were elucidated on the basis of NMR and MS spectroscopic analyses. The acaricidal and nematicidal activities of them against Tetranychus cinnabarinus and Bursaphelenchus xylophilus were tested. The results indicated that compound 1 had potent acaricidal activity against adult mites with an LC₅₀ value of 0.0022 mg L^-1, while compounds 5 and 7 possessed potent nematicidal activity with LC₅₀ values of 4.56 and 4.30 mg L^-1, respectively.

Exploring the interaction between Salvia miltiorrhiza and α-glucosidase: insights from computational analysis and experimental studies

α-Glucosidase has emerged as an important target for type 2 diabetes mellitus. Salvia miltiorrhiza is a widely used traditional Chinese medicine. The interaction between the chemicals of S. miltiorrhiza and α-glucosidase are still not clear, and need to be deeply investigated. Herein, an integrated approach consisting of computational analysis and experimental studies was employed to illustrate the interactions between S. miltiorrhiza and α-glucosidase. Molecular docking simulations were performed to reveal the proposed binding characteristics of the chemicals identified in S. miltiorrhiza on the basis of the total docking scores and key molecular determinants for binding. The affinities of 13 representative compounds from the medicinal herb to α-glucosidase were predicted and then confirmed by enzyme inhibitory assay in vitro. The obtained results suggested that two compounds including salvianolic acid C and salvianolic acid A in S. miltiorrhiza showed potent α-glucosidase inhibitory activity with IC₅₀ values of 4.31 and 19.29 μM, respectively. The active inhibitor, salvianolic acid C, exerted a mixed-competitive inhibition mode when binding to α-glucosidase. Such findings could be helpful to efficiently discover bioactive molecules from complex natural products, which suggests the usefulness of the integrated approach for this scenario.

An integrated approach was used to explore the interaction between Salvia miltiorrhiza and α-glucosidase.

[Clinical useness of multimodal techniques in microsurgical resection of cerebral arteriovenous malformation]

Objective: To explore the clinical useness of intraoperative functional neuronavigation and fluorescent indocyanine green(ICG) angiography as well as electrophysiological evaluation during microsurgical resection of cerebral arteriovenous malformations (AVM). Methods: A series of 42 consecutive cases with AVM underwent microsurgery by intraoperative functional neuronavigation at Department of Neurosurgery of People's Liberation Army General Hospital from January 2009 to February 2015 were retrospectively analyzed. Of the 42 patients, 29 were males and 13 were females aging from 4 to 62 years (mean age 32.6 years). Preoperative assessment included functional magnetic resonance imaging and diffusion tensor imaging to identify the relationship between lesions and eloquent areas. The results of images were integrated into three-dimensional datasets to achieve intraoperative microscopic-based functional neuronavigation during AVM resection. Operations involved in motor areas and corticospinal tract were performed under continuous electrophysiological monitoring. ICG angiography was performed at pre-dissection, post-clipping of the feeders, and post-resection of the nidus. FLOW 800 software presented a color map and ICG intensity-time curve to demostrate the vascular architecture. Postoperative digital subtraction angiography was re-examined routinely to evaluate the extent of resection. Clinical outcomes were evaluated with the modified Rankin Scale. Results: All patients underwent surgery under intraoperative navigation. Of the 42 patients, total resection was achieved in 36 cases (85.7%, 36/42) including 14 cases of AVM in eloquent areas. A total of 40 ICG angiographies were successfully performed among 11 patients. Average number of ICG injections per operation was 3.6 (ranging from 3 to 6). Feeders were visualized in 10 patients and drainers were visualized in 9 cases. The post-surgical follow-up period varied from 3 months to 70 months (mean 22.5 months). 83.8% of the patients returned to normal work and life during the followed-up period. Conclusion: Combining intraoperative neuronavigation and electrophysiological monitoring, as well as fluorescent ICG angiography contribute to microsurgical resection of cerebral AVM effectively in selecting suitable patients, further avoiding neurologic compromise as well.