Kinetic pathway of HIV-1 TAR cotranscriptional folding

The Trans-Activator Receptor (TAR) RNA, located at the 5'-end untranslated region (5' UTR) of the human immunodeficiency virus type 1 (HIV-1), is pivotal in the virus's life cycle. As the initial functional domain, it folds during the transcription of viral mRNA. Although TAR's role in recruiting the Tat protein for trans-activation is established, the detailed kinetic mechanisms at play during early transcription, especially at points of temporary transcriptional pausing, remain elusive. Moreover, the precise physical processes of transcriptional pause and subsequent escape are not fully elucidated. This study focuses on the folding kinetics of TAR and the biological implications by integrating computer simulations of RNA folding during transcription with nuclear magnetic resonance (NMR) spectroscopy data. The findings reveal insights into the folding mechanism of a non-native intermediate that triggers transcriptional pause, along with different folding pathways leading to transcriptional pause and readthrough. The profiling of the cotranscriptional folding pathway and identification of kinetic structural intermediates reveal a novel mechanism for viral transcriptional regulation, which could pave the way for new antiviral drug designs targeting kinetic cotranscriptional folding pathways in viral RNAs.

Comparison of Efficacy and Safety of Different Second-line Therapies for Patients With Advanced Thymic Carcinoma

AIMS

Thymic carcinoma (TC) is a rare form of highly invasive tumors. Currently, the standard first-line therapy involves paclitaxel plus carboplatin treatment, while the recommended regimen for second-line therapy remains uncertain. The purpose of this study is to explore the second-line mode of TC patients.

MATERIALS AND METHODS

We evaluated the outcome of subjects with advanced TC between 2009 and 2023 in three medical centers, retrospectively. Tumor response was evaluated according to the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). Kaplan-Meier was used for calculating Progression-free survival (PFS) and overall survival (OS). The factors affecting survival in the real world were evaluated by Cox analysis.

RESULTS

Totally 136 patients were included in this study, the median PFS (mPFS) for all subjects was 5.97 months, and the median OS (mOS) was 25.03 months. According to patient's treatment modes, they are divided into monotherapy (n = 95) and combination therapy (n = 41), PFS manifested the difference between two groups (5.17 vs. 9.00 months, P = 0.043). OS also indicated a significant distinction (22.50 vs. 38.00 months, P = 0.017). Furthermore, there was a significant difference in PFS between patients using immunotherapy combined with chemotherapy and those with antivascular therapy (8.57 vs. 13.10 months, P = 0.047).

CONCLUSION

In the second-line therapy for advanced TC, the efficacy of combination therapy was better than monotherapy, especially for immunotherapy combined with antivascular therapy.

Early-life risk factors, accelerated biological aging and the late-life risk of mortality and morbidity

BACKGROUND

Early-life exposure increases health risks throughout an individual's lifetime. Biological aging is influenced by early-life risks as a key process of disease development, but whether early-life risks could accelerate biological aging and elevate late-life mortality and morbidity risks remains unknown. Knowledge is also limited on the potential moderating role of healthy lifestyle.

METHODS

We investigate associations of three early-life risks around birth, breastfeeding, maternal smoking and birth weight, with biological aging of 202 580 UK Biobank participants (54.9 ± 8.1 years old). Biological aging was quantified as KDM-BA, PhenoAge and frailty. Moderate alcohol intake, no current smoking, healthy diet, BMI <30 kg/m2 and regular physical activity were considered as healthy lifestyles. Mortality and morbidity data were retrieved from health records.

RESULTS

Individual early-life risk factors were robustly associated with accelerated biological aging. A one-unit increase in the 'early-life risk score' integrating the three factors was associated with 0.060 (SE=0.0019) and 0.036-unit (SE = 0.0027) increase in z-scored KDM-BA acceleration and PhenoAge acceleration, respectively, and with 22.3% higher odds (95% CI: 1.185-1.262) of frailty. Increased chronological age and healthy lifestyles could mitigate the accelerations of KDM-BA and PhenoAge, respectively. Associations of early-life risk score with late-life mortality and morbidity were mediated by biological aging (proportions: 5.66-43.12%). KDM-BA and PhenoAge accelerations could significantly mediate the impact on most outcomes except anxiety, and frailty could not mediate the impact on T2D.

CONCLUSION

Biological aging could capture and mediate the late-life health risks stemming from the early-life risks, and could be potentially targeted for healthy longevity promotion.

Causal relationship between cigarette smoking behaviors and the risk of hernias: a Mendelian randomization study

PURPOSE

As the global population continues to age, there is a noticeable yearly rise in the incidence of hernias. Simultaneously, smoking, a widespread addictive behavior and a significant contributor to mortality, has evolved into a pervasive public health concern. Existing literature has already established a connection between smoking and an increased risk of postoperative recurrence and postoperative infections following hernia surgery. However, there remains a dearth of research exploring the association between smoking and hernia morbidity. In this study, our objective is to systematically evaluate the causal relationship between cigarette smoking behaviors and hernia morbidity using a Mendelian randomization (MR) approach.

METHODS

Hernia-related data were sourced from the FinnGen Biobank database, while cigarette smoking behavior data were gathered from the GWAS and Sequencing Consortium of Alcohol and Nicotine Use. To assess the causal relationship, we employed five methods: the weighted median, the weighted mode the inverse variance weighted (IVW), MR-Egger, and the simple mode. Sensitivity analysis was conducted, incorporating Cochran's Q test, the MR-Egger intercept test, leave-one-out analysis, and funnel plot. The presentation of the causal relationship is expressed as an odds ratio (OR) along with their corresponding 95% confidence intervals (CI).

RESULTS

Employing the IVW method as the reference standard, we found that smoking intensity is associated with an increased risk of diaphragmatic hernia (OR = 1.21, 95% CI 1.00-1.46, P = 0.047). These consistent findings were further corroborated by the weighted median and weighted mode methods (OR = 1.26, 95% CI 1.03-1.54, P = 0.026; OR = 1.25, 95% CI 1.02-1.52, P = 0.045). Conversely, when applying the IVW method, we identified no statistically significant causal relationship between smoking age, smoking initiation status, smoking cessation status, and the incidence of hernia.

CONCLUSIONS

Our MR study has uncovered genetic evidence linking smoking intensity and the occurrence of diaphragmatic hernia. The risk of developing diaphragmatic hernia rises in tandem with the intensity of smoking. This emphasizes the crucial role of regularly advising patients to cease smoking in clinical settings.

[Use of the ETV6/RUNX1 probe to verify the performance of the fluorescence in situ hybridization probe before clinical detection]

Objective: To explore the standardized performance of a FISH probe before clinical detection. Methods: The probe sensitivity and specificity of ETV6/RUNX1 were analyzed via interphase and metaphase FISH in 20 discarded healthy bone marrow samples. The threshold system of the probe was established using an inverse beta distribution, and an interpretation standard was established. Finally, a parallel-controlled polymerase chain reaction detection study was conducted on 286 bone marrow samples from patients at our hospital. The clinical sensitivity, specificity, and diagnostic coincidence rate of ETV6/RUNX1 FISH detection were analyzed, and the diagnostic consistency of the two methods was analyzed by the kappa test. Results: The probe sensitivity and specificity of the ETV6/RUNX1 probe were 98.47% and 100%, respectively. When 50, 100, and 200 cells were counted, the typical positive signal pattern cutoffs were 5.81%, 2.95%, and 1.49%, respectively, and the atypical positive signal pattern cutoffs were 13.98%, 9.75%, and 6.26%, respectively. The clinical sensitivity of FISH was 96.1%, clinical specificity was 99.6%, diagnostic coincidence rate was 99.00%, diagnostic consistency test kappa value was 0.964, and P value was <0.001. Conclusion: For FISH probes without a national medical device registration certificate, standardized performance verification and methodology performance verification can be performed using laboratory developed test verification standards to ensure a reliable and accurate reference basis for clinical diagnosis and treatment.

Differentiation SELEX approach identifies RNA aptamers with different specificities for HIV-1 capsid assembly forms

The HIV-1 capsid protein (CA) assumes distinct assembly forms during replication, each presenting unique, solvent-accessible surfaces that facilitate multifaceted functions and host factor interactions. However, contributions of individual CA assemblies remain unclear, as the evaluation of CA in cells presents several technical challenges. To address this need, we sought to identify CA assembly form-specific aptamers. Aptamer subsets with different specificities emerged from within a highly converged, pre-enriched aptamer library previously selected to bind the CA hexamer lattice. Subsets were either highly specific for CA lattice or bound both CA lattice and CA hexamer. We further evaluated four representatives to reveal aptamer structural features required for binding, highlighting interesting features and challenges in aptamer structure determination. Importantly, our aptamers bind biologically relevant forms of CA and we demonstrate aptamer-mediated affinity purification of CA from cell lysates without virus or host modification. Thus, we have identified CA assembly form-specific aptamers that represent exciting new tools for the study of CA.

[Evaluation of the clinical manifestations of COVID-19 in patients with aplastic anemia undergoing immunosuppressive therapy: a prospective cohort study (NICHE)]

Objective: To investigate the clinical features of coronavirus disease 2019 (COVID-19) in patients with aplastic anemia (AA) undergoing immunosuppressive therapy (IST) . Methods: In this prospective cohort study, we collected the demographic and clinical data of patients with AA and COVID-19 from December 1, 2022, to January 31, 2023. We described the clinical features of COVID-19 among patients with AA and evaluated the effects of IST on the signs and severity of COVID-19. Results: A total of 170 patients with AA and COVID-19 were included. The common early symptoms, including fever, dizziness or headache, muscle or body aches, and sore throat, disappeared within 1-2 weeks. Approximately 25% of the patients had persistent fatigue within 2 weeks. Many patients experienced cough after an initial 1-3 days of infection, which lasted for more than 2 weeks. There were no differences in the duration of total fever episodes and maximum body temperature when patients were stratified according to whether or not they underwent IST, by IST duration, or by use of anti-lymphocyte globulin (ALG) (P>0.05). No differences were observed in the occurrence of symptoms in either the early or recovery stages when patients with AA were stratified according to whether or not they underwent IST, or by IST duration (P>0.05). However, patients who received ALG had fewer fever episodes within 1 week after infection (P=0.035) and more sore throat episodes within 2 weeks after infection (P=0.015). There were no other significant differences in clinical symptoms between patients who did and patients who did not receive ALG (P>0.05) . Conclusion: The majority of patients with AA and COVID-19 recovered within 2 weeks of noticing symptoms when treated with IST.

Effect of dietary lutein on the egg production, fertility, and oxidative injury indexes of aged hens

OBJECTIVE

The present study aimed to investigate the effect of dietary lutein on egg production, follicles, reproductive hormones, fertility, hatchability, and oxidative injury indexes of hens.

METHODS

Treatments consisted of a control diet (CON) and three lutein-supplementing diets at 25 (L1), 50 (L2), or 75 (L3) mg/kg of diet. Egg production was measured using 576 Arbor Acres breeder hens at 61 to 65 wk and follicles grades, reproductive hormones, fertility, hatchability, tissue lutein contents, and oxidative injury indexes were determined at 65 wk.

RESULTS

The results showed that at 65 wk, lutein- supplementing diets increased (p<0.05) egg production, follicular grades, fertility, hatchability, estradiol (E2), luteinizing hormone, progesterone (PROG), lutein content in the serum and yolk, compared to CON. L2 and L3 showed more pronounced (p<0.05) effects on egg production, PROG, and yolk lutein content than L1. With the increase of lutein doses from 25 to 75 mg/kg, there were linear increases (p<0.05) in egg production, lutein content, and PROG, and a quadratic trend (p<0.05) in E2. For the oxidative injury products, lutein-supplementing diets decreased (p<0.05) malondialdehyde (MDA) and protein carbonyl (PCO) in the serum, MDA and 8-hydroxy 2 deoxyguanosine (8-OHdG) in the yolk. There were linear decreases (p<0.05) in 8-OHdG in the serum, MDA, PCO, and 8-OHdG in the yolk, a quadratic trend (p<0.05) on serum 8-OHdG.

CONCLUSION

It is concluded that lutein supplementation can improve egg production and fertility by beneficially regulating reproductive hormones and oxidative status in aged hens.

[Value of Improved Mayo Endoscopic Score for evaluating treatment efficacy for active ulcerative colitis]

OBJECTIVE

To assess the value of Improved Mayo Endoscopic Score (IMES) for evaluation of treatment efficacy for active ulcerative colitis (UC).

METHODS

We retrospectively analyzed the clinical and endoscopic data of 103 patients diagnosed with active UC in Beijing Tsinghua Changgung Hospital from January, 2015 to December, 2020. The severity of endoscopic lesions was determined by Mayo Endoscopic Score and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the area of the endoscopic lesions was evaluated based on the Montreal classification system. The IMES was established by combining the MES with the Montreal classification.

RESULTS

Univariate analysis suggested that young patients (<40 years old), patients with extensive disease type (E3), patients with high endoscopic scores (MES=3, UCEIS>4, and IMES>4), and patients receiving advanced drug therapy (with systemic hormones, immunosuppressants, immunomodulators, and biological agents, etc.) had lower clinical and endoscopic remission rates. COX survival analysis showed that IMES≤4 was an independent risk factor for clinical and endoscopic remission. ROC curve indicated that the predictive value of IMSE≤4 for clinical and endoscopic remission (AUC=0.7793 and 0.7095, respectively; P<0.01) was better than that of Montreal (AUC=0.7357 and 0.6847, respectively; P<0.01), MES=2 (AUC=0.6671 and 0.5929, respectively; P<0.01), and UCEIS≤4 (AUC=0.6823 and 0.6459, respectively; P<0.01); IMES=5 had a better predictive value for patients with active UC undergoing colectomy tham E3 and MES=3.

CONCLUSION

IMES has good value in evaluating treatment efficacy for active UC.

[Genomics of next generation sequencing in pediatric B-acute lymphoblastic leukemia and its impact on minimal residual disease]

Objective: To describe the gene mutation profile of newly diagnosed pediatric B-acute lymphoblastic leukemia (B-ALL) and analyze its effect on minimal residual disease (MRD). Methods: A total of 506 newly diagnosed B-ALL children treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from September 2018 to July 2021 were enrolled in this retrospective cohort study. The enrolled children were divided into MRD ≥1.00% group and <1.00% group according to MRD results on the 19th day since chemotherapy, and MRD ≥0.01% group and <0.01% group according to MRD results on the 46th day. Clinical characteristics and gene mutations of two groups were compared. Comparisons between groups were performed with chi-square test or Fisher's exact test. Independent risk factors of MRD results on the 19th day and the 46th day were analyzed by Logistic regression model. Results: Among all 506 patients, there were 318 males and 188 females. On the 19th day, there were 114 patients in the MRD ≥1.00% group and 392 patients in the MRD <1.00% group. On the 46th day, there were 76 patients in the MRD ≥0.01% group and 430 patients in the MRD <0.01% group. A total of 187 gene mutations were detected in 487 (96.2%) of 506 children. The most common gene mutations were signal transduction-related KRAS gene mutations in 111 cases (22.8%) and NRAS gene mutations in 99 cases (20.3%). Multivariate analysis showed that PTPN11 (OR=1.92, 95%CI 1.00-3.63), KMT2A (OR=3.51, 95%CI 1.07-11.50) gene mutations and TEL-AML1 (OR=0.48, 95%CI 0.27-0.87), BCR-ABL1 (OR=0.27, 95%CI 0.08-0.92) fusion genes and age >10 years (OR=1.91, 95%CI 1.12-3.24) were independent influencing factors for MRD ≥1.00% on the 19th day. BCORL1 (OR=2.96, 95%CI 1.18-7.44), JAK2 (OR=2.99, 95%CI 1.07-8.42) and JAK3 (OR=4.83, 95%CI 1.50-15.60) gene mutations and TEL-AML1 (OR=0.43, 95%CI 0.21-0.87) fusion gene were independent influencing factors for MRD ≥0.01% on the 46th day. Conclusions: Children with B-ALL are prone to genetic mutations, with abnormalities in the RAS signaling pathway being the most common. Signal transduction related PTPN11, JAK2 and JAK3 gene mutations, epigenetic related KMT2A gene mutation and transcription factor related BCORL1 gene mutation are independent risk factors for MRD.

Alleviating effect of mulberry leaf 1-deoxynojirimycin on resistin-induced hepatic steatosis and insulin resistance in mice

Resistin is upregulated in obese humans and mice, and elevated serum resistin induces insulin resistance and hepatic steatosis. Previous studies have revealed that mulberry 1-deoxynojirimycin (DNJ) is important for a variety of physiological processes, especially carbohydrate and lipid metabolism. However, it remains unclear whether DNJ has a positive effect on insulin resistance and hepatic steatosis, and what the exact mechanism is. Male C57BL/6J mice were treated with resistin with or without DNJ. DNJ reversed the homeostasis model assessment of insulin resistance (HOMA-IR)-induced by resistin and significantly decreased triglyceride levels both in the serum and liver. A histological analysis demonstrated that lipid accumulation significantly decreased in the DNJ group compared to the resistin group. A mechanistic analysis showed that DNJ significantly inhibited the resistin-induced decline in enzyme activities of hormone-sensitive lipase (HSL) and hepatic lipase (HL) in serum and lipoprotein lipase (LPL) in liver. FAS and Acox13α were significantly altered by resistin but restored by DNJ. Furthermore, DNJ partially but significantly restored insulin-stimulated glucose uptake compared with the resistin group, suggesting that DNJ reversed the insulin sensitivity impaired by hyperresistinemia. Treatment of AML12 cells with DNJ significantly restored the expression level and phosphorylation of Akt. The transcriptional levels of InsR and IRS1, as well as the protein levels of InsR and Glut4 and phosphorylation of PI3K and GSK3β, were also normalized in the DNJ-treated group. In conclusion: mulberry DNJ significantly alleviated liver steatosis and insulin resistance in hyperresistinemia.

Predictive model for deep venous thrombosis caused by closed lower limb fracture after thromboprophylactic treatment

OBJECTIVE

Currently, there are still no convincing clinical models predicting closed lower extremity fracture-associated deep vein thrombosis in patients treated through thromboprophylactic methods. We aimed at using two retrospective cohorts to develop and externally verify a clinical prediction model for deep vein thrombosis in patients treated with anticoagulants after suffering closed lower extremity fractures.

PATIENTS AND METHODS

We evaluated the patients' pre- and post-operatively, to accurately determine the predictive power of the biomarkers and clinical risk factors. Two retrospective cohorts were used for the development and external verification of a pre-operative clinical prediction model (development: n = 2,253; verification: n = 833) and post-operative clinical prediction model (development: n = 1,422; verification: n = 449), respectively.

RESULTS

The C-indices were used to show the predicted incidence of objective thrombosis at the pre- and post-operative stage, which were then compared with the observed incidence of thrombosis in both cohorts. Biomarkers and clinical indicators were included in pre- and post-operative nomograms, which were adequately calibrated in both cohorts. The cross-validated C-indices of the pre- and post-operative clinical prediction models in the verification cohort were 0.706 (95% Cl, 0.67-0.74) and 0.875 (95% Cl, 0.84-0.91), respectively.

CONCLUSIONS

We present our findings of novel pre- and post-operative nomograms for the prediction of deep venous thrombosis in patients who received thromboprophylaxis after suffering closed lower extremity fractures.

Exceptional spectrum and dynamic magnetization

A macroscopic effect can be induced by a local non-Hermitian term in a many-body system, when it manifests simultaneously level coalescence of a full real degeneracy spectrum, leading to exceptional spectrum. In this paper, we propose a family of systems that support such an intriguing property. It is generally consisted of two arbitrary identical Hermitian sub-lattices in association with unidirectional couplings between them. We show exactly that all single-particle eigenstates coalesce in pairs even only single unidirectional coupling appears. It means that all possible initial states obey the exceptional dynamics, resulting in some macroscopic phenomena, which never appears in a Hermitian system. As an application, we study the dynamic magnetization induced by complex fields in an itinerant electron system. It shows that an initial saturated ferromagnetic state at half-filling can be driven into its opposite state according to the dynamics of high-order exceptional point. Any Hermitian quench term cannot realize a steady opposite saturated ferromagnetic state. Numerical simulations for the dynamical processes of magnetization are performed for several representative situations, including lattice dimensions, global random and local impurity distributions. It shows that the dynamic magnetization processes exhibit universal behavior.

[Improved Mayo Endoscopic Score has a higher value for evaluating clinical severity of ulcerative colitis]

OBJECTIVE

To assess the value of Improved Mayo Endoscopic Score (IMES) for evaluation of the clinical severity of ulcerative colitis (UC).

METHODS

We retrospectively analyzed the clinical and endoscopic data of 167 patients diagnosed with UC in Beijing Tsinghua Changgung Hospital from January, 2015 to November, 2021. The severity of endoscopic lesions was determined by Mayo Endoscopic Score (MES, 0-3 points) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score (0-8 points), and the scope of endoscopic lesions was evaluated based on the Montreal classification system. The IMES was established by combining the MES with the Montreal classification.

RESULTS

The IMSE showed stronger correlations with modified Truelove and Witts Disease Severity, Mayo score and partial Mayo score (r=0.712, 0.784, and 0.703, respectively) than MES (r=0.642, 0.754, and 0.604, respectively), Montreal classification (r=0.598, 0.628, and 0.603, respectively) and UCEIS (r= 0.670, 0.767, and 0.677, respectively). ROC curve analysis showed that IMES was superior to MES, Montreal and UCEIS in diagnosis of severe and moderate- to-severe UC. IMES also showed stronger correlations with the laboratory indicators including CRP (r=0.583), WBC (r=0.235), HB (r=-0.280), PLT (r=0.352), ALB (r=-0.396) and ESR (r=0.471) than MES and Montreal classification. An IMES score of 5 was of greater value than a MES score of 3, E3, and UCEIS≥6 for predicting the administration of systemic hormones, immunosuppressants, or surgery in the near future.

CONCLUSION

IMES can better reflect the clinical severity of UC and has good correlations with the laboratory indicators of the patients.

[Juglone induces proliferation inhibition and apoptosis of cervical cancer cells via promoting c-Myc ubiquitination]

OBJECTIVE

To observe the expression of c-Myc protein in cervical cancer HeLa cells and explore the effect of juglone on the proliferation and apoptosis of HeLa cells by affecting c-Myc ubiquitination.

METHODS

HeLa cells treated with different concentrations (0, 10, 20, or 50 μmol/L) of juglone or with 20 μmol/L juglone for different time lengths were examined for expression of c-Myc protein with Western blotting. The half-life of c-Myc protein was determined using cycloheximide (CHX) and c-Myc protein degradation was detected using coimmunoprecipitation. We also assessed the effects of 20 μmol/L juglone combined with 0, 1.0 or 2.0 μmol/L MG132 (a proteasome inhibitor) on c-Myc expression. The effects of 20 μmol/L juglone on the proliferation and apoptosis of HeLa cells with RNA interference-mediated knockdown of c-Myc were evaluated with MTT assay and flow cytometry.

RESULTS

Treatment with juglone significantly lowered c-Myc protein expression in HeLa cells in a concentration-and time-dependent manner (P < 0.05). Juglone obviously shortened the half-life of c-Myc protein, and the addition of MG132 significantly up-regulated the expression level of c-Myc protein (P < 0.05). Juglone treatment also promoted ubiquitination of c-Myc protein in HeLa cells. Compared with the cells transfected with a negative control construct, the cells transfected with si-c-Myc showed significantly decreased proliferation inhibition and a lowered cell rate with early apoptosis after juglone treatment (P < 0.05).

CONCLUSION

Juglone inhibits proliferation and promotes apoptosis of HeLa cells by affecting the ubiquitination of c-Myc protein.

From "blood transfusion" to "hematopoiesis": watershed eco-compensation in China

At present, the number of watershed eco-compensations in China is increasing. And the area covered by a single project is also increasing. Under the current model, governments are the primary source of funding. It is difficult to meet the growing funding gap of subsidies. Researches on watershed eco-compensation need to reform and explore a new model for it, expand the fund source of watershed eco-compensation expense, and establish a sustainable "hematopoietic" model. This paper clarifies the concept of watershed eco-compensation and then compares the design principles of eco-compensation projects, definitions of stakeholders, analysis, and summary of watershed eco-compensation models in different regions. It can be found that the model in which the government dominates is still the mainstream. However, the considerable cost of this model will be a heavy burden for governments. Therefore, it becomes an important option to involve more stakeholders in these projects, and governments should transfer part of the lead to dilute costs. How to reduce the expenditures of governments in watershed eco-compensation projects under the premise of maintaining normal operation of the projects has become an important exploration direction concerning watershed eco-compensation in China, which requires transforming from "blood transfusion" to "hematopoiesis."

Differentiation Trajectory of Limbal Stem and Progenitor Cells under Normal Homeostasis and upon Corneal Wounding

Limbal stem cells (LSCs) reside discretely at limbus surrounded by niche cells and progenitor cells. The aim of this study is to identify the heterogeneous cell populations at limbus under normal homeostasis and upon wounding using single-cell RNA sequencing in a mouse model. Two putative LSC types were identified which showed a differentiation trajectory into limbal progenitor cell (LPC) types under normal homeostasis and during wound healing. They were designated as “putative active LSCs” and “putative quiescent LSCs”, respectively, because the former type actively divided upon wounding while the later type stayed at a quiescent status upon wounding. The “putative quiescent LSCs” might contribute to a barrier function due to their characteristic markers regulating vascular and epithelial barrier and growth. Different types of LPCs at different proliferative statuses were identified in unwounded and wounded corneas with distinctive markers. Four maturation markers (Aldh3, Slurp1, Tkt, and Krt12) were screened out for corneal epithelium, which showed an increased expression along the differentiation trajectory during corneal epithelial maturation. In conclusion, our study identified two different types of putative LSCs and several types of putative LPCs under normal homeostasis and upon wounding, which will facilitate the understanding of corneal epithelial regeneration and wound healing.

Targeted inhibition of STAT3 induces immunogenic cell death of hepatocellular carcinoma cells via glycolysis

In hepatocellular carcinoma (HCC), the signal transducer and activator of transcription 3 (STAT3) is present in an overactive state that is closely related to tumour development and immune escape. STAT3 inhibition reshapes the tumour immune microenvironment, but the underlying mechanisms have not been fully clarified. We found that STAT3 inhibition could induce immunogenic cell death (ICD) of HCC cells via translocation of the “eat me” molecule calreticulin to the cell surface and a significant reduction in the expression of the “don’t eat me” molecule leucocyte surface antigen CD47. STAT3 inhibition promoted dendritic cell (DC) activation and enhanced the recognition and phagocytosis of HCC cells by macrophages. Furthermore, STAT3 inhibition prevented the expression of key glycolytic enzymes, facilitating the induction of ICD in HCC. Interestingly, STAT3 directly regulated the transcription of CD47 and solute carrier family 2 member 1 (SLC2A1; also known as GLUT1). In subcutaneous and orthotopic transplantation mouse tumour models, the STAT3 inhibitor napabucasin prevented tumour growth and induced the expression of calreticulin and the protein disulfide isomerase family A member 3 (PDIA3; also known as ERp57) but suppressed that of CD47 and GLUT1. Meanwhile, the amount of tumour‐infiltrated DCs and macrophages increased, along with the expression of costimulatory molecules. More CD4⁺ and CD8⁺ T cells accumulated in tumour tissues, and CD8⁺ T cells had lower expression of checkpoint molecules such as lymphocyte activation gene 3 protein (LAG‐3) and programmed cell death protein 1 (PD‐1). Significantly, the antitumour immune memory response was induced by treatment targeting STAT3. These findings provide a new mechanism for targeting STAT3‐induced ICD in HCC, and confirms STAT3 as a potential target for the treatment of HCC via reshaping the tumour immune microenvironment.

POS0330 DIFFERENCES IN GUT MICROBIOTA ASSOCIATED WITH LYMPHOCYTE SUBSETS, CYTOKINES AND DISEASE ACTIVITY IN ANKYLOSING SPONDYLITIS

Background

Ankylosing spondylitis (AS), a common chronic inflammatory disease, is a prototype of spondyloarthritis affecting sacroiliac joints and spine with or without peripheral arthritis and other systemic symptoms[1]. Environmental factors, especially microorganisms have been suggested to implicate with AS pathogenesis[2].

Objectives

Utilizing 16S rRNA genes sequencing on the feces of untreated AS patients and healthy controls (HCs), our study aimed to provide an in-depth understanding of AS gut microbiota and identifying a feasible diagnostic strategy for AS.

Methods

Fecal samples were collected from 62 AS patients and 62 age-and-gender- matched HCs. Microbial genome was extracted from approximately 250mg fresh fecal samples from all participants using QIAamp PowerFecal DNA Kit (Qiagen). The V3-V4 variable regions of bacterial 16S rRNA genes were sequenced with the Illumina Miseq PE300 system. QIIME2 based pipeline was used to process the raw sequence data. Alpha and beta diversities were assessed using result from QIIME2, and comparisons of gut microbiome profile were performed using linear discriminant analysis (LDA) effect size (LEfSe) to examine differences between AS and HCs. R (version 4. 0.1) was used for comparative statistics, and pearson’s correlation was used to assess the correlations between the relative abundances of bacterial genera and clinical parameters; correlations with p<0.05 were considered significant.

Results

AS for alpha-diversity, ACE and Chao1 indices were lower in AS compared with those HCs(Figure 1A, p<0.05), though no significant differences observed in Shannon and Simpson index. Bray curtis distance-based beta-diversity analysis revealed significant differences in the microbial community between AS and HCs (Figure 1B, p=0.003, ANOSIM). Fecal microbial communities in AS differed significantly from those in HCs, driven by higher abundances of Escherichia-Shigella, Turicibacter, Enterococcus, et al. and a lower abundance of Agathobacter, Roseburia, Eubacterium_eligens_group, et al (Figure 1C, p<0.05). There was a significant positive correlation between ESR and Klebsiella, Butyricicoccus, Roseburia, CRP and Faecalibacterium, Muribaculaceae, ASDAS-CRP score and Faecalibacterium, Ruminococcus, total lymphocyte cells and Agathobacter, Ruminococcus, T cell and Agathobacter, CD4+T cell and Agathobacter, B cell and Agathobacter, Streptococcus, Th1 and Prevotella, CAG−352, Th2 and Agathobacter, Th17 and Prevotella, Agathobacter, IL-2 and Agathobacter, IL-4 and Agathobacter, IL-6 and Lachnospiraceae_UCG−004, Muribaculaceae, IL-17 and Eubacterium_hallii_group, IFN-gama and Phascolarctobacterium.There were negative correlations between total lymphocytes and Escherichia−Shigella, CD4+T cell and Enterobacteriaceae, Th2 cell and Escherichia−Shigella, IL-10 and CAG−352, Ruminococcus (Figure 2, p<0.05).

Figure 1.

Feature of gut microbiota in AS patients and HCs. (A) Alpha-diversity assessed by richness (Chao1, ACE) and diversity (Shannon, Simpson), Median estimates compared across cohorts. (B) PCoA plot based on the Bray curtis distance of gut microbiota samples from AS patients vs. HC group(p=0.003, ANOSIM). (C) Panel demonstrated the average relative abundance of different genus in AS and HCs. (D) Distribution of gut microbiota at genus level.

Figure 2.

Correlations between the relative abundance of significantly different bacteria and clinical variables. *p<0.05, **p < 0.01, ***p <0 .001, ****p < 0.0001.

Conclusion

Human gut microbiome in patients with AS differed from that of the HCs. Characters of bacteria communities were associated with disease activity.

References

[1]Simone D, Al Mossawi M H, Bowness P. Progress in our understanding of the pathogenesis of ankylosing spondylitis [J]. Rheumatology (Oxford), 2018, 57(suppl_6): vi4-vi9.

[2]Zhou C, Zhao H, Xiao X Y, et al. Metagenomic profiling of the pro-inflammatory gut microbiota in ankylosing spondylitis [J]. J Autoimmun, 2020, 107(102360.

Acknowledgements

This project was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

POS1081 SERUM MPO-DNA COMPLEX LEVEL CORRELATES WITH DISEASE ACTIVITY IN PSORIATIC ARTHRITIS

Background

NETosis has been found to participate in the pathogenesis of many autoimmune diseases, however rarely reported in psoriatic arthritis (PsA).

Objectives

We aimed to explore the involvement of NETosis in the inflammation of PsA.

Methods

Serum MPO-DNA complex was detected by a modified enzyme-linked immunosorbent assay (ELISA) and compared among 74 patients with PsA, 58 patients with psoriasis (PsO) and 20 healthy controls. The association of MPO-DNA level with disease activity index at baseline and follow-up was analyzed in PsA patients. Receiver operating characteristic curve was used to evaluate the predictive value of MPO-DNA for treatment response.

Results

MPO-DNA complex level in serum was significantly increased in PsA/PsO patients compared to healthy controls (p<0.001). The level of MPO-DNA was positively associated with DAPSA score and its components (including TJC, SJC, PGA, EGA, VAS-pain and CRP, r=0.25-0.409, all p-value<0.05). Serum MPO-DNA level was downregualted at 12-week after treatment compared to baseline (p=0.022). The decrease of MPO-DNA level was more dramatic in PsA patients who achieved both ACR50 and PASI50 response than those achieving neither of them at 12 weeks (p=0.023). ROC analysis revealed that the serum MPO-DNA level predicted both ACR50 and PASI50 achievement at week 12 (p=0.04, 95% CIs 0.56-0.94). Moreover, the baseline MPO-DNA level (p=0.009, 95% CIs 0.748-1) and change of MPO-DNA at week 12 from baseline (p=0.004, 95% CIs 0.802-1) were associated with the achievement of both ACR70 and PASI75 response.

Conclusion

NETosis plays an important role in psoriatic diseases. The level of MPO-DNA complex in serum reflects disease activity. Serum MPO-DNA complex may be a useful biomarker to predict the therapeutic response in PsA.

Table 1.

Treatment response and changes of serum MPO-DNA of 29 PsA patients.

ItemsBaseline12 weeks24weeksTJC, median (IQR)3(7)3(4)2(3.5)SJC, median (IQR)2(5)2(2)1(3)ESR, median (IQR) mm/h13(15)8(10)10(14)CRP, median (IQR) mg/L3(10.2)†2.6(3.72)2.3(3.8)PGA, median (IQR)40(30)*††20(30)††10(17.5)EGA, median (IQR)30(20)††20(10)††10(20.4)VAS-pain, median (IQR)30(30)*††20(20)††10(10)PASI, median (IQR)2.8(6.2)*†0.7(1.5)0.35(1.55)DAPSA, median (IQR)15(15.1)†8.4(8.4)6.15(10.3)MPO-DNA, median (IQR)0.416(0.615)*0.231(0.321)-Minimal disease activity, n (%)4(13.7%)6(20.6%)12(41.3%)ACR50, n (%)-13(44.8%)15(51.7%)PASI50, n (%)-14(48.2%)17(58.6%)ACR70, n (%)-4(13.7%)7(24.1%)PASI75, n (%)-11(37.9%)14(48.2%)Both ACR50PASI50, n (%)-8(27.5%)13(44.8%)Both ACR70PASI75, n (%)-3(10.3%)5(17.2%)Figure 1.

ROC curves for predictions of treatment achievements at 12 and 24weeks.

Disclosure of Interests

None declared

POS0315 DIAGNOSTIC PERFORMANCE OF CASPAR CRITERIA FOR PSORIATIC ARTHRITIS WITH OR WITHOUT INTEGRATION OF ULTRASOUND

Background

Although the CASPAR criteria in the diagnosis of psoriatic arthritis (PsA) have been validated, CASPAR based on physical examination (PE) is not “gold standard”. The ultrasound (US) could improve the diagnostic accuracy as compared to clinical examination alone.

Objectives

To evaluate the diagnostic performance of CASPAR criteria for psoriatic arthritis (PsA) with or without integration of ultrasound (US).

Methods

The patients with hint of PsA were enrolled. Tender and swollen joint counts, presents of enthesitis and dactylitis were collected by physical examination (PE). US was performed to evaluate peripheral joints, entheses and tendons. The additional value of US to CASPAR criteria were analysed.

Results

326 consecutive patients were enrolled, with 164 PsA and 162 non-PsA. Significantly higher frequencies of tenosynovitis and enthesitis on US and new bone formation on X-ray were found in PsA than non-PsA patients (56.7% vs. 13.0%; 62.2% vs. 14.2%; 62.2% vs. 8.0%, p<0.01 for all). Logistic regression analysis showed that dactylitis (OR=12.0, p<0.01), family history of PsO/PsA (OR=3.1, p<0.05), nail involvement (OR=3.5, p=0.01), new bone formation (OR=14.8, p<0.01) and tenosynovitis on US (OR=21.3, p<0.01), enthesitis on US (OR=21.7, p<0.01) were independent risk factors for PsA. Adding US tenosynovitis and/or enthesitis to CASPAR criteria showed better performance by improving the specificity (91.4% vs. 67.9%) and meanwhile keeping sensitivity (92.1% vs. 96.3%). When replacing hand X-ray by US in CASPAR criteria, the sensitivity and specificity were comparable to CASPAR criteria adding with US. The diagnostic accuracy was 82.2% for CASPAR criteria based on PE, 91.7% for CASPAR integrated with US, and 91.4% for CASPAR with US to replace X-ray.

Conclusion

CASPAR criteria based on US improve the diagnosis utility of PsA than CASPAR criteria based on PE. US assessment is valuable in the diagnosis of PsA.

References

[1]Fiorenza A, Bonitta G, Gerratana E, et al. Assessment of enthesis in patients with psoriatic arthritis and fibromyalgia using clinical examination and ultrasound. Clinical and experimental rheumatology 2020;38 Suppl 123:31-9.

[2]Zabotti A, Bandinelli F, Batticciotto A, et al. Musculoskeletal ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review. Rheumatology (Oxford) 2017;56:1518-32.

Figure 1.

ROC curves for adding US or substituting X-ray by US in CASPAR criteria. Receiver operating characteristic (ROC) curve illustrates the diagnosis performance of CASPAR criteria adding US or substituting X-ray by US in CASPAR criteria and CASPAR criteria based on PE alone. The area under the curve of the ROC curve (AUC) was 0.929 (95%CI 0.897, 0.961) (p<0.01) for adding US to CASPAR criteria. AUC was 0.908 (95%CI 0.876, 0.940) (p<0.01) for CASPAR criteria based on PE. And AUC was 0.916 (95%CI 0.880, 0.951) (p<0.01) for substituting X-ray by US in CASPAR criteria. CASPAR: ClASsification criteria for Psoriatic ARthritis; PE: physical examination; US: ultrasound.

Disclosure of Interests

None declared

Unexpected Parabolic Temperature Dependency of CH4 Emissions from Rice Paddies

Global warming is expected to affect methane (CH₄) emissions from rice paddies, one of the largest human-induced sources of this potent greenhouse gas. However, the large variability in warming impacts on CH₄ emissions makes it difficult to extrapolate the experimental results over large regions. Here, we show, through meta-analysis and multi-site warming experiments using the free air temperature increase facility, that warming stimulates CH₄ emissions most strongly at background air temperatures during the flooded stage of ∼26 °C, with smaller responses of CH₄ emissions to warming at lower and higher temperatures. This pattern can be explained by divergent warming responses of plant growth, methanogens, and methanotrophs. The effects of warming on rice biomass decreased with the background air temperature. Warming increased the abundance of methanogens more strongly at the medium air temperature site than the low and high air temperature sites. In contrast, the effects of warming on the abundance of methanotrophs were similar across the three temperature sites. We estimate that 1 °C warming will increase CH₄ emissions from paddies in China by 12.6%─substantially higher than the estimates obtained from leading ecosystem models. Our findings challenge model assumptions and suggest that the estimates of future paddy CH₄ emissions need to consider both plant and microbial responses to warming.

Retraction Note: A candidate Chinese medicine preparation-Fructus Viticis Total Flavonoids inhibits stem-like characteristics of lung cancer stem-like cells

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12906-022-03569-2.

An RNA aptamer that shifts the reduction potential of metabolic cofactors

The discovery of ribozymes has inspired exploration of RNA's potential to serve as primordial catalysts in a hypothesized RNA world. Modern oxidoreductase enzymes employ differential binding between reduced and oxidized forms of redox cofactors to alter cofactor reduction potential and enhance the enzyme's catalytic capabilities. The utility of differential affinity has been underexplored as a chemical strategy for RNA. Here we show an RNA aptamer that preferentially binds oxidized forms of flavin over reduced forms and markedly shifts flavin reduction potential by -40 mV, similar to shifts for oxidoreductases. Nuclear magnetic resonance structural analysis revealed π-π and donor atom-π interactions between the aptamer and flavin that cause unfavorable contacts with the electron-rich reduced form, suggesting a mechanism by which the local environment of the RNA-binding pocket drives the observed shift in cofactor reduction potential. It seems likely that primordial RNAs could have used similar strategies in RNA world metabolisms.

The Burden of Colorectal Cancer Attributable to Diet Low in Fiber from 1990 to 2019: A Global, Regional and National Analysis

OBJECTIVES

The colorectal cancer (CRC) burden is increasingly high. The aim of this study was to investigate temporal and geographical trends in CRC deaths and disability-adjusted life-years (DALYs) attributable to diet low in fiber globally from 1990 to 2019.

DESIGN

Cross-sectional study.

SETTING

The study based on the Global Burden of Disease Study (GBD) 2019.

PARTICIPANTS

The population comprised individuals from 204 countries and territories who were diagnosed with CRC attributable to diet low in fiber from 1990 to 2019.

MEASUREMENTS

Deaths, DALYs, age-standardized mortality rates (ASMR), and age-standardized DALY rates (ASDR) for CRC attributable to diet low in fiber were described, and estimated annual percentage change (EAPC) was further calculated to assess the burden in different regions, countries, sexes, and age groups. Additionally, we explored the association between EAPC and ASMR/ASDR (in 1990) and Human Development Index (HDI, in 2019).

RESULTS

From 1990 to 2019, global ASMR and ASDR for CRC attributable to diet low in fiber decreased slightly, but the corresponding deaths and DALYs increased by 63.37% and 51.36%, respectively. Those burden varied considerably between regions and countries. The burden was higher in high, high-middle and middle SDI regions, especially in Asia and Western Europe, but when HDI > 0.7, an increasingly rapid decline in ASMR and ASDR was revealed. Unexpectedly, many less well-developed countries within the traditionally low deaths and DALYs regions of Africa, Central Latin America, and Middle East showed gradual increases in ASMR and ASDR.

CONCLUSION

The global burden of CRC attributable to diet low in fiber has decreased over the last 30 years, but remains at a high level. It is essential for decision-makers to take targeted measures for improving population awareness and intake of dietary fiber.

Human Hepatocyte Transduction with Adeno-Associated Virus Vector

As the adeno-associated virus (AAV) vectors hold unique advantages over other viral vectors, AAV gene therapy has accumulated rapid progress and development. Liver-targeted gene therapy by AAV vectors has been successfully applied in clinical trials for many diseases. Low transduction efficiency and high prevalence of neutralizing antibodies (Nabs), however, are the major obstacles to further translate this therapeutic strategy into clinical trials. Pre-clinical evaluation on hepatocytes could help to elucidate the tropism of AAV serotypes for liver-targeted gene therapy, and could also provide a test model to develop novel AAV mutants with Nabs evasion and high liver tropism. Here, we described the basic laboratory procedure to apply the AAV vector to transduce human hepatocytes in vitro and in vivo with some tips gained from our own experience.

Comparison of different methods to isolate mouse limbal epithelial cells

Limbal stem cells (LSCs) are the stem cell reservoir for corneal epithelium. The protocol to isolate LSCs from human cornea has been examined and optimized. However, the isolation protocol has not been optimized for mouse cornea, which is crucial for the downstream cell analysis. Here we compared four different isolation methods evolved from the previous reports to obtain mouse limbal epithelial cells which are heterogeneous and contain LSCs in a single-cell suspension: (1) the dissected limbal rim was cut into pieces and digested by 10-cycle incubation in trypsin; (2) after the removal of corneal epithelium by a rotating bur, the remaining eyeball was incubated in dispase at 4 °C for overnight to obtain limbal epithelial sheet, followed by trypsin digestion into a single-cell suspension; (3) same as method 2 except that the incubation was in dispase at 37 °C for 2h and an additional collagenase incubation at 37 °C for 20 min; (4) same as method 3 except that the corneal epithelium was punctured by a 1.5 mm trephine instead of being removed by a rotating bur. Method 1 showed the lowest cell yield, the lowest percentage of single cells, and the lowest number of limbal epithelial stem/progenitor cells in the harvested cells among the four methods, thus not a recommended protocol. Method 2, 3, and 4 isolated a comparable number of K14⁺ and p63α-bright stem/progenitor cells per eye. The remaining eye globe after cell collection in the three methods showed a complete removal of limbal epithelium albeit different extent of corneal and limbal stromal digestion. Among the three methods, method 2 showed a higher cell viability than method 4; method 3 yielded the lowest cell number; method 4 led to the highest percentage of single cells in cell suspension. Results suggest that method 2, 3, and 4 are preferred methods to isolate heterogeneous-LSCs from mouse corneas.

P–728 Can in couples with unexplained infertility the use of a prediction model to triage assisted reproduction technology save costs?

Study question

Can in couples with unexplained infertility a prognosis-tailored management strategy, that delays treatment if natural conception prospects are good, reduce costs without affecting live-birth rate?

Summary answer

In couples with unexplained infertility, use of a prognostic tool for natural conception followed by expectant management in good-prognosis couples is cost-effective.

What is known already

Few countries have guidelines for the assessment of the likelihood of natural conception to determine access to publicly funded ART. In the Netherlands and New-Zealand, couples with unexplained infertility who have a good prognosis for natural conception are encouraged to delay starting ART. However, the cost-effectiveness of this prognosis-tailored treatment strategy has not been determined.

Study design, size, duration

We studied couples with unexplained infertility to compare a prognosis-tailored strategy to care-as-usual. In the prognosis-tailored strategy, couples were assessed using Hunault’s prediction model. In good-prognosis couples (12-months natural conception &gt;40%), outcomes without ART were modelled by censoring observations after start of ART. We then assumed that poor-prognosis couples (&lt;40% natural conception) were treated, while good-prognosis couples delayed the start of treatment for 12 months. Data for the care-as-usual model were based on real observations.

Participants/materials, setting, methods

We studied 272 couples with unexplained infertility. Costs of in vitro fertilisation (IVF) and intra-uterine insemination (IUI) were calculated based on the out-of-pocket costs and Australian Medicare costs. In a cost-effectiveness model, we compared costs and effects of both strategies.

Main results and the role of chance

The prognostic model classified 272 couples with unexplained infertility as favourable (N = 107 (39.3%) or unfavourable prognosis (N = 165 (60.7%)) for natural conception. In the prognosis-tailored strategy, the cumulative live-birth rate was 71.1% (95% CI 64.7% - 76.4%) while the number of ART cycles was 393 (353 IVF; 40 IUI). In care-as-usual strategy, the cumulative conception rate leading to live-birth for the cohort of 272 couples, who underwent a total of 398 IVF cycles and 48 IUI cycles, was 72.1% (95% CI 65.7% - 77.4%). Mean time to conception leading to live birth was 388 days in the prognosis-tailored strategy and 419 days in the care-as-usual strategy.

This translated for the 272 couples into potential savings of 45 IVF cycles and eight IUI cycles, which cost a total of AUD$ 125,817 for out-of-pocket and AUD$ 264,497 for Australian Medicare. The average cost savings per couple was AUD$ 1,435 (out-of-pocket AUD$ 463 per couple and Australian Medicare AUD$ 962 per couple). The incremental cost-effectiveness ratio, which was calculated as the total costs per additional live-births, was AUD$ 143,497 per additional live birth.

Limitations, reasons for caution

This study was limited to couples at a single IVF clinic. The modelling was also based on several key assumptions, particularly the number of fresh and frozen embryo transfer cycles for each couple.

Wider implications of the findings: Our results show that in couples with unexplained infertility the use of a prognostic model guiding the start of an IVF-treatment reduces costs without compromising live birth rates.

Trial registration number

Not applicable

The efficacy and safety of dupilumab in Chinese patients with moderate-to-severe atopic dermatitis: a randomized, double-blind, placebo-controlled study

BACKGROUND

Dupilumab is an antibody against interleukin 4 receptor α, used in treating atopic dermatitis (AD).

OBJECTIVES

To evaluate the efficacy and safety of dupilumab in adult Chinese patients with moderate-to-severe AD.

METHODS

In this randomized, double-blind, placebo-controlled, parallel-group, phase III study, conducted between December 2018 and February 2020, patients with AD received dupilumab (300mg) or placebo once every 2 weeks for 16 weeks, and were followed up for 12 weeks. The primary efficacy endpoint was the proportion of patients with both Investigator's Global Assessment (IGA) score of 0-1 and a reduction from baseline of ≥2 points at week 16.

RESULTS

Overall, 165 patients (mean age: 30.6 years; 71.5% male) were randomized: 82 to dupilumab and 83 to placebo. At week 16, 26.8% of patients in the dupilumab group and 4.8% of patients in the placebo group achieved the primary endpoint (difference, 22.0%; 95% confidence interval [CI], 11.37-32.65%; p<0.0001). Compared with placebo, higher proportions of patients in the dupilumab group achieved ≥75% reduction in the Eczema Area and Severity Index score (57.3% vs 14.5%; difference, 42.9%; 95% CI, 29.75-55.97%; p<0.0001) and had ≥3-point (52.4% vs 9.6%; difference, 42.8%; 95% CI, 30.26-55.34%; p<0.0001) and ≥4-point (39.0% vs 4.8%; difference, 34.2%; 95% CI, 22.69-45.72%; p<0.0001) reductions in weekly average daily peak daily pruritus numerical rating scale scores. The incidence of TEAEs during the treatment period was similar in the two groups. The incidence of conjunctivitis, allergic conjunctivitis, and injection site reaction was higher in the dupilumab group than in the placebo group.

CONCLUSIONS

In adult Chinese patients, dupilumab was effective in improving the signs and symptoms of AD and demonstrated a favorable safety profile.

Localization transitions and mobility edges in quasiperiodic ladder

We investigate localization properties of two-coupled uniform chains (ladder) with quasiperiodic modulation on interchain coupling strength. We demonstrate that this ladder is equivalent to two Aubry-André chains when two legs are symmetric. Analytical and numerical results indicate the appearance of mobility edges in asymmetric ladder systems. We propose an easy-to-engineer quasiperiodic Moiré superlattice ladder system comprising two-coupled uniform chains. An irrational lattice constant difference results in a quasiperiodic structure. Numerical simulations indicate that such a system supports the existence of mobility edges. Furthermore, we demonstrate that the mobility edges can be detected through a dynamical method, that is based on the measurement of survival probability in the presence of a single imaginary negative potential. The results provide insights into localization transitions and mobility edges in experiments.

The three-way junction structure of the HIV-1 PBS-segment binds host enzyme important for viral infectivity

HIV-1 reverse transcription initiates at the primer binding site (PBS) in the viral genomic RNA (gRNA). Although the structure of the PBS-segment undergoes substantial rearrangement upon tRNALys3 annealing, the proper folding of the PBS-segment during gRNA packaging is important as it ensures loading of beneficial host factors. DHX9/RNA helicase A (RHA) is recruited to gRNA to enhance the processivity of reverse transcriptase. Because the molecular details of the interactions have yet to be defined, we solved the solution structure of the PBS-segment preferentially bound by RHA. Evidence is provided that PBS-segment adopts a previously undefined adenosine-rich three-way junction structure encompassing the primer activation stem (PAS), tRNA-like element (TLE) and tRNA annealing arm. Disruption of the PBS-segment three-way junction structure diminished reverse transcription products and led to reduced viral infectivity. Because of the existence of the tRNA annealing arm, the TLE and PAS form a bent helical structure that undergoes shape-dependent recognition by RHA double-stranded RNA binding domain 1 (dsRBD1). Mutagenesis and phylogenetic analyses provide evidence for conservation of the PBS-segment three-way junction structure that is preferentially bound by RHA in support of efficient reverse transcription, the hallmark step of HIV-1 replication.

EphA3 promotes the proliferation of NPC cells through negatively regulating the ability of FOG2

OBJECTIVE

The purpose of this study was to investigate the expression level of EphA3 in nasopharyngeal carcinoma (NPC) and its effect on the proliferative capacity of NPC. Meanwhile, the underlying mechanism by which EphA3 prompts NPC malignant progression was further explored.

PATIENTS AND METHODS

In this study, the expression of EphA3 in 42 pairs of tumor tissue specimens and paracancerous ones collected from NPC patients was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), and the interplay between EphA3 expression and clinical indicators, as well as prognosis of NPC patients was analyzed. Meanwhile, qRT-PCR was also applied to further verify EphA expression in NPC cell lines. In addition, EphA knockdown model was constructed in NPC cell lines, CNE2, and 6-10B, and the impacts of EphA on NPC cell functions was assessed through Cell Counting Kit-8 (CCK-8), cell colony formation, as well as 5-Ethynyl-2'- deoxyuridine (EdU) assays. Finally, a potential interplay between EphA3 and FOG2 was also investigated.

RESULTS

In this study, qRT-PCR results revealed that EphA3 expression levels in tumor tissues of patients with NPC were markedly higher than those in adjacent tissues. Compared with patients with low expression of EphA3, those with highly expressed EphA3 had a more advanced pathological stage. In addition, in vitro experiments showed that knocking down EphA3 notably attenuated the proliferation capacity of NPC cells. Subsequently, it was found that the expression of FOG2 in NPC cells was remarkably decreased both in NPC cell lines and tissues, which had a negative correlation with EphA3. Finally, cell recovery experiment revealed a mutual regulation between EphA3 and FOG2, which then together affected the malignant progression of NPC.

CONCLUSIONS

EphA3 is significantly relevant to pathological staging and poor prognosis of patients with NPC and may enhance the proliferation ability of NPC cells by modulating FOG2.

Association of disease condition with changes in intestinal flora, and plasma endotoxin and vascular endothelial growth factor levels in patients with liver cancer

OBJECTIVE

Currently, the therapeutic effect on patients with liver cancer is associated with disease development. Meanwhile, the efficacy in patients with advanced liver cancer is far from satisfactory. Therefore, the aim of this study was to explore the association of disease condition with changes in liver function indexes, intestinal flora, and plasma endotoxin (ET) and vascular endothelial growth factor (VEGF) levels in patients with liver cancer.

PATIENTS AND METHODS

A total of 300 patients with primary liver cancer in our hospital were enrolled in this study. All patients were divided into three groups, including early liver cancer group, middle liver cancer group, and advanced liver cancer group. Peripheral blood was collected from each subject to detect liver function indexes, procalcitonin (PCT), plasma ET, and VEGF levels. Furthermore, mid-posterior-segment stools were collected from 15 cases in each group, and sent to the company for detection of intestinal flora.

RESULTS

Liver function indexes in peripheral blood of patients with liver cancer changed with the changes in disease condition. With the progression of liver cancer, the level of aspartate aminotransferase (AST) increased significantly, and the highest was observed in advanced liver cancer patients [(91.18±10.34) U/L] (p=0.046). However, the level of plasma total protein declined significantly, which was (24.83±1.75) g/L in advanced liver cancer patients (p=0.035). The changes in total bilirubin were significantly associated with the progression of liver cancer (p=0.003). The abundance of Clostridiales, Firmicutes, and Streptococcus in the intestinal tract was high in early liver cancer group. The abundance of Ruminococcaceae, Pasteurellaceae, Tanticharoenia, and Vagococcus in the intestinal tract was high in middle liver cancer group. Meanwhile, the abundance of Bifidobacteriales, Actinobacteria, Barnesiella, Porphyromonadaceae, and Pseudomonadales in the intestinal tract was high in advanced liver cancer group. In patients with liver cancer, the level of Enterobacteriaceae was positively correlated with that of Firmicutes (r=0.36, p=0.003), whereas it was negatively correlated with Lactobacillus (r=-0.72, p=0.021). The level of Lactobacillus was positively correlated with that of Ruminococcaceae (r=0.39, p=0.043), whereas it was negatively correlated with that of Firmicutes (r=-0.27, p=0.019). In addition, the level of PCT markedly rose in advanced liver cancer group [(6.89±0.35) ng/mL] (p=0.021). The level of ET increased significantly with the development of liver cancer, with the highest level observed in advanced liver cancer group [(0.71±0.09) EU/mL] (p=0.004). The level of VEGF also increased remarkably with the aggravation of liver cancer, and the highest was found in advanced liver cancer group [(112.33±2.11) μmol/L], showing differences among groups (p<0.05).

CONCLUSIONS

With the progression of liver cancer, the abundance of Barnesiella, etc., rose and that of Ruminococcaceae, etc., declined in the intestinal tract. Meanwhile, the composition of intestinal flora was changed, and the levels of plasma ET and VEGF increased.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Quantum Phase Transition in a Quantum Ising Chain at Nonzero Temperatures

We study the response of a thermal state of an Ising chain to a nonlocal non-Hermitian perturbation, which coalesces the topological Kramer-like degeneracy in the ferromagnetic phase. The dynamic responses for initial thermal states in different quantum phases are distinct. The final state always approaches its half component with a fixed parity in the ferromagnetic phase but remains almost unchanged in the paramagnetic phase. This indicates that the phase diagram at zero temperature is completely preserved at finite temperatures. Numerical simulations for Loschmidt echoes demonstrate such dynamical behaviors in finite-size systems. In addition, it provides a clear manifestation of the bulk-boundary correspondence at nonzero temperatures. This work presents an alternative approach to understanding the quantum phase transitions of quantum spin systems at nonzero temperatures.

The gene NtMYC2a acts as a 'master switch' in the regulation of JA-induced nicotine accumulation in tobacco

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.

Extended Interactions between HIV-1 Viral RNA and tRNALys3 Are Important to Maintain Viral RNA Integrity

The reverse transcription of the human immunodeficiency virus 1 (HIV-1) initiates upon annealing of the 3′-18-nt of tRNA^Lys3 onto the primer binding site (PBS) in viral RNA (vRNA). Additional intermolecular interactions between tRNA^Lys3 and vRNA have been reported, but their functions remain unclear. Here, we show that abolishing one potential interaction, the A-rich loop: tRNA^Lys3 anticodon interaction in the HIV-1 MAL strain, led to a decrease in viral infectivity and reduced the synthesis of reverse transcription products in newly infected cells. In vitro biophysical and functional experiments revealed that disruption of the extended interaction resulted in an increased affinity for reverse transcriptase (RT) and enhanced primer extension efficiency. In the absence of deoxyribose nucleoside triphosphates (dNTPs), vRNA was degraded by the RNaseH activity of RT, and the degradation rate was slower in the complex with the extended interaction. Consistently, the loss of vRNA integrity was detected in virions containing A-rich loop mutations. Similar results were observed in the HIV-1 NL4.3 strain, and we show that the nucleocapsid (NC) protein is necessary to promote the extended vRNA: tRNA^Lys3 interactions in vitro. In summary, our data revealed that the additional intermolecular interaction between tRNA^Lys3 and vRNA is likely a conserved mechanism among various HIV-1 strains and protects the vRNA from RNaseH degradation in mature virions.