Systematic identification and expression analysis of bHLH gene family reveal their relevance to abiotic stress response and anthocyanin biosynthesis in sweetpotato

BACKGROUND

bHLH transcription factors play significant roles in regulating plant growth and development, stress response, and anthocyanin biosynthesis. Sweetpotato is a pivotal food and industry crop, but little information is available on sweetpotato bHLH genes.

RESULTS

Herein, 227 putative IbbHLH genes were defined on sweetpotato chromosomes, and fragment duplications were identified as the dominant driving force for IbbHLH expansion. These IbbHLHs were divided into 26 subfamilies through phylogenetic analysis, as supported by further analysis of exon-intron structure and conserved motif composition. The syntenic analysis between IbbHLHs and their orthologs from other plants depicted evolutionary relationships of IbbHLHs. Based on the transcriptome data under salt stress, the expression of 12 IbbHLHs was screened for validation by qRT-PCR, and differential and significant transcriptions under abiotic stress were detected. Moreover, IbbHLH123 and IbbHLH215, which were remarkably upregulated by stress treatments, had obvious transactivation activity in yeasts. Protein interaction detections and yeast two-hybrid assays suggested an intricate interaction correlation between IbbHLHs. Besides, transcriptome screening revealed that multiple IbbHLHs may be closely related to anthocyanin biosynthesis based on the phenotype (purple vs. white tissues), which was confirmed by subsequent qRT-PCR analysis.

CONCLUSIONS

These results shed light on the promising functions of sweetpotato IbbHLHs in abiotic stress response and anthocyanin biosynthesis.

Parental preferences for rotavirus vaccination for their children under 5 years old in China: A discrete choice experiment

Rotavirus vaccination is the most effective means to prevent rotavirus gastroenteritis, but its coverage in China is not ideal. We aimed to explore parental preferences for rotavirus vaccination for their children under 5years old to improve vaccination coverage. A Discrete Choice Experiment was conducted online on 415 parents with at least one child under 5years old in 3 cities. Five attributes including vaccine effectiveness, protection duration, risk of mild side-effects, out-of-pocket costs, and time required for vaccination were identified. Each attribute was set at three levels. Mixed-logit models were used to measure parental preferences and the relative importance of vaccine attributes. The optimal vaccination strategy was also explored. 359 samples were included in the analysis. The impacts of the vaccine attribute levels on vaccine choice were all statistically significant (p < .01), except for 1-hour vaccination time. The risk of mild side-effects was the most important factor influencing vaccination. The time required for vaccination was the least important attribute. The largest increase in vaccination uptake (74.45%) occurred with decreased the vaccine risk of mild side-effects from 1/10 to 1/50. The predicted vaccination uptake of the optimal vaccination scenario was 91.79%. When deciding about vaccination, parents preferred the rotavirus vaccination with lower risk of mild side-effects, higher effectiveness, longer protection duration, 2-hour vaccination time and lower cost. The authorities should support enterprises to develop vaccines with lower side-effects, higher effectiveness and longer protection duration in the future. We call for appropriate government subsidies for the rotavirus vaccine.

TFAM Modulates Cardiomyocytes Pyroptosis Induced by Ionizing Radiation through mtDNA/TLR9/NF-kB Pathway

PURPOSE/OBJECTIVE(S)

Mitochondrial transcription factor A (TFAM) is a pivotal factor for regulating mitochondrial DNA (mtDNA) replication, transcription and biogenesis. Previous studies have reported that cytosolic mtDNA stress can lead to cardiomyocytes pyroptosis, which is characterized by inflammasome formation. In this study, we attempted to investigate the mechanism of TFAM regulate cardiomyocytes pyroptosis induced by ionizing radiation.

MATERIALS/METHODS

The peripheral blood serum of patients with esophageal cancer before and after definitive chemoradiotherapy was collected for Luminex multiplex cytokine assays. C57BL/6 mice were irradiated with the whole heart using small animal radiation research platform (SARRP) to construct a radiation-induced myocardial damage (RIMD) mouse model, and the ventricular function was evaluated using 9.4T Bruker magnetic resonance (MR) scanner. The function changes of cardiomyocytes exposed to radiation were observed in vitro and in vivo after knocking out GSDMD. Furthermore, the changes of mitochondrial function, the levels of cytosolic mtDNA, and the protein levels of NF-kB and pyroptosis pathway in irradiated cardiomyocytes were analyzed by knockdown and overexpression of TFAM in vitro and in vivo.

RESULTS

By multifactor cytokine assays we found that pyroptosis related IL-1β and IL-18 were significantly increased in patients with high mean heart dose (MHD) after radiotherapy, while those with low MHD were not significantly increased after radiotherapy. Next, we successfully constructed the RIMD mouse model using a single heart irradiation of 20 Gy. We found that the gene expression of pyroptosis pathway was significantly up-regulated after cardiac irradiation by myocardial tissue transcriptomic sequencing. Compared with wild-type (WT) mice, cardiac systolic function of Gsdmd-/- mice was significantly improved at 1, 2, 6, 12, and 24 weeks after heart irradiation. In vitro, we also demonstrated increased viability of irradiated cardiomyocytes by knocking out GSDMD. In vitro and in vivo experiments confirmed the expression of TFAM decreased after radiation. By overexpression of TFAM, we found that irradiated cardiomyocytes showed improved mitochondrial function, decreased release of mtDNA into cytoplasm through mitochondrial permeability transition pores (mPTPs), decreased binding of cytosolic mtDNA to TLR9, and decreased expression of NF-kB and pyroptosis pathway proteins. Dual luciferase gene reporter assays and Chromatin immunoprecipitation (CHIP) assay confirmed that p65 could bind the NLRP3 promoter region. In addition, we found that ventricular function deteriorated and improved in mice with knockdown and overexpression of TFAM through adeno-associated virus serotype 9 (AAV9), respectively.

CONCLUSION

Our study indicated that TFAM regulate irradiated cardiomyocytes pyroptosis through mtDNA/TLR9/NF-kB pathway. We provide a novel mechanism of RIMD, revealing an underappreciated intervention target for RIMD.

Safety and Efficacy Analysis of Patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC) Treated with SHR-1316 Plus Chemotherapy and Sequential Chest Radiotherapy as First-Line Therapy from a Phase II Trial

PURPOSE/OBJECTIVE(S)

CAPSTONE-1, a phase 3 trial, showed that SHR-1316 (PD-L1 antibody) combined with standard first-line chemotherapy could prolong overall survival (OS) in patients (pts) with ES-SCLC. The CREST trial reported consolidative thoracic radiotherapy (TRT) of 30 Gy in 10 fractions provided a 10% 2-year OS benefit and more intensive TRT should be investigated in ES-SCLC. In the era of immunotherapy, the role of TRT also needs further exploration. Therefore, we designed this clinical trial to investigate the efficacy and safety of SHR-1316 plus first-line chemotherapy followed by TRT combined with SHR-1316.

MATERIALS/METHODS

Key inclusion criteria were pts aged 18-75 years, with previously untreated histologically or cytologically confirmed ES-SCLC, and an ECOG performance status of 0-1. Eligible pts would receive 4∼6 cycles of SHR-1316 (20mg/kg, D1, q3w) combined with EP/EC (etoposide, 100mg/m2, D1-5, q3w and cisplatin, 75mg/m², D1-3, q3w or carboplatin, AUC = 5, D1, q3w), followed by SHR-1316 combined with TRT (≥3 Gy*10 f or ≥2 Gy*25 f, involved-field irradiation), and then the maintenance therapy with SHR-1316 until disease progression or intolerable adverse events (AEs). The main endpoints included ORR, PFS and safety.

RESULTS

From October 2020 to January 2023, 33 pts received SHR-1316 and sequential consolidative TRT. Among them, 19 pts received high-dose TRT (>3 Gy*10 f or ≥2 Gy*25 f) and 14 pts received low-dose TRT (≤3 Gy*10 f or<2 Gy*25 f). The median age was 62 (range: 38-73). Most pts were male (28, 84.8%), former smokers (22, 66.7%) with an ECOG performance status 1 (32, 97%). Ten (30.3%) pts were diagnosed with brain metastasis and 10 (30.3%) pts had liver metastasis at baseline. At the data cutoff date, 9 pts remained on treatment, the average number of treatment cycles was 9.2. 33 pts had at least one 1 post-treatment tumor assessment. The confirmed ORR and DCR were 90.9% (30/33) and 100% (33/33) in all pts, were 89.5% (17/19) and 100% (19/19) in high-dose TRT group, and were 92.9% (13/14) and 100% (14/14) in low-dose TRT group. The median PFS was 10.2(CI: 5.8∼14.7) months in all pts, was 7 (CI: 3.8∼10.2) months in high-dose TRT group and 10.4 (CI: 8.4∼12.3) months in low-dose TRT group. AEs occurred in 27 (81.8%) pts and grade 3 or 4 AEs occurred in 20 (60.6%) pts. The most common grade 3 or 4 AEs included neutropenia (15, 45.5%), leukopenia (8, 24.2%), lymphocytopenia (5, 15.2%), pneumonia (3, 9.1%), anemia (3, 9.1%) and thrombocytopenia (2, 6.1%).

CONCLUSION

SHR-1316 plus chemotherapy and sequential TRT as first-line therapy for ES-SCLC showed promising efficacy and acceptable safety. There is no significant difference between high-dose and low-dose TRT groups in terms of safety and efficacy according to current data.

Performance Evaluation in Automatic Plan Generation for Ethos Intelligent Optimization Engine

PURPOSE/OBJECTIVE(S)

To evaluate the automatic optimization performance and clinical feasibility of the Intelligent Optimization Engine (IOE) of Ethos online adaptive radiotherapy platform.

MATERIALS/METHODS

Eleven patients with cervical cancer treated with Halcyon accelerator were retrospectively selected. All the patients manually planned with four full arc volume rotating intensity modulated radiotherapy (VMAT) (Manual-4Arc), and the prescription dose was 45 Gy/25F. All patient images and structures were imported into Ethos simulator, and clinical goals were added appropriately based on clinical requirements. The target coverage was normalized to 95%. 7F, 9F, 12F IMRT plans and 2Arc, 3Arc VMAT plans were automatically generated by IOE. Dosimetric index comparisons were made among the Manual-4Arc plans and five group IOE generated plan to evaluate the automatic optimization performance of IOE.

RESULTS

In terms of hot dose area, for PTV, D1% of IMRT-12F plans was the lowest, and there were significant differences between IMRT-12F plans and Manual-4Arc plans (46.936 ± 0.241 vs 48.639 ± 2.395, p = 0.004); In terms of target coverage, the CTVs of all groups meet clinical requirements. Although the Ethos online adaptive plans have been normalized during planning, the PTV coverage is slightly insufficient (12F: 94.913 ± 0.154; 9F: 94.585 ± 1.148). For OARs close to target, such as bladder, V30Gy, V40Gy and Dmean have significant differences among the six group plans. The order of bladder dose is basically followed by IMRT-12F

CONCLUSION

The plans automatically generated by Ethos IOE can achieve similar performance as the manual plan, and the automatically generated IMRT-12F and 9F plans are preferred for clinical use.

Collapse

Key Words Collapse

MESH Headings Collapse

Grants Collapse

Affiliation(s)

Z Wang Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
B Yang Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
X Meng Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
Y Liang Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
T Pang Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
J Qiu Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China

Collapse

Dose DIBH Really Reduce the Subclinical Cardiac Acute Injury? Analysis of Clinical Real World from Our Institute

PURPOSE/OBJECTIVE(S)

The study is aim to investigate whether Deep-inspirational breath-hold (DIBH), compared with free breathing (FB), could provide a short-term cardiac benefit in patients with early left breast cancer after breast-conserving surgery combined whole breast radiotherapy.

MATERIALS/METHODS

A total of 78 patients with early stage left breast cancer treated with radiotherapy between 2021-2022 after breast-conserving surgery were enrolled. Among them, 32 cases were treated with DIBH technique and 46 cases were treated with free breathing. Patients with previous cardiac disease such as coronary artery disease were excluded. We performed myocardial enzymes, ECG, and ECHO in all patients within 2 weeks before, during, and 6 months after radiotherapy. The results of the two groups were compared using nonparametric tests and chi-square tests, and P < 0.05 indicated statistical significance. Where subclinical acute cardiac injury was defined as new above-normal myocardial enzymes and/or electrocardiographic ST-T or T-wave changes and/or ECHO abnormalities after the start of radiotherapy.

RESULTS

The median follow-up of patients was 6 months and the mean age of patients was 52.3 years for FB and 44.9 years for DIBH. There were no significant differences in staging, molecular subtype, chemotherapy and endocrine therapy history. The proportion of subclinical acute cardiac injury was smaller in the DIBH group compared to the FB group (DIBH = 31/46 and FB = 28/32, p = 0.042). The most sensitive of the subclinical acute cardiac injury events were detected by myocardial enzymes rising, with cTnI (p = 0.034) and NT-proBNP (p = 0.023) appearing significantly lower in the DIBH patients during radiotherapy. The difference of cTnI between 2 groups at 6 months after radiotherapy became non-significant. In contrast, CK-MB was higher in DIBH compared with FB only 6 months after radiotherapy (p = 0.006). The differences in ECG and ECHO were not significant between the two groups.

CONCLUSION

After breast-conserving surgery combined with radiotherapy for left early breast cancer, DIBH compared to FB reduces the proportion of acute subclinical cardiac injury that occurs with the most sensitive changes in myocardial enzymes. Subsequent studies will explore the relationship between the short-term subclinical injury and irradiated dose, as well as long term cardiac injury.

The Predictive Value of Changes in Basal Myocardial F-18 Fluorodeoxyglucose Uptake for Cardiotoxicity in Locally Advanced Esophageal Cancer Patients Receiving Definitive Radiotherapy

PURPOSE/OBJECTIVE(S)

To investigate the predictive value of changes in myocardial 18F-FDG uptake for major adverse cardiac events (MACEs) in locally advanced esophageal cancer patients receiving definitive radiotherapy.

MATERIALS/METHODS

Between August 2012 and January 2018, 400 patients with stage II-III esophageal cancer receiving definitive radiotherapy at two institutions were divided into the training (n = 240) and external validation cohorts (n = 160). All patients underwent FDG-PET imaging within 1 week before treatment and 3 months after treatment. Myocardium delineation was performed by Carimas software (version 2.10) based on the AHA 17-segment model. When contouring the left ventricle, the myocardium was automatically divided into basal (segments 1-6), middle (segments 7-12), and apical (segments 13-16) regions, and the mean dose and FDG uptake parameters of each region were obtained by Carimas. Our primary endpoint was MACEs. Patient clinicopathologic factors, dosimetric parameters for the whole heart and cardiac substructures, and myocardial changes within the three regions on 18F-FDG PET were utilized to seek the best predictive models for cardiotoxicity. To avoid multicollinearity between dose-volume histogram (DVH) parameters, we selected the variables with the lowest Akaike Information Criterion (AIC) value from the DVH parameters of the same cardiac structure for the actual modeling procedure. Competing risk analysis and Cox regressions analysis were performed. The predictive performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC) and Brier score.

RESULTS

At a median follow-up interval of 78 months, 28 patients (11.7%) developed MACEs. The basal region of the myocardium received the highest radiation dose, followed by the middle and the apex region. The basal myocardial SUVmax and SUVmean significantly increased after radiotherapy while the apical and middle myocardial SUVmax and SUVmean not significantly increased. In univariate analysis, age, pre-existing cardiac disease, changes in pre- and post-treatment basal myocardial SUVmax and SUVmean (∆SUVmax and ∆SUVmean), and dosimetric parameters for MHD, mean LCX, mean LAD, and mean LV dose were associated with an increased hazard of MACEs. Multivariate analysis showed that basal ∆SUVmean retained significance after adjusting for age, pre-existing cardiac disease, and dosimetric parameters for whole heart and cardiac substructures. The AUCs and Brier scores demonstrated favorable predictive accuracies of the model's integrating variables with significant difference in multivariate analysis when predicting MACEs in the training and validation cohorts.

CONCLUSION

∆SUVmean was an independent indicator of MACE in locally advanced esophageal cancer patients receiving definitive radiotherapy. Changes in basal myocardial FDG uptake is a promising biomaker for predicting radiation-induced cardiotoxicity.

PD-L1 Inhibitors Combined with Thoracic Radiotherapy in First-Line Treatment of Extensive Stage Small Cell Lung Cancer: A Propensity Score-Matched, Real-World Study

PURPOSE/OBJECTIVE(S)

The CREST study showed that the addition of thoracic radiotherapy (TRT) could improve the survival of extensive stage small cell lung cancer (ES-SCLC), but whether TRT can bring survival benefit in the era of immunotherapy is controversial. This study aims to explore the efficacy and safety of adding TRT to the combination of PD-L1 inhibitors and chemotherapy.

MATERIALS/METHODS

Thepatients who received PD-L1 inhibitors combined with platinum-based chemotherapy as the first-line treatment of ES-SCLC from January 2019 to December 2021 were retrospectively collected. According to whether they received TRT, they were divided into two groups, and the follow-up analysis was performed. Propensity score matching (PSM) in with a 1:1 ratio was performed to balance the baseline characteristics of the two cohorts. The endpoints were progression-free survival (PFS) and OS.

RESULTS

A total of 211 patients with ES-SCLC were enrolled, of whom 70 (33.2%) patients received standard therapy plus TRT as first-line treatment, and 141 (66.8%) patients in the control group received PD-L1 inhibitors plus chemotherapy. After PSM, a total of 65 pairs of patients were enrolled in the analysis. There were no significant differences in baseline characteristics between the two groups of patients who received TRT and those who did not. In all patients, the median PFS (mPFS) in the TRT group and the non-TRT groupwere 9.5 months and 7.2 months, respectively, with HR = 0.60 (95% CI 0.41-0.87, p = 0.007). The median OS (mOS) in the TRT group was also significantly longer than that in the non-TRT group (24.1 months vs. 18.5 months, HR = 0.53, 95% CI 0.32-0.85, p = 0.009). Multivariable analysis showed that baseline liver metastasis and bone metastasis were independent prognostic factors for OS. In terms of safety, immunotherapy combined with thoracic radiotherapy increased the incidence of treatment-related pneumonia (p<0.001), most of which were grade 1-2.

CONCLUSION

This real-world study shows that adding TRT to durvalumab or atezolizumab plus chemotherapy significantly improves survival in ES-SCLC. It leads to more treatment-related pneumonia, but most of them can be relieved after symptomatic treatment. This treatment model deserves to be explored in prospective clinical trials.

Enhanced Radiosensitivity of Esophagus Cancer through Loss of ADAR1 and Cell Apoptosis via NF-kB Signaling Pathway

PURPOSE/OBJECTIVE(S)

RNA editing is a common posttranslational mechanism for generating genomic diversity by modifying selected RNA sequences without altering the genome. A new understanding of cancer therapy can be enhanced by the discovery of ADAR1 in the control of signal transduction pathways. However, the study of the biological effects of ADAR1 in radioresistance of esophageal cancer is not very deep.

MATERIALS/METHODS

The TCGA data sets were used to explore the correlations between ADAR1 and prognosis in esophageal cancer. Two pairs of ADAR1 gene siRNA fragments (siADAR1-1 and siADAR1-2) were designed and transiently transfected into KYSE410 cells and KYSE410-RT cells. The expression of ADAR1 was detected by RT-PCR and WB. Colony formation assay was used to evaluate the radiosensitivity. Apoptosis was measured using a flow cytometric apoptosis assay. Furthermore, transcriptome sequencing was performed to elucidate the pathways regulated by ADAR1.

RESULTS

In this study, we found that ADAR1 is overexpressed in esophageal tumors and is associated with poor prognosis in bioinformatics analysis. Colony formation experiment showed that siRNA-mediated depletion of ADAR1 in KYSE410 cells could inhibit cell proliferation and reduce radiosensitivity significantly. Consistently results were showed in KYSE410-RT cells. Mechanism studies revealed loss of ADAR1 induced cell apoptosis and radiotherapy could enhance this process. Transcriptomic data indicated that ADAR1 could regulate apoptosis through the NF-kB pathway.

CONCLUSION

RNA editing was found to be involved in the regulation of radiosensitivity of esophageal cancer and loss of ADAR1 can cause cell apoptosis though NF-kB pathway. A better understanding of A-to-I RNA editing and its oncogenic mechanisms may facilitate the development of radiotherapy in esophageal cancer.

NHC-mediated photocatalytic deoxygenation of alcohols for the synthesis of internal alkynes via a Csp3-Csp coupling reaction

NHC-mediated deoxygenation of alcohols under photocatalytic conditions is described. The process provides various alkyl radicals, which can react with 1-bromoalkyne via Csp3-Csp coupling to afford internal alkynes in moderate to good yields. The method offers a new and convenient approach to synthesize internal alkynes.

Comparative Analysis of the PYL Gene Family in Three Ipomoea Species and the Expression Profiling of IbPYL Genes during Abiotic Stress Response in Sweetpotato

Abscisic acid (ABA), a critical phytohormone that regulates plant development and stress response, is sensed by the ABA receptors PYR/PYL/RCAR (PYLs). The PYL genes have been widely studied in multiple plant species, while a systematic analysis of PYL genes in the genus Ipomoea remains unperformed. Here, a total of 13, 14, and 14 PYLs were identified in Ipomoea batatas, Ipomoea trifida, and Ipomoea triloba, respectively. Fragment duplication was speculated to play prominent roles in Ipomoea PYL gene expansions. These Ipomoea PYLs were classified into three subfamilies via phylogenetic analysis, which was supported by exon-intron structures and conserved motif analyses. Additionally, the interspecies collinearity analysis further depicted a potential evolutionary relationship between them. Moreover, qRT-PCR analysis showed that multiple IbPYLs are highly and differentially responsive to abiotic stress treatments, suggesting their potential roles in sweetpotato stress responses. Taken together, these data provide valuable insights into the PYLs in the genus Ipomoea, which may be useful for their further functional analysis of their defense against environmental changes.

Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

[Advances in clinical characteristics of talaromycosis combined with other opportunistic infections]

Talaromycosis (TSM) is an opportunistic deep mycosis prevalent in southeast Asia and southern China, affecting HIV-positive, anti-interferon-gamma autoantibody-positive and other immunodeficiency hosts. These hosts are often co-infected with mycobacterium tuberculosis, non-tuberculosis mycobacteria, bacteria, fungi, viruses and other opportunistic infections. The clinical characteristics and the pathogenic spectrum of TSM with opportunistic infections vary with different immune states. The rates of misdiagnosis, missed diagnosis and mortality are high. This review summarized the clinical characteristics of TSM with opportunistic infections in order to improve the level of clinical diagnosis and treatment.

[Persistence follow-up of immune memory to hepatitis B vaccine among infants with non- and low-response to primary vaccination after revaccination with three doses]

This study followed up the immune memory after 3-dose revaccination among infants with non-and low-response following primary hepatitis B (HepB) vaccination. About 120 children without self-booster doses were finally included who had anti-HBs<10 mIU/ml (anti-HBs negative) at the time of follow-up, of whom 86 children completed blood sampling and anti-HBs testing. Before the challenge dose, all 86 children were negative for anti-HBs, and the GMC of anti-HBs was<10 mIU/ml. The seropositive conversion rate of anti-HBs was 100% and the GMC of anti-HBs was 886.11 (95%CI: 678.15-1 157.84) mIU/ml after the challenge dose. Compared with those with GMC<7 mIU/ml before the challenge dose, infants with GMC>7 mIU/ml had a higher anti-HBs level after the challenge dose. The β value (95%CI) was 0.82 (0.18-1.46) (P=0.012). Compared with those with GMC<1 000 mIU/ml at primary vaccination, infants with GMC≥1 000 mIU/ml had a higher anti-HBs level after the challenge dose. The β value (95%CI) was 0.78 (0.18-1.38)(P=0.012). The results showed a stronger immune memory was found at 9 years after revaccination among infants with non-and low-response to HepB.

Genome-wide survey and expression analysis of Dof transcription factor family in sweetpotato shed light on their promising functions in stress tolerance

DNA-binding with one finger (Dof) transcription factors play a crucial role in plant abiotic stress regulatory networks, although massive Dofs have been systematically characterized in plants, they have not been identified in the hexaploid crop sweetpotato. Herein, 43 IbDof genes were detected to be disproportionally dispersed across 14 of the 15 chromosomes of sweetpotato, and segmental duplications were discovered to be the major driving force for the expansion of IbDofs. The collinearity analysis of IbDofs with their related orthologs from eight plants revealed the potential evolutionary history of Dof gene family. Phylogenetic analysis displayed that IbDof proteins were assigned into nine subfamilies, and the regularity of gene structures and conserved motifs was consistent with the subgroup classification. Additionally, five chosen IbDof genes were shown to be substantially and variably induced under various abiotic conditions (salt, drought, heat, and cold), as well as hormone treatments (ABA and SA), according to their transcriptome data and qRT-PCR experiments. Consistently, the promoters of IbDofs contained a number of cis-acting elements associated with hormone and stress responses. Besides, it was noted that IbDof2 had transactivation activity in yeasts, while IbDof-11/-16/-36 did not, and protein interaction network analysis and yeast two-hybrid experiments revealed a complicated interaction connection amongst IbDofs. Collectively, these data lay a foundation for further functional explorations of IbDof genes, especially with regards to the possible application of multiple IbDof members in breeding the tolerant plants.

The unique sweet potato NAC transcription factor IbNAC3 modulates combined salt and drought stresses

Plants often simultaneously experience combined stresses rather than a single stress, causing more serious damage, but the underlying mechanisms remain unknown. Here, we identified the stress-induced IbNAC3 from sweet potato (Ipomoea batatas) as a nucleus-localized transcription activator. IbNAC3 contains a unique activation domain whose MKD sequence confers transactivation activities to multiple other TFs and is essential for the activated expression of downstream target genes. Ectopic expression of IbNAC3 conferred tolerance to single and combined salt and drought stresses in Arabidopsis (Arabidopsis thaliana), and a group of NAM, ATAF1/2, and CUC2 (NAC) TFs, including ANAC011, ANAC072, ANAC083, ANAC100, and NAP, interacted with IbNAC3, and the specific domains responsible for each interaction varied. Intriguingly, IbNAC3 repressed the interaction among the five NACs, and knockout or mutation of ANAC011 and ANAC072 dramatically impaired combined stress tolerance. IbNAC3-ANAC072 and IbNAC3-NAP modules synergistically activated the MICROTUBULE-RELATED E3 LIGASE57 (MREL57) gene. Consistently, mutation of MREL57 and overexpression of WAVE-DAM-PENED2-LIKE7, encoding a target protein of MREL57, both remarkably impaired combined stress tolerance. Moreover, transgenic plants displayed abscisic acid (ABA) hyposensitivity by directly promoting the transcription of ENHANCED RESPONSE TO ABA 1, a key negative regulator of ABA signaling. The data unravel the unique IbNAC3 TF functions as a pivotal component in combined stress tolerance by integrating multiple regulatory events and ubiquitin pathways, which is essential for developing high-tolerant plants in natural environments.

A systematical genome-wide analysis and screening of WRKY transcription factor family engaged in abiotic stress response in sweetpotato

BACKGROUND

WRKY transcription factors play pivotal roles in regulating plant multiple abiotic stress tolerance, however, a genome-wide systematical analysis of WRKY genes in sweetpotato is still missing.

RESULTS

Herein, 84 putative IbWRKYs with WRKY element sequence variants were identified in sweetpotato reference genomes. Fragment duplications, rather than tandem duplications, were shown to play prominent roles in IbWRKY gene expansion. The collinearity analysis between IbWRKYs and the related orthologs from other plants further depicted evolutionary insights into IbWRKYs. Phylogenetic relationships displayed that IbWRKYs were divided into three main groups (I, II and III), with the support of the characteristics of exon-intron structures and conserved protein motifs. The IbWRKY genes, mainly from the group Ib, displayed remarkable and diverse expression profiles under multiple abiotic stress (NaCl, PEG6000, cold and heat) and hormone (ABA, ACC, JA and SA) treatments, which were determined by RNA-seq and qRT-PCR assays, suggesting their potential roles in mediating particular stress responses. Moreover, IbWRKY58L could interact with IbWRKY82 as revealed by yeast two-hybrid based on the protein interaction network screening. And abiotic stress-remarkably induced IbWRKY21L and IbWRKY51 were shown to be localized in the nucleus and had no transactivation activities.

CONCLUSION

These results provide valuable insights into sweetpotato IbWRKYs and will lay a foundation for further exploring functions and possible regulatory mechanisms of IbWRKYs in abiotic stress tolerance.

To what extent do social support and mastery mediate the association between childhood maltreatment and depression? A sequential causal mediation analysis

AIMS

This study aimed to examine the independent roles of various childhood maltreatment (CM) subtypes in the development of depression; quantify the joint mediation effect of social support and mastery in the association between subtypes of CM and depression and examine the additional contribution of mastery beyond the effect that is operating through social support to this relationship.

METHODS

Data analysed were from the Zone d'Épidémiologie Psychiatrique du Sud-Ouest de Montréal, an ongoing longitudinal population-based study. In total, 1351 participants with complete information on the studied variables were included. The propensity score matching and inverse-probability weighted regression adjustment estimation methods were used to minimise the potential confounding in the relationship between CM and major depression. We then used inverse odds ratio-weighted estimation to estimate the direct effects of maltreatment and indirect effects of social support and mastery.

RESULTS

We found that exposures to all maltreatment subtypes increased the risk of subsequent depression. The joint mediating effect of social support and mastery explained 37.63-46.97% of the association between different maltreatment subtypes and depression. The contribution of these two mediators differed by maltreatment subtypes, with social support being the major contributor to the mediating effect.

CONCLUSIONS

The findings of the study not only provide scientific evidence on the importance of psychosocial attributes in the development of major depression but also suggest that prevention and invention strategies should focus on these psychosocial attributes to effectively break the vicious cycle of CM on major depression.

Abstract 5287: Aggregation of HER2 receptors on the tumor cell surface induced by a novel anti-HER2 bispecific antibody led to enhanced tumor cell growth inhibition

Trastuzumab, an anti-HER2 monoclonal antibody developed by Roche, is now a standard of care for treating HER2 overexpressing cancers. However, patients treated with trastuzumab generally develop resistance to the drug within a year after initiation of the treatment. Pertuzumab, another anti-HER2 monoclonal antibody developed by Roche, targets the domain 2 of the HER2 excellular domain (ECD) instead of the domain 4 to which trastuzumab binds and demonstrates enhanced antitumor activities when combined with trastuzumab. Here, we developed a tetravalent bispecific antibody (BsAb) which targets the domain 2 and 4 of the HER2 ECD simultaneously. Using time-lapse microscopy, we showed that the BsAb induced aggregation of HER2 on NCI-N87 tumor cells, possibly indicating that the receptors could be crosslinked by the BsAb intermolecularly. Furthermore, the tetravalent BsAb induced aggregation faster than did the bivalent BsAb. Importantly, the tetravalent BsAbs exhibited superior tumor cell growth inhibition to that of the two parental monoclonal antibodies alone or combined. In line with the aggregation rates, the tetravalent BsAb was also more potent in inhibiting tumor cell growth than that of the bivalent BsAb. Thus we provide a piece of evidence that the BsAbs targeting two distinct domains of HER2 simultaneously might induce the receptor aggregation which might associate with the enhanced inhibition of tumor cell growth.

Citation Format: Lan Deng, Jie Zhao, Xiaoqing Meng, Aotian Xiao, Zhenping Zhu, Haomin Huang. Aggregation of HER2 receptors on the tumor cell surface induced by a novel anti-HER2 bispecific antibody led to enhanced tumor cell growth inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5287.

[Anti-HBs persistence after primary vaccination with three doses of 5 μg recombinant hepatitis B vaccine among normal and high-responder infants: 10-year of follow-up]

Objective: Assess the 10-year Immune persistence and the predictors after primary vaccination hepatitis B vaccine (HepB) among normal and high-responder infants. Methods: A total of 1 838 Infants of 7-12 months old located in Jinan, Weifang, Yantai and Weihai of Shandong Province who were induced normal or high antibody response (anti-HBs titer ≥ 100 mIU/ml) after primary vaccination (three dose with 0-1-6 procedure) with 5 μg recombinant HepB among newborns were included in the study, in 2009. 3 ml of venous blood samples were collected at baseline survey (T₀) and antibodies against hepatitis B surface antigen (anti-HBs), antibody against hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg) were detected using chemiluminescence microparticle immunoassay (CMIA) method. A self-designed questionnaire was used to collect information including the infant's age, sex, birth weight, premature birth, birth number, delivery location and mother's HBV infection status. In 2014 (followed up for 5 years) and in 2019 (followed up for 10 years) (T₁), 2 ml of venous blood samples were collected. Anti HBS and anti HBC were detected by CMIA method. Those with anti HBS<10 mIU/ml were detected by CMIA method. Multivariate unconditional logistic and linear regression models were used to analyze the influencing factors of anti-HBs positive rate and geometric mean concentration (GMC) at T₁. Results: After 10 years follow-up, 73.94% of the subjects (1 359/1 835) finished the follow-up. 51.15% of the subjects, a total of 625 were boys. The positive rate of anti-HBs was 100% at T₀ and decreased to 53.44% (95%CI: 50.59%-56.26%) at T₁. The average annual decline rate of anti-HBs positive rate from T₀ to T₁ was 6.07%. The GMC of anti-HBs decreased from 607.89 (95%CI: 579.01-642.62) mIU/ml to 16.44 (95%CI: 15.06-18.00) mIU/ml. The average annual decline rate of anti-HBs GMC in 10-year follow-up was 30.30%. Multivariate logistic analysis showed that the positive rate of anti-HBs at T₁ was lower in those who did not vaccinate the first dose in time (OR=0.25, 95%CI:0.07-0.71). Compared with those with GMC<1 000 mIU/ml at T₀, those with GMC ≥ 1 000 mIU/ml had a higher positive rate of anti-HBs at T₁ (OR=2.29, 95%CI:1.76-2.97). Multivariate regression analysis showed that the GMC of anti-HBs at T₁ was lower in those who did not vaccinate the first dose in time (β=-0.50, 95%CI:-1.24-0.24). Compared with those with GMC<1 000 mIU/ml at T₀, those with GMC ≥ 1 000 mIU/ml had a higher GMC of anti-HBs at T₁ (β=0.81, 95%CI: 0.62-1.05). Conclusion: Anti-HBs GMC decreased in 10 years after primary vaccination of 5 μg recombinant hepatitis B vaccine among normal and high-responders. The anti-HBs persistence was mainly associated with whether the first dose was vaccinated in time and the level of anti-HBs at the end of primary vaccination.

The efficacy and safety of different doses of calcitriol combined with neutral phosphate in X-linked hypophosphatemia: a prospective study

The present study was the first prospective cohort evaluated the efficacy and safety of different doses of calcitriol in XLH children. The results suggested that a dose of 40 ng/kg/day calcitriol, compared with 20 ng/kg/day, was more effective in relieving the rickets, with similar safety outcomes. Further investigations were expected to set more dose groups.

INTRODUCTION

Dose recommended for calcitriol in X-linked hypophosphatemia (XLH) varies in different studies. Therefore, we aimed to compare the efficacy as well as the safety of 20 ng/kg/d and 40 ng/kg/d calcitriol in Chinese XLH pediatrics population.

METHODS

A 2-year, randomized, open-label, prospective study recruited 68 XLH children, which were randomized to receive either 40 ng/kg/day or 20 ng/kg/day calcitriol. Efficacy endpoints were the total Thacher ricket severity score (RSS) change from baseline to month 12 and 24, the difference in serum TALP level, fasting serum phosphate level, body height Z-score, and frequency of dental abscess. Safety assessments were done using renal ultrasound nephrocalcinosis grades (0-4), fasting serum and 24 h urine calcium level, and the occurrence of hyperparathyroidism.

RESULTS

The decrease in the total RSS from baseline was more significant in the high-dose group at 12 (difference 0.87, p = 0.049) and 24 month (difference 1.23, p = 0.011). The serum TALP level was significantly lower in the high-dose group at 6 months. Pi level, height Z-score change, frequency of dental abscess and ratio of de novo nephrocalcinosis were comparable. A lower incidence of secondary hyperparathyroidism was seen in the high-dose group (p < 0.0001).

CONCLUSION

For the first time in this prospective cohort, 40 ng/kg/d calcitriol was shown to be the more effective therapy in XLH children than the 20 ng/kg/d. Moreover, 40 ng/kg/d calcitriol was not associated with increasing adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT 03,820,518.

POS1016 RELATIONSHIPS BETWEEN DISEASE DURATION AND RADIOGRAPHIC PROGRESSION AMONG PATIENTS WITH PSORIATIC ARTHRITIS TREATED WITH SECUKINUMAB IN FUTURE 5

Background

For patients with psoriatic arthritis (PsA), delays in diagnosis and treatment can lead to permanent radiographic damage, even early in the course of disease.1 In the phase 3 FUTURE 5 study (NCT02404350), treatment with secukinumab (SEC) was shown to inhibit progression of structural damage through Week 104 in patients with PsA.2 However, the effect of disease duration on inhibition of radiographic progression by SEC has not been characterized.

Objectives

This post hoc analysis explored relationships between time since diagnosis (TSD) of ≤1 year vs >1 year and radiographic progression among patients with PsA receiving SEC over 2 years in FUTURE 5.

Methods

Patient data from FUTURE 5 were stratified by TSD ≤1 year vs >1 year and analyzed by treatment arm. Through Week 24, patients received SEC 300 or 150 mg with subcutaneous loading dose (LD), SEC 150 mg without LD, or placebo (PBO) (period 1). After Week 24, patients receiving PBO were switched to SEC 300 or 150 mg (period 2), and a protocol amendment allowed those with suboptimal clinical response to SEC 150 mg to escalate to SEC 300 mg after Week 52 per investigator judgment.2 The proportion of patients with no radiographic progression, defined as change from baseline in van der Heijde total modified Sharp score ≤0.0, was analyzed at Weeks 24, 52, and 104. Mean total Sharp score was evaluated at baseline, and mean change from baseline was determined at Weeks 24, 52, and 104.

Results

Of 996 patients with PsA included here, 217 (21.8%) had a TSD ≤1 year and 779 (78.2%) had a TSD >1 year. At baseline, patients with TSD >1 year had greater radiographic damage than patients with TSD ≤1 year as determined by mean total Sharp score (Table 1). As early as Week 24, patients receiving SEC had less radiographic progression than those receiving PBO, regardless of TSD. From Week 24 to Week 104, radiographic progression remained low among all patients receiving SEC, with a trend of least progression among patients randomized to SEC 300 mg at baseline. Regardless of treatment, patients with TSD >1 year had numerically greater radiographic progression than those patients with TSD ≤1 year. Overall, the proportion of patients receiving SEC who did not have any radiographic progression was higher than that of placebo at Week 24 irrespective of TSD, with a trend towards a higher number of non-progressors among those treated with SEC 300 mg (Figure). Patients randomized to SEC 300 mg were the least likely to experience radiographic progression through 52 weeks.

Table 1.

Baseline Total Sharp Score and Change From Baseline at Weeks 24, 52, and 104 by TSD

Total Sharp scoreTSD ≤1 yearTSD >1 yearPeriod 1SEC 300 mg n = 54SEC 150 mg n = 46SEC 150 mg NL n = 43PBO n = 74SEC 300 mg n = 168SEC 150 mg n = 174SEC 150 mg NL n = 179PBO n = 258Baseline, mean (SD)8.02 (20.77)8.82 (12.06)12.74 (33.67)8.84 (20.42)14.37 (24.17)14.67 (28.01)15.56 (37.52)17.34 (41.21)Week 24 change from baseline, mean (SD)0.05 (0.72)−0.08 (1.40)−0.61 (5.25)0.76 (2.05)0.09 (1.37)0.23 (1.24)0.03 (2.05)0.42 (1.56)Period 2SEC 300 mg* n = 54SEC 150 mg†n = 46SEC 150 mg NL†n = 43PBO ‒ 300 mg n = 40PBO ‒ 150 mg†n = 30SEC 300 mg* n = 168SEC 150 mg†n = 174SEC 150 mg NL†n = 179PBO ‒ 300 mg n = 113PBO ‒ 150 mg†n = 123Week 52 change from baseline, mean (SD)0.05 (0.48)−0.03 (1.22)0.35 (2.25)0.22 (0.70)0.18 (0.75)−0.07 (1.16)0.26 (1.96)0.26 (1.05)0.16 (0.94)0.40 (2.00)Week 104 change from baseline, mean (SD)0.06 (0.63)0.11 (0.99)0.20 (2.71)0.11 (0.68)−0.07 (0.50)0.11 (2.00)0.62 (2.94)0.46 (2.08)0.12 (0.90)0.81 (2.66)

NL, no loading dose; PBO, placebo; SEC, secukinumab; TSD, time since diagnosis.

* One outlier in the 300-mg dose group was excluded.

† Includes patients who received dose escalation to SEC 300 mg after Week 52.

Conclusion

SEC resulted in low rates of radiographic progression through 2 years of treatment among patients in FUTURE 5, regardless of time since PsA diagnosis.

References

[1]Haroon M, et al. Ann Rheum Dis. 2015;74:1045-50.

[2]Mease P, et al. RMD Open. 2021;7:e001600.

Acknowledgements

This study was funded by Novartis Pharmaceuticals Corporation. Medical writing support was provided by Richard Karpowicz, PhD, CMPP, of Health Interactions, Inc, and was funded by Novartis Pharmaceuticals Corporation. This abstract was developed in accordance with Good Publication Practice (GPP3) guidelines. Authors had full control of the content and made the final decision on all aspects of this publication.

Disclosure of Interests

Christopher T. Ritchlin Consultant of: AbbVie, Amgen, Eli Lilly, Janssen, Pfizer, Novartis, Gilead, and UCB, Ana-Maria Orbai Consultant of: Bristol Myers Squibb, Janssen, Lilly, Novartis, Pfizer, and UCB, Grant/research support from: to Johns Hopkins University from AbbVie, Amgen, Celgene, Horizon, Janssen, Lilly, and Novartis, Bhumik Parikh Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Corine Gaillez Employee of: Novartis Pharma AG, Basel, Switzerland, Xiangyi Meng Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Philip J Mease Speakers bureau: AbbVie, Amgen, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Galapagos, Gilead, GlaxoSmithKline, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Gilead, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB

Multi-modal imaging for uptake of peptide ligand specific for CD44 by hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is rising steadily in incidence, and more effective methods are needed for early cancer detection and image-guided surgery.

METHODS

We used a structural model to optimize the peptide sequence. Specific binding was validated in vitro with knockdown, competition, and co-localization assays. Multi-modal imaging was performed to validate specific binding in vivo in orthotopically-implanted human xenograft tumors.

RESULTS

Binding properties of WKGWSYLWTQQA were characterized by an apparent dissociation constant of k_d = 43 nM, and an apparent association time constant of k = 0.26 min^-1. The target-to-background ratio was significantly higher for the target versus control for both modalities. Ex-vivo evaluation using human HCC specimens supported the ability of the peptide to distinguish HCC from other liver pathologies.

CONCLUSIONS

We have identified a peptide specific for CD44 with properties that are promising for clinical translation to image HCC in vivo.

OP0076 L-ARGININE REPROGRAMS OSTEOCLAST PURINE METABOLISM AMELIORATING BONE LOSS IN RHEUMATOID ARTHRITIS

Background

Bone erosion is a clinical feature of rheumatoid arthritis related to disease severity and poor functional prognosis. Excessive osteoclast differentiation and insufficient osteoblast function are the main reasons for the erosive process in RA. Our previous investigation indicated that L-arginine supplementation not only diminished arthritic inflammation in the serum-induced arthritis (K/BxN) model but also decreased inflammatory joints osteoclast numbers (1).

Objectives

In the present study, we aim to investigate the metabolic action of L-arginine supplementation in RA, especially on periarticular bone erosion and systemic bone loss. We plan to depict the metabolic features of TNFα induced inflammatory osteoclasts after in vitro L-arginine supplementation.

Methods

Three murine arthritis models (serum-induced arthritis (K/BxN) model, collagen-induced arthritis model, and hTNFtg mice model) were analysed in this study. L-arginine was supplemented within the drinking water after the onset of arthritis. Bone parameters for axial skeleton (spine) and peripheral skeleton (tibia) from the respective group were quantified by μCT. HE and TRAP staining were performed to address further the erosion area and osteoclast numbers in periarticular sites. In vitro osteoclast differentiation was conducted with or without L-arginine treatment, in the presence or not of TNFα activation. Seahorse and SCENITH analyses were adopted to delineate the metabolic features. JC-1 staining and transmission electron microscopy (TEM) were used to depict the mitochondria metabolism. RNA-seq and mass spectrometry (MS) were performed to investigate the underlying molecular mechanism.

Results

Inflammation was diminished in all three arthritis models after L-arginine supplementation with a significant reduction in arthritic score. Moreover, an amelioration of periarticular bone erosion, systemic bone loss, and decreased osteoclast numbers in periarticular sites were observed in arthritic mice after L-arginine treatment. L-arginine also inhibited osteoclastogenesis in vitro, particularly under TNFα activation. Seahorse and SCENITH analyses indicated TNFα promoted glycolysis while blocking mitochondria-driven oxidative phosphorylations (OXPHOS) in pre-osteoclasts. Meanwhile, JC-1 staining and TEM images also showed that TNFα decreased mitochondria membrane potential and prompted damage of mitochondria. Surprisingly, L-arginine rescued the TNFα inhibition of OXPHOS while promoting ATP production.

RNA-seq and MS data confirmed the boost of OXPHOS after L-arginine treatment under TNFα activation. To interfere with OXPHOS, L-arginine inhibited cJun thus altered arginase-1 and arginase-2 expression. Moreover, the increased ATP in L-arginine treated cells facilitated purine metabolism, especially the production of inosine and hypoxanthine, contributing to the inhibition of osteoclastogenesis. Increasing Adenosine deaminase (ADA) is essential for the production of inosine and hypoxanthine due to the decreased inhibitory regulation of the transcription factor c-Jun.

Conclusion

These data strongly demonstrated that L-arginine ameliorates bone erosion in RA through metabolic reprogramming and perturbation of purine metabolism in osteoclasts. L-arginine might therefore benefit RA therapy by reducing joint inflammation and also ameliorating bone destruction.

References

[1]Hannemann, Nicole, et al. “Transcription factor Fra-1 targets arginase-1 to enhance macrophage-mediated inflammation in arthritis.” The Journal of clinical investigation 129.7 (2019): 2669-2684.

Disclosure of Interests

Shan Cao: None declared, Rui Song: None declared, Xianyi Meng: None declared, Katerina Kachler: None declared, Maximilian Fuchs: None declared, Xinyu Meng: None declared, Yixuan Li: None declared, Verena Taudte: None declared, Meik Kunz: None declared, Ursula Schloetzer-Schrehardt: None declared, Ulrike Schleicher: None declared, Xiaoxiang Chen Speakers bureau: AbbVie, Roche and Novartis, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Aline Bozec: None declared.

POS0409 INTESTINAL HIF1α EXPRESSION PROTECTS AGAINST EPITHELIAL CELL DEATH IN ARTHRITIS

Background

While a so-called gut-joint axis is supported by many clinical observations, the current knowledge on such axis is mostly confined to descriptive and correlative data, e.g. showing the microbiota changes are associated with arthritis. In contrast, mechanistic data on how molecular changes in the intestinal epithelium influence the development of arthritis are scarce.

Objectives

To investigate, whether the mucosal barrier in the intestine dependent of the epithelial cell survival maintenance, influences the development of arthritis.

Methods

Intestinal hypoxia inducible factor (HIF)-1α expression was assessed before, at onset and during experimental arthritis and human rheumatoid arthritis (RA). Intestinal epithelial cell-specific HIF1α conditional knock-out mice were generated (HIF1αΔIEC) and subjected to collagen-induced arthritis (CIA). Clinical and histological courses of arthritis were recorded, and T and B cell subsets were analyzed in the gut and secondary lymphatic organs, and intestinal epithelial cells were subjected to molecular mRNA sequencing in HIF1αΔIEC and littermate control mice. Furthermore, pharmacologic HIF1α stabilization by PHD inhibitor was used for the treatment of arthritis.

Results

Intestinal HIF1α expression peaked at onset and remained high in experimental arthritis and RA. Conditionally deletion of HIF1α in gut epithelial cells strongly exacerbate arthritis and was associated with increased gut epithelial cell death, intestinal and lymphatic Th1 and Th17 activation. Mechanistically, HIF1α inhibits the transcription of necroptotic and apoptotic markers, which leads to a defect in the intestinal barrier integrity. Furthermore, treatment with HIF1α stabilization reinforced the gut epithelial cell survival and inhibited arthritis.

Conclusion

These findings show that the HIF1α regulating epithelial cells survival is critical for the breakdown of the intestinal barrier function in arthritis highlighting the functional link between intestinal homeostasis and arthritis.

Disclosure of Interests

None declared.

POS1022 RELATIONSHIPS BETWEEN INHIBITION OF RADIOGRAPHIC PROGRESSION AND ACHIEVEMENT OF LOW DISEASE ACTIVITY OR REMISSION AND THEIR CORE COMPONENTS IN PATIENTS WITH PSORIATIC ARTHRITIS TREATED WITH SECUKINUMAB IN FUTURE 5 DURING THE FIRST 24 WEEKS

Background

Patients with active psoriatic arthritis (PsA) experience inflammation that may result in structural damage and disability. In the phase 3 FUTURE 5 study, treatment with secukinumab (SEC) inhibited radiographic progression and led to sustained remission and low disease activity (LDA) through Week 104.1,2

Objectives

This post hoc analysis of FUTURE 5 explored relationships between radiographic progression status and achievement of LDA or remission in patients treated with SEC.

Methods

Patients were randomized 2:2:2:3 to receive SEC 300 mg with loading dose (LD), 150 mg LD, SEC 150 mg without LD, or placebo (PBO) at Baseline, Weeks 1, 2, 3, 4, and every 4 weeks thereafter until Week 24. In this post hoc analysis, patients were grouped by radiographic progression status at Week 24 (non-radiographic progressors: change from baseline in modified total Sharp score [mTSS] ≤0.0; radiographic progressors: change from baseline in mTSS >0.0). Efficacy (achievement of Minimal Disease Activity [MDA] or Very Low Disease Activity [VLDA] and their individual components, and Disease Activity Index for Psoriatic Arthritis [DAPSA] LDA or remission) was assessed at Week 24.

Results

Of 933 patients with available data, 675 (72.3%) were classified as non-radiographic progressors and 258 (27.7%) were radiographic progressors at Week 24. Non-progressors at Week 24 were more likely than progressors to achieve DAPSA LDA and remission at Week 24 across all treatment arms (Figure 1A). In addition, non-progressors were more likely to achieve MDA and VLDA at Week 24 than progressors across all treatment arms (Figure 1B). Similar trends were observed for all of the individual MDA/VLDA criteria at Week 24 among patients treated with SEC 300 mg or SEC 150 mg LD (Table 1). Notably, non-progressors were more likely to achieve improvements in physical function, pain, and patient global assessment of disease activity than progressors across all treatment arms.

Table 1.

Proportion of Patients Achieving MDA/VLDA Components at Week 24 Grouped by Radiographic Progression Status at Week 24

Week 24 non-progressorsWeek 24 progressorsOutcome, n/N (%)SEC 300 mg n = 166SEC 150 mg n = 150SEC 150 mg NL n = 159PBO n = 200SEC 300 mg n = 51SEC 150 mg n = 63SEC 150 mg NL n = 51PBO n = 93TJC78 ≤152/161 (32.3)46/146 (31.5)37/150 (24.7)38/196 (19.4)15/50 (30.0)13/62 (21.0)13/49 (26.5)11/90 (12.2)SJC76 ≤1105/160 (65.6)85/146 (58.2)83/150 (55.3)88/196 (44.9)32/50 (64.0)28/62 (45.2)20/49 (40.8)30/90 (33.3)PASI ≤1 or BSA ≤3%99/128 (77.3)90/128 (70.3)69/109 (63.3)64/153 (41.8)29/38 (76.3)27/47 (57.4)28/40 (70.0)26/70 (37.1)Patient pain VAS ≤1557/144 (39.6)50/133 (37.6)50/141 (35.5)33/179 (18.4)14/42 (33.3)15/60 (25.0)13/43 (30.2)7/82 (8.5)PtGA VAS ≤2063/145 (43.4)47/125 (37.6)50/135 (37.0)39/173 (22.5)13/41 (31.7)14/61 (23.0)13/41 (31.7)7/81 (8.6)HAQ-DI ≤0.572/135 (53.3)55/118 (46.6)54/122 (44.3)47/158 (29.7)13/39 (33.3)18/58 (31.0)17/39 (43.6)19/77 (24.7)Tender entheseal points ≤170/87 (80.5)44/63 (69.8)42/76 (55.3)45/88 (51.1)13/18 (72.2)17/31 (54.8)11/19 (57.9)23/38 (60.5)

BSA, body surface area; HAQ-DI, Health Assessment Questionnaire Disability Index; MDA, Minimal Disease Activity; NL, no loading dose; PASI, Psoriasis Area and Severity Index; PBO, placebo; PtGA, patient global assessment of disease activity; SEC, secukinumab; SJC, swollen joint count; TJC, tender joint count; VAS, visual analog scale; VLDA, Very Low Disease Activity.

Conclusion

Patients who did not have radiographic progression over 6 months of SEC treatment were more likely to achieve LDA or remission and improvement in physical function at Week 24. Additional analyses will explore relationships between radiographic progression and additional clinical and patient-reported outcomes over longer time periods.

References

[1]Mease P, et al. RMD Open. 2021;7:e001600.

[2]Coates LC, et al. Ann Rheum Dis. 2021;80:803-4.

Acknowledgements

This study was funded by Novartis Pharmaceuticals Corporation. Medical writing support was provided by Eric Deutsch, PhD, CMPP, of Health Interactions, Inc, and was funded by Novartis Pharmaceuticals Corporation. This abstract was developed in accordance with Good Publication Practice (GPP3) guidelines. Authors had full control of the content and made the final decision on all aspects of this publication.

Disclosure of Interests

Philip J Mease Speakers bureau: AbbVie, Amgen, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Galapagos, Gilead, GlaxoSmithKline, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Gilead, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB, Ana-Maria Orbai Consultant of: Bristol Myers Squibb, Janssen, Lilly, Novartis, Pfizer, and UCB, Grant/research support from: To Johns Hopkins University from AbbVie, Amgen, Celgene, Horizon, Janssen, Lilly, and Novartis, Bhumik Parikh Employee of: Novartis Pharmaceuticals Corporation, Corine Gaillez Employee of: Novartis Pharma AG, Xiangyi Meng Employee of: Novartis Pharmaceuticals Corporation, Christopher T. Ritchlin Consultant of: AbbVie, Amgen, Eli Lilly, Janssen, Pfizer, Novartis, Gilead, and UCB

Free radicals removing extracellular polymeric substances to enhance the degradation of intracellular antibiotic resistance genes in multi-resistant Pseudomonas Putida by UV/H2O2 and UV/peroxydisulfate disinfection processes

UV-based advanced oxidation processes (UV-AOPs) have been recommended to disinfect wastewater treatment plant (WWTP) effluents to control the dissemination of antibiotic resistance, but the mechanism of intracellular antibiotic resistance genes (i-ARGs) degradation by UV-AOPs is still poorly understood. Here we compared the efficacies of UV, UV/H₂O₂, and UV/PDS in degrading seven i-ARGs carried by a multi-drug resistant P. putida MX-2 isolated from sewage sludge and investigated the roles of free radicals and UV irradiation in degrading the carried i-ARGs in UV-AOPs. The results suggested that although UV/H₂O₂ and UV/PDS were only slightly superior to UV to inactivate P. putida MX-2, they significantly promoted the degradation of i-ARGs. The generated free radicals mainly reacted with the bacterial extracellular polymeric substances (EPS), increased the cell membrane permeability of bacteria, and consequently facilitated UV irradiation enter into the intracellular environment to damage the i-ARGs, thus enhancing their degradation during UV-AOPs processes. Our findings suggested that the removal of bacterial EPS by free radicals greatly contributed to the degradation of i-ARGs by UV irradiation in UV-AOPs, and more efficient approaches that are capable of removing EPS should be further developed to effectively control the dissemination of antibiotic resistance by UV treatment of wastewater effluent.

Genome-wide survey and expression analysis of GRAS transcription factor family in sweetpotato provides insights into their potential roles in stress response

BACKGROUND

The plant-specific GRAS transcription factors play pivotal roles in various adverse environmental conditions. Numerous GRAS genes have been explored and characterized in different plants, however, comprehensive survey on GRASs in sweetpotato is lagging.

RESULTS

In this study, 72 putative sweetpotato IbGRAS genes with uneven distribution were isolated on 15 chromosomes and classified into 12 subfamilies supported by gene structures and motif compositions. Moreover, both tandem duplication and segmental duplication events played critical roles in the expansion of sweetpotato GRAS genes, and the collinearity between IbGRAS genes and the related orthologs from nine other plants further depicted evolutionary insights into GRAS gene family. RNA-seq analysis under salt stress and qRT-PCR detection of 12 selected IbGRAS genes demonstrated their significant and varying inductions under multiple abiotic stresses (salt, drought, heat and cold) and hormone treatments (ABA, ACC and JA). Consistently, the promoter regions of IbGRAS genes harbored a series of stress- and hormone-associated cis-acting elements. Among them, IbGRAS71, the potential candidate for breeding tolerant plants, was characterized as having transactivation activity in yeasts, while IbGRAS-2/-4/-9 did not. Moreover, a complex interaction relationship between IbGRASs was observed through the interaction network analysis and yeast two-hybrid assays.

CONCLUSIONS

Our results laid a foundation for further functional identifications of IbGRAS genes, and multiple members may serve as potential regulators for molecular breeding of tolerant sweetpotato.

Bioleaching rather than chemical conditioning using Fe[III]/CaO or polyacrylamide mitigates antibiotic resistance in sludge composting via pre-removing antibiotic resistance genes and limiting horizontal gene transfer

Conditioning can drastically improve the dewaterability of sewage sludge and is widely practiced in most wastewater treatment plants (WWTPs). Sludge conditioning was also reported as a crucial step in sludge treatment to attenuate antibiotic resistance, but it remains unclear whether the attenuated antibiotic resistance by conditioning treatments would guarantee low abundance of antibiotic resistance genes (ARGs) in the compost products of municipal sewage sludge. Herein, the impacts of three conditioning treatments, including bioleaching and chemical conditioning using Fe[III]/CaO or polyacrylamide (PAM), on the abundances of 20 ARGs and 4 mobile genetic elements (MGEs) during conventional aerobic composting of dewatered sludge were investigated. It was found that the absolute and relative abundances of total ARGs in compost product of bioleached sludge accounted for only 13.8%-28.8% of that in compost products of un-conditioned, Fe[III]/CaO-conditioned, or PAM-conditioned sludges. Besides, bioleaching conditioning resulted in the lowest abundances of ARG subtypes and ARG-associated bacteria in the sludge compost product. The shift of ARG profiles in the bioleached sludge composting can be mainly ascribed to the ARG-associated bacteria, while the MGEs drove the ARG profiles during conventional composting of un-conditioned sludge and the two chemically conditioned sludge. Thus, bioleaching conditioning is superior to the chemical conditioning using Fe[III]/CaO or PAM in mitigating antibiotic resistance in sludge compost products, which was contributed by the pre-removal of ARGs prior to composting treatment and the potential limitation of ARGs transfer during conventional composting.

A strategy for the efficient construction of anti-PD1-based bispecific antibodies with desired IgG-like properties

Targeting PD1/PDL1 with blocking antibodies for cancer therapy has shown promising benefits in the clinic, but only approximately 20-30% of patients develop durable clinical responses to the treatment. Bispecific antibodies (BsAbs) that combine PD1/PDL1 blockade with the modulation of another immune checkpoint target may have greater potential to enhance immune checkpoint blockade therapy. In this study, we identified an anti-PD1 monoclonal antibody, 609A, whose heavy chain can pair with a variety of light chains from different antibodies while maintaining its PD1 binding/blocking activity. Taking advantage of this property and using a linear F(ab')₂ format, we successfully produced a series of tetravalent IgG-like BsAbs that simultaneously target PD1 and other immune checkpoint targets, including PDL1 and CTLA4. The BsAbs exhibited superior bioactivities in vitro and in vivo compared to their respective parental mAbs. Importantly, the BsAbs demonstrated the desired IgG-like physicochemical properties in terms of high-level expression, ease of purification to homogeneity, good stability and in vivo pharmacokinetics. In summary, we describe a novel and flexible plug-and-play platform to engineer IgG-like BsAbs with excellent development potential for clinical applications.

Multi-Modal Imaging Probe for Glypican-3 Overexpressed in Orthotopic Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is rising steadily in incidence, and more effective methods are needed for early detection and image-guided surgery. Glypican-3 (GPC3) is a cell surface biomarker that is overexpressed in early-stage cancer but not in cirrhosis. An IRDye800-labeled 12-mer amino acid sequence was identified, and specific binding to GPC3 was validated in vitro and in orthotopically implanted HCC tumors in vivo. Over 4-fold greater binding affinity and 2-fold faster kinetics were measured by comparison with previous GPC3 peptides. Photoacoustic images showed peak tumor uptake at 1.5 h post-injection and clearance within ∼24 h. Laparoscopic and whole-body fluorescence images showed strong intensity from tumor versus adjacent liver with about a 2-fold increase. Immunofluorescence staining of human liver specimens demonstrated specific binding to HCC versus cirrhosis with 79% sensitivity and 79% specificity, and normal liver with 81% sensitivity and 84% specificity. The near-infrared peptide is promising for early HCC detection in clinical trials.

[Antibodies persistence after revaccination with three doses of hepatitis B vaccine in non-responsive adults: results from 8-year follow-up study]

Objective: To evaluate the persistence of HBsAg-specific antibodies eight years after revaccination with hepatitis B vaccine (HepB) among adults who were non-responsive to primary immunization. Methods: From August to September 2009, rural communities in Zhangqiu district of Ji'nan city were selected as the study site. The subject's inclusion criteria were 18 to 49 years old, local resident population, without HBV infection history and HepB vaccination history, and good health status. Antibodies against hepatitis B surface antigen (anti-HBs) were detected in adults following the standard primary vaccination. Those who were non-responders (anti-HBs titer <10 mIU/ml) were revaccinated with three doses of HepB and included in the study. Blood samples were collected from all of them at one month (T₁), two years, four years, and eight years after revaccination. The three indexes of anti-HBs, hepatitis B surface antigen (HBsAg), together with antibody against hepatitis B core antigen (anti-HBc), were measured by chemiluminescence microparticle immunoassay (CMIA). Results: The proportion of subjects with anti-HBs titers ≥10 mIU/ml was 85.12% (549/645) at T₁, 60.60% (283/467) at two years, 55.90% (199/356) at four years and 55.09% (222/403) at eight years after revaccination. The first two years' annual decline rates, three to four years and five to eight years, were 15.62%, 3.96%, and 0.36%. The GMC of anti-HBs was 153.92 mIU/ml at T₁, 21.43 mIU/ml at two years, 15.02 mIU/ml at four years, and 13.68 mIU/ml at eight years. In the first two years, three to four years and five to eight years, the annual decline rate of GMC was 62.69%,16.28%, and 2.31%, respectively. Multivariable analysis showed that the titer of anti-HBs at T₁ was independently associated with the persistence of anti-HBs at eight years after revaccination. Compared with anti-HBs titer <100 mIU/ml , those whose anti-HBs titers were 100-mIU/ml and ≥1 000 mIU/ml at T₁ had a higher positive rate of anti-HBs (OR=14.13, P<0.001; OR= 62.91, P<0.001) and a higher probability of anti-HBs titer (β=1.88, P<0.001; β=3.24, P<0.001) at 8 years after revaccination. Nobody was found seroconversion of HBsAg, and the anti-HBc positive rate was 14.14% (57/403). Conclusions: Following revaccination with three doses of HepB in adults who were non-responsive to primary immunization, anti-HBs titers declined rapidly within the first four years. They then maintained a stable level after the fifth year. More than half still kept anti-HBs protective titer at eight years after revaccination. The immunity persistence was associated with anti-HBs titer at one month after revaccination.

Fabrication of Ag/TiO2 Cotton Fabric to Enhance Photocatalytic Degradation of Anionic Dye

Ag/TiO2 composite fabric was prepared by coprecipitation with TiCl4 as a titanium source and AgNO3 as a silver source. The samples were characterized by scanning electron microscope (SEM), thermogravimetric analyzer (TG) and Fourier transform infrared spectrometer (FTIR). The photocatalytic activity of synthetic fabrics was measured by the degradation of anion dyes under ultraviolet light. The effects of silver loading concentration, fabric area, initial concentration, and photocatalytic time on photocatalytic activity were investigated. The experimental results showed that the degradation rate of Ag/TiO2 composite fabric on anion dyes could reach 70.76% in 50 minutes, indicating that the prepared Ag/TiO2 composite fabrics had high photocatalytic activity.