Comparative genomic analyses reveal evidence for adaptive A-to-I RNA editing in insect Adar gene

Although A-to-I RNA editing leads to similar effects to A-to-G DNA mutation, nonsynonymous RNA editing (recoding) is believed to confer its adaptiveness by 'epigenetically' regulating proteomic diversity in a temporospatial manner, avoiding the pleiotropic effect of genomic mutations. Recent discoveries on the evolutionary trajectory of Ser>Gly auto-editing site in insect Adar gene demonstrated a selective advantage to having an editable codon compared to uneditable ones. However, apart from pure observations, quantitative approaches for justifying the adaptiveness of individual RNA editing sites are still lacking. We performed a comparative genomic analysis on 113 Diptera species, focusing on the Adar Ser>Gly auto-recoding site in Drosophila. We only found one species having a derived Gly at the corresponding site, and this occurrence was significantly lower than genome-wide random expectation. This suggests that the Adar Ser>Gly site is unlikely to be genomically replaced with G during evolution, and thus indicating the advantage of editable status over hardwired genomic alleles. Similar trends were observed for the conserved Ile>Met recoding in gene Syt1. In the light of evolution, we established a comparative genomic approach for quantitatively justifying the adaptiveness of individual editing sites. Priority should be given to such adaptive editing sites in future functional studies.

Narrowing down the candidates of beneficial A-to-I RNA editing by comparing the recoding sites with uneditable counterparts

Adar-mediated adenosine-to-inosine (A-to-I) RNA editing mainly occurs in nucleus and diversifies the transcriptome in a flexible manner. It has been a challenging task to identify beneficial editing sites from the sea of total editing events. The functional Ser>Gly auto-recoding site in insect Adar gene has uneditable Ser codons in ancestral nodes, indicating the selective advantage to having an editable status. Here, we extended this case study to more metazoan species, and also looked for all Drosophila recoding events with potential uneditable synonymous codons. Interestingly, in D. melanogaster, the abundant nonsynonymous editing is enriched in the codons that have uneditable counterparts, but the Adar Ser>Gly case suggests that the editable orthologous codons in other species are not necessarily edited. The use of editable versus ancestral uneditable codon is a smart way to infer the selective advantage of RNA editing, and priority might be given to these editing sites for functional studies due to the feasibility to construct an uneditable allele. Our study proposes an idea to narrow down the candidates of beneficial recoding sites. Meanwhile, we stress that the matched transcriptomes are needed to verify the conservation of editing events during evolution.

New comparative genomic evidence supporting the proteomic diversification role of A-to-I RNA editing in insects

Adenosine-to-inosine (A-to-I) RNA editing, resembling A-to-G mutation, confers adaptiveness by increasing proteomic diversity in a temporal-spatial manner. This evolutionary theory named "proteomic diversifying hypothesis" has only partially been tested in very few organisms like Drosophila melanogaster, mainly by observing the positive selection on nonsynonymous editing events. To find additional genome-wide evidences supporting this interesting assumption, we retrieved the genomes of four Drosophila species and collected 20 deep-sequenced transcriptomes of different developmental stages and neuron populations of D. melanogaster. We systematically profiled the RNA editomes in these samples and performed meticulous comparative genomic analyses. Further evidences were found to support the diversifying hypothesis. (1) None of the nonsynonymous editing sites in D. melanogaster had ancestral G-alleles, while the silent editing sites had an unignorable fraction of ancestral G-alleles; (2) Only very few nonsynonymous editing sites in D. melanogaster had corresponding G-alleles derived in the genomes of sibling species, and the fraction of such situation was significantly lower than that of silent editing sites; (3) The few nonsynonymous editing with corresponding G-alleles had significantly more variable editing levels (across samples) than other nonsynonymous editing sites in D. melanogaster. The proteomic diversifying nature of RNA editing in Drosophila excludes the restorative role which favors an ancestral G-allele. The few fixed G-alleles in sibling species might facilitate the adaptation to particular environment and the corresponding nonsynonymous editing in D. melanogaster would introduce stronger advantage of flexible proteomic diversification. With multi-Omics data, our study consolidates the nature of evolutionary significance of A-to-I RNA editing sites in model insects.

The first A-to-I RNA editome of hemipteran species Coridius chinensis reveals overrepresented recoding and prevalent intron editing in early-diverging insects

BACKGROUND

Metazoan adenosine-to-inosine (A-to-I) RNA editing resembles A-to-G mutation and increases proteomic diversity in a temporal-spatial manner, allowing organisms adapting to changeable environment. The RNA editomes in many major animal clades remain unexplored, hampering the understanding on the evolution and adaptation of this essential post-transcriptional modification.

METHODS

We assembled the chromosome-level genome of Coridius chinensis belonging to Hemiptera, the fifth largest insect order where RNA editing has not been studied yet. We generated ten head RNA-Seq libraries with DNA-Seq from the matched individuals.

RESULTS

We identified thousands of high-confidence RNA editing sites in C. chinensis. Overrepresentation of nonsynonymous editing was observed, but conserved recoding across different orders was very rare. Under cold stress, the global editing efficiency was down-regulated and the general transcriptional processes were shut down. Nevertheless, we found an interesting site with "conserved editing but non-conserved recoding" in potassium channel Shab which was significantly up-regulated in cold, serving as a candidate functional site in response to temperature stress.

CONCLUSIONS

RNA editing in C. chinensis largely recodes the proteome. The first RNA editome in Hemiptera indicates independent origin of beneficial recoding during insect evolution, which advances our understanding on the evolution, conservation, and adaptation of RNA editing.

Molecular insights into the adaptive evolution of SARS-CoV-2 spike protein

The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has substantially damaged the global economy and human health. The spike (S) protein of coronaviruses plays a pivotal role in viral entry by binding to host cell receptors. Additionally, it acts as the primary target for neutralizing antibodies in those infected and is the central focus for currently utilized or researched vaccines. During the virus's adaptation to the human host, the S protein of SARS-CoV-2 has undergone significant evolution. As the COVID-19 pandemic has unfolded, new mutations have arisen and vanished, giving rise to distinctive amino acid profiles within variant of concern strains of SARS-CoV-2. Notably, many of these changes in the S protein have been positively selected, leading to substantial alterations in viral characteristics, such as heightened transmissibility and immune evasion capabilities. This review aims to provide an overview of our current understanding of the structural implications associated with key amino acid changes in the S protein of SARS-CoV-2. These research findings shed light on the intricate and dynamic nature of viral evolution, underscoring the importance of continuous monitoring and analysis of viral genomes. Through these molecular-level investigations, we can attain deeper insights into the virus's adaptive evolution, offering valuable guidance for designing vaccines and developing antiviral drugs to combat the ever-evolving viral threats.

Natural selection and genetic diversity maintenance in a parasitic wasp during continuous biological control application

Aphidius gifuensis is a parasitoid wasp and primary endoparasitoid enemy of the peach potato aphid, Myzus persicae. Artificially reared, captive wasps of this species have been extensively and effectively used to control populations of aphids and limit crop loss. However, the consequences of large-scale releasing of captive A. gifuensis, such as genetic erosion and reduced fitness in wild populations of this species, remains unclear. Here, we sequence the genomes of 542 A. gifuensis individuals collected across China, including 265 wild and 277 human-intervened samples. Population genetic analyses on wild individuals recovered Yunnan populations as the ancestral group with the most complex genetic structure. We also find genetic signature of environmental adaptation during the dispersal of wild populations from Yunnan to other regions. While comparative genomic analyses of captive wasps revealed a decrease in genetic diversity during long-term rearing, population genomic analyses revealed signatures of natural selection by several biotic (host plants) or abiotic (climate) factors, which support maintenance of the gene pool of wild populations in spite of the introduction of captive wasps. Therefore, the impact of large-scale release is reduced. Our study suggests that A. gifuensis is a good system for exploring the genetic and evolutionary effects of mass rearing and release on species commonly used as biocontrol agents.

Chromosome-level genome of the poultry shaft louse Menopon gallinae provides insight into the host-switching and adaptive evolution of parasitic lice

BACKGROUND

Lice (Psocodea: Phthiraptera) are one important group of parasites that infects birds and mammals. It is believed that the ancestor of parasitic lice originated on the ancient avian host, and ancient mammals acquired these parasites via host-switching from birds. Here we present the first chromosome-level genome of Menopon gallinae in Amblycera (earliest diverging lineage of parasitic lice). We explore the transition of louse host-switching from birds to mammals at the genomic level by identifying numerous idiosyncratic genomic variations.

RESULTS

The assembled genome is 155 Mb in length, with a contig N50 of 27.42 Mb. Hi-C scaffolding assigned 97% of the bases to 5 chromosomes. The genome of M. gallinae retains a basal insect repertoire of 11,950 protein-coding genes. By comparing the genomes of lice to those of multiple representative insects in other orders, we discovered that gene families of digestion, detoxification, and immunity-related are generally conserved between bird lice and mammal lice, while mammal lice have undergone a significant reduction in genes related to chemosensory systems and temperature. This suggests that mammal lice have lost some of these genes through the adaption to environment and temperatures after host-switching. Furthermore, 7 genes related to hematophagy were positively selected in mammal lice, suggesting their involvement in the hematophagous behavior.

CONCLUSIONS

Our high-quality genome of M. gallinae provides a valuable resource for comparative genomic research in Phthiraptera and facilitates further studies on adaptive evolution of host-switching within parasitic lice.

Identification and Interpretation of A-to-I RNA Editing Events in Insect Transcriptomes

Adenosine-to-inosine (A-to-I) RNA editing is the most prevalent RNA modification in the nervous systems of metazoans. To study the biological significance of RNA editing, we first have to accurately identify these editing events from the transcriptome. The genome-wide identification of RNA editing sites remains a challenging task. In this review, we will first introduce the occurrence, regulation, and importance of A-to-I RNA editing and then describe the established bioinformatic procedures and difficulties in the accurate identification of these sit esespecially in small sized non-model insects. In brief, (1) to obtain an accurate profile of RNA editing sites, a transcriptome coupled with the DNA resequencing of a matched sample is favorable; (2) the single-cell sequencing technique is ready to be applied to RNA editing studies, but there are a few limitations to overcome; (3) during mapping and variant calling steps, various issues, like mapping and base quality, soft-clipping, and the positions of mismatches on reads, should be carefully considered; (4) Sanger sequencing of both RNA and the matched DNA is the best verification of RNA editing sites, but other auxiliary evidence, like the nonsynonymous-to-synonymous ratio or the linkage information, is also helpful for judging the reliability of editing sites. We have systematically reviewed the understanding of the biological significance of RNA editing and summarized the methodology for identifying such editing events. We also raised several promising aspects and challenges in this field. With insightful perspectives on both scientific and technical issues, our review will benefit the researchers in the broader RNA editing community.

Genetic Modification of a Hox Locus Drives Mimetic Color Pattern Variation in a Highly Polymorphic Bumble Bee

Müllerian mimicry provides natural replicates ideal for exploring mechanisms underlying adaptive phenotypic divergence and convergence, yet the genetic mechanisms underlying mimetic variation remain largely unknown. The current study investigates the genetic basis of mimetic color pattern variation in a highly polymorphic bumble bee, Bombus breviceps (Hymenoptera, Apidae). In South Asia, this species and multiple comimetic species converge onto local Müllerian mimicry patterns by shifting the abdominal setal color from orange to black. Genetic crossing between the orange and black phenotypes suggested the color dimorphism being controlled by a single Mendelian locus, with the orange allele being dominant over black. Genome-wide association suggests that a locus at the intergenic region between 2 abdominal fate-determining Hox genes, abd-A and Abd-B, is associated with the color change. This locus is therefore in the same intergenic region but not the same exact locus as found to drive red black midabdominal variation in a distantly related bumble bee species, Bombus melanopygus. Gene expression analysis and RNA interferences suggest that differential expression of an intergenic long noncoding RNA between abd-A and Abd-B at the onset setal color differentiation may drive the orange black color variation by causing a homeotic shift late in development. Analysis of this same color locus in comimetic species reveals no sequence association with the same color shift, suggesting that mimetic convergence is achieved through distinct genetic routes. Our study establishes Hox regions as genomic hotspots for color pattern evolution in bumble bees and demonstrates how pleiotropic developmental loci can drive adaptive radiations in nature.

The Many Roles of A-to-I RNA Editing in Animals: Functional or Adaptive?

Metazoan adenosine-to-inosine (A-to-I) RNA editing is a highly conserved mechanism that diversifies the transcriptome by post-transcriptionally converting adenosine to inosine. Millions of editing sites have been identified in different species and, based on abnormal editing observed in various disorders, it is intuitive to conclude that RNA editing is both functional and adaptive. In this review, we propose the following major points: (1) "Function/functional" only represents a molecular/phenotypic consequence and is not necessarily connected to "adaptation/adaptive"; (2) Adaptive editing should be judged in the light of evolution and emphasize advantages of temporal-spatial flexibility; (3) Adaptive editing could, in theory, be extended from nonsynonymous sites to all potentially functional sites. This review seeks to conceptually bridge the gap between molecular biology and evolutionary biology and provide a more objective understanding on the biological functions and evolutionary significance of RNA editing.

Genome-Wide Analysis on Driver and Passenger RNA Editing Sites Suggests an Underestimation of Adaptive Signals in Insects

Adenosine-to-inosine (A-to-I) RNA editing leads to a similar effect to A-to-G mutations. RNA editing provides a temporo-spatial flexibility for organisms. Nonsynonymous (Nonsyn) RNA editing in insects is over-represented compared with synonymous (Syn) editing, suggesting adaptive signals of positive selection on Nonsyn editing during evolution. We utilized the brain RNA editome of Drosophila melanogaster to systematically study the LD (r2) between editing sites and infer its impact on the adaptive signals of RNA editing. Pairs of editing sites (PESs) were identified from the transcriptome. For CDS PESs of two consecutive editing sites, their occurrence was significantly biased to type-3 PES (Syn-Nonsyn). The haplotype frequency of type-3 PES exhibited a significantly higher abundance of AG than GA, indicating that the rear Nonsyn site is the driver that promotes the editing of the front Syn site (passenger). The exclusion of passenger Syn sites dramatically amplifies the adaptive signal of Nonsyn RNA editing. Our study for the first time quantitatively demonstrates that the linkage between RNA editing events comes from hitchhiking effects and leads to the underestimation of adaptive signals for Nonsyn editing. Our work provides novel insights for studying the evolutionary significance of RNA editing events.

PD-1 Inhibitors and Chemotherapy Combined with or without Radiotherapy for Patients with Oligometastatic Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Oligometastatic esophageal cancer (OMEC) is an intermediate state between local advanced and widespread metastatic disease, which is associated with better prognosis compared to poly-metastatic esophageal cancer (EC). The previous studies demonstrated the survival benefit from local radiotherapy for OMEC patients. But the data of PD-1 inhibitors combined with radiotherapy for OMEC is still scarce. The purpose of the present study was to determine the efficacy and safety of PD-1 inhibitors plus radiotherapy in OMEC.

MATERIALS/METHODS

OMEC was defined as "up to five measurable metastatic lesions and up to three organs involved". Patients with OMEC receiving PD-1 inhibitors plus chemotherapy in a single center were retrospectively analyzed in this study. They were dichotomized according to whether or not they had received radiotherapy. The efficacy and safety of immunochemotherapy combined with radiotherapy (RT group) and immunochemotherapy alone (NRT group) were investigated.

RESULTS

A total of 226 patients were included; 108 patients received PD-1 inhibitors plus chemotherapy and radiotherapy, while other 118 patients were treated with immunochemotherapy alone. Baseline characteristics were well balanced between the groups. The overall response rate (ORR) was 58.3% in the RT group and 41.5% in the NRT group (P = 0.012), respectively. The median PFS was 13.5 months (95% CI, 10.0-17.1) for the RT group and 8.8 months (95% CI, 9.2-12.0) for the NRT group (P = 0.000). The addition of radiotherapy was the major prognostic factor for PFS (hazard ratio, 0.56; 95% CI, 0.406-0.761; P = 0.000) by univariate Cox regression analysis. Patients were well-tolerated, and the overall incidence of adverse events was similar between the RT group and NRT group. In addition, the incidence of treatment-related pneumonitis did not differ between the two groups. Grade 3-5 pneumonitis was observed in 3.7% and 5.1% of patients in the RT and NRT groups, respectively.

CONCLUSION

The additional of radiotherapy to PD-1 inhibitors and chemotherapy improved PFS of patients with OMEC and showed acceptable toxicity. Further prospective studies investigating the combination of immunochemotherapy and radiotherapy are warranted.

Evaluating the Effects of Bone Marrow Sparing Radiotherapy on Acute Hematologic Toxicity for Patients with Locoregionally Advanced Cervical Cancer: A Prospective Phase II Randomized Controlled Trial

PURPOSE/OBJECTIVE(S)

Bone marrow sparing intensity modulated radiotherapy (BMS-IMRT) can reduce the incidence of acute hematologic toxicity (HT) for locoregionally advanced cervical cancer (LACC) patients receiving concurrent chemoradiotherapy (CCRT), but the norm has been controversial. The purpose of the study was to evaluate the effects of bone marrow (BM) V40 <25% on decreasing the incidence of acute HT in a prospective clinical trial.

MATERIALS/METHODS

A total of 242 LACC patients were recruited from May 2021 to May 2022, who were evenly randomized into BMS-IMRT group and standard IMRT group according to a computer-generated random number list. All patients received pelvic irradiation with concurrent cisplatin (40 mg/m2 weekly), followed by brachytherapy. For patients in BMS-IMRT group, the outer contour of pelvic bone, lumbar spine and left and right femur heads were additionally delineated as a surrogate for BM, and V40 <25% was prescribed. Blood counts were tested weekly, of which nadirs during external beam radiotherapy (EBRT) were graded to assess acute HT as primary observation index. Second observation index were dosimetric parameters of EBRT plan from the dose volume histograms (DVHs). Binary logistic regression model and receiver operating characteristic (ROC) curve were used for predictive value analysis.

RESULTS

Baseline demographic, disease and treatment characteristics were all balanced between BMS-IMRT group and standard IMRT group. BMS-IMRT was associated with a lower incidence of grade ≥2 and grade ≥3 acute HT, leukopenia and neutropenia (72.70% vs 90.90%, P <0.001*; 16.50% vs 65.30%, P <0.001*; 66.10% vs 85.10%, P = 0.001*; 13.20% vs 54.50%, P <0.001*; 37.20% vs 66.10%, P <0.001*; 10.70% vs 43.80%, P <0.001*). Plan target volume (PTV) for all patients satisfied the clinical requirement of V(100%) ≥95%, and conformity and homogeneity were both comparable between 2 groups. BMS also decreased dose delivered to the organs at risk (OARs) including rectum, bladder and left and right femur head. Univariate and multivariate analyses showed that BM V40 was an independent risk factor for grade ≥3 acute HT (odds ratio [OR] = 2.734, 95% confidence interval [CI] = 1.959-3.815, P <0.001*). Cutoff value was 25.036% and area under the curve (AUC) was 0.786. The nomogram was constructed, which was rigorously evaluated and internally cross-validated, showing good predictive performance.

CONCLUSION

BM V40 <25% can reduce the risks of acute HT for LACC patients receiving CCRT while the dose delivery of target volume and other normal tissues were not compromised. With great practicality and applicability, BM V40 <25% is a promising strategy, making BMS-IMRT widespread especially in the area where application of image guided radiotherapy (IGRT) such as 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET)/CT is not popularized. Chinese clinical trial registry (ChiCTR2200066485).

Autorecoding A-to-I RNA editing sites in the Adar gene underwent compensatory gains and losses in major insect clades

As one of the most prevalent RNA modifications in animals, adenosine-to-inosine (A-to-I) RNA editing facilitates the environmental adaptation of organisms by diversifying the proteome in a temporal-spatial manner. In flies and bees, the editing enzyme Adar has independently gained two different autorecoding sites that form an autofeedback loop, stabilizing the overall editing efficiency. This ensures cellular homeostasis by keeping the normal function of target genes. However, in a broader range of insects, the evolutionary dynamics and significance of this Adar autoregulatory mechanism are unclear. We retrieved the genomes of 377 arthropod species covering the five major insect orders (Hemiptera, Hymenoptera, Coleoptera, Diptera, and Lepidoptera) and aligned the Adar autorecoding sites across all genomes. We found that the two autorecoding sites underwent compensatory gains and losses during the evolution of two orders with the most sequenced species (Diptera and Hymenoptera), and that the two editing sites were mutually exclusive among them: One editable site is significantly linked to another uneditable site. This autorecoding mechanism of Adar could flexibly diversify the proteome and stabilize global editing activity. Many insects independently selected different autorecoding sites to achieve a feedback loop and regulate the global RNA editome, revealing an interesting phenomenon during evolution. Our study reveals the evolutionary force acting on accurate regulation of RNA editing activity in insects and thus deepens our understanding of the functional importance of RNA editing in environmental adaptation and evolution.

[Influence of family with sequence similarity 134, member B-mediated reticulophagy on lipopolysaccharide-induced apoptosis of mouse dendritic cells]

Objective: To investigate the influence of family with sequence similarity 134, member B (FAM134B)-mediated reticulophagy on lipopolysaccharide (LPS)-induced apoptosis of mouse dendritic cells (DCs), so as to provide a basis for improving the immune suppression of sepsis caused by wound infection and other factors. Methods: The experimental research methods were used. The DC line DC2.4 of the 3rd to 10th passage in the logarithmic growth stage was collected for experiments. DCs were divided into LPS stimulation 0 h (no stimulation) group, LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group, which were cultured with 1 μg/mL LPS (the same concentration below) for the corresponding time. The protein expressions of FAM134B, microtubule-associated protein 1 light chain 3B (LC3B), and transporter protein SEC61B were determined by Western blotting, and the ratio of LC3B-Ⅱ/LC3B-Ⅰ was calculated (n=3). DCs were divided into phosphate buffer solution (PBS) group and LPS group for corresponding treatment. After 24 hours of culture, the expression of FAM134B and its co-localization with lysosomal probes and LC3B were detected using immunofluorescence method, while the number of autolysosomes in cells were observed through transmission electron microscope. DCs were divided into the FAM134B-knockdown group that were transfected with lentivirus containing small interfering RNA (siRNA) sequence of FAM134B gene and the empty vector group with empty lentivirus transfected. At post transfection hour 72, the fluorescence expression of cells was observed under the inverted fluorescence phase contrast microscope, meanwhile, the normally cultured DCs were set as blank control group, and the same observation was performed at the corresponding time point. DCs were divided into PBS alone group and LPS alone group, DCs successfully transfected with lentivirus containing siRNA sequence of FAM134B gene were divided into FAM134B-knockdown+PBS group and FAM134B-knockdown+LPS group, and DCs successfully transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. These cells were stimulated correspondingly and cultured for 24 hours. The protein expression of FAM134B was detected using Western blotting (n=3); the apoptotic rate of cells was determined by flow cytometry (n=3); the situation of apoptosis was observed by Hoechst staining, and the apoptotic rate was calculated (n=5); the protein expressions of cleaved cysteine aspartic acid specific protease-3 (caspase-3), B cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) were detected using Western blotting, and the ratio of Bax/Bcl-2 was calculated (n=5). Data were statistically analyzed with one-way analysis of variance (ANOVA), least significant difference test, and ANOVA for factorial design. Results: Compared with those in LPS stimulation 0 h group, the protein expressions of FAM134B of cells in LPS stimulation 12 h group and LPS stimulation 24 h group were significantly increased (P<0.05), the protein expressions of SEC61B of cells in LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group were significantly decreased (P<0.05), and the ratios of LC3B-Ⅱ/LC3B-Ⅰ of cells in LPS stimulation 24 h group and LPS stimulation 72 h group were obviously increased (P<0.05). As the most significant changes of three proteins were seen in the cells of LPS stimulation 24 h group, 24 h was used as the duration of subsequent LPS stimulation. After 24 hours of culture, the expression of FAM134B and its co-localization with LC3B and lysosomal probes in the cells of LPS group were all significantly enhanced, with a significant increase in the number of autolysosomes in comparison with those in PBS group. Both the empty vector group and the FAM134B-knockdown group showed high intensity fluorescence in the cells at post transfection hour 72, but the blank control group showed no fluorescence in the cells at the corresponding time point. After 24 hours of culture, the protein expression of FAM134B of cells in FAM134B-knockdown+PBS group was significantly lower than the expressions in PBS alone group and empty vector+PBS group (with P values all <0.05), the protein expression of FAM134B of cells in FAM134B-knockdown+LPS group was significantly lower than the expressions in LPS alone group and empty vector+LPS group (with P values all <0.05), the protein expression of FAM134B of cells in LPS alone group was significantly higher than that in PBS alone group (P<0.05), while the protein expression of FAM134B of cells in empty vector+LPS group was significantly higher than that in empty vector+PBS group (P<0.05). After 24 hours of culture, flow cytometry assay revealed that the apoptotic rate of cells in PBS alone group, LPS alone group, empty vector+PBS group, empty vector+LPS group, FAM134B-knockdown+PBS group, and FAM134B-knockdown+LPS group were (13.3±0.8)%, (32.6±4.3)%, (17.0±1.5)%, (51.7±3.3)%, (52.4±3.1)%, and (62.3±2.6)%, respectively. After 24 hours of culture, compared with those in LPS alone group and empty vector+LPS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in FAM134B-knockdown+LPS group (P<0.05); compared with those in the corresponding PBS treatment group, namely, PBS alone group, empty vector+PBS group, and FAM134B-knockdown+PBS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in LPS alone group, empty vector+LPS group, and FAM134B-knockdown+LPS group (P<0.05). Conclusions: The activation of reticulophagy mediated by FAM134B in mouse DCs is enhanced and peaked in 24 hours under LPS stimulation, and the activated reticulophagy has a significant inhibitory effect on cell apoptosis.

Differential adaptive RNA editing signals between insects and plants revealed by a new measurement termed haplotype diversity

BACKGROUND

C-to-U RNA editing in plants is believed to confer its evolutionary adaptiveness by reversing unfavorable DNA mutations. This "restorative hypothesis" has not yet been tested genome-wide. In contrast, A-to-I RNA editing in insects like Drosophila and honeybee is already known to benefit the host by increasing proteomic diversity in a spatial-temporal manner (namely "diversifying hypothesis").

METHODS

We profiled the RNA editomes of multiple tissues of Arabidopsis thaliana, Drosophila melanogaster, and Apis melifera. We unprecedentedly defined the haplotype diversity (HD) of RNA molecules based on nonsynonymous editing events (recoding sites).

RESULTS

Signals of adaptation is confirmed in Arabidopsis by observing higher frequencies and levels at nonsynonymous editing sites over synonymous sites. Compared to A-to-I recoding sites in Drosophila, the C-to-U recoding sites in Arabidopsis show significantly lower HD, presumably due to the stronger linkage between C-to-U events.

CONCLUSIONS

C-to-U RNA editing in Arabidopsis is adaptive but it is not designed for diversifying the proteome like A-to-I editing in Drosophila. Instead, C-to-U recoding sites resemble DNA mutations. Our observation supports the restorative hypothesis of plant C-to-U editing which claims that editing is used for fixing unfavorable genomic sequences.

Chromosome-level genome assembly of bean flower thrips Megalurothrips usitatus (Thysanoptera: Thripidae)

Bean flower thrips Megalurothrips usitatus is a staple pest of cowpea and other legumes and causes dramatic economic losses. Its small size allows for easy concealment, and large reproductive capacity easily leads to infestations. Despite the importance of a genome in developing novel management strategies, genetic studies on M. usitatus remain limited. Thus, we generated a chromosome-level M. usitatus genome using a combination of PacBio long read and Hi-C technologies. The assembled genome was 238.14 Mb with a scaffold N50 of 13.85 Mb. The final genome was anchored into 16 pseudo-chromosomes containing 14,000 genes, of which 91.74% were functionally annotated. Comparative genomic analyses revealed that expanded gene families were enriched in fatty acid metabolism and detoxification metabolism (ABC transporters), and contracted gene families were strongly associated with chitin-based cuticle development and sensory perception of taste. In conclusion, this high-quality genome provides an invaluable resource for us to understand the thrips' ecology and genetics, contributing to pest management.

Chloroplast C-to-U RNA editing in vascular plants is adaptive due to its restorative effect: testing the restorative hypothesis

The adaptiveness of nonsynonymous RNA editing (recoding) could be conferred by the flexibility of the temporal-spatially controllable proteomic diversity, or by its restorative effect which fixes unfavorable genomic mutations at the RNA level. These two complementary hypotheses, namely, the diversifying hypothesis and the restorative hypothesis, have distinct predictions on the landscape of RNA editing sites. We collected the chloroplast C-to-U RNA editomes of 21 vascular plants (11 angiosperms, four gymnosperms, and six ferns) from a previous study, aiming to testify whether the plant editomes typically conform to the restorative hypothesis. All predictions made by the restorative hypothesis are verified: (i) nonsynonymous editing sites are more frequent and have higher editing levels than synonymous sites; (ii) nonsynonymous editing levels are extremely high and show weak tissue-specificity in plants; (iii) on the inferred genomic sites with recent T-to-C mutations, nonsynonymous sites but not synonymous sites are compensated by C-to-U RNA editing. In conclusion, nonsynonymous C-to-U RNA editing in plants is adaptive due to its restorative effects. The recoding levels are high and are constantly required across the whole plant so that the recoding events could perfectly mimic DNA mutations. The evolutionary significance of plant RNA editing is systematically demonstrated at the genome-wide level.

Full-Length Transcriptome Profiling of Coridius chinensis Mitochondrial Genome Reveals the Transcription of Genes with Ancestral Arrangement in Insects

Coridius chinensis (Hemiptera: Dinidoridae) is a medicinal insect. Its mitochondrial gene arrangement is consistent with that of Drosophila melanogaster and Erthesina fullo, the two insects with well-studied mitochondrial transcription. To investigate whether the structural consistency of mitochondrial genes leads to similarities in transcription and post-transcriptional processing, we improved the gene annotation and constructed a quantitative transcription map for the C. chinensis mitochondrial genome (mitogenome) using full-length transcriptome sequencing. The size of this mitogenome was 16,214 bp and the proposed model of mitochondrial transcription was similar to that of Drosophila. Both strands were nearly entirely transcribed except for the antisense genes downstream of trnS2 on N strand. The expression of cytochrome c subunit genes is higher than that of NADH-dehydrogenase subunit genes. The post-transcriptional cleavage process followed the "tRNA punctuation" model, and both the "reverse cleavage" model in Drosophila and "forward cleavage" model in E. fullo were found in C. chinensis. In addition, we found that long non-coding RNAs from the control region contained tandem repeats. Polyadenylation was performed after CCA triplet at the 3' end of tRNA. The isoform diversity of lrRNA was identified. Our study sheds light on the transcriptional regulation and RNA processing of insect mitogenomes with the putative ancestral gene arrangement.

Plant-Based Diet and Risk of Frailty in Older Chinese Adults

OBJECTIVES

This study examined the relationship between the consumption of plant-based diet and frailty in older Chinese adults.

DESIGN

Prospective cohort study.

SETTING

Community-based setting in 22 provinces of China.

PARTICIPANTS

The final sample included data from 3990 older adults from 2011-2014 from the Chinese Longitudinal Healthy Longevity Survey.

MEASUREMENTS

A plant-based diet index (PDI) was calculated based on a qualitative food frequency questionnaire. Frailty was defined using modified Fried criteria. A Generalized Estimating Equation was used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for frailty. We further performed subgroup analyses stratified by sex and lifestyle factors.

RESULTS

557 cases of frailty were observed. After adjustment for covariates, the RR for frailty of a high PDI was 0.792 (95% CI: 0.644-0.973), relative to a low PDI. During follow-up, compared with respondents with a continually low PDI, the respondents with a continually high PDI had a significantly reduced risk of frailty (RR = 0.683, 95% CI: 0.514-0.908). In further subgroup analysis, a consistently high PDI over time resulted in a significantly reduced risk of frailty for male (RR = 0.591, 95% CI: 0.391-0.893); for never smokers (RR = 0.670, 95% CI: 0.458-0.979); for people who did never consume alcohol (RR = 0.654, 95% CI: 0.454-0.941); and for people with current or former exercise habits (RR = 0.488, 95% CI: 0.313-0.762).

CONCLUSION

Plant-based diet was associated with low risk of frailty in men and in older adults with healthy lifestyle. These findings stress that plant-based diet should be recommended as a dietary strategy to prevent and reduce frailty in older adults; in addition, more dietary interventions along with lifestyle modification should be adopted to promote successful ageing, especially for women.

A full repertoire of Hemiptera genomes reveals a multi-step evolutionary trajectory of auto-RNA editing site in insect Adar gene

Adenosine-to-inosine (A-to-I) RNA editing, mediated by metazoan ADAR enzymes, is a prevalent post-transcriptional modification that diversifies the proteome and promotes adaptive evolution of organisms. The Drosophila Adar gene has an auto-recoding site (termed S>G site) that forms a negative-feedback loop and stabilizes the global editing activity. However, the evolutionary trajectory of Adar S>G site in many other insects remains largely unknown, preventing us from a deeper understanding on the significance of this auto-editing mechanism. In this study, we retrieved the well-annotated genomes of 375 arthropod species including the five major insect orders (Lepidoptera, Diptera, Coleoptera, Hymenoptera and Hemiptera) and several outgroup species. We performed comparative genomic analysis on the Adar auto-recoding S>G site. We found that the ancestral state of insect S>G site was an uneditable serine codon (unSer) and that this state was largely maintained in Hymenoptera. The editable serine codon (edSer) appeared in the common ancestor of Lepidoptera, Diptera and Coleoptera and was almost fixed in the three orders. Interestingly, Hemiptera species possessed comparable numbers of unSer and edSer codons, and a few 'intermediate codons', demonstrating a multi-step evolutionary trace from unSer-to-edSer with non-synchronized mutations at three codon positions. We argue that the evolution of Adar S>G site is the best genomic evidence supporting the 'proteomic diversifying hypothesis' of RNA editing. Our work deepens our understanding on the evolutionary significance of Adar auto-recoding site which stabilizes the global editing activity and controls transcriptomic diversity.

[Clinical and StAR genetic characteristics of 33 children with congenital lipoid adrenal hyperplasia]

Objective: To analyze the clinical and genetic characteristics of 33 children with congenital lipoid adrenal hyperplasia (CLAH) caused by StAR gene defects. Methods: The clinical, biochemical, genetic, and follow-up (until December 2021) data of 33 children diagnosed with CLAH from 2006 to 2021 were retrospectively analyzed in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Results: Of the 33 children with CLAH, 17 had a karyotype of 46, XX and 16 had a karyotype of 46, XY; 31 were female and 2 were male by social gender. Classic type and non-classic type were found in 30 and 3 children respectively. The age at diagnosis was 9.0 (3.0, 34.5) months. All the 30 cases with classic CLAH presented within the first year of life with skin hyperpigmentation (28 cases, 93%), vomiting and(or) diarrhea (19 cases, 63%), no increase in body weight (8 cases, 27%), elevated adrenocorticotropic hormone levels (21cases (70%)>275 pmol/L), decreased cortisol levels (47 (31,126) nmol/L), hyponatremia ((126±13) mmol/L), hyperkalemia ((5.7±1.1) mmol/L), and normal 17α-hydroxyprogesterone levels (30 cases, 100%). All these with classic CLAH exhibited female external genitalia. Three children with non-classic CLAH (including 2 cases of 46, XY and 1 case of 46, XX) also showed signs and symptoms of adrenal insufficiency, but 2 of them had an age of onset later than 1 year of age, including 1 case of 46, XY with male external genitalia and 1 case of 46, XX with female external genitalia. The other 46, XY patient with non-classic CLAH presented with adrenal insufficiency at 2 months of age, showing micropenis and hypospadias. In the 17 females with 46, XX, 4 older than 10 years of age showed spontaneous pubertal development. A total of 25 StAR gene pathogenic variants were identified in 33 patients, with p.Q258* (18/66, 27%), p.K236Tfs*47 (8/66, 12%) and p.Q77* (6/66, 9%) being the common variantion. Six novel variants were found, including c.358T>G, c.713_714del, c.125del, c.745-1G>A, c.179-2A>C, and exon 1 deletion. Conclusions: Patients with classic CLAH typically present with signs and symptoms of primary adrenal insufficiency in the early infancy period and female external genitalia. p.Q258*, p.K236Tfs*47 and p.Q77* are common variants in CLAH patients.

POS0081 LONG-TERM EFFICACY AND SAFETY OF UPADACITINIB IN PATIENTS WITH PSORIATIC ARTHRITIS: 2-YEAR RESULTS FROM THE PHASE 3 SELECT-PsA 1 STUDY

Background

In SELECT-PsA 1, patients (pts) with psoriatic arthritis (PsA) and an inadequate response or intolerance to ≥1 non-biologic disease-modifying antirheumatic drug showed improvement in the signs and symptoms of PsA with upadacitinib 15 mg (UPA15) or 30 mg (UPA30), an oral Janus kinase (JAK) inhibitor, through week (wk) 56.1

Objectives

To evaluate the efficacy and safety of UPA and UPA vs adalimumab (ADA) at wk 104 from the ongoing long-term extension of SELECT-PsA 1.

Methods

Pts received UPA15, UPA30, ADA 40 mg, or placebo (PBO) for 24 wks, at which point, PBO pts switched to UPA15 or UPA30. Efficacy endpoints were analyzed using non-responder imputation (NRI) and as observed (AO) (binary endpoints) or mixed-effect model repeated measures and AO (continuous endpoints), with nominal P-values shown, for continuous UPA and ADA treatment groups. Treatment-emergent adverse events were summarized for pts who received ≥1 dose of study drug using a visit-based cut-off at wk 104.

Results

1704 pts received ≥1 dose of study drug. At wk 104, 25.4% of patients had discontinued study drug. The proportions of pts who achieved ACR20/50/70, MDA, PASI75/90/100, and resolution of enthesitis or dactylitis showed consistent responses, or further improvements, from wk 561 to wk 104 (Table 1). ACR20/50/70 and MDA responses, as well as mean change from baseline (BL) in HAQ-DI, patient’s assessment of pain, BASDAI, and ASDAS, were greater with UPA vs ADA. Mean change from BL in modified total Sharp/van der Heijde Score (mTSS) was generally similar across groups and comparable to wk 56.1 The safety profile of UPA was generally comparable to ADA (Figure 1) and consistent with wk 561 data. Rates of serious infection, herpes zoster, lymphopenia, and elevated CPK remained numerically higher with UPA30 vs UPA15; rates in both UPA groups were higher vs ADA. Rates of malignancies, MACE, or VTE were similar across groups, and consistent with wk 561 data. Two deaths were reported with UPA15, 1 with UPA30, and 1 with ADA.

Table 1.

Efficacy Endpoints at Week 104

EndpointUPA15(n=429)UPA30(n=423)ADA(n=429)Proportion of Pts (%)aNRIAONRIAONRIAOACR2069.087.969.587.963.485.1ACR5053.667.459.3*74.147.162.3ACR7038.0*47.443.5*54.429.439.1Minimal Disease Activity (MDA)42.054.845.9*56.837.850.3PASI75b57.973.462.478.658.876.5PASI90b46.759.053.366.548.863.3PASI100b34.143.442.451.434.144.0Resolution of enthesitis by LEIc53.375.552.272.049.173.9Resolution of dactylitis by LDId69.994.571.796.272.495.2Change from BLeMMRMAOMMRMAOMMRMAOHealth Assessment Questionnaire - Disability Index (HAQ-DI)-0.55*-0.57-0.55*-0.59-0.45-0.47Patient’s assessment of pain (numeric rating scale)-3.3-3.5-3.4*-3.6-3.0-3.2Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)f-3.0-3.2-3.3-3.6-2.7-2.6Ankylosing Spondylitis Disease Activity Score (ASDAS)f-1.6-1.8-1.9*-2.1-1.5-1.6Modified total Sharp/van der Heijde Score (mTSS)0.030.010.010.000.110.11

ACR20/50/70, ≥20%/50%/70% improvement in American College of Rheumatology criteria; ADA, adalimumab; AO, as observed; BL, baseline; LDI, Leeds Dactylitis Index; LEI, Leeds Enthesitis Index; MMRM, mixed effect model repeated measurement; NRI, non-responder imputation; PASI75/90/100, ≥75%/90%/100% improvement in Psoriasis Area and Severity Index; pts, patients; UPA, upadacitinib.

aData shown as NRI and AO for binary endpoints.

bFor pts with psoriasis affecting ≥3% of body surface area at BL.

cFor pts with LEI >0 at BL; resolution LEI=0.

dFor pts with LDI >0 at BL; resolution LDI=0.

eData shown as MMRM (LS mean) and AO (mean) for continuous endpoints.

fFor pts with psoriatic spondylitis at BL.

Nominal *P<0.05, UPA15 or UPA30 vs ADA for NRI and MMRM; AO descriptive only.

Conclusion

In PsA pts, efficacy responses were similar or greater with UPA15 or UPA30 vs ADA at wk 104, and inhibition of radiographic progression was maintained. No new safety signals were identified with long-term exposure to UPA up to 2 years.

References

[1]McInnes I, et al. RMD Open, 2021; 7(3):e001838.

Acknowledgements

AbbVie and the authors thank the patients, study sites, and investigators who participated in this clinical trial (NCT03104400). AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, reviewing, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by Monica R.P. Elmore, PhD of AbbVie.

Disclosure of Interests

Iain McInnes Consultant of: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sanofi Regeneron, and UCB Pharma, Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sanofi Regeneron, and UCB Pharma, Koji Kato Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie, Marina Magrey Consultant of: UCB, Novartis, Eli Lilly, Pfizer, and Janssen, Grant/research support from: Amgen, AbbVie, and UCB Pharma, Joseph F. Merola Consultant of: Merck, Bristol-Myers Squibb, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Celgene, Sanofi, Regeneron, Arena, Sun Pharma, Biogen, Pfizer, EMD Sorono, Avotres, and Leo Pharma, Mitsumasa Kishimoto Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Celgene, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Derek Haaland Speakers bureau: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, GlaxoSmithKline, Janssen, Novartis, Pfizer, Roche, Sanofi Genzyme, Takeda, Consultant of: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, Eli-Lilly, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi Genzyme, Takeda, UCB, Grant/research support from: AbbVie, Adiga Life-Sciences, Amgen, Bristol-Myers Squibb, Can-Fite Biopharma, Celgene, Eli-Lilly, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, Regeneron, Sanofi-Genzyme, UCB, Liang Chen Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie, Yuanyuan Duan Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie, Jianzhong Liu Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie, Ralph Lippe Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie, Peter Wung Shareholder of: Employee of AbbVie and may hold stock or options, Employee of: Employee of AbbVie

OP0016 EFFICACY AND SAFETY OF UPADACITINIB IN PATIENTS WITH ACTIVE NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS: A DOUBLE-BLIND, RANDOMIZED, PLACEBO-CONTROLLED PHASE 3 TRIAL

Background

Janus kinase (JAK) inhibitors have been recognized as a potential therapeutic option in ankylosing spondylitis (AS), also known as radiographic axial spondyloarthritis (r-axSpA).1 Upadacitinib (UPA), a JAK inhibitor, has demonstrated efficacy and safety in the treatment of AS2; however, no JAK inhibitor studies have been conducted in non-radiographic axSpA (nr-axSpA) to date.

Objectives

To assess the efficacy and safety of UPA in patients (pts) with active nr-axSpA.

Methods

SELECT-AXIS 2 (NCT04169373) was conducted under a master protocol comprising two independent studies, one in an AS population with an inadequate response to biologic disease-modifying antirheumatic drugs and one in an nr-axSpA population. The nr-axSpA study is a randomized, double-blind, placebo(PBO)-controlled, phase 3 trial that enrolled adults ≥18 years with a clinical diagnosis of nr-axSpA (who also fulfilled 2009 ASAS classification criteria for axSpA but did not meet the radiologic criterion of modified New York criteria), who had objective signs of active inflammation consistent with axSpA on MRI of the sacroiliac (SI) joints and/or high sensitivity C-reactive protein (hs-CRP) >upper limit of normal (2.87 mg/L) at screening, and who had BASDAI and pt’s assessment of total back pain scores ≥4 based on a 0 to 10 numeric rating scale at study entry. Pts were randomized 1:1 to receive oral UPA 15 mg once daily (QD) or PBO during a 52-week (wk) double-blind treatment period. The primary endpoint was ASAS40 response at wk 14. Multiplicity-controlled secondary endpoints assessed at wk 14 included BASDAI50, ASDAS ID (<1.3), ASDAS LDA (<2.1), ASDAS PR, and ASAS20, and the change from baseline (Δ) in ASDAS (CRP), SPARCC MRI SI joint inflammation score, total and nocturnal back pain, BASFI, ASQoL, ASAS HI, BASMI, and MASES. Treatment-emergent adverse events (TEAEs) are reported through wk 14 for pts who received ≥1 dose of study drug.

Results

Of 314 pts randomized at baseline, 313 received study drug (UPA 15 mg, n=156; PBO, n=157) and 295 (94%) received study drug through wk 14. Baseline demographic and disease characteristics were balanced across treatment groups and consistent with an active nr-axSpA population (58% female; mean age 42.1 years; mean BASDAI 6.9; mean hs-CRP 12.1 mg/L). A significantly higher ASAS40 response rate at wk 14 was achieved with UPA vs PBO (45% vs 23%; P<0.0001; Figure 1). Statistical significance was also achieved in the first 12 of the 14 multiplicity-controlled secondary endpoints (ie, all endpoints except BASMI and MASES) at wk 14 for UPA compared with PBO (P<0.01; Figure 1). The proportion of pts who experienced a TEAE was similar between treatment groups (UPA, 48%; PBO, 46%). Serious TEAEs and TEAEs leading to discontinuation were reported in 4 (2.6%) pts treated with UPA and 2 (1.3%) pts treated with PBO, respectively. Few pts had serious infection or herpes zoster (each 2 [1.3%] pts on UPA; each 1 [0.6%] pt on PBO, respectively). Uveitis was reported in 1 (0.6%) pt on UPA who had a history of uveitis and none on PBO. No malignancy other than non-melanoma skin cancer, major adverse cardiovascular events, venous thromboembolic events, inflammatory bowel disease (IBD), or death were reported in the study; 1 event of basal cell carcinoma occurred with PBO.

Conclusion

UPA 15 mg QD demonstrated significantly greater improvements in disease activity, pain, function, quality of life, and MRI-detected SI joint inflammation than PBO after 14 wks of treatment in pts with active nr-axSpA. The safety profile of UPA was consistent with what has been observed with other inflammatory musculoskeletal diseases,3–5 and no new risks were identified. These results support the potential use of UPA in pts with active nr-axSpA.

References

[1]Ward MM, et al. Arthritis Rheumatol. 2019;71(10):1599–63.

[2]van der Heijde D, et al. Arthritis Rheumatol. 2021;73(suppl 10).

[3]Cohen SB, et al. ARD. 2021;80:304–311.

[4]Burmester G, et al. Rheumatol Ther. 2021;1–19.

[5]van der Heijde D, et al. Lancet. 2019;394(10214):2108–2117.

Acknowledgements

AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, review, and approval of the abstract. No honoraria or payments were made for authorship. Medical writing support was provided by Julia Zolotarjova, MSc, MWC, of AbbVie.

Disclosure of Interests

Atul Deodhar Consultant of: AbbVie, Amgen, Aurinia, BMS, Celgene, GSK, Janssen, Lilly, MoonLake, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, GSK, Lilly, Novartis, Pfizer, and UCB, Filip van den Bosch Speakers bureau: AbbVie, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Celgene, Janssen, Lilly, Merck, Novartis, Pfizer, and UCB, Denis Poddubnyy Speakers bureau: AbbVie, BMS, Celgene, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, and UCB, Consultant of: AbbVie, BMS, Celgene, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, MSD, Novartis, and Pfizer, Walter P Maksymowych Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Novartis, and Pfizer, Désirée van der Heijde Consultant of: AbbVie, Bayer, BMS, Cyxone, Eisai, Galapagos, Gilead, GSK, Janssen, Lilly, Novartis, Pfizer, UCB, Employee of: Director of Imaging Rheumatology BV, Tae-Hwan Kim Speakers bureau: AbbVie, Celltrion, Kirin, Lilly, and Novartis, Mitsumasa Kishimoto Consultant of: AbbVie, Amgen Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumid Pharma, BMS, Chugai, Daiichi Sankyo, Eisai, Gilead, Janssen, Kyowa Kirin, Lilly, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB, Yuanyuan Duan Shareholder of: May own AbbVie stock or options, Employee of: AbbVie, Yihan Li Shareholder of: May own AbbVie stock or options, Employee of: AbbVie, Aileen Pangan Shareholder of: May own AbbVie stock or options, Employee of: AbbVie, Peter Wung Shareholder of: May own AbbVie stock or options, Employee of: AbbVie, In-Ho Song Shareholder of: May own AbbVie stock or options, Employee of: AbbVie.

Acceleration of Brain Susceptibility-Weighted Imaging with Compressed Sensitivity Encoding: A Prospective Multicenter Study

BACKGROUND AND PURPOSE

While three-dimensional susceptibility-weighted imaging has been widely suggested for intracranial vessel imaging, hemorrhage detection, and other neuro-diseases, its relatively long scan time has necessitated the clinical verification of recent progresses of fast imaging techniques. Our aim was to evaluate the effectiveness of brain SWI accelerated by compressed sensitivity encoding to identify the optimal acceleration factors for clinical practice.

MATERIALS AND METHODS

Ninety-nine subjects, prospectively enrolled from 5 centers, underwent 8 brain SWI sequences: 5 different folds of compressed sensitivity encoding acceleration (CS2, CS4, CS6, CS8, and CS10), 2 different folds of sensitivity encoding acceleration (SF2 and SF4), and 1 without acceleration. Images were assessed quantitatively on both the SNR of the red nucleus and its contrast ratio to the CSF and, subjectively, with scoring on overall image quality; visibility of the substantia nigra-red nucleus, basilar artery, and internal cerebral vein; and diagnostic confidence of the cerebral microbleeds and other intracranial diseases.

RESULTS

Compressed sensitivity encoding showed a promising ability to reduce the acquisition time (from 202 to 41 seconds) of SWI while increasing the acceleration factor from 2 to 10, though at the cost of decreasing the SNR, contrast ratio, and the scores of visual assessments. The visibility of the substantia nigra-red nucleus and internal cerebral vein became unacceptable in CS6 to CS10. The basilar artery was well-distinguished, and diseases including cerebral microbleeds, cavernous angiomas, intracranial gliomas, venous malformations, and subacute hemorrhage were well-diagnosed in all compressed sensitivity encoding sequences.

CONCLUSIONS

Compressed sensitivity encoding factor 4 is recommended in routine practice. Compressed sensitivity encoding factor 10 is potentially a fast surrogate for distinguishing the basilar artery and detecting susceptibility-related abnormalities (eg, cerebral microbleeds, cavernous angiomas, gliomas, and venous malformation) at the sacrifice of visualization of the substantia nigra-red nucleus and internal cerebral vein.

[Analysis of the detection of metals and metalloids in the bronchoalveolar lavage fluid for the etiological diagnosis value of pneumoconiosis]

Objective: To analyze the differences of the concentrations of metals and metalloids in bronchoalveolar lavage fluid (BALF) of patients with pneumoconiosis, so as to provide reference for the etiological diagnosis of pneumoconiosis. Methods: From September 2019 to August 2020, 47 pneumoconiosis patients hospitalized in Chongqing Prevention and Treatment Center for Occupational Diseases and undergoing bronchoalveolar lavage were selected as the research objects using cluster sampling method. The general situation and occupational history of patients were investigated by questionnaire, The BALF of 47 pneumoconiosis patients was collected, and the concentrations of metals and metalloids in BALF were detected by inductively coupled plasma mass spectrometry (ICP-MS) , the differences among patients with different types of pneumoconiosis, different stages of silicosis and different occupational history were analyzed by one-way ANOVA. Results: The concentrations of 50 metals and metalloids in BALF were detected, and 21 of them were analyzed. Compared with different types of pneumoconiosis, the concentrations of Zn, Mn and Sn in BALF were statistically significant (F=9.959, 3.635, 9.488, P<0.05) . The concentrations of K, Mg, Fe, Zn, Cu and Ni in BALF were significantly different in different stages of silicosis (F=4.271, 4.334, 3.588, 5.120, 7.340, 3.905, P<0.05) . The concentrations of Zn and Sn in pneumoconiosis patients with different types of work and types of exposed dust were significantly different (P<0.05) . Conclusion: The detection of Zn, Mn, Sn, and other metals in BALF can provide reference basis for the etiological diagnosis of pneumoconiosis and provide a new idea for the diagnostic method of pneumoconiosis.

Search for Displaced Leptons in sqrt[s]=13 TeV pp Collisions with the ATLAS Detector

A search for charged leptons with large impact parameters using 139  fb^{-1} of sqrt[s]=13  TeV pp collision data from the ATLAS detector at the LHC is presented, addressing a long-standing gap in coverage of possible new physics signatures. Results are consistent with the background prediction. This search provides unique sensitivity to long-lived scalar supersymmetric lepton partners (sleptons). For lifetimes of 0.1 ns, selectron, smuon, and stau masses up to 720, 680, and 340  GeV, respectively, are excluded at 95% confidence level, drastically improving on the previous best limits from LEP.

AB0523 LONG-TERM SAFETY AND EFFECTIVENESS OF UPADACITINIB IN PATIENTS WITH PSORIATIC ARTHRITIS: RESULTS AT 56 WEEKS FROM THE SELECT-PsA 1 STUDY

Background:

In the SELECT-PsA 1 study, through 24 weeks (wks), once daily upadacitinib 15 mg (UPA15) and 30 mg (UPA30) showed improvements in musculoskeletal symptoms, psoriasis, physical function, pain, fatigue, and quality of life, as well as inhibition of radiographic progression in patients (pts) with psoriatic arthritis (PsA) and inadequate response or intolerance to ≥1 non-biologic disease-modifying antirheumatic drug (DMARD).1

Objectives:

To report the efficacy and safety of UPA vs adalimumab (ADA) up to 56 wks from the ongoing long-term extension of SELECT-PsA 1.

Methods:

Pts received UPA15 or UPA30, ADA 40mg every other wk for 56 wks, or PBO through wk 24 switched thereafter to either UPA15 or UPA30 until wk 56. Efficacy endpoints as listed and defined in the Table 1 were analyzed at wk 56. Results for binary endpoints are based on non-responder imputation analysis; treatments were compared using the Cochran-Mantel-Haenszel test. Results for non-radiographic continuous endpoints are based on mixed model repeated measures model based on as observed data. Radiographic endpoints were analyzed based on linear extrapolation. Treatment-emergent adverse events (TEAEs) per 100 pt years (PY) were summarized for pts who received ≥1 dose of study drug.

Table 1.

Efficacy Endpoints at Week 56

EndpointPBO → UPA15PBO → UPA30UPA15UPA30ADAACR20, %73.074.174.474.7#68.5ACR50, %54.560.459.7*60.5#51.3ACR70, %29.935.840.6*43.7#31.2Minimal Disease Activity, %29.435.844.847.3#39.6PASI75a, %58.360.265.463.361.1PASI90a, %41.753.749.149.546.9PASI100a, %22.338.934.639.531.3Resolution of enthesitis by Leeds Enthesitis Index b, %38.145.559.358.154.0Resolution of dactylitis by Leeds Dactylitis Index c, %47.759.075.074.874.0Δ from BL in Bath Ankylosing Spondylitis Disease Activity Index d-3.1-3.1-3.3-3.2-2.8Δ from BL in modified total Sharp/van der Heijde Score (mTSS)0.44e-0.05†0.02‡-0.06

* and †, p≤0.05; for UPA15 vs ADA and PBO, respectively; # and ‡, p≤0.05; for UPA30 vs ADA and PBO, respectively.

a for pts with psoriasis affecting ≥3% of body surface area at BL. b for pts with LEI >0 at BL. c for pts with LDI >0 at BL. d for pts with psoriatic spondylitis at BL. epooled PBO.

ACR20/50/70, ≥20%/50%/70% improvement in American College of Rheumatology criteria; ADA, adalimumab; BL, baseline; PASI75/90/100, ≥75%/90%/100% improvement in Psoriasis Area and Severity Index; PBO, placebo; pts, patients; UPA, upadacitinib.

Results:

Of 1704 pts who received ≥1 dose of study drug, 1419 (83.2%) completed 56 wks of treatment on study drug. Across all treatment groups, the proportions of pts who had achieved ACR20/50/70, MDA, PASI75/90/100, resolution of enthesitis, and resolution of dactylitis were maintained or further improved from wk 241 through wk 56; these proportions were generally greater for pts originally randomized to UPA vs ADA (Table 1). At wk 56, mean change from BL in mTSS was similar with UPA15, UPA30, and ADA. Improvements in pts who switched from PBO to UPA were generally similar to those originally randomized to UPA at wk 56. Through wk 56, the rates of TEAEs and serious AEs, including serious infections, were similar in the UPA15 and ADA arms and higher with UPA30 (Figure 1). The rate of herpes zoster was higher with UPA vs ADA in a dose-dependent manner. Malignancies were reported at similar rates among all treatment groups. Adjudicated venous thromboembolic events and major adverse cardiovascular events were reported in all groups with comparable rates. Two deaths were reported with UPA15, 2 with UPA30, and 1 with ADA; 1 death was reported with PBO during the 24-wk PBO-controlled period.

Conclusion:

Efficacy responses were maintained or further improved with UPA15 and UPA30 over 56 wks and were numerically higher vs ADA. The inhibition of radiographic progression was maintained at wk 56 and was similar with UPA and ADA. At wk 56, improvements in efficacy were observed in pts who switched from PBO to UPA. No new safety findings were observed with longer exposure to UPA.

References:

[1]McInnes IB et al. Ann Rheum Dis, 2020; 79:12

Figure 1

Acknowledgements:

AbbVie and the authors thank the patients, study sites, and investigators who participated in this clinical trial. AbbVie, Inc was the study sponsor, contributed to study design, data collection, analysis & interpretation, and to writing, reviewing, and approval of final version. No honoraria or payments were made for authorship. Medical writing support was provided by Ramona Vladea, PhD of AbbVie Inc.

Disclosure of Interests:

Iain McInnes Consultant of: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sanofi Regeneron, UCB Pharma, Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sanofi Regeneron, UCB Pharma, Koji Kato Shareholder of: AbbVie, Employee of: AbbVie, Marina Magrey Consultant of: UCB, Novartis, Eli Lilly, Pfizer and Janssen, Grant/research support from: Amgen, AbbVie, and UCB Pharma, Joseph F. Merola Consultant of: Merck, Bristol-Myers Squibb, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Celgene, Sanofi, Regeneron, Arena, Sun Pharma, Biogen, Pfizer, EMD Sorono, Avotres and Leo Pharma, Mitsumasa Kishimoto Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Celgene, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Cesar Francisco Pacheco Tena Consultant of: Eli Lilly, AbbVie, Roche, Pfizer, Janssen, Astra-Zeneca, UCB, Gilead, R-Pharm, Sanofi Regeneron, Grant/research support from: Eli Lilly, AbbVie, Roche, Pfizer, Janssen, Astra-Zeneca, UCB, Gilead, R-Pharm, Sanofi Regeneron, Derek Haaland Speakers bureau: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, GlaxoSmithKline, Janssen, Novartis, Pfizer, Roche, Sanofi Genzyme, Takeda, Consultant of: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, Eli Lilly, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi Genzyme, Takeda, UCB, Grant/research support from: AbbVie, Adiga Life-Sciences, Amgen, Bristol-Myers Squibb, Can-Fite Biopharma, Celgene, Eli Lilly, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, Regeneron, Sanofi-Genzyme, UCB, Liang Chen Shareholder of: AbbVie, Employee of: AbbVie, Yuanyuan Duan Shareholder of: AbbVie, Employee of: AbbVie, Patrick Zueger Shareholder of: AbbVie, Employee of: AbbVie, Jianzhong Liu Shareholder of: AbbVie, Employee of: AbbVie, Ralph Lippe Shareholder of: AbbVie, Employee of: AbbVie, Aileen Pangan Shareholder of: AbbVie, Employee of: AbbVie, Frank Behrens Consultant of: Pfizer, AbbVie, Sanofi, Lilly, Novartis, Genzyme, Boehringer, Janssen, MSD, Celgene, Roche, Chugai, BMS, UCB Pharma, Grant/research support from: Pfizer, Janssen, Chugai, Celgene and Roche.

Evolutionary driving forces of A-to-I editing in metazoans

Adenosine-to-inosine (A-to-I) RNA editing is an evolutionarily conserved mechanism that converts adenosines to inosines in metazoans' transcriptomes. However, the landscapes of editomes have considerably changed during evolution. Here, we review some of our current knowledge of A-to-I editing in the metazoan transcriptomes, focusing on the possible evolutionary driving forces underlying the editing events. First, we review the evolution of ADAR gene family in animals. Then, we summarize the recent advances in characterizing the editomes of various metazoan species. Next, we highlight several factors contributing to the interspecies differences in editomes, including variations in copy number and expression patterns of ADAR genes, the differences in genomic architectures and contents, and the differences in the efficacy of natural selection. After that, we review the possible diversifying and restorative effects of the editing (recoding) events that change the protein sequences. Finally, we discuss the possible convergent evolution of RNA editing in distantly related clades. This article is categorized under: RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Processing > RNA Editing and Modification.

Acceleration of Brain TOF-MRA with Compressed Sensitivity Encoding: A Multicenter Clinical Study

BACKGROUND AND PURPOSE

The clinical practice of three-dimensional TOF-MRA, despite its capability in brain artery assessment, has been hampered by the relatively long scan time, while recent developments in fast imaging techniques with random undersampling has shed light on an improved balance between image quality and imaging speed. Our aim was to evaluate the effectiveness of TOF-MRA accelerated by compressed sensitivity encoding and to identify the optimal acceleration factors for routine clinical use.

MATERIALS AND METHODS

One hundred subjects, enrolled at 5 centers, underwent 8 brain TOF-MRA sequences: 5 sequences using compressed sensitivity encoding with acceleration factors of 2, 4, 6, 8, and 10 (CS2, CS4, CS6, CS8, and CS10), 2 using sensitivity encoding with factors of 2 and 4 (SF2 and SF4), and 1 without acceleration as a reference sequence (RS). Five large arteries, 6 medium arteries, and 6 small arteries were evaluated quantitatively (reconstructed signal intensity, structural similarity, contrast ratio) and qualitatively (scores on arteries, artifacts, overall image quality, and diagnostic confidence for aneurysm and stenosis). Comparisons were performed among the 8 sequences.

RESULTS

The quantitative measurements showed that the reconstructed signal intensities of the assessed arteries and the structural similarity consistently decreased as the compressed sensitivity encoding acceleration factor increased, and no significant difference was found for the contrast ratios in pair-wise comparisons among SF2, CS2, and CS4. Qualitative evaluations showed no significant difference in pair-wise comparisons among RS, SF2, and CS2 (P > .05). The visualization of all the assessed arteries was acceptable for CS2 and CS4, while 2 small arteries in images of CS6 were not reliably displayed, and the visualization of large arteries was acceptable in images of CS8 and CS10.

CONCLUSIONS

CS4 is recommended for routine brain TOF-MRA with balanced image quality and acquisition time; CS6, for examinations when small arteries are not evaluated; and CS10, for fast visualization of large arteries.

Longitudinal Flow Decorrelations in Xe+Xe Collisions at sqrt[s_{NN}]=5.44 TeV with the ATLAS Detector

The first measurement of longitudinal decorrelations of harmonic flow amplitudes v_{n} for n=2-4 in Xe+Xe collisions at sqrt[s_{NN}]=5.44  TeV is obtained using 3  μb^{-1} of data with the ATLAS detector at the LHC. The decorrelation signal for v_{3} and v_{4} is found to be nearly independent of collision centrality and transverse momentum (p_{T}) requirements on final-state particles, but for v_{2} a strong centrality and p_{T} dependence is seen. When compared with the results from Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV, the longitudinal decorrelation signal in midcentral Xe+Xe collisions is found to be larger for v_{2}, but smaller for v_{3}. Current hydrodynamic models reproduce the ratios of the v_{n} measured in Xe+Xe collisions to those in Pb+Pb collisions but fail to describe the magnitudes and trends of the ratios of longitudinal flow decorrelations between Xe+Xe and Pb+Pb. The results on the system-size dependence provide new insights and an important lever arm to separate effects of the longitudinal structure of the initial state from other early and late time effects in heavy-ion collisions.

Search for Dark Matter Produced in Association with a Dark Higgs Boson Decaying into W^{±}W^{∓} or ZZ in Fully Hadronic Final States from sqrt[s]=13 TeV pp Collisions Recorded with the ATLAS Detector

Several extensions of the Standard Model predict the production of dark matter particles at the LHC. An uncharted signature of dark matter particles produced in association with VV=W^{±}W^{∓} or ZZ pairs from a decay of a dark Higgs boson s is searched for using 139  fb^{-1} of pp collisions recorded by the ATLAS detector at a center-of-mass energy of 13 TeV. The s→V(qq[over ¯])V(qq[over ¯]) decays are reconstructed with a novel technique aimed at resolving the dense topology from boosted VV pairs using jets in the calorimeter and tracking information. Dark Higgs scenarios with m_{s}>160  GeV are excluded.

Medium-Induced Modification of Z-Tagged Charged Particle Yields in Pb+Pb Collisions at 5.02 TeV with the ATLAS Detector

The yield of charged particles opposite to a Z boson with large transverse momentum (p_{T}) is measured in 260  pb^{-1} of pp and 1.7  nb^{-1} of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The Z boson tag is used to select hard-scattered partons with specific kinematics, and to observe how their showers are modified as they propagate through the quark-gluon plasma created in Pb+Pb collisions. Compared with pp collisions, charged-particle yields in Pb+Pb collisions show significant modifications as a function of charged-particle p_{T} in a way that depends on event centrality and Z boson p_{T}. The data are compared with a variety of theoretical calculations and provide new information about the medium-induced energy loss of partons in a p_{T} regime difficult to measure through other channels.

LINC01255 combined with BMI1 to regulate human mesenchymal stromal senescence and acute myeloid leukemia cell proliferation through repressing transcription of MCP-1

BACKGROUND

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular biology processes, for example, participate in chromatin remodeling, imprinting, splicing, transcriptional regulation and translation. Dysregulation of lncRNA expression is act as a feature of various diseases and cancers, including hematopoietic malignancies. However, the clinical relevance of myelodysplastic syndrome (MDS) and acute myeloid leukemia preceded by MDS (MDS-AML) requires further research. Recently, lncRNAs have been demonstrated, which play an important role in hematopoiesis, thus, to further finding more functional lncRNA seemed particularly important.

METHODS

Western blotting, real-time PCR, RNA-pulldown, RIP (RNA immunoprecipitation), Chromatin immunoprecipitation (ChIP), cellular compartments extraction assays, SA-β-gal staining, lentivirus transfection, cell viability assay and cell proliferation assays were used to examine the relationship between lncRNA LINC01255 and its regulation of p53-p21 pathway in human mesenchymal stromal and acute myeloid leukemia cells.

RESULTS

LncRNA LINC01255 is highly expressed in bone marrow cells of AML patients, CD34+ cells of MDS-AML patients and AML cell lines and the higher expression of LINC01255 is associated with poor survival rate of AML patients. LINC01255 can interact with BMI1 and repress the transcription of MCP-1 to active p53-p21 pathway, thus inhibiting the senescence of human mesenchymal stromal and proliferation of acute myeloid leukemia cell.

CONCLUSIONS

We discovered a novel functional lncRNA LINC01255, which can regulate the senescence of human mesenchymal stromal and the proliferation of acute myeloid leukemia cell through inhibiting the transcription of MCP-1.

A-to-I RNA editing in honeybees shows signals of adaptation and convergent evolution

Social insects exhibit extensive phenotypic diversities among the genetically similar individuals, suggesting a role for the epigenetic regulations beyond the genome level. The ADAR-mediated adenosine-to-inosine (A-to-I) RNA editing, an evolutionarily conserved mechanism, facilitates adaptive evolution by expanding proteomic diversities. Here, we characterize the A-to-I RNA editome of honeybees (Apis mellifera), identifying 407 high-confidence A-to-I editing sites. Editing is most abundant in the heads and shows signatures for positive selection. Editing behavior differs between foragers and nurses, suggesting a role for editing in caste differentiation. Although only five sites are conserved between bees and flies, an unexpectedly large number of genes exhibit editing in both species, albeit at different locations, including the nonsynonymous auto-editing of Adar. This convergent evolution, where the same target genes independently acquire recoding events in distant diverged clades, together with the signals of adaptation observed in honeybees alone, further supports the notion of recoding being adaptive.

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Nonsynonymous editing sites in honeybees were under positive selection

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Differential editing may contribute to the phenotypic diversity between sub-castes

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Target genes acquire editing in different clades, suggesting convergent evolution

Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS

The observation of forward proton scattering in association with lepton pairs (e^{+}e^{-}+p or μ^{+}μ^{-}+p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of sqrt[s]=13  TeV are analyzed, corresponding to an integrated luminosity of 14.6  fb^{-1}. A total of 57 (123) candidates in the ee+p (μμ+p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced for cross-section measurements in the fiducial detector acceptance, corresponding to σ_{ee+p}=11.0±2.6(stat)±1.2(syst)±0.3(lumi) and σ_{μμ+p}=7.2±1.6(stat)±0.9(syst)±0.2(lumi)  fb in the dielectron and dimuon channel, respectively.

Search for Heavy Resonances Decaying into a Photon and a Hadronically Decaying Higgs Boson in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter presents a search for the production of new heavy resonances decaying into a Higgs boson and a photon using proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 139  fb^{-1}. The analysis is performed by reconstructing hadronically decaying Higgs boson (H→bb[over ¯]) candidates as single large-radius jets. A novel algorithm using information about the jet constituents in the center-of-mass frame of the jet is implemented to identify the two b quarks in the single jet. No significant excess of events is observed above the expected background. Upper limits are set on the production cross-section times branching fraction for narrow spin-1 resonances decaying into a Higgs boson and a photon in the resonance mass range from 0.7 to 4 TeV, cross-section times branching fractions are excluded between 11.6 fb and 0.11 fb at a 95% confidence level.

Search for Higgs Boson Decays into a Z Boson and a Light Hadronically Decaying Resonance Using 13 TeV pp Collision Data from the ATLAS Detector

A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139  fb^{-1} collected at sqrt[s]=13  TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar sector or a charmonium state. Multivariate discriminants are used for the event selection and for evaluating the mass of the light resonance. No excess of events above the expected background is found. Observed (expected) 95% confidence-level upper limits are set on the Higgs boson production cross section times branching fraction to a Z boson and the signal resonance, with values in the range 17-340 pb (16_{-5}^{+6}-320_{-90}^{+130}  pb) for the different light spin-0 boson mass and branching fraction hypotheses, and with values of 110 and 100 pb (100_{-30}^{+40} and 100_{-30}^{+40}  pb) for the η_{c} and J/ψ hypotheses, respectively.