Reshaped DNA methylation cooperating with homoeolog-divergent expression promotes improved root traits in synthesized tetraploid wheat

Polyploidization is a major event driving plant evolution and domestication. However, how reshaped epigenetic modifications coordinate gene transcription to generate phenotypic variations during wheat polyploidization is currently elusive. Here, we profiled transcriptomes and DNA methylomes of two diploid wheat accessions (SlSl and AA) and their synthetic allotetraploid wheat line (SlSlAA), which displayed elongated root hair and improved root capability for nitrate uptake and assimilation after tetraploidization. Globally decreased DNA methylation levels with a reduced difference between subgenomes were observed in the roots of SlSlAA. DNA methylation changes in first exon showed strong connections with altered transcription during tetraploidization. Homoeolog-specific transcription was associated with biased DNA methylation as shaped by homoeologous sequence variation. The hypomethylated promoters showed significantly enriched binding sites for MYB, which may affect gene transcription in response to root hair growth. Two master regulators in root hair elongation pathway, AlCPC and TuRSL4, exhibited upregulated transcription levels accompanied by hypomethylation in promoter, which may contribute to the elongated root hair. The upregulated nitrate transporter genes, including NPFs and NRTs, also are significantly associated with hypomethylation, indicating an epigenetic-incorporated regulation manner in improving nitrogen use efficiency. Collectively, these results provided new insights into epigenetic changes in response to crop polyploidization and underscored the importance of epigenetic regulation in improving crop traits.

Integrative omics analysis elucidates the genetic basis underlying seed weight and oil content in soybean

Synergistic optimization of key agronomic traits by traditional breeding has dramatically enhanced crop productivity in the past decades. However, the genetic basis underlying coordinated regulation of yield- and quality-related traits remains poorly understood. Here, we dissected the genetic architectures of seed weight and oil content by combining genome-wide association studies (GWAS) and transcriptome-wide association studies (TWAS) using 421 soybean (Glycine max) accessions. We identified 26 and 33 genetic loci significantly associated with seed weight and oil content by GWAS, respectively, and detected 5,276 expression quantitative trait loci (eQTLs) regulating expression of 3,347 genes based on population transcriptomes. Interestingly, a gene module (IC79), regulated by two eQTL hotspots, exhibited significant correlation with both seed weigh and oil content. Twenty-two candidate causal genes for seed traits were further prioritized by TWAS, including Regulator of Weight and Oil of Seed 1 (GmRWOS1), which encodes a sodium pump protein. GmRWOS1 was verified to pleiotropically regulate seed weight and oil content by gene knockout and overexpression. Notably, allelic variations of GmRWOS1 were strongly selected during domestication of soybean. This study uncovers the genetic basis and network underlying regulation of seed weight and oil content in soybean and provides a valuable resource for improving soybean yield and quality by molecular breeding.

Advanced glycation end products promote intervertebral disc degeneration by transactivation of matrix metallopeptidase genes

OBJECTIVE

Examine the mechanism by which advanced glycation end products (AGEs) induce intervertebral disc degeneration (IDD) in C57BL/6J mice.

METHODS

Matrix metallopeptidase (MMP) gene mRNA levels were assessed using RT-qPCR. Immunoprecipitation and co-immunoprecipitation were performed to identify the transcriptional complex regulating MMP expression due to AGEs. The preventive effects of inhibitors targeting this complex were tested in mice on high AGE diets.

RESULTS

IDD and AGE accumulation were evident in mice on high-AGE diets (HAGEs), persisting across dietary shifts but absent in mice exclusively on low-AGE diets. Molecularly, HAGEs activated p21-activated kinase 1 (PAK1), prompting peroxisome proliferator-activated receptor gamma coactivator-related protein 1 (PPRC1) phosphorylation. Ubiquitin-specific protease 12 (USP12) interacted with the phosphorylated PPRC1 (pPPRC1), safeguarding it from proteasomal degradation. This pPPRC1, in collaboration with two histone acetyltransferases p300/CREB-binding protein (CBP) and a transcription factor activator protein 1(AP1), enhanced the expression of 12 MMP genes (MMP1a/1b/3/7/9/10/12/13/16/19/23/28). In vitro AGE exposure on nucleus pulposus and annulus fibrosus cells replicated this gene activation pattern, driven by the PAK1/pPPRC1-p300/CBP-AP1 pathway. The application of PAK1, p300, and AP1 inhibitors reduced pPPRC1-p300/CBP-AP1 binding to MMP promoters, diminishing their expression. These inhibitors effectively thwarted IDD in HAGE mice.

CONCLUSION

Our results revealed that HAGEs instigate IDD via the PAK1/pPPRC1-p300/CBP-AP1 signaling pathway. This insight can guide therapeutic strategies to slow IDD progression in prediabetic/diabetic patients.

DNA methylation remodeled amino acids biosynthesis regulates flower senescence in carnation (Dianthus caryophyllus)

Dynamic DNA methylation regulatory networks are involved in many biological processes. However, how DNA methylation patterns change during flower senescence and their relevance with gene expression and related molecular mechanism remain largely unknown. Here, we used whole genome bisulfite sequencing to reveal a significant increase of DNA methylation in the promoter region of genes during natural and ethylene-induced flower senescence in carnation (Dianthus caryophyllus L.), which was correlated with decreased expression of DNA demethylase gene DcROS1. Silencing of DcROS1 accelerated while overexpression of DcROS1 delayed carnation flower senescence. Moreover, among the hypermethylated differentially expressed genes during flower senescence, we identified two amino acid biosynthesis genes, DcCARA and DcDHAD, with increased DNA methylation and reduced expression in DcROS1 silenced petals, and decreased DNA methylation and increased expression in DcROS1 overexpression petals, accompanied by decreased or increased amino acids content. Silencing of DcCARA and DcDHAD accelerates carnation flower senescence. We further showed that adding corresponding amino acids could largely rescue the senescence phenotype of DcROS1, DcCARA and DcDHAD silenced plants. Our study not only demonstrates an essential role of DcROS1-mediated remodeling of DNA methylation in flower senescence but also unravels a novel epigenetic regulatory mechanism underlying DNA methylation and amino acid biosynthesis during flower senescence.

Improving rice nitrogen-use efficiency by modulating a novel monouniquitination machinery for optimal root plasticity response to nitrogen

Plant nitrogen (N)-use efficiency (NUE) is largely determined by the ability of root to take up external N sources, whose availability and distribution in turn trigger the modification of root system architecture (RSA) for N foraging. Therefore, improving N-responsive reshaping of RSA for optimal N absorption is a major target for developing crops with high NUE. In this study, we identified RNR10 (REGULATOR OF N-RESPONSIVE RSA ON CHROMOSOME 10) as the causal gene that underlies the significantly different root developmental plasticity in response to changes in N level exhibited by the indica (Xian) and japonica (Geng) subspecies of rice. RNR10 encodes an F-box protein that interacts with a negative regulator of auxin biosynthesis, DNR1 (DULL NITROGEN RESPONSE1). Interestingly, RNR10 monoubiquitinates DNR1 and inhibits its degradation, thus antagonizing auxin accumulation, which results in reduced root responsivity to N and nitrate (NO3-) uptake. Therefore, modulating the RNR10-DNR1-auxin module provides a novel strategy for coordinating a desirable RSA and enhanced N acquisition for future sustainable agriculture.

The circ_006573/miR-376b-3p Axis Advances Spinal Cord Functional Recovery after Injury by Modulating Vascular Regeneration

Abnormal expression of non-coding RNAs after spinal cord injury (SCI) is associated with pathophysiological outcomes. We bioinformatically predicted a circRNA-miRNA-mRNA axis in SCI. A total of 4690 mRNAs, 17 miRNAs, and 3928 circRNAs were differentially expressed, with co-expressed RNAs predicted to regulate pathways related to wound healing. Among the most highly differentially expressed circRNAs, circ_006573, but not circ_016395, weakened the viability and migration of rat aortic endothelial cells, and its biological effects were rescued with miR-376b-3p mimics. Furthermore, circ_006573 overexpression induced changes in Cebpb, IL-18, and Plscr1 expression that were reversed by miR-376b-3p. In a rat model, circ_006573 shRNA administration improved the pathological manifestations of SCI and ameliorated motor function. Moreover, the expression of CD31, CD34, and VEGF-A in spinal cord tissues was significantly elevated after circ_006573 shRNA treatment, indicating that circ_006573 may be involved in vascular regeneration and functional recovery after SCI. Thus, the circ_006573-miR-376b-3p axis offers a foundation for understanding pathophysiological mechanisms and predicting strategies for treating SCI.

Asymmetric variation in DNA methylation during domestication and de-domestication of rice

Hundreds of plant species have been domesticated to feed human civilization, while some crops have undergone de-domestication into agricultural weeds, threatening global food security. To understand the genetic and epigenetic basis of crop domestication and de-domestication, we generated DNA methylomes from 95 accessions of wild rice (Oryza rufipogon L.), cultivated rice (Oryza sativa L.) and weedy rice (O. sativa f. spontanea). We detected a significant decrease in DNA methylation over the course of rice domestication but observed an unexpected increase in DNA methylation through de-domestication. Notably, DNA methylation changes occurred in distinct genomic regions for these 2 opposite stages. Variation in DNA methylation altered the expression of nearby and distal genes through affecting chromatin accessibility, histone modifications, transcription factor binding, and the formation of chromatin loops, which may contribute to morphological changes during domestication and de-domestication of rice. These insights into population epigenomics underlying rice domestication and de-domestication provide resources and tools for epigenetic breeding and sustainable agriculture.

Polyploidy and diploidization in soybean

Polyploidy is widespread and particularly common in angiosperms. The prevalence of polyploidy in the plant suggests it as a crucial driver of diversification and speciation. The paleopolyploid soybean (Glycine max) is one of the most important crops of plant protein and oil for humans and livestock. Soybean experienced two rounds of whole genome duplication around 13 and 59 million years ago. Due to the relatively slow process of post-polyploid diploidization, most genes are present in multiple copies across the soybean genome. Growing evidence suggests that polyploidization and diploidization could cause rapid and dramatic changes in genomic structure and epigenetic modifications, including gene loss, transposon amplification, and reorganization of chromatin architecture. This review is focused on recent progresses about genetic and epigenetic changes during polyploidization and diploidization of soybean and represents the challenges and potentials for application of polyploidy in soybean breeding.

Glucose-stimulated PGC-1α couples with CBP and Runx2 to mediate intervertebral disc degeneration through transactivation of ADAMTS4/5 in diet-induced obesity mice

Emerging evidence suggests that type 2 diabetes mellitus (T2DM) is associated with the pathogenesis of intervertebral disc degeneration (IDD). However, it is still unclear how T2DM contributes to IDD. Herein, we observed the accumulation of blood glucose and degenerative lumbar discs in mice fed a high-fat diet. Detection of differentially expressed genes in degenerative lumbar discs revealed that ADAMTS4 (A Disintegrin and Metalloproteinase with Thrombospondin motifs) and ADAMTS5 genes were significantly increased. In vitro analyses demonstrated that Runt-Related Transcription Factor 2 (Runx2) recruited both PPARgamma Coactivator 1alpha (PGC-1α) and CREB-Binding Protein (CBP) to transactivate the expression of ADAMTS4/5. Glucose stimulation could dose-dependently induce the accumulation of PGC-1α and promoted the binding of the CBP-PGC-1α-Runx2 complex to the promoters of ADAMTS4/5. Depletion of CBP-PGC-1α-Runx2 complex members and treatment with either PGC-1α inhibitor SR-18292 or CBP inhibitor EML425 in vitro could dramatically inhibit the glucose-induced expression of ADAMTS4/5. Administration of SR-18292 and EML425 in diabetic mice could prevent the degeneration of lumbar discs. Collectively, our results revealed a molecular mechanism by which the hyperglycemia-dependent CBP-PGC-1α-Runx2 complex was required for the transactivation of ADAMTS4/5. The blockage of this complex in diabetic mice may help prevent IDD.

The CRL4DCAF6 E3 ligase ubiquitinates CtBP1/2 to induce apoptotic signalling and promote intervertebral disc degeneration

Inflammation and apoptosis are two important pathological causes of intervertebral disc degeneration (IDD). The crosstalk between these two biological processes during IDD pathogenesis remains elusive. Herein, we discovered that chronic inflammation induced apoptosis through a cullin-RING E3 ligase (CRL)-dependent mechanism. Two cullin proteins, CUL4A and 4B, recruited DNA damage-binding protein 1 (DDB1), RING-box protein 1 (RBX1) and DDB1- and CUL4-associated factor 6 (DCAF6) to assemble a CRL4^DCAF6 E3 ligase in intervertebral discs (IVDs) derived from IDD patients. The CRL4^DCAF6 E3 ligase ubiquitinated and degraded C-terminal-binding protein 1 and 2 (CtBP1/2), two homologues of transcriptional corepressors. The degradation of CtBP1/2 disassociated from the p300-forkhead box O3a (FOXO3a) complex, inducing the expression of B-cell lymphoma 2 (Bcl2)-binding component 3 (BBC3) and causing BBC3-dependent apoptosis. TSC01131, a small molecule that specifically targets CUL4-DDB1 interaction, could inhibit the ubiquitination of CtBP1/2 in vitro and in vivo, thereby decreasing the BBC3 expression level and preventing apoptosis signalling. Using a mouse chronic inflammation model, we found that chronic inflammation could accelerate the IDD process through a conserved CRL4^DCAF6-mediated mechanism. The administration of TSC01131 to mice could significantly improve the outcome of IDD. Collectively, our results revealed that inflammation-dependent CRL4^DCAF6 E3 ligase triggered apoptosis through the removal of CtBP-mediated transrepression. The blockage of the CRL4^DCAF6 E3 ligase by TSC01131 may represent a new therapeutic strategy for IDD treatment. KEY MESSAGES: CUL4A and CUL4B recruited DDB1, RBX1 and DCAF6 to assemble a CRL4^DCAF6 E3 ligase in human IDD biopsies. The CRL4^DCAF6 E3 ligase ubiquitinated and degraded CtBP1/2, causing BBC3-dependent apoptosis. A small molecule TSC01131 that specifically targets CUL4-DDB1 interaction could inhibit the ubiquitination of CtBP1/2, improving the outcome of IDD in a mouse model.

Transitional Dynamics of Sarcopenia and Associations of Nutritional Indices with State Transitions in Chinese aged ≥ 50

OBJECTIVES

Sarcopenia's temporal profile can be regarded as a dynamic process with distinct states, in which malnutrition plays an important role. This study aimed to address two research gaps: sarcopenia's transitional dynamics and associations of nutritional indices with state transitions in community-dwelling Chinese adults aged 50 and older.

DESIGN

A prospective population-based cohort study.

SETTING

Community-based setting in western China.

PARTICIPANTS

The analytic sample included data from 1910 participants aged ≥ 50 in the West China Health and Aging Trend study between 2018-2022.

MEASUREMENTS

We defined three states: the initial normal state (normal muscle strength, physical performance and muscle mass), the worst sarcopenia state (low muscle mass plus low muscle strength and/or low physical performance) and the intermediate subclinical state (the other scenarios). The relevant measurement methods and cut-off points were based on the 2019 AWGS consensus. Using a continuous-time multistate Markov model, we calculated probabilities of transitions between different states over 1, 2 and 4 years; we also examined associations between nutritional indices and transitions, including body mass index (BMI), calf circumference (CC), mid-arm circumference (MAC), triceps skinfold thickness (TST), albumin (ALB), geriatric nutrition risk index (GNRI), vitamin D (VitD) and prealbumin (PA).

RESULTS

For individuals in the normal state, their probabilities of remaining stable versus progressing to a subclinical state were 53.4% versus 42.1% at 2 years, and 40.6% versus 49.0% at 4 years. In the subclinical population, their 2- and 4-year chances were 60.2% and 51.2% for maintaining this state, 11.8% and 16.2% for developing sarcopenia, 28.0% and 32.6% for reverting to normal. For sarcopenic individuals, the likelihood of staying stable versus retrogressing to the subclinical state were 67.0% versus 26.3% at 2 years, and 48.3% versus 36.3% at 4 years. Increased BMI, CC, MAC, TST, ALB, GNRI and PA correlated with reversion from the subclinical state, among which increased TST, ALB and PA were also paralleled with reversion from sarcopenia, while decreased BMI, CC, MAC, TST and GNRI were associated with progression to sarcopenia. VitD was not significantly associated with any transitions.

CONCLUSION

This study reveals how sarcopenia changes over time in a Chinese population. It also highlights the usefulness of simple and cost-effective nutritional status indices for indicating state transitions, which can help identify individuals at risk of sarcopenia and guide targeted interventions within the optimal time window.

Using transcriptomic and metabolomic data to investigate the molecular mechanisms that determine protein and oil contents during seed development in soybean

Soybean [Glycine max (L.) Merri.] is one of the most valuable global crops. And vegetable soybean, as a special type of soybean, provides rich nutrition in people's life. In order to investigate the gene expression networks and molecular regulatory mechanisms that regulate soybean seed oil and protein contents during seed development, we performed transcriptomic and metabolomic analyses of soybean seeds during development in two soybean varieties that differ in protein and oil contents. We identified a total of 41,036 genes and 392 metabolites, of which 12,712 DEGs and 315 DAMs were identified. Analysis of KEGG enrichment demonstrated that DEGs were primarily enriched in phenylpropanoid biosynthesis, glycerolipid metabolism, carbon metabolism, plant hormone signal transduction, linoleic acid metabolism, and the biosynthesis of amino acids and secondary metabolites. K-means analysis divided the DEGs into 12 distinct clusters. We identified candidate gene sets that regulate the biosynthesis of protein and oil in soybean seeds, and present potential regulatory patterns that high seed-protein varieties may be more sensitive to desiccation, show earlier photomorphogenesis and delayed leaf senescence, and thus accumulate higher protein contents than high-oil varieties.

[Activation of cannabinoid receptor 2 alleviates acute lung injury in rats with lipopolysaccharide-induced sepsis]

OBJECTIVE

To investigate the protective effect of cannabinoid receptor 2 (CB2) activation against acute lung injury in rats with lipopolysaccharide (LPS)-induced sepsis and explore the underlying mechanism.

METHODS

Forty-eight SD rats were randomly assigned into control group, model group, CB2 agonist group and P38 MAPK inhibitor group (n=12). In the latter 3 groups, the rats received intraperitoneal injection of LPS to induce sepsis, and the control rats were given saline injection. In CB2 agonist group, JWH133 (3 mg/kg) was injected intraperitoneally 30 min before LPS injection; in P38 MAPK inhibitor group, the rats received intraperitoneal injection of SB203580 (5 mg/kg) 30 min prior to JWH133 injection. The changes in lung histopathology, water content, fluid clearance rate, inflammatory factors, pulmonary expressions of CB2 and tight junctionrelated genes, and phosphorylation of P38 MAPK in the lung tissues were examined.

RESULTS

The rat models of sepsis showed severe damage of alveolar structures with significantly decreased fluid clearance rate, lowered pulmonary expressions of CB2, occludin and ZO-1 mRNA and proteins, increased water content in the lung tissue, and increased phosphorylation level of P38 MAPK and TNF-α and IL-1β levels in lung lavage fluid (all P < 0.05). Treatment with JWH133 improved alveolar pathology in the septic rats, but there was still inflammatory infiltration; lung tissue water content, phosphorylation of P38 MAPK, and TNF-α and IL-1β levels in lung lavage fluid were all significantly decreased, and the fluid clearance rate, pulmonary expressions of CB2, occludin and ZO-1 were significantly increased (all P < 0.05). Additional treatment with SB203580 resulted in further improvements of alveolar pathologies, lowered phosphorylation levels of P38 MAPK in the lung tissue and TNF-α and IL-1β levels in lung lavage fluid, and increased the protein expressions of occludin and ZO-1 (P < 0.05) without causing significant changes in mRNA and protein expression of CB2 (P > 0.05).

CONCLUSION

In rats with LPS-induced sepsis, activation of CB2 can inhibit the p38 MAPK signaling pathway, reduce the release of inflammatory factors in the lung tissues, promote tight junction protein expressions, and thus offer protection against acute lung injury.

POS0969 GENETIC AND MOLECULAR DISTINCTIONS BETWEEN AXIAL PSORIATIC ARTHRITIS AND ANKYLOSING SPONDYLITIS

Background

Psoriatic arthritis (PsA) and ankylosing spondylitis (AS) represent the prototypical spondyloarthritides. PsA patients may also suffer from axial disease (axPsA). Despite overlapping symptoms, axPsA and AS may be distinct disorders with differing clinical manifestations, genetic associations, and radiographic findings.1 These disorders also respond differently to immunomodulatory therapies such as anti-interleukin (IL)-23 inhibitors. While guselkumab, a human monoclonal antibody targeting the IL-23p19 subunit, improved symptoms of axPsA,2 risankizumab, a humanized monoclonal antibody targeting the IL-23p19 subunit, did not show improvement in the primary endpoint of proportion of AS patients achieving an Assessment of SpondyloArthritis International Society 40% (ASAS40) response at week (W) 12.3

Objectives

To understand molecular distinctions between axPsA and AS to differentiate these diseases and guide treatment choice.

Methods

Whole blood and serum samples were collected from consenting patients in the NCT03162796/NCT0315828 studies of guselkumab in PsA and the NCT02437162/NCT02438787 studies of ustekinumab in AS. axPsA patients were investigator-verified as having magnetic resonance imaging- or pelvic x-ray-confirmed sacroiliitis at screening (locally read). Human leukocyte antigen (HLA) genotypes were determined by RNA sequencing, limited to Caucasian patients to reduce genetic variability,4 and select serum cytokine levels were analyzed alongside samples from healthy individuals. Differential prevalence of HLA alleles in axPsA versus AS was determined using a Fisher’s Exact test. Statistical significance of differential baseline serum cytokine expression among axPsA versus non-axPsA versus AS patients, and of guselkumab effect on serum cytokine reduction versus placebo among axPsA and non-axPsA patients, were determined with a generalized linear model performed on log2-transformed data. Biomarker data from guselkumab every-4-weeks and every-8-weeks treatment arms were pooled.

Results

Among the 186/234 Caucasian axPsA/AS patients with available data, 34%/15% were female, 70%/14% used methotrexate at baseline, mean serum C-reactive protein (CRP) levels were 2.8/2.4 mg/dL and mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were 6.4/7.5, respectively. Aside from race, baseline demographics and disease characteristics were representative of the overall population. The prevalence of class I HLA allele -B27, -C01, and -C02 carriers was significantly lower in axPsA than AS patients (30.7% versus 92.3%, p<0.001; 5.9% versus 31.6%, p<0.001; and 28.0% versus 62.0%, p<0.001, respectively), while the prevalence of HLA-C06 was significantly higher in axPsA than AS populations (36.0% versus 8.6%, p<0.001). Baseline serum levels of IL-17A and IL-17F were significantly higher in axPsA (N=71) than in AS (N=58) patients (p<0.01 and p<0.001, respectively). Comparable IL-17A/F expression was seen for axPsA and non-axPsA (N=229) patients (both p=not significant). Significant and comparable reductions from baseline in serum IL-17A/F in axPsA and non-axPsA patients were seen with guselkumab treatment (axPsA N=41, non-axPsA N=160) versus placebo (axPsA N=30, non-axPsA N=69) at W4/24 (all p<0.05).

Conclusion

Adults with axPsA and AS exhibit different genetic risk factors and serum IL-17 levels, supporting the concept of distinct disorders. Guselkumab demonstrated significant pharmacodynamic effects in axPsA patients that aligned with such effects in non-axPsA patients, consistent with observed clinical improvement.2

References

[1]Feld et al. Nat Rev Rheumatol. 2018;14(6):363-371.

[2]Mease et al. Lancet Rheumatol. 2021;3(10)E715-E723.

[3]Baeten et al. Ann Rheum Dis. 2018;77(9):1295-1302.

[4]Buchkovich et al. Genome Med. 2017;9(86).

Disclosure of Interests

Arthur Kavanaugh Consultant of: AbbVie, Amgen, BMS, Genentech, Janssen, Eli Lilly, Merck, Novartis, Pfizer and UCB, Xenofon Baraliakos Consultant of: AbbVie, Chugai, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, MSD, and Novartis, Sheng Gao Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Warner Chen Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Kristen Sweet Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Soumya D Chakravarty Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Qingxuan Song Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, May Shawi Employee of: Janssen Pharmaceutical Companies of Johnson & Johnson, and may own stock or stock options in Johnson & Johnson, Frank Behrens Speakers bureau: AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, Eli Lilly, Galapagos, Genzyme, Gilead, Janssen, MSD, Novartis, Pfizer, Roche, Sanofi, and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, Eli Lilly, Galapagos, Genzyme, Gilead, Janssen, MSD, Novartis, Pfizer, Roche, Sanofi, and UCB, Grant/research support from: Celgene, Chugai, Janssen, Pfizer, and Roche, Proton Rahman Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Eli Lilly, Janssen, Merck, Novartis, Pfizer, and UCB, Grant/research support from: Janssen, research grants from Janssen and Novartis

Effects of residual feed intake divergence on growth performance, carcass traits, meat quality, and blood biochemical parameters in small-sized meat ducks

Feed efficiency (FE) is a major economic trait of meat duck. This study aimed to evaluate the effects of residual feed intake (RFI) divergence on growth performance, carcass traits, meat quality, and blood biochemical parameters in small-sized meat ducks. A total of 500 healthy 21-day-old male ducks were housed in individual cages until slaughter at 63 d of age. The growth performance was determined for all the ducks. The carcass yield, meat quality, and blood biochemical parameters were determined for the selected 30 high-RFI (HRFI) and 30 low-RFI (LRFI) ducks. In terms of growth performance, the RFI, feed conversion ratio (FCR), and average daily feed intake (ADFI) were found to be significantly lower in the LRFI group (P < 0.01), whereas no differences were observed in the BW and body weight gain (P > 0.05). For slaughter performance, no differences were observed in the carcass traits between the LRFI and HRFI groups (P > 0.05). For meat quality, the shear force of breast muscle was significantly lower in the LRFI group (P < 0.05), while the other meat quality traits of breast and thigh muscles demonstrated no differences (P > 0.05). For blood biochemical parameters, the serum concentrations of triglycerides (TG) and glucose (GLU) were significantly lower in the LRFI group (P < 0.05), while the other parameters showed no differences (P > 0.05). The correlation analysis demonstrated a high positive correlation between RFI, FCR, and ADFI (P < 0.01). The RFI demonstrated a negative effect on the breast muscle and lean meat yields, but a positive effect on the shear force of breast muscle (P < 0.05). Further, the RFI demonstrated a positive effect on the TG and GLU levels (P < 0.05). These results indicate that the selection for low RFI could improve the FE of small-sized meat ducks without affecting the production performance. This study provides valuable insight into the biological processes underlying the variations in FE in small-sized meat ducks.

OP0013 LOSS OF SYNOVIAL TISSUE MACROPHAGE HOMEOSTASIS PRECEDES RHEUMATOID ARTHRITIS CLINICAL ONSET

Background

Synovial tissue macrophages significantly contribute to Rheumatoid Arthritis, yet the precise nature/function of macrophage subsets within the inflamed joint remains unexplored.

Objectives

To fully explore the spectrum of distinct macrophage activation states residing within the synovium of RA, at risk and healthy individuals.

Methods

Single-cell synovial tissue suspensions from RA (n=44), IAR (n=5), HC (n=11), PsA (n=11) and OA (n=4) were obtained, and synovial macrophage subsets examined by advanced multiparameter flow cytometric analysis, bulk RNA-sequencing, metabolic and functional assays.

Results

Multidimensional analysis identifies enrichment of CD206+CD163+ synovial-tissue macrophages co-expressing CD40 in the RA joint compared to healthy synovial-tissue, with frequency of CD206+CD163+CD40+ macrophages associated with increased disease activity and treatment response. In contrast, CX3CR1-expressing macrophages which form a protective barrier in healthy synovium are significantly depleted in RA. Importantly this signature of enriched CD40 expression coupled with depleted CX3CR1 expression is an early phenomenon, occurring prior to clinical manifestation of disease in individuals ‘at-risk’ of RA (IAR). RNAseq and metabolic profiling of sorted RA synovial-macrophages identified that this population is transcriptionally distinct, displaying unique inflammatory, phagocytic and tissue-resident gene signatures, paralleled by a bioenergetically stable profile as indicated by NAD(P)H emission. Functionally CD206+CD163+ RA macrophages are potent producers of pro-inflammatory mediators (reversed by CD40-signalling inhibition) and induce an invasive phenotype in healthy synovial-fibroblasts. These findings identify a distinct pathogenic population of synovial-tissue macrophage involved in shaping the immune response in RA. Crucially, this signature is present pre-disease representing a unique opportunity for early diagnosis and therapeutic intervention.

Conclusion

We have identified a novel population of tissue-resident macrophages in the RA synovium which are transcriptionally/metabolically distinct and capable of contributing to disease pathology. Uncovering the molecular patterns and cues that transform this immunoregulatory macrophage population into a dysfunctional inflammatory activation state may provide opportunities to reinstate joint homeostasis in RA patients.

Disclosure of Interests

Megan Hanlon: None declared, Mary Canavan: None declared, Nuno Neto: None declared, Qingxuan Song Employee of: Employee of Janssen Pharmaceuticals, Phil Gallagher: None declared, Ronan Mullan: None declared, Conor Hurson: None declared, Barry Moran: None declared, Michael Monaghan: None declared, Sunil Nagpal Employee of: Employee of Janssen Pharmaceuticals, Douglas Veale Consultant of: Janssen, Eli Lilly, Pfizer, Ursula Fearon Consultant of: Janssen, Eli Lilly, Pfizer

[Status of vaccination and related influencing factors in patients with chronic obstructive pulmonary disease: a real-world cross-sectional study]

Objective: To investigate the influenza and pneumonia vaccination rates in patients with chronic obstructive pulmonary disease (COPD), and analyze the factors affecting vaccination. Methods: Totally 4 016 COPD patients at the initial visit were included in the Respiratory Department of Xiangya Second Hospital of Central South University from December, 2016 to December, 2019. Each patient's vaccination status after the visit for 1 year was reviewed, and finally 3 177 patients were included in the analysis. Relevant factors affecting vaccination were analyzed with logistic regression. Results: The overall vaccination rates of COPD patients with influenza vaccine, pneumonia vaccine and influenza combined pneumonia vaccine were 2.3% (72/3 177), 1.1% (34/3 177) and 1.1% (34/3 177), respectively. The influenza vaccination rate of urban patients (3.3%, 41/1 252) was higher than that of rural patients (1.6%, 31/1 925,P=0.002). The rates of influenza vaccine, pneumonia vaccine and influenza combined pneumonia vaccine in ex-smokers with COPD were 3.3% (33/993), 2.1% (21/993), 2.1% (21/993), respectively and 1.7% (25/1 467), 0.7% (11/1 467), 0.7% (11/1 467), in current smokers with COPD, respectively (P=0.034, P=0.015, P=0.015, respectively). The influenza vaccination rate was higher in patients with COPD assessment test (CAT) scored less than 10 (4%, 27/673) than patients with CAT scored more than 10 (1.8%, 45/2 504,P=0.002). In a multifactor analysis, patients who lived in country side, were current smokers, and had more symptoms were less likely to be vaccinated, with an aOR 1.73(95%CI 1.02-2.93), 2.10(95%CI 1.18-3.76), 2.06(95%CI 1.24-3.43), respectively. 81.2% of COPD patients did not receive the vaccine because they did not know the vaccine. Conclusions: Vaccination rates for influenza vaccine, pneumonia vaccine and both of them in COPD patients were low and the patients lacked knowledge of vaccine. The residence, smoking status and symptoms were related to the vaccination of COPD patients, and these should be taken into account in the vaccination health education.

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.

Small RNAs mediate transgenerational inheritance of genome-wide trans-acting epialleles in maize

Background

Hybridization and backcrossing are commonly used in animal and plant breeding to induce heritable variation including epigenetic changes such as paramutation. However, the molecular basis for hybrid-induced epigenetic memory remains elusive.

Results

Here, we report that hybridization between the inbred parents B73 and Mo17 induces trans-acting hypermethylation and hypomethylation at thousands of loci; several hundreds (~ 3%) are transmitted through six backcrossing and three selfing generations. Notably, many transgenerational methylation patterns resemble epialleles of the nonrecurrent parent, despite > 99% of overall genomic loci are converted to the recurrent parent. These epialleles depend on 24-nt siRNAs, which are eliminated in the isogenic hybrid Mo17xB73:mop1-1 that is defective in siRNA biogenesis. This phenomenon resembles paramutation-like events and occurs in both intraspecific (Mo17xB73) and interspecific (W22xTeosinte) hybrid maize populations. Moreover, siRNA abundance and methylation levels of these epialleles can affect expression of their associated epigenes, many of which are related to stress responses.

Conclusion

Divergent siRNAs between the hybridizing parents can induce trans-acting epialleles in the hybrids, while the induced epigenetic status is maintained for transgenerational inheritance during backcross and hybrid breeding, which alters epigene expression to enhance growth and adaptation. These genetic and epigenetic principles may apply broadly from plants to animals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-022-02614-0.

Open chromatin interaction maps reveal functional regulatory elements and chromatin architecture variations during wheat evolution

BACKGROUND

Bread wheat (Triticum aestivum) is an allohexaploid that is generated by two subsequent allopolyploidization events. The large genome size (16 Gb) and polyploid complexity impede our understanding of how regulatory elements and their interactions shape chromatin structure and gene expression in wheat. The open chromatin enrichment and network Hi-C (OCEAN-C) is a powerful antibody-independent method to detect chromatin interactions between open chromatin regions throughout the genome.

RESULTS

Here we generate open chromatin interaction maps for hexaploid wheat and its tetraploid and diploid relatives using OCEAN-C. The anchors of chromatin loops show high chromatin accessibility and are concomitant with several active histone modifications, with 67% of them interacting with multiple loci. Binding motifs of various transcription factors are significantly enriched in the hubs of open chromatin interactions (HOCIs). The genes linked by HOCIs represent higher expression level and lower coefficient expression variance than the genes linked by other loops, which suggests HOCIs may coordinate co-expression of linked genes. Thousands of interchromosomal loops are identified, while limited interchromosomal loops (0.4%) are identified between homoeologous genes in hexaploid wheat. Moreover, we find structure variations contribute to chromatin interaction divergence of homoeologs and chromatin topology changes between different wheat species. The genes with discrepant chromatin interactions show expression alteration in hexaploid wheat compared with its tetraploid and diploid relatives.

CONCLUSIONS

Our results reveal open chromatin interactions in different wheat species, which provide new insights into the role of open chromatin interactions in gene expression during the evolution of polyploid wheat.

Baicalein protects against MPP+/MPTP-induced neurotoxicity by ameliorating oxidative stress in SH-SY5Y cells and mouse model of Parkinson's disease

Baicalein, a major bioactive flavone constituent isolated from Scutellaria baicalensis Georgi, has neuroprotective properties in several neurological disorders. Many studies suggest that oxidative stress plays a central role in the pathogenesis of Parkinson's disease (PD). Baicalein has also been shown to have antioxidant effects. Therefore, the current study was designed to investigate whether baicalein could protect against MPP⁺/MPTP-induced neurotoxicity via suppressing oxidative stress in vitro and in vivo. In vitro, our results showed that baicalein increased cell viability in MPP⁺-treated SH-SY5Y cells. Treatment with baicalein could reversed the increased MDA and ROS levels, and the decreased GSH levels in MPP⁺-treated SH-SY5Y cells. In MPTP-treated mice, baicalein ameliorated MPTP-induced motor impairment and suppressed the MPTP-induced accumulation of iron and lipid peroxides. Besides, baicalein improved the neurotoxicity induced by MPTP as seen by a significant raise of tyrosine hydroxylase (TH) and simultaneous decrease of monoamine-oxidase-B (MAO-B). The inhibitory effect of baicalein on oxidative stress probably was partially governed by inhibition of ERK activation. In conclusion, our results suggest that baicalein could prevent MPP+/MPTP-induced neurotoxicity via suppressing oxidative stress.

Concerted genomic and epigenomic changes accompany stabilization of Arabidopsis allopolyploids

During evolution successful allopolyploids must overcome 'genome shock' between hybridizing species but the underlying process remains elusive. Here, we report concerted genomic and epigenomic changes in resynthesized and natural Arabidopsis suecica (TTAA) allotetraploids derived from Arabidopsis thaliana (TT) and Arabidopsis arenosa (AA). A. suecica shows conserved gene synteny and content with more gene family gain and loss in the A and T subgenomes than respective progenitors, although A. arenosa-derived subgenome has more structural variation and transposon distributions than A. thaliana-derived subgenome. These balanced genomic variations are accompanied by pervasive convergent and concerted changes in DNA methylation and gene expression among allotetraploids. The A subgenome is hypomethylated rapidly from F1 to resynthesized allotetraploids and convergently to the T-subgenome level in natural A. suecica, despite many other methylated loci being inherited from F1 to all allotetraploids. These changes in DNA methylation, including small RNAs, in allotetraploids may affect gene expression and phenotypic variation, including flowering, silencing of self-incompatibility and upregulation of meiosis- and mitosis-related genes. In conclusion, concerted genomic and epigenomic changes may improve stability and adaptation during polyploid evolution.

JS01.3.A Oncogenic chaperoning of Hsp90 in glioma with FGFR3-TACC3

BACKGROUND

Fusion genes are chromosomal aberrations in malignancies that can be used as prognostic markers as well as therapeutic targets. The FGFR3-TACC3 (F3-T3) was initially discovered as an oncogenic molecule in glioblastoma and bladder cancer and subsequently found in many other cancer types. Based on clinical evidence, F3-T3 was found in glioblastoma patients before and after TMZ and radiotherapy treatment, suggesting that targeting F3-T3 is a valid strategy for glioblastoma treatment.

MATERIAL AND METHODS

We profiled the proteins that interacted with F3-T3 fusion protein in U-251 MG cells with F3-T3 through 2-D liquid chromatography-tandem mass spectrometry. To validate the result of proteomic analysis, we performed reverse immunoprecipitation by pulling down Hsp90 or Cdc37 in U-251 MG cells stably expressing F3-T3. To inhibit the association between F3-T3 and the Hsp90-Cdc37 complex, we treated U-251 MG and LN-229 cells stably expressing F3-T3 with Hsp90 inhibitors or siRNA of Cdc37. We applied the CCK8 assay to evaluate the sensitivity of glioblastoma cells stably expressing F3-T3, wild-type FGFR3, kinase-dead F3-T3 (K508R), and empty vectors to TMZ. Immunoblot and immunofluorescence staining were used to detect DNA damage marker pH2AX. The drug combination effect index was analyzed using software CalcuSyn. U-251 MG cells stably expressing F3-T3 infected with luciferase virus were intracranially injected in nude mice. The experimental group was administered with temozolomide (5mg/kg/day) by oral gavage, Hsp90 inhibitor Onalespib (30mg/kg/day) by tail vein injection or the combination of the two for indicated days.

RESULTS

We identified the proteins that showed increased binding ratios to F3-T3 over full-length FGFR3, the molecular chaperone proteins encoded by the genes HSP90AB1, HSP90AA1, and CDC37 emerged as 5th, 6th, and 7th on the top ten list, showing an approximately 4-fold increase in normalized spectral counts. Using Hsp90 inhibitors or Cdc37 siRNA disrupted the formation of the F3-T3/Hsp90/Cdc37 complex. Disruption of Hsp90-Cdc37 chaperoning caused a ubiquitination-mediated degradation of the glycosylated form of F3-T3 and abrogated the maturation of nascent F3-T3, resulting in suppression of F3-T3 signaling pathways. Additionally, our results provide evidence that the F3-T3 signaling pathway confers drug resistance to TMZ induced DNA damage. However, the resistance of TMZ was disrupted in glioblastoma cells harboring kinase-dead F3-T3 (K508R). We also demonstrated Hsp90 inhibitor significantly sensitized glioblastoma cells harboring the F3-T3 fusion gene to TMZ treatment and improved survival of xenograft model bearing F3-T3 tumor in vivo.

CONCLUSION

F3-T3 is a strong Hsp90 client that shows strong addiction to the Hsp90-Cdc37 chaperone system. Combination therapy with Hsp90 inhibitor overcomes the TMZ resistance conferred by F3-T3.

[Free rectus abdominis myocutaneous flap for the reconstruction of major and complex defects in the craniofacial regions after ablation of advanced sinonasal carcinomas]

Objective: To explore the method and plausibility of using free rectus abdominis flap (FRAF) to reconstruct the major and complex defects in the craniofacial regions after ablation of advanced sinonasal carcinoma. Methods: From 2007 to 2018 at No. 980 Hospital of Joint Logistic Supportive Force of People's Liberation Army of China, 13 patients with advanced carcinoma of nasal cavity and paranasal sinuses, including 11 males and 2 females, aged from 33 to 67 years, were treated with FRAF to repair the invasion of skull base, face and orbit. Based on adequate and meticulous preoperative evaluations on patients and tumors, complete resection of tumor bulks was performed. According to the sites, characters and extents of the defects, FRAF was introduced in different ways into reconstruction of major and complex defects in the craniofacial regions after resection of advanced sinonasal carcinomas, restoring the structure and contour of the craniofacial region. Results: Complete resection of tumors was achieved in all cases. For repairing the major and complex defects resulted from tumor ablation, FRAF graft was conducted in 13 patients with advanced sinonasal carcinomas. The recipient vessels were facial artery and vein in 9 cases, superficial temporal artery and vein in 4 cases. Vascular bridging with the external jugular vein was carried out in 2 cases who underwent submandibular neck dissections, in which facial artery and vein were used as recipient vessels. Free fibular flap was used along with FRAF in a case undergone bilateral maxillectomy. Pedicled galea capitis and periosteal flap were applied simultaneously in 3 cases with dura defects at the skullbase resulted from tumor resection. All flaps used in 13 cases survived uneventfully without major complications, with successful repair of defects, reconstruction of structures and restoration of contour of craniofacial regions. Conclusion: With adequate evaluation of resectability of tumors as well as nature and extent of defects after tumor removal, FRAF transplantation is an ideal method and strategy of choice for reconstructing the major and complex defects in craniofacial regions resulted from tumor ablation of advanced sinonasal carcinomas.

Temozolomide Drives Ferroptosis via a DMT1-Dependent Pathway in Glioblastoma Cells

PURPOSE

Temozolomide is used in first-line treatment for glioblastoma. However, chemoresistance to temozolomide is common in glioma patients. In addition, mechanisms for the anti-tumor effects of temozolomide are largely unknown. Ferroptosis is a form of programmed cell death triggered by disturbed redox homeostasis, overloaded iron, and increased lipid peroxidation. The present study was performed to elucidate the involvement of ferroptosis in the anti-tumor mechanisms of temozolomide.

MATERIALS AND METHODS

We utilized the CCK8 assay to evaluate cytotoxicity. Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), iron, and glutathione (GSH) were measured. Flow cytometry and fluorescence microscope were used to detect the production of reactive oxygen species (ROS). Western blotting, RT-PCR and siRNA transfection were used to investigate molecular mechanisms.

RESULTS

Temozolomide increased the levels of LDH, MDA, and iron and reduced GSH levels in TG905 cells. Furthermore, we found that ROS levels and DMT1 expression were elevated in TG905 cells treated with temozolomide and were accompanied by a decrease in the expression of glutathione peroxidase 4, indicating an iron-dependent cell death, ferroptosis. Our results also showed that temozolomide-induced ferroptosis is associated with regulation of the Nrf2/HO-1 pathway. Conversely, DMT1 knockdown by siRNA evidently blocked temozolomide-induced ferroptosis in TG905 cells.

CONCLUSION

Taken together, our findings indicate that temozolomide may suppress cell growth partly by inducing ferroptosis by targeting DMT1 expression in glioblastoma cells.

An epigenetic basis of inbreeding depression in maize

Inbreeding depression is widespread across plant and animal kingdoms and may arise from the exposure of deleterious alleles and/or loss of overdominant alleles resulting from increased homozygosity, but these genetic models cannot fully explain the phenomenon. Here, we report epigenetic links to inbreeding depression in maize. Teosinte branched1/cycloidea/proliferating cell factor (TCP) transcription factors control plant development. During successive inbreeding among inbred lines, thousands of genomic regions across TCP-binding sites (TBS) are hypermethylated through the H3K9me2-mediated pathway. These hypermethylated regions are accompanied by decreased chromatin accessibility, increased levels of the repressive histone marks H3K27me2 and H3K27me3, and reduced binding affinity of maize TCP-proteins to TBS. Consequently, hundreds of TCP-target genes involved in mitochondrion, chloroplast, and ribosome functions are down-regulated, leading to reduced growth vigor. Conversely, random mating can reverse corresponding hypermethylation sites and TCP-target gene expression, restoring growth vigor. These results support a unique role of reversible epigenetic modifications in inbreeding depression.

Altered chromatin architecture and gene expression during polyploidization and domestication of soybean

Polyploidy or whole-genome duplication (WGD) is widespread in plants and is a key driver of evolution and speciation, accompanied by rapid and dynamic changes in genomic structure and gene expression. The 3D structure of the genome is intricately linked to gene expression, but its role in transcription regulation following polyploidy and domestication remains unclear. Here, we generated high-resolution (∼2 kb) Hi-C maps for cultivated soybean (Glycine max), wild soybean (Glycine soja), and common bean (Phaseolus vulgaris). We found polyploidization in soybean may induce architecture changes of topologically associating domains and subsequent diploidization led to chromatin topology alteration around chromosome-rearrangement sites. Compared with single-copy and small-scale duplicated genes, WGD genes displayed more long-range chromosomal interactions and were coupled with higher levels of gene expression and chromatin accessibilities but void of DNA methylation. Interestingly, chromatin loop reorganization was involved in expression divergence of the genes during soybean domestication. Genes with chromatin loops were under stronger artificial selection than genes without loops. These findings provide insights into the roles of dynamic chromatin structures on gene expression during polyploidization, diploidization, and domestication of soybean.

OP0028 CD206+CD163+ PATHOGENIC MACROPHAGES ENRICHED IN RHEUMATOID ARTHRITIS SYNOVIAL TISSUE WITH DISTINCT TRANSCRIPTIONAL SIGNATURES

Background:

Synovial tissue macrophages are an exquisitely plastic pool of innate cells that play a key role in RA disease progression. However, the precise nature, diversity, and function of macrophage subsets within the inflamed joint remains unexplored.

Objectives:

Therefore, the aims of this study are to phenotypically, transcriptionally and functionally characterise synovial tissue macrophages residing within the inflamed joint.

Methods:

Rheumatoid Arthritis, Psoriatic Arthritis, Osteoarthritis and healthy control synovial-tissue biopsies and synovial-fluid mononuclear cells were analysed using the following panel (CD40,-CD45,-CD64,-CD68,-CD163,-CD206,-CD253,-CCR4,-CCR7,-CXCR1,-CXCR3). CD206+CD163+ and CD206-CD163- macrophages were sorted from RA synovial-tissue by FACSAria sorter; RNAseq and FLIM analysis, autologous T-cell co-culture and heathy fibroblast experiments performed. Cytokine expression was measured by MSD immunoassay.

Results:

RA synovial tissue and fluid macrophages display markers typical of both M1 (CD40+CD253+) and M2 (CD206+CD163+) macrophages with a spectrum of macrophage activation states identified. Within this spectrum, significant enrichment of dominant CD206+CD163+ macrophage-subtype is present in synovial tissue versus fluid (p<0.05). CD206+CD163+ synovial tissue macrophages express significantly more CD40 than synovial fluid (p<0.0003), positively correlate with disease activity (r=0.6, p<0.01), with baseline levels predicting response to therapy (p<0.05). Moreover, CD206+CD163+CD40+ macrophages are enriched in RA synovial tissue compared to PsA and OA pathotypes (p<0.05). While the CD206+CD163+ subset is present in healthy synovial tissue, expression of CD40 is completely absent in healthy synovium (p<0.05) with dramatically decreased expression of CX3CR1 on RA macrophages. RNA-seq analysis indicates that CD206+CD163+ population is transcriptionally distinct from synovial tissue CD206-CD163-, synovial fluid CD206+CD163+, and RA monocyte-derived M1/M2 macrophages, with unique tissue-resident gene signatures. Moreover, differing metabolic demands between CD206+CD163+ and CD206-CD163- subsets was demonstrated by RNAseq and FLIM analysis. CD206+CD163+ macrophages enhance autologous T-cell responses, spontaneously secrete high levels of pro-inflammatory cytokines and activate healthy fibroblasts towards pro-inflammatory mechanisms thus further contributing to the local inflammatory response. Finally, inhibition of CD40 activity abrogates the expression of pro-inflammatory mediators (TNFa, IL-1B, IL-6, IFNy) and induces IL-10 expression in sorted CD206+CD163+ synovial tissue-macrophages suggesting a key role for CD40 in driving this pathogenic phenotype.

Conclusion:

This data identifies for the first-time enrichment of a previously undescribed dysfunctional dominant and transcriptionally distinct macrophage subtype in RA synovial tissue. Taken together, this data provides a greater understanding of the critical role tissue-resident macrophages play in perpetuating inflammation in RA. Further investigation of the molecular patterns and cues that shape specific synovial macrophage subsets may provide opportunities to reinstate RA joint homeostasis.

Disclosure of Interests:

Megan Hanlon: None declared, Mary Canavan: None declared, Qingxuan Song Employee of: Janssen Research & Development, Nuno Neto: None declared, Phil Gallagher: None declared, Ronan Mullan: None declared, Conor Hurson: None declared, Michael Monaghan: None declared, Sunil Nagpal Employee of: Janssen Research & Development, Douglas Veale Speakers bureau: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Consultant of: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Grant/research support from: Janssen, Abbvie, Pfizer, UCB, Ursula Fearon Speakers bureau: Abbvie, Grant/research support from: Janssen, Abbvie, Pfizer, UCB

POS0195 GUSELKUMAB TREATMENT MODULATES CORE PSORIATIC ARTHRITIS GENE EXPRESSION IN TWO PHASE 3 CLINICAL TRIALS (DISCOVER-1 AND -2)

Background:

Guselkumab (GUS), an interleukin-23 p19-subunit monoclonal antibody, demonstrated efficacy compared with placebo (PBO) in reducing signs and symptoms of psoriatic arthritis (PsA) in the phase 3 DISCOVER-1 & 2 studies.1,2

Objectives:

To evaluate gene expression in the blood of PsA patients (pts) in the DISCOVER-1 & -2 studies and the impact of GUS on the expression of these genes.

Methods:

Pts were treated with GUS 100 mg every 4 weeks (Q4W); GUS 100 mg at W0, W4, then Q8W; or matching PBO. Whole transcriptome profiling by RNA-sequencing was performed using the Novaseq platform on blood samples obtained from a subset of 673 pts with PsA at baseline across the 2 DISCOVER studies, as well as from 21 demographically (age, sex, and ethnicity) matched healthy controls procured independently of the clinical program. A subgroup (N=227) also had serial blood samples (W0/W4/W24) evaluated; the subgroup pts were selected based on having baseline characteristics (demographics, disease activity, medication use) representative of the overall cross-study PsA population. Significance of differentially expressed genes (DEGs) between PsA and healthy controls was defined by a false discovery rate (FDR) <0.05 based on a log-linear model using edgeR. Top genes were defined by significance and |logFC| >1. For cell type analysis, genes that changed with GUS treatment were tested for enrichment using Cibersort. Gene enrichment scores were calculated using Gene Set Variation Analysis (GSVA).

Results:

To define disease genes, we compared genes at baseline in pts with active PsA vs. healthy control whole blood transcriptomes and detected 355 upregulated and 314 downregulated (top genes shown in Table 1), defined here as core disease genes. Upregulated genes were largely related to neutrophils, monocytes, macrophages, and extracellular matrix, whereas downregulated genes were related to T cells. The upregulated disease genes were significantly decreased and the downregulated disease genes were significantly increased by GUS treatment vs. PBO at W4 and W24 (Fig 1). Upon stratification by Psoriasis Area and Severity Index 75% response and American College of Rheumatology 20% response, changes in core disease gene expression from W0 were statistically significant among responders, but not in non-responders, at W4 and W24 (data not shown). We then performed the second differential expression analysis comparing baseline to W4 and W24 for both PBO and GUS treatment arms to define genes that change with treatment arm over time. At W4 and W24 we found many DEGs from baseline with GUS treatment and none with PBO. These included genes related to B-, T-, NK-, and plasma cells (increased by GUS) and neutrophils, monocytes, eosinophils, and macrophages (decreased by GUS), suggestive of a partial normalization of immune cell composition in whole blood.

Conclusion:

Using whole transcriptome profiling, we detected DEGs in blood samples obtained from PsA pts vs. healthy controls, suggesting a dysregulation of immune cell profiles in PsA. The majority of these disease-associated genes were modulated by GUS, with directionality toward a normalization of whole blood transcriptomic signatures.

References:

[1]Deodhar A et al. Lancet. 2020;395:1115.

[2]Mease P et al. Lancet. 2020;395:1126.

Table 1.

Top DEGs derived from PsA vs. healthy whole blood transcriptomes.

Upregulated in PsADownregulated in PsAGenelogFClogCPMFDRGenelogFClogCPMFDRADGRG75.92-0.900.02101AK8-1.36-1.061.61E-07ADAMTS24.060.820.006466FTCD-1.48-1.741.67E-05PGF3.21-0.680.006466GPR15-1.541.811.67E-05PCSK93.21-2.960.023872CHRM3-1.54-2.629.6E-08OLAH2.760.750.004539RFPL4AL1-1.69-3.340.009738MAOA2.55-0.260.005463SPACA3-1.85-3.230.000216SLC2A142.300.590.022594VANGL2-1.95-1.799.6E-08MMP12.25-1.160.004745RFPL4A-2.04-1.280.004539DAAM22.124.310.024628GLYATL2-2.77-2.781.93E-15BCAR1-3.13-2.586.24E-26

Bold indicates positive change. CPM = counts per million.

Disclosure of Interests:

Stefan Siebert Consultant of: AbbVie, Janssen, Novartis, UCB, Grant/research support from: AbbVie, Amgen (previously Celgene), Bristol Myers Squibb, Boehringer Ingelheim, GSK, Janssen, Novartis, UCB, Kristen Sweet Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC, Christopher T. Ritchlin Consultant of: AbbVie, Amgen, Gilead, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, and UCB, Elizabeth C Hsia Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC, Alexa Kollmeier Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC, Xie L Xu Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC, Qingxuan Song Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC, Michelle Miron Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development LLC

Robot-assisted minimally invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion: a retrospective matched-control analysis for clinical and quality-of-life outcomes

Aim: To compare the screw accuracy and clinical outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and open TLIF in the treatment of one-level lumbar degenerative disease. Materials & methods: From May 2018 to December 2019, a consecutive series of patients undergoing robot-assisted minimally invasive one-level lumbar fusion procedures were retrospectively compared with matched controls who underwent one-level open TLIF procedures for clinical and quality-of-life outcomes. Results: A total of 52 patients underwent RA MIS-TLIF procedures (robot-assisted [RA] group) and 52 matched controls received freehand open TLIF procedures (open [OP] group). The RA group had more grade A screws with 96.2% one-time success rate of screw placement (p < 0.05). Besides, the RA group experienced less intraoperative blood loss and shorter length of hospital stay, while the OP group had shorter operative duration and cumulative radiation time (p < 0.001). What is more, the average VAS score for low back pain and ODI score in the RA group were lower than that in the OP group 1 month after operation (p < 0.05). Conclusion: The use of real-time, image-guided robot system may further expand the advantages of MIS-TLIF technique in terms of accuracy and safety.

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.

Inhibition of connexin 43 induces hearing loss in postnatal mice

BACKGROUND

Connexin 43 (Cx43) is the most ubiquitously expressed member of the family of connexins, constituting gap junctions and mediating cell communication, still its role in hearing loss has been little studied.

METHODS

Immunohistochemistry was used to detect the expression pattern of Cx43. Spiral ganglia neurons (SGNs) and Corti co-culture were utilized to assay the re-innervation of hair cells by newborn SGNs. Gap19 was utilized to inhibit Cx43 hemichannels. Auditory brainstem responses (ABR) and endocochlear potential (E.P.) were measured to confirm the hearing loss.

RESULTS

The expression of Cx43 in P14 mice was higher than in P0 and P28 (adult) mice, the earlier time point coinciding with the early inner ear development. Additionally, the growth and synapse generation of fibers were inhibited after Gap 19 treatment of the co-cultures of the Corti and SGNs from newborn mice. Furthermore, the inhibition of Cx43 could increase the ABR threshold and decrease E.P. level in postnatal mice, whereas such an effect was not observed in adult mice.

CONCLUSION

The function of Cx43 is critical during the early development of mouse cochlea but is dispensable in adult mice.

Histone H3K27 dimethylation landscapes contribute to genome stability and genetic recombination during wheat polyploidization

Bread wheat (Triticum aestivum) is an allohexaploid that was formed via two allopolyploidization events. Growing evidence suggests histone modifications are involved in the response to 'genomic shock' and environmental adaptation during polyploid formation and evolution. However, the role of histone modifications, especially histone H3 lysine-27 dimethylation (H3K27me2), in genome evolution remains elusive. Here we analyzed H3K27me2 and H3K27me3 profiles in hexaploid wheat and its tetraploid and diploid relatives. Although H3K27me3 levels were relatively stable among wheat species with different ploidy levels, H3K27me2 intensities increased concurrent with increased ploidy levels, and H3K27me2 peaks were colocalized with massively amplified DTC transposons (CACTA family) in euchromatin, which may silence euchromatic transposons to maintain genome stability during polyploid wheat evolution. Consistently, the distribution of H3K27me2 is mutually exclusive with another repressive histone mark, H3K9me2, that mainly silences transposons in heterochromatic regions. Remarkably, the regions with low H3K27me2 levels (named H3K27me2 valleys) were associated with the formation of DNA double-strand breaks in genomes of wheat, maize (Zea mays) and Arabidopsis. Our results provide a comprehensive view of H3K27me2 and H3K27me3 distributions during wheat evolution, which support roles for H3K27me2 in silencing euchromatic transposons to maintain genome stability and in modifying genetic recombination landscapes. These genomic insights may empower breeding improvement of crops.

MiR-874-3p plays a protective role in intervertebral disc degeneration by suppressing MMP2 and MMP3

Intervertebral disc degeneration (IDD) is a spinal degenerative disease and one of the most important causes of musculoskeletal disability. Matrix metalloproteinase (MMP)-mediated extracellular matrix degradation is the core process of IDD. The regulators of MMPs in the intervertebral disc are still not fully known. In this study, using quantitative reverse transcription PCR, luciferase reporter assay, Western blotting, immunofluorescence, flow cytometry, and Cell Counting Kit-8 assay, we found that the miR-874-3p expression level was significantly decreased in IDD patients. MiR-874-3p could target and repress MMP2 and MMP3 expression in nucleus pulposus cells. These results could improve the understanding of IDD and provide a possible diagnostic marker and treatment candidate for IDD. The miR-874-3p/MMP2/MMP3 axis might also provide direction for future cancer and inflammation investigations.

Bandwidth-unlimited polarization-maintaining metasurfaces

Any arbitrary state of polarization of light beam can be decomposed into a linear superposition of two orthogonal oscillations, each of which has a specific amplitude of the electric field. The dispersive nature of diffractive and refractive optical components generally affects these amplitude responses over a small wavelength range, tumbling the light polarization properties. Although recent works suggest the realization of broadband nanophotonic interfaces that can mitigate frequency dispersion, their usage for arbitrary polarization control remains elusively chromatic. Here, we present a general method to address broadband full-polarization properties of diffracted fields using an original superposition of circular polarization beams transmitted through metasurfaces. The polarization-maintaining metasurfaces are applied for complex broadband wavefront shaping, including beam deflectors and white-light holograms. Eliminating chromatic dispersion and dispersive polarization response of conventional diffractive elements lead to broadband polarization-maintaining devices of interest for applications in polarization imaging, broadband-polarimetry, augmented/virtual reality imaging, full color display, etc.