NOMOGRAM COMBINING PREOPERATIVE ULTRASONOGRAPHY WITH CLINICAL FEATURES FOR PREDICTING LYMPH NODES POSTERIOR TO THE RIGHT RECURRENT LARYNGEAL NERVE METASTASIS IN PATIENTS WITH PAPILLARY THYROID CANCER

Aim

To establish a nomogram combining preoperative ultrasonic and clinical features for predicting lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in papillary thyroid carcinoma (PTC) patients.

Methods

Preoperative ultrasonic and clinical variables of patients with PTC from 2014 to 2021 were retrospectively analyzed. The risk factors associated with LN-prRLN metastasis were identified and validated through a developed nomogram model based on univariate and multivariate logistic regression analysis.

Results

A total of 615 patients (690 lesions) were enrolled for the training dataset and 207 patients (226 lesions) for the validation dataset with 54 (6.57%) patients developing LN-prRLN metastasis. Multivariate logistic regression analysis demonstrated that the preoperative ultrasound measurement of larger tumors (≥20 mm), higher TI-RADS category (category 5), and higher thyroglobulin level (9.86 ng/mL) in patients with PTC were predictive factors for LN-prRLN metastasis. The nomogram model was established and verified yielding a relatively good predictive performance in the training and validation dataset (AUC: 0.868 vs. 0.851).

Conclusions

The nomogram combining preoperative ultrasonography with clinical features in this study is highly predictive of LN-prRLN metastasis in patients with PTC, which may provide more personalized recommendations for clinicians in preoperative decision-making for complete dissection of LN-prRLN.

[Characteristics of the immune microenvironment and related treatment strategies in patients with periprosthetic joint infection]

Periprosthetic joint infection (PJI) involves complex immunomodulatory interactions between pathogens,biomaterials,and hosts,and correlates with alterations in the ratio of immune cells as well as in the concentration of immune checkpoint molecules.Prosthesis,biofilm,microorganisms,and host constitute a special and complex immune microenvironment.Fully studying the characteristics of immune microenvironment and potential targets of immunotherapy in orthopedic implant-associated infections are expected to provide a new direction for clinical treatment of PJI. An overview of the literature related to PJI and immune regulation at domestic and international sites was conducted to summarize and analyze the characteristics of the immune microenvironment and the potential value of related immunotherapy, aiming to provide new insights for the targeted treatment of PJI.

[Efficacy comparison and safety analysis of subcutaneous specific immunotherapy with standardized house dust mite allergen in patients with single and multiple allergic rhinitis]

Objective: To investigate the efficacy and safety of house dust mite (HDM) allergen subcutaneous specific immunotherapy (SCIT) in patients with allergic rhinitis (AR) with single dust mite allergy and multiple allergen allergy. Methods: A retrospective study was conducted. A total of 372 patients with allergic rhinitis induced by house dust mite were diagnosed in the allergy clinic of General Hospital of North Theater Command from January 2013 to January 2018.They were treated with house dust mite allergen preparation for standardized SCIT for 3 years or more, and had complete follow-up data. The age ranged from 5 to 55 years, the median age was 13 years, and the average age was (19.4±14.7) years; 216 males and 156 females. According to their age, they were divided into the older group (age >14 years) and younger group (age ≤ 14 years). According to the number of allergens, they were divided into single group (only HDM group allergic to house dust mites) and multi recombination (including 2 or more allergens including house dust mites). The multi recombination was further divided into HDM+1 group, HDM+2 group, HDM+3 group, HDM+4 and above group. Before treatment (T0), 1 year (T1) and 3 years (T2) after SCIT treatment, the patients in each group established files, analyzed and compared the average total nasal symptoms score (TNSS), total non nasal symptoms score (TNNSS), visual analogue scale (VAS), total medicine score (TMS) and rhinoconjunctivitis quality of life questionnaire (RQLQ), and evaluated the clinical efficacy of the treatment and the comparison of various scores in the efficacy of SCIT with different allergens and ages. Record the occurrence of local and systemic adverse reactions of all patients during treatment, and evaluate the safety of SCIT. All scores are measurement data that do not conform to normal distribution. Mann-Whitney U and Kruskai-Wallis test of independent samples are used for inter group comparison, and Bonferroni correction is used for further pairwise comparison; Chi square test and continuity correction method were used for the comparison between count data groups such as the incidence of adverse reactions and the effective rate of TNSS, and a-division method was used for further pairwise comparison. Results: After SCIT treatment, the scores of TNSS, TNNSS, TMS, VAS and RQLQ in T1 and T2 were significantly lower than those in T0, and the scores in T2 were significantly lower than those in T1 (Z=-11.168, -4.786, -6.639, -13.012, -10.652 in T0 vs T1; Z=-13.527, -8.746, -13.397, -14.477, -11.833 in T0 vs T2; Z=-4.721, -4.607, -10.020, -7.180, -5.721 in T1 vs T2; P<0.05). In T1 and T2, compared with the older group, the scores of TNSS, TNNSS, TMS, VAS and RQLQ in younger group were lower, and the differences of various indexes were statistically significant(the median scores of T1: M_younger=3.0, 1.0, 2.0, 4.0, 2.6, M_older=5.0, 2.0, 3.0, 5.0, 3.2; the median scores of T2: M_younger=3.0, 1.0, 0, 2.0, 1.3, M_older=4.0, 1.0, 1.5, 3.0, 2.3; Z_T1=-4.525, -5.830, -4.061, -3.608, -2.785; Z_T2=-3.847, -4.055, -2.820, -2.998, -3.418; P<0.05). In T1 and T2, the scores of TNSS, VAS and RQLQ in a single group after SCIT treatment were lower than those in multiple recombination(the median scores of T1:M_single=4.0, 4.0, 2.6, M_multiple=5.0, 5.0, 3.2; the median scores of T2: M_single=3.0, 2.0, 1.4, M_multiple=4.0, 3.0, 2.1), and the difference was statistically significant (Z_T1=-3.002, -2.092, -1.977; Z_T2=-3.354, -2.469, -2.116; P<0.05). There was no significant difference in TMS (the median score during T1 period: M_single=2.0, M_multiple=3.0, Z_T1=-1.130; the median score during T2 period: M_single=1.0, M_multiple=1.0, Z_T2=-1.544; P>0.05). Further comparison within the group showed that there was no significant difference in the improvement rate of TNSS during T2 period among HDM group, HDM+1 group, HDM+2 group and HDM+3 group (HDM vs HDM+1 group χ²=0.277, HDM vs HDM+2 group χ²=0.78, HDM vs HDM+3 group χ²=0.075, HDM+1 vs HDM+2 group χ²=0.057, HDM+1 vs HDM+3 group χ²=0.019, HDM+2 vs HDM+3 group χ²=0.003; P>0.005), the improvement rates were 92.5%, 90.3%, 89.1% and 89.5%. Respectively in HDM group,HDM+1 group, HDM+2 group, HDM+3 group, compared with HDM+4 and above group, the difference was statistically significant (χ²=26.144, 13.254, 15.144, 8.808; P<0.005). The improvement rate of TNSS in HDM+4 and above group was 60.9%. 122 patients had local adverse reactions during the treatment of SCIT, accounting for 32.8%. The local adverse reactions were 759 injections (15 336 injections in total), accounting for 4.95%. Most of them were swelling, dizziness, induration and pruritus at the injection site, which could be relieved by oral antihistamines or within 2 hours. There were 2 cases of local urticaria, once for each case. The symptoms were relieved within 1 week after oral antihistamine. No serious systemic adverse reactions occurred. Conclusion: Standardized SCIT may be a safe and effective treatment for AR patients, and the type of allergen may be one of the important factors affecting the efficacy of SCIT. The efficacy of SCIT was significant in AR patients with three or less allergens other than house dust mite.

POS0450 TEMPORAL MIGRATION OF IMMUNE CELLS FROM PSORIATIC SKIN TO JOINTS INITIATING SYNOVIAL INFLAMMATION IN PSORIATIC ARTHRITIS

Background

Spreading of inflammation from skin to joint is a key question behind the pathogenesis of psoriatic arthritis (PsA). Psoriasis (PsO), being one of the most prevalent skin diseases, usually anticipates joint manifestations, suggesting spreading of skin to joint disease, which happens in about 30% of the patients with psoriasis.1 To date, it is still obscure why the inflammatory process in some patients with PsO remains restrained to the skin, whereas in other patients it extents to tendons and joints.

Objectives

Using a pre-clinical model of PsA, we aimed to unveil the skin-joint axis, i.e. the spreading of psoriatic inflammation from the skin to the joints.

Methods

KAEDE transgenic mice expressing a photo-convertible fluorescent reporter were used to assess cell trafficking from inflamed skin to other organs in the mouse model of IL-23 overexpression (IL-23OE) induced PsA. Psoriatic skin lesions were irradiated with UV light to trigger the photoswitch from KAEDEGREEN to KAEDERED. Migration to different organs was determined by flow cytometry. Imaging flow cytometry was used to characterize the type of cells migrating from the skin to the joints. Migrating cells were further characterized by single-cell RNA-sequencing (scRNAseq) and functional analyses.

Results

MRI imaging and histological evaluation of IL-23OE mice revealed skin inflammation preceding joint inflammation in both wild-type and KAEDE-transgenic mice. Specific leukocyte migration from the skin to the joints started shortly after the onset of skin inflammation and before onset of inflammation within the joints of KAEDE transgenic mice. No migration was observed in healthy control animals. Other organs such as spleen or lymph nodes showed no model-dependent migration. Imaging flow cytometry revealed that the cells migrating to the joints were predominantly CD45+ CD11b+ cells. ScRNAseq analysis of sorted KAEDERED cells from inflamed joints confirmed that approximately 80% of the migrating cells were macrophages. Differential gene expression and pathway analysis revealed an imbalance between pro- and anti-inflammatory macrophages in the joints of experimental psoriatic arthritis.

Conclusion

We describe IL-23-mediated migration of skin-derived macrophages from the skin to the joints during the onset of experimental psoriatic arthritis. This process may explain the spreading from psoriatic skin to joint disease as these cells foster the development by local cytokine production once arrived in the joints.

References

[1]Veale, D.J. & Fearon, U. The pathogenesis of psoriatic arthritis. Lancet391, 2273-2284 (2018).

Disclosure of Interests

None declared.

AB0113 A MINIMAL-INVASIVE METHOD TO RETRIEVE AND IDENTIFY ENTHESEAL TISSUE FROM PSORIATIC ARTHRITIS PATIENTS

Background

Enthesitis represents a hallmark feature of spondyloarthritis, including psoriatic arthritis (PsA).1 So far, most of the data on enthesitis in PsA are based on clinical assessment of tenderness as well as MRI or ultrasound examinations.2 These approaches, however, do not allow molecular analysis of entheses, which will require acquisition of entheseal tissue. Up today, it is unknown, which entheseal structure in humans would qualify for a feasible biopsy and how correct sampling of entheseal structures could be ascertained within such biopsy material. These technical challenges have led to substantial lack of knowledge on human entheseal tissues.

Objectives

To establish a minimally invasive biopsy technique of human entheses for the analysis of entheseal tissue in patients with PsA.

Methods

Human cadavers were used for establishing the technique to retrieve tissue from the lateral humeral epicondyle enthesis (cadaveric biopsies). After biopsy, the entire entheses was surgically resected (cadaveric resections). Biopsies and resections were assessed by label-free second-harmonic-generation (SHG) microscopy. The same biopsy technique was then applied in PsA patients with subsequent definition of entheseal tissue by SHG.

Results

Entheseal biopsies were performed in five cadavers and allowed the retrieval of entheseal tissue, validated by analysis of the resection material. Thus, microscopy of biopsy and resection sections allowed differentiation of entheseal, tendon and muscle tissue by SHG and definition of specific intensity thresholds for entheseal tissue. The same method was then successfully applied to 10 PsA patients. Hence, the fraction of entheseal tissue within the PsA biopsy specimens was high (65%) and comparable to the fraction retrieved in cadaveric biospies (68%) as assessed by SHG microscopy.

Conclusion

Entheseal biopsy of the tendon plate of the lateral epicondyle is feasible in PsA patients allowing reliable retrieval of entheseal tissue and its identification by SHG microscopy.

References

[1]Schett, G, Lories D, D´Agostino MA, Elewaut E, Kirkham B, Soriano ER, McGonagle D. Enthesitis: from pathophysiology to treatment Nat Rev Rheumatol 2017 Nov 21;13(12):731-741.

[2]Groves C, Chandramohan M, Chew NS, et al. Clinical Examination, Ultrasound and MRI Imaging of The Painful Elbow in Psoriatic Arthritis and Rheumatoid Arthritis: Which is Better, Ultrasound or MR, for Imaging Enthesitis? Rheumatol Ther 2017;4:71-84.

Disclosure of Interests

None declared

POS0200 POST-mRNA VACCINE FLARES IN AUTOIMMUNE INFLAMMATORY RHEUMATIC DISEASES: INTERIM RESULTS FROM THE CORONAVIRUS NATIONAL VACCINE REGISTRY FOR IMMUNE DISEASES SINGAPORE (CONVIN-SING)

Background

Published data suggest no increased rate of flare of autoimmune inflammatory rheumatic diseases (AIIRD) after COVID-19 mRNA vaccination; however, the studies are limited by small sample size, short follow up or at risk of selection bias (voluntary physician reports or patient surveys).

Objectives

To study flares of AIIRD within three months of the first dose of an anti-SARS-COV2 mRNA vaccine.

Methods

A retrospective cohort study of consecutive AIIRD patients ≥ 12 years old, across six public hospitals in Singapore who received at least one dose of an mRNA (Pfizer/BioNTech or Moderna) vaccine. Data were censored at the first post-vaccine clinic visit when the patient had flared or if ≥ three months had elapsed since the first dose of the vaccine, whichever came first. Predictors of flare were determined by Cox proportional hazards analysis and time to flare was examined using a Nelson Aalen cumulative hazard estimate (Figure 1).

Figure 1.

Nelson-Aalen curve of flares over time

Results

2339 patients (74% Chinese, 72% female) of median (IQR) age 64 (53, 71) years were included in the interim analysis (Table 1). 2112 (90%) had the Pfizer/BioNTech vaccine and 195 (8%) had Moderna, with a median (IQR) interval of 21 (21, 23) days between the two doses. The most common AIIRD diagnoses were Rheumatoid arthritis (1063, 45%), Psoriatic arthritis (296, 12.6%) and Systemic lupus erythematosus (SLE) (288, 12.3%). 186 (8%) were treated with biologics/ targeted disease modifying agents. 2125 (91%) patients were in low disease activity or remission. Treatment was interrupted for vaccination in only 18 (0.8%) patients. Seven (0.3%) patients had previous COVID-19 infection.

Table 1.

Patient characteristics

Baseline characteristicsNo flares(n = 1887, %)Flares within 0—3 months of 1st vaccine dose (n= 272, %)Flares outside of 0 – 3 months after 1st vaccine dose (n = 180, %)Age (median years, IQR)64 (53, 71)61 (50, 69)65 (55, 71)RaceChinese1386 (73)206 (76)129 (72)Malay193 (10)28 (10)20 (11)Indian195 (10)27 (10)26 (14)GenderFemale1367 (72)200 (74)117 (65)Vaccine typePfizer/BioNTech1713 (92)239 (90)160 (90)Moderna149 (8)28 (10)18 (10)DiagnosisRheumatoid Arthritis831 (44)139 (51)93 (52)Systemic Lupus Erythematosus269 (14)20 (7)9 (5)Psoriatic Arthritis225 (12)42 (15)29 (16)Spondyloarthropathies141 (7)21 (7)17 (9)Sjogren’s Syndrome114 (6)15 (6)8 (4)Systemic sclerosis94 (5)4 (1)6 (3)Baseline Physician Disease ActivityRemission1007 (53)99 (36)63 (35)Low Disease Activity731 (39)128 (47)97 (54)Moderate Disease Activity134 (7)40 (15)20 (11)High Disease Activity15 (1)5 (2)0

452 (19%) flares were recorded during 9798.8 patient-months [4.6/100 patient-months, median (IQR) follow up duration 4.2 (3.3, 5.3) months], of which 272 (11.6%) patients flared within the 3-month period of interest and 180 (7.7%) flared outside of the 3-month period (Table 1). Median (IQR) time-to-flare was 40.5 (18, 56.6) days. 60 (22.1%) were mild and self-limiting, 170 (62.5%) were mild-moderate and 42 (15.4%) were severe. 190 (69.8%) of those who flared required escalation of treatment and 15 (5.5%) required hospital admission. 239 (10.2%) had improved disease activity after the vaccine.

On multivariate Cox regression analysis, patients in the oldest age tertile [median (IQR) 74 (71, 79) years] were less likely to flare [HR 0.80 (95% CI 0.63, 1.00), p = 0.05] Patients with inflammatory arthritis (compared with connective tissue disease, vasculitis and others) and patients with baseline active disease were more likely to flare [HR 1.72 (95% CI 1.35, 2.20), p < 0.001 and 1.82 (95% CI 1.39, 2.39), p < 0.001 respectively]

Conclusion

There was a moderately high rate of AIIRD flares after mRNA vaccination; however, there was no clustering of flares in the immediate post-vaccine period to suggest causality. Older patients were less likely to flare, while those with inflammatory arthritis and active disease at baseline were more likely to flare.

Disclosure of Interests

Margaret Ma Grant/research support from: Support grant from multiple companies for the Singapore Biologics registry, Amelia Santosa Speakers bureau: Amgen Talk, Consultant of: Pfizer ad board, Kok Ooi Kong: None declared, Chuanhui Xu: None declared, Johnston Tang Gin Xiang: None declared, Gim Gee Teng Speakers bureau: Boehringer Ingleheim, Anselm Mak Speakers bureau: J&J and GSK, Grant/research support from: GSK - the supported studies programme, Sen Hee Tay: None declared, Victoria Wei Wen Ng: None declared, Joshua Zhi En Koh: None declared, Warren Fong Speakers bureau: speaker for Abbvie, DKSH, GSK, Novartis, Li-Ching Chew Speakers bureau: pfizer and Abbvie, Consultant of: Pfizer and Abbvie Advisory Board meeting, Grant/research support from: Abbvie educational grant for ultrasound conference, Andrea Low Speakers bureau: Boehringer Ingeilheim, Consultant of: Consultant/steering group committee for BI and J&J, annie law: None declared, Yih Jia Poh: None declared, Siaw Ing Yeo Grant/research support from: Multiple pharmaceutical companies for the support of the National Biologics Registry, Ying Ying Leung Speakers bureau: Abbvie, DKSH, Jassen, Novartis and Pfizer, Wei-Rui Goh: None declared, Chuah Tyng Yu: None declared, Nur Emillia Roslan: None declared, Stanley Angkodjojo Speakers bureau: Boehringer Ingeilheim, Consultant of: Abbvie and DKSH, Kee Fong Phang: None declared, Thaschawee Arkachaisri: None declared, Melonie Sriranganathan: None declared, Teck Choon TAN: None declared, Peter Cheung Consultant of: Ad board for Boehringer Ingleheim, novartis, janssen and abbvie, Grant/research support from: Novartis, Manjari Lahiri Speakers bureau: J&J, DSKH, Consultant of: DSKH, Gilead, Grant/research support from: Multiple pharma companies contributed to the Singapore Biologics registry

Novartis

Axin2+ PDL Cells Directly Contribute to New Alveolar Bone Formation in Response to Orthodontic Tension Force

Wnt-β-catenin signaling plays a key role in orthodontic tooth movement (OTM), a common clinical practice for malocclusion correction. However, its targeted periodontal ligament (PDL) progenitor cells remain largely unclear. In this study, we first showed a synchronized increase in Wnt-β-catenin levels and Axin2+ PDL progenitor cell numbers during OTM using immunostaining of β-catenin in wild-type mice and X-gal staining in the Axin2-LacZ knock-in line. Next, we demonstrated time-dependent increases in Axin2+ PDL progenitors and their progeny cell numbers within PDL and alveolar bones during OTM using a one-time tamoxifen-induced Axin2 tracing line (Axin2CreERT2/+; R26RtdTomato/+). Coimmunostaining images displayed both early and late bone markers (such as RUNX2 and DMP1) in the Axin2Lin PDL cells. Conversely, ablation of Axin2+ PDL cells via one-time tamoxifen-induced diphtheria toxin subunit A (DTA) led to a drastic decrease in osteogenic activity (as reflected by alkaline phosphatase) in PDL and alveolar bone. There was also a decrease in new bone mass and a significant reduction in the mineral apposition rate on both the control side (to a moderate degree) and the OTM side (to a severe degree). Thus, we conclude that the Axin2+ PDL cells (the Wnt-targeted key cells) are highly sensitive to orthodontic tension force and play a critical role in OTM-induced PDL expansion and alveolar bone formation. Future drug development targeting the Axin2+ PDL progenitor cells may accelerate alveolar bone formation during orthodontic treatment.

Dietary amylose and amylopectin ratio changes starch digestion and intestinal microbiota diversity in goslings

1. Research has confirmed that amylopectin (AP) is more easily digested than amylose (AM) because AP polymers have more intramolecular hydrogen bonds and less surface area. Studying the relationship between the amylose:amylopectin (AM:AP) ratio and intestine digestion in goslings can provide useful information for effective utilisation of starch.2. A total of 288 healthy male Jiangnan White Goslings, aged three days old, were randomly allotted to four groups, which included six pen replicates per treatment with 12 goslings per replicate. Four diets were formulated with maize, long-grained rice and glutinous rice as starch sources, with AM:AP ratios of 0.12, 0.23, 0.34, and 0.45. In vitro starch digestion of the four diets was measured, as well as the effect of AM:AP ratio on growth performance, serum amino-acid concentration and intestinal microbiota diversity of goslings.3. In terms of in vitro starch digestion, the increase in dietary AM:AP ratio resulted in a decrease followed by an increase in both rapidly and slowly digestible starch. The glucose release rate at an AM:AP ratio of 0.34 showed a steady upward trend.4. The in vivo study showed that increasing the AM:AP ratio resulted in a quadratic increase in body weight (BW) and average daily feed intake (ADFI; P<0.05). Goslings fed diets with an AM:AP ratio of 0.34 had lower (P<0.05) histidine and valine serum concentrations compared with the other three starch sources. Higher AM was beneficial to jejunal microbial and diversity. The species colonisation level of the jejunum microbiota samples at an AM:AP ratio of 0.34 was higher than that in the other groups.5. The results indicated that diets with an AM:AP ratio of 0.34 improved the growth performance and intestinal microbiota diversity of goslings. This may have been due to the higher level of resistant starch in amylose, which resulted in a slow release of intestinal glucose that acted as a substrate for the microbial species, thus providing conditions that were more conducive to growth.

Cross-tissue immune cell analysis reveals tissue-specific features in humans

Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. We surveyed the immune compartment of 16 tissues from 12 adult donors by single-cell RNA sequencing and VDJ sequencing generating a dataset of ~360,000 cells. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of finely phenotyped immune cell types, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. Our multitissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis, and antigen receptor sequencing.

HIV-1 mutants that escape the cytotoxic T-lymphocytes are defective in viral DNA integration

HIV-1 replication is durably controlled without antiretroviral therapy (ART) in certain infected individuals called elite controllers (ECs). These individuals express specific human leukocyte antigens (HLA) that tag HIV-infected cells for elimination by presenting viral epitopes to CD8+ cytotoxic T-lymphocytes (CTL). In HIV-infected individuals expressing HLA-B27, CTLs primarily target the viral capsid protein (CA)-derived KK10 epitope. While selection of CA mutation R264K helps HIV-1 escape this potent CTL response, the accompanying fitness cost severely diminishes virus infectivity. Interestingly, selection of a compensatory CA mutation S173A restores HIV-1 replication. However, the molecular mechanism(s) underlying HIV-1 escape from this ART-free virus control by CTLs is not fully understood. Here, we report that the R264K mutation-associated infectivity defect arises primarily from impaired HIV-1 DNA integration, which is restored by the S173A mutation. Unexpectedly, the integration defect of the R264K variant was also restored upon depletion of the host cyclophilin A. These findings reveal a nuclear crosstalk between CA and HIV-1 integration as well as identify a previously unknown role of cyclophilin A in viral DNA integration. Finally, our study identifies a novel immune escape mechanism of an HIV-1 variant escaping a CA-directed CTL response.

Computational design of mechanically coupled axle-rotor protein assemblies

Natural molecular machines contain protein components that undergo motion relative to each other. Designing such mechanically constrained nanoscale protein architectures with internal degrees of freedom is an outstanding challenge for computational protein design. Here we explore the de novo construction of protein machinery from designed axle and rotor components with internal cyclic or dihedral symmetry. We find that the axle-rotor systems assemble in vitro and in vivo as designed. Using cryo-electron microscopy, we find that these systems populate conformationally variable relative orientations reflecting the symmetry of the coupled components and the computationally designed interface energy landscape. These mechanical systems with internal degrees of freedom are a step toward the design of genetically encodable nanomachines.

Magic angle spinning NMR structure of human cofilin-2 assembled on actin filaments reveals isoform-specific conformation and binding mode

Actin polymerization dynamics regulated by actin-binding proteins are essential for various cellular functions. The cofilin family of proteins are potent regulators of actin severing and filament disassembly. The structural basis for cofilin-isoform-specific severing activity is poorly understood as their high-resolution structures in complex with filamentous actin (F-actin) are lacking. Here, we present the atomic-resolution structure of the muscle-tissue-specific isoform, cofilin-2 (CFL2), assembled on ADP-F-actin, determined by magic-angle-spinning (MAS) NMR spectroscopy and data-guided molecular dynamics (MD) simulations. We observe an isoform-specific conformation for CFL2. This conformation is the result of a unique network of hydrogen bonding interactions within the α2 helix containing the non-conserved residue, Q26. Our results indicate F-site interactions that are specific between CFL2 and ADP-F-actin, revealing mechanistic insights into isoform-dependent F-actin disassembly.

[Predictive values of serum 8-hydroxydeoxyguanosine on disease progression and prognosis of patients with sepsis]

Objective: To investigate the values of serum 8-hydroxydeoxyguanosine (8-OHdG) in predicting disease progression and prognosis of patients with sepsis. Methods: The prospective observational research methods were used. A total of 124 patients with sepsis who met the inclusion criteria were admitted to the Department of Emergency of the First Affiliated Hospital of Wenzhou Medical University from April 2015 to July 2016, including 79 males and 45 females, aged (62±15) years. The sepsis-related organ failure assessment (SOFA) scores of all patients on admission and on the second day of admission and their difference (ΔSOFA) were calculated. The patients were divided into non-progression group with ΔSOFA score <2 (n=101) and progression group with ΔSOFA score ≥2 (n=23), and according to the survival during hospitalization, the patients were divided into survival group (n=85) and death group (n=39). Data of patients between non-progression group and progression group, survival group and death group were compared, including the gender, age, days in emergency intensive care unit (ICU), smoking, hypertension, diabetes mellitus, serum white blood cell count, serum C-reactive protein, and serum procalcitonin on admission, and serum 8-OHdG within 24 h of admission. The multivariate logistic regression analysis was used to screen the independent risk factors of disease progression and death during hospitalization in 124 patients with sepsis, the receiver's operating characteristic (ROC) curves were drawn according to the independent risk factors, and the area under the curve (AUC), the best threshold, and the sensitivity and specificity under the best threshold were calculated. The patients were divided into high 8-OHdG group (n=35) and low 8-OHdG group (n=89) according to the best threshold in ROC curve of death during hospitalization. The data including the gender, age, SOFA score on admission, SOFA score on the second day of admission, and ΔSOFA score of patients in the two groups were compared. The survival rates of patients within 90 d of admission in the two groups were compared by the Kaplan-Meier method. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test, and Log-rank test. Results: The gender, age, days in emergency ICU, smoking, complicated with hypertension, complicated with diabetes mellitus, serum white blood cell count, serum C-reactive protein, and serum procalcitonin on admission of patients in non-progression group and progression group were similar (P>0.05). The serum 8-OHdG within 24 h of admission of patients in progression group was significantly higher than that in non-progression group (Z=-2.31, P<0.05). Multivariate logistic regression analysis showed that the serum 8-OHdG within 24 h of admission was the independent risk factor for disease progression of 124 patients with sepsis (odds ratio=1.06, with 95% confidence interval of 1.01-1.11, P<0.05). The AUC under the ROC curve of serum 8-OHdG within 24 h of admission to predict disease progression of 124 patients with sepsis was 0.65 (with 95% confidence interval of 0.52-0.79, P<0.05), the optimal threshold was 32.88 ng/mL, and the sensitivity and specificity under the optimal threshold was 52.2% and 79.2%, respectively. The gender, age, days in emergency ICU, smoking, complicated with hypertension, complicated with diabetes mellitus, and serum white blood cell count, serum C-reactive protein, and serum procalcitonin on admission of patients in survival group and death group were similar (P>0.05). The serum 8-OHdG within 24 h of admission of patients in death group was significantly higher than that in survival group (Z=-2.37, P<0.05). Multivariate logistic regression analysis showed that the serum 8-OHdG within 24 h of admission was the independent risk factor for death of 124 patients with sepsis (odd ratio=1.04, with 95% confidence interval of 1.00-1.09, P<0.05). The AUC under the ROC curve of serum 8-OHdG within 24 h of admission to predict death of patients during hospitalization was 0.63 (with 95% confidence interval of 0.52-0.75, P<0.05), the optimal threshold was 32.43 ng/mL, the sensitivity and specificity under the optimal threshold was 51.3% and 84.7%, respectively. The gender and age of patients in high 8-OHdG group and low 8-OHdG group were similar (P>0.05). The SOFA score on admission, SOFA score on the second day of admission, and ΔSOFA score of patients in high 8-OHdG group were significantly higher than those in low 8-OHdG group (with Z values of -2.49, -3.01, and -2.64, respectively, P<0.05 or P<0.01). The survival rate within 90 d of admission of patients in low 8-OHdG group was significantly higher than that in high 8-OHdG group (χ2=14.57, P<0.01). Conclusions: Serum 8-OHdG level is an independent risk factor for disease progression and death in sepsis patients with limited ability for predicting disease progression and prognosis of sepsis of patients. The patients with higher serum 8-OHdG level have higher death risk within 90 d of admission.

A223 THE CHAIR STAND TEST IS A RELIABLE FRAILTY METRIC FOR PREDICTING WAITLIST MORBIDITY AND MORTALITY IN PATIENTS WITH CIRRHOSIS

Background

Frailty is defined as a clinical state of increased vulnerability to health and age associated stressors. The liver frailty index (LFI), composed of grip strength, chair stand and balance testing, is an accepted predictor of morbidity and mortality in cirrhosis. With the need for COVID-19 related social distancing, many appointments are being carried out virtually. The chair stand subcomponent of the LFI has the potential to be evaluated virtually, with a high reliability as compared to in-person testing noted in other disease populations.

Aims

To determine if the chair stand test is an independent predictor of morbidity and mortality in patients with cirrhosis.

Methods

822 adult patients with cirrhosis were prospectively enrolled from five centers (3 in Canada, 1 in the United States, and 1 in India). Inclusion criteria included adult patients with cirrhosis. 787 of these patients completed a chair stand test at baseline, measured as the time (seconds) a patient takes to rise from sitting with their arms folded across their chest five times (measured in-person). The times were divided into 3 categories: >15 seconds, between 10 and 15 seconds, and <10 seconds. Patients who could not complete 5 chair stands were classified in the >15 seconds category. Primary outcome was all-cause mortality. Secondary outcome was unplanned all-cause hospital admission. Fine-Gray proportional hazard regression models were used to evaluate the association between the chair stand time and the outcomes. We adjusted for baseline age, sex, and MELD score and accounted for liver transplantation as a competing risk. Cumulative incidence functions were used to create a graphical representation of the survival analysis.

Results

Patients were divided into three groups: group 1, <10 seconds (n = 276); group 2, 10–15 seconds (n = 290); and group 3, >15 seconds (n = 221). Mortality was increased in group 3 in comparison to group 1 (HR 3.21, 95% CI: 2.16–4.78, p<0.001). Similarly, the hazard of non-elective hospitalizations was higher in group 3 in comparison to group 1 (HR 2.24, 95% CI: 1.73–2.91, p<0.001). Overall, patients with chair stand times greater than 15 seconds had increased all-cause mortality (HR 2.78, 95% CI 2.01–3.83, p<0.001) and non-elective hospitalizations (HR 1.84, 95% CI 1.48–2.29, p<0.001) when compared to patients with times less than 15 seconds.

Conclusions

A time to complete 5 chair stands of >15 seconds predicts morbidity and mortality in patients with cirrhosis. This test shows promise as a frailty measure that could be evaluated over a virtual platform.

Funding Agencies

None

PERK signaling activation restores nucleus pulposus degeneration by activating autophagy under hypoxia environment

OBJECTIVES

Intervertebral disc (IVD) degeneration is an important disease with no efficient biological therapy identified. Autophagy, a wildly known therapeutic target for human disease, has been demonstrated to be activated under hypoxia, with underlying mechanism remains elusive. Thus, this study aims to specify the role of autophagy in IVD degeneration, the regulating mechanism of hypoxia-inducing autophagy, and the therapeutic value of autophagy for IVD degeneration.

METHODS

RNA-seq was used to screen the primary pathway affected in NP cells under hypoxia, the specific link between hypoxia and autophagy were investigated using ChIP-seq and dual luciferase reporter assay. Conditional ATG7 knockout mice (ATG7^-/-) were constructed for assessing the effect of autophagy on IVD degeneration, and puncture induced mice model of IVD degeneration were used for intradiscal injection to evaluate the therapeutic value of autophagy.

RESULTS

We demonstrated that hypoxia induces autophagy by transcriptional activation of autophagic gene LC3B and ATG7, which is controlled by PERK signaling. Then, we observed that inhibiting autophagy or PERK signaling leads to impaired NP cell viability and function, furthermore, using ATG7 knockout (ATG7^-/-) mice, we identified the protective role of autophagy in IVD. Furthermore, we found that intradiscal injection of PERK signaling agonist, CCT020312, significantly restores the degeneration level of needle punctured mice IVD.

CONCLUSION

We showed that the activation of PERK signaling upon hypoxia serves as a vital mechanism to induce autophagy and identified the therapeutic value of PERK signaling agonist for IVD degeneration treatment.

[Association between CD137 and ischemia-reperfusion injury in patients with acute ST-segment elevation myocardial infarction]

Objective: To explore the relationship between the levels of serum soluble CD137 (sCD137) and membrane-bound CD137 (mCD137) and the occurrence of ischemia reperfusion injury (IRI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods: This is a cross-sectional study. Consecutive patients with acute STEMI, who underwent emergency percutaneous coronary intervention (PCI) in the Department of Cardiology, Jiangsu University Affiliated Hospital from May 2019 to September 2020, were enrolled. According to the absence or presence of IRI, patients were divided into IRI group and non-IRI group. Clinical data of the two groups were collected and compared. sCD137 level was detected by enzyme linked immunosorbent assay. Ficoll density gradient centrifugation was used to separate peripheral blood mononuclear cells (PBMC) and RNA was extracted, mCD137 mRNA expression level was detected by PCR. Serum sCD137 levels and the mCD137 mRNA levels of PBMC before, after PCI and 24 hours after PCI were compared. The correlation between serum sCD137 level, PBMC mCD137 mRNA level and clinical indicators was observed. The univariate and multivariate logistic binary regression analyses were performed to evaluate the related risk factors of IRI. ROC curve was used to analyze the predictive value of defined parameters for IRI. Results: A total of 112 STEMI patients were enrolled. There were 42 cases (of which 33 were males (78.6%), mean age was (58.6±12.7) years) in non-IRI group and 70 cases(of which 56 were males (80.0%), mean age was (64.5±11.6) years) in IRI group. Compared with the non-IRI group, patients in the IRI group had longer hospital stays, older age, lower rates of obesity, lower systolic and diastolic blood pressure at admission, higher proportion of the the right coronary artery as culprit vessel, lower rate of the use of angiotensin-converting enzyme inhibitor/angiotensin-Ⅱ receptor blocker/angiotensin receptor neprilysin inhibitor, higher levels of urea nitrogen and creatinine, lower glomerular filtration rate, lower triglycerides, higher D-dimer and B-type natriuretic peptide_max, higher proportion of Killip grade Ⅳ and cardiovascular adverse events (all P<0.05). sCD137 levels at the preoperative, postoperative and 24 hours after surgery were significantly higher in the IRI group than in the non-IRI group, while the mRNA levels of CD137 was similar between the two groups. The level of sCD137 in patients after PCI was lower than that before operation, the level of mCD137 mRNA was higher than that before operation (P<0.05). Serum sCD137 levels were positively correlated with hospitalization days, age, B-type natriuretic peptide, creatinine, ischemic time, C Reactive protein (CRP) and CRP/albumin (P<0.05), and negatively correlated with body mass index, glomerular filtration rate and albumin (P<0.05). The mCD137 mRNA expression level of PBMC was positively correlated with hospital stay, age, B-type natriuretic peptide, ischemic time, CRP and CRP/albumin (P<0.05), and negatively correlated with body mass index, glomerular filtration rate, albumin (P<0.05). Multivariate logistic regression analysis showed that higher sCD137 (OR=1.038, 95%CI: 1.009-1.069), aspartate aminotransferase, (OR=1.029, 95%CI: 1.009-1.050) and lower albumin (OR=0.829, 95%CI: 0.703-0.829) before surgery were independent risk factors of IRI (P<0.05). Receiver operating characteristic curve showed that the area under the curve of sCD137 was 0.672 (95%CI: 0.574-0.770, P=0.002) for the prediction of IRI, the best cut-off value was 28.43×10^-3 μg/L with sensitivity of 95.2% and specificity of 48.6%. Conclusion: The significantly increased level of sCD137 in acute STEMI patients is positively correlated with reperfusion injury, which is an independent risk factor of IRI and may be related to the prognosis of patients with IRI.

Structure of native HIV-1 cores and their interactions with IP6 and CypA

The viral capsid plays essential roles in HIV replication and is a major platform engaging host factors. To overcome challenges in study native capsid structure, we used the perfringolysin O to perforate the membrane of HIV-1 particles, thus allowing host proteins and small molecules to access the native capsid while improving cryo–electron microscopy image quality. Using cryo–electron tomography and subtomogram averaging, we determined the structures of native capsomers in the presence and absence of inositol hexakisphosphate (IP6) and cyclophilin A and constructed an all-atom model of a complete HIV-1 capsid. Our structures reveal two IP6 binding sites and modes of cyclophilin A interactions. Free energy calculations substantiate the two binding sites at R18 and K25 and further show a prohibitive energy barrier for IP6 to pass through the pentamer. Our results demonstrate that perfringolysin O perforation is a valuable tool for structural analyses of enveloped virus capsids and interactions with host cell factors.

[Prevalence of hyperkalemia and its effects on mortality in hospitalized patients: a single center 10-year retrospective analysis]

Objective: To investigate the prevalence of hyperkalemia in hospitalized patients, and analyze the effects of different serum potassium levels and change rates of serum potassium on the mortality of hospitalized patients. Methods: The clinical data of 944 446 hospitalized patients in Sichuan Provincial People's Hospital from January 2009 to December 2018 were retrospectively analyzed. Hyperkalemia is defined as serum potassium ≥ 5.5 mmol/L. The effects of serum potassium level and its change rate on hospitalized mortality were analyzed. Results: There were 15 771 patients with hyperkalemia, and the prevalence of hyperkalemia was 1.7% (15 771/944 446). However, the discharge diagnosis rate was only 11.0% (1 735/15 771), and the missed diagnosis rate was 89.0% (14 036/15 771). Cox regression analysis showed that serum potassium<3.5 mmol/L (HR=1.338, 95%CI: 1.164-1.537, P<0.001) or ≥ 6.5 mmol/L (HR=1.421, 95%CI: 1.158-1.744, P=0.001) increased the risk of hospitalized mortality compared with patients with normal serum potassium. Compared with the increased rate of serum potassium by 0.01-0.10 mmol/d, patients who reached the peak of serum potassium at admission (HR=1.251, 95%CI: 1.077-1.453, P=0.003), increased rate of serum potassium by 0.11-0.51 mmol/d (HR=1.499, 95%CI: 1.315-1.709, P<0.001) or >0.51 mmol/d (HR=2.431, 95%CI: 2.105-2.807, P<0.001) increased the risk of mortality. Of patients with hyperkalemia, those who did not repeat the serum potassium test had a higher risk of mortality (HR=1.656, 95%CI: 1.434-1.914, P<0.001). Conclusions: The prevalence of hyperkalemia in hospitalized patients was 1.7%, and the missed diagnosis rate was high at discharge. Patients who had hypokalemia at admission, severe hyperkalemia, rapid increased serum potassium, or failed to repeat serum potassium test during hospitalization, had higher risk of mortality.

[Deep learning reconstruction algorithm for coronary CT angiography in assessing obstructive coronary artery disease caused by calcified lesions: the clinical application value]

Objective: To investigate the image quality of coronary CT angiography (CCTA) subjected to deep learning-based reconstruction algorithm (DLR) method and its diagnostic performance for stenosis caused by coronary calcified lesions. Methods: We enrolled 33 consecutive patients with known or suspected coronary artery disease (CAD) who underwent CCTA and subsequently invasive coronary angiography (ICA) within 1 month in the department of radiology, Peking Union Medical College Hospital between February 2020 and February 2021. Among them, there are 26 males and 7 females, age range from 45 to 86 (61.9±9.0) years. The CCTA images were reconstructed with DLR and hybrid iterative reconstruction (HIR). Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated on the aorta root, left main artery, proximal left anterior descending, left circumflex, and right coronary artery of the CCTA images and were used to evaluate the objective image quality (IQ). Subjective IQ score was graded using Likert four-point scale (1 for excellent and 4 for poor). The diagnostic performance of obstructive coronary artery disease caused by calcified lesions on CCTA subjected to DLR and HIR methods were evaluated using ICA as the reference standard. Results: A total of 123 lesions in 33 patients were included in the analysis. Image noise of DLR image was significantly lower than that on HIR image(defined as the standard deviation of the attenuation values in the aortic root: 18.12±3.66 vs 24.19±5.71, P<0.001), CNR and SNR of DLR image in the aortic root were higher (CNR:43.83±23.73 vs 26.38±9.69, P<0.001,SNR:26.66±7.83 vs 21.23±8.65, P<0.001). Subjective scores of DLR was better than HIR image (1.12±0.41 vs 1.46±0.60,P<0.001). The sensitivity, specificity and accuracy of DLR and HIR images for diagnosing obstructive coronary artery disease caused by calcified lesions were 100.0%, 77.4%, 78.9% and 100.0%, 63.5%, 65.9%%, respectively. The number of false positive cases on DLR image decreased by 38% compared with HIR. Conclusions: Artificial intelligence based DLR can significantly reduce the image noise and improve the image quality of CCTA. DLR helps to improve the diagnostic performance of CCTA in assessing obstructive coronary artery disease caused by calcified lesions, which may have good clinical application value.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Plasma metabolite changes in anestrous dairy cows with negative energy balance identified using 1H NMR technology

ABSTRACT The objective of the present study was to investigate the different plasma metabolites between anestrus and estrus postpartum dairy cows and to provide a theoretical basis for prevention of anestrus in dairy farm cows. In the experiment, one hundred and sixty-seven Holstein dairy cows were selected with similar age and parity. According to the concentration of β-hydroxybutyric acid, non-esterified fatty acids and glucose in plasma during 14 to 21 days in milk, all dairy cows were determined as having a status of energy balance. According to the results of clinical symptom, rectal and B ultrasound examination at 60 to 90 days postpartum, these cows were divided into twenty estrus and twenty-four anestrus group, other dairy cows were removed. 1H nuclear magnetic resonance technology was utilized to detect the plasma metabolites changes and screen different plasma metabolites between anestrus and estrus cows. Ten different metabolites including alanine, glutamic acid, asparagine, creatine, choline, phosphocholine, glycerophosphocholine, low-density lipoprotein, and very-low-density lipoprotein were significantly decreased in anestrous cows compared with estrous cows. Metabolic pathway analyses indicated that differential metabolites were primarily involved in amino acid and glycerophospholipid metabolism. These metabolites and their enrichment pathways indicate that reduced steroid hormone synthesis precursors result in lower levels of estradiol and progesterone and cause anestrus in negative energy balance. These data provide a better understanding of the changes that may affect estrus of postpartum dairy cows at NEB status and lay the ground for further research.

Taraxasterol inhibits TGF-β1-induced epithelial-to-mesenchymal transition in papillary thyroid cancer cells through regulating the Wnt/β-catenin signaling

Taraxasterol (TAR) is a kind of active compound extracted from dandelion and its molecular structure resembles steroid hormones. Recently, TAR has been reported to show an anti-tumor activity. However, the specific role of TAR in papillary thyroid cancer (PTC) has not been clarified. In this study, we investigated the effect of TAR on PTC cell migration, invasion and epithelial-to-mesenchymal transition (EMT) induced by TGF-β1. PTC cells were exposed to TGF-β1 (5 ng/mL) and then treated with different concentrations of TAR. We found that TAR showed no obvious cytotoxicity below 10 μg/mL but notably reduced migration and invasion of TGF-β1-treated PTC cells. Moreover, TAR treatment decreased MMP-2 and MMP-9 levels, and obviously affected the expression of EMT markers. We also observed that Wnt3a and β-catenin levels were significantly increased in TGF-β1-treated PTC cells while TAR inhibited these effects in a concentration-dependent manner. Additionally, activation of the Wnt pathway by LiCl attenuated the suppressive effect of TAR on TGF-β1-induced migration, invasion and EMT in PTC cells. Taken together, we highlighted that TAR could significantly suppress TGF-β1-regulated migration and invasion by reversing the EMT process via the Wnt/β-catenin pathway, suggesting that TAR may be a potential anti-cancer agent for PTC treatment.

[Establishment of a 3D ultrasound imaging system based on pulse-triggered image acquisition]

OBJECTIVE

To establish a 3D ultrasound imaging system based on pulse-triggered image acquisition using the linear probe on the Verasonics^TM vantage 128 platform and evaluate its performance in scanning standard phantom and human carotid artery.

OBJECTIVE

The 3D ultrasound imaging system included 3 modules for probe motion control, image acquisition and storage, and 3D image reconstruction and display. To improve the precision of image acquisition, we used fixed frequency pulses to control the external trigger function combined with mechanical scanning. Voxel-based 3D reconstruction was used for image reconstruction and display. The user interface was designed to allow direct operations of the platform. We carried out scanning tests of standard ultrasound phantom and human carotid artery to evaluate the performance of this imaging system.

OBJECTIVE

We successfully constructed a 3D ultrasound imaging system based on pulse-triggered image acquisition. The results of standard phantom and human carotid scanning tests showed that each module of the system was fully functional. The self-designed user interface of this ultrasound imaging system allowed full control of the system functions for original image acquisition, 3D image reconstruction, and display of cross-sections in 3 different views.

OBJECTIVE

This 3D ultrasound imaging system achieves high-quality 3D ultrasound imaging and provides the basis for further study and clinical application of 3D ultrasound imaging.

POS0219 EFFECT OF LOW-DOSE METHOTREXATE ON ESTIMATED GLOMERULAR FILTRATION RATE AND KIDNEY ADVERSE EVENTS IN THE CARDIOVASCULAR INFLAMMATION REDUCTION TRIAL

Background:

Low-dose methotrexate (LD-MTX) is a common first-line treatment for systemic rheumatic diseases, and its use is contraindicated in advanced chronic kidney disease (CKD) because it is primarily excreted by the kidneys. Among patients with preserved kidney function, the safety of LD-MTX on estimated glomerular filtration rate (eGFR) and kidney adverse events (AEs) has not been established.

Objectives:

To investigate the effect of LD-MTX on eGFR and kidney AEs using data from a randomized clinical trial.

Methods:

We performed a secondary analysis for eGFR and kidney AEs using the randomized double-blind, placebo-controlled Cardiovascular Inflammation Reduction Trial. Adults with known cardiovascular disease and diabetes and/or metabolic syndrome were randomly allocated to oral LD-MTX (target dose 15-20 mg/week) or placebo. All participants took folic acid 1 mg six days/week. Exclusion criteria included systemic inflammatory disease and creatinine clearance <40 mL/min (by Cockcroft-Gault). eGFR was calculated using the CKD-EPI formula. Clinical kidney AEs were blindly adjudicated. The least-squares mean change of eGFR from baseline was calculated at each study visit; the difference in eGFR slopes between LD-MTX and placebo was compared using a modified intention-to-treat approach. We also compared rates of kidney AEs for LD-MTX versus placebo using Cox proportional hazards models.

Results:

A total of 2,391 subjects were randomized to LD-MTX and 2,395 to placebo. At baseline, mean age was 66 years, 19% were female, mean eGFR was 80.0 mL/min/1.73m2, and 18% had stage 3 CKD or worse. Median follow-up duration was 23 months, and median LD-MTX dose was 16 mg/week. Those randomized to LD-MTX had less decline in eGFR over the entire follow-up compared to placebo (slope difference 1.12, 95%CI 0.59-1.65, p<0.001, Figure 1). Those with CKD stage 3 or worse on LD-MTX saw less eGFR decline than those with CKD stage 2 or better (slope difference among CKD stage 3 or worse: 2.46, 95%CI 1.10-3.82, p<0.001; p for interaction 0.02). The LD-MTX group had higher eGFR than placebo over the first 24 months of study follow-up (p<0.05 at each visit). On safety laboratory monitoring, there were 159 acute kidney injury AEs in the LD-MTX group and 187 in the placebo group (HR 0.83, 95%CI 0.67-1.02, Table 1). There were 37 clinical kidney AEs in the LD-MTX group and 42 in the placebo group (0.87, 95%CI 0.56-1.36). One subject began dialysis in the LD-MTX group compared to 3 in the placebo group.

Table 1.

Rates and hazard ratios for kidney adverse events per random assignment of low-dose methotrexate or placebo in the Cardiovascular Inflammation Reduction Trial (n=4,786).

Low-dose methotrexate (n=2,391)Placebo (n=2,395) (reference)HR (95%CI)EventsRate per 100 person-years (95%CI)EventsRate per 100 person-years (95%CI)SCr collected at safety visitsAny event*1593.42 (2.93, 3.98)1874.06 (3.53, 4.67)0.83 (0.67, 1.02)Mild (SCr 1.5-1.9x baseline)1543.47 (2.97, 4.06)1774.06 (3.51, 4.69)0.85 (0.68, 1.06)Moderate (SCr 2-2.9x baseline)190.41 (0.26, 0.64)240.52 (0.35, 0.78)0.78 (0.43, 1.43)Severe (SCr ≥3x baseline)20.04 (0.01, 0.17)50.11 (0.05, 0.26)0.40 (0.08, 2.04)Adjudicated clinical kidney adverse eventsAny event*370.80 (0.58, 1.11)420.92 (0.68, 1.24)0.87 (0.56, 1.36)Mild240.52 (0.35, 0.77)250.55 (0.37, 0.81)0.95 (0.55, 1.67)Moderate110.24 (0.13, 0.43)110.24 (0.13, 0.43)1.00 (0.43, 2.29)Severe40.09 (0.03, 0.23)80.17 (0.09, 0.35)0.50 (0.15, 1.64)New dialysis10.02 (0.00, 0.15)30.17 (0.09, 0.35)0.34 (0.04, 3.17)

*Acute kidney injury presence and severity was defined by KDIGO (Kidney Disease: Improving Global Outcomes) classification.

CI, confidence interval; HR, hazard ratio; SCr, serum creatinine.

Conclusion:

These results demonstrate the kidney safety of LD-MTX among patients without advanced CKD at baseline. We observed a possible beneficial effect of LD-MTX on preserving kidney function, suggesting that inflammation may be involved in the pathogenesis of CKD in this population.

Disclosure of Interests:

Jeffrey Sparks Consultant of: Dr. J Sparks has performed consultancy for Bristol-Myers Squibb, Gilead, Inova Diagnostics, Optum, and Pfizer unrelated to this work., Grant/research support from: Dr. J Sparks has received research support from Bristol-Myers Squibb., Kathleen Vanni: None declared, Matthew Sparks: None declared, Chang Xu: None declared, Leah Santacroce: None declared, Robert Glynn Grant/research support from: Dr. Glynn has received grant support unrelated to the present research from AstraZeneca, Kowa, Pfizer, and Novartis., Paul Ridker Consultant of: Dr. Ridker has served as a consultant to Corvidia, Inflazome, and CiviBioPharm., Grant/research support from: Dr. Ridker receives research support unrelated to the present study from Kowa, Novartis, and Amarin., Daniel Solomon Grant/research support from: Dr. Solomon receives research support unrelated to the present study from Abbvie, Amgen, Corrona, Genentech, Janssen, and Pfizer.

POS0400 METABOLIC CHANGES INDUCED BY ANTI-MALONDIALDEHYDE/MALINDIALDEHYDE-ACETALDEHYDE ANTIBODIES PROMOTE OSTEOCLAST DEVELOPMENT

Background:

Malondialdehyde (MDA) is a highly reactive compound generated during lipid-peroxidation in conditions associated with oxidative stress. MDA can irreversibly modify proteins (e.g. lysine, arginine and histidine residues). In addition, acetaldehyde can further react with MDA adducts to form malondialdehyde-acetaldehyde (MAA) modification. Such protein modifications can lead to immunogenic neo-epitopes that are recognized by autoantibodies. In fact, anti-MDA/MAA IgG antibodies are significantly increased in the serum of patients with autoimmune diseases, such as rheumatoid arthritis (RA) (1). Interestingly, anti-MDA/MAA antibodies have been shown to promote osteoclast (OC) differentiation in vitro suggesting a potential role for these autoantibodies in bone damage associated with RA (1).

Objectives:

Little is known about the molecular mechanisms activated by autoantibodies in RA. Here, we elucidate the pathways specifically triggered by anti-MDA/MAA autoantibodies in developing osteoclasts.

Methods:

Recombinant human monoclonal anti-MDA/MAA antibodies, which were previously cloned from single synovial B cells of RA patients, were added to different OC assays. OCs were generated from monocyte-derived macrophages in the presence of the cytokines RANK-L and M-CSF. OC development was monitored by light microscopy following tartrate-resistant acid phosphatase staining and by erosion assays using calcium phosphate-coated plates. Bone morphometrics were studied in anti-MDA/MAA-injected mice using X-ray microscopy. Cellular metabolism was analyzed by mass spectrometry, Seahorse XF Analyzer and a colorimetric L-Lactate assay.

Results:

Anti-MDA/MAA antibodies induced a robust OC differentiation in vitro and bone loss in vivo. The anti-MDA/MAA antibodies acted on developing OCs by increasing glycolysis via an Fcγ receptor I-mediated pathway and the upregulation of the transcription factors HIF-1α, Myc and CHREBP. Such regulation of cellular metabolism was exclusively observed in the presence of the osteoclastogenic anti-MDA/MAA clones, whereas other RA-associated autoantibodies (anti-MDA/MAA or anti-citrullinated protein antibodies) had no effect on metabolism. The anti-MDA/MAA treatment induced a shift in the tricarboxylic acid (TCA) cycle activity in developing OCs, leading to the accumulation of citrate and aconitate.

Conclusion:

We described a novel type of autoantibody-induced pathway in RA, which might contribute to increased OC activation and a consequent bone loss. Anti-MDA/MAA antibodies promoted osteoclast development by increasing glycolysis and by modulating the TCA cycle through a signaling pathway that included Fcγ receptor I and a network of transcription factors acting on glycolysis. A TCA cycle bias towards citrate production suggests that the anti-MDA/MAA antibodies might stimulate OCs via increasing lipid biosynthesis in the cells.

References:

[1]Grönwall C. et al. J. Autoimmunity 84 (2017): 29-45.

Acknowledgements:

This Project has received funding from FOREUM, Foundation for Research in Rheumatology, from the European Research Council (ERC) grant agreement CoG 2017 - 7722209_PREVENT RA, the EU/EFPIA Innovative Medicine Initiative grant agreement 777357_RTCure, the Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse and Knut and Alice Wallenberg Foundation.

Disclosure of Interests:

Koji Sakuraba: None declared, Akilan Krishnamurthy: None declared, Alexandra Circiumaru: None declared, Vijay Joshua: None declared, Heidi Wähämaa: None declared, Marianne Engström: None declared, Meng Sun: None declared, Xiaowei Zheng: None declared, Cheng Xu: None declared, Khaled Amara: None declared, Vivianne Malmström Grant/research support from: collaboration with Pfizer, unrelated to the abstract, Sergiu-Bogdan Catrina: None declared, Caroline Grönwall: None declared, Bence Réthi: None declared, Anca Catrina Grant/research support from: collaboration with BMS and Pfizer, unrelated to the present abstract

Molecular determinants of Ebola nucleocapsid stability from molecular dynamics simulations

Ebola virus (EBOV) is a human pathogen with the ability to cause hemorrhagic fever and bleeding diathesis in hosts. The life cycle of EBOV depends on its nucleocapsid. The Ebola nucleocapsid consists of a helical assembly of nucleoproteins (NPs) encapsidating single-stranded viral RNA (ssRNA). Knowledge of the molecular determinants of Ebola nucleocapsid stability is essential for the development of therapeutics against EBOV. However, large degrees of freedom associated with the Ebola nucleocapsid helical assembly pose a computational challenge, thereby limiting the previous simulation studies to the level of monomers. In the present work, we have performed all atom molecular dynamics (MD) simulations of the helical assembly of EBOV nucleoproteins in the absence and presence of ssRNA. We found that ssRNA is essential for maintaining structural integrity of the nucleocapsid. Other molecular determinants observed to stabilize the nucleocapsid include NP-RNA and NP-NP interactions and ion distributions. Additionally, the structural and dynamical behavior of the nucleocapsid monomer depends on its position in the helical assembly. NP monomers present on the longitudinal edges of the helical tube are more exposed, flexible, and have weaker NP-NP interactions than those residing in the center. This work provides key structural features stabilizing the nucleocapsid that may serve as therapeutic targets.

Long non-coding RNA LINC00346 regulates proliferation and apoptosis by targeting miR-128-3p/SZRD1 axis in glioma

OBJECTIVE

Long non-coding RNAs (lncRNAs) participate in multiple processes of malignant tumors, including glioma. In this study, we aimed to explore the effect of LINC00346 on glioma and its underlying mechanism.

MATERIALS AND METHODS

The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA) databases were used to analyze the expression patterns and survival risk of LINC00346, miR-128-3p and SUZ RNA binding domain containing 1 (SZRD1) in glioma tissues. The binding sites were predicted by bioinformatic databases, and then, validated by Dual-Luciferase assay and RNA immunoprecipitation (RIP). qRT-PCR and Western blot were performed to evaluate the gene expression levels. CellTiter-Glo® and colony formation assays were used to detect the proliferation of glioma cells. Flow cytometric analysis was used to evaluate the apoptosis of glioma cells. The xenograft models were established to investigate the impact of LINC00346 on tumor growth in vivo.

RESULTS

We found that both LINC00346 and SZRD1 expression were negatively related to the poor overall survival rate in glioma patients. However, miR-128-3p showed the opposite effect of survival outcomes. LINC00346 knockdown remarkably restrained cell proliferation both in vitro and in vivo, as well as inducing apoptosis by acting as a molecular sponge of miR-128-3p. Moreover, miR-128-3p bound to SZRD1 3'-UTR in a sequence-specific manner. In addition, LINC00346 knockdown significantly inhibited the expression of SZRD1 and the inhibition could be reversed by miR-128-3p mimics. Furthermore, cell proliferation and apoptosis affected by LINC00346 were partially rescued by modulating miR-128-3p or SZRD1 expression.

CONCLUSIONS

LINC00346/miR-128-3p/SZRD1 axis played a crucial role in modulating the malignant progression of glioma, which may serve as a prognostic indicator and a probable therapeutic target for glioma.

LncRNA XIST promotes proliferation and epithelial-mesenchymal transition of retinoblastoma cells through sponge action of miR-142-5p

OBJECTIVE

The aim of the study was to investigate the effect of lncRNA XIST on the proliferation and epithelial-mesenchymal transition (EMT) of retinoblastoma (RB) and its relevant mechanism.

PATIENTS AND METHODS

60 RB patients who were treated in our hospital were collected. The expression of XIST in tissues and cells was detected by qRT-PCR, and the effect of XIST on the prognosis of RB cells was observed. Stable and transient over-expression and suppression vectors were established and transfected into RB cells WERI-RB1 and Y79. CCK-8, transwell, and flow cytometry were used to evaluate the proliferation, invasion, and apoptosis of transfected cells. Western Blot was used to detect apoptosis-related proteins and EMT-related proteins. Dual-Luciferase report was used to determine the relationship between XIST and miR-142-5p. RNA pull-down and RIP experiments were used to determine the relationship between XIST and miR-142-5p.

RESULTS

XIST was highly expressed in RB patients, which had a high diagnostic value. Patients with XIST high expression had a poor prognosis. After overexpression of XIST, the proliferation, invasion and EMT of cells increased, and apoptosis rate decreased, while inhibition of Ptv1 had the opposite effect. Dual-Luciferase report confirmed that XIST could target miR-142-5p. Functional analysis showed that the overexpression of miR-142-5p inhibited the proliferation, invasion and EMT of RB cells and promoted cell apoptosis. Rescue experiments showed that miR-142-5p could eliminate the inhibition of miR-142-5p on the proliferation, invasion, and EMT of RB cells by upregulating XIST expression.

CONCLUSIONS

Ptv1 can promote the proliferation, invasion, and EMT of RB cells by regulating miR-142-5p.

A Biphasic Feature of Gli1+-Mesenchymal Progenitors during Cementogenesis That Is Positively Controlled by Wnt/β-Catenin Signaling

Cementum, a specialized bony layer covering an entire molar root surface, anchors teeth into alveolar bone. Gli1, a key transcriptional activator in Hedgehog signaling, has been identified as a mesenchymal progenitor cell marker in various tissues, including the periodontal ligament (PDL). To address the mechanisms by which Gli1⁺ progenitor cells contribute to cementogenesis, we used the Gli1^lacZ/+ knock-in line to mark Gli1⁺ progenitors and the Gli1^CreERT2/+; R26R^tdTomato/+ line (named Gli1^Lin) to trace Gli1 progeny cells during cementogenesis. Our data unexpectedly displayed a biphasic feature of Gli1⁺ PDL progenitor cells and cementum growth: a negative relationship between Gli1⁺ progenitor cell number and cementogenesis but a positive correlation between Gli1-derived acellular and cellular cementoblast cell number and cementum growth. DTA-ablation of Gli1^Lin cells led to a cementum hypoplasia, including a significant reduction of both acellular and cellular cementoblast cells. Gain-of-function studies (by constitutive stabilization of β-catenin in Gli1^Lin cells) revealed a cementum hyperplasia. A loss of function (by conditional deletion of β-catenin in Gli1⁺ cells) resulted in a reduction of postnatal cementum growth. Together, our studies support a vital role of Gli1⁺ progenitor cells in contribution to both types of cementum, in which canonical Wnt/β-catenin signaling positively regulates the differentiation of Gli1⁺ progenitors to cementoblasts during cementogenesis.

Effect of inundation on greenhouse gas emissions from temperate coastal wetland soils with different vegetation types in southern Australia

Predicted sea level fluctuations and sea level rise with climate change will lead to inundation of coastal and estuarine soils. Coastal wetlands usually contain large amounts of organic matter, which can be potential sources of greenhouse gas emissions (GHGs; CO₂, CH₄, N₂O) during decomposition, but there are limited studies on the effects of sea level variation on GHGs in coastal wetlands. We measured the effect of brackish water inundation and wetting and drying cycles on GHG emissions from coastal wetland soil cores that supported four different vegetation types: Apium gravedens (AG), Leptospermum lanigerum (LL), Phragmites australis (PA) and Paspalum distichum (PD) from the estuarine floodplain of the Aire River in south-western Victoria, Australia. Intact soil cores were incubated under either dry, flooded, or a 14 day wet-dry cycle treatments for a total of 56 days at a constant temperature of 23 °C. CO₂, CH₄, and N₂O fluxes were investigated in closed chambers and measured with gas chromatography. In the dry treatment, a positive correlation was found between soil organic carbon (SOC) and CO₂ flux, and between SOC and CH₄ flux. Higher SOC is indicative of higher amounts of soil organic matter (SOM) which acts as a source of substrate for microbes to produce CO₂ or CH₄ emissions under aerobic or anaerobic conditions. The NO₂^- and NO₃^- concentrations were positively correlated with N₂O emissions in the wet-dry cycle treatment. NO₂^- and NO₃^- provide a supply of substrate for denitrification. The flooded treatment decreased cumulative CO₂ emissions by 34%, 25% and 14% at the LL, PA, PD sites, respectively, and decreased cumulative N₂O emissions by 42%, 39% and 43% at the AG, LL and PA sites, compared to the dry treatment. The wet-dry cycle treatment and dry treatment decreased cumulative CH₄ emissions for all vegetation types compared to the flooded treatment. The redox potential (Eh) was negatively correlated with CH₄ flux and positively correlated N₂O flux at all sites. This study highlights the significance of sea level fluctuations when estimating GHG flux from coastal and estuarine floodplains which are highly vulnerable to inundation, and the role of SOC and mineral N as important drivers affecting GHG flux.

Long non-coding RNA SNHG11 promotes cell proliferation, invasion and migration in glioma by targeting miR-154-5p

OBJECTIVE

Long non-coding RNAs (lncRNAs) play critical roles in tumour progression. However, the function of lncRNA small nucleolar RNA host gene 11 (SNHG11) in glioma has not been mentioned before. Our study aims to uncover the biological roles of SNHG11 in the progression of glioma and throw light for clinical treatment of glioma.

MATERIALS AND METHODS

The Gene Expression Profiling Interactive Analysis (GEPIA) dataset was used to analyze the SNHG11 expression between glioma and normal tissue, as well as survival benefit. The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect SNHG11 and miR-154-5p expression. Celltiter-Glo, colony formation, and transwell assays were utilized to detect the influence of SNHG11 to the malignancy of U87 and U251 cells. The underlying pathways affected by SNHG11 were measured using Western blot. Furthermore, Luciferase reporter assay was applied to verify the interaction between SNHG11 and miR-154-5p.

RESULTS

SNHG11 was upregulated in glioblastoma tissues and five malignant glioma cell lines. SNHG11 expression was negatively correlated with overall survival of glioma patients. Moreover, silencing of SNHG11 could decrease glioma cell viability both in vitro and in vivo. Furthermore, the inhibition of SNHG11 suppressed proliferation, invasion and migration via regulating epithelial-mesenchymal transition (EMT). In addition, SNHG11 could bind miRNA-154-5p and negatively regulate its level.

CONCLUSIONS

SNHG11 functioned as an oncogene in glioma and promoted proliferation, invasion, and migration via EMT by sponging miR-154-5p. These findings provided a new therapeutic target for glioma.