A deletion in FLS2 and its expansion after domestication caused global dissemination of melon cultivars defective in flagellin recognition.

FLAGELLIN SENSING 2 (FLS2) encodes a pattern recognition receptor that perceives bacterial flagellin. While putative FLS2 orthologs are broadly conserved in plants, their functional characterization remains limited. Here, we report the identification of orthologs in cucumber (Cucumis sativus) and melon (C. melo), named CsFLS2 and CmFLS2, respectively. Homology searching identified CsFLS2, and virus-induced gene silencing (VIGS) demonstrated that CsFLS2 is required for flg22-triggered ROS generation. Interestingly, genome re-sequencing of melon cv. Lennon and subsequent genomic PCR revealed that Lennon has two CmFLS2 haplotypes, haplotype I encoding full-length CmFLS2 and haplotype II encoding a truncated form. We show that VIGS-mediated knockdown of CmFLS2 haplotype I resulted in a significant reduction in both flg22-triggered ROS generation and immunity to a bacterial pathogen in melon cv. Lennon. Remarkably, genomic PCR of CmFLS2 revealed that 68% of tested commercial melon cultivars possess only CmFLS2 haplotype II: these cultivars thus lack functional CmFLS2. To explore evolutionary aspects of CmFLS2 haplotype II occurrence, we genotyped the CmFLS2 locus in 142 melon accessions by genomic PCR and analyzed 437 released sequences. The results suggest that CmFLS2 haplotype II is derived from C. melo subsp. melo. Furthermore, we suggest that the proportion of CmFLS2 haplotype II increased among the improved melo group compared with the primitive melo group. Collectively, these findings suggest that the deleted FLS2 locus generated in the primitive melo subspecies expanded after domestication, resulting in the spread of commercial melon cultivars defective in flagellin recognition, which is critical for bacterial immunity.

Notch ligands are biomarkers of anti-TNF response in RA patients.

Notch and its ligands play a critical role in rheumatoid arthritis (RA) pathogenesis. Hence, studies were conducted to delineate the functional significance of the Notch pathway in RA synovial tissue (ST) cells and the influence of RA therapies on their expression. Morphological studies reveal that JAG1, DLL4, and Notch1 are highly enriched in RA ST lining and sublining CD68+CD14+ MΦs. JAG1 and DLL4 transcription is jointly upregulated in RA MΦs reprogrammed by TLR4/5 ligation and TNF, whereas Syntenin-1 exposure expands JAG1, DLL4, and Notch1 expression levels in these cells. Single-cell RNA-seq data exhibit that JAG1 and Notch3 are overexpressed on all fibroblast-like synoviocyte (FLS) subpopulations, in parallel, JAG2, DLL1, and Notch1 expression levels are modest on RA FLS and are predominately potentiated by TLR4 ligation. Intriguingly, JAG1, DLL1/4, and Notch1/3 are presented on RA endothelial cells, and their expression is mutually reconfigured by TLR4/5 ligation in the endothelium. Synovial JAG1/JAG2/DLL1 or Notch1/3 transcriptomes were unchanged in patients who received disease-modifying anti-rheumatic drugs (DMARDs) or IL-6R Ab therapy regardless of disease activity score. Uniquely, RA MΦs and endothelial cells rewired by IL-6 displayed DLL4 transcriptional upregulation, and IL-6R antibody treatment disrupted RA ST DLL4 transcription in good responders compared to non-responders or moderate responders. Nevertheless, the JAG1/JAG2/DLL1/DLL4 transcriptome was diminished in anti-TNF good responders with myeloid pathotype and was unaltered in the fibroid pathotype except for DLL4. Taken together, our findings suggest that RA myeloid Notch ligands can serve as markers for anti-TNF responsiveness and trans-activate Notch receptors expressed on RA FLS and/or endothelial cells.

Targeting TNF-α-induced expression of TTR and RAGE in rheumatoid arthritis: Apigenin's mediated therapeutic approach.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory disease induced by TNF-α, which increases fibroblast-like synoviocytes inflammation, resulting in cartilage destruction. The current work sought to comprehend the pathophysiological importance of TNF-α stimulation on differential protein expression and their regulation by apigenin using in-vitro and in-vivo models of RA. METHODS: The human RA synovial fibroblast cells were stimulated with or without TNF-α (10 ng/ml) and treated with 40 µM apigenin. In-silico, in-vitro and in-vivo studies were performed to confirm the pathophysiological significance of apigenin on pro-inflammatory cytokines and on differential expression of TTR and RAGE proteins. RESULTS: TNF-α induced inflammatory response in synoviocytes revealed higher levels of IL-6, IL-1ß, and TNF-α cytokines and upregulated differential expression of TTR and RAGE. In-silico results demonstrated that apigenin has a binding affinity towards TNF-α, indicating its potential effect in the inflammatory process. Both in-vitro and in-vivo results obtained by Western Blot analysis suggested that apigenin reduced the level of p65 (p = 0.005), TTR (p = 0.002), and RAGE (p = 0.020). CONCLUSION: The findings of this study suggested that TNF-α promotes the differential expression of pro-inflammatory cytokines, TTR, and RAGE via NF-kB pathways activation. Anti-inflammatory effect of apigenin impedes TNF-α mediated dysregulation or expression associated with RA pathogenesis.

Ferroptosis in Arthritis: Driver of the Disease or Therapeutic Option?

Ferroptosis is a form of iron-dependent regulated cell death caused by the accumulation of lipid peroxides. In this review, we summarize research on the impact of ferroptosis on disease models and isolated cells in various types of arthritis. While most studies have focused on rheumatoid arthritis (RA) and osteoarthritis (OA), there is limited research on spondylarthritis and crystal arthropathies. The effects of inducing or inhibiting ferroptosis on the disease strongly depend on the studied cell type. In the search for new therapeutic targets, inhibiting ferroptosis in chondrocytes might have promising effects for any type of arthritis. On the other hand, ferroptosis induction may also lead to a desired decrease of synovial fibroblasts in RA. Thus, ferroptosis research must consider the cell-type-specific effects on arthritis. Further investigation is needed to clarify these complexities.

Shoot Maturation Strengthens FLS2-Mediated Resistance to Pseudomonas syringae.

Temporospatial regulation of immunity components is essential for properly activating plant defense response. Flagellin-sensing 2 (FLS2) is a surface-localized receptor that recognizes bacterial flagellin. The immune function of FLS2 is compromised in early stages of shoot development. However, the underlying mechanism for the age-dependent FLS2 signaling is not clear. Here, we show that the reduced basal immunity of juvenile leaves against Pseudomonas syringae pv. tomato DC3000 is independent of FLS2. The flg22-induced marker gene expression and reactive oxygen species activation were comparable in juvenile and adult stages, but callose deposition was more evident in the adult stage than the juvenile stage. We further demonstrated that microRNA156, a master regulator of plant aging, does not influence the expression of FLS2 and FRK1 (Flg22-induced receptor-like kinase 1) but mildly suppresses callose deposition in juvenile leaves. Our experiments revealed an intrinsic mechanism that regulates the amplitude of FLS2-mediated resistance during aging. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Arabidopsis Dynamin-Related Protein AtDRP2A Contributes to Late Flg22-Signaling and Effective Immunity Against Pseudomonas syringae Bacteria.

In eukaryotes, dynamins and dynamin-related proteins (DRPs) are high-molecular weight GTPases responsible for mechanochemical fission of organelles or membranes. Of the six DRP subfamilies in Arabidopsis thaliana, AtDRP1 and AtDRP2 family members serve as endocytic accessory proteins in clathrin-mediated endocytosis. Most studies have focused on AtDRP1A and AtDRP2B as critical modulators of plant pattern-triggered immunity (PTI) against pathogenic, flagellated Pseudomonas syringae pv. tomato DC3000 bacteria and immune signaling in response to the bacterial flagellin peptide flg22. Much less is known about AtDRP2A, the closely related paralog of AtDRP2B. AtDRP2A and AtDRP2B are the only classical, or bona fide, dynamins in Arabidopsis, based on their evolutionary conserved domain structure with mammalian dynamins functioning in endocytosis. AtDRP2B but not AtDRP2A is required for robust ligand-induced endocytosis of the receptor kinase FLAGELLIN SENSING2 for dampening of early flg22 signaling. Here, we utilized Arabidopsis drp2a null mutants to identify AtDRP2A as a positive contributor to effective PTI against P. syringae pv. tomato DC3000 bacteria, consistent with reduced PATHOGEN RELATED1 (PR1) messenger RNA accumulation. We provide evidence that AtDRP2A is a novel modulator of late flg22 signaling, contributing positively to PR1 gene induction but negatively to polyglucan callose deposition. AtDRP2A has no apparent roles in flg22-elicited mitogen-activated protein kinase defense marker gene induction. In summary, this study adds the evolutionary conserved dynamin AtDRP2A to a small group of vesicular trafficking proteins with roles as non-canonical contributors in immune responses, likely due to modulating one or both the localization and activity of multiple different proteins with distinct contributions to immune signaling. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Altered lipid metabolism in synovial fibroblasts of individuals at risk of developing rheumatoid arthritis.

OBJECTIVE: Fibroblast-like synoviocytes (FLS) can augment the inflammatory process observed in synovium of patients with rheumatoid arthritis (RA). A recent transcriptomic study in synovial biopsies revealed changes in metabolic pathways before disease onset in absence of synovial tissue inflammation. This raises the question whether alterations in cellular metabolism in tissue resident FLS underlie disease pathogenesis. MATERIALS AND METHODS: To study this, we compared the metabolic profile of FLS isolated from synovial biopsies from individuals with arthralgia who were autoantibody positive but without any evidence of arthritis (RA-risk individuals, n = 6) with FLS from patients with RA (n = 6), osteoarthritis (OA, n = 6) and seronegative controls (n = 6). After synovial digestion, FLS were cultured in vitro and cellular metabolism was assessed using quantitative PCR, flow cytometry, XFe96 Seahorse Analyzer and tritium-labelled oleate oxidation assays. RESULTS: Real-time metabolic profiling revealed that basal (p < 0.0001) and maximum mitochondrial respiration (p = 0.0024) were significantly lower in RA FLS compared with control FLS. In all donors, basal respiration was largely dependent on fatty acid oxidation while glucose was only highly used by FLS from RA patients. Moreover, we showed that RA-risk and RA FLS are less metabolically flexible. Strikingly, mitochondrial fatty acid ß-oxidation was significantly impaired in RA-risk (p = 0.001) and RA FLS (p < 0.0001) compared with control FLS. CONCLUSION: Overall, this study showed several metabolic alterations in FLS even in absence of synovial inflammation, suggesting that these alterations already start before clinical manifestation of disease and may drive disease pathogenesis.

A prophage tail-like protein facilitates the endophytic growth of Burkholderia gladioli and mounting immunity in tomato.

A prophage tail-like protein (Bg_9562) of Burkholderia gladioli strain NGJ1 possesses broad-spectrum antifungal activity, and it is required for the bacterial ability to forage over fungi. Here, we analyzed whether heterologous overexpression of Bg_9562 or exogenous treatment with purified protein can impart disease tolerance in tomato. The physiological relevance of Bg_9562 during endophytic growth of NGJ1 was also investigated. Bg_9562 overexpressing lines demonstrate fungal and bacterial disease tolerance. They exhibit enhanced expression of defense genes and activation of mitogen-activated protein kinases. Treatment with Bg_9562 protein induces defense responses and imparts immunity in wild-type tomato. The defense-inducing ability lies within 18-51 aa region of Bg_9562 and is due to sequence homology with the bacterial flagellin epitope. Interaction studies suggest that Bg_9562 is perceived by FLAGELLIN-SENSING 2 homologs in tomato. The silencing of SlSERK3s (BAK1 homologs) prevents Bg_9562-triggered immunity. Moreover, type III secretion system-dependent translocation of Bg_9562 into host apoplast is important for elicitation of immune responses during colonization of NGJ1. Our study emphasizes that Bg_9562 is important for the endophytic growth of B. gladioli, while the plant perceives it as an indirect indicator of the presence of bacteria to mount immune responses. The findings have practical implications for controlling plant diseases.

Preparing for and passing the fundamentals of laparoscopic surgery (FLS) exam improves general surgery resident operative performance and autonomy.

BACKGROUND: The American Board of Surgery made the Fundamentals of Laparoscopic Surgery (FLS) exam a prerequisite for board certification in 2009. Some residency programs have questioned the need for a continued FLS testing mandate given limited evidence that supports the impact of FLS on intraoperative skills. The Society for Improving Medical Professional Learning (SIMPL) app is a tool to evaluate resident intraoperative performance. We hypothesized that general surgery resident operative performance would improve immediately after preparing for the FLS exam. METHODS: The national public FLS data registry was matched with SIMPL resident evaluations from 2015 to 2021 and de-identified. SIMPL evaluations are scored in three categories: supervision required (Zwisch scale 1-4, 1 = show and tell and 4 = supervision only), performance (scale 1-5, 1 = exceptional and 5 = unprepared), and case complexity (scale 1-3, 1 = easiest and 3 = hardest). Statistical analyses compared pre and post-FLS exam resident average operative evaluation scores. RESULTS: There were a total of 76 general surgery residents, and 573 resident SIMPL evaluations included in this study. Residents required more supervision in laparoscopic cases performed before compared to after the FLS exam (2.84 vs. 3.03, respectively, p = 0.007). Residents performance scores improved from cases before compared to after the FLS exam (2.70 vs. 2.43, respectively, p = 0.001). Case complexity did not differ before versus after the FLS exam (2.13 vs. 2.18, respectively, p = 0.202). PGY level significantly predicted evaluation scores with a moderate correlation. A sub analysis grouped by PGY level revealed a significant improvement after the FLS exam in supervision among PGY-2 residents (2.33 vs. 2.58, respectively, p = 0.04) and performance among PGY-4 residents (2.67 vs 2.04, respectively, p < 0.001). CONCLUSIONS: Preparation for, and passing, the FLS exam improves resident intraoperative laparoscopic performance and independence. We recommend taking the exam in the first two years of residency to enhance the laparoscopic experience for the remainder of training.

Automatic assessment of performance in the FLS trainer using computer vision.

BACKGROUND: Fundamentals of Laparoscopic Surgery (FLS) box trainer is a well-accepted method for training and evaluating laparoscopic skills. It mandates an observer that will measure and evaluate the trainee's performance. Measuring performance in the Peg Transfer task includes time and penalty for dropping pegs. This study aimed to assess whether computer vision (CV) may be used to automatically measure performance in the FLS box trainer. METHODS: Four groups of metrics were defined and measured automatically using CV. Validity was assessed by dividing participants to 3 groups of experience levels. Twenty-seven participants were recorded performing the Peg Transfer task 2-4 times, amounting to 72 videos. Frames were sampled from the videos and labeled to create an image dataset. Using these images, we trained a deep neural network (YOLOv4) to detect the different objects in the video. We developed an evaluation system that tracks the transfer of the triangles and produces a feedback report with the metrics being the main criteria. The metric groups were Time, Grasper Movement Speed, Path Efficiency, and Grasper Coordination. The performance was compared based on their last video (3 participants were excluded due to technical issues). RESULTS: The ANOVA tests show that for all metrics except one, the variance in performance can be explained by the experience level of participants. Senior surgeons and residents significantly outperform students and interns on almost every metric. Senior surgeons usually outperform residents, but the gap is not always significant. CONCLUSION: The statistical analysis shows that the metrics can differentiate between the experts and novices performing the task in several aspects. Thus, they may provide a more detailed performance analysis than is currently used. Moreover, these metrics calculation is automatic and relies solely on the video camera of the FLS trainer. As a result, they allow independent training and assessment.

The entrustable professional activities of laparoscopic surgery: moving toward an integrated training model.

BACKGROUND: Entrustable Professional Activities (EPAs) provide the opportunity to integrate multiple competencies into meaningful units that facilitate curriculum development and assessment design. As part of the process of reviewing and enhancing the Fundamentals of Laparoscopic of Surgery (FLS) program, we used the concept of EPAs to create a framework of reference that articulates a contemporary definition of Laparoscopic Surgery (LS). METHODS: The framework of reference of LS was created with data gathered from a literature review and during series of educational retreats with subject matter experts (SMEs). Various activities were implemented during these retreats to develop the LS EPAs, their constitutive competencies, and related observable behaviors. RESULTS: Ten EPAs and associated competency descriptors (articulated as observable behaviors) specific to LS were identified. In addition, knowledge areas were associated to each EPA. DISCUSSION: A comprehensive list of EPAs for LS were identified. These EPAs will be used in the development and update of the FLS program. Further, they can be used to guide the development of curriculum, clinical teaching, and assessment in any surgical program with a laparoscopic training component. They are applicable to any level of training by defining the expected observable behaviors associated with a given level of expertise. These fundamental aspects of LS provide a common framework of reference across different surgical specialties.

An argument-based validation study of the fundamentals of laparoscopic surgery (FLS) program.

BACKGROUND: The Fundamentals of Laparoscopy Surgery (FLS) program was launched over 15 years ago. Since then, there has been an exponential rise in advancements of laparoscopy and its uses. In response, we conducted an argument-based validation study of FLS. The purpose of this paper is to exemplify this approach to validation for surgical education researchers using FLS as an illustrative case. METHODS: The argument-based approach to validation involves three key actions: (1) developing interpretation and use arguments; (2) research; and (3) building a validity argument. Drawing from the validation study of FLS each step is exemplified. RESULTS: Qualitative and quantitative data sources from the FLS validity examination study provided evidence that both supported claims, but also generated backing for rebuttals. Some of the key findings were synthesized in a validity argument to illustrate its structure. DISCUSSION: The argument-based validation approach described numerous advantages over other validation approaches: (1) it is endorsed by the foundational documents in assessment and evaluation research; (2) its specific language of claims, inferences, warrants, assumptions and rebuttals provides a systematic and unified way to communicate both the processes and outcomes of validation; and (3) the use of logic reasoning in building the validity document clearly delineates the relationship between evidence and the inferences made to support desired uses and interpretations from assessments.

Virtual fundamentals of laparoscopic surgery (FLS) boot-camp using telesimulation: an educational solution during the COVID-19 pandemic.

BACKGROUND: The Fundamentals of Laparoscopic Surgery (FLS) is an internationally recognized educational and certification program designed to teach the knowledge and skills required for basic laparoscopic surgery. Previously, our institution has organized an FLS boot-camp to teach PGY1 residents the FLS manual skills. During the COVID-19 pandemic, in-person sessions were not possible. The purpose of this study was to utilize telesimulation as an education solution for teaching FLS technical skills to PGY1 residents during the COVID-19 pandemic. METHODS: A virtual FLS program was established. A complete, easily portable FLS kit was distributed to participants and instructors to set up an FLS box and connect remotely using telesimulation. The program was delivered by three senior residents using the Zoom™ platform. Participants were split into groups of 3-4 individuals, each receiving three 1-h sessions. Sessions were structured with initial demonstration of tasks followed by individual coaching of participants in 'break-out' rooms. The official FLS exam was administered in-person on the 4th week. Pre- and post-course surveys were administered to participants gauging self-reported proficiency with FLS tasks and overall course feedback. Anonymized FLS exam results were collected. RESULTS: A total of 14 residents participated, and 11 responded to the survey. Participants reported that their overall FLS skills proficiency significantly improved on a 5-point likert scale from 1.5 ± 0.5 pre-course to 4.0 ± 0.5 post-course (mean ± SD). Participants unanimously stated that having the FLS box at home was valuable and enabled them to practice more. On the FLS exam, 13 of 14 participants passed the manual skills component. CONCLUSIONS: We developed a telesimulation hands-on FLS course as an alternative to in-person training. The course was practical and effective and was preferred to traditional methods by participants. With ever-expanding technological solutions, virtual telesimulation education is an attractive and underutilized tool, not only in the setting of COVID-19, but also more broadly across current educational programs.

Cost Analysis of a Fracture Liaison Service: A Randomized Controlled Trial for the Secondary Prevention After Fragility Fractures of the Hip.

OBJECTIVE: Fracture liaison services (FLSs) have proven to be effective for secondary fracture prevention. In this study, we evaluated the essential factors in determining whether the FLS saves or loses more than it costs. METHODS: A randomized controlled trial was performed in patients with hip fragility fractures using a hospital-based FLS program in parallel with a cost analysis. Data were generated from a cohort of patients using actual data for FLS effectiveness, individual costs of hip fracture treatment, and medication costs based on an accepted treatment algorithm. RESULTS: A total of 200 patients were randomized, and 180 were analyzed for costs. The FLS program had an overall cost despite the savings in reducing secondary fractures. Medication was 89% of the costs and was the main factor for the FLS costs exceeding the savings. Specifically, using the medication algorithm in this study, the overall cost per patient enrolled in the FLS was $1189 for a 2-year period. If intravenous zoledronic acid had been used, then the overall cost would have been $489. If only oral bisphosphonates had been used, then the FLS would have cost $159 per patient for a 2-year period. CONCLUSION: The present analysis shows that medication cost is the critical component in cost-effectiveness of an FLS program. The FLS program costs would be significantly lower if patients are prescribed less expensive drugs to treat osteoporosis. Additional work needs to be performed refining the medication algorithm considering medication costs but individualized to patient needs based on fracture risk.

Molecular phylogenetic study of flavonoids in medicinal plants: a case study family Apiaceae.

The current study examined the phylogenetic pattern of medicinal species of the family Apiaceae based on flavonoid groups production, as well as the overall mechanism of the key genes involved in flavonol and flavone production. Thirteen species of the family Apiaceae were used, including Eryngium campestre from the subfamily Saniculoideae, as well as Cuminum cyminum, Carum carvi, Coriandrum sativum, Apium graveolens, Petroselinum crispum, Pimpinella anisum, Anethum graveolens, Foeniculum vulgare, Daucus carota, Ammi majus, Torilis arvensis, and Deverra tortuosa from the subfamily Apioideae. The seeds were cultivated, and the leaves were collected to estimate flavonoids and their groups, physiological factors, transcription levels of flavonol and flavone production-related genes. The phylogenetic relationship between the studied species was established using the L-ribosomal 16 (rpl16) chloroplast gene. The results revealed that the studied species were divided into two patterns: six plant species, E. campestre, C. carvi, C. sativum, P. anisum, An. graveolens, and D. carota, contained low content of flavonoids, while the other seven species had high content. This pattern of flavonoids production coincided with the phylogenetic relationships between the studied species. In contrast, the phylogeny of the flavonol and flavone synthase genes was incompatible with the quantitative production of their products. The study concluded that the increment in the production of flavonol depends on the high expression of chalcone synthase, chalcone isomerase, flavanone 3 hydroxylase, flavonol synthase, the increase of Abscisic acid, sucrose, and phenyl ammonia lyase, while flavone mainly depends on evolution and on the high expression of the flavone synthase gene.

Multiple-Factors-Induced Rheumatoid Arthritis Synoviocyte Activation Is Attenuated by the α2-Adrenergic Receptor Agonist Dexmedetomidine.

Dexmedetomidine (Dex) has analgesic and sedative properties and anti-inflammatory functions. Although the effects of Dex on arthritis have been revealed, the physiological mechanism underlying the interaction between Dex and rheumatoid arthritis (RA)-mediated inflammatory cytokines has not been fully studied. Inflamed and migrated fibroblast-like synoviocytes (FLSs) are involved in RA severity. Thus, we aimed to determine the effects of Dex on RA-FLSs treated with inflammatory cytokines and a growth factor as multiple stimulating inputs. TNF-α, IL-6, and EGF as multiple stimulating inputs increased the cAMP concentration of RA-FLSs, while Dex treatment reduced cAMP concentration. Dex reduced electroneutral sodium-bicarbonate cotransporter 1 (NBCn1) expression, NBC activity, and subsequent RA-FLS migration. The mRNA expression levels of RA-related factors, such as inflammatory cytokines and osteoclastogenesis factors, were enhanced by multiple-input treatment. Notably, Dex effectively reduced these expression levels in RA-FLSs. These results indicate that multiple inflammatory or stimulating inputs enhance RA-FLS migration, and treatment with Dex relieves activated RA-FLSs, suggesting that Dex is a potential therapeutic drug for RA.

The pathogenesis and regulatory role of HIF-1 in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a prevalent autoimmune disease that involves the overgrowth and inflammation of synovial tissue, leading to the degeneration and impairment of joints. In recent years, numerous studies have shown a close relationship between the hypoxic microenvironment in joints and the occurrence and progression of RA. The main cause of the pathological changes in RA is widely believed to be the abnormal expression of hypoxia-inducible factor-1 (HIF-1) in joints. This paper describes and illustrates the structure and primary functions of HIF-1 and explains the main regulatory methods of HIF-1, including the PHDs/HIF-1 α/pVHL pathway, factor-inhibiting HIF (FIH), regulation of inflammatory cytokines, and the NF-κB pathway. Furthermore, this paper discusses the mechanism of HIF-1 and its impact on inflammation, angiogenesis, and cartilage destruction in greater detail. We summarize previous research findings on the mechanism of HIF-1 and propose new potential treatments for RA based on the pathogenesis of HIF-1 in RA.

Tofacitinib therapy intercepts macrophage metabolic reprogramming instigated by SARS-CoV-2 Spike protein.

The molecular mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein was characterized to identify novel therapies. The impact of tofacitinib, IL-6R Ab, or TNFi therapy was determined on Spike protein or LPS/IFN-γ-induced signaling, inflammation, and metabolic reprogramming in MΦs and/or rheumatoid arthritis (RA) fibroblast-like synoviocyte (FLS). ACE2 frequency was markedly expanded in MΦs compared to T cells and RA FLS. Tofacitinib suppresses Spike protein potentiated STAT1 signaling, whereas this function was unchanged by TNFi. Tofacitinib impairs IL-6/IFN/LPS-induced STAT1 and STAT3 phosphorylation in RA MΦs and FLS. Interestingly, tofacitinib had a broader inhibitory effect on the monokines, glycolytic regulators, or oxidative metabolites compared to IL-6R Ab and TNFi in Spike-protein-activated MΦs. In contrast, all three therapies disrupted IFN-α and IFN-ß secretion in response to Spike protein; nonetheless, the IFN-γ was only curtailed by tofacitinib or IL-6R Ab. While tofacitinib counteracted MΦ metabolic rewiring instigated by Spike protein, it was inconsequential on the glycolysis expansion mediated via HK2 and/or LDHA in the activated RA MΦ and FLS. Nevertheless, the potentiated inflammatory response and the diminished oxidative phosphorylation modulated by Spike protein and/or LPS/IFN-γ stimulation in MΦs or RA FLS were reversed by tofacitinib. In conclusion, tofacitinib suppresses MΦ inflammation and immunometabolism triggered by Spike protein and may provide a promising strategy for COVID-19 patients.

TNFR2 is critical for TNF-induced rheumatoid arthritis fibroblast-like synoviocyte inflammation.

OBJECTIVES: TNF-induced activation of fibroblast-like synoviocytes (FLS) is a critical determinant for synovial inflammation and joint destruction in RA. The detrimental role of TNF-receptor 1 (TNFR1) has thoroughly been characterized. The contributions of TNFR2, however, are largely unknown. This study was performed to delineate the role of TNFR2 in human FLS activation. METHODS: TNFR2 expression in synovial tissue samples was determined by immunohistochemistry. Expression of TNFR2 was silenced using RNAi or CRISPR/Cas9 technologies. Global transcriptional changes were determined by RNA-seq. QPCR, ELISA and immunoblotting were used to validate RNA-seq results and to uncover pathways operating downstream of TNFR2 in FLS. RESULTS: TNFR2 expression was increased in RA when compared with OA synovial tissues. In particular, RA-FLS demonstrated higher levels of TNFR2 when compared with OA-FLS. TNFR2 expression in RA-FLS correlated with RA disease activity, synovial T- and B-cell infiltration. TNF and IL1ß were identified as inflammatory mediators that upregulate TNFR2 in RA-FLS. Silencing of TNFR2 in RA-FLS markedly diminished the TNF-induced expression of inflammatory cytokines and chemokines, including CXCR3-binding chemokines and the B-cell activating factor TNFSF13B. Immunobiochemical analyses revealed that TNFR2-mediated expression of inflammatory mediators critically depends on STAT1. CONCLUSION: Our results define a critical role for TNFR2 in FLS-driven inflammation and unfold its participation in the unresolved course of synovial inflammation in RA.

Multiple myeloma screening within a fracture liaison service (FLS).

Multiple myeloma (MM) remains incurable. Although early diagnosis improves outcomes, it has been unclear which populations to target for screening with serum electrophoresis, serum free light chains and urine electrophoresis. Here, we assessed the value of MM screening in a Fracture Liaison Service, finding that 1 per 195 fragility fractures has undiagnosed MM, which can be expedited to Haematology Services. PURPOSE: A key role of the Fracture Liaison Service (FLS) is screening for secondary causes of osteoporosis. In 2019, the Royal Osteoporosis Society recommended that all patients attending FLS who are recommended anti-osteoporosis therapy have universal screening for myeloma based on serum electrophoresis, serum free light chains and urine electrophoresis. Here, we examined the impact of universal myeloma screening within an FLS. METHODS: We sampled all patients seen by the Oxfordshire FLS between January and April 2018. The completion rates and outcomes of screening were checked using the hospital and FLS databases. RESULTS: Of 950 patients identified by the FLS, 628 were eligible for MM screening; 473 (75%) of these were female, and the average age was 78.4 years. Overall, 584 had some form of myeloma screening, of which 577 (92%) had serum electrophoresis, 525 (84%) had serum free light chains and 407 (65%) had urine electrophoresis measured. A total of 327 (59%) patients had complete screening. Three patients (0.5%) had newly diagnosed myeloma and were urgently referred to Haematology Services. Furthermore, 46 (8%) patients had a detectable serum paraprotein with a likely diagnosis of monoclonal gammopathy of uncertain significance (MGUS) and referred for community annual surveillance according to local guidelines. CONCLUSION: Addition of universal myeloma screening to laboratory testing identified myeloma in 1 per 195 patients, and its precursor state MGUS in 1 per 13 patients, which may have otherwise been missed. Further analysis with long-term follow-up is needed to clearly define the value of diagnosing MGUS within the FLS setting and establish the benefits vs. costs and methods to improve screening completion rates.