GSK2334470 attenuates high salt-exacerbated rheumatoid arthritis progression by restoring Th17/Treg homeostasis.

High salt (HS) consumption is a risk factor for multiple autoimmune disorders via disturbing immune homeostasis. Nevertheless, the exact mechanisms by which HS exacerbates rheumatoid arthritis (RA) pathogenesis remain poorly defined. Herein, we found that heightened phosphorylation of PDPK1 and SGK1 upon HS exposure attenuated FoxO1 expression to enhance the glycolytic capacity of CD4 T cells, resulting in strengthened Th17 but compromised Treg program. GSK2334470 (GSK), a dual PDPK1/SGK1 inhibitor, effectively mitigated the HS-induced enhancement in glycolytic capacity and the overproduction of IL-17A. Therefore, administration of GSK markedly alleviated HS-exacerbated RA progression in collagen-induced arthritis (CIA) model. Collectively, our data indicate that HS consumption subverts Th17/Treg homeostasis through the PDPK1-SGK1-FoxO1 signaling, while GSK could be a viable drug against RA progression in clinical settings.

Kynurenine acts as a signaling molecule to attenuate pulmonary fibrosis by enhancing the AHR-PTEN axis.

INTRODUCTION: Pulmonary fibrosis (PF) is a fatal fibrotic lung disease without any options to halt disease progression. Feasible evidence suggests that aberrant metabolism of amino acids may play a role in the pathoetiology of PF. However, the exact impact of kynurenine (Kyn), a metabolite derived from tryptophan (Trp) on PF is yet to be addressed. OBJECTIVES: This study aims to elucidate the role of kynurenine in both the onset and advancement of PF. METHODS: Liquid chromatography-tandem mass spectrometry was employed to assess Kyn levels in patients with idiopathic PF and PF associated with Sjögren's syndrome. Additionally, a mouse model of PF induced by bleomycin was utilized to study the impact of Kyn administration. Furthermore, cell models treated with TGF-ß1 were used to explore the mechanism by which Kyn inhibits fibroblast functions. RESULTS: We demonstrated that high levels of Kyn are a clinical feature in both idiopathic PF patients and primary Sjögren syndrome associated PF patients. Further studies illustrated that Kyn served as a braking molecule to suppress fibroblast functionality, thereby protecting mice from bleomycin-induced lung fibrosis. The protective effects depend on AHR, in which Kyn induces AHR nuclear translocation, where it upregulates PTEN expression to blunt TGF-ß mediated AKT/mTOR signaling in fibroblasts. However, in fibrotic microenviroment, the expression of AHR is repressed by methyl-CpG-binding domain 2 (MBD2), a reader interpreting the effect of DNA methylation, which results in a significantly reduced sensitivity of Kyn to fibroblasts. Therefore, exogenous administration of Kyn substantially reversed established PF. CONCLUSION: Our studies not only highlighted a critical role of Trp metabolism in PF pathogenesis, but also provided compelling evidence suggesting that Kyn could serve as a promising metabolite against PF.

PDIA3 orchestrates effector T cell program by serving as a chaperone to facilitate the non-canonical nuclear import of STAT1 and PKM2.

Dysregulated T cell activation underpins the immunopathology of rheumatoid arthritis (RA), yet the machineries that orchestrate T cell effector program remain incompletely understood. Herein, we leveraged bulk and single-cell RNA sequencing data from RA patients and validated protein disulfide isomerase family A member 3 (PDIA3) as a potential therapeutic target. PDIA3 is remarkably upregulated in pathogenic CD4 T cells derived from RA patients and positively correlates with C-reactive protein level and disease activity score 28. Pharmacological inhibition or genetic ablation of PDIA3 alleviates RA-associated articular pathology and autoimmune responses. Mechanistically, T cell receptor signaling triggers intracellular calcium flux to activate NFAT1, a process that is further potentiated by Wnt5a under RA settings. Activated NFAT1 then directly binds to the Pdia3 promoter to enhance the expression of PDIA3, which complexes with STAT1 or PKM2 to facilitate their nuclear import for transcribing T helper 1 (Th1) and Th17 lineage-related genes, respectively. This non-canonical regulatory mechanism likely occurs under pathological conditions, as PDIA3 could only be highly induced following aberrant external stimuli. Together, our data support that targeting PDIA3 is a vital strategy to mitigate autoimmune diseases, such as RA, in clinical settings.

Machine-learning-based models assist the prediction of pulmonary embolism in autoimmune diseases: A retrospective, multicenter study.

BACKGROUND: Pulmonary embolism (PE) is a severe and acute cardiovascular syndrome with high mortality among patients with autoimmune inflammatory rheumatic diseases (AIIRDs). Accurate prediction and timely intervention play a pivotal role in enhancing survival rates. However, there is a notable scarcity of practical early prediction and risk assessment systems of PE in patients with AIIRD. METHODS: In the training cohort, 60 AIIRD with PE cases and 180 age-, gender-, and disease-matched AIIRD non-PE cases were identified from 7254 AIIRD cases in Tongji Hospital from 2014 to 2022. Univariable logistic regression (LR) and least absolute shrinkage and selection operator (LASSO) were used to select the clinical features for further training with machine learning (ML) methods, including random forest (RF), support vector machines (SVM), neural network (NN), logistic regression (LR), gradient boosted decision tree (GBDT), classification and regression trees (CART), and C5.0 models. The performances of these models were subsequently validated using a multicenter validation cohort. RESULTS: In the training cohort, 24 and 13 clinical features were selected by univariable LR and LASSO strategies, respectively. The five ML models (RF, SVM, NN, LR, and GBDT) showed promising performances, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.962-1.000 in the training cohort and 0.969-0.999 in the validation cohort. CART and C5.0 models achieved AUCs of 0.850 and 0.932, respectively, in the training cohort. Using D-dimer as a pre-screening index, the refined C5.0 model achieved an AUC exceeding 0.948 in the training cohort and an AUC above 0.925 in the validation cohort. These results markedly outperformed the use of D-dimer levels alone. CONCLUSION: ML-based models are proven to be precise for predicting the onset of PE in patients with AIIRD exhibiting clinical suspicion of PE. TRIAL REGISTRATION: Chictr.org.cn: ChiCTR2200059599.

Mid1 promotes synovitis in rheumatoid arthritis via ubiquitin-dependent post-translational modification.

INTRODUCTION: Current anti-rheumatic drugs are primarily modulating immune cell activation, yet their effectiveness remained suboptimal. Therefore, novel therapeutics targeting alternative mechanisms, such as synovial activation, is urgently needed. OBJECTIVES: To explore the role of Midline-1 (Mid1) in synovial activation. METHODS: NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice were used to establish a subcutaneous xenograft model. Wild-type C57BL/6, Mid1-/-, Dpp4-/-, and Mid1-/-Dpp4-/- mice were used to establish a collagen-induced arthritis model. Cell viability, cell cycle, qPCR and western blotting analysis were used to detect MH7A proliferation, dipeptidyl peptidase-4 (DPP4) and Mid1 levels. Co-immunoprecipitation and proteomic analysis identified the candidate protein of Mid1 substrates. Ubiquitination assays were used to determine DPP4 ubiquitination status. RESULTS: An increase in Mid1, an E3 ubiquitin ligase, was observed in human RA synovial tissue by GEO dataset analysis, and this elevation was confirmed in a collagen-induced mouse arthritis model. Notably, deletion of Mid1 in a collagen-induced arthritis model completely protected mice from developing arthritis. Subsequent overexpression and knockdown experiments on MH7A, a human synoviocyte cell line, unveiled a previously unrecognized role of Mid1 in synoviocyte proliferation and migration, the key aspects of synovial activation. Co-immunoprecipitation and proteomic analysis identified DPP4 as the most significant candidate of Mid1 substrates. Mechanistically, Mid1 promoted synoviocyte proliferation and migration by inducing ubiquitin-mediated proteasomal degradation of DPP4. DPP4 deficiency led to increased proliferation, migration, and inflammatory cytokine production in MH7A, while reconstitution of DPP4 significantly abolished Mid1-induced augmentation of cell proliferation and activation. Additionally, double knockout model showed that DPP4 deficiency abolished the protective effect of Mid1 defect on arthritis. CONCLUSION: Overall, our findings suggest that the ubiquitination of DPP4 by Mid1 promotes synovial cell proliferation and invasion, exacerbating synovitis in RA. These results reveal a novel mechanism that controls synovial activation, positioning Mid1 as a promising target for therapeutic intervention in RA.

Precision Medicine in Rheumatic Diseases: Unlocking the Potential of Antibody-Drug Conjugates.

In the era of precision medicine, antibody-drug conjugates (ADCs) have emerged as a cutting-edge therapeutic strategy. These innovative compounds combine the precision of monoclonal antibodies with the potent cell-killing or immune-modulating abilities of attached drug payloads. This unique strategy not only reduces off-target toxicity but also enhances the therapeutic effectiveness of drugs. Beyond their well established role in oncology, ADCs are now showing promising potential in addressing the unmet needs in the therapeutics of rheumatic diseases. Rheumatic diseases, a diverse group of chronic autoimmune diseases with varying etiologies, clinical presentations, and prognoses, often demand prolonged pharmacological interventions, creating a pressing need for novel, efficient, and low-risk treatment options. ADCs, with their ability to precisely target the immune components, have emerged as a novel therapeutic strategy in this context. This review will provide an overview of the core components and mechanisms behind ADCs, a summary of the latest clinical trials of ADCs for the treatment of rheumatic diseases, and a discussion of the challenges and future prospects faced by the development of next-generation ADCs. SIGNIFICANCE STATEMENT: There is a lack of efficient and low-risk targeted therapeutics for rheumatic diseases. Antibody-drug conjugates, a class of cutting-edge therapeutic drugs, have emerged as a promising targeted therapeutic strategy for rheumatic disease. Although there is limited literature summarizing the progress of antibody-drug conjugates in the field of rheumatic disease, updating the advancements in this area provides novel insights into the development of novel antirheumatic drugs.

Proliferative features of IgG4-related disease.

IgG4-related disease is an immune-mediated disease that can lead to substantial morbidity and organ damage. Capable of affecting nearly any organ system or anatomic site, and showing considerable overlap in clinical presentation with various other diseases, IgG4-related disease often poses a diagnostic challenge for clinicians. Furthermore, there are no diagnostic biomarkers with high specificity for IgG4-related disease, and histopathological examination is nuanced and requires clinical correlation for accurate diagnosis. Therefore, it is crucial for clinicians to recognise the clinical phenotypes of IgG4-related disease. The disease is generally considered to have predominantly fibrotic and proliferative (or inflammatory) manifestations, with distinct clinical, serological and histopathological findings associated with each manifestation. However, the fibrotic and proliferative manifestations of this disease frequently occur together, thereby blurring this dichotomous distinction. In this Series paper, we provide a detailed overview of the clinical manifestations typical of the proliferative features of IgG4-related disease, with an emphasis on the diagnostic evaluation and differential diagnosis of each proliferative disease manifestation. In addition, we summarise the immune mechanisms underlying IgG4-related disease, suggest a framework for how to approach management and monitoring after the diagnosis is established, and highlight current unmet needs for patient care surrounding this disease.

Waardenburg syndrome type 2 with a de novo variant of the SOX10 gene: a case report.

BACKGROUND: Waardenburg syndrome type 2 (WS2) has been reported to be a rare hereditary disorder, which is distinguished by vivid blue eyes, varying degrees of hearing impairment, and abnormal pigment deposition in the skin and hair. Variants in the sex-determining region Y-box containing gene 10 (SOXl0) gene may cause congenital deafness and have been demonstrated to be important during the development of WS2. METHODS: Complete clinical data of the proband and her family members (her parents and 2 sisters) was collected and physical examinations were performed in the hospital. The laboratory examination including hemoglobin, Coomb's test, urine protein, ENA, autoimmune hepatitis-related autoantibodies and ultrasonography were all conducted. We obtained the peripheral blood samples from all the participants and performed whole exome sequencing and sanger sequencing validation. RESULTS: The present study identified a family of 5 members, and only the proband exhibited typical WS2. Beyond the characteristics of WS2, the proband also manifested absence of puberty. The proband and her younger sister manifested systemic lupus erythematosus (SLE). Whole exome sequencing revealed a de novo variant in the SOX10 gene. The variant c.175 C > T was located in exon 2 of the SOX10 gene, which is anticipated to result in early termination of protein translation. CONCLUSION: The present study is the first to report a case of both WS2 and SLE, and the present findings may provide a new insight into WS2.

A membrane associated tandem kinase from wild emmer wheat confers broad-spectrum resistance to powdery mildew.

Crop wild relatives offer natural variations of disease resistance for crop improvement. Here, we report the isolation of broad-spectrum powdery mildew resistance gene Pm36, originated from wild emmer wheat, that encodes a tandem kinase with a transmembrane domain (WTK7-TM) through the combination of map-based cloning, PacBio SMRT long-read genome sequencing, mutagenesis, and transformation. Mutagenesis assay reveals that the two kinase domains and the transmembrane domain of WTK7-TM are critical for the powdery mildew resistance function. Consistently, in vitro phosphorylation assay shows that two kinase domains are indispensable for the kinase activity of WTK7-TM. Haplotype analysis uncovers that Pm36 is an orphan gene only present in a few wild emmer wheat, indicating its single ancient origin and potential contribution to the current wheat gene pool. Overall, our findings not only provide a powdery mildew resistance gene with great potential in wheat breeding but also sheds light into the mechanism underlying broad-spectrum resistance.

Expression of USP25 associates with fibrosis, inflammation and metabolism changes in IgG4-related disease.

IgG4-related disease (IgG4-RD) has complex clinical manifestations ranging from fibrosis and inflammation to deregulated metabolism. The molecular mechanisms underpinning these phenotypes are unclear. In this study, by using IgG4-RD patient peripheral blood mononuclear cells (PBMCs), IgG4-RD cell lines and Usp25 knockout mice, we show that ubiquitin-specific protease 25 (USP25) engages in multiple pathways to regulate fibrotic and inflammatory pathways that are characteristic to IgG4-RD. Reduced USP25 expression in IgG4-RD leads to increased SMAD3 activation, which contributes to fibrosis and induces inflammation through the IL-1ß inflammatory axis. Mechanistically, USP25 prevents ubiquitination of RAC1, thus, downregulation of USP25 leads to ubiquitination and degradation of RAC1. Decreased RAC1 levels result in reduced aldolase A release from the actin cytoskeleton, which then lowers glycolysis. The expression of LYN, a component of the B cell receptor signalosome is also reduced in USP25-deficient B cells, which might result in B cell activation deficiency. Altogether, our results indicate a potential anti-inflammatory and anti-fibrotic role for USP25 and make USP25 a promising diagnostic marker and potential therapeutic target in IgG4-RD.

The development and initial validation of IgG4-related disease damage index: a consensus report from Chinese IgG4-RD Consortium.

OBJECTIVE: To develop and conduct an initial validation of the Damage Index for IgG4-related disease (IgG4-RD DI). METHODS: A draft of index items for assessing organ damages in patients with IgG4-RD was generated by experts from the Chinese IgG4-RD Consortium (CIC). The preliminary DI was refined using the Delphi method, and a final version was generated by consensus. 40 IgG4-RD cases representing four types of clinical scenarios were then selected, each with two time points of assessment for at least 3 years of follow-up. 48 rheumatologists from 35 hospitals nationwide were invited to evaluate organ damage using the CIC IgG4-RD DI. The intraclass correlation coefficient (ICC) and the Kendall-W coefficient of concordance (KW) were used to assess the inter-rater reliability. The criterion validity of IgG4-RD DI was tested by calculating the sensitivity and specificity of raters. RESULTS: IgG4-RD DI is a cumulative index consisting of 14 domains of organ systems, including a total of 39 items. The IgG4-RD DI was capable of distinguishing stable and increased damage across the active disease subgroup and stable disease subgroup. In terms of scores at baseline and later observations by all raters, overall consistency in scores at baseline and later observations by all raters was satisfactory. ICC at the two time points was 0.69 and 0.70, and the KW was 0.74 and 0.73, respectively. In subgroup analysis, ICC and KW in all subgroups were over 0.55 and 0.61, respectively. The analysis of criterion validity showed a good performance with a sensitivity of 0.86 (95% CI 0.82 to 0.88), a specificity of 0.79 (95% CI 0.76 to 0.82) and an area under the curve of 0.88 (95% CI 0.85 to 0.91). CONCLUSION: The IgG4-RD DI is a useful approach to analyse disease outcomes, and it has good operability and credibility. It is anticipated that the DI will become a useful tool for therapeutic trials and studies of prognosis in patients with IgG4-RD.

Midline-1 regulates effector T cell motility in experimental autoimmune encephalomyelitis via mTOR/microtubule pathway.

Background: Effector T cell activation, migration, and proinflammatory cytokine production are crucial steps in autoimmune disorders such as multiple sclerosis (MS). While several therapeutic approaches targeting T cell activation and proinflammatory cytokines have been developed for the treatment of autoimmune diseases, there are no therapeutic agents targeting the migration of effector T cells, largely due to our limited understanding of regulatory mechanisms of T cell migration in autoimmune disease. Here we reported that midline-1 (Mid1) is a key regulator of effector T cell migration in experimental autoimmune encephalomyelitis (EAE), a widely used animal model of MS. Methods: Mid1-/- mice were generated by Crispr-Cas9 technology. T cell-specific Mid1 knockout chimeric mice were generated by adoptive transfer of Mid1-/- T cells into lymphocyte deficient Rag2-/- mice. Mice were either immunized with MOG35-55 (active EAE) or received adoptive transfer of pathogenic T cells (passive EAE) to induce EAE. In vitro Transwell® assay or in vivo footpad injection were used to assess the migration of T cells. Results: Mid1 was significantly increased in the spinal cord of wild-type (Wt) EAE mice and disruption of Mid1 in T cells markedly suppressed the development of both active and passive EAE. Transcriptomic and flow cytometric analyses revealed a marked reduction in effector T cell number in the central nervous system of Mid1-/- mice after EAE induction. Conversely, an increase in the number of T cells was observed in the draining lymph nodes of Mid1-/- mice. Mice that were adoptively transferred with pathogenic Mid1-/- T cells also exhibited milder symptoms of EAE, along with a lower T cell count in the spinal cord. Additionally, disruption of Mid1 significantly inhibited T-cell migration both in vivo and in vitro. RNA sequencing suggests a suppression in multiple inflammatory pathways in Mid1-/- mice, including mTOR signaling that plays a critical role in cell migration. Subsequent experiments confirmed the interaction between Mid1 and mTOR. Suppression of mTOR with rapamycin or microtubule spindle formation with colcemid blunted the regulatory effect of Mid1 on T cell migration. In addition, mTOR agonists MHY1485 and 3BDO restored the migratory deficit caused by Mid1 depletion. Conclusion: Our data suggests that Mid1 regulates effector T cell migration to the central nervous system via mTOR/microtubule pathway in EAE, and thus may serve as a potential therapeutic target for the treatment of MS.

Immunomodulatory effects of iTr35 cell subpopulation and its research progress.

The spotlight in recent years has increasingly focused on inducible regulatory T cells 35 (iTr35), a novel subpopulation of regulatory T cells characterized by phenotypic stability, heightened reactivity, and potent immunosuppressive function through the production of IL-35. Despite being in the exploratory phase, research on iTr35 has garnered significant interest. In this review, we aim to consolidate our understanding of the biological characteristics and immunomodulatory mechanisms of iTr35, offering fresh perspectives that may pave the way for its potential applications in disease diagnosis and treatment.

A comparative study on the clinical and magnetic resonance imaging features between seronegative and seropositive rheumatoid arthritis.

OBJECTIVES: Seronegative rheumatoid arthritis (SNRA) is less common and less known compared with seropositive rheumatoid arthritis (SPRA). The aim of this study was to characterise the clinical and magnetic resonance imaging (MRI) features of SNRA and investigate the associated factors of structural damage. METHODS: We retrospectively collected newly diagnosed RA patients who had MRI data of the hands at baseline. The clinical and MRI features and treatment responses during the 12-month follow-up were compared between SNRA and SPRA. The associated factors of the erosion rate were analysed. RESULTS: A total of 310 RA patients were included in this study. Compared with SPRA, SNRA had a higher level of inflammation (p-values were all <0.001), a higher incidence of low bone mineral density (p=0.009), but a lower erosion score (p<0.001) and a lower probability of interstitial lung disease (ILD) (p=0.019). The main eroded bones were different between SNRA (the scaphoid and the lunate) and SPRA (the capitate and the hamate). In the multivariate analysis, synovitis score, the levels of IL-6 and TNF-α, and hyperglobulinaemia were positively associated with the erosion rate of SNRA (p-values were all <0.05). During the 12-month follow-up, the treatment response between the two groups was comparable (p-values were all >0.05). CONCLUSIONS: SNRA had more severe inflammation but milder erosion compared with SPRA. SNRA with severe inflammation or hyperglobulinaemia needs the same powerful therapy of SPRA to prevent erosion progression.

Composite poly(ethylene oxide)-based solid electrolyte with consecutive and fast ion transport channels constructed by upper-dimensional MIL-53(Al) nanofibers.

Novel structural designs for metal organic frameworks (MOFs) are expected to improve ion-transport behavior in composite solid electrolytes. Herein, upper-dimensional MIL-53(Al) nanofibers (MNFs, MIL-53 belongs to the MIL (Material Institute Lavoisier) group) with flower-like nanoflake structures have been designed and constructed via modified hydrothermal coordination. The optimized MNFs with high surface area and porosity can form abundant interfaces with poly(ethylene oxide) (PEO) matrix. The plasticization of MNFs to the PEO matrix will facilitate segmental movement of PEO chains to facilitate Li+ conduction. The unsaturated open metal centers of MNFs can effectively capture bis(trifluoromethanesulfonyl)imide anions (TFSI-) to deliver more free lithium ions for transfer. Moreover, the upper-dimensional nanofiber structure endows lithium ions with a long-range and consecutive transport pathway. The obtained composite solid electrolyte (MNFs@PEO) presents a high ionic conductivity of 4.1 × 10-4 S cm-1 and a great Li+ transference number of 0.4 at 60 °C. The electrolyte also exhibits a stable Li plating/stripping behavior over 1000 h at 0.1 mA cm-1 with inhibited Li dendrite growth. Furthermore, the Li/LiFePO4 and Li/LiNi0.8Mn0.1Co0.1O2 batteries with MNFs@PEO as electrolytes both display great cycling stabilities with high-capacity retention, indicating their potential applications in lithium metal batteries. The study will put forward new inspirations for designing advanced MOF-based composite solid electrolytes.

The Role of the IL-33/ST2 Axis in CpG-Induced Macrophage Activation Syndrome.

Background: Macrophage activation syndrome (MAS) is a fatal inflammatory condition, which is often associated with the elevation of multiple proinflammatory cytokines and multiple organ dysfunction. Previous studies have shown that ST2 contributes to T cell overactivation and plays a detrimental role in mouse models of primary hemophagocytic lymphohistiocytosis. The purpose of this study was to investigate the role of the IL-33/ST2 axis in a mouse model of MAS induced by repeated injections of cytosine-phosphate-guanine (CpG). Methods: Serum cytokines were determined using the cytometric bead array by flow cytometry. IL-33 and ST2 were detected by immunohistochemistry and real-time quantitative PCR in the liver and spleen of mice. CD3 and F4/80 in the liver were detected by immunohistochemistry. Inflammatory macrophages and effector memory T lymphocytes were detected by flow cytometry. Result: The CpG-induced MAS model was successfully induced after repeated CpG injections, presenting with hypercytokinemia and hepatosplenomegaly. The numbers of IL-33 positive cells in the liver and spleen decreased significantly, while the expression of ST2 in the liver tended to increase in the mice with MAS. IL-33 and St2 knockout mice showed similar levels of hepatosplenomegaly, peripheral blood count, and cytokine storm when compared with wild-type (WT) mice after induction of MAS. There were also no significant differences in liver pathology (including inflammatory cell infiltration of CD3 and F4/80) and levels of splenic inflammatory macrophages and effector memory T cells between the WT and knockout mice. Conclusion: These results suggested that IL-33 decreased in the liver and spleen tissues of MAS mice. Further results suggest that IL-33 and St2 knockout mice have no treatment potential in CpG-induced MAS. Thus, the IL-33/ST2 axis has little effect on the prognosis of CpG-induced MAS.

Spontaneous intramuscular hemorrhage in cancer-associated dermatomyositis: a case and literature review.

BACKGROUND: Spontaneous intramuscular hemorrhage (SIH) is a rare but life-threatening complication of dermatomyositis (DM). The pathogenetic mechanism and management of intramuscular hematoma in these patients remains unclear. Here we discuss a case of recurrent hemorrhage in a patient with cancer-associated DM, and review the relevant literature for timely diagnosis and treatment. CASE PRESENTATION: A 53-year-old male patient presented with rashes, muscle weakness, and dysphagia and was diagnosed with DM. During treatment, he developed SIH of the arm and right psoas major muscle successively. MRI showed extensive edema of the right shoulder girdle muscle and muscle groups of the upper arm. During the second SIH, a CT scan showed new-onset hematoma formation in the right psoas major muscle. The detection of D-dimer, thrombin-antithrombin III complex (TAT), plasmin-α2-plasmininhibitor complex (PIC) and tissue plasminogen activator-inhibitor complex (t-PAIC) indicated predominant hyperfibrinolysis over thrombosis. Blood transfusion and supportive treatment were immediately performed, and the hematoma did not expand. However, his abdominal distension was not relieved after active treatment. Further electronic gastroscopy discovered gastric sinus ulcers, and histopathology of the biopsy confirmed signet-ring cell carcinoma. CONCLUSIONS: Although patients with cancer-associated DM have an increased risk of thrombosis, prophylactic anticoagulation therapy needs deliberate consideration. It is important to monitor the coagulation parameters dynamically during anticoagulation therapy. Especially when the level of D-dimer is high, and it is uncertain whether the patient is in a state of thrombosis or hyperfibrinolysis, the detection of TAT, PIC, t-PAIC can help to determine whether to initiate anticoagulation therapy.

JAK2/STAT5 inhibition protects mice from experimental autoimmune encephalomyelitis by modulating T cell polarization.

Multiple sclerosis (MS) has been considered as a T cell-mediated autoimmune disease. However, the signaling pathways regulating effector T cells in MS have yet to be elucidated. Janus kinase 2 (JAK2) plays a crucial role in hematopoietic/immune cytokine receptor signal transduction. Here, we tested the mechanistic regulation of JAK2 and the therapeutic potential of pharmacological JAK2 inhibition in MS. Both inducible whole-body JAK2 knockout and T cell-specific JAK2 knockout completely prevented the onset of experimental autoimmune encephalomyelitis (EAE), a widely used MS animal model. Mice with JAK2 deficiency in T cells exhibited minimal demyelination and minimal CD45+ leukocyte infiltration in the spinal cord, accompanied by a remarkable reduction of T helper cell type 1 (TH1) and type 17 (TH17) in the draining lymph nodes and spinal cord. In vitro experiments showed that disruption of JAK2 markedly suppressed TH1 differentiation and IFNγ production. The phosphorylation of signal transducer and activator of transcription 5 (STAT5) was reduced in JAK2 deficient T cells, while STAT5 overexpression significantly increased TH1 and IFNγ production in STAT5 transgenic mice. Consistent with these results, JAK1/2 inhibitor baricitinib or selective JAK2 inhibitor fedratinib attenuated the frequencies of TH1 as well as TH17 in the draining lymph nodes and alleviated the EAE disease activity in mice. Our findings suggest that overactive JAK2 signaling in T lymphocytes is the culprit in EAE, which may serve as a potent therapeutic target for autoimmune disease.

Regulatory T cells: a new therapeutic link for Sjögren syndrome?

Great advancements have been made in understanding the pathogenesis of SS, but there remain unmet needs for effective and targeted treatments. Glandular and extraglandular dysfunction in SS is associated with autoimmune lymphocytic infiltration that invades the epithelial structures of affected organs. Regulatory T (Treg) cells are a subset of CD4+ T lymphocytes that maintain self-tolerance during physiological conditions. Besides inhibiting excessive inflammation and autoimmune response by targeting various immune cell subsets and tissues, Treg cells have also been shown to promote tissue repair and regeneration in pathogenic milieus. The changes of quantity and function of Treg cells in various autoimmune and chronic inflammatory disorders have been reported, owing to their effects on immune regulation. Here we summarize the recent findings from murine models and clinical data about the dysfunction of Treg cells in SS pathogenesis and discuss the therapeutic strategies of direct or indirect targeting of Treg cells in SS. Understanding the current knowledge of Treg cells in the development of SS will be important to elucidate disease pathogenesis and may guide research for successful therapeutic intervention in this disease.