Cannabinoid receptor 2 selective agonist alleviates systemic sclerosis by inhibiting Th2 differentiation through JAK/SOCS3 signaling.

Systemic sclerosis (SSc) poses a significant challenge in autoimmunology, characterized by the development of debilitating fibrosis of skin and internal organs. The pivotal role of dysregulated T cells, notably the skewed polarization toward Th2 cells, has been implicated in the vascular damage and progressive fibrosis observed in SSc. In this study, we explored the underlying mechanisms by which cannabinoid receptor 2 (CB2) highly selective agonist HU-308 restores the imbalance of T cells to alleviate SSc. Using a bleomycin-induced SSc (BLM-SSc) mouse model, we demonstrated that HU-308 effectively attenuates skin and lung fibrosis by specifically activating CB2 on CD4+ T cells to inhibit the polarization of Th2 cells in BLM-SSc mice, which was validated by Cnr2-specific-deficient mice. Different from classical signaling downstream of G protein-coupled receptors (GPCRs), HU-308 facilitates the expression of SOCS3 protein and subsequently impedes the IL2/STAT5 signaling pathway during Th2 differentiation. The deficiency of SOCS3 partially mitigated the impact of HU-308. Analysis of a cohort comprising 80 SSc patients and 82 healthy controls revealed an abnormal elevation in the Th2/Th1 ratio in SSc patients. The proportion of Th2 cells showed a significant positive correlation with mRSS score and positivity of anti-Scl-70. Administration of HU-308 to PBMCs and peripheral CD4+ T cells from SSc patients led to the upregulation of SOCS3, which effectively suppressed the aberrantly activated STAT5 signaling pathway and the proportion of CD4+IL4+ T cells. In conclusion, our findings unveil a novel mechanism by which the CB2 agonist HU-308 ameliorates fibrosis in SSc by targeting and reducing Th2 responses. These insights provide a foundation for future therapeutic approaches in SSc by modulating Th2 responses.

Disease-associated immune cell endotypes in anti-MDA5-positive dermatomyositis using unbiased hierarchical clustering.

Objective: Clinical and prognostic features of Anti-MDA5-Positive Dermatomyositis (MDA5+ DM) are diverse. This study aimed to examine the peripheral immune cell profiles of patients with MDA5+ DM, identify disease endotypes related to the heterogeneous manifestations and prognosis, and guide individualized therapy regimen. Methods: This inpatient cohort included 123 patients with MDA5+ DM. Unsupervised hierarchical clustering analysis was used to derive disease endotypes from the circulating immune cell profiles on admission. Clinical symptoms, laboratory test results, inpatient treatments, and disease outcomes were then analyzed among the identified endotypes. Results: Three disease endotypes in MDA5+ DM were identified from peripheral immune cell profiles. Endotype1 had the highest percentages of CD4+ T cells and monocytes, and the lowest percentage of neutrophils; Endotype2 had the highest percentage of B cells; Endotype3 had the highest percentage of CD8+ T cells and NK cells. Clinical and prognostic heterogeneity of the endotypes were revealed. Endotype1 had the lowest 3-month mortality with the high incidence of periungual capillary changes. Endotype2 and Endotype3 had higher prevalence of rapidly progressive interstitial lung disease (RPILD) and mortality at 3 months than Endotype1. Meanwhile, Endotype3 had higher pneumocystis jiroveci and CMV viremia cases with significantly elevated of activated CD8+ T cells and multiple cytokines than Endotype1. Conclusion: Clustering analysis of peripheral immune cell profiles identified three different endotypes in MDA5+ dermatomyositis. Endotpye2 and 3 showed higher RPILD, 3-month mortality, pneumocystis jiroveci and CMV viremia.

Endothelial Response to Type I Interferon Contributes to Vasculopathy and Fibrosis and Predicts Disease Progression of Systemic Sclerosis.

OBJECTIVE: Interferon (IFN)-1 signatures are a hallmark of patients with systemic sclerosis (SSc). However, its significance in clinical stratification and contribution to deterioration still need to be better understood. METHODS: For hypothesis generation, we performed single-cell RNA sequencing (scRNA-seq) on skin biopsies (four patients with SSc and two controls) using the BD Rhapsody platform. Two publicly available data sets of skin scRNA-seq were used for validation (GSE138669: 12 patients with diffuse cutaneous SSc [dcSSc] and 10 controls; GSE195452: 52 patients with dcSSc and 41 patients with limited cutaneous SSc [lcSSc] and 54 controls). The IFN-1 signature was mapped, functionally investigated in a bleomycin plus IFNα-2 adenovirus-associated virus (AAV)-induced model and verified in an SSc cohort (n = 61). RESULTS: The discovery and validation data sets showed similar findings. Endothelial cells (ECs) had the most prominent IFN-1 signature among dermal nonimmune cells. The EC IFN-1 signature was increased both in patients with SSc versus controls and in patients with dcSSc versus those with lcSSc. Among EC subclusters, the IFN-1 signature was statistically higher in the capillary ECs of patients with dcSSc, which was higher than those in patients with lcSSc, which in turn was higher than those in healthy controls (HCs). Endothelial-to-mesenchymal transition (EndoMT) scores increased in parallel. Deteriorated bleomycin-induced dermal fibrosis, EndoMT, and perivascular fibrosis and caused blood vessel loss with EC apoptosis. Vascular myxovirus resistance (MX) 1, an IFN-1 response protein, was significantly increased both in total SSc versus HC skin and in dcSSc versus lcSSc skin. Baseline vascular MX1 performed similarly to skin score in predicting disease progression over 6 to 34 months in total SSc and was superior in the dcSSc subpopulation. CONCLUSION: The EC IFN-1 signature distinguished SSc skin subtypes and disease progression and may contribute to vasculopathy and fibrosis.

Clinical phenotypes and prognoses of microscopic polyangiitis based on kidney biopsies.

BACKGROUND: To classify the different clinical phenotypes and compare the distinct prognoses of microscopic polyangiitis (MPA). METHODS: A retrospective analysis of 436 patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) from 2015 to 2022 was conducted in our center, of which 90 patients were diagnosed with MPA and underwent renal biopsy. RESULTS: Among the 90 MPA patients, 63% were female, and the median age at onset was 63 years (25th-75th percentile: 58-68). The median follow-up time was 26 months (25th-75th percentile: 10-53). We identified four subtypes: renal impairment type (cluster 1, 39%), pure type (cluster 2, 22%), systemic inflammation type (cluster 3, 26%), and rapid progress type (cluster 4, 13%). Cluster 1, characterized by renal dysfunction at onset (80%), demonstrated poor prognoses with only 26% achieved complete remission (CR), 11% dying, and 19% developing renal failure. In contrast, patients in cluster 2, exclusively female, most had only kidney involvement showed the best prognoses with 55% achieving CR and none experiencing death or renal failure within 10 years. Cluster 3 mostly consisted of males; high fever and C-reactive protein levels were the primary characteristics. These cases exhibited moderate prognoses with 53% achieving CR, 9% dying, and 4% developing renal failure. Finally, patients in cluster 4, which was characterized by rapidly progressive glomerulonephritis, had the worst prognoses, with none achieving CR, 8% dying, and 75% developing renal failure despite aggressive treatment. CONCLUSIONS: MPA is classified into four subtypes with distinct clinical manifestations and prognoses.

Immune profile alterations of systemic lupus erythematosus patients with infections.

This study aimed to elucidate the immune status of systemic lupus erythematosus (SLE) patients with infections. We enrolled 253 SLE patients including 77 patients with infections. Clinical features and immunological parameters were analyzed, with particular reference to neutrophil CD64 (nCD64) expression, myeloid-derived suppressor cells (MDSCs), activated T cells and multiple cytokines. Among the 77 SLE patients with infections, 32 patients (41.56%) developed fever and 20 patients (25.97%) developed serositis, which were higher compared to the non-infection group. A considerably higher level of nCD64 was found in the infection group (4.65 vs 1.01, P < 0.001). In addition, the infection group exhibited higher percentages of total MDSCs (6.99 vs 4.30%, P = 0.003), polymorphonuclear MDSCs (PMN-MDSCs) (P = 0.032) and monocytic MDSCs (M-MDSCs) (P = 0.015). T cells were more activated during infections, with an elevated level of IL-2R (P < 0.001). Specifically, higher percentages of CD4+CD38+ T cells (55.73 vs 50.17%, P = 0.036), CD8+HLA-DR+ T cells (59.82 vs 47.99%, P < 0.001) and CD8+CD38+ T cells (68.59 vs 63.90%, P = 0.044) were identified in the infection group. Furthermore, the serum levels of IL-6, IL-8 and IL-10 were elevated in the infection group (all P < 0.001). Higher proportions of neutrophils, CD4+ and CD8+ T cells, and MDSCs were activated during infections in SLE patients. Additionally, the serum cytokines altered during infections, with noticeably elevated levels of IL-6, IL-8 and IL-10. Infections may lead to the amplification of immune alterations in SLE.

Efficacy and safety of tripterygium wilfordii Hook F plus TNF inhibitor for active rheumatoid arthritis: A multicentre, randomized, double-blind, triple-dummy controlled trial.

An investigator-initiated, multicentre, randomized, double-blind, triple-dummy, controlled trial was conducted at 14 tertiary rheumatology centers in China to evaluate the efficacy and safety of Tripterygium wilfordii Hook F (TwHF) with recombinant human TNF receptor IgGFc fusion protein (rhTNFR-Fc) in active Rheumatoid Arthritis (RA). Primary endpoint was the proportion of patients achieved a 50% improvement of American College of Rheumatology criteria (ACR50) in TwHF+rhTNFR-Fc vs. methotrexate (MTX) group at week 12. ACR50 was achieved in 57.1% (72/126), 41.3% (52/126), 23.0% (29/126), and 26.2% (33/126) patients receiving TwHF+rhTNFR-Fc, MTX + rhTNFR-Fc, TwHF and MTX monotherapy, respectively, at week 12 (TwHF+rhTNFR-Fc vs. other three groups, all p < 0.05). No statistical difference in serious adverse events or adverse events leading to discontinuation of study across all groups was documented. TwHF+rhTNFR-Fc was superior to MTX for active RA, and was more effective than MTX + rhTNFR-Fc on ACR50, with a similar safety profile. Trial registration:ClinicalTrials.govNCT03589833.

Magnesium bioactive glass hybrid functionalized polyetheretherketone with immunomodulatory function to guide cell fate and bone regeneration.

Polyetheretherketone (PEEK) is being increasingly recognized as a highly promising polymer implant in orthopaedics due to its advantageous biocompatibility, favorable processability, and radiation resistance. Nonetheless, the long-term application of PEEK implants in vivo faces challenges due to unfavorable post-implantation inflammatory and immune reactions, which result in suboptimal osseointegration rates. Hence, biofunctionalizing the surface of PEEK implants emerges as a viable strategy to enhance osseointegration and increase the success rate. In this study, we developed a multifunctional PEEK implant through the in-situ incorporation of chitosan-coated bioactive glass nanoparticles (BGNs). This approach can impart immunomodulatory properties and enhance the potential for osseointegration. The resulting biofunctionalized PEEK material exhibited multiple beneficial effects. For instance, it facilitated M2 phenotypic polarization of macrophages, diminished the expression of inflammatory factors, and enhanced the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. Moreover, it exhibited an improved capacity for osseointegration when tested in vivo. The findings of the experiment highlighted the pivotal and complex role of the biofunctionalized PEEK implant in maintaining typical bone immunity and metabolism. The study proposes that the application of chitosan-BGNs presents a straightforward approach to developing multifunctional implants with the ability to promote biomineralization and immunomodulation, specifically tailored for orthopaedic applications.

Iguratimod attenuated fibrosis in systemic sclerosis via targeting early growth response 1 expression.

BACKGROUND: The early growth response 1 (EGR1) is a central transcription factor involved in systemic sclerosis (SSc) pathogenesis. Iguratimod is a synthesized anti-rheumatic disease-modifying drug, which shows drastic inhibition to EGR1 expression in B cells. This study is aiming to investigate the anti-fibrotic effect of iguratimod in SSc. METHODS: EGR1 was detected by immunofluorescence staining real-time PCR or western blot. Iguratimod was applied in EGR1 overexpressed or knockdown human dermal fibroblast, bleomycin pre-treated mice, tight skin 1 mice, and SSc skin xenografts. RNA sequencing was performed in cultured fibroblast and xenografts to identify the iguratimod regulated genes. RESULTS: EGR1 overexpressed predominantly in non-immune cells of SSc patients. Iguratimod reduced EGR1 expression in fibroblasts and neutralized changes of EGR1 response genes regulated by TGFß. The extracellular matrix (ECM) production and activation of fibroblasts were attenuated by iguratimod while EGR1 overexpression reversed this effect of iguratimod. Iguratimod ameliorated the skin fibrosis induced by bleomycin and hypodermal fibrosis in TSK-1 mice. Decreasing in the collagen content as well as the density of EGR1 or TGFß positive fibroblasts of skin xenografts from naïve SSc patients was observed after local treatment of iguratimod. CONCLUSION: Targeting EGR1 expression is a probable underlying mechanism for the anti-fibrotic effect of iguratimod.

Interleukin 4-driven reversal of self-reactive B cell anergy contributes to the pathogenesis of systemic lupus erythematosus.

OBJECTIVES: Reactivation of anergic autoreactive B cells (BND cells) is a key aetiological process in systemic lupus erythematosus (SLE), yet the underlying mechanism remains largely elusive. This study aimed to investigate how BND cells participate in the pathogenesis of SLE and the underlying mechanism. METHODS: A combination of phenotypical, large-scale transcriptome and B cell receptor (BCR) repertoire profiling were employed at molecular and single cell level on samples from healthy donors and patients with SLE. Isolated naïve B cells from human periphery blood were treated with anti-CD79b mAb in vitro to induce anergy. IgM internalisation was tracked by confocal microscopy and was qualified by flow cytometer. RESULTS: We characterised the decrease and disruption of BND cells in SLE patients and demonstrated IL-4 as an important cytokine to drive such pathological changes. We then elucidated that IL-4 reversed B cell anergy by promoting BCR recycling to the cell surface via STAT6 signalling. CONCLUSIONS: We demonstrated the significance of IL-4 in reversing B cell anergy and established the scientific rationale to treat SLE via blocking IL-4 signalling, also providing diagnostic and prognostic biomarkers to identify patients who are most likely going to benefit from such treatments.