Metabolic alterations in vitamin D deficient systemic lupus erythematosus patients.

Vitamin D deficiency is increasingly common in systemic lupus erythematosus (SLE) patients and is associated with the disease activity and proteinuria. Recently, alterations in metabolism have been recognized as key regulators of SLE pathogenesis. Our objective was to identify differential metabolites in the serum metabolome of SLE with vitamin D deficiency. In this study, serum samples from 31 SLE patients were collected. Levels of 25(OH)D3 were assayed by ELISA. Patients were divided into two groups according to their vitamin D level (20 ng/ml). Untargeted metabolomics were used to study the metabolite profiles in serum by high-performance liquid chromatography-tandem mass spectrometry. Subsequently, we performed metabolomics profiling analysis to identify 52 significantly altered metabolites in vitamin D deficient SLE patients. The area under the curve (AUC) from ROC analyses was calculated to assess the diagnostic potential of each candidate metabolite biomarker. Lipids accounted for 66.67% of the differential metabolites in the serum, highlighted the disruption of lipid metabolism. The 52 differential metabolites were mapped to 27 metabolic pathways, with fat digestion and absorption, as well as lipid metabolism, emerging as the most significant pathways. The AUC of (S)-Oleuropeic acid and 2-Hydroxylinolenic acid during ROC analysis were 0.867 and 0.833, respectively, indicating their promising diagnostic potential. In conclusion, our results revealed vitamin D deficiency alters SLE metabolome, impacting lipid metabolism, and thrown insights into the pathogenesis and diagnosis of SLE.

CX-5461 ameliorates disease in lupus-prone mice by triggering B-cell ferroptosis via p53-SLC7A11-ALOX12 pathway.

CX-5461, a first-in-class compound, is widely recognized as a selective inhibitor of RNA polymerase I. Recently, it has been reported to possess novel immunosuppressive properties with significant therapeutic effects in transplantation immune rejection. However, the potential use of CX-5461 for Systemic Lupus Erythematosus (SLE) treatment remains unknown. In this study, we elucidated the mechanism underlying the therapeutic efficacy of CX-5461 in lupus. Our findings demonstrated that CX-5461 selectively targets B cells and effectively reduces the proportions of B cells, germinal center B cells, and plasma cells in MRL/MPJ-Faslpr and Resiquimod (R848)-induced lupus mice. Molecular studies revealed that CX-5461 modulates CD36-Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4)-mediated glycerolipid metabolism in B cells, triggering ferroptosis through the p53- Solute Carrier Family 7 Member 11 (SLC7A11)- Arachidonate 12-Lipoxygenase (ALOX12) pathway, thereby decreasing IgG and Anti-Double-Stranded Deoxyribonucleic Acid (dsDNA) antibody levels and attenuating lupus. Collectively, these results suggest that CX-5461 holds promise as an effective candidate for targeted therapy against lupus.

Telitacicept: A novel horizon in targeting autoimmunity and rheumatic diseases.

BLyS and APRIL have the capability to bind to B cells within the body, allowing these cells to evade elimination when they should naturally be removed. While BLyS primarily plays a role in B cell development and maturation, APRIL is linked to B cell activation and the secretion of antibodies. Thus, in theory, inhibiting BLyS or APRIL could diminish the population of aberrant B cells that contribute to SLE and reduce disease activity in patients. Telitacicept functions by binding to and neutralizing the activities of both BLyS and APRIL, thus hindering the maturation and survival of plasma cells and fully developed B cells. The design of telitacicept is distinctive; it is not a monoclonal antibody but a TACI-Fc fusion protein generated through recombinant DNA technology. This fusion involves merging gene segments of the TACI protein, which can target BLyS/APRIL simultaneously, with the Fc gene segment of the human IgG protein. The TACI-Fc fusion protein exhibits the combined characteristics of both proteins. Currently utilized for autoimmune disease treatment, telitacicept is undergoing clinical investigations globally to assess its efficacy in managing various autoimmune conditions. This review consolidates information on the mechanistic actions, dosing regimens, pharmacokinetics, efficacy, and safety profile of telitacicept-a dual-targeted biological agent. It integrates findings from prior experiments and pharmacokinetic analyses in the treatment of RA and SLE, striving to offer a comprehensive overview of telitacicept's research advancements.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases.

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

MicroRNA-19b exacerbates systemic sclerosis through promoting Th9 cells.

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis of the skin and multiple vital organs, but the immunological pathogenesis of SSc remains unclear. We show here that miR-19b promotes Th9 cells that exacerbate SSc. Specifically, miR-19b and interleukin (IL)-9 increase in CD4+ T cells in experimental SSc in mice induced with bleomycin. Inhibiting miR-19b reduces Th9 cells and ameliorates the disease. Mechanistically, transforming growth factor beta (TGF-ß) plus IL-4 activates pSmad3-Ser213 and TRAF6-K63 ubiquitination by suppressing NLRC3. Activated TRAF6 sequentially promotes TGF-ß-activated kinase 1 (TAK1) and nuclear factor κB (NF-κB) p65 phosphorylation, leading to the upregulation of miR-19b. Notably, miR-19b activated Il9 gene expression by directly suppressing atypical E2F family member E2f8. In patients with SSc, higher levels of IL9 and MIR-19B correlate with worse disease progression. Our findings reveal miR-19b as a key factor in Th9 cell-mediated SSc pathogenesis and should have clinical implications for patients with SSc.

Efficacy of Traditional Chinese Medicine Combined Online Group Psychotherapy (TCM-eRhab) on improving quality of life and relieving psychological burden for colorectal cancer survivors: a study protocol for a phase-II randomized controlled trial.

BACKGROUND: More than 50% of colorectal cancer(CRC) patients experience cancer-related psychological burden after radical surgery, which can seriously affect their physical wellness, quality of life and even survival outcomes. Our research team developed a six-week Traditional Chinese Medicine Combined Online Group Psychotherapy (TCM-eRhab) and proved its efficacy on relieving cancer-related anxiety, depression and fear of cancer recurrence though phase I single arm clinical trial (n = 40). Large sample size randomized controlled clinical trial(RCT) is necessary to further evaluate TCM-eRhab's role on improving quality of life and survival outcomes among this population. METHODS: We design a phase II RCT study, in which 210 CRC patients who have received radical surgery (stage I-III) will be recruited. Eligible patients will be randomly assigned to TCM-eRhab group or usual care group by 2:1 ratio. Patients in the intervention group will receive the structured TCM-eRhab program for six weeks, while patients in control group will receive usual care only. The primary outcomes are quality of life, severity of anxiety, depression and fear of cancer recurrence. Cancer recurrence rate will also be calculated according to long term follow-up data. DISCUSSION: As one of the first RCTs to evaluate the impacts of TCM combined psychological therapy to improve CRC patients' quality of life after surgery, the results from this study will provide innovative knowledge and evidence on integrating TCM into CRC survivorship care and mind-body intervention model.

Allogeneic CD19-targeted CAR-T therapy in patients with severe myositis and systemic sclerosis.

Allogeneic chimeric antigen receptor (CAR)-T cells hold great promise for expanding the accessibility of CAR-T therapy, whereas the risks of allograft rejection have hampered its application. Here, we genetically engineered healthy-donor-derived, CD19-targeting CAR-T cells using CRISPR-Cas9 to address the issue of immune rejection and treated one patient with refractory immune-mediated necrotizing myopathy and two patients with diffuse cutaneous systemic sclerosis with these cells. This study was registered at ClinicalTrials.gov (NCT05859997). The infused cells persisted for over 3 months, achieving complete B cell depletion within 2 weeks of treatment. During the 6-month follow-up, we observed deep remission without cytokine release syndrome or other serious adverse events in all three patients, primarily shown by the significant improvement in the clinical response index scores for the two diseases, respectively, and supported by the observations of reversal of inflammation and fibrosis. Our results demonstrate the high safety and promising immune modulatory effect of the off-the-shelf CAR-T cells in treating severe refractory autoimmune diseases.

Efficacy and safety of culture-expanded mesenchymal stromal cell therapy in the treatment of 4 types of inflammatory arthritis: A systematic review and meta-analysis of 36 randomized controlled trials.

OBJECTIVE: This study aims to assess the effectiveness and safety of mesenchymal stem cell (MSC) transplantation in the treatment of inflammatory arthritis. METHODS: Two researchers conducted a comprehensive search of Chinese and English databases from their inception until July 2023. The literature screening and data extraction were then performed. Statistical analysis was carried out using RevMan 5.4 software. RESULTS: A total of 36 relevant RCTs, involving 2,076 participants, were ultimately included in this study. These RCTs encompassed four types of inflammatory arthritis, namely rheumatoid arthritis (RA), osteoarthritis (OA), ankylosing spondylitis (AS), and systemic sclerosis (SSc). The results demonstrated that MSC therapy exhibited improvements in the Visual Analog Scale (VAS) for pain in OA patients (bone marrow: SMD=-0.95, 95 % CI: -1.55 to -0.36, P = 0.002; umbilical cord: SMD=-2.03, 95 % CI: -2.99 to -1.07, P < 0.0001; adipose tissue: SMD=-1.26, 95 % CI: -1.99 to -0.52, P = 0.0009). Specifically, MSCs sourced from adipose tissue showed enhancements in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain (P = 0.0001), WOMAC physical function (P = 0.001), and total WOMAC scores (P = 0.0003). As for MSC therapy in RA, AS, and SSc, the current systematic review suggests a potential therapeutic effect of MSCs on these inflammatory arthritic conditions. Safety assessments indicated that MSC therapy did not increase the incidence of adverse events. CONCLUSION: MSCs have the potential to alleviate joint pain and improve joint function in patients with inflammatory arthritis. Moreover, MSC therapy appears to be relatively safe and could be considered as a viable alternative treatment option for inflammatory arthritis.

Curcumin attenuates lupus nephritis by inhibiting neutrophil migration via PI3K/AKT/NF-κB signalling pathway.

OBJECTIVE: To investigate the role of curcumin in the treatment of lupus nephritis (LN) by inhibiting the migration of neutrophils and the underlying mechanism involved. METHODS: Two lupus mouse models, MRL/lpr mice and R848-treated mice, were treated with 50 mg/kg curcumin by intraperitoneal injection. H&E and Masson staining were used to estimate histopathological changes in the kidney. Immunofluorescence was used to assess the deposition of immune complexes. The expression of inflammatory factors was detected by enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcription polymerase reaction (RT-PCR), and the protein expression was detected by western blotting. RESULTS: We revealed the remarkable potential of curcumin in improving inflammatory conditions in both MRL/lpr mice and R848-induced lupus mice. Curcumin effectively decelerates the progression of inflammation and diminishes the infiltration of neutrophils and their release of pivotal inflammatory factors, thereby reducing inflammation in renal tissues. Mechanistically, curcumin significantly inhibits the expression of p-PI3K, p-AKT and p-NF-κB, which are upregulated by interleukin-8 to induce neutrophil migration and renal inflammation, thereby reducing neutrophil migration and the release of inflammatory factors. CONCLUSION: Curcumin significantly inhibits the recruitment of neutrophils and the release of proinflammatory factors in the kidney by inhibiting the PI3K/AKT/NF-κB signalling pathway, providing new therapeutic targets and medication strategies for the treatment of LN.

Intra-bone marrow mesenchymal stem cell transplantation modulates myeloid bias tendency of hematopoietic stem and progenitor cells in severe MRL/lpr lupus mice.

The hematopoietic homeostasis in the bone marrow is inextricably intertwined with the immune milieu in peripheral circulation. Researches investigating the pathogenesis of systemic lupus erythematosus (SLE) have defined considerable secretion of inflammatory mediators and activation of pro-inflammatory cells. However, the impacts of "extrinsic" factors on hematopoietic stem and progenitor cells (HSPCs) remain unclear, and it is uncertain whether treatments can help coordinate the biased differentiation. In this study, we showed differences in the proportions of common myeloid progenitors (CMP) and myeloid output in the bone marrow of premorbid and morbid MRL/lpr mice using flow cytometry. RNA-seq analysis of lineage-affiliated transcriptional factors and dysregulated genes within lin- HSPCs revealed inflammation potentiation during disease progression. Further, intra-bone marrow mesenchymal stem cells transplantation (IBM-MSCT) partially coordinated myeloid generation and counteracted lupus-associated inflammation gene alterations, compared to intravenous injection. Additionally, co-culturing with umbilical cord mesenchymal stem cells (UC-MSCs) intervened in myeloid lineage tendency, as detected by RT-qPCR of myeloid-related genes. Our research demonstrated enhanced tendency toward myeloid differentiation and highlighted the feasibility of IBM-MSCT for lineage-biased HSPCs in MRL/lpr lupus model, providing novel insight into hematopoiesis and MSC-related treatments for SLE.

Podophyllotoxin via SIRT1/PPAR /NF-κB axis induced cardiac injury in rats based on the toxicological evidence chain (TEC) concept.

BACKGROUND: The study of cardiotoxicity of drugs has become an important part of clinical safety evaluation of drugs. It is commonly known that podophyllotoxin (PPT) and its many derivatives and congeners are broad-spectrum pharmacologically active substances. Clinical cardiotoxicity of PPT and its derivatives has been raised, basic research on the mechanism of cardiotoxicity remains insufficient. PURPOSE: In present study, our group's innovative concept of toxicological evidence chain (TEC) was applied to reveal the cardiac toxicity mechanism of PPT by targeted metabolomics, TMT-based quantitative proteomics and western blot. METHODS: The injury phenotype evidence (IPE) acquired from the toxicity manifestations, such as weight and behavior observation of Sprague-Dawley rat. The damage to rat hearts were assessed through histopathological examination and myocardial enzymes levels, which were defined as Adverse Outcomes Evidence (AOE). The damage to rat hearts was assessed through histopathological examination and myocardial enzyme levels, which were defined as evidence of adverse outcomes.Overall measurements of targeted metabolomics based on energy metabolism and TMT-based quantitative proteomics were obtained after exposure to PPT to acquire the Toxic Event Evidence (TEE). The mechanism of cardiac toxicity was speculated based on the integrated analysis of targeted metabolomics and TMT-based quantitative proteomics, which was verified by western blot. RESULTS: The results indicated that exposure to PPT could result in significant elevation of myocardial enzymes and pathological alterations in rat hearts. In addition, we found that PPT caused disorders in cardiac energy metabolism, characterized by a decrease in energy metabolism fuels. TMT-based quantitative proteomics revealed that the PPAR (Peroxisome proliferators-activated receptor) signaling pathway needs further study. It is worth noting that PPT may suppress the expression of SIRT1, subsequently inhibiting AMPK, decreasing the expression of PGC-1α, PPARα and PPARγ. This results in disorders of glucose oxidation, glycolysis and ketone body metabolism. Additionally, the increase in the expression of p-IKK and p-IκBα, leads to the nuclear translocation of NF-κB p65 from the cytosol, thus triggering inflammation. CONCLUSION: This study comprehensively evaluated cardiac toxicity of PPT and initially revealed the mechanism of cardiotoxicity,suggesting that PPT induced disorders of energy metabolism and inflammation via SIRT1/PPAR/NF-κB axis, potentially contributing to cardiac injury.

Rapid and Sustained Effect of Ixekizumab on Patient Global, Spinal Pain, Stiffness, and Fatigue in Chinese Patients with Radiographic Axial Spondyloarthritis.

INTRODUCTION: Ixekizumab, an interleukin 17A (IL-17A) inhibitor, has demonstrated rapid and sustained improvement in the signs and symptoms in patients with active radiographic axial spondyloarthritis (r-axSpA) in global and Chinese populations. We studied the effect of ixekizumab on patient-reported outcomes (PROs) (including patient global, spinal pain, stiffness, and fatigue) and overall health-related quality of life (HRQoL) of ixekizumab in the phase 3 study in China. METHODS: In this Chinese phase 3, randomized, double-blind, placebo-controlled study, patients with r-axSpA were randomized (1:1) to receive ixekizumab 80 mg every 4 weeks (IXEQ4W; starting dose 160 mg) or placebo for 16 weeks. At week 16, patients receiving placebo were switched to IXEQ4W, and those receiving IXEQ4W continued, until week 52. Data for patient global, spinal pain, spinal pain at night, stiffness, and fatigue were collected through week 52. Minimally clinical important differences (MCIDs) were determined for spinal pain and spinal pain at night. The subgroup analyses by baseline disease duration since diagnosis and baseline C-reactive protein (CRP) level were conducted post hoc. RESULTS: Compared with placebo, patients treated with IXEQ4W reported significantly greater improvement with a rapid onset in changes from baseline of PROs (patient global, spinal pain, spinal pain at night, stiffness, and fatigue) through week 16. Improvements were maintained through week 52. A similar trend of improvement was also observed in MCID response in spinal pain and spinal pain at night. The improvement in overall HRQoL was supported by EQ-5D-5L assessment. Subgroup analyses demonstrated that IXEQ4W provided significantly greater efficacy at week 16 compared with placebo, irrespective of baseline disease duration or baseline CRP level. CONCLUSION: IXEQ4W provided rapid and sustained improvement in clinically relevant PROs and overall HRQoL through 1-year treatment in Chinese patients with r-axSpA. Regardless of the baseline disease duration or baseline CRP level, consistent efficacy was observed. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04285229.

Artesunate alleviates Sjögren's Syndrome by inhibiting the interferon-α signaling in plasmacytoid dendritic cells via TLR-MyD88-IRF7.

Sjögren's syndrome (SS) is an autoimmune disease in which the salivary glands (SGs) and the lacrimal glands (LGs) are affected by lymphocytic infiltration and inflammation. It has been reported that interferon-α (IFN-α) released by plasmacytoid dendritic cells (pDCs) contribute to the pathology of SS, and ART has been shown to effectively ameliorates SS. Despite the current research endeavors, the mechanism of how ART works in the treatment of SS remains to be fully elucidated. Whether ART can treat SS by inhibiting IFN-α remains unclear. This hypothesis was tested both in vivo and in vitro settings during the study. The SS model mice, which were treated with ART, showed amelioration in symptoms related to dryness. RNA-seq analysis revealed strong anti-IFN-α signaling response upon ART treatment. Additional in vitro studies provided further confirmation that the application of ART inhibits the MyD88 protein expression and the nuclear translocation of IRF7. This suggests that the intervention of ART in the TLR-MyD88-IRF7 pathway plays a role in the therapeutic approach for SS. In summary, this study highlighted the therapeutic potential of ART in SS and ART inhibited the IFN-α signaling in pDCs via the TLR-MyD88-IRF7 pathway.

Viral Mimicking Polyplexes as Hierarchical Unpacking Vectors for Rheumatoid Arthritis Treatment.

Nano-delivery systems hold great promise for the treatment of rheumatoid arthritis (RA). Current research efforts are primarily focused on enhancing their targeting capabilities and efficacy. Here, this study proposes a novel viral-mimicking ternary polyplexes system for the controlled delivery of the anti-inflammatory drug Cyclosporin A (CsA) to effectively treat RA. The ternary polyplexes consist of a nanogel core loaded with CsA and a hyaluronic acid shell, which facilitates CD44-mediated targeting. By mimicking the Trojan Horse strategy employed by viruses, these polyplexes undergo a stepwise process of deshielding and disintegration within the inflamed joints. This process leads to the release of CsA within the cells and the scavenging of pathogenic factors. This study demonstrates that these viral-mimicking ternary polyplexes exhibit rapid targeting, high accumulation, and prolonged persistence in the joints of RA mice. As a result, they effectively reduce inflammation and alleviate symptoms. These results highlight the potential of viral-mimicking ternary polyplexes as a promising therapeutic approach for the targeted and programmed delivery of drugs to treat not only RA but also other autoimmune diseases.

Efficacy and safety of inactivated SARS-CoV-2 vaccination in COVID-19-associated pneumonia among patients with rheumatic and musculoskeletal diseases: A real-world retrospective observational study.

OBJECTIVES: To identify the effectiveness and safety of inactivated SARS-CoV-2 vaccines in rheumatic and musculoskeletal diseases (RMDs) patients. METHODS: RMD patients with COVID-19 in Jiangsu Province were polled between December 8, 2022, and February 1, 2023. Information on demographics, disease characteristics, antirheumatic drug use, vaccination status and survival state were collected. COVID-19-associated pneumonia was the primary outcome. The effect of COVID-19 immunization on RMD patients was assessed using multivariate logistic regression, and the adverse events (AEs) following vaccination were evaluated. RESULTS: Among 592 RMD patients with COVID-19, 276 (46.6%) individuals experienced COVID-19-associated pneumonia, and 290 (49.0%) patients were injected with inactivated vaccines. In multivariate logistic regression analysis, vaccines reduced the incidence of COVID-19-associated pneumonia, and receiving booster vaccine was an independent protective factor for COVID-19-associated pneumonia in RMD patients (OR 0.64, 95% CI 0.41-0.98, p = .034). In particular, inactivated vaccines have a protective impact on RMD patients with a high risk of developing pneumonia, including those aged 45 years and older (OR 0.53, 95% CI 0.34-0.83), and who have lung involvement (OR 0.43, 95% CI 0.23-0.82). The total AEs rate of vaccines was 13.9% (40/290), only 11 (3.8%) experienced the recurrence or deterioration of RMDs, and no serious AEs occurred. CONCLUSION: Inactivated COVID-19 vaccines were safe and effective in reducing the risk of COVID-19-associated pneumonia of RMD patients in China.

Characterization of lipids and volatile compounds in boiled donkey meat by lipidomics and volatilomics.

Lipids are crucial substances for the formation and retention of volatile compounds (VOCs). The lipid and VOC profiles of boiled donkey meat were investigated by lipidomics and volatilomics. In total, 4277 lipids belonging to 39 subclasses were identified, comprising 26.93% triglycerides (TGs), 15.74% phosphatidylcholins (PCs), and 9.40% phosphatidylethanolamines. The relative percentage of TG in the meat significantly decreases (p < 0.001) from 0 to 40 min, after which there is no significant change, whereas PCs, sphingomyelins, and methyl phosphatidylcholines (MePCs) show the opposite trend. TG(16:1_18:1_18:2) and TG(16:0_16:1_18:2) appear to be key lipids for retaining VOCs in boiled donkey meat. Furthermore, PC(18:3e_16:0) and MePC(31:0e) were found to be potential markers for discriminating donkey meat. A total of 83 VOCs were detected, including 25.30% aldehydes, 18.07% hydrocarbons, 14.46% ketones, and 13.25% alcohols. Eleven characteristic VOCs with relative odor activity values >1 were identified as the predominant flavor compounds in boiled donkey meat, mainly hexanal and 1-octen-3-ol. Of the 258 differential lipids, 72 of them, especially polyunsaturated-fatty acid-rich lipids, are the main contributors to the formation of VOCs. Together, the key lipids for retention and formation of VOCs in donkey meat were revealed, providing a theoretical basis for VOC regulation.

Risk factors for initial and recurrent severe infections in first hospitalized patients with systemic lupus erythematosus: A retrospective study of a Chinese cohort.

OBJECTIVE: To evaluate the incidence and associated factors of initial and recurrent severe infections in hospitalized patients with systemic lupus erythematosus (SLE). METHODS: SLE patients that first hospitalized between 2010 and 2021 were studied retrospectively and divided into SLE with and without baseline severe infection groups. The primary outcome was the occurrence of severe infection during follow-up. Cox regression models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for initial and recurrent severe infections. RESULTS: Among 1051 first hospitalized SLE patients, 164 (15.6%) had severe infection on admission. During a median follow-up of 4.1 years, 113 (10.8%) patients reached severe infection outcomes, including 27 with reinfection and 86 with initial severe infection (16.5% vs. 9.7%, p = .010). Patients with baseline severe infection had a higher cumulative incidence of reinfection (p = .007). After adjusting for confounding factors, renal involvement, elevated serum creatinine, hypoalbuminemia, cyclophosphamide, and mycophenolate mofetil treatment were associated with an increased risk of severe infection, especially initial severe infection. Low immunoglobulin, anti-dsDNA antibody positivity, and cyclophosphamide use significantly increased the risk of recurrent severe infection, with adjusted HR (95% CI) of 3.15 (1.22, 8.14), 3.60 (1.56, 8.28), and 2.14 (1.01, 5.76), respectively. Moreover, baseline severe infection and low immunoglobulin had a multiplicative interaction on reinfection, with adjusted RHR (95% CI) of 3.91 (1.27, 12.09). CONCLUSION: In this cohort of SLE, patients with severe infection had a higher risk of reinfection, and low immunoglobulin, anti-dsDNA antibody positivity, and cyclophosphamide use were independent risk factors for recurrent severe infection.

Mesenchymal Stem Cells Regulate Microglial Polarization via Inhibition of the HMGB1/TLR4 Signaling Pathway in Diabetic Retinopathy.

Diabetic retinopathy (DR) is recognized as the most prevalent retinal degenerative disorder. Inflammatory response usually precedes microvascular alteration and is the primary factor of diabetic retinopathy. Activated microglia express many pro-inflammatory cytokines that exacerbate retina inflammation and disruption. In the present study, we found that MSCs alleviated blood-retina barrier (BRB) breakdown in diabetic rats, as evidenced by reduced retinal edema, decreased vascular leakage, and increased occludin expression. The MSC-treated retinal microglia exhibited reduced expression of M1-phenotype markers in the diabetic rats, including inducible nitric oxide synthase (iNOS), CD16, and pro-inflammatory cytokines. On the other hand, MSCs increased the expression of M2-phenotype markers, such as arginase-1 (Arg-1), CD206, and anti-inflammatory cytokines. HMGB1/TLR4 signaling pathway is activated in DR and inhibited after MSC treatment. Consistent with in vivo evidence, MSCs drove BV2 microglia toward M2 phenotype in vitro. Overexpression of HMGB1 in microglia reversed the effects of MSC treatment, suggesting HMGB1/TLR4 pathway is necessary for MSCs' regulatory effects on microglia polarization. Collectively, MSCs exert beneficial effects on DR by polarizing microglia from M1 toward M2 phenotype via inhibiting the HMGB1/TLR4 signaling pathway.

Microglia orchestrate synaptic and neuronal stripping: Implication in neuropsychiatric lupus.

Systemic lupus erythematosus (SLE), a multifactorial autoimmune disease, can affect the brain and cause neuropsychiatric dysfunction, also named neuropsychiatric lupus (NPSLE). Microglial activation is observed in NPSLE patients. However, the mechanisms regulating microglia-mediated neurotoxicity in NPSLE remain elusive. Here, we showed that M1-like proinflammatory cytokine levels were increased in the cerebrospinal fluid (CSF) of SLE patients, especially those with neuropsychiatric symptoms. We also demonstrated that MRL/lpr lupus mice developed anxiety-like behaviours and cognitive deficits in the early and active phases of lupus, respectively. An increase in microglial number was associated with upregulation of proinflammatory cytokines in the MRL/lpr mouse brain. RNA sequencing revealed that genes associated with phagocytosis and M1 polarization were upregulated in microglia from lupus mice. Functionally, activated microglia induced synaptic stripping in vivo and promoted neuronal death in vitro. Finally, tofacitinib ameliorated neuropsychiatric disorders in MRL/lpr mice, as evidenced by reductions in microglial number and synaptic/neuronal loss and alleviation of behavioural abnormalities. Thus, our results indicated that classically activated (M1) microglia play a crucial role in NPSLE pathogenesis. Minocycline and tofacitinib were found to alleviate NPSLE by inhibiting micrglial activation, providing a promising therapeutic strategy.

Phosphatidic Acid Promoting the Generation of Interleukin-17A Producing Double-Negative T Cells by Enhancing mTORC1 Signaling in Lupus.

OBJECTIVE: The goal was to investigate the role and intracellular regulatory mechanisms of double-negative T (DNT) cells in the pathogenesis of systemic lupus erythematosus (SLE). METHODS: DNT cells were assessed in murine models, patients with SLE, and controls using flow cytometry (FCM). DNT cells from either resiquimod (R848) or vehicle-treated C57BL/6 (B6) mice were cultured with B cells from R848-treated mice to explore functions. Differential mechanistic target of rapamycin (mTOR) pathway signaling in DNT cells measured using FCM and quantitative polymerase chain reaction was validated by rapamycin inhibition. Candidate lipid metabolites detected using liquid chromatography with electrospray ionization mass spectrometry/mass spectrometry were functionally assessed in DNT cell cultures. RESULTS: DNT cells were markedly increased in both spontaneous and induced mouse lupus models and in patients with SLE. Expanded DNT cells from R848-treated B6 mice produced elevated interleukin (IL)-17A and IgG with increased germinal center B (GCB) cells. Expansion of DNT cells associated with activation of mTORC1 pathway that both IL-17A levels and the number of DNT cells exhibited dose-dependent reduction with rapamycin treatment. Lipidomics studies revealed differential patterns of lipid metabolites in T cells of R848-treated mice. Among candidate metabolites, elevated phosphatidic acid (PA) that was partially controlled by phospholipase D2 increased the expression of the mTORC1 downstream target p-S6 and positively expanded IL-17A-producing DNT cells. Similarly, elevated proportions of circulating DNT cells in patients with SLE correlated with disease activity and proteinuria, and IL-17A secretion was elevated after in vitro PA stimulation. CONCLUSION: The accumulation of PA in T cells could activate the mTORC1 pathway, promoting DNT cell expansion and IL-17A secretion, resulting in GCB cell abnormalities in lupus.