Single center clinical analysis of macrophage activation syndrome complicating juvenile rheumatic diseases.

BACKGROUND: Macrophage activation syndrome (MAS), an example of secondary hemophagocytic lymphohistiocytosis, is a potentially fatal complication of rheumatic diseases. We aimed to study the clinical and laboratory characteristics, treatment schemes, and outcomes of different rheumatic disorders associated with MAS in children. Early warning indicators of MAS have also been investigated to enable clinicians to make a prompt and accurate diagnosis. METHODS: Fifty-five patients with rheumatic diseases complicated by MAS were enrolled between January 2017 and December 2022. Clinical and laboratory data were collected before disease onset, at diagnosis, and after treatment with MAS, and data were compared between patients with systemic juvenile idiopathic arthritis (sJIA), Kawasaki disease (KD), and systemic lupus erythematosus (SLE). A random forest model was established to show the importance score of each variable with a significant difference. RESULTS: Most (81.8%) instances of MAS occurred during the initial diagnosis of the underlying disease. Compared to the active stage of sJIA, the platelet count, erythrocyte sedimentation rate, and fibrinogen level in sJIA-MAS were significantly decreased, whereas ferritin, ferritin/erythrocyte sedimentation rate, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and D-dimer levels were significantly increased. Ferritin level, ferritin/erythrocyte sedimentation rate, and platelet count had the greatest predictive value for sJIA-MAS. The level of IL-18 in the sJIA-MAS group was significantly higher than in the active sJIA group, whereas IL-6 levels were significantly lower. Most patients with MAS were treated with methylprednisolone pulse combined with cyclosporine, and no deaths occurred. CONCLUSIONS: Thrombocytopenia, ferritin levels, the ferritin/erythrocyte sedimentation rate, and elevated aspartate aminotransferase levels can predict the occurrence of MAS in patients with sJIA. Additionally, our analysis indicates that IL-18 plays an important role in the pathogenesis of MAS in sJIA-MAS.

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis, the first Chinese experience.

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as fever, rash, and organ involvement. Anti-IL-6 receptor monoclonal antibody tocilizumab is an effective treatment. However, some patients still experience persisting or recurrent symptoms and the real-world effectiveness of canakinumab in Chinese patients with sJIA has never been reported. Therefore, this study aimed to assess the efficacy and safety of canakinumab in Chinese patients with sJIA using real-world data. METHODS: We conducted a retrospective study on children with active sJIA. Clinical features, laboratory data, corticosteroid dosage, and adverse events (AEs) were collected at baseline and at 4, 8, 12, and 24 weeks after initiating canakinumab treatment. RESULTS: Seven female and four male patients were included in the study. All patients had previously been treated with tocilizumab and were administered canakinumab for 12.4 ± 3.4 months. Notably, significant improvements were observed in both clinical signs and symptoms as well as laboratory indicators. Four children under corticosteroid treatment were able to successfully discontinue their corticosteroid therapy: one at week 4, two at week 12, and one at week 24. Notably, there was a significant reduction in the number of tender and swollen joints (P = 0.0059) as well as the systemic juvenile arthritis disease activity score (P < 0.0001). The most common AE was infection, but no patients experienced serious AEs. No cases of macrophage activation syndrome or death were reported during the follow-up period. CONCLUSIONS: Canakinumab was found to be potentially efficacious and safe in Chinese patients with sJIA. No new AEs were observed with canakinumab treatment.

A retrospective study of infantile-onset Takayasu arteritis: experience from a tertiary referral center in China.

Objective: Takayasu artery (TAK) is a chronic inflammatory disease that mainly affects the aorta and its major branches and is rarely reported in infants. We aimed to summarize the clinical features of infant TA (I-TA) in a tertiary care center. Methods: We performed a retrospective study involving 10 infants diagnosed with TAK. A comprehensive evaluation of clinical, laboratory, radiographic features, disease activity, treatment and outcomes was carried out. Results: A consecutive cohort was composed of 8 girls and 2 boys, with an age at diagnosis of 11.1 (1.7-36) months. The median time to diagnosis and the average time to follow-up were 9.5 days (2-235 days) and 10.9 (1-21) months, respectively. The most common initial manifestations were malaise (80%), fever (70%), hypertension (50%) and rash (30%). The mean Pediatric Vasculitis Activity Score (PVAS), Takayasu Clinical Activity Score (ITAS-2010) and ITAS-A scores were 2.8/63, 2.6/51, and 5.6/54, respectively. All patients had aberrant laboratory parameters. The most common lesions were in the thoracic aorta (60%) and abdominal aorta (60%). Corticosteroids combined with cyclophosphamide followed by long-term mycophenolate mofetil were initiated in most cases (70%). Biologics were attempted in 5 cases. Mortality was 40%. Conclusions: It is challenging to diagnose TAK in infants in a timely manner. Considering the more vessels involved, more severe inflammation and higher mortality, aggressive treatment is warranted in infants. GCs and CYC treatment seem to be effective.

Long non-coding RNA ENSMUST00000197208 promotes a shift in the Th17/Treg ratio via the P2X7R-NLRP3 inflammasome axis in collagen-induced arthritis.

Recently, long non­coding RNAs (lncRNAs) have been implicated in several human diseases, including arthritis. However, the role of lncRNAs in regulating the Th17/Treg ratio during the progression of collagen-induced arthritis (CIA) is poorly understood. Therefore, the aim of this study was to determine the role of the lncRNA ENSMUST00000197208 and the P2X7R-NLRP3 inflammasome axis in changes in the Th17/Treg ratio in CIA. To achieve this, the distribution of T cell subgroups in the spleen cells of a CIA mouse model and control mice was examined. Additionally, we examined the expression profile of ENSMUST00000197208 in a CIA mouse model and healthy mice. The results showed that ENSMUST00000197208 expression was significantly upregulated in the CIA models compared with the control group. Additionally, the P2X7R-NLRP3 inflammasome axis participated in the pathogenesis of CIA and knockdown of ENSMUST00000197208 inhibited CD4+ T cell differentiation into Th17 cells. Compared with the control group, joint inflammation was less visible in NLRP3 knockout mice. Additionally, the P2X7R-NLRP3 inflammasome axis, which is downstream of ENSMUST00000197208, can be positively targeted and regulated by ENSMUST00000197208 through miR-107. Overall, the findings of this study showed that the "lncRNA ENSMUST00000197208-miR 107-P2X7R/NLRP3" axis plays an important role in CIA and knocking down ENSMUST00000197208 can efficiently inhibit Th17 differentiation by suppressing the P2X7R-NLRP3 inflammasome axis. Therefore, targeting this axis may represent a novel strategy for arthritis treatment.

tRF-21-LNK8KEP1B as a potential novel diagnostic biomarker for enthesitis-related arthritis.

OBJECTIVE: tRNA-derived fragments (tRFs) play crucial roles in the progression of various diseases, and widely distribute in human tissues, including blood and urine. The diagnosis of enthesitis-related arthritis (ERA) is based on the observation of clinical manifestations. Therefore, we aimed to investigate whether serum tRFs can be used as diagnostic markers for ERA. METHODS: Serum was collected from children admitted to the Children's Hospital Affiliated with Nanjing Medical University between February 2022 to October 2022. The expression profiles of tRFs in the serum of ERA patients (n = 5) and healthy controls (HCs; n = 5) were investigated using small RNA high-throughput sequencing. The level and diagnostic value of tRF-21-LNK8KEP1B were evaluated by real-time quantitative PCR in serum samples from 30 ERA patients and 31 HCs. The specificity and sensitivity of tRFs were determined using receiver operating characteristic analyses. Bioinformatics analysis was performed to explore and identify the potential biological pathways induced by tRFs. RESULTS: Ninety-eight upregulated and 63 downregulated tRFs were identified in the serum. We selected tRF-21-LNK8KEP1B as a candidate marker using KEGG pathway enrichment and PCR validation. tRF-21-LNK8KEP1B was substantially increased in the serum of ERA patients compared with that in HCs. The area under the curve (AUC) for tRF-21-LNK8KEP1B in the ERA group was 0.7849. CONCLUSIONS: Collectively, we demonstrated the promising role of serum tRF-21-LNK8KEP1B -levels as a diagnostic biomarker for ERA.

Novel Predictive Scoring System for Intravenous Immunoglobulin Resistance Helps Timely Intervention in Kawasaki Disease: The Chinese Experience.

Background: Approximately 10%-20% of patients with Kawasaki disease (KD) are nonresponsive to intravenous immunoglobulin (IVIG) treatment, placing them at higher risk of developing coronary heart lesions. Early detection of nonresponsiveness is crucial to curtail this risk; however, the applicability of existing predictive scoring systems is limited to the Japanese population. Our study aimed to identify a predictive scoring system for IVIG resistance in KD specific to the Chinese population. We aimed to assess the utility of three commonly used risk-scoring systems in predicting IVIG resistance and compare them to the newly developed predictive scoring system. Methods: A total of 895 patients with KD were enrolled in this retrospective review and divided into two groups: IVIG responders and nonresponders. Clinical and laboratory variables were compared between the two groups. Multivariable logistic regression models were used to construct a new scoring system. The utility of the existing and new scoring systems was assessed and compared using the area under the receiver operating characteristic curve. Results: Albumin levels, percentage of neutrophils, and hemoglobin were independent predictors of resistance by logistic regression analysis. The new predictive scoring system was derived with improved sensitivity (60.5%) and specificity (87.8%). The area under the receiver operating characteristic curve was 0.818. Conclusion: This study developed a novel risk-scoring system for predicting resistance to IVIG treatment in KD specific to the Chinese population. Although this new model requires further validation, it may be useful for improving prognostic outcomes and reducing the risk of complications associated with KD.

Evaluation of belimumab in treatment of Chinese childhood-onset systemic lupus erythematosus: a prospective analysis from multicenter study.

OBJECTIVE: The aim of this study is to identify whether low lupus disease activity status (LLDAS) and clinical remission (CR) of belimumab plus standard of care (SoC) therapy are achievable goals in childhood-onset SLE (cSLE). METHODS: This multicentre, one arm pre-post intervention study was conducted at 15 centers in China. The primary end point was to describe the proportion of patients who achieved LLDAS and CR after 3, 6, and 12 months after treatment with belimumab plus SoC therapy. A multiple regression model was used to impute missing data. A Poisson regression model was used to calculate the effect of belimumab treatment on the reduced risk of serious diseases and the incidence of new damage. RESULT: 193 (92.2% female) with active cSLE from 15 centers were included. At 3, 6 and 12 months, the proportion of LLDAS (CR) was 12.4% (1.0%), 25.6% (4.5%) and 70.3% (29.7%), respectively. The mean SELENA-SLEDAI score decreased from 11.0 at baseline to 3.7, 2.9 and 1.7 at 3, 6, and 12 months. At baseline, all patients received steroids at a mean (SD) prednisone equivalent dose of 31.0 (18.2) mg/day, which decreased to 19.4 (10.8) mg/day at month 3, 12.6 (7.2) mg/day at month 6 and 6.7 (5.3) mg/day at month 12. The symptoms and immunological indicators were also significantly improved. CONCLUSION: This is the first and largest sample size prospective clinical intervention study of cSLE patients treated with belimumab in China. LLDAS and CR were attainable treat-to-target of belimumab plus SoC therapy in cSLE.

Effectiveness of tumor necrosis factor inhibitors in children with enthesitis-related arthritis: a single-center retrospective analysis.

Objective: In children with enthesitis-related arthritis (ERA), the hip and sacroiliac joint function might be impaired if not properly treated. We sought to evaluate the effectiveness of anti-tumor necrosis factor-α (TNF-α) therapy using the inflammatory indicators, Juvenile Arthritis Disease Activity Score 27 (JADAS27) and magnetic resonance imaging (MRI). Methods: We conducted a single-center retrospective study of 134 patients with ERA. We evaluated the effect of anti-TNF therapy on the inflammatory indicators, active joint count, MRI quantitative score, and JADAS27 over 18 months. We used the Spondyloarthritis Research Consortium of Canada (SPARCC) and the Hip Inflammation MRI Scoring System (HIMRISS) scoring systems for hip and sacroiliac joints scoring. Results: The average age of onset of children with ERA was 11.62 ± 1.95 years, and they were treated with disease-modifying antirheumatic drugs (DMARDs) combined with biologics (n = 87, 64.93%). There were no differences in HLA-B27 positivity between the biologics and non-biologics treatment groups [66 (49.25%) vs. 68 (50.75%), P > 0.05]. Children who received anti-TNF (71 received etanercept, 13 adalimumab, 2 golimumab, and 1 infliximab) therapy improved significantly. Children with ERA used DMARDs and biologics at baseline (Group A) were followed up to 18 months, and their active joint count (4.29 ± 1.99 vs. 0.76 ± 1.33, P = 0.000), JADAS27 (13.70 ± 4.80 vs. 4.53 ± 4.52, P = 0.000) and MRI quantitative scores (P = 0.001) were significantly lower than those at baseline. Some of the patients (n = 13, 9.70%) were treated with DMARDs at the onset of the disease, but did not show significant improvement (Group B). After 6-18 months of switching to anti-TNF therapy, related indicators of the children were significantly lower than at baseline and 1 month (P < 0.013). At 18 months, a total of 33 patients (n = 74, 44.59%) in Group A and 7 (n = 13, 53.85%) in Group B reached inactive state. Conclusion: Eighteen months after diagnosis, anti-TNF therapy was found to be effective in children diagnosed with ERA. MRI is important for the early diagnosis of juvenile idiopathic arthritis. TNF-α inhibitors can significantly improve the clinical manifestations of sacroiliac joint and hip involvement in patients with ERA. Overall, the real-world study provides more evidence for precision diagnosis and treatment for other hospitals, families and patients.

Purine metabolites promote ectopic new bone formation in ankylosing spondylitis.

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease that mainly affects the axial skeleton, whose typical features are inflammatory back pain, bone structural damage and pathological new bone formation. The pathology of ectopic new bone formation is still little known. In this study, we found increased purine metabolites in plasma of patients with AS. Similarly, metabolome analysis indicated increased purine metabolites in both serum of CD4-Cre; Ptpn11fl/fl and SHP2-deficient chondrocytes. SHP2-deficient chondrocytes promoted the growth of wild type chondrocytes and differentiation of osteoblasts in CD4-Cre; Ptpn11fl/fl mice, which spontaneously developed AS-like bone disease. Purine metabolites, along with PTHrP derived from SHP2-deficient chondrocytes, accelerated the growth of chondrocytes and ectopic new bone formation through PKA/CREB signaling. Moreover, Suramin, a purinergic receptor antagonist, suppressed pathological new bone formation in AS-like bone disease. Overall, these results highlight the potential role of targeting purinergic signaling in retarding ectopic new bone formation in AS.

Axial involvement in enthesitis-related arthritis: results from a single-center cohort.

BACKGROUND: Axial involvement in children with enthesitis-related arthritis (ERA) has characteristics that differ from those of peripheral involvement. This study characterized their clinical characteristics and treatment. METHODS: Patients with ERA at the Children's Hospital of Nanjing Medical University between January 2018 and December 2020 were included. The ERA cohort was divided into two based on the presence or absence of axial joint involvement. Demographic characteristics, clinical features, and treatments were described and compared. RESULTS: In total, 105 children with ERA were enrolled (axial ERA, n = 57; peripheral ERA, n = 48). The age at disease onset of the axial group tended to be higher (11.93 ± 1.72 vs. 11.09 ± 1.91 years) and the diagnosis delay was bigger in patients with axial ERA (10.26 ± 11.66 months vs. 5.13 ± 7.92 months). The inflammatory marker levels were significantly higher in patients with axial. There were no differences in HLA-B27 positivity between the groups (34 [59.65%] vs. 28 [58.33%], P > 0.05). Hip involvement was more frequent in the axial group (52.63% vs 27.08%; X2 = 7.033). A total of 38 (66.67%) and 10 (20.83%) patients with axial and peripheral ERA, respectively, were treated with biological disease-modifying anti-rheumatic drugs (DMARDs) at diagnosis. The administration of biologics increased gradually in the axial ERA group, peaking at 18 months and decreasing thereafter, whereas that in the peripheral ERA group peaked at 6 months and began to decline thereafter. CONCLUSIONS: Axial ERA is a persistent active disease and requires a more aggressive treatment. Classification and early recognition of axial involvement may help with timely diagnosis and appropriate management.

Inositol-Triphosphate 3-Kinase C and DNA Methylation Involvement in NLRP3 Inflammasome Activation in Kawasaki Disease.

OBJECTIVE: To evaluate ITPKC and NLRP3 expression in children with Kawasaki disease (KD) and investigate the relationship between serum pro-inflammatory cytokines triggered by NLRP3 and inflammatory indices. Simultaneously, the methylation level in the ITPKC promoter was evaluated in children with KD. METHODS: Children who satisfied the American Heart Association diagnostic criteria for KD were enrolled in the study from August 2018 to January 2019. The levels of ITPKC, NLRP3, IL-1ß, and IL-18 were measured. The effect of DNA methylation on the activity of the ITPKC promoter was observed. Methylation-specific PCR was used to verify methylation modification of the ITPKC promoter region in children with KD. RESULTS: ITPKC expression was downregulated in patients with KD, whereas NLRP3 was upregulated. Expression of the downstream cytokine, IL-18, was significantly upregulated in children with KD and correlated positively with inflammatory indices. Modifying DNA methylation significantly decreased the luciferase activity of the plasmid containing the ITPKC promoter region and thus, may inhibit ITPKC gene promoter activity. Furthermore, methylation modification was observed in the ITPKC promoter region of children with KD. CONCLUSION: Modification of DNA methylation inhibits ITPKC promoter activity and is involved in NLRP3 inflammasome activation in children with KD.

Case report: A STAT1 gain-of-function mutation causes a syndrome of combined immunodeficiency, autoimmunity and pure red cell aplasia.

Inherited autosomal dominant gain-of-function (GOF) mutations of signal transducer and activator of transcription 1 (STAT1) cause a wide range of symptoms affecting multiple systems, including chronic mucocutaneous candidiasis (CMC), infections, and autoimmune disorders. We describe a rare case of STAT1 mutation with recurrent CMC, lung infections, and anemia. According to the whole-exome sequencing (WES), the patient was genetically mutated in STAT1 GOF (c.854A>G, p.Q285R), and bone marrow biopsy suggested pure red cell aplasia (PRCA). As a functional verification, STAT1 levels and phosphorylation (p-STAT1) of peripheral blood mononuclear cells (PBMCs) following IFN-γ stimulation in STAT1 GOF patient was higher than in the healthy control. Combination therapy of blood transfusion, antimicrobials, intravenous immunoglobulin, methylprednisolone, and the Janus Kinase (JAK) specific inhibitor ruxolitinib was used during treatment of patients. The patient also received a hematopoietic stem cell transplant (HSCT) to help with infections and anemia. This is the first reported case of STAT1 GOF disease complicated with PRCA. This complication might be attributed to immune disorders caused by STAT1 GOF. Furthermore, ruxolitinib may be a viable therapeutic option before HSCT to improve disease management.

Identifying a novel KLF2/lncRNA SNHG12/miR-494-3p/RAD23B axis in Spare Nerve Injury-induced neuropathic pain.

Spinal cord injury (SCI) is a devastating condition for patients, affecting nearly 2.5 million people globally. Multiple side effects of SCI have resulted in a terrible life experience for SCI patients, of which neuropathic pain has attracted the most scientific interest. Even though many efforts have been made to attenuate or eliminate neuropathic pain induced by SCI, the outcomes for patients are still poor. Therefore, identifying novel diagnosis or therapeutic targets of SCI-induced neuropathic pain is urgently needed. Recently, multiple functions of long non-coding RNA (lncRNA) have been elucidated, including those in SCI-induced neuropathic pain. In this study, lncRNA small nucleolar RNA host gene 12 (SNHG12) was found to be upregulated in the dorsal root ganglion (DRGs) of rats with spare nerve injury (SNI). By constructing SCI rat models, we found that lncRNA SNHG12 expression was increased in the DRGs, and mainly distributed in the cytoplasm of PC12 cells. Paw withdrawal threshold (PWT), paw withdrawal latency (PWL), and enzyme linked immunosorbent assay (ELISA) results indicated that lncRNA SNHG12 knockdown attenuated SNI-induced neuropathic pain, and decreased the expression levels of interleukin (IL)-1ß, IL-6, and tumour necrosis factor α (TNF-α) in the DRGs. Bioinformatics analysis, RNA pull-down, chromatin immunoprecipitation (ChIP), and luciferase reporter gene assays showed that lncRNA SNHG12 regulates the RAD23 homologue B, nucleotide excision repair protein (RAD23B) expression, through targeting micro RNA (miR)-494-3p. Furthermore, the study indicated that Kruppel-Like Factor 2 (KLF2) could regulate lncRNA SNHG12 expression in PC12 cells. This study identified a novel KLF2/lncRNA SNHG12/miR-494-3p/RAD23B axis in SNI-induced neuropathic pain, which might provide a new insight for developing novel diagnosis, or therapeutic targets of SCI-induced neuropathic pain in the future.

Targeting chondrocytes for arresting bony fusion in ankylosing spondylitis.

Bony fusion caused by pathological new bone formation manifests the clinical feature of ankylosing spondylitis (AS). However, the underlying mechanism remains elusive. Here we discovered spontaneous kyphosis, arthritis and bony fusion in mature CD4-Cre;Ptpn11f/f mice, which present the pathophysiological features of AS. A population of CD4-Cre-expressing proliferating chondrocytes was SHP2 deficient, which could differentiate into pre-hypertrophic and hypertrophic chondrocytes. Functionally, SHP2 deficiency in chondrocytes impeded the fusion of epiphyseal plate and promoted chondrogenesis in joint cavity and enthesis. Mechanistically, aberrant chondrocytes promoted ectopic new bone formation through BMP6/pSmad1/5 signaling. It is worth emphasizing that such pathological thickness of growth plates was evident in adolescent humans with enthesitis-related arthritis, which could progress to AS in adulthood. Targeting dysfunctional chondrogenesis with Smo inhibitor sonidegib significantly alleviated the AS-like bone disease in mice. These findings suggest that blockade of chondrogenesis by sonidegib would be a drug repurposing strategy for AS treatment.

Kikuchi-Fujimoto Disease With Encephalopathy in Children: Case Reports and Literature Review.

Background: Kikuchi-Fujimoto disease (KFD) is a benign and self-limiting disease characterized by regional lymphadenitis and low-grade fever. Encephalopathy may present in children with KFD. We present three cases of KFD with encephalopathy in children and a literature review. Methods: Literature published between 2010 and 2020 was reviewed to understand the clinical features, laboratory findings, and treatments for encephalopathy occurring in children with KFD. Results: The interval between KFD and onset of neurological symptoms was 10 days to 3 months. Laboratory results were normal, except for high protein levels in cerebrospinal fluid findings. Brain magnetic resonance imaging (MRI) findings include hyperintense T2 and FLAIR signal in the supratentorial white matter, deep gray matter, brain stem, cerebellum, temporal lobes, pons, and basal ganglia. Glucocorticoids and immunoglobulin could be effective for treating KFD with encephalopathy. Conclusion: The early clinical manifestations of KFD with encephalopathy in children lack specificity, and the diagnosis is mainly based on CSF analysis and brain MRI findings. Early and timely immunomodulatory therapy is effective and can improve the prognosis of patients with KFD with encephalopathy.

Involvement of TFAP2A in the activation of GSDMD gene promoter in hyperoxia-induced ALI.

Oxygen therapy is a common treatment in neonatal intensive care units, but long-term continuous hyperoxia ventilation may induce acute lung injury (ALI). Gasdermin D (GSDMD)-mediated pyroptosis participates in various diseases including ALI, but the role of GSDMD in hyperoxia-induced ALI is yet understood. Here, we showed a significant increase in GSDMD after exposure to high oxygen. To elucidate the molecular mechanisms involved in GSDMD regulation, we identified the core promoter of GSDMD, -98 ~ -12 bp relative to the transcriptional start site (TSS). The results of mutational analysis, overexpression or siRNA interference, EMSA and ChIP demonstrated that E2F4 and TFAP2A positively regulate the transcriptional activity of the GSDMD by binding to its promoter. However, only TFAP2A showed a regulatory effect on the expression of GSDMD. Moreover, TFAP2A was increased in the lung tissues of rats exposed to hyperoxia and showed a strong linear correlation with GSDMD. Our results indicated that TFAP2A positively regulates the GSDMD expression via binding to the promoter region of GSDMD.

Long non­coding RNA RP11­340F14.6 promotes a shift in the Th17/Treg ratio by binding with P2X7R in juvenile idiopathic arthritis.

Long non­coding RNA (lncRNAs) have been identified to play important roles in multiple human diseases via the regulation of cell proliferation, cell invasion, or cell death. However, little is known about the role of lncRNAs in the process of shifts in the Th17/Treg ratio during the progression of juvenile idiopathic arthritis (JIA). The aim of the present study was to determine the role of lncRNA RP11­340F14.6 in the shifting of the Th17/Treg ratio in JIA. The distribution of the T cell subgroup was detected by flow cytometry in peripheral blood mononuclear cells from patients with JIA and healthy controls. It was found that the expression of lncRNA RP11­340F14.6 was upregulated, and to positively correlate with that of retinoic acid­related orphan receptor gamma t (RORγt), and to negatively correlate with Foxp3 expression in patients with JIA. RP11­340F14.6 induced the expression of its neighbor, P2X7R. Through a P2X7R­independent approach, this lncRNA was also found to play a pivotal role in stimulating Th17 differentiation and simultaneously suppressing Treg distribution. Taken together, the findings of the present study demonstrate that RP11­340F14.6 specifically binds to P2X7R, which results in the continuous activation of P2X7R. Thus, RP11­340F14.6 may serve as a promising therapeutic target for the treatment of JIA.

MicroRNA-125b regulates Th17/Treg cell differentiation and is associated with juvenile idiopathic arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood driven by aberrant pathways of T-cell activation. T helper 17 (Th17)/regulatory T cell (Treg) imbalance plays critical roles in the pathogenesis of arthritis. MicroRNA-125b (miR-125b) was upregulated after the activation of the initial CD4+ T cells, and could regulate the differentiation of CD4+ T cells. However, the effects of miR-125b on Th17/Treg imbalance and differentiation of Th17/Treg cells remain unknown. METHODS: In this study, we evaluated the expression of miR-125b in the peripheral blood mononuclear cells (PBMCs) of children with JIA, and the relationship of miR-125b with Th17/Treg imbalance. Then, we used lentivirus vector-mediated overexpression technology to investigate the regulatory function of miR-125b in CD4+ T cells or dendritic cell/CD4+ T co-culture system. RESULTS: Decreased miR-125b expression in PBMCs and CD4+ T cells of JIA patients was negatively correlated with the ratio of Th17/Treg cells. It also correlated negatively with retinoic acid receptor-related orphan receptor γt but positively with Forkhead box protein 3 at transcriptional levels. Furthermore, we found that miR-125b overexpression inhibited Th17 cell differentiation, whereas facilitated the differentiation of Treg cells. MiR-125b upregulation led to the decrease of Th17-secreting cytokines but the increase of the Treg-secreting cytokines. CONCLUSIONS: Our results demonstrate that miR-125b participated in regulating Th17/Treg cell differentiation and imbalance in JIA patients. These findings provide novel insight into the critical role of miR-125b in the Th17/Treg imbalance of JIA, and raise the distinct possibility that miR-125b may prove to be a potential therapeutic target for JIA.

Platelet-Derived Microparticles: A New Index of Monitoring Platelet Activation and Inflammation in Kawasaki Disease.

OBJECTIVE: To investigate the dynamic changes of platelet-derived microparticles (PDMP) in Kawasaki disease (KD) and its clinical significance and to study its relationship with intravenous immunoglobulin (IVIG) resistance, inflammatory indicators and aspirin treatment in children with KD. METHODS: Twenty children with KD were enrolled as the experimental group, while 20 age- and gender-matched children with common febrile disease were included in the control group. Blood samples were drawn before and 7-10 d after IVIG infusion and thereafter at 1, 2, and 3 mo after the onset of KD to estimate the PDMP concentrations by enzyme linked immunosorbent assay (ELISA). C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), and cytokines [Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α), and Soluble interleukin-2 (sIL-2R)] were also measured. RESULTS: The level of PDMP in KD children before IVIG was significantly higher than that in controls (P < 0.0001). The PDMP level in KD children decreased significantly at 7 to 10 d after IVIG (P < 0.0001) and then decreased to the lowest level in the course of 1 to 2 mo. Some children's PDMP level rebounded in the course of 3 mo (P = 0.047). In addition, the mean level of PDMP in IVIG-resistant children was higher than that in IVIG-effective children; however, there was no significant difference between the two groups (P = 0.1945). Furthermore, PDMP was positively correlated with hs-CRP, IL-6, and sIL-2R levels, but no correlation was observed with ESR, PCT, and TNF-α levels. CONCLUSIONS: PDMP can be used as an index to monitor inflammation in children at the acute stage of KD. And the duration of platelet activation in KD is individualized.

IRF5 is elevated in childhood-onset SLE and regulated by histone acetyltransferase and histone deacetylase inhibitors.

Interferon regulatory factor 5 (IRF5) plays a critical role in the induction of type I interferon, proinflammatory cytokines and chemokines, and participates in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). However, the relationship between IRF5 and childhood-onset SLE remains elusive. In the present study, we demonstrated that levels of mRNA expression of IRF5, IFN-α, and Sp1 were significantly increased in childhood-onset SLE, as seen on quantitative real-time PCR, and the expression of Sp1 and IFN-α was positively correlated with IRF5. In addition to being used as antitumor drugs, a number of histone deacetylase inhibitors (HDACi) display potent anti-inflammatory properties; however, their effects on IRF5 expression remain unclear. In this study, we identified that HDACi trichostatin A (TSA) and histone acetyltransferase (HAT)-p300 downregulated IRF5 promoter activity, mRNA expression, and protein level, whereas the HAT-p300/CBP-associated factor had no effect. Moreover, TSA inhibited the production of TNF-α and IL-6 in differentiated THP-1cells. Furthermore, chromatin immunoprecipitation assays revealed that TSA inhibited DNA binding of Sp1, RNA polymerase II, HDAC3, and p300 to the core promoter region of IRF5. Our results suggest that HDACi may have therapeutic potential in patients with autoimmune diseases such as SLE through repression of IRF5 expression.