Disabled-2 overexpression mediates immune suppression in systemic lupus erythematosus by modulating Treg/Th17 cell differentiation.

Systemic lupus erythematosus (SLE) is an autoimmune disorder. T helper 17 (Th17) and regulatory T (Treg) cells play key roles in SLE progression. Disabled-2 (DAB2) exhibits immunomodulatory effects in inflammatory diseases. However, the role of DAB2 in SLE and the precise mechanisms remain unknown. Here, a decreased DAB2 expression and an increased miR-448-3p level were observed in peripheral blood mononuclear cells (PBMCs) from SLE patients. DAB2 level was negatively correlated with SLE Disease Activity Index (SLEDAI), suggesting a functional correlation between DAB2 and SLE. To test this, we used 8-week-old MRL/lpr mice and treated them with lentivirus-mediated DAB2 (LV-DAB2) or its negative control (LV-NC). LV-DAB2 treatment increased DAB2 expression and reduced serum immunoglobulin G (IgG) and anti-dsDNA IgG levels. DAB2 upregulation alleviated splenomegaly and lymphadenopathy and SLE-related organ damage. Moreover, DAB2 enhanced the percentage of CD25+ Foxp3+ Treg cells, but reduced Th17 cell frequency in lupus, along with the reduction in tumour necrosis factor α (TNF-α), interleukin (IL)-6 (IL-6) and IL-17A levels, and the elevation in IL-10. In vitro, naive CD4+ T cells isolated from MRL/lpr mice were polarized into Th17 or Treg phenotypes and treated with lentivirus. LV-DAB2 treatment downregulated IL-17A expression and inhibited the generation of CD4+ IL-17A+ Th17 cells. DAB2 triggered the production of IL-10 and the activation of Treg cells. Furthermore, DAB2 was verified as a direct target for miR-448-3p. MiR-448-3p overexpression cancelled the promoting effect of DAB2 on Treg cell differentiation. Taken together, DAB2 exerts an immunosuppressive effect on SLE through promoting Treg cell activation and inhibiting Th17 cell differentiation, which may be modulated by miR-448-3p.

Exacerbating lupus nephritis following BPA exposure is associated with abnormal autophagy in MRL/lpr mice.

For the development of Lupus nephritis, environmental factors are reasoned to be one of the risk factors. In recent years, the role of bisphenol A (BPA) in kidney injury has attracted wide attention. In this study, we explored the nephrotoxicity and its possible mechanism of BPA exposure to lupus-prone MRL/lpr mice. Orally exposure of BPA increased serum anti-dsDNA level and urinary protein, and aggravated renal pathological injury in MRL/lpr mice. BPA increased the expression of NF-κB protein and activated the inflammatory response in both MRL/lpr and C57 mice. Unlike C57 mice, BPA exposure partially activated autophagy associated proteins, but the autophagy signaling pathway lacked the regulation of Becline1 and LC3-associated phagocytosis deficiency, and decreased Nrf2 protein expression in renal tissue of MRL/lpr mice. Therefore, exacerbating lupus nephritis induced by BPA exposure was associated with the activation of inflammation, abnormal autophagy and decreased antioxidant ability.

MiR-410 Down-Regulates the Expression of Interleukin-10 by Targeting STAT3 in the Pathogenesis of Systemic Lupus Erythematosus.

BACKGROUND/AIMS: Systemic lupus erythematosus (SLE) is a heterogeneous chronic inflammatory autoimmune disorder, in the pathogenesis of which miRNAs play a versatile function. The purpose of this study was to investigate the effect of miRNA-410 on the pathogenesis of SLE in T cells of SLE patients. METHODS: Real-time PCR was used to test the mRNA levels of miRNA-410 in SLE patients and healthy controls. ELISA analysis was performed to examine the production levels of IL-10. Luciferase Assay was used to confirm the targeting effect of miRNA-410 on 3'UTR of STAT3 mRNA. RESULTS: We found that the expression level of miR-410 in T cells of SLE patients was decreased comparing to that in healthy controls, whereas overexpression of miR-410 significantly reduced the expression levels of IL-10. Furthermore, miR-410 suppresses the transcription activity of STAT3 by binding directly to the 3 'UTR of STAT3 mRNA. Moreover, silence of STAT3 down regulated IL-10 expression in CD3+ T cells. CONCLUSION: Our results demonstrate that miR-410 is the key regulatory factor in the pathogenesis of SLE by regulating the expression of IL-10 through targeting STAT3. These data suggest a novel function of miR-410 and bring new insight into understanding the complex mechanisms involved in SLE.

Changes in peripheral CD19(+)Foxp3(+) and CD19(+)TGFß(+) regulatory B cell populations in rheumatoid arthritis patients with interstitial lung disease.

OBJECTIVE: Although the role of regulatory B cells (Bregs) in rheumatic disease has gained increasing attention, two lesser-known Breg subsets that express either Foxp3 or transforming growth factor beta (TGFß) are rarely examined in studies of rheumatic disease. This study investigates the association between the relative proportions of CD19(+)Foxp3(+) and CD19(+)TGFß(+) Bregs, and clinical indicators of disease severity in rheumatoid arthritis (RA) patients with or without interstitial lung disease (ILD). METHODS: A total of 31 RA patients (14 with and 17 without ILD) and 26 healthy control subjects were included. All subjects did not have other autoimmune disease except RA, tumor, active infection, or a history of related drug administration. Peripheral blood mononuclear cells (PBMCs) were isolated and analyzed by flow cytometry (FCM). The relationship between the relative proportions of CD19(+)Foxp3(+) and CD19(+)TGFß(+) Bregs and their associations to RA and ILD incidence, as well as disease severity assessed by common clinical indicators, were then examined. RESULTS: Our analyses revealed RA patients had significantly lower proportions of peripheral CD19(+)Foxp3(+) and CD19(+)TGFß(+) Bregs as compared to healthy controls. While no association was observed between CD19(+)Foxp3(+) Bregs and ILD incidence, patients with ILD had a substantially lower percentage of CD19(+)TGFß(+) Bregs compared to RA patients without ILD. In addition, CD19(+)Foxp3(+) Bregs were negatively correlated with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels in RA patients, whereas CD19(+)TGFß(+) Bregs were only correlated with CRP in RA patients with ILD. Furthermore, there was a negative association between CD19(+)Foxp3(+) Bregs and disease severity scores, which was not found in analyses with CD19(+)TGFß(+) Bregs. CONCLUSIONS: The proportions CD19(+)Foxp3(+) and CD19(+)TGFß(+) Bregs were significantly decreased in RA patients, particularly in those with ILD complications, suggesting that Breg phenotypes may have different functions in the pathogenesis of RA and ILD.

Elevated levels of serum sCXCL16 in systemic lupus erythematosus; potential involvement in cutaneous and renal manifestations.

The aim of this study was to investigate the levels and clinical significance of serum soluble chemokine (C-X-C motif) ligand 16 (sCXCL16) in patients with systemic lupus erythematosus (SLE), as well as the sCXCL16 molecule's associations with disease activity and organ damage. Thirty-five patients with SLE, 16 patients with rheumatoid arthritis (RA), and 15 healthy controls were included in this study. The demographic and clinical features of the patients were recorded. The serum levels of sCXCL16 were determined. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI), and organ damage was evaluated with the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (SDI). The serum levels of sCXCL16 in the patients with SLE were higher than those in the patients with RA (P = 0.002) or healthy controls (P < 0.0001). The levels in the patients with active SLE were higher than those in the disease inactive patients (P = 0.008). Positive correlations were identified between serum sCXCL16 concentrations and both SLEDAI (r = 0.564; P < 0.0001) and SDI scores (r = 0.396; P = 0.018). Both SLEDAI (P = 0.021) and serum levels of CXCL16 (P = 0.023) decreased after conventional treatment in 12 initial onset cases of SLE patients. Elevated serum sCXCL16 levels were discovered in the SLE patients with cutaneous (P = 0.006) and renal involvement (P = 0.032). Soluble CXCL16 may become a useful serological marker of disease activity and skin and renal involvement in SLE patients; thus, it may be used for evaluation of therapeutic interventions.