SLE is an autoimmune inflammatory disease in which various pro- and anti-inflammatory cytokines, including TGF-β, IL-10, BAFF, IL-6, IFN-α, IFN-γ, IL-17, and IL-23, play crucial pathogenic roles. Virtually, all these cytokines can be generated by both innate and adaptive immune cells and exert different effects depending on specific local microenvironment. They can also interact with each other, forming a complex network to maintain delicate immune homeostasis. In this paper, we elaborate on the abnormal secretion and functions of these cytokines in SLE, analyze their potential pathogenic roles, and probe into the possibility of them being utilized as targets for therapy.

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The senescence of mesenchymal stem cells (MSCs) plays a crucial role in the development and progression of systemic lupus erythematosus (SLE). Exosomes, small spherical bilayer proteolipid vesicles, contribute to the communication between various cells and their microenvironment by transferring information via their cargo, including the proteins, lipids, and RNAs. While exosomal miRNAs participate in various biological activities, correlations of circulating exosomes with senescent signs of BM-MSCs remain unclear. In our study, we aimed at exploring the roles of circulating exosomal miRNAs in the senescence of MSCs. We found that exosomes derived from SLE serum could increase the proportions of SA-β-gal positive cells, disorganize cytoskeletons, and reduce growth rates. Moreover, the expression of miR-146a declined significantly in serum exosomes of SLE patients compared with healthy controls. miR-146a could be internalized into MSCs via exosomes and participate in MSCs senescence through targeting TRAF6/NF-κB signaling. These results clarified the novel mechanism of MSCs senescence in SLE patients.

Umbilical cord-derived mesenchymal stem cell transplantation (UC-MSCT) has been proved to be effective in the treatment of systemic lupus erythematosus (SLE), based on animal experiments and clinical trials. Diffuse alveolar hemorrhage (DAH) is a rare complication of SLE with a high mortality usually over 50%. This study aimed to assess the efficacy of UC-MSCT in the treatment of SLE-associated DAH. Four SLE patients complicated with DAH, who underwent UC-MSCT, were included. Clinical changes before and after transplantation were assessed by measurements of hemoglobin, platelet level, oxygen saturation, and serological factors. High-resolution CT (HRCT) scans of the chest were performed to evaluate pulmonary manifestation. All the four patients showed dramatic improvements of their clinical manifestations. Hemoglobin was elevated after UC-MSCT and was sustained at a normal level 6 months after UC-MSCT in the four patients. Platelet level was upregulated in two patients who had thrombocytopenia at baseline. Oxygen saturation appeared to be normal at 1 month after UC-MSCT, and this result was confirmed by the HRCT scan of the chest. Serum albumin elevated to 3.5 g/dl 6 months after transplantation. Our findings suggest that UC-MSCT results in amelioration of oxygen saturation as well as hematological and serologic changes, which revealed that UC-MSCT could be applied as a salvage strategy for DAH patients.

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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs and systems. Mesenchymal stem cells (MSCs) from SLE patients have demonstrated defects such as impaired growth, senescence phenotype and immunomodulatory functions. Some studies have suggested the close connection between inflammation microenvironment and cellular senescence. In the current study, we detected cytokines levels in bone marrow supernatant by the quantitative proteomics analysis, and found the expression of HMGB1 was remarkably increased in bone marrow from SLE patients. Senescence associated-β-galactosidase (SA-β-gal) staining, F-actin staining and flow cytometry were used to detect the senescence of cells. After stimulation of HMGB1 in normal MSCs, the ratio of SA-β-gal positive in BM-MSCs was increased, the organization of cytoskeleton was disordered, and TLR4-NF-κB signaling was activated. Finally, Ethyl pyruvate (EP) (40 mg/kg and 100 mg/kg, three times a week), a high security HMGB1 inhibitor, was injected intraperitoneally to treat MRL/lpr mice for 8 weeks. We demonstrated that EP alleviated the clinical aspects of lupus nephritis and prolonged survival of MRL/lpr mice. In the meantime, EP reversed the senescent phenotype of BM-MSCs from MRL/lpr mice. HMGB1 could be a promising target in SLE patients, and might be one of the reasons of recurrence after MSCs transplantation.

One of the most common promoters of the initiation and growth of the tumor is an immune disturbance. Numerous immune cells and inflammatory factors play a role in the tumor‐immune microenvironment. However, few studies have investigated the correlation between these immunological events and clinical consequences in cervical cancer. We measured the levels of numerous inflammatory mediators and frequencies of regulatory T cells (Tregs), myeloid‐derived suppressor cells (MDSCs) and mucosal‐associated invariant T (MAIT) cells in peripheral blood (PB) of cervical cancer patients. Cervical cancer patients showed elevated production of interleukin (IL)‐18 and plasma C‐C chemokine ligand (CCL) 3/5. Meanwhile, an accumulation of C‐C chemokine receptor 5 (CCR5) monocytic (Mo)‐MDSCs and Tregs was observed. The cervical cancer group displayed increased frequencies of CD8+, CD4+ and highly activated CD38+CD8+MAIT cells, and reduction of double‐negative (DN) and PD1(CD279+) DN MAIT cells. Importantly, it was demonstrated that MAIT cells were positively related to Mo‐MDSCs. Furthermore, an elevated concentration of PD1(CD279+) DN MAIT cells was significantly related to increased progression‐free survival of patients with cervical cancer. In conclusion, our study suggests that the combined action of Mo‐MDSCs and MAIT cells might be associated with the progression of cervical cancer, and the frequency of DN MAIT cells in the peripheral blood mononuclear cells was associated with the survival benefit of patients.

Increasing evidence shows miR-155 plays an important role in regulating inflammatory processes in systemic lupus erythematosus (SLE), especially in lupus nephritis (LN). Because the chemokine CXCL13 is implicated in the pathogenesis of LN, here we examined whether miR-155 can modulate the activity of CXCL13 or its receptor CXCR5. We determined the expression of CXCL13 in normal and MRL/lpr mice and found elevated levels of CXCL13 in the kidneys of MRL/lpr mice compared with normal kidneys. Besides, CXCL13 expression was mainly detected in the glomerulus, specifically to mesangial areas. We then transfected a miR-155 mimic in human renal mesangial cells (HRMCs) to overexpress miR-155 and detected decreased protein levels of CXCR5 by western blot analysis. Transfection of the miR-155 mimic into CXCL13-treated HRMCs resulted in a significantly reduced proliferation rate of HRMCs as measured by the cell-counting assay and flow cytometry. Moreover, increased intracellular miR-155 also led to decreased phosphorylation of ERK and TGF-β1 production. Together, these results revealed that miR-155 may play a role in the pathogenesis of LN.