Genhong Yao

Transplantation of Human Bone Marrow Mesenchymal Stem Cell Ameliorates the Autoimmune Pathogenesis in MRL/lpr Mice

Recent evidence indicates that mesenchymal stem cells (MSC) possess immunosuppressive properties both in vitro and in vivo. We previously demonstrated the functional abnormality of bone marrow derived MSC in patients with systemic lupus erythematosus (SLE). In this study, we aimed to investigate whether transplantation of human bone marrow derived MSC affects the autoimmune pathogenesis in MRL/lpr mice. We found that human MSC from healthy donors reduced the proliferation of T lymphocytes from MRL/lpr mice in a dose-dependent fashion. Two weeks after in vivo transfer of MSC, we detected significantly reduced serum levels of anti ds-DNA antibodies and 24 hour proteinuria in MRL/lpr mice as compared with control groups without MSC transplantation. Moreover, flow cytometric analysis revealed markedly reduced number of CD4+ T cells while increased Th1 subpopulation in MSC group and MSC + CTX group when compared with controls. Histopathological examination showed significantly reduced renal pathology in MSC-treated mice. Immunohistochemical studies further revealed reduced expression of TGF-β, FN, VEGF and the deposition of complement C3 in renal tissue after MSC and MSC + CTX treatment. Taken together, we have demonstrated that transplantation of human MSC can significantly inhibit the autoimmune progression in MRL/lpr mice.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 106 UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production. Lupus (2010) 19, 1502—1514.

The regulation of the Treg/Th17 balance by mesenchymal stem cells in human systemic lupus erythematosus

Background and objective: Umbilical cord (UC)-derived mesenchymal stem cells (MSCs) have shown immunoregulation of various immune cells. The aim of this study was to investigate the mechanism of UC MSCs in the regulation of peripheral regulatory T cells (Treg) and T helper 17 (Th17) cells in patients with systemic lupus erythematosus (SLE). Methods: Thirty patients with active SLE, refractory to conventional therapies, were given UC MSCs infusions. The percentages of peripheral blood CD4+CD25+Foxp3+ regulatory T cells (Treg) and CD3+CD8-IL17A+ Th17 cells and the mean fluorescence intensities (MFI) of Foxp3 and IL-17 were measured at 1 week, 1 month, 3 months, 6 months, and 12 months after MSCs transplantation (MSCT). Serum cytokines, including transforming growth factor beta (TGF-β), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-17A were detected using ELISA. Peripheral blood mononuclear cells from patients were collected and co-cultured with UC MSCs at ratios of 1:1, 10:1, and 50:1, respectively, for 72 h to detect the proportions of Treg and Th17 cells and the MFIs of Foxp3 and IL-17 were determined by flow cytometry. The cytokines in the supernatant solution were detected using ELISA. Inhibitors targeting TGF-β, IL-6, indoleamine 2,3-dioxygenase (IDO), and prostaglandin E2 were added to the co-culture system, and the percentages of Treg and Th17 cells were observed. Results: The percentage of peripheral Treg and Foxp3 MFI increased 1 week, 1 month, and 3 months after UC MSCs transplantation, while the Th17 proportion and MFI of IL-17 decreased 3 months, 6 months, and 12 months after the treatment, along with an increase in serum TGF-β at 1 week, 3 months, and 12 months and a decrease in serum TNF-α beginning at 1 week. There were no alterations in serums IL-6 and IL-17A before or after MSCT. In vitro studies showed that the UC MSCs dose-dependently up-regulated peripheral Treg proportion in SLE patients, which was not depended on cell–cell contact. However, the down-regulation of Th17 cells was not dose-dependently and also not depended on cell–cell contact. Supernatant TGF-β and IL-6 levels significantly increased, TNF-α significantly decreased, but IL-17A had no change after the co-culture. The addition of anti-TGF-β antibody significantly abrogated the up-regulation of Treg, and the addition of PGE2 inhibitor significantly abrogated the down-regulation of Th17 cells. Both anti-IL-6 antibody and IDO inhibitor had no effects on Treg and Th17 cells. Conclusions: UC MSCs up-regulate Treg and down-regulate Th17 cells through the regulation of TGF-β and PGE2 in lupus patients.

Mesenchymal Stem Cells from Patients with Rheumatoid Arthritis Display Impaired Function in Inhibiting Th17 Cells

Mesenchymal stem cells (MSCs) possess multipotent and immunomodulatory properties and are suggested to be involved in the pathogenesis of immune-related diseases. This study explored the function of bone marrow MSCs from rheumatoid arthritis (RA) patients, focusing on immunomodulatory effects. RA MSCs showed decreased proliferative activity and aberrant migration capacity. No significant differences were observed in cytokine profiles between RA and control MSCs. The effects of RA MSCs on proliferation of peripheral blood mononuclear cells (PBMCs) and distribution of specific CD4+ T cell subtypes (Th17, Treg, and Tfh cells) were investigated. RA MSCs appeared to be indistinguishable from controls in suppressing PBMC proliferation, decreasing the proportion of Tfh cells, and inducing the polarization of Treg cells. However, the capacity to inhibit Th17 cell polarization was impaired in RA MSCs, which was related to the low expression of CCL2 in RA MSCs after coculture with CD4+ T cells. These findings indicated that RA MSCs display defects in several important biological activities, especially the capacity to inhibit Th17 cell polarization. These functionally impaired MSCs may contribute to the development of RA disease.

Hypoxia Inducible Factor-1 Alpha Promotes Mesangial Cell Proliferation in Lupus Nephritis

Background: Evidence has accumulated that hypoxia plays a significant role in the pathogenesis and progression of both acute renal injury and chronic renal disease. However, little was known about the effects of hypoxia on lupus nephritis (LN). In the current study, we investigated the expression of hypoxia inducible factor-1 alpha (HIF-1α) in LN. Methods: Renal biopsies from 22 LN patients and 20 patients with renal carcinoma were obtained. In situ HIF-1α expression was examined by immunohistochemical staining, and the relationship between HIF-1α and clinical/pathological features was analyzed. HIF-1α expression in kidney from both MRL/lpr and C57BL/6 mice was detected by immunohistochemical technology. Dimethyloxaloylglycine (DMOG), an inhibitor of HIF-degrading prolylhydroxylases, was utilized to prevent HIF-1α degradation in mouse mesangial cells (MCs). After DMOG treatment, the proliferation and apoptosis rates of mouse MCs were determined. Results: LN patients showed larger amounts of HIF-1α in both glomerular and tubulointerstitial areas. The levels of intraglomerular HIF-1α were closely associated with renal pathology activity index and clinical manifestations in LN patients. In MRL/lpr mice, intraglomerular HIF-1α-positive cells were also significantly increased. Interestingly, the levels of HIF-1α positively correlated with cell density in glomerulus in both LN patients and MRL/lpr mice. Upon treatment with DMOG, the proliferation of MCs was upregulated, and apoptosis was downregulated. Conclusion: HIF-1α is highly expressed in both glomerular and tubulointerstitial tissues in LN, especially in proliferative LN. HIF-1α may promote MCs growth through the induction of proliferation and inhibition of apoptosis, and hence plays an important role in the pathogenesis of LN.

Mesenchymal stem cells promote CD206 expression and phagocytic activity of macrophages through IL-6 in systemic lupus erythematosus.

Human umbilical cord-derived mesenchymal stem cells (UCMSCs) show therapeutic effects on systemic lupus erythematosus (SLE). Deficiency in functional polarization and phagocytosis in macrophages has been suggested in the pathogenesis of SLE. We found that macrophages from B6.MRL-Fas(lpr) mice exhibited lower level of CD206, the marker for alternatively activated macrophage (AAM, also called M2). In addition, the phagocytic activity of B6.MRL-Fas(lpr) macrophages was also decreased. UCMSC transplantation improved the proportion of CD206(+) macrophages and their phagocytic activity in B6.MRL-Fas(lpr) mice. Importantly, macrophages from SLE patients also showed lower expression of CD206 and reduced phagocytic activity, which were corrected by being co-cultured with UCMSCs in vitro and in SLE patients receiving UCMSC transplantation. Mechanistically, we demonstrated that IL-6 was required for the up-regulation of CD206 expression and phagocytic activity of UCMSC-treated SLE macrophages. Our results indicate that UCMSCs alleviate SLE through promoting CD206 expression and phagocytic activity of macrophages in an IL-6 dependent manner.

Exacerbation of lupus nephritis by high sodium chloride related to activation of SGK1 pathway

The objective of this study is to explore the effects of high salt diet (HSD) on the severity of lupus nephritis (LN) and its mechanism. MRL/lpr mice were randomly divided into two groups, which were fed with normal diet or sodium-rich chow and tap. C57BL/6 mice were selected as control. Spleen Th1, Th2, Th17 and Treg cells were detected by flow cytometry. Serum TGF-β and IL-17 were measured by enzyme-linked immunosorbent assay. CD4(+) T cells from Systemic Lupus Erythematosus (SLE) patients and healthy donors were treated by NaCl with or without SGK1 inhibitor. Then, Th17 and Treg cells were detected. The HSD MRL/lpr mice had decreased survival rate and increased disease severity. The frequencies of Th1 and Th17 cells increased in HSD treatment group. The ratios of Th1/Th2 and Th17/Treg in HSD treated MRL/lpr mice significantly increased. Serum TGF-β increased after HSD treatment. In vitro, high salt could up-regulate Th17 cells of CD4(+) T cells. The effects of high salt treatment on CD4(+) T cells were reversed by SGK1 inhibitor. Our findings demonstrated that excessive intake of salt in diet is an aggravating factor for LN. High salt diet may deteriorate LN through SGK1 pathway.

Human Umbilical Cord Mesenchymal Stem Cells Inhibit T Follicular Helper Cell Expansion through the Activation of iNOS in Lupus-Prone B6.MRL-Faslpr Mice

The aberrant generation or activation of T follicular helper (Tfh) cells contributes to the pathogenesis of systemic lupus erythematosus (SLE), yet little is known about how these cells are regulated. In this study, we demonstrated that the frequency of Tfh cells was increased in lupus-prone B6.MRL-Faslpr (B6.lpr) mice and positively correlated to plasma cell proportions and serum total IgG as well as anti-dsDNA antibody levels. Transplantation of mesenchymal stem cells derived from Whartons jelly of human umbilical cords (hUC-MSCs) ameliorated lupus symptoms in B6.lpr mice, along with decreased percentages of Tfh cells. In vitro studies showed that the differentiation and proliferation of Tfh cells were markedly suppressed by hUC-MSCs. The production of inducible nitric oxide synthase (iNOS) was dramatically upregulated in hUC-MSCs when cocultured with CD4+ T cells directly, while adding the specific inhibitor of iNOS into the coculture system significantly reversed the inhibitory effect of hUC-MSCs on Tfh cell generation. Interestingly, the efficacy of hUC-MSCs in inhibiting Tfh cells was impaired in the Transwell system, with the reduction of iNOS in both mRNA and protein levels. Taken together, our findings suggest that hUC-MSCs could effectively inhibit Tfh cell expansion through the activation of iNOS in lupus-prone B6.lpr mice, which is highly dependent on cell-to-cell contacts.

MicroRNA-663 induces immune dysregulation by inhibiting TGF-β1 production in bone marrow-derived mesenchymal stem cells in patients with systemic lupus erythematosus

Mesenchymal stem cells (MSCs) are critical for immune regulation. Although several microRNAs (miRNAs) have been shown to participate in autoimmune pathogenesis by affecting lymphocyte development and function, the roles of miRNAs in MSC dysfunction in autoimmune diseases remain unclear. Here, we show that patients with systemic lupus erythematosus (SLE) display a unique miRNA signature in bone marrow-derived MSCs (BMSCs) compared with normal controls, among which miR-663 is closely associated with SLE disease activity. MiR-663 inhibits the proliferation and migration of BMSCs and impairs BMSC-mediated downregulation of follicular T helper (Tfh) cells and upregulation of regulatory T (Treg) cells by targeting transforming growth factor β1 (TGF-β1). MiR-663 overexpression weakens the therapeutic effect of BMSCs, while miR-663 inhibition improves the remission of lupus disease in MRL/lpr mice. Thus, miR-663 is a key mediator of SLE BMSC regulation and may serve as a new therapeutic target for the treatment of lupus.Mesenchymal stem cells (MSCs) are critical for immune regulation. Although several microRNAs (miRNAs) have been shown to participate in autoimmune pathogenesis by affecting lymphocyte development and function, the roles of miRNAs in MSC dysfunction in autoimmune diseases remain unclear. Here, we show that patients with systemic lupus erythematosus (SLE) display a unique miRNA signature in bone marrow-derived MSCs (BMSCs) compared with normal controls, among which miR-663 is closely associated with SLE disease activity. MiR-663 inhibits the proliferation and migration of BMSCs and impairs BMSC-mediated downregulation of follicular T helper (Tfh) cells and upregulation of regulatory T (Treg) cells by targeting transforming growth factor β1 (TGF-β1). MiR-663 overexpression weakens the therapeutic effect of BMSCs, while miR-663 inhibition improves the remission of lupus disease in MRL/lpr mice. Thus, miR-663 is a key mediator of SLE BMSC regulation and may serve as a new therapeutic target for the treatment of lupus.

Mesenchymal stem cells upregulate Treg cells via sHLA-G in SLE patients

Background: Soluble human leukocyte antigen‐G (sHLA‐G) is a non‐classical HLA class I molecule, exhibiting strong immunosuppressive properties by inducing the differentiation of T regulatory cells (Treg). Mesenchymal stem cells (MSCs) transplantation alleviates disease progression in systemic lupus erythematosus (SLE) patients. However, the underlying mechanisms are largely unknown. Objectives: To explore whether sHLA‐G is involved in upregulating effects of MSCs on Treg, which contributes to therapeutic effects of MSCs transplantation in SLE. Methods: The serum sHLA‐G levels of SLE patients and healthy controls were detected by ELISA. The percentages of peripheral blood CD4+ILT2+, CD8+ILT2+, CD19+ILT2+ cells and Treg cells were examined by flow cytometry. Ten patients with active SLE, refractory to conventional therapies, were infused with umbilical cord derived MSCs (UC‐MSCs) and serum sHLA‐G was measured 24 h and 1 month after infusion. The mice were divided into three groups: C57BL/6 mice, B6.MRL‐Faslpr mice infused with phosphate buffer saline (PBS), and B6.MRL‐Faslpr mice infused with bone marrow MSCs (BM‐MSCs). Then, the concentrations of serum Qa‐2 were detected. Peripheral blood mononuclear cells (PBMCs) were isolated from SLE patients and co‐cultured with UC‐MSCs for 3 days at different ratios (50:1, 10:1, and 2:1) with or without HLA‐G antibody, and the frequencies of CD4+CD25+Foxp3+ T cells were then determined by flow cytometry. Results: The concentrations of serum sHLA‐G were comparable between SLE patients and healthy controls. However, there was a negative correlation between sHLA‐G levels and SLE disease activity index (SLEDAI) scores in active SLE patients (SLEDAI > 4). We found that serum sHLA‐G levels were negatively correlated with blood urea nitrogen, serum creatinine and 24‐hour urine protein in SLE patients. The sHLA‐G levels were significantly lower in SLE patients with renal involvement than those without renal involvement. The expression of ILT2 on CD4+ T cells from SLE patients decreased significantly compared to that of healthy controls. A positive correlation between the frequencies of Treg and CD4+ILT2+ T cells was found in SLE patients. The levels of sHLA‐G increased 24 h post UC‐MSCs transplantation. The concentrations of Qa‐2 in BM‐MSCs transplanted mice were significantly higher than those of control group. In vitro studies showed that MSCs increased the frequency of Treg cells in SLE patients in a dose‐dependent manner, which was partly abrogated by the anti‐HLA‐G antibody. Conclusions: Our results suggested that MSCs may alleviate SLE through upregulating Treg cells, which was partly dependent on sHLA‐G. HighlightsSerum sHLA‐G levels are correlated with creatinine in SLE patients.ILT2 expression on T and B lymphocytes was downregulated in SLE patients.Serum sHLA‐G and mouse Qa‐2 increased after MSCs transplantation.MSCs upregulated Treg cells via HLA‐G/ILT2.