Polyamines from myeloid-derived suppressor cells promote Th17 polarization and disease progression

Soufeng Sanjie formula alleviates the progression of lupus and joint injury by regulating the ALKBH5-FoxO1-PFKFB3 axis in M-MDSCs

BACKGROUND

Systemic lupus erythematosus (SLE) cases present with impaired immune function and injured organs, with joint injury being one of the most common complications. Soufeng Sanjie formula (SF) is a traditional Chinese medicine (TCM) that alleviates rheumatoid arthritis and has a significant regulatory effect on T cells. Recently, myeloid-derived suppressor cells (MDSCs) have been considered an essential factor contributing to SLE pathogenesis, as they can mediate the abnormal amplification of Th17 cells. However, it remains unclear whether SF targets MDSCs to alleviate SLE and joint injury.

PURPOSE

We aim to examine SF for therapeutic effects in lupus mice and the potential molecular mechanisms.

STUDY DESIGN AND METHODS

We developed an IMQ-induced lupus mouse model for assessing the high and low doses of SF for their effects. The manifestations of joint injury were also examined. Changes in immune cell populations were analyzed by flow cytometry and in vitro co-culture experiments. The key targets and active components of the SF were identified through network pharmacological analysis. Moreover, SF-containing serum was prepared to stimulate TLR7 against R848-induced-MDSCs in vitro. We also developed a pristane-induced lupus model in myeloid FoxO1-deficient mice. ECAR and OCR detection, measurements of glucose and lactic acid levels, luciferase reporter gene assays and ChIP-qPCR were employed to assess the transcriptional regulatory mechanisms of FoxO1. Dot blot analysis in conjunction with RNA immunoprecipitation (RIP) was used to assess post-transcriptional regulation.

RESULTS

SF significantly alleviated the symptoms of IMQ-induced lupus in mice, including joint damage. SF decreased the proportion of monocytic MDSCs (M-MDSCs), with no significant effects on granulocytic MDSCs (G-MDSCs), in both blood and spleen. Network pharmacological analysis indicated that FoxO1 was a key target of SF in M-MDSCs. Expectedly, SF-containing serum enhanced the immunosuppressive effect of M-MDSCs on Th17 cells by increasing FoxO1. The therapeutic efficacy of SF was diminished in the pristane-induced lupus model with myeloid FoxO1-deficient mice. Mechanistically, FoxO1 impaired the glycolytic process in M-MDSCs by inhibiting PFKFB3 transcription, thereby enhancing their immunosuppressive effect on Th17 cells. Additionally, delphinidin chloride (DP), an important constituent of SF, increased FoxO1 mRNA stability by downregulating ALKBH5-m6A modification in M-MDSCs.

CONCLUSION

This study confirmed that SF enhanced glycolysis in M-MDSCs by regulating the ALKBH5-FoxO1-PFKFB3 axis, which decreased Th17 cells and alleviated lupus and joint injury. These data firstly indicate SF may represent a potential treatment option for SLE and joint damage, revealing regulatory effects of DP, the key active component of SF, at the post-transcriptional level.

Immune cells in systemic lupus erythematosus: biology and traditional Chinese medicine therapy

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by a progressive breakdown of immune tolerance to self-antigens, resulting in multiple tissue damage and clinical symptoms. Innate and adaptive immune cells including dendritic cells, macrophages, myeloid-derived suppressor cells (MDSCs), T cells and B cells are the key drivers in perpetuating and amplifying of this systemic disease. In this review we offer a comprehensive overview of recent advances in understanding the immune-pathogenesis of SLE with particular emphasis on regulatory immune cells exhibiting immunosuppressive properties, as well as newly identified factors influencing immune cell function and lineage differentiation. Furthermore, we discuss traditional Chinese medicine and natural extracts that have shown therapeutic effects on SLE by modulating immune cell differentiation and function, which may provide insights into their clinical applications.

FoxO1 Deficiency in Monocytic Myeloid-Derived Suppressor Cells Exacerbates B Cell Dysfunction in Systemic Lupus Erythematosus

OBJECTIVE

Myeloid-derived suppressor cells (MDSCs) contribute to the pathogenesis of systemic lupus erythematosus (SLE), in part due to promoting the survival of plasma cells. FoxO1 expression in monocytic MDSCs (M-MDSCs) exhibits a negative correlation with the SLE Disease Activity Index score. This study aimed to investigate the hypothesis that M-MDSC-specific FoxO1 deficiency enhances aberrant B cell function in aggressive SLE.

METHODS

We used GEO data sets and clinical cohorts to verify the clinical significance of FoxO1 expression and circulating M-MDSCs. Using Cre-LoxP technology, we generated myeloid FoxO1 deficiency mice (mFoxO1-/-) to establish murine lupus-prone models. The transcriptional stage was assessed by integrating chromatin immunoprecipitation (ChIP)-sequencing with transcriptomic analysis, luciferase reporter assay, and ChIP-quantitative polymerase chain reaction. Methylated RNA immunoprecipitation sequencing, RNA sequencing, and CRISPR-dCas9 were used to identify N6-adenosine methylation (m6A) modification. In vitro B cell coculture experiments, capmatinib intragastric administration, m6A-modulated MDSCs adoptive transfer, and sample validation of patients with SLE were performed to determine the role of FoxO1 on M-MDSCs dysregulation during B cell autoreacted with SLE.

RESULTS

We present evidence that low FoxO1 is predominantly expressed in M-MDSCs in both patients with SLE and lupus mice, and mice with myeloid FoxO1 deficiency (mFoxO1-/-) are more prone to B cell dysfunction. Mechanically, FoxO1 inhibits mesenchymal-epithelial transition factor protein (Met) transcription by binding to the promoter region. M-MDSCs FoxO1 deficiency blocks the Met/cyclooxygenase2/prostaglandin E2 secretion pathway, promoting B cell proliferation and hyperactivation. The Met antagonist capmatinib effectively mitigates lupus exacerbation. Furthermore, alkB homolog 5 (ALKBH5) targeting catalyzes m6A modification on FoxO1 messenger RNA in coding sequences and 3' untranslated regions. The up-regulation of FoxO1 mediated by ALKBH5 overexpression in M-MDSCs improves lupus progression. Finally, these correlations were confirmed in untreated patients with SLE.

CONCLUSION

Our findings indicate that effective inhibition of B cells mediated by the ALKBH5/FoxO1/Met axis in M-MDSCs could offer a novel therapeutic approach to manage SLE.

RNA modification: a promising code to unravel the puzzle of autoimmune diseases and CD4+ T cell differentiation

Dynamic changes in various forms of RNA modification are critical to the functional homeostasis of the immune system and the pathophysiology of autoimmune diseases. RNA modification-related proteins play an essential role in these processes. At present, the research methods of RNA modification in autoimmune diseases are mainly to detect the expression changes of RNA modification-related proteins in tissues or cells, but there is a lack of explorations of target RNAs and in-depth mechanisms. Considering the important role of CD4+ T cell dysfunction in the pathogenesis and progression of autoimmune diseases, the regulatory effect of abnormal RNA modification on CD4+ T cells deserves attention, which will provide a perspective for further exploring the mechanism of RNA modification in autoimmune diseases. In this Review, we discuss the abnormal RNA modification changes in patients with autoimmune diseases and highlight the effects of these abnormal changes on CD4+ T cells.

X-chromosome-linked miR-542-5p as a key regulator of sex disparity in rats with adjuvant-induced arthritis by promoting Th17 differentiation

BACKGROUND

Studies have indicated that X-linked microRNAs (miRNAs) play a role in the pathogenesis of rheumatoid arthritis (RA) and its gender-specific differences. However, research on specific miRNAs remains limited. This study aims to investigate the possible role of X-linked miR-542-5p in RA pathogenesis and gender differences.

METHODS

We investigated the impact of miR-542-5p on RA pathogenesis and gender differences by manipulating its expression in various rat models.

RESULTS

Our findings revealed a significant overexpression of miR-542-5p in RA patients compared with healthy individuals, with a notable gender difference among RA patients. In vivo experiments confirmed that upregulation of miR-542-5p could accelerate RA pathogenesis. Further analysis showed that the onset of adjuvant-induced arthritis (AIA) in rats exhibited significant gender differences, with more severe clinical phenotypes found in female rats. This may be attributed to their stronger immune responses and elevated levels of miR-542-5p. Subsequent in vitro and in vivo experiments demonstrated that miR-542-5p contributes to the regulation of gender differences in RA pathogenesis by promoting the differentiation of Th17 cells.

CONCLUSIONS

This study offers new insights into the sex-specific nature of RA, suggesting X-linked miR-542-5p as a potential target for both diagnostic and therapeutic purposes. These findings lay the groundwork for the development of gender-specific therapeutic strategies for RA and underscore the importance of gender consideration in RA research.

Bidirectional Interplay Among Non-Coding RNAs, the Microbiome, and the Host During Development and Diseases

It is widely known that the dysregulation of non-coding RNAs (ncRNAs) and dysbiosis of the gut microbiome play significant roles in host development and the progression of various diseases. Emerging evidence has highlighted the bidirectional interplay between ncRNAs and the gut microbiome. This article aims to review the current understanding of the molecular mechanisms underlying the crosstalk between ncRNAs, especially microRNA (miRNA), and the gut microbiome in the context of development and diseases, such as colorectal cancer, inflammatory bowel diseases, neurological disorders, obesity, and cardiovascular disease. Ultimately, this review seeks to provide a foundation for exploring the potential roles of ncRNAs and gut microbiome interactions as biomarkers and therapeutic targets for clinical diagnosis and treatment, such as ncRNA mimics, antisense oligonucleotides, and small-molecule compounds, as well as probiotics, prebiotics, and diets.

High Humidity Alters Myeloid-Derived Suppressor Cells in Spleen Tissue: Insights into Rheumatoid Arthritis Progression

Background

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and bone destruction, leading to severe complications. Previous research has suggested that high humidity conditions may exacerbate RA, however, the underlying mechanisms remain unclear. Furthermore, there is a lack of evidence linking humidity to the worsening of RA symptoms in animal models.

Methods

The Collagen-induced arthritis (CIA) mouse model was established using C57BL/6 mice. The arthritis status of the mice was evaluated under two distinct humidity conditions (50% and 80%). The aim of the present study was to investigate the impact of elevated humidity levels on the types of splenic cells present using mass spectrometry flow. Additionally, the study utilized MDSCs, which are significantly upregulated by high humidity, to assess the levels of oxidative stress and conducted mRNA sequencing of sorted MDSCs to investigate their impact on arthritis in CIA mice.

Results

Compared to normal humidity, high humidity exacerbated arthritis incidence in mice, resulting in increased arthritis scores, swelling, serum autoantibodies (anti-COII and anti-CCP), and upregulation of pro-inflammatory cytokines. Significant variations were observed in the spleen index under high humidity condition, accompanied by noticeable inflammatory alterations. Moreover, elevated humidity levels induced a substantial modulation in MDSCs population in the spleen of CIA mice, along with alterations in oxidative stress markers such as heightened serum ROS levels, and increased expression of COX, SOD, and Nrf2 mRNA. Following successful sorting of MDSCs, mRNA sequencing revealed a decrease in the expression of Rap1 signaling pathway under high humidity environment, which may contribute to the increase of MDSCs cells and aggravate the progression of RA disease.

Conclusion

A comprehensive analysis of the available data reveals a detrimental impact of high humidity on MDSCs numbers within spleen tissue, with potential implications for the development of RA.

Tumor cell-derived spermidine promotes a protumorigenic immune microenvironment in glioblastoma via CD8+ T cell inhibition

The glioblastoma (GBM) microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly affect the immune system, but the mechanisms driving these interactions are not completely clear. Here, we demonstrate that the polyamine metabolite spermidine (SPD) was elevated in the GBM tumor microenvironment. Exogenous administration of SPD drove tumor aggressiveness in an immune-dependent manner in preclinical mouse models via reduction of CD8+ T cell frequency and reduced cytotoxic function. Knockdown of ornithine decarboxylase, the rate-limiting enzyme in SPD synthesis, did not affect cancer cell growth in vitro but did result in extended survival. Furthermore, patients with GBM with a more favorable outcome had a significant reduction in SPD compared with patients with a poor prognosis. Our results demonstrate that SPD functions as a cancer cell-derived metabolite that drives tumor progression by reducing CD8+ T cell numbers and function.

Unveiling shared biomarkers and therapeutic targets between systemic lupus erythematosus and heart failure through bioinformatics analysis

Background

Systemic lupus erythematosus (SLE) is frequently accompanied by various complications, with cardiovascular diseases being particularly concerning due to their high mortality rate. Although there is clinical evidence suggesting a potential correlation between SLE and heart failure (HF), the underlying shared mechanism is not fully understood. Therefore, it is imperative to explore the potential mechanisms and shared therapeutic targets between SLE and HF.

Methods

The SLE and HF datasets were downloaded from the NCBI Gene Expression Omnibus database. Differentially expressed genes (DEGs) in both SLE and HF were performed using "limma" R package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genes (KEGG) analyses were conducted to analyze the enriched functions and pathways of DEGs in both SLE and HF datasets. Protein-Protein Interaction network (PPI) and the molecular complex detection (MCODE) plugins in the Cytoscape software were performed to identify the shared hub genes between SLE and HF datasets. R package "limma" was utilized to validate the expression of hub genes based on SLE (GSE122459) and HF (GSE196656) datasets. CIBERSORT algorithm was utilized to analyze the immune cell infiltration of SLE and HF samples based on SLE (GSE112087) and HF (GSE116250) datasets. A weighted gene co-expression network analysis (WGCNA) network was established to further validate the hub genes based on HF dataset (GSE116250). Molecular biology techniques were conducted to validate the hub genes.

Results

999 shared DGEs were identified between SLE and HF datasets, which were mainly enriched in pathways related to Th17 cell differentiation. 5 shared hub genes among the common DGEs between SLE and HF datasets were screened and validated, including HSP90AB1, NEDD8, RPLP0, UBB, and UBC. Additionally, 5 hub genes were identified in the central part of the MEbrown module, showing the strongest correlation with dilated cardiomyopathy. HSP90AB1 and UBC were upregulated in failing hearts compared to non-failing hearts, while UBB, NEDD8, and RPLP0 did not show significant changes.

Conclusion

HSP90AB1 and UBC are closely related to the co-pathogenesis of SLE and HF mediated by immune cell infiltration. They serve as promising molecular markers and potential therapeutic targets for the treatment of SLE combined with HF.

MDSC-derived S100A8/9 contributes to lupus pathogenesis by promoting TLR7-mediated activation of macrophages and dendritic cells

Toll-like receptors (TLRs), especially TLR7, play an important role in systemic lupus erythematosus (SLE) pathogenesis. However, the regulatory mechanism underlying the abnormal activation of TLR pathways in patients with SLE has not been elucidated. Notably, accumulating evidence indicates that myeloid-derived suppressor cells (MDSCs) are important regulators of inflammation and autoimmune diseases. Compared with healthy control subjects, patients with SLE have a greater proportion of MDSCs among peripheral blood mononuclear cells (PBMCs); however, the effect of MDSCs on TLR7 pathway activation has not been determined. In the present study, lupus MDSCs significantly promoted TLR7 pathway activation in macrophages and dendritic cells (DCs), exacerbating the imiquimod-induced lupus model. RNA-sequencing analysis revealed significant overexpression of S100 calcium-binding protein A8 (S100A8) and S100A9 in MDSCs from diseased MRL/lpr mice. In vitro and in vivo studies demonstrated that S100A8/9 effectively promoted TLR7 pathway activation and that S100A8/9 deficiency reversed the promoting effect of MDSCs on TLR7 pathway activation in lupus. Mechanistically, MDSC-derived S100A8/9 upregulated interferon gamma (IFN-γ) secretion by macrophages and IFN-γ subsequently promoted TLR7 pathway activation in an autocrine manner. Taken together, these findings suggest that lupus MDSCs promote TLR7 pathway activation and lupus pathogenesis through the S100A8/9-IFN-γ axis. Our study identified an important target for SLE therapy.

The role of miRNAs in T helper cell development, activation, fate decisions and tumor immunity

T helper (Th) cells are central members of adaptive immunity and comprise the last line of defense against pathogen infection and malignant cell invasion by secreting specific cytokines. These cytokines then attract or induce the activation and differentiation of other immune cells, including antibody-producing B cells and cytotoxic CD8+ T cells. Therefore, the bidirectional communication between Th cells and tumor cells and their positioning within the tumor microenvironment (TME), especially the tumor immune microenvironment (TIME), sculpt the tumor immune landscape, which affects disease initiation and progression. The type, number, and condition of Th cells in the TME and TIME strongly affect tumor immunity, which is precisely regulated by key effectors, such as granzymes, perforins, cytokines, and chemokines. Moreover, microRNAs (miRNAs) have emerged as important regulators of Th cells. In this review, we discuss the role of miRNAs in regulating Th cell mediated adaptive immunity, focusing on the development, activation, fate decisions, and tumor immunity.

Myeloid-derived suppressor cells in the therapy of autoimmune diseases

Myeloid-derived suppressor cells (MDSCs) are well recognized as critical factors in the pathology of tumors. However, their roles in autoimmune diseases are still unclear, which hampers the development of efficient immunotherapies. The role of different MDSCs subsets in multiple sclerosis, inflammatory bowel diseases, rheumatoid arthritis, type 1 diabetes, and systemic lupus erythematosus displayed different mechanisms of immune suppression, and several studies pointed to MDSCs' capacity to induce T-helper (Th)17 cells and tissue damage. These results also suggested that MDSCs could be present in different functional states and utilize different mechanisms for controlling the activity of T and B cells. Therefore, various therapeutic strategies should be employed to restore homeostasis in autoimmune diseases. The therapies harnessing MDSCs could be designed either as cell therapy or rely on the expansion and activation of MDSCs in vivo, or their depletion. Cumulatively, MDSCs are inevitable players in autoimmunity, and rational approaches in developing therapies are required to avoid the adverse effects of MDSCs and harness their suppressive mechanisms to improve the overall efficacy of autoimmunity therapy.

Tumor cell-derived spermidine promotes a pro-tumorigenic immune microenvironment in glioblastoma via CD8+ T cell inhibition

The glioblastoma microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly impact the immune system, but the mechanisms driving these interactions are not completely clear. Here we demonstrate that the polyamine metabolite spermidine is elevated in the glioblastoma tumor microenvironment. Exogenous administration of spermidine drives tumor aggressiveness in an immune-dependent manner in pre-clinical mouse models via reduction of CD8+ T cell frequency and phenotype. Knockdown of ornithine decarboxylase, the rate-limiting enzyme in spermidine synthesis, did not impact cancer cell growth in vitro but did result in extended survival. Furthermore, glioblastoma patients with a more favorable outcome had a significant reduction in spermidine compared to patients with a poor prognosis. Our results demonstrate that spermidine functions as a cancer cell-derived metabolite that drives tumor progression by reducing CD8+T cell number and function.

Coenzyme Q10 Stimulate Reproductive Vatality

Female infertility and pregnancy maintenance are associate with various factors, including quantity and quality of oocytes, genital inflammation, endometriosis, and other diseases. Women are even diagnosed as unexplained infertility or unexplained recurrent spontaneous abortion when failed to achieve pregnancy with current treatment, which are urgent clinical issues need to be addressed. Coenzyme Q10 (CoQ10) is a lipid-soluble electron carrier in the mitochondrial electron transport chain. It is not only essential for the mitochondria to produce energy, but also function as an antioxidant to maintain redox homeostasis in the body. Recently, the capacity of CoQ10 to reduce oxidative stress (OS), enhance mitochondrial activity, regulate gene expression and inhibit inflammatory responses, has been discovered as a novel adjuvant in male reproductive performance enhancing in both animal and human studies. Furthermore, CoQ10 is also proved to regulate immune balance, antioxidant, promote glucose and lipid metabolism. These properties will bring highlight for ovarian dysfunction reversing, ovulation ameliorating, oocyte maturation/fertilization promoting, and embryonic development optimizing. In this review, we systematically discuss the pleiotropic effects of CoQ10 in female reproductive disorders to investigate the mechanism and therapeutic potential to provide a reference in subsequent studies.