Excessive miR-152-3p Results in Increased BAFF Expression in SLE B-Cells by Inhibiting the KLF5 Expression

Reduced miR-99a-3p levels in systemic lupus erythematosus may promote B cell proliferation via NCAPG and the PI3K/AKT signaling pathway

BACKGROUND

Systemic lupus erythematosus is an immunologically dysregulated disease characterized by the presence of multiple autoantibodies. In SLE, B lymphocytes contribute to the dysregulated production of autoantibodies and cytokines. Recently, we discovered that miR-99a-3p binds to both EIF4EBP1 and NCAPG mRNA and that lowering miR-99a-3p can promote B cell autophagy in SLE by increasing EIF4EBP1 expression. However, the functions of miR-99a-3p and NCAPG in SLE have not been extensively investigated.

OBJECTIVE

This work aims to evaluate the levels of miR-99a-3p and NCAPG expression in SLE B cells and to determine whether the aberrant expression of miR-99a-3p and NCAPG contributes to the pathological mechanisms in SLE.

METHODS

B lymphocytes were obtained through immunomagnetic negative selection. Using RT-qPCR, miR-99a-3p and NCAPG mRNA expressions in B lymphocytes and in the BALL-1 cell line were measured. To determine the relative abundance of NCAPG, PI3K, p-PI3K, AKT, and p-AKT, we normalize them to the level of β-actin using Western blotting. Evaluation of miR-99a-3p and NCAPG's impact on cell proliferation was done utilizing CCK-8 assay. Using flow cytometry, the cell cycle and apoptosis were both measured.

RESULTS

Comparing SLE B cells to healthy controls, miR-99a-3p expression was significantly downregulated. Additionally, it was observed that SLE B cells had significantly higher NCAPG mRNA expression. Blocking miR-99a-3p expression in BALL-1 cells with an antagomir elevated NCAPG expression, facilitated PI3K/AKT pathway activation, improved cell proliferation, raised the fraction of S-phase cells, and prevented cell apoptosis. The opposite effects of upregulated miR-99a-3p levels on BALL-1 cells were observed by using an agomir. Furthermore, the effect of decreased miR-99a-3p expression on cell proliferation was partially mediated by elevating NCAPG levels and activating the PI3K/AKT pathway.

CONCLUSION

Our research indicates that lower miR-99a-3p expression in SLE B cells appears to boost B cell number via the NCAPG and PI3K/AKT pathways.

Epigenetic Dysregulation in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease in which immune disorders lead to autoreactive immune responses and cause inflammation and tissue damage. Genetic and environmental factors have been shown to trigger SLE. Recent evidence has also demonstrated that epigenetic factors contribute to the pathogenesis of SLE. Epigenetic mechanisms play an important role in modulating the chromatin structure and regulating gene transcription. Dysregulated epigenetic changes can alter gene expression and impair cellular functions in immune cells, resulting in autoreactive immune responses. Therefore, elucidating the dysregulated epigenetic mechanisms in the immune system is crucial for understanding the pathogenesis of SLE. In this paper, we review the important roles of epigenetic disorders in the pathogenesis of SLE.

miR-130b regulates B cell proliferation via CYLD-mediated NF-κB signaling

Previous studies have revealed that B cell activation is regulated by various microRNAs(miRNAs). However, the role of microRNA-130b regulating B cell activation and apoptosis is still unclear. In the present study, we first found that the expression of miR-130b was the lowest in Pro/Pre-B cells and the highest in immature B cells. Besides, the expression of miR-130b decreased after activation in B cells. Through the immuno-phenotypic analysis of miR-130b transgenic and knockout mice, we found that miR-130b mainly promoted the proliferation of B cells and inhibited B cell apoptosis. Furthermore, we identified that Cyld, a tumor suppressor gene was the target gene of miR-130b in B cells. Besides, the Cyld-mediated NF-κB signaling was increased in miR-130b overexpressed B cells, which further explains the enhanced proliferation of B cells. In conclusion, we propose that miR-130b promotes B cell proliferation via Cyld-mediated NF-κB signaling, which provides a new theoretical basis for the molecular regulation of B cell activation.

Advances in the study of exosome-derived miRNAs in the pathogenesis, diagnosis, and treatment of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory disease caused by autoantibodies, with high morbidity and mortality. It involves multiple systems, particularly the renal, which can lead to lupus nephritis (LN); its multi-system effects have a significant impact on the physical and mental health of patients. Exosomes are vesicles that are secreted during cell activity and carry a variety of nucleic acids, proteins, and lipids. They are distributed through body fluids for cellular communication. MicroRNAs (miRNAs) are nucleic acids that are packaged within the exosome that are taken up and released in response to changes in plasma membrane structure. MiRNAs are potential participants in immune and inflammatory responses, which are transported to target cells and can inhibit gene expression in receptor cells. It has been suggested that exosomal miRNA can regulate the pathogenesis of SLE and, as such, they are of value in diagnosis and treatment. In this paper, we focus on the research progress into exosomal miRNA in SLE and inspire new directions for SLE related research.

Systemic lupus erythematosus: From non-coding RNAs to exosomal non-coding RNAs

Systemic lupus erythematosus (SLE), as an immunological illness, frequently impacts young females. Both vulnerabilities to SLE and the course of the illness's clinical symptoms have been demonstrated to be affected by individual differences in non-coding RNA expression. Many non-coding RNAs (ncRNAs) are out of whack in patients with SLE. Because of the dysregulation of several ncRNAs in peripheral blood of patients suffering from SLE, these ncRNAs to be showed valuable as biomarkers for medication response, diagnosis, and activity. NcRNAs have also been demonstrated to influence immune cell activity and apoptosis. Altogether, these facts highlight the need of investigating the roles of both families of ncRNAs in the progress of SLE. Being aware of the significance of these transcripts perhaps elucidates the molecular pathogenesis of SLE and could open up promising avenues to create tailored treatments during this condition. In this review we summarized various non-coding RNAs and Exosomal non-coding RNAs in SLE.

Dysregulated MicroRNAs in the Pathogenesis of Systemic Lupus Erythematosus: A Comprehensive Review

Systemic lupus erythematosus is a chronic autoimmune disease of which clinical presentation is vastly heterogeneous, ranging from mild skin rashes to severe renal diseases. Treatment goal of this illness is to minimize disease activity and prevent further organ damage. In recent years, much research has been done on the epigenetic aspects of SLE pathogenesis, for among the various factors known to contribute to the pathogenic process, epigenetic factors, especially microRNAs, bear the most therapeutic potential that can be altered unlike congenital genetic factors. This article reviews and updates what has been discovered so far about the pathogenesis of lupus, while focusing on the dysregulation of microRNAs in lupus patients in comparison to healthy controls along with the potentially pathogenic roles of the microRNAs commonly reported to be either upregulated or downregulated. Furthermore, this review includes microRNAs of which results are controversial, suggesting possible explanations for such discrepancies and directions for future research. Moreover, we aimed to emphasize the point that had been overlooked so far in studies regarding microRNA expression levels; that is, which specimen was used to assess the dysregulation of microRNAs. To our surprise, a vast number of studies have not considered this factor and have analyzed the potential role of microRNAs in general. Despite extensive investigations done on microRNA levels, their significance and potential role remain a mystery, which calls for further studies on this particular subject in regard of which specimen is used for assessment.

Epigenetic Regulations in Autoimmunity and Cancer: from Basic Science to Translational Medicine

Epigenetics, as a discipline that aims to explain the differential expression of phenotypes arising from the same gene sequence and the heritability of epigenetic expression, has received much attention in medicine. Epigenetic mechanisms are constantly being discovered, including DNA methylation, histone modifications, noncoding RNAs and m6A. The immune system mainly achieves an immune response through the differentiation and functional expression of immune cells, in which epigenetic modification will have an important impact. Because of immune infiltration in the tumor microenvironment, immunotherapy has become a research hotspot in tumor therapy. Epigenetics plays an important role in autoimmune diseases and cancers through immunology. An increasing number of drugs targeting epigenetic mechanisms, such as DNA methyltransferase inhibitors, histone deacetylase inhibitors, and drug combinations, are being evaluated in clinical trials for the treatment of various cancers (including leukemia and osteosarcoma) and autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis). This review summarizes the progress of epigenetic regulation for cancers and autoimmune diseases to date, shedding light on potential therapeutic strategies.

An update on epigenetic regulation in autoimmune diseases

Autoimmune diseases (AIDs) generally manifest as chronic immune disorders characterized by significant heterogeneity and complex symptoms. The discordant incidence of AIDs between monozygotic twins guided people to attach importance to environmental factors. Epigenetics is one of the major ways to be influenced, some of them can even occur years before clinical diagnosis. With the advent of high-throughput omics times, the mysterious veil of epigenetic modification in AIDs has been gradually unraveled, and some progress has been made in utilizing it as indicators of diagnosis and disease activity. For example, the hypomethylated IFI44L promoter in diagnosing systematic lupus erythematosus (SLE). More recently, newly identified noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are also believed to be involved in the etiology of AIDs while the initial factor behind those epigenetic alterations can be diverse from metabolism to microbiota. Update and comprehensive insights into epigenetics in AIDs can help us understand the pathogenesis and further orchestrate it to benefit patients in the future. Therefore, we reviewed the latest epigenetic findings in SLE, rheumatoid arthritis (RA), Type 1 diabetes (T1D), systemic sclerosis (SSc) primarily from cellular levels.

Novel insight into miRNA biology and its role in the pathogenesis of systemic lupus erythematosus

MicroRNAs(miRNAs) have emerged as key regulators that control and influence gene expression as well as multiple biological processes depending on their potential binding sites in human-protein coding genes and other unconventional patterns, including coding for peptides, activating Toll-like receptors as a ligand, and other manners. Accumulating evidence has demonstrated that microRNA expression is tightly regulated during phases of development, differentiation, and effector functions of immune cells, immunological disorders of systemic lupus erythematosus (SLE). This review outlines the biogenesis of miRNAs and their unconventional functions as well as underlying cellular and molecular mechanisms. It then summarizes our current knowledge about how the biogenesis of miRNAs is regulated. Moreover, an overview was provided concerning the role of abnormal expression of miRNAs in lupus immune cells. In particular, we will shed some light on the recent advances in the role of miRNAs and exosome-derived miRNAs in immunological and epigenetic pathways in the pathogenesis of SLE.

Mesenchymal Stem Cells and MSCs-Derived Extracellular Vesicles in Infectious Diseases: From Basic Research to Clinical Practice

Mesenchymal stem cells (MSCs) are attractive in various fields of regenerative medicine due to their therapeutic potential and complex unique properties. Basic stem cell research and the global COVID-19 pandemic have given impetus to the development of cell therapy for infectious diseases. The aim of this review was to systematize scientific data on the applications of mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (MSC-EVs) in the combined treatment of infectious diseases. Application of MSCs and MSC-EVs in the treatment of infectious diseases has immunomodulatory, anti-inflammatory, and antibacterial effects, and also promotes the restoration of the epithelium and stimulates tissue regeneration. The use of MSC-EVs is a promising cell-free treatment strategy that allows solving the problems associated with the safety of cell therapy and increasing its effectiveness. In this review, experimental data and clinical trials based on MSCs and MSC-EVs for the treatment of infectious diseases are presented. MSCs and MSC-EVs can be a promising tool for the treatment of various infectious diseases, particularly in combination with antiviral drugs. Employment of MSC-derived EVs represents a more promising strategy for cell-free treatment, demonstrating a high therapeutic potential in preclinical studies.

Deficiency of p53 Causes the Inadequate Expression of miR-1246 in B Cells of Systemic Lupus Erythematosus

Underexpression of p53 is considered the leading cause of the decreased miR-1246 expression in B cells of systemic lupus erythematosus (SLE) patients, yet the exact mechanism of action still remains unclear. To further explore the molecular mechanism of p53 upregulating miR-1246 expression, we targeted the methylation and acetylation of histone H3 in the miR-1246 promoter region of SLE B cells. We found that increased histone H3 trimethylation at Lys27 (H3K27me3) and decreased histone H3 acetylation at Lys9 and Lys14 (H3K9/K14ac) in the miR-1246 promoter region are essential for the low expression of miR-1246 in SLE B cells. p53 can promote miR-1246 transcription by recruiting Jumonji domain-containing protein 3 (JMJD3), E1A-binding protein p300 (EP300), and CREB-binding protein (CBP) to bind to the miR-1246 promoter, downregulating H3K27me3 and upregulating H3K9/K14ac. Furthermore, early B cell factor 1 (EBF1), CD40, CD38, and X box binding protein-1 (XBP-1) expression levels in SLE B cells transfected with p53 expression plasmid were significantly decreased, whereas autoantibody IgG production in autologous CD4+ T cells cocultured with overexpressed p53 SLE B cells was reduced. Collectively, our data suggest that the reduction of p53 decreases miR-1246 expression via upregulation of H3K27me3 and downregulation of H3K9/14ac, which in turn results in SLE B cell hyperactivity.

A time to heal: microRNA and circadian dynamics in cutaneous wound repair

Many biological systems have evolved circadian rhythms based on the daily cycles of daylight and darkness on Earth. Such rhythms are synchronised or entrained to 24-h cycles, predominantly by light, and disruption of the normal circadian rhythms has been linked to elevation of multiple health risks. The skin serves as a protective barrier to prevent microbial infection and maintain homoeostasis of the underlying tissue and the whole organism. However, in chronic non-healing wounds such as diabetic foot ulcers (DFUs), pressure sores, venous and arterial ulcers, a variety of factors conspire to prevent wound repair. On the other hand, keloids and hypertrophic scars arise from overactive repair mechanisms that fail to cease in a timely fashion, leading to excessive production of extracellular matrix (ECM) components such as such as collagen. Recent years have seen huge increases in our understanding of the functions of microRNAs (miRNAs) in wound repair. Concomitantly, there has been growing recognition of miRNA roles in circadian processes, either as regulators or targets of clock activity or direct responders to external circadian stimuli. In addition, miRNAs are now known to function as intercellular signalling mediators through extracellular vesicles (EVs). In this review, we explore the intersection of mechanisms by which circadian and miRNA responses interact with each other in relation to wound repair in the skin, using keratinocytes, macrophages and fibroblasts as exemplars. We highlight areas for further investigation to support the development of translational insights to support circadian medicine in the context of these cells.

The emerging role non-coding RNAs in B cell-related disorders

Long non-coding RNAs and microRNAs have recently attained much attention regarding their role in the development of B cell lineage as well as participation in the lymphomagenesis. These transcripts have a highly cell type specific signature which endows them the potential to be used as biomarkers for clinical situations. Aberrant expression of several non-coding RNAs has been linked with B cell malignancies and immune related disorders such as rheumatoid arthritis, systemic lupus erythematous, asthma and graft-versus-host disease. Moreover, these transcripts can alter response of immune system to infectious conditions. miR-7, miR-16-1, miR-15a, miR-150, miR-146a, miR-155, miR-212 and miR-132 are among microRNAs whose role in the development of B cell-associated disorders has been investigated. Similarly, SNHG14, MALAT1, CRNDE, AL133346.1, NEAT1, SMAD5-AS1, OR3A4 and some other long non-coding RNAs participate in this process. In the current review, we describe the role of non-coding RNAs in B cell malignancies.

Immunomodulatory Effect of MSCs and MSCs-Derived Extracellular Vesicles in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a common autoimmune connective tissue disease with unclear etiology and pathogenesis. Mesenchymal stem cell (MSC) and MSC derived extracellular vesicles (EVs) play important roles in regulating innate and adaptive immunity, which are involved in many physiological and pathological processes and contribute to the immune homeostasis in SLE. The effects of MSCs and EVs on SLE have been drawing more and more attention during the past few years. This article reviews the immunomodulatory effects and underlying mechanisms of MSC/MSC-EVs in SLE, which provides novel insight into understanding SLE pathogenesis and guiding the biological therapy.

Immunological Involvement of MicroRNAs in the Key Events of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an archetype autoimmune disease characterized by a myriad of immunoregulatory abnormalities that drives injury to multiple tissues and organs. Due to the involvement of various immune cells, inflammatory cytokines, and related signaling pathways, researchers have spent a great deal of effort to clarify the complex etiology and pathogenesis of SLE. Nevertheless, current understanding of the pathogenesis of SLE is still in the early stages, and available nonspecific treatment options for SLE patients remain unsatisfactory. First discovered in 1993, microRNAs (miRNAs) are small RNA molecules that control the expression of 1/3 of human genes at the post-transcriptional level and play various roles in gene regulation. The aberrant expression of miRNAs in SLE patients has been intensively studied, and further studies have suggested that these miRNAs may be potentially relevant to abnormal immune responses and disease progression in SLE. The aim of this review was to summarize the specific miRNAs that have been observed aberrantly expressed in several important pathogenetic processes in SLE, such as DCs abnormalities, overactivation and autoantibody production of B cells, aberrant activation of CD4⁺ T cells, breakdown of immune tolerance, and abnormally increased production of inflammatory cytokines. Our summary highlights a novel perspective on the intricate regulatory network of SLE, which helps to enrich our understanding of this disorder and ignite future interest in evaluating the molecular regulation of miRNAs in autoimmunity SLE.

miRNA-Mediated Control of B Cell Responses in Immunity and SLE

Loss of B cell tolerance is central to autoimmune diseases such as systemic lupus erythematosus (SLE). As such, the mechanisms involved in B cell development, maturation, activation, and function that are aberrantly regulated in SLE are of interest in the design of targeted therapeutics. While many factors are involved in the generation and regulation of B cell responses, miRNAs have emerged as critical regulators of these responses within the last decade. To date, miRNA involvement in B cell responses has largely been studied in non-autoimmune, immunization-based systems. However, miRNA profiles have also been strongly associated with SLE in human patients and these molecules have proven critical in both the promotion and regulation of disease in mouse models and in the formation of autoreactive B cell responses. Functionally, miRNAs are small non-coding RNAs that bind to complementary sequences located in target mRNA transcripts to mediate transcript degradation or translational repression, invoking a post-transcriptional level of genetic regulation. Due to their capacity to target a diverse range of transcripts and pathways in different immune cell types and throughout the various stages of development and response, targeting miRNAs is an interesting potential therapeutic avenue. Herein, we focus on what is currently known about miRNA function in both normal and SLE B cell responses, primarily highlighting miRNAs with confirmed functions in mouse models. We also discuss areas that should be addressed in future studies and whether the development of miRNA-centric therapeutics may be a viable alternative for the treatment of SLE.

The roles and regulation of the KLF5 transcription factor in cancers

Krüppel‐like factor 5 (KLF5) is a member of the KLF family. Recent studies have suggested that KLF5 regulates the expression of a large number of new target genes and participates in diverse cellular functions, such as stemness, proliferation, apoptosis, autophagy, and migration. In response to multiple signaling pathways, various transcriptional modulation and posttranslational modifications affect the expression level and activity of KLF5. Several transgenic mouse models have revealed the physiological and pathological functions of KLF5 in different cancers. Studies of KLF5 will provide prognostic biomarkers, therapeutic targets, and potential drugs for cancers.

Regulation of Toll-like receptor-mediated inflammatory response by microRNA-152-3p-mediated demethylation of MyD88 in systemic lupus erythematosus

OBJECTIVE

microRNAs (miRNAs) play critical roles in embryogenesis, cell differentiation and the pathogenesis of several human diseases, including systemic lupus erythematosus (SLE). Toll-like receptors (TLRs) are also known to exert crucial functions in the immune response activation occurring in the pathogenesis of autoimmune diseases like SLE. Herein, the current study aimed to explore the potential role of miR-152-3p in TLR-mediated inflammatory response in SLE.

METHODS

We determined the miR-152-3p expression profiles in CD4+ T cells and peripheral blood mononuclear cells (PBMCs) harvested from patients with SLE and healthy controls, and analyzed the correlation between miR-152-3p expression and clinicopathological parameters. CD70 and CD40L expression patterns in CD4+ T cells were assessed by RT-qPCR and flow cytometry. ChIP was adopted to determine the enrichment of DNA methyltransferase 1 (DNMT1) in the promoter region of myeloid differentiation factor 88 (MyD88).

RESULTS

The obtained findings revealed that miR-152-3p was highly-expressed in CD4+ T cells and PBMCs of patients with SLE, and this high expression was associated with facial erythema, joint pain, double-stranded DNA, and IgG antibody. DNMT1 could be enriched in the MyD88 promoter, and miR-152-3p inhibited the methylation of MyD88 by targeting DNMT1. We also found that silencing miR-152-3p inhibited MyD88 expression not only to repress the autoreactivity of CD4+ T cells and but also to restrain their cellular inflammation, which were also validated in vivo.

CONCLUSION

Our study suggests that miR-152-3p promotes TLR-mediated inflammatory response in CD4+ T cells by regulating the DNMT1/MyD88 signaling pathway, which highlights novel anti-inflammatory target for SLE treatment.

Discovering the signature of a lupus-related microRNA profile in the Gene Expression Omnibus repository

Lupus is one of the most prevalent systemic autoimmune diseases. It is a multifactorial disease in which genetic, epigenetic and environmental factors play significant roles. The pathogenesis of lupus is not yet well understood. However, deregulation of microRNAs (miRNAs) - one of the post-transcriptional regulators of genes - can contribute to the development of autoimmune diseases. Over the last two decades, advances in the profiling of miRNA using microarray have received much attention, and it has been demonstrated that miRNAs play a regulatory role in the pathogenesis of lupus. Therefore, dysregulated miRNAs can be considered as promising diagnostic biomarkers for lupus. This article is an overview of lupus-related miRNA profiling studies and arrays in the Gene Expression Omnibus (GEO) database. The aims of our study were to widen current knowledge of known dysregulated miRNAs as potential biomarkers of SLE and to introduce a bioinformatics approach to using microarray data and finding novel miRNA and gene candidates for further study. We identified hsa-miR-4709-5p, hsa-miR-140, hsa-miR-145, hsa-miR-659, hsa-miR-134, hsa-miR-150, hsa-miR-584, hsa-miR-409 and hsa-miR-152 as potential biomarkers by integrated bioinformatics analysis.

Transcriptional meta-analysis of regulatory B cells

Regulatory B cells (Bregs) have the ability to regulate inflammation in various pathological situations, making them key players in immune regulation. Several mechanisms have been described and we recently identified a GZMB expressing Breg population in kidney transplanted patients who tolerate a kidney graft. To further investigate their biology and mechanisms, we conducted a transcriptomic analysis by RNAseq of these cells and we performed the first weighted meta-analysis of publicly available transcriptomic data from published Breg studies both in humans and mice. We identified two distinct and unique transcriptional signatures of 126 and 93 genes, respectively, associated with these Bregs. While we highlighted genes coding for proteins with potent involvement in regulatory functions, proliferation, and coding for transcription factors, the comparison between humans and mice did not allow identifying a common pattern. Thus, our results suggest distinct species-restricted Breg transcriptional signatures in humans and mice.

Exploring the Role of Non-Coding RNAs in the Pathophysiology of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic immune-related disorder designated by a lack of tolerance to self-antigens and the over-secretion of autoantibodies against several cellular compartments. Although the exact pathophysiology of SLE has not been clarified yet, this disorder has a strong genetic component based on the results of familial aggregation and twin studies. Variation in the expression of non-coding RNAs has been shown to influence both susceptibility to SLE and the clinical course of this disorder. Several long non-coding RNAs (lncRNAs) such as GAS5, MALAT1 and NEAT1 are dysregulated in SLE patients. Moreover, genetic variants within lncRNAs such as SLEAR and linc00513 have been associated with risk of this disorder. The dysregulation of a number of lncRNAs in the peripheral blood of SLE patients has potentiated them as biomarkers for diagnosis, disease activity and therapeutic response. MicroRNAs (miRNAs) have also been shown to affect apoptosis and the function of immune cells. Taken together, there is a compelling rationale for the better understanding of the involvement of these two classes of non-coding RNAs in the pathogenesis of SLE. Clarification of the function of these transcripts has the potential to elucidate the molecular pathophysiology of SLE and provide new opportunities for the development of targeted therapies for this disorder.