The upregulation of miR-98-5p affects the glycosylation of IgA1 through cytokines in IgA nephropathy

A Systematic Review and Meta-Analysis of microRNA Profiling Studies in Chronic Kidney Diseases

Chronic kidney disease (CKD) represents an increasing health burden. Evidence suggests the importance of miRNA in diagnosing CKD, yet the reports are inconsistent. This study aimed to determine novel miRNA biomarkers and potential therapeutic targets from hypothesis-free miRNA profiling studies in human and murine CKDs. Comprehensive literature searches were conducted on five databases. Subgroup analyses of kidney diseases, sample types, disease stages, and species were conducted. A total of 38 human and 12 murine eligible studies were analyzed using Robust Rank Aggregation (RRA) and vote-counting analyses. Gene set enrichment analyses of miRNA signatures in each kidney disease were conducted using DIANA-miRPath v4.0 and MIENTURNET. As a result, top target genes, Gene Ontology terms, the interaction network between miRNA and target genes, and molecular pathways in each kidney disease were identified. According to vote-counting analysis, 145 miRNAs were dysregulated in human kidney diseases, and 32 were dysregulated in murine CKD models. By RRA, miR-26a-5p was significantly reduced in the kidney tissue of Lupus nephritis (LN), while miR-107 was decreased in LN patients' blood samples. In both species, epithelial-mesenchymal transition, Notch, mTOR signaling, apoptosis, G2/M checkpoint, and hypoxia were the most enriched pathways. These miRNA signatures and their target genes must be validated in large patient cohort studies.

Deciphering roles of protein post-translational modifications in IgA nephropathy progression and potential therapy

Immunoglobulin A nephropathy (IgAN), one type of glomerulonephritis, displays the accumulation of glycosylated IgA in the mesangium. Studies have demonstrated that both genetics and epigenetics play a pivotal role in the occurrence and progression of IgAN. Post-translational modification (PTM) has been revealed to critically participate in IgAN development and progression because PTM dysregulation results in impaired degradation of proteins that regulate IgAN pathogenesis. A growing number of studies identify that PTMs, including sialylation, o-glycosylation, galactosylation, phosphorylation, ubiquitination and deubiquitination, modulate the initiation and progression of IgAN. Hence, in this review, we discuss the functions and mechanisms of PTMs in regulation of IgAN. Moreover, we outline numerous compounds that govern PTMs and attenuate IgAN progression. Targeting PTMs might be a useful strategy to ameliorate IgAN.

Exploring the pathogenesis and treatment of IgA nephropathy based on epigenetics

IgA nephropathy is the most common primary glomerulonephritis worldwide. However, its exact cause remains unclear, with known genetic factors explaining only 11% of the variation. Recently, researchers have turned their attention to epigenetic abnormalities in immune-related diseases, recognizing their significance in IgA nephropathy's development and progression. This emerging field has revolutionized our understanding of epigenetics in IgA nephropathy research. Though in its early stages, studying IgA nephropathy's epigenetics holds promise for unraveling its pathogenesis and identifying new biomarkers and therapies. This review aims to comprehensively analyze epigenetics' role in IgA nephropathy's development and suggest avenues for potential therapeutic interventions. In the future, assessing and modulating epigenetics may become integral in diagnosing, tailoring treatments and assessing prognoses for IgA nephropathy.

Identification of the Genetic Influence of SARS-CoV-2 Infections on IgA Nephropathy Based on Bioinformatics Method

INTRODUCTION

Coronavirus disease-2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. It was initially detected in Wuhan, China, in December 2019. In March 2020, the World Health Organization (WHO) declared COVID-19 a global pandemic. Compared to healthy individuals, patients with IgA nephropathy (IgAN) are at a higher risk of SARS-CoV-2 infection. However, the potential mechanisms remain unclear. This study explores the underlying molecular mechanisms and therapeutic agents for the management of IgAN and COVID-19 using the bioinformatics and system biology way.

METHODS

We first downloaded GSE73953 and GSE164805 from the Gene Expression Omnibus (GEO) database to obtain common differentially expressed genes (DEGs). Then, we performed the functional enrichment analysis, pathway analysis, protein-protein interaction (PPI) analysis, gene regulatory networks analysis, and potential drug analysis on these common DEGs.

RESULTS

We acquired 312 common DEGs from the IgAN and COVID-19 datasets and used various bioinformatics tools and statistical analyses to construct the PPI network to extract hub genes. Besides, we performed gene ontology (GO) and pathway analyses to reveal the common correlation between IgAN and COVID-19. Finally, on the basis of common DEGs, we determined the interactions between DEGs-miRNAs, the transcription factor-genes (TFs-genes), protein-drug, and gene-disease networks.

CONCLUSION

We successfully identified hub genes that may act as biomarkers of COVID-19 and IgAN and also screened out some potential drugs to provide new ideas for COVID-19 and IgAN treatment.

Noncoding RNAs associated with IgA nephropathy

IgA nephropathy (IgAN) is one of the most common glomerulonephritides. The disease is characterized by haematuria, proteinuria, deposition of galactose-deficient IgA1 in the glomerular mesangium and mesangial hypercellularity, further leading to extracellular matrix expansion. Kidney biopsy is the gold standard for IgAN diagnosis. Due to the invasiveness of renal biopsy, there is an unmet need for noninvasive biomarkers to diagnose and estimate the severity of IgAN. Understanding the role of RNA molecules as genetic markers to target diseases may allow developing therapeutic and diagnostic markers. In this review we have focused on intrarenal, extrarenal and extracellular noncoding RNAs involved in the progression of IgAN. This narrative review summarizes the pathogenesis of IgAN along with the correlation of noncoding RNA molecules such as microRNAs, small interfering RNAs, circular RNAs and long non-coding RNAs that play an important role in regulating gene expression, and that represent another type of regulation affecting the expression of specific glycosyltranferases, a key element contributing to the development of IgAN.

Cytokines and Production of Aberrantly O-Glycosylated IgA1, the Main Autoantigen in IgA Nephropathy

Immunoglobulin A (IgA) nephropathy is the most common primary glomerulonephritis worldwide, with no disease-specific treatment and up to 40% of patients progressing to kidney failure. IgA nephropathy (IgAN), characterized by IgA1-containing immunodeposits in the glomeruli, is considered to be an autoimmune disease in which the kidneys are injured as innocent bystanders. Glomerular immunodeposits are thought to originate from the circulating immune complexes that contain aberrantly O-glycosylated IgA1, the main autoantigen in IgAN, bound by IgG autoantibodies. A common clinical manifestation associated with IgAN includes synpharyngitic hematuria at disease onset or during disease activity. This observation suggests a connection of disease pathogenesis with an activated mucosal immune system of the upper-respiratory and/or gastrointestinal tract and IgA1 glycosylation. In fact, some cytokines can enhance production of aberrantly O-glycosylated IgA1. This process involves abnormal cytokine signaling in IgA1-producing cells from patients with IgAN. In this article, we present our view of pathogenesis of IgAN and review how some cytokines can contribute to the disease process by enhancing production of aberrantly glycosylated IgA1. We also review current clinical trials of IgAN based on cytokine-targeting therapeutic approaches.

Recent findings on the role of microRNAs in genetic kidney diseases

BACKGROUND

MicroRNAs (miRNAs) are non-coding, endogenous, single-stranded, small (21-25 nucleotides) RNAs. Various target genes at the post-transcriptional stage are modulated by miRNAs that are involved in the regulation of a variety of biological processes such as embryonic development, differentiation, proliferation, apoptosis, inflammation, and metabolic homeostasis. Abnormal miRNA expression is strongly associated with the pathogenesis of multiple common human diseases including cardiovascular diseases, cancer, hepatitis, and metabolic diseases.

METHODS AND RESULTS

Various signaling pathways including transforming growth factor-β, apoptosis, and Wnt signaling pathways have also been characterized to play an essential role in kidney diseases. Most importantly, miRNA-targeted pharmaceutical manipulation has represented a promising new therapeutic approach against kidney diseases. Furthermore, miRNAs such as miR-30e-5p, miR-98-5p, miR-30d-5p, miR-30a-5p, miR-194-5p, and miR-192-5p may be potentially employed as biomarkers for various human kidney diseases.

CONCLUSIONS

A significant correlation has also been found between some miRNAs and the clinical markers of renal function like baseline estimated glomerular filtration rate (eGFR). Classification of miRNAs in different genetic renal disorders may promote discoveries in developing innovative therapeutic interventions and treatment tools. Herein, the recent advances in miRNAs associated with renal pathogenesis, emphasizing genetic kidney diseases and development, have been summarized.

Prediction and analysis of microRNAs involved in COVID-19 inflammatory processes associated with the NF-kB and JAK/STAT signaling pathways

COVID-19 is the cause of a pandemic associated with substantial morbidity and mortality. As yet, there is no available approved drug to eradicate the virus. In this review article, we present an alternative study area that may contribute to the development of therapeutic targets for COVID-19. Growing evidence is revealing further pathophysiological mechanisms of COVID-19 related to the disregulation of inflammation pathways that seem to play a critical role toward COVID-19 complications. The NF-kB and JAK/STAT signaling pathways are highly activated in acute inflammation, and the excessive activity of these pathways in COVID-19 patients likely exacerbates the inflammatory responses of the host. A group of non-coding RNAs (miRNAs) manage certain features of the inflammatory process. In this study, we discuss recent advances in our understanding of miRNAs and their connection to inflammatory responses. Additionally, we consider the link between perturbations in miRNA levels and the onset of COVID-19 disease. Furthermore, previous studies published in the online databases, namely web of science, MEDLINE (PubMed), and Scopus, were reviewed for the potential role of miRNAs in the inflammatory manifestations of COVID-19. Moreover, we disclosed the interactions of inflammatory genes using STRING DB and designed interactions between miRNAs and target genes using Cityscape software. Several miRNAs, particularly miR-9, miR-98, miR-223, and miR-214, play crucial roles in the regulation of NF-kB and JAK-STAT signaling pathways as inflammatory regulators. Therefore, this group of miRNAs that mitigate inflammatory pathways can be further regarded as potential targets for far-reaching-therapeutic strategies in COVID-19 diseases.

Downregulation of miR‑214-3p attenuates mesangial hypercellularity by targeting PTEN‑mediated JNK/c-Jun signaling in IgA nephropathy

Mesangial cell (MC) proliferation and matrix expansion are basic pathological characteristics of IgA nephropathy (IgAN). However, the stepwise mechanism of MC proliferation and the exact set of related signaling molecules remain largely unclear. In this study, we found a significant upregulation of miR-214-3p in the renal cortex of IgAN mice by miRNA sequencing. In situ hybridization analysis showed that miR-214-3p expression was obviously elevated in MCs in the renal cortex in IgAN. Functionally, knockdown of miR-214-3p alleviated mesangial hypercellularity and renal lesions in IgAN mice. In vitro, the inhibition of miR-214-3p suppressed MC proliferation and arrested G1-S cell cycle pSrogression in IgAN. Mechanistically, a luciferase reporter assay verified PTEN as a direct target of miR-214-3p. Downregulation of miR-214-3p increased PTEN expression and reduced p-JNK and p-c-Jun levels, thereby inhibiting MC proliferation and ameliorating renal lesions in IgAN. Moreover, these changes could be attenuated by co-transfection with PTEN siRNA. Collectively, these results illustrated that miR-214-3p accelerated MC proliferation in IgAN by directly targeting PTEN to modulate JNK/c-Jun signaling. Therefore, miR-214-3p may represent a novel therapeutic target for IgAN.

The Non-Coding RNA Landscape in IgA Nephropathy-Where Are We in 2021?

IgA nephropathy (IgAN) is the most commonly diagnosed primary glomerulonephritis worldwide. It is a slow progressing disease with approximately 30% of cases reaching end-stage kidney disease within 20 years of diagnosis. It is currently only diagnosed by an invasive biopsy and treatment options are limited. However, the current surge in interest in RNA interference is opening up new horizons for the use of this new technology in the field of IgAN management. A greater understanding of the fundamentals of RNA interference offers exciting possibilities both for biomarker discovery and, more importantly, for novel therapeutic approaches to target key pathogenic pathways in IgAN. This review aims to summarise the RNA interference literature in the context of microRNAs and their association with the multifaceted aspects of IgA nephropathy.

Astragaloside IV Inhibits Galactose-Deficient IgA1 Secretion via miR-98-5p in Pediatric IgA Nephropathy

Purpose: The factor associated with IgA nephropathy (IgAN) is an abnormality of IgA known as galactose-deficient IgA1 (Gd-IgA1). The purpose of this study was to determine the molecular role played by miRNAs in the formation of Gd-IgA1 in IgAN and investigate the regulatory role of Astragaloside IV (AS-IV) in miRNAs.

Patients and methods: Bioinformatics analysis, along with functional and mechanistic experiments, were used to investigate the relationship and function of miRNA, β-1, 3-galactosyltransferase (C1GALT1), Gd-IgA1, and AS-IV. Analyses involved a series of tools, including quantitative real-time polymerase chain reaction (qRT-qPCR), Western blot, enzyme-linked immunosorbent assay (ELISA), Vicia Villosa lectin-binding assay (VVA), Cell counting kit-8 assay (CCK-8), and the dual-luciferase reporter assay.

Results: miRNA screening and validation showed that miR-98-5p was significantly upregulated in the peripheral blood mononuclear cells (PBMCs) of pediatric patients with IgAN compared with patients diagnosed with mesangial proliferative glomerulonephritis (MsPGN) and immunoglobulin A vasculitis nephritis (IgAV-N), and healthy controls (p < 0.05). Experiments with the dual-luciferase reporter confirmed that miR-98-5p might target C1GALT1. The overexpression of miR-98-5p in DAKIKI cells decreased both the mRNA and protein levels of C1GALT1 and increased the levels of Gd-IgA1 levels; these effects were reversed by co-transfection with the C1GALT1 plasmid, and vice versa. In addition, AS-IV downregulated the levels of Gd-IgA1 level in DAKIKI cells by inhibiting miR-98-5p.

Conclusions: Our results revealed that AS-IV could inhibit Gd-IgA1 secretion via miR-98-5p. Increased levels of miR-98-5p in pediatric IgAN patients might affect the glycosylation of IgA1 by targeting C1GALT1. In addition, our analyses suggest that the pathogenesis of IgAN may differ from that of IgAV-N. Collectively, these results provide significant insight into the pathogenesis of IgAN and identify a potential therapeutic target.

Epigenetic Regulation of Glycosylation in Cancer and Other Diseases

In the last few decades, the newly emerging field of epigenetic regulation of glycosylation acquired more importance because it is unraveling physiological and pathological mechanisms related to glycan functions. Glycosylation is a complex process in which proteins and lipids are modified by the attachment of monosaccharides. The main actors in this kind of modification are the glycoenzymes, which are translated from glycosylation-related genes (or glycogenes). The expression of glycogenes is regulated by transcription factors and epigenetic mechanisms (mainly DNA methylation, histone acetylation and noncoding RNAs). This review focuses only on these last ones, in relation to cancer and other diseases, such as inflammatory bowel disease and IgA1 nephropathy. In fact, it is clear that a deeper knowledge in the fine-tuning of glycogenes is essential for acquiring new insights in the glycan field, especially if this could be useful for finding novel and personalized therapeutics.

Diminution of microRNA-98 alleviates renal fibrosis in diabetic nephropathy by elevating Nedd4L and inactivating TGF-β/Smad2/3 pathway

MicroRNAs (miRNAs) have already been documented to function in diabetic nephropathy (DN), yet little research has focused on the role of miR-98 in this disease. Here, we discuss the mechanism of miR-98 on the renal fibrosis in DN. Recombinant adeno-associated virus carrying miR-98 inhibitor or Nedd4L overexpression plasmid was injected into DN modeled rats to explore their roles in DN. Renal tubular epithelial cell injury models (NRK-52E cells) were induced by high glucose (HG). HG-treated NRK-52E cells were transfected with miR-98 inhibitor or Nedd4L overexpression plasmid for further verification. MiR-98 was upregulated, Nedd4L was downregulated and TGF-β/Smad2/3 signaling was activated in kidney tissues of DN rats and HG-treated NRK-52E cells. miR-98 targeted Nedd4L mRNA 3'UTR. MiR-98 depletion and Nedd4L overexpression inactivated TGF-β/Smad2/3 signaling pathway, alleviated pathological damage and fibrosis, ameliorated inflammation, and depressed cell apoptosis of kidney tissues of DN rats. MiR-98 depletion and Nedd4L overexpression inactivated TGF-β/Smad2/3 signaling pathway, strengthened viability, and limited apoptosis of HG-treated renal tubular epithelial cells. Nedd4L overexpression reversed the effect of up-regulating miR-98 on DN rats and HG-treated renal tubular epithelial cells. Altogether, we find that miR-98 is upregulated in kidney tissues of DN rats, and miR-98 diminution and Nedd4L elevation attenuate renal fibrosis through inactivation of the TGF-β/Smad2/3 pathway, which provides a novel therapy for DN.