Glomerular and tubulointerstitial miR-638, miR-198 and miR-146a expression in lupus nephritis

Comprehensive assessment of the combined impact of dyslipidemia and inflammation on chronic kidney disease development: A prospective cohort study

BACKGROUND

There remains a limited comprehensive understanding of how dyslipidemia and chronic inflammation collectively contribute to the development of chronic kidney disease (CKD).

OBJECTIVE

We aimed to identify clusters of individuals with five variables, including lipid profiles and C-reactive protein (CRP) levels, and to assess whether the clusters were associated with incident CKD risk.

METHODS

We used the Korean Genome and Epidemiology Study-Ansan and Ansung data. K-means clustering analysis was performed to identify distinct clusters based on total cholesterol, triglyceride, non-high-density lipoprotein (HDL)-C, HDL-C, and CRP levels. Cox proportional hazards models were used to examine the association between incident CKD risk and the different clusters.

RESULTS

During the mean 10-year follow-up period, CKD developed in 1,645 participants (690 men and 955 women) among a total of 8,053 participants with a mean age of 51.8 years. Four distinct clusters were identified: C1, low cholesterol group (LC); C2, high-density lipoprotein cholesterol group (HC); C3, insulin resistance and inflammation group (IIC); and C4, dyslipidemia and inflammation group (DIC). Cluster 4 had a significantly higher risk of incident CKD compared to clusters 2 (hazard ratio (HR) 1.455 [95% confidence interval (CI) 1.234-1.715]; p < 0.001) and cluster 1 (HR 1.264 [95% CI 1.067-1.498]; p = 0.007) after adjusting for confounders. Cluster 3 had a significantly higher risk of incident CKD compared to clusters 2 and 1.

CONCLUSION

Clusters 4 and 3 had higher risk of incident CKD compared to clusters 2 and 1. The combination of dyslipidemia with inflammation or insulin resistance with inflammation appears to be pivotal in the development of incident CKD.

Recent advances in the involvement of epigenetics in the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a typical systemic autoimmune disease that manifests as skin rash, arthritis, lymphadenopathy, and multiple organ lesions. Epigenetics, including DNA methylation, histone modification, and non-coding RNA regulation, mainly affect the function and characteristics of cells through the regulation of gene transcription or translation. Increasing evidence indicates that there are a variety of complex epigenetic effects in patients with SLE, which interfere with the differentiation and function of T, and B lymphocytes, monocytes, and neutrophils, and enhance the expression of SLE-associated pathogenic genes. This paper summarizes our currently knowledge regarding pathogenesis of SLE, and introduces current advances in the epigenetic regulation of SLE from three aspects: immune function, inflammatory response, and lupus complications. We propose that epigenetic changes could be used as potential biomarkers and therapeutic targets of SLE.

Pathogenesis of lupus nephritis: the contribution of immune and kidney resident cells

PURPOSE OF REVIEW

Lupus nephritis is associated with significant mortality and morbidity. We lack effective therapeutics and biomarkers mostly because of our limited understanding of its complex pathogenesis. We aim to present an overview of the recent advances in the field to gain a deeper understanding of the underlying cellular and molecular mechanisms involved in lupus nephritis pathogenesis.

RECENT FINDINGS

Recent studies have identified distinct roles for each resident kidney cell in the pathogenesis of lupus nephritis. Podocytes share many elements of innate and adaptive immune cells and they can present antigens and participate in the formation of crescents in coordination with parietal epithelial cells. Mesangial cells produce pro-inflammatory cytokines and secrete extracellular matrix contributing to glomerular fibrosis. Tubular epithelial cells modulate the milieu of the interstitium to promote T cell infiltration and formation of tertiary lymphoid organs. Modulation of specific genes in kidney resident cells can ward off the effectors of the autoimmune response including autoantibodies, cytokines and immune cells.

SUMMARY

The development of lupus nephritis is multifactorial involving genetic susceptibility, environmental triggers and systemic inflammation. However, the role of resident kidney cells in the development of lupus nephritis is becoming more defined and distinct. More recent studies point to the restoration of kidney resident cell function using cell targeted approaches to prevent and treat lupus nephritis.

Candidate MicroRNA Biomarkers in Lupus Nephritis: A Meta-analysis of Profiling Studies in Kidney, Blood and Urine Samples

CONTEXT

Lupus nephritis (LN) is a kidney disease caused by systemic lupus erythematosus in which kidneys are attacked by the immune system. So far, various investigations have reported altered miRNA expression profiles in LN patients and different miRNAs have been introduced as biomarkers and/or therapeutic targets in LN. The aim of this study was to introduce a consensus panel of potential miRNA biomarkers by performing a meta-analysis of miRNA profiles in the LN patients.

MATERIALS AND METHODS

A comprehensive literature review approach was performed to find LN-related miRNA expression profiles in renal tissues, blood, and urine samples. After selecting the eligible studies and performing the data extraction, meta-analysis was done based on the vote-counting rank strategy as well as meta-analysis of p-values. The meta-miRNAs and their related genes were subjected to functional enrichment analyses and network construction.

RESULTS

The results of the meta-analysis of 41 studies were three lists of consensus miRNAs with altered expression profiles in the various tissue samples of LN patients (meta-analysis of p-values < 0.05). Of the 13 studies on kidney tissue, the meta-miRNAs were let-7a, miR-198, let-7e, miR-145, and miR-26a. In addition, meta-miRNAs of miR-199a, miR-21, miR-423, miR-1260b, miR-589, miR-150, miR-155, miR-146a, and miR-183 from 21 studies on blood samples, and miR-146a, miR-204, miR-30c, miR-3201, and miR-1273e from 11 studies on urine samples can be considered as non-invasive biomarker panels for LN. Functional enrichment analysis on the meta-miRNA lists confirmed the involvement of their target genes in nephropathy-related signaling pathways.

CONCLUSION

Using a meta-analytical approach, our study proposes three meta-miRNA panels that could be the target of further research to assess their potential as therapeutic targets/biomarkers in LN disease.

Molecular profiling of urinary extracellular vesicles in chronic kidney disease and renal fibrosis

Chronic kidney disease (CKD) is a long-term kidney damage caused by gradual loss of essential kidney functions. A global health issue, CKD affects up to 16% of the population worldwide. Symptoms are often not apparent in the early stages, and if left untreated, CKD can progress to end-stage kidney disease (ESKD), also known as kidney failure, when the only possible treatments are dialysis and kidney transplantation. The end point of nearly all forms of CKD is kidney fibrosis, a process of unsuccessful wound-healing of kidney tissue. Detection of kidney fibrosis, therefore, often means detection of CKD. Renal biopsy remains the best test for renal scarring, despite being intrinsically limited by its invasiveness and sampling bias. Urine is a desirable source of fibrosis biomarkers as it can be easily obtained in a non-invasive way and in large volumes. Besides, urine contains biomolecules filtered through the glomeruli, mirroring the pathological state. There is, however, a problem of highly abundant urinary proteins that can mask rare disease biomarkers. Urinary extracellular vesicles (uEVs), which originate from renal cells and carry proteins, nucleic acids, and lipids, are an attractive source of potential rare CKD biomarkers. Their cargo consists of low-abundant proteins but highly concentrated in a nanosize-volume, as well as molecules too large to be filtered from plasma. Combining molecular profiling data (protein and miRNAs) of uEVs, isolated from patients affected by various forms of CKD, this review considers the possible diagnostic and prognostic value of uEVs biomarkers and their potential application in the translation of new experimental antifibrotic therapeutics.

Analysis of TNF-like weak inducer of apoptosis for detecting lupus nephritis

Lupus is an autoimmune disease that has various manifestations in various organs. One of the manifestations of lupus is lupus nephritis (LN), which often causes kidney failure and death. Cytokines play an essential role in the pathogenesis of LN and might be helpful for LN biomarkers. This study aimed to evaluate urine TNF-like weak inducer of apoptosis (TWEAK) for detecting LN since this is not an invasive procedure and is more cost-effective. The gold standard procedure for diagnosing LN needs a biopsy of the kidney. However, the procedure is invasive, high cost, and takes time. Thus, a biomarker from urine is needed for early diagnosis of LN. This research conducted was cross-sectional. The total participants were 57, consisting of 29 lupus nephritis and 28 lupus without nephritis. TWEAK levels were determined by ELISA method; urine protein, urine erythrocyte, and leukocyte were examined by a urine autoanalyzer. Statistical analysis using Mann–Whitney, Spearman correlation, Kruskal–Wallis, ROC curve analysis, and a 2 × 2 contingency table. This study showed a significant difference in TWEAK levels between lupus nephritis and lupus without nephritis (p < 0.05), but no significant difference between TWEAK level and renal domain scores of SLEDAI. There were significant correlations between TWEAK level and urine erythrocyte and urine protein, but there was no significant correlation with urine leukocytes. The sensitivity and specificity of TWEAK for determining LN were 72.4% and 72.5%, respectively, with AUC 0.77. TWEAK had a good diagnostic test for detecting lupus nephritis and substantially correlated with urine erythrocyte and urine protein.

Lipid-Based Nanocarriers in Renal RNA Therapy

Kidney disease is a multifactorial problem, with a growing prevalence and an increasing global burden. With the latest worldwide data suggesting that chronic kidney disease (CKD) is the 12th leading cause of death, it is no surprise that CKD remains a public health problem that requires urgent attention. Multiple factors contribute to kidney disease, each with its own pathophysiology and pathogenesis. Furthermore, microRNAs (miRNAs) have been linked to several types of kidney diseases. As dysregulation of miRNAs is often seen in some diseases, there is potential in the exploitation of this for therapeutic applications. In addition, uptake of interference RNA has been shown to be rapid in kidneys making them a good candidate for RNA therapy. The latest advancements in RNA therapy and lipid-based nanocarriers have enhanced the effectiveness and efficiency of RNA-related drugs, thereby making RNA therapy a viable treatment option for renal disease. This is especially useful for renal diseases, for which a suitable treatment is not yet available. Moreover, the high adaptability of RNA therapy combined with the low risk of lipid-based nanocarriers make for an attractive treatment choice. Currently, there are only a small number of RNA-based drugs related to renal parenchymal disease, most of which are in different stages of clinical trials. We propose the use of miRNAs or short interfering RNAs coupled with a lipid-based nanocarrier as a delivery vehicle for managing renal disease.

Emerging role and function of miR-198 in human health and diseases

Ever since their discovery, microRNAs (miRNAs/miRs) have astonished us by the plethora of processes they regulate, and thus adding another dimension to the gene regulation. They have been implicated in several diseases affecting cardiovascular, neurodegenerative, hepatic, autoimmune and inflammatory functions. A primate specific exonic miRNA, miR-198 has been vastly studied during the past decade, and shown to have a critical role in wound healing. The aberrant expression of miR-198 was first reported in schizophrenia, linking it to neural development. Later, its dysregulation and tumor suppressive role was reported in hepatocellular carcinoma. However, this was just a beginning, and after which there was an explosion of reports linking miR-198 deregulation to cancers and other ailments. The first target to be identified for miR-198 was Cyclin T1 in monocytes affecting HIV1 replication. Depending on the type of cancer, miR-198 has been shown to function either as a tumor suppressor or an oncomir. Interestingly, miR-198 is not only known to regulate multiple targets and pathways, but also is itself regulated by several circular RNAs and long-non-coding RNAs, highlighting a complex regulatory network. This review highlights the currently understood mechanism and regulation of miR-198 in different diseases, and its possible diagnostic and therapeutic potential.

Dysregulation of miR-638 in diabetic nephropathy and its role in inflammatory response

BACKGROUND

MicroRNA (miRNA) can be used as a biomarker for the early diagnosis of diabetic nephropathy (DN). The purpose of this study was to evaluate the diagnostic value of miR-638 in DN and to analyse its regulatory effect on inflammation.

METHODS

This retrospective study involved 98 subjects, including non-diabetic healthy controls (n = 30), patients with type 2 diabetes (T2DM, n = 36) without complications and patients with DN (n = 32). After the anthropometric and biochemical evaluation, serum miR-638 levels were assessed by real-time reverse transcription-polymerase chain reaction (qRT-PCR). The levels of inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor-alpha [TNF-α]) were detected using enzyme-linked immunosorbent assay. The Spearman correlations were used to analyze the correlation between miR-638 and urinary albumin excretion (UAE), estimated glomerular filtration rate (eGFR), and inflammatory factors. Furthermore, the receiver operating characteristic (ROC) curve was used to measure the diagnostic value of miR-638 in DN. Human mesangial cells (HMCs) were treated with normal glucose (NG, 5.5 mM glucose), high glucose (HG, 30 mM glucose), or high osmotic pressure solution (HO, 5.5 mM glucose + 24.5 mM mannitol) in vitro to simulate the hyperglycamic state in vivo. Subsequently, the HMCs were transfected with miR-638 mimics to regulate the level of miR-638 in the cells and detect its regulation on cell inflammation and proliferation.

RESULTS

Compared with healthy controls and patients with T2DM, serum miR-638 in patients with DN was significantly lower. The reduced miR-638 expression has a significant diagnostic value, which can significantly distinguish patients with DN from healthy controls or patients with T2DM. Inflammatory factors were significantly upregulated in patients with DN and negatively correlated with miR-638 levels. In addition, miR-638 was negatively correlated with UAE and positively correlated with eGFR. HG decreased the level of miR-638 and promoted the expression of inflammatory factors and proliferation in HMCs. However, miR-638 mimic significantly decreased the levels of inflammatory factors and inhibited the proliferative ability induced by HG.

CONCLUSIONS

Serum miR-638 expression was low in DN and can be a potentially valuable biomarker for DN. This miRNA seems to influence inflammatory responses and participate in the progression of DN by regulating proliferation.

MicroRNAs in Lupus Nephritis-Role in Disease Pathogenesis and Clinical Applications

MicroRNAs (miRs) are non-coding small RNAs that act as epigenetic modulators to regulate the protein levels of target mRNAs without modifying the genetic sequences. The role of miRs in the pathogenesis of lupus nephritis (LN) is increasingly recognized and highly complex. Altered levels of different miRs are observed in the blood, urine and kidney tissues of murine LN models and LN patients. Accumulating evidence suggests that these miRs can modulate immune cells and various key inflammatory pathways, and their perturbations contribute to the aberrant immune response in LN. The dysregulation of miRs in different resident renal cells and urinary exosomes can also lead to abnormal renal cell proliferation, inflammation and kidney fibrosis in LN. While miRs may hold promise in various clinical applications in LN patients, there are still many potential limitations and safety concerns for their use. Further studies are worthwhile to examine the clinical utility of miRs in the diagnosis, disease activity monitoring, prognostication and treatment of LN.

Small RNA sequencing evaluation of renal microRNA biomarkers in dogs with X-linked hereditary nephropathy

Dogs with X-linked hereditary nephropathy (XLHN) are an animal model for Alport syndrome in humans and progressive chronic kidney disease (CKD). Using mRNA sequencing (mRNA-seq), we have characterized the gene expression profile affecting the progression of XLHN; however, the microRNA (miRNA, miR) expression remains unknown. With small RNA-seq and quantitative RT-PCR (qRT-PCR), we used 3 small RNA-seq analysis tools (QIAGEN OmicSoft Studio, miRDeep2, and CPSS 2.0) to profile differentially expressed renal miRNAs, top-ranked miRNA target genes, and enriched biological processes and pathways in CKD progression. Twenty-three kidney biopsies were collected from 5 dogs with XLHN and 4 age-matched, unaffected littermates at 3 clinical time points (T1: onset of proteinuria, T2: onset of azotemia, and T3: advanced azotemia). We identified up to 23 differentially expressed miRNAs at each clinical time point. Five miRNAs (miR-21, miR-146b, miR-802, miR-142, miR-147) were consistently upregulated in affected dogs. We identified miR-186 and miR-26b as effective reference miRNAs for qRT-PCR. This study applied small RNA-seq to identify differentially expressed miRNAs that might regulate critical pathways contributing to CKD progression in dogs with XLHN.

The pathogenic, therapeutic and diagnostic role of exosomal microRNA in the autoimmune diseases

Exosomes are a nano-vesicle surrounded by a bilipid layer that can release from almost all cells and could be detected in tissues and biological liquids. These vesicles contain lipids, proteins, and nucleic acids (including DNA, mRNA, and miRNA) inside and on the exosomes' surface constitute their content. Exosomes can transfer their cargo into the recipient cell, which can modify recipient cells' biological activities. Recently it has been deciphering that the miRNA pattern of exosomes reveals the cellular pathophysiological situation and modifies various biological processes. Increasing data regarding exosomes highlights that the exosomes and their cargo, especially miRNAs, are implicated in the pathophysiology of various disorders, such as autoimmune disease. The current evidence on the deciphering of mechanisms in which exosomal miRNAs contributed to autoimmunity was indicated that exosomal miRNA might hold information that can reprogram the function of many of the immune cells involved in autoimmune diseases' pathogenesis. In the present study, we summarized the pathogenic role of exosomal miRNAs in several autoimmune diseases, including myasthenia gravis (MG), psoriasis, inflammatory bowel disease (IBD), type 1 diabetes (T1D), multiple sclerosis (MS), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's Syndrome (SS), systemic sclerosis (SSc), vitiligo, and autoimmune thyroid diseases (AITD). Moreover, in this work, we present evidence of the potential role of exosomal miRNAs as therapeutic and diagnostic agents in autoimmune diseases.

Macrophage interactions with collecting duct epithelial cells are capable of driving tubulointerstitial inflammation and fibrosis in immunoglobulin A nephropathy

BACKGROUND

Tubulointerstitial fibrosis is a powerful predictor of future progression inimmunoglobulin A (IgA) nephropathy (IgAN). Proximal tubular epithelial cells (PTECs), in concert with infiltrating macrophages, are regarded as the agents provocateurs for driving this fibrotic process. However, evidence is now emerging for a contributory role of the distal nephron. The aim of this study was to examine the potential influence of macrophages on collecting duct epithelial cells (CDECs) and their combined role in the progression of IgAN.

METHODS

CDECs were cultured with macrophage-conditioned media (MCM) generated from human monocyte cell lines U937 and THP-1 stimulated with or without 100 μg/mL galactose-deficient IgA1. CDECs were analysed for evidence of inflammation and fibrosis.

RESULTS

Staining of IgAN biopsies for CD68+ macrophages revealed the presence of macrophages juxtaposed to collecting ducts and within their lumina. CDEC exposed to MCM from IgA1-stimulated THP-1 cells (THP-1-IgA-MCM) exhibited markedly increased expression of neutrophil-associated gelatinase (NGAL) and proinflammatory cytokinesinterleukin (IL)-1β, tumour necrosis factor-α, IL-6 and IL-8 compared with MCM from non-IgA-stimulated THP-1 cells (THP-1-MCM). U937-IgA-MCM increased fibronectin levels and reduced E-cadherinmRNA expression. THP-1-IgA-MCM-derived exosomes induced similar increases in NGAL and cytokine expression while in cross-over experiments exosomes extracted from IL-1β-exposed CDEC induced IL-1β and IL-6 mRNA expression in both sets of macrophages. MiRnome analysis revealed that microRNA (miR)-146a, -155 and -200b exhibited a >2-fold increase in expression in CDEC treated with THP-1-IgA-MCM compared with THP-1-MCM. Enforced miR-146a suppression further enhanced NGAL expression, while ectopic miR-146a over-expression downregulated it. NGAL mRNA and miR-146a were upregulated in the biopsies of patients with progressive IgAN compared with non-progressive IgAN.

CONCLUSIONS

Taken together, these data suggest that CDEC-macrophage interactions potentially contribute to the tubulointerstitial fibrosis characteristic of progressive IgAN.

Aberrant Non-Coding RNA Expression in Patients with Systemic Lupus Erythematosus: Consequences for Immune Dysfunctions and Tissue Damage

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease with heterogeneous clinical manifestations. A diverse innate and adaptive immune dysregulation is involved in the immunopathogenesis of SLE. The dysregulation of immune-related cells may derive from the intricate interactions among genetic, epigenetic, environmental, and immunological factors. Of these contributing factors, non-coding RNAs (ncRNAs), including microRNAs (miRNAs, miRs), and long non-coding RNAs (lncRNAs) play critical roles in the post-transcriptional mRNA expression of cytokines, chemokines, and growth factors, which are essential for immune modulation. In the present review, we emphasize the roles of ncRNA expression in the immune-related cells and cell-free plasma, urine, and tissues contributing to the immunopathogenesis and tissue damage in SLE. In addition, the circular RNAs (circRNA) and their post-translational regulation of protein synthesis in SLE are also briefly described. We wish these critical reviews would be useful in the search for biomarkers/biosignatures and novel therapeutic strategies for SLE patients in the future.

miR-150-Based RNA Interference Attenuates Tubulointerstitial Fibrosis through the SOCS1/JAK/STAT Pathway In Vivo and In Vitro

We investigated whether microRNA-150 (miR-150)-based RNA interference (RNAi) ameliorates tubular injury and tubulointerstitial fibrosis. Mice injected with folic acid developed tubulointerstitial fibrosis at day 30. miR-150 levels were increased at day 7 and peaked at day 30. At day 30, protein levels of α-smooth muscle actin, fibronectin (FN), and collagen 1 (COL-1) were increased, while suppressor of cytokine signal 1 (SOCS1) was decreased. Kidneys manifested increased macrophage numbers and increased expression of potential mediators: interferon-γ, interleukin-6, and tumor necrosis factor-α. Locked nucleic acid-anti-miR-150, started prior to or after tubular injury and administered twice weekly for 4 weeks, reversed renal inflammation and fibrosis. In HK-2 cells, co-culture with macrophages increased miR-150 expression and decreased SOCS1. Janus kinase (JAK) and signal transducer and activators of transcription (STAT) pathway-related proteins p-JAK1, p-JAK2, p-STAT1, p-STAT3, and pro-fibrotic genes encoding α-smooth muscle actin, FN, and COL-1 were all upregulated. The miR-150 antagonist reversed these transcriptional changes. Lastly, in renal biopsies from patients with chronic interstitial fibrosis, renal miR-150, and pro-fibrotic gene expression and macrophage numbers were increased, while SOCS1 expression was decreased. In conclusion, miR-150-based RNAi is as a potential novel therapeutic agent for tubulointerstitial fibrosis, suppressing the SOCS1/JAK/STAT pathway and reducing macrophage influx.

A comprehensive review on miR-146a molecular mechanisms in a wide spectrum of immune and non-immune inflammatory diseases

MicroRNAs (miRNAs) are single-strand endogenous and non-coding RNA molecules with a length of about 22 nucleotides, which regulate genes expression, through modulating the translation and stability of their target mRNAs. miR-146a is one of the most studied miRNAs, due to its central role in immune system homeostasis and control of the innate and acquired immune responses. Accordingly, abnormal expression or function of miR-146a results in the incidence and progression of immune and non-immune inflammatory diseases. Its deregulated expression pattern and inefficient function have been reported in a wide spectrum of these illnesses. Based on the existing evidence, this miRNA qualifies as an ideal biomarker for diagnosis, prognosis, and activity evaluation of immune and non-immune inflammatory disorders. Moreover, much attention has recently been paid to therapeutic potential of miR-146a and several researchers have assessed the effects of different drugs on expression and function of this miRNA at diverse experimental, animal, besides human levels, reporting motivating results in the treatment of the diseases. Here, in this comprehensive review, we provide an overview of miR-146a role in the pathogenesis and progression of several immune and non-immune inflammatory diseases such as Rheumatoid arthritis, Systemic lupus erythematosus, Inflammatory bowel disease, Multiple sclerosis, Psoriasis, Graves' disease, Atherosclerosis, Hepatitis, Chronic obstructive pulmonary disease, etc., discuss about its eligibility for being a desirable biomarker for these disorders, and also highlight its therapeutic potential. Understanding these mechanisms underlies the selecting and designing the proper therapeutic targets and medications, which eventually facilitate the treatment process.

Comprehensive bioinformatics analysis of mRNA expression profiles and identification of a miRNA-mRNA network associated with lupus nephritis

OBJECTIVE

Lupus nephritis (LN) is one of the serious complications of systemic lupus erythematosus. The aim of this study was to identify core genes and pathways involved in the pathogenesis of LN.

METHODS

We screened differentially expressed genes (DEGs) in LN patients using mRNA expression profile data from the Gene Expression Omnibus. The functional and pathway enrichment analysis of DEGs was performed utilizing the Database for annotation, Visualization and Integrated Discovery. Target genes with differentially expressed miRNAs (DEMIs) were predicted using the miRTarBase database, and the intersection between these target genes and DEGs was selected to be studied further.

RESULTS

In total, 107 common DEGs (CDEGs) were identified from the Tub_LN group and Glom_LN group, and 66 DEMIs were identified. Fifty-three hub genes and two significant modules were identified from the protein-protein interaction (PPI) network, and a miRNA-mRNA network was constructed. The CDEGs, module genes in the PPI network and genes intersecting with the CDEGs and target genes of DEMIs were all associated with the PI3K-Akt signalling pathway.

CONCLUSION

In summary, this study reveals some crucial genes and pathways potentially involving in the pathogenesis of LN. These findings provide a new insight for the research and treatment of LN.

New therapeutic targets in chronic kidney disease progression and renal fibrosis

INTRODUCTION

The current therapeutic armamentarium to prevent chronic kidney disease (CKD) progression is limited to the control of blood pressure and in diabetic patients, the strict control of glucose levels. Current research is primarily focused on the reduction of inflammation and fibrosis at different levels.

AREAS COVERED

This article examines the latest progress in this field and places an emphasis on inflammation, oxidative stress, and fibrosis. New therapeutic targets are described and evidence from experimental and clinical studies is summarized. We performed a search in Medline for articles published over the last 10 years.

EXPERT OPINION

The search for therapeutic targets of renal inflammation is hindered by an incomplete understanding of the pathophysiology. The determination of the specific inducers of inflammation in the kidney is an area of heightened potential. Prevention of the progression of renal fibrosis by blocking TGF-β signaling has been unsuccessful, but the investigation of signaling pathways involved in late stages of fibrosis progression could yield improved results. Preventive strategies such as the modification of microbiota-inducers of uremic toxins involved in CKD progression is a promising field because of the interaction between the gut microbiota and the renal system.

Dysregulation of Inflammasome Priming and Activation by MicroRNAs in Human Immune-Mediated Diseases

Inflammasomes are protein complexes that respond to a wide range of pathogens and cellular damage signals. Their activation prompts the caspase-1-mediated cleavage of the proinflammatory cytokines IL-1β and IL-18. Inflammasome dysregulation has been demonstrated to play a role in a range of diseases involving the adaptive immune system like multiple sclerosis, rheumatic diseases, and type 1 diabetes. Priming and activation of inflammasomes can be modulated by microRNAs (miRNAs), small noncoding RNAs that regulate gene expression posttranscriptionally. miRNAs, such as miR-223-3p, have been demonstrated to directly target the inflammasome components NLRP3, caspase-1, and caspase-8. Other miRNAs like miR-155-5p modulate TLR-, IL-1R-, TNFR-, and IFNAR-mediated signaling pathways upstream of the inflammasomes. In this study, we discuss how a more detailed elucidation of miRNA-driven inflammasome regulation helps in understanding the molecular processes underlying immune-mediated human diseases, holds potential for the identification of biomarkers and may offer novel targets for the development of future therapeutics.

LNA-anti-miR-150 ameliorated kidney injury of lupus nephritis by inhibiting renal fibrosis and macrophage infiltration

Background

The prevalence of lupus nephritis (LN) remains high despite various emerging monoclonal antibodies against with targeting systemic lupus erythematosus (SLE). Renal fibrosis is the main feature of late stage LN, and novel therapeutic agents are still needed. We previously reported that microRNA (miR)-150 increases in renal biopsies of American LN patients and that miR-150 agonist promotes fibrosis in cultured kidney cells. Presently, we aim to verify whether locked nucleic acid (LNA)-anti-miR-150 can ameliorate LN in mice and to investigate its corresponding mechanisms.

Methods

We first observed natural history and renal miR-150 expression in female Fcgr2b^−/− mice of a spontaneously developed LN model. We then verified miR-150 renal absorption and determined the dose of the suppressed miR-150 by subcutaneous injection of LNA-anti-miR-150 (2 and 4 mg/kg). Thirdly, we investigated the therapeutic effects of LNA-anti-miR-150 (2 mg/kg for 8 weeks) on LN mice and the corresponding mechanisms by studying fibrosis-related genes, cytokines, and kidney resident macrophages. Lastly, we detected the expression of renal miR-150 and the mechanism-associated factors in renal biopsies from new onset untreated LN patients.

Results

Fcgr2b^−/− mice developed SLE indicated by positive serum autoantibodies at age 19 weeks and LN demonstrated by proteinuria at age 32 weeks. Renal miR-150 was overexpressed in LN mice compared to wild type mice. FAM-labeled LNA-anti-miR-150 was absorbed by both glomeruli and renal tubules. LNA-anti-miR-150 suppressed the elevated renal miR-150 levels in LN mice compared to the scrambled LNA without systemic toxicity. Meanwhile, serum double strand-DNA antibody, proteinuria, and kidney injury were ameliorated. Importantly, the elevated renal pro-fibrotic genes (transforming growth factor-β1, α-smooth muscle antibody, and fibronectin) and decreased anti-fibrotic gene suppressor of cytokine signal 1 were both reversed. Renal pro-inflammatory cytokines (interferon-γ, interleukin-6, and tumor necrosis factor-α) and macrophages were also decreased. In addition, the changes of renal miR-150 and associated proteins shown in LN mice were also seen in human subjects.

Conclusions

LNA-anti-miR-150 may be a promising novel therapeutic agent for LN in addition to the current emerging monoclonal antibodies, and its renal protective mechanism may be mediated by anti-fibrosis and anti-inflammation as well as reduction of the infiltrated kidney resident macrophages.

The Role of MicroRNAs in Selected Forms of Glomerulonephritis

Glomerulonephritis (GN) represents a collection of kidney diseases characterized by inflammation within the renal glomeruli and small blood vessels. The lesions that occur in other nephron structures mainly result from the harmful effects of proteinuria. In recent years, an emphasis has been placed on gaining a better insight into the pathogenesis and pathophysiology of GN in order to facilitate diagnoses and provide efficient and targeted treatments of the disease. Owing to the advanced molecular and genetic diagnostic techniques available today, researchers have been able to elucidate that most cases of GN are determined by genetic risk factors and are associated with the abnormal functioning of the immune system (the immunologically mediated forms of GN). MicroRNAs (miRNAs) are a group of single-stranded, non-coding molecules, approximately 20 nucleotides in length, that act as regulatory factors in the post-transcriptional processes capable of regulating the expression of multiple genes. In this paper we present the available research aiming to determine effects of miRNAs on the development and progression of GN and discuss the potential role of miRNAs as new diagnostic markers and therapeutic targets.

Clinical value of microRNA-198-5p downregulation in lung adenocarcinoma and its potential pathways

Lung adenocarcinoma (LUAD), the main subtype of non-small cell lung cancer, is known to be regulated by various microRNAs (miRs/miRNAs); however, the role of miR-198-5p in LUAD has not been clarified. In the present study, the clinical value of miR-198-5p in LUAD and its potential molecular mechanism was evaluated. miR-198-5p expression was examined by reverse transcription-quantitative PCR (RT-qPCR) in 101 paired LUAD and adjacent normal lung tissues. Subsequently, the miR-198-5p expression level was determined from microarray data from the Gene Expression Omnibus, ArrayExpress and by meta-analyses. Furthermore, the target mRNAs of miR-198-5p from 12 miRNA-mRNA predictive tools were intersected with The Cancer Genome Atlas (TCGA)-based differentially expressed genes. In addition, Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to determine the possible mechanism of miR-198-5p in LUAD. The Search Tool for the Retrieval of Interacting Genes/Proteins database was employed to construct a protein-protein interaction network among the potential target genes of miR-198-5p. The results showed that miR-198-5p expression was lower in LUAD tissues than in adjacent non-cancerous lung tissues (4.469±2.495 vs. 5.301±2.502; P=0.015). Meta-analyses, including the data from the present study and online microarray data, also verified the downregulation of miR-198-5p in 584 cases of LUAD. The expression of miR-198-5p was associated with the age, blood vessel invasion, Tumor-Node-Metastasis stage, and lymph node metastasis of patients with LUAD and served as an independent prognostic factor for survival. The hub genes of miR-198-5p were upregulated in LUAD, according to TCGA and The Human Protein Atlas. For the KEGG pathway analysis, the most enriched KEGG pathway was the p53 signaling pathway (P=1.42×10⁻⁶). These findings indicated that the downregulation of miR-198-5p may play a pivotal role in the development of LUAD by targeting various signaling pathways.

Noncoding RNAs Involved in the Pathogenesis of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a form of arthritis that can lead to fusion of vertebrae and sacroiliac joints following syndesmophyte formation. The etiology of this painful disease remains poorly defined due to its complex genetic background. There are no commonly accepted methods for early diagnosis of AS, nor are there any effective or efficient clinical treatments. Several noncoding RNAs (ncRNAs) have been linked to AS pathogenesis and inflammation via selective binding of their downstream targets. However, major gaps in knowledge remain to be filled before such findings can be translated into clinical treatments for AS. In this review, we outline recent findings that demonstrate essential roles of ncRNAs in AS mediated via multiple signaling pathways such as the Wnt, transforming growth factor-β/bone morphogenetic protein, inflammatory, T-cell prosurvival, and nuclear factor-κB pathways. The summary of these findings provides insight into the molecular mechanisms by which ncRNAs can be targeted for AS diagnosis and the development of therapeutic drugs against a variety of autoimmune diseases.

Associations of Circulating MicroRNAs (miR-17, miR-21, and miR-150) and Chronic Kidney Disease in a Japanese Population

Background

MicroRNAs (miRNAs) play crucial roles in the development of various diseases, including chronic kidney disease (CKD). Although previous studies in clinically severe patients have investigated associations between CKD and miRNAs, with particular attention on renal fibrosis, relationships in a general population have yet to be established. The aim of this study was to examine the relationship between expression level of circulating miRNAs and CKD in a middle-aged Japanese population.

Methods

A final total of 513 individuals (216 men and 297 women) who participated in the health check-up program in 2012 were included in our analysis. Quantitative real-time polymerase chain reaction was used to determine expression levels of 22 miRNAs. Estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine level, sex, and age. Participants with eGFR <60 mL/min/1.73 m² were defined as having CKD.

Results

Three different miRNAs (miR-17, miR-21, and miR-150) showed significant correlations with eGFR after Bonferroni correction and were selected for further analyses. Expression levels of miR-17, miR-21, and miR-150 miRNAs were positively associated with eGFR after adjusting for potential confounders (P = 0.004, 0.002, and 0.004, respectively). Logistic regression analyses showed significantly lower odds ratios for CKD (eGFR <60 mL/min/1.73 m²) in the highest tertile of all three miRNAs (miR-17, miR-21, and miR-150) compared with the lowest tertile (P = 0.003, 0.01, and 0.02, respectively).

Conclusions

We found that three circulating miRNAs were significantly associated with CKD in a general Japanese population, which suggested that these miRNAs may be biomarkers for CKD among general adults.

The role of exosome in autoimmune connective tissue disease

Exosomes have generated significant interest in the last few decades owing to their important roles in a diverse range of biological pathways. They are nano-sized lipid bilayer membrane vesicles of endosomal origin, and are produced by a vast number of cell types. They are released into the extracellular environment and are found in most biological fluids. Exosomes can contain proteins, lipids and nucleic acids. The cargo of exosomes allows them to play roles in cell communication, antigen presentation, as biomarkers and in immune regulation. Substantial efforts have been made to understand their biology and potential clinical use in various diseases, including autoimmune connective tissue diseases (ACTD). In this review, we highlight the known functions of exosomes and detail recent advances made in the elucidation of the roles of exosomes in ACTDs with an emphasis on their potential use as a biomarker for disease diagnosis and as a therapeutic target. Key messages Exosome with the function of cell communication, antigen presentation, biomarkers, immune responses and immune regulation have become a hot area and have played an important role in several areas of science and technology especially in medicine. Exosomes play important roles in numerous biological processes as well as in the pathogenesis of ACTDs. Exosome comes into being the non-invasive procedure as potential biomarkers and excellent treatment means in ACTDs.

MicroRNA expression profile of urinary exosomes in Type IV lupus nephritis complicated by cellular crescent

Background

Type IV lupus nephritis (LNIV) is a severe disease characterized by diffuse proliferative lesions, and its prognosis is worse with cellular crescent (LNIV-CC) involvement. Urinary exosomes have been shown to reflect the degree of kidney injury. This study was aimed to identify non-invasive diagnostic markers for LNIV-CC. We analysed the expression profile of microRNAs (miRNAs) isolated from urinary exosomes in patients with LNIV-CC and LNIV, and healthy individuals using high-throughput sequencing.

Results

A total of 66 differentially expressed miRNAs were identified, which were significantly enriched in 15 signalling pathways. Bioinformatic analysis revealed a co-expression network of miRNAs, predicted transcription factors and target mRNAs. Expression of three miRNAs including miR-3135b, miR-654-5p, and miR-146a-5p were further analysed and validated by reverse transcription-quantitative polymerase chain reaction. ROC analysis suggested these as candidate biomarkers for LNIV-CC.

Conclusions

LNIV-CC has a unique miRNA expression profile of urinary exosome and complex regulatory network. miR-3135b, miR-654-5p and miR-146a-5p in urinary exosomes could be used as novel non-invasive diagnostic markers for LNIV-CC.

MicroRNA-638 inhibits human airway smooth muscle cell proliferation and migration through targeting cyclin D1 and NOR1

Abnormal airway smooth muscle cell (ASMC) proliferation and migration contribute significantly to increased ASM mass associated with asthma. MicroRNA (miR)-638 is a primate-specific miRNA that plays important roles in development, DNA damage repair, hematopoiesis, and tumorigenesis. Although it is highly expressed in ASMCs, its function in ASM remodeling remains unknown. In the current study, we found that in response to various mitogenic stimuli, including platelet-derived growth factor-two B chains (PDGF-BB), transforming growth factor β1, and fetal bovine serum, the expression of miR-638, as determined by quantitative real-time polymerase chain reaction (qRT-PCR), was significantly downregulated in the proliferative human ASMCs. Both gain- and loss-of-function studies were performed to study the role of miR-638 in ASMC proliferation and migration. We found that adenovirus-mediated miR-638 overexpression markedly inhibits ASMC proliferation and migration, while ablation of miR-638 by anti-miR-638 markedly increases cell proliferation and migration, as determined by WST-8 proliferation and scratch wound assays. Dual-luciferase reporter assay, qRT-PCR, and immunoblot analysis were used to investigate the effects of miR-638 on the expression of the downstream target genes in ASMCs. Our results demonstrated that miR-638 overexpression significantly reduced the expression of downstream target cyclin D1 and NOR1, both of which have been shown to be essential for cell proliferation and migration. Together, our study provides the first in vitro evidence highlighting the antiproliferative and antimigratory roles of miR-638 in human ASMC remodeling and suggests that targeted overexpression of miR-638 in ASMCs may provide a novel therapeutic strategy for preventing ASM hyperplasia associated with asthma.

Role of MicroRNAs in Renal Parenchymal Diseases-A New Dimension

Since their discovery in 1993, numerous microRNAs (miRNAs) have been identified in humans and other eukaryotic organisms, and their role as key regulators of gene expression is still being elucidated. It is now known that miRNAs not only play a central role in the processes that ensure normal development and physiology, but they are often dysregulated in various diseases. In this review, we present an overview of the role of miRNAs in normal renal development and physiology, in maladaptive renal repair after injury, and in the pathogenesis of renal parenchymal diseases. In addition, we describe methods used for their detection and their potential as therapeutic targets. Continued research on renal miRNAs will undoubtedly improve our understanding of diseases affecting the kidneys and may also lead to new therapeutic agents.

Altered levels of immune-regulatory microRNAs in plasma samples of patients with lupus nephritis

Introduction: Lupus nephritis (LN) is a major cause of mortality and morbidity in the patients with lupus, a chronic autoimmune disease. The role of genetic and epigenetic factors is emphasized in the pathogenesis of LN. The aim of the present study was to evaluate the levels of immune-regulatory microRNAs (e.g., miR-31, miR-125a, miR-142-3p, miR-146a, and miR-155) in plasma samples of patients with LN.

Methods: In this study, 26 patients with LN and 26 healthy individuals were included. The plasma levels of the microRNAs were evaluated by a quantitative real-time PCR. Moreover, the correlation of circulating plasma microRNAs with disease activity and pathological findings along with their ability to distinguish patients with LN were assessed.

Results: Plasma levels of miR-125a (P = 0.048), miR-146a (P = 0.005), and miR-155 (P< 0.001) were significantly higher in comparison between the cases and controls. The plasma level of miR-146a significantly correlated with the level of anti-double strand-DNA antibody and proteinuria. Moreover, there was a significant correlation between miR-142-3p levels and disease chronicity and activity index (P <0.05). The multivariate ROC curve analysis indicated the plasma circulating miR-125a, miR-142-3p, miR-146, and miR-155 together could discriminate most of the patients with LN from controls with area an under curve (AUC) of 0.89 [95% CI, 0.80-0.98, P<0.001], 88% sensitivity, and 78% specificity.

Conclusion: Based on the findings of the present study, the studied microRNAs may be involved in the pathogenesis and development of LN and have the potential to be used as diagnostic and therapeutic markers in LN.

Dysregulation of PTEN caused by the underexpression of microRNA‑130b is associated with the severity of lupus nephritis

There are several reports in the literature regarding microRNA (miR)‑130b. It has been reported that miR‑130b is involved in several diseases. The present study aimed to understand the association between the levels of miR‑130b and lupus nephritis in patients. A total of 61 blood samples were collected and the expression level of miR‑130b was determined. The online miRNA database was then searched using the 'seed sequence' located within the 3'‑untranslated region of the target gene. Linear analysis and a luciferase assay were performed to understand the regulatory association between miR‑130b and phosphatase and tensin homolog (PTEN). In addition, reverse transcription‑polymerase chain reaction and western blot analyses were performed to examine the mRNA and protein expression levels of PTEN among individuals with lupus nephritis (n=28) and those without lupus nephritis (n=31), and in mesangial cells treated with scramble control, miR‑130b mimics, PTEN small interfering (si)RNA and miR‑130b inhibitors. In addition mesangial cells were treated with scramble control, miR‑130b mimics, PTEN siRNA and miR‑130b inhibitors to investigate the affect of miR‑130b and PTEN on the viability and apoptosis of mesangial cells. The results demonstrated that miR‑130b was downregulated in the hormone‑resistant group of lupus nephritis patients. PTEN was a virtual target of miR‑130b. There was a negative regulatory association between miR‑130b and PTEN. The mRNA and protein expression levels of PTEN were increased in the hormone‑resistant group. miR‑130b decreased the expression of PTEN. miR‑130b negatively interfered with the viability of mesangial cells and PTEN positively interfered with the viability of mesangial cells. miR‑130b accelerated apoptosis and PTEN inhibited apoptosis. Taken together, the results showed that miR‑130b was upregulated in the lupus nephritis group. PTEN was a virtual target of miR‑130b, and there was a negative regulatory association between miR‑130b and PTEN. miR‑130b and PTEN interfered with the viability and apoptosis of the mesangial cells.

Clinical value of miR-198-5p in lung squamous cell carcinoma assessed using microarray and RT-qPCR

Background

To examine the clinical value of miR-198-5p in lung squamous cell carcinoma (LUSC).

Methods

Gene Expression Omnibus (GEO) microarray datasets were used to explore the miR-198-5p expression and its diagnostic value in LUSC. Real-time reverse transcription quantitative polymerase chain reaction was used to evaluate the expression of miR-198-5p in 23 formalin-fixed, paraffin-embedded (FFPE) LUSC tissues and corresponding non-cancerous tissues. The correlation between miR-198-5p expression and clinic pathological features was assessed. Meanwhile, putative target messenger RNAs of miR-198-5p were identified based on the analysis of differentially expressed genes in the Cancer Genome Atlas (TCGA) and 12 miRNA prediction tools. Subsequently, the putative target genes were sent to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses.

Results

MiR-198-5p was low expressed in LUSC tissues. The combined standard mean difference (SMD) values of miR-198-5p expression based on GEO datasets were − 0.30 (95% confidence interval (CI) − 0.54, − 0.06) and − 0.39 (95% CI − 0.83, 0.05) using fixed effect model and random effect model, respectively. The sensitivity and specificity were not sufficiently high, as the area under the curve (AUC) was 0.7749 (Q* = 0.7143) based on summarized receiver operating characteristic (SROC) curves constructed using GEO datasets. Based on the in-house RT-qPCR, miR-198-5p expression was 4.3826 ± 1.7660 in LUSC tissues and 4.4522 ± 1.8263 in adjacent normal tissues (P = 0.885). The expression of miR-198-5p was significantly higher in patients with early TNM stages (I-II) than that in cases with advanced TNM stages (III-IV) (5.4400 ± 1.5277 vs 3.5690 ± 1.5228, P = 0.008). Continuous variable-based meta-analysis of GEO and PCR data displayed the SMD values of − 0.26 (95% CI − 0.48, − 0.04) and − 0.34 (95% CI − 0.71, 0.04) based on fixed and random effect models, respectively. As for the diagnostic value of miR-198-5p, the AUC based on the SROC curve using GEO and PCR data was 0.7351 (Q* = 0.6812). In total, 542 genes were identified as the targets of miR-198-5p. The most enriched Gene Ontology terms were epidermis development among biological processes, cell junction among cellular components, and protein dimerization activity among molecule functions. The pathway of non-small cell lung cancer was the most significant pathway identified using Kyoto Encyclopedia of Genes and Genomes analysis.

Conclusion

The expression of miR-198-5p is related to the TNM stage. Thus, miR-198-5p might play an important role via its target genes in LUSC.

MicroRNAs associated with the development of kidney diseases in humans and animals

Mature microRNAs (miRNAs) are single-stranded RNAs with approximately 18-25 bases, and their sequences are highly conserved among animals. miRNAs act as posttranscriptional regulators by binding mRNAs, and their main function involves the degradation of their target mRNAs. Recent studies revealed altered expression of miRNAs in the kidneys during the progression of acute kidney injury (AKI) and chronic kidney disease (CKD) in humans and experimental rodent models by using high-throughput screening techniques including microarray and small RNA sequencing. Particularly, miR-21 seems to be strongly associated with renal pathogenesis both in the glomerulus and tubulointerstitium. Furthermore, abundant evidence has been gathered showing the involvement of miRNAs in renal fibrosis. Because of the complex morphofunctional organization of the mammalian kidneys, it is crucial both to determine the exact localization of the kidney cells that express the miRNAs, which has been addressed mainly using in situ hybridization methods, and to identify precisely which mRNAs are bound and degraded by these miRNAs, which has been studied mostly through in vitro analysis. To discover novel biomarker candidates, miRNA levels in urine supernatant, sediment, and exosomal fraction were comprehensively investigated in different types of kidney disease, including drug-induced AKI, ischemia-induced AKI, diabetic nephropathy, lupus nephritis, and IgA nephropathy. Recent studies also demonstrated the therapeutic effect of miRNA and/or anti-miRNA administrations. The intent of this review is to illustrate the state-of-the-art research in the field of miRNAs associated with renal pathogenesis, especially focusing on AKI and CKD in humans and animal models.

circHLA-C Plays an Important Role in Lupus Nephritis by Sponging miR-150

Circular RNAs (circRNAs) participate in the pathogenesis of various diseases by sponging microRNAs (miRs). However, the roles of circRNAs remain unreported in glomerular diseases. We previously reported that miR-150 positively correlated with renal chronicity index in patients with lupus nephritis (LN). We aimed to investigate renal circRNA profiling and the interaction between circRNAs and miR-150 in LN patients. Six renal biopsies from untreated female patients with LN class IV and five normal kidney tissues from urology patients were used for circRNA sequencing. 171 circRNAs with 2-fold differential expression were identified in LN compared with normal control. Ten selected circRNAs were validated by real-time qPCR, and seven circRNAs showed the same significant increases as the sequencing results. circHLA-C positively correlated with proteinuria (R = 0.92, p < 0.01), serum creatinine (R = 0.76, p = 0.08), renal activity index (R = 0.88, p < 0.05), and crescentic glomeruli (R = 0.93, p < 0.01). Renal circHLA-C increased 2.72-fold, and miR-150 decreased 66% in LN compared with normal control (p < 0.05). Bio-informatic analysis predicted miR-150 was regulated by circHLA-C and displayed one perfect match seed between circHLA-C and miR-150. The renal miR-150 showed a tendency of negative correlation with circHLA-C in LN patients. In conclusion, circHLA-C may play an important role in the pathogenesis of lupus nephritis by sponging miR-150.

miR-638 suppresses DNA damage repair by targeting SMC1A expression in terminally differentiated cells

The reduction of DNA damage repair capacity in terminally differentiated cells may be involved in sensitivity to cancer chemotherapy drugs; however, the underlying molecular mechanism is still not fully understood. Herein, we evaluated the role of miR-638 in the regulation of DNA damage repair in terminally differentiated cells. Our results show that miR-638 expression was up-regulated during cellular terminal differentiation and involved in mediating DNA damage repair processes. Results from a luciferase reporting experiment show that structural maintenance of chromosomes (SMC)1A was a potential target of miR-638; this was verified by western blot assays during cell differentiation and DNA damage induction. Overexpression of miR-638 enhanced the sensitivity of cancer cells to cisplatin, thus reducing cell viability in response to chemotherapy drug treatment. Furthermore, miR-638 overexpression affected DNA damage repair processes by interfering with the recruitment of the DNA damage repair-related protein, γH2AX, to DNA break sites. These findings indicate that miR-638 might act as a sensitizer in cancer chemotherapy and accompany chemotherapy drugs to enhance chemotherapeutic efficacy and to improve the chance of recovery from cancer.

Transcriptomic profiling in human mesangial cells using patient-derived lupus autoantibodies identified miR-10a as a potential regulator of IL8

Autoantibody-mediated inflammation directed at resident kidney cells mediates lupus nephritis (LN) pathogenesis. This study investigated the role of miRNA in human mesangial cells (HMCs) stimulated with auto anti-dsDNA immunoglobulin (Ig)G antibodies. HMCs were treated with antibodies purified from active LN patients or non-specific IgG controls in the presence of normal serum. Aberrant miRNA was screened using high throughput sequencing. Anti-dsDNA IgG up-regulated 103 miRNAs and down-regulated 30 miRNAs. The miRNAs regulated genes in the cell cycle, catabolic processes, regulation of transcription and apoptosis signalling. miR-10a was highly abundant in HMCs but was specifically downregulated upon anti-dsDNA IgG induction. Interestingly, the expression of miR-10a in kidney biopsies from class III and IV LN patients (n = 26) was downregulated compared with cadaveric donor kidneys (n = 6). Functional studies highlighted the downstream regulator of miR-10a in the chemokine signalling and cell proliferation or apoptosis pathways. Luciferase assay confirmed for the first time that IL8 was a direct target of miR-10a in HMCs. In conclusion, anti-dsDNA IgG Ab down-regulated miR-10a expression in HMCs resulting in the induction of various target genes involved in HMC proliferation and chemokine expression.

MicroRNA‑198 contributes to lupus nephritis progression by inhibition of phosphatase and tensin homology deleted on chromosome ten expression

A number of short noncoding microRNAs (miRs) have been demonstrated to be highly expressed in many kidney diseases such as renal cancer and lupus nephritis (LN); however, these results have not been extensively investigated. The aim of the present study was to investigate the expression and function of miR‑198 in LN based on the previous studies. miR‑198 expression level in systemic lupus erythematosus (SLE) patients was determined to determine its clinicopathological significance and effect on glomerular cell proliferation. It was demonstrated that higher expression of miR‑198 was observed in patients with SLE, and was correlated with disease activity. Bioinformatics prediction and luciferase assays were used to demonstrate that miR‑198 could directly bind to the phosphatase and tensin homology deleted on chromosome ten (PTEN) 3'‑untranslated region. Furthermore, miR‑198 overexpression reduced PTEN expression levels, while miR‑198 silencing increased its expression at both the mRNA and protein level. Furthermore, there was a negative association between miR‑198 and PTEN in the patients with active SLE. Thus, miR‑198 may promote proliferation and contribute to SLE progression by targeting PTEN.

Urinary Exosomal MicroRNA Profiling in Incipient Type 2 Diabetic Kidney Disease

BACKGROUND

Albuminuria is an early sign but not a strong predictor of diabetic kidney disease (DKD). Owing to their high stability, urinary exosomal miRNAs can be useful predictors of the progression of early-stage DKD to renal failure; fluid biopsies are ideal for detecting abnormalities in these miRNAs. The aim of this study was to identify novel differentially expressed miRNAs as urine biomarkers for type 2 DKD by comparing between patients of type 2 diabetes (T2D) with and without macroalbuminuria.

METHODS

Ten patients with T2D, including five who had no renal disease and five with macroalbuminuria (DKD G1-2A3), were selected for this study. Exosome- (UExo-) derived miRNA profiles were used to identify candidate biomarkers, a subset of which was verified using quantitative reverse transcription PCR.

RESULTS

A total of 496 UExo-derived miRNA species were found to be differentially expressed (>2-fold) in patients with DKD, compared to those with T2D. A validation analysis revealed that three miRNAs (miR-362-3p, miR-877-3p, and miR-150-5p) were upregulated and one (miR-15a-5p) was downregulated. These miRNAs might regulate DKD through p53, mTOR, and AMPK pathways.

CONCLUSIONS

In conclusion, UExo-derived miRNAs were altered in type 2 DKD. MiR-362-3p, miR-877-3p, miR-150-5p, and miR-15a-5p might be novel biomarkers for incipient DKD.

Tubulointerstitial damage predicts end stage renal disease in lupus nephritis with preserved to moderately impaired renal function: A retrospective cohort study

OBJECTIVES

The presence of tubulointerstitial damage (TID) on renal biopsy is considered to be a late sequela of lupus nephritis (LN). The objective of this study was to determine if TID predicts progression to end stage renal disease (ESRD) in LN patients without advanced kidney disease.

METHODS

All SLE patients with an index biopsy consistent with LN between January 2005 and July 2015, and eGFR ≥ 30mL/min/1.73m² were included. Moderate-to-severe TID was defined as the presence of moderate-to-severe tubular atrophy and/or interstitial fibrosis. Time to ESRD was defined as time from the index biopsy date to incident ESRD date; non-ESRD patients were censored at the time of death or the last visit before December 2015. Time-dependent analyses were conducted to evaluate whether moderate-to-severe TID was predictive of ESRD progression.

RESULTS

Of the 131 LN patients with eGFR ≥ 30mL/min/1.73m², 17 (13%) patients progressed to ESRD. Moderate-to-severe TID was present in 13% of biopsies with eGFR ≥ 60mL/min/1.73m² and in 33% of biopsies with eGFR between 30 and 60mL/min/1.73m². Moderate-to-severe TID was associated with a higher risk of ESRD progression: adjusted hazard ratio (HR) = 4.1, 95% CI: 1.4-12.1, p = 0.01 for eGFR ≥ 30mL/min/1.73m²; HR = 6.2, 95% CI: 1.7-23.2, p = 0.008 for eGFR ≥ 60mL/min/1.73m². There was no association between tubulointerstitial inflammation (TII) and ESRD progression.

CONCLUSIONS

Moderate-to-severe TID, but not TII, was a strong predictor of ESRD progression independent of eGFR or glomerular findings, therefore, providing an important window for potential early interventions.

Dysregulation of miRNA-146a contributes to the development of lupus nephritis via targeting of TRAF6

Aim: The objective of this study was to identify the association between genotypes of miR-146a rs2910164 and expression of TRAF6 as well as the risk of lupus nephritis (LN). Results: A total of 567 systemic lupus erythematosus patients both with and without LN were included in the study. The luciferase activity of cells that carried miR-146a mimics was much lower than control and the miR-146a mRNA expression with the GG SNP was significantly overexpressed compared with that in GC and CC groups. Expressions of TRAF6 mRNA and protein with GG were markedly lower than those in GC and CC groups. Mesangial cells treated with miR-146a inhibitors displayed higher expression of TRAF6 mRNA and protein compared with scramble control, miR-146a mimics and TRAF6 siRNA groups. Conclusion: Rs2910164 is associated with the risk of LN and could function as a therapeutic target of the disease.

High-Throughput Sequencing Reveals Circulating miRNAs as Potential Biomarkers of Kidney Damage in Patients with Systemic Lupus Erythematosus

Renal involvement is one of the most severe manifestations of systemic lupus erythematosus (SLE). Renal biopsy is the gold standard when it comes to knowing whether a patient has lupus nephritis, and the degree of renal disease present. However, the biopsy has various complications, bleeding being the most common. Therefore, the development of alternative, non-invasive diagnostic tests for kidney disease in patients with SLE is a priority. Micro RNAs (miRNAs) are differentially expressed in various tissues, and changes in their expression have been associated with several pathological processes. The aim of this study was to identify changes in the abundance of miRNAs in plasma samples from patients with lupus nephritis that could potentially allow the diagnosis of renal damage in SLE patients. This is an observational case-control cross-sectional study, in which we characterized the differential abundance profiles of miRNAs among patients with different degrees of lupus compared with SLE patients without renal involvement and healthy control individuals. We found 89 miRNAs with changes in their abundance between lupus nephritis patients and healthy controls, and 17 miRNAs that showed significant variations between SLE patients with or without renal involvement. Validation for qPCR of a group of miRNAs on additional samples from lupus patients with or without nephritis, and from healthy individuals, showed that five miRNAs presented an average detection sensitivity of 97%, a specificity of 70.3%, a positive predictive value of 82.5%, a negative predictive value of 96% and a diagnosis efficiency of 87.9%. These results strongly suggest that miR-221-5p, miR-380-3p, miR-556-5p, miR-758-3p and miR-3074-3p are potential diagnostic biomarkers of lupus nephritis in patients with SLE. The observed differential pattern of miRNA abundance may have functional implications in the pathophysiology of SLE renal damage.

Comparison of different normalization strategies for the analysis of glomerular microRNAs in IgA nephropathy

Small nucleolar RNAs (snoRNAs) have been used for normalization in glomerular microRNA (miRNA) quantification without confirmation of validity. Our aim was to identify glomerular reference miRNAs in IgA nephropathy. We compared miRNAs in human paraffin-embedded renal biopsies from patients with cellular-crescentic IgA-GN (n = 5; crescentic IgA-GN) and non-crescentic IgA-GN (n = 5; IgA-GN) to mild interstitial nephritis without glomerular abnormalities (controls, n = 5). Laser-microdissected glomeruli were used for expression profiling of 762 miRNAs by low-density TaqMan arrays (cards A and B). The comparison of different normalization methods (GeNormPlus, NormFinder, global mean and snoRNAs) in crescentic IgA-GN, IgA-GN and controls yielded similar results. However, levels of significance and the range of relative expression differed. In median, two normalization methods demonstrated similar results. GeNormPlus and NormFinder gave different top ranked reference miRNAs. Stability ranking for snoRNAs varied between cards A and B. In conclusion, we suggest the geometric mean of the most stable reference miRNAs found in GeNormPlus (miR-26b-5p), NormFinder (miR-28-5p) and snoRNAs (RNU44) as reference. It should be considered that significant differences could be missed using one particular normalization method. As a starting point for glomerular miRNA studies in IgA nephropathy we provide a library of miRNAs.

Lower expressed miR-198 and its potential targets in hepatocellular carcinoma: a clinicopathological and in silico study

Purpose

To investigate the clinicopathological value and potential roles of microRNA-198 (miR-198) in hepatocellular carcinoma (HCC).

Methods

Ninety-five formalin-fixed paraffin-embedded HCC and the para-cancerous liver tissues were gathered. Real-time reverse transcription quantitative polymerase chain reaction was applied to determine the miR-198 expression. The association between the miR-198 expression and clinicopathological features was examined. Meanwhile, potential target messenger RNAs of miR-198 in HCC were obtained from 14 miRNA prediction databases and natural language processing method, in which we pooled the genes related to the tumorigenesis and progression of HCC and classified them by their frequency. The selected target genes were finally analyzed in the Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway.

Results

miR-198 expression was significantly lower in HCC than that in adjacent noncancerous liver tissues (1.30±0.72 vs 2.01±0.58, P<0.001). Low miR-198 expression was also correlated to hepatitis C virus infection (r=−0.48, P<0.001), tumor capsular infiltration (r=−0.43, P<0.001), metastasis (r=−0.26, P<0.010), number of tumor nodes (r=−0.25, P=0.013), vaso-invasion (r=−0.24, P=0.017), and clinical tumor node metastasis stage (r=−0.23, P=0.024). Altogether, 1,048 genes were achieved by the concurrent prediction from at least four databases and natural language processing indicated 1,800 genes for HCC. Further, 127 overlapping targets were further proceeded with for pathway analysis. The most enriched Gene Ontology terms in the potential target messenger RNAs of miR-198 were cell motion, cell migration, cell motility, and regulation of cell proliferation in biological process; organelle lumen, membrane-enclosed lumen, and nuclear lumen in cellular component; and enzyme binding, protein domain-specific binding, and protein kinase activity in molecular function. Kyoto Encyclopedia of Genes and Genomes analysis showed that these target genes were obviously involved in focal adhesion and pathways in cancer.

Conclusion

Lower expression of miR-198 was related to several clinicopathological parameters in HCC patients. miR-198 might play a regulatory role through its target genes in the development of HCC.

MicroRNAs differentially expressed in Behçet disease are involved in interleukin-6 production

Background

Behcet’s disease (BD) is characterized by systemic recurrent inflammation with increased production of tumor necrosis factor (TNF)–α and interleukin (IL)-6 by peripheral blood mononuclear cells (PBMCs). To gain insight into the underlying mechanisms of this disease, the expression levels of distinct microRNAs in PBMCs of BD patients were determined and their association with TNF-α and IL-6 production was evaluated.

Findings

The expression levels of microRNAs, miR-638 and miR-4488, were reduced in patients with stable BD in comparison with healthy controls. In addition, the expression of miR-3591-3p was increased in patients with active BD when compared to patients with stable BD. Transfection of miR-638 and miR-4488 inhibitors, together with miR-3591-3p mimics, increased IL-6 mRNA levels in THP-1 cells in response to LPS stimulation.

Conclusions

We observed differential expression of microRNAs associated with increased production of IL-6 in BD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12950-016-0130-7) contains supplementary material, which is available to authorized users.

Global miRNA expression is temporally correlated with acute kidney injury in mice

MicroRNAs (miRNAs) are negative regulators of gene expression and protein abundance. Current evidence shows an association of miRNAs with acute kidney injury (AKI) leading to substantially increased morbidity and mortality. Here, we investigated whether miRNAs are inductive regulators responsible for the pathological development of AKI. Microarray analysis was used to detect temporal changes in global miRNA expression within 48 h after AKI in mice. Results indicated that global miRNA expression gradually increased over 24 h from ischemia reperfusion injury after 24 h, and then decreased from 24 h to 48 h. A similar trend was observed for the index of tubulointerstitial injury and the level of serum creatinine, and there was a significant correlation between the level of total miRNA expression and the level of serum creatinine (p < 0.05). This expression-phenotype correlation was validated by quantitative reverse transcription PCR on individual miRNAs, including miR-18a, -134, -182, -210 and -214. Increased global miRNA expression may lead to widespread translational repression and reduced cellular activity. Furthermore, significant inflammatory cytokine release and peritubular capillary loss were observed, suggesting that the initiation of systematic destruction programs was due to AKI. Our findings provide new understanding of the dominant role of miRNAs in promoting the pathological development of AKI.

The Role of MicroRNAs in Kidney Disease

MicroRNAs (miRNAs) are short noncoding RNAs that regulate pathophysiological processes that suppress gene expression by binding to messenger RNAs. These biomolecules can be used to study gene regulation and protein expression, which will allow better understanding of many biological processes such as cell cycle progression and apoptosis that control the fate of cells. Several pathways have also been implicated to be involved in kidney diseases such as Transforming Growth Factor-β, Mitogen-Activated Protein Kinase signaling, and Wnt signaling pathways. The discovery of miRNAs has provided new insights into kidney pathologies and may provide new innovative and effective therapeutic strategies. Research has demonstrated the role of miRNAs in a variety of kidney diseases including renal cell carcinoma, diabetic nephropathy, nephritic syndrome, renal fibrosis, lupus nephritis and acute pyelonephritis. MiRNAs are implicated as playing a role in these diseases due to their role in apoptosis, cell proliferation, differentiation and development. As miRNAs have been detected in a stable condition in different biological fluids, they have the potential to be tools to study the pathogenesis of human diseases with a great potential to be used in disease prognosis and diagnosis. The purpose of this review is to examine the role of miRNA in kidney disease.

The Role of MicroRNAs and Human Epidermal Growth Factor Receptor 2 in Proliferative Lupus Nephritis

OBJECTIVE

To understand the roles of microRNAs (miRNAs) in proliferative lupus nephritis (LN).

METHODS

A high-throughput analysis of the miRNA pattern of the kidneys of LN patients and controls was performed by molecular digital detection. Urinary miRNAs were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Target gene expression in human mesangial cells was evaluated by arrays and qRT-PCR. Human epidermal growth factor receptor 2 (HER-2) was analyzed by immunohistochemistry in kidney samples from LN patients and in a murine model of lupus. Urinary levels of HER-2, monocyte chemotactic protein 1 (MCP-1), and vascular cell adhesion molecule 1 (VCAM-1) were measured by enzyme-linked immunosorbent assay.

RESULTS

Levels of the miRNAs miR-26a and miR-30b were decreased in the kidneys and urine of LN patients. In vitro these miRNAs controlled mesangial cell proliferation, and their expression was regulated by HER-2. HER-2 was overexpressed in lupus-prone NZM2410 mice and in the kidneys of patients with LN, but not in other mesangioproliferative glomerulonephritides. HER-2 was found to be up-regulated by interferon-α and interferon regulatory factor 1. Urinary HER-2 was increased in LN and reflected disease activity, and its levels correlated with those of 2 other recognized LN biomarkers, MCP-1 and VCAM-1.

CONCLUSION

The kidney miRNA pattern is broadly altered in LN, which contributes to uncontrolled cell proliferation. Levels of the miRNAs miR-26a and miR-30b are decreased in the kidneys and urine of LN patients, and they directly regulate the cell cycle in mesangial cells. The levels of these miRNAs are controlled by HER-2, which is overexpressed in NZM2410 mice and in the kidneys and urine of LN patients. HER-2, miR-26a, and miR-30b are thus potential LN biomarkers, and blocking HER-2 may be a promising new strategy to decrease cell proliferation and damage in this disease.