Circulating miRNAs in extracellular vesicles related to treatment response in patients with idiopathic membranous nephropathy.

BACKGROUND: Extracellular vesicle (EV)-microRNAs (miRNAs) are potential biomarkers for various renal diseases. This study attempted to identify the circulating EV-miRNA signature not only for discriminating idiopathic membranous nephropathy (IMN) from idiopathic nephrotic syndrome (INS), but also to predict the treatment response of patients with IMN. METHODS: We prospectively enrolled 60 participants, including those with IMN (n = 19) and INS (n = 21) and healthy volunteers (HVs; n = 20) in this study. Using RNA sequencing, we assessed the serum EV-miRNA profiles of all participants. To identify the EV-miRNAs predictive of treatment response in IMN, we also analyzed EV-miRNAs among patients with IMN with and without clinical remission. RESULTS: The expression levels of 3 miRNAs differed between IMN patients, INS patients and HVs. In addition, compared to HVs, RNA sequencing revealed differential expression of 77 and 44 EV-miRNAs in patients with IMN without and with remission, respectively. We also identified statistically significant (|fold change ≥ 2, p < 0.05) differences in the expression levels of 23 miRNAs in IMN without remission. Biological pathway analysis of miRNAs in IMN without remission indicated that they are likely involved in various pathways, including renal fibrosis. CONCLUSION: Our study identified EV-miRNAs associated with IMN as well as those associations with therapeutic response. Therefore, these circulating EV-miRNAs may be used as potential markers for the diagnosis and prediction of treatment response in patients with IMN.

Weight Change Alters the Small RNA Profile of Urinary Extracellular Vesicles in Obesity.

INTRODUCTION: Various kidney diseases reportedly show different urinary extracellular vesicle (EV) RNA profiles. Although obesity is one of the main causes of chronic kidney disease, the expression pattern of urinary EV RNA in obesity is uncertain. Our aim was to sequence the small RNA profiles of urinary EVs in obese patients before and after weight reduction and compare them to those of healthy volunteers (HVs). METHODS: We recruited age-sex-matched obese patients and HVs. The small RNA profiles of urinary EVs were analyzed using RNA sequencing. To evaluate the effect of weight reduction, small RNA profiles of urinary EVs 6 months after bariatric surgery were also analyzed. RESULTS: The proportion of urinary EVs transfer RNA and microRNA of obese patients differed from that of HVs. Obese patients showed differential expression of 1,343 small RNAs in urinary EVs compared to HVs (fold change ≥2 and p value <0.05). Among those, 61 small RNAs were upregulated in obese patients and downregulated after weight reduction, whereas 167 small RNAs were downregulated in obese patients and upregulated after weight reduction. RNA sequencing revealed the correlation between the specific urinary EV small RNAs and clinical parameters including body weight, low-density lipoprotein cholesterol, triglyceride, high-density lipoprotein cholesterol, serum glucose, estimated glomerular filtration rate, and albuminuria. CONCLUSION: Obese patients showed distinct urinary EV small RNA profiles compared to HVs. Weight reduction altered urinary EV small-RNA profiles in obese patients.

Association of Protein Z with Prediabetes and Type 2 Diabetes.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a progressive metabolic disease. Early detection of prediabetes is important to reduce the risk of T2DM. Some cytokines are known to be associated with T2DM. Therefore, we aimed to identify cytokines as novel biomarkers of glucose dysmetabolism. METHODS: The first stage of the study included 43 subjects (13 subjects with newly diagnosed T2DM, 13 with prediabetes, and 16 with normoglycemia) for cytokine microarray analysis. Blood samples of the subjects were assessed for 310 cytokines to identify potential indicators of prediabetes. The second stage included 142 subjects (36 subjects with T2DM, 35 with prediabetes, and 71 with normoglycemia) to validate the potential cytokines associated with prediabetes. RESULTS: We identified 41 cytokines that differed by 1.5-fold or more in at least one out of the three comparisons (normoglycemia vs. prediabetes, normoglycemia vs. T2DM, and prediabetes vs. T2DM) among 310 cytokines. Finally, we selected protein Z (PROZ) and validated this finding to determine its association with prediabetes. Plasma PROZ levels were found to be decreased in patients with prediabetes (1,490.32±367.19 pg/mL) and T2DM (1,583.34±465.43 pg/mL) compared to those in subjects with normoglycemia (1,864.07±450.83 pg/mL) (P<0.001). There were significantly negative correlations between PROZ and fasting plasma glucose (P=0.001) and hemoglobin A1c (P=0.010). CONCLUSION: PROZ levels were associated with prediabetes and T2DM. We suggest that PROZ may be a promising biomarker for the early detection of prediabetes. Further large-scale studies are needed to evaluate the relationship and mechanism between PROZ and prediabetes and T2DM.

Effect of diabetes on exosomal miRNA profile in patients with obesity.

INTRODUCTION: Obesity is a risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease. T2DM increases the risk of cardiovascular-related death. We investigated changes in circulating exosomal microRNA (miRNA) profiles in patients with DM with obesity compared with patients without DM with obesity. RESEARCH DESIGN AND METHODS: This prospective study involved 29 patients with obesity (patients without DM=16, patients with DM=13) and healthy volunteers (HVs) (n=18). We measured circulating levels of exosomal miRNAs by next-generation sequencing and compared miRNA levels across the three groups. RESULTS: The expression levels of 25 miRNAs (upregulated=14, downregulated=11) differed between patients with obesity with DM and patients with obesity without DM. Compared with HV, patients with DM with obesity had 53 dysregulated miRNAs. Additionally, moving stepwise from HV to patients with obesity without DM to patients with obesity with DM, there was a consistent increase in expression levels of miR-23a-5p and miR-6087 and a consistent decrease in expressions levels of miR-6751-3p. CONCLUSIONS: Our data show that the exosomal miRNAs is altered by dysregulated glucose metabolism in patients with obesity. This circulating exosomal miRNA signature in patients with obesity with or without DM is a potential biomarker and therapeutic target in these patients.

Enhancement of Liposomal Plasmid DNA and siRNA Delivery by Itraconazole through Intracellular Cholesterol Accumulation.

PURPOSE: Efficient and safe vehicle that can enhance gene transfer is still needed. Since intracellular cholesterol is known to have an important role in gene delivery and itraconazole alters intracellular cholesterol trafficking, we investigated the effect of itraconazole on pDNA and siRNA delivery. METHODS: The pDNA and Bcl2 siRNA transfection efficiency was measured by luciferase assay and cytotoxicity. Cellular cholesterol was observed using filipin staining, and intracellular uptake was analyzed by flow cytometry. Lipoplex localization was observed by fluorescent labeling of DNA and lysosome after treatment of itraconazole or co-treatment of itraconazole and bafilomycin A1. RESULTS: Itraconazole enhanced the transfection efficiency of pDNA and siRNA compared to that of control through the accumulation of cholesterol. Bafilomycin A1 diminished the effect of itraconazole on gene delivery and the increment of cholesterol. Itraconazole did not increase the cellular uptake of lipoplex, but increased free pDNA during the endosome-lysosome pathway was observed during the endosome-lysosome pathway. Treating cells with both imipramine and itraconazole caused an additive effect in pDNA and siRNA delivery. CONCLUSIONS: Itraconazole enhanced gene delivery of pDNA and siRNA, and it can be used to potentiate nucleic acid therapeutics.

microRNA in Extracellular Vesicles Released by Damaged Podocytes Promote Apoptosis of Renal Tubular Epithelial Cells.

Tubular injury and fibrosis are associated with progressive kidney dysfunction in advanced glomerular disease. Glomerulotubular crosstalk is thought to contribute to tubular injury. microRNAs (miRNAs) in extracellular vesicles (EVs) can modulate distant cells. We hypothesized that miRNAs in EVs derived from injured podocytes lead to tubular epithelial cell damage. As proof of this concept, tubular epithelial (HK2) cells were cultured with exosomes from puromycin-treated or healthy human podocytes, and damage was assessed. Sequencing analysis revealed the miRNA repertoire of podocyte EVs. RNA sequencing identified 63 upregulated miRNAs in EVs from puromycin-treated podocytes. Among them, five miRNAs (miR-149, -424, -542, -582, and -874) were selected as candidates for inducing tubular apoptosis according to a literature-based search. To validate the effect of the miRNAs, HK2 cells were treated with miRNA mimics. EVs from injured podocytes induced apoptosis and p38 phosphorylation of HK2 cells. The miRNA-424 and 149 mimics led to apoptosis of HK2 cells. These results show that miRNAs in EVs from injured podocytes lead to damage to tubular epithelial cells, which may contribute to the development of tubular injury in glomerular disease.

The circulating exosomal microRNAs related to albuminuria in patients with diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is associated with high risk of cardiovascular disease and mortality. Exosomal microRNAs (miRNAs) regulate gene expression in a variety of tissues and play important roles in the pathology of various diseases. We hypothesized that the exosomal miRNA profile would differ between DN patients and patients without nephropathy. METHODS: We prospectively enrolled 74 participants, including healthy volunteers (HVs), diabetic patients without nephropathy, and those with DN. The serum exosomal miRNA profiles of participants were examined using RNA sequencing. RESULTS: The expression levels of 107 miRNAs differed between HVs and patients without DN, whereas the expression levels of 95 miRNAs differed between HVs and patients with DN. Among these miRNAs, we found 7 miRNAs (miR-1246, miR-642a-3p, let-7c-5p, miR-1255b-5p, let-7i-3p, miR-5010-5p, miR-150-3p) that were uniquely up-regulated in DN patients compared to HVs, and miR-4449 that was highly expressed in DN patients compared to patients without DN. A pathway analysis revealed that these eight miRNAs are likely involved in MAPK signaling, integrin function in angiogenesis, and regulation of the AP-1 transcription factor. Moreover, they were all significantly correlated with the degree of albuminuria. CONCLUSIONS: Patients with DN have a different serum exosomal miRNA profile compared to HVs. These miRNAs may be promising candidates for the diagnosis and treatment of DN and cardiovascular disease.

Bariatric Surgery Alters microRNA Content of Circulating Exosomes in Patients with Obesity.

OBJECTIVE: Exosomal microRNAs (miRNAs) are potential biomarkers for obesity, in which they regulate biological processes. Bariatric surgery has health benefits for patients with obesity; however, the mechanisms of these benefits are not clear. This study attempted to identify the exosomal miRNA signature associated with obesity and how it changed after bariatric surgery. METHODS: Healthy volunteers (HVs) and nondiabetic patients with obesity were prospectively enrolled in the study. The study assessed the serum exosomal miRNA profiles of HVs and patients with obesity using RNA sequencing. To evaluate the effects of bariatric surgery, the study also analyzed exosomal miRNAs in patients 6 months after surgery. RESULTS: RNA sequencing revealed differential expression of 72 exosomal miRNAs in patients with obesity compared with HVs and differential expression of 41 miRNAs in post- versus presurgery blood. Among the differentially expressed miRNAs, the study identified nine surgery-responsive miRNAs that were highly expressed in patients before surgery compared with HVs. Biological pathway analysis of the nine miRNAs indicated that they are likely involved in WNT, neurotrophin, and insulin signaling; the insulin receptor signaling cascade; and focal adhesion. CONCLUSIONS: Patients with obesity have a distinct exosomal miRNA expression profile compared with HVs. In addition, weight loss after surgery alters the exosomal miRNA profile of patients with obesity.

Embryonic Stem Cell-Derived mmu-miR-291a-3p Inhibits Cellular Senescence in Human Dermal Fibroblasts Through the TGF-ß Receptor 2 Pathway.

Senescent cells accumulate in various tissues over time and contribute to tissue dysfunction and aging-associated phenotypes. Accumulating evidence suggests that cellular senescence can be inhibited through pharmacological intervention, as well as through treatment with soluble factors derived from embryonic stem cells (ESCs). In an attempt to investigate the anti-senescence factors secreted by ESCs, we analyzed mouse ESC-derived extracellular microRNAs in conditioned medium via microRNA array analysis. We selected mmu-miR-291a-3p as a putative anti-senescence factor via bioinformatics analysis. We validated its inhibitory effects on replicative, Adriamycin-induced, and ionizing radiation-induced senescence in human dermal fibroblasts. Treatment of senescent cells with mmu-miR-291a-3p decreased senescence-associated ß-galactosidase activity, enhanced proliferative potential, and reduced mRNA and protein expression of TGF-ß receptor 2, p53, and p21. mmu-miR-291a-3p in conditioned medium was enclosed in ESC-derived exosomes and exosomes purified from ESC conditioned medium inhibited cellular senescence. The inhibitory effects of mmu-miR-291a-3p were mediated through the TGF-ß receptor 2 signaling pathway. Hsa-miR-371a-3p and hsa-miR-520e, the human homologs of mmu-miR-291a-3p, showed similar anti-senescence activity. Furthermore, mmu-miR-291a-3p accelerated the excisional skin wound healing process in aged mice. Our results indicate that the ESC-derived mmu-miR-291a-3p is a novel candidate agent that can be utilized for cell-free therapeutic intervention against aging and aging-related diseases.