Serum micro-rna profiles in patients with autosomal dominant polycystic kidney disease according to hypertension and renal function

RNA G-quadruplex in functional regulation of noncoding RNA: Challenges and emerging opportunities

G-quadruplexes (G4s) are stable, noncanonical structures formed in guanine (G)-rich sequences of DNA/RNA. G4 structures are reported to play a regulatory role in various cellular processes and, recently, a considerable number of studies have attributed new biological functions to these structures, especially in RNA. Noncoding RNA (ncRNA), which does not translate into a functional protein, is widely expressed and has been shown to play a key role in shaping cellular activity. There has been growing evidence of G4 formation in several ncRNA classes, and it has been identified as a key part for diverse biological functions and physio-pathological contexts in neurodegenerative diseases and cancer. This review discusses RNA G4s (rG4s) in ncRNA, focusing on the molecular mechanism underlying its function. This review also aims to highlight potential and emerging opportunities to identify and target the rG4s in ncRNA to understand its function and, ultimately, treat many diseases.

Predicting autosomal dominant polycystic kidney disease progression: review of promising Serum and urine biomarkers

Autosomal dominant polycystic kidney disease (ADPKD) is one of the leading causes of end-stage renal disease. In spite of the recent tremendous progress in the understanding of ADPKD pathogenesis, the molecular mechanisms of the disease remain incompletely understood. Considering emerging new targeted therapies for ADPKD, it has become crucial to disclose easily measurable and widely available biomarkers for identifying patients with future rapid disease progression. This review encompasses all the research with a shared goal of identifying promising serum or urine biomarkers for predicting ADPKD progression or response to therapy. The rate of the ADPKD progress varies significantly between patients. The phenotypic variability is only partly explained by the underlying genetic lesion diversity. Considering significant decline in kidney function in ADPKD is not usually evident until at least 50% of the parenchyma has been destroyed, conventional kidney function measures, such as glomerular filtration rate (GFR), are not suitable for monitoring disease progression in ADPKD, particularly in its early stages. Since polycystic kidney enlargement usually precedes the decline in GFR, height-adjusted total kidney volume (ht-TKV) has been accepted as an early biomarker for assessing disease severity in ADPKD patients. However, since measuring ht-TKV is time-consuming and observer-dependent, the identification of a sensitive and quickly measurable biomarker is of a great interest for everyday clinical practice. Throughout the last decade, due to development of proteomic and metabolomic techniques and the enlightenment of multiple molecular pathways involved in the ADPKD pathogenesis, a number of urine and serum protein biomarkers have been investigated in ADPKD patients, some of which seem worth of further exploring. These include copeptin, angiotensinogen, monocyte chemoattractant protein 1, kidney injury molecule-1 and urine-to-plasma urea ratio among many others. The aim of the current review is to provide an overview of all of the published evidence on potentially clinically valuable serum and urine biomarkers that could be used for predicting disease progression or response to therapy in patients with ADPKD. Hopefully, this review will encourage future longitudinal prospective clinical studies evaluating proposed biomarkers as prognostic tools to improve management and outcome of ADPKD patients in everyday clinical practice.

G-quadruplex from precursor miR-1587 modulated its maturation and function

A certain proportion of pre-miRNAs, which contained potential G-quadruplex forming sequences, was found to act as a mediator to Dicer-mediated cleavage, and that the regulation of miRNA production and function may be achieved through the G-quadruplex structure. In this study, human precursor miR-1587 sequence was transfected after the incubation with different solution conditions (K⁺, TMPyP4, etc.). Firstly, the formation of G-quadruplex from precursor miR-1587 sequences was confirmed by CD and UV melting. The expression of miR-1587 level was then evaluated by Q-RT-PCR, and the results showed that the formation of G-quadruplex inhibited the miR-1587 maturation process, resulting in a reduced miR-1587 expression. Meanwhile the destabilization of G-quadruplex led to an increased miR-1587 expression by contrast. Then, the weakened inhibition of miR-1587 towards its target genes, such as TAGLN or NCOR1, was presented confirming by Q-RT-PCR and western blot. Molecular mechanism by dual-luciferase assays showed that the modulations of miR-1587 expression and function were due to the G-quadruplex structure transformation, but not the simple change of solution conditions. This study highlighted the importance of maintaining specific structures during miRNA biosynthesis and provided a way to alter the function of G-rich precursor miRNAs by modulating molecular conformation using ionic solutions or ligands.

Identification of the miRNAome in human fracture callus and nonunion tissues

Background

Nonunions remain a challenging post-traumatic complication that often leads to a financial and health burden that affects the patient's quality of life. Despite a wealth of knowledge about fracture repair, especially gene and more recently miRNA expression, much remains unknown about the molecular differences between normal physiological repair (callus tissue) and a nonunion. To probe this lack of knowledge, we embarked on a study that sought to identify and compare the human miRNAome of normal bone to that present in a normal fracture callus and those from two different classic nonunion types, hypertrophic and oligotrophic.

Methods

Normal bone and callus tissue samples were harvested during revision surgery from patients with physiological fracture repair and nonunions (hypertrophic and oligotrophic) and analyzed using histology. Also, miRNAs were isolated and screened using microarrays followed by bioinformatic analyses, including, differential expression, pathways and biological processes, as well as elucidation of target genes.

Results

Out of 30,424 mature miRNAs (from 203 organisms) screened via microarrays, 635 (∼2.1%) miRNAs were found to be upregulated and 855 (∼2.8%) downregulated in the fracture callus and nonunion tissues as compared to intact bone. As our tissue samples were derived from humans, we focused on the human miRNAs and out of the 4223 human miRNAs, 86 miRNAs (∼2.0%) were upregulated and 51 (∼1.2%) were downregulated. Although there were similarities between the three experimental samples, we also found specific miRNAs that were unique to individual samples. We further identified the predicted target genes from these differentially expressed miRNAs as well as the relevant biological processes, including specific signaling pathways that are activated in all three experimental samples.

Conclusion

Collectively, this is the first comprehensive study reporting on the miRNAome of intact bone as compared to fracture callus and nonunion tissues. Further, we identify specific miRNAs involved in normal physiological fracture repair as well as those of nonunions.

The translational potential of this article

The data generated from this study further increase our molecular understanding of the roles of miRNAs during normal and aberrant fracture repair and this knowledge can be used in the future in the development of miRNA-based therapeutics for skeletal regeneration.

Non-coding RNAs as potential biomarkers and therapeutic targets in polycystic kidney disease

Polycystic kidney disease (PKD) is a significant cause of end-stage kidney failure and there are few effective drugs for treating this inherited condition. Numerous aberrantly expressed non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs), may contribute to PKD pathogenesis by participating in multiple intracellular and intercellular functions through post-transcriptional regulation of protein-encoding genes. Insights into the mechanisms of miRNAs and other ncRNAs in the development of PKD may provide novel therapeutic strategies. In this review, we discuss the current knowledge about the roles of dysregulated miRNAs and other ncRNAs in PKD. These roles involve multiple aspects of cellular function including mitochondrial metabolism, proliferation, cell death, fibrosis and cell-to-cell communication. We also summarize the potential application of miRNAs as biomarkers or therapeutic targets in PKD, and briefly describe strategies to overcome the challenges of delivering RNA to the kidney, providing a better understanding of the fundamental advances in utilizing miRNAs and other non-coding RNAs to treat PKD.

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.

Lessons from microRNA biology: Top key cellular drivers of Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Numerous microRNAs (miRs), small RNAs that target several pathways, have been implicated in the development of Autosomal Dominant Polycystic Kidney Disease (ADPKD), which is the most common genetic cause of kidney failure. The hallmark of ADPKD is tissue overgrowth and hyperproliferation, eventually leading to kidney failure.

SCOPE OF THE REVIEW

Many miRs are dysregulated in disease, yet the intracellular pathways regulated by miRs are less well described in ADPKD. Here, I summarise all the differentially expressed miRs in ADPKD and highlight the top miR-regulated cellular driver of disease.

MAJOR CONCLUSIONS

Literature review has identified 53 abnormally expressed miRs in ADPKD. By performing bioinformatics analysis of their target genes I present 10 key intracellular pathways that drive ADPKD progression. The top key drivers are divided into three main areas: (i) hyperproliferation and the role of JAK/STAT and PI3K pathways (ii) DNA damage and (iii) inflammation and NFκB.

GENERAL SIGNIFICANCE

The description of the 10 top cellular drivers of ADPKD, derived by analysis of miR signatures, is of paramount importance in better understanding the key processes resulting in pathophysiological changes that underlie disease.

MicroRNAs as Potential Biomarkers for the Diagnosis of Chronic Kidney Disease: A Systematic Review and Meta-Analysis

For Chronic Kidney Disease (CKD), the study of microRNA as a biomarker has become an exciting area, so we carried out a meta-analysis to investigate the potential diagnostic values of miRNAs in CKD. We searched Pubmed, Cochrane Library, Embase, and Web of science databases to identify relevant publications published from the establishment of the database to April 30, 2021. We included a total of 26 articles containing 56 studies. There were 4,098 patients with CKD and 2,450 patients without CKD. We found that the overall sensitivity and specificity of miRNAs in CKD diagnosis were 0.86 (95% CI: 0.83–0.89) and 0.79 (95% CI: 0.75–0.83), respectively. In addition, we plotted the summary receiver operator characteristic (SROC) curve to assess diagnostic accuracy, with the area under the curve (AUC) of 0.90 (95% CI: 0.87–0.92). Subgroup analysis showed that sensitivity, specificity, and AUC of miRNAs in plasma and serum were 0.84, 0.78, 0.88; and 0.79, 0.76, 0.83, respectively, while miRNAs in urine were 0.89 for sensitivity, 0.82 for specificity, and 0.92 for AUC. Moreover, we found that the panel of microRNAs (miRNAs) could improve the pooled sensitivity (0.88, 0.81, and 0.91 for sensitivity, specificity, and AUC, respectively). We believe that miRNAs have great potential to become an effective diagnostic biomarker for CKD. Panels of miRNA have higher accuracy than single miRNAs. Additionally, miRNAs in both blood and urine have significant accuracy in the diagnosis of CKD; nevertheless, urine is superior.

Uncovering of Key Pathways and miRNAs for Intracranial Aneurysm Based on Weighted Gene Co-Expression Network Analysis

BACKGROUND

Intracranial aneurysm (IA) is a serious cerebrovascular disease. The identification of key regulatory genes can provide research directions for early diagnosis and treatment of IA.

METHODS

Initially, the miRNA and mRNA data were downloaded from the Gene Expression Omnibus database. Subsequently, the limma package in R was used to screen for differentially expressed genes. In order to investigate the function of the differentially expressed genes, a functional enrichment analysis was performed. Moreover, weighted gene co-expression network analysis (WGCNA) was performed to identify the hub module and hub miRNAs. The correlations between miRNAs and mRNAs were assessed by constructing miRNA-mRNA regulatory networks. In addition, in vitro validation was performed. Finally, diagnostic analysis and electronic expression verification were performed on the GSE122897 dataset.

RESULTS

In the present study, 955 differentially expressed mRNAs (DEmRNAs, 480 with increased and 475 with decreased expression) and 46 differentially expressed miRNAs (DEmiRNAs, 36 with increased and 10 with decreased expression) were identified. WGCNA demonstrated that the yellow module was the hub module. Moreover, 16 hub miRNAs were identified. A total of 1,124 negatively regulated miRNA-mRNA relationship pairs were identified. Functional analysis demonstrated that DEmRNAs in the targeted network were enriched in vascular smooth muscle contraction and focal adhesion pathways. In addition, the area under the curve of 16 hub miRNAs was >0.8. It is implied that 16 hub miRNAs may be used as potential diagnostic biomarkers of IA.

CONCLUSION

Hub miRNAs and key signaling pathways were identified by bioinformatics analysis. This evidence lays the foundation for understanding the underlying molecular mechanisms of IA and provided potential therapeutic targets for the treatment of this disease.

Eight Differential miRNAs in DN Identified by Microarray Analysis as Novel Biomarkers

BACKGROUND

Diabetic nephropathy (DN) is the common cause of renal diseases such as end-stage renal disease (ESRD) and chronic kidney disease (CKD). Various diagnostic applications and treatment methods are used for clinical but remain some prognosis issues. To avoid morbidity and mortality related to DN, early detection of disease complications as well as targeted therapeutic strategies is essential. Considerable evidence indicates that non-coding RNA plays a vital role in the biological processes of various diseases, used as biomarkers and therapeutic targets. And the most known ncRNAs are the microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs).

MATERIALS AND METHODS

Our study aimed to identify potential prognostic ncRNAs involved in DN by bioinformatics analysis and validated expression levels through quantitative polymerase chain reaction (qPCR) and GEO database. Our research focuses on differential expression miRNAs (DEmiRNAs) in DN and their interactions with critical genes.

RESULTS

We identified 8 up-regulated DEmiRNAs, including miR-103a-2-5p, miR-297, miR-548x-3p, miR-604, miR-644a, miR-1256, miR-3911 and miR-5047 finally. We further validated these miRNAs in a murine model.

CONCLUSION

Identifying these up-regulated genes and elucidating these miRNAs regulatory network will contribute to a better understanding of the molecular mechanism of DN and how they can be used as new biomarkers and potential therapeutic targets for DN.

Recent Discoveries in Epigenetic Modifications of Polycystic Kidney Disease

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a heritable renal disease that results in end-stage kidney disease, due to the uncontrolled bilateral growth of cysts throughout the kidneys. While it is known that a mutation within a PKD-causing gene is required for the development of ADPKD, the underlying mechanism(s) causing cystogenesis and progression of the disease are not well understood. Limited therapeutic options are currently available to slow the rate of cystic growth. Epigenetic modifications, including DNA methylation, are known to be altered in neoplasia, and several FDA-approved therapeutics target these disease-specific changes. As there are many similarities between ADPKD and neoplasia, we (and others) have postulated that ADPKD kidneys contain alterations to their epigenetic landscape that could be exploited for future therapeutic discovery. Here we summarise the current understanding of epigenetic changes that are associated with ADPKD, with a particular focus on the burgeoning field of ADPKD-specific alterations in DNA methylation.

MicroRNA-3907 promotes the proliferation and migration of sebaceous gland carcinoma of the eyelid by targeting thrombospondin 1

MicroRNAs (miRNAs/miRs) play an important role in various types of carcinoma, including sebaceous gland carcinoma (SGC) of the eyelid. miR-3907 was found to be highly expressed in lung cancer; however, to the best of our knowledge, the biological role of miR-3907 in SGC has not previously been evaluated. The aim of the present study was to determine the role and mechanism of miR-3907 in the occurrence and development of SGC. miR-3907 was screened and identified as a novel upregulated miRNA in SGC tissues and cells, as determined using miRNA microarrays and reverse transcription-quantitative (RT-q) PCR analyses. Compared with the control group, cellular proliferation and migration were enhanced in the miR-3907 mimics group, and decreased in the miR-3907 inhibitor group. Moreover, miR-3907 negatively regulated thrombospondin 1 (THBS1) expression, as shown by bioinformatics prediction, RT-qPCR, western blotting and dual-luciferase reporter assays. In addition, compared with the control group, the small interfering (si) siRNA-THBS1 group exhibited enhanced proliferation and migration abilities, which were decreased in the THBS1 overexpression group. Furthermore, THBS1 overexpression was found to attenuate the stimulative effect of miR-3907 mimics, and THBS1-knockdown reversed the inhibitory effect of the miR-3907 inhibitor in SGC cells. Collectively, the results of the present study indicated that miR-3907 promoted the proliferation and migration of SGC by downregulating THBS1, and that this axis may be a potential target for the prognostic assessment and treatment of SGC.

Exosomal miRNAs in urine associated with children's cardiorenal parameters: a cross-sectional study

Aims:

The authors sought to examine associations between urinary exosomal miRNAs (exo-miRs), emerging biomarkers of renal health, and cardiorenal outcomes in early childhood.

Materials & methods:

The authors extracted exo-miRs in urine from 88 healthy Mexican children aged 4–6 years. The authors measured associations between 193 exo-miRs and cardiorenal outcomes: systolic/diastolic blood pressure, estimated glomerular filtration rate and urinary sodium and potassium levels. The authors adjusted for age, sex, BMI, socioeconomic status, indoor tobacco smoke exposure and urine specific gravity.

Results:

Multiple exo-miRs were identified meeting a false discovery rate threshold of q < 0.1. Specifically, three exo-miRs had increased expression with urinary sodium, 17 with urinary sodium-to-potassium ratio and one with decreased estimated glomerular filtration rate.

Conclusions:

These results highlight urinary exo-miRs as early-life biomarkers of children's cardiorenal health.

MicroRNA profiling in BEAS-2B cells exposed to alpha radiation reveals potential biomarkers for malignant cellular transformation

The carcinogenicity of radon has been convincingly documented through epidemiological studies of underground miners. The risk of lung cancer from radon exposure is due to the continuous radioactive decay of this gas and subsequent emission of high-energy alpha decay particles. And the bronchial epithelial cells are the main targets of radon exposure. However, there is a lack of early warning indicators of lung cancer caused by radon in the physical examination of populations involved in occupations with higher exposure to radon. To assess the potential of a molecular-based marker approach for the early detection of human lung cancer induced by radon, human bronchial epithelial cell injury models induced by alpha-particle irradiation were constructed. The results of transwell migration assay, transwell invasion assay, and the expression of the epithelial-mesenchymal transition-related proteins showed that malignant cell transformation could be triggered by alpha irradiation. Potential microRNAs (miRNAs) (hsa-miR-3907, hsa-miR-6732-3p, hsa-miR-4788, hsa-miR-5001-5p, and hsa-miR-4257) were screened using miRNA chips in cell models. The pathway analyses of miRNAs selected using DIANA-miRPath v3.0 showed that miRNAs involved in malignant cell transformation were associated with cell adhesion molecules, extracellular matrix receptor interaction, and proteoglycans in cancer, among others, which are closely related to the occurrence and development of carcinogenesis. Reverse Transcription Quantitative Real-Time PCR (RT-qPCR) assay showed that five screened miRNAs were up-regulated in five lung cancer tissue samples. In conclusion, the results indicated that hsa-miR-3907, hsa-miR-6732-3p, hsa-miR-4788, hsa-miR-5001-5p, and hsa-miR-4257 may be potential early markers of the malignant transformation of bronchial epithelial cells induced by alpha-particle irradiation.

Epigenetic Programming Through Breast Milk and Its Impact on Milk-Siblings Mating

Background

The epigenetic effects of transmission of certain regulatory molecules, such as miRNAs, through maternal milk on future generations, are still unknown and have not been fully understood yet. We hypothesized that breastfeeding regularly by adoptive-mother may cause transmission of miRNAs as epigenetic regulating factors to the infant, and the marriage of milk-siblings may cause various pathologies in the future generations.

Results

A cross-fostering model using a/a and A^vy/a mice had been established. F2 milk-sibling and F2 control groups were obtained from mating of milk-siblings or unrelated mice. Randomized selected animals in the both F2 groups were sacrificed for miRNA expression studies and the remainings were followed for phenotypic changes (coat color, obesity, hyperglycemia, liver pathology, and life span). The lifespan in the F2 milk-sibling group was shorter than the control group (387 vs 590 days, p = 0.011) and they were more obese during the aging period. Histopathological examination of liver tissues revealed abnormal findings in F2 milk-sibling group. In order to understand the epigenetic mechanisms leading to these phenotypic changes, we analyzed miRNA expression differences between offspring of milk-sibling and control matings and focused on the signaling pathways regulating lifespan and metabolism. Bioinformatic analysis demonstrated that differentially expressed miRNAs were associated with pathways regulating metabolism, survival, and cancer development such as the PI3K-Akt, ErbB, mTOR, and MAPK, insulin signaling pathways. We further analyzed the expression patterns of miR-186-5p, miR-141-3p, miR-345-5p, and miR-34c-5p and their candidate target genes Mapk8, Gsk3b, and Ppargc1a in ovarian and liver tissues.

Conclusion

Our findings support for the first time that the factors modifying the epigenetic mechanisms may be transmitted by breast milk and these epigenetic interactions may be transferred transgenerationally. Results also suggested hereditary epigenetic effects of cross-fostering on future generations and the impact of mother-infant dyad on epigenetic programming.

The effect of baicalein on Wnt/β-catenin pathway and miR-25 expression in Saos-2 osteosarcoma cell line

Background/aim

Osteosarcoma is the most common primary bone malignancy that occurs frequently in children and adolescents. Baicalein, a flavonoid that has attracted great attention in recent years with its strong antitumor activity, shows a wide range of biological and pharmaceutical effects.MicroRNAs have been found to be involved in many critical processes in cancers. This study aimed to investigate the effect of baicalein and miR-25 on Wnt/β-catenin signaling pathway of osteosarcoma cell line Saos-2.

Materials and methods

Cell viability was assessed, and qRT-PCR and Western blot were performed to study the effects of baicalein on expression of Wnt/β-catenin signaling pathway-realted genes (β-catenin, GSK-3β, and Axin2) of Saos-2 cells.

Results

Our results indicated that baicalein can inhibit the proliferation (IC50 value 35 μM), regulate Wnt/β-catenin pathway and also increase miR-25 expression of Saos-2. Baicalein and also miR-25 decreased the expression of β-catenin and Axin2, while increasing the expression of GSK-3β. Down regulation of miR-25 decreased the expression of GSK-3β, while β-catenin and Axin2 expression increased.

Conclusion

These findings demonstrate that baicalein may target genes related to the Wnt/β-catenin pathway by regulating miR-25 expression and may be a potential Wnt/β-catenin pathway inhibitor for osteosarcoma therapy.

Identification of housekeeping genes for microRNA expression analysis in kidney tissues of Pkd1 deficient mouse models

Polycystic kidney disease is a complex clinical entity which comprises a group of genetic diseases that leads to renal cyst development. We evaluated the most suitable housekeeping genes for microRNA expression by RT-qPCR analyses of kidney tissues in Pkd1-deficient mouse models from a panel of five candidates genes (miR-20a, miR-25, miR-26a, miR-191 and U6) and 3 target genes (miR-17, miR-21 and let-7a) using samples from kidneys of cystic mice (Pkd1^flox/flox:Nestin^cre, CY), non-cystic controls (Pkd1^flox/flox, NC), Pkd1-haploinsufficient (Pkd1^+/−, HT), wild-type controls (Pkd1^+/+, WT), severely cystic mice (Pkd1^V/V, SC), wild-type controls (CO). The stability of the candidate genes was investigated using NormFinder, GeNorm, BestKeeper, DataAssist, and RefFinder software packages and the comparative ΔCt method. The analyses identified miR-26a as the most stable housekeeping gene for all kidney samples, miR-20a for CY and NC, miR-20a and miR-26a for HT and WT, and miR-25 and miR-26a for SC and CO. Expression of miR-21 was upregulated in SC compared to CO and trends of miR-21 upregulation and let-7a downregulation in CY and HT compared to its control kidneys, when normalized by different combinations of miR-20a, miR-25 and miR-26a. Our findings established miR-20a, miR-25, and miR-26a as the best housekeeping genes for miRNA expression analyses by RT-qPCR in kidney tissues of Pkd1-deficient mouse models.

Epigenetic response of endothelial cells to different wall shear stress magnitudes: A report of new mechano-miRNAs

Endothelial cells (ECs) respond to flow stress via a variety of mechanisms, leading to various intracellular responses that can modulate the vessel wall and lead to diseases if the flow is disturbed. Mechano-microRNAs (miRNAs) are a subset of miRNAs in the ECs that are flow responsive. Mechano-miRNAs were shown to be related to atherosclerosis pathophysiology, and a number of them were identified as pathologic. Here, we exposed human carotid ECs to different wall shear stresses (WSS), high and low, and evaluated the response of miRNAs by microarray and quantitative polymerase chain reaction analysis. We discovered five new mechano-miRNAs that were not reported in that context previously to the best of our knowledge. Moreover, functional pathway analysis revealed that under low WSS conditions, several pathways regulating apoptosis are affected. In addition, KLF2 and KLF4, known atheroprotective genes, were downregulated under low WSS and upregulated under high WSS. KLF2 and VCAM1, both angiogenic, were upregulated under high WSS. NOS3, which is vascular protective, was also upregulated with higher WSS. On the contrary, ICAM-1 and E-selectin, both atherogenic and proinflammatory, were upregulated with high WSS. Collectively, the epigenetic landscape with the gene expression analysis reveals that low WSS is associated with a proapoptotic state, while high WSS is associated with a proliferative and proinflammatory state.

Urinary Exosomal MiRNA-4534 as a Novel Diagnostic Biomarker for Diabetic Kidney Disease

Urinary exosomal miRNAs can reflect the physiological and possibly pathophysiological state of cells lining the kidney and participate in the regulation of transcription and translation of proteins, which are playing an important role in the pathogenesis of diabetic kidney disease. In the present study, urine was collected from DM and DKD patients with a duration more than 10 years and urinary exosomal miRNA profiling was conducted in urinary exosomes obtained from three patients with type 2 diabetes (DM) and three patients with type 2 diabetic kidney disease (DKD) using Exiqon's microRNA arrays. In total, the expression of 14 miRNAs (miR-4491, miR-2117, miR-4507, miR-5088-5P, miR-1587, miR-219a-3p, miR-5091, miR-498, miR-4687-3p, miR-516b-5p, miR-4534, miR-1275, miR-5007-3p, and miR-4516) was up-regulated (>2-fold) in DKD patients compared to healthy controls and DM patients. We used qRT-PCR based analysis of these 14 miRNAs in urinary exosomes from 14 DKD to 14 DM patients in confirmation cohort, among which seven miRNAs were consistent with the microarray results. The expressions of miR-4534 and miR-516b-5p correlated with trace proteinuria levels in the confirmation cohort. In conclusion, it has been confirmed that the expression of urinary exosomal miRNA in patients with type 2 diabetes DKD has changed. Mir-4534 might affect the FoxO signaling pathway by targeting BNIP3, and is expected to become a new biomarker for the progression of type 2 DKD disease, which will provide further research on the pathogenesis of DKD.

Impact of miR-192 and miR-194 on cyst enlargement through EMT in autosomal dominant polycystic kidney disease

Altered miRNA (miR) expression occurs in various diseases. However, the therapeutic effect of miRNAs in autosomal dominant polycystic kidney disease (ADPKD) is unclear. Genome-wide analyses of miRNA expression and DNA methylation status were conducted to identify crucial miRNAs in end-stage ADPKD. miR-192 and -194 levels were down-regulated with hypermethylation at these loci, mainly in the intermediate and late stages, not in the early stage, of cystogenesis, suggesting their potential impact on cyst expansion. Cyst expansion has been strongly associated with endothelial-mesenchymal transition (EMT). Zinc finger E-box-binding homeobox-2 and cadherin-2, which are involved in EMT, were directly regulated by miR-192 and -194. The therapeutic effect of miR-192 and -194 in vivo and in vitro were assessed. Restoring these miRs by injection of precursors influenced the reduced size of cysts in Pkd1 conditional knockout mice. miR-192 and -194 may act as potential therapeutic targets to control the expansion and progression of cysts in patients with ADPKD.-Kim, D. Y., Woo, Y. M., Lee, S., Oh, S., Shin, Y., Shin, J.-O., Park, E. Y., Ko, J. Y., Lee, E. J., Bok, J., Yoo, K. H., Park, J. H. Impact of miR-192 and miR-194 on cyst enlargement through EMT in autosomal dominant polycystic kidney disease.

miR-93‑mediated collagen expression in stress urinary incontinence via calpain-2

The aim of the present study was to investigate the expression and mechanism of microRNA (miR)‑93 in collagen expression in stress urinary incontinence (SUI). Vaginal tissue, primary fibroblasts and SUI primary fibroblasts were obtained to detect the expression of miR‑93, interstitial collagenase (MMP1), collagen I and calpain‑2. Reverse transcription‑quantitative polymerase chain reaction analysis was performed to detect the levels of miR‑93 and MMP1. Western blotting was used to evaluate the protein levels of calpain‑2, MMP1 and collagen I. MMP1 and hydroxyproline levels in the supernatant were measured by ELISA. The association between miR‑93 and calpain‑2 was investigated by luciferase reporter assays. The expression of miR‑93 and collagen I was significantly downregulated in the SUI group, while the expression of calpain‑2 and MMP1 was significantly upregulated. ELISA analysis demonstrated that the MMP1 level increased and the hydroxyproline level decreased in the SUI group. Additionally, calpain‑2 was identified to be a target of miR‑93, and miR‑93 was able to negatively regulate the expression of calpain‑2. Restoration of calpain‑2 in miR‑93‑overexpresseing SUI primary fibroblasts reversed the alteration in hydroxyproline expression, indicating that calpain‑2 was negatively associated with collagen expression. The results of the present study suggested that miR‑93 regulated MMP1 and collagen I expression in fibroblasts via calpain‑2. miR‑93 mediated collagen expression in stress urinary incontinence via calpain‑2.