Development of MicroRNA-Based Therapeutics for Vascular Disease

Nucleus Pulposus-Targeting Nanocarriers Facilitate Mirna-Based Therapeutics for Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) is a common cause of low back pain. Understanding its molecular mechanisms is the basis for developing specific treatment. To demonstrate that miR-22-3p is critical in the regulation of IDD, miRNA microarray analyses are conducted in conjunction with in vivo and in vitro experiments. The miR-22-3p knockout (KO) mice show a marked decrease in the histological scores. Bioinformatic analysis reveals that miR-22-3p plays a mechanistic role in the development of IDD by targeting SIRT1, which in turn activates the JAK1/STAT3 signaling pathway. This is confirmed by a luciferase reporter assay and western blot analysis. Therapeutically, the delivery of miR-22-3p inhibitors and mimics through the synthesized nanoparticles in the IDD model alleviates and aggravates IDD, respectively. The nanocarriers enhance transportation of miR-22-3p to nucleus pulposus cells, thus enabling the in vivo inhibition of miR-22-3p for therapeutic purposes and consequently promoting the development of miRNA-specific drugs for IDD.

Inhibition of microRNA-122 alleviates pyroptosis by targeting dual-specificity phosphatase 4 in myocardial ischemia/reperfusion injury

Pyroptosis is a type of programmed cell death that induces myocardial ischemia-reperfusion injury (I/RI), which leads to cardiac dysfunction and even lethal reperfusion injury. MiR-122 is a liver-specific miRNA associated with coronary heart disease, but its role in pyroptosis activation in myocardial I/RI remains unclear. Thus, this study aimed to determine whether miR-122 inhibition exerts myocardial I/RI protection in in vivo and in vitro models. An I/RI model was established in vivo using C57BL/J6 male mice. MiR-122 expression was upregulated in the heart tissues from the I/RI group. Quantitative results of echocardiography parameters showed that miR-122 inhibition improved cardiac function and downregulated interleukin (IL)-1β, IL-18, caspase 1, and caspase 11. However, pretransfection with recombinant adeno-associated virus type 9 encoding a DUSP4-specific siRNA (AAV9-siDUSP4) blocked the protective effects of miR-122 inhibition. A hypoxia/reoxygenation (H/R) model was established to mimic the I/R condition in vitro using H9C2 cells. Results showed that miR-122 inhibition increased superoxide dismutase activity (SOD) and cell viability and decreased malondialdehyde (MDA) level, IL-1β, IL-18, caspase 1, caspase 11, and cell death. These protective effects were abolished by transfection with DUSP4-specific siRNA. In summary, miR-122 expression is upregulated in I/RI, and miR-122 inhibition alleviates I/RI by suppressing pyroptosis through targeting DUSP4. Thus, miR-122 may be a novel therapeutic target for treating myocardial I/RI.

Brain AVMs-Related microRNAs: Machine Learning Algorithm for Expression Profiles of Target Genes

INTRODUCTION

microRNAs (miRNAs) are a class of non-coding RNAs playing a myriad of important roles in regulating gene expression. Of note, recent work demonstrated a critical role of miRNAs in the genesis and progression of brain arteriovenous malformations (bAVMs). Accordingly, here we examine miRNA signatures related to bAVMs and associated gene expression. In so doing we expound on the potential prognostic, diagnostic, and therapeutic significance of miRNAs in the clinical management of bAVMs.

METHODS

A PRISMA-based literature review was performed using PubMed/Medline database with the following search terms: "brain arteriovenous malformations", "cerebral arteriovenous malformations", "microRNA", and "miRNA". All preclinical and clinical studies written in English, regardless of date, were selected. For our bioinformatic analyses, miRWalk and miRTarBase machine learning algorithms were employed; the Kyoto Encyclopedia of Genes and Genomes (KEGG) database was quired for associated pathways/functions.

RESULTS

four studies were ultimately included in the final analyses. Sequencing data consistently revealed the decreased expression of miR-18a in bAVM-endothelial cells, resulting in increased levels of vascular endodermal growth factor (VEGF), Id-1, matrix metalloproteinase, and growth signals. Our analyses also suggest that the downregulation of miR-137 and miR-195* within vascular smooth muscle cells (VSMCs) may foster the activation of inflammation, aberrant angiogenesis, and phenotypic switching. In the peripheral blood, the overexpression of miR-7-5p, miR-629-5p, miR-199a-5p, miR-200b-3p, and let-7b-5p may contribute to endothelial proliferation and nidus development. The machine learning algorithms employed confirmed associations between miRNA-related target networks, vascular rearrangement, and bAVM progression.

CONCLUSION

miRNAs expression appears to be critical in managing bAVMs' post-transcriptional signals. Targets of microRNAs regulate canonical vascular proliferation and reshaping. Although additional scientific evidence is needed, the identification of bAVM miRNA signatures may facilitate the development of novel prognostic/diagnostic tools and molecular therapies for bAVMs.

MicroRNA regulatory networks associated with abnormal muscle repair in survivors of critical illness

BACKGROUND

Intensive care unit (ICU)-acquired weakness is characterized by muscle atrophy and impaired contractility that may persist after ICU discharge. Dysregulated muscle repair and regeneration gene co-expression networks are present in critical illness survivors with persistent muscle wasting and weakness. We aimed to identify microRNAs (miRs) regulating the gene networks and determine their role in the self-renewal of muscle in ICU survivors.

METHODS

Muscle whole-transcriptome expression was assessed with microarrays in banked quadriceps biopsies obtained at 7 days and 6 months post-ICU discharge from critically ill patients (n = 15) in the RECOVER programme and healthy individuals (n = 8). We conducted an integrated miR-messenger RNA analysis to identify miR/gene pairs associated with muscle recovery post-critical illness and evaluated their impact on myoblast proliferation and differentiation in human AB1167 and murine C2C12 cell lines in vitro. Select target genes were validated with quantitative PCR.

RESULTS

Twenty-two miRs were predicted to regulate the Day 7 post-ICU muscle transcriptome vs. controls. Thirty per cent of all differentially expressed genes shared a 3'UTR regulatory sequence for miR-424-3p/5p, which was 10-fold down-regulated in patients (P < 0.001) and correlated with quadriceps size (R = 0.86, P < 0.001), strength (R = 0.75, P = 0.007), and physical function (Functional Independence Measures motor subscore, R = 0.92, P < 0.001) suggesting its potential role as a master regulator of early recovery of muscle mass and strength following ICU discharge. Network analysis demonstrated enrichment for cellular respiration and muscle fate commitment/development related genes. At 6 months post-ICU discharge, a 14-miR expression signature, including miRs-490-3p and -744-5p, identified patients with muscle mass recovery vs. those with sustained atrophy. Constitutive overexpression of the novel miR-490-3p significantly inhibited AB1167 and C2C12 myoblast proliferation (cell count AB1167 miR-490-3p mimic or scrambled-miR transfected myoblasts 7926 ± 4060 vs. 14 159 ± 3515 respectively, P = 0.006; proportion Ki67-positive nuclei AB1167 miR-490-3p mimic or scrambled-miR transfected myoblasts 0.38 ± 0.07 vs. 0.54 ± 0.06 respectively, P < 0.001; proliferating cell nuclear antigen expression AB1167 miR-490-3p mimic or scrambled-miR transfected myoblasts 11.48 ± 1.97 vs. 16.75 ± 1.19 respectively, P = 0.040). Constitutive overexpression of miR-744-5p, a known regulator of myogenesis, significantly inhibited AB1167 and C2C12 myoblast differentiation (fusion index AB1167 miR-744-5p mimic or scrambled-miR transfected myoblasts 8.31 ± 7.00% vs. 40.29 ± 9.37% respectively, P < 0.001; myosin heavy chain expression miR-744-5p mimic or scrambled-miR transfected myoblasts 0.92 ± 0.39 vs. 13.53 ± 5.5 respectively, P = 0.01).

CONCLUSIONS

Combined functional transcriptomics identified 36 miRs including miRs-424-3p/5p, -490-3p, and -744-5p as potential regulators of gene networks associated with recovery of muscle mass and strength following critical illness. MiR-490-3p is identified as a novel regulator of myogenesis.