Inhibition Of miR-21 Research Articles

Exploiting the Metabolic Vulnerability of Leukemic Stem Cells (LSCs) in Inv(16) Acute Myeloid Leukemia (AML) with the Combination of Miristen, a Mir-126 Inhibitor, and Venetoclax

AML with inv(16)(p13q22) expresses the leukemogenic fusion gene CBFB-MYH11 and upregulates microRNA (miR)-126 that supports homeostasis, quiescence, and activity of LSCs. Genetic or pharmacologic depletion of miR-126 via miR-126 knock out (KO) or miRisten (a CpG-anti-miR-126 inhibitor) reduces LSCs in a Cbfb-MYH11 ( CM) knock-in (KI) AML model and inv(16) AML patient-derived xenografts (PDXs), respectively [PMID: 34686664]. However, the antileukemic underpinnings of miR-126 inhibition in inv(16) AML remain to be elucidated. LSCs reportedly rely on fatty acid metabolism/oxidative phosphorylation (OXPHOS) for their bioenergetic metabolic needs. To assess the role of miR-126 in metabolism, we performed metabolomic profiling for Lin-/c-Kit+ cells isolated from CM KI AML (miR-126 high) mice and CM with miR-126 KO mice ( CM/miR-126 Δ /Δ). Our data revealed that CM/miR-126 Δ /Δ had a significant decrease of short, medium as well as long-chain acyl carnitines and fatty acid (2 to 11 fold, p<0.05) compared to CM/miR-126 WT/ WT mice, suggesting that miR-126 deficit decreased fatty acid oxidation (FAO). Moreover, electron microscope imaging demonstrated mitochondrial fusion (i.e., larger and networked mitochondria) in CM Lin-/c-Kit+Sca1+ (LSK) cells vs syngeneic controls. In contrast, mitochondria fragmentation (fission) and decreased FAO/OXPHOS were observed in murine CM with miR-126 KO LSK. Accordingly, FAO and Seahorse assays demonstrated miRisten treatment led to mitochondria fragmentation and reduced FAO/OXPHOS and in human CD34 + CD38 ‒ inv(16) blasts (enriched for LSCs) vs normal CD34 + CD38 ‒ cells. Sprouty Related EVH1 Domain Containing 1 (SPRED1), a downstream target of miR-126, inhibits ERK/CREB activation and in turn increases antiapoptotic protein BCL-2 via phosphorylation and stabilization. In inv(16) AML cells, upregulated miR-126 downregulated SPRED1 and in turn increased ERK/CREB signaling and BCL-2 levels. This increase augments the ubiquitination of DRP1, a protein otherwise involved in mitochondrial fission, via NFE2-related factor 2 (NRF2), and increases Carnitine Palmitoyltransferase 1B (CPT1B), a rate-controlling protein for FAO and OXPHOS. In contrast, miR-126 KO or miR-126 inhibition by miRisten led to SPRED1 upregulation and decreased ERK/CREB signaling and BCL-2 levels, thereby resulting in increased Dynamin-related protein 1 (DRP1) and mitochondrial fission and a decrease in CPT1B, FAO, and OXPHOS. Thus, given the interplay of miR-126 with BCL-2 and its implication in mitochondrial fusion and increase of OXPHOS in inv(16) blasts and LSCs, we hypothesized a synergism between miRisten and the BCL-2 inhibitor venetoclax (VEN). In fact, combination of miRisten/VEN synergistically decreased FAO/OXPHOS, enhanced mitochondria fission and increased apoptosis of murine and human inv(16) blasts and LSCs [combination indices (CIs)<1, (ED50-ED95)]. Thus, we treated CM mice with scrambled oligonucleotides (sODN) (20 mg/kg i.v., daily for 3 weeks), miRisten (20 mg/kg i.v., daily for 3 weeks), VEN (100 mg/kg oral gavage, daily for 2 weeks), or miRisten/VEN (same dosages as single agents). Compared with sODN or single agents, miRisten/VEN significantly reduced bone marrow (BM) leukemic blast infiltration [miRisten/VEN 33.6±3.4% vs miRisten 49.8±2.6% (p=0.001), VEN 56.2±4.7% (p=0.001), or sODN 60.0±2.6% (p<0.0001)] and spleen weights [miRisten/VEN 0.228±0.038g vs miRisten 0.495±0.058g (p=0.001), VEN 0.479±0.06g (p=0.002), or sODN 0.853±0.039g (p<0.0001)] and prolonged survival of CM mice [median survival miRisten/VEN 125d vs miRisten 108d (p=0.005), VEN 106.5d (p=0.039), or sODN 91d (p<0.0001), respectively; secondary transplant median survival: miRisten/VEN 92d vs miRisten 70.5d (p=0.048), VEN 54d (p=0.006), or sODN 45d (p=0.0002)]. Similar results were also observed in inv(16) PDXs with significant reduction of BM huCD45+ leukemic blasts by miRisten/VEN compared to single agents or sODN [miRisten/VEN 13.7±1.9% vs miRisten 27.9±3.4% (p=0.003), VEN 25.3±4.6%(p=0.032), or sODN 68.6±5.3% (p<0.0001)]; survival analyses for treated PDX mice and secondary transplant recipients are in progress. In summary, our study provides the mechanism for combining miRisten with VEN in the treatment of inv(16) AML. While VEN is FDA approved for AML, miRisten has just undergone a successful toxicology evaluation and is underway to the clinic.

METTL3-mediated m6A RNA methylation induces the differentiation of lung resident mesenchymal stem cells into myofibroblasts via the miR-21/PTEN pathway

BackgroundThe accumulation of myofibroblasts is the key pathological feature of pulmonary fibrosis (PF). Aberrant differentiation of lung-resident mesenchymal stem cells (LR-MSCs) has been identified as a critical source of myofibroblasts, but the molecular mechanisms underlying this process remain largely unknown. In recent years, N6-methyladenosine (m6A) RNA modification has been implicated in fibrosis development across diverse organs; however, its specific role in promoting the differentiation of LR-MSCs into myofibroblasts in PF is not well defined.MethodsIn this study, we examined the levels of m6A RNA methylation and the expression of its regulatory enzymes in both TGF-β1-treated LR-MSCs and fibrotic mouse lung tissues. The downstream target genes of m6A and their related pathways were identified according to a literature review, bioinformatic analysis and experimental verification. We also assessed the expression levels of myofibroblast markers in treated LR-MSCs and confirmed the involvement of the above-described pathway in the aberrant differentiation direction of LR-MSCs under TGF-β1 stimulation by overexpressing or knocking down key genes within the pathway.ResultsOur results revealed that METTL3-mediated m6A RNA methylation was significantly upregulated in both TGF-β1-treated LR-MSCs and fibrotic mouse lung tissues. This process directly led to the aberrant differentiation of LR-MSCs into myofibroblasts by targeting the miR-21/PTEN pathway. Moreover, inhibition of METTL3 or miR-21 and overexpression of PTEN could rescue this abnormal differentiation.ConclusionOur study demonstrated that m6A RNA methylation induced aberrant LR-MSC differentiation into myofibroblasts via the METTL3/miR-21/PTEN signaling pathway. We indicated a novel mechanism to promote PF progression. Targeting METTL3-mediated m6A RNA methylation and its downstream targets may present innovative therapeutic approaches for the prevention and treatment of PF.

The relationship between miR-21, DNA methylation, and bisphenol a in bovine COCs and granulosa cells.

Introduction: miR-21 is a critical microRNA for the regulation of various processes in oocytes and granulosa cells. It is involved in the modulation of apoptosis and can influence other epigenetic mechanisms. Among these mechanisms, DNA methylation holds significant importance, particularly during female gametogenesis. Evidence has demonstrated that microRNAs, including miR-21, can regulate DNA methylation. Bisphenol A (BPA) is a widespread chemical that disrupts oocyte maturation and granulosa cell function. Recent findings suggested that BPA can act through epigenetic pathways, including DNA methylation and microRNAs. Methods: This study uses anti-miR-21 LNAs to explore the involvement of miR-21 in the regulation of DNA methylation in bovine Cumulus-Oocyte-Complexes (COCs) and granulosa cells, in the presence and absence of BPA. This study investigated 5mC/5hmC levels as well as gene expression of various methylation enzymes using qPCR and western blotting. Results and discussion: Results reveal that BPA reduces 5mC levels in granulosa cells but not in COCs, which can be attributed to a decrease in the methylating enzymes DNMT1 and DNMT3A, and an increase in the demethylating enzyme TET2. We observed a significant increase in the protein levels of DNMT1, DNMT3A, and TET2 upon inhibition of miR-21 in both COCs and granulosa cells. These findings directly imply a strong correlation between miR-21 signaling and the regulation of DNA methylation in bovine COCs and granulosa cells under BPA exposure.

Abstract 15096: miR-132 Inhibition Shows Anti-Hypertrophic Effects in Preclinical Heart Failure Models and in Exploratory Pharmacodynamic Parameters of a First-in-Human Phase 1b Clinical Trial

Introduction: Cardiac expression levels of miR-132 are elevated in patients with heart failure (HF) and have been associated and provoke pathological cardiac hypertrophy. To inhibit these cardiac remodeling processes and restore normal cardiac function, we developed the synthetic antisense oligonucleotide inhibitor CDR132L targeting miR-132. Anti-hypertrophic effects of miR-132 inhibition have been shown previously in cell culture models and a mouse model of pressure overload-induced HF. Methods and Results: MiR-132 inhibition with CDR132L was now tested in a mouse model of pressure overload induced HF induced by transverse aortic constriction (TAC) and in three different porcine HF models to further confirm the translatability of therapeutic effects. The first pig model was an early post-myocardial infarction (MI). Pigs were treated with CDR132L by intravenous (IV) or intracoronary (IC) infusion on day 3 and day 28 and analyzed on day 56 post-MI. As a second model, chronic post-MI HF pigs received monthly IV treatments over 3 or 5 months starting from month 1 post-MI. Third, percutaneous aortic constriction was induced in pigs by reduction stent implantation and CDR132L was administered IC on day 0 and day 28 followed by analysis on day 56. Hypertrophy was determined by cell size measurements in wheat germ agglutinin (WGA) stained cardiac sections and was significantly decreased between 15% and 29% in CDR132L-treated groups with sufficient dose levels compared to placebo-treatment independent from the large animal model and dosing regimen. Furthermore, TAC mice treated with CDR132L showed a significant decrease in left ventricular mass by 14 % compared to placebo. In line with these data, the cardiac remodeling marker lipocalin-2 (NGAL) was reduced in plasma of chronic HF patients assessed in a first-in-human phase 1b clinical to test safety, efficacy, and also exploratory pharmacodynamics of CDR132L (NCT04045405). Conclusions: Our results confirm beneficial effects of CDR132L treatment on pathological cardiac remodeling in HF.

Abstract 15259: The Novel Antisense Oligonucleotide CDR132L Improves Cardiac Function in Heart Failure Across Different Species

Introduction: The chronic progressive condition of heart failure (HF) is, to date, largely irreversible and continues to impose global morbidity. MicroRNAs exert substantial roles in HF progression by orchestrating pathological genes and pathways. Medications directly tackling the roots of the disease are rare, but inhibition of miR-132, a microRNA that was shown to be upregulated upon cardiac remodeling and HF, is a promising approach. Thus, CDR132L, a clinical-stage synthetic antisense oligonucleotide miR-132 inhibitor, can be an innovative therapy for patients with HF. Hypothesis: To examine the effect of CDR132L, different studies were conducted, including in mice and pigs and in a first-inhuman phase 1b safety and tolerability study that revealed preclinical and exploratory efficacy data. Results: MiR-132 transgenic mice developed reduced left-ventricular ejection fraction (LVEF) and cardiac dilatation. CDR132L treatment significantly improved LVEF and reversed cardiac dilatation. The results were confirmed in a porcine transverse aortic constriction model, where the LVEF was significantly improved in the CDR132L treatment group compared to control animals (48.9% vs. 36.1%). In post-MI HF pigs subjected to different treatment and dosing regimens, resulted in a significant and dose-dependent improvement of the cardiac function, illustrated by an up to 10.4% improvement in LVEF to the placebo group at day 56. During a monthly treatment, 87.5% of the animals treated 5x 5 mg/kg with CDR132L showed a ΔLVEF of >7% compared to the placebo group. Additionally, CDR132L improved contractility and the diastolic function by reducing cardiac stiffness. A successful translation of these preclinical results into humans was performed in a CDR132L safety and tolerability Phase 1b clinical trial in HF patients. In an exploratory analysis, the combined endpoint, consisting of patients with a decrease in NT-proBNP levels and/or an absolute increase in LVEF, was significantly met by 79% of the patients in the pharmacodynamically active CDR132L group. Conclusion: Pharmacological miR-132 inhibition by CDR132L improved cardiac function in multi-species models of HF, highlighting the therapeutic potential for clinical use in HF patients.

Abstract 15205: miR-132 Inhibition Improves Myocardial Strain in a Large Animal Model of Chronic Adverse Remodeling

Background: MicroRNAs (miRNAs) are transcriptional regulators and essential drivers of heart failure (HF). The miR-132 is necessary and sufficient to progress adverse cardiac remodeling. The strong effects are exhibited by, amongst others, cardiomyocyte hypertrophy and calcium signaling impairment. Treatments directly targeting the roots of the disease are scarce, but miR-132 inhibition by CDR132L, a rationally designed synthetic oligonucleotide, significantly improves cardiac dysfunction in HF early after myocardial infarction (MI). Rational: The aim of the current study was to gain further data on myocardial function and efficacy of CDR132L by analyzing left ventricular (LV) and atrial (LA) wall motion by serial cardiac magnetic resonance (cMRI) strain imaging in a clinically relevant large animal (pig) model of chronic HF. Methods and Results: Mangalica pigs (n=15) were randomized 1-month post-MI, initiated by left anterior descending artery occlusion followed by reperfusion as a chronic model of post-MI HF. Animals received CDR132L over 5 months by monthly intravenous treatments with 5 mg/kg. LV and LA strain parameters were deteriorated after MI over time but significantly ameliorated by CDR132L treatment, compared to placebo. Strain parameters showed significant correlations with pharmacodynamic measures such as left-ventricular ejection fraction, NT-proBNP and cardiac interstitial fibrosis in remodeling hearts 6 months post-MI. Conclusions: LV and LA motion and contractility were improved by repeated dosing of CDR132L with monthly frequency in a large animal model of chronic post-MI HF. The results highlight the translational value and usability of MRI-based cardiac strain imaging in HF drug development and support further clinical development of CDR132L.

Abstract 15057: miR-132 Inhibitor CDR 132L Attenuates Cardiac Remodeling by Exhibiting Anti-Fibrotic Effects

Introduction: Increased cardiac expression levels of miRNA miR-132 have been associated with pathological cardiac remodeling including cardiac fibrosis. As a selective inhibitor for miR-132, the synthetic antisense oligonucleotide CDR132L, is capable to reverse cellular pathology and restore normal heart function. Pharmacological inhibition of miR-132 as well as genetic knockout has been shown to protect mice from transverse aortic constriction induced cardiac remodeling including interstitial fibrosis. Methods and Results: Treatment effects of CDR132L were investigated in several different pig models of ischemic and non-ischemic heart failure (HF) with the aim to further elucidate CDR132L’s mode of action and confirm species-independent effects on fibrotic remodeling. In a pig model of subacute post myocardial infarction (MI) induced HF, CDR132L was administered on day 3 and day 28 by intravenous (IV) or intracoronary (IC) infusion at doses of 1, 5 and 10 mg/kg and followed until day 56. In a chronic post-MI HF large animal model, beneficial effects were confirmed in a 6-month study comparing 5 monthly and 3 monthly repeated IV administrations of 5 mg/kg CDR132L starting one month post-MI. Further, CDR132L was tested in a porcine model of percutaneous aortic constriction by implantation of a reduction stent in the thoracic aorta and two IC injections of CDR132L on day 0 and day 28 followed for 56 days. As part of the pharmacodynamic analyses in these models, paraffin sections of cardiac tissue from the left ventricular remote region were stained with picrosirius red (PSR) and fibrosis was assessed based on collagen quantity. Analysis of fibrosis in PSR-staining revealed that the degree of interstitial fibrosis was significantly reduced in CDR132L treatment groups compared to placebo between 22% and 61%. Moreover, results of the first-in-human safety and tolerability study of CDR132L in patients with stable HF of ischemic origin (NCT04045405) showed encouraging positive trends for relevant cardiac fibrosis biomarkers. Conclusion: By blocking aberrant miR-132 expression, CDR132L is capable to halt and reverse pathological cardiac remodeling partly due to its anti-fibrotic effects.

Abstract 15115: Efficacy and Safety of miR-132 Inhibitor CDR132L in Patients With Reduced Left Ventricular Ejection Fraction After Myocardial Infarction: Rationale for and Design of the HF-REVERT Trial

Background: Inhibition of miR-132 effectively prevents and reverses heart failure (HF) in relevant models, making it an attractive HF target. CDR132L is a synthetic antisense oligonucleotide (ASO) selectively blocking miR-132. Translational in vitro and in vivo studies have demonstrated meaningful efficacy of CDR132L on left ventricular (LV) structure and function. CDR132L was safe and well tolerated in a Phase 1b study in chronic HF patients. The indicative effects of the miR-132 inhibitor CDR132L may be particularly beneficial in patients with active adverse remodelling, e.g. after acute myocardial infarction with early decline in ejection fraction. These patients have been relatively understudied and therapeutic options are limited. Method: The HF-REVERT (P h ase 2, Multicenter, Randomized, Parallel, 3-arm, Placebo-controlled Study to Assess E f ficacy and Safety of CD R 132L in Pati e nts with Reduced Left V entricular E jection F r ac t ion (≤ 45%) after Myocardial Infarction; NCT05350969) is a proof-of-concept study to evaluate the efficacy of CDR132L in improving cardiac function and safety in patients with reduced LV ejection fraction (LVEF). HF-REVERT aims to assess the efficacy and safety of 5 mg/kg and 10 mg/kg CDR132L, given as 3 single intravenous doses administered 28 days apart as an add-on to standard-of-care treatment, in a larger cohort of patients (N = 280) with HF and reduced LVEF (≤ 45%) after MI with a follow-up of 10 months. Key inclusion criteria are the diagnosis of acute STEMI/NSTEMI and the development of systolic dysfunction (LVEF ≤ 45%) after MI index event and elevated N-terminal pro B-type natriuretic peptide (NT-proBNP). The study consists of a 6-month double-blind treatment period with a read out of the primary endpoint LVESVI (left ventricular end systolic volume index) followed by a 6-month open label observation period. Discussion: The HF-REVERT trial currently tests CDR132L in patients with MI and systolic dysfunction. This trial may therefore underpin the concept of miR-132 inhibition to prevent/reverse cardiac remodeling in HF patients. The results will inform the design of a subsequent outcome trial to test the effect of CDR132L in HF patients.

MiR-22 inhibits angiotensin II-induced aortic dissection and protects aortic vessel wall in mice by targeting MAPK14

Purpose: To study the effect of miR-22 on angiotensin II-induced aortic dissection in mice, and its protective effect on aortic vessel wall, as well the involvement of MAPK-14 in these processes.
 Methods: A mouse aortic dissection model was established via subcutaneous implantation of angiotensin II (1 µg/kg/min) micropump in the dorsal region. The mice (n = 30) were assigned in equal numbers to 5 groups (n = 6). All injections were given via the tail vein. The miR-22 expressions in aortas of mice in each group were determined with quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Western blot assay was used to determine the expressions of MAPK-14 protein, while H&E staining was used to measure the ratio of aortic thickness-to-diameter, and contents of collagen and elastic fibers.
 Results: The expression of miR-22 in aorta of mice in miR-22 overexpression group was significantly higher than that in overexpression control group, but significantly lower in miR-22 inhibition mouse than in inhibition control mouse (p < 0.05). There was significantly lower protein expression of MAPK-14 in mice aorta in miR-22 overexpression mice than in overexpression control mice, but significantly upregulated in miR-22 inhibition mice, relative to that in inhibition control mice (p < 0.05). In the miR-22 overexpression mice, the ratio of membrane thickness-to-diameter was higher than the corresponding value in miR-22 inhibition mice. There were significantly higher contents of aortic elastic and collagen fibers in miR-22 overexpression mice than in overexpression control and miR-22 inhibition groups (p < 0.05).
 Conclusion: Overexpression of miR-22 inhibits the up-regulation of expression of its target gene mapk14, increases thickness of aortic media and aortic elasticity in mice, and increase the content of collagen fibers, thereby exerting protective effect on aortic wall structure.

MiR-155 Negatively Regulates Anti-Viral Innate Responses among HIV-Infected Progressors.

HIV infection impairs host immunity, leading to progressive disease. An anti-retroviral treatment efficiently controls viremia but cannot completely restore the immune dysfunction in HIV-infected individuals. Both host and viral factors determine the rate of disease progression. Among the host factors, innate immunity plays a critical role; however, the mechanism(s) associated with dysfunctional innate responses are poorly understood among HIV disease progressors, which was investigated here. The gene expression profiles of TLRs and innate cytokines in HIV-infected (LTNPs and progressors) and HIV-uninfected individuals were examined. Since the progressors showed a dysregulated TLR-mediated innate response, we investigated the role of TLR agonists in restoring the innate functions of the progressors. The stimulation of PBMCs with TLR3 agonist-poly:(I:C), TLR7 agonist-GS-9620 and TLR9 agonist-ODN 2216 resulted in an increased expression of IFN-α, IFN-β and IL-6. Interestingly, the expression of IFITM3, BST-2, IFITM-3, IFI-16 was also increased upon stimulation with TLR3 and TLR7 agonists, respectively. To further understand the molecular mechanism involved, the role of miR-155 was explored. Increased miR-155 expression was noted among the progressors. MiR-155 inhibition upregulated the expression of TLR3, NF-κB, IRF-3, TNF-α and the APOBEC-3G, IFITM-3, IFI-16 and BST-2 genes in the PBMCs of the progressors. To conclude, miR-155 negatively regulates TLR-mediated cytokines as wel l as the expression of host restriction factors, which play an important role in mounting anti-HIV responses; hence, targeting miR-155 might be helpful in devising strategic approaches towards alleviating HIV disease progression.

Icariin alleviates high-fat diet-induced nonalcoholic fatty liver disease via up-regulating miR-206 to mediate NF-κB and MAPK pathways.

Nonalcoholic fatty liver disease (NAFLD) is an abnormal lipid accumulation disease in hepatocytes. The existing drugs for NAFLD have some side effects, so new therapeutic agents are required to be explored. In this study, the effect and mechanism of icariin (ICA) on high-fat diet-induced NAFLD were investigated. Firstly, a high-fat diet was used to construct a NAFLD rat model and HepG2 cells were treated with 1 mM free fatty acid (FFA). After ICA treatment, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured; liver injury and lipid deposition were observed by H&E and Oil Red O staining; interleukin-1β (IL-1β), IL-12, and IL-6 were measured by enzyme-linked immunosorbent assay. Additionally, qRT-PCR and western blot were performed to detect miR-206 expression and NF-κB/MAPK pathway-related protein expression in liver tissues and cells. After a variety of trials, we discovered that compared with the NAFLD group, ICA significantly reduced ALT, AST, TBil, TG, TC, and LDL-C levels and increased HDL-C levels, and improved liver tissue injury and lipid deposition. Moreover, ICA reduced IL-1β, IL-12, and IL-6 levels in liver tissues and cells as well as inhibited MAPK and NF-κB-related protein expression in the liver tissues. Notably, ICA could significantly increase miR-206 expression in liver tissues and cells. Further experiments confirmed that inhibition of miR-206 was able to reverse the effect of ICA on NAFLD. In conclusion, ICA can alleviate NAFLD by upregulating miR-206 to mediate NF-κB and MAPK pathways.

MiR-7 is recruited to the high molecular weight RNA-induced silencing complex in CD8+ T cells upon activation and suppresses IL-2 signaling.

Increasing evidence suggests mammalian Argonaute (Ago) proteins partition into distinct complexes within cells, but there is still little biochemical or functional understanding of the miRNAs differentially associated with these complexes. In naïve T cells, Ago2 is found almost exclusively in low molecular weight (LMW) complexes which are associated with miRNAs but not their target mRNAs. Upon T-cell activation, a proportion of these Ago2 complexes move into a newly formed high molecular weight (HMW) RNA-induced silencing complex (RISC), which is characterized by the presence of the GW182 protein that mediates translational repression. Here, we demonstrate distinct partitioning of miRNAs and isomiRs in LMW versus HMW RISCs upon antigen-mediated activation of CD8+ T cells. We identify miR-7 as highly enriched in HMW RISC and demonstrate that miR-7 inhibition leads to increased production of IL-2 and up-regulation of the IL-2 receptor, the transferrin receptor, CD71 and the amino acid transporter, CD98. Our data support a model where recruitment of miR-7 to HMW RISC restrains IL-2 signaling and the metabolic processes regulated by IL-2.

Astragaloside IV Regulates Insulin Resistance and Inflammatory Response of Adipocytes via Modulating MIR-21/PTEN/PI3K/AKT Signaling.

The progression of Type 2 Diabetes Mellitus (T2DM) can lead to various complications. Compounds derived from natural products have been found to be effective in combatting T2DM. This study aimed to investigate the effects of Astragaloside IV (AS-IV) on insulin resistance and the inflammatory response of adipocytes. The study also aimed to determine the downstream signaling pathways involved. The glucose consumption of adipocytes was assessed using a glucose assay kit. qRT-PCR, Western blot, and ELISA assays were used to measure mRNA and protein levels. The interaction between miR-21 and PTEN was assessed using a Dual-luciferase reporter assay. The results showed that AS-IV increased glucose consumption and the expression of GLUT-4 in adipocytes with insulin resistance in a concentration-dependent manner. However, ASIV decreased the protein levels of TNF-α and IL-6 in these cells. Additionally, AS-IV up-regulated miR-21 expression in adipocytes with insulin resistance in a concentration-dependent manner. Furthermore, miR-21 overexpression increased glucose consumption and GLUT-4 expression but decreased TNF-α and IL-6 protein levels in adipocytes. Conversely, miR-21 inhibition attenuated the AS-IV-induced increase in glucose consumption and GLUT-4 expression and the decrease in TNF- α and IL-6 protein levels in adipocytes. MiR-21 also inversely regulated PTEN in adipocytes, and PTEN overexpression had effects similar to miR-21 inhibition in AS-IV-treated adipocytes. Finally, AS-IV up-regulated p-PI3K and p-AKT protein expression in adipocytes, which was attenuated by miR-21 inhibition. The study concluded that AS-IV attenuated insulin resistance and the inflammatory response in adipocytes. The mechanistic studies indicated that AS-IV modulated the miR- 21/PTEN/PI3K/AKT signaling in adipocytes to exert these effects.

MiR-21 Participates in Anti-VEGF-Induced Epithelial Mesenchymal Transformation in RPE Cells.

To explore the role and possible mechanism of miR-21 in anti-VEGF drug-induced epithelial-mesenchymal transformation (EMT) in human retinal pigment epithelium (ARPE-19) cells, and to seek more therapeutic targets to improve prognosis vision. ARPE-19 cells were exposed to clinical dosage of bevacizumab and miR-21 expression was measured by real-time polymerase chain reaction (RT-PCR) assay. MiR-21 mimic and inhibitor were transfected into bevacizumab-induced ARPE-19, the expression of α-smooth muscle actin (α-SMA), E-cadherin, and SNAI1 were detected by cell immunofluorescence and Western blotting. Clinical dosage of bevacizumab caused EMT and enhanced miR-21 expression in ARPE-19 cells (P<0.05). The inhibition of miR-21 attenuated the EMT effect of bevacizumab, while overexpression of miR-21 promoted this activity (P<0.05). The SNAI1 was up-regulated by bevacizumab and promotion was partially suppressed by the miR-21 inhibitor and aggravated by the miR-21 mimic (P<0.05). MiR-21 promotes bevacizumab-induced EMT in ARPE cells which is significantly positively correlated with SNAI1. MiR-21 might be a potential miRNA-based therapeutic target for reducing bevacizumab-induced subretinal fibrosis.

Extracellular shuttling miR-21 contributes to esophageal cancers and human umbilical vein endothelial cell communication in the tumor microenvironment and promotes tumor angiogenesis by targeting phosphatase and tensinhomolog.

Cell-cell communication by carcinoma-derived exosomes can influence the tumor microenvironment (TME) and regulate cancer progression. Based on the overexpression of microRNA-21-5p (miR-21) in plasma from patients diagnosed with esophageal squamous cell carcinoma (ESCC) and exosomes from ESCC cell lines identified earlier, this study aimed to explore the influence of exosomal miR-21 within the TME. ScRNA-Seq and Bulk RNA-Seq were integrated to elucidate the communication between cancer and endothelial cells. The functionality and mechanisms by which exo-miR-21 derived from carcinoma regulate endothelial cell-mediated angiogenesis were assessed using a cocultivation model of EC9706 cells and recipient human umbilical vein endothelial cells (HUVECs), through blood vessel formation experiments, luciferase reporter assays, RT-qPCR, and western blot analysis. A total of 3842 endothelial cells were extracted from the scRNA-seq data of ESCC samples and reclustered into five cell subtype. Cell-cell communication analysis revealed cancer cells presented a strong interaction with angiogenesis-like endothelial cells in secreted signaling. MiR-21 was unregulated in ESCC and the carcinoma-derived exo-miR-21 was significantly raised in HUVECs. The exo-miR-21 promoted the proliferation and migration of HUVECs while also enhancing, closed mesh count, and junction number in HUVECs. Mechanistically, dual-luciferase reporter assay revealed that PTEN was the target of miR-21. Meanwhile, p-Akt was significantly increased and suppressed by inhibition of miR-21 and PI3K inhibitor LY294002. Exo-miR-21-mediated communication between endothelial and cancer cells plays a pivotal role in promoting the angiogenesis of ESCC. Therefore, controlling exo-miR-21 could serve as a novel therapeutic strategy for ESCC by targeting angiogenesis.

Cognitive–exercise dual-task intervention ameliorates cognitive decline in natural aging rats via inhibiting the promotion of LncRNA NEAT1/miR-124–3p on caveolin-1-PI3K/Akt/GSK3β Pathway

Aging-related cognitive impairment (ARCI) is rapidly becoming a healthcare priority. However, there is currently no excellent cure for it. Cognitive-exercise dual-task intervention (CEDI) is a promising method to improve ARCI, while the underlying mechanisms remain unclear. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in the onset, development, and rehabilitation of ARCI. This study aimed to investigate the effects of CEDI and the role of regulation of the lncRNA NEAT1/miR-124–3p on the caveolin-1-PI3K/Akt/GSK3β pathway in CEDI improving cognitive function. Forty 18-month-old natural aging rats were randomly assigned to four groups: exercise training group, cognitive training group, CEDI group, and aging control group, and underwent 12 weeks of intervention. A novel object recognition test was performed to determine the cognitive function, and the hippocampus was separated three days after the behavioral tests for further molecular detection. In an in vitro study, the mouse hippocampal neuronal cell line HT22 was cultured. MiR-124–3p and lncRNA NEAT1 were over-expressed or down-expressed, respectively. The expressions of related proteins, lncRNA, and miRNA were examined by WB and/or qRT-PCR. The results showed that compared with the aging control group, the CEDI group had a higher discrimination index, and significantly decreased the expressions of lncRNA NEAT1, and the protein expressions of caveolin-1 and p-GSK3β, while significantly increased the expressions of miR-124–3p, and the protein expressions of p-PI3K and p-Akt. Inhibition of the lncRNA NEAT1 could significantly increase the protein expressions of p-PI3K and p-Akt in HT22 cells. Upregulation of miR-124–3p decreased the protein expressions of caveolin-1 and p-GSK3β, and increased the protein expressions of p-PI3K and p-Akt significantly. Inhibition of miR-124–3p had the opposite effects. Our study demonstrated that CEDI improved cognitive function in aging rats better than a single intervention. The mechanisms of cognitive improvement could be related to the regulation of the lncRNA NEAT1/miR-124–3p on the caveolin-1-PI3K/Akt/GSK3β pathway.

MDMA targets miR-124/MEKK3 via MALAT1 to promote Parkinson’s disease progression

BackgroundParkinson’s disease (PD) is a well-known neurodegenerative disease that is usually caused by the progressive loss of dopamine neurons and the formation of Lewy vesicles. 3,4-Methylenedioxymethamphetamine (MDMA) has been reported to cause damage to human substantia nigra neurons and an increased risk of PD, but the exact molecular mechanisms need further investigation.MethodsMPTP- and MPP+-induced PD cells and animal models were treated with Nissl staining to assess neuronal damage in the substantia nigra (SN) area; immunohistochemistry to detect TH expression in the SN; TUNEL staining to detect apoptosis in the SN area; Western blotting to detect the inflammatory factors NF-κB, TNF-α, IL-6 and mitogen-activated protein kinase kinase kinase 3 (MEKK3); Griess assay for NO; RT‒qPCR for metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-124 expression; Cell proliferation was assessed by CCK-8. Dual luciferase reporter genes were used to verify targeting relationships.ResultsMDMA promoted MALAT1 expression, and knockdown of MALAT1 alleviated the MDMA-induced inhibition of SH-SY5Y cell proliferation, inflammation, NO release, SN neuronal injury, and TH expression inhibition. Both inhibition of miR-124 and overexpression of MEKK3 reversed the neuroprotective effects exhibited by knockdown of MALAT1.ConclusionMDMA promotes MALAT1 expression and inhibits the targeted downregulation of MEKK3 by miR-124, resulting in upregulation of the expression of MEKK3 and finally jointly promoting PD progression.

Quercetin suppresses retinoblastoma cell proliferation and invasion and facilitates oxidative stress-induced apoptosis through the miR-137/FNDC5 axis

Retinoblastoma (RB) constitutes a prevalent malignancy in clinic and usually occurs in children under the age of 5 years old. The increased frequency of malignant tumor metastases and the delayed diagnosis and treatment caused unsatisfactory therapeutic efficiency. Quercetin was formerly identified to impede tumor growth in certain malignancies. Our study attempted to investigate the effects and mechanisms of quercetin in Rb development, in order to provide an effective clinical therapeutic approach. Rb cell lines (WER1-RB1 and Y79) were incubated with different concentrations of quercetin, and then cell proliferation, invasion, apoptosis, and oxidative stress were determined. It was showed that quercetin restrained Rb cell proliferation and invasion, and induced cell apoptosis and oxidative stress in a dose dependent manner. Moreover, we found that quercetin incubation upregulated miR-137 expression in Rb cells. MiR-137 inhibition abrogated quercetin-mediated inhibition of Rb cell progression. Furthermore, dual-luciferase reporter gene assay validated that fibronectin type III domain-containing protein 5 (FNDC5) was a target for miR-137. MiR-137 overexpression restrained proliferation and invasion, and enhanced apoptosis and oxidative stress in Rb cells, whereas FNDC5 overexpression abrogated these effects. Additionally, nude mice were injected with WER1-RB1 cells to establish a xenograft tumor model, and then treated with 50 or 100 mg/kg quercetin. Quercetin treatment mitigated xenograft tumor growth in nude mice. In conclusion, quercetin restrained proliferation and invasion, and induced apoptosis and oxidative stress in Rb cells through regulating the miR-137/FNDC5 pathway. We expected that our study could provide an effective approach for Rb treatment. However, quercetin and miR-137 may have off-target effects in Rb cells, and our study still has certain limitations. Therefore, we will investigate the effects of quercetin on other signaling pathways in Rb cells and explore the application of combination therapy in follow-up experiments, in order to provide a rigorous research basis for the treatment of Rb with quercetin.

Nanoparticles carrying paclitaxel and anti-miR-221 for breast cancer therapy triggered by ultrasound

Nanomaterials have been well demonstrated to have the potential to be used for tumor cell-targeted drug delivery. Targeted inhibition of miR-221 was proved to promote the sensitivity of triple genitive breast cancer (TNBC) cells to chemo-drugs. In order to improve the chemotherapeutic effect in TNBC, herein, we developed a novel kind of nanoparticles shelled with PLGA and loaded with perfluoropentane (PFP), paclitaxel (PTX), and anti-miR-221 inhibitor, which was named PANP. Ultrasound-triggered vaporization of PFP in PANPs was utilized for real-time imaging track of the nanoparticles in vivo. In addition, macrophages were applied for the internalization of PANPs to form RAW-PANP with strong chemotaxis to accumulate around cancer cells. Nanoparticles with different contents did not cause M2 polarization compared with the control group but caused polarization toward M1. We compared the inherent tumor-homing behavior of macrophages containing different contents with that of normal macrophages and no significant abnormalities were observed. After injection into the tumor-burden mice, RAW-PANPs showed enrichment within tumor tissues. Upon the ultrasound cavitation-triggered burst, PTX was released in the tumor. Meanwhile, the release of anti-miR-221 improved the sensitivity of tumor cells to PTX. As a result, RAW-PANPs showed high efficiency in suppressing TNBC cell proliferation in vitro and inhibiting tumor growth and progression in vivo. The treatments did not induce liver, heart, or kidney injury. In conclusion, the current study not only developed a macrophage-carried, ultrasound-triggered, cancer cell-targeted chemotherapeutic system, but also demonstrated a miRNA-based technique to promote drug sensitivity of cancer cells, which holds strong potential to treat patients with TNBC, especially for those suffering drug-resistance. The innovation of this study is to use macrophages to deliver nanoparticles to the tumors and then use ultrasound locally to burst the nanoparticles to release the miRNA and PTX.

Simultaneous suppression of miR-21 and restoration of miR-145 in gastric cancer cells; a promising strategy for inhibition of cell proliferation and migration.

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide. microRNAs are a group of regulatory non-coding RNAs that are involved in GC progression. miR-145 as a tumor suppressor and miR-21 as an oncomiR were shown to be dysregulated in many cancers including GC. This research aimed to enhance the expression of miR-145 while reducing the expression of miR-21 and examine their impact on the proliferation, apoptosis, and migration of GC cells. KATO III cells with high expression levels of miR-21-5p and low expression of miR-145-5p were selected. These cells were then transfected with either miR-145-5p mimics or anti-miR-21-5p, alone or in combination. Afterward, the cell survival rate was determined using the MTT assay, while apoptosis induction was investigated through V-FITC/PI and DAPI staining. Additionally, cell migration was examined using the wound healing assay, and cell cycle progression was analyzed through flow cytometry. Furthermore, gene expression levels were quantified utilizing the qRT-PCR technique. The study's findings indicated that the co-replacement of miR-145-5p and anti-miR-21-5p led to a decrease in cell viability and the induction of apoptosis in GC cells. This was achieved via modulating the expression of Bax and Bcl-2, major cell survival regulators. Additionally, the combination therapy significantly increased sub-G1 cell cycle arrest and reduced cell migration by downregulating MMP-9 expression as an epithelial-mesenchymal transition marker. This study provides evidence for the therapeutic possibility of the combination of miR-145-5p and anti-miR-21-5p and also suggests that they could inhibit cell proliferation by modulating the PTEN/AKT1 signaling pathway. Our research revealed that utilizing miR-145-5p and anti-miR-21-5p together could be a promising therapeutic approach for treating GC.