MicroRNA-138 inhibits hypoxia-induced proliferation of endothelial progenitor cells via inhibition of HIF-1α-mediated MAPK and AKT signaling

A Multifunctional Scaffold for Bone Infection Treatment by Delivery of microRNA Therapeutics Combined With Antimicrobial Nanoparticles

Treating bone infections and ensuring bone repair is one of the greatest global challenges of modern orthopedics, made complex by antimicrobial resistance (AMR) risks due to long-term antibiotic treatment and debilitating large bone defects following infected tissue removal. An ideal multi-faceted solution would will eradicate bacterial infection without long-term antibiotic use, simultaneously stimulating osteogenesis and angiogenesis. Here, a multifunctional collagen-based scaffold that addresses these needs by leveraging the potential of antibiotic-free antimicrobial nanoparticles (copper-doped bioactive glass, CuBG) to combat infection without contributing to AMR in conjunction with microRNA-based gene therapy (utilizing an inhibitor of microRNA-138) to stimulate both osteogenesis and angiogenesis, is developed. CuBG scaffolds reduce the attachment of gram-positive bacteria by over 80%, showcasing antimicrobial functionality. The antagomiR-138 nanoparticles induce osteogenesis of human mesenchymal stem cells in vitro and heal a large load-bearing defect in a rat femur when delivered on the scaffold. Combining both promising technologies results in a multifunctional antagomiR-138-activated CuBG scaffold inducing hMSC-mediated osteogenesis and stimulating vasculogenesis in an in vivo chick chorioallantoic membrane model. Overall, this multifunctional scaffold catalyzes killing mechanisms in bacteria while inducing bone repair through osteogenic and angiogenic coupling, making this platform a promising multi-functional strategy for treating and repairing complex bone infections.

The SNHG10-miR-495-3p-PTEN axis is involved in sevoflurane-mediated protective effects in cardiomyocytes against hypoxia/reoxygenation injury

Myocardial infarction (MI) has been considered a leading cause of death worldwide. Relieving ischemia-reperfusion myocardial damage is one of the major roles in treating MI. Sevoflurane postconditioning provides myocardial protection, and this study probes the mechanism of sevoflurane-mediated protective effects. A hypoxia/reoxygenation (H/R) model was constructed in cardiomyocytes, which were pretreated with 2.4% sevoflurane. Alterations in SNHG10, miR-495-3p, and PTEN levels were determined, and gain- or loss-of functional assays were conducted to confirm the role of the SNHG10/miR-495-3p axis, which is potentially regulated by sevoflurane. Cell viability, oxidative stress, and inflammatory reactions were all evaluated. The results indicated that sevoflurane post-conditioning attenuated H/R-induced cardiomyocyte damage and reduced the SHNH10 level. SNHG10 overexpression reversed sevoflurane-mediated protective effects on cardiomyocytes. Moreover, SNHG10 targeted miR-495-3p and restrained its expression, while miR-495-3p targeted PTEN, suppressed PTEN levels, and promoted HIF-1α expression. miR-495-3p overexpression decreased SNHG10-mediated myocardial injury and enhanced HIF-1α levels. However, no additional protection was found when sevoflurane was administered to H/R-exposed cardiomyocytes following treatment with the HIF-1α inhibitor LW6. Overall, sevoflurane protects cardiomyocytes from H/R by modulating the SNHG10-miR-495-3p-PTEN-HIF-1α axis.

Role of LCN2 in a murine model of hindlimb ischemia and in peripheral artery disease patients, and its potential regulation by miR-138-5P

BACKGROUND AND AIMS

Peripheral arterial disease (PAD) is a leading cause of morbimortality worldwide. Lipocalin-2 (LCN2) has been associated with higher risk of amputation or mortality in PAD and might be involved in muscle regeneration. Our aim is to unravel the role of LCN2 in skeletal muscle repair and PAD.

METHODS AND RESULTS

WT and Lcn2-/- mice underwent hindlimb ischemia. Blood and crural muscles were analyzed at the inflammatory and regenerative phases. At day 2, Lcn2-/- male mice, but not females, showed increased blood and soleus muscle neutrophils, and elevated circulating pro-inflammatory monocytes (p < 0.05), while locally, total infiltrating macrophages were reduced (p < 0.05). Moreover, Lcn2-/- soleus displayed an elevation of Cxcl1 (p < 0.001), and Cxcr2 (p < 0.01 in males), and a decrease in Ccl5 (p < 0.05). At day 15, Lcn2 deficiency delayed muscle recovery, with higher density of regenerating myocytes (p < 0.04) and arterioles (αSMA+, p < 0.025). Reverse target prediction analysis identified miR-138-5p as a potential regulator of LCN2, showing an inverse correlation with Lcn2 mRNA in skeletal muscles (rho = -0.58, p < 0.01). In vitro, miR-138-5p mimic reduced Lcn2 expression and luciferase activity in murine macrophages (p < 0.05). Finally, in human serum miR-138-5p was inversely correlated with LCN2 (p ≤ 0.001 adjusted, n = 318), and associated with PAD (Odds ratio 0.634, p = 0.02, adjusted, PAD n = 264, control n = 54).

CONCLUSIONS

This study suggests a possible dual role of LCN2 in acute and chronic conditions, with a probable role in restraining inflammation early after skeletal muscle ischemia, while being associated with vascular damage in PAD, and identifies miR-138-5p as one potential post-transcriptional regulator of LCN2.

Aberrant expression of miR-138 as a novel diagnostic biomarker in systemic sclerosis

BACKGROUND

MicroRNAs are short nucleotide sequences that contribute to the regulation of various biological functions and therefore their roles have been investigated in many pathologic conditions such as epithelial to mesenchymal transition in cancer and fibrosis; among them, miR-138 has been mostly studied in cancer biology and is well-known for its suppressing effect on cancer progression. Being able to suppress major pathways involved in EMT, miR-138 could be a good candidate to be investigated in fibrotic responses too. Based on our previous studies, and the capability of miR-138 to target and regulate several components of the EMT pathway; we hypothesized a role for miR-138 in systemic sclerosis. Accordingly, the gene expression of miR-138 was assessed to find any alterations in the whole blood of the SSc patients.

METHODS

Blood was collected from 70 patients with systemic sclerosis (equally divided between 2 groups of limited and diffuse categories) and 30 healthy individuals as controls. RNA was immediately isolated from the fresh whole blood; afterward, the resulting RNA was reverse transcribed into cDNA and then the relative expression of miR-138 was compared between the patients and the controls by the means of qPCR, and specific TaqMan primer and probes.

RESULTS

The relative expression of miR-138 was significantly lower in patients with systemic sclerosis compared to the controls. No significant difference was observed between the limited and diffuse patient groups. ROC curve analysis showed an appropriate diagnostic value of miR-138 in effectively differentiating SSc patients from the healthy controls.

CONCLUSION

miR-138 is likely involved in the pathogenesis of SSc and with further evaluations may be utilized as a diagnostic biomarker in SSc. Also, targeting miR-138 in future studies could be promising for finding a novel treatment option for patients with SSc.

miR-138-5p Inhibits Vascular Mimicry by Targeting the HIF-1α/VEGFA Pathway in Hepatocellular Carcinoma

Tumour vascular mimicry (VM) is the process by which new blood vessels are formed by tumour cells rather than endothelial cells. An increasing number of studies have revealed that the VM process is associated with cancer progression and metastasis. MiR-138-5p has been reported to act as a tumour suppressor in many cancers. However, the role and underlying mechanism of miR-138-5p in hepatocellular carcinoma (HCC) VM remain unclear. In this study, VM density was detected by CD31/periodic acid-Schiff double staining in HCC clinical specimens. We found that miR-138-5p expression correlated strongly and negatively with microvessel density. Additionally, the miR-138-5p mimic or inhibitor decreased or increased, respectively, tube formation capacity in HepG2 and Hep3B cells. Consistent with this finding, miR-138-5p repressed vessel density in vivo. Moreover, miR-138-5p targeted hypoxia-inducible factor 1α (HIF-1α) and regulated the expression of HIF-1α and vascular endothelial growth factor A (VEGFA), which are established classical master regulators for angiogenesis. Consistent with these findings, the HIF-1α inhibitor CAY10585 effectively blocked HCC cell VM and VEGFA expression. In conclusion, miR-138-5p inhibits HepG2 and Hep3B cell VM by blocking the HIF-1α/VEGFA pathway. Therefore, miR-138-5p may serve as a useful therapeutic target for miRNA-based HCC therapy.

MicroRNA‑126 and VEGF enhance the function of endothelial progenitor cells in acute myocardial infarction

Previous studies have found that microRNA-126 (miR-126) overexpression can exert beneficial effects on endothelial function and angiogenesis. The role of miR-126 was previously reported to be by directly limiting the activities of negative regulators of the vascular endothelial growth factor (VEGF) pathway, such as PI3K regulation subunit 2 (PIK3R2). The aim of the present study was to investigate the role of the miR-126/PIK3R2/VEGF axis in endothelial progenitor cells (EPCs) under hypoxic conditions. An in vitro hypoxia model in EPCs was established by exposing EPCs to hypoxia (O²/N²/CO², 1/94/5) for 72 h, before reverse transcription-quantitative PCR (RT-qPCR) and western blot analyzes were used to measure miR-126 and PIK3R2 expression in EPCs. The proliferation, migration and tube-forming ability of the transfected cells were measured using MTT, Transwell and tube formation assays, respectively. miR-126 expression was found to be lower in EPCs in the hypoxia group compared with that in the control group (P<0.01). The expression of PIK3R2, a direct target gene of miR-126, was found to be higher in the hypoxia group compared with that in the control group (P<0.01). miR-126 mimic and VEGF-plasmid co-transfection improved the proliferation, migration, tube-forming ability and restored the phosphorylation of AKT in EPCs under hypoxic conditions (all P<0.01). In addition, the effects of miR-126 mimic on hypoxia-induced EPCs were reversed by PIK3R2-plasmid co-transfection, whilst the effects of VEGF-plasmid were enhanced further by co-transfection with the miR-126 mimic. In conclusion, miR-126 promoted the functions of EPCs under hypoxic conditions by negatively targeting PIK3R2, whilst the combined overexpression of miR-126 and VEGF enhanced these aforementioned effects.

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.

MicroRNA-138-1-3p sensitizes sorafenib to hepatocellular carcinoma by targeting PAK5 mediated β-catenin/ABCB1 signaling pathway

Background

Sorafenib is a kinase inhibitor that is used as a first-line therapy in advanced hepatocellular carcinoma (HCC) patients. However, the existence of sorafenib resistance has limited its therapeutic effect. Through RNA sequencing, we demonstrated that miR-138-1-3p was downregulated in sorafenib resistant HCC cell lines. This study aimed to investigate the role of miR-138-1-3p in sorafenib resistance of HCC.

Methods

In this study, quantitative real-time PCR (qPCR) and Western Blot were utilized to detect the levels of PAK5 in sorafenib-resistant HCC cells and parental cells. The biological functions of miR-138-1-3p and PAK5 in sorafenib-resistant cells and their parental cells were explored by cell viability assays and flow cytometric analyses. The mechanisms for the involvement of PAK5 were examined via co-immunoprecipitation (co-IP), immunofluorescence, dual luciferase reporter assay and chromatin immunoprecipitation (ChIP). The effects of miR-138-1-3p and PAK5 on HCC sorafenib resistant characteristics were investigated by a xenotransplantation model.

Results

We detected significant down-regulation of miR-138-1-3p and up-regulation of PAK5 in sorafenib-resistance HCC cell lines. Mechanistic studies revealed that miR-138-1-3p reduced the protein expression of PAK5 by directly targeting the 3′-UTR of PAK5 mRNA. In addition, we verified that PAK5 enhanced the phosphorylation and nuclear translocation of β-catenin that increased the transcriptional activity of a multidrug resistance protein ABCB1.

Conclusions

PAK5 contributed to the sorafenib resistant characteristics of HCC via β-catenin/ABCB1 signaling pathway. Our findings identified the correlation between miR-138-1-3p and PAK5 and the molecular mechanisms of PAK5-mediated sorafenib resistance in HCC, which provided a potential therapeutic target in advanced HCC patients.

Sevoflurane Postconditioning Attenuates Hypoxia/Reoxygenation Injury of Cardiomyocytes Under High Glucose by Regulating HIF-1α/MIF/AMPK Pathway

Subject: Cardiovascular disease, as a very common and serious coexisting disease in diabetic patients, and is one of the risk factors that seriously affect the prognosis and complications of surgical patients. Previous studies have shown that sevoflurane post-conditioning (SPostC) exerts a protective effect against myocardial ischemia/reperfusion injury by HIF-1α, but the protective effect is weakened or even disappeared under hyperglycemia. This study aims to explore whether regulating the HIF-1α/MIF/AMPK signaling pathway can restore the protective effect and reveal the mechanism of SPostC on cardiomyocyte hypoxia/reoxygenation injury under high glucose conditions.

Methods: H9c2 cardiomyocytes were cultured in normal and high-concentration glucose medium to establish a hypoxia/reoxygenation (H/R) injury model of cardiomyocytes. SPostC was performed with 2.4% sevoflurane for 15 min before reoxygenation. Cell damage was determined by measuring cell viability, lactate dehydrogenase activity, and apoptosis; Testing cell energy metabolism by detecting reactive oxygen species (ROS) generation, ATP content and mitochondrial membrane potential; Analysis of the change of HIF-1α, MIF and AMPKα mRNA expression by RT-PCR. Western blotting was used to examine the expression of HIF-1α, MIF, AMPKα and p-AMPKα proteins. HIF-1α and MIF inhibitors and agonists were administered 40 min before hypoxia.

Results: 1) SPostC exerts a protective effect by increasing cell viability, reducing LDH levels and cell apoptosis under low glucose (5 μM) after undergoing H/R injury; 2) High glucose concentration (35 μM) eliminated the cardioprotective effect of SPostC, which is manifested by a significantly decrease in the protein and mRNA expression level of the HIF-1α/MIF/AMPK signaling pathway, accompanied by decreased cell viability, increased LDH levels and apoptosis, increased ROS production, decreased ATP synthesis, and decreased mitochondrial membrane potential; 3. Under high glucose (35 μM), the expression levels of HIF-1α and MIF were up-regulated by using agonists, which can significantly increase the level of p-AMPKα protein, and the cardioprotective effect of SPostC was restored.

Conclusion: The signal pathway of HIF-1α/MIF/AMPK of H9c2 cardiomyocytes may be the key point of SPostC against H/R injure. The cardioprotective of SPostC could be restored by upregulating the protein expression of HIF-1α and MIF under hyperglycemia.

Exogenous FGF-2 improves biological activity of endothelial progenitor cells exposed to high glucose conditions

Purpose: To investigate the effects of exogenous basic fibroblast growth factor -2 (FGF-2) on the biological activity of endothelial progenitor cells (EPCs) exposed to high glucose conditions.

Materials and Methods: 1) Bone marrow EPCs from C57BL/6 mice were isolated and cultured in vitro. EPC purity was identified by flow cytometry and immunofluorescence staining. 2) Apoptosis was detected by TUNEL assay. Migration and tube formation ability was detected by Transwell chamber and Matrigel assays, respectively. The expression and activation of β-catenin was detected by Western blot. 3) Doppler flowmetry was used to detect the effect of FGF2 on blood flow recovery in ischemic hind limbs of mice.

Results: 1) FGF-2 treatment reversed high glucose induced growth inhibition of EPCs. FGF-2 treatment also increased migration and tube formation ability of EPCs even in high glucose conditions. 2) Western blot analysis demonstrated that the percentage of activated β-catenin/total β-catenin in the high glucose group were significantly lower than that in the control group, while FGF-2 treatment reversed high glucose induced β-catenin inhibition. 3) In vivo experiments demonstrated that the blood flow recovery in ischemic hind limbs of mice was significantly improved after FGF-2 treatment.

Conclusion: Exogenous FGF-2 could play a role in the functional repair of damaged EPC exposed to high glucose conditions, via the activation of the Wnt/β-catenin signaling pathway.

Exercise and Cardiovascular Progenitor Cells

Autologous stem/progenitor cell-based methods to restore blood flow and function to ischemic tissues are clinically appealing for the substantial proportion of the population with cardiovascular diseases. Early preclinical and case studies established the therapeutic potential of autologous cell therapies for neovascularization in ischemic tissues. However, trials over the past ∼15 years reveal the benefits of such therapies to be much smaller than originally estimated and a definitive clinical benefit is yet to be established. Recently, there has been an emphasis on improving the number and function of cells [herein generally referred to as circulating angiogenic cells (CACs)] used for autologous cell therapies. CACs include of several subsets of circulating cells, including endothelial progenitor cells, with proangiogenic potential that is largely exerted through paracrine functions. As exercise is known to improve CV outcomes such as angiogenesis and endothelial function, much attention is being given to exercise to improve the number and function of CACs. Accordingly, there is a growing body of evidence that acute, short-term, and chronic exercise have beneficial effects on the number and function of different subsets of CACs. In particular, recent studies show that aerobic exercise training can increase the number of CACs in circulation and enhance the function of isolated CACs as assessed in ex vivo assays. This review summarizes the roles of different subsets of CACs and the effects of acute and chronic exercise on CAC number and function, with a focus on the number and paracrine function of circulating CD34+ cells, CD31+ cells, and CD62E+ cells. © 2019 American Physiological Society. Compr Physiol 9:767-797, 2019.

A perspective on the diagnostics, prognostics, and therapeutics of microRNAs of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive and prevalent subtype of breast cancer in women worldwide. Currently, chemotherapy remains the main modality for the treatment at an early stage, as there is no approved targeted therapy for early TNBC. In this review, we investigate the use of microRNAs (miRNAs), which play a key role in the post-transcriptional regulation of genes involved in the key biological processes, namely proliferation, differentiation, angiogenesis, migration, apoptosis, and carcinogenesis. Here, we emphasize the importance of the recent advances related to miRNAs, involving diagnosis, prognosis, and treatment of TNBC. We focus on the development, optimization, and stabilization of miRNA-based drugs; improvement of miRNA delivery; and control of the off-target effects of miRNA therapeutics. We speculate as to which features may present themselves as promising approaches in the treatment of TNBC.

MicroRNA-126 Priming Enhances Functions of Endothelial Progenitor Cells under Physiological and Hypoxic Conditions and Their Therapeutic Efficacy in Cerebral Ischemic Damage

Endothelial progenitor cells (EPCs) have shown the potential for treating ischemic stroke (IS), while microRNA-126 (miR-126) is reported to have beneficial effects on endothelial function and angiogenesis. In this study, we investigated the effects of miR-126 overexpression on EPCs and explore the efficacy of miR-126-primed EPCs (EPC^miR-126) in treating IS. The effects of miR-126 overexpression on EPC proliferation, migratory, tube formation capacity, reactive oxygen species (ROS) production, and nitric oxide (NO) generation were determined. In in vivo study, the effects of EPC^miR-126 on the cerebral blood flow (CBF), neurological deficit score (NDS), infarct volume, cerebral microvascular density (cMVD), and angiogenesis were determined. Moreover, the levels of circulating EPCs (cEPCs) and their contained miR-126 were measured. We found (1) miR-126 overexpression promoted the proliferation, migration, and tube formation abilities of EPCs; decreased ROS; and increased NO production of EPCs via activation of PI3K/Akt/eNOS pathway; (2) EPC^miR-126 was more effective than EPCs in attenuating infarct volume and NDS and enhancing cMVD, CBF, and angiogenesis; and (3) infusion of EPC^miR-126 increased the number and the level of miR-126 in cEPCs. Our data indicate that miR-126 overexpression enhanced the function of EPCs in vitro and in vivo.

Critical effects of epigenetic regulation in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by persistent pulmonary vasoconstriction and pulmonary vascular remodeling. The pathogenic mechanisms of PAH remain to be fully clarified and measures of effective prevention are lacking. Recent studies; however, have indicated that epigenetic processes may exert pivotal influences on PAH pathogenesis. In this review, we summarize the latest research findings regarding epigenetic regulation in PAH, focusing on the roles of non-coding RNAs, histone modifications, ATP-dependent chromatin remodeling and DNA methylation, and discuss the potential of epigenetic-based therapies for PAH.