miR-101-3p induces vascular endothelial cell dysfunction by targeting tet methylcytosine dioxygenase 2

Hypoxia-Induced miR-101 Impairs Endothelial Barrier Integrity Through Altering VE-Cadherin and Claudin-5

Stroke is a life-threatening medical condition across the world that adversely affects the integrity of the blood-brain barrier (BBB). The brain microvascular endothelial cells are the important constituent of the BBB. These cells line the blood vessels and form a semipermeable barrier. Disruptions in adherens junction and tight junction proteins of brain microvascular endothelial cells compromise the integrity of BBB. The Vascular Endothelial (VE)-cadherin is an integral adherens junction protein required for the establishment and maintenance of the endothelial barrier integrity. This study aims to investigate the role of miRNA in hypoxia-induced endothelial barrier disruption. In this study, brain endothelial cells were exposed to hypoxic conditions for different time points. Western blotting, overexpression and knockdown of miRNA, real-time PCR, TEER, and sodium fluorescein assay were used to examine the effect of hypoxic conditions on brain endothelial cells. Hypoxic exposure was validated using HIF-1α protein. Exposure to hypoxic conditions resulted to a significant decrease in endothelial barrier resistance and an increase in sodium fluorescein migration across the endothelial barrier. Reduction in endothelial barrier resistance demonstrated compromised barrier integrity, whereas the increase in migration of sodium fluorescein across the barrier indicated the increase in barrier permeability. The present study revealed microRNA-101 decreases the expression of VE-cadherin and claudin-5 in brain endothelial cells exposed to the hypoxic conditions.

Fat mass and obesity associated protein inhibits neuronal ferroptosis via the FYN/Drp1 axis and alleviate cerebral ischemia/reperfusion injury

OBJECTIVES

FTO is known to be involved in cerebral ischemia/reperfusion (I/R) injury. However, its related specific mechanisms during this condition warrant further investigations. This study aimed at exploring the impacts of FTO and the FYN/DRP1 axis on mitochondrial fission, oxidative stress (OS), and ferroptosis in cerebral I/R injury and the underlying mechanisms.

METHODS

The cerebral I/R models were established in mice via the temporary middle cerebral artery occlusion/reperfusion (tMCAO/R) and hypoxia/reoxygenation models were induced in mouse hippocampal neurons via oxygen-glucose deprivation/reoxygenation (OGD/R). After the gain- and loss-of-function assays, related gene expression was detected, along with the examination of mitochondrial fission, OS- and ferroptosis-related marker levels, neuronal degeneration and cerebral infarction, and cell viability and apoptosis. The binding of FTO to FYN, m6A modification levels of FYN, and the interaction between FYN and Drp1 were evaluated.

RESULTS

FTO was downregulated and FYN was upregulated in tMCAO/R mouse models and OGD/R cell models. FTO overexpression inhibited mitochondrial fission, OS, and ferroptosis to suppress cerebral I/R injury in mice, which was reversed by further overexpressing FYN. FTO overexpression also suppressed mitochondrial fission and ferroptosis to increase cell survival and inhibit cell apoptosis in OGD/R cell models, which was aggravated by additionally inhibiting DRP1. FTO overexpression inhibited FYN expression via the m6A modification to inactive Drp1 signaling, thus reducing mitochondrial fission and ferroptosis and enhancing cell viability in cells.

CONCLUSIONS

FTO overexpression suppressed FYN expression through m6A modification, thereby subduing Drp1 activity and relieving cerebral I/R injury.

Up-regulation of microRNA 101-3p during erythropoiesis in β-thalassemia/HbE

Ineffective erythropoiesis is the main cause of anemia in β-thalassemia. The crucial hallmark of ineffective erythropoiesis is the high proliferation of erythroblast. microRNA (miR/miRNA) involves several biological processes, including cell proliferation and erythropoiesis. miR-101 was widely studied and associated with proliferation in several types of cancer. However, the miR-101-3p has not been studied in β-thalassemia/HbE. Therefore, this study aims to investigate the expression of miR-101-3p during erythropoiesis in β-thalassemia/HbE. The results showed that miR-101-3p was upregulated in the erythroblast of β-thalassemia/HbE patients on day 7, indicating that miR-101-3p may be involved with high proliferation in β-thalassemia/HbE. Therefore, the mRNA targets of miR-101-3p including Rac1, SUB1, TET2, and TRIM44 were investigated to determine the mechanisms involved with high proliferation of β-thalassemia/HbE erythroblasts. Rac1 expression was significantly reduced at day 11 in severe β-thalassemia/HbE compared to normal controls and mild β-thalassemia/HbE. SUB1 gene expression was significantly lower in severe β-thalassemia/HbE compared to normal controls at day 9 of culture. For TET2 and TRIM44 expression, a significant difference was not observed among normal and β-thalassemia/HbE. However, the high expression of miR-101-3p at day 7 and these target genes was not correlated, suggesting that this miRNA may regulate ineffective erythropoiesis in β-thalassemia/HbE via other target genes.

Monocyte exposure to fine particulate matter results in miRNA release: A link between air pollution and potential clinical complication

Chronic exposure to PM_2.5 contributes to the pathogenesis of numerous disorders, although the underlying mechanisms remain unknown. The study investigated whether exposure of human monocytes to PM_2.5 is associated with alterations in miRNAs. Monocytes were exposed in vitro to PM_2.5 collected during winter and summer, followed by miRNA isolation from monocytes. Additionally, in 140 persons chronically exposed to air pollution, some miRNA patterns were isolated from serum seasonally. Between-season differences in chemical PM_2.5 composition were observed. Some miRNAs were expressed both in monocytes and in human serum. MiR-34c-5p and miR-223-5p expression was more pronounced in winter. Bioinformatics analyses showed that selected miRNAs were involved in the regulation of several pathways. The expression of the same miRNA species in monocytes and serum suggests that these cells are involved in the production of miRNAs implicated in the development of disorders mediated by inflammation, oxidative stress, proliferation, and apoptosis after exposure to PM_2.5.

microRNA-301a-3p is a potential biomarker in venous ulcers vein and gets involved in endothelial cell dysfunction

Venous ulcer is a common contributor to chronic venous insufficiency (CVI) of lower limbs, which seriously affects the life quality of patients. In this study, we researched the expression characteristics of microRNA-301a-3p (miR-301a-3p) in patients with CVI and investigated the impact of miR-301a-3p on the dysfunction of human umbilical vein endothelial cells (HUVECs). The plasma level of miR-301a-3p in normal controls, patients with varicose great saphenous vein, and patients with the venous ulcer of lower limbs were measured. We adopted Interleukin-1β (IL-1β), H2O2, and oxygen and glucose deprivation (OGD) to induce endothelial cell injury in vitro. In this way, we evaluated the influence of miR-301a-3p on HUVEC viability, apoptosis, inflammatory response, and oxidative stress. Our data showed that miR-301a-3p was substantially overexpressed in patients with lower limb venous ulcers. The viability of HUVECs decreased, and miR-301a-3p was up-regulated after IL-1β, H2O2, and OGD treatment. miR-301a-3p inhibition greatly ameliorated the dysfunction and cell damage of HUVECs, promoted IGF1/PI3K/Akt/PPARγ, and down-regulated NF-κB/MMPs. The phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002) or the peroxisome proliferator-activated receptor-γ (PPARγ) inhibitor (GW9661) reversed the anti-inflammatory, antioxidant, and anti-apoptotic effects mediated by miR-301a-3p down-regulation. The nuclear factor-κB (NF-κB) inhibitor lessened cell injury mediated by miR-301a-3p overexpression. In terms of the mechanism, miR-301a-3p targeted the 3'UTR of Insulin-like growth factor-1 (IGF1) and repressed the profile of IGF1. Thus, miR-301a-3p mediates venous endothelial cell damage by targeting IGF1 and regulating the IGF1/PI3K/Akt/PPARγ/NF-κB/MMPs pathway.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

CTRP15 promotes macrophage cholesterol efflux and attenuates atherosclerosis by increasing the expression of ABCA1

C1q tumor necrosis factor-related protein 15 (CTRP15), a newly identified myokine, is closely implicated in cardiovascular disease. However, the role of CTRP15 in atherosclerosis is still unclear. This study aims to determine the role of CTRP15 in atherosclerosis and explore the underlying mechanisms. Our findings revealed that lentivirus-mediated CTRP15 overexpression significantly decreased atherosclerotic plaque lesions and increased reverse cholesterol transport (RCT) efficiency and circulating HDL-C levels in apolipoprotein E-deficient (apoE^-/-) mice. Consistently, in vitro, overexpression of CTRP15 also inhibited intracellular lipid accumulation and promoted cholesterol efflux from macrophages. Mechanistically, CTRP15 decreased the expression of miR-101-3p by upregulating T-cadherin, thereby facilitating ABCA1 expression and cholesterol efflux. In summary, these data indicate that CTRP15 inhibits the development of atherosclerosis by enhancing RCT efficiency and increasing plasma HDL-C levels via the T-cadherin/miR-101-3p/ABCA1 pathway. Targeting CTRP15 may serve as a novel and promising therapeutic strategy for atherosclerotic cardiovascular diseases.

Cancer-Associated Fibroblasts Promote Migration and Invasion of Non-Small Cell Lung Cancer Cells via miR-101-3p Mediated VEGFA Secretion and AKT/eNOS Pathway

Cancer-associated fibroblasts (CAFs) are major component of tumor microenvironment (TME), which plays crucial roles in tumor growth, invasion and metastasis; however, the underling mechanism is not fully elucidated. Despite many studies are focused on the tumor promoting effect of CAFs-derived cytokines, the upstream regulators of cytokine release in CAFs is largely unknown. Here we found that miR-101-3p was downregulated in primary lung cancer-associated CAFs compared to normal fibroblasts (NFs). Ectopic overexpression of miR-101-3p suppressed CAFs activation, and abrogated the promoting effect of CAFs on migration and invasion of non-small cell lung cancer cells (NSCLC), through attenuating CAFs’ effect on epithelial mesenchymal transition (EMT) process, metastasis-related genes (MMP9, TWIST1) and AKT/endothelial nitric oxide synthase (eNOS) signaling pathway. Further study indicated that vascular endothelial growth factor A (VEGFA) was a novel target of miR-101-3p, and CAFs-derived VEGFA mediated the effect of miR-101-3p on migration and invasion of lung cancer cells, demonstrated by using recombinant VEGFA and VEGFA neutralizing antibody. Interestingly, the analysis of the Cancer Genome Atlas (TCGA) database revealed that lung cancer tissues expressed lower level of miR-101-3p than non-cancerous tissues, and low/medium-expression of miR-101-3p was associated with poor overall survival (OS) rate. Moreover, the mouse xenograft experiment also showed that CAFs accelerated tumor growth whereas miR-101-3p diminished CAFs’ effect. These findings revealed a novel mechanism that CAFs facilitated lung cancer metastasis potential via miR-101-3p/VEGFA/AKT signaling pathway, suggesting miR-101-3p as a potential candidate for metastasis therapy.

Zika Virus NS1 Suppresses VE-Cadherin and Claudin-5 via hsa-miR-101-3p in Human Brain Microvascular Endothelial Cells

Zika virus (ZIKV) is a neurotropic virus that causes microcephaly in newborns and Guillain-Barré syndrome (GBS) in adults. ZIKV is known to transmigrate through the blood-brain barrier (BBB) by utilizing different strategies. NS1 is a conserved flavivirus protein, which is secreted extracellularly. ZIKV-NS1 has been shown to target adherens junctions (AJs) and tight junctions (TJs) to disrupt the endothelial barrier integrity. The microRNAs are short non-coding RNAs, which post-transcriptionally regulate the gene expression by binding to 3' UTR of the target gene. In the present study, we studied the ZIKV-NS1-mediated effect through hsa-miR-101-3p on the junctional barrier integrity in human brain microvascular endothelial cells. We exposed hBMVECs and hCMEC/D3 cells with ZIKV-NS1 at different time points (12 h and 24 h) with the doses 500 ng/mL and 1000 ng/mL. The change in the expression of VE-cadherin and claudin-5 was quantified using immunoblotting. The expression of the hsa-miR-101-3p was quantified using qRT-PCR. To prove the targeting of hsa-miR-101-3p to VE-cadherin, we transfected hsa-miR-101-3p mimic, scramble, hsa-miR-101-3p inhibitor, and Cy3 in the ZIKV-NS1-exposed hCMEC/D3 cells. The distribution and expression of the VE-cadherin and claudin-5 were observed using immunofluorescence and immunoblotting. The ZIKV-NS1 compromises the endothelial barrier integrity by disrupting the VE-cadherin and claudin-5 protein expression via hsa-miR-101-3p. The findings of this study suggest that ZIKV-NS1 dysregulates the adherens junction and tight junction proteins through hsa-miR-101-3p, which compromises the barrier integrity of human brain microvascular endothelial cells.

Enhancer-Driven lncRNA BDNF-AS Induces Endocrine Resistance and Malignant Progression of Breast Cancer through the RNH1/TRIM21/mTOR Cascade

Epigenomic alterations can give rise to various tumor-promoting properties, including therapeutic resistance of cancer cells. Here, we identify an lncRNA, BDNF-AS, whose overexpression is specifically driven by a MEF2A-regulated enhancer in endocrine-resistant and triple-negative breast cancer (TNBC). High levels of BDNF-AS in breast cancer tissues not only feature endocrine resistance in hormone receptor (HR)-positive patients but also correlate with poor outcomes in both HR-positive and TNBC patients. Mechanistically, BDNF-AS acts as a molecular scaffold to promote RNH1 protein degradation via TRIM21-mediated ubiquitination of RNH1 at K225. Subsequently, BDNF-AS abolishes RNH1-regulated and RISC-mediated mTOR mRNA decay, therefore sustaining the activation of mTOR signaling. Importantly, mTOR inhibitor, but not PI3K inhibitor, could reverse tamoxifen resistance induced by the overexpression of BDNF-AS. These results point toward a master regulatory role of an enhancer-activated cascade of BDNF-AS/RNH1/TRIM21/mTOR in endocrine resistance and malignant progression of breast cancer.

The Potential Equivalents of TET2 Mutations

Simple Summary

In acute myeloid leukemia (AML) TET2 mutations have been observed to be mutually exclusive with IDH1, IDH2, and WT1 mutations, all of them showing a similar impact on the transcription profile. Because of this, it is possible that TET2/IDH1/2/WT1 mutated AML could be considered as having similar characteristics between each other. Nonetheless, other genes also interact with TET2 and influence its activity. Because of this, it is possible that other signatures exist that would mimic the effect of TET2 mutations. Thus, in this review, we searched the literature for the genes that were observed to interact with TET2 and classified them in the following manner: transcription alteration, miRs, direct interaction, posttranslational changes, and substrate reduction.

Abstract

TET2 is a dioxygenase dependent on Fe²⁺ and α-ketoglutarate which oxidizes 5-methylcytosine (5meC) to 5-hydroxymethylcytosine (5hmeC). TET proteins successively oxidize 5mC to yield 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Among these oxidized methylcytosines, 5fC and 5caC are directly excised by thymine DNA glycosylase (TDG) and ultimately replaced with unmethylated cytosine. Mutations in TET2 have been shown to lead to a hypermethylated state of the genome and to be responsible for the initiation of the oncogenetic process, especially in myeloid and lymphoid malignancies. Nonetheless, this was also shown to be the case in other cancers. In AML, TET2 mutations have been observed to be mutually exclusive with IDH1, IDH2, and WT1 mutations, all of them showing a similar impact on the transcription profile of the affected cell. Because of this, it is possible that TET2/IDH1/2/WT1 mutated AML could be considered as having similar characteristics between each other. Nonetheless, other genes also interact with TET2 and influence its effect, thus making it possible that other signatures exist that would mimic the effect of TET2 mutations. Thus, in this review, we searched the literature for the genes that were observed to interact with TET2 and classified them in the following manner: transcription alteration, miRs, direct interaction, posttranslational changes, and substrate reduction. What we propose in the present review is the potential extension of the TET2/IDH1/2/WT1 entity with the addition of certain expression signatures that would be able to induce a similar phenotype with that induced by TET2 mutations. Nonetheless, we recommend that this approach be taken on a disease by disease basis.

Targeting the epigenome in in-stent restenosis: from mechanisms to therapy

Coronary artery disease (CAD) is one of the most common causes of death worldwide. The introduction of percutaneous revascularization has revolutionized the therapy of patients with CAD. Despite the advent of drug-eluting stents, restenosis remains the main challenge in treating patients with CAD. In-stent restenosis (ISR) indicates the reduction in lumen diameter after percutaneous coronary intervention, in which the vessel's lumen re-narrowing is attributed to the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) and dysregulation of endothelial cells (ECs). Increasing evidence has demonstrated that epigenetics is involved in the occurrence and progression of ISR. In this review, we provide the latest and comprehensive analysis of three separate but related epigenetic mechanisms regulating ISR, namely, DNA methylation, histone modification, and non-coding RNAs. Initially, we discuss the mechanism of restenosis. Furthermore, we discuss the biological mechanism underlying the diverse epigenetic modifications modulating gene expression and functions of VSMCs, as well as ECs in ISR. Finally, we discuss potential therapeutic targets of the small molecule inhibitors of cardiovascular epigenetic factors. A more detailed understanding of epigenetic regulation is essential for elucidating this complex biological process, which will assist in developing and improving ISR therapy.

Interaction Between microRNA and DNA Methylation in Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease accompanied by complex pathological changes, such as endothelial dysfunction, foam cell formation, and vascular smooth muscle cell proliferation. Many approaches, including regulating AS-related gene expression in the transcriptional or post-transcriptional level, contribute to alleviating AS development. The DNA methylation is a crucial epigenetic modification in regulating cell function by silencing the relative gene expression. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene post-transcriptional regulation and disease development. The DNA methylation and the miRNA are important epigenetic factors in AS. However, recent studies have found a mutual regulation between these two factors in AS development. In this study, recent insights into the roles of miRNA and DNA methylation and their interaction in the AS progression are reviewed.

miRNA/Target Gene Profile of Endothelial Cells Treated with Human Triglyceride-Rich Lipoproteins Obtained after a High-Fat Meal with Extra-Virgin Olive Oil or Sunflower Oil

SCOPE

The effects of triglyceride-rich lipoproteins (TRLs) on the miRNA expression of endothelial cells, which are very involved in atherosclerosis, according to the type of diet are not known.

METHODS AND RESULTS

The differences between the effects of TRLs isolated from blood of subjects after a high-fat meal with extra-virgin olive oil (EVOO) and sunflower oil (SO) on the microRNA-Seq profile related to atherosclerosis in human umbilical vein endothelial cells are analyzed. 28 upregulated microRNAs with EVOO-derived TRLs, which can regulate 22 genes related to atherosclerosis, are found. 21 upregulated microRNAs with SO-derived TRLs, which can regulate 20 genes related to atherosclerosis, are found. These microRNAs are mainly involved in angiogenesis, with a predominance of an anti-angiogenic effect with EVOO-derived TRLs. Other microRNAs upregulated with SO-derived TRLs are involved in cardiovascular diseases. Pathways for the target genes obtained from the upregulated microRNA with EVOO-derived TRLs are involved in lipid metabolism and inflammatory and defense response, while those with SO-derived TRLs are involved in lipid metabolic process.

CONCLUSION

EVOO-derived TRLs seem to produce a more atheroprotective profile than SO-derived TRLs. This study provides alternative mechanisms on the protective role of EVOO against the atherogenic process through microRNA regulation in endothelial cells.