MiR-590-5p-meidated LOX-1 upregulation promotes Angiotensin II-induced endothelial cell apoptosis

Glycolytic enzyme PFKFB3 regulates sphingosine 1-phosphate receptor 1 in proangiogenic glomerular endothelial cells under diabetic condition

Glomerular angiogenesis is a characteristic feature of diabetic nephropathy (DN). Enhanced glycolysis plays a crucial role in angiogenesis. The present study was designed to investigate the role of glycolysis in glomerular endothelial cells (GECs) in a mouse model of DN. Mouse renal cortex and isolated glomerular cells were collected for single-cell and RNA sequencing. Cultured GECs were exposed to high glucose in the presence (proangiogenic) and absence of a vascular sprouting regimen. MicroRNA-590-3p was delivered by lipofectamine in vivo and in vitro. In the present study, a subgroup of GECs with proangiogenic features was identified in diabetic kidneys by using sequencing analyses. In cultured proangiogenic GECs, high glucose increased glycolysis and phosphofructokinase/fructose bisphosphatase 3 (PFKFB3) protein expression, which were inhibited by overexpressing miRNA-590-3p. Mimics of miRNA-590-3p also increased receptor for sphingosine 1-phosphate (S1pR1) expression, an angiogenesis regulator, in proangiogenic GECs challenged with high glucose. Inhibition of PFKFB3 by pharmacological and genetic approaches upregulated S1pR1 protein in vitro. Mimics of miRNA-590-3p significantly reduced migration and angiogenic potential in proangiogenic GECs challenged with high glucose. Ten-week-old type 2 diabetic mice had elevated urinary albumin levels, reduced renal cortex miRNA-590-3p expression, and disarrangement of glomerular endothelial cell fenestration. Overexpressing miRNA-590-3p via perirenal adipose tissue injection restored endothelial cell fenestration and reduced urinary albumin levels in diabetic mice. Therefore, the present study identifies a subgroup of GECs with proangiogenic features in mice with DN. Local administration of miRNA-590-3p mimics reduces glycolytic rate and upregulates S1pR1 protein expression in proangiogenic GECs. The protective effects of miRNA-590-3p provide therapeutic potential in DN treatment.NEW & NOTEWORTHY Proangiogenetic glomerular endothelial cells (GECs) are activated in diabetic nephropathy. High glucose upregulates glycolytic enzyme phosphofructokinase/fructose bisphosphatase 3 (PFKFB3) in proangiogenetic cells. PFKFB3 protects the glomerular filtration barrier by targeting endothelial S1pR1. MiRNA-590-3p restores endothelial cell function and mitigates diabetic nephropathy.

Smooth muscle liver kinase B1 inhibits foam cell formation and atherosclerosis via direct phosphorylation and activation of SIRT6

Foam cell formation is a hallmark of the early phase of atherosclerosis. Growing evidence has demonstrated that vascular smooth muscle cells (VSMCs) comprise a considerable proportion of foam cells. Liver kinase B1 (LKB1) plays a crucial part in cardiovascular diseases. However, the role of LKB1 in VSMC-derived foam cell formation and atherosclerosis remains unclear. To explore the effects of LKB1 on VSMC-derived foam cell formation and atherosclerosis, we generated smooth muscle-specific LKB1 knockout (LKB1SMKO) mice by crossbreeding LKB1flox/flox mice with SM22α-CreERT2 mice. LKB1 expression decreased in plaque-loaded aortas and oxidized low-density lipoprotein (oxLDL)-treated VSMCs. Compared with controls, atherosclerosis development was exacerbated in LKB1SMKO mice via the promotion of VSMC-derived foam cell formation. Conversely, LKB1 overexpression inhibited lipid uptake and foam cell formation in VSMCs. Mechanistically, LKB1 binds to SIRT6 and directly phosphorylates and activates it, thereby reducing lectin-like oxLDL receptor-1 (LOX-1) via SIRT6-dependent histone deacetylation. Finally, adeno-associated virus (AAV)-mediated LOX-1 deficiency in smooth muscle ameliorated atherosclerosis in LKB1SMKO mice. Our findings suggest that LKB1 may modulate VSMC-derived foam cell formation and atherosclerosis via the phosphorylation and activation of SIRT6.

Inhibition of circ_0000231 suppresses oxidized low density lipoprotein-induced apoptosis, autophagy and inflammation in human umbilical vein endothelial cells by regulating miR-590-5p/PDCD4 axis

BACKGROUND

Circular RNAs (circRNAs) are the emerging informative RNAs, involved in cardiovascular diseases including atherosclerosis (AS). Endothelial injury is the initial qualitative change of AS. Thus, the objective of this study was to confirm the dysregulation and mechanism of circ_0000231 in cell model of AS at early stage in human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (ox-LDL).

METHODS

The expression of circ_0000231, miR-590-5p and programmed cell death 4 (PDCD4) was detected using real-time quantitative PCR and western blot. Cell injury was measured with MTT, flow cytometry, caspase-3 activity assay and enzyme-linked immunosorbent assay (ELISA). The interaction among circ_0000231, miR-590-5p and PDCD4 was validated by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assays.

RESULTS

Stress ox-LDL decreased cell viability, and increased apoptosis rate and caspase-3 activity in HUVECs in a dose- and time-dependent manner in concomitant with promotions of interleukin-6, interleukin-1β, tumor necrosis factor-α, LC3-II/I and Beclin-1 levels. Besides, circ_0000231 and PDCD4 expressions were upregulated, and miR-590-5p was downregulated in ox-LDL-stimulated HUVECs. Functionally, knockdown of circ_0000231 and overexpression of miR-590-5p could suppress ox-LDL-elicited above effects on apoptosis, autophagy and inflammatory response, accompanied with PDCD4 downregulation. Physically, miR-590-5p could directly interact with circ_0000231 and PDCD4.

CONCLUSION

Downregulation of circ_0000231 suppresses HUVECs from ox-LDL-induced injury partially through regulating miR-590-5p/PDCD4 axis via competing endogenous RNA mechanism, showing a novel potential target for the pathology and treatment of endothelial injury in AS.

Ang II Controls the Expression of Mapkap1 by miR-375 and Affects the Function of Islet β Cells

BACKGROUND

The RAS system is involved in the regulation of islet function, but its regulation remains unclear.

OBJECTIVE

This study investigates the role of an islet-specific miR-375 in the effect of RAS system on islet β-cells.

METHODS

miR-375 mimics and inhibitors were transfected into insulin-secreting MIN6 cells in the presence or absence of RAS component.

RESULTS

Compared to control, in Ang II-treated MIN6 cells, miR-375 mimic transfection results in a decrement in cell viability and Akt-Ser levels (0.739±0.05 vs. 0.883±0.06 and 0.40±0.04 vs. 0.79±0.04, respectively), while the opposite occurred in miR-375 inhibitor-transfected cells (1.032±0.11 vs. 0.883±0.06 and 0.98±0.05 vs. 0.79±0.04, respectively, P<0.05). Mechanistically, transfection of miR- 375 mimics into Ang II-treated MIN6 cells significantly reduced the expression of Mapkap1 protein (0.97±0.15 vs. 0.63±0.06, P<0.05); while miR-375 inhibitor-transfected cells elevated Mapkap1 expression level (0.35±0.11 vs. 0.90±0.05, P<0.05), without changes in mRNA expression. Transfection of miR-375 specific inhibitors TSB-Mapkap1 could elevate Mapkap1 (1.62±0.02 vs. 0.68±0.01, P<0.05), while inhibition of Mapkap1 could significantly reduce the level of Akt-Ser473 phosphorylation (0.60±0.14 vs. 1.80±0.27, P<0.05).

CONCLUSION

The effects of Ang II on mouse islet β cells were mediated by miR-375 through miR- 375/Mapkap 1 axis. This targeted regulation may occur by affecting Akt phosphorylation of β cells. These results may provide new ideas and a scientific basis for further development of miRNA-targeted islet protection measures.

miR-590-5p Targets Skp2 to Inhibit the Growth and Invasion of Malignant Melanoma Cells

Skp2 participates in the regulation of cell growth cycle and promotes the growth of tumor cells. It was speculated that miR-590-5p could regulate the expression of Skp2 and have therapeutic effects on malignant melanin. In this study, the expression of Skp2 was detected by qRT-PCR and Western blot (WB), and the targeted binding between miR-590-5p and Skp2 was verified by dual luciferase reporting assay. Subsequently, cell proliferation activity was detected by CCK8, cell invasion was detected by Transwell, and cell apoptosis was detected by mitochondrial membrane potential assay. The results indicate that Skp2 is highly expressed in melanoma cells and inhibits the proliferation and invasion of melanoma cells. However, miR-590-5p can bind to Skp2 in a targeted manner. miR-590-5p is underexpressed in melanoma cells, and its overexpression can inhibit Skp2 expression and proliferation and invasion of melanoma cells. Our results showed that miR-590-5p could inhibit melanoma cell development by targeting Skp2. This study provides more therapeutic targets for the treatment of melanoma.

Decoding microRNA drivers in Atherosclerosis

An estimated 97% of the human genome consists of non-protein-coding sequences. As our understanding of genome regulation improves, this has led to the characterization of a diverse array of non-coding RNAs (ncRNA). Among these, micro-RNAs (miRNAs) belong to the short ncRNA class (22–25 nucleotides in length), with approximately 2500 miRNA genes encoded within the human genome. From a therapeutic perspective, there is interest in exploiting miRNA as biomarkers of disease progression and response to treatments, as well as miRNA mimics/repressors as novel medicines. miRNA have emerged as an important class of RNA master regulators with important roles identified in the pathogenesis of atherosclerotic cardiovascular disease. Atherosclerosis is characterized by a chronic inflammatory build-up, driven largely by low-density lipoprotein cholesterol accumulation within the artery wall and vascular injury, including endothelial dysfunction, leukocyte recruitment and vascular remodelling. Conventional therapy focuses on lifestyle interventions, blood pressure-lowering medications, high-intensity statin therapy and antiplatelet agents. However, a significant proportion of patients remain at increased risk of cardiovascular disease. This continued cardiovascular risk is referred to as residual risk. Hence, a new drug class targeting atherosclerosis could synergise with existing therapies to optimise outcomes. Here, we review our current understanding of the role of ncRNA, with a focus on miRNA, in the development and progression of atherosclerosis, highlighting novel biological mechanisms and therapeutic avenues.

Altered Expression of Specific MicroRNAs in Plasma of Aneurysmal Subarachnoid Hemorrhage Patients

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition with high disability and mortality. MicroRNAs (miRNAs) are reported to play a modulating role in aSAH. We investigated specific plasma microRNAs (miRNAs) associated with aSAH and gained comprehensive insight into its pathological mechanisms.

Methods

This is a prospective case–control study. We used a two-stage approach, with primary screening and ensuing two-step validation stages. Significantly differentially expressed plasma miRNAs between aSAH patients and neurologically healthy controls were initially screened by microarray analysis. These miRNAs were then validated in two groups of independent cohorts using reverse transcription quantitative real-time polymerase chain reaction assays. Functional annotation of these miRNA targets was performed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses.

Results

In the primary screening stage, 14 miRNAs were identified as differentially expressed at a significance level of P < 0.05 and fold change >2 between 5 aSAH patients and 5 neurologically healthy controls. In the two validation steps (20 patients vs. 20 control; 40 patients vs. 30 controls), miR-23b-3p, miR-590-5p, miR-20b-5p, miR-142-3p, and miR-29b-3p were found to be significantly down-regulated in patients with aSAH compared with controls. Through these 5 miRNAs, we obtained 32 overlapping target genes, including TGM2, EREG, EDN1, and COL4A1, in three databases that may affect the progression of aSAH. The results of functional annotation revealed mechanisms mainly related to inflammation, smooth muscle cell proliferation and cell adhesion, potentially contributing to the occurrence of aSAH.

Conclusion

We demonstrate that specific miRNAs in plasma, including miR-23b-3p, miR-590-5p, miR-20b-5p, miR-142-3p, and miR-29b-3p, are significantly down-regulated in aSAH patients and may play a modulating role in its progression.

The protective effect of harpagoside on angiotensin II (Ang II)-induced blood-brain barrier leakage in vitro

Hypertension and its associated dysfunction of the blood-brain barrier (BBB) contribute to cerebral small vessel disease (cSVD). Angiotensin II (Ang II), a vasoactive peptide of the renin-angiotensin system (RAS), is not only a pivotal molecular signal in hypertension but also causes BBB leakage, cSVD, and cognitive impair. Harpagoside, the major bioactive constituent of Scrophulariae Radix, has been commonly used for the treatment of multiple diseases including hypertension in China. The effect of harpagoside on Ang II-induced BBB damage is unclear. We employed an immortalized endothelial cell line (bEnd.3) to mimic a BBB monolayer model in vitro and investigated the effect of harpagoside on BBB and found that harpagoside alleviated Ang II-induced BBB destruction, inhibited Ang II-associated cytotoxicity in a concentration-dependent manner and attenuated Ang II-induced reactive oxygen species (ROS) impair by downregulation of Nox2, Nox4, and COX-2. Harpagoside prevented Ang II-induced apoptosis via keeping Bax/Bcl-2 balance, decreasing cytochrome c release, and inactivation of caspase-8, caspase-9, and caspase-3 (the mitochondria-dependent and death receptor-mediated apoptosis pathways). Moreover, harpagoside can alleviate Ang II-induced BBB damage through upregulation of tight junction proteins and decrease of caveolae-mediated endocytosis. Thus, harpagoside might be a potential drug to treat Ang II-induced cSVD.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1): a crucial driver of atherosclerotic cardiovascular disease

Cardiovascular diseases (CVDs), specifically lipid-driven atherosclerotic CVDs, remain the number one cause of death worldwide. The lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1), a scavenger receptor that promotes endothelial dysfunction by inducing pro-atherogenic signalling and plaque formation via the endothelial uptake of oxidized LDL (oxLDL) and electronegative LDL, contributes to the initiation, progression, and destabilization of atheromatous plaques, eventually leading to the development of myocardial infarction and certain forms of stroke. In addition to its expression in endothelial cells, LOX-1 is expressed in macrophages, cardiomyocytes, fibroblasts, dendritic cells, lymphocytes, and neutrophils, further implicating this receptor in multiple aspects of atherosclerotic plaque formation. LOX-1 holds promise as a novel diagnostic and therapeutic target for certain CVDs; therefore, understanding the molecular structure and function of LOX-1 is of critical importance. In this review, we highlight the latest scientific findings related to LOX-1, its ligands, and their roles in the broad spectrum of CVDs. We describe recent findings from basic research, delineate their translational value, and discuss the potential of LOX-1 as a novel target for the prevention, diagnosis, and treatment of related CVDs.

Exosomes-Mediated LncRNA ZEB1-AS1 Facilitates Cell Injuries by miR-590-5p/ETS1 Axis Through the TGF-β/Smad Pathway in Oxidized Low-density Lipoprotein-induced Human Umbilical Vein Endothelial Cells

ABSTRACT

Atherosclerosis is a chronic lipid-induced inflammation of the vessel wall. Oxidized low-density lipoprotein was confirmed to drive the onset of atherogenesis. Zinc finger e-box-binding homeobox 1 antisense 1 (ZEB1-AS1) is a long noncoding RNA that is involved in human diseases, including atherosclerosis. In this study, the role of exosomes-mediated ZEB1-AS1 and its underlying mechanisms in atherosclerosis were explored in oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs). Exosomes were extracted from HUVECs. Quantitative real-time polymerase chain reaction was conducted to measure the expression of ZEB1-AS1, microRNA-590-5p (miR-590-5p), or erythroblastosis virus E26 oncogene homolog 1 (ETS1) in cells or exosomes. Cell proliferation and apoptosis were assessed by MTT assay and flow cytometry analysis, respectively. Western blot was performed to detect apoptosis-related factors, ETS1, and TGF-β/Smad pathway protein levels. The secretion of inflammatory factors in supernatant was detected by ELISA assay. Oxidative stress damage indicators were used to assess cellular damage. Relationship between miR-590-5p and ZEB1-AS1 or ETS1 was analyzed. Our data indicated that ox-LDL-induced exosomes-mediated ZEB1-AS1 in HUVECs. Ox-LDL treatment resulted in limited proliferation, proapoptosis, inflammation, and oxidative stress damage, whereas knockdown of ZEB1-AS1 could reverse these effects. Mechanically, ZEB1-AS1 sponged miR-590-5p to regulate ETS1 expression. MiR-590-5p knockdown inverted effects above of si-ZEB1-AS1 on HUVECs under ox-LDL exposure. Moreover, ETS1 reversed miR-590-5p-induced effects and activated the TGF-β/Smad pathway in ox-LDL-treated HUVECs. Taken together, our findings demonstrated that exosomes-mediated ZEB1-AS1 enhanced cell injuries by miR-590-5p/ETS1 axis through the TGF-β/Smad pathway in ox-LDL-induced HUVECs, suggesting that inhibiting ZEB1-AS1 might be an effective way for atherosclerosis treatment.

Atherosclerosis: Conventional intake of cardiovascular drugs versus delivery using nanotechnology - A new chance for causative therapy?

Atherosclerosis is the leading cause of death in developed countries. The pathogenetic mechanism relies on a macrophage-based immune reaction to low density lipoprotein (LDL) deposition in blood vessels with dysfunctional endothelia. Thus, atherosclerosis is defined as a chronic inflammatory disease. A plethora of cardiovascular drugs have been developed and are on the market, but the major shortcoming of standard medications is that they do not address the root cause of the disease. Statins and thiazolidinediones that have recently been recognized to exert specific anti-atherosclerotic effects represent a potential breakthrough on the horizon. But their whole potential cannot be realized due to insufficient availability at the pathological site and severe off-target effects. The focus of this review will be to elaborate how both groups of drugs could immensely profit from nanoparticulate carriers. This delivery principle would allow for their accumulation in target macrophages and endothelial cells of the atherosclerotic plaque, increasing bioavailability where it is needed most. Based on the analyzed literature we conclude design criteria for the delivery of statins and thiazolidinediones with nanoparticles for anti-atherosclerotic therapy. Nanoparticles need to be below a diameter of 100 nm to accumulate in the atherosclerotic plaque and should be fabricated using biodegradable materials. Further, the thiazolidinediones or statins must be encapsulated into the particle core, because especially for thiazolidindiones the uptake into cells is prerequisite for their mechanism of action. For optimal uptake into targeted macrophages and endothelial cells, the ideal particle should present ligands on its surface which bind specifically to scavenger receptors. The impact of statins on the lectin-type oxidized LDL receptor 1 (LOX1) seems particularly promising because of its outstanding role in the inflammatory process. Using this pioneering concept, it will be possible to promote the impact of statins and thiazolidinediones on macrophages and endothelial cells and significantly enhance their anti-atherosclerotic therapeutic potential.

Interplay between C-type lectin receptors and microRNAs in cellular homeostasis and immune response

C-type lectin receptors (CLRs) belong to the family of pattern recognition receptors (PRRs). They have a critical role to play in the regulation of a range of physiological functions including development, respiration, angiogenesis, inflammation, and immunity. CLRs can recognize distinct and conserved exogenous pathogen-associated as well as endogenous damage-associated molecular patterns. These interactions set off downstream signaling cascades, leading to the production of inflammatory mediators, activation of effector immune cells as well as regulation of the developmental and physiological homeostasis. CLR signaling must be tightly controlled to circumvent the excessive inflammatory burden and to maintain the cellular homeostasis. Recently, MicroRNAs (miRNAs) have been shown to be important regulators of expression of CLRs and their downstream signaling. The delicate balance between miRNAs and CLRs seems crucial in almost all aspects of multicellular life. Any dysregulations in the miRNA-CLR axes may lead to tumorigenesis or inflammatory diseases. Here, we present an overview of the current understanding of the central role of miRNAs in the regulation of CLR expression, profoundly impacting upon homeostasis and immunity, and thus, development of therapeutics against immune disorders.

The Interplay between Oxidative Stress and miRNAs in Obesity-Associated Hepatic and Vascular Complications

Nowadays, the obesity pandemic is one of the most relevant health issues worldwide. This condition is tightly related to comorbidities such as non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs), namely atherosclerosis. Dysregulated lipid metabolism and inflammation link these three diseases, leading to a subsequent increase of oxidative stress (OS) causing severe cellular damage. On the other hand, microRNAs (miRNAs) are short, single-stranded, non-coding RNAs that act as post-transcriptional negative regulators of gene expression, thus being involved in the molecular mechanisms that promote the development of many pathologies including obesity and its comorbidities. The involvement of miRNAs in promoting or opposing OS in disease progression is becoming more evident. Some miRNAs, such as miR-200a and miR.421, seem to play important roles in OS control in NAFLD. On the other hand, miR-92a and miR-133, among others, are important in the development of atherosclerosis. Moreover, since both diseases are linked to obesity, they share common altered miRNAs, being miR-34a and miR-21 related to OS. This review summarizes the latest advances in the knowledge about the mechanisms of oxidative stress (OS) generation in obesity-associated NAFLD and atherosclerosis, as well as the role played by miRNAs in the regulation of such mechanisms.

LOX-1: Regulation, Signaling and Its Role in Atherosclerosis

Atherosclerosis has long been known to be a chronic inflammatory disease. In addition, there is intense oxidative stress in atherosclerosis resulting from an imbalance between the excess reactive oxygen species (ROS) generation and inadequate anti-oxidant defense forces. The excess of the oxidative forces results in the conversion of low-density lipoproteins (LDL) to oxidized LDL (ox-LDL), which is highly atherogenic. The sub-endothelial deposition of ox-LDL, formation of foamy macrophages, vascular smooth muscle cell (VSMC) proliferation and migration, and deposition of collagen are central pathophysiologic steps in the formation of atherosclerotic plaque. Ox-LDL exerts its action through several different scavenger receptors, the most important of which is LOX-1 in atherogenesis. LOX-1 is a transmembrane glycoprotein that binds to and internalizes ox-LDL. This interaction results in variable downstream effects based on the cell type. In endothelial cells, there is an increased expression of cellular adhesion molecules, resulting in the increased attachment and migration of inflammatory cells to intima, followed by their differentiation into macrophages. There is also a worsening endothelial dysfunction due to the increased production of vasoconstrictors, increased ROS, and depletion of endothelial nitric oxide (NO). In the macrophages and VSMCs, ox-LDL causes further upregulation of the LOX-1 gene, modulation of calpains, macrophage migration, VSMC proliferation and foam cell formation. Soluble LOX-1 (sLOX-1), a fragment of the main LOX-1 molecule, is being investigated as a diagnostic marker because it has been shown to be present in increased quantities in patients with hypertension, diabetes, metabolic syndrome and coronary artery disease. LOX-1 gene deletion in mice and anti-LOX-1 therapy has been shown to decrease inflammation, oxidative stress and atherosclerosis. LOX-1 deletion also results in damage from ischemia, making LOX-1 a promising target of therapy for atherosclerosis and related disorders. In this article we focus on the different mechanisms for regulation, signaling and the various effects of LOX-1 in contributing to atherosclerosis.

Peroxisome Proliferator-Activated Receptor-γ Antagonizes LOX-1-Mediated Endothelial Injury by Transcriptional Activation of miR-590-5p

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is one of the major receptors expressed on the endothelium of arterial wall with a key role in endothelial dysfunction and the development of atherosclerosis. Recent evidence suggested that LOX-1 is upregulated under the condition of insulin resistance and could be suppressed by the antidiabetic drugs. We previously also confirmed that Thiazolidinedione (TZD) has the inhibitory effect on LOX-1 in ox-LDL-induced endothelial cells. However, the underlying mechanism is unclear. Here we showed that Rosiglitazone treatment significantly attenuated the expressions of LOX-1, ICAM-1, VCAM-1, p47^phox, and the atherosclerotic lesions in ApoE^−/− mice with high-fat diet. In vitro, we revealed that Rosiglitazone inhibited LOX-1 by regulating miR-590-5p. Ox-LDL-mediated ICAM-1, VCAM-1, and p47^phox were significantly reduced by Rosiglitazone, but all reversed after pretreating the cells with antagomiR-590-5p. Induction with Rosiglitazone activated PPAR-γ and promoted its nuclear translocation in cultured human umbilical vein endothelial cells (HUVECs). The nuclear PPAR-γ upregulated the miR-590-5p level through binding to its transcriptional promoter region. Retaining PPAR-γ in cytoplasm by transfecting with PPAR-γ^⊿NLS plasmid in HUVECs failed to activate miR-590-5p. Mutation of the promoter region of PPAR-γ also reduced the miR-590-5p promoter luciferase activity. Collectively, these data indicated that PPAR-γ may have the therapeutic potential in atherosclerosis via the transcriptional regulation of miR-590-5p in endothelial cells.

MiR-590 Inhibits Endothelial Cell Apoptosis by Inactivating the TLR4/NF-κB Pathway in Atherosclerosis

PURPOSE

Previous study has well documented the anti-apoptotic effects of miR-590 on oxidized low-density lipoprotein (ox-LDL)-treated endothelial cells (ECs). However, the mechanism underlying the anti-apoptotic effects of miR-590 in ox-LDL-treated ECs remains to be further addressed.

MATERIALS AND METHODS

ApoE^-/- mice fed with a high-fat diet (HFD) and human aortic endothelial cells (HAECs) treated with ox-LDL were used as in vivo and in vitro models of atherosclerosis. The expressions of miR-590 and toll-like receptor 4 (TLR4) were detected by quantitative real-time PCR and Western blot, respectively. Atherosclerotic lesion analysis was performed using Evans blue and hematoxylin-eosin staining. Cell proliferation was assessed by MTT assay. Apoptosis was examined using flow cytometry analysis and Western blot analysis of Cleaved poly (ADP-ribose) polymerase (PARP) and Cleaved Caspase-3 levels. The effect of miR-590 on TLR4/nuclear factor kappa B (NF-κB) pathway was evaluated by Western blot. Binding between miR-590 and TLR4 was confirmed by luciferase reporter assay and Western blot.

RESULTS

miR-590 was downregulated in the aorta tissues from HFD-fed apoE^-/- mice and ox-LDL-treated HAECs. miR-590 overexpression inhibited atherosclerotic lesion in HFD-induced apoE^-/- mice and promoted proliferation and inhibited apoptosis of ox-LDL-treated HAECs. Additionally, TLR4 was identified as a direct target of miR-590 in ox-LDL-treated HAECs. Moreover, anti-miR-590 reversed TLR4 knockdown-mediated promotion of cell proliferation and suppression of apoptosis in ox-LDL-treated HAECs. miR-590 overexpression suppressed the TLR4/NF-κB pathway, and inhibition of the TLR4/NF-κB pathway promoted cell proliferation and impeded apoptosis in ox-LDL-treated HAECs.

CONCLUSION

miR-590 promoted proliferation and blocked ox-LDL-induced apoptosis in HAECs through inhibition of the TLR4/NF-κB pathway.

MicroRNA-590-5p functions as a tumor suppressor in breast cancer conferring inhibitory effects on cell migration, invasion, and epithelial-mesenchymal transition by downregulating the Wnt-β-catenin signaling pathway

Breast cancer remains one of the foremost primary causes of female morbidity and mortality worldwide. During the current study, the effect of miR-590-5p and paired-like homeodomain transcription factor 2 (PITX2) on proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) of human breast cancer via the Wnt-β-catenin signaling pathway was investigated. Breast cancer-related genes and related signaling pathways were obtained from KEGG database. The PITX2 regulatory microRNA was predicted. To define the contributory role by which miR-590-5p influences the progression of breast cancer, the interaction between miR-590-5p and PITX2 was explored; the proliferation, invasion, and migration abilities as well as the tumor growth and metastasis in nude mice were detected following the overexpression or silencing of miR-590-5p. PITX2 was determined to share a correlation with breast cancer and miR-590-5p was selected for further analysis. PITX2, Wnt-1, β-catenin, N-cadherin, and vimentin all displayed higher levels, while miR-590-5p and E-cadherin expression were lower among breast cancer tissues than in the adjacent normal tissue. After overexpression of miR-590-5p or si-PITX2, the expression of E-cadherin was markedly increased, decreases in the expression of Wnt-1, β-catenin, N-cadherin, and vimentin, as well as inhibited cell proliferation, invasion, migration, metastasis, and EMT were observed. This study provides evidence suggesting that the transfection of overexpressed miR-590-5p can act to alleviate the effects of breast cancer demonstrating an ability to inhibit the processes of cell proliferation, migration, and invasion as well as EMT by suppressing the expression of PITX2 and activation of the Wnt-β-catenin pathway.

microRNA-590-5p targets transforming growth factor β1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury

This study aimed to investigate the role of miR-590-5p in chondrocyte apoptosis and autophagy in response to mechanical pressure injury in vitro, as well as to elucidate its regulatory mechanism in the pathogenesis of osteoarthritis. We applied mechanical pressure of 10 MPa to chondrocytes for 60 minutes to establish the chondrocyte model of experimentally induced mechanical injury. We then investigated the expression of miR-590-5p in the injury model and the effects of miR-590-5p dysregulation on the expression of cell apoptosis-related and autophagy-related proteins. Cell apoptosis was detected by flow cytometry. Moreover, the potential targets of miR-590-5p were investigated. Mechanical pressure injury resulted in a significantly increased expression of miR-590-5p. Suppression of miR-590-5p significantly increased chondrocytes viability, inhibited chondrocytes apoptosis and autophagy in response to mechanical pressure injury. In addition, mechanical pressure injury led to a decreased expression of transforming growth factor β1 (TGFβ1). Moreover, TGFβ1 was confirmed as a direct target of miR-590-5p. Knockdown of TGFβ1 significantly induced chondrocytes apoptosis and autophagy in response to mechanical pressure injury, which was contrary to the effects of miR-590-5p suppression. Furthermore, overexpression of TGFβ1 and miR-590-5p at the same time significantly reversed the effects of overexpression of miR-590-5p alone on chondrocytes apoptosis and autophagy. Our results indicate that upregulation of miR-590-5p may target TGFβ1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury, thus contributing to the pathogenesis of osteoarthritis.

Targeting LOX-1 in atherosclerosis and vasculopathy: current knowledge and future perspectives

LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1; also known as OLR1) is the dominant receptor that recognizes and internalizes oxidized low-density lipoproteins (ox-LDLs) in endothelial cells. Several genetic variants of LOX-1 are associated with the risk and severity of coronary artery disease. The LOX-1-ox-LDL interaction induces endothelial dysfunction, leukocyte adhesion, macrophage-derived foam cell formation, smooth muscle cell proliferation and migration, and platelet activation. LOX-1 activation eventually leads to the rupture of atherosclerotic plaques and acute cardiovascular events. In addition, LOX-1 can be cleaved to generate soluble LOX-1 (sLOX-1), which is a useful diagnostic and prognostic marker for atherosclerosis-related diseases in human patients. Of therapeutic relevance, several natural products and clinically used drugs have emerged as LOX-1 inhibitors that have antiatherosclerotic actions. We hereby provide an updated overview of role of LOX-1 in atherosclerosis and associated vascular diseases, with an aim to highlighting the potential of LOX-1 as a novel theranostic tool for cardiovascular disease prevention and treatment.

Contribution of lectin-like oxidized low-density lipoprotein receptor-1 and LOX-1 modulating compounds to vascular diseases

The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is the major receptor for binding and uptake of oxidized low-density lipoprotein (oxLDL) in endothelial cells. LOX-1 is also expressed in macrophages, smooth muscle cells and platelets. Following internalization of oxLDL, LOX-1 initiates a vicious cycle from activation of pro-inflammatory signaling pathways, thus promoting an increased reactive oxygen species formation and secretion of pro-inflammatory cytokines. LOX-1 plays a pivotal role in the development of endothelial dysfunction, foam cell and advanced lesions formation as well as in myocardial ischemia. Furthermore, it is known that LOX-1 plays a pivotal role in mitochondrial DNA damage, vascular cell apoptosis, and autophagy. A large number of studies provide evidence of a LOX-1's role in endothelial dysfunction, hypertension, diabetes, and obesity. In addition, novel insights into LOX-1 ligands and the activated signaling pathways have been gained. Recent studies have shown an interaction of LOX-1 with microRNA's, thus providing novel tools to regulate LOX-1 function. Because LOX-1 is increased in atherosclerotic plaques and contributes to endothelial dysfunction, several compounds were tested in vivo and in vitro to modulate the LOX-1 expression in therapeutic approaches.

Low density lipoprotein - rosiglitazone - chitosan-calcium alginate/nanoparticles inhibition of human tenon's fibroblasts activation and proliferation

Anti-fibrotic therapeutic methods with safety and efficiency after glaucoma filtration surgery (GFS) are desirable. In our previous study, by using Human Tenon's Fibroblasts (HTFs) as a model, we proved the expression of peroxisome proliferator activates receptor-γ (PPAR-γ) in HTFs; in addition, rosiglitazone (RSG), an agonist of PPAR-γ, can inhibit transforming growth factorsβ1 (TGF-β1)-induced reactivation of HTFs, thus to inhibit specifically scarring after GFS through intervening TGF-β/Smads signal pathway. However, a better drug delivery way of RSG, to prolong the duration of its function, and to reduce the toxicity of RSG to ocular tissue still remains challenges. Low density lipoprotein receptor (LDLr) is strongly expressed in hyper-proliferation HTFs after GFS. Therefore, we structured targeting LDL-RSG complexes and channel them into HTFs through LDL-LDLr pathway in order to promote anti-proliferation of HTFs and reduce the toxicity to ocular tissue. Meanwhile, in order to improve the release properties of LDL-RSG complexes, we structured slow release system of LDL-RSG/chitosan-calcium alginate - nanoparticles (CSNP), which effectively inhibited TGF-β1-induced HTFs proliferation, synthesis of extracellular matrix and activation of TGF-β1/SMAD pathway. These data suggested that LDL-RSG/CSNP can be a new anti-fibrotic therapeutic method on scarring after GFS and also a novelty administration of RSG.

MicroRNA-384-mediated Herpud1 upregulation promotes angiotensin II-induced endothelial cell apoptosis

BACKGROUND

Angiotensin II (Ang II)-induced damage to endothelial cells (ECs) plays a crucial role in the pathogenesis of atherosclerosis. This study aimed to investigate the role of microRNA-384 (miR-384) in endothelial cell apoptosis.

METHODS

The expression of five various miRNAs in Ang II-treated human umbilical vein endothelial cells (HUVECs) were detected by qPCR. The Ang II-induced apoptosis of HUVECs was determined by flow cytometry, TUNEL staining and western blot. Endoplasmic reticulum (ER) stress markers were detected by western blot analysis. The target gene of miR-384 was determined by bioinformatics analyses. qPCR, western blotting and immunofluorescence were performed to determine the expression level of homocysteine inducible ER protein with ubiquitin like domain 1 (Herpud1).

RESULTS

miR-384 expression level was significantly decreased in Ang II-treated HUVECs. Ang II-induced HUVEC apoptosis was accompanied by the occurrence of ER stress. A decreased rate of HUVEC apoptosis and a decreased rate of ER stress were observed following restoration of miR-384 expression. Herpud1 expression level was increased in HUVECs treated with Ang II, and miR-384 mimics effectively inhibited Herpud1 expression. Mechanistically, miR-384 directly targets the 3'-untranslated region of Herpud1. Furthermore, effects of miR-384 on HUVECs apoptosis and ER stress were at least partly reversed by knockdown of Herpud1 expression.

CONCLUSION

The results of the present study collectively indicated that miR-384 expression level was downregulated in Ang II-treated HUVECs and miR-384 overexpression protected HUVECs against Ang II-induced apoptosis by negatively regulating Herpud1. These findings point towards new strategies by which apoptosis of ECs can be suppressed.

MiR-590-5p, a density-sensitive microRNA, inhibits tumorigenesis by targeting YAP1 in colorectal cancer

YAP1, a transcription co-activator, mediates the biological functions of the Hippo pathway. YAP1 inactivation is involved in cell-cell contact inhibition. In various tumors, YAP1 is upregulated through multiple mechanisms, and it functions as an oncogene. Here, we provided evidence that YAP1 influenced multiple signaling pathways in colorectal cancer (CRC) cells. We reported that miR-590-5p directly targets YAP1 and inhibits tumorigenesis in CRC cells both in vitro and in vivo xenograft model. We analyzed different cell densities and found that increased density caused increased expression of miR-590-5p, and decreased expression of its precursors (pri- and pre-miR-590). Increasing cancer cell density upregulated the expression of a RNase III endonuclease, DICER1. DICER1 increased miR-590 biogenesis and inhibited YAP1. In DICER1-defective CRC cells, addition of pre-miR-590 did not inhibit YAP1 expression. Analyses of clinical data demonstrated that the DICER1-miR-590-5p-YAP1 axis was dysregulated in CRC specimens and affected patient survival. Cell-cell contact inhibition is crucial to prevent uncontrolled cell proliferation. Identification of this cell density-sensitive, DICER1-miR-590-5p-YAP1 axis may provide a basis for developing new biomarkers or targeted therapies for CRC.

LOX-1 and Its Splice Variants: A New Challenge for Atherosclerosis and Cancer-Targeted Therapies

Alternative splicing (AS) is a process in which precursor messenger RNA (pre-mRNA) splicing sites are differentially selected to diversify the protein isoform population. Changes in AS patterns have an essential role in normal development, differentiation and response to physiological stimuli. It is documented that AS can generate both “risk” and “protective” splice variants that can contribute to the pathogenesis of several diseases including atherosclerosis. The main endothelial receptor for oxidized low-density lipoprotein (ox-LDLs) is LOX-1 receptor protein encoded by the OLR1 gene. When OLR1 undergoes AS events, it generates three variants: OLR1, OLR1D4 and LOXIN. The latter lacks exon 5 and two-thirds of the functional domain. Literature data demonstrate a protective role of LOXIN in pathologies correlated with LOX-1 overexpression such as atherosclerosis and tumors. In this review, we summarize recent developments in understanding of OLR1 AS while also highlighting data warranting further investigation of this process as a novel therapeutic target.

microRNA-590 suppresses the tumorigenesis and invasiveness of non-small cell lung cancer cells by targeting ADAM9

microRNAs (miRNAs), a family of small non-coding RNA molecules, are implicated in cancer growth and progression. In the present study, we examined the expression and biological roles of miR-590 in non-small cell lung cancer (NSCLC). Compared to normal lung tissues, miR-590 expression was downregulated in primary NSCLCs and, to a greater extent, in corresponding brain metastases. NSCLC cell lines with high metastatic potential had significantly (P < 0.05) lower levels of miR-590 than those with low metastatic potential. Re-expression of miR-590 suppressed NSCLC cell proliferation, colony formation, migration, and invasion in vitro and tumorigenesis in vivo. In contrast, inhibition of miR-590 enhanced the migration and invasion of NSCLC cells. Mechanistic studies revealed that a disintegrin and metalloproteinase 9 (ADAM9) was a direct target of miR-590. Delivery of miR-590 mimic was found to decrease endogenous ADAM9 expression in NSCLC cells. Enforced expression of a miRNA-resistant form of ADAM9 significantly restored the aggressive behaviors in miR-590-overexpressing NSCLC cells. Taken together, our data reveal miR-590 as a tumor suppressor in NSCLC, which is at least partially mediated through targeting of ADAM9. Restoration of miR-590 may provide a promising therapeutic strategy for NSCLC.