Oxidative stress activates endothelial innate immunity via sterol regulatory element binding protein 2 (SREBP2) transactivation of microRNA-92a

Unraveling the miRNA Puzzle in Atherosclerosis: Revolutionizing Diagnosis, Prognosis, and Therapeutic Approaches

PURPOSE OF REVIEW

To eradicate atherosclerotic diseases, novel biomarkers, and future therapy targets must reveal the burden of early atherosclerosis (AS), which occurs before life-threatening unstable plaques form. The chemical and biological features of microRNAs (miRNAs) make them interesting biomarkers for numerous diseases. We summarized the latest research on miRNA regulatory mechanisms in AS progression studies, which may help us use miRNAs as biomarkers and treatments for difficult-to-treat diseases.

RECENT FINDINGS

Recent research has demonstrated that miRNAs have a regulatory function in the observed changes in gene and protein expression during atherogenesis, the process that leads to atherosclerosis. Several miRNAs play a role in the development of atherosclerosis, and these miRNAs could potentially serve as non-invasive biomarkers for atherosclerosis in various regions of the body. These miRNAs have the potential to serve as biomarkers and targets for early treatment of atherosclerosis. The start and development of AS require different miRNAs. It reviews new research on miRNAs affecting endothelium, vascular smooth muscle, vascular inflammation, lipid retention, and cholesterol metabolism in AS. A miRNA gene expression profile circulates with AS everywhere. AS therapies include lipid metabolism, inflammation reduction, and oxidative stress inhibition. Clinical use of miRNAs requires tremendous progress. We think tiny miRNAs can enable personalized treatment.

Role of inflammasomes in endothelial dysfunction

The vascular endothelium dynamically responds to environmental cues and plays a pivotal role in maintaining vascular homeostasis by regulating vasomotor tone, blood cell trafficking, permeability and immune responses. However, endothelial dysfunction results in various pathological conditions. Inflammasomes are large intracellular multimeric complexes activated by pathogens or cellular damage. Inflammasomes in vascular endothelial cells (ECs) initiate innate immune responses, which have emerged as significant mediators in endothelial dysfunction, contributing to the pathophysiology of an array of diseases. This review summarizes the mechanisms and ramifications of inflammasomes in ECs and related vascular diseases such as atherosclerosis, abdominal aortic aneurysm, stroke, and lung and kidney diseases. We also discuss potential drugs targeting EC inflammasomes and their applications in treating vascular diseases.

Exploring the impact of MiR-92a-3p on FOLFOX chemoresistance biomarker genes in colon cancer cell lines

Introduction: One of the primary obstacles faced by individuals with advanced colorectal cancer (CRC) is the potential development of acquired chemoresistance as the disease advances. Studies have indicated a direct association between elevated levels of miR-92a-3p and the progression, metastasis, and chemoresistance observed in CRC. We proposed that miR-92a-3p impairs FOLFOX (fluorouracil/oxaliplatin) chemotherapy response by upregulating the expression of chemoresistance biomarker genes through the activation of β-catenin and epithelial-mesenchymal transition (EMT). These FOLFOX biomarker genes include the pyrimidine biosynthesis pathway genes dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), methylenetetrahydrofolate reductase (MTHFR), and the genes encoding the DNA repair complexes subunits ERCC1 and ERCC2, and XRCC1. Methods: To assess this, we transfected SW480 and SW620 colon cancer cell lines with miR-92a-3p mimics and then quantified the expression of DPYD, TYMS, MTHFR, ERCC1, ERCC2, and XRCC1, the expression of EMT markers and transcription factors, and activation of β-catenin. Results and discussion: Our results reveal that miR-92a-3p does not affect the expression of DPYD, TYMS, MTHFR, and ERCC1. Furthermore, even though miR-92a-3p affects ERCC2, XRCC1, E-cadherin, and β-catenin mRNA levels, it has no influence on their protein expression. Conclusion: We found that miR-92a-3p does not upregulate the expression of proteins of DNA-repair pathways and other genes involved in FOLFOX chemotherapy resistance.

LncRNA GAS5 restrains ISO-induced cardiac fibrosis by modulating mir-217 regulation of SIRT1

Considering the effect of SIRT1 on improving myocardial fibrosis and GAS5 inhibiting occurrence and development of myocardial fibrosis at the cellular level, the aim of the present study was to investigate whether LncRNA GAS5 could attenuate cardiac fibrosis through regulating mir-217/SIRT1, and whether the NLRP3 inflammasome activation was involved in this process. Isoprenaline (ISO) was given subcutaneously to the male C57BL/6 mice to induce myocardial fibrosis and the AAV9 vectors were randomly injected into the left ventricle of each mouse to overexpress GAS5. Primary myocardial fibroblasts (MCFs) derived from neonatal C57BL/6 mice and TGF-β1 were used to induce fibrosis. And the GAS5 overexpressed MCFs were treated with mir-217 mimics and mir-217 inhibitor respectively. Then the assays of expression levels of NLRP3, Caspase-1, IL-1β and SIRT1 were conducted. The findings indicated that the overexpression of GAS5 reduced the expression levels of collagen, NLRP3, Capase-1, IL-1β and SIRT1 in ISO treated mice and TGF-β1 treated MCFs. However, this effect was significantly weakened after mir-217 overexpression, but was further enhanced after knockdown of mir-217. mir-217 down-regulates the expression of SIRT1, leading to increased activation of the NLRP3 inflammasome and subsequent pyroptosis. LncRNA GAS5 alleviates cardiac fibrosis induced via regulating mir-217/SIRT1 pathway.

SIRT1/SREBPs-mediated regulation of lipid metabolism

Sirtuins, also called silent information regulator 2, are enzymes that rely on nicotinamide adenine dinucleotide (NAD+) to function as histone deacetylases. Further investigation is warranted to explore the advantageous impacts of Sirtuin 1 (SIRT1), a constituent of the sirtuin group, on lipid metabolism, in addition to its well-researched involvement in extending lifespan. The regulation of gene expression has been extensively linked to SIRT1. Sterol regulatory element-binding protein (SREBP) is a substrate of SIRT1 that has attracted significant interest due to its role in multiple cellular processes including cell cycle regulation, DNA damage repair, and metabolic functions. Hence, the objective of this analysis was to investigate and elucidate the correlation between SIRT1 and SREBPs, as well as assess the contribution of SIRT1/SREBPs in mitigating lipid metabolism dysfunction. The objective of this research was to investigate whether SIRT1 and SREBPs could be utilized as viable targets for therapeutic intervention in managing complications associated with diabetes.

Hypercapnia increases ACE2 expression and pseudo-SARS-CoV-2 entry in bronchial epithelial cells by augmenting cellular cholesterol

Patients with chronic lung disease, obesity, and other co-morbid conditions are at increased risk of severe illness and death when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hypercapnia, the elevation of CO2 in blood and tissue, commonly occurs in patients with severe acute and chronic lung disease, including those with pulmonary infections, and is also associated with high mortality risk. We previously reported that hypercapnia increases viral replication and mortality of influenza A virus infection in mice. We have also shown that culture in elevated CO2 upregulates expression of cholesterol synthesis genes in primary human bronchial epithelial cells. Interestingly, factors that increase the cholesterol content of lipid rafts and lipid droplets, platforms for viral entry and assembly, enhance SARS-CoV-2 infection. In the current study, we investigated the effects of hypercapnia on ACE2 expression and entry of SARS-CoV-2 pseudovirus (p-SARS-CoV-2) into airway epithelial cells. We found that hypercapnia increased ACE2 expression and p-SARS-CoV-2 uptake by airway epithelium in mice, and in cultured VERO and human bronchial epithelial cells. Hypercapnia also increased total cellular and lipid raft-associated cholesterol in epithelial cells. Moreover, reducing cholesterol synthesis with inhibitors of sterol regulatory element binding protein 2 (SREBP2) or statins, and depletion of cellular cholesterol, each blocked the hypercapnia-induced increases in ACE2 expression and p-SARS-CoV-2 entry into epithelial cells. Cigarette smoke extract (CSE) also increased ACE2 expression, p-SARS-CoV-2 entry and cholesterol accumulation in epithelial cells, an effect not additive to that of hypercapnia, but also inhibited by statins. These findings reveal a mechanism that may account, in part, for poor clinical outcomes of SARS-CoV-2 infection in patients with advanced lung disease and hypercapnia, and in those who smoke cigarettes. Further, our results suggest the possibility that cholesterol-lowering therapies may be of particular benefit in patients with hypercapnia when exposed to or infected with SARS-CoV-2.

Kinases in cerebral cavernous malformations: Pathogenesis and therapeutic targets

Cerebral cavernous malformations (CCMs) are low-flow, hemorrhagic vascular lesions of the central nervous system of genetic origin, which can cause stroke-like symptoms and seizures. From the identification of CCM1, CCM2 and CCM3 as genes related to disease progression, molecular and cellular mechanisms for CCM pathogenesis have been established and the search for potential drugs to target CCM has begun. Broadly speaking, kinases are the major group signaling in CCM pathogenesis. These include the MEKK3/MEK5/ERK5 cascade, Rho/Rock signaling, CCM3/GCKIII signaling, PI3K/mTOR signaling, and others. Since the discovery of Rho/Rock in CCM pathogenesis, inhibitors for Rho signaling and subsequently other components in CCM signaling were discovered and applied in preclinical and clinical trials to ameliorate CCM progression. This review discusses the general aspects of CCM disease, kinase-mediated signaling in CCM pathogenesis and the current state of potential treatment options for CCM. It is suggested that kinase target drug development in the context of CCM might facilitate and meet the unmet requirement - a non-surgical option for CCM disease.

Vascular mechanotransduction

This review aims to survey the current state of mechanotransduction in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), including their sensing of mechanical stimuli and transduction of mechanical signals that result in the acute functional modulation and longer-term transcriptomic and epigenetic regulation of blood vessels. The mechanosensors discussed include ion channels, plasma membrane-associated structures and receptors, and junction proteins. The mechanosignaling pathways presented include the cytoskeleton, integrins, extracellular matrix, and intracellular signaling molecules. These are followed by discussions on mechanical regulation of transcriptome and epigenetics, relevance of mechanotransduction to health and disease, and interactions between VSMCs and ECs. Throughout this review, we offer suggestions for specific topics that require further understanding. In the closing section on conclusions and perspectives, we summarize what is known and point out the need to treat the vasculature as a system, including not only VSMCs and ECs but also the extracellular matrix and other types of cells such as resident macrophages and pericytes, so that we can fully understand the physiology and pathophysiology of the blood vessel as a whole, thus enhancing the comprehension, diagnosis, treatment, and prevention of vascular diseases.

Obstructive Sleep Apnea-induced Endothelial Dysfunction Is Mediated by miR-210

Rationale: Obstructive sleep apnea (OSA)-induced endothelial cell (EC) dysfunction contributes to OSA-related cardiovascular sequelae. The mechanistic basis of endothelial impairment by OSA is unclear. Objectives: The goals of this study were to identify the mechanism of OSA-induced EC dysfunction and explore the potential therapies for OSA-accelerated cardiovascular disease. Methods: The experimental methods include data mining, bioinformatics, EC functional analyses, OSA mouse models, and assessment of OSA human subjects. Measurements and Main Results: Using mined microRNA sequencing data, we found that microRNA 210 (miR-210) conferred the greatest induction by intermittent hypoxia in ECs. Consistently, the serum concentration of miR-210 was higher in individuals with OSA from two independent cohorts. Importantly, miR-210 concentration was positively correlated with the apnea-hypopnea index. RNA sequencing data collected from ECs transfected with miR-210 or treated with OSA serum showed a set of genes commonly altered by miR-210 and OSA serum, which are largely involved in mitochondrion-related pathways. ECs transfected with miR-210 or treated with OSA serum showed reduced [Formula: see text]o2 rate, mitochondrial membrane potential, and DNA abundance. Mechanistically, intermittent hypoxia-induced SREBP2 (sterol regulatory element-binding protein 2) bound to the promoter region of miR-210, which in turn inhibited the iron-sulfur cluster assembly enzyme and led to mitochondrial dysfunction. Moreover, the SREBP2 inhibitor betulin alleviated intermittent hypoxia-increased systolic blood pressure in the OSA mouse model. Conclusions: These results identify an axis involving SREBP2, miR-210, and mitochondrial dysfunction, representing a new mechanistic link between OSA and EC dysfunction that may have important implications for treating and preventing OSA-related cardiovascular sequelae.

microRNAs Associated with Carotid Plaque Development and Vulnerability: The Clinician's Perspective

Ischemic stroke (IS) related to atherosclerosis of large arteries is one of the leading causes of mortality and disability in developed countries. Atherosclerotic internal carotid artery stenosis (ICAS) contributes to 20% of all cerebral ischemia cases. Nowadays, atherosclerosis prevention and treatment measures aim at controlling the atherosclerosis risk factors, or at the interventional (surgical or endovascular) management of mature occlusive lesions. There is a definite lack of the established circulating biomarkers which, once modulated, could prevent development of atherosclerosis, and consequently prevent the carotid-artery-related IS. Recent studies emphasize that microRNA (miRNA) are the emerging particles that could potentially play a pivotal role in this approach. There are some research studies on the association between the expression of small non-coding microRNAs with a carotid plaque development and vulnerability. However, the data remain inconsistent. In addition, all major studies on carotid atherosclerotic plaque were conducted on cell culture or animal models; very few were conducted on humans, whereas the accumulating evidence demonstrates that it cannot be automatically extrapolated to processes in humans. Therefore, this paper aims to review the current knowledge on how miRNA participate in the process of carotid plaque formation and rupture, as well as stroke occurrence. We discuss potential target miRNA that could be used as a prognostic or therapeutic tool.

Clinical Application of Serum microRNAs in Atherosclerotic Coronary Artery Disease

MicroRNAs (miRs) are promising diagnostic, prognostic and therapeutic biomolecules for atherosclerotic cardiovascular disease. Atherosclerotic occlusive disease concerns a large population of patients, carrying the highest incidence of fatal and non-fatal adverse events, such as myocardial infarction, ischemic stroke, and limb ischemia, worldwide. Consistently, miRs are involved in regulation and pathogenesis of atherosclerotic coronary artery disease (CAD), acute coronary syndromes (ACS), both with ST-segment (STEMI) and non-ST segment elevation myocardial infarctions (NSTEMI), as well as cardiac remodeling and fibrosis following ACS. However, the genetic and molecular mechanisms underlying adverse outcomes in CAD are multifactorial, and sometimes difficult to interpret for clinicians. Therefore, in the present review paper we have focused on the clinical meaning and the interpretation of various miRs findings, and their potential application in routine clinical practice.

Shear Stress and Metabolic Disorders-Two Sides of the Same Plaque

Significance: Shear stress and metabolic disorder are the two sides of the same atherosclerotic coin. Atherosclerotic lesions are prone to develop at branches and curvatures of arteries, which are exposed to oscillatory and low shear stress exerted by blood flow. Meanwhile, metabolic disorders are pivotal contributors to the formation and advancement of atherosclerotic plaques. Recent Advances: Accumulated evidence has provided insight into the impact and mechanisms of biomechanical forces and metabolic disorder on atherogenesis, in association with mechanotransduction, epigenetic regulation, and so on. Moreover, recent studies have shed light on the cross talk between the two drivers of atherosclerosis. Critical Issues: There are extensive cross talk and interactions between shear stress and metabolic disorder during the pathogenesis of atherosclerosis. The communications may amplify the proatherogenic effects through increasing oxidative stress and inflammation. Nonetheless, the precise mechanisms underlying such interactions remain to be fully elucidated as the cross talk network is considerably complex. Future Directions: A better understanding of the cross talk network may confer benefits for a more comprehensive clinical management of atherosclerosis. Critical mediators of the cross talk may serve as promising therapeutic targets for atherosclerotic vascular diseases, as they can inhibit effects from both sides of the plaque. Hence, further in-depth investigations with advanced omics approaches are required to develop novel and effective therapeutic strategies against atherosclerosis. Antioxid. Redox Signal. 37, 820-841.

MicroRNAs in Mechanical Homeostasis

Mechanical variables such as stiffness, stress, strain, and fluid shear stress are central to tissue functions, thus, must be maintained within the proper range. Mechanics are especially important in the cardiovascular system and lung, the functions of which are essentially mechanical. Mechanical homeostasis is characterized by negative feedback in which deviations from the optimal value or set point activates mechanisms to return the system to the correct range. In chronic diseases, homeostatic mechanisms are generally overcome or replaced with positive feedback loops that promote disease progression. Recent work has shown that microRNAs (miRNAs) are essential to mechanical homeostasis in a number of biological systems and that perturbations to miRNA biogenesis play key roles in cardiovascular and pulmonary diseases. In this review, we integrate current knowledge of miRNAs in mechanical homeostasis and how these mechanisms are altered in disease.

Noncoding RNAs in age-related cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality in the adult population worldwide and represent a severe economic burden and public health concern. The majority of human genes do not code for proteins. However, noncoding transcripts play important roles in ageing that significantly increases the risk for CVDs. Noncoding RNAs (ncRNAs) are critical regulators of multiple biological processes related to ageing such as oxidative stress, mitochondrial dysfunction and chronic inflammation. NcRNAs are also involved in pathophysiological developments within the cardiovascular system including arrhythmias, cardiac hypertrophy, fibrosis, myocardial infarction and heart failure. In this review article, we cover the roles of ncRNAs in cardiovascular ageing and disease as well as their potential therapeutic applications in CVDs.

The Endothelium as a Hub for Cellular Communication in Atherogenesis: Is There Directionality to the Message?

Endothelial cells line every blood vessel and thereby serve as an interface between the blood and the vessel wall. They have critical functions for maintaining homeostasis and orchestrating vascular pathogenesis. Atherosclerosis is a chronic disease where cholesterol and inflammatory cells accumulate in the artery wall below the endothelial layer and ultimately form plaques that can either progress to occlude the lumen or rupture with thromboembolic consequences – common outcomes being myocardial infarction and stroke. Cellular communication lies at the core of this process. In this review, we discuss traditional (e.g., cytokines, chemokines, nitric oxide) and novel (e.g., extracellular vesicles) modes of endothelial communication with other endothelial cells as well as circulating and vessel wall cells, including monocytes, macrophages, neutrophils, vascular smooth muscle cells and other immune cells, in the context of atherosclerosis. More recently, the growing appreciation of endothelial cell plasticity during atherogenesis suggests that communication strategies are not static. Here, emerging data on transcriptomics in cells during the development of atherosclerosis are considered in the context of how this might inform altered cell-cell communication. Given the unique position of the endothelium as a boundary layer that is activated in regions overlying vascular inflammation and atherosclerotic plaque, there is a potential to exploit the unique features of this group of cells to deliver therapeutics that target the cellular crosstalk at the core of atherosclerotic disease. Data are discussed supporting this concept, as well as inherent pitfalls. Finally, we briefly review the literature for other regions of the body (e.g., gut epithelium) where cells similarly exist as a boundary layer but provide discrete messages to each compartment to govern homeostasis and disease. In this light, the potential for endothelial cells to communicate in a directional manner is explored, along with the implications of this concept – from fundamental experimental design to biomarker potential and therapeutic targets.

MicroRNAs in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading causes of death and disability worldwide, despite the wide diversity of molecular targets identified and the development of therapeutic methods. MicroRNAs (miRNAs) are a class of small (about 22 nucleotides) non-coding RNAs (ncRNAs) that negatively regulate gene expression at the post-transcriptional level in the cytoplasm and play complicated roles in different CVDs. While miRNA overexpression in one type of cell protects against heart disease, it promotes cardiac dysfunction in another type of cardiac cell. Moreover, recent studies have shown that, apart from cytosolic miRNAs, subcellular miRNAs such as mitochondria- and nucleus-localized miRNAs are dysregulated in CVDs. However, the functional properties of cellular- and subcellular-localized miRNAs have not been well characterized. In this review article, by carefully revisiting animal-based miRNA studies in CVDs, we will address the regulation and functional properties of miRNAs in various CVDs. Specifically, the cell-cell crosstalk and subcellular perspective of miRNAs are highlighted. We will provide the background for attractive molecular targets that might be useful in preventing the progression of CVDs and heart failure (HF) as well as insights for future studies.

Endothelial-derived extracellular microRNA-92a promotes arterial stiffness by regulating phenotype changes of vascular smooth muscle cells

Endothelial dysfunction and vascular smooth muscle cell (VSMC) plasticity are critically involved in the pathogenesis of hypertension and arterial stiffness. MicroRNAs can mediate the cellular communication between vascular endothelial cells (ECs) and neighboring cells. Here, we investigated the role of endothelial-derived extracellular microRNA-92a (miR-92a) in promoting arterial stiffness by regulating EC-VSMC communication. Serum miR-92a level was higher in hypertensive patients than controls. Circulating miR-92a level was positively correlated with pulse wave velocity (PWV), systolic blood pressure (SBP), diastolic blood pressure (DBP), and serum endothelin-1 (ET-1) level, but inversely with serum nitric oxide (NO) level. In vitro, angiotensin II (Ang II)-increased miR-92a level in ECs mediated a contractile-to-synthetic phenotype change of co-cultured VSMCs. In Ang II-infused mice, locked nucleic acid-modified antisense miR-92a (LNA-miR-92a) ameliorated PWV, SBP, DBP, and impaired vasodilation induced by Ang II. LNA-miR-92a administration also reversed the increased levels of proliferative genes and decreased levels of contractile genes induced by Ang II in mouse aortas. Circulating serum miR-92a level and PWV were correlated in these mice. These findings indicate that EC miR-92a may be transported to VSMCs via extracellular vesicles to regulate phenotype changes of VSMCs, leading to arterial stiffness.

Regulatory Non-coding RNAs in Atherosclerosis

Regulatory RNAs like microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) control vascular and immune cells' phenotype and thus play a crucial role in atherosclerosis. Moreover, the mutual interactions between miRNAs and lncRNAs link both types of regulatory RNAs in a functional network that affects lesion formation. In this review, we deduce novel concepts of atherosclerosis from the analysis of the current data on regulatory RNAs' role in endothelial cells (ECs) and macrophages. In contrast to arterial ECs, which adopt a stable phenotype by adaptation to high shear stress, macrophages are highly plastic and quickly change their activation status. At predilection sites of atherosclerosis, such as arterial bifurcations, ECs are exposed to disturbed laminar flow, which generates a dysadaptive stress response mediated by miRNAs. Whereas the highly abundant miR-126-5p promotes regenerative proliferation of dysadapted ECs, miR-103-3p stimulates inflammatory activation and impairs endothelial regeneration by aberrant proliferation and micronuclei formation. In macrophages, miRNAs are essential in regulating energy and lipid metabolism, which affects inflammatory activation and foam cell formation.Moreover, lipopolysaccharide-induced miR-155 and miR-146 shape inflammatory macrophage activation through their oppositional effects on NF-kB. Most lncRNAs are not conserved between species, except a small group of very long lncRNAs, such as MALAT1, which blocks numerous miRNAs by providing non-functional binding sites. In summary, regulatory RNAs' roles are highly context-dependent, and therapeutic approaches that target specific functional interactions of miRNAs appear promising against cardiovascular diseases.

Targeted polyelectrolyte complex micelles treat vascular complications in vivo

Vascular disease is a leading cause of morbidity and mortality in the United States and globally. Pathological vascular remodeling, such as atherosclerosis and stenosis, largely develop at arterial sites of curvature, branching, and bifurcation, where disturbed blood flow activates vascular endothelium. Current pharmacological treatments of vascular complications principally target systemic risk factors. Improvements are needed. We previously devised a targeted polyelectrolyte complex micelle to deliver therapeutic nucleotides to inflamed endothelium in vitro by displaying the peptide VHPKQHR targeting vascular cell adhesion molecule 1 (VCAM-1) on the periphery of the micelle. This paper explores whether this targeted nanomedicine strategy effectively treats vascular complications in vivo. Disturbed flow-induced microRNA-92a (miR-92a) has been linked to endothelial dysfunction. We have engineered a transgenic line (miR-92aEC-TG /Apoe-/- ) establishing that selective miR-92a overexpression in adult vascular endothelium causally promotes atherosclerosis in Apoe-/- mice. We tested the therapeutic effectiveness of the VCAM-1-targeting polyelectrolyte complex micelles to deliver miR-92a inhibitors and treat pathological vascular remodeling in vivo. VCAM-1-targeting micelles preferentially delivered miRNA inhibitors to inflamed endothelial cells in vitro and in vivo. The therapeutic effectiveness of anti-miR-92a therapy in treating atherosclerosis and stenosis in Apoe-/- mice is markedly enhanced by the VCAM-1-targeting polyelectrolyte complex micelles. These results demonstrate a proof of concept to devise polyelectrolyte complex micelle-based targeted nanomedicine approaches treating vascular complications in vivo.

Regulation of TLR4 signaling through the TRAF6/sNASP axis by reversible phosphorylation mediated by CK2 and PP4

Recognition of invading pathogens by Toll-like receptors (TLRs) activates innate immunity through signaling pathways that involved multiple protein kinases and phosphatases. We previously demonstrated that somatic nuclear autoantigenic sperm protein (sNASP) binds to TNF receptor-associated factor 6 (TRAF6) in the resting state. Upon TLR4 activation, a signaling complex consisting of TRAF6, sNASP, interleukin (IL)-1 receptor-associated kinase 4, and casein kinase 2 (CK2) is formed. CK2 then phosphorylates sNASP to release phospho-sNASP (p-sNASP) from TRAF6, initiating downstream signaling pathways. Here, we showed that protein phosphatase 4 (PP4) is the specific sNASP phosphatase that negatively regulates TLR4-induced TRAF6 activation and its downstream signaling pathway. Mechanistically, PP4 is directly recruited by phosphorylated sNASP to dephosphorylate p-sNASP to terminate TRAF6 activation. Ectopic expression of PP4 specifically inhibited sNASP-dependent proinflammatory cytokine production and downstream signaling following bacterial lipopolysaccharide (LPS) treatment, whereas silencing PP4 had the opposite effect. Primary macrophages and mice infected with recombinant adenovirus carrying a gene encoding PP4 (Ad-PP4) showed significant reduction in IL-6 and TNF-α production. Survival of Ad-PP4-infected mice was markedly increased due to a better ability to clear bacteria in a sepsis model. These results indicate that the serine/threonine phosphatase PP4 functions as a negative regulator of innate immunity by regulating the binding of sNASP to TRAF6.

Role of endothelial cells in pulmonary fibrosis via SREBP2 activation

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with limited treatment options. Despite endothelial cells (ECs) comprising 30% of the lung cellular composition, the role of EC dysfunction in pulmonary fibrosis (PF) remains unclear. We hypothesize that sterol regulatory element-binding protein 2 (SREBP2) plays a critical role in the pathogenesis of PF via EC phenotypic modifications. Transcriptome data demonstrate that SREBP2 overexpression in ECs led to the induction of the TGF, Wnt, and cytoskeleton remodeling gene ontology pathways and the increased expression of mesenchymal genes, such as snail family transcriptional repressor 1 (snai1), α-smooth muscle actin, vimentin, and neural cadherin. Furthermore, SREBP2 directly bound to the promoter regions and transactivated these mesenchymal genes. This transcriptomic change was associated with an epigenetic and phenotypic switch in ECs, leading to increased proliferation, stress fiber formation, and ECM deposition. Mice with endothelial-specific transgenic overexpression of SREBP2 (EC-SREBP2[N]-Tg mice) that were administered bleomycin to induce PF demonstrated exacerbated vascular remodeling and increased mesenchymal transition in the lung. SREBP2 was also found to be markedly increased in lung specimens from patients with IPF. These results suggest that SREBP2, induced by lung injury, can exacerbate PF in rodent models and in human patients with IPF.

Resistance exercise affects catheter-related thrombosis in rats through miR-92a-3p, oxidative stress and the MAPK/NF-κB pathway

BACKGROUND

MiR-92a-3p and oxidative stress are associated with catheter-related thrombosis (CRT). As a kind of physical intervention, resistance exercise can effectively promote blood circulation. In this study, we investigated the roles of miR-92a-3p, oxidative stress and the P38 mitogen-activated protein kinase/nuclear factor-κB (MAPK/NF-κB) pathway in CRT during resistance exercise.

METHODS

The rat CRT model was used for resistance exercise intervention. Moreover, pathological changes from the right jugular vein to the right auricle were observed under an electron microscope. In addition, reactive oxygen species (ROS) production, malondialdehyde (MDA) activity and heme oxygenase (HO-1) level in rat serum were detected via ELISA. The expression levels of miR-92A-3p and HO-1 in the vascular tissues of the rats were determined via real-time quantitative PCR. Additionally, the expression levels of HO-1, NF-κB P65, p38MAPK and IκBa in the venous tissues of the rats were analysed by Western blot analysis.

RESULTS

The pathological results showed that the thrombosis incidence rate in the CRT + RE group was lower than that in the CRT group. In the CRT group, the expression levels of ROS and MDA, which are markers related to oxidative stress in serum, significantly increased whilst the expression of HO-1 decreased. In the venous tissue, the expression of miR-92a-3p increased, the level of HO-1 decreased, the levels of p38MAPK and NF-κB p65 significantly increased but that of P-IκBa and IκBa significantly decreased. In the CRT + RE group, after administering the resistance exercise intervention, ROS production and MDA activity in serum significantly decreased, the expression level of HO-1 increased and the expression level of miR-92a-3p in the venous tissues significantly decreased and was negatively correlated with that of HO-1. The levels of p38MAPK and NF-κB p65 significantly decreased but that of P- IκBa and IκBa significantly increased.

CONCLUSION

Resistance exercise intervention downregulated miR-92a-3p expression, repaired oxidative stress injury and prevented CRT formation.

Epigenetic Alterations in Pediatric Sleep Apnea

Pediatric obstructive sleep apnea has significant negative effects on health and behavior in childhood including depression, failure to thrive, neurocognitive impairment, and behavioral issues. It is strongly associated with an increased risk for chronic adult disease such as obesity and diabetes, accelerated atherosclerosis, and endothelial dysfunction. Accumulating evidence suggests that adult-onset non-communicable diseases may originate from early life through a process by which an insult applied at a critical developmental window causes long-term effects on the structure or function of an organism. In recent years, there has been increased interest in the role of epigenetic mechanisms in the pathogenesis of adult disease susceptibility. Epigenetic mechanisms that influence adaptive variability include histone modifications, non-coding RNAs, and DNA methylation. This review will highlight what is currently known about the phenotypic associations of epigenetic modifications in pediatric obstructive sleep apnea and will emphasize the importance of epigenetic changes as both modulators of chronic disease and potential therapeutic targets.

Gout-induced endothelial impairment: The role of SREBP2 transactivation of YAP

Gout is a multifaceted inflammatory disease involving vascular impairments induced by hyperuricemia. Experiments using human umbilical vein endothelial cells treated with uric acid (UA), monosodium urate (MSU), or serum from gout patients showed increased expression of pro-inflammatory genes (ie, VCAM1, ICAM1, CYR61, CCNA1, and E2F1) with attendant increase in monocyte adhesion. Mechanistically, UA- or MSU-induced SREBP2 expression and its transcriptional activity. RNA sequencing analysis and real-time PCR showed the induction of YAP signaling and pro-inflammatory pathways in HUVECs transfected with adenovirus-SREBP2. The SREBP2 knockdown by siRNA partially abolished UA- or MSU-induced YAP activity, pro-inflammatory gene expression, and monocytes adhesion. Vascular intima from transgenic mice overexpressing SREBP2 in endothelium or mice with hyperuricemia exhibited activated YAP signaling and increased expression of pro-inflammatory genes. Betulin, an SREBP pharmacological inhibitor, attenuated the UA-, MSU-, or gout serum-induced endothelial cell inflammation and dysfunction. In the human study, endothelial cell function, assessed by EndoPAT, was negatively correlated with serum UA level among gouty patients and healthy controls. Collectively, UA or MSU causes endothelial dysfunction via SREBP2 transactivation of YAP. Betulin inhibition of SREBP2 may restrain gout-induced endothelial dysfunction.

MicroRNA-494 Regulates Endoplasmic Reticulum Stress in Endothelial Cells

Defects in stress responses are important contributors in many chronic conditions including cancer, cardiovascular disease, diabetes, and obesity-driven pathologies like non-alcoholic steatohepatitis (NASH). Specifically, endoplasmic reticulum (ER) stress is linked with these pathologies and control of ER stress can ameliorate tissue damage. MicroRNAs have a critical role in regulating diverse stress responses including ER stress. Here, we show that miR-494 plays a functional role during ER stress. Pharmacological ER stress inducers (tunicamycin (TCN) and thapsigargin) and hyperglycemia robustly increase the expression of miR-494 in vitro. ATF6 impacts the primary miR-494 levels whereas all three ER stress pathways are necessary for the increase in mature miR-494. Surprisingly, miR-494 pretreatment dampens the induction and magnitude of ER stress in response to TCN in endothelial cells and increases cell viability. Conversely, inhibition of miR-494 increases ER stress de novo and amplifies the effects of ER stress inducers. Using Mass Spectrometry (TMT-MS) we identified 23 proteins that are downregulated by both TCN and miR-494 in cultured human umbilical vein endothelial cells. Among these, we found 6 transcripts which harbor a putative miR-494 binding site. We validated the anti-apoptotic gene BIRC5 (survivin) and GINS4 as targets of miR-494 during ER stress. In summary, our data indicates that ER stress driven miR-494 may act in a feedback inhibitory loop to dampen downstream ER stress signaling.

NRF2-mediated signaling is a master regulator of transcription factors in bovine granulosa cells under oxidative stress condition

Transcription factors (TFs) are known to be involved in regulating the expression of several classes of genes during folliculogenesis. However, the regulatory role of TFs during oxidative stress (OS) is not fully understood. The current study was aimed to investigate the regulation of the TFs in bovine granulosa cells (bGCs) during exposure to OS induced by H₂O₂ in vitro. For this, bGCs derived from ovarian follicles were cultured in vitro till their confluency and then treated with H₂O₂ for 40 min. Twenty-four hours later, cells were subjected to various phenotypic and gene expression analyses for genes related to TFs, endoplasmic reticulum stress, apoptosis, cell proliferation, and differentiation markers. The bGCs exhibited higher reactive oxygen species accumulation, DNA fragmentation, and endoplasmic reticulum stress accompanied by reduction of mitochondrial activity after exposure to OS. In addition, higher lipid accumulation and lower cell proliferation were noticed in H₂O₂-challenged cells. The mRNA level of TFs including NRF2, E2F1, KLF6, KLF9, FOS, SREBF1, SREBF2, and NOTCH1 was increased in H₂O₂-treated cells compared with non-treated controls. However, the expression level of KLF4 and its downstream gene, CCNB1, were downregulated in the H₂O₂-challenged group. Moreover, targeted inhibition of NRF2 using small interference RNA resulted in reduced expression of KLF9, FOS, SREBF2, and NOTCH1 genes, while the expression of KLF4 was upregulated. Taken together, bovine granulosa cells exposed to OS exhibited differential expression of various transcription factors, which are mediated by the NRF2 signaling pathway.

Altered endothelial dysfunction-related miRs in plasma from ME/CFS patients

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by unexplained debilitating fatigue. Although the etiology is unknown, evidence supports immunological abnormalities, such as persistent inflammation and immune-cell activation, in a subset of patients. Since the interplay between inflammation and vascular alterations is well-established in other diseases, endothelial dysfunction has emerged as another player in ME/CFS pathogenesis. Endothelial nitric oxide synthase (eNOS) generates nitric oxide (NO) that maintains endothelial homeostasis. eNOS is activated by silent information regulator 1 (Sirt1), an anti-inflammatory protein. Despite its relevance, no study has addressed the Sirt1/eNOS axis in ME/CFS. The interest in circulating microRNAs (miRs) as potential biomarkers in ME/CFS has increased in recent years. Accordingly, we analyze a set of miRs reported to modulate the Sirt1/eNOS axis using plasma from ME/CFS patients. Our results show that miR-21, miR-34a, miR-92a, miR-126, and miR-200c are jointly increased in ME/CFS patients compared to healthy controls. A similar finding was obtained when analyzing public miR data on peripheral blood mononuclear cells. Bioinformatics analysis shows that endothelial function-related signaling pathways are associated with these miRs, including oxidative stress and oxygen regulation. Interestingly, histone deacetylase 1, a protein responsible for epigenetic regulations, represented the most relevant node within the network. In conclusion, our study provides a basis to find endothelial dysfunction-related biomarkers and explore novel targets in ME/CFS.

Focal Adhesion Kinase Inhibitor Inhibits the Oxidative Damage Induced by Central Venous Catheter via Abolishing Focal Adhesion Kinase-Protein Kinase B Pathway Activation

The vascular injury induced by central venous catheter (CVC) indwelling is the basis for the occurrence and development of CVC-related complications, such as phlebitis, venous thrombosis, and catheter-related infections. Focal adhesion kinase (FAK) and FAK-protein kinase B (AKT) signaling pathway are of great significance in tissue repair after trauma. Here, we investigated the role and mechanism of the FAK inhibitor (1,2,4,5-phenyltetramine tetrahydrochloride (Y15)) in oxidative damage caused by CVC. EA.hy926 cells were divided into the control group (normal control), CVCs+scratches group (the intercepted CVC segments coculturing with scratched EA.hy926 cells), and CVCs+scratches+Y15 group (Y15 was added to the cell culture supernatant with CVCs + scratches at a final concentration of 50 μmol·L⁻¹). New Zealand rabbits were randomly divided into the control group (normal control), CVC group (CVC was inserted through the rabbit's right jugular vein to the junction of the right atrium and superior vena cava), and CVC+Y15 group (CVC was immersed in a 50 μmol·L⁻¹ Y15 solutions before insertion). The levels of markers and proteins related to oxidative damage in cells, cell culture supernatant, serum, and external jugular vein were measured by commercial kits and western blot, respectively. We found that Y15 treatment significantly decreased ROS and MDA levels and increased cell viability, NO, and SOD levels in a time-dependent manner in rabbit serum and cell culture supernatant. In addition, Y15 effectively reduced the CVC-induced pathological changes of damaged vascular tissues. Y15 also downregulated the levels of p-FAK Tyr 397 and p-Akt Ser 473 in damaged external jugular vein and EA.hy926 cells. These findings suggest that Y15 alleviated CVC-induced oxidative damage to blood vessels by suppressing focal FAK-Akt pathway activation.

A Fundamental Role for Oxidants and Intracellular Calcium Signals in Alzheimer's Pathogenesis-And How a Comprehensive Antioxidant Strategy May Aid Prevention of This Disorder

Oxidative stress and increased cytoplasmic calcium are key mediators of the detrimental effects on neuronal function and survival in Alzheimer's disease (AD). Pathways whereby these perturbations arise, and then prevent dendritic spine formation, promote tau hyperphosphorylation, further amplify amyloid β generation, and induce neuronal apoptosis, are described. A comprehensive program of nutraceutical supplementation, comprised of the NADPH oxidase inhibitor phycocyanobilin, phase two inducers, the mitochondrial antioxidant astaxanthin, and the glutathione precursor N-acetylcysteine, may have important potential for antagonizing the toxic effects of amyloid β on neurons and thereby aiding prevention of AD. Moreover, nutraceutical antioxidant strategies may oppose the adverse impact of amyloid β oligomers on astrocyte clearance of glutamate, and on the ability of brain capillaries to export amyloid β monomers/oligomers from the brain. Antioxidants, docosahexaenoic acid (DHA), and vitamin D, have potential for suppressing microglial production of interleukin-1β, which potentiates the neurotoxicity of amyloid β. Epidemiology suggests that a health-promoting lifestyle, incorporating a prudent diet, regular vigorous exercise, and other feasible measures, can cut the high risk for AD among the elderly by up to 60%. Conceivably, complementing such lifestyle measures with long-term adherence to the sort of nutraceutical regimen outlined here may drive down risk for AD even further.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

Circulating microRNA changes in patients with impaired glucose regulation

We analysed if levels of four miRNAs would change after a lifestyle intervention involving dietary and exercises in prediabetes. MiRNAs previously shown to be associated with diabetes (Let-7a, Let-7e, miR-144 and miR-92a) were extracted from serum pre- and post-intervention. mRNA was extracted from fat-tissue for gene expression analyses. The intervention resulted in increased Let-7a and miR-92a. We found correlations between miRNAs and clinical variables (triglycerides, cholesterol, insulin, weight and BMI). We also found correlations between miRNAs and target genes, revealing a link between miR-92a and IGF system. A lifestyle intervention resulted in marked changes in miRNAs. The association of miRNAs with insulin and the IGF system (both receptors and binding proteins) may represent a mechanism of regulating IGFs metabolic actions.

Hsa-miRNA-23a-3p promotes atherogenesis in a novel mouse model of atherosclerosis

Of the known regulators of atherosclerosis, miRNAs have been demonstrated to play critical roles in lipoprotein homeostasis and plaque formation. Here, we generated a novel animal model of atherosclerosis by knocking in LDLRW483X in C57BL/6 mice, as the W483X mutation in LDLR is considered the most common newly identified pathogenic mutation in Chinese familial hypercholesterolemia (FH) individuals. Using the new in vivo mouse model combined with a well-established atherosclerotic in vitro human cell model, we identified a novel atherosclerosis-related miRNA, miR-23a-3p, by microarray analysis of mouse aortic tissue specimens and human aortic endothelial cells (HAECs). miR-23a-3p was consistently downregulated in both models, which was confirmed by qPCR. Bioinformatics analysis and further validation experiments revealed that the TNFα-induced protein 3 (TNFAIP3) gene was the key target of miR-23a-3p. The miR-23a-3p-related functional pathways were then analyzed in HAECs. Collectively, the present results suggest that miR-23a-3p regulates inflammatory and apoptotic pathways in atherogenesis by targeting TNFAIP3 through the NF-κB and p38/MAPK signaling pathways.

Reactive oxygen species regulate miR-17-5p expression via DNA methylation in paraquat-induced nerve cell damage

There is emerging evidence suggesting that oxidative stress and DNA methylation can alter miRNA expression. However, little is known on the mechanism of miR-17-5p expression changes in paraquat (PQ)-induced nerve cell damage. In the present study, neuro-2a cells were pretreated with antioxidant N-acetylcysteine (NAC) or DNA methylation inhibitor decitabine (DAC), then exposed to different concentrations of PQ, while the expression levels of miR-17-5p were detected by qRT-PCR. Here, it is showed that PQ downregulated the expression of miR-17-5p dose-dependently in neuro-2a cells. The DNA methylation level was upregulated after PQ exposure, while downregulated with the pretreatment of NAC in the above content, detected by 5-mC immunofluorescence technique. The interaction effect of NAC and PQ in alternating DNA methylation level was further confirmed by flow cytometry. NAC and DAC individually had an interaction effect in PQ-induced nerve cell damage. After using NAC, PQ-induced ROS elevation and DNA methylation are reduced, thereby preventing the proapoptotic effect of miR-17-5p. Above all, PQ can induce DNA methylation variations through ROS production, leading to the downregulation of miR-17-5p expression in PQ-induced nerve cell damage.

AIBP, Angiogenesis, Hematopoiesis, and Atherogenesis

PURPOSE OF REVIEW

The goal of this manuscript is to summarize the current understanding of the secreted APOA1 binding protein (AIBP), encoded by NAXE, in angiogenesis, hematopoiesis, and inflammation. The studies on AIBP illustrate a critical connection between lipid metabolism and the aforementioned endothelial and immune cell biology.

RECENT FINDINGS

AIBP dictates both developmental processes such as angiogenesis and hematopoiesis, and pathological events such as inflammation, tumorigenesis, and atherosclerosis. Although cholesterol efflux dictates AIBP-mediated lipid raft disruption in many of the cell types, recent studies document cholesterol efflux-independent mechanism involving Cdc42-mediated cytoskeleton remodeling in macrophages. AIBP disrupts lipid rafts and impairs raft-associated VEGFR2 but facilitates non-raft-associated NOTCH1 signaling. Furthermore, AIBP can induce cholesterol biosynthesis gene SREBP2 activation, which in turn transactivates NOTCH1 and supports specification of hematopoietic stem and progenitor cells (HSPCs). In addition, AIBP also binds TLR4 and represses TLR4-mediated inflammation. In this review, we summarize the latest research on AIBP, focusing on its role in cholesterol metabolism and the attendant effects on lipid raft-regulated VEGFR2 and non-raft-associated NOTCH1 activation in angiogenesis, SREBP2-upregulated NOTCH1 signaling in hematopoiesis, and TLR4 signaling in inflammation and atherogenesis. We will discuss its potential therapeutic applications in angiogenesis and inflammation due to selective targeting of activated cells.

NOX5-induced uncoupling of endothelial NO synthase is a causal mechanism and theragnostic target of an age-related hypertension endotype

Hypertension is the most important cause of death and disability in the elderly. In 9 out of 10 cases, the molecular cause, however, is unknown. One mechanistic hypothesis involves impaired endothelium-dependent vasodilation through reactive oxygen species (ROS) formation. Indeed, ROS forming NADPH oxidase (Nox) genes associate with hypertension, yet target validation has been negative. We re-investigate this association by molecular network analysis and identify NOX5, not present in rodents, as a sole neighbor to human vasodilatory endothelial nitric oxide (NO) signaling. In hypertensive patients, endothelial microparticles indeed contained higher levels of NOX5—but not NOX1, NOX2, or NOX4—with a bimodal distribution correlating with disease severity. Mechanistically, mice expressing human Nox5 in endothelial cells developed—upon aging—severe systolic hypertension and impaired endothelium-dependent vasodilation due to uncoupled NO synthase (NOS). We conclude that NOX5-induced uncoupling of endothelial NOS is a causal mechanism and theragnostic target of an age-related hypertension endotype. Nox5 knock-in (KI) mice represent the first mechanism-based animal model of hypertension.

The causes of hypertension are not understood; treatments are symptomatic and prevent only few of the associated risks. This study applies network medicine to identify a subgroup of patients with NADPH oxidase 5-induced uncoupling of nitric oxide synthase as the cause of age-related hypertension, enabling a first-in-class mechanism-based treatment of hypertension.

Targeting the renin angiotensin system for the treatment of anxiety and depression

Emotional disorders like anxiety and depression are responsible for considerable morbidity and mortality all over the world. Several antidepressant and anxiolytic medications are available for the treatment of anxiety and depression. However, a significant number of patients either do not respond to these medications or respond inadequately. Hence, there is a need to identify novel targets for the treatment of anxiety and depression. In this review we focus on the renin angiotensin system (RAS) as a potential target for the treatment of these disorders. We review work that has evaluated the effects of various compounds targeting the RAS on anxiety- and depression-like behaviors. Further, we suggest future work that must be carried out to fully exploit the RAS for the treatment of anxiety and depression. The RAS provides an attractive target for both the identification of novel anxiolytic and antidepressant medications and/or for enhancing the efficacy of currently available medications used for the treatment of anxiety and depression.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.

The role of oxidized phospholipids in the development of disease

Oxidized phospholipids (OxPLs), complex mixtures of phospholipid oxidation products generated during normal or pathological processes, are increasingly recognized to show bioactive effects on many cellular signalling pathways. There is a growing body of evidence showing that OxPLs play an important role in many diseases, so it is essential to define the specific role of OxPLs in different diseases for the design of disease therapies. In vastly diverse pathological processes, OxPLs act as pro-inflammatory agents and contribute to the progression of many diseases; in addition, they play a role in anti-inflammatory processes, promoting the dissipation of inflammation and inhibiting the progression of some diseases. In addition to participating in the regulation of inflammatory responses, OxPLs affect the occurrence and development of diseases through other pathways, such as apoptosis promotion. In this review, the different and even opposite effects of different OxPL molecular species are discussed. Furthermore, the specific effects of OxPLs in various diseases, as well as the receptor and cellular mechanisms involved, are summarized.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

NLRP3 inflammasome in endothelial dysfunction

Inflammasomes are a class of cytosolic protein complexes. They act as cytosolic innate immune signal receptors to sense pathogens and initiate inflammatory responses under physiological and pathological conditions. The NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex. Its activation triggers the cleavage of pro-interleukin (IL)-1β and pro-IL-18, which are mediated by caspase-1, and secretes mature forms of these mediators from cells to promote the further inflammatory process and oxidative stress. Simultaneously, cells undergo pro-inflammatory programmed cell death, termed pyroptosis. The danger signals for activating NLRP3 inflammasome are very extensive, especially reactive oxygen species (ROS), which act as an intermediate trigger to activate NLRP3 inflammasome, exacerbating subsequent inflammatory cascades and cell damage. Vascular endothelium at the site of inflammation is actively involved in the regulation of inflammation progression with important implications for cardiovascular homeostasis as a dynamically adaptable interface. Endothelial dysfunction is a hallmark and predictor for cardiovascular ailments or adverse cardiovascular events, such as coronary artery disease, diabetes mellitus, hypertension, and hypercholesterolemia. The loss of proper endothelial function may lead to tissue swelling, chronic inflammation, and the formation of thrombi. As such, elimination of endothelial cell inflammation or activation is of clinical relevance. In this review, we provided a comprehensive perspective on the pivotal role of NLRP3 inflammasome activation in aggravating oxidative stress and endothelial dysfunction and the possible underlying mechanisms. Furthermore, we highlighted the contribution of noncoding RNAs to NLRP3 inflammasome activation-associated endothelial dysfunction, and outlined potential clinical drugs targeting NLRP3 inflammasome involved in endothelial dysfunction. Collectively, this summary provides recent developments and perspectives on how NLRP3 inflammasome interferes with endothelial dysfunction and the potential research value of NLRP3 inflammasome as a potential mediator of endothelial dysfunction.

NLRP3 sparks the Greek fire in the war against lipid-related diseases

In recent years, the obesity rate worldwide has reached epidemic proportions and contributed to the growing prevalence of lipid-related diseases. A strong link between inflammation and metabolism is becoming increasingly evident. Compelling evidence has indicated the activation of the nucleotide-binding and oligomerization domain-like receptor, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome, a cytoplasmic complex containing multiple proteins, in a variety of lipid-related diseases including obesity, atherosclerosis, liver diseases, and type 2 diabetes. Recent studies have further clarified the regulatory mechanisms and the optional therapeutic agents that target NLRP3 inflammasomes. In this study, we review the recent progress in the research on NLRP3 inflammasomes and discuss their implications for a better understanding of inflammation in lipid-related disease and the prospects of targeting the NLRP3 inflammasome for therapeutic intervention.

Neointimal hyperplasia in the inferior vena cava of adenine-induced chronic kidney disease rats with aortocaval fistulas

BACKGROUND

The failure of autologous arteriovenous fistulas (AVFs) occurs primarily due to stenosis in the anastomotic site, which is mainly related to the development of neointimal hyperplasia (NIH). Therefore, we conducted a study to establish a novel approach to create aortocaval fistulas (ACFs) in adenine-induced (AD) chronic kidney disease (CKD) rats to study the NIH in the inferior vena cava.

METHODS

Ten adult female rats received a 0.75% adenine-rich diet for 4 weeks to induce CKD and underwent ACF surgery. Ten healthy rats served as controls. A 5-10-mm segment of a vein immediately adjacent to that the portion of the vein used for creating the fistula was surgically removed at the time of creating the fistula, and reconstruction of the failed fistula from the same patient was used as controls. ACF was assessed using duplex scans and histopathological analyses.

RESULTS

At the end of the experiment, AD rats showed higher serum creatinine and urea nitrogen than those of vehicle-treated rats. Remarkable histological changes in kidney tissues demonstrated successful CKD models. Sections of the ACF in AD rats and veins removed at the time of the reconstruction of the failed fistula of the patient demonstrated that the eccentric neointima formation is irregularly thickened, with several small vessels within a more cellular region of the neointima. Immunohistochemistry demonstrated the presence of myofibroblasts, contractile smooth muscle cells and macrophages within the neointima.

CONCLUSIONS

Our rat models with ACFs showed typical features of NIH in the formation of fistula stenosis, which can resemble clinical findings in uremic patients.

The sterol regulatory element binding protein homolog of Penaeus vannamei modulates fatty acid metabolism and immune response

The sterol regulatory element binding proteins (SREBPs) transcription factors family, which regulate the expression of genes involved in cellular lipid metabolism and homeostasis, have recently been implicated in various physiological and pathophysiological processes such as immune regulation and inflammation in vertebrates. Consistent with other invertebrates, we identified a single SREBP ortholog in Penaeus vannamei (designated PvSREBP) with transcripts ubiquitously expressed in tissues and induced by lipopolysaccharide (LPS), Vibrio parahaemolyticus and Streptococcus iniae. In vivo RNA interference (RNAi) of PvSREBP attenuated the expression of several fatty acid metabolism-related genes (i.e., cyclooxygenase (PvCOX), lipoxygenase (PvLOX), fatty acid binding protein (PvFABP) and fatty acid synthase (PvFASN)), which consequently decreased the levels of total polyunsaturated fatty acids (ΣPUFAs). In addition, PvSREBP silencing decreased transcript levels of several immune-related genes such as hemocyanin (PvHMC) and trypsin (PvTrypsin), as well as genes encoding for heat-shock proteins (i.e., PvHSP60, PvHSP70 and PvHSP90). Moreover, in silico analysis revealed the presence of SREBP binding motifs on the promoters of most of the dysregulated genes, while shrimp depleted of PvSREBP were more susceptible to V. parahaemolyticus infection. Collectively, we demonstrated the involvement of shrimp SREBP in fatty acids metabolism and immune response, and propose that PvSREBP and PvHMC modulate each other through a feedback mechanism to establish homeostasis. The current study is the first to show the dual role of SREBP in fatty acid metabolism and immune response in invertebrates and crustaceans.

Suppression of Endothelial AGO1 Promotes Adipose Tissue Browning and Improves Metabolic Dysfunction

BACKGROUND

Metabolic disorders such as obesity and diabetes mellitus can cause dysfunction of endothelial cells (ECs) and vascular rarefaction in adipose tissues. However, the modulatory role of ECs in adipose tissue function is not fully understood. Other than vascular endothelial growth factor-vascular endothelial growth factor receptor-mediated angiogenic signaling, little is known about the EC-derived signals in adipose tissue regulation. We previously identified Argonaute 1 (AGO1; a key component of microRNA-induced silencing complex) as a crucial regulator in hypoxia-induced angiogenesis. In this study, we intend to determine the AGO1-mediated EC transcriptome, the functional importance of AGO1-regulated endothelial function in vivo, and the relevance to adipose tissue function and obesity.

METHODS

We generated and subjected mice with EC-AGO1 deletion (EC-AGO1-knockout [KO]) and their wild-type littermates to a fast food-mimicking, high-fat high-sucrose diet and profiled the metabolic phenotypes. We used crosslinking immunoprecipitation- and RNA-sequencing to identify the AGO1-mediated mechanisms underlying the observed metabolic phenotype of EC-AGO1-KO. We further leveraged cell cultures and mouse models to validate the functional importance of the identified molecular pathway, for which the translational relevance was explored using human endothelium isolated from healthy donors and donors with obesity/type 2 diabetes mellitus.

RESULTS

We identified an antiobesity phenotype of EC-AGO1-KO, evident by lower body weight and body fat, improved insulin sensitivity, and enhanced energy expenditure. At the organ level, we observed the most significant phenotype in the subcutaneous and brown adipose tissues of KO mice, with greater vascularity and enhanced browning and thermogenesis. Mechanistically, EC-AGO1 suppression results in inhibition of thrombospondin-1 (THBS1/TSP1), an antiangiogenic and proinflammatory cytokine that promotes insulin resistance. In EC-AGO1-KO mice, overexpression of TSP1 substantially attenuated the beneficial phenotype. In human endothelium isolated from donors with obesity or type 2 diabetes mellitus, AGO1 and THBS1 are expressed at higher levels than the healthy controls, supporting a pathological role of this pathway.

CONCLUSIONS

Our study suggests a novel mechanism by which ECs, through the AGO1-TSP1 pathway, control vascularization and function of adipose tissues, insulin sensitivity, and whole-body metabolic state.

Hematopoiesis is regulated by cholesterol efflux pathways and lipid rafts: connections with cardiovascular diseases

Lipid rafts are highly ordered regions of the plasma membrane that are enriched in cholesterol and sphingolipids and play important roles in many cells. In hematopoietic stem and progenitor cells (HSPCs), lipid rafts house receptors critical for normal hematopoiesis. Lipid rafts also can bind and sequester kinases that induce negative feedback pathways to limit proliferative cytokine receptor cycling back to the cell membrane. Modulation of lipid rafts occurs through an array of mechanisms, with optimal cholesterol efflux one of the major regulators. As such, cholesterol homeostasis also regulates hematopoiesis. Increased lipid raft content, which occurs in response to changes in cholesterol efflux in the membrane, can result in prolonged receptor occupancy in the cell membrane and enhanced signaling. In addition, certain diseases, like diabetes, may contribute to lipid raft formation and affect cholesterol retention in rafts. In this review, we explore the role of lipid raft-related mechanisms in hematopoiesis and CVD (specifically, atherosclerosis) and discuss how defective cholesterol efflux pathways in HSPCs contribute to expansion of lipid rafts, thereby promoting myelopoiesis and thrombopoiesis. We also discuss the utility of cholesterol acceptors in contributing to lipid raft regulation and disruption, and highlight the potential to manipulate these pathways for therapeutic gain in CVD as well as other disorders with aberrant hematopoiesis.jlr;61/5/667/F1F1f1.

Sirtuins family as a target in endothelial cell dysfunction: implications for vascular ageing

The vascular endothelium is a protective barrier between the bloodstream and the vasculature that may be disrupted by different factors such as the presence of diseased states. Diseases like diabetes and obesity pose a great risk toward endothelial cell inflammation and oxidative stress, leading to endothelial cell dysfunction and thereby cardiovascular complications such as atherosclerosis. Sirtuins are NAD⁺-dependent histone deacetylases that are implicated in the pathophysiology of cardiovascular diseases, and they have been identified to be important regulators of endothelial cell function. A handful of recent studies suggest that disbalance in the regulation of endothelial sirtuins, mainly sirtuin 1 (SIRT1), contributes to endothelial cell dysfunction. Herein, we summarize how SIRT1 and other sirtuins may contribute to endothelial cell function and how presence of diseased conditions may alter their expressions to cause endothelial dysfunction. Moreover, we discuss how the beneficial effects of exercise on the endothelium are dependent on SIRT1. These mainly include regulation of signaling pathways related to endothelial nitric oxide synthase phosphorylation and nitric oxide production, mitochondrial biogenesis and mitochondria-mediated apoptotic pathways, oxidative stress and inflammatory pathways. Sirtuins as modulators of the adverse conditions in the endothelium hold a promising therapeutic potential for health conditions related to endothelial dysfunction and vascular ageing.

Role of miR-92a-3p, oxidative stress, and p38MAPK/NF-κB pathway in rats with central venous catheter related thrombosis

BACKGROUND

miR-92a-3p and oxidative stress are reportedly associated with venous thrombosis. However, the role of miR-92a-3p and oxidative stress in catheter-related thrombosis (CRT) remains ambiguous. Herein, we studied the roles of miR-92a-3p, oxidative stress, and p38-mitogen-activated protein kinase/nuclear factor kappa-B (MAPK/NF-κB) pathway in CRT.

METHODS

Forty-five male rats were randomly and equally divided into control, sham operation, and CRT groups. The rats were sacrificed after 10 days. Reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in the serum were determined by enzyme-linked immunosorbent assay (ELISA). The expression levels of miR-92a-3p, heme oxygenase-1 (HO-1), NF-κB p65, and p38 MAPK in the venous tissues were detected with quantitative polymerase chain reaction (qPCR) and Western blot.

RESULTS

Thrombosis was observed only in the CRT group. Compared with the levels in the control and sham operation groups, ROS and MDA significantly increased in the CRT group, but SOD significantly decreased. qPCR and Western blot results showed that miR-92a-3p, HO-1, p38 MAPK, and NF-κB p65 expression was significantly upregulated in the venous tissues of the CRT group. Moreover, miR-92a-3p was positively correlated with HO-1, which was positively correlated with p38 MAPK and NF-κB p65.

CONCLUSION

miR-92a-3p was correlated with oxidative stress in CRT. miR-92a-3p and oxidative stress contributed to endothelial dysfunction and simultaneously was associated with CRT.

Endothelial mechanobiology

Lining the luminal surface of the vasculature, endothelial cells (ECs) are in direct contact with and differentially respond to hemodynamic forces depending on their anatomic location. Pulsatile shear stress (PS) is defined by laminar flow and is predominantly located in straight vascular regions, while disturbed or oscillatory shear stress (OS) is localized to branch points and bifurcations. Such flow patterns have become a central focus of vascular diseases, such as atherosclerosis, because the focal distribution of endothelial dysfunction corresponds to regions exposed to OS, whereas endothelial homeostasis is maintained in regions defined by PS. Deciphering the mechanotransduction events that occur in ECs in response to differential flow patterns has required the innovation of multidisciplinary approaches in both in vitro and in vivo systems. The results from these studies have identified a multitude of shear stress-regulated molecular networks in the endothelium that are implicated in health and disease. This review outlines the significance of scientific findings generated in collaboration with Dr. Shu Chien.

Serum miR-92a is Elevated in Children and Adults with Obstructive Sleep Apnea

BACKGROUND

Obstructive Sleep Apnea (OSA) is a highly prevalent condition that is associated with several comorbidities including cardiovascular disease (CVD). Recent studies have revealed mixed results as to whether standard OSA therapy reverses CVD in adult patients. Thus, many advocate for earlier recognition of OSA induced CVD, as early as childhood, to prompt treatment antecedent to the onset of irreversible CVD. Here we investigated if the serum level of miR-92a, a known biomarker for CVD, can be used to identify patients with OSA in both children and adults.

METHODS

Consecutive snoring patients undergoing polysomnography were recruited for determination of circulating miR-92a, in addition to inflammatory and metabolic profiles. We assessed whether circulating miR-92a was associated with OSA severity.

RESULTS

Using two separate cohorts of adults (n=57) and children (n=13), we report a significant increase in the serum level of miR-92a in patients with severe OSA (p=0.021) and further demonstrate a significant correlation (Spearman rank correlation 0.308, p=0.010) with serum miR-92a levels and the apnea hypopnea index (AHI), a primary measure of OSA severity. Stepwise regression analysis revealed that serum miR-92a levels were independently associated with AHI (ß=0.332, p=0.003), age (ß=0.394, p=0.002) and LDL cholesterol levels (ß=0.368, p=0.004).

CONCLUSION

Our study is the first to establish that miR-92a is a useful biomarker for OSA severity in both children and adults. Given the canonical role of miR-92a on endothelial dysfunction, miR-92a may be useful to identify early onset CVD in OSA patients or stratify patient CVD risk to identify those that may benefit from earlier OSA treatment.