Metabolic memory: mechanisms and diseases

Metabolic diseases and their complications impose health and economic burdens worldwide. Evidence from past experimental studies and clinical trials suggests our body may have the ability to remember the past metabolic environment, such as hyperglycemia or hyperlipidemia, thus leading to chronic inflammatory disorders and other diseases even after the elimination of these metabolic environments. The long-term effects of that aberrant metabolism on the body have been summarized as metabolic memory and are found to assume a crucial role in states of health and disease. Multiple molecular mechanisms collectively participate in metabolic memory management, resulting in different cellular alterations as well as tissue and organ dysfunctions, culminating in disease progression and even affecting offspring. The elucidation and expansion of the concept of metabolic memory provides more comprehensive insight into pathogenic mechanisms underlying metabolic diseases and complications and promises to be a new target in disease detection and management. Here, we retrace the history of relevant research on metabolic memory and summarize its salient characteristics. We provide a detailed discussion of the mechanisms by which metabolic memory may be involved in disease development at molecular, cellular, and organ levels, with emphasis on the impact of epigenetic modulations. Finally, we present some of the pivotal findings arguing in favor of targeting metabolic memory to develop therapeutic strategies for metabolic diseases and provide the latest reflections on the consequences of metabolic memory as well as their implications for human health and diseases.

Long-term outcomes of offspring from multiple gestations: a two-sample Mendelian randomization study on multi-system diseases using UK Biobank and FinnGen databases

BACKGROUND

Assisted reproductive technologies (ART) have increased the incidence of multiple births, which can have a negative impact on maternal and offspring health. The study aimed to investigate the association between genetically predicted multiple birth and the risk of 42 common diseases of the nervous, psychiatric, cardiovascular, respiratory, digestive, and endocrine systems.

METHODS

The study utilized two-sample Mendelian randomization (MR) analysis to explore the potential causal relationship between genetically predicted multiple birth and the genetically predicted risk of diseases. The study used the FinnGen and UK Biobank datasets for analysis.

RESULTS

The study found no significant causal relationship between multiple birth and psychiatric disorders. However, the lower limits of the 95% confidence intervals for bipolar affective disorder and anxiety disorders were not robust, indicating a need for further investigation. The study found that multiple birth may be a strong risk factor for infantile cerebral palsy, and caution is necessary in both natural and ART multiple births. The study revealed a potential causal relationship between multiple birth and coronary heart disease, ischemic heart disease, and deep vein thrombosis, which may be related to abnormal intrauterine environments in multiple pregnancies. Surprisingly, multiple birth appears to have a protective effect against some respiratory diseases, such as chronic obstructive pulmonary disease and asthma.

CONCLUSIONS

The study highlights the need for caution regarding the risk of infantile cerebral palsy, cardiovascular diseases, and psychiatric disorders in multiple birth. Our study can lead to the development of preventive strategies and improved clinical management for affected infants.

Profile analysis of differentially expressed long non‑coding RNAs in metabolic memory induced by high glucose in human umbilical vein endothelial cells

Numerous long non-coding RNAs (lncRNAs) are dysregulated in the hyperglycemia-induced phenomenon of metabolic memory (MM). In the present study, the significance of these lncRNAs in MM was explored by screening for MM-involved differentially expressed lncRNAs (MMDELs) in human umbilical vein endothelial cells (HUVECs) induced by high glucose. A total of nine HUVEC samples were divided into three groups to mimic conditions of low and high glucose environments, as well as induce the state of metabolic memory. The expression of lncRNAs was profiled using RNA sequencing. Bioinformatic analysis was performed using the Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes databases to explore the parental genes from which the lncRNAs are transcribed and target genes of the MMDELs and generate enrichment datasets. Reverse transcription-quantitative PCR was performed to validate the expression levels of the selected lncRNAs. The present study identified 308 upregulated and 157 downregulated MMDELs, which were enriched in numerous physiologic processes. Key functional enrichment terms included 'cell cycle', 'oocyte meiosis' and 'p53 signaling pathway'. In conclusion, certain MMDELs may regulate the expression level of highly associated mRNAs through various mechanisms and pathways, thereby interfering with several processes, such as the regulation of the cell cycle, and affecting vascular endothelial cell function. Furthermore, the disorders of these lncRNAs can be retained in MM, further investigation into the functions of these lncRNAs may result in novel insights and treatments, which could help control MM in patients with diabetes.

LncRNA LYPLAL1-DT screening from type 2 diabetes with macrovascular complication contributes protective effects on human umbilical vein endothelial cells via regulating the miR-204-5p/SIRT1 axis

Long noncoding RNAs (lncRNAs) are involved in diabetes related diseases. However, the role of lncRNAs in the pathogenesis of type 2 diabetes with macrovascular complication (DMC) has seldomly been recognized. This study screened lncRNA profiles of leukocytes from DMC patients and explored protective role of lncRNA LYPLAL1-DT in endothelial cells (EC) under high glucose (HG) and inflammatory conditions (IS). Between DMC and healthy controls, 477 differential expression lncRNAs (DE-lncRNAs) were identified. The enrichment and pathway analysis showed that most of the DE-lncRNAs belonged to inflammatory, metabolic, and vascular diseases. A total of 12 lncRNAs was validated as significant DE-lncRNAs in expanding cohorts. Furthermore, these DE-lncRNAs were shown to be significantly related to hypoxia, HG, and IS in EC, especially lncRNA LYPLAL1-DT. LYPLAL1-DT overexpression results in the promotion of the proliferation, and migration of EC, as well as an elevation of autophagy. Overexpressed LYPLAL1-DT reduces the adhesion of monocytes to EC, boosts anti-inflammation, and suppresses inflammatory molecules secreted in the medium. Mechanistically, LYPLAL1-DT acts as competing endogenous RNA (ceRNA) by downregulating miR-204-5p, therefore enhancing SIRT1 and protecting EC autophagy function; thus, alleviating apoptosis. Finally, exosome sequencing revealed LYPLAL1-DT expression was 4 times lower in DMC cells than in healthy samples. In general, we identified LYPLAL1-DT having protective effects on EC as ceRNA mediated through the miR-204-5p/SIRT1 pathway. Therefore, it inhibits the autophagy of EC as well as modulating systemic inflammation. This approach could be regarded as a new potential therapeutic target in DMC.

Old and New Biomarkers Associated with Endothelial Dysfunction in Chronic Hyperglycemia

Chronic hyperglycemia and vascular damage are strictly related. Biomarkers of vascular damage have been intensively studied in the recent years in the quest of reliable cardiovascular risk assessment tools able to facilitate risk stratification and early detection of vascular impairment. The present study is a narrative review with the aim of revising the available evidence on current and novel markers of hyperglycemia-induced vascular damage. After a discussion of classic tools used to investigate endothelial dysfunction, we provide an in-depth description of novel circulating biomarkers (chemokines, extracellular vesicles, and epigenetic and metabolomic biomarkers). Appropriate use of a single as well as a cluster of the discussed biomarkers might enable in a near future (a) the prompt identification of targeted and customized treatment strategies and (b) the follow-up of cardiovascular treatment efficacy over time in clinical research and/or in clinical practice.

Long non-coding RNAs in diabetic wound healing: Current research and clinical relevance

Diabetic wounds are a protracted complication of diabetes mainly characterised by chronic inflammation, obstruction of epithelialization, damaged blood vessels and collagen production (maturation), as well as neuropathy. As a non‐coding RNA (ncRNA) that lack coding potential, long non‐coding RNAs (lncRNAs) have recently been reported to play a salient role in diabetic wound healing. Here, this review summarises the roles of lncRNAs in the pathology and treatments of diabetic wounds, providing references for its potential clinical diagnostic criteria or therapeutic targets in the future.

Epigenetic Regulation of Autophagy in Cardiovascular Pathobiology

Cardiovascular diseases (CVDs) are the number one cause of debilitation and mortality worldwide, with a need for cost-effective therapeutics. Autophagy is a highly conserved catabolic recycling pathway triggered by various intra- or extracellular stimuli to play an essential role in development and pathologies, including CVDs. Accordingly, there is great interest in identifying mechanisms that govern autophagic regulation. Autophagic regulation is very complex and multifactorial that includes epigenetic pathways, such as histone modifications to regulate autophagy-related gene expression, decapping-associated mRNA degradation, microRNAs, and long non-coding RNAs; pathways are also known to play roles in CVDs. Molecular understanding of epigenetic-based pathways involved in autophagy and CVDs not only will enhance the understanding of CVDs, but may also provide novel therapeutic targets and biomarkers for CVDs.

Endothelial response to glucose: dysfunction, metabolism, and transport

The endothelial cell response to glucose plays an important role in both health and disease. Endothelial glucose-induced dysfunction was first studied in diabetic animal models and in cells cultured in hyperglycemia. Four classical dysfunction pathways were identified, which were later shown to result from the common mechanism of mitochondrial superoxide overproduction. More recently, non-coding RNA, extracellular vesicles, and sodium-glucose cotransporter-2 inhibitors were shown to affect glucose-induced endothelial dysfunction. Endothelial cells also metabolize glucose for their own energetic needs. Research over the past decade highlighted how manipulation of endothelial glycolysis can be used to control angiogenesis and microvascular permeability in diseases such as cancer. Finally, endothelial cells transport glucose to the cells of the blood vessel wall and to the parenchymal tissue. Increasing evidence from the blood-brain barrier and peripheral vasculature suggests that endothelial cells regulate glucose transport through glucose transporters that move glucose from the apical to the basolateral side of the cell. Future studies of endothelial glucose response should begin to integrate dysfunction, metabolism and transport into experimental and computational approaches that also consider endothelial heterogeneity, metabolic diversity, and parenchymal tissue interactions.

Pravastatin-induced changes in expression of long non-coding and coding RNAs in endothelial cells

OBJECTIVE

Atherosclerosis is the main cause of the cardiovascular disease (CVD). Elevated blood cholesterol and inflammation of the endothelium are two major mechanisms contributing to the establishment of atherosclerotic plaques. Statins, such as pravastatin, are blood-cholesterol lowering drugs commonly prescribed for patients with or at risk for CVDs. In addition to lowering blood cholesterols, statins have recently been shown to improve endothelial function in both hyper- and normocholesterolemic patients with atherosclerosis. To understand the molecular mechanisms underlying the endothelial function improvement by statins, we assessed the RNA profile of pravastatin-treated endothelial cells, particularly their mRNAs and long non-coding RNAs (lncRNAs).

METHODS

Human umbilical vein endothelial cells (HUVECs) treated with pravastatin (10 µM) for 24 hr were profiled for lncRNAs and mRNAs using the Arraystar Human lncRNA Expression Microarray V3.0.

RESULTS

Of the 30,584 different lncRNAs screened, 95 were significantly upregulated, while 86 were downregulated in HUVECs responding to pravastatin. LINC00281 and BC045663 were the most upregulated (~8-fold) and downregulated (~3.5-fold) lncRNAs, respectively. Of the 26,106 different mRNAs screened in the pravastatin-treated HUVEC samples, 190 were significantly upregulated, while 90 were downregulated. Assigning the differentially expressed genes by bioinformatics into functional groups revealed their molecular signaling involvement in the following physiological processes: osteoclast differentiation, Rap1 signaling pathway, hematopoiesis, immunity, and neurotrophin signaling pathway.

CONCLUSIONS

This is the first lncRNA and mRNA expression profiling of pravastatin-mediated changes in human endothelial cells. Our results reveal potential novel targets and mechanisms for pravastatin-mediated vascular protection in atherosclerosis.

Antisense long non‑coding RNA WEE2‑AS1 regulates human vascular endothelial cell viability via cell cycle G2/M transition in arteriosclerosis obliterans

Long non-coding RNAs (lncRNAs) affect atherosclerosis by regulating the physiological and pathological processes of endothelial cells; however, the role of lncRNA WEE2 antisense RNA 1 (WEE2-AS1) in arteriosclerosis obliterans (ASO) is not completely understood. The present study aimed to explore the function of lncRNA WEE2-AS1 in human vascular endothelial cells. The results indicated that lncRNA WEE2-AS1 was significantly elevated in plasma and artery tissue samples of patients with ASO compared with healthy controls. The fluorescence in situ hybridization results suggested that lncRNA WEE2-AS1 was expressed in the cytoplasm and nuclei of primary human umbilical vein endothelial cells (HUVECs). The Cell Counting Kit-8 assay results suggested that lncRNA WEE2-AS1 knockdown significantly promoted HUVEC viability, whereas lncRNA WEE2-AS1 overexpression inhibited HUVEC viability compared with the negative control groups. Furthermore, analysis of the cell cycle by flow cytometry indicated that lncRNA WEE2-AS1 knockdown significantly decreased the proportion of cells in the G₀/G₁ phase and significantly increased the proportion of cells in the G₂/M phase compared with the negative control group. However, lncRNA WEE2-AS1 overexpression had no significant effect on cell cycle distribution compared with the negative control group. The western blotting results indicated that lncRNA WEE2-AS1 knockdown significantly reduced the expression levels of phosphorylated cyclin dependent kinase 1, WEE1 homolog 2 and myelin transcription factor 1, but increased the expression level of cell division cycle 25B compared with the negative control group. lncRNA WEE2-AS1 overexpression displayed the opposite effect on protein expression. Collectively, the present study suggested that lncRNA WEE2-AS1 was significantly upregulated in ASO and may serve a role in regulating human vascular endothelial cell viability. Further investigation into lncRNA WEE2-AS1 may broaden the current understanding of the molecular mechanism underlying ASO, and aid with the identification of specific probes and precise targeted drugs for the diagnosis and treatment of ASO.

Analysis of long non-coding RNA expression profiles in high-glucose treated vascular endothelial cells

BACKGROUND

Diabetes mellitus is often associated with microvascular and macrovascular lesions, and hyperglycemia-induced vascular endothelial cell damage is a key factor.

METHODS

We investigated long non-coding RNAs (lncRNAs) and mRNAs that are affected by hyperglycemia-induced damage using human umbilical vein endothelial cells (HUVECs) as a model. HUVECs were cultured under high (25 mmol/L) or normal (5 mmol/L) glucose conditions for 6 d, and then lncRNAs and protein-coding transcripts were profiled by RNA-seq.

RESULT

Among 40,379 lncRNAs screened, 214 were upregulated (log2 [fold-change] > 1, FDR < 0.05) and 197 were downregulated (log2 [fold-change] < - 1, FDR < 0.05) in response to high-glucose. Furthermore, among 28,431 protein-coding genes screened, 778 were upregulated and 998 were downregulated. A total of 945 lncRNA/mRNA pairs were identified, including 126 differentially expressed lncRNAs predicted to target 201 mRNAs, among which 26 were cis-regulatory interactions. The corresponding lncRNA-mRNA network was composed of 354 lncRNA nodes, 1167 mRNA nodes and 9735 edges. Dozens of lncRNAs with high degree may play important roles in high-glucose-induced HUVEC damage, including ENST00000600527, NONHSAT037576.2, NONHSAT135706.2, ENST00000602127, NONHSAT200243.1, NONHSAT217282.1, NONHSAT176260.1, NONHSAT199075.1, NONHSAT067063.2, NONHSAT058417.2.

CONCLUSION

These observations may provide novel insights into the regulatory molecules and pathways of hyperglycemia-related endothelial dysfunction in diabetes-associated vascular disease.

The vascular epigenome in patients with obesity and type 2 diabetes: opportunities for personalized therapies

Our genetic background provides limited information on individual risk of developing vascular complications overtime. New biological layers, namely epigenetic modifications, are now emerging as potent regulators of gene expression thus leading to altered transcriptional programs and vascular disease phenotypes. Such epigenetic modifications, defined as changes to the genome that do not involve changes in DNA sequence, are generally induced by environmental factors and poor lifestyle habits. Of note, adverse epigenetic signals acquired during life can be transmitted to the offspring thus leading to premature alterations of the epigenetic and transcriptional landscape eventually leading to early endothelial dysfunction and vascular senescence. Modifications of the epigenome play a pivotal role in the pathophysiology of cardiometabolic disturbances such as obesity and type 2 diabetes. In these patients, changes of DNA methylation and chromatin structure contribute to alter pathways regulating insulin sensitivity, glucose homeostasis, adipogenesis and vascular function. In this perspective, unveiling the 'epigenetic landscape' in cardiometabolic patients may help to identify new players implicated in obesity and diabetes-related vascular dysfunction and may pave the way for personalized therapies in this setting. In the present review, we discuss current knowledge of the epigenetic routes implicated in vascular damage and cardiovascular disease in patients with metabolic alterations.

Expedition to the missing link: Long noncoding RNAs in cardiovascular diseases

With the advances in deep sequencing-based transcriptome profiling technology, it is now known that human genome is transcribed more pervasively than previously thought. Up to 90% of the human DNA is transcribed, and a large proportion of the human genome is transcribed as long noncoding RNAs (lncRNAs), a heterogenous group of non-coding transcripts longer than 200 nucleotides. Emerging evidence suggests that lncRNAs are functional and contribute to the complex regulatory networks involved in cardiovascular development and diseases. In this article, we will review recent evidence on the roles of lncRNAs in the biological processes of cardiovascular development and disorders. The potential applications of lncRNAs as biomarkers and targets for therapeutics are also discussed.

A Brief Overview of lncRNAs in Endothelial Dysfunction-Associated Diseases: From Discovery to Characterization

Long non-coding RNAs (lncRNAs) are a novel class of regulatory RNA molecules and they are involved in many biological processes and disease developments. Several unique features of lncRNAs have been identified, such as tissue-and/or cell-specific expression pattern, which suggest that they could be potential candidates for therapeutic and diagnostic applications. More recently, the scope of lncRNA studies has been extended to endothelial biology research. Many of lncRNAs were found to be critically involved in the regulation of endothelial function and its associated disease progression. An improved understanding of endothelial biology can thus facilitate the discovery of novel biomarkers and therapeutic targets for endothelial dysfunction-associated diseases, such as abnormal angiogenesis, hypertension, diabetes, and atherosclerosis. Nevertheless, the underlying mechanism of lncRNA remains undefined in previous published studies. Therefore, in this review, we aimed to discuss the current methodologies for discovering and investigating the functions of lncRNAs and, in particular, to address the functions of selected lncRNAs in endothelial dysfunction-associated diseases.

Can Epigenetics of Endothelial Dysfunction Represent the Key to Precision Medicine in Type 2 Diabetes Mellitus?

In both developing and industrialized Countries, the growing prevalence of Type 2 Diabetes Mellitus (T2DM) and the severity of its related complications make T2DM one of the most challenging metabolic diseases worldwide. The close relationship between genetic and environmental factors suggests that eating habits and unhealthy lifestyles may significantly affect metabolic pathways, resulting in dynamic modifications of chromatin-associated proteins and homeostatic transcriptional responses involved in the progression of T2DM. Epigenetic mechanisms may be implicated in the complex processes linking environmental factors to genetic predisposition to metabolic disturbances, leading to obesity and type 2 diabetes mellitus (T2DM). Endothelial dysfunction represents an earlier marker and an important player in the development of this disease. Dysregulation of the endothelial ability to produce and release vasoactive mediators is recognized as the initial feature of impaired vascular activity under obesity and other insulin resistance conditions and undoubtedly concurs to the accelerated progression of atherosclerotic lesions and overall cardiovascular risk in T2DM patients. This review aims to summarize the most current knowledge regarding the involvement of epigenetic changes associated with endothelial dysfunction in T2DM, in order to identify potential targets that might contribute to pursuing “precision medicine” in the context of diabetic illness.

mRNAs expression profiles of high glucose-induced memory in human umbilical vein endothelial cells

PURPOSE

A long-term "memory" of hyperglycemic stress, even when glycemia is normalized, has been previously reported in endothelial cells. However, the molecular mechanism of "metabolic memory" (MM) remains unknown. In this report, we sought to screen at the whole transcriptome level the genes that participate in MM.

METHODS

In the present research, RNA sequencing was used to determine the protein-coding mRNA expression profiles of human umbilical vein endothelial cells (HUVECs) under normal-glucose concentration (LG), high-glucose concentration (HG), and MM. A series of bioinformatic analyses was performed. HG-induced MM-involved up-regulated genes (up-HGMMGs) and HG-induced MM-involved down-regulated genes (down-HGMMGs) were identified. Afterward, based on up-HGMMGs and down-HGMMGs, the biological functions and signaling pathways were analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, several of the identified genes were validated by RT-qPCR.

RESULTS

A total of 726 HGMMGs were identified, including 210 down- and 516 up-HGMMGs, which were enriched in the cell cycle (hsa04110), oocyte meiosis (hsa04114), p53 signaling pathway (hsa04115), and oxidative phosphorylation (hsa00190), among others. The protein-protein-interaction (PPI) network consisted of 462 nodes and 2656 connections, and four main modules were identified by MCODE. The cell cycle (hsa04110), oocyte meiosis (hsa04114), p53 signaling pathway (hsa04115), and oxidative phosphorylation (hsa00190), among others, could be potential therapeutic targets of HG-induced MM in endothelial cells. The real-time PCR results validated the RNA-seq data.

CONCLUSION

This study identified crucial mRNAs related to MM-persistent injury in endothelial cells even after switching the cells from high- glucose to normal glucose levels. Further research focusing on these mRNA may unravel new ways to modify MM in diabetes.

Endothelial dysfunction in diabetes and hypertension: Role of microRNAs and long non-coding RNAs

The vascular endothelium acts as a barrier between the blood flow and the inner lining of the vessel wall, and it functions as a filtering machinery to filter out any unwanted transfer of materials from both sides (i.e. the blood and the surrounding tissues). It is evident that diseases such as diabetes, obesity, and hypertension disturb the normal endothelial functions in humans and lead to endothelial dysfunction, which may further precede to the development of atherosclerosis. Long non-coding RNAs and micro RNAs both are types of non-coding RNAs which, in the recent years, have increasingly been studied in the pathophysiology of many diseases including diabetes, obesity, cardiovascular diseases, neurological diseases, and others. Recent findings have pointed out important aspects on their relevance to endothelial function as well as dysfunction of the system which may arise from presence of diseases such as diabetes and hypertension. Diabetes or hypertension-mediated endothelial dysfunction show characteristics such as reduced nitric oxide synthesis through suppression of endothelial nitric oxide synthase activity in endothelial cells, reduced sensitivity of nitric oxide in smooth muscle cells, and inflammation - all of which have been either shown to be directly caused by gene regulatory mechanisms of non-coding RNAs or shown to be having a correlation with them. In this review, we aim to discuss such findings on the role of these non-coding RNAs in diabetes or hypertension-associated endothelial dysfunction and the related mechanisms that may pave the way for alleviating endothelial dysfunction and its related complications such as atherosclerosis.

Angio-LncRs: LncRNAs that regulate angiogenesis and vascular disease

Long noncoding RNAs (lncRNAs) represent a large subgroup of RNAs that are longer than 200 nucleotides and have no apparent protein coding potential. They have diverse functions in different biological processes by regulating chromatin remodeling or protein translation. This review summarizes the recent progress of lncRNAs in angiogenesis and vascular diseases. A general overview of lncRNA functional mechanisms will be introduced. A list of lncRNAs, which are termed "Angio-LncRs", including MALAT1, MANTIS, PUNISHER, MEG3, MIAT, SENCR and GATA6-AS, will be discussed regarding their expression, regulation, function and mechanism of action in angiogenesis. Implications of lncRNAs in vascular diseases, such as atherosclerosis, hypertension, vascular retinopathies and tumor angiogenesis will also be discussed.

Circulating miRNA Profiles Associated With Hyperglycemia in Patients With Type 1 Diabetes

We investigated plasma microRNA (miRNA) profiles associated with variation of hyperglycemia, measured as hemoglobin A_1c (HbA_1c), in two panels of patients with type 1 diabetes (T1D). Using the HTG Molecular Diagnostics EdgeSeq platform, 2,083 miRNAs were measured in plasma from 71 patients included in a screening panel. Quantitative real-time PCR was used to measure the candidate miRNAs in plasma from 95 patients included in an independent replication panel. We found 10 miRNAs replicated in both panels and 4 with high statistical significance. The strongest positive correlations with HbA_1c were found with miR-125b-5p (r_s = 0.40, P = 6.0 × 10^-5) and miR-365a-3p (r_s = 0.35, P = 5.9 × 10^-4). The strongest negative correlations were found with miR-5190 (r_s = -0.30, P = 0.003) and miR-770-5p (r_s = -0.27, P = 0.008). Pathway analysis revealed that 50 Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched by genes targeted by these four miRNAs. The axon guidance signaling pathway was enriched (P < 1 × 10^-7) by genes targeted by all four miRNAs. In addition, three other pathways (Rap1 signaling, focal adhesion, and neurotrophin signaling) were also significantly enriched but with genes targeted by only by three of the identified miRNAs. In conclusion, our study identified four circulating miRNAs that were influenced by variation in hyperglycemia. Dysregulation of these miRNAs, which are associated with hyperglycemia in patients with T1D, may contribute to the development of diabetes complications. However, there are multitudes of possible mechanisms/pathways through which dysregulation of these miRNAs may impact risk of diabetes complications.

Endothelial long non-coding RNAs regulated by oxidized LDL

Oxidized low-density lipoprotein (oxLDL) plays a central role in the pathogenesis of atherosclerosis, in part via an effect to promote endothelial dysfunction. In the present study, we evaluated the expression profiles of long non-coding RNAs (lncRNAs) and protein-coding mRNAs in endothelial cells following oxLDL stimulation. LncRNAs and mRNAs from human umbilical vein endothelial cells (HUVECs) were profiled with the Arraystar Human lncRNA Expression Microarray V3.0 following 24 h of oxLDL treatment (100 µg/mL). Of the 30,584 lncRNAs screened, 923 were significantly up-regulated and 975 significantly down-regulated (P < 0.05) in response to oxLDL exposure. In the same HUVEC samples, 518 of the 26,106 mRNAs screened were up-regulated and 572 were down-regulated. Of these differentially expressed lncRNAs, CLDN10-AS1 and CTC-459I6.1 were the most up-regulated (~87-fold) and down-regulated (~28-fold), respectively. Bioinformatic assignment of the differentially regulated genes into functional groups indicated that many are involved in signaling pathways among which are the cytokine receptor, chemokine, TNF, MAPK and Ras signaling pathways, olfactory transduction, and vascular smooth muscle cell function. This is the first report profiling oxLDL-mediated changes in lncRNA and mRNA expression in human endothelial cells. The novel targets revealed substantially extend the list of potential candidate genes involved in atherogenesis.