miR133a regulates cardiomyocyte hypertrophy in diabetes

Interplay Between TGF-β Signaling and MicroRNA in Diabetic Cardiomyopathy

In diabetic patients, concomitant cardiovascular disease is the main factor contributing to their morbidity and mortality. Diabetic cardiomyopathy (DCM) is a form of cardiovascular disease associated with diabetes that can result in heart failure. Transforming growth factor-β (TGF-β) isoforms play a crucial role in heart remodeling and repair and are elevated and activated in myocardial disorders. Alterations in certain microRNAs (miRNA) are closely related to diabetic cardiomyopathy. One or more miRNA molecules target the majority of TGF-β pathway components, and TGF-β directly or via SMADs controls miRNA synthesis. Based on these interactions, this review discusses potential cross-talk between TGF-β signaling and miRNA in DCM in order to investigate the creation of potential therapeutic targets.

Mechanistic insight into the role of cardiac-enriched microRNAs in diabetic heart injury

Cardiovascular complications, particularly diabetic cardiomyopathy (DCM), are the primary causes of morbidity and mortality among individuals with diabetes. Hyperglycemia associated with diabetes leads to cardiomyocyte hypertrophy, apoptosis, and myocardial fibrosis, culminating in heart failure (HF). Patients with diabetes face a 2-4 times greater risk of developing HF compared with those without diabetes. Consequently, there is a growing interest in exploring the molecular mechanisms that contribute to the development of DCM. MicroRNAs (miRNAs) are short, single-stranded, noncoding RNA molecules that participate in the maintenance of physiological homeostasis through the regulation of essential processes such as metabolism, cell proliferation, and apoptosis. At the posttranscriptional level, miRNAs modulate gene expression by binding directly to genes' mRNAs. Multiple cardiac-enriched miRNAs were reported to be dysregulated under diabetic conditions. Different studies revealed the role of specific miRNAs in the pathogenesis of diabetes and related cardiovascular complications, including cardiomyocyte hypertrophy and fibrosis, mitochondrial dysfunction, metabolic impairment, inflammatory response, or cardiomyocyte death. Circulating miRNAs have been shown to represent the potential biomarkers for early detection of diabetic heart injury. A deeper understanding of miRNAs and their role in diabetes-related pathophysiological processes could lead to new therapeutic strategies for addressing cardiac complications associated with diabetes.

Integrated analysis of long non‑coding RNA megacluster, microRNA‑132 and microRNA‑133a and their implications for cardiovascular risk and kidney failure progression in diabetic patients

Inefficient control of elevated blood sugar levels can lead to certain health complications such as diabetic nephropathy (DN) and cardiovascular disease (CVD). The identification of effective biomarkers for monitoring diabetes was performed in the present study. The present study aimed to investigate the implications of long non-coding RNA megacluster (lnc-MGC), microRNA (miR)-132 and miR-133a, and their correlation with lactate dehydrogenase (LDH) activity and glycated hemoglobin (HbA1C) levels to identify biomarkers for the early diagnosis of diabetes mellitus, induced DN and CVD. The present study included a total of 200 patients with type 2 diabetes, as well as 40 healthy subjects as controls. The diabetic patients were classified into six groups based on their estimated HbA1c level, glomerular filtration rate and LDH activity, while the healthy controls constituted the seventh group. Diabetic patients exhibited significant increases in parameters related to diabetes as fasting blood sugar, HbA1c levels, cardiac injury and kidney failure. Furthermore, the expression levels of TNF-α were significantly increased in the diabetic groups compared with healthy controls. Diabetic patients with cardiovascular dysfunction showed significantly increased expression levels of miR-132, miR-133a and lnc-MGC, compared with the healthy group. The expression of circulating miR-132 in blood was low in the groups of diabetic patients compared with the healthy controls, and demonstrated a negative correlation with LDH and HbA1C levels. Expression levels of miR-132, miR-133a and lnc-MGC, along with their correlations with LDH and HbA1C levels, could be used to distinguish diabetic patients with reduced CVD from those at early stage diabetes, which indicated their potential as biomarkers for CV complications associated with diabetes mellitus in the future.

Diabetic myocardial disorder. A clinical consensus statement of the Heart Failure Association of the ESC and the ESC Working Group on Myocardial & Pericardial Diseases

The association between type 2 diabetes mellitus (T2DM) and heart failure (HF) has been firmly established; however, the entity of diabetic myocardial disorder (previously called diabetic cardiomyopathy) remains a matter of debate. Diabetic myocardial disorder was originally described as the occurrence of myocardial structural/functional abnormalities associated with T2DM in the absence of coronary heart disease, hypertension and/or obesity. However, supporting evidence has been derived from experimental and small clinical studies. Only a minority of T2DM patients are recognized as having this condition in the absence of contributing factors, thereby limiting its clinical utility. Therefore, this concept is increasingly being viewed along the evolving HF trajectory, where patients with T2DM and asymptomatic structural/functional cardiac abnormalities could be considered as having pre-HF. The importance of recognizing this stage has gained interest due to the potential for current treatments to halt or delay the progression to overt HF in some patients. This document is an expert consensus statement of the Heart Failure Association of the ESC and the ESC Working Group on Myocardial & Pericardial Diseases. It summarizes contemporary understanding of the association between T2DM and HF and discuses current knowledge and uncertainties about diabetic myocardial disorder that deserve future research. It also proposes a new definition, whereby diabetic myocardial disorder is defined as systolic and/or diastolic myocardial dysfunction in the presence of diabetes. Diabetes is rarely exclusively responsible for myocardial dysfunction, but usually acts in association with obesity, arterial hypertension, chronic kidney disease and/or coronary artery disease, causing additive myocardial impairment.

Roles of non-coding RNA in diabetic cardiomyopathy

In recent years, the incidence of diabetes has been increasing rapidly, posing a serious threat to human health. Diabetic cardiomyopathy (DCM) is characterized by cardiomyocyte hypertrophy, myocardial fibrosis, apoptosis, ventricular remodeling, and cardiac dysfunction in individuals with diabetes, ultimately leading to heart failure and mortality. However, the underlying mechanisms contributing to DCM remain incompletely understood. With advancements in molecular biology technology, accumulating evidence has shown that numerous non-coding RNAs (ncRNAs) crucial roles in the development and progression of DCM. This review aims to summarize recent studies on the involvement of three types of ncRNAs (micro RNA, long ncRNA and circular RNA) in the pathophysiology of DCM, with the goal of providing innovative strategies for the prevention and treatment of DCM.

The role of exosomes and exosomal microRNA in diabetic cardiomyopathy

Diabetic cardiomyopathy, a formidable cardiovascular complication linked to diabetes, is witnessing a relentless surge in its incidence. Despite extensive research efforts, the primary pathogenic mechanisms underlying this condition remain elusive. Consequently, a critical research imperative lies in identifying a sensitive and dependable marker for early diagnosis and treatment, thereby mitigating the onset and progression of diabetic cardiomyopathy (DCM). Exosomes (EXOs), minute vesicles enclosed within bilayer lipid membranes, have emerged as a fascinating frontier in this quest, capable of transporting a diverse cargo that mirrors the physiological and pathological states of their parent cells. These exosomes play an active role in the intercellular communication network of the cardiovascular system. Within the realm of exosomes, MicroRNA (miRNA) stands as a pivotal molecular player, revealing its profound influence on the progression of DCM. This comprehensive review aims to offer an introductory exploration of exosome structure and function, followed by a detailed examination of the intricate role played by exosome-associated miRNA in diabetic cardiomyopathy. Our ultimate objective is to bolster our comprehension of DCM diagnosis and treatment strategies, thereby facilitating timely intervention and improved outcomes.

Current understanding of structural and molecular changes in diabetic cardiomyopathy

Diabetic Mellitus has been characterized as the most prevalent disease throughout the globe associated with the serious morbidity and mortality of vital organs. Cardiomyopathy is the major leading complication of diabetes and within this, myocardial dysfunction or failure is the leading cause of the emergency hospital admission. The review is aimed to comprehend the perspectives associated with diabetes-induced cardiovascular complications. The data was collected from several electronic databases such as Google Scholar, Science Direct, ACS publication, PubMed, Springer, etc. using the keywords such as diabetes and its associated complication, the prevalence of diabetes, the anatomical and physiological mechanism of diabetes-induced cardiomyopathy, the molecular mechanism of diabetes-induced cardiomyopathy, oxidative stress, and inflammatory stress, etc. The collected scientific data was screened by different experts based on the inclusion and exclusion criteria of the study. This review findings revealed that diabetes is associated with inefficient substrate utilization, inability to increase glucose metabolism and advanced glycation end products within the diabetic heart resulting in mitochondrial uncoupling, glucotoxicity, lipotoxicity, and initially subclinical cardiac dysfunction and finally in overt heart failure. Furthermore, several factors such as hypertension, overexpression of renin angiotensin system, hypertrophic obesity, etc. have been seen as majorly associated with cardiomyopathy. The molecular examination showed biochemical disability and generation of the varieties of free radicals and inflammatory cytokines and becomes are the substantial causes of cardiomyopathy. This review provides a better understanding of the involved pathophysiology and offers an open platform for discussing and targeting therapy in alleviating diabetes-induced early heart failure or cardiomyopathy.

Epigenetics of the Pathogenesis and Complications of Type 2 Diabetes Mellitus

Epigenetics of type 2 diabetes mellitus (T2DM) has widened our knowledge of various aspects of the disease. The aim of this review is to summarize the important epigenetic changes implicated in the disease risks, pathogenesis, complications and the evolution of therapeutics in our current understanding of T2DM. Studies published in the past 15 years, from 2007 to 2022, from three primary platforms namely PubMed, Google Scholar and Science Direct were included. Studies were searched using the primary term 'type 2 diabetes and epigenetics' with additional terms such as 'risks', 'pathogenesis', 'complications of diabetes' and 'therapeutics'. Epigenetics plays an important role in the transmission of T2DM from one generation to another. Epigenetic changes are also implicated in the two basic pathogenic components of T2DM, namely insulin resistance and impaired insulin secretion. Hyperglycaemia-i nduced permanent epigenetic modifications of the expression of DNA are responsible for the phenomenon of metabolic memory. Epigenetics influences the development of micro-and macrovascular complications of T2DM. They can also be used as biomarkers in the prediction of these complications. Epigenetics has expanded our understanding of the action of existing drugs such as metformin, and has led to the development of newer targets to prevent vascular complications. Epigenetic changes are involved in almost all aspects of T2DM, from risks, pathogenesis and complications, to the development of newer therapeutic targets.

Research status and trends of the diabetic cardiomyopathy in the past 10 years (2012–2021): A bibliometric analysis

Background

Diabetic cardiomyopathy is one of the most life-threatening diabetic complications. However, the previous studies only discuss a particular aspect or characteristic of DCM, the current state and trends were explored by limited research. We aimed to perform a systemically bibliometric study of DCM research progress status in the past decade, visualize the internal conceptual structure and potential associations, and further explore the prospective study trends.

Methods

Articles related to DCM published from January 2012 to December 2021 were collected in the Web of Science core collection (WoSCC) database on June 24, 2022. We exported all bibliographic records, including titles, abstracts, keywords, authorship, institutions, addresses, publishing sources, references, citation times, and year of publication. In addition, the journal Impact Factor and Hirsch index were obtained from the Journal Citation Report. We conducted the data screening, statistical analysis, and visualization via the Bibliometrix R package. VOS viewer software was employed to generate the collaboration network map among countries and institutions for better performance in visualization.

Results

In total, 1,887 original research articles from 2012 to 2021 were identified. The number of annual publications rapidly increased from 107 to 278, and a drastic increase in citation times was observed in 2017–2019. As for global contributions, the United States was the most influential country with the highest international collaboration, while China was the most productive country. Professor Cai Lu was the most prolific author. Shandong University published the most articles. Cardiovascular Diabetology journal released the most DCM-related articles. “Metabolic Stress-induced Activation of FoxO1 Triggers Diabetic Cardiomyopathy in Mice” Battiprolu PK et al., J Clin Invest, 2012. was the most top-cited article regarding local citations. The top three keywords in terms of frequency were apoptosis, oxidative stress, and fibrosis. The analysis of future topic trends indicated that “Forkhead box protein O1,” “Heart failure with preserved ejection fraction,” “Dapagliflozin,” “Thioredoxin,” “Mitochondria dysfunction,” “Glucose,” “Pyroptosis,” “Cardiac fibroblast” and “Long non-coding RNA” could be promising hotspots.

Conclusion

This study provides meaningful insights into DCM, which is expected to assist cardiologists and endocrinologists in exploring frontiers and future research directions in the domain through a refined and concise summary.

Endothelial derived miRNA-9 mediated cardiac fibrosis in diabetes and its regulation by ZFAS1

Diabetic cardiomyopathy (DCM) is one of the most prevalent causes of morbidity and mortality in diabetic patients. Hyperglycemia induces increased expression/deposition of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (Col) and plays an important role in fibrosis in diabetic cardiomyopathy (DCM). The roles of RNAs including microRNA (miRNA) and long non-coding RNAs (lncRNA) have begun to be understood in many conditions. In this study, we investigated the role of a specific miRNA, miR-9, and its interactions with lncRNA ZFAS1 in mediating fibrosis in DCM. Treatment with 25 mM glucose (HG) decreased miR-9 expression and increased expressions of ZFAS1, ECM proteins and inflammatory markers, compared to 5 mM glucose (NG) in the HCMECs by using qRT-PCR. Glucose-induced upregulation of ECM proteins can be prevented by ZFAS1 siRNA or miR-9 mimic transfection. Luciferase assay was confirmed miR-9 binding to FN 3’-UTR. miR-9 expression can be regulated by ZFAS1 through polycomb repressive complex 2 (PRC2) components using RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays. In the in vivo experiment, hyperglycemia-induced the ECM production can be prevented by the miR-9 overexpression in the fibrosis in DCM. These studies showed a novel glucose-induced molecular mechanism in which ZFAS1 participates in the transcriptional regulation of ECM protein production in diabetes through miR-9.

In Vivo Inhibition of miR-34a Modestly Limits Cardiac Enlargement and Fibrosis in a Mouse Model with Established Type 1 Diabetes-Induced Cardiomyopathy, but Does Not Improve Diastolic Function

MicroRNA 34a (miR-34a) is elevated in the heart in a setting of cardiac stress or pathology, and we previously reported that inhibition of miR-34a in vivo provided protection in a setting of pressure overload-induced pathological cardiac hypertrophy and dilated cardiomyopathy. Prior work had also shown that circulating or cardiac miR-34a was elevated in a setting of diabetes. However, the therapeutic potential of inhibiting miR-34a in vivo in the diabetic heart had not been assessed. In the current study, type 1 diabetes was induced in adult male mice with 5 daily injections of streptozotocin (STZ). At 8 weeks post-STZ, when mice had established type 1 diabetes and diastolic dysfunction, mice were administered locked nucleic acid (LNA)-antimiR-34a or saline-control with an eight-week follow-up. Cardiac function, cardiac morphology, cardiac fibrosis, capillary density and gene expression were assessed. Diabetic mice presented with high blood glucose, elevated liver and kidney weights, diastolic dysfunction, mild cardiac enlargement, cardiac fibrosis and reduced myocardial capillary density. miR-34a was elevated in the heart of diabetic mice in comparison to non-diabetic mice. Inhibition of miR-34a had no significant effect on diastolic function or atrial enlargement, but had a mild effect on preventing an elevation in cardiac enlargement, fibrosis and ventricular gene expression of B-type natriuretic peptide (BNP) and the anti-angiogenic miRNA (miR-92a). A miR-34a target, vinculin, was inversely correlated with miR-34a expression, but other miR-34a targets were unchanged. In summary, inhibition of miR-34a provided limited protection in a mouse model with established type 1 diabetes-induced cardiomyopathy and failed to improve diastolic function. Given diabetes represents a systemic disorder with numerous miRNAs dysregulated in the diabetic heart, as well as other organs, strategies targeting multiple miRNAs and/or earlier intervention is likely to be required.

The role of microRNAs in the pathophysiology, diagnosis, and treatment of diabetic cardiomyopathy

INTRODUCTION

Diabetic cardiomyopathy (DCM) is an end-point macrovascular complication associated with increased morbidity and mortality in 12% of diabetic patients. MicroRNAs (miRNAs) are small noncoding RNAs that can act as cardioprotective or cardiotoxic agents in DCM.

METHODS

We used PubMed as a search engine to collect and analyse data in published articles on the role of miRNAs on the pathophysiology, diagnosis and treatment of DCM.

RESULTS

MiRNAs play an essential role in the pathophysiology, diagnosis and treatment of DCM due to their distinct gene expression patterns in diabetic patients compared to healthy individuals. Advances in gene therapy have led to the discovery of potential circulating miRNAs, which can be used as biomarkers for DCM diagnosis and prognosis. Furthermore, targeted miRNA therapies in preclinical and clinical studies, such as using miRNA mimics and anti-miRNAs, have yielded promising results. Application of miRNA mimics and anti-miRNAs via different nanodrug delivery systems alleviate hypertrophy, fibrosis, oxidative stress and apoptosis of cardiomyocytes.

CONCLUSION

MiRNAs serve as attractive potential targets for DCM diagnosis, prognosis and treatment due to their distinctive expression profile in DCM development.

Intrauterine hyperglycemia impairs endometrial receptivity via up-regulating SGK1 in diabetes

Diabetes is a complex metabolic disorder which can adversely affect reproductive function. SGK1 is found to be up-regulated in multiple tissues of diabetic patients. However, the effects of diabetes on endometrial SGK1 expression and endometrial receptivity remain unknown. In this study, we established a streptozotocin-induced diabetic mouse model and observed reduced implantation sites, retarded development of pinopodes, increased SGK1, and aberrant expression of LIF and MUC1 in the endometrial epithelium. We injected the uterine lumen of normal mice with high-glucose solution and cultured endometrial cells in high-glucose medium to mimic intrauterine hyperglycemia. Both studies provided compelling evidence that hyperglycemia could lead to diminished embryo implantation and dysregulated SGK1, LIF and MUC1. Additionally, through over-expression of SGK1 in vivo and in vitro, we found that enhanced SGK1 also decreased LIF expression, increased MUC1 expression, and attenuated embryo implantation rate. We further identified that hyperglycemia-activated SMAD2/3 might be responsible for the enhancement of SGK1 and verified directly the interaction between SMAD3 and corresponding SMAD binding elements within SGK1 promoter. Taken together, our study confirmed the association between diabetes-related hyperglycemia and endometrial receptivity defects. Hyperglycemia-induced SGK1 has a tremendous role in this pathological process, rendering it as an attractive therapeutic target for diabetes-related reproductive disorders.

miR-133a-A Potential Target for Improving Cardiac Mitochondrial Health and Regeneration After Injury

ABSTRACT

The various roles of muscle secretory factors and myokines have been well studied, but in recent decades, the role of myocyte-specific microRNAs (myomiRs) has gained momentum. These myomiRs are known to play regulatory roles in muscle health in general, both skeletal muscle and cardiac muscle. In this review, we have focused on the significance of a myomiR termed miR-133a in cardiovascular health. The available literature supports the claim that miR-133a could be helpful in the healing process of muscle tissue after injury. The protective function could be due to its regulatory effect on muscle or stem cell mitochondrial function. In this review, we have shed light on the protective mechanisms offered by miR-133a. Most of the beneficial effects are due to the presence of miR-133a in circulation or tissue-specific expression. We have also reviewed the potential mechanisms by which miR-133a could interact with cell surface receptors and also transcriptional mechanisms by which they offer cardioprotection and regeneration. Understanding these mechanisms will help in finding an ideal strategy to repair cardiac tissue after injury.

Exosomal microRNAs in diabetic heart disease

Diabetes is a metabolic disorder that affects millions of people worldwide. Diabetic heart disease (DHD) comprises coronary artery disease, heart failure, cardiac autonomic neuropathy, peripheral arterial disease, and diabetic cardiomyopathy. The onset and progression of DHD have been attributed to molecular alterations in response to hyperglycemia in diabetes. In this context, microRNAs (miRNAs) have been demonstrated to have a significant role in the development and progression of DHD. In addition to their effects on the host cells, miRNAs can be released into circulation after encapsulation within the exosomes. Exosomes are extracellular nanovesicles ranging from 30 to 180 nm in diameter secreted by all cell types. They carry diverse cargos that are altered in response to various conditions in their parent cells. Exosomal miRNAs have been extensively studied in recent years due to their role and therapeutic potential in DHD. This review will first provide an overview of exosomes, their biogenesis and function, followed by the role of exosomes in cardiovascular disease and then focuses on the known role of exosomes and associated miRNAs in DHD.

Metabolic, structural and biochemical changes in diabetes and the development of heart failure

Diabetes contributes to the development of heart failure through various metabolic, structural and biochemical changes. The presence of diabetes increases the risk for the development of cardiovascular disease (CVD), and since the introduction of cardiovascular outcome trials to test diabetic drugs, the importance of improving our understanding of the mechanisms by which diabetes increases the risk for heart failure has come under the spotlight. In addition to the coronary vasculature changes that predispose individuals with diabetes to coronary artery disease, diabetes can also lead to cardiac dysfunction independent of ischaemic heart disease. The hyperlipidaemic, hyperglycaemic and insulin resistant state of diabetes contributes to a perturbed energy metabolic milieu, whereby the heart increases its reliance on fatty acids and decreases glucose oxidative rates. In addition to changes in cardiac energy metabolism, extracellular matrix remodelling contributes to the development of cardiac fibrosis, and impairments in calcium handling result in cardiac contractile dysfunction. Lipotoxicity and glucotoxicity also contribute to impairments in vascular function, cardiac contractility, calcium signalling, oxidative stress, cardiac efficiency and lipoapoptosis. Lastly, changes in protein acetylation, protein methylation and DNA methylation contribute to a myriad of gene expression and protein activity changes. Altogether, these changes lead to decreased cardiac efficiency, increased vulnerability to an ischaemic insult and increased risk for the development of heart failure. This review explores the above mechanisms and the way in which they contribute to cardiac dysfunction in diabetes.

Research Progress on Epigenetics of Diabetic Cardiomyopathy in Type 2 Diabetes

Diabetic cardiomyopathy (DCM) is characterized by diastolic relaxation abnormalities in its initial stages and by clinical heart failure (HF) without dyslipidemia, hypertension, and coronary artery disease in its last stages. DCM contributes to the high mortality and morbidity rates observed in diabetic populations. Diabetes is a polygenic, heritable, and complex condition that is exacerbated by environmental factors. Recent studies have demonstrated that epigenetics directly or indirectly contribute to pathogenesis. While epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNAs, have been recognized as key players in the pathogenesis of DCM, some of their impacts remain not well understood. Furthering our understanding of the roles played by epigenetics in DCM will provide novel avenues for DCM therapeutics and prevention strategies.

Regulating Polyamine Metabolism by miRNAs in Diabetic Cardiomyopathy

PURPOSE OF REVIEW

Insulin is at the heart of diabetes mellitus (DM). DM alters cardiac metabolism causing cardiomyopathy, ultimately leading to heart failure. Polyamines, organic compounds synthesized by cardiomyocytes, have an insulin-like activity and effect on glucose metabolism, making them metabolites of interest in the DM heart. This review sheds light on the disrupted microRNA network in the DM heart in relation to developing novel therapeutics targeting polyamine biosynthesis to prevent/mitigate diabetic cardiomyopathy.

RECENT FINDINGS

Polyamines prevent DM-induced upregulation of glucose and ketone body levels similar to insulin. Polyamines also enhance mitochondrial respiration and thereby regulate all major metabolic pathways. Non-coding microRNAs regulate a majority of the biological pathways in our body by modulating gene expression via mRNA degradation or translational repression. However, the role of miRNA in polyamine biosynthesis in the DM heart remains unclear. This review discusses the regulation of polyamine synthesis and metabolism, and its impact on cardiac metabolism and circulating levels of glucose, insulin, and ketone bodies. We provide insights on potential roles of polyamines in diabetic cardiomyopathy and putative miRNAs that could regulate polyamine biosynthesis in the DM heart. Future studies will unravel the regulatory roles these miRNAs play in polyamine biosynthesis and will open new doors in the prevention/treatment of adverse cardiac remodeling in diabetic cardiomyopathy.

The circRAB3IP Mediated by eIF4A3 and LEF1 Contributes to Enzalutamide Resistance in Prostate Cancer by Targeting miR-133a-3p/miR-133b/SGK1 Pathway

An increasing number of studies have shown that circRNAs are closely related to the carcinogenesis and development of prostate cancer (PCa). However, little is known about the effect of the biological functions of circRNAs on the enzalutamide resistance of PCa. Through bioinformatic analysis and experiments, we investigated the expression pattern of circRNAs in enzalutamide-resistant PCa cells. Quantitative real-time PCR was used to detect the expression of circRAB3IP, and plasmids that knock down or overexpress circRAB3IP were used to evaluate its effect on the enzalutamide sensitivity of PCa cells. Mechanistically, we explored the potential regulatory effects of eIF4A3 and LEF1 on the biogenesis of circRAB3IP. Our in vivo and in vitro data indicated that increased expression of circRAB3IP was found in enzalutamide-resistant PCa, and knockdown of circRAB3IP significantly enhanced enzalutamide sensitivity in PCa cells. However, upregulation of circRAB3IP resulted in the opposite effects. Further mechanistic research demonstrated that circRAB3IP could regulate the expression of serum and glucocorticoid-regulated kinase 1 (SGK1) by serving as a sponge that directly targets miR-133a-3p/miR-133b. Then, we showed that circRAB3IP partially exerted its biological functions via SGK1 signaling. Furthermore, we discovered that eIF4A3 and LEF1 might increase circRAB3IP expression in PCa.

Recent Developments in Delivery of MicroRNAs Utilizing Nanosystems for Metabolic Syndrome Therapy

Metabolic syndrome (MetS) is a set of complex, chronic inflammatory conditions that are characterized by central obesity and associated with an increased risk of cardiovascular diseases. In recent years, microRNAs (miRNAs) have become an important type of endocrine factors, which play crucial roles in maintaining energy balance and metabolic homeostasis. However, its unfavorable properties such as easy degradation in blood and off-target effect are still a barrier for clinical application. Nanosystem based delivery possess strong protection, high bioavailability and control release rate, which is beneficial for success of gene therapy. This review first describes the current progress and advances on miRNAs associated with MetS, then provides a summary of the therapeutic potential and targets of miRNAs in metabolic organs. Next, it discusses recent advances in the functionalized development of classic delivery systems (exosomes, liposomes and polymers), including their structures, properties, functions and applications. Furthermore, this work briefly discusses the intelligent strategies used in emerging novel delivery systems (selenium nanoparticles, DNA origami, microneedles and magnetosomes). Finally, challenges and future directions in this field are discussed provide a comprehensive overview of the future development of targeted miRNAs delivery for MetS treatment. With these contributions, it is expected to address and accelerate the development of effective NA delivery systems for the treatment of MetS.

MicroRNAs as monitoring markers for right-sided heart failure and congestive hepatopathy

The last decades showed a worrying increase in the evolution of cardiovascular diseases towards different stages of heart failure (HF), as a stigma of the western lifestyle. MicroRNAs (miRNAs), non-coding RNAs, which are approximately 22-nucleotide long, were shown to regulate gene expression at the post-transcriptional level and play a role in the pathogenesis and progression of HF. miRNAs research is of high interest nowadays, as these molecules display mechanisms of action that can influence the course of evolution of common chronic diseases, including HF. The potential of post-transcriptional regulation by miRNAs concerning the diagnosis, management, and therapy for HF represents a new promising approach in the accurate assessment of cardiovascular diseases. This review aims to assess the current knowledge of miRNAs in cardiovascular diseases, especially right-sided heart failure and hepatomegaly. Moreover, attention is focused on their role as potential molecular biomarkers and more promising aspects involving miRNAs as future therapeutic targets in the pathophysiology of HF.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Upregulation of microRNA-532 enhances cardiomyocyte apoptosis in the diabetic heart

Type 2 diabetes has a strong association with the development of cardiovascular disease, which is grouped as diabetic heart disease (DHD). DHD is associated with the progressive loss of cardiovascular cells through the alteration of molecular signalling pathways associated with cell death. In this study, we sought to determine whether diabetes induces dysregulation of miR-532 and if this is associated with accentuated apoptosis. RT-PCR analysis showed a significant increase in miR-532 expression in the right atrial appendage tissue of type 2 diabetic patients undergoing coronary artery bypass graft surgery. This was associated with marked downregulation of its anti-apoptotic target protein apoptosis repressor with caspase recruitment domain (ARC) and increased TUNEL positive cardiomyocytes. Further analysis showed a positive correlation between apoptosis and miR-532 levels. Time-course experiments in a mouse model of type 2 diabetes showed that diabetes-induced activation of miR-532 occurs in the later stage of the disease. Importantly, the upregulation of miR-532 preceded the activation of pro-apoptotic caspase-3/7 activity. Finally, inhibition of miR-532 activity in high glucose cultured human cardiomyocytes prevented the downregulation of ARC and attenuated apoptotic cell death. Diabetes induced activation of miR-532 plays a critical role in accelerating cardiomyocytes apoptosis. Therefore, miR-532 may serve as a promising therapeutic agent to overcome the diabetes-induced loss of cardiomyocytes.

The Impact of microRNAs in Renin-Angiotensin-System-Induced Cardiac Remodelling

Current knowledge on the renin-angiotensin system (RAS) indicates its central role in the pathogenesis of cardiovascular remodelling via both hemodynamic alterations and direct growth and the proliferation effects of angiotensin II or aldosterone resulting in the hypertrophy of cardiomyocytes, the proliferation of fibroblasts, and inflammatory immune cell activation. The noncoding regulatory microRNAs has recently emerged as a completely novel approach to the study of the RAS. A growing number of microRNAs serve as mediators and/or regulators of RAS-induced cardiac remodelling by directly targeting RAS enzymes, receptors, signalling molecules, or inhibitors of signalling pathways. Specifically, microRNAs that directly modulate pro-hypertrophic, pro-fibrotic and pro-inflammatory signalling initiated by angiotensin II receptor type 1 (AT1R) stimulation are of particular relevance in mediating the cardiovascular effects of the RAS. The aim of this review is to summarize the current knowledge in the field that is still in the early stage of preclinical investigation with occasionally conflicting reports. Understanding the big picture of microRNAs not only aids in the improved understanding of cardiac response to injury but also leads to better therapeutic strategies utilizing microRNAs as biomarkers, therapeutic agents and pharmacological targets.

Possible key microRNAs and corresponding molecular mechanisms for atrial fibrillation

Objective:

We aimed to find crucial microRNAs (miRNAs) associated with the development of atrial fibrillation (AF), and then try to elucidate the possible molecular mechanisms of miRNAs in AF.

Methods:

The miRNA microarray, GSE68475, which included 10 right atrial appendage samples from patients with persistent AF and 11 samples from patients with normal sinus rhythm, was used for the analysis. After data preprocessing, differentially expressed miRNAs were screened using limma. Target genes of miRNAs were predicted using miRWalk2.0. We then conducted functional enrichment analyses for miRNA and target genes. Protein-protein interaction (PPI) network and module analyses for target genes were performed. Finally, transcription factors (TFs)-target genes regulatory network was predicted and constructed.

Results:

Seven genes, including CAMK2D, IGF2R, PPP2R2A, PAX6, POU3F2, YWHAE, and AP2A2, were targeted by TFs. Among these seven genes, CAMK2D (targeted by miR-31-5p), IGF2R (targeted by miR-204-5p), PAX6 (targeted by miR-223-3p), POU3F2 (targeted by miR-204-5p), YWHAE (targeted by miR-31-5p), and AP2A2 (targeted by miR-204-5p) belonged to the top 10 degree genes in the PPI network. Notably, MiR-204-5p, miR-31-5p, and miR-223-3p had more target genes. Besides, CAMK2D was enriched in some pathways, such as adrenergic signaling in cardiomyocytes pathway and cAMP signaling pathway. YWHAE was enriched in the Hippo signaling pathway.

Conclusion:

miR-31-5p played a crucial role in cardiomyocytes by targeting CAMK2D and YWHAE via cAMP and Hippo signaling pathways. miR-204 was involved in the progression of AF by regulating its target genes IGF2R, POU3F2, and AP2A2. On the other hand, miR-223-3p functioned in AF by targeting PAX6, which was associated with the regulation of apoptosis in AF. This study would provide a theoretical basis and potential therapeutic targets for the treatment of AF.

Concurrent diabetes and heart failure: interplay and novel therapeutic approaches

Diabetes mellitus increases the risk of developing heart failure, and the co-existence of both diseases worsens cardiovascular outcomes, hospitalization and the progression of heart failure. Despite current advancements on therapeutic strategies to manage hyperglycemia, the likelihood of developing diabetes-induced heart failure is still significant, especially with the accelerating global prevalence of diabetes and an ageing population. This raises the likelihood of other contributing mechanisms beyond hyperglycemia in predisposing diabetic patients to cardiovascular disease risk. There has been considerable interest in understanding the alterations in cardiac structure and function in the diabetic patients, collectively termed as "diabetic cardiomyopathy". However, the factors that contribute to the development of diabetic cardiomyopathies is not fully understood. This review summarizes the main characteristics of diabetic cardiomyopathies, and the basic mechanisms that contribute to its occurrence. This includes perturbations in insulin resistance, fuel preference, reactive oxygen species generation, inflammation, cell death pathways, neurohormonal mechanisms, advanced glycated end-products accumulation, lipotoxicity, glucotoxicity, and posttranslational modifications in the heart of the diabetic. This review also discusses the impact of antihyperglycemic therapies on the development of heart failure, as well as how current heart failure therapies influence glycemic control in diabetic patients. We also highlight the current knowledge gaps in understanding how diabetes induces heart failure.

MicroRNAs and long non-coding RNAs in the pathophysiological processes of diabetic cardiomyopathy: emerging biomarkers and potential therapeutics

The epidemic of diabetes mellitus (DM) necessitates the development of novel therapeutic and preventative strategies to attenuate complications of this debilitating disease. Diabetic cardiomyopathy (DCM) is a frequent disorder affecting individuals diagnosed with DM characterized by left ventricular hypertrophy, diastolic and systolic dysfunction and myocardial fibrosis in the absence of other heart diseases. Progression of DCM is associated with impaired cardiac insulin metabolic signaling, increased oxidative stress, impaired mitochondrial and cardiomyocyte calcium metabolism, and inflammation. Various non-coding RNAs, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), as well as their target genes are implicated in the complex pathophysiology of DCM. It has been demonstrated that miRNAs and lncRNAs play an important role in maintaining homeostasis through regulation of multiple genes, thus they attract substantial scientific interest as biomarkers for diagnosis, prognosis and as a potential therapeutic strategy in DM complications. This article will review the different miRNAs and lncRNA studied in the context of DM, including type 1 and type 2 diabetes and the contribution of pathophysiological mechanisms including inflammatory response, oxidative stress, apoptosis, hypertrophy and fibrosis to the development of DCM .

TRPV4 Mediates Cardiac Fibrosis via the TGF-β1/Smad3 Signaling Pathway in Diabetic Rats

Emerging evidence shows that the transient receptor potential vanilloid 4 (TRPV4) channel is involved in fibrosis in many organs. However, its role in diabetic cardiac fibrosis remains unclear. Our aim was to evaluate the expression level of TRPV4 in the diabetic heart and clarify its role in diabetes-induced cardiac fibrosis. A diabetic animal model was induced by a single intraperitoneal injection of streptozotocin into Sprague-Dawley rats. We also investigated cardiac fibroblasts isolated from neonatal Sprague-Dawley rats. TRPV4 expression was significantly upregulated in both diabetic myocardium and cardiac fibroblasts cultured in high-glucose medium. Masson's trichrome staining revealed that the TRPV4 antagonist HC067047 attenuated the diabetes-induced cardiac fibrosis. Furthermore, HC067047 reduced collagen Ι synthesis and suppressed the transforming growth factor beta 1 (TGF-β1) level as well as the phosphorylation of Smad3 in the diabetic heart. In addition, the TRPV4 antagonist inhibited the proliferation of cardiac fibroblasts, collagen Ι synthesis, and activation of the TGF-β1/Smad3 signaling pathway induced by high-glucose culture medium. Our findings demonstrate that the upregulation of TRPV4 expression mediates diabetic cardiac fibrosis via activation of the TGF-β1/Smad3 signaling pathway.

Current Status and Potential Therapeutic Strategies for Using Non-coding RNA to Treat Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DMCM) is the leading cause of mortality and morbidity among diabetic patients. DMCM is characterized by an increase in oxidative stress with systemic inflammation that leads to cardiac fibrosis, ultimately causing diastolic and systolic dysfunction. Even though DMCM pathophysiology is well studied, the approach to limit this condition is not met with success. This highlights the need for more knowledge of underlying mechanisms and innovative therapies. In this regard, emerging evidence suggests a potential role of non-coding RNAs (ncRNAs), including micro-RNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) as novel diagnostics, mechanisms, and therapeutics in the context of DMCM. However, our understanding of ncRNAs’ role in diabetic heart disease is still in its infancy. This review provides a comprehensive update on pre-clinical and clinical studies that might develop therapeutic strategies to limit/prevent DMCM.

Diabetic Cardiomyopathy: Clinical and Metabolic Approach

BACKGROUND

Having in mind that diabetes mellitus (DM) and obesity are some of the greatest health challenges of the modern era, diabetic cardiomyopathy (DCM) is becoming more and more recognized in clinical practice. Main Text: Initially, DM is asymptomatic, but it may progress to diastolic and then systolic left ventricular dysfunction, which results in congestive heart failure. A basic feature of this DM complication is the absence of hemodynamically significant stenosis of the coronary blood vessels. Clinical manifestations are the result of several metabolic disorders that are present during DM progression. The complexity of metabolic processes, along with numerous regulatory mechanisms, has been the subject of research that aims at discovering new diagnostic (e.g. myocardial strain with echocardiography and cardiac magnetic resonance) and treatment options. Adequate glycaemic control is not sufficient to prevent or reduce the progression of DCM. Contemporary hypoglycemic medications, such as sodium-glucose transport protein 2 inhibitors, significantly reduce the frequency of cardiovascular complications in patients with DM. Several studies have shown that, unlike the above-stated medications, thiazolidinediones and dipeptidyl peptidase-4 inhibitors are associated with deterioration of heart failure.

CONCLUSION

Imaging procedures, especially myocardial strain with echocardiography and cardiac magnetic resonance, are useful to identify the early signs of DCM. Research and studies regarding new treatment options are still "in progress".

Overexpression of MicroRNA-133a Inhibits Apoptosis and Autophagy in a Cell Model of Parkinson's Disease by Downregulating Ras-Related C3 Botulinum Toxin Substrate 1 (RAC1)

Background

Parkinson’s disease (PD) is a movement disorder. microRNA (miR)-133 expression is reduced in PD patients and in mice with a dopamine neuron deficiency. We aimed to identify the mechanism of miR-133a in apoptosis and autophagy in PD.

Material/Methods

The optimal concentration of MPP⁺ (1-methyl-4-phenylpyridinium ion) was initially determined to construct a PD cell model. Gain-of function experiments were carried out to evaluate the role of miR-133a in PD. The levels of miR-133a, RAC1 (Ras-related C3 botulinum toxin substrate 1), apoptosis-related factors, and autophagy-related factors were detected after detection of cell proliferation, cell cycle, and apoptosis. Transmission electron microscopy was applied to observe autophagosomes, and immunofluorescence staining was performed to detect LC3 and further analyze the effect of miR-133a on autophagy in a PD cell model.

Results

Low miR-133a expression was detected in a cell model of MPP⁺-induced PD. After overexpressing miR-133a, cell proliferation increased, and apoptosis (cleaved caspase-3 and Bax levels decreased, while Bcl2 levels increased) and autophagy was inhibited (LC3II/I and Beclin-1 levels decreased, while p62 levels increased). MiR-133a targeted RAC1. RACY upregulation attenuated the inhibitory effects of miR-133a on PC12 cell apoptosis and autophagy.

Conclusions

Our data highlighted that miR-133a overexpression prevented apoptosis and autophagy in a cell model of MPP⁺-induced PD by inhibiting RAC1 expression.

The functional duality of SGK1 in the regulation of hyperglycemia

Hyperglycemia is the consequence of blood glucose dysregulation and a driving force of diabetic complications including retinopathy, nephropathy and cardiovascular diseases. The serum and glucocorticoid inducible kinase-1 (SGK1) has been suggested in the modulation of various pathophysiological activities. However, the role of SGK1 in blood glucose homeostasis remains less appreciated. In this review, we intend to summarize the function of SGK1 in glucose level regulation and to examine the evidence supporting the therapeutic potential of SGK1 inhibitors in hyperglycemia. Ample evidence points to the controversial roles of SGK1 in pancreatic insulin secretion and peripheral insulin sensitivity, which reflects the complex interplay between SGK1 activation and blood glucose fluctuation. Furthermore, SGK1 is engaged in glucose absorption and excretion in intestine and kidney and participates in the progression of hyperglycemia-induced secondary organ damage. As a net effect, blockage of SGK1 activation via either pharmacological inhibition or genetic manipulation seems to be helpful in glucose control at varying diabetic stages.

TGF-β and WNT signaling pathways in cardiac fibrosis: non-coding RNAs come into focus

Cardiac fibrosis describes the inappropriate proliferation of cardiac fibroblasts (CFs), leading to accumulation of extracellular matrix (ECM) proteins in the cardiac muscle, which is found in many pathophysiological heart conditions. A range of molecular components and cellular pathways, have been implicated in its pathogenesis. In this review, we focus on the TGF-β and WNT signaling pathways, and their mutual interaction, which have emerged as important factors involved in cardiac pathophysiology. The molecular and cellular processes involved in the initiation and progression of cardiac fibrosis are summarized. We focus on TGF-β and WNT signaling in cardiac fibrosis, ECM production, and myofibroblast transformation. Non-coding RNAs (ncRNAs) are one of the main players in the regulation of multiple pathways and cellular processes. MicroRNAs, long non-coding RNAs, and circular long non-coding RNAs can all interact with the TGF-β/WNT signaling axis to affect cardiac fibrosis. A better understanding of these processes may lead to new approaches for diagnosis and treatment of many cardiac conditions. Video Abstract.

Basic Mechanisms of Diabetic Heart Disease

Diabetes mellitus predisposes affected individuals to a significant spectrum of cardiovascular complications, one of the most debilitating in terms of prognosis is heart failure. Indeed, the increasing global prevalence of diabetes mellitus and an aging population has given rise to an epidemic of diabetes mellitus-induced heart failure. Despite the significant research attention this phenomenon, termed diabetic cardiomyopathy, has received over several decades, understanding of the full spectrum of potential contributing mechanisms, and their relative contribution to this heart failure phenotype in the specific context of diabetes mellitus, has not yet been fully resolved. Key recent preclinical discoveries that comprise the current state-of-the-art understanding of the basic mechanisms of the complex phenotype, that is, the diabetic heart, form the basis of this review. Abnormalities in each of cardiac metabolism, physiological and pathophysiological signaling, and the mitochondrial compartment, in addition to oxidative stress, inflammation, myocardial cell death pathways, and neurohumoral mechanisms, are addressed. Further, the interactions between each of these contributing mechanisms and how they align to the functional, morphological, and structural impairments that characterize the diabetic heart are considered in light of the clinical context: from the disease burden, its current management in the clinic, and where the knowledge gaps remain. The need for continued interrogation of these mechanisms (both known and those yet to be identified) is essential to not only decipher the how and why of diabetes mellitus-induced heart failure but also to facilitate improved inroads into the clinical management of this pervasive clinical challenge.

Prospective Advances in Non-coding RNAs Investigation

Non-coding RNAs (ncRNAs) play significant roles in numerous physiological cellular processes and molecular alterations during pathological conditions including heart diseases, cancer, immunological disorders and neurological diseases. This chapter is focusing on the basis of ncRNA relation with their functions and prospective advances in non-coding RNAs particularly miRNAs investigation in the cardiovascular disease management.The field of ncRNAs therapeutics is a very fascinating and challenging too. Scientists have opportunity to develop more advanced therapeutics as well as diagnostic approaches for cardiovascular conditions. Advanced studies are critically needed to deepen the understanding of the molecular biology, mechanism and modulation of ncRNAs and chemical formulations for managing CVDs.

Human induced pluripotent stem cell-derived cardiomyocytes reveal abnormal TGFβ signaling in type 2 diabetes mellitus

Diabetes mellitus is a serious metabolic condition associated with a multitude of cardiovascular complications. Moreover, the prevalence of diabetes in heart failure populations is higher than that in control populations. However, the role of cardiomyocyte alterations in type 2 diabetes mellitus (T2DM) has not been well characterized and the underlying mechanisms remain elusive. In this study, two patients who were diagnosed as T2DM were recruited and patient-specific induced pluripotent stem cells (iPSCs) were generated from urine epithelial cells using nonintegrated Sendai virus. The iPSC lines derived from five healthy subjects were used as controls. All iPSCs were differentiated into cardiomyocytes (iPSC-CMs) using the monolayer-based differentiation protocol. T2DM iPSC-CMs exhibited various disease phenotypes, including cellular hypertrophy and lipid accumulation. Moreover, T2DM iPSC-CMs exhibited higher susceptibility to high-glucose/high-lipid challenge than control iPSC-CMs, manifesting an increase in apoptosis. RNA-Sequencing analysis revealed a differential transcriptome profile and abnormal activation of TGFβ signaling pathway in T2DM iPSC-CMs. We went on to show that inhibition of TGFβ significantly rescued the hypertrophic phenotype in T2DM iPSC-CMs. In conclusion, we demonstrate that the iPSC-CM model is able to recapitulate cellular phenotype of T2DM. Our results indicate that iPSC-CMs can therefore serve as a suitable model for investigating molecular mechanisms underlying diabetic cardiomyopathies and for screening therapeutic drugs.

Mitochondrial Mechanisms in Diabetic Cardiomyopathy

Mitochondrial medicine is increasingly discussed as a promising therapeutic approach, given that mitochondrial defects are thought to contribute to many prevalent diseases and their complications. In individuals with diabetes mellitus (DM), defects in mitochondrial structure and function occur in many organs throughout the body, contributing both to the pathogenesis of DM and complications of DM. Diabetic cardiomyopathy (DbCM) is increasingly recognized as an underlying cause of increased heart failure in DM, and several mitochondrial mechanisms have been proposed to contribute to the development of DbCM. Well established mechanisms include myocardial energy depletion due to impaired adenosine triphosphate (ATP) synthesis and mitochondrial uncoupling, and increased mitochondrial oxidative stress. A variety of upstream mechanisms of impaired ATP regeneration and increased mitochondrial reactive oxygen species have been proposed, and recent studies now also suggest alterations in mitochondrial dynamics and autophagy, impaired mitochondrial Ca²⁺ uptake, decreased cardiac adiponectin action, increased O-GlcNAcylation, and impaired activity of sirtuins to contribute to mitochondrial defects in DbCM, among others. In the current review, we present and discuss the evidence that underlies both established and recently proposed mechanisms that are thought to contribute to mitochondrial dysfunction in DbCM.

Circulating miR-135 May Serve as a Novel Co-biomarker of HbA1c in Type 2 Diabetes

Hemoglobin A1c (HbA1c) is a reliable marker of insulin resistance in normal glucose tolerance patients; however, several physiological, environmental, and genetic factors may affect HbA1c and cause false results. Therefore, it is essential to use new biomarkers due to increasing diabetes predictive value. Recently, it has been indicated that microRNAs (miRNAs) are involved in the pathophysiology of diabetes, particularly, in insulin resistance pathways. Therefore, miRNAs have the potential to be introduced as new glycemic control biomarkers. The aim of this study was to investigate the association between plasma level of miRNA-135a and HbA1c in patients with prediabetes and type 2 diabetes. In this case-control study, 120 samples were enrolled (healthy individuals, people with type 2 diabetes, and prediabetes) and HbA1c and miR-135a expression level in their plasma samples were evaluated. Multinomial logistic regression and ROC curve analysis were conducted to assess the diagnostic accuracy of plasma miR-135a in T2D , prediabetes, and healthy control groups. Data analysis indicated that miR-135a was significantly elevated in both diabetes/prediabetes samples. Then, subjects were reclassified based on the calculated cutoff value of miRNA. Logistic Regression analysis showed that an increased level of miRNA positively correlated with HbA1c level in prediabetes (Adjusted OR = 1.14, p value = 0.033) and diabetic status (Adjusted OR = 1.27, p value = 0.024 ). miR-135 may provide an assistant marker for HbA1c to detect type 2 diabetes.

Circulating miR-30c as a predictive biomarker of type 2 diabetes mellitus with coronary heart disease by regulating PAI-1/VN interactions

AIMS

Type 2 diabetes mellitus (DM2) is associated with coronary heart disease (CHD) and is characterized by high levels of plasminogen activator inhibitor (PAI)-1. Circulating microRNAs have been reported as potential diagnostic biomarkers for DM2 and CHD. However, the underlying mechanisms have largely remained unclear.

MAIN METHODS

The changes of circulating miR-30c, PAI-1 and vitronetin (VN) in plasma from CHD, noncomplicated (NC) + DM2, CHD + DM2 subjects and control individuals were assessed by quantitative reverse transcription PCR (qRT-PCR) and ELISA assays, respectively. The effects of miR-30c on VN expression by targeting PAI-1 were assessed in vitro SMC and in ex vivo plasma, using bioinformatic analysis, miRNA transfection, luciferase assays, qRT-PCR and western blot, respectively.

KEY FINDINGS

We found that decreased circulating miR-30c was negatively correlated with the severity of coronary lesions and the resulting elevated PAI-1 and VN levels. Circulating miR-30c significantly distinguished between patients with CHD + DM2, NC + DM2, CHD and control subjects, and that were significantly associated with certain risk factors for progression from a normal individual to one with CHD + DM2. Furthermore, we also showed that miR-30c plays a previously unrecognized role in regulating the expression of VN levels via regulating PAI-1 levels in vitro SMC and in ex vivo plasma.

SIGNIFICANCE

These findings provide a novel regulatory mechanism of miR-30c in regulating PAI-1/VN interactions and that may serve as a diagnostic biomarker of DM2 that is complicated with CHD.

miR-22-3p is involved in gluconeogenic pathway modulated by 3,5-diiodo-L-thyronine (T2)

The 3,5-diiodo-L-thyronine (T2) has emerged as an active iodothyronine and its beneficial effects on glucose metabolism including glucose tolerance and insulin resistance is well established. However, little is known about its molecular mechanisms. Given the emerging importance of microRNAs in various metabolic diseases, in this study a possible link between the effects of T2 on glucose metabolism and miRNA expression was investigated by using an in vivo model in which T2 was administered in rats receiving a high fat diet, a condition known to impair glucose homeostasis. The results showed that T2-treated rats had a better tolerance to glucose load and a better performance at the insulin tolerance test in comparison to high fat diet animals. Interestingly, in the serum of the animals treated with T2 there was a general decrease of miRNAs with miR-22a-3p, miR-34c-5p and miR-33a-3p significantly downregulated. Furthermore, miR-22a-3p had the largest variation pointing toward its preeminent role in T2 metabolic effect. In fact, in liver there was an up-regulation of its target (Transcription Factor 7) Tcf7, which had an important impact on gluconeogenesis. This study provide, for the first time, evidences that miRNAs are involved in the effects exerted by T2 on glucose homeostasis.

MicroRNAs in Cardiac Hypertrophy

Like other organs, the heart undergoes normal adaptive remodeling, such as cardiac hypertrophy, with age. This remodeling, however, is intensified under stress and pathological conditions. Cardiac remodeling could be beneficial for a short period of time, to maintain a normal cardiac output in times of need; however, chronic cardiac hypertrophy may lead to heart failure and death. MicroRNAs (miRNAs) are known to have a role in the regulation of cardiac hypertrophy. This paper reviews recent advances in the field of miRNAs and cardiac hypertrophy, highlighting the latest findings for targeted genes and involved signaling pathways. By targeting pro-hypertrophic genes and signaling pathways, some of these miRNAs alleviate cardiac hypertrophy, while others enhance it. Therefore, miRNAs represent very promising potential pharmacotherapeutic targets for the management and treatment of cardiac hypertrophy.

Non-coding RNA involvement in the pathogenesis of diabetic cardiomyopathy

In recent years, the incidence of diabetes has been increasing rapidly, which seriously endangers human health. Diabetic cardiomyopathy, an important cardiovascular complication of diabetes, is characterized by myocardial fibrosis, ventricular remodelling and cardiac dysfunction. It has been documented that mitochondrial dysfunction, oxidative stress, inflammatory response, autophagy, apoptosis, diabetic microangiopathy and myocardial fibrosis are implicated in the pathogenesis of diabetic cardiomyopathy. With the development of molecular biology technology, accumulating evidence demonstrates that non‐coding RNAs (ncRNAs) are critically involved in the molecular mechanisms of diabetic cardiomyopathy. In this review, we summarize the pathological roles of three types of ncRNAs (microRNA, long ncRNA and circular RNA) in the progression of diabetic cardiomyopathy, which may provide valuable insights into the pathogenesis of diabetic cardiovascular complications.

Identification of microRNAs and genes as biomarkers of atrial fibrillation using a bioinformatics approach

Objective

We aimed to explore potential microRNAs (miRNAs) and target genes related to atrial fibrillation (AF).

Methods

Data for microarrays GSE70887 and GSE68475, both of which include AF and control groups, were downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs between AF and control groups were identified within each microarray, and the intersection of these two sets was obtained. These miRNAs were mapped to target genes in the miRNet database. Functional annotation and enrichment analysis of these target genes was performed in the DAVID database. The protein-protein interaction (PPI) network from the STRING database and the miRNA-target-gene network were merged into a PPI-miRNA network using Cytoscape software. Modules of this network containing miRNAs were detected and further analyzed.

Results

Ten differentially expressed miRNAs and 1520 target genes were identified. Three PPI-miRNA modules were constructed, which contained miR-424, miR-15a, miR-542-3p, and miR-421 as well as their target genes, CDK1, CDK6, and CCND3.

Conclusion

The identified miRNAs and genes may be related to the pathogenesis of AF. Thus, they may be potential biomarkers for diagnosis and targets for treatment of AF.

Transgenic Expression of miR-133a in the Diabetic Akita Heart Prevents Cardiac Remodeling and Cardiomyopathy

Advanced diabetes mellitus (DM) may have both insulin resistance and deficiency (double DM) that accelerates diabetic cardiomyopathy (DMCM), a cardiac muscle disorder. Reduced cardiac miR-133a, a cardioprotective miRNA, is associated with DMCM. However, it is unclear whether increasing miR-133a levels in the double DM heart could prevent DMCM. We hypothesized that increasing cardiac levels of miR-133a could prevent DMCM in Akita, a mouse model of double DM. To test the hypothesis, we created Akita/miR-133aTg mice, a new strain of Akita where miR-133a is overexpressed in the heart, by crossbreeding male Akita with female cardiac-specific miR-133a transgenic mice. We validated Akita/miR-133aTg mice by genotyping and phenotyping (miR-133a levels in the heart). To determine whether miR-133a overexpression could prevent cardiac remodeling and cardiomyopathy, we evaluated cardiac fibrosis, hypertrophy, and dysfunction (P-V loop) in 13-15 week male WT, Akita, Akita/miR-133aTg, and miR-133aTg mice. Our results revealed that miR-133a overexpression in the Akita heart prevents DM-induced cardiac fibrosis (reduced collagen deposition), hypertrophy (decreased beta-myosin heavy chain), and impaired contractility (downregulated calcium handling protein sarco-endoplasmic reticulum-ATPase-2a). These results demonstrate that increased levels of miR-133a in the DM heart could prevent cardiac remodeling. Our P-V loop analysis showed a trend of decreased cardiac output, stroke volume, and ± dp/dt in Akita, which were blunted in Akita/miR-133aTg heart. These findings suggest that 13-15 week Akita heart undergoes adverse remodeling toward cardiomyopathy, which is prevented by miR-133a overexpression. In addition, increased cardiac miR-133a in the Akita heart did not change blood glucose levels but decreased lipid accumulation in the heart, suggesting inhibition of metabolic remodeling in the heart. Thus, miR-133a could be a promising therapeutic candidate to prevent DMCM.

Increased Extracellular Matrix Protein Production in Chronic Diabetic Complications: Implications of Non-Coding RNAs

Management of chronic diabetic complications remains a major medical challenge worldwide. One of the characteristic features of all chronic diabetic complications is augmented production of extracellular matrix (ECM) proteins. Such ECM proteins are deposited in all tissues affected by chronic complications, ultimately causing organ damage and dysfunction. A contributing factor to this pathogenetic process is glucose-induced endothelial damage, which involves phenotypic transformation of endothelial cells (ECs). This phenotypic transition of ECs, from a quiescent state to an activated dysfunctional state, can be mediated through alterations in the synthesis of cellular proteins. In this review, we discussed the roles of non-coding RNAs, specifically microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in such processes. We further outlined other epigenetic mechanisms regulating the biogenesis and/or function of non-coding RNAs. Overall, we believe that better understanding of such molecular processes may lead to the development of novel biomarkers and therapeutic strategies in the future.

Research Progress on the Biological Effects of Low-Dose Radiation in China

Human are exposed to ionizing radiation from natural and artificial sources, which consequently poses a possible risk to human health. However, accumulating evidence indicates that the biological effects of low-dose radiation (LDR) are different from those of high-dose radiation (HDR). Low-dose radiation–induced hormesis has been extensively observed in different biological systems, including immunological and hematopoietic systems. Adaptive responses in response to LDR that can induce cellular resistance to genotoxic effects from subsequent exposure to HDR have also been described and researched. Bystander effects, another type of biological effect induced by LDR, have been shown to widely occur in many cell types. Furthermore, the influence of LDR-induced biological effects on certain diseases, such as cancer and diabetes, has also attracted the interest of researchers. Many studies have suggested that LDR has the potential antitumor and antidiabetic complications effects. In addition, the researches on whether LDR could induce stochastic effects were also debated. Studies on the biological effects of LDR in China started in 1970s and considerable progress has been made since. In the present article, we provide an overview of the research progress on the biological effects of LDR in China.

Different expression of Micro RNA-126, 133a and 145 in aorta and saphenous vein samples of patients undergoing coronary artery bypass graft surgery

Introduction: microRNAs (miRNAs) are highly conserved, noncoding RNA molecules that regulate gene expression on the post-transcriptional level. Some evidence indicates that microRNAs dysfunction plays a crucial role in human disease development. The role of microRNAs in cardiac growth, hypertrophy, heart failure, cardiovascular complications in diabetes and many other hearth conditions are demonstrated. In this study we aimed to evaluate the expression of six microRNAs (mir-100, mir-126, mir-127, mir-133a, mir-133b and mir-145) that have been shown to overexpress in aortic and carotid plaques.

Methods: Thirty Coronary Artery Disease patients who underwent elective coronary artery bypass graft surgery were enrolled in the study. The expression patterns of six miRNAs (mir-100, mir-126, mir-127, mir-133a, mir-133b, and mir-145) were examined in 30 patients of whom we obtained aorta and saphenous vein samples.

Results: In three miRNAs, mir-100, mir-127 and mir-133b, we did not obtain expression data from real-time experiments. We found that the expression level of mir-126, mir-133a and mir145 were lower in aorta in comparison with saphenous vein. Mir-126 was highly expressed in saphenous vein samples (13.8±1.1) when compared with aorta samples (20.2±1.1), although mir133a was highly expressed in saphenous vein samples (16.1±0.5) when compared with the aorta (17.9±1.5). Expression of mir-145 saphenous vein samples was also dramatically higher than aorta (7.2±0.5 versus 10.8±0.6) that was statistically significant (P<0.05).

Conclusion: Understanding the role of miRNAs in cardiovascular physiology and diseases might suggest miRNA- based therapeutic methods in the management of coronary artery disease.

Early dysregulation of cardiac-specific microRNA-208a is linked to maladaptive cardiac remodelling in diabetic myocardium

BACKGROUND

The diabetic heart undergoes remodelling contributing to an increased incidence of heart failure in individuals with diabetes at a later stage. The molecular regulators that drive this process in the diabetic heart are still unknown.

METHODS

Real-time (RT) PCR analysis was performed to determine the expression of cardiac specific microRNA-208a in right atrial appendage (RAA) and left ventricular (LV) biopsy tissues collected from diabetic and non-diabetic patients undergoing coronary artery bypass graft surgery. To determine the time-dependent changes, cardiac tissue were collected from type 2 diabetic mice at different age groups. A western blotting analysis was conducted to determine the expression of contractile proteins α- and β-myosin heavy chain (MHC) and thyroid hormone receptor-α (TR-α), the negative regulator of β-MHC. To determine the beneficial effects of therapeutic modulation of miR-208a, high glucose treated adult mouse HL-1 cardiomyocytes were transfected with anti-miR-208a.

RESULTS

RT-PCR analysis showed marked upregulation of miR-208a from early stages of diabetes in type 2 diabetic mouse heart, which was associated with a marked increase in the expression of pro-hypertrophic β-MHC and downregulation of TR-α. Interestingly, upregulation of miR-208a preceded the switch of α-/β-MHC isoforms and the development of diastolic and systolic dysfunction. We also observed significant upregulation of miR-208a and modulation of miR-208a associated proteins in the type 2 human diabetic heart. Therapeutic inhibition of miR-208a activity in high glucose treated HL-1 cardiomyocytes prevented the activation of β-MHC and hence the hypertrophic response.

CONCLUSION

Our results provide the first evidence that early modulation of miR-208a in the diabetic heart induces alterations in the downstream signaling pathway leading to cardiac remodelling and that therapeutic inhibition of miR-208a may be beneficial in preventing diabetes-induced adverse remodelling of the heart.

MiR-133a Mimic Alleviates T1DM-Induced Systolic Dysfunction in Akita: An MRI-Based Study

Diabetic cardiomyopathy is a leading cause of heart failure. Developing a novel therapeutic strategy for diabetic cardiomyopathy and characterizing animal models used for diabetes mellitus (DM) are important. Insulin 2 mutant (Ins2^+/-) Akita is a spontaneous, genetic, mouse model for T1DM, which is relevant to humans. There are contrasting reports on systolic dysfunction and pathological remodeling (hypertrophy and fibrosis) in Akita heart. Here, we used magnetic resonance imaging (MRI) approach, a gold standard reference for evaluating cardiac function, to measure ejection fraction (indicator of systolic dysfunction) in Akita. Moreover, we performed Wheat Germ Agglutinin (WGA) and hematoxylin and Eosin stainings to determine cardiac hypertrophy, and Masson's Trichrome and picrosirius red stainings to determine cardiac fibrosis in Akita. MiR-133a, an anti-hypertrophy and anti-fibrosis miRNA, is downregulated in Akita heart. We determined if miR-133a mimic treatment could mitigate systolic dysfunction and remodeling in Akita heart. Our MRI results revealed decreased ejection fraction in Akita as compared to WT and increased ejection fraction in miR-133a mimic-treated Akita. We also found that miR-133a mimic treatment mitigates T1DM-induced cardiac hypertrophy and fibrosis in Akita. We conclude that Akita shows cardiac hypertrophy, fibrosis and systolic dysfunction and miR-133a mimic treatment to Akita could ameliorate them.