MiR-30c/PGC-1β protects against diabetic cardiomyopathy via PPARα

Novel Insights Into the Pathogenesis of Diabetic Cardiomyopathy and Pharmacological Strategies

Diabetic cardiomyopathy (DCM) is a severe complication of diabetes developed mainly in poorly controlled patients. In DCM, several clinical manifestations as well as cellular and molecular mechanisms contribute to its phenotype. The production of reactive oxygen species (ROS), chronic low-grade inflammation, mitochondrial dysfunction, autophagic flux inhibition, altered metabolism, dysfunctional insulin signaling, cardiomyocyte hypertrophy, cardiac fibrosis, and increased myocardial cell death are described as the cardinal features involved in the genesis and development of DCM. However, many of these features can be associated with broader cellular processes such as inflammatory signaling, mitochondrial alterations, and autophagic flux inhibition. In this review, these mechanisms are critically discussed, highlighting the latest evidence and their contribution to the pathogenesis of DCM and their potential as pharmacological targets.

Signaling Pathways Related to Oxidative Stress in Diabetic Cardiomyopathy

Diabetes is a chronic metabolic disease that is increasing in prevalence and causes many complications. Diabetic cardiomyopathy (DCM) is a complication of diabetes that is associated with high mortality, but it is not well defined. Nevertheless, it is generally accepted that DCM refers to a clinical disease that occurs in patients with diabetes and involves ventricular dysfunction, in the absence of other cardiovascular diseases, such as coronary atherosclerotic heart disease, hypertension, or valvular heart disease. However, it is currently uncertain whether the pathogenesis of DCM is directly attributable to metabolic dysfunction or secondary to diabetic microangiopathy. Oxidative stress (OS) is considered to be a key component of its pathogenesis. The production of reactive oxygen species (ROS) in cardiomyocytes is a vicious circle, resulting in further production of ROS, mitochondrial DNA damage, lipid peroxidation, and the post-translational modification of proteins, as well as inflammation, cardiac hypertrophy and fibrosis, ultimately leading to cell death and cardiac dysfunction. ROS have been shown to affect various signaling pathways involved in the development of DCM. For instance, OS causes metabolic disorders by affecting the regulation of PPARα, AMPK/mTOR, and SIRT3/FOXO3a. Furthermore, OS participates in inflammation mediated by the NF-κB pathway, NLRP3 inflammasome, and the TLR4 pathway. OS also promotes TGF-β-, Rho-ROCK-, and Notch-mediated cardiac remodeling, and is involved in the regulation of calcium homeostasis, which impairs ATP production and causes ROS overproduction. In this review, we summarize the signaling pathways that link OS to DCM, with the intention of identifying appropriate targets and new antioxidant therapies for DCM.

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.

miR-320a induces pancreatic β cells dysfunction in diabetes by inhibiting MafF

A variety of studies indicate that microRNAs (miRNAs) are involved in diabetes. However, the direct role of miR-320a in the pathophysiology of pancreatic β cells under diabetes mellitus remains unclear. In the current study, islet transplantation and hyperglycemic clamp assays were performed in miR-320a transgenic mice to explore the effects of miR-320a on pancreatic β cells in vivo. Meanwhile, β cell-specific overexpression or inhibition of miR-320a was delivered by adeno-associated virus (AAV8). In vitro, overexpression or downregulation of miR-320a was introduced in cultured rat islet tumor cells (INS1). RNA immunoprecipitation sequencing (RIP-Seq), luciferase reporter assay, and western blotting were performed to identify the target genes. Results showed that miR-320a was increased in the pancreatic β cells from high-fat-diet (HFD)-treated mice. Overexpression of miR-320a could not only deteriorate the HFD-induced pancreatic islet dysfunction, but also initiate pancreatic islet dysfunction spontaneously in vivo. Meanwhile, miR-320a increased the ROS level, inhibited proliferation, and induced apoptosis of cultured β cells in vitro. Finally, we identified that MafF was the target of miR-320a that responsible for the dysfunction of pancreatic β cells. Our data suggested that miR-320a could damage the pancreatic β cells directly and might be a potential therapeutic target of diabetes.

Heart failure in diabetes

Heart failure and cardiovascular disorders represent the leading cause of death in diabetic patients. Here we present a systematic review of the main mechanisms underlying the development of diabetic cardiomyopathy. We also provide an excursus on the relative contribution of cardiomyocytes, fibroblasts, endothelial and smooth muscle cells to the pathophysiology of heart failure in diabetes. After having described the preclinical tools currently available to dissect the mechanisms of this complex disease, we conclude with a section on the most recent updates of the literature on clinical management.

Medium & long-chain acylcarnitine's relation to lipid metabolism as potential predictors for diabetic cardiomyopathy: a metabolomic study

Background

Acylcarnitine is an intermediate product of fatty acid oxidation. It is reported to be closely associated with the occurrence of diabetic cardiomyopathy (DCM). However, the mechanism of acylcarnitine affecting myocardial disorders is yet to be explored. This current research explores the different chain lengths of acylcarnitines as biomarkers for the early diagnosis of DCM and the mechanism of acylcarnitines for the development of DCM in-vitro.

Methods

In a retrospective non-interventional study, 50 simple type 2 diabetes mellitus patients and 50 DCM patients were recruited. Plasma samples from both groups were analyzed by high throughput metabolomics and cluster heat map using mass spectrometry. Principal component analysis was used to compare the changes occurring in the studied 25 acylcarnitines. Multivariable binary logistic regression was used to analyze the odds ratio of each group for factors and the 95% confidence interval in DCM. Myristoylcarnitine (C14) exogenous intervention was given to H9c2 cells to verify the expression of lipid metabolism-related protein, inflammation-related protein expression, apoptosis-related protein expression, and cardiomyocyte hypertrophy and fibrosis-related protein expression.

Results

Factor 1 (C14, lauroylcarnitine, tetradecanoyldiacylcarnitine, 3-hydroxyl-tetradecanoylcarnitine, arachidic carnitine, octadecanoylcarnitine, 3-hydroxypalmitoleylcarnitine) and factor 4 (octanoylcarnitine, hexanoylcarnitine, decanoylcarnitine) were positively correlated with the risk of DCM. Exogenous C14 supplementation to cardiomyocytes led to increased lipid deposition in cardiomyocytes along with the obstacles in adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathways and affecting fatty acid oxidation. This further caused myocardial lipotoxicity, ultimately leading to cardiomyocyte hypertrophy, fibrotic remodeling, and increased apoptosis. However, this effect was mitigated by the AMPK agonist acadesine.

Conclusions

The increased plasma levels in medium and long-chain acylcarnitine extracted from factors 1 and 4 are closely related to the risk of DCM, indicating that these factors can be an important tool for DCM risk assessment. C14 supplementation associated lipid accumulation by inhibiting the AMPK/ACC/CPT1 signaling pathway, aggravated myocardial lipotoxicity, increased apoptosis apart from cardiomyocyte hypertrophy and fibrosis were alleviated by the acadesine.

MicroRNA regulation of the proliferation and apoptosis of Leydig cells in diabetes

BACKGROUND

The number of patients with diabetes is increasing worldwide. Diabetic testicular damage can cause spermiogenesis disorders and sexual dysfunction. We thus explored the role of miRNAs in diabetic testicular damage, and revealed that they could serve as effective prevention and treatment therapeutic targets.

METHODS

Streptozotocin (STZ) was used to generate a rat model of type 2 diabetes. Rat testicular tissues were used for miRNA and mRNA sequencing. Through bioinformatics analysis, we constructed an miRNA-mRNA diabetic testicular damage regulatory network and screened for key miRNAs. We also used Leydig cells to generate a diabetic cell model and detected the downstream target genes of miRNAs, secretion of testosterone, and proliferation and apoptotic levels to elucidate the role and mechanism of the selected miRNAs in diabetic testicular damage.

RESULTS

Using second-generation sequencing, we identified 19 differentially expressed miRNAs and 555 mRNAs in the testes of diabetic rats. Based on computational prediction of targets and negative regulation relationships, we constructed a miRNA-mRNA regulatory network, including 12 miRNAs and 215 mRNAs. KEGG enrichment analysis revealed that genes were more concentrated on the survival signalling pathway. Based on this, we screened 2 key miRNAs, miR-504 and miR-935. In vitro, glucose could induce an increase in miR-504 and miR-935, whereas a decrease in MEK5 and MEF2C in a dose-dependent manner. Overexpression of miR-504 and miR-935 led to the decreased expression of MEK5 and MEF2C, decreased proliferation rate of Leydig cells, increased apoptotic rate, and decreased secretion of testosterone. Whereas, knockdown of miR-504 and miR-935 displayed opposite tendencies.

CONCLUSIONS

miRNAs play important roles in diabetic testicular damage. miR-504 and miR-935 might regulate testicular damage through the classic survival pathway of MEK5-ERK5-MEF2C. Targeted inhibition of miR-504 and miR-935 could reverse the high-glucose-induced testicular complications, thus posing as a potential therapeutic approach in diabetic testicular injury.

MicroRNA-30c-5p protects against myocardial ischemia/reperfusion injury via regulation of Bach1/Nrf2

MicroRNAs (miRNAs) are critical regulatory factors in myocardial ischemia/reperfusion (I/R) injury. The miRNA miR-30c-5p has been reported as a key mediator in several myocardial abnormalities. However, the precise roles and mechanisms of miR-30c-5p in myocardial I/R injury remain not well-studied. This project aimed to explore the potential function of this miRNA in mediating myocardial I/R injury. Significant induction of miR-30c-5p was observed in myocardial tissue of rats with myocardial I/R injury in vivo and cardiomyocytes with hypoxia/re‑oxygenation (H/R) injury in vitro. Functional studies elucidated that forced expression of miR-30c-5p in rats effectively reduced infarct area, cardiac apoptosis, oxidative stress and inflammation induced by myocardial I/R injury. Moreover, in vitro cardiomyocytes with forced expression of miR-30c-5p were also protected from H/R-induced apoptosis, oxidative stress and inflammation. Importantly, BTB domain and CNC homology 1 (Bach1) was identified as a new target of miR-30c-5p. miR-30c-5p was shown to promote the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via the inhibition of Bach1. The re-expression of Bach1 reversed miR-30c-5p-mediated-cardioprotective effects against myocardial I/R injury in vivo or H/R injury in vitro. Overall, our results demonstrate that forced expression of miR-30c-5p exhibited beneficial effects against myocardial I/R injury through enhancement of Nrf2 activation via inhibition of Bach1. This work reveals a novel molecular mechanism for myocardial I/R injury at the miRNA level and suggests a therapeutic value of miR-30c-5p in treatment of myocardial I/R injury.

Roles of MicroRNAs in Glucose and Lipid Metabolism in the Heart

MicroRNAs (miRNAs) are small non-coding RNAs that participate in heart development and pathological processes mainly by silencing gene expression. Overwhelming evidence has suggested that miRNAs were involved in various cardiovascular pathological processes, including arrhythmias, ischemia-reperfusion injuries, dysregulation of angiogenesis, mitochondrial abnormalities, fibrosis, and maladaptive remodeling. Various miRNAs could regulate myocardial contractility, vascular proliferation, and mitochondrial function. Meanwhile, it was reported that miRNAs could manipulate nutrition metabolism, especially glucose and lipid metabolism, by regulating insulin signaling pathways, energy substrate transport/metabolism. Recently, increasing studies suggested that the abnormal glucose and lipid metabolism were closely associated with a broad spectrum of cardiovascular diseases (CVDs). Therefore, maintaining glucose and lipid metabolism homeostasis in the heart might be beneficial to CVD patients. In this review, we summarized the present knowledge of the functions of miRNAs in regulating cardiac glucose and lipid metabolism, as well as highlighted the miRNA-based therapies targeting cardiac glucose and lipid metabolism.

PGC1s and Beyond: Disentangling the Complex Regulation of Mitochondrial and Cellular Metabolism

Metabolism is the central engine of living organisms as it provides energy and building blocks for many essential components of each cell, which are required for specific functions in different tissues. Mitochondria are the main site for energy production in living organisms and they also provide intermediate metabolites required for the synthesis of other biologically relevant molecules. Such cellular processes are finely tuned at different levels, including allosteric regulation, posttranslational modifications, and transcription of genes encoding key proteins in metabolic pathways. Peroxisome proliferator activated receptor γ coactivator 1 (PGC1) proteins are transcriptional coactivators involved in the regulation of many cellular processes, mostly ascribable to metabolic pathways. Here, we will discuss some aspects of the cellular processes regulated by PGC1s, bringing up some examples of their role in mitochondrial and cellular metabolism, and how metabolic regulation in mitochondria by members of the PGC1 family affects the immune system. We will analyze how PGC1 proteins are regulated at the transcriptional and posttranslational level and will also examine other regulators of mitochondrial metabolism and the related cellular functions, considering approaches to identify novel mitochondrial regulators and their role in physiology and disease. Finally, we will analyze possible therapeutical perspectives currently under assessment that are applicable to different disease states.

TSH attenuates fatty acid oxidation in hepatocytes by reducing the mitochondrial distribution of miR-449a/449b-5p/5194

The elevated thyroid-stimulating hormone (TSH) levels contribute to the abnormal expression/activity of several key hepatic lipid metabolism enzymes. Although miRNAs have been shown to play key roles in hepatic lipid metabolism and are found in isolated mitochondria, very little is known about the pathological and physiological significance of their mitochondrial distributions in regulating liver lipid metabolism. Here, we found that TSH significantly reduced the distribution of some miRNAs in mitochondria of hepatocytes, especially miR-449a, miR-449b-5p, and miR-5194. These three miRNAs inhibited their target genes PGC1B, ABCD1, ADIPOR1 and the downstream molecule PPARA. These effects synergistically suppressed fatty acid (FA) β-oxidation in mitochondria and peroxisomes and decreased the translocation of cytosolic very long chain fatty acids to peroxisomes, which noticeably reduced FA catabolism and promoted triglyceride accumulation in hepatocytes. This study reveals the functional significance of changed miRNA mitochondrial-cytoplasmic distribution in the regulation of hepatic lipid metabolism.

Adeno-associated viral (AAV) vector-mediated therapeutics for diabetic cardiomyopathy - current and future perspectives

Diabetes increases the prevalence of heart failure by 6-8-fold, independent of other comorbidities such as hypertension and coronary artery disease, a phenomenon termed diabetic cardiomyopathy. Several key signalling pathways have been identified that drive the pathological changes associated with diabetes-induced heart failure. This has led to the development of multiple pharmacological agents that are currently available for clinical use. While fairly effective at delaying disease progression, these treatments do not reverse the cardiac damage associated with diabetes. One potential alternative avenue for targeting diabetes-induced heart failure is the use of adeno-associated viral vector (AAV) gene therapy, which has shown great versatility in a multitude of disease settings. AAV gene therapy has the potential to target specific cells or tissues, has a low host immune response and has the possibility to represent a lifelong cure, not possible with current conventional pharmacotherapies. In this review, we will assess the therapeutic potential of AAV gene therapy as a treatment for diabetic cardiomyopathy.

Insulin micro-secretion in Type 1 diabetes and related microRNA profiles

The aim of this cross-sectional study was to compare plasma C-peptide presence and levels in people without diabetes (CON) and with Type 1 diabetes and relate C-peptide status to clinical factors. In a subset we evaluated 50 microRNAs (miRs) previously implicated in beta-cell death and associations with clinical status and C-peptide levels. Diabetes age of onset was stratified as adult (≥ 18 y.o) or childhood (< 18 y.o.), and diabetes duration was stratified as ≤ 10 years, 10–20 years and > 20 years. Plasma C-peptide was measured by ultrasensitive ELISA. Plasma miRs were quantified using TaqMan probe-primer mix on an OpenArray platform. C-peptide was detectable in 55.3% of (n = 349) people with diabetes, including 64.1% of adults and 34.0% of youth with diabetes, p < 0.0001 and in all (n = 253) participants without diabetes (CON). C-peptide levels, when detectable, were lower in the individuals with diabetes than in the CON group [median lower quartile (LQ)–upper quartile (UQ)] 5.0 (2.6–28.7) versus 650.9 (401.2–732.4) pmol/L respectively, p < 0.0001 and lower in childhood versus adult-onset diabetes [median (LQ–UQ) 4.2 (2.6–12.2) pmol/L vs. 8.0 (2.3–80.5) pmol/L, p = 0.02, respectively]. In the childhood-onset group more people with longer diabetes duration (> 20 years) had detectable C-peptide (60%) than in those with shorter diabetes duration (39%, p for trend < 0.05). Nine miRs significantly correlated with detectable C-peptide levels in people with diabetes and 16 miRs correlated with C-peptide levels in CON. Our cross-sectional study results are supportive of (a) greater beta-cell function loss in younger onset Type 1 diabetes; (b) persistent insulin secretion in adult-onset diabetes and possibly regenerative secretion in childhood-onset long diabetes duration; and (c) relationships of C-peptide levels with circulating miRs. Confirmatory clinical studies and related basic science studies are merited.

Interleukin-33 alleviates diabetic cardiomyopathy through regulation of endoplasmic reticulum stress and autophagy via insulin-like growth factor-binding protein 3

Prolonged endoplasmic reticulum (ER) stress is the key driving force behind diabetic cardiomyopathy (DCM). Autophagy is extensively implicated in adaptive mechanisms for cell survival. Interleukin-33 (IL-33) is known to be a potent cardiac protector, but its roles in DCM, ER stress, and autophagy are currently unknown. We aimed to explore the effects of IL-33 on DCM and characterize the roles that ER stress and autophagy play in DCM. The effects of IL-33 on DCM, ER stress, and autophagy were characterized both in db/db mice and in palmitic acid (PA)-treated cardiomyocytes. The manipulators of ER stress and autophagy were used to clarify their roles in DCM remittance conferred by IL-33. Gene expression analysis was used to identify IL-33-dependent regulators of ER stress and autophagy. Both db/db mice and PA-treated cells presented with enhanced levels of ER stress, apoptosis, and lipid deposition, as well as impaired autophagy, all of which could be reversed by IL-33. Treatment with IL-33 improved the cardiac diastolic function of diabetic mice. Nonselective autophagy inhibitors, such as 3-methyladenine (3-MA) or wortmannin, abolished the protective effects of IL-33, resulting in an increase in both ER stress and apoptosis. Strikingly, insulin-like growth factor-binding protein 3 (IGFBP3) was identified as the gene most significantly differentially expressed between IL-33 and control groups. Knockdown of IGFBP3 expression, similar to the effect of nonselective autophagy inhibitors, resulted in high levels of ER stress, impaired autophagy, and apoptosis that were not rescued upon treatment with IL-33. IL-33 abates DCM by alleviating ER stress and promoting autophagy. IGFBP3 is essential for IL-33-induced ER stress resolution and autophagic enhancement during DCM.

CD36 Signaling in Diabetic Cardiomyopathy

Cluster of differentiation 36 (CD36), also referred to as scavenger receptor B2, has been shown to serve multiple functions in lipid metabolism, inflammatory signaling, oxidative stress, and energy reprogramming. As a scavenger receptor, CD36 interacts with various ligands, such as oxidized low-density lipoprotein (oxLDL), thrombospondin 1 (TSP-1), and fatty acid (FA), thereby activating specific downstream signaling pathways. Cardiac CD36 is mostly expressed on the surface of cardiomyocytes and endothelial cells. The pathophysiological process of diabetic cardiomyopathy (DCM) encompasses diverse metabolic abnormalities, such as enhanced transfer of cardiac myocyte sarcolemmal FA, increased levels of advanced glycation end-products, elevation in oxidative stress, impaired insulin signaling cascade, disturbance in calcium handling, and microvascular rarefaction which are closely related to CD36 signaling. This review presents a summary of the CD36 signaling pathway that acts mainly as a long-chain FA transporter in cardiac myocytes and functions as a receptor to bind to numerous ligands in endothelial cells. Finally, we summarize the recent basic research and clinical findings regarding CD36 signaling in DCM, suggesting a promising strategy to treat this condition.

MicroRNAs Regulating Mitochondrial Function in Cardiac Diseases

Mitochondria are the key organelles that supply cellular energy. As the most active organ in the body, the energy required to maintain the mechanical function of the heart requires a high quantity of high-quality mitochondria in cardiomyocytes. MicroRNAs (miRNAs) are single-stranded noncoding RNAs, approximately 22 nt in length, which play key roles in mediating post-transcriptional gene silencing. Numerous studies have confirmed that miRNAs can participate in the occurrence and development of cardiac diseases by regulating mitochondrial function-related genes and signaling pathways. Therefore, elucidating the crosstalk that occurs between miRNAs and mitochondria is important for the prevention and treatment of cardiac diseases. In this review, we discuss the biogenesis of miRNAs, the miRNA-mediated regulation of major genes involved in the maintenance of mitochondrial function, and the effects of miRNAs on mitochondrial function in cardiac diseases in order to provide a theoretical basis for the clinical prevention and treatment of cardiac disease and the development of new drugs.

Sex Differences of the Diabetic Heart

Type 2 diabetes is a chronic disease associated with micro- and macro-vascular complications, including myocardial ischemia, and also with a specific and intrinsic cardiac dysfunction called diabetic cardiomyopathy (DCM). Both clinical and animal studies demonstrate significant sex differences in prevalence, pathophysiology, and outcomes of cardiovascular diseases (CVDs), including those associated with diabetes. The increased risk of CVDs with diabetes is higher in women compared to men with 50% higher risk of coronary artery diseases and increased mortality when exposed to acute myocardial infarction. Clinical studies also reveal a sexual dimorphism in the incidence and outcomes of DCM. Based on these clinical findings, growing experimental research was initiated to understand the impact of sex on CVDs associated with diabetes and to identify the molecular mechanisms involved. Endothelial dysfunction, atherosclerosis, coagulation, and fibrosis are mechanisms found to be sex-differentially modulated in the diabetic cardiovascular system. Recently, impairment of energy metabolism also emerged as a determinant of multiple CVDs associated with diabetes. Therefore, future studies should thoroughly analyze the sex-specific metabolic determinants to propose new therapeutic targets. With current medicine tending toward more personalized care of patients, we finally propose to discuss the importance of sex as determinant in the treatment of diabetes-associated cardiac diseases to promote a more systemic inclusion of both males and females in clinical and preclinical studies.

Hengshun Aromatic Vinegar Improves Glycolipid Metabolism in Type 2 Diabetes Mellitus via Regulating PGC-1α/PGC-1β Pathway

Hengshun aromatic vinegar (HSAV), produced by typical solid-state or liquid-state fermentation techniques, is consumed worldwide as a food condiment. HSAV shows multiple bioactivities, but its activity in type 2 diabetes mellitus (T2DM) and possible mechanisms have not been reported. In this study, the effects of HSAV against T2DM were evaluated in insulin-induced HepG2 cells and high-fat diet (HFD) and streptozotocin (STZ) induced T2DM rats. Then, the mechanisms of HSAV against T2DM were explored by Real-time PCR, Western blot, immunofluorescence assays, siRNA transfection and gene overexpression experiments. Results indicated that HSAV significantly improved glucose consumption and reduced triglycerides (TG) contents in metabolic disordered HepG2 cells. Meanwhile, HSAV obviously alleviated general status, liver and kidney functions of T2DM rats, and decreased hyperglycemia and hyperlipidemia, improved insulin resistance, and reduced lipid accumulation in liver. Mechanism studies indicated that HSAV markedly down-regulated the expression of proliferator-activated receptor γ coactivator-1α (PGC-1α), then regulated peroxisome proliferators-activated receptor α (PPAR-α)/protein kinase B (AKT) signal pathway mediated gluconeogenesis and glycogen synthesis. Meanwhile, HSAV significantly up-regulated proliferator-activated receptor γ coactivator-1β (PGC-1β), and subsequently decreased sterol regulatory element binding protein-1c (SREBP-1c) pathway mediated lipogenesis. In conclusion, HSAV showed potent anti-T2DM activity in ameliorating dysfunction of glycolipid metabolism through regulating PGC-1α/PGC-1β pathway, which has a certain application prospect as an effective diet supplement for T2DM therapy in the future.

MiR-20a-5p overexpression prevented diabetic cardiomyopathy via inhibition of cardiomyocyte apoptosis, hypertrophy, fibrosis, and JNK/NF-κB signaling pathway

Diabetic cardiomyopathy (DCM) is a common cardiovascular disease. A declined miR-20a-5p was observed in hearts of diabetic mice, while its effect on DCM remains unknown. Herein, we established streptozotocin-induced DCM rat model and high glucose-stimulated H9C2 model of DCM. They then were treated with adenovirus expressing miR-20a-5p to explore the function of miR-20a-5p. ITT and ipGTT assay revealed that miR-20a-5p reduced blood glucose level. Besides, miR-20a-5p improved cardiac dysfunction reflected by reduced HW/BW and LVDP, and increased LVSP and ±LV dp/dt max. MiR-20a-5p prevented cardiomyocyte apoptosis, along with the up-regulated c-caspase-3, bax and down-regulated bcl-2. Moreover, miR-20a-5p alleviated cardiac hypertrophy as the parameters of ANP, BNP and MyHC-β decreased. Also, miR-20a-5p attenuated the cardiac fibrosis demonstrated by decreased TGF-β1, collagen I levels and the inflammatory response manifested by reduced IL-6, TNF-α and IL-1β production. Furthermore, miR-20a-5p prevented JNK phosphorylation and NF-κB p65nuclear translocation. Similarly, the effects of miR-20a-5p on DCM were confirmed in our in vitro experiments. Additionally, ROCK2 is a possible target gene of miR-20a-5p. ROCK2 overexpression reversed the protective effect of miR-20a-5p on DCM. Overall, miR-20a-5p may effectively ameliorate DCM through improving cardiac metabolism, and subsequently inhibiting inflammation, apoptosis, hypertrophy, fibrosis, and JNK/NF-κB pathway via modulating ROCK2.

miR-30c-1 encourages human corneal endothelial cells to regenerate through ameliorating senescence

In the present study, we studied the role of microRNA-30c-1 (miR-30c-1) on transforming growth factor beta1 (TGF-β1)-induced senescence of hCECs. hCECs were transfected by miR-30c-1 and treated with TGF-β1 to assess the inhibitory effect of miR-30c-1 on TGF-β1-induced senescence. Cell viability and proliferation rate in miR-30c-1-transfected cells was elevated compared with control. Cell cycle analysis revealed that cell abundance in S phase was elevated in miR-30c-1-treated cells compared with control. TGF-β1 increased the senescence of hCECs; however, this was ameliorated by miR-30c-1. TGF-β1 increased the size of hCECs, the ratio of senescence-associated beta-galactosidase-stained cells, secretion of senescence-associated secretory phenotype factors, the oxidative stress, and arrested the cell cycle, all of which were ameliorated by miR-30c-1 treatment. miR-30c-1 also suppressed a TGF-β1-induced depolarization of mitochondrial membrane potential and a TGF-β1 stimulated increase in levels of cleaved poly (ADP-ribose) polymerase (PARP), cleaved caspase 3, and microtubule-associated proteins 1A/1B light chain 3B II. In conclusion, miR-30c-1 promoted the proliferation of hCECs through ameliorating the TGF- β1-induced senescence of hCECs and reducing cell death of hCECs. Thus, miR-30c-1 may be a therapeutic target for hCECs regeneration.

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 .

Impact of peroxisome proliferator-activated receptor-α on diabetic cardiomyopathy

The prevalence of cardiomyopathy is higher in diabetic patients than those without diabetes. Diabetic cardiomyopathy (DCM) is defined as a clinical condition of abnormal myocardial structure and performance in diabetic patients without other cardiac risk factors, such as coronary artery disease, hypertension, and significant valvular disease. Multiple molecular events contribute to the development of DCM, which include the alterations in energy metabolism (fatty acid, glucose, ketone and branched chain amino acids) and the abnormalities of subcellular components in the heart, such as impaired insulin signaling, increased oxidative stress, calcium mishandling and inflammation. There are no specific drugs in treating DCM despite of decades of basic and clinical investigations. This is, in part, due to the lack of our understanding as to how heart failure initiates and develops, especially in diabetic patients without an underlying ischemic cause. Some of the traditional anti-diabetic or lipid-lowering agents aimed at shifting the balance of cardiac metabolism from utilizing fat to glucose have been shown inadequately targeting multiple aspects of the conditions. Peroxisome proliferator-activated receptor α (PPARα), a transcription factor, plays an important role in mediating DCM-related molecular events. Pharmacological targeting of PPARα activation has been demonstrated to be one of the important strategies for patients with diabetes, metabolic syndrome, and atherosclerotic cardiovascular diseases. The aim of this review is to provide a contemporary view of PPARα in association with the underlying pathophysiological changes in DCM. We discuss the PPARα-related drugs in clinical applications and facts related to the drugs that may be considered as risky (such as fenofibrate, bezafibrate, clofibrate) or safe (pemafibrate, metformin and glucagon-like peptide 1-receptor agonists) or having the potential (sodium-glucose co-transporter 2 inhibitor) in treating DCM.

Fisetin protects against streptozotocin-induced diabetic cardiomyopathy in rats by suppressing fatty acid oxidation and inhibiting protein kinase R

This study examined if the Fisetin against streptozotocin-induced diabetic cardiomyopathy (DC) in rats involves regulating cardiac metabolism and suppressing protein kinase R (PKR). Male rats were divided (12/groups) as control (non-diabetic), control + Fisetin, T1DM, and T1DM + Fisetin. Fisetin was administered orally at a final dose of 2.5 mg/kg for 12 weeks. In T1DM1-induced rats, Fisetin prevented heart and final body weights loss, lowered circulatory levels troponin I and creatinine kinase-MB (CK-MB), increased fasting insulin levels, and improved ventricular systolic and diastolic functions. It also preserved the structure of the cardiomyocytes and reduced oxidative stress, fibrosis, protein levels of transforming growth factor-β1 (TGF-β1), collagenase 1A, caspase-3, and the activation of JNK, p53, and p38 MAPK. In the control and diabetic rats, Fisetin attenuated fasting hyperglycaemia, the increases in glucose levels after the oral and insulin tolerance tests, and HOMA-IR. It also increased cardiac glucose oxidation by increasing the activity of private dehydrogenase (PDH), phosphofructokinase (PFK), protein levels of PPAR-α and suppressed cardiac inflammation by inhibiting NF-κB. These effects were associated with a reduction in the activity of PKR and subsequent increase in the activity of eeukaryotic initiation factor 2 (eIF2) with a parallel increase in protein levels of p67, a cellular inhibitor of PKR. In cultured cardiomyocytes, Fisetin, prevented high glucose (HG)-induced activation of PKR and reduction in p67, in a dose-dependent manner. However, the effect of Fisetin on PKR was diminished in LG and HG-treated cardiomyocytes with p67-siRNA. In conclusion, Fisetin protects against DC in rats by improving cardiac glucose metabolism and suppressing PKR.

MiR-30c-5p/ROCK2 axis regulates cell proliferation, apoptosis and EMT via the PI3K/AKT signaling pathway in HG-induced HK-2 cells

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus. Increasing evidence suggests that microRNA-30c-5p (miR-30c-5p) participates in the pathogenesis of DN, but the mechanism has not been clearly understood. Therefore, this study aimed to investigate the biological role of miR-30c-5p in human DN progression in vitro. Compared with the controls, DN tissues and high glucose-induced HK-2 cells had significantly reduced miR-30c-5p levels, while ROCK2 expression was prominently elevated. Additionally, the miR-30c-5p mimic distinctly facilitated cell proliferation and blocked cell apoptosis and epithelial–mesenchymal transition (EMT). However, ROCK2 was a target gene of miR-30c-5p, and the effects of miR-30c-5p mimic on cell proliferation, apoptosis and EMT were reversed by ROCK2 upregulation in vitro. Furthermore, the pathogenesis of DN was regulated by the miR-30c-5p/ROCK2 axis via the PI3K/AKT pathway. MiR-30c-5p regulating cell proliferation, apoptosis and EMT through targeting ROCK2 via the PI3K/AKT pathway provides the novel potential target for clinical treatment of DN.

Subcellular microRNAs in diabetic cardiomyopathy

Cardiovascular complications are the leading causes of diabetes-related morbidity and mortality. The high incidence and poor prognosis of heart failure in diabetic patients have been associated, in part, to the presence of an underlying cardiomyopathy characterized by cardiac hypertrophy, cardiomyocytes apoptosis, and fibrosis. It has been unclear about the mechanism that connects diabetes mellitus to the development of cardiovascular dysfunction. Micro(mi)RNAs represent a class of small, 18- to 28-nucleotide-long, non-coding RNA molecules. MiRNAs typically suppress gene expression at the post-transcriptional levels by binding directly to the 3'-UTR of the target mRNAs in the cytoplasm. Interestingly, recent studies suggest that miRNAs may also regulate gene expression in a positive manner. Our recent studies have shown that subcellular miRNAs, such as cytosol-, mitochondria- and nucleus-localized miRNAs, were dramatically dysregulated in diabetic cardiomyopathy. Specifically, cytoplasm localized miRNAs regulate genes expression in a post-transcriptional manner. Nuclear localized miRNAs regulate gene transcription or chromosomal reconstruction through the non-canonical mechanism. Mitochondrial miRNAs stimulate, rather than repress, the translation of specific mitochondrial genome-encoded transcripts. By reviewing these latest discovered functions of subcellular miRNAs in diabetic animal models, we identified new mechanistic insights for diabetic cardiomyopathy. Understanding the nature of subcellular miRNAs will provide new therapeutic targets against diabetes-associated cardiac complications in the near future.

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".

Associations between dietary patterns and gene expression pattern in peripheral blood mononuclear cells: A cross-sectional study

BACKGROUND AND AIMS

Diet may alter gene expression in immune cells involved in atherosclerotic cardiovascular disease susceptibility. However, we still lack a robust understanding of the association between diet and immune cell-related gene expression in humans. Therefore, we examined associations between dietary patterns (DPs) and gene expression profiles in peripheral blood mononuclear cells (PBMCs) in a population of healthy, Norwegian adults (n = 130 women and 105 men).

METHODS AND RESULTS

We used factor analysis to define a posteriori DPs from food frequency questionnaire-based dietary assessment data. In addition, we derived interpretable features from microarray-based gene expression data (13 967 transcripts) using two algorithms: CIBERSORT for estimation of cell subtype proportions, and weighted gene co-expression network analysis (WGCNA) for cluster discovery. Finally, we associated DPs with either CIBERSORT-predicted PBMC leukocyte distribution or WGCNA gene clusters using linear regression models. We detected three DPs that broadly reflected Western, Vegetarian, and Low carbohydrate diets. CIBERSORT-predicted percentage of monocytes associated negatively with the Vegetarian DP. For women, the Vegetarian DP associated with a large gene cluster consisting of 600 genes mainly involved in regulation of DNA transcription, whereas for men, the Western DP inversely associated with a smaller cluster of 36 genes mainly involved in regulation of metabolic and inflammatory processes. A subsequent protein-protein interaction network analysis suggested that genes within these clusters might physically interact in biological networks.

CONCLUSIONS

Although the present findings are exploratory, our analysis pipeline serves as a useful framework for studying the association between diet and gene expression.

MicroRNAs and obesity-induced endothelial dysfunction: key paradigms in molecular therapy

The endothelium plays a pivotal role in maintaining vascular health. Obesity is a global epidemic that has seen dramatic increases in both adult and pediatric populations. Obesity perturbs the integrity of normal endothelium, leading to endothelial dysfunction which predisposes the patient to cardiovascular diseases. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that play important roles in a variety of cellular processes such as differentiation, proliferation, apoptosis, and stress response; their alteration contributes to the development of many pathologies including obesity. Mediators of obesity-induced endothelial dysfunction include altered endothelial nitric oxide synthase (eNOS), Sirtuin 1 (SIRT1), oxidative stress, autophagy machinery and endoplasmic reticulum (ER) stress. All of these factors have been shown to be either directly or indirectly caused by gene regulatory mechanisms of miRNAs. In this review, we aim to provide a comprehensive description of the therapeutic potential of miRNAs to treat obesity-induced endothelial dysfunction. This may lead to the identification of new targets for interventions that may prevent or delay the development of obesity-related cardiovascular disease.

The Multifunctionality of CD36 in Diabetes Mellitus and Its Complications-Update in Pathogenesis, Treatment and Monitoring

CD36 is a multiligand receptor contributing to glucose and lipid metabolism, immune response, inflammation, thrombosis, and fibrosis. A wide range of tissue expression includes cells sensitive to metabolic abnormalities associated with metabolic syndrome and diabetes mellitus (DM), such as monocytes and macrophages, epithelial cells, adipocytes, hepatocytes, skeletal and cardiac myocytes, pancreatic β-cells, kidney glomeruli and tubules cells, pericytes and pigment epithelium cells of the retina, and Schwann cells. These features make CD36 an important component of the pathogenesis of DM and its complications, but also a promising target in the treatment of these disorders. The detrimental effects of CD36 signaling are mediated by the uptake of fatty acids and modified lipoproteins, deposition of lipids and their lipotoxicity, alterations in insulin response and the utilization of energy substrates, oxidative stress, inflammation, apoptosis, and fibrosis leading to the progressive, often irreversible organ dysfunction. This review summarizes the extensive knowledge of the contribution of CD36 to DM and its complications, including nephropathy, retinopathy, peripheral neuropathy, and cardiomyopathy.

The Mitochondria: A Target of Polyphenols in the Treatment of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is a constellation of symptoms consisting of ventricular dysfunction and cardiomyocyte disarray in the presence of diabetes. The exact cause of this type of cardiomyopathy is still unknown; however, several processes involving the mitochondria, such as lipid and glucose metabolism, reactive oxygen species (ROS) production, apoptosis, autophagy and mitochondrial biogenesis have been implicated. In addition, polyphenols have been shown to improve the progression of diabetes. In this review, we discuss some of the mechanisms by which polyphenols, particularly resveratrol, play a role in slowing the progression of DCM. The most important intermediates by which polyphenols exert their protective effect include Bcl-2, UCP2, SIRT-1, AMPK and JNK1. Bcl-2 acts to attenuate apoptosis, UCP2 decreases oxidative stress, SIRT-1 increases mitochondrial biogenesis and decreases oxidative stress, AMPK increases autophagy, and JNK1 decreases apoptosis and increases autophagy. Our dissection of these molecular players aims to provide potential therapeutic targets for the treatment of DCM.

Role of Non-coding RNA in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is the leading cause of morbidity and mortality in diabetic population worldwide, characteristic by cardiomyocyte hypertrophy, apoptosis and myocardial interstitial fibrosis and eventually developing into heart failure. Non-coding RNAs, such as microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs) and other RNAs without the protein encoding function were emerging as a popular regulator in various types of processes during human diseases. The evidences have shown that miRNAs are regulators in diabetic cardiomyopathy, such as insulin resistance, cardiomyocytes apoptosis, and inflammatory, especially their protective effect on heart function. Besides that, the functions of lncRNAs and circRNAs have been gradually confirmed in recent years, and their functions in DCM have become increasingly prominent. We highlighted the nonnegligible roles of non-coding RNAs in the pathological process of DCM and showed the future possibilities of these non-coding RNAs in DCM treatment. In this chapter, we summarized the present advance of the researches in this filed and raised the concern and the prospect in the future.

MicroRNA and ROS Crosstalk in Cardiac and Pulmonary Diseases

Reactive oxygen species (ROS) affect many cellular functions and the proper redox balance between ROS and antioxidants contributes substantially to the physiological welfare of the cell. During pathological conditions, an altered redox equilibrium leads to increased production of ROS that in turn may cause oxidative damage. MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level contributing to all major cellular processes, including oxidative stress and cell death. Several miRNAs are expressed in response to ROS to mediate oxidative stress. Conversely, oxidative stress may lead to the upregulation of miRNAs that control mechanisms to buffer the damage induced by ROS. This review focuses on the complex crosstalk between miRNAs and ROS in diseases of the cardiac (i.e., cardiac hypertrophy, heart failure, myocardial infarction, ischemia/reperfusion injury, diabetic cardiomyopathy) and pulmonary (i.e., idiopathic pulmonary fibrosis, acute lung injury/acute respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, lung cancer) compartments. Of note, miR-34a, miR-144, miR-421, miR-129, miR-181c, miR-16, miR-31, miR-155, miR-21, and miR-1/206 were found to play a role during oxidative stress in both heart and lung pathologies. This review comprehensively summarizes current knowledge in the field.

Sodium-glucose cotransporter 2 inhibitors antagonize lipotoxicity in human myeloid angiogenic cells and ADP-dependent activation in human platelets: potential relevance to prevention of cardiovascular events

BACKGROUND

The clear evidence of cardiovascular benefits in cardiovascular outcome trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in type 2 diabetes might suggest an effect on atherosclerotic plaque vulnerability and/or thrombosis, in which myeloid angiogenic cells (MAC) and platelets (PLT) are implicated. We tested the effects of SGLT2i on inflammation and oxidant stress in a model of stearic acid (SA)-induced lipotoxicity in MAC and on PLT activation. The possible involvement of the Na⁺/H⁺ exchanger (NHE) was also explored.

METHOD

MAC and PLT were isolated from peripheral blood of healthy subjects and incubated with/without SGLT2i [empagliflozin (EMPA) and dapagliflozin (DAPA) 1-100 μM] to assess their effects on SA (100 μM)-induced readouts of inflammation, oxidant stress and apoptosis in MAC and on expression of PLT activation markers by flow-cytometry after ADP-stimulation. Potential NHE involvement was tested with amiloride (aspecific NHE inhibitor) or cariporide (NHE1 inhibitor). Differences among culture conditions were identified using one-way ANOVA or Friedman test.

RESULTS

NHE isoforms (1,5-9), but not SGLT2 expression, were expressed in MAC and PLT. EMPA and DAPA (100 μM) significantly reduced SA-induced inflammation (IL1β, TNFα, MCP1), oxidant stress (SOD2, TXN, HO1), but not apoptosis in MAC. EMPA and DAPA (both 1 μM) reduced PLT activation (CD62p and PAC1 expression). SGLT2i effects were mimicked by amiloride, and only partially by cariporide, in MAC, and by both inhibitors in PLT.

CONCLUSIONS

EMPA and DAPA ameliorated lipotoxic damage in stearate-treated MAC, and reduced ADP-stimulated PLT activation, potentially via NHE-inhibition, thereby pointing to plaque stabilization and/or thrombosis inhibition as potential mechanism(s) involved in SGLT2i-mediated cardiovascular protection.

MiR-144 protects the heart from hyperglycemia-induced injury by regulating mitochondrial biogenesis and cardiomyocyte apoptosis

Several lines of evidence have revealed the potential of microRNAs (miRNAs, miRs) as biomarkers for detecting diabetic cardiomyopathy, although their functions in hyperglycemic cardiac dysfunction are still lacking. In this study, mitochondrial biogenesis was markedly impaired induced by high glucose (HG), as evidenced by dysregulated mitochondrial structure, reduced mitochondrial DNA contents, and biogenesis-related mRNA levels, accompanied by increased cell apoptosis. MiR-144 was identified to be decreased in HG-induced cardiomyocytes and in streptozotocin (STZ)-challenged heart samples. Forced miR-144 expression enhanced mitochondrial biogenesis and suppressed cell apoptosis, while miR-144 inhibition exhibited the opposite results. Rac-1 was identified as a target gene of miR-144. Decreased Rac-1 levels activated AMPK phosphorylation and PGC-1α deacetylation, leading to increased mitochondrial biogenesis and reduced cell apoptosis. Importantly, the systemic neutralization of miR-144 attenuated mitochondrial disorder and ventricular dysfunction following STZ treatment. Additionally, plasma miR-144 decreased markedly in diabetic patients with cardiac dysfunction. The receiver-operator characteristic curve showed that plasma miR-144 could specifically predict diabetic patients developing cardiac dysfunction. In conclusion, this study provides strong evidence suggesting that miR-144 protects heart from hyperglycemia-induced injury by improving mitochondrial biogenesis and decreasing cell apoptosis via targeting Rac-1. Forced miR-144 expression might, thus, be a protective strategy for treating hyperglycemia-induced cardiac dysfunction.

The Role of MicroRNAs in Diabetes-Related Oxidative Stress

Cellular stress, combined with dysfunctional, inadequate mitochondrial phosphorylation, produces an excessive amount of reactive oxygen species (ROS) and an increased level of ROS in cells, which leads to oxidation and subsequent cellular damage. Because of its cell damaging action, an association between anomalous ROS production and disease such as Type 1 (T1D) and Type 2 (T2D) diabetes, as well as their complications, has been well established. However, there is a lack of understanding about genome-driven responses to ROS-mediated cellular stress. Over the last decade, multiple studies have suggested a link between oxidative stress and microRNAs (miRNAs). The miRNAs are small non-coding RNAs that mostly suppress expression of the target gene by interaction with its 3'untranslated region (3'UTR). In this paper, we review the recent progress in the field, focusing on the association between miRNAs and oxidative stress during the progression of diabetes.