Upregulation of microRNA processing enzymes Drosha and Dicer in gestational diabetes mellitus

The role of microRNAs in pregnancies complicated by maternal diabetes

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

Circulating extracellular vesicle-derived miR-1299 disrupts hepatic glucose homeostasis by targeting the STAT3/FAM3A axis in gestational diabetes mellitus

BACKGROUND

Extracellular vesicles (EVs) are membrane-enclosed structures containing lipids, proteins, and RNAs that play a crucial role in cell-to-cell communication. However, the precise mechanism through which circulating EVs disrupt hepatic glucose homeostasis in gestational diabetes mellitus (GDM) remains unclear.

RESULTS

Circulating EVs isolated from human plasma were co-cultured with mammalian liver cells to investigate the potential induction of hepatic insulin resistance by GDM-EVs using glucose output assays, Seahorse assays, metabolomics, fluxomics, qRT-PCR, bioinformatics analyses, and luciferase assays. Our findings demonstrated that hepatocytes exposed to GDM-EVs exhibited increased gluconeogenesis, attenuated energy metabolism, and upregulated oxidative stress. Particularly noteworthy was the discovery of miR-1299 as the predominant miRNA in GDM-EVs, which directly targeting the 3'-untranslated regions (UTR) of STAT3. Our experiments involving loss- and gain-of-function revealed that miR-1299 inhibits the insulin signaling pathway by regulating the STAT3/FAM3A axis, resulting in increased insulin resistance through the modulation of mitochondrial function and oxidative stress in hepatocytes. Moreover, experiments conducted in vivo on mice inoculated with GDM-EVs confirmed the development of glucose intolerance, insulin resistance, and downregulation of STAT3 and FAM3A.

CONCLUSIONS

These results provide insights into the role of miR-1299 derived from circulating GDM-EVs in the progression of insulin resistance in hepatic cells via the STAT3/FAM3A axis and downstream metabolic reprogramming.

Human gestational diabetes mellitus-derived exosomes impair glucose homeostasis in pregnant mice and stimulate functional maturation of offspring-islets

AIMS

Pancreatic islets undergo critical development and functional maturation during the perinatal period when they are highly sensitive to microenvironment. We aim to determine the effects and mechanisms of gestational diabetes mellitus (GDM) hypermetabolic stress on glucose homeostasis in pregnant mice and functional maturation of the islets of their offspring.

MAIN METHODS

Exosomes were extracted from the umbilical vein blood of individuals with or without GDM for administration to pregnant mice. The blood glucose, serum insulin, glycosylated hemoglobin, and lipopolysaccharide levels were measured in pregnant mice. The expression and localization of insulin, glucagon, PC1/3, PDX1, and p-S6 in the islets of neonatal rats were continuously monitored using immunofluorescence to evaluate their functional status. Primary islet cells were cultured and treated with GDM exosomes and exendin to determine the expression of GLP-1R, AKT, p-AKT, and p-S6 via western blotting.

KEY FINDINGS

GDM exosomes induced remarkable oral glucose intolerance, hyperinsulinemia, and metabolic inflammation in pregnant mice. The islets of GDM offspring exhibited high insulin, glucagon, PC1/3, PDX1, and p-S6 expression at and after birth, and activation of the local GLP-1/GLP-1R axis. The functional maturation of normal-offspring islets did not commence until after birth, while it was activated prior to birth in GDM offspring, seriously disrupting the whole process. GDM exosomes activated the GLP-1/GLP-1R axis between α and β cells, and stimulated functional maturation of β cells via the Akt-mTORC1-pS6 pathway.

SIGNIFICANCE

These findings provide preliminary insights into the mechanisms underlying the high incidence of diabetes in the offspring of mothers with GDM.

Novel Therapeutic Agents for Management of Diabetes Mellitus: A Hope for Drug Designing against Diabetes Mellitus

Diabetes mellitus (DM) is characterized by an absolute decline in insulin secretion and peripheral resistance and is the most prevalent metabolic and endocrine disorder. However, the pathogenesis of DM also includes adipocyte insulin resistance, increased glucagon secretion, increased renal glomerular glucose absorption, and neurotransmitter dysfunction. Although there is a wide spectrum of therapeutics available for glycemic control, owing to the identification of various pathogenic determinants of DM, management of DM remains challenging and complex. Current therapeutic interventions against DM focus mostly on glycemic control without considering the other pathological determinants that eventually lead to treatment failure and the progression of DM. Furthermore, long-term use of these conventionally available anti-diabetic drugs leads to various side effects, henceforth development of novel drugs against DM remains an unending search strategy for researchers. Various studies conducted in various parts of the world have proposed that these novel therapeutic interventions target multiple and alternate pathogenic hotspots involved in DM. The current review article discusses novel therapeutic options that hold particular promise to support their safety and discuss the side effects resulting from their use so that these novel candidate drugs can be effectively fabricated into potential drugs for the treatment of DM.

The Mystery of Exosomes in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the common pregnancy complications, which increases the risk of short-term and long-term adverse consequences in both the mother and offspring. However, the pathophysiological mechanism of GDM is still poorly understood. Inflammation, insulin resistance and oxidative stress are considered critical factors in the occurrence and development of GDM. Although the lifestyle intervention and insulin are the primary treatment, adverse pregnancy outcomes still cannot be ignored. Exosomes have a specific function of carrying biological information, which can transmit information to target cells and play an essential role in intercellular communication. Their possible roles in normal pregnancy and GDM have been widely concerned. The possibility of exosomal cargos as biomarkers of GDM is proposed. This paper reviews the literature in recent years and discusses the role of exosomes in GDM and their possible mechanisms to provide some reference for the prediction, prevention, and treatment of GDM and improve the outcome of pregnancy.

Periodontitis and Gestational Diabetes Mellitus: A Potential Inflammatory Vicious Cycle

Periodontitis is a chronic inflammatory immune disease associated with a dysbiotic state, influenced by keystone bacterial species responsible for disrupting the periodontal tissue homeostasis. Furthermore, the severity of periodontitis is determined by the interaction between the immune cell response in front of periodontitis-associated species, which leads to the destruction of supporting periodontal tissues and tooth loss in a susceptible host. The persistent bacterial challenge induces modifications in the permeability and ulceration of the sulcular epithelium, which facilitates the systemic translocation of periodontitis-associated bacteria into distant tissues and organs. This stimulates the secretion of pro-inflammatory molecules and a chronic activation of immune cells, contributing to a systemic pro-inflammatory status that has been linked with a higher risk of several systemic diseases, such as type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM). Although periodontitis and GDM share the common feature of systemic inflammation, the molecular mechanistic link of this association has not been completely clarified. This review aims to examine the potential biological mechanisms involved in the association between periodontitis and GDM, highlighting the contribution of both diseases to systemic inflammation and the role of new molecular participants, such as extracellular vesicles and non-coding RNAs, which could act as novel molecular intercellular linkers between periodontal and placental tissues.

Pregnancy-Related Extracellular Vesicles Revisited

Extracellular vesicles (EVs) are small vesicles ranging from 20–200 nm to 10 μm in diameter that are discharged and taken in by many different types of cells. Depending on the nature and quantity of their content—which generally includes proteins, lipids as well as microRNAs (miRNAs), messenger-RNA (mRNA), and DNA—these particles can bring about functional modifications in the receiving cells. During pregnancy, placenta and/or fetal-derived EVs have recently been isolated, eliciting interest in discovering their clinical significance. To date, various studies have associated variations in the circulating levels of maternal and fetal EVs and their contents, with complications including gestational diabetes and preeclampsia, ultimately leading to adverse pregnancy outcomes. Furthermore, EVs have also been identified as messengers and important players in viral infections during pregnancy, as well as in various congenital malformations. Their presence can be detected in the maternal blood from the first trimester and their level increases towards term, thus acting as liquid biopsies that give invaluable insight into the status of the feto-placental unit. However, their exact roles in the metabolic and vascular adaptations associated with physiological and pathological pregnancy is still under investigation. Analyzing peer-reviewed journal articles available in online databases, the purpose of this review is to synthesize current knowledge regarding the utility of quantification of pregnancy related EVs in general and placental EVs in particular as non-invasive evidence of placental dysfunction and adverse pregnancy outcomes, and to develop the current understanding of these particles and their applicability in clinical practice.

Extracellular vesicles and their role in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a complex disorder that is defined by glucose intolerance with onset during pregnancy. The incidence of GDM is increasing worldwide. Pregnancies complicated with GDM have higher rates of maternal and fetal morbidity with short- and long-term consequences, including increased rates of cardiovascular disease and type II diabetes for both the mother and offspring. The pathophysiology of GDM still remains unclear and there has been interest in the role of small extracellular vesicles (sEVs) in the maternal metabolic adaptations that occur in pregnancy and GDM. Small EVs are nanosized particles that contain bioactive content, including miRNAs and proteins, which are released by cells to provide cell-to-cell communication. Pregnancy induces an increase in total and placental-secreted sEVs across gestation, with a further increase in sEV number and changes in the protein and miRNA composition of these sEVs in GDM. Research has suggested that these sEVs have an impact on maternal adaptations during pregnancy, including targeting the pancreas, skeletal muscle and adipose tissue. Consequently, this review will focus on the differences in total and placental sEVs in GDM compared to normal pregnancy, the role of sEVs in the pathophysiology of GDM and their clinical application as potential GDM biomarkers.

Overview of host miRNA properties and their association with epigenetics, long non-coding RNAs, and Xeno-infectious factors

MicroRNA-derived structures play impressive roles in various biological processes. So dysregulation of miRNAs can lead to different human diseases. Recent studies have extended our comprehension of the control of miRNA function and features. Here, we overview some remarkable miRNA properties that have potential implications for the miRNA functions, including different variants of a miRNA called isomiRs, miRNA arm selection/arm switching, and the effect of these factors on miRNA target selection. Besides, we review some aspects of miRNA interactions such as the interaction between epigenetics and miRNA (different miRNAs and their related processing enzymes are epigenetically regulated by multiple DNA methylation enzymes. moreover, DNA methylation could be controlled by diverse mechanisms related to miRNAs), direct and indirect crosstalk between miRNA and lnc (Long Non-Coding) RNAs as a further approach to conduct intercellular regulation called "competing endogenous RNA" (ceRNA) that is involved in the pathogenesis of different diseases, and the interaction of miRNA activities and some Xeno-infectious (virus/bacteria/parasite) factors, which result in modulation of the pathogenesis of infections. This review provides some related studies to a better understanding of miRNA involvement mechanisms and overcoming the complexity of related diseases that may be applicable and useful to prognostic, diagnostic, therapeutic purposes and personalized medicine in the future.

Epigenetic alternations of microRNAs and DNA methylation contribute to gestational diabetes mellitus

This study aimed to identify epigenetic alternations of microRNAs and DNA methylation for gestational diabetes mellitus (GDM) diagnosis and treatment using in silico approach. Data of mRNA and miRNA expression microarray (GSE103552 and GSE104297) and DNA methylation data set (GSE106099) were obtained from the GEO database. Differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs) and differentially methylated genes (DMGs) were obtained by limma package. Functional and enrichment analyses were performed with the DAVID database. The protein‐protein interaction (PPI) network was constructed by STRING and visualized in Cytoscape. Simultaneously, a connectivity map (CMap) analysis was performed to screen potential therapeutic agents for GDM. In GDM, 184 low miRNA‐targeting up‐regulated genes and 234 high miRNA‐targeting down‐regulated genes as well as 364 hypomethylation–high‐expressed genes and 541 hypermethylation–low‐expressed genes were obtained. They were mainly enriched in terms of axon guidance, purine metabolism, focal adhesion and proteasome, respectively. In addition, 115 genes (67 up‐regulated and 48 down‐regulated) were regulated by both aberrant alternations of miRNAs and DNA methylation. Ten chemicals were identified as putative therapeutic agents for GDM and four hub genes (IGF1R, ATG7, DICER1 and RANBP2) were found in PPI and may be associated with GDM. Overall, this study identified a series of differentially expressed genes that are associated with epigenetic alternations of miRNA and DNA methylation in GDM. Ten chemicals and four hub genes may be further explored as potential drugs and targets for GDM diagnosis and treatment, respectively.

Exosomal MicroRNA Expression Profiling Analysis of the Effects of Lycium Barbarum Polysaccharide on Gestational Diabetes Mellitus Mice

Objective

Gestational diabetes mellitus (GDM) is a pathological condition, affecting an increasing number of pregnant women worldwide. Safe and effective treatment for GDM is very important for the public health. In this study, we utilized a high-fat diet-induced GDM model to evaluate the effects of LBP on GDM and examined the changes of exosomal microRNA expression profiling to decipher the potential underlying mechanism of LBP.

Methods

Female C57BL/6J mice were fed a control diet, HFD, or 150 mg/kg LBP-supplemented HFD for 6 weeks before conception and throughout gestation. Oral glucose tolerance test and plasma lipid levels were determined, and liver histopathology was assessed. Sequencing was used to define the microRNA expression profiling of plasma exosomes in the three groups of mice, and protein expression levels of the candidate target genes were analyzed.

Results

LBP significantly relieved glucose intolerance, abnormal plasma lipid levels, and pathomorphological changes of liver histopathology in HFD-induced GDM mice. Moreover, we found that this effect of LBP was mediated by downregulation of the increase of 6 miRNAs (miR-93-3p, miR-188-5p, miR-466k, miR-1188-5p, miR-7001-3p, and miR-7115-5p) and reversing the increase of the protein expression of CPT1A, which is the target gene of miR-188-5p.

Conclusions

Our findings provide novel insights into the biological activities of LBP in the treatment of GDM.

Hydrogen sulfide rescues high glucose-induced migration dysfunction in HUVECs by upregulating miR-126-3p

Diabetes (especially Type II) is one of the primary threats to cardiovascular health. Wound healing defects and vascular dysfunction are common in diabetic patients, and the primary cause of deterioration is sustained high plasma glucose. microRNA, a noncoding RNA, has regulatory functions that are critical to maintaining homeostasis. MicroRNA (miR)-126-3p is a potential diabetes biomarker and a proangiogenic factor, and its plasma level decreases in diabetic patients. Previous studies have revealed the proangiogenic character of the gasotransmitter hydrogen sulfide (H₂S). However, little is known about the relationship between H₂S and miR-126-3p when the extracellular glucose level is high, let alone their influences on deteriorated endothelial cell migration, a key component of angiogenesis, which is crucial for wound healing. Human umbilical vein endothelial cells (HUVECs) were treated with high glucose (33.3 mmol/L) or normal glucose (5.5 mmol/L) for 48 h. Affymetrix miRNA profiling and real-time PCR were used to validate the miRNA expression. An H₂S probe (HSip-1) was used to detect endogenous H₂S. Scratch wound-healing assays were used to evaluate HUVEC migration. The protein levels were quantified by Western blot. Both exogenous and endogenous H₂S could upregulate the miR-126-3p levels in HUVECs or muscle tissue. High glucose decreased the H₂S level and the protein expression of the H₂S-producing enzyme cystathionine γ-lyase (CSE) in HUVECs; however, the DNA methyltransferase 1 (DNMT1) protein level was upregulated. CSE overexpression not only increased the miR-126-3p level by decreasing the DNMT1 protein level but also rescued the deteriorated cell migration in HUVECs treated with high glucose. DNMT1 overexpression decreased the miR-126-3p level and inhibited the migration of HUVECs, whereas silencing DNMT1 improved cell migration. High glucose decreased the endogenous H₂S and miR-126-3p levels and increased the DNMT1 expression, thus inducing the migration dysfunction of HUVECs. Treatment with exogenous H₂S or the overexpression of the endogenously produced enzyme CSE would rescue this migration dysfunction through H₂S-DNMT1-miR-126-3p.

Exosomes Could Offer New Options to Combat the Long-Term Complications Inflicted by Gestational Diabetes Mellitus

Gestational diabetes Mellitus (GDM) is a complex clinical condition that promotes pelvic floor myopathy, thus predisposing sufferers to urinary incontinence (UI). GDM usually regresses after birth. Nonetheless, a GDM history is associated with higher risk of subsequently developing type 2 diabetes, cardiovascular diseases (CVD) and UI. Some aspects of the pathophysiology of GDM remain unclear and the associated pathologies (outcomes) are poorly addressed, simultaneously raising public health costs and diminishing women's quality of life. Exosomes are small extracellular vesicles produced and actively secreted by cells as part of their intercellular communication system. Exosomes are heterogenous in their cargo and depending on the cell sources and environment, they can mediate both pathogenetic and therapeutic functions. With the advancement in knowledge of exosomes, new perspectives have emerged to support the mechanistic understanding, prediction/diagnosis and ultimately, treatment of the post-GMD outcomes. Here, we will review recent advances in knowledge of the role of exosomes in GDM and related areas and discuss the possibilities for translating exosomes as therapeutic agents in the GDM clinical setting.

The expression of Drosha, DGCR8, Dicer and Ago-2 genes are upregulated in human umbilical vein endothelial cells under hyperglycemic condition

OBJECTIVES

It has been shown that dysregulation of miRNAs expression contributes to the pathogenesis and progression of the diabetes and diabetes-related complications. Drosha, DGCR8, Dicer, and Ago-2 are involved in the miRNA maturation. The aim of the present study was to investigate the mRNA expression levels of these genes in the human umbilical vein endothelial cells (HUVECs) under hyperglycemic condition.

METHODS

HUVECs were cultured in normo-(5 mM) and hyperglycemic (25 mM) conditions for 24 h. As osmotic control, cells were treated with D-mannitol (25 mM, for 24 h). The mRNA expression levels of Drosha, DGCR8, Dicer and Ago-2 were evaluated using quantitative real-time PCR.

RESULTS

The expression level of Drosha, DGCR8, Dicer, and Ago-2 were increased in hyperglycemic HUVECs compared to the control group.

CONCLUSION

Our results show that under hyperglycemic condition, expression of genes involved in the miRNA maturation was significantly increased in HUVECs. Upregulation of these genes may have role in diabetic complications through the dysregulation of the miRNA expression.

Trophoblastic microRNAs are downregulated in a diabetic pregnancy through an inhibition of Drosha

MicroRNAs are promising biological markers for prenatal diagnosis. They regulate placental development and are present in maternal plasma. Maternal metabolic diseases are major risk factors for placental deterioration. We analysed the influence of a maternal insulin-dependent diabetes mellitus on microRNA expression in maternal plasma and in blastocysts employing an in vivo rabbit diabetic pregnancy model and an in vitro embryo culture in hyperglycaemic and hypoinsulinaemic medium. Maternal diabetes led to a marked downregulation of Dicer protein in embryoblast cells and Drosha protein in trophoblast cells. MiR-27b, miR-141 and miR-191 were decreased in trophoblast cells and in maternal plasma of diabetic rabbits. In vitro studies indicate, that maternal hyperglycaemia and hypoinsulinaemia partially contribute to the downregulation of trophoblastic microRNAs. As the altered microRNA expression was detectable in maternal plasma, too, the plasma microRNA signature could serve as an early biological marker for the prediction of trophoblast function during a diabetic pregnancy.

Association of Polymorphisms in miRNA Processing Genes With Type 2 Diabetes Mellitus and Its Vascular Complications in a Southern Chinese Population

Objective: To evaluate the potential association between the genetic variants in miRNA processing genes (RAN, XPO5, DICER1, and TARBP2) and susceptibility to type 2 diabetes mellitus (T2DM) and its vascular complications, as well as to further investigate their interaction with environmental factors in type 2 diabetes. Methods: We conducted a case-control study in genotyping of five polymorphic loci, including RAN rs14035, XPO5 rs11077, DICER1 rs13078, DICER1 rs3742330, and TARBP2 rs784567, in miRNA processing genes to explore the risk factors for T2DM and diabetic vascular complications. Haplotype analyses, interactions of gene-gene and interactions of gene-environment were performed too. Results: We identified a 36% decreased risk of developing T2DM in individuals with the minor A allele in DICER1 rs13078 (OR: 0.64; 95%CI: 0.42-0.95; P: 0.026). The AA haplotype in DICER1 was also associated with a protective effect on T2DM compared with the AT haplotype (OR: 0.63; 95%CI: 0.42-0.94; P-value: 0.023). T2DM patients with the TT+TC genotype at RAN rs14035 had a 1.89-fold higher risk of developing macrovascular complications than patients with the CC genotype (OR: 1.89; 95%CI: 1.04-3.45; P-value: 0.037). We also identified two three-factor interaction models. One is a three-factor [DICER1 rs13078, body mass index (BMI), and triglyceride (TG)] interaction model for T2DM (OR: 5.93; 95%CI: 1.25-28.26; P = 0.025). Another three-factor [RAN rs14035, hypertension (HP), and duration of T2DM (DOD)] interaction model was found for macrovascular complications of T2DM (OR = 41.60, 95%CI = 11.75-147.35, P < 0.001). Conclusion: Our study provides new evidence that two single nucleotide polymorphisms (SNPs) of the miRNA processing genes, DICER1 and RAN, and their interactions with certain environmental factors might contribute to the risk of T2DM and its vascular complications in the southern Chinese population.

Diabetes in Pregnancy and MicroRNAs: Promises and Limitations in Their Clinical Application

Maternal diabetes is associated with an increased risk of complications for the mother and her offspring. The latter have an increased risk of foetal macrosomia, hypoglycaemia, respiratory distress syndrome, preterm delivery, malformations and mortality but also of life-long development of obesity and diabetes. Epigenetics have been proposed as an explanation for this long-term risk, and microRNAs (miRNAs) may play a role, both in short- and long-term outcomes. Gestation is associated with increasing maternal insulin resistance, as well as β-cell expansion, to account for the increased insulin needs and studies performed in pregnant rats support a role of miRNAs in this expansion. Furthermore, several miRNAs are involved in pancreatic embryonic development. On the other hand, maternal diabetes is associated with changes in miRNA both in maternal and in foetal tissues. This review aims to summarise the existing knowledge on miRNAs in gestational and pre-gestational diabetes, both as diagnostic biomarkers and as mechanistic players, in the development of gestational diabetes itself and also of short- and long-term complications for the mother and her offspring.

MicroRNA array analysis of the regulation of microRNAs in rats exhibiting hyperplasia of mammary glands

Hyperplasia of mammary glands (HMG) is also termed mammary dysplasia. In China, the number of patients suffering from breast hyperplasia is increasing annually. MicroRNAs (miRNAs; length, 19–24 nucleotides), a group of small endogenous non-coding RNAs, post-transcriptionally regulate gene expression via RNA interference and gene silencing pathways. The cause of disease of HMG because remains unclear. Thus, the aim of the present study was to establish comprehensive profile of drug treatments following at different time intervals on rat models of differentially expressed miRNAs, using miRNA microarray data. After scanning the chip, 13 up-regulated and 20 down-regulated miRNAs were identified. MiR-31 and miR-30 exhibited different expression levels between rats exhibiting mammary gland hyperplasia treated with or without Jiedu Capsule water solution once a day for 4 weeks, and the two demonstrated a strong association with HMG and breast cancer. Therefore, the functions of these miRNAs may provide the basis for further investigation of HMG.

High glucose induces dysfunction of human umbilical vein endothelial cells by upregulating miR-137 in gestational diabetes mellitus

Recent studies have revealed considerable dysfunction of vascular endothelial cells (VECs) and abnormal expression of microRNA (miR)-137 in women with gestational diabetes mellitus (GDM), and the aim of this study was to clarify the underlying mechanism and possible role of microRNA (miR)-137 in dysfunction of VECs during GDM. We found increased levels of miR-137 in the plasma of GDM women and high-glucose (HG)-exposed HUVECs. Upregulating miR-137 in HUVECs elevated the chemokine (C-C motif) ligand 2 (CCL2) secretion and enhanced the chemotaxis and adhesion of U937 and THP-1 (two human acute monocytic leukemia cell lines) cells to HUVECs in a co-culture system. Moreover, HG stimulation and/or overexpression of miR-137 inhibited the viability, upregulated the expression levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), E-selectin, and inflammatory cytokine interleukin (IL)-6, and downregulated the production of IL-8, vascular endothelial growth factor (VEGF), and angiogenesis of HUVECs in vitro. These results imply that up-regulated miR-137 by HG can restrict the viability and angiogenesis, promote the activation and inflammatory cytokine secretion of VECs, and stimulate the monocyte chemotaxis and adhesion to VECs. Ultimately, we have concluded that miR-137 is crucial to HG-induced VEC dysfunction and may be involved in pathology of GDM.

Regulating microRNA expression: at the heart of diabetes mellitus and the mitochondrion

Type 2 diabetes mellitus is a major risk factor for cardiovascular disease and mortality. Uncontrolled type 2 diabetes mellitus results in a systemic milieu of increased circulating glucose and fatty acids. The development of insulin resistance in cardiac tissue decreases cellular glucose import and enhances mitochondrial fatty acid uptake. While triacylglycerol and cytotoxic lipid species begin to accumulate in the cardiomyocyte, the energy substrate utilization ratio of free fatty acids to glucose changes to almost entirely free fatty acids. Accumulating evidence suggests a role of miRNA in mediating this metabolic transition. Energy substrate metabolism, apoptosis, and the production and response to excess reactive oxygen species are regulated by miRNA expression. The current momentum for understanding the dynamics of miRNA expression is limited by a lack of understanding of how miRNA expression is controlled. While miRNAs are important regulators in both normal and pathological states, an additional layer of complexity is added when regulation of miRNA regulators is considered. miRNA expression is known to be regulated through a number of mechanisms, which include, but are not limited to, epigenetics, exosomal transport, processing, and posttranscriptional sequestration. The purpose of this review is to outline how mitochondrial processes are regulated by miRNAs in the diabetic heart. Furthermore, we will highlight the regulatory mechanisms, such as epigenetics, exosomal transport, miRNA processing, and posttranslational sequestration, that participate as regulators of miRNA expression. Additionally, current and future treatment strategies targeting dysfunctional mitochondrial processes in the diseased myocardium, as well as emerging miRNA-based therapies, will be summarized.

Expression levels of the microRNA maturing microprocessor complex components; Drosha, Dicer, and DGCR8 in PBMCs from ankylosing spondylitis patients

Objective/Aim:

Two major enzymes in the microRNA maturation process, Dicer and Drosha, as well as DGCR8, the assistant of Drosha, function in the microprocessor complex. In this survey, the mRNA expression profiles of Drosha, Dicer, and DGCR8 in peripheral blood mononuclear cells (PBMCs) from ankylosing spondylitis (AS) patients and healthy controls were measured

Methods:

Forty patients with AS and 40 age and gender matched healthy individuals were included in the study. PBMCs were separated, total RNA content of the cells was isolated, and first strand cDNA was synthesized. Quantitative analysis was performed through real-time PCR using the SYBR Green gene expression master mix.

Results:

AS cases expressed the Drosha mRNA almost equal to that of healthy controls (Fold Change= −0.94; P= 0.200). However, both Dicer and DGCR8 mRNA expressions were downregulated in patients relative to healthy subjects (Fold Change= −0.54 and −0.60; P= 0.002 and 0.004, respectively).

Conclusion:

Our results suggest that downregulation of miRNA maturation components, namely Dicer and DGCR8 may be contributing in the pathogenesis procedure of AS.

Sex-gender-related therapeutic approaches for cardiovascular complications associated with diabetes

Diabetes is a chronic disease associated with micro- and macrovascular complications and is a well-established risk factor for cardiovascular disease. Cardiovascular complications associated with diabetes are among the most important causes of death in diabetic patients. Interestingly, several sex-gender differences have been reported to significantly impact in the pathophysiology of diabetes. In particular, sex-gender differences have been reported to affect diabetes epidemiology, risk factors, as well as cardiovascular complications associated with diabetes. This suggests that different therapeutic approaches are needed for managing diabetes-associated cardiovascular complications in men and women. In this review, we will discuss about the sex-gender differences that are known to impact on diabetes, mainly focusing on the cardiovascular complications associated with the disease. We will then discuss the therapeutic approaches for managing diabetes-associated cardiovascular complications and how differences in sex-gender can influence the existing therapeutic approaches.

Review: Bio-compartmentalization of microRNAs in exosomes during gestational diabetes mellitus

Analysis of the human genome revealed that only 1.2% encoded for proteins, which raised questions regarding the biological significance of the remaining genome. We now know that approximately 80% of the genome serves at least one biochemical function within the cell. A portion of this 80% consists of a family of non-coding regulatory RNAs, one important member being microRNAs (miRNAs). miRNAs can be detected in tissues and biofluids, where miRNAs in the latter can be bound to proteins or encapsulated within lipid vesicles such as exosomes. Gestational diabetes mellitus (GDM) is a complication of pregnancy, which has harmful health impacts on both the fetus as well as the mother. The incidence of GDM worldwide varies, but reached 18% in the HAPO cohort using the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Not only has GDM been associated with increased risks of further complications during pregnancy, but also poses long-term risks for both the mother and the baby. Thus, understanding the pathophysiology of GDM is important from a public health perspective. Literature has demonstrated that GDM is associated with elevated levels of circulating exosomes in maternal circulation. However, there is a paucity of data defining the expression, role, and diagnostic utility of miRNAs in GDM. This review briefly summarizes recent advances in the function and quantification of intracellular and extracellular miRNAs in GDM.

Expression of miR-181a and miR-181b in human gastric cancer cells and tissues

AIM: To investigate the expression of miR-181a and miR-181b in human gastric cancer cell lines and tissues, and to explore their role in the development and progression of gastric cancer.

METHODS: Three gastric cancer cell lines with different degrees of differentiation (AGS, SGC-7901, MGC-803) and normal gastric mucosa cell line GES-1 were cultured in vitro, and gastric cancer tissue and normal tissue samples from 28 patients who underwent surgical operation were collected. The expression levels of miR-181a and miR-181b in the above cell lines and tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and compared among different groups.

RESULTS: The expression of miR-181a and miR-181b in AGS, SGC-7901 and MGC-803 cells was significantly higher than that in GES-1 cells (P < 0.05), but had no significant difference among the three gastric cancer cell lines (P > 0.05). Compared with normal gastric tissues, the expression of miR-181a and miR-181b in gastric cancer tissues was significantly higher (P < 0.05). The expression of miR-181a and miR-181b was significantly higher in stage Ⅲ/Ⅳ gastric cancer tissues than in stage Ⅰ/Ⅱ (P < 0.05), and in gastric cancer patients with lymph node metastasis than in patients without (P < 0.05). There was no significant correlation between the expression of miR-181a/miR-181b and age, gender, or degree of tumor differentiation (P > 0.05).

CONCLUSION: MiR-181a and miR-181b are highly expressed in gastric cancer cell lines and tissues, and their expression levels in gastric cancer are associated with tumor stage and lymph node metastasis. They might play a role as oncogenes in gastric carcinogenesis.