MicroRNA hsa-let-7g targets lectin-like oxidized low-density lipoprotein receptor-1 expression and inhibits apoptosis in human smooth muscle cells

Relevance of oxidative stress biomarkers, hemoglobin A1c, troponin-I, and angiotensin-converting enzyme metabolism to blood pressure in acute myocardial infarction: a case-control study

The aim was to investigate this relationship by calculating 1) the correlation between peak troponin-C (peak-cTnI), levels of oxidative stress biomarkers, including lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CD)), and antioxidant enzyme activity (glutathione peroxidase (GPx)), and HbA1c and 2) the correlation between HbA1c and serum angiotensin-converting enzyme (ACE) activity, and its impact on the rate pressure product (RPP) in acute myocardial infarction (AMI). A case-control study was performed in 306 AMI patients having undergone coronary angiography and on 410 controls. GPx activity was reduced in association with increased MDA and CD in patients. Peak-cTnI was positively correlated with HbA1c, MDA, and CD levels. Serum ACE activity was negatively correlated with GPx. HbA1c was positively correlated with ACE activity and RPP. Linear regression analysis showed that peak-cTnI, ACE activity and HbA1c are significant predictors of AMI. Elevated HbA1c and peak-cTnI levels are associated with RPP elevation causing AMI. In conclusions, patients with elevated HbA1c, elevated ACE activity and cTnI are at increased risk of AMI with increasing RPP. Patients at risk of AMI can be identified at an early stage if the biomarkers HbA1c, ACE activity, and cTnI are measured and preventive measures are taken in a targeted manner.

Protective Effects of 2-Methoxyestradiol on Acute Isoproterenol-Induced Cardiac Injury in Rats

Myocardial injury (MI) is an important pathological driver of mortality worldwide., and arises as a result of imbalances between myocardial oxygen demand and supply. In MI, oxidative stress often leads to inflammatory changes and apoptosis. Current therapies for MI are known to cause various adverse effects. Consequently, the development of new therapeutic agents with a reduced adverse event profile is necessary. In this regard, 2-methoxyestradiol (2ME), the metabolic end-product of oestradiol, possesses anti-inflammatory and antioxidant properties. The aim of this research is to assess the impact of 2ME on cardiac injury caused by isoproterenol (ISO) in rats. Animals were separated into six groups; controls, and those receiving 2ME (1 mg/kg), ISO (85 mg/kg), ISO + 2ME (0.25 mg/kg), ISO + 2ME (0.5 mg/kg), and ISO + 2ME (1 mg/kg). 2ME significantly attenuated ISO-induced changes in electrocardiographic changes and the cardiac histological pattern. This compound also decreased lactate dehydrogenase activity, creatine kinase myocardial band and troponin levels. The ability of 2ME to act as an antioxidant was shown by a decrease in malondialdehyde concentration, and the restoration of glutathione levels and superoxide dismutase activity. Additionally, 2ME antagonized inflammation and cardiac cell apoptosis, a process determined to be mediated, at least partially, by suppression of Gal-3/TLR4/MyD88/NF-κB signaling pathway. 2ME offers protection against acute ISO-induced MI in rats and offers a novel therapeutic management option.

Vascular smooth muscle cell c-Fos is critical for foam cell formation and atherosclerosis

BACKGROUND

Hyperlipidemia-induced vascular smooth muscle cell (VSMC)-derived foam cell formation is considered a crucial event in the development of atherosclerosis. Since c-Fos emerges as a key modulator of lipid metabolism, we investigated whether c-Fos plays a role in hyperlipidemia-induced VSMC-derived foam cell formation and atherosclerosis.

APPROACH AND RESULTS

c-Fos expression was observed in VSMCs in atherosclerotic plaques from patients and western diet-fed atherosclerosis-prone LDLR^-/- and ApoE^-/- mice by immunofluorescence staining. To ascertain c-Fos's function in atherosclerosis development, VSMC-specific c-Fos deficient mice in ApoE^-/- background were established. Western diet-fed c-Fos^VSMCKOApoE^-/- mice exhibited a significant reduction of atherosclerotic lesion formation as measured by hematoxylin and eosin staining, accompanied by decreased lipid deposition within aortic roots as determined by Oil red O staining. Primary rat VSMCs were isolated to examine the role of c-Fos in lipid uptake and foam cell formation. oxLDL stimulation resulted in VSMC-derived foam cell formation and elevated intracellular mitochondrial reactive oxygen species (mtROS), c-Fos and LOX-1 levels, whereas specific inhibition of mtROS, c-Fos or LOX-1 lessened lipid accumulation in oxLDL-stimulated VSMCs. Mechanistically, oxLDL acts through mtROS to enhance transcription activity of c-Fos to facilitate the expression of LOX-1, exerting a feedforward mechanism with oxLDL to increase lipid uptake and propel VSMC-derived foam cell formation and atherogenesis.

CONCLUSION

Our study demonstrates a fundamental role of mtROS/c-Fos/LOX-1 signaling pathway in promoting oxLDL uptake and VSMC-derived foam cell formation during atherosclerosis. c-Fos may represent a promising therapeutic target amenable to clinical translation in the future.

The role of non-coding RNA network in atherosclerosis

Atherosclerosis is the primary culprit of cardiovascular and cerebrovascular diseases. Also, atherogenesis and the development of atherosclerosis involve endothelial cells, monocytes/macrophages, smooth myocytes, and others. Increasingly, studies have found that non-coding RNA (ncRNA) which can regulate apoptosis, pyroptosis, autophagy, proliferation, and monocyte migration participates in atherogenesis and progress of atherosclerosis by the above. The ncRNA networks may be essential in regulating the complicated process of atherosclerosis. Accordingly, this review delves into the regulatory roles of ncRNA, which were introduced previously. The answer above is particularly crucial to explain further the regulatory mechanism of ncRNA in cardiovascular disorders. Furthermore, we discuss the possibility and related research of ncRNAs as a biomarker and therapeutic target for the prevention, diagnosis, and treatment of atherosclerosis.

The Interplay between Oxidative Stress and miRNAs in Obesity-Associated Hepatic and Vascular Complications

Nowadays, the obesity pandemic is one of the most relevant health issues worldwide. This condition is tightly related to comorbidities such as non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs), namely atherosclerosis. Dysregulated lipid metabolism and inflammation link these three diseases, leading to a subsequent increase of oxidative stress (OS) causing severe cellular damage. On the other hand, microRNAs (miRNAs) are short, single-stranded, non-coding RNAs that act as post-transcriptional negative regulators of gene expression, thus being involved in the molecular mechanisms that promote the development of many pathologies including obesity and its comorbidities. The involvement of miRNAs in promoting or opposing OS in disease progression is becoming more evident. Some miRNAs, such as miR-200a and miR.421, seem to play important roles in OS control in NAFLD. On the other hand, miR-92a and miR-133, among others, are important in the development of atherosclerosis. Moreover, since both diseases are linked to obesity, they share common altered miRNAs, being miR-34a and miR-21 related to OS. This review summarizes the latest advances in the knowledge about the mechanisms of oxidative stress (OS) generation in obesity-associated NAFLD and atherosclerosis, as well as the role played by miRNAs in the regulation of such mechanisms.

Non-coding RNAs in cardiovascular cell biology and atherosclerosis

Atherosclerosis underlies the predominant number of cardiovascular diseases and remains a leading cause of morbidity and mortality worldwide. The development, progression and formation of clinically relevant atherosclerotic plaques involves the interaction of distinct and over-lapping mechanisms which dictate the roles and actions of multiple resident and recruited cell types including endothelial cells, vascular smooth muscle cells, and monocyte/macrophages. The discovery of non-coding RNAs (ncRNAs) including microRNAs, long non-coding RNAs, and circular RNAs, and their identification as key mechanistic regulators of mRNA and protein expression has piqued interest in their potential contribution to atherosclerosis. Accruing evidence has revealed ncRNAs regulate pivotal cellular and molecular processes during all stages of atherosclerosis including cell invasion, growth, and survival; cellular uptake and efflux of lipids, expression and release of pro- and anti-inflammatory intermediaries, and proteolytic balance. The expression profile of ncRNAs within atherosclerotic lesions and the circulation have been determined with the aim of identifying individual or clusters of ncRNAs which may be viable therapeutic targets alongside deployment as biomarkers of atherosclerotic plaque progression. Consequently, numerous in vivo studies have been convened to determine the effects of moderating the function or expression of select ncRNAs in well-characterized animal models of atherosclerosis. Together, clinicopathological findings and studies in animal models have elucidated the multifaceted and frequently divergent effects ncRNAs impose both directly and indirectly on the formation and progression of atherosclerosis. From these findings' potential novel therapeutic targets and strategies have been discovered which may pave the way for further translational studies and possibly taken forward for clinical application.

Nerolidol inhibits the LOX-1 / IL-1β signaling to protect against the Aspergillus fumigatus keratitis inflammation damage to the cornea

PURPOSE

Nerolidol, a naturally occurring sesquiterpene has both anti-microbial and anti-inflammatory properties. The current study aims to investigate the antifungal and the anti-inflammatory effects of nerolidol against mouse Aspergillus fumigatus (A. fumigatus) keratitis.

METHODS

The minimum inhibitory concentration (MIC) and cytotoxicity tests were used to study the antifungal ability. For in vivo and in vitro studies, the mouse corneas and the human corneal epithelial cells (HCECs) infected with A. fumigatus spores were intervented with nerolidol or phosphate buffer saline (PBS). Thereafter, the effect of the nerolidol on the response against inflammation was analyzed using the following parameters: recruitment of the neutrophils or macrophages and the expression of the lectin-type oxidized low density lipoprotein receptor-1 (LOX-1) and interleukin 1β (IL-1β). Techniques used were the slit lamp, immunofluorescence, myeloperoxidase (MPO) detection, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.

RESULTS

Nerolidol directly inhibits the growth of A. fumigatus. The administration of nerolidol reduced the severity of fungal keratitis with infiltration of fewer inflammatory cells and reduced levels of the LOX-1, as well the anti-inflammatory cytokines such as IL-1β were reduced compared with the PBS group. Additionally, in vitro studies showed that treatment with nerolidol inhibited the production of the LOX-1 / IL-1β levels in A. fumigatus stimulated HCECs.

CONCLUSION

Nerolidol attenuated the A. fumigatus keratitis inflammatory response by inhibiting the growth of A. fumigatus, reducing the recruitment of the neutrophils and the macrophages, and inhibiting the LOX-1/ IL-1β signaling.

LOX-1: Regulation, Signaling and Its Role in Atherosclerosis

Atherosclerosis has long been known to be a chronic inflammatory disease. In addition, there is intense oxidative stress in atherosclerosis resulting from an imbalance between the excess reactive oxygen species (ROS) generation and inadequate anti-oxidant defense forces. The excess of the oxidative forces results in the conversion of low-density lipoproteins (LDL) to oxidized LDL (ox-LDL), which is highly atherogenic. The sub-endothelial deposition of ox-LDL, formation of foamy macrophages, vascular smooth muscle cell (VSMC) proliferation and migration, and deposition of collagen are central pathophysiologic steps in the formation of atherosclerotic plaque. Ox-LDL exerts its action through several different scavenger receptors, the most important of which is LOX-1 in atherogenesis. LOX-1 is a transmembrane glycoprotein that binds to and internalizes ox-LDL. This interaction results in variable downstream effects based on the cell type. In endothelial cells, there is an increased expression of cellular adhesion molecules, resulting in the increased attachment and migration of inflammatory cells to intima, followed by their differentiation into macrophages. There is also a worsening endothelial dysfunction due to the increased production of vasoconstrictors, increased ROS, and depletion of endothelial nitric oxide (NO). In the macrophages and VSMCs, ox-LDL causes further upregulation of the LOX-1 gene, modulation of calpains, macrophage migration, VSMC proliferation and foam cell formation. Soluble LOX-1 (sLOX-1), a fragment of the main LOX-1 molecule, is being investigated as a diagnostic marker because it has been shown to be present in increased quantities in patients with hypertension, diabetes, metabolic syndrome and coronary artery disease. LOX-1 gene deletion in mice and anti-LOX-1 therapy has been shown to decrease inflammation, oxidative stress and atherosclerosis. LOX-1 deletion also results in damage from ischemia, making LOX-1 a promising target of therapy for atherosclerosis and related disorders. In this article we focus on the different mechanisms for regulation, signaling and the various effects of LOX-1 in contributing to atherosclerosis.

Circulating Oxidized Low-Density Lipoprotein Levels Independently Predict 10-Year Progression of Subclinical Carotid Atherosclerosis: A Community-Based Cohort Study

Aims: To investigate the association between circulating oxidized low-density lipoprotein (ox-LDL) levels and progression of subclinical atherosclerosis and to examine whether this link is independent of other low-density lipoprotein (LDL)-related parameters.

Methods: Totally, 804 subjects who were free of cardiovascular disease at baseline completed risk factor surveys and carotid ultrasound measurements in 2002 and 2012. Modified Poisson regression was performed to examine the association between baseline serum ox-LDL levels and the 10-year risk of progression of carotid atherosclerosis which was defined as the development of at least one new plaque in a previously plaque-free carotid segment at re-examination.

Results: The mean age of the subjects was 58.6 ± 7.7 years at baseline and 43.3% were men. A total of 504 (62.7%) subjects had carotid plaque progression at re-examination. Subjects in the intermediate and highest tertiles of ox-LDL had a significantly higher adjusted risk of atherosclerosis progression than those in the lowest tertile [relative risk (95% confidence interval) 1.17 (1.01–1.34) for the intermediate tertile and 1.23 (1.07–1.42) for the highest tertile]. This association was independent of baseline levels of LDL-C, total LDL particle number, and small LDL particle number.

Conclusion: This study demonstrates that serum ox-LDL levels predict 10-year progression of subclinical atherosclerosis. Moreover, this effect is independent of the cholesterol content, the number, and the size of LDL particles.

Contribution of lectin-like oxidized low-density lipoprotein receptor-1 and LOX-1 modulating compounds to vascular diseases

The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is the major receptor for binding and uptake of oxidized low-density lipoprotein (oxLDL) in endothelial cells. LOX-1 is also expressed in macrophages, smooth muscle cells and platelets. Following internalization of oxLDL, LOX-1 initiates a vicious cycle from activation of pro-inflammatory signaling pathways, thus promoting an increased reactive oxygen species formation and secretion of pro-inflammatory cytokines. LOX-1 plays a pivotal role in the development of endothelial dysfunction, foam cell and advanced lesions formation as well as in myocardial ischemia. Furthermore, it is known that LOX-1 plays a pivotal role in mitochondrial DNA damage, vascular cell apoptosis, and autophagy. A large number of studies provide evidence of a LOX-1's role in endothelial dysfunction, hypertension, diabetes, and obesity. In addition, novel insights into LOX-1 ligands and the activated signaling pathways have been gained. Recent studies have shown an interaction of LOX-1 with microRNA's, thus providing novel tools to regulate LOX-1 function. Because LOX-1 is increased in atherosclerotic plaques and contributes to endothelial dysfunction, several compounds were tested in vivo and in vitro to modulate the LOX-1 expression in therapeutic approaches.

Redox regulation of microRNAs in endometriosis-associated pain

Endometriosis is a chronic, painful condition with unknown etiology. A differential expression of microRNAs in the endometriotic tissues from women with endometriosis with pain compared to those without suggested a plausible role for miRNA or epigenetic mechanisms in the etiology of endometriotic pain. The peritoneal milieu is involved in maintenance of endometriotic lesion and nociception. We recently showed the mechanistic role for oxidized-lipoproteins (ox-LDLs) present in peritoneal fluid (PF) in endometriosis and pain. We explored the possibility of ox-LDLs modulating the expression of miRNAs in a manner similar to PF from women with endometriosis. Expression levels of miRNAs and their predicted nociceptive and inflammatory targets were determined in PF and ox-LDL treated human endometrial cell-lines. Samples from IRB-approved and consented patients with and without endometriosis or pain were used. These were compared to endometrial cell-lines treated with various forms of oxidized-lipoproteins. RNA (including miRNAs) were isolated from treated endometrial cells and expression levels were determined using commercial miRNome arrays. Cell lysates were used in immunoblotting for inflammatory proteins using a protein array. Twenty miRNAs including isoforms of miR-29, miR-181 and let-7 were mutually differentially expressed in cells treated with PF from endometriosis patients with pain and those treated with ox-LDL components. The ox-LDLs and endo-PF treatment also produced significant overexpression of microRNA predicted target genes nerve growth factor, interleukin-6 and prostaglandin E synthase and overexpression of their downstream protein targets Mip1α and MCP1. This study showed similarities between miRNA regulation in PF from endometriotic women and ox-LDLs present in abundance in the PF of these women. Key miRNAs responsible for targeting nociceptive and inflammatory molecules were downregulated in the presence of ox-LDLs and endo-PF, thus playing a role in the etiology of endometriotic pain. These redox-sensitive miRNAs can be of potential use as targets in the treatment of endometriosis-associated pain.

MicroRNA let-7g alleviates atherosclerosis via the targeting of LOX-1 in vitro and in vivo

Atherosclerosis is a chronic arterial disease and the leading cause of stroke and myocardial infarction. Micro-RNAs (miRNAs or miRs) have been reported to act as essential modulators during the progression of atherosclerosis. Although miR-let-7g has been demonstrated to contribute to maintaining endothelial function and vascular homeostasis, it is not known whether miR-let-7g exerts a therapeutic effect on experimental atherosclerosis. The aim of this study was to investigate the effects of miR-let-7g on atherosclerosis in vivo and in vitro and to explore its underlying mechanisms. Data from our study showed that exogenous lectin‑like oxidized low‑density lipoprotein receptor‑1 (LOX-1 or OLR1) overexpression resulted in the significant promotion of proliferation and migration of human aortic smooth muscle cells (ASMCs), whereas such changes induced by LOX-1 were obviously suppressed by transfection of miR‑let‑7g. We later confirmed that LOX-1 is a potential target of miR-let-7g, and miR-let-7g markedly inhibited LOX-1 expression in ASMCs by directly binding to the 3' untranslated region of LOX-1. Furthermore, in a hyperlipidemic apolipoprotein E knockout (ApoE-/-) mouse model, intravenous delivery of miR-let-7g mimics obviously attenuated high-fat diet-induced neointima formation and atherosclerotic lesions, accompanied by the significant downregulation of LOX-1, which was consistent with the effect of miR-let-7g on ASMCs. Taken together, our data revealed that miR-let-7g exhibits anti-atherosclerotic activity, at least partially by targeting the LOX-1 signaling pathway. This study suggests that miR-let-7g may be a therapeutic candidate for treating atherosclerosis, and provides novel insight into miRNA-based therapy for this disease.

Proof-of-concept study: profile of circulating microRNAs in Bovine serum harvested during acute and persistent FMDV infection

Background

Changes in the levels of circulating microRNAs (miRNAs) in the serum of humans and animals have been detected as a result of infection with a variety of viruses. However, to date, such a miRNA profiling study has not been conducted for foot-and-mouth disease virus (FMDV) infection.

Methods

The relative abundance of 169 miRNAs was measured in bovine serum collected at three different phases of FMDV infection in a proof-of-concept study using miRNA PCR array plates.

Results

Alterations in specific miRNA levels were detected in serum during acute, persistent, and convalescent phases of FMDV infection. Subclinical FMDV persistence produced a circulating miRNA profile distinct from cattle that had cleared infection. bta-miR-17-5p was highest expressed during acute infection, whereas bta-miR-31 was the highest during FMDV persistence. Interestingly, miR-1281was significantly down-regulated during both acute and persistent infection. Cattle that cleared infection resembled the baseline profile, adding support to applying serum miRNA profiling for identification of sub-clinically infected FMDV carriers. Significantly regulated miRNAs during acute or persistent infection were associated with cellular proliferation, apoptosis, modulation of the immune response, and lipid metabolism.

Conclusions

These findings suggest a role for non-coding regulatory RNAs in FMDV infection of cattle. Future studies will delineate the individual contributions of the reported miRNAs to FMDV replication, determine if this miRNA signature is applicable across all FMDV serotypes, and may facilitate development of novel diagnostic applications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-017-0743-3) contains supplementary material, which is available to authorized users.

LOX-1 and Its Splice Variants: A New Challenge for Atherosclerosis and Cancer-Targeted Therapies

Alternative splicing (AS) is a process in which precursor messenger RNA (pre-mRNA) splicing sites are differentially selected to diversify the protein isoform population. Changes in AS patterns have an essential role in normal development, differentiation and response to physiological stimuli. It is documented that AS can generate both “risk” and “protective” splice variants that can contribute to the pathogenesis of several diseases including atherosclerosis. The main endothelial receptor for oxidized low-density lipoprotein (ox-LDLs) is LOX-1 receptor protein encoded by the OLR1 gene. When OLR1 undergoes AS events, it generates three variants: OLR1, OLR1D4 and LOXIN. The latter lacks exon 5 and two-thirds of the functional domain. Literature data demonstrate a protective role of LOXIN in pathologies correlated with LOX-1 overexpression such as atherosclerosis and tumors. In this review, we summarize recent developments in understanding of OLR1 AS while also highlighting data warranting further investigation of this process as a novel therapeutic target.

Negative feedback regulation between microRNA let-7g and LOX-1 mediated hypoxia-induced PASMCs proliferation

BACKGROUND

Pulmonary hypertension (PH) is a proliferative disorder associated with enhanced proliferation and suppressed apoptosis of pulmonary artery smooth muscle cells (PASMCs). Our lately study demonstrated that let-7g inhibited hypoxia-induced proliferation of PASMCs via repressing c-myc-Bmi-1-p16 signaling pathway. However, the upstream of let-7g has not yet been fully defined. Previous studies have shown that LOX-1, a target of let-7g, could also regulate the expression of let-7g in human aortic endothelial cells. In this present study, we aimed to investigate whether there is a negative feedback regulation between microRNA let-7g and LOX-1 in hypoxia-induced proliferation of PASMCs.

METHODS

SD Rats were exposed to hypoxia (10% O₂, 3 weeks) to induce PH. HE staining was used to evaluate pulmonary artery remodeling. in situ hybridization and immunohistochemistry were performed to assess the expression and distribution of let-7g and LOX-1, respectively. MTS, EDU and flow cytometry were performed to evaluate PASMCs proliferation. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were conducted to assess the expression of let-7g, LOX-1, calpain-1,-2,-4, and OCT-1.

RESULTS

The expression of let-7g was significantly down-regulated in pulmonary arteries of hypoxia-induced PH rats accompanied by pulmonary vascular remodeling, whereas let-7g mimic inhibited hypoxia-induced proliferation of PASMCs and up-regulation of LOX-1 expression. LOX-1 blocking reversed hypoxia-induced down-regulation of let-7g expression. Calpains, protein kinase C and OCT-1 were involved in negative feedback regulation between let-7g and LOX-1.

CONCLUSION

Negative feedback regulation between let-7g and LOX-1 mediated hypoxia-induced proliferation of in PASMCs.

Function, Role, and Clinical Application of MicroRNAs in Vascular Aging

Vascular aging, a specific type of organic aging, is related to age-dependent changes in the vasculature, including atherosclerotic plaques, arterial stiffness, fibrosis, and increased intimal thickening. Vascular aging could influence the threshold, process, and severity of various cardiovascular diseases, thus making it one of the most important risk factors in the high mortality of cardiovascular diseases. As endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cell biological basis of these pathology changes of the vasculature, the structure and function of ECs and VSMCs play a key role in vascular aging. MicroRNAs (miRNAs), small noncoding RNAs, have been shown to regulate the expression of multiple messenger RNAs (mRNAs) posttranscriptionally, contributing to many crucial aspects of cell biology. Recently, miRNAs with functions associated with aging or aging-related diseases have been studied. In this review, we will summarize the reported role of miRNAs in the process of vascular aging with special emphasis on EC and VSMC functions. In addition, the potential application of miRNAs to clinical practice for the diagnosis and treatment of cardiovascular diseases will also be discussed.

Influence of gestational diabetes mellitus on human umbilical vein endothelial cell miRNA

We aimed to identify miRNAs whose expression levels in fetal tissues are altered by exposure to a diabetic milieu and elucidate the impact on target protein expression. Gestational diabetes mellitus (GDM) affects both immediate and future disease risk in the offspring. We hypothesized that GDM alters miRNA expression in human umbilical vein endothelial cells (HUVECs) that may influence metabolic processes. A cross-sectional design compared differences in miRNA expression in HUVECs and target protein abundance in placentae between infants of women with GDM (IGDM) and infants born to normoglycaemic controls. miRNAs were identified using microarray profiling and literature review and validated by quantitative PCR (qPCR). In vitro transfection studies explored the impact of the miRNA on target protein expression. Expression of seven miRNA species, miR-30c-5p, miR-452-5p, miR-126-3p, miR-130b-3p, miR-148a-3p, miR-let-7a-5p and miR-let-7g-5p, was higher in the HUVECs of IGDM. Abundance of the catalytic subunit of AMP-activated protein kinase α1 (AMPKα1) was decreased in the HUVECs and BeWo cells (transformed trophoblast cell line) transfected with miR-130b and miR-148a mimics. AMPKα1 expression was also decreased in placental tissues of IGDM. The expression of several miRNAs were altered by in utero exposure to DM in infants of women whose dysglycaemia was very well controlled by current standards. Decreased expression of AMPKα1 as a result of increased levels of miR-130b and miR-148a may potentially explain the decrease in fat oxidation we reported in infants at 1 month of age and, if persistent, may predispose offspring to future metabolic disease.

Scavenger receptors and non-coding RNAs: relevance in atherogenesis

Scavenger receptors (SRs), which recognize modified low-density lipoprotein (LDL) by oxidation or acetylation, are a group of receptors on plasma membrane of macrophages and other cell types. These receptors by facilitating modified LDL uptake are a primary step in the intracellular accumulation of modified LDL and formation of fatty streak. Non-coding RNAs (ncRNAs) are a group of functional RNA nucleotides that are not translated into protein, and include microRNAs (miRs), snoRNAs, siRNAs, snRNAs, exRNAs, piRNAs, and the long ncRNAs (lncRNAs). Recently, ncRNAs have received much attention due to their effects in a variety of disease states such as atherosclerotic cardiovascular disease and cancers. A host of ncRNAs, such as miRs and lncRNAs, have been found to be involved in the regulation of SRs and the inflammatory cascade and subsequently atherosclerosis. Here, we review this important area to create interest in this growing field among researchers and clinicians alike.

Let-7g induces granulosa cell apoptosis by targeting MAP3K1 in the porcine ovary

Follicular atresia mainly results from apoptosis of granulosa cells (GCs). Our previous microRNA array data indicated that the miRNA let-7g level increases significantly during porcine ovary follicular atresia. It is uncertain if GCs apoptosis is mediated by microRNA let-7g. In this study, the expression levels of the apoptosis-associated genes CASP3, BAX and BIM were significantly upregulated when let-7g mimic was transfected into porcine GCs, and the anti-apoptotic genes BCL-2 and MCL-1 were significantly downregulated. The apoptosis rate was measured by flow cytometry, and our results indicated that let-7g significantly enhanced GCs apoptosis. In further studies, we found that overexpression of let-7g induced the expression of FoxO1 in GCs and led to nuclear accumulation of dephosphorylated FoxO1. In addition, the effect of let-7g on FoxO1 expression and dephosphorylation resulted from repression of the expression of the MAP3K1 gene in porcine GCs. The site on MAP3K1 mRNA targeted by let-7g was confirmed by luciferase reporter assay. The anti-apoptotic effect of MAP3K1 was validated by silencing MAP3K1 using small interfering RNA technology. In conclusion, our data indicate that let-7g induces porcine GCs apoptosis by inhibiting the MAP3K1 gene, which promotes FoxO1 expression and dephosphorylation with nuclear accumulation.

The let-7g microRNA promotes follicular granulosa cell apoptosis by targeting transforming growth factor-β type 1 receptor

The intronic microRNA let-7g controls cell differentiation and proliferation during angiogenesis and oncogenesis. Here, we demonstrate that let-7g regulates granulosa cell (GC) apoptosis and follicular atresia in the pig ovary. Bioinformatics analyses and luciferase reporter assays showed that transforming growth factor-β type 1 receptor (TGFBR1) is a let-7g target. Overexpression of let-7g induced apoptosis of porcine GCs in vitro and repressed the mRNA and protein levels of TGFBR1, as well as the level of phosphorylated SMAD3 (p-SMAD3) protein. RNA interference-mediated knockdown of TGFBR1 and inhibitor LY2157299-mediated blocking of TGFBR1 significantly increased the rate of apoptosis of GCs and Caspase-3 activity. In addition, treatment of porcine GCs with TGF-β1 reduced the level of let-7g and increased the levels of the TGFBR1 mRNA and proteins significantly. Overall, these results demonstrate that let-7g regulates the apoptosis of GCs in the pig ovary by targeting TGFBR1 and down-regulating the TGF-β signaling pathway.

Atorvastatin protects cardiomyocytes from oxidative stress by inhibiting LOX-1 expression and cardiomyocyte apoptosis

Coronary artery disease (CAD) is a major health problem worldwide. The most severe form of CAD is acute coronary syndrome (ACS). Recent studies have demonstrated the beneficial role of atorvastatin in ACS; however, the mechanisms underlying this effect have not been fully clarified. Growing evidence indicates that activation of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) plays an important role in oxidative stress-induced cardiomyocyte apoptosis during ACS. In this study, we examined whether atorvastatin inhibits H2O2-induced LOX-1 expression and H9c2 cardiomyocyte apoptosis, and investigated the underlying signaling pathway. Treatment of H9c2 cardiomyocytes with H2O2 resulted in elevated expression of LOX-1 mRNA and protein, as well as increased caspase-3 and -9 protein expression and cell apoptosis. H2O2-induced LOX-1 expression, caspase protein expression, and cardiomyocyte apoptosis were attenuated by pretreatment with atorvastatin. Atorvastatin activated H2O2-inhibited phosphorylation of Akt in a concentration-dependent manner. The Akt inhibitor, LY294002, inhibited the effect of atorvastatin on inducing Akt phosphorylation and on suppressing H2O2-mediated caspase up-regulation and cell apoptosis. These findings indicate that atorvastatin protects cardiomyocyte from oxidative stress via inhibition of LOX-1 expression and apoptosis, and that activation of H2O2-inhibited phosphorylation of Akt may play an important role in the protective function of atorvastatin.

Hsa-let-7g miRNA targets caspase-3 and inhibits the apoptosis induced by ox-LDL in endothelial cells

It has been well confirmed ox-LDL plays key roles in the development of atherosclerosis via binding to LOX-1 and inducing apoptosis in vascular endothelial cells. Recent studies have shown ox-LDL can suppress microRNA has-let-7g, which in turn inhibits the ox-LDL induced apoptosis. However, details need to be uncovered. To determine the anti-atherosclerosis effect of microRNA has-let-7g, and to evaluate the possibility of CASP3 as an anti-atherosclerotic drug target by has-let-7g, the present study determined the role of hsa-let-7g miRNA in ox-LDL induced apoptosis in the vascular endothelial cells. We found that miRNA has-let-7g was suppressed during the ox-LDL-induced apoptosis in EAhy926 endothelial cells. In addition, overexpression of has-let-7g negatively regulated apoptosis in the endothelial cells by targeting caspase-3 expression. Therefore, miRNA let-7g may play important role in endothelial apoptosis and atherosclerosis.

Deciphering microRNA code in pain and inflammation: lessons from bladder pain syndrome

MicroRNAs (miRNAs), a novel class of molecules regulating gene expression, have been hailed as modulators of many biological processes and disease states. Recent studies demonstrated an important role of miRNAs in the processes of inflammation and cancer, however, there are little data implicating miRNAs in peripheral pain. Bladder pain syndrome/interstitial cystitis (BPS/IC) is a clinical syndrome of pelvic pain and urinary urgency/frequency in the absence of a specific cause. BPS is a chronic inflammatory condition that might share some of the pathogenetic mechanisms with its common co-morbidities inflammatory bowel disease (IBD), asthma and autoimmune diseases. Using miRNA profiling in BPS and the information about validated miRNA targets, we delineated the signaling pathways activated in this and other inflammatory pain disorders. This review projects the miRNA profiling and functional data originating from the research in bladder cancer and immune-mediated diseases on the BPS-specific miRNAs with the aim to gain new insight into the pathogenesis of this enigmatic disorder, and highlighting the common regulatory mechanisms of pain and inflammation.

Regulation of the Nrf2 antioxidant pathway by microRNAs: New players in micromanaging redox homeostasis

MicroRNAs are now thought to play a central role in the regulation of many diverse aspects of cell biology; however, it remains to be fully elucidated how microRNAs can orchestrate cellular redox homeostasis, which plays a central role in a multitude of physiological and pathophysiological processes. The redox-sensitive transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) serves as a "master regulator" of cell survival through the coordinated induction of phase II and antioxidant defense enzymes to counteract oxidative stress and modulate redox signaling events. MicroRNAs are able to "fine-tune" the regulation of processes including those directly interacting with the Nrf2 pathway and the generation of reactive oxygen species (ROS). This review highlights that cellular redox homeostasis can be regulated by microRNAs through their modulation of Nrf2-driven antioxidant gene expression as well as key enzymes that generate ROS, which in turn can alter the biogenesis and processing of microRNAs. Therefore redox sensitive microRNAs or "redoximiRs" add an important regulatory mechanism for redox signaling beyond the well-characterized actions of Nrf2. The potential exists for microRNA-based therapies where diminished antioxidant defenses and dysregulated redox signaling can lead to cardiovascular diseases, cancers, neurodegeneration, and accelerated aging.

MicroRNA modulation of lipid metabolism and oxidative stress in cardiometabolic diseases

The regulation of the metabolism of cholesterol has been one of the most studied biological processes since its first isolation from gallstones in 1784. High levels of plasma low-density lipoprotein (LDL) cholesterol and reduced levels of plasma high-density lipoprotein (HDL) cholesterol are widely recognized as major risk factors of cardiovascular disease. An imbalance in the production of reactive oxygen species can oxidize LDL particles, increasing the levels of the highly proatherogenic oxidized LDL. Furthermore, under pathological scenarios, numerous molecules can function as pro-oxidants, such as iron or (high levels of) glucose. In addition to the classical mechanisms regulating lipid homeostasis, recent studies have demonstrated the important role of microRNAs (miRNAs) as regulators of lipoprotein metabolism, oxidative derivatives of lipoprotein, and redox balance. Here, we summarize recent findings in the field, highlighting the contributions of some miRNAs to lipid- and oxidative-associated pathologies. We also discuss how therapeutic intervention of miRNAs may be a promising strategy to decrease LDL, increase HDL, and ameliorate lipid- and oxidative-related disorders, including atherosclerosis, nonalcoholic fatty liver disease, and metabolic syndrome.

An intronic miRNA regulates expression of the human endothelial nitric oxide synthase gene and proliferation of endothelial cells by a mechanism related to the transcription factor SP-1

OBJECTIVE

This study was to investigate the molecular mechanisms underlying the 27nt-miRNA-mediated regulation of expression of the endothelial nitric oxide synthase (eNOS) gene.

METHODS

Cell lines overexpressing 27nt-miRNA or its mutant were established by transfecting the miRNA expression vector into the endothelial cells. eNOS mRNA and protein expression were examined by RT-PCR and Western Blotting, respectively. Luciferase activity reporter system was used to study the target of 27nt-miRNA.

RESULTS

The results showed that overexpression of 27nt-miRNA significantly inhibited eNOS mRNA level and protein expression, and reduced the eNOS transcriptional efficiency. Such inhibitory effects of 27nt-miRNA were attenuated by the sequence mutations in 27nt-miRNA. Interestingly, the transcription factor SP-1 expression was reduced by 27nt-miRNA. Meanwhile, overxpression of SP-1 protein partially restored eNOS expression, and rescued the 27nt-miRNA-mediated reduction of endothelial cell proliferation. Moreover, certain sites in the SP-1 mRNA were found to be the direct target of 27nt-miRNA by a luciferase reporter system.

CONCLUSIONS

These results demonstrate that the 27nt-miRNA suppresses eNOS gene expression and SP-1 expression in vascular endothelial cells. The 27nt-miRNA directly target to SP-1 mRNA, thereby contributing to proliferation of endothelial cells.

The lectin-like oxidized low-density lipoprotein receptor-1 as therapeutic target for atherosclerosis, inflammatory conditions and longevity

INTRODUCTION

The lectin-like oxidized LDL receptor-1 (LOX-1) is a scavenger receptor and is regarded as a central element in the initiation of endothelial dysfunction and its further progression to atherosclerosis. Increasing numbers of studies suggest that therapeutic strategies to modulate LOX-1 will have a broad spectrum of applications ranging from cardiovascular diseases to longevity.

AREAS COVERED

The dual role of LOX-1 as a culprit molecule in the process of atherosclerosis and as a danger signal in various tissues is introduced. The structure of the receptor, its ligands and its modulation by known drugs, by natural products (e.g., statins, imipramine, salicylate-based drugs, procyanidins, curcumin) and by new strategies (antisenseRNA, miRNA, pyrrole-imidazol-polyamides, LOX-1 antibodies, lipid apheresis) are described.

EXPERT OPINION

Therapeutic approaches via transcript regulation, allowing a modulation of LOX-1, may be an easier and safer strategy than a blockade of the receptor. Considering the wide distribution of LOX-1 on different tissues, research on the mechanisms of LOX-1 modulation by drugs and natural products applying "omic"-technologies will not only allow a better understanding of the role of LOX-1 in the processes of atherosclerosis, inflammation and longevity but also support the development of specific LOX-1 modulators, avoiding the initiation of molecular mechanisms which lead to adverse events.

Microarray analysis of microRNA expression in peripheral blood mononuclear cells of critically ill patients with influenza A (H1N1)

BACKGROUND

With concerns about the disastrous health and economic consequences caused by the influenza pandemic, comprehensively understanding the global host response to influenza virus infection is urgent. The role of microRNA (miRNA) has recently been highlighted in pathogen-host interactions. However, the precise role of miRNAs in the pathogenesis of influenza virus infection in humans, especially in critically ill patients is still unclear.

METHODS

We identified cellular miRNAs involved in the host response to influenza virus infection by performing comprehensive miRNA profiling in peripheral blood mononuclear cells (PBMCs) from critically ill patients with swine-origin influenza pandemic H1N1 (2009) virus infection via miRNA microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assays. Receiver operator characteristic (ROC) curve analysis was conducted and area under the ROC curve (AUC) was calculated to evaluate the diagnostic accuracy of severe H1N1 influenza virus infection. Furthermore, an integrative network of miRNA-mediated host-influenza virus protein interactions was constructed by integrating the predicted and validated miRNA-gene interaction data with influenza virus and host-protein-protein interaction information using Cytoscape software. Moreover, several hub genes in the network were selected and validated by qRT-PCR.

RESULTS

Forty-one significantly differentially expressed miRNAs were found by miRNA microarray; nine were selected and validated by qRT-PCR. QRT-PCR assay and ROC curve analyses revealed that miR-31, miR-29a and miR-148a all had significant potential diagnostic value for critically ill patients infected with H1N1 influenza virus, which yielded AUC of 0.9510, 0.8951 and 0.8811, respectively. We subsequently constructed an integrative network of miRNA-mediated host-influenza virus protein interactions, wherein we found that miRNAs are involved in regulating important pathways, such as mitogen-activated protein kinase signaling pathway, epidermal growth factor receptor signaling pathway, and Toll-like receptor signaling pathway, during influenza virus infection. Some of differentially expressed miRNAs via in silico analysis targeted mRNAs of several key genes in these pathways. The mRNA expression level of tumor protein T53 and transforming growth factor beta receptor 1 were found significantly reduced in critically ill patients, whereas the expression of Janus kinase 2, caspase 3 apoptosis-related cysteine peptidase, interleukin 10, and myxovirus resistance 1 were extremely increased in critically ill patients.

CONCLUSIONS

Our data suggest that the dysregulation of miRNAs in the PBMCs of H1N1 critically ill patients can regulate a number of key genes in the major signaling pathways associated with influenza virus infection. These differentially expressed miRNAs could be potential therapeutic targets or biomarkers for severe influenza virus infection.