Hypoxia-induced miR-210 modulates tissue response to acute peripheral ischemia

Hypoxia-preconditioned WJ-MSC spheroid-derived exosomes delivering miR-210 for renal cell restoration in hypoxia-reoxygenation injury

BACKGROUND

Recent advancements in mesenchymal stem cell (MSC) technology have paved the way for innovative treatment options for various diseases. These stem cells play a crucial role in tissue regeneration and repair, releasing local anti-inflammatory and healing signals. However, challenges such as homing issues and tumorigenicity have led to exploring MSC-exosomes as a promising alternative. MSC-exosomes have shown therapeutic potential in conditions like renal ischemia-reperfusion injury, but low production yields hinder their clinical use.

METHODS

To address this limitation, we examined hypoxic preconditioning of Wharton jelly-derived MSCs (WJ-MSCs) 3D-cultured in spheroids on isolated exosome yields and miR-21 expression. We then evaluated their capacity to load miR-210 into HEK-293 cells and mitigate ROS production, consequently enhancing their survival and migration under hypoxia-reoxygenation conditions.

RESULTS

MiR-210 overexpression was significantly induced by optimized culture and preconditioning conditions, which also improved the production yield of exosomes from grown MSCs. The exosomes enriched with miR-210 demonstrated a protective effect by improving survival, reducing apoptosis and ROS accumulation in damaged renal cells, and ultimately promoting cell migration.

CONCLUSION

The present study underscores the possibility of employing advanced techniques to maximize the therapeutic attributes of exosomes produced from WJ-MSC spheroid for improved recovery outcomes in ischemia-reperfusion injuries.

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

Dysregulated Genes, MicroRNAs, Biological Pathways, and Gastrocnemius Muscle Fiber Types Associated With Progression of Peripheral Artery Disease: A Preliminary Analysis

Background Peripheral artery disease (PAD) is associated with gastrocnemius muscle abnormalities. However, the biological pathways associated with gastrocnemius muscle dysfunction and their associations with progression of PAD are largely unknown. This study characterized differential gene and microRNA (miRNA) expression in gastrocnemius biopsies from people without PAD compared with those with PAD. Participants with PAD included those with and without PAD progression. Methods and Results mRNA and miRNA sequencing were performed to identify differentially expressed genes, differentially expressed miRNAs, mRNA-miRNA interactions, and associated biological pathways for 3 sets of comparisons: (1) PAD progression (n=7) versus non-PAD (n=7); (2) PAD no progression (n=6) versus non-PAD; and (3) PAD progression versus PAD no progression. Immunohistochemistry was performed to determine gastrocnemius muscle fiber types and muscle fiber size. Differentially expressed genes and differentially expressed miRNAs were more abundant in the comparison of PAD progression versus non-PAD compared with PAD with versus without progression. Among the top significant cellular pathways in subjects with PAD progression were muscle contraction or development, transforming growth factor-beta, growth/differentiation factor, and activin signaling, inflammation, cellular senescence, and notch signaling. Subjects with PAD progression had increased frequency of smaller Type 2a gastrocnemius muscle fibers in exploratory analyses. Conclusions Humans with PAD progression exhibited greater differences in the number of gene and miRNA expression, biological pathways, and Type 2a muscle fiber size compared with those without PAD. Fewer differences were observed between people with PAD without progression and control patients without PAD. Further study is needed to confirm whether the identified transcripts may serve as potential biomarkers for diagnosis and progression of PAD.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.

Skeletal muscle MiR-210 expression is associated with mitochondrial function in peripheral artery disease patients

Previous studies have demonstrated that circulating microRNA (miR)-210 levels are elevated in peripheral artery disease (PAD) patients. MiR-210 is known to be a negative regulator of mitochondrial respiration; however, the relationship between miR-210 and mitochondrial function has yet to be studied in PAD. We aimed to compare skeletal muscle miR-210 expression of PAD patients to non-PAD controls (CON) and to examine the relationship between miR-210 expression and mitochondrial function. Skeletal muscle biopsies from CON (n = 20), intermittent claudication (IC) patients (n = 20), and critical limb ischemia (CLI) patients (n = 20) were analyzed by high-resolution respirometry to measure mitochondrial respiration of permeabilized fibers. Samples were also analyzed for miR-210 expression by real-time PCR. MiR-210 expression was significantly elevated in IC and CLI muscle compared to CON (P = 0.008 and P < 0.001, respectively). Mitochondrial respiration of electron transport chain (ETC) Complexes II (P = 0.001) and IV (P < 0.001) were significantly reduced in IC patients. Further, CLI patients demonstrated significant reductions in respiration during Complexes I (state 2: P = 0.04, state 3: P = 0.003), combined I and II (P < 0.001), II (P < 0.001), and IV (P < 0.001). The expression of the miR-210 targets, cytochrome c oxidase assembly factor heme A: farnesyltransferase (COX10), and iron-sulfur cluster assembly enzyme (ISCU) were down-regulated in PAD muscle. MiR-210 may play a role in the cellular adaptation to hypoxia and may be involved in the metabolic myopathy associated with PAD.

miR-210 hypoxamiR in Angiogenesis and Diabetes

Significance: microRNA-210 (miR-210) is the master hypoxia-inducible miRNA (hypoxamiR) since it has been found to be significantly upregulated under hypoxia in a wide range of cell types. Recent advances: Gene ontology analysis of its targets indicates that miR-210 modulates several aspects of cellular response to hypoxia. Due to its high pleiotropy, miR-210 not only plays a protective role by fine-tuning mitochondrial metabolism and inhibiting red-ox imbalance and apoptosis, but it can also promote cell proliferation, differentiation, and migration, substantially contributing to angiogenesis. Critical issues: As most miRNAs, modulating different gene pathways, also miR-210 can potentially lead to different and even opposite effects, depending on the physio-pathological contexts in which it acts. Future direction: The use of miRNAs as therapeutics is a fast growing field. This review aimed at highlighting the role of miR-210 in angiogenesis in the context of ischemic cardiovascular diseases and diabetes in order to clarify the molecular mechanisms underpinning miR-210 action. Particular attention will be dedicated to experimentally validated miR-210 direct targets involved in cellular processes related to angiogenesis and diabetes mellitus, such as mitochondrial metabolism, redox balance, apoptosis, migration, and adhesion. Antioxid. Redox Signal. 36, 685-706.

MicroRNAs in peripheral artery disease: potential biomarkers and pathophysiological mechanisms

Peripheral artery disease (PAD) is a disease of atherosclerosis in the lower extremities. PAD carries a massive burden worldwide, while diagnosis and treatment options are often lacking. One of the key points of research in recent years is the involvement of microRNAs (miRNAs), which are short 20-25 nucleotide single-stranded RNAs that can act as negative regulators of post-transcriptional gene expression. Many of these miRNAs have been discovered to be misregulated in PAD patients, suggesting a potential utility as biomarkers for PAD diagnosis. miRNAs have also been shown to play an important role in many different pathophysiological aspects involved in the initiation and progression of the disease including angiogenesis, hypoxia, inflammation, as well as other cellular functions like cell proliferation and migration. The research on miRNAs in PAD has the potential to lead to a whole new class of diagnostic tools and treatments.

Regulation of Hypoxic Signaling and Oxidative Stress via the MicroRNA-SIRT2 Axis and Its Relationship with Aging-Related Diseases

The sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylase and ADP-ribosyl transferases plays key roles in aging, metabolism, stress response, and aging-related diseases. SIRT2 is a unique sirtuin that is expressed in the cytosol and is abundant in neuronal cells. Various microRNAs were recently reported to regulate SIRT2 expression via its 3'-untranslated region (UTR), and single nucleotide polymorphisms in the miRNA-binding sites of SIRT2 3'-UTR were identified in patients with neurodegenerative diseases. The present review highlights recent studies into SIRT2-mediated regulation of the stress response, posttranscriptional regulation of SIRT2 by microRNAs, and the implications of the SIRT2-miRNA axis in aging-related diseases.

Downregulation of microRNA-185 expression in diabetic patients increases the expression of NOS2 and results in vascular injury

The aim of the present study was to investigate the regulatory effect and mechanism of microRNA (miR)-185 in diabetic angiopathy. The expression of miR-185 and nitric oxide synthase 2 (NOS2) in the blood from diabetic patients was examined by reverse transcription-quantitative PCR and enzyme-linked immunosorbent assay. After establishment of diabetic rats, the expression of miR-185 and NOS2 in vascular tissues and blood was also measured. Then, miR-185 was overexpressed in HMEC-1 cells and the expression of NOS2 was determined. Dual-luciferase reporter assay was used to identify the direct interaction between miR-185 and NOS2 mRNA. The expression of NOS2 was upregulated and the expression of miR-185 was downregulated in the blood from patients with diabetes. Vascular tissues and blood of diabetic rats showed similar trends compared with that of human. HMEC-1 cells with overexpression of miR-185 had decreased expression of NOS2. Dual-luciferase reporter assay demonstrated the direct binding between miR-185 and NOS2. The present study demonstrates that upregulation of NOS2 in diabetic patients is associated with the downregulation of miR-185, which participates in the progression of diabetes possibly through regulating NOS2 expression.

Genetics of macrovascular complications in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that currently affects more than 400 million worldwide and is projected to cause 552 million cases by the year 2030. Long-term vascular complications, such as coronary artery disease, myocardial infarction, stroke, are the leading causes of morbidity and mortality among diabetic patients. The recent advances in genome-wide technologies have given a powerful impetus to the study of risk markers for multifactorial diseases. To date, the role of genetic and epigenetic factors in modulating susceptibility to T2DM and its vascular complications is being successfully studied that provides the accumulation of genomic knowledge. In the future, this will provide an opportunity to reveal the pathogenetic pathways in the development of the disease and allow to predict the macrovascular complications in T2DM patients. This review is focused on the evidence of the role of genetic variants and epigenetic changes in the development of macrovascular pathology in diabetic patients.

Macrophage miR-210 induction and metabolic reprogramming in response to pathogen interaction boost life-threatening inflammation

Unbalanced immune responses to pathogens can be life-threatening although the underlying regulatory mechanisms remain unknown. Here, we show a hypoxia-inducible factor 1α-dependent microRNA (miR)-210 up-regulation in monocytes and macrophages upon pathogen interaction. MiR-210 knockout in the hematopoietic lineage or in monocytes/macrophages mitigated the symptoms of endotoxemia, bacteremia, sepsis, and parasitosis, limiting the cytokine storm, organ damage/dysfunction, pathogen spreading, and lethality. Similarly, pharmacologic miR-210 inhibition improved the survival of septic mice. Mechanistically, miR-210 induction in activated macrophages supported a switch toward a proinflammatory state by lessening mitochondria respiration in favor of glycolysis, partly achieved by downmodulating the iron-sulfur cluster assembly enzyme ISCU. In humans, augmented miR-210 levels in circulating monocytes correlated with the incidence of sepsis, while serum levels of monocyte/macrophage-derived miR-210 were associated with sepsis mortality. Together, our data identify miR-210 as a fine-tuning regulator of macrophage metabolism and inflammatory responses, suggesting miR-210-based therapeutic and diagnostic strategies.

Hypoxia-induced miR-210 modulates the inflammatory response and fibrosis upon acute ischemia

Hypoxia-induced miR-210 is a crucial component of the tissue response to ischemia, stimulating angiogenesis and improving tissue regeneration. Previous analysis of miR-210 impact on the transcriptome in a mouse model of hindlimb ischemia showed that miR-210 regulated not only vascular regeneration functions, but also inflammation. To investigate this event, doxycycline-inducible miR-210 transgenic mice (Tg-210) and anti-miR-210 LNA-oligonucleotides were used. It was found that global miR-210 expression decreased inflammatory cells density and macrophages accumulation in the ischemic tissue. To dissect the underpinning cell mechanisms, Tg-210 mice were used in bone marrow (BM) transplantation experiments and chimeric mice underwent hindlimb ischemia. MiR-210 overexpression in the ischemic tissue was sufficient to increase capillary density and tissue repair, and to reduce inflammation in the presence of Wt-BM infiltrating cells. Conversely, when Tg-210-BM cells migrated in a Wt ischemic tissue, dysfunctional angiogenesis, inflammation, and impaired tissue repair, accompanied by fibrosis were observed. The fibrotic regions were positive for α-SMA, Vimentin, and Collagen V fibrotic markers and for phospho-Smad3, highlighting the activation of TGF-β1 pathway. Identification of Tg-210 cells by in situ hybridization showed that BM-derived cells contributed directly to fibrotic areas, where macrophages co-expressing fibrotic markers were observed. Cell cultures of Tg-210 BM-derived macrophages exhibited a pro-fibrotic phenotype and were enriched with myofibroblast-like cells, which expressed canonical fibrosis markers. Interestingly, inhibitors of TGF-β type-1-receptor completely abrogated this pro-fibrotic phenotype. In conclusion, a context-dependent regulation by miR-210 of the inflammatory response was identified. miR-210 expression in infiltrating macrophages is associated to improved angiogenesis and tissue repair when the ischemic recipient tissue also expresses high levels of miR-210. Conversely, when infiltrating an ischemic tissue with mismatched miR-210 levels, macrophages expressing high miR-210 levels display a pro-fibrotic phenotype, leading to impaired tissue repair, fibrosis, and dysfunctional angiogenesis.

The Role of Circulating Biomarkers in Peripheral Arterial Disease

Peripheral arterial disease (PAD) of the lower extremities is a chronic illness predominantly of atherosclerotic aetiology, associated to traditional cardiovascular (CV) risk factors. It is one of the most prevalent CV conditions worldwide in subjects >65 years, estimated to increase greatly with the aging of the population, becoming a severe socioeconomic problem in the future. The narrowing and thrombotic occlusion of the lower limb arteries impairs the walking function as the disease progresses, increasing the risk of CV events (myocardial infarction and stroke), amputation and death. Despite its poor prognosis, PAD patients are scarcely identified until the disease is advanced, highlighting the need for reliable biomarkers for PAD patient stratification, that might also contribute to define more personalized medical treatments. In this review, we will discuss the usefulness of inflammatory molecules, matrix metalloproteinases (MMPs), and cardiac damage markers, as well as novel components of the liquid biopsy, extracellular vesicles (EVs), and non-coding RNAs for lower limb PAD identification, stratification, and outcome assessment. We will also explore the potential of machine learning methods to build prediction models to refine PAD assessment. In this line, the usefulness of multimarker approaches to evaluate this complex multifactorial disease will be also discussed.

Treatment of Oxidative Stress with Exosomes in Myocardial Ischemia

A thrombus in a coronary artery causes ischemia, which eventually leads to myocardial infarction (MI) if not removed. However, removal generates reactive oxygen species (ROS), which causes ischemia–reperfusion (I/R) injury that damages the tissue and exacerbates the resulting MI. The mechanism of I/R injury is currently extensively understood. However, supplementation of exogenous antioxidants is ineffective against oxidative stress (OS). Enhancing the ability of endogenous antioxidants may be a more effective way to treat OS, and exosomes may play a role as targeted carriers. Exosomes are nanosized vesicles wrapped in biofilms which contain various complex RNAs and proteins. They are important intermediate carriers of intercellular communication and material exchange. In recent years, diagnosis and treatment with exosomes in cardiovascular diseases have gained considerable attention. Herein, we review the new findings of exosomes in the regulation of OS in coronary heart disease, discuss the possibility of exosomes as carriers for the targeted regulation of endogenous ROS generation, and compare the advantages of exosome therapy with those of stem-cell therapy. Finally, we explore several miRNAs found in exosomes against OS.

Elevated level of microRNA-210 at the initiation of muscular regeneration in acetic acid-induced non-ischemic skeletal muscular injury in mice

The alteration in microRNA-210 level, a hypoxia-inducible microRNA, is not well known in non-ischemic tissue injury. In this study, we characterized the histopathological time course of acetic acid-induced skeletal muscle injury as a non-ischemic tissue injury model and investigated the expression of microRNA-210, hypoxia-inducible factor 1α, and growth factors using quantitative polymerase chain reaction analysis. After a single intramuscular dose of 3% (v/v) acetic acid to C57BL/6J mice, focal coagulative necrosis of muscle fibers was noted from 3 h after dosing and infiltration of F4/80 and Galectin-3 positive M2 macrophage was noted at 1 d after dosing. Muscular regeneration was initiated from 3 d, when M2 macrophage infiltration was most prominent, till 14 d after dosing. Hif1α and Hgf expression increased from 3 h onwards, and microRNA-210 level increased after 3 d after the treatment. However, no clear elevation in the levels of Igf1 or Vegf was observed. The infiltrative macrophages and regenerative muscle fibers were positive for hypoxia-inducible factor 1α, microRNA-210, and hepatocyte growth factor as assessed by immunohistochemistry or in situ hybridization. In this study, dominant infiltration of M2 macrophages at muscular necrosis and subsequent regeneration after a single intramuscular injection of acetic acid in mice were observed. The increase in hif1α level was observed just after the muscular injury in this non-ischemic tissue injury model, and the elevation in microRNA-210 level was noted at the initiation of tissue regeneration, indicating its effects on tissue protection and repair.

HypoxamiR-210 accelerates wound healing in diabetic mice by improving cellular metabolism

Wound healing is a high energy demanding process that needs a good coordination of the mitochondria with glycolysis in the characteristic highly hypoxic environment. In diabetes, hyperglycemia impairs the adaptive responses to hypoxia with profound negative effects on different cellular compartments of wound healing. miR-210 is a hypoxia-induced microRNA that regulates cellular metabolism and processes important for wound healing. Here, we show that hyperglycemia blunted the hypoxia-dependent induction of miR-210 both in vitro and in human and mouse diabetic wounds. The impaired regulation of miR-210 in diabetic wounds is pathogenic, since local miR-210 administration accelerated wound healing specifically in diabetic but not in non-diabetic mice. miR-210 reconstitution restores the metabolic balance in diabetic wounds by reducing oxygen consumption rate and ROS production and by activating glycolysis with positive consequences on cellular migration. In conclusion, miR-210 accelerates wound healing specifically in diabetes through improvement of the cellular metabolism.

Histopathological significance of microRNA-210 expression in acute peripheral ischemia in a murine femoral artery ligation model

Under hypoxic conditions, microRNA-210 is upregulated and plays multiple physiological roles including in cell growth arrest, stem cell survival, repression of mitochondrial respiration, angiogenesis, and arrest of DNA repair. In this study, we investigated the histopathological expression of microRNA-210 under hypoxic conditions using a femoral artery ligation model established in C57BL/6J mice to determine the pathological significance of microRNA-210. Following femoral artery ligation, ischemia was represented by decreased blood flow compared to the control, in which a sham operation was performed. On histopathology, degeneration/necrosis of the muscle fibers, inflammatory cell infiltration, and regeneration of the muscle fibers were sequentially observed from 3 h to 3 d after ligation of the artery. The degree of these effects was more severe in the area in which type I muscular fibers are dominant. The histological expression of hypoxia-inducible factor 1α, a well-known biomarker of hypoxia, and microRNA-210 was observed in a few necrotic muscle fibers, macrophages, and myoblasts, a distribution consistent with the histopathological lesions, and their signal increased over time. The expression of microRNA-210 in macrophages and myoblasts under ischemia might be indicative of a significant role in the recovery from ischemic lesions. In addition, the in situ hybridization of microRNA-210 could potentially be used for the detection of hypoxia as a histological marker in addition to the immunohistochemistry of hypoxia-inducible factor 1α.

MicroRNA-210 improves perfusion recovery following hindlimb ischemia via suppressing reactive oxygen species

In peripheral arterial disease (PAD), angiogenesis is a major process involved in repairing the microvasculature in the ischemic lower limb. MicroRNA-210 (miR-210) is a microRNA that is substantially increased in patients with PAD. However, the effects of miR-210 on angiogenesis following PAD remain elusive. In the present study, mice with hindlimb ischemia (HLI) were generated as an animal model of PAD, and miR-210 levels were overexpressed in the ischemic limb. The overexpression of miR-210 using microRNA mimics greatly improved angiogenesis and perfusion recovery; in contrast, the knockdown of miR-210 impaired perfusion recovery 28 days after HLI. Ischemic muscle tissue was harvested 7 days after experimental PAD in order to perform biochemical tests, and miR-210 antagonism resulted in increased malondialdehyde levels. In cultured endothelial cells under simulated ischemia, miR-210 mimic improved endothelial cell viability and enhanced tube formation; and a miR-210 inhibitor decreased cell survival, reduced tube formation and increased reactive oxygen species (ROS) levels. Furthermore, miR-210 antagonism increased the protein disulfide-isomerase levels in cultured endothelial cells. These results demonstrate that ischemia-induced miR-210 elevation is adaptive in PAD, and that miR-210 improves angiogenesis at least partially through decreasing ROS production.

Liraglutide Increases Serum Levels of MicroRNA-27b, -130a and -210 in Patients with Type 2 Diabetes Mellitus: A Novel Epigenetic Effect

Liraglutide has shown favourable effects on several cardiometabolic risk factors, beyond glucose control. MicroRNAs (miRNAs) regulate gene expression, resulting in post-transcriptional modifications of cell response and function. Specific miRNAs, including miRNA-27b, miRNA-130a, and miRNA-210, play a role in cardiometabolic disease. We aimed to determine the effect of liraglutide on the serum levels of miRNA-27b, miRNA-130a and miRNA-210. Twenty-five subjects with type-2 diabetes mellitus (T2DM), naïve to incretin-based therapy, were treated with liraglutide (1.2 mg/day as an add-on to metformin) for 4 months. miRNAs were quantified using real-time polymerase chain reaction. After liraglutide treatment, we found significant reductions in fasting glucose (from 9.8 ± 5.3 to 6.7 ± 1.6 mmol/L, p = 0.0042), glycosylated haemoglobin (HbA1c) (from 8.1 ± 0.8 to 6.6 ± 1.0%, p = 0.0008), total cholesterol (from 5.0 ± 1.0 to 4.0 ± 0.7 mmol/L, p = 0.0011), triglycerides (from 1.9 ± 1.0 to 1.5 ± 0.8 mmol/L, p = 0.0104) and low-density lipoprotein cholesterol (from 2.9 ± 1.2 to 2.2 ± 0.6 mmol/L, p = 0.0125), while the serum levels of miRNA-27b, miRNA-130a and miRNA-210a were significantly increased (median (interquartile range, IQR) changes: 1.73 (7.12) (p = 0.0401), 1.91 (3.64) (p = 0.0401) and 2.09 (11.0) (p = 0.0486), respectively). Since the changes in miRNAs were independent of changes in all the metabolic parameters investigated, liraglutide seems to exert a direct epigenetic effect in T2DM patients, regulating microRNAs involved in the maintenance of endothelial cell homeostasis. These changes might be implicated in liraglutide’s benefits and may represent useful targets for cardiometabolic management.

Preoperative Circulating MiR-210, a Risk Factor for Postoperative Delirium Among Elderly Patients with Gastric Cancer Undergoing Curative Resection

BACKGROUND

Postoperative delirium (POD) is a very common complication in elderly patients with gastric cancer (GC) and associated with poor prognosis. MicroRNAs (miRNAs) serve as key post-transcriptional regulators of gene expression via targeting mRNAs and play important roles in the nervous system. This study aimed to investigate the potential predictive role of miRNAs for POD.

METHODS

Elderly GC patients who were scheduled to undergo elective curative resection were consequently enrolled in this study. POD was assessed at 1 day before surgery and 1-7 days after surgery following the guidance of the 5th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM V, 2013). The demographics, clinicopathologic characteristics and preoperative circulating miRNAs by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were compared between patients with or without POD. Risk factors for POD were assessed via univariate and multivariate logistic regression analyses.

RESULTS

A total of 370 participants were enrolled, of which 63 had suffered from POD within postoperative 7 days with an incidence of 17.0%. Preoperative miR-210 was a predictor for POD with an area under the curve (AUC) of 0.921, a cut-off value of 1.67, a sensitivity of 95.11%, and a specificity of 92.06%, (P<0.001). In the multivariate logistic regression model, the relative expression of serum miR-210 was an independent risk factor for POD (OR: 3.37, 95%CI: 1.98-5.87, P=0.003).

CONCLUSIONS

In conclusion, the present study highlighted that preoperative miR-210 could serve as a potential predictor for POD in elderly GC patients undergoing curative resection.

Noncoding RNAs in Critical Limb Ischemia

Peripheral artery disease, caused by chronic arterial occlusion of the lower extremities, affects over 200 million people worldwide. Peripheral artery disease can progress into critical limb ischemia (CLI), its more severe manifestation, which is associated with higher risk of limb amputation and cardiovascular death. Aiming to improve tissue perfusion, therapeutic angiogenesis held promise to improve ischemic limbs using delivery of growth factors but has not successfully translated into benefits for patients. Moreover, accumulating studies suggest that impaired downstream signaling of these growth factors (or angiogenic resistance) may significantly contribute to CLI, particularly under harsh environments, such as diabetes mellitus. Noncoding RNAs are essential regulators of gene expression that control a range of pathophysiologies relevant to CLI, including angiogenesis/arteriogenesis, hypoxia, inflammation, stem/progenitor cells, and diabetes mellitus. In this review, we summarize the role of noncoding RNAs, including microRNAs and long noncoding RNAs, as functional mediators or biomarkers in the pathophysiology of CLI. A better understanding of these ncRNAs in CLI may provide opportunities for new targets in the prevention, diagnosis, and therapeutic management of this disabling disease state.

Hypoxia-Induced miR-210 Is Necessary for Vascular Regeneration upon Acute Limb Ischemia

Critical limb ischemia is the most serious form of peripheral artery disease, characterized by severe functional consequences, difficult clinical management and reduced life expectancy. The goal of this study was to investigate the miR-210 role in the neo-angiogenic response after acute limb ischemia. Complementary approaches were used in a mouse model of hindlimb ischemia: miR-210 loss-of-function was obtained by administration of LNA-oligonucleotides anti-miR-210; for miR-210 gain-of-function, a doxycycline-inducible miR-210 transgenic mouse was used. We tested miR-210 ability to stimulate vascular regeneration following ischemia. We found that miR-210 was necessary and sufficient to stimulate blood perfusion recovery, as well as arteriolar and capillary density increase, in the ischemic muscle. To clarify the molecular events underpinning miR-210 pro-angiogenic action, the transcriptomic changes in ischemic muscles upon miR-210 blocking were analyzed. We found that miR-210 impacted the transcriptome significantly, regulating pathways and functions linked to vascular regeneration. In agreement with a pro-angiogenic role, miR-210 also improved cardiac function and left ventricular remodeling after myocardial infarction. Moreover, miR-210 blocking decreased capillary density in a Matrigel plug assay, indicating that miR-210 is necessary for angiogenesis independently of ischemia. Collectively, these data indicate that miR-210 plays a pivotal role in promoting vascular regeneration.

Noncoding RNAs in the Vascular System Response to Oxidative Stress

SIGNIFICANCE

Redox homeostasis plays a pivotal role in vascular cell function and its imbalance has a causal role in a variety of vascular diseases. Accordingly, the response of mammalian cells to redox cues requires precise transcriptional and post-transcriptional modulation of gene expression patterns. Recent Advances: Mounting evidence shows that nonprotein-coding RNAs (ncRNAs) are important for the functional regulation of most, if not all, cellular processes and tissues. Not surprisingly, a prominent role of ncRNAs has been identified also in the vascular system response to oxidative stress.

CRITICAL ISSUES

The highly heterogeneous family of ncRNAs has been divided into several groups. In this article we focus on two classes of regulatory ncRNAs: microRNAs and long ncRNAs (lncRNAs). Although knowledge in many circumstances, and especially for lncRNAs, is still fragmentary, ncRNAs are clinically interesting because of their diagnostic and therapeutic potential. We outline ncRNAs that are regulated by oxidative stress as well as ncRNAs that modulate reactive oxygen species production and scavenging. More importantly, we describe the role of these ncRNAs in vascular physiopathology and specifically in disease conditions wherein oxidative stress plays a crucial role, such as hypoxia and ischemia, ischemia reperfusion, inflammation, diabetes mellitus, and atherosclerosis.

FUTURE DIRECTIONS

The therapeutic potential of ncRNAs in vascular diseases and in redox homeostasis is discussed.

Exosome-mediated targeted delivery of miR-210 for angiogenic therapy after cerebral ischemia in mice

Background

Accumulating evidence shows that microRNA-210 (miR-210) holds great promise to improve angiogenesis for brain tissue repair after cerebral ischemia. However, safe and efficient delivery of miR-210 via intravenous administration is still a challenge. In the past decade, exosomes have emerged as a novel endogenous delivery system. Here, c(RGDyK) peptide is conjugated to exosomes, and they are loaded with cholesterol-modified miR-210 (RGD-exo:miR-210).

Results

In a transient middle cerebral artery occlusion (MCAO) mouse model, the RGD-exo:miR-210 targets the lesion region of the ischemic brain after intravenous administration, resulting in an increase in miR-210 at the site. Furthermore, RGD-exo:miR-210 are administered once every other day for 14 days, and the expressions of integrin β₃, vascular endothelial growth factor (VEGF) and CD34 are significantly upregulated. The animal survival rate is also enhanced.

Conclusions

These results suggest a strategy for the targeted delivery of miR-210 to ischemic brain and provide an angiogenic agent for the treatment of ischemic stroke.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0461-7) contains supplementary material, which is available to authorized users.

Postnatal Expression Profile of microRNAs Associated with Cardiovascular and Cerebrovascular Diseases in Children at the Age of 3 to 11 Years in Relation to Previous Occurrence of Pregnancy-Related Complications

Children descending from pregnancies complicated by gestational hypertension (GH), preeclampsia (PE) or fetal growth restriction (FGR) have a lifelong cardiovascular risk. The aim of the study was to verify if pregnancy complications induce postnatal alterations in gene expression of microRNAs associated with cardiovascular/cerebrovascular diseases. Twenty-nine microRNAs were assessed in peripheral blood, compared between groups, and analyzed in relation to both aspects, the current presence of cardiovascular risk factors and cardiovascular complications and the previous occurrence of pregnancy complications with regard to the clinical signs, dates of delivery, and Doppler ultrasound examination. The expression profile of miR-21-5p differed between controls and children with a history of uncomplicated pregnancies with abnormal clinical findings. Abnormal expression profile of multiple microRNAs was found in children affected with GH (miR-1-3p, miR-17-5p, miR-20a-5p, miR-21-5p, miR-23a-3p, miR-26a-5p, miR-29a-3p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-133a-3p, miR-146a-5p, miR-181a-5p, miR-195-5p, and miR-342-3p), PE (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-103a-3p, miR-133a-3p, miR-342-3p), and FGR (miR-17-5p, miR-126-3p, miR-133a-3p). The index of pulsatility in the ductus venosus showed a strong positive correlation with miR-210-3p gene expression in children exposed to PE and/or FGR. Any of changes in epigenome (up-regulation of miR-1-3p and miR-133a-3p) that were induced by pregnancy complications are long-acting and may predispose children affected with GH, PE, or FGR to later development of cardiovascular/cerebrovascular diseases. Novel epigenetic changes (aberrant expression profile of microRNAs) appeared in a proportion of children that were exposed to GH, PE, or FGR. Screening of particular microRNAs may stratify a highly risky group of children that might benefit from implementation of early primary prevention strategies.

Loss of miR-210 leads to progressive retinal degeneration in Drosophila melanogaster

Depletion of miRNA-210 disrupts photoreceptor integrity and visual function in Drosophila melanogaster.

miRNAs are small, non-coding RNAs that regulate gene expression post-transcriptionally. We used small RNA sequencing to identify tissue-specific miRNAs in the adult brain, thorax, gut, and fat body of Drosophila melanogaster. One of the most brain-specific miRNAs that we identified was miR-210, an evolutionarily highly conserved miRNA implicated in the regulation of hypoxia in mammals. In Drosophila, we show that miR-210 is specifically expressed in sensory organs, including photoreceptors. miR-210 knockout mutants are not sensitive toward hypoxia but show progressive degradation of photoreceptor cells, accompanied by decreased photoreceptor potential, demonstrating an important function of miR-210 in photoreceptor maintenance and survival.

MicroRNA-532-5p Regulates Pericyte Function by Targeting the Transcription Regulator BACH1 and Angiopoietin-1

MicroRNAs regulate endothelial function and angiogenesis, but their implication in pericyte biology remains undetermined. A PCR array, covering a panel of 379 human microRNAs, showed microRNA-532-5p to be one of the most differentially modulated by hypoxia, which was confirmed by qPCR in both skeletal muscle and adventitial pericytes. Furthermore, microRNA-532-5p was upregulated in murine muscular pericytes early after experimentally induced ischemia, decreasing below baseline after reperfusion. Transfection of human pericytes with anti-microRNA, microRNA-mimic, or controls indicates microRNA-532-5p modulates pro-angiogenic activity via transcriptional regulation of angiopoietin-1. Tie-2 blockade abrogated the ability of microRNA-532-5p-overexpressing pericytes to promote endothelial network formation in vitro. However, angiopoietin-1 is not a direct target of microRNA-532-5p. In silico analysis of microRNA-532-5p inhibitory targets associated with angiopoietin-1 transcription indicated three potential candidates, BACH1, HIF1AN, and EGLN1. Binding of microRNA-532-5p to the BACH1 3' UTR was confirmed by luciferase assay. MicroRNA-532-5p silencing increased BACH1, while a microRNA-532-5p mimic decreased expression. Silencing of BACH1 modulated angiopoietin-1 gene and protein expression. ChIP confirmed BACH1 transcriptional regulation of angiopoietin-1 promoter. Finally, microRNA-532-5p overexpression increased pericyte coverage in an in vivo Matrigel assay, suggesting its role in vascular maturation. This study provides a new mechanistic understanding of the transcriptional program orchestrating angiopoietin-1/Tie-2 signaling in human pericytes.

miR-210 Enhances the Therapeutic Potential of Bone-Marrow-Derived Circulating Proangiogenic Cells in the Setting of Limb Ischemia

Therapies based on circulating proangiogenic cells (PACs) have shown promise in ischemic disease models but require further optimization to reach the bedside. Ischemia-associated hypoxia robustly increases microRNA-210 (miR-210) expression in several cell types, including endothelial cells (ECs). In ECs, miR-210 represses EphrinA3 (EFNA3), inducing proangiogenic responses. This study provides new mechanistic evidences for a role of miR-210 in PACs. PACs were obtained from either adult peripheral blood or cord blood. miR-210 expression was modulated with either an inhibitory complementary oligonucleotide (anti-miR-210) or a miRNA mimic (pre-miR-210). Scramble and absence of transfection served as controls. As expected, hypoxia increased miR-210 in PACs. In vivo, migration toward and adhesion to the ischemic endothelium facilitate the proangiogenic actions of transplanted PACs. In vitro, PAC migration toward SDF-1α/CXCL12 was impaired by anti-miR-210 and enhanced by pre-miR-210. Moreover, pre-miR-210 increased PAC adhesion to ECs and supported angiogenic responses in co-cultured ECs. These responses were not associated with changes in extracellular miR-210 and were abrogated by lentivirus-mediated EFNA3 overexpression. Finally, ex-vivo pre-miR-210 transfection predisposed PACs to induce post-ischemic therapeutic neovascularization and blood flow recovery in an immunodeficient mouse limb ischemia model. In conclusion, miR-210 modulates PAC functions and improves their therapeutic potential in limb ischemia.

Physiological culture conditions alter myotube morphology and responses to atrophy treatments: implications for in vitro research on muscle wasting

Standard in vitro myotube culture conditions are nonphysiological and there is increasing evidence that this may distort adaptations to both catabolic and anabolic stimuli and hamper preclinical research into mechanisms and treatments for muscle atrophy in cancer and other chronic diseases. We tested a new model of myotube culture which mimics more accurately the basal conditions for muscle tissue in patients with chronic disease, such as cancer. Myotubes derived from C2C12 myoblasts, cultured under the modified conditions were thinner, more numerous, with more uniform morphology and an increased proportion of mature myotubes. Furthermore, modified conditions led to increased expression of mir-210-3p, genes related to slow-twitch, oxidative phenotype and resistance to commonly used experimental atrophy-inducing treatments. However, treatment with a combination of drugs used in anti-cancer treatment (doxorubicin and dexamethasone) under the modified culture conditions did lead to myotube atrophy which was only partially prevented by co-administration of curcumin. The results underline the importance and potential advantages of using physiological conditions for in vivo experiments investigating mechanisms of muscle atrophy and especially for preclinical screening of therapies for cancer-related muscle wasting.

Dynamic Regulation of Circulating microRNAs During Acute Exercise and Long-Term Exercise Training in Basketball Athletes

Emerging evidence indicates the beneficial effects of physical exercise on human health, which depends on the intensity, training time, exercise type, environmental factors, and the personal health status. Conventional biomarkers provide limited insight into the exercise-induced adaptive processes. Circulating microRNAs (miRNAs, miRs) are dynamically regulated in response to acute exhaustive exercise and sustained rowing, running and cycling exercises. However, circulating miRNAs in response to long-term basketball exercise remains unknown. Here, we enrolled 10 basketball athletes who will attend a basketball season for 3 months. Specifically, circulating miRNAs which were involved in angiogenesis, inflammation and enriched in muscle and/or cardiac tissues were analyzed at baseline, immediately following acute exhaustive exercise and after 3-month basketball matches in competitive male basketball athletes. Circulating miR-208b was decreased and miR-221 was increased after 3-month basketball exercise, while circulating miR-221, miR-21, miR-146a, and miR-210 were reduced at post-acute exercise. The change of miR-146a (baseline vs. post-acute exercise) showed linear correlations with baseline levels of cardiac marker CKMB and the changes of inflammation marker Hs-CRP (baseline vs. post-acute exercise). Besides, linear correlation was observed between miR-208b changes (baseline vs. after long-term exercise) and AT VO₂ (baseline). The changes of miR-221 (baseline vs. after long-term exercise) were significantly correlated with AT VO₂, peak work load and CK (after 3-month basketball matches). Although further studies are needed, present findings set the stage for defining circulating miRNAs as biomarkers and suggesting their physiological roles in long-term exercise training induced cardiovascular adaptation.

miR-210 protects renal cell against hypoxia-induced apoptosis by targeting HIF-1 alpha

The kidney is vulnerable to hypoxia-induced injury. One of the mechanisms underlying this phenomenon is cell apoptosis triggered by hypoxia-inducible factor-1-alpha (HIF-1α) activation. MicroRNA-210 (miR-210) is known to be induced by HIF-1α and can regulate various pathological processes, but its role in hypoxic kidney injury remains unclear. Here, in both kinds of rat systemic hypoxia and local kidney hypoxia models, we found miR-210 levels were upregulated significantly in injured kidney, especially in renal tubular cells. A similar increase was observed in hypoxia-treated human renal tubular HK-2 cells. We also verified that miR-210 can directly suppress HIF-1α expression by targeting the 3' untranslated region (UTR) of HIF-1α mRNA in HK-2 cells in severe hypoxia. Accordingly, miR-210 overexpression caused significant inhibition of the HIF-1α pathway and attenuated apoptosis caused by hypoxia, while miR-210 knockdown exerted the opposite effect. Taken together, our findings verify that miR-210 is involved in the molecular response in hypoxic kidney lesions in vivo and attenuates hypoxia-induced renal tubular cell apoptosis by targeting HIF-1α directly and suppressing HIF-1α pathway activation in vitro.

Overexpression of miR-210 and its significance in ischemic tissue damage

Hypoxia-induced miR-210 displays a pro-survival, cytoprotective and pro-angiogenic role in several in vitro systems. In vivo, we previously found that miR-210 inhibition increases ischemic damage. Here we describe the generation of a versatile transgenic mouse model allowing the evaluation of miR-210 therapeutic potential in ischemic cardiovascular diseases. We generated a Tet-On miR-210 transgenic mouse strain (TG-210) by targeted transgenesis in the ROSA26 locus. To functionally validate miR-210 transgenic mice, hindlimb ischemia was induced by femoral artery dissection. Blood perfusion was evaluated by power Doppler while tissue damage and inflammation were assessed by histological evaluation. We found that miR-210 levels were rapidly increased in TG-210 mice upon doxycycline administration. miR-210 overexpression was maintained over time and remained within physiological levels in multiple tissues. When hindlimb ischemia was induced, miR-210 overexpression protected from both muscular and vascular ischemic damage, decreased inflammatory cells density and allowed to maintain a better calf perfusion. In conclusion, we generated and functionally validated a miR-210 transgenic mouse model. Albeit validated in the context of a specific cardiovascular ischemic disease, miR-210 transgenic mice may also represent a useful model to assess the function of miR-210 in other physio-pathological conditions.

Protection of Human Umbilical Vein Endothelial Cells against Oxidative Stress by MicroRNA-210

Oxidative stress induces endothelial cell apoptosis and promotes atherosclerosis development. MicroRNA-210 (miR-210) is linked with apoptosis in different cell types. This study aimed to investigate the role of miR-210 in human umbilical vein endothelial cells (HUVECs) under oxidative stress and to determine the underlying mechanism. HUVECs were treated with different concentrations of hydrogen peroxide (H₂O₂), and cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ATP assay. To evaluate the role of miR-210 in H₂O₂-mediated apoptosis, gain-and-loss-of-function approaches were used, and the effects on apoptosis and reactive oxygen species (ROS) level were assayed using flow cytometry. Moreover, miR-210 expression was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and expression of the following apoptosis-related genes was assessed by qRT-PCR and Western blot at the RNA and protein level, respectively: caspase-8-associated protein 2 (CASP8AP2), caspase-8, and caspase-3. The results showed that H₂O₂ induced apoptosis in HUVECs in a dose-dependent manner and increased miR-210 expression. Overexpression of miR-210 inhibited apoptosis and reduced ROS level in HUVECs treated with H₂O₂. Furthermore, miR-210 downregulated CASP8AP2 and related downstream caspases at protein level. Thus, under oxidative stress, miR-210 has a prosurvival and antiapoptotic effect on HUVECs by reducing ROS generation and downregulating the CASP8AP2 pathway.

Regulation of microvascularization in heart failure - an endothelial cell, non-coding RNAs and exosome liaison

Heart failure is a complex syndrome involving various pathophysiological processes. An increasing body of evidence shows that the myocardial microvasculature is essential for the homeostasis state and that a decompensated heart is associated with microvascular dysfunction as a result of impaired endothelial angiogenic capacity. The intercellular communication between endothelial cells and cardiomyocytes through various signaling molecules, such as vascular endothelial growth factor, nitric oxide, and non-coding RNAs is an important determinant of cardiac microvascular function. Non-coding RNAs are transported from endothelial cells to cardiomyocytes, and vice versa, regulating microvascular properties and angiogenic processes in the heart. Small-exocytosed vesicles, called exosomes, which are secreted by both cell types, can mediate this intercellular communication. The purpose of this review is to highlight the contribution of the microvasculature to proper heart function maintenance by focusing on the interaction between cardiac endothelial cells and myocytes with a specific emphasis on non-coding RNAs (ncRNAs) in this form of cell-to-cell communication. Finally, the potential of ncRNAs as targets for angiogenesis therapy will also be discussed.

MicroRNA-210 induces endothelial cell apoptosis by directly targeting PDK1 in the setting of atherosclerosis

Background

Atherosclerosis is a chronically inflammatory disease and one of the leading causes of deaths worldwide. Endothelial cell apoptosis plays a crucial role in its development. Several microRNAs (miRNAs) are reportedly involved in atherosclerotic plaque formation, including miRNA-210 (miR-210). However, the underlying mechanism of its role in endothelial cell apoptosis during atherosclerosis is still largely unknown.

Methods

A mouse model with atherosclerosis induced by a high-fat diet (HFD) was built in ApoE (-/-) mice. The levels of endothelial cell apoptosis were determined via flow cytometry. The expressions of miR-210 and PDK1 in purified CD31+ endothelial cells from mouse aorta were measured via RT-qPCR and western blot. Binding between miR-210 and the 3′-untranslated region (UTR) of PDK1 mRNA was predicted using bioinformatics analyses and confirmed with a dual luciferase reporter assay. The effects of miR-210 were further analyzed in an in vitro model using human aortic endothelial cells (HAECs) treated with oxidized low-density lipoprotein (ox-LDL).

Results

We found that the HFD mice developed atherosclerosis in 12 weeks and had a significantly higher percentage of endothelial cell apoptosis. The upregulated level of miR-210 in the HFD mice and HAECs inversely correlated with the level of PDK1. Inhibiting miR-210 expression significantly reduced HAEC apoptosis, as evidenced by the results of the MTT and flow cytometry experiments. Further analysis identified PDK1 as the target of miR-210 and showed that PDK1 overexpression reversed the pro-apoptotic effect of miR-210 through mediation of the P13K/Akt/mTOR pathways.

Conclusion

Our study suggests a novel role for miR-210 in the progression of atherosclerosis through the regulation of endothelial apoptosis. This indicates that miR-210 might have potential in treatment of atherosclerosis.

MicroRNAs as regulators of endothelial cell functions in cardiometabolic diseases

Endothelial cells (ECs) provide nutrients and oxygen essential for tissue homeostasis. Metabolic imbalances and other environmental stimuli, like cytokines or low shear stress, trigger endothelial inflammation, increase permeability, compromise vascular tone, promote cell proliferation, and ultimately cause cell death. These factors contribute to EC dysfunction, which is crucial in the development of cardiometabolic diseases. microRNAs (miRNAs) are small non-coding RNAs that have important functions in the regulation of ECs. In the present review, we discuss the role of miRNAs in various aspects of EC pathology in cardiometabolic diseases like atherosclerosis, type 2 diabetes, obesity, and the metabolic syndrome, and in complication of those pathologies, like ischemia. We also discuss the potential therapeutic applications of miRNAs in promoting angiogenesis and neovascularization in tissues where the endothelium is damaged in different cardiometabolic diseases. This article is part of a Special Issue entitled: MicroRNAs and lipid/energy metabolism and related diseases edited by Carlos Fernández-Hernando and Yajaira Suárez.

Circulating miR-130a, miR-27b, and miR-210 in Patients With Peripheral Artery Disease and Their Potential Relationship With Oxidative Stress

Some emerging risk factors such as oxidative stress biomarkers and microRNAs (miRs) may add additional value to the established risk factors for peripheral artery disease (PAD). We enrolled 27 patients with PAD and 27 age-matched controls. We examined the levels of a series of miRs (miR-130a, miR-27b, and miR-210) in serum samples. The level of well-established oxidative stress biomarkers, such as lipid hydroperoxides, isoprostanes, hemeoxygenase-1 (HO-1) and reduced glutathione, was also measured in plasma and their relationship with the miRs was determined. Levels of miR-130a, miR-27b, and miR-210 were significantly increased in patients with PAD when compared to the controls. The level of miR-130 was positively correlated with body mass index, whereas miR-210 was inversely associated with pain-free walking distance (PfWD). None of the evaluated miRs was associated with lowered PfWD of patients with PAD (stage IIa > 250 m, IIb < 250 m) or oxidative stress parameters. In conclusion, our findings suggest the need for more research to assess if miRs can serve as useful markers for the early diagnosis and monitoring of PAD.

microRNAs in ischaemic cardiovascular diseases

microRNAs (miRNAs) are non-coding RNA molecules that modulate the stability and/or the translational efficiency of specific messenger RNAs. They have been shown to play a regulatory role in most biological processes and their expression is disrupted in many cardiovascular diseases. This review describes studies performed at Policlinico San Donato-IRCCS in cell cultures, animal models, and patients, showing a penetrant role of miRNAs in cell response to hypoxia and in ischaemic cardiovascular diseases. These experiments indicate miRNA as an emerging class of therapeutic targets.

Magnetic Resonance Imaging Allows the Evaluation of Tissue Damage and Regeneration in a Mouse Model of Critical Limb Ischemia

Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.

Network analysis of microRNA and mRNA seasonal dynamics in a highly plastic sensorimotor neural circuit

Background

Adult neurogenesis and the incorporation of adult-born neurons into functional circuits requires precise spatiotemporal coordination across molecular networks regulating a wide array of processes, including cell proliferation, apoptosis, neurotrophin signaling, and electrical activity. MicroRNAs (miRs) - short, non-coding RNA sequences that alter gene expression by post-transcriptional inhibition or degradation of mRNA sequences - may be involved in the global coordination of such diverse biological processes. To test the hypothesis that miRs related to adult neurogenesis and related cellular processes are functionally regulated in the nuclei of the avian song control circuit, we used microarray analyses to quantify changes in expression of miRs and predicted target mRNAs in the telencephalic nuclei HVC, the robust nucleus of arcopallium (RA), and the basal ganglia homologue Area X in breeding and nonbreeding Gambel’s white-crowned sparrows (Zonotrichia leucophrys gambelli).

Results

We identified 46 different miRs that were differentially expressed across seasons in the song nuclei. miR-132 and miR-210 showed the highest differential expression in HVC and Area X, respectively. Analyzing predicted mRNA targets of miR-132 identified 33 candidate target genes that regulate processes including cell cycle control, calcium signaling, and neuregulin signaling in HVC. Likewise, miR-210 was predicted to target 14 mRNAs differentially expressed across seasons that regulate serotonin, GABA, and dopamine receptor signaling and inflammation.

Conclusions

Our results identify potential miR–mRNA regulatory networks related to adult neurogenesis and provide opportunities to discover novel genetic control of the diverse biological processes and factors related to the functional incorporation of new neurons to the adult brain.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2175-z) contains supplementary material, which is available to authorized users.

Noncoding RNA in age-related cardiovascular diseases

Eukaryotic gene expression is tightly regulated transcriptionally and post-transcriptionally by a host of noncoding (nc)RNAs. The best-studied class of short ncRNAs, microRNAs, mainly repress gene expression post-transcriptionally. Long noncoding (lnc)RNAs, which comprise RNAs differing widely in length and function, can regulate gene transcription as well as post-transcriptional mRNA fate. Collectively, ncRNAs affect a broad range of age-related physiologic deteriorations and pathologies, including reduced cardiovascular vigor and age-associated cardiovascular disease. This review presents an update of our understanding of regulatory ncRNAs contributing to cardiovascular health and disease as a function of advancing age. We will discuss (1) regulatory ncRNAs that control aging-associated cardiovascular homeostasis and disease, (2) the concepts, approaches, and methodologies needed to study regulatory ncRNAs in cardiovascular aging and (3) the challenges and opportunities that age-associated regulatory ncRNAs present in cardiovascular physiology and pathology. This article is part of a Special Issue entitled "CV Aging".

HypoxamiR regulation and function in ischemic cardiovascular diseases

SIGNIFICANCE

MicroRNAs (miRNAs) are deregulated and play a causal role in numerous cardiovascular diseases, including myocardial infarction, coronary artery disease, hypertension, heart failure, stroke, peripheral artery disease, kidney ischemia-reperfusion.

RECENT ADVANCES

One crucial component of ischemic cardiovascular diseases is represented by hypoxia. Indeed, hypoxia is a powerful stimulus regulating the expression of a specific subset of miRNAs, named hypoxia-induced miRNAs (hypoxamiR). These miRNAs are fundamental regulators of the cell responses to decreased oxygen tension. Certain hypoxamiRs seem to have a particularly pervasive role, such as miR-210 that is virtually induced in all ischemic diseases tested so far. However, its specific function may change according to the physiopathological context.

CRITICAL ISSUES

The discovery of HypoxamiR dates back 6 years. Thus, despite a rapid growth in knowledge and attention, a deeper insight of the molecular mechanisms underpinning hypoxamiR regulation and function is needed.

FUTURE DIRECTIONS

An extended understanding of the function of hypoxamiR in gene regulatory networks associated with cardiovascular diseases will allow the identification of novel molecular mechanisms of disease and indicate the development of innovative therapeutic approaches.

Involvement of miRNAs in placental alterations mediated by oxidative stress

Oxidative stress (OS) is known to be strongly involved in a large number of fetal, neonatal, and adult diseases, including placental disorders, leading to pregnancy loss and stillbirths. A growing body of research links OS to preeclampsia, gestational diabetes, obesity, spontaneous abortion, recurrent pregnancy, preterm labor, and intrauterine growth restriction. While a considerable number of miRNAs have been related to physiological functions and pathological conditions of the placenta, a direct link among these miRNAs, placental functions, and OS is still lacking. This review summarizes data describing the role of miRNAs in placental pathophysiological processes and their possible impact on OS damaging responses. As miRNAs can be found in circulation, improving our understanding on their role in the pathogenesis of pregnancy related disorders could have an important impact on the diagnosis and prognosis of these diseases.

Nitric oxide, oxidative stress, and p66Shc interplay in diabetic endothelial dysfunction

Increased oxidative stress and reduced nitric oxide (NO) bioavailability play a causal role in endothelial cell dysfunction occurring in the vasculature of diabetic patients. In this review, we summarized the molecular mechanisms underpinning diabetic endothelial and vascular dysfunction. In particular, we focused our attention on the complex interplay existing among NO, reactive oxygen species (ROS), and one crucial regulator of intracellular ROS production, p66Shc protein.