Circulating p53-responsive microRNAs are predictive indicators of heart failure after acute myocardial infarction

The therapeutic and diagnostic role of exosomes in cardiovascular diseases

Exosomes are nano-sized membranous vesicles that are secreted by cells. They have an important role in transferring proteins, mRNA, miRNA and other bioactive molecules between cells and regulate gene expression in recipient cells. Therefore, exosomes are a mechanism by which communication between cells is achieved and they are involved in a wide range of physiological processes, especially those requiring cell-cell communication. In the cardiovascular system, exosomes are associated with endothelial cells, cardiac myocytes, vascular cells, stem and progenitor cells, and play an essential role in development, injury and disease of the cardiovascular system. In recent years, accumulating evidence implicates exosomes in the development and progression of cardiovascular disease. Additionally, exosomal microRNAs are considered to be key players in cardiac regeneration and confer cardioprotective and regenerative properties on both cardiac and non-cardiac cells and, additionally, stem and progenitor cells. Notably, miRNAs may be isolated from blood and offer a potential source of novel diagnostic and prognostic biomarkers for cardiovascular disease. In this review, we summarize and assess the functional roles of exosomes in cardiovascular physiology, cell-to-cell communication and cardio-protective effects in cardiovascular disease.

Circulating microRNAs -192 and -194 are associated with the presence and incidence of diabetes mellitus

We sought to identify circulating microRNAs as biomarkers of prevalent or incident diabetes. In a pilot study of 18 sex- and age-matched patients with metabolic syndrome, nine of whom developed diabetes during 6 years of follow-up, an array of 372 microRNAs discovered significantly elevated serum levels of microRNAs -122, -192, -194, and -215 in patients who developed diabetes mellitus type 2 (T2DM). In two cross-sectional validation studies, one encompassing sex- and age-matched groups of patients with T2DM, impaired fasting glucose (IFG) and euglycemic controls (n = 43 each) and the other 53 patients with type 1 diabetes and 54 age- and BMI-matched euglycemic controls, serum levels of miR-192, miR-194, and mi215 were significantly higher in diabetic subjects than in probands with euglycemia or IFG. In a longitudinal study of 213 initially diabetes-free patients of whom 35 developed diabetes during 6 years of follow-up, elevated serum levels of microRNAs 192 and 194 were associated with incident T2DM, independently of fasting glucose, HbA1c and other risk factors. Serum levels of miR-192 and miR-194 were also elevated in diabetic Akt2 knockout mice compared to wild type mice. In conclusion, circulating microRNAs -192 and -194 are potential biomarkers for risk of diabetes.

HMGB1 represses the anti-cancer activity of sunitinib by governing TP53 autophagic degradation via its nucleus-to-cytoplasm transport

Sunitinib, a multikinase inhibitor approved for a number of cancer indications has a low response rate. Identifying mechanisms of resistance could lead to rational combination regimens that could improve clinical outcomes. Here we report that resistance to sunitinib therapy was driven by autophagic degradation of TP53/p53. Deletion of ATG7 or ATG5 suppressed TP53 degradation, as did knockdown of SQSTM1/p62. Mechanistically, the transport of TP53 from the nucleus to the cytoplasm was essential for the sunitinib-induced autophagic degradation of TP53 and did not require TP53 nuclear export signals (NESs). Moreover, TP53 degradation was achieved by the transport of its nuclear binding target, HMGB1, which shifted TP53 from the nucleus to the cytoplasm. The inhibition of HMGB1 sensitized cancer cells to sunitinib. Importantly, sunitinib induced the degradation of all TP53 proteins, except for TP53 proteins with mutations in the interaction domain of TP53 with HMGB1 (amino acids 313 to 352). In conclusion, our data identify an alternative HMGB1-mediated TP53 protein turnover mechanism that participates in the resistance of sunitinib and suggest HMGB1 as a potential therapeutic target for improving clinical outcomes of sunitinib.

Significance of non-coding circular RNAs and micro RNAs in the pathogenesis of cardiovascular diseases

Heart failure, coronary artery disease and myocardial infarction are the most prominent cardiovascular diseases contributing significantly to death worldwide. In the majority of situations, except for surgical interventions and transplantation, there are no reliable therapeutic approaches available to address these health problem. Despite several advances that led to the development of biomarkers and therapies based on the renin–angiotensin system, adrenergic pathways, etc, more definitive and consistent biomarkers and specific target based molecular therapies are still being sought. Recent advances in the field of genomic research has helped in identifying non-coding RNAs, including circular RNAs, piRNAs, micro RNAs, and long non-coding RNAs, that play a significant role in the regulation of gene expression and function and have direct impact on pathophysiological mechanisms. This new knowledge is currently being explored with much hope for the development of novel treatments and biomarkers. Circular RNAs and micro RNAs have been described in myocardium and aortic valves and were shown to be involved in the regulation of pathophysiological processes that potentially contribute to cardiovascular diseases. Approximately 32 000 human exonic circular RNAs have been catalogued and their functions are still being ascertained. In the heart, circular RNAs were shown to bind micro RNAs in a specific manner and regulate the expression of transcription factors and stress response genes, and expression of these non-coding RNAs were found to change in conditions such as cardiac hypertrophy, heart failure and cardiac remodelling, reflecting their significance as diagnostic and prognostic biomarkers. In this review, we address the present state of understanding on the biogenesis, regulation and pathophysiological roles of micro and circular RNAs in cardiovascular diseases, and on the potential future perspectives on their use as biomarkers and therapeutic agents.

New Insights into the Role of Exosomes in the Heart After Myocardial Infarction

Intercellular communications play a pivotal role in several cardiac pathophysiological processes. One subtype of extracellular vesicles, so-called exosomes, became known as important intercellular communication mediators in the heart. Exosomes are lipid bilayer biological nanovesicles loaded with diverse proteins, lipids, and mRNAs/microRNAs. All major cardiac cell types can modulate recipient cellular function via the release of exosomes. After myocardial infarction (MI), exosomes, especially those secreted by different cardiac stem cells, have been shown to confer cardioprotective effects, activate regenerative signals, and participate into cardiac repair. In this review, we rapidly recall the biology of exosomes at the beginning. Then we summarize the exosomes secreted by different myocardial cells and their function in cardiac intercellular communication. At last, we discuss the role of these vesicles in cardiac repair after MI.

Stem cell-derived exosomes - an emerging tool for myocardial regeneration

Cardiovascular diseases (CVDs) continue to represent the number one cause of death and disability in industrialized countries. The most severe form of CVD is acute myocardial infarction (AMI), a devastating disease associated with high mortality and disability. In a substantial proportion of patients who survive AMI, loss of functional cardiomyocytes as a result of ischaemic injury leads to ventricular failure, resulting in significant alteration to quality of life and increased mortality. Therefore, many attempts have been made in recent years to identify new tools for the regeneration of functional cardiomyocytes. Regenerative therapy currently represents the ultimate goal for restoring the function of damaged myocardium by stimulating the regeneration of the infarcted tissue or by providing cells that can generate new myocardial tissue to replace the damaged tissue. Stem cells (SCs) have been proposed as a viable therapy option in these cases. However, despite the great enthusiasm at the beginning of the SC era, justified by promising initial results, this therapy has failed to demonstrate a significant benefit in large clinical trials. One interesting finding of SC studies is that exosomes released by mesenchymal SCs (MSCs) are able to enhance the viability of cardiomyocytes after ischaemia/reperfusion injury, suggesting that the beneficial effects of MSCs in the recovery of functional myocardium could be related to their capacity to secrete exosomes. Ten years ago, it was discovered that exosomes have the unique property of transferring miRNA between cells, acting as miRNA nanocarriers. Therefore, exosome-based therapy has recently been proposed as an emerging tool for cardiac regeneration as an alternative to SC therapy in the post-infarction period. This review aims to discuss the emerging role of exosomes in developing innovative therapies for cardiac regeneration as well as their potential role as candidate biomarkers or for developing new diagnostic tools.

Extracellular vesicles and their nucleic acids for biomarker discovery

Extracellular vesicles (EVs) are a heterogenous population of vesicles originate from cells. EVs are found in different biofluids and carry different macromolecules, including proteins, lipids, and nucleic acids, providing a snap shot of the parental cells at the time of release. EVs have the ability to transfer molecular cargoes to other cells and can initiate different physiological and pathological processes. Mounting lines of evidence demonstrated that EVs' cargo and machinery is affected in disease states, positioning EVs as potential sources for the discovery of novel biomarkers. In this review, we demonstrate a conceptual overview of the EV field with particular focus on their nucleic acid cargoes. Current knowledge of EV subtypes, nucleic acid cargo and pathophysiological roles are outlined, with emphasis placed on advantages against competing analytes. We review the utility of EVs and their nucleic acid cargoes as biomarkers and critically assess the newly available advances in the field of EV biomarkers and high throughput technologies. Challenges to achieving the diagnostic potential of EVs, including sample handling, EV isolation, methodological considerations, and bioassay reproducibility are discussed. Future implementation of 'omics-based technologies and integration of systems biology approaches for the development of EV-based biomarkers and personalized medicine are also considered.

The role of cardiac biomarkers in cardio-oncology

Major advances in cancer therapy have resulted in an unprecedented improvement in patient survival for many cancers. Partially as a consequence of increased longevity, it has become evident that the cardiovascular system is frequently impacted by chemotherapy, radiation, and particularly certain targeted therapy. Cardiotoxicity continues to be a dose-limiting side effect of many chemotherapeutic agents including the anthracyclines. Early identification of patients at increased risk of cardiotoxicity or detecting cardiac injury at the earliest point will allow for initiation of cardio-protective strategies and hopefully prevent or reduce the need to modify life-saving cancer therapies. Biomarkers offer a potential solution to this clinical challenge because they may assist us in early identification of subclinical cardiac disease. In this review, we will summarize studies conducted evaluating the use of cardiac troponins (TnI, TnT) and natriuretic peptides, BNP and NT-proBNP. Other biomarkers for cardiotoxicity that have been at least preliminarily investigated, including myeloperoxidase and microRNAs, will be discussed as an exploratory tool for evidence of cardiac dysfunction during cancer treatment.

Circulating miR-192 is a prognostic marker in patients with ischemic cardiomyopathy

Ischemic cardiomyopathy (ICM) is characterized by accumulation of p53 causing apoptosis of cardiomyocytes and resulting in upregulation of miRNA (miR)-192, which plays an important role in the development of heart failure after acute myocardial infarction. However, for other cardiomyopathies, miR-192 seems to have minor relevance. We tested in a prospective, observational study comprising 91 patients with diagnosed heart failure (59.3% ICM and 40.7% non-ICM), the hypothesis that miR-192 expression predicts survival in patients with ICM. Median follow-up was 59 months (range: 1–118). While miR-192 expression was significantly associated with age (p = 0.028), log-rank analysis revealed significant association with survival in ICM (p = 0.003) but not in non-ICM (p = 0.6). In ICM, median age at time of death was 84 years in patients with low miR-192 expression but 67 years with high miR-192 expression. Thus, miR-192 expression is associated with survival in ICM and represents a prognostic marker in ischemic heart failure.

Non-coding RNAs as biomarkers for acute myocardial infarction

Acute myocardial infarction (AMI) is a main threat to human lives worldwide. Early and accurate diagnoses warrant immediate medical care, which would reduce mortality and improve prognoses. Circulating non-coding RNAs have been demonstrated to serve as competent biomarkers for various diseases. Following the identification of cardiac-specific microRNA miR-208a in circulation, more non-coding RNAs (miR-1, miR-499 and miR-133) have been identified as biomarkers not only for the diagnosis of AMI but also for prognosis post infarction. Here, we summarized recent findings on non-coding RNAs as biomarkers for early diagnosis of ST-segment elevation myocardial infarction and for disease monitoring of myocardial infarction. In addition, the prognostic potential of non-coding RNAs in patients treated with percutaneous coronary intervention was also described. We also include studies based on biobanks, and build a miRNA release spectrum after AMI, which provides quantitative and time-lapse monitoring of AMI progress. With this spectrum, we are able to customize personal medical care, which prevents further damage. By constructing a network of circulating non-coding RNAs with high specificity and sensitivity, detailed diagnostic information was provided for personalized medicine. Unveiling the roles and kinetics of circulating non-coding RNAs may lead to a revolution in clinical diagnosis.

The circulating non-coding RNA landscape for biomarker research: lessons and prospects from cardiovascular diseases

Pervasive transcription of the human genome is responsible for the production of a myriad of non-coding RNA molecules (ncRNAs) some of them with regulatory functions. The pivotal role of ncRNAs in cardiovascular biology has been unveiled in the last decade, starting from the characterization of the involvement of micro-RNAs in cardiovascular development and function, and followed by the use of circulating ncRNAs as biomarkers of cardiovascular diseases. The human non-coding secretome is composed by several RNA species that circulate in body fluids and could be used as biomarkers for diagnosis and outcome prediction. In cardiovascular diseases, secreted ncRNAs have been described as biomarkers of several conditions including myocardial infarction, cardiac failure, and atrial fibrillation. Among circulating ncRNAs, micro-RNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) have been proposed as biomarkers in different cardiovascular diseases. In comparison with standard biomarkers, the biochemical nature of ncRNAs offers better stability and flexible storage conditions of the samples, and increased sensitivity and specificity. In this review we describe the current trends and future prospects of the use of the ncRNA secretome components as biomarkers of cardiovascular diseases, including the opening questions related with their secretion mechanisms and regulatory actions.

miRNAS in cardiovascular diseases: potential biomarkers, therapeutic targets and challenges

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the world. Although considerable progress has been made in the diagnosis, treatment and prognosis of CVD, there is still a critical need for novel diagnostic biomarkers and new therapeutic interventions to decrease the incidence of this disease. Recently, there is increasing evidence that circulating miRNAs (miRNAs), i.e. endogenous, stable, single-stranded, short, non-coding RNAs, can be used as diagnostic biomarkers for CVD. Furthermore, miRNAs represent potential novel therapeutic targets for several cardiovascular disorders. In this review we provides an overview of the effects of several CVD; including heart failure, acute myocardial infarction, arrhythmias and pulmonary hypertension; on levels of circulating miRNAs. In addition, the use of miRNA as therapeutic targets is also discussed, as well as challenges and recommendations in their use in the diagnosis of CVD.

MicroRNA expression profiling in human acute organophosphorus poisoning and functional analysis of dysregulated miRNAs

OBJECTIVE

Acute organophosphorus(OP) pesticide poisoning is associated with dysfunctions in multiple organs, especially skeletal muscles, the nervous system and the heart. However, little is known about the specific microRNA (miRNA) changes that control the pathophysiological processes of acute OP poisoning damage. We aimed to explore miRNA expression profiles and gain insight into molecular mechanisms of OP toxic effects.

METHODS

MicroRNA expression was analyzed by TaqMan Human MicroRNA Array analysis and subsequent validated with quantitive PCR. The targets of the significantly different miRNAs were predicted with miRNA prediction databases, and pathway analysis of the predicted target genes was performed using bioinformatics resources.

RESULTS

37 miRNAs were significantly different in the sera of poisoned patients compared to the healthy controls, including 29 miRNAs that were up-regulated and 8 miRNAs that were down-regulated. Functional analysis indicated that many pathways potentially regulated by these miRNAs are involved in skeletal muscle, nervous system and heart disorders.

CONCLUSION

This study mapped changes in the serum miRNA expression profiles of poisoning patients and predicted functional links between miRNAs and their target genes in the regulation of acute OP poisoning. Our findings are an important resource for further understanding the role of these miRNAs in the regulation of OP-induced injury.

Stem Cell-Derived Exosome in Cardiovascular Diseases: Macro Roles of Micro Particles

The stem cell-based therapy has emerged as the promising therapeutic strategies for cardiovascular diseases (CVDs). Recently, increasing evidence suggest stem cell-derived active exosomes are important communicators among cells in the heart via delivering specific substances to the adjacent/distant target cells. These exosomes and their contents such as certain proteins, miRNAs and lncRNAs exhibit huge beneficial effects on preventing heart damage and promoting cardiac repair. More importantly, stem cell-derived exosomes are more effective and safer than stem cell transplantation. Therefore, administration of stem cell-derived exosomes will expectantly be an alternative stem cell-based therapy for the treatment of CVDs. Furthermore, modification of stem cell-derived exosomes or artificial synthesis of exosomes will be the new therapeutic tools for CVDs in the future. In addition, stem cell-derived exosomes also have been implicated in the diagnosis and prognosis of CVDs. In this review, we summarize the current advances of stem cell-derived exosome-based treatment and prognosis for CVDs, including their potential benefits, underlying mechanisms and limitations, which will provide novel insights of exosomes as a new tool in clinical therapeutic translation in the future.

Molecular mechanism of diabetic cardiomyopathy and modulation of microRNA function by synthetic oligonucleotides

Diabetic cardiomyopathy (DCM) is a chronic complication in individuals with diabetes and is characterized by ventricular dilation and hypertrophy, diastolic dysfunction, decreased or preserved systolic function and reduced ejection fraction eventually resulting in heart failure. Despite being well characterized, the fundamental mechanisms leading to DCM are still elusive. Recent studies identified the involvement of small non-coding small RNA molecules such as microRNAs (miRs) playing a key role in the etiology of DCM. Therefore, miRs associated with DCM represents a new class of targets for the development of mechanistic therapeutics, which may yield marked benefits compared to other therapeutic approaches. Indeed, few miRs currently under active clinical investigation, with many expressing cautious optimism that miRs based therapies will succeed in the coming years. The major caution in using miRs based therapy is the need to improve the stability and specificity following systemic injection, which can be achieved through chemical and structural modification. In this review, we first discuss the established role of miRs in DCM and the advances in miRs based therapeutic strategies for the prevention/treatment of DCM. We next discuss the currently employed chemical modification of miR oligonucleotides and their utility in therapies specifically focusing on the DCM. Finally, we summarize the commonly used delivery system and approaches for assessment of miRNA modulation and potential off-target effects.

Roles of exosomes in cardioprotection

Exosomes are extracellular vesicles of endosomal origin which have emerged as key mediators of intercellular communication. All major cardiac cell types-including cardiomyocytes, endothelial cells, and fibroblasts-release exosomes that modulate cellular functions. Exosomes released from human cardiac progenitor cells (CPCs) are cardioprotective and improve cardiac function after myocardial infarction to an extent comparable with that achieved by their parent cells. Cardiac progenitor cell-derived exosomes are enriched in cardioprotective microRNAs, particularly miR-146a-3p. Circulating exosomes mediate remote ischaemic preconditioning. Moreover, they currently are being investigated as diagnostic markers. The discovery that cell-derived extracellular signalling organelles mediate the paracrine effects of stem cells suggests that cell-free strategies could supplant cell transplantation. This review discusses emerging roles of exosomes in cardiovascular physiology, with a focus on cardioprotective activities of CPC-derived exosomes.

The Potential of Stem Cells and Stem Cell-Derived Exosomes in Treating Cardiovascular Diseases

In recent years, the cardiac protective mechanisms of stem cells have become a research focus. Increasing evidence has suggested that stem cells release vesicles, including exosomes and micro-vesicles. The content of these vesicles relies on an extracellular stimulus, and active ingredients are extensively being studied. Previous studies have confirmed that stem cell-derived exosomes have a cardiac protective function similar to that of stem cells, and promote angiogenesis, decrease apoptosis, and respond to stress. Compared to stem cells, exosomes are more stable without aneuploidy and immune rejection, and may be a promising and effective therapy for cardiovascular diseases. In this review, the biological functions and molecular mechanisms of stem cells and stem cell-derived exosomes are discussed.

Prevalence of IgG Autoantibodies against GD3 Ganglioside in Acute Zika Virus Infection

Zika virus (ZIKV) disease has become a global health emergency with devastating effects on public health. Recent evidences implicate the virus as an emergent neuropathological agent promoting serious pathologies of the human nervous system, that include destructive and malformation consequences such as development of ocular and fetal brain lesions, microcephaly in neonates, and Guillain–Barré syndrome (GBS) in adults. These neurological disorders of both central and peripheral nervous systems are thought to be associated to the neurotropic properties of the virus that has ability to infect neural stem cells as well as peripheral neurons, a hallmark of its pathogenicity. The presence of autoantibodies against gangliosides plays a pivotal role in the etiogenesis of GBS and a variety of neurological disorders. Gangliosides are a class of galactose-containing cerebrosides mainly expressed in nervous system tissues playing a critical role in the physiology of neural cells and neurogenesis. Herein, our findings indicate that patients at acute phase of ZIKV infection without any neurological signs show increased levels of IgG autoantibody against GD3 gangliosides, a class of glycolipid found to be highly expressed in neural stem cell acting in the maintenance of their self-renewal cellular capacity. It is possible that a pathological threshold of these antibodies is only acquired in secondary or subsequent infections. In the light of these evidences, we propose that the target of GD3 by autoimmune responses may possibly has an effect in the neuropathy and neurogenesis disorder seen during ZIKV infection.

Microparticles as new markers of cardiovascular risk in diabetes and beyond

The term microparticle (MP) identifies a heterogeneous population of vesicles playing a relevant role in the pathogenesis of vascular diseases, cancer and metabolic diseases such as diabetes mellitus. MPs are released by virtually all cell types by shedding during cell growth, proliferation, activation, apoptosis or senescence processes. MPs, in particular platelet- and endothelial-derived MPs (PMPs and EMPs), are increased in a wide range of thrombotic disorders, with an interesting relationship between their levels and disease pathophysiology, activity or progression. EMP plasma levels have been associated with several cardiovascular diseases and risk factors. PMPs are also shown to be involved in the progressive formation of atherosclerotic plaque and development of arterial thrombosis, especially in diabetic patients. Indeed, diabetes is characterised by an increased procoagulant state and by a hyperreactive platelet phenotype, with enhanced adhesion, aggregation, and activation. Elevated MP levels, such as TF+ MPs, have been shown to be one of the procoagulant determinants in patients with type 2 diabetes mellitus. Atherosclerotic plaque constitutes an opulent source of sequestered MPs, called “plaque” MPs. Otherwise, circulating MPs represent a TF reservoir, named “blood-borne” TF, challenging the dogma that TF is a constitutive protein expressed in minute amounts. “Blood-borne” TF is mainly harboured by PMPs, and it can be trapped within the developing thrombus. MP detection and enumeration by polychromatic flow cytometry (PFC) have opened interesting perspectives in clinical settings, particularly for the evaluation of MP numbers and phenotypes as independent marker of cardiovascular risk, disease and outcome in diabetic patients.

Circulating Plasma MicroRNA-208a as Potential Biomarker of Chronic Indeterminate Phase of Chagas Disease

Chagas cardiomyopathy is the most severe clinical manifestation of chronic Chagas disease. The disease affects most of the Latin American countries, being considered one of the leading causes of morbidity and death in the continent. The pathogenesis of Chagas cardiomyopathy is very complex, with mechanisms involving parasite-dependent cytopathy, immune-mediated myocardial damage and neurogenic disturbances. These pathological changes eventually result in cardiac myocyte hypertrophy, arrhythmias, congestive heart failure and stroke during chronic infection phase. Herein, we show that miR-208a, a microRNA that is a key factor in promoting cardiovascular dysfunction during cardiac hypertrophy processes of heart failure, has its circulating levels increased during chronic indeterminate phase when compared to cardiac (CARD) clinical forms in patients with Chagas disease. In contrast, we have not found altered serum levels of miR-34a, a microRNA known to promote pro-apoptotic role in myocardial infarction during degenerative process of cardiac injuries thus indicating intrinsic differences in the nature of the mechanisms underlying the heart failure triggered by Trypanosoma cruzi infection. Our findings support that the chronic indeterminate phase is a progressive phase involved in the genesis of chagasic cardiopathy and point out the use of plasma levels of miR-208a as candidate biomarker in risk-prediction score for the clinical prognosis of Chagas disease.

In Silico Analysis of Differential Gene Expression in Three Common Rat Models of Diastolic Dysfunction

Standard therapies for heart failure with preserved ejection fraction (HFpEF) have been unsuccessful, demonstrating that the contribution of the underlying diastolic dysfunction pathophysiology differs from that of systolic dysfunction in heart failure and currently is far from being understood. Complicating the investigation of HFpEF is the contribution of several comorbidities. Here, we selected three established rat models of diastolic dysfunction defined by three major risk factors associated with HFpEF and researched their commonalities and differences. The top differentially expressed genes in the left ventricle of Dahl salt sensitive (Dahl/SS), spontaneous hypertensive heart failure (SHHF), and diabetes 1 induced HFpEF models were derived from published data in Gene Expression Omnibus and used for a comprehensive interpretation of the underlying pathophysiological context of each model. The diversity of the underlying transcriptomic of the heart of each model is clearly observed by the different panel of top regulated genes: the diabetic model has 20 genes in common with the Dahl/SS and 15 with the SHHF models. Advanced analytics performed in Ingenuity Pathway Analysis (IPA^®) revealed that Dahl/SS heart tissue transcripts triggered by upstream regulators lead to dilated cardiomyopathy, hypertrophy of heart, arrhythmia, and failure of heart. In the heart of SHHF, a total of 26 genes were closely linked to cardiovascular disease including cardiotoxicity, pericarditis, ST-elevated myocardial infarction, and dilated cardiomyopathy. IPA Upstream Regulator analyses revealed that protection of cardiomyocytes is hampered by inhibition of the ERBB2 plasma membrane-bound receptor tyrosine kinases. Cardioprotective markers such as natriuretic peptide A (NPPA), heat shock 27 kDa protein 1 (HSPB1), and angiogenin (ANG) were upregulated in the diabetes 1 induced model; however, the model showed a different underlying mechanism with a majority of the regulated genes involved in metabolic disorders. In conclusion, our findings suggest that multiple mechanisms may contribute to diastolic dysfunction and HFpEF, and thus drug therapies may need to be guided more by phenotypic characteristics of the cardiac remodeling events than by the underlying molecular processes.

MicroRNA-34a regulates doxorubicin-induced cardiotoxicity in rat

New strategies to prevent and early detect the cardiotoxic effects of the anticancer drug doxorubicin (DOXO) are required. MicroRNAs emerged as potential diagnostic, therapeutic and prognostic approaches in cardiovascular diseases. MiR-34a has a role in cardiac dysfunction and ageing and is involved in several cellular processes associated with DOXO cardiotoxicity. Our in vitro and in vivo results indicated that after DOXO exposure the levels of miR-34a are enhanced in cardiac cells, including Cardiac Progenitor Cells (CPCs). Since one of the determining event responsible for the initiation and evolution of the DOXO toxicity arises at the level of the CPC compartment, we evaluated if miR-34a pharmacological inhibition in these cells ameliorates the detrimental aftermath of the drug. AntimiR-34a has beneficial consequences on vitality, proliferation, apoptosis and senescence of DOXO-treated rat CPC. These effects are mediated by an increase of prosurvival miR-34a targets Bcl-2 and SIRT1, accompanied by a decrease of acetylated-p53 and p16^INK4a. Importantly, miR-34a silencing also reduces the release of this miRNA from DOXO-exposed rCPCs, decreasing its negative paracrine effects on other rat cardiac cells. In conclusion, the silencing of miR-34a could represent a future therapeutic option for cardioprotection in DOXO toxicity and at the same time, it could be considered as a circulating biomarker for anthracycline-induced cardiac damage.

miR-483-3p regulates acute myocardial infarction by transcriptionally repressing insulin growth factor 1 expression

The aim of the present study was to evaluate the functional association between the expression of miR‑483‑3p and acute myocardial infarction (AMI) in patients and in vitro. H9c2 cells were incubated in a vacuum with 5% CO2, 5% H2 and 90% N2 for 2 h, which generated the AMI model in vitro. Reverse transcription‑quantitative polymerase chain reaction was used to measure miR‑483‑3p expression, and flow cytometry analysis and ELISA analysis were used to analyze apoptosis rate via caspase‑3 and caspase‑9 activity kits. B‑cell lymphoma 2 (Bcl‑2)/Bcl‑2‑associated X protein (Bax) and transcriptionally suppressed the protein expression of insulin growth factor 1 (IGF‑1) were analyze using western blot analysis. The results demonstrated that the expression of miR‑483‑3p in patients with AMI was increased when compared with the control group. In the in vitro model, the overexpression of miR‑483‑3p promoted apoptosis, increased caspase‑3 and caspase‑9 activity levels, induced the protein expression of Bcl‑2/Bax and IGF‑1. Picropodophyllotoxin, an IGF‑1 inhibitor, was administered to cells following the overexpression of miR‑483‑3p. Administration of picropodophyllotoxin suppressed IGF‑1 protein expression, promoted apoptosis, increased caspase‑3 and caspase‑9 activity levels, and induced the protein expression of Bax/Bcl‑2. The results of the present study revealed that miR‑483‑3p may regulate AMI via the IGF‑1 signaling pathway and may support the restoration of functional performance following AMI.

Clinical Phenotyping of Heart Failure with Biomarkers: Current and Future Perspectives

INTRODUCTION

Heart failure (HF) is a complex clinical syndrome with diverse risk factors and etiologies, differing underlying pathophysiology, and large phenotypic heterogeneity.

RECENT FINDINGS

Advances in imaging techniques coupled with clinical trials that targeted only in those with impaired left ventricular ejection fraction (LVEF) have largely shaped the current management strategy for HF that focuses predominantly in patients with systolic HF. In contrast, there are no effective treatments for HF with preserved ejection fraction (HFpEF). Instead of this "one-size-fits-all" approach to treatment, better precision to define HF phenotypic classifications may lead to more efficient and effective HF disease management.

CONCLUSION

Integrating variables-including clinical variables, HF biomarkers, imaging, genotypes, metabolomics, and proteomics-can identify different pathophysiologies, lead to more precise phenotypic classification, and warrant investigation in future clinical trials.

Oxidative Stress and Cellular Response to Doxorubicin: A Common Factor in the Complex Milieu of Anthracycline Cardiotoxicity

The production of reactive species is a core of the redox cycling profile of anthracyclines. However, these molecular characteristics can be viewed as a double-edged sword acting not only on neoplastic cells but also on multiple cellular targets throughout the body. This phenomenon translates into anthracycline cardiotoxicity that is a serious problem in the growing population of paediatric and adult cancer survivors. Therefore, better understanding of cellular processes that operate within but also go beyond cardiomyocytes is a necessary step to develop more effective tools for the prevention and treatment of progressive and often severe cardiomyopathy experienced by otherwise successfully treated oncologic patients. In this review, we focus on oxidative stress-triggered cellular events such as DNA damage, senescence, and cell death implicated in anthracycline cardiovascular toxicity. The involvement of progenitor cells of cardiac and extracardiac origin as well as different cardiac cell types is discussed, pointing to molecular signals that impact on cell longevity and functional competence.

Potential Role of Exosomes in Mending a Broken Heart: Nanoshuttles Propelling Future Clinical Therapeutics Forward

Stem cell transplantation therapy is a promising adjunct for regenerating damaged heart tissue; however, only modest improvements in cardiac function have been observed due to poor survival of transplanted cells in the ischemic heart. Therefore, there remains an unmet need for therapies that can aid in attenuating cardiac damage. Recent studies have demonstrated that exosomes released by stem cells could serve as a potential cell-free therapeutic for cardiac repair. These exosomes/nanoshuttles, once thought to be merely a method of waste disposal, have been shown to play a crucial role in physiological functions including short- and long-distance intercellular communication. In this review, we have summarized studies demonstrating the potential role of exosomes in improving cardiac function, attenuating cardiac fibrosis, stimulating angiogenesis, and modulating miRNA expression. Furthermore, exosomes carry an important cargo of miRNAs and proteins that could play an important role as a diagnostic marker for cardiovascular disease post-myocardial infarction. Although there is promising evidence from preclinical studies that exosomes released by stem cells could serve as a potential cell-free therapeutic for myocardial repair, there are several challenges that need to be addressed before exosomes could be fully utilized as off-the-shelf therapeutics for cardiac repair.

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

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

Extracellular Vesicles in Cardiovascular Theranostics

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells play essential roles in pathophysiological processes such as cardiac hypertrophy, cardiomyocyte survival and apoptosis, cardiac fibrosis, and angiogenesis in relation to CVDs. In this review, we will first outline the current knowledge about the physical characteristics, biological contents, and isolation methods of EVs. We will then focus on the functional roles of cardiovascular EVs and their pathophysiological effects in CVDs, as well as summarize the potential of EVs as therapeutic agents and biomarkers for CVDs. Finally, we will discuss the specific application of EVs as a novel drug delivery system and the utility of EVs in the field of regenerative medicine.

Exosomes as agents of change in the cardiovascular system

Exosomes have an evolving role in paracrine and autocrine signaling, which is enhanced because these lipid vesicles are quite stable and can deliver miRNA, DNA, protein and other molecules to cells throughout the body. Most cell types release exosomes, and exosomes are found in all biological fluids, making them accessible biomarkers. Significantly, exosomes can carry a biologically potent cargo, which can alter the phenotype of recipient cells. In the cardiovascular system exosomes have been primarily studied for their role in mediating the beneficial effects of mesenchymal stem cells after myocardial injury. Exosomes released by cardiac cells in disease states, such as myocardial ischemia, can potentially have important pathophysiologic effects on other cardiac cells as well as on distant organs.

MicroRNAs in injury and repair

Organ damage and resulting pathologies often involve multiple deregulated pathways. MicroRNAs (miRNAs) are short, non-coding RNAs that regulate a multitude of genes at the post-transcriptional level. Since their discovery over two decades ago, miRNAs have been established as key players in the molecular mechanisms of mammalian biology including the maintenance of normal homeostasis and the regulation of disease pathogenesis. In recent years, there has been substantial progress in innovative techniques to measure miRNAs along with advances in targeted delivery of agents modulating their expression. This has expanded the scope of miRNAs from being important mediators of cell signaling to becoming viable quantitative biomarkers and therapeutic targets. Currently, miRNA therapeutics are in clinical trials for multiple disease areas and vast numbers of patents have been filed for miRNAs involved in various pathological states. In this review, we summarize miRNAs involved in organ injury and repair, specifically with regard to organs that are the most susceptible to injury: the liver, heart and kidney. In addition, we review the current state of knowledge on miRNA biology, miRNA biomarkers and nucleotide-based therapeutics designed to target miRNAs to prevent organ injury and promote repair.

Comparison of the release of microRNAs and extracellular vesicles from platelets in response to different agonists

On activation platelets release microRNAs and extracellular vesicles (EV) into circulation. The release of EV from platelets has been shown to be dependent on the agonist; in this study, we investigated whether the microRNA profile or EV released from platelets was also agonist specific. Washed platelets from healthy subjects were maximally stimulated with agonists specific for the receptors for collagen (Glycoprotein VI (GPVI)), thrombin (PAR1/PAR4), or ADP (P2Y1/P2Y12) with/without inhibiting secondary mediators, using aspirin to block cyclooxygenase-1 and apyrase to remove ADP. The released microRNAs were profiled using TaqMan microRNA microarray cards. Platelet-derived EV (pdEV) were characterized by size (Nanoparticle Tracking Analysis, NTA), for procoagulant activity (Annexin-V binding and support of thrombin generation), and for the EV markers CD63 and HSP70. Platelet activation triggered the release of 57-79 different microRNAs, dependent upon agonist, with a core of 46 microRNAs observed with all agonists. There was a high level of correlation between agonists (r² > 0.98; p < 0.0001 for all), and with the microRNA content of the parent platelets (r² > 0.98; p < 0.0001). The 46 microRNAs seen in all samples are predicted to have significant effects on the translation of proteins involved in endocytosis, cell cycle control, and differentiation. MiR-223-3p was the most abundant in all samples and has previously been implicated in myeloid lineage development and demonstrated to have anti-inflammatory effects. Stimulation through GPVI produced a pdEV population with significantly more procoagulant activity than the other agonists. Apyrase significantly reduced microRNA and pdEV release, while aspirin had little effect. These data suggest that all tested agonists trigger the release of a similar microRNA profile while the procoagulant activity of the pdEV was agonist dependent. ADP was shown to play an important role in the release of both microRNAs and pdEV.

Exosomes: A Rising Star in Falling Hearts

Although exosomes were previously recognized as a mechanism for discharging useless cellular components, growing evidence has elucidated their roles in conveying information between cells. They contribute to cell-cell communication by carrying nucleic acids, proteins and lipids that can, in turn, regulate behavior of the target cells. Recent research suggested that exosomes extensively participate in progression of diverse cardiovascular diseases (CVDs), such as myocardial infarction, cardiomyopathy, pulmonary arterial hypertension and others. Here, we summarize effects of exosome-derived molecules (mainly microRNAs and proteins) on cardiac function, to examine their potential applications as biomarkers or therapeutics in CVDs.

[Use of microRNAs in heart failure management]

Heart failure (HF) is a high impact disease that affects all human populations, demanding the development of new strategies and methods to manage this pathology. That's why microRNAs, small noncoding RNAs that regulate gene expression, appear as an important option in the diagnosis, prognosis and treatment of this disease. MiRNAs seems to have a future on HF handling, because can be isolated from body fluids such as blood, and changes in its levels can be associated with the presence, stage and specific disease features, which makes them an interesting option as biomarkers. Also, due to the important role of these molecules on regulation of gene expression and cell homeostasis, it has been explored its potential use as a therapeutic method to prevent or treat HF. That is why this review seeks to show the importance of biomedical research involving the use of miRNAs as a method to approach the HF, showing the impact of disease in the world, aspects of miRNAs biology, and their use as biomarkers and as important therapeutic targets.

Ankyrin Repeat Domain 1 Protein: A Functionally Pleiotropic Protein with Cardiac Biomarker Potential

The ankyrin repeat domain 1 (ANKRD1) protein is a cardiac-specific stress-response protein that is part of the muscle ankyrin repeat protein family. ANKRD1 is functionally pleiotropic, playing pivotal roles in transcriptional regulation, sarcomere assembly and mechano-sensing in the heart. Importantly, cardiac ANKRD1 has been shown to be highly induced in various cardiomyopathies and in heart failure, although it is still unclear what impact this may have on the pathophysiology of heart failure. This review aims at highlighting the known properties, functions and regulation of ANKRD1, with focus on the underlying mechanisms that may be involved. The current views on the actions of ANKRD1 in cardiovascular disease and its utility as a candidate cardiac biomarker with diagnostic and/or prognostic potential are also discussed. More studies of ANKRD1 are warranted to obtain deeper functional insights into this molecule to allow assessment of its potential clinical applications as a diagnostic or prognostic marker and/or as a possible therapeutic target.

Exosomes: promising sacks for treating ischemic heart disease?

Ischemic heart disease(IHD) is the leading cause of death worldwide. Despite the development of continuously improving therapeutic strategies, morbidity and mortality of patients with IHD remain relatively high. Exosomes are a subpopulation of vesicles that are universally recognized as major mediators in intercellular communication. Numerous preclinical studies have shown that these tiny vesicles were protective in IHD, through such actions as alleviating myocardial ischemia-reperfusion injury, promoting angiogenesis, inhibiting fibrosis, and facilitating cardiac regeneration. Our review focused on these beneficial exosome-mediated processes. In addition, we discuss in detail how to fully exploit the therapeutic potentials of exosomes in the field of IHD. Topics include identifying robust sources of exosomes, loading protective agents into exosomes, developing heart-specific exosomes, optimizing isolation methods, and translating the cardioprotective effects of exosomes into clinical practice. Finally, both the advantages and disadvantages of utilizing exosomes in clinical settings are addressed.

Acute Rejection After Kidney Transplantation Associates With Circulating MicroRNAs and Vascular Injury

Supplemental digital content is available in the text.

Background

Acute rejection (AR) of kidney transplants is associated with the loss of endothelial integrity, microvascular rarefaction and, ultimately, graft dysfunction. Circulating angiogenic microRNAs (miRNAs) may serve as markers for microvascular injury. Here, we investigated the short- and long-term effects of AR after kidney transplantation on systemic vascular injury and the associated circulating miRNA profile.

Methods

Systemic vascular injury was determined by measuring capillary tortuosity and density within the oral mucosa as well as by assessing circulating levels of angiopoietin-2/angiopoietin-1 ratio, vascular endothelial growth factor and soluble thrombomodulin. After a pilot study, we selected 48 miRNAs to assess the AR- and microvascular injury associated circulating miRNAs.

Results

In stable transplant recipients (n = 25) and patients with AR (n = 13), which were also studied longitudinally (1, 6, and 12 months post-AR), we found an AR-associated increase in markers of systemic vascular injury, of which vascular endothelial growth factor and soluble thrombomodulin normalized within 1 year after AR. Of the 48 selected miRNAs, 8 were either decreased (miR-135a, miR-199a-3p, and miR-15a) or increased (miR-17, miR-140-3p, miR-130b, miR-122 and miR-192) in AR. Of these, miR-130b, miR-199a, and miR-192 associated with markers of vascular injury, whereas miR-140-3p, miR-130b, miR-122, and miR-192 normalized within 1 year after AR.

Conclusions

AR after kidney transplantation is characterized by systemic microvascular injury and associates with specific circulating miRNA levels.

miR199a-3p regulates P53 by targeting CABLES1 in mouse cardiac c-kit+ cells to promote proliferation and inhibit apoptosis through a negative feedback loop

Background

MicroRNAs (miRNAs) have emerged as crucial factors that regulate proliferation and apoptosis of cardiac c-kit⁺ cells. Although much is known about their role in maintaining cardiac c-kit⁺ cell pluripotency, the mechanisms by which they affect cell fate decisions that are an essential part of the repair of heart failure remain poorly understood.

Methods

Cardiac c-kit⁺ cells were obtained from Balb/c mice and cultured in vitro. Lentiviral vectors of miR199a-3p, its corresponding anti-miRNA, or short hairpin RNA against Cables1 were transfected into cells. The proliferation of cardiac c-kit⁺ cells was evaluated using EdU and flow cytometry. Furthermore, we examined cell apoptosis by flow cytometry under treatment with 200nM angiotensin II for 48 h. The levels of miR199a-3p and Cables1 mRNA were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to examine the expression of Cables1 and P53 proteins.

Results

We demonstrated a significantly decreased expression of miR199a-3p in heart failure samples compared with healthy donors. Meanwhile, we identified miR199a-3p as a proliferation- and apoptosis-associated regulator impacted through Cdk5 and Abl enzyme substrate 1 (CABLES1) targeting, and also attributed their repression to P53 protein expression. We further demonstrated that P53 induced miR199a-3p expression and, in turn, miR199-3p decreased P53 activity.

Conclusion

Collectively, our findings uncover one new mechanism by which P53 induced miR199a-3p expression and, in turn, miR199-3p decreased P53 activity. Therefore, miR199a-3p and P53 are coupled through CABLES1 and comprise a novel negative feedback loop that likely contributes to cardiac c-kit⁺ cell proliferation and apoptosis.

miRNAs as biomarkers for diagnosis of heart failure: A systematic review and meta-analysis

BACKGROUND

With the rapid development of molecular biology, the kind of mircoRNA (miRNA) has been introduced into emerging role both in cardiac development and pathological procedure. Thus, we conduct this meta-analysis to find out the role of circulating miRNA as a biomarker in detecting heart failure.

METHODS

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and World Health Organization clinical trials registry center to identify relevant studies up to August 2016. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 14.0 to estimate the publication bias and meta-regression. Besides, we took use of SPSS 17.0 to evaluate variance between several groups. Information on true positive, false positive, false negative, and true negative, as well as the quality of research was extracted.

RESULTS

We use results from 10 articles to analyze the pooled accuracy. The overall performance of total mixed miRNAs (TmiRs) detection was: pooled sensitivity, 0.74 (95% confidence interval [CI], 0.72 to 0.75); pooled specificity, 0.69 (95%CI, 0.67 to 0.71); and area under the summary receiver operating characteristic curves value (SROC), 0.7991. The miRNA-423-5p (miR-423-5p) detection was: pooled sensitivity, 0.81 (95%CI, 0.76 to 0.85); pooled specificity, 0.67 (95%CI, 0.61 to 0.73); and SROC, 0.8600. However, taken the same patients population, we extracted the data of BNP for detecting heart failure and performed meta-analysis with acceptable SROC as 0.9291. Among the variance analysis, the diagnostic performance of miR-423-5p claimed significant advantages of other pooled results. However, the combination of miRNAs and BNP could increase the accuracy of detecting of heart failure. Unfortunately, there was no dramatic advantage of miR-423-5p compared to BNP protocol.

CONCLUSION

Despite interstudy variability, the performance test of miRNA for detecting heart failure revealed that miR-423-5p demonstrated the potential to be a biomarker. However, other miRNAs were not able to provide enough evidence on promising diagnostic value for heart failure based on the current data. Moreover, the combination of miRNAs and BNP could work as a better method to detection. Unfortunately, BNP was still the most convinced biomarker for such disease.

Non-coding microRNAs for cardiac regeneration: Exploring novel alternatives to induce heart healing

In recent years, different studies have revealed that adult mammalian cardiomyocytes have the capacity to self-renew under homeostatic conditions and after myocardial injury. Interestingly, data from animal models capable of regeneration, such as the adult zebrafish and neonatal mice, have identified different non-coding RNAs (ncRNAs) as functional RNA molecules driving cardiac regeneration and repair. In this review, we summarize the current knowledge of the roles that a specific subset of ncRNAs, namely microRNAs (miRNA), plays in these animal models. We also emphasize the importance of characterizing and manipulating miRNAs as a novel approach to awaken the dormant regenerative potential of the adult mammalian heart by the administration of miRNA mimics or inhibitors. Overall, the use of these strategies alone or in combination with current cardiac therapies may represent new avenues to pursue for cardiac regeneration.

Circulating Noncoding RNAs as Biomarkers of Cardiovascular Disease and Injury

The discovery of thousands of noncoding RNAs (ncRNAs) has expanded our view on mammalian genomes and transcriptomes, as well as their organization and regulation. Accumulating evidence on aberrantly regulated ncRNAs, including short microRNAs, long ncRNAs and circular RNAs, across various heart diseases indicates that ncRNAs are critical contributors to cardiovascular pathophysiology. In addition, ncRNAs are released into the circulation where they are present in concentration levels that differ between healthy subjects and diseased patients. Although little is known about the origin and function of such circulating ncRNAs, these molecules are increasingly recognized as noninvasive and readily accessible biomarker for risk stratification, diagnosis and prognosis of cardiac injury, and multiple forms of cardiovascular disease. In this review, we summarize recent findings on biological characteristics of circulating ncRNAs and highlight their value as potential biomarker in selected pathologies of cardiovascular disease.

MiRNA Deregulation in Cardiac Aging and Associated Disorders

The prevalence of age-related diseases is increasing dramatically, among which cardiac disease represents the leading cause of death. Aging of the heart is characterized by various molecular and cellular hallmarks impairing both cardiomyocytes and noncardiomyocytes, and resulting in functional deteriorations of the cardiac system. The aging process includes desensitization of β-adrenergic receptor (βAR)-signaling and decreased calcium handling, altered growth signaling and cardiac hypertrophy, mitochondrial dysfunction and impaired autophagy, increased programmed cell death, low-grade inflammation of noncanonical inflammatory cells, and increased ECM deposition. MiRNAs play a fundamental role in regulating the processes underlying these detrimental changes in the cardiac system, indicating that MiRNAs are crucially involved in aging. Among others, MiR-34, MiR-146a, and members of the MiR-17-92 cluster, are deregulated during senescence and drive cardiac aging processes. It is therefore suggested that MiRNAs form possible therapeutic targets to stabilize the aged failing myocardium.

Creating a Biomarker Panel for Early Detection of Chemotherapy Related Cardiac Dysfunction in Breast Cancer Patients

Cardiotoxicity is an important issue for breast cancer patients receiving anthracycline-trastuzumab therapy in the adjuvant setting. Studies show that 3-36% of patients receiving anthracyclines and/or trastuzumab experience chemotherapy related cardiac dysfunction (CRCD) and approximately 17% of patients must stop chemotherapy due to the consequences of CRCD. There is currently no standardized, clinically verified way to detect CRCD early, but common practices include serial echocardiography and troponin measurements, which can be timely, costly, and not always available in areas where health care resources are scarce. Furthermore, detection of CRCD, before there is any echocardiographic evidence of dysfunction or clinical symptoms present, would allow maximal benefit of chemotherapy and minimize cardiac complications. Creating a panel of serum biomarkers would allow for more specificity and sensitivity in the early detection of CRCD, which would be easy to implement and cost effective in places with limited health care. Based on a review of the literature, we propose creating a biomarker panel consisting of topoisomerase 2β, serum troponin T/I, myeloperoxidase, NT-proBNP, miR-208b, miR-34a, and miR-150 in breast cancer patients receiving anthracyclines and/or trastuzumab to detect CRCD before any signs of overt cardiotoxicity are apparent.

Tissue-specific exosome biomarkers for noninvasively monitoring immunologic rejection of transplanted tissue

In transplantation, there is a critical need for noninvasive biomarker platforms for monitoring immunologic rejection. We hypothesized that transplanted tissues release donor-specific exosomes into recipient circulation and that the quantitation and profiling of donor intra-exosomal cargoes may constitute a biomarker platform for monitoring rejection. Here, we have tested this hypothesis in a human-into-mouse xenogeneic islet transplant model and validated the concept in clinical settings of islet and renal transplantation. In the xenogeneic model, we quantified islet transplant exosomes in recipient blood over long-term follow-up using anti-HLA antibody, which was detectable only in xenoislet recipients of human islets. Transplant islet exosomes were purified using anti-HLA antibody-conjugated beads, and their cargoes contained the islet endocrine hormone markers insulin, glucagon, and somatostatin. Rejection led to a marked decrease in transplant islet exosome signal along with distinct changes in exosomal microRNA and proteomic profiles prior to appearance of hyperglycemia. In the clinical settings of islet and renal transplantation, donor exosomes with respective tissue specificity for islet β cells and renal epithelial cells were reliably characterized in recipient plasma over follow-up periods of up to 5 years. Collectively, these findings demonstrate the biomarker potential of transplant exosome characterization for providing a noninvasive window into the conditional state of transplant tissue.