MicroRNA-22 and promoter motif polymorphisms at the Chga locus in genetic hypertension: functional and therapeutic implications for gene expression and the pathogenesis of hypertension

Current perspectives and trends of the research on hypertensive nephropathy: a bibliometric analysis from 2000 to 2023

Hypertensive nephropathy continues to be a major cause of end-stage renal disease and poses a significant global health burden. Despite the staggering development of research in hypertensive nephropathy, scientists and clinicians can only seek out useful information through articles and reviews, it remains a hurdle for them to quickly track the trend in this field. This study uses the bibliometric method to identify the evolutionary development and recent hotspots of hypertensive nephropathy. The Web of Science Core Collection database was used to extract publications on hypertensive nephropathy from January 2000 to November 2023. CiteSpace was used to capture the patterns and trends from multi-perspectives, including countries/regions, institutions, keywords, and references. In total, 557 publications on hypertensive nephropathy were eligible for inclusion. China (n = 208, 37.34%) was the most influential contributor among all the countries. Veterans Health Administration (n = 19, 3.41%) was found to be the most productive institution. Keyword bursting till now are renal fibrosis, outcomes, and mechanisms which are predicted to be the potential frontiers and hotspots in the future. The top seven references were listed, and their burst strength was shown. A comprehensive overview of the current status and research frontiers of hypertensive nephropathy has been provided through the bibliometric perspective. Recent advancements and challenges in hypertensive nephropathy have been discussed. These findings can offer informative instructions for researchers and scholars.

Recent advancements in nanotechnology based drug delivery for the management of cardiovascular disease

Cardiovascular diseases (CVDs) constitute a predominant cause of both global mortality and morbidity. To address the challenges in the early diagnosis and management of CVDs, there is growing interest in the field of nanotechnology and nanomaterials to develop innovative diagnostic and therapeutic approaches. This review focuses on the recent advancements in nanotechnology-based diagnostic techniques, including cardiac immunoassays (CIA), cardiac circulating biomarkers, cardiac exosomal biomarkers, and molecular Imaging (MOI). Moreover, the article delves into the exciting developments in nanoparticles (NPs), biomimetic NPs, nanofibers, nanogels, and nanopatchs for cardiovascular applications. And discuss how these nanoscale technologies can improve the precision, sensitivity, and speed of CVD diagnosis and management. While highlighting their vast potential, we also address the limitations and challenges that must be overcome to harness these innovations successfully. Furthermore, this review focuses on the emerging opportunities for personalized and effective cardiovascular care through the integration of nanotechnology, ultimately aiming to reduce the global burden of CVDs.

MicroRNAs (miRNAs) role in hypertension: pathogenesis and promising therapeutics

Background

MicroRNAs (miRNAs) are small, non-coding RNA molecules that play a crucial role in regulating various cellular processes, including cell proliferation, differentiation, apoptosis, and disease development. Recent studies have highlighted the importance of miRNAs in the development and progression of essential hypertension, a common form of high blood pressure that affects millions of individuals worldwide. The molecular mechanisms by which miRNAs regulate hypertension are complex and multifaceted. MiRNAs target the 3' untranslated regions of mRNA molecules, thereby regulating the synthesis of specific proteins involved in cardiovascular function. For instance, miRNAs are known to regulate the expression of genes involved in blood vessel tone, cardiac function, and inflammation. The growing body of research on miRNAs in hypertension has highlighted their potential as therapeutic targets for managing this condition. Studies have shown that miRNA-based therapies can modulate the expression of key genes involved in hypertension, leading to improvements in blood pressure and cardiovascular function. However, more research is needed to fully understand the mechanisms of miRNA-mediated hypertension and to develop effective therapeutic strategies.

Conclusions

In summary, this review highlights the current understanding of the role of miRNAs in essential hypertension, including their molecular mechanisms and potential therapeutic applications. Further research is needed to fully understand the impact of miRNAs on hypertension and to develop new treatments for this common and debilitating condition.

Future treatments in hypertension: Can we meet the unmet needs of patients?

The prevalence of arterial hypertension is approximately 47% in the United States and 55% in Europe. Multiple different medical therapies are used to treat hypertension including diuretics, beta blockers, calcium channel blockers, angiotensin receptor blockers, angiotensin converting enzyme inhibitors, alpha blockers, central acting alpha receptor agonists, neprilysin inhibitors and vasodilators. However, despite the numerous number of medications, the prevalence of hypertension is on the rise, a considerable proportion of the hypertensive population is resistant to these therapeutic modalities and a definitive cure is not possible with the current treatment approaches. Therefore, there is a need for novel therapeutic strategies to provide better treatment and control of hypertension. In this review, our aim is to describe the latest developments in the treatment of hypertension including novel medication classes, gene therapies and RNA-based modalities.

Chromogranin A and its derived peptides: potential regulators of cholesterol homeostasis

Chromogranin A (CHGA), a member of the granin family of proteins, has been an attractive therapeutic target and candidate biomarker for several cardiovascular, neurological, and inflammatory disorders. The prominence of CHGA stems from the pleiotropic roles of several bioactive peptides (e.g., catestatin, pancreastatin, vasostatins) generated by its proteolytic cleavage and by their wide anatomical distribution. These peptides are emerging as novel modulators of cardiometabolic diseases that are often linked to high blood cholesterol levels. However, their impact on cholesterol homeostasis is poorly understood. The dynamic nature of cholesterol and its multitudinous roles in almost every aspect of normal body function makes it an integral component of metabolic physiology. A tightly regulated coordination of cholesterol homeostasis is imperative for proper functioning of cellular and metabolic processes. The deregulation of cholesterol levels can result in several pathophysiological states. Although studies till date suggest regulatory roles for CHGA and its derived peptides on cholesterol levels, the mechanisms by which this is achieved still remain unclear. This review aims to aggregate and consolidate the available evidence linking CHGA with cholesterol homeostasis in health and disease. In addition, we also look at common molecular regulatory factors (viz., transcription factors and microRNAs) which could govern the expression of CHGA and genes involved in cholesterol homeostasis under basal and pathological conditions. In order to gain further insights into the pathways mediating cholesterol regulation by CHGA/its derived peptides, a few prospective signaling pathways are explored, which could act as primers for future studies.

Activation of Gαq sequesters specific transcripts into Ago2 particles

The Gαq/phospholipase Cβ1 (PLCβ1) signaling system mediates calcium responses from hormones and neurotransmitters. While PLCβ1 functions on the plasma membrane, there is an atypical cytosolic population that binds Argonaute 2 (Ago2) and other proteins associated with stress granules preventing their aggregation. Activation of Gαq relocalizes cytosolic PLCβ1 to the membrane, releasing bound proteins, promoting the formation of stress granules. Here, we have characterized Ago2 stress granules associated with Gαq activation in differentiated PC12 cells, which have a robust Gαq/PLCβ1 signaling system. Characterization of Ago2-associated stress granules shows shifts in protein composition when cells are stimulated with a Gαq agonist, or subjected to heat shock or osmotic stress, consistent with the idea that different stresses result in unique stress granules. Purified Ago2 stress granules from control cells do not contain RNA, while those from heat shock contain many different mRNAs and miRs. Surprisingly, Ago2 particles from cells where Gαq was stimulated show only two transcripts, chromogranin B, which is involved in secretory function, and ATP synthase 5f1b, which is required for ATP synthesis. RT-PCR, western blotting and other studies support the idea that Gαq-activation protects these transcripts. Taken together, these studies show a novel pathway where Gαq/PLCβ regulates the translation of specific proteins.

Benefits of Curcumin in the Vasculature: A Therapeutic Candidate for Vascular Remodeling in Arterial Hypertension and Pulmonary Arterial Hypertension?

Growing evidence suggests that hypertension is one of the leading causes of cardiovascular morbidity and mortality since uncontrolled high blood pressure increases the risk of myocardial infarction, aortic dissection, hemorrhagic stroke, and chronic kidney disease. Impaired vascular homeostasis plays a critical role in the development of hypertension-induced vascular remodeling. Abnormal behaviors of vascular cells are not only a pathological hallmark of hypertensive vascular remodeling, but also an important pathological basis for maintaining reduced vascular compliance in hypertension. Targeting vascular remodeling represents a novel therapeutic approach in hypertension and its cardiovascular complications. Phytochemicals are emerging as candidates with therapeutic effects on numerous pathologies, including hypertension. An increasing number of studies have found that curcumin, a polyphenolic compound derived from dietary spice turmeric, holds a broad spectrum of pharmacological actions, such as antiplatelet, anticancer, anti-inflammatory, antioxidant, and antiangiogenic effects. Curcumin has been shown to prevent or treat vascular remodeling in hypertensive rodents by modulating various signaling pathways. In the present review, we attempt to focus on the current findings and molecular mechanisms of curcumin in the treatment of hypertensive vascular remodeling. In particular, adverse and inconsistent effects of curcumin, as well as some favorable pharmacokinetics or pharmacodynamics profiles in arterial hypertension will be discussed. Moreover, the recent progress in the preparation of nano-curcumins and their therapeutic potential in hypertension will be briefly recapped. The future research directions and challenges of curcumin in hypertension-related vascular remodeling are also proposed. It is foreseeable that curcumin is likely to be a therapeutic agent for hypertension and vascular remodeling going forwards.

MicroRNAs in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading causes of death and disability worldwide, despite the wide diversity of molecular targets identified and the development of therapeutic methods. MicroRNAs (miRNAs) are a class of small (about 22 nucleotides) non-coding RNAs (ncRNAs) that negatively regulate gene expression at the post-transcriptional level in the cytoplasm and play complicated roles in different CVDs. While miRNA overexpression in one type of cell protects against heart disease, it promotes cardiac dysfunction in another type of cardiac cell. Moreover, recent studies have shown that, apart from cytosolic miRNAs, subcellular miRNAs such as mitochondria- and nucleus-localized miRNAs are dysregulated in CVDs. However, the functional properties of cellular- and subcellular-localized miRNAs have not been well characterized. In this review article, by carefully revisiting animal-based miRNA studies in CVDs, we will address the regulation and functional properties of miRNAs in various CVDs. Specifically, the cell-cell crosstalk and subcellular perspective of miRNAs are highlighted. We will provide the background for attractive molecular targets that might be useful in preventing the progression of CVDs and heart failure (HF) as well as insights for future studies.

MicroRNAs Regulating Renin-Angiotensin-Aldosterone System, Sympathetic Nervous System and Left Ventricular Hypertrophy in Systemic Arterial Hypertension

MicroRNAs are small non-coding RNAs that regulate gene and protein expression. MicroRNAs also regulate several cellular processes such as proliferation, differentiation, cell cycle, apoptosis, among others. In this context, they play important roles in the human body and in the pathogenesis of diseases such as cancer, diabetes, obesity and hypertension. In hypertension, microRNAs act on the renin-angiotensin-aldosterone system, sympathetic nervous system and left ventricular hypertrophy, however the signaling pathways that interact in these processes and are regulated by microRNAs inducing hypertension and the worsening of the disease still need to be elucidated. Thus, the aim of this review is to analyze the pattern of expression of microRNAs in these processes and the possible associated signaling pathways.

Differential Antihypertensive Effects of Oral Doses of Acetylcholine between Spontaneously Hypertensive Rats and Normotensive Rats

Acetylcholine (ACh) is a novel antihypertensive food component. Here, we demonstrate the differential effects of oral ACh on high and normal blood pressure in rats. Spontaneously hypertensive rats (SHRs) and Wistar–Kyoto (WKY) rats were administered ACh orally. The blood pressure and heart rate of SHRs were significantly lowered with ACh doses of 10⁻⁵ and 10⁻³ mol/kg body weight (b.w.), and the urinary catecholamine levels were significantly decreased with 10⁻³ mol/kg b.w. In contrast, oral ACh administration had no effect on WKY rats. This difference was likely caused by differences in sympathetic nervous activity and the baroreflex between strains. Comparison of gene sequences between the two strains revealed Chga mutations, suggesting that changes in the expression of chromogranin A might be involved in the baroreflex in SHRs. Oral ACh had an antihypertensive effect under hypertension but not normotension, indicating that this may be used safely to prevent hypertension.

Chromogranin A pathway: from pathogenic molecule to renal disease

BACKGROUND

Chromogranin A (CHGA) is an index granin protein critical for biogenesis and exocytotic release of catecholamine storage granules. It is elevated in plasma of patients with sympathetic over-activity and kidney dysfunction. Several CHGA polymorphisms are associated with hypertensive kidney disease. Previously, we unraveled the molecular mechanism by which CHGA expression is regulated in African Americans carrying a genetic variation associated with hypertensive chronic kidney disease (CKD).

METHOD

Experimental CKD mouse model were created by 5/6th nephrectomy (Npx) using wild-type and Chga-/- knockout mouse strains to delineate the role of CHGA in CKD.

RESULT

Wild-type-Npx mice expressing Chga developed exacerbated azotemia and fibrosis as compared with their knockout-Npx counterparts. Gene expression profiling revealed downregulation of mitochondrial respiratory complexes genes consistent with maladaptive mitochondria in wild-type-Npx mice, contrasted to knockout-Npx. In healthy individuals, an inverse relationship between circulating CHGA levels and glomerular function was observed. In vitro, mesangial cells treated with CHGA-triggered nitric oxide release by a signaling mechanism involving scavenger receptor SR-A. The CHGA-treated and untreated mesangial cells displayed differential expression of cytokine, chemokine, complement, acute phase inflammatory and apoptotic pathway genes. Thus, build-up of plasma CHGA because of kidney injury served as an insult to the mesangial cells resulting in expression of genes promoting inflammation, fibrosis, and progression of CKD.

CONCLUSION

These findings improve understanding of the role of elevated CHGA in the progression of CKD and reveal novel pathways that could be exploited for therapeutic strategies in hypertensive kidney disease.

Acute ischemic stroke biomarkers: a new era with diagnostic promise?

Stroke is considered as the first cause of neurological dysfunction and second cause of death worldwide. Recombinant tissue plasminogen activator is the only chemical treatment for ischemic stroke approved by the US Food and Drug Administration. It was the only standard of care for a long time with a very narrow therapeutic window, which usually ranges from 3 to 4.5 h of stroke onset; until 2015, when multiple trials demonstrated the benefit of mechanical thrombectomy during the first 6 h. In addition, recent trials showed that mechanical thrombectomy can be beneficial up to 24 h if the patients meet certain criteria including the presence of magnetic resonance imaging/computed tomography perfusion mismatch, which allows better selectivity and higher recruitment of eligible stroke patients. However, magnetic resonance imaging/computed tomography perfusion is not available in all stroke centers. Hence, physicians need other easy and available diagnostic tools to select stroke patients eligible for mechanical thrombectomy. Moreover, stroke management is still challenging for physicians, particularly those dealing with patients with "wake-up" stroke. The resulting brain tissue damage of ischemic stroke and the subsequent pathological processes are mediated by multiple molecular pathways that are modulated by inflammatory markers and post-transcriptional activity. A considerable number of published works suggest the role of inflammatory and cardiac brain-derived biomarkers (serum matrix metalloproteinase, thioredoxin, neuronal and glial markers, and troponin proteins) as well as different biomarkers including the emerging roles of microRNAs. In this review, we assess the accumulating evidence regarding the current status of acute ischemic stroke diagnostic biomarkers that could guide physicians for better management of stroke patients. Our review could give an insight into the roles of the different emerging markers and microRNAs that can be of high diagnostic value in patients with stroke. In fact, the field of stroke research, similar to the field of traumatic brain injury, is in immense need for novel biomarkers that can stratify diagnosis, prognosis, and therapy.

Curcumin inhibits proliferation, migration and neointimal formation of vascular smooth muscle via activating miR-22

Context: Curcumin has antitumor, antioxidative, anti-inflammatory, and anti-proliferative properties.Objective: To investigate the role of miR-22 during curcumin-induced changes in vascular smooth muscle cells (VSMC) and neointima formation in balloon-injured rat abdominal aorta.Materials and methods: Sprague-Dawley rats were randomised to the sham-operated (n = 10), operated control (injured, n = 10), and curcumin treatment (n = 10) groups. miR-22 expression was determined by real-time PCR. SP1 was assessed by western blot and real-time PCR. Rat aortic smooth muscle A7r5 cells were used to determine VSMC proliferation and migration, which were measured by the MTS, EdU staining, Transwell, and wound healing assays.Results: miR-22 levels declined following arterial balloon injury in vivo (48% at 3d, p < 0.05) and serum stimulation in vitro (45% at 24 h, p < 0.01). Functional studies revealed that miR-22 negatively regulated the proliferation and migration of VSMCs by directly targeting the SP1 transcription factor in VSMCs. Curcumin increased the expression of miR-22 (81%, p < 0.05) and decreased the protein expression of SP1 in VSMCs (25%, p < 0.05). miR-22 inhibition was found to attenuate the effects of curcumin on VSMC functions. Curcumin increased miR-22 (46%, p < 0.01), decreased the SP1 protein (19%, p < 0.05), and inhibited vascular neointimal area (48%, p < 0.01) in vivo.Discussion: The miR-22/SP1 pathway is involved in the protective role of curcumin during arterial balloon injury, but the mechanisms remain unclear.Conclusion: miR-22 is involved in the inhibitory effects of curcumin on VSMCs' proliferation, migration and neointima hyperplasia after arterial balloon injury in rats. Curcumin could be used to prevent neointimal hyperplasia after angioplasty.

Can miRNAs Be Considered as Diagnostic and Therapeutic Molecules in Ischemic Stroke Pathogenesis?-Current Status

Ischemic stroke is one of the leading causes of death worldwide. Clinical manifestations of stroke are long-lasting and causing economic burden on the patients and society. Current therapeutic modalities to treat ischemic stroke (IS) are unsatisfactory due to the intricate pathophysiology and poor functional recovery of brain cellular compartment. MicroRNAs (miRNA) are endogenously expressed small non-coding RNA molecules, which can act as translation inhibitors and play a pivotal role in the pathophysiology associated with IS. Moreover, miRNAs may be used as potential diagnostic and therapeutic tools in clinical practice; yet, the complete role of miRNAs is enigmatic during IS. In this review, we explored the role of miRNAs in the regulation of stroke risk factors viz., arterial hypertension, metabolic disorders, and atherosclerosis. Furthermore, the role of miRNAs were reviewed during IS pathogenesis accompanied by excitotoxicity, oxidative stress, inflammation, apoptosis, angiogenesis, neurogenesis, and Alzheimer's disease. The functional role of miRNAs is a double-edged sword effect in cerebral ischemia as they could modulate pathological mechanisms associated with risk factors of IS. miRNAs pertaining to IS pathogenesis could be potential biomarkers for stroke; they could help researchers to identify a particular stroke type and enable medical professionals to evaluate the severity of brain injury. Thus, ascertaining the role of miRNAs may be useful in deciphering their diagnostic role consequently it is plausible to envisage a suitable therapeutic modality against IS.

Nanoscale Technologies in Highly Sensitive Diagnosis of Cardiovascular Diseases

Cardiovascular diseases (CVD) are the leading cause of death and morbidity in the world and are a major contributor to healthcare costs. Although enormous progress has been made in diagnosing CVD, there is an urgent need for more efficient early detection and the development of novel diagnostic tools. Currently, CVD diagnosis relies primarily on clinical symptoms based on molecular imaging (MOI) or biomarkers associated with CVDs. However, sensitivity, specificity, and accuracy of the assay are still challenging for early-stage CVDs. Nanomaterial platform has been identified as a promising candidate for improving the practical usage of diagnostic tools because of their unique physicochemical properties. In this review article, we introduced cardiac biomarkers and imaging techniques that are currently used for CVD diagnosis. We presented the applications of various nanotechnologies on diagnosis within cardiac immunoassays (CIAs) and molecular imaging. We also summarized and compared different cardiac immunoassays based on their sensitivities and working ranges of biomarkers.

Evolutionary Patterns of Non-Coding RNA in Cardiovascular Biology

Cardiovascular diseases (CVDs) affect the heart and the vascular system with a high prevalence and place a huge burden on society as well as the healthcare system. These complex diseases are often the result of multiple genetic and environmental risk factors and pose a great challenge to understanding their etiology and consequences. With the advent of next generation sequencing, many non-coding RNA transcripts, especially long non-coding RNAs (lncRNAs), have been linked to the pathogenesis of CVD. Despite increasing evidence, the proper functional characterization of most of these molecules is still lacking. The exploration of conservation of sequences across related species has been used to functionally annotate protein coding genes. In contrast, the rapid evolutionary turnover and weak sequence conservation of lncRNAs make it difficult to characterize functional homologs for these sequences. Recent studies have tried to explore other dimensions of interspecies conservation to elucidate the functional role of these novel transcripts. In this review, we summarize various methodologies adopted to explore the evolutionary conservation of cardiovascular non-coding RNAs at sequence, secondary structure, syntenic, and expression level.

Exercise Training-Induced Changes in MicroRNAs: Beneficial Regulatory Effects in Hypertension, Type 2 Diabetes, and Obesity

MicroRNAs are small non-coding RNAs that regulate gene expression post-transcriptionally. They are involved in the regulation of physiological processes, such as adaptation to physical exercise, and also in disease settings, such as systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2D), and obesity. In SAH, microRNAs play a significant role in the regulation of key signaling pathways that lead to the hyperactivation of the renin-angiotensin-aldosterone system, endothelial dysfunction, inflammation, proliferation, and phenotypic change in smooth muscle cells, and the hyperactivation of the sympathetic nervous system. MicroRNAs are also involved in the regulation of insulin signaling and blood glucose levels in T2D, and participate in lipid metabolism, adipogenesis, and adipocyte differentiation in obesity, with specific microRNA signatures involved in the pathogenesis of each disease. Many studies report the benefits promoted by exercise training in cardiovascular diseases by reducing blood pressure, glucose levels, and improving insulin signaling and lipid metabolism. The molecular mechanisms involved, however, remain poorly understood, especially regarding the participation of microRNAs in these processes. This review aimed to highlight microRNAs already known to be associated with SAH, T2D, and obesity, as well as their possible regulation by exercise training.

Long-term high altitude hypoxia during gestation suppresses large conductance Ca2+ -activated K+ channel function in uterine arteries: a causal role for microRNA-210

KEY POINTS

Gestational hypoxia represses ten-eleven translocation methylcytosine dioxygenase 1 (TET1) expression in uterine arteries, which is recovered by inhibiting endogenous miR-210. Inhibition of miR-210 rescues BK_Ca channel expression and current in uterine arteries of pregnant animals acclimatized to high altitude hypoxia in a TET-dependent manner. miR-210 blockade restores BK_Ca channel-mediated relaxations and attenuates pressure-dependent myogenic tone in uterine arteries of pregnant animals acclimatized to high altitude.

ABSTRACT

Gestational hypoxia at high altitude has profound adverse effects on the uteroplacental circulation, and is associated with increased incidence of preeclampsia and fetal intrauterine growth restriction. Previous studies demonstrated that suppression of large-conductance Ca²⁺ -activated K⁺ (BK_Ca ) channel function played a critical role in the maladaptation of uteroplacental circulation caused by gestational hypoxia. Yet, the mechanisms underlying gestational hypoxia-induced BK_Ca channel repression remain undetermined. The present study investigated a causal role of microRNA-210 (miR-210) in hypoxia-mediated repression of BK_Ca channel expression and function in uterine arteries using a sheep model. The results revealed that gestational hypoxia significantly decreased ten-eleven translocation methylcytosine dioxygenase 1 (TET1) expression in uterine arteries, which was recovered by inhibiting endogenous miR-210 with miR-210 locked nucleic acid (miR-210-LNA). Of importance, miR-210-LNA restored BK_Ca channel β1 subunit expression in uterine arteries, which was blocked by a competitive TET inhibitor, fumarate, thus functionally linking miR-210 to the TET1-BK_Ca channel cascade. In addition, miR-210-LNA reversed hypoxia-mediated suppression of BK_Ca channel function and rescued the effect of steroid hormones in upregulating BK_Ca channel expression and function in uterine arteries, which were also ablated by fumarate. Collectively, the present study demonstrates a causative effect of miR-210 in the downregulation of TET1 and subsequent repression of BK_Ca channel expression and function, providing a novel mechanistic insight into the regulation of BK_Ca channel function and the molecular basis underlying the maladaptation of uterine vascular function in gestational hypoxia.

Impact of microRNAs on ischemic stroke: From pre- to post-disease

Stroke is the number one cause of neurological dysfunction in adults and has a heavy socioeconomic burden worldwide. The etiological origins of ischemic stroke and resulting pathological processes are mediated by a multifaceted cascade of molecular mechanisms that are in part modulated by posttranscriptional activity. Accumulating evidence has revealed a role for microRNAs (miRNAs) as essential mediators of posttranscriptional gene silencing in both the physiology of brain development and pathology of ischemic stroke. In this review, we compile miRNAs that have been reported to regulate various stroke risk factors and pre-disease mechanisms, including hypertension, atherosclerosis, and diabetes, followed by an in-depth analysis of miRNAs in ischemic stroke pathogenesis, such as excitotoxicity, oxidative stress, inflammation, apoptosis, angiogenesis and neurogenesis. Since promoting or suppressing expression of miRNAs by specific pharmaceutical and non-pharmaceutical therapies may be beneficial to post-stroke recovery, we also highlight the potential therapeutic value of miRNAs in clinical settings.

Non-Coding RNA in the Pathogenesis, Progression and Treatment of Hypertension

Hypertension is a complex, multifactorial disease that involves the coexistence of multiple risk factors, environmental factors and physiological systems. The complexities extend to the treatment and management of hypertension, which are still the pursuit of many researchers. In the last two decades, various genes have emerged as possible biomarkers and have become the target for investigations of specialized drug design based on its risk factors and the primary cause. Owing to the growing technology of microarrays and next-generation sequencing, the non-protein-coding RNAs (ncRNAs) have increasingly gained attention, and their status of redundancy has flipped to importance in normal cellular processes, as well as in disease progression. The ncRNA molecules make up a significant portion of the human genome, and their role in diseases continues to be uncovered. Specifically, the cellular role of these ncRNAs has played a part in the pathogenesis of hypertension and its progression to heart failure. This review explores the function of the ncRNAs, their types and biology, the current update of their association with hypertension pathology and the potential new therapeutic regime for hypertension.

MiR-664a-3p expression in patients with obstructive sleep apnea: A potential marker of atherosclerosis

The early prediction of atherosclerosis (AS) is important in the management of obstructive sleep apnea patients (OSA). MicroRNA (miRNA) plays a vital role in the evolution of OSA and AS. Its differential expression may therefore serve as a diagnostic and prognostic biomarker of AS in OSA. The aim of this study was to identify specific serum miRNAs that could serve as a novel screening signature of AS in OSA patients. The specificity and sensitivity of these miRNAs in the early diagnosis of AS in OSA patients were then determined.The 128 participants in this study underwent maximum carotid intima-media thickness (CIMT) measurements and polysomnography and were divided into 4 groups: 27 healthy volunteers with normal max-CIMT, 31 healthy volunteers with increased max-CIMT, 35 OSA patients with normal max-CIMT, and 35 OSA patients with iCIMT. MiRNA was extracted from the 12 participants' serum (3 participants each groups) and used to establish miRNA libraries for deep sequencing. A total of 116 participants were quantified by qRT- PCR. Correlations between differential expression of miRNAs and CIMT were assessed using the Spearman correlation coefficient. Our study was approved by the Ethics Committee of our hospital and was conducted in line with the Helsinki Declaration.MiR-664a-3p expression was quantified by qRT-PCR. Correlations between miR-664a-3p expression and CIMT were assessed using the Spearman correlation coefficient. The results showed that the miR-664a-3p was downregulated in the OSA, OSA with iCMIT, and nCIMT groups compared with the control group.The demonstrated potential of circulating miR-664a-3p as a noninvasive marker of AS in essential OSA patients should be confirmed in further studies.

Non-coding RNAs in cardiac hypertrophy

Heart failure is one of the largest contributors to disease burden and healthcare outflow in the Western world. Despite significant progress in the treatment of heart failure, disease prognosis remains very poor, with the only curative therapy still being heart transplantation. To counteract the current situation, efforts have been made to better understand the underlying molecular pathways in the progression of cardiac disease towards heart failure, and to link the disease to novel therapeutic targets such as non‐coding RNAs. The non‐coding part of the genome has gained prominence over the last couple of decades, opening a completely new research field and establishing different non‐coding RNAs species as fundamental regulators of cellular functions. Not surprisingly, their dysregulation is increasingly being linked to pathology, including to cardiac disease. Pre‐clinically, non‐coding RNAs have been shown to be of great value as therapeutic targets in pathological cardiac remodelling and also as diagnostic/prognostic biomarkers for heart failure. Therefore, it is to be expected that non‐coding RNA‐based therapeutic strategies will reach the bedside in the future and provide new and more efficient treatments for heart failure. Here, we review recent discoveries linking the function and molecular interactions of non‐coding RNAs with the pathophysiology of cardiac hypertrophy and heart failure.

Phosphodiesterase-5 inhibition preserves renal hemodynamics and function in mice with diabetic kidney disease by modulating miR-22 and BMP7

Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease. Preclinical and experimental studies show that PDE5 inhibitors (PDE5is) exert protective effects in DN improving perivascular inflammation. Using a mouse model of diabetic kidney injury we investigated the protective proprieties of PDE5is on renal hemodynamics and the molecular mechanisms involved. PDE5i treatment prevented the development of DN-related hypertension (P < 0.001), the increase of urine albumin creatinine ratio (P < 0.01), the fall in glomerular filtration rate (P < 0.001), and improved renal resistive index (P < 0.001) and kidney microcirculation. Moreover PDE5i attenuated the rise of nephropathy biomarkers, soluble urokinase-type plasminogen activator receptor, suPAR and neutrophil gelatinase-associated lipocalin, NGAL. In treated animals, blood vessel perfusion was improved and vascular leakage reduced, suggesting preserved renal endothelium integrity, as confirmed by higher capillary density, number of CD31⁺ cells and pericyte coverage. Analysis of the mechanisms involved revealed the induction of bone morphogenetic protein-7 (BMP7) expression, a critical regulator of angiogenesis and kidney homeostasis, through a PDE5i-dependent downregulation of miR-22. In conclusion PDE5i slows the progression of DN in mice, improving hemodynamic parameters and vessel integrity. Regulation of miR-22/BMP7, an unknown mechanism of PDE5is in nephrovascular protection, might represent a novel therapeutic option for treatment of diabetic complications.

Blood pressure and expression of microRNAs in whole blood

Background

Blood pressure (BP) is a complex, multifactorial clinical outcome driven by genetic susceptibility, behavioral choices, and environmental factors. Many molecular mechanisms have been proposed for the pathophysiology of high BP even as its prevalence continues to grow worldwide, increasing morbidity and marking it as a major public health concern. To address this, we evaluated miRNA profiling in blood leukocytes as potential biomarkers of BP and BP-related risk factors.

Methods

The Beijing Truck Driver Air Pollution Study included 60 truck drivers and 60 office workers examined in 2008. On two days separated by 1–2 weeks, we examined three BP measures: systolic, diastolic, and mean arterial pressure measured at both pre- and post-work exams for blood NanoString nCounter miRNA profiles. We used covariate-adjusted linear mixed-effect models to examine associations between BP and increased miRNA expression in both pooled and risk factor-stratified analyses.

Results

Overall 43 miRNAs were associated with pre-work BP (FDR<0.05). In stratified analyses different but overlapping groups of miRNAs were associated with pre-work BP in truck drivers, high-BMI participants, and usual alcohol drinkers (FDR<0.05). Only four miRNAs were associated with post-work BP (FDR<0.05), in ever smokers.

Conclusion

Our results suggest that many miRNAs were significantly associated with BP in subgroups exposed to known hypertension risk factors. These findings shed light on the underlying molecular mechanisms of BP, and may assist with the development of a miRNA panel for early detection of hypertension.

MicroRNAs in cardiovascular disease

PURPOSE OF REVIEW

Noncoding RNAs regulate many aspects of cardiovascular biology and are potential therapy targets. In this review, we summarize and highlight current discoveries in the field of microRNAs, a class of noncoding RNAs.

RECENT FINDINGS

miRNAs regulate posttranscriptional gene expression and have been shown to control cardiac development, hypertrophy, fibrosis, and regeneration. Of note are the miRNAs that regulate cardiac contractility (for example, miR-25 and miR-22), cardiac regeneration (like miR-302-367 and miR99/100 families), and fibrosis (as miR-125b). Consistently with these roles of miRNAs, pharmacological intervention using anti-miRNA oligonucleotides (antagomirs or LNA-anti-miRs) has been shown to improve cardiac contractility and mitigate fibrosis, alleviating cardiac dysfunction in the setting of heart failure.

SUMMARY

miRNAs are crucial regulators of cardiac phenotype and have enthused both basic scientists and clinicians alike. With advancement of technology and better understanding of mechanisms governing miRNA deregulation, we are at the crossroads for deciphering miRNA function and modulating it for therapeutics.

Analysis and validation of traits associated with a single nucleotide polymorphism Gly364Ser in catestatin using humanized chromogranin A mouse models

OBJECTIVE

The human prohormone chromogranin A (CHGA), an index member of the granin family is processed to generate catestatin, a peptide that is hypotensive in action and modulates catecholamine release within the sympathoadrenal system. Hypertensive patients with excess sympathetic activity have diminished catestatin. Often the study of physiological consequences of human genetic variation is confounded by elements such as other variations in obligatory linkage disequilibrium with the variant being studied. Also the phenotype of the variant may be influenced by genetic background that varies amongst individuals. This study addresses the effects of a human catestatin polymorphism (rs9658667) using humanized CHGA mouse models.

METHODS

We created pertinent humanized mouse models wherein the mouse Chga gene locus was replaced by the human ortholog wild-type and the variant versions. This allowed for probing of the effects of catestatin variation in vivo with controls for other variations and global genetic background.

RESULTS

Both the wild-type and variant human catestatin expressing mouse models were normotensive. The variant catestatin mouse model recapitulated physiological influence of the polymorphism on autonomic traits. These mice had diminished catecholamine, attenuated stress response and increased baroreceptor slopes that would suggest reduced risk of developing hypertension. Elevated plasma glucose, a trait observed in humans was not observed in mice expressing the variant catestatin.

CONCLUSION

This functional genomics approach of creating humanized mouse models to study rs9658667 polymorphism recapitulated and validated many of the human trait associations. This approach can also be applied in the study of other human gene polymorphisms.

MicroRNAs and Endothelial (Dys) Function

Accumulating evidence indicates that microRNAs (miRs)-non-coding RNAs that can regulate gene expression via translational repression and/or post-transcriptional degradation-are becoming one of the most fascinating areas of physiology, given their fundamental roles in countless pathophysiological processes. The relative roles of different miRs in vascular biology as direct or indirect post-transcriptional regulators of fundamental genes implied in vascular remodeling designate miRs as potential biomarkers and/or promising drug targets. The mechanistic importance of miRs in modulating endothelial cell (EC) function in physiology and in disease is addressed here. Drawbacks of currently available therapeutic options are also discussed, pointing at the challenges and clinical opportunities provided by miR-based treatments. J. Cell. Physiol. 231: 1638-1644, 2016. © 2015 Wiley Periodicals, Inc.

Mechanisms and therapeutic potential of microRNAs in hypertension

Hypertension is the major risk factor for the development of stroke, coronary artery disease, heart failure and renal disease. The underlying cellular and molecular mechanisms of hypertension are complex and remain largely elusive. MicroRNAs (miRNAs) are short, noncoding RNA fragments of 22-26 nucleotides and regulate protein expression post-transcriptionally by targeting the 3'-untranslated region of mRNA. A growing body of recent research indicates that miRNAs are important in the pathogenesis of arterial hypertension. Herein, we summarize the current knowledge regarding the mechanisms of miRNAs in cardiovascular remodeling, focusing specifically on hypertension. We also review recent progress of the miRNA-based therapeutics including pharmacological and nonpharmacological therapies (such as exercise training) and their potential applications in the management of hypertension.

Signatures of natural selection at the FTO (fat mass and obesity associated) locus in human populations

Background and aims

Polymorphisms in the first intron of FTO have been robustly replicated for associations with obesity. In the Sorbs, a Slavic population resident in Germany, the strongest effect on body mass index (BMI) was found for a variant in the third intron of FTO (rs17818902). Since this may indicate population specific effects of FTO variants, we initiated studies testing FTO for signatures of selection in vertebrate species and human populations.

Methods

First, we analyzed the coding region of 35 vertebrate FTO orthologs with Phylogenetic Analysis by Maximum Likelihood (PAML, ω = dN/dS) to screen for signatures of selection among species. Second, we investigated human population (Europeans/CEU, Yoruba/YRI, Chinese/CHB, Japanese/JPT, Sorbs) SNP data for footprints of selection using DnaSP version 4.5 and the Haplotter/PhaseII. Finally, using ConSite we compared transcription factor (TF) binding sites at sequences harbouring FTO SNPs in intron three.

Results

PAML analyses revealed strong conservation in coding region of FTO (ω<1). Sliding-window results from population genetic analyses provided highly significant (p<0.001) signatures for balancing selection specifically in the third intron (e.g. Tajima’s D in Sorbs = 2.77). We observed several alterations in TF binding sites, e.g. TCF3 binding site introduced by the rs17818902 minor allele.

Conclusion

Population genetic analysis revealed signatures of balancing selection at the FTO locus with a prominent signal in intron three, a genomic region with strong association with BMI in the Sorbs. Our data support the hypothesis that genes associated with obesity may have been under evolutionary selective pressure.

Non-coding RNAs and hypertension-unveiling unexpected mechanisms of hypertension by the dark matter of the genome

Hypertension is a major risk factor of cardiovascular diseases and a most important health problem in developed countries. Investigations on pathophysiology of hypertension have been based on gene products from coding region that occupies only about 1% of total genome region. On the other hand, non-coding region that occupies almost 99% of human genome has been regarded as "junk" for a long time and went unnoticed until these days. But recently, it turned out that noncoding region is extensively transcribed to non-coding RNAs and has various functions. This review highlights recent updates on the significance of non-coding RNAs such as micro RNAs and long non-coding RNAs (lncRNAs) on the pathogenesis of hypertension, also providing an introduction to basic biology of noncoding RNAs. For example, microRNAs are associated with hypertension via neuro-fumoral factor, sympathetic nerve activity, ion transporters in kidneys, endothelial function, vascular smooth muscle phenotype transformation, or communication between cells. Although reports of lncRNAs on pathogenesis of hypertension are scarce at the moment, new lncRNAs in relation to hypertension are being discovered at a rapid pace owing to novel techniques such as microarray or next-generation sequencing. In the clinical settings, clinical use of non-coding RNAs in identifying cardiovascular risks or developing novel tools for treating hypertension such as molecular decoy or mimicks is promising, although improvement in chemical modification or drug delivery system is necessary.

microRNAs in Essential Hypertension and Blood Pressure Regulation

Unravelling the complete genetic predisposition to high blood pressure (BP) has proven to be challenging. This puzzle and the fact that coding regions of the genome account for less than 2 % of the entire human DNA support the hypothesis that mechanisms besides coding genes are likely to contribute to BP regulation. Non-coding RNAs, especially microRNAs, are emerging as key players of transcription regulation in both health and disease states. They control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct involvement with BP regulation is highly probable. Here we review the literature about microRNAs associated with regulation of BP and hypertension, highlighting investigations, methodology and difficulties arising in the field. These molecules are being studied for exploitation in diagnostics, prognostics and therapeutics in many diseases. There have been some studies that examined biological fluid microRNAs as biomarkers for hypertension, but most remain inconclusive due to the small sample sizes and differences in methodological standardisation. Fewer studies have analysed tissue microRNA levels in vascular smooth muscle cells and the kidney. Others focused on the interaction between single nucleotide polymorphisms and microRNA binding sites. Studies in animals have shown that angiotensin II, high-salt diet and exercise change microRNA levels in hypertension. Treatment of spontaneously hypertensive rats with a miR-22 inhibitor and treatment of hypertensive Schlager BPH/2J mice with a miR-181a mimic decreased their BP. This supports the use of microRNAs as therapeutic targets in hypertension, and future studies should test the use of other microRNAs found in human association studies. In conclusion, there is a clear need of increased pace of human, animal and functional studies to help us understand the multifaceted roles of microRNAs as critical regulators of the development and physiology of BP.

The emerging role of non-coding RNA in essential hypertension and blood pressure regulation

Unravelling the complete genetic predisposition to high blood pressure (BP) has proven to be challenging. This puzzle and the fact that coding regions of the genome account for less than 2% of the entire human DNA support the hypothesis that genetic mechanism besides coding genes are likely to contribute to BP regulation. Non-coding RNAs (ncRNAs) are emerging as key players of transcription regulation in both health and disease states. They control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct involvement with BP regulation is highly probable. Here, we review the literature about ncRNAs associated with human BP and essential hypertension, highlighting investigations, methodology and difficulties arising in the field. The most investigated ncRNAs so far are microRNAs (miRNAs), small ncRNAs that modulate gene expression by posttranscriptional mechanisms. We discuss studies that have examined miRNAs associated with BP in biological fluids, such as blood and urine, and tissues, such as vascular smooth muscle cells and the kidney. Furthermore, we review the interaction between miRNA binding sites and single nucleotide polymorphisms in genes associated with BP. In conclusion, there is a clear need for more human and functional studies to help elucidate the multifaceted roles of ncRNAs, in particular mid- and long ncRNAs in BP regulation.

Molecular Mechanism for Hypertensive Renal Disease: Differential Regulation of Chromogranin A Expression at 3'-Untranslated Region Polymorphism C+87T by MicroRNA-107

Chromogranin A (CHGA) is coreleased with catecholamines from secretory vesicles in adrenal medulla and sympathetic axons. Genetic variation in the CHGA 3'-region has been associated with autonomic control of circulation, hypertension, and hypertensive nephropathy, and the CHGA 3'-untranslated region (3'-UTR) variant C+87T (rs7610) displayed peak associations with these traits in humans. Here, we explored the molecular mechanisms underlying these associations. C+87T occurred in a microRNA-107 (miR-107) motif (match: T>C), and CHGA mRNA expression varied inversely with miR-107 abundance. In cells transfected with chimeric luciferase/CHGA 3'-UTR reporters encoding either the T allele or the C allele, changes in miR-107 expression levels had much greater effects on expression of the T allele. Cotransfection experiments with hsa-miR-107 oligonucleotides and eukaryotic CHGA plasmids produced similar results. Notably, an in vitro CHGA transcription/translation experiment revealed that changes in hsa-miR-107 expression altered expression of the T allele variant only. Mice with targeted ablation of Chga exhibited greater eGFR. Using BAC transgenesis, we created a mouse model with a humanized CHGA locus (T/T genotype at C+87T), in which treatment with a hsa-miR-107 inhibitor yielded prolonged falls in SBP/DBP compared with wild-type mice. We conclude that the CHGA 3'-UTR C+87T disrupts an miR-107 motif, with differential effects on CHGA expression, and that a cis:trans (mRNA:miR) interaction regulates the association of CHGA with BP and hypertensive nephropathy. These results indicate new strategies for probing autonomic circulatory control and ultimately, susceptibility to hypertensive renal sequelae.

miR-22 in cardiac remodeling and disease

Regulation of gene expression during cardiac development and remodeling is very complicated, involving epigenetic, transcriptional, post-transcriptional, and translational regulation. Our understanding of the molecular mechanisms underlying cardiac remodeling is still far from complete. MicroRNAs are a class of small non-coding RNAs that have been shown to play critical roles in gene regulation in cardiovascular biology and disease. microRNA-22 (miR-22) is an evolutionally conserved miRNA that is highly expressed in the heart. Recent studies uncovered miR-22 as an important regulator for cardiac remodeling. miR-22 modulates the expression and function of genes involved in hypertrophic response, sarcomere reorganization, and metabolic program shift during cardiac remodeling. In this review, we will focus on the recent findings of miR-22 in cardiac remodeling and the therapeutic potential of this miRNA in the treatment of related defects resulting from adverse cardiac remodeling.

Diagnosis, prognosis and therapeutic role of circulating miRNAs in cardiovascular diseases

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the world. Although much progress has been made for cardiovascular diseases in diagnosis, treatment and prognosis during the past two decades, the clinical need for a novel diagnostic biomarker and new therapeutic interventions to decrease the cardiovascular disease incidence is ongoing. MicroRNAs (miRNAs) are endogenous, small (∼22 nucleotides), single-stranded, non-coding RNAs that regulate gene expression and are detectable in whole blood, serum, plasma, urine and other body fluids in a highly stable form. Accumulating evidence suggests that miRNAs are potential novel biomarkers with high sensitivity for early diagnosis and modern treatment for cardiovascular diseases. Altered circulating miRNAs expressions have been reported in acute myocardial infarction (AMI), acute coronary syndrome (ACS), stable coronary artery disease, heart failure, atherosclerosis, essential hypertension and stroke. In the present review, we examine more recent data regarding circulating miRNAs and their potential roles in diagnosis, prognosis and therapeutic strategies for cardiovascular diseases. In addition, we briefly present our own recent experience in detecting circulating miRNAs, and the significance of these miRNAs in AMI prognosis.

Recent Progress in the Genetics of Spontaneously Hypertensive Rats

The spontaneously hypertensive rat (SHR) is the most widely used animal model of essential hypertension and accompanying metabolic disturbances. Recent advances in sequencing of genomes of BN-Lx and SHR progenitors of the BXH/HXB recombinant inbred (RI) strains as well as accumulation of multiple data sets of intermediary phenotypes in the RI strains, including mRNA and microRNA abundance, quantitative metabolomics, proteomics, methylomics or histone modifications, will make it possible to systematically search for genetic variants involved in regulation of gene expression and in the etiology of complex pathophysiological traits. New advances in manipulation of the rat genome, including efficient transgenesis and gene targeting, will enable in vivo functional analyses of selected candidate genes to identify QTL at the molecular level or to provide insight into mechanisms whereby targeted genes affect pathophysiological traits in the SHR.