Glucocorticoid-induced fetal origins of adult hypertension: Association with epigenetic events

Age- and sex-dependent cardiovascular impact of maternal perinatal stress and altered dopaminergic metabolism in the medulla oblongata of the offspring

Maternal major depressive disorder with peripartum onset presents health risks to the mother and the developing fetus. Using a rat model of chronic mild stress, we previously reported on the neurodevelopmental impact of maternal perinatal stress on their offspring. This study examined the cardiovascular impact of maternal perinatal stress on their offspring. The cardiovascular impact was assessed in terms of blood pressure and echocardiographic parameters. The results examined by a three-way ANOVA showed a significant association of cardiovascular parameters with maternal perinatal stress and offspring sex and age. Increased blood pressure was observed in adolescent female and adult male offspring of stress-exposed dams. Echocardiography showed an increase in left atrial dimension and a reduction in left ventricular systolic function in adolescent stress-exposed female offspring. Increased interventricular septum thickness at end-diastole and left ventricular diastolic dysfunction were observed in adult stress-exposed male offspring. The underlying mechanisms of cardiovascular impact were examined in stress-exposed adult offspring by assessing the levels of neurotransmitters and their metabolites in the medulla oblongata using high-performance liquid chromatography. A significant decrease in homovanillic acid, a dopamine metabolite and indicator of dopaminergic activity, was observed in adult stress-exposed female offspring. These results suggest a significant sex- and age-dependent impact of maternal stress during the peripartum period on the cardiovascular system in the offspring that extends to adulthood and suggests a multigenerational effect. The presented data urgently need follow-up to confirm their potential clinical and public health relevance.NEW & NOTEWORTHY We demonstrate that maternal perinatal stress is associated with sex- and age-dependent impact on the cardiovascular system in their offspring. The effect was most significant in adolescent female and adult male offspring. Observed changes in hemodynamic parameters and dopaminergic activity of the medulla oblongata are novel results relevant to understanding the cardiovascular impact of maternal perinatal stress on the offspring. The cardiovascular changes observed in adult offspring suggest a potential long-term, multigenerational impact of maternal perinatal stress.

Independent and Combined Effects of Prenatal Alcohol Exposure and Prenatal Stress on Fetal HPA Axis Development

Prenatal alcohol exposure (PAE) and prenatal stress (PS) are highly prevalent conditions known to affect fetal programming of the hypothalamic-pituitary-adrenal (HPA) axis. The objectives of this study were to assess the effect of light PAE, PS, and PAE-PS interaction on fetal HPA axis activity assessed via placental and umbilical cord blood biomarkers. Participants of the ENRICH-2 cohort were recruited during the second trimester and classified into the PAE and unexposed control groups. PS was assessed by the Perceived Stress Scale. Placental tissue was collected promptly after delivery; gene and protein analysis for 11β-HSD1, 11β-HSD2, and pCRH were conducted by qPCR and ELISA, respectively. Umbilical cord blood was analyzed for cortisone and cortisol. Pearson correlation and multivariable linear regression examined the association of PAE and PS with HPA axis biomarkers. Mean alcohol consumption in the PAE group was ~2 drinks/week. Higher PS was observed in the PAE group (p < 0.01). In multivariable modeling, PS was associated with pCRH gene expression (β = 0.006, p < 0.01), while PAE was associated with 11β-HSD2 protein expression (β = 0.56, p < 0.01). A significant alcohol-by-stress interaction was observed with respect to 11β-HSD2 protein expression (p < 0.01). Results indicate that PAE and PS may independently and in combination affect fetal programming of the HPA axis.

The molecular mechanisms in prenatal drug exposure-induced fetal programmed adult cardiovascular disease

The "developmental origins of health and disease" (DOHaD) hypothesis posits that early-life environmental exposures have a lasting impact on individual's health and permanently shape growth, structure, and metabolism. This reprogramming, which results from fetal stress, is believed to contribute to the development of adulthood cardiovascular diseases such as hypertension, coronary artery disease, heart failure, and increased susceptibility to ischemic injuries. Recent studies have shown that prenatal exposure to drugs, such as glucocorticoids, antibiotics, antidepressants, antiepileptics, and other toxins, increases the risk of adult-onset cardiovascular diseases. In addition, observational and animal experimental studies have demonstrated the association between prenatal drug exposure and the programming of cardiovascular disease in the offspring. The molecular mechanisms underlying these effects are still being explored but are thought to involve metabolism dysregulation. This review summarizes the current evidence on the relationship between prenatal drug exposure and the risk of adult cardiovascular disorders. Additionally, we present the latest insights into the molecular mechanisms that lead to programmed cardiovascular phenotypes after prenatal drug exposure.

Insights into the Mechanisms of Fetal Growth Restriction-Induced Programming of Hypertension

In recent decades, both clinical and animal studies have shown that fetal growth restriction (FGR), caused by exposure to adverse uterine environments, is a risk factor for hypertension as well as for a variety of adult diseases. This observation has shaped and informed the now widely accepted theory of developmental origins of health and disease (DOHaD). There is a plethora of evidence supporting the association of FGR with increased risk of adult hypertension; however, the underlying mechanisms responsible for this correlation remain unclear. This review aims to explain the current advances in the field of fetal programming of hypertension and a brief narration of the underlying mechanisms that may link FGR to increased risk of adult hypertension. We explain the theory of DOHaD and then provide evidence from both clinical and basic science research which support the theory of fetal programming of adult hypertension. In addition, we have explored the underlying mechanisms that may link FGR to an increased risk of adult hypertension. These mechanisms include epigenetic changes, metabolic disorders, vascular dysfunction, neurohormonal impairment, and alterations in renal physiology and function. We further describe sex differences seen in the developmental origins of hypertension and provide insights into the opportunities and challenges present in this field.

Cannabinoids and myocardial ischemia: Novel insights, updated mechanisms, and implications for myocardial infarction

Cannabis is the most widely trafficked and abused illicit drug due to its calming psychoactive properties. It has been increasingly recognized as having potential health benefits and relatively less adverse health effects as compared to other illicit drugs; however, growing evidence clearly indicates that cannabis is associated with considerable adverse cardiovascular events. Recent studies have linked cannabis use to myocardial infarction (MI); yet, very little is known about the underlying mechanisms. A MI is a cardiovascular disease characterized by a mismatch in the oxygen supply and demand of the heart, resulting in ischemia and subsequent necrosis of the myocardium. Since cannabis is increasingly being considered a risk factor for MI, there is a growing need for better appreciating its potential health benefits and consequences. Here, we discuss the cellular mechanisms of cannabis that lead to an increased risk of MI. We provide a thorough and critical analysis of cannabinoids' actions, which include modulation of adipocyte biology, regional fat distribution, and atherosclerosis, as well as precipitation of hemodynamic stressors relevant in the setting of a MI. By critically dissecting the modulation of signaling pathways in multiple cell types, this paper highlights the mechanisms through which cannabis may trigger life-threatening cardiovascular events. This then provides a framework for future pharmacological studies which can identify targets or develop drugs that modulate cannabis' effects on the cardiovascular system as well as other organ systems. Cannabis' impact on the autonomic outflow, vascular smooth muscle cells, myocardium, cortisol levels and other hemodynamic changes are also mechanistically reviewed.

Developmental programming of cardiovascular function: a translational perspective

The developmental origins of health and disease (DOHaD) is a concept linking pre- and early postnatal exposures to environmental influences with long-term health outcomes and susceptibility to disease. It has provided a new perspective on the etiology and evolution of chronic disease risk, and as such is a classic example of a paradigm shift. What first emerged as the 'fetal origins of disease', the evolution of the DOHaD conceptual framework is a storied one in which preclinical studies played an important role. With its potential clinical applications of DOHaD, there is increasing desire to leverage this growing body of preclinical work to improve health outcomes in populations all over the world. In this review, we provide a perspective on the values and limitations of preclinical research, and the challenges that impede its translation. The review focuses largely on the developmental programming of cardiovascular function and begins with a brief discussion on the emergence of the 'Barker hypothesis', and its subsequent evolution into the more-encompassing DOHaD framework. We then discuss some fundamental pathophysiological processes by which developmental programming may occur, and attempt to define these as 'instigator' and 'effector' mechanisms, according to their role in early adversity. We conclude with a brief discussion of some notable challenges that hinder the translation of this preclinical work.

Does Prenatal Exposure to CNS Stimulants Increase the Risk of Cardiovascular Disease in Adult Offspring?

Prenatal exposure to an adverse uterine environment can have long lasting effects on adult offspring through DNA methylation, histone acetylation, and other epigenetic effects that alter gene expression and physiology. It is well-known that consumption of CNS stimulants such as caffeine, nicotine, amphetamines, and cocaine during pregnancy can adversely impact the offspring. However, most work in this area has focused on neurological and behavioral outcomes and has been limited to assessments in young offspring. The impact of prenatal exposure to these agents on the adult cardiovascular system has received relatively little attention. Evidence from both animal and human studies indicate that exposure to CNS stimulants during the gestational period can negatively impact the adult heart and vasculature, potentially leading to cardiovascular diseases later in life. This review discusses our current understanding of the impact of prenatal exposure to cocaine, methamphetamine, nicotine, and caffeine on the adult cardiovascular system.

Understanding Asthma and Allergies by the Lens of Biodiversity and Epigenetic Changes

Exposure to different organisms (bacteria, mold, virus, protozoan, helminths, among others) can induce epigenetic changes affecting the modulation of immune responses and consequently increasing the susceptibility to inflammatory diseases. Epigenomic regulatory features are highly affected during embryonic development and are responsible for the expression or repression of different genes associated with cell development and targeting/conducting immune responses. The well-known, "window of opportunity" that includes maternal and post-natal environmental exposures, which include maternal infections, microbiota, diet, drugs, and pollutant exposures are of fundamental importance to immune modulation and these events are almost always accompanied by epigenetic changes. Recently, it has been shown that these alterations could be involved in both risk and protection of allergic diseases through mechanisms, such as DNA methylation and histone modifications, which can enhance Th2 responses and maintain memory Th2 cells or decrease Treg cells differentiation. In addition, epigenetic changes may differ according to the microbial agent involved and may even influence different asthma or allergy phenotypes. In this review, we discuss how exposure to different organisms, including bacteria, viruses, and helminths can lead to epigenetic modulations and how this correlates with allergic diseases considering different genetic backgrounds of several ancestral populations.

Differential effects of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats

Dexamethasone (DEX)-induced hypertension is observed in normotensive rats, but little is known about the effects of DEX on spontaneously hypertensive animals (SHR). This study aimed to evaluate the effects of DEX on hemodynamics, cardiac hypertrophy and arterial stiffness in normotensive and hypertensive rats. Wistar rats and SHR were treated with DEX (50 μg/kg s.c., 14 d) or saline. Pulse wave velocity (PWV), echocardiographic parameters, blood pressure (BP), autonomic modulation and histological analyses of heart and thoracic aorta were performed. SHR had higher BP compared with Wistar, associated with autonomic unbalance to the heart. Echocardiographic changes in SHR (vs. Wistar) were suggestive of cardiac remodeling: higher relative wall thickness (RWT, +28%) and left ventricle mass index (LVMI, +26%) and lower left ventricle systolic diameter (LVSD, -19%) and LV diastolic diameter (LVDD, -10%), with slightly systolic dysfunction and preserved diastolic dysfunction. Also, SHR had lower myocardial capillary density and similar collagen deposition area. PWV was higher in SHR due to higher aortic collagen deposition. DEX-treated Wistar rats presented higher BP (~23%) and autonomic unbalance. DEX did not change cardiac structure in Wistar, but PWV (+21%) and aortic collagen deposition area (+21%) were higher compared with control. On the other side, DEX did not change BP or autonomic balance to the heart in SHR, but reduced RWT and LV collagen deposition area (-12% vs. SHR_CT ). In conclusion, the results suggest a differential effect of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats.

Nasser S, Younis N, Bhagani H, Al-Dhaheri Y, Pintus G, Eid AA, El-Yazbi AF, Eid AH. Visfatin: A Possible Role in Cardiovasculo-Metabolic Disorders

Visfatin/NAMPT (nicotinamide phosphoribosyltransferase) is an adipocytokine with several intriguing properties. It was first identified as pre-B-cell colony-enhancing factor but turned out to possess enzymatic functions in nicotinamide adenine dinucleotide biosynthesis, with ubiquitous expression in skeletal muscles, liver, cardiomyocytes, and brain cells. Visfatin exists in an intracellular (iNAMPT) and extracellular (eNAMPT) form. Intracellularly, visfatin/iNAMPT plays a regulatory role in NAD⁺ biosynthesis and thereby affects many NAD-dependent proteins such as sirtuins, PARPs, MARTs and CD38/157. Extracellularly, visfatin is associated with many hormone-like signaling pathways and activates some intracellular signaling cascades. Importantly, eNAMPT has been associated with several metabolic disorders including obesity and type 1 and 2 diabetes. In this review, a brief overview about visfatin is presented with special emphasis on its relevance to metabolic diseases. Visfatin/NAMPT appears to be a unique molecule with clinical significance with a prospective promising diagnostic, prognostic, and therapeutic applications in many cardiovasculo-metabolic disorders.

Sham surgical embryo transfer affects offspring neurodevelopment and manifestation of hypertensive phenotype in ISIAH rats

The study investigates how surgery during pregnancy, i.e., sham operation associated with embryo transfer, affects hypertensive phenotype in ISIAH rats genetically predisposed to hypertension. ISIAH rats born after maternal surgery at fourth day of pregnancy were compared with naturally conceived controls. Surgery during pregnancy in ISIAH rats caused acceleration of neurodevelopment in young offspring, as well as aggravating hypertension, suppressing exploratory activity, reducing hippocampal BDNF expression, and compensatory increasing of hippocampal neuronal density in adult ISIAH offspring. Maternal surgery during early pregnancy caused alterations in offspring phenotype in hypertensive ISIAH rat model.

Perinatal programming of metabolic diseases: The role of glucocorticoids

The worldwide increase in metabolic diseases has urged the scientific community to improve our understanding about the mechanisms underlying its cause and effects. A well supported area of studies had related maternal stress with early programming to the later metabolic diseases. Mechanisms upon origins of metabolic disturbances are not yet fully understood, even though stressful factors rising glucocorticoids have been put out as pivotal trigger by programming metabolic diseases as long-term consequence. Considering energy balance and glucose homeostasis, by producing and/or sensing regulator signals, hypothalamus-pituitary-adrenal axis and endocrine pancreas are directly affected by glucocorticoids excess. We focus on the evidences reporting the role of increased glucocorticoids due to perinatal insults on the physiological systems involved in the metabolic homeostasis and in the target organs such as endocrine pancreas, white adipose tissue and blood vessels. Besides, we review some mechanisms underlining the malprogramming of type 2 diabetes, obesity and hypertension. Studies on this field are currently ongoing and even there is a good understanding regarding the effects of glucocorticoids addressing metabolic diseases, few is known about the relationship between maternal insults rising glucocorticoids to pups' metabolic disturbances, a thorough understanding about that may provide pivotal clinical clues regarding those disorders.

Estrogen and Bisphenol A in Hypertension

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a non-subsiding disease that remains a leading cause of morbidity and mortality. CVD has been associated with endocrine disruptors, such as bisphenol A (BPA). This review critically summarizes existing findings on BPA and hypertension, with particular attention to genomic, non-genomic, molecular, and cellular mechanisms of action that render BPA as a cardiovascular estrogenic disruptor.

RECENT FINDINGS

Owing to its similar estrogenic structure, BPA has been shown to affect various phenotypes that are regulated by the natural hormone, estrogen. Indeed, BPA has been shown to interact with estrogen receptors, located both in the cell membrane and in the cytoplasm/nucleus. Given that estrogen plays an important role in cardiovascular physiology, a contributing role for BPA in CVD would not be unexpected. Existing literature, though limited, established BPA as a source of disruption in cardiovascular health, particularly hypertension. However, effects of BPA are largely dependent on the dose, patient gender, tissue, and developmental stage of the exposed tissue/organ. Accumulating evidence argues for an adverse effect of BPA on blood pressure, with this effect being gender, dose, and time specific. Thus, comprehensive studies which take these factors and other parameters, like epigenetic factors, into account are warranted before a thorough understanding is at hand.

Maternal diabetes and obesity influence the fetal epigenome in a largely Hispanic population

Background

Obesity and diabetes mellitus are directly implicated in many adverse health consequences in adults as well as in the offspring of obese and diabetic mothers. Hispanic Americans are particularly at risk for obesity, diabetes, and end-stage renal disease. Maternal obesity and/or diabetes through prenatal programming may alter the fetal epigenome increasing the risk of metabolic disease in their offspring. The aims of this study were to determine if maternal obesity or diabetes mellitus during pregnancy results in a change in infant methylation of CpG islands adjacent to targeted genes specific for obesity or diabetes disease pathways in a largely Hispanic population.

Methods

Methylation levels in the cord blood of 69 newborns were determined using the Illumina Infinium MethylationEPIC BeadChip. Over 850,000 different probe sites were analyzed to determine whether maternal obesity and/or diabetes mellitus directly attributed to differential methylation; epigenome-wide and regional analyses were performed for significant CpG sites.

Results

Following quality control, agranular leukocyte samples from 69 newborns (23 normal term (NT), 14 diabetes (DM), 23 obese (OB), 9 DM/OB) were analyzed for over 850,000 different probe sites. Contrasts between the NT, DM, OB, and DM/OB were considered. After correction for multiple testing, 15 CpGs showed differential methylation from the NT, associated with 10 differentially methylated genes between the diabetic and non-diabetic subgroups, CCDC110, KALRN, PAG1, GNRH1, SLC2A9, CSRP2BP, HIVEP1, RALGDS, DHX37, and SCNN1D. The effects of diabetes were partly mediated by the altered methylation of HOOK2, LCE3C, and TMEM63B. The effects of obesity were partly mediated by the differential methylation of LTF and DUSP22.

Conclusions

The presented data highlights the associated altered methylation patterns potentially mediated by maternal diabetes and/or obesity. Larger studies are warranted to investigate the role of both the identified differentially methylated loci and the effects on newborn body composition and future health risk factors for metabolic disease. Additional future consideration should be targeted to the role of Hispanic inheritance. Potential future targeting of transgenerational propagation and developmental programming may reduce population obesity and diabetes risk.

DNA methylation profile is a quantitative measure of biological aging in children

DNA methylation changes within the genome can be used to predict human age. However, the existing biological age prediction models based on DNA methylation are predominantly adult-oriented. We established a methylation-based age prediction model for children (9-212 months old) using data from 716 blood samples in 11 DNA methylation datasets. Our elastic net model includes 111 CpG sites, mostly in genes associated with development and aging. The model performed well and exhibited high precision, yielding a 98% correlation between the DNA methylation age and the chronological age, with an error of only 6.7 months. When we used the model to assess age acceleration in children based on their methylation data, we observed the following: first, the aging rate appears to be fastest in mid-childhood, and this acceleration is more pronounced in autistic children; second, lead exposure early in life increases the aging rate in boys, but not in girls; third, short-term recombinant human growth hormone treatment has little effect on the aging rate of children. Our child-specific methylation-based age prediction model can effectively detect epigenetic changes and health imbalances early in life. This may thus be a useful model for future studies of epigenetic interventions for age-related diseases.

Cardiovascular effects of prenatal stress-Are there implications for cerebrovascular, cognitive and mental health outcome?

Prenatal stress programs offspring cognitive and mental health outcome. We reviewed whether prenatal stress also programs cardiovascular dysfunction which potentially modulates cerebrovascular, cognitive and mental health disorders. We focused on maternal stress and prenatal glucocorticoid (GC) exposure which have different programming effects. While maternal stress induced cortisol is mostly inactivated by the placenta, synthetic GCs freely cross the placenta and have different receptor-binding characteristics. Maternal stress, particularly anxiety, but not GC exposure, has adverse effects on maternal-fetal circulation throughout pregnancy, probably by co-activation of the maternal sympathetic nervous system, and by raising fetal catecholamines. Both effects may impair neurodevelopment. Experimental data also suggest that severe maternal stress and GC exposure during early and mid-gestation may increase the risk for cardiovascular disorders. Human data are scarce and especially lacking for older age. Programming mechanisms include aberrations in cardiac and kidney development, and functional changes in the renin-angiotensin-aldosterone-system, stress axis and peripheral and coronary vasculature. Adequate experimental or human studies examining the consequences for cerebrovascular, cognitive and mental disorders are unavailable.

Antenatal Hypoxia and Programming of Glucocorticoid Receptor Expression in the Adult Rat Heart

Glucocorticoid receptor (GR) signaling is critical for development and function of the heart. Our previous study demonstrated that gestational hypoxia induced epigenetic repression of the GR gene in the developing heart. The present study aims to determine that the alterations of promoter methylation level and epigenetic repression of the GR gene in the developing heart in response to maternal hypoxia is sustained in adult offspring and potential gender differences in the programming of GR gene. Pregnant rats were treated with 10.5% O₂ from gestational day 15 (E15) to 21 (E21). Hearts were isolated from 5-month-old male and female offspring with the developing stage being equivalent to 18-year-old human. GR mRNA and protein abundance was determined with real time qRT-PCR and Western blot. GR gene promoter methylation and binding of transcription factors were measured with methylated DNA immunoprecipitation (MeDIP) and Chromatin immunoprecipitation (ChIP). The results showed that antenatal hypoxia significantly decreased the expression of GR mRNA and protein in the hearts of adult male offspring, but not in females, which is ascribed to the differential changes of alternative exon1 mRNA variants of GR gene in male and female hearts in response to prenatal hypoxia. In addition, the downregulation of GR expression in the male heart was correlated with increased methylation levels of CpG dinucleotides in promoters of exon 1₄, 1₅, 1₆, 1₇, and 1₁₀, which resulted in a decrease in the binding of their transcription factors. Thus, the study reveals that antenatal hypoxia results in a reprogramming and long-term change in GR gene expression in the heart by hypermethylation of GR promoter in a sex-differential pattern, which provides a novel mechanism regarding the increased vulnerability of heart later in life with exposure of prenatal hypoxia.

Prenatal therapeutics and programming of cardiovascular function

Cardiovascular diseases (CVD) are a leading cause of mortality worldwide. Despite recognizing the importance of risk factors in dictating CVD susceptibility and onset, patient treatment remains a challenging endeavor. Increasingly, the benefits of prevention and mitigation of risk factors earlier in life are being acknowledged. The developmental origins of health and disease posits that insults during specific periods of development can influence long-term health outcomes; this occurs because the developing organism is highly plastic, and hence vulnerable to environmental perturbations. By extension, targeted therapeutics instituted during critical periods of development may confer long-term protection, and thus reduce the risk of CVD in later life. This review provides a brief overview of models of developmental programming, and then discusses the impact of perinatal therapeutic interventions on long-term cardiovascular function in the offspring. The discussion focuses on bioactive food components, as well as pharmacological agents currently approved for use in pregnancy; in short, those agents most likely to be used in pregnancy and early childhood.

Estrogen in vascular smooth muscle cells: A friend or a foe?

Cardiovascular disease (CVD) continues to be the leading cause of death worldwide. The effect of estrogen on these diseases has been assessed in in vitro and in vivo models, as well as in observational studies. Collectively, these studies alluded to a cardiovasculo-protective effect of estrogen. However, comprehensive clinical investigation failed to produce concrete proof of a cardiovascular protective effect for hormone replacement therapy (HRT), let alone rule out potential harm. These seemingly paradoxical effects of estrogen were explained by the 'theory of timing and opportunity'. This theory states that the effect of estrogen, whether cardiovasculo-protective or pathological, significantly depends on the age of the individual when estrogen administration takes place. Here, we review the conflicting effects of estrogen on vascular smooth muscle cells, mainly proliferation and migration as two cellular capacities intimately related to physiology and pathophysiology of the cardiovascular system. Furthermore, we critically discuss the major parameters and signaling pathways that may account for the aforementioned paradoxical observations, as well as the key molecular players involved.

Implication of Oxidative Stress in Fetal Programming of Cardiovascular Disease

Lifestyle and genetic background are well known risk factors of cardiovascular disease (CVD). A third contributing factor is suboptimal fetal development, due to nutrient or oxygen deprivation, placental insufficiency, or exposure to toxic substances. The fetus adapts to adverse intrauterine conditions to ensure survival; the immediate consequence is low birth weight (LBW) and the long-term effect is an increased susceptibility to develop CVD in adult life. This process is known as Developmental Origins of Health and Disease (DOHaD) or fetal programming of CVD. The influence of fetal life for the future cardiovascular health of the individual has been evidenced by numerous epidemiologic studies in populations suffering from starvation during intrauterine life. Furthermore, experimental animal models have provided support and enabled exploring the underlying mechanisms. Oxidative stress seems to play a central role in fetal programming of CVD, both in the response of the feto-placental unit to the suboptimal intrauterine environment and in the alterations of physiologic systems of cardiovascular control, ultimately leading to disease. This review aims to summarize current knowledge on the alterations in oxidative balance in response to fetal stress factors covering two aspects. Firstly, the evidence from human studies of the implication of oxidative stress in LBW induced by suboptimal conditions during intrauterine life, emphasizing the role of the placenta. In the second part we summarize data on specific redox alterations in key cardiovascular control organs induced by exposure to known stress factors in experimental animals and discuss the emerging role of the mitochondria.

Salvia fruticosa Induces Vasorelaxation In Rat Isolated Thoracic Aorta: Role of the PI3K/Akt/eNOS/NO/cGMP Signaling Pathway

Salvia fruticosa (SF) Mill. is traditionally used for its antihypertensive actions. However, little is known about its pharmacologic and molecular mechanisms of action. Here we determined the effects of an ethanolic extract of SF leaves on rings of isolated thoracic aorta from Sprague-Dawley rats. Our results show that SF extract increased nitric oxide production and relaxed endothelium-intact rings in a dose-dependent (0.3 µg/ml–1 mg/ml) manner, and the maximum arterial relaxation (R_max) was significantly reduced with endothelium denudation. Pretreatment of endothelium-intact rings with L-NAME (a non-selective inhibitor of nitric oxide synthase, 100 µM), or ODQ (an inhibitor of soluble guanylyl cyclase, 10 µM) significantly diminished SF-mediated vasorelaxation. Furthermore, SF induced Akt phosphorylation as well as increased cGMP levels in rings treated with increasing doses of SF. Prior exposure to PI3K inhibitors, wortmannin (0.1 µM) or LY294002 (10 µM), decreased cGMP accumulation and attenuated the SF-induced vasorelaxation by approximately 50% (R_max). SF-evoked relaxation was not affected by indomethacin, verapamil, glibenclamide, tetraethylammonium, pyrilamine or atropine. Taken together, our results indicate that SF induces endothelium-dependent vasorelaxation through the PI3K/Akt/eNOS/NO/sGC/cGMP signaling pathway. Our data illustrate the health-orientated benefits of consuming SF which may act as an antihypertensive agent to reduce the burden of cardiovascular complications.

Neuronal nitric oxide synthase in hypertension - an update

Hypertension is a prevalent condition worldwide and is the key risk factor for fatal cardiovascular complications, such as stroke, sudden cardiac death and heart failure. Reduced bioavailability of nitric oxide (NO) in the endothelium is an important precursor for impaired vasodilation and hypertension. In the heart, NO deficiency deteriorates the adverse consequences of pressure-overload and causes cardiac hypertrophy, fibrosis and myocardial infarction which lead to fatal heart failure and sudden cardiac death. Recent consensus is that both endothelial and neuronal nitric oxide synthases (eNOS or NOS3 and nNOS or NOS1) are the constitutive sources of NO in the myocardium. Between the two, nNOS is the predominant isoform of NOS that controls intracellular Ca²⁺ homeostasis, myocyte contraction, relaxation and signaling pathways including nitroso-redox balance. Notably, our recent research indicates that cardiac eNOS protein is reduced but nNOS protein expression and activity are increased in hypertension. Furthermore, nNOS is induced by the interplay between angiotensin II (Ang II) type 1 receptor (AT1R) and Ang II type 2 receptor (AT2R), mediated by NADPH oxidase and reactive oxygen species (ROS)-dependent eNOS activity in cardiac myocytes. nNOS, in turn, protects the heart from pathogenesis via positive lusitropy in hypertension. Soluble guanylate cyclase (sGC)-cGMP/PKG-dependent phosphorylation of myofilament proteins are novel targets of nNOS in hypertensive myocardium. In this short review, we will endeavor to overview new findings of the up-stream and downstream regulation of cardiac nNOS in hypertension, shed light on the underlying mechanisms which may be of therapeutic value in hypertensive cardiomyopathy.

Inflammogenesis of Secondary Spinal Cord Injury

Spinal cord injury (SCI) and spinal infarction lead to neurological complications and eventually to paraplegia or quadriplegia. These extremely debilitating conditions are major contributors to morbidity. Our understanding of SCI has certainly increased during the last decade, but remains far from clear. SCI consists of two defined phases: the initial impact causes primary injury, which is followed by a prolonged secondary injury consisting of evolving sub-phases that may last for years. The underlying pathophysiological mechanisms driving this condition are complex. Derangement of the vasculature is a notable feature of the pathology of SCI. In particular, an important component of SCI is the ischemia-reperfusion injury (IRI) that leads to endothelial dysfunction and changes in vascular permeability. Indeed, together with endothelial cell damage and failure in homeostasis, ischemia reperfusion injury triggers full-blown inflammatory cascades arising from activation of residential innate immune cells (microglia and astrocytes) and infiltrating leukocytes (neutrophils and macrophages). These inflammatory cells release neurotoxins (proinflammatory cytokines and chemokines, free radicals, excitotoxic amino acids, nitric oxide (NO)), all of which partake in axonal and neuronal deficit. Therefore, our review considers the recent advances in SCI mechanisms, whereby it becomes clear that SCI is a heterogeneous condition. Hence, this leads towards evidence of a restorative approach based on monotherapy with multiple targets or combinatorial treatment. Moreover, from evaluation of the existing literature, it appears that there is an urgent requirement for multi-centered, randomized trials for a large patient population. These clinical studies would offer an opportunity in stratifying SCI patients at high risk and selecting appropriate, optimal therapeutic regimens for personalized medicine.