Blood pressure increase and incidence of hypertension in relation to inflammation-sensitive plasma proteins

Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications

Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.

Regulatory T-cell subset distribution in children with primary hypertension is associated with hypertension severity and hypertensive target organ damage

BACKGROUND

The relationship between circulating regulatory T-cell (Tregs) subset distribution and hypertension severity in children with primary hypertension is not known. We aimed to find out if target organ damage (TOD) in children with primary hypertension is related to defects in Tregs distribution reflected by their phenotype characteristics.

METHODS

The study constituted 33 nontreated hypertensive children and 35 sex-matched and age-matched controls. Using multicolor flow cytometry technique, we assessed a distribution of the total Tregs (CD4CD25CD127) and their subsets (CD45RA-naive Tregs, CD45RA memory/activated Tregs, CD45RACD31 recent thymic emigrants Tregs and mature naive CD45RACD31 Tregs) in the whole blood.

RESULTS

Hypertensive children showed decreased percentage of the total Tregs, the CD45RA-naive Tregs, the total CD31 Tregs and the recent thymic emigrants Tregs but elevation of the CD45RA memory/activated Treg and mature naive CD45RACD31 Tregs. Decreased frequency of the total Tregs, naive Tregs and CD31-bearing Treg cell subsets (CD31 total Tregs, CD45RACD31 recent thymic emigrants Tregs) negatively correlated to TOD markers, arterial stiffness and blood pressure elevation. In contrast, increased percentage of memory Tregs and CD31 Tregs subsets positively correlated to organ damage markers, arterial stiffness and blood pressure values. These changes were independent of BMI, age, sex and hsCRP.

CONCLUSION

Both diagnosis of hypertension, TOD and arterial stiffness in hypertensive children were associated with decreased population of total CD4 Tregs, limited output of recent thymic emigrants Tregs, and increased pool of activated/memory Tregs. Hypertension was an independent predictor of the circulating Treg subsets distribution irrespective of hsCRP.

The association between hypertension and other cardiovascular risk factors among non-diabetic Saudis adults-A cross sectional study

Population specific associations between cardiovascular disease with various risk factors including pre-hypertension and hypertension were reported. We aimed to investigate the association of higher than optimal blood pressure with measures of dysglycemia, dyslipidemia, and markers of inflammation in non-diabetic Saudi adults hoping to improve current Saudi guidelines to prevent cardiovascular disease. Volunteers were recruited randomly from public healthcare centers in Jeddah. Demographic information, blood pressure (BP), and anthropometric measurements were taken. Fasting blood samples were drawn, then again following 1-hour oral glucose tolerance test. Glycated hemoglobin, fasting plasma glucose (FPG), lipid profile, highly sensitive C- reactive protein, gamma glutamyl transferase, and 1-hour plasma glucose were measured. Complete data was found for 742 men and 592 women. Pre-hypertension was found in 47.2% of men, and 24.7% of women, while 15.1% of men, and 14.6% of women were hypertensive. Means of measured variables differed significantly between normotensive, pre-hypertensive, and hypertensive groups of men and women in gender specific manner. Association between measured variables and elevated BP, and hypertension were assessed using logistic regression models. After adjustment for age, body mass index and waist circumference, elevated blood pressure was associated with elevated triglycerides in men, while hypertension was significantly associated with elevated fasting plasma glucose, total cholesterol, triglycerides, low density lipoprotein- cholesterol, and low high density lipoprotein- cholesterol in men, and elevated triglycerides, and total cholesterol in women. Therefore, it is strongly recommended to measure lipid profile, specifically TG, for all diagnosed pre-hypertensive and hypertensive patients in addition to FPG for men.

Protein Misfolding during Pregnancy: New Approaches to Preeclampsia Diagnostics

Preeclampsia (PE) is a multisystem heterogeneous complication of pregnancy remaining a leading cause of maternal and perinatal morbidity and mortality over the world. PE has a large spectrum of clinical features and symptoms, which make diagnosis challenging. Despite a long period of studying, PE etiology is still unclear and there are no reliable rapid tests for early diagnosis of this disease. During the last decade, it was shown that proteins misfolding and aggregation are associated with PE. Several proteins, including amyloid beta peptide, transthyretin, alpha-1 antitrypsin, albumin, IgG k-free light chains, and ceruloplasmin are dysregulated in PE, resulting in toxic deposition of amyloid-like aggregates in the placenta and body fluids. It is also possible that aggregated proteins induce defective trophoblast invasion, placental ischemia, ER stress, and promote PE manifestation. The fact that protein aggregation is an emerging biomarker of PE provides an opportunity to develop new diagnostic approaches based on amyloids special features, such as Congo red (CR) staining and thioflavin T (ThT) enhanced fluorescence.

The bidirectional interaction between the sympathetic nervous system and immune mechanisms in the pathogenesis of hypertension

Over the last few years, evidence has accumulated to suggest that hypertension is, at least in part, an immune-mediated inflammatory disorder. Many links between immunity and hypertension have been established and provide a complex framework of mechanistic interactions contributing to the rise in BP. These include immune-mediated inflammatory processes affecting regulatory brain nuclei and interactions with other mediators of cardiovascular regulation such as the sympathetic nervous system. Sympathoexcitation differentially regulates T-cells based upon activation status of the immune cell as well as the resident organ. Exogenous and endogenous triggers activate signalling pathways in innate and adaptive immune cells resulting in pro-inflammatory cytokine production and activation of T-lymphocytes in the cardiovascular and renal regions, now considered major factors in the development of essential hypertension. The inflammatory cascade is sustained and exacerbated by the immune flow via the brain-bone marrow-spleen-gastrointestinal axis and thereby further aggravating immune-mediated pathways resulting in a vicious cycle of established hypertension and target organ damage. This review summarizes the evidence and recent advances in linking immune-mediated inflammation, sympathetic activation and their bidirectional interactions with the development of hypertension. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Inflammation, Immunity, and Oxidative Stress in Hypertension-Partners in Crime?

Hypertension is considered as the most common risk factor for cardiovascular disease. Inflammatory processes link hypertension and cardiovascular disease, and participate in their pathophysiology. In recent years, there has been an increase in research focused on unraveling the role of inflammation and immune activation in development and maintenance of hypertension. Although inflammation is known to be associated with hypertension, whether inflammation is a cause or effect of hypertension remains to be elucidated. This review describes the recent studies that link inflammation and hypertension and demonstrate the involvement of oxidative stress and endothelial dysfunction-two of the key processes in the development of hypertension. Etiology of hypertension, including novel immune cell subtypes, cytokines, toll-like receptors, inflammasomes, and gut microbiome, found to be associated with inflammation and hypertension are summarized and discussed. Most recent findings in this field are presented with special emphasis on potential of anti-inflammatory drugs and statins for treatment of hypertension.

Acute phase proteins as prospective risk markers for arterial stiffness: The Malmö Diet and Cancer cohort

BACKGROUND AND OBJECTIVES

Arterial stiffness plays a significant role in the development and progression of adverse cardiovascular events and all-cause mortality. This observational study aims to explore the relationship between six acute phase proteins namely, ceruloplasmin, alpha-1-antitrypsin, orosomucoid, haptoglobin, complement C3 and C-reactive protein (CRP), and carotid-femoral pulse wave velocity (c-f PWV) in a population-based cohort, and to also explore the effect of low-grade inflammation on the relationship between diabetes and c-f PWV.

METHOD

The study consisted of participants from the Malmö Diet and Cancer study with data from baseline examinations (1991-1994) and follow-up examinations (2007-2012). Arterial stiffness was measured at follow-up by determining c-f PWV. After excluding participants with missing data, the total study population included 2338 subjects. General linear models were used to assess the relationship between baseline acute phase proteins and c-f PWV.

RESULTS

After adjusting for traditional risk factors the participants in the 4th quartile vs 1st quartile of alpha-1-antitrypsin (geometric mean: 10.32 m/s vs 10.04 m/s) (p<0.05), C3 (10.35 m/s vs 10.06 m/s) (p<0.05) and CRP (10.37 m/s vs 9.96 m/s) (p<0.001) showed significant association with c-f PWV. Diabetes at follow-up was also associated with high c-f PWV, however, this relationship was independent of low grade inflammation.

CONCLUSION

Alpha-1-antitrypsin, C3 and CRP are associated with arterial stiffness. The results indicate that low grade inflammation is associated with arterial stiffness in addition to established cardiovascular risk factors.

Incidence of Myocardial Infarction and Death in Relation to Walking-Induced Calf Pain and Plasma Levels of Inflammation-Sensitive Proteins

Walking-induced calf pain as well as levels of different inflammation-sensitive plasma proteins (ISPs) are related to cardiovascular disease (CVD). This prospective cohort study explored the relationship between ISPs and walking-related calf pain and the interrelationships between ISPs and calf pain in the prediction of death and incidence of coronary events (CE). In 5,725 apparently healthy men, 46 ±3.0 years old, plasma concentrations of orosomucoid (a1-acid glycoprotein), a1-antitrypsin, haptoglobin, fibrinogen, and ceruloplasmin were measured. Walking-induced calf pain was assessed by questionnaire. Mortality and incidence of CE were monitored over a mean follow-up of 18 years in subjects defined by the presence of calf pain and ISP level (0 to 1 or 2 to 5 ISP(s) in the top quartile). The prevalence of calf pain (7.3%) was significantly related to age, lifestyle, and traditional risk factors of CVD and ISP levels. The risk factor-adjusted relative risks for CE, CVD- and all-cause mortality were 1.89 (CI: 1.27 to 2.82), 2.90 (CI: 1.82 to 4.62), and 2.67 (CI: 1.97 to 3.57), respectively, for men with calf pain and high ISP levels (reference: no calf pain and low ISP levels). The corresponding risk for those with calf pain and low ISP levels were 1.34 (CI: 0.91 to 1.97), 1.47 (CI: 0.90 to 2.41), and 1.31 (CI: 0.95 to 1.81), respectively. These results indicate, on the one hand, that walking-induced calf pain is associated with high ISP levels and, on the other, that the risk of CVD in men with calf pain is substantially higher in those with high ISP levels than in those with low levels.

Recent advances in central cardiovascular control: sex, ROS, gas and inflammation

The central nervous system (CNS) in concert with the heart and vasculature is essential to maintaining cardiovascular (CV) homeostasis. In recent years, our understanding of CNS control of blood pressure regulation (and dysregulation leading to hypertension) has evolved substantially to include (i) the actions of signaling molecules that are not classically viewed as CV signaling molecules, some of which exert effects at CNS targets in a non-traditional manner, and (ii) CNS locations not traditionally viewed as central autonomic cardiovascular centers. This review summarizes recent work implicating immune signals and reproductive hormones, as well as gasotransmitters and reactive oxygen species in the pathogenesis of hypertension at traditional CV control centers. Additionally, recent work implicating non-conventional CNS structures in CV regulation is discussed.

Increased plasma level of soluble urokinase plasminogen activator receptor is associated with incidence of heart failure but not atrial fibrillation

AIMS

Soluble urokinase plasminogen activator receptor (suPAR) in plasma is a novel inflammatory marker thought to be released from the cell surface of neutrophils, T cells, and macrophages. Other inflammatory markers, mainly acute phase proteins produced in the liver, have been associated with the incidence of heart failure (HF) and atrial fibrillation (AF). We investigated the association between suPAR and incident HF and AF in a population-based cohort.

METHODS AND RESULTS

Soluble urokinase plasminogen activator receptor was measured in 4530 subjects (aged 46–68 years, 61% women), who participated in the Malmö Diet and Cancer study during 1991–1996. Incident cases of HF and AF were identified from the Swedish hospital discharge register during a median follow-up of 16.3 years. During follow-up, 109 subjects (55% men) were diagnosed with new-onset HF and 321 individuals (50% men) with AF. suPAR was significantly associated with increased plasma levels of NT-proBNP (P<0.001). suPAR was significantly associated with incidence of HF [hazard ratio (HR) for the third vs. first tertile 3.33, 95% confidence interval (CI) 1.91–5.81 after adjustment for age and sex; and HR 1.82, 95% CI 1.02–3.27, P for trend 0.018 after adjustment for conventional risk factors and biomarkers]. suPAR was significantly associated with incidence of AF, when adjusted for age and sex (HR 1.40, 95% CI 1.06–1.85). However, this relationship was non-significant after adjustment for conventional risk factors and biomarkers.

CONCLUSION

Soluble urokinase plasminogen activator receptor was associated with increased plasma levels of NT-proBNP and incidence of HF, but not with AF among middle-aged subjects.

Immunity in arterial hypertension: associations or causalities?

Numerous studies describe associations between markers of inflammation and arterial hypertension (aHT), but does that imply causality? Interventional studies that reduce blood pressure reduced also markers of inflammation, but does immunosuppression improve hypertension? Here, we review the available mechanistic data. Aberrant immunity can trigger endothelial dysfunction but is hardly ever the primary cause of aHT. Innate and adaptive immunity get involved once hypertension has caused vascular wall injury as immunity is a modifier of endothelial dysfunction and vascular wall remodelling. As vascular remodelling progresses, immunity-related mechanisms can become significant cofactors for cardiovascular (CV) disease progression; vice versa, suppressing immunity can improve hypertension and CV outcomes. Innate and adaptive immunity both contribute to vascular wall remodelling. Innate immunity is driven by danger signals that activate Toll-like receptors and other pattern-recognition receptors. Adaptive immunity is based on loss of tolerance against vascular autoantigens and includes autoreactive T-cell immunity as well as non-HLA angiotensin II type 1 receptor-activating autoantibodies. Such processes involve numerous other modulators such as regulatory T cells. Together, immunity is not causal for hypertension but rather an important secondary pathomechanism and a potential therapeutic target in hypertension.

The immunological basis of hypertension

A large number of investigations have demonstrated the participation of the immune system in the pathogenesis of hypertension. Studies focusing on macrophages and Toll-like receptors have documented involvement of the innate immunity. The requirements of antigen presentation and co-stimulation, the critical importance of T cell-driven inflammation, and the demonstration, in specific conditions, of agonistic antibodies directed to angiotensin II type 1 receptors and adrenergic receptors support the role of acquired immunity. Experimental findings support the concept that the balance between T cell-induced inflammation and T cell suppressor responses is critical for the regulation of blood pressure levels. Expression of neoantigens in response to inflammation, as well as surfacing of intracellular immunogenic proteins, such as heat shock proteins, could be responsible for autoimmune reactivity in the kidney, arteries, and central nervous system. Persisting, low-grade inflammation in these target organs may lead to impaired pressure natriuresis, an increase in sympathetic activity, and vascular endothelial dysfunction that may be the cause of chronic elevation of blood pressure in essential hypertension.

Beneficial effects of renal sympathetic denervation on cardiovascular inflammation and remodeling in essential hypertension

BACKGROUND

Renal sympathetic denervation (RSD) represents a potential treatment option for certain patients with resistant arterial hypertension (HT). HT is associated with chronic vascular inflammation and remodeling, contributing to progressive vascular damage, and atherosclerosis. The present study aimed to evaluate the influence of RSD on cardiovascular inflammation and remodeling by determining serum levels of interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP), matrix metalloproteinases (MMP), and tissue inhibitor of metalloproteinases (TIMP).

METHODS

A total of 60 consecutive patients (age 67.9 ± 9.6 years) undergoing RSD were included. A therapeutic response was defined as an office systolic blood pressure (SBP) reduction of >10 mmHg 6 months after RSD. Venous serum samples for measurement of hsCRP, IL-6, MMP-2, MMP-9, and TIMP-1 were collected prior to and 6 months after RSD.

RESULTS

A significant reduction in office SBP of 26.4 mmHg [SBPbaseline 169.3 mmHg (SD 11.3), p < 0.001] was documented 6 months after RSD. The serum levels of hsCRP (p < 0.001) and the pro-inflammatory cytokine IL-6 (p < 0.001) were significantly decreased compared to baseline values. The levels of MMP-9 (p = 0.024) and MMP-2 (p < 0.01) were significantly increased compared to baseline values.

CONCLUSION

In addition to the effective blood pressure reduction in response to RSD, this study demonstrates a positive effect of RSD on biomarkers reflecting vascular inflammation and remodeling. These results suggest a possible prognostic benefit of RSD in high-risk patients for endothelial dysfunction and cardiovascular remodeling as well as end-organ damage.

Comparative effects of nebivolol and metoprolol on red cell distribution width and neutrophil/lymphocyte ratio in patients with newly diagnosed essential hypertension

High level of circulating red cell distribution width (RDW) and neutrophil/lymphocyte (N/L) ratio may reflect ongoing vascular inflammation and play an important role in pathophysiology of hypertension. We evaluate the effects of nebivolol and metoprolol on the RDW and N/L in new essential hypertensive patients. After baseline assessment, 72 patients were randomly allocated to 5 mg/d of nebivolol (n = 37, 20 men) or 100 mg/d of metoprolol (n = 35, 18 men) and treated for 6 months. Blood pressure (BP), heart rate (HR), RDW, and N/L were measured before and after treatment. BP significantly decreased with both drugs (P < 0.001). Analog reduction was observed for resting HRs (P < 0.001), but metoprolol caused greater HR fall as compared with nebivolol (P < 0.001). After 6 months of treatment, nebivolol significantly lowered not only RDW but also the total white blood cell and N/L (P < 0.001, P = 0.023, P = 0.017, respectively). No changes were observed in metoprolol group. Percent decrease in RDW was found to be significantly higher in nebivolol than in the metoprolol group (P = 0.001) and remained also after correction for confounders (P = 0.012). Nebivolol improved RDW and N/L to a greater extent than metoprolol in patients with hypertension. These favorable effects may participate, together with the BP reduction, at the favorable properties of the drug in hypertension.

Increased platelet activation and inflammatory response in patients with masked hypertension

Masked hypertension is associated with an increase in cardiovascular risk. Mean platelet volume (MPV), a determinant of platelet function, is a new risk factor for atherothrombosis. High-sensitive C-reactive protein (CRP) is an exquisitely sensitive systemic marker of inflammatory response. We designed this study to evaluate MPV and CRP in masked hypertensive patients and to compare those with essential hypertensive and healthy normotensive individuals. Forty-two untreated masked hypertensive patients, 53 untreated essential hypertensive patients and age-sex matched 37 normotensive healthy individuals were included in the study. Blood samples were collected and haematological parameters were measured. Plasma CRP level was measured by immunonephelometery method. The MPV was significantly higher in masked hypertensive (8.8 ± 1.6 fl) and essential hypertensive patients (9.1 ± 1.7 fl) than those of normotensive control individuals (7.8 ± 0.8 fl) (P = 0.01 and P = 0.003, respectively), whereas there was no significant difference between the masked hypertensive and essential hypertensive individuals (P > 0.05). CRP levels were also significantly higher in masked hypertensive patients than in normotensives individuals (3.31 ± 1.70, 1.98 ± 1.56 mg/l, P < 0.001, respectively). There was a significant positive correlation between MPV and CRP levels (P < 0.001, r = 0.850) in masked hypertensive patients. Patients with masked hypertension have higher MPV and CRP values than controls. Increased MPV and CRP levels may be the possible mechanisms behind the increased cardiovascular risk in masked hypertensive patients.

Emerging new biomarkers of preeclampsia

Preeclampsia continues to plague some of the most vulnerable women and fetuses. It is surprisingly prevalent in developing and developed nations. According to the World Health Organization, hypertension during pregnancy is a leading cause of maternal mortality in industrialized countries at 16% and up to 25% in developing countries. As the pathogenesis of this disease is being unraveled, we are afforded new opportunities to develop novel biomarkers for early identification and prevention of disease. The angiogenic markers including soluble fms-like tyrosine kinase 1, placental growth factor, and soluble endoglin have demonstrated to be the most promising, perhaps in conjunction with traditional markers such as plasma protein-13 and uterine artery Doppler studies. There is also increasing evidence that the podocyte is shed during the course of preeclampsia, which may be useful for diagnosis. Systems biology approaches to biomarker discovery such as proteomics and metabolomics are also gaining more attention and will most certainly open new avenues of research. In this review, we present the best studied biomarkers of preeclampsia to date.

Neurogenic hypertension and elevated vertebrobasilar arterial resistance: is there a causative link?

There is evidence of sympathetic overdrive in a significant proportion of patients with essential hypertension and an animal model of the condition, the spontaneously hypertensive rat (SHR). The reasons for this remain elusive. However, there is also evidence of narrowing of the arteries supplying the brainstem in the SHR and hypertensive humans. In this review, we discuss the possible role of brainstem hypoperfusion in driving increased sympathetic activity and hypertension.

Vascular inflammation and endothelial dysfunction in experimental hypertension

Essential hypertension is characterized by increased peripheral vascular resistance to blood flow. The endothelium is a crucial regulator of vascular tone. Its function is impaired in patients with hypertension, with reduced vasodilation, increased vascular tone associated with a proinflammatory and prothrombotic state. Low-grade inflammation localized in vascular tissue is therefore recognized as an important contributor to the pathophysiology of hypertension, to the initiation and progression of atherosclerosis as well as to the development of cardiovascular diseases.

Eating disturbance in behavioural-variant frontotemporal dementia

Behavioural-variant frontotemporal dementia (bvFTD) is a progressive neurodegenerative brain disorder, clinically characterised by changes in cognition, personality and behaviour. Marked disturbances in eating behaviour, such as overeating and preference for sweet foods, are also commonly reported. This paper reviews the current literature on eating abnormalities in bvFTD, their clinical characteristics and biological correlates, and the contribution of hypothalamus to eating regulation. Existing literature shows that disturbance in an orbitofrontal-insular-striatal brain network underlies the emergence of eating disturbance in bvFTD. In addition, recent evidence indicates that degeneration and consequent dysregulation within the hypothalamus relates to significant feeding disturbance in this disease. These findings could provide a basis for the development of therapeutic models in bvFTD.

Urinary proteomics analysis for renal injury in hypertensive disorders of pregnancy with iTRAQ labeling and LC-MS/MS

PURPOSE

As a noninvasive examination, urinary proteomics is a very useful tool to identify renal disease. The purpose of the present study was to find differential proteins among women with preeclampsia, gestational hypertension and normal pregnancy, and to screen potential biomarkers for the early diagnosis of preeclampsia.

EXPERIMENTAL DESIGN

Urinary proteins were identified by iTRAQ labeling coupled with 2-D LC-MS/MS. The bioinformatics analysis was performed with the Metacore software and the International Protein Index (IPI) and the Gene Ontology (GO) Database. The differentially expressed proteins were verified by ELISA.

RESULTS

362 nonredundant proteins were identified, 113 of which were expressed differentially between preeclampsia and normal pregnant group and 31 differential proteins among three groups. These differential proteins were associated with biological processes of blood coagulation, cell adhesion and differentiation, immune response and cytoskeleton development, etc. They interacted with each other in the network. The urinary angiotensinogen (AGT) was downregulated, which was consistent with the ELISA validation results.

CONCLUSIONS AND CLINICAL RELEVANCE

The present study found a multitude of differential proteins that might provide a clue for investigating the mechanism of proteinuria development in preeclampsia. Low urinary angiotensinogen levels were useful for identifying preeclampsia.

Transcriptome profiling and network analysis of genetically hypertensive mice identifies potential pharmacological targets of hypertension

Hypertension is a condition with major cardiovascular and renal complications, affecting nearly a billion patients worldwide. Few validated gene targets are available for pharmacological intervention, so there is a need to identify new biological pathways regulating blood pressure and containing novel targets for treatment. The genetically hypertensive “blood pressure high” (BPH), normotensive “blood pressure normal” (BPN), and hypotensive “blood pressure low” (BPL) inbred mouse strains are an ideal system to study differences in gene expression patterns that may represent such biological pathways. We profiled gene expression in liver, heart, kidney, and aorta from BPH, BPN, and BPL mice and determined which biological processes are enriched in observed organ-specific signatures. As a result, we identified multiple biological pathways linked to blood pressure phenotype that could serve as a source of candidate genes causal for hypertension. To distinguish in the kidney signature genes whose differential expression pattern may cause changes in blood pressure from those genes whose differential expression pattern results from changes in blood pressure, we integrated phenotype-associated genes into Genetic Bayesian networks. The integration of data from gene expression profiling and genetics networks is a valuable approach to identify novel potential targets for the pharmacological treatment of hypertension.

Enhanced blood pressure variability in a high cardiovascular risk group of African Americans: FIT4Life Study

High blood pressure (BP) levels in African Americans elicit vascular inflammation resulting in vascular remodeling. BP variability (BPV) correlates with target organ damage. We aimed to investigate the relationship between inflammatory markers and BPV in African Americans. Thirty-six African Americans underwent 24-hour ambulatory BP monitoring (ABPM). BPV was calculated using the average real variability index. Fasting blood samples were assayed for high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), and white blood cell (WBC) count. Significant associations between hs-CRP and 24-hour systolic variability (r=0.50; P=.012) and awake systolic variability (r=0.45; P=.02) were identified after adjusting for age, body mass index, and 24-hour mean BP. ABPM variables were compared between the hs-CRP tertile groups. In post-hoc analysis, there was a significant difference in 24-hour and awake periods for both systolic and diastolic variability among the groups. TNF-alpha and WBC count showed no associations with ABPM variables. hs-CRP was associated with systolic variability, and higher levels of hs-CRP were related with greater BPV. Higher inflammatory status influences wider fluctuations in systolic BP, which in turn could facilitate early progression to target organ damage independent of absolute BP levels in African Americans.

Fibrinogen kinetics and protein turnover in hypertension: Effects of insulin

BACKGROUND AND AIM

Hyperfibrinogenemia, a cardiovascular risk factor, is frequent in hypertension and largely unexplained. In this study, we measured fibrinogen production and whole-body protein turnover under both basal and hyperinsulinemic states, in hypertensive [H] and control [C] subjects, using a leucine stable isotope tracer and precursor-product relationships.

METHODS AND RESULTS

Since hypertension is often a feature of the "metabolic", insulin resistance syndrome, which in turn affects both fibrinogen kinetics and whole-body protein turnover, we selected hypertensive subjects without the metabolic syndrome. Following basal measurements, an euglycemic, approximately euaminoacidemic, hyperinsulinemic clamp was performed, with plasma insulin raised to 700-900 pmol/L. In H, rates of the fractional and absolute synthesis (FSR and ASR, respectively) of fibrinogen were 30%-40% greater (p<0.05 or less) than in C in both states, whereas leucine turnover was normal. Hyperinsulinemia did not modify fibrinogen synthesis in either group with respect to baseline, whereas it suppressed leucine appearance from endogenous proteolysis by approximately 40% to same extent in both groups. Amino acid clearance was similar in both the H and C subjects. In H, the insulin-mediated glucose disposal (M) was approximately 25% lower, (although insignificantly) than in controls, showing no overall insulin resistance. There was an inverse correlation between M and fibrinogen FSR during the clamp.

CONCLUSIONS

In essential hypertension fibrinogen production is increased, is not further stimulated by insulin, and is inversely related to insulin sensitivity at high-physiological insulin concentrations. Amino acid disposal and basal as well as insulin-responsive protein degradation rates are instead normal.

The American Journal of Cardiology and Journal of Periodontology editors' consensus: periodontitis and atherosclerotic cardiovascular disease

ACKNOWLEDGMENT

This Editors' Consensus is supported by an educational grant from Colgate-Palmolive, Inc., New York, New York, and is based on a meeting of the authors held in Boston, Massachusetts, on January 9, 2009.

DISCLOSURE

Dr. Friedewald has received honoraria for speaking from Novartis, East Hanover, New Jersey. Dr. Kornman is a full-time employee and shareholder of Interleukin Genetics, Waltham, Massachusetts, which owns patents on genetic biomarkers for chronic inflammatory diseases. Dr. Genco is a consultant to Merck, Whitehouse Station, New Jersey. Dr. Ridker has received research support from AstraZeneca, Wilmington, Delaware; Novartis; Pfizer, New York, New York; Roche, Nutley, New Jersey; Sanofi-Aventis, Bridgewater, New Jersey; and Abbott Laboratories, Abbott Park, Illinois. Dr. Ridker has received non-financial research support from Amgen, Thousand Oaks, California. Dr. Ridker is a co-inventor on patents held by Brigham and Women's Hospital that relate to the use of inflammatory biomarkers in cardiovascular disease. Dr. Ridker is a research consultant for Schering-Plough, Kenilworth, New Jersey; Sanofi-Aventis; AstraZeneca; Isis, Carlsbad, California; Novartis; and Vascular Biogenics, Tel Aviv, Israel. Dr. Van Dyke is a co-inventor on patents held by Boston University, Boston, Massachusetts, that relate to inflammation control, including consulting fees. Dr. Roberts has received honoraria for speaking from Merck, Schering-Plough, AstraZeneca, and Novartis. All other individuals in a position to control content disclosed no relevant financial relationships.

Genetic variation in the fibrinogen-alpha and fibrinogen-gamma genes in relation to arterial stiffness: the Rotterdam Study

OBJECTIVE

Arterial stiffness increases with age and predicts cardiovascular disease. Fibrinogen is an acute-phase protein and some studies showed an association with arterial stiffness. We studied genetic variation in the fibrinogen-alpha (FGA) and fibrinogen-gamma (FGG) genes, by means of single nucleotide polymorphisms (FGA: -58 G/A, 1374 G/A, 1526 T/C, 312 Thr/Ala, and FGG: 4288 G/A, 6326 G/A, 7792 T/C) and resultant haplotypes in relation to arterial stiffness.

METHODS

The present study (n = 3891) was embedded in the Rotterdam Study. Associations of the fibrinogen level, genotypes and haplotypes with aortic stiffness (pulse wave velocity), carotid stiffness (distensibility coefficient) and pulse pressure were investigated in men and women by analyses of variance, linear regression and by haplotype analyses. Analyses were adjusted for age, mean arterial pressure, heart rate, known cardiovascular risk factors and atherosclerosis.

RESULTS

Genotype analyses yielded associations of FGA-58 G/A (P = 0.040, for trend) and FGA-1526 T/C (P = 0.004, for trend) with the fibrinogen levels, but no consistent associations with arterial stiffness, in women. FGA-haplotype 4 was associated with the fibrinogen level (P = 0.02) in women. FGA-haplotype 3 and FGG-haplotype 2 were associated with aortic stiffness (P = 0.05) in women. No associations were found in men.

CONCLUSION

Findings indicate that the fibrinogen level and genetic variation in the FGA and FGG genes may influence arterial stiffness in women.

Prediction of incident hypertension risk in women with currently normal blood pressure

BACKGROUND

We examined whether a hypertension risk prediction model based on clinical characteristics and blood biomarkers might improve on risk prediction based on current blood pressure alone.

METHODS

A prospective cohort of 14,822 normotensive women aged 45 years and older were followed over 8 years beginning in 1992 for the development of hypertension. Among a randomly selected two-thirds sample (N=9427), hypertension prediction models were developed using 52 potential predictors and compared with a model based on blood pressure alone. Each prediction model was validated in the remaining one third (N=5395).

RESULTS

In the development cohort, the best prediction model for incident hypertension included age, blood pressure, ethnicity, body mass index, total grain intake, apolipoprotein B, lipoprotein(a), and C-reactive protein (Bayes Information Criteria [BIC]=8788). Although this model was superior to a model based on blood pressure alone (BIC=8957), it was only marginally better than a simplified model including age, blood pressure, ethnicity, and body mass index (BIC=8820). In the validation cohort, the simplified model demonstrated adequate calibration, a c-index similar to that of the best model (0.703 vs 0.705), and when compared with the model based on blood pressure alone, reclassified 1499 participants to hypertension risk categories that proved to be closer to observed risk in all but one instance.

CONCLUSION

In this prospective cohort of initially normotensive women, a model based on readily available clinical information predicted incident hypertension better than a model based on blood pressure alone.

Relations of biomarkers representing distinct biological pathways to left ventricular geometry

BACKGROUND

Several biological pathways are activated concomitantly during left ventricular (LV) remodeling. However, the relative contribution of circulating biomarkers representing these distinct pathways to LV geometry is unclear.

METHODS AND RESULTS

We evaluated 2119 Framingham Offspring Study participants (mean age, 57 years; 57% women) who underwent measurements of biomarkers of inflammation (C-reactive protein), hemostasis (fibrinogen and plasminogen activator inhibitor-1), neurohormonal activation (B-type natriuretic peptide), and renin-angiotensin-aldosterone system (aldosterone and renin modeled as a ratio [ARR]) and echocardiography at a routine examination. LV geometry was defined on the basis of sex-specific distributions of LV mass (LVM) and relative wall thickness (RWT): normal (LVM and RWT <80th percentile), concentric remodeling (LVM <80th percentile but RWT >or=80th percentile), eccentric hypertrophy (LVM >or=80th percentile but RWT <80th percentile), and concentric hypertrophy (LVM and RWT >or=80th percentile). We related the biomarker panel to LV geometry using polytomous logistic regression adjusting for clinical covariates and used backwards elimination to identify a parsimonious set of biomarkers associated with LV geometry. Modeled individually, C-reactive protein, fibrinogen, plasminogen activator inhibitor-1, and ARR were related to LV geometry (P<0.01). In multivariable analyses, the biomarker panel was significantly related to altered LV geometry (P<0.0001). On backwards elimination, logARR alone was significantly and positively associated with eccentric (odds ratio per SD increment, 1.20; 95% confidence interval, 1.05 to 1.37) and concentric LV hypertrophy (odds ratio per SD increment, 1.29; 95% confidence interval, 1.06 to 1.58).

CONCLUSIONS

Our cross-sectional observations on a large community-based sample identified ARR as a key correlate of concentric and eccentric LV hypertrophy, consistent with a major role for the renin-angiotensin-aldosterone system in LV remodeling.

Proteomic profiling of urine identifies specific fragments of SERPINA1 and albumin as biomarkers of preeclampsia

OBJECTIVE

The cause of preeclampsia remains unknown and the diagnosis can be uncertain. We used proteomic-based analysis of urine to improve disease classification and extend the pathophysiologic understanding of preeclampsia.

STUDY DESIGN

Urine samples from 284 women were analyzed by surface-enhanced laser desorption/ionization. In the exploratory phase, 59 samples were used to extract the proteomic fingerprint characteristic of severe preeclampsia requiring mandated delivery and to develop a diagnostic algorithm. In the challenge phase, we sought to prospectively validate the algorithm in 225 women screened for a variety of high- and low-risk conditions, including preeclampsia. Of these, 19 women were followed longitudinally throughout pregnancy. The presence of biomarkers was interpreted relative to clinical classification, need for delivery, and other urine laboratory measures (ratios of protein to creatinine and soluble fms-like tyrosine kinase-1 to placental growth factor). In the translational phase, biomarker identification by tandem mass spectrometry and validation experiments in urine, serum, and placenta were used to identify, quantify, and localize the biomarkers or related proteins.

RESULTS

We report that women with preeclampsia appear to present a unique urine proteomic fingerprint that predicts preeclampsia in need of mandated delivery with highest accuracy. This characteristic proteomic profile also has the ability to distinguish preeclampsia from other hypertensive or proteinuric disorders in pregnancy. Pregnant women followed longitudinally who developed preeclampsia displayed abnormal urinary profiles more than 10 weeks before clinical manifestation. Tandem mass spectrometry and de novo sequencing identified the biomarkers as nonrandom cleavage products of SERPINA1 and albumin. Of these, the 21 amino acid C-terminus fragment of SERPINA1 was highly associated with severe forms of preeclampsia requiring early delivery. In preeclampsia, increased and aberrant SERPINA1 immunoreactivity was found in urine, serum, and placenta, in which it localized predominantly to placental villi and placental vascular spaces adherent to the endothelium. In addition, significant perivascular deposits of misfolded SERPINA1 aggregates were exclusively identified in preeclamptic placentae.

CONCLUSION

Proteomics-based characterization of urine in preeclampsia identified a proteomic fingerprint composed of SERPINA1 and albumin fragments, which can accurately diagnose preeclampsia and shows promise to discriminate it from other hypertensive proteinuric diseases. These findings provide insight into a novel pathophysiological mechanism of preeclampsia related to SERPINA1 misfolding, which may offer new therapeutic opportunities in the future.

Inflammation-sensitive plasma proteins are associated with increased incidence of heart failure: a population-based cohort study

BACKGROUND

Although inflammation has been associated with different cardiovascular diseases, the relationships with future heart failure (HF) are unclear. This population-based study explored whether elevated plasma levels of inflammatory proteins are associated with incidence of HF.

METHODS

Five inflammation-sensitive plasma proteins (ISPs, fibrinogen, ceruloplasmin, haptoglobin, orosomucoid, and alpha1-antitrypsin) was measured in 6071 men (mean age 46 years) without history of myocardial infarction (MI) or stroke. Incidence of hospitalizations due to HF (primary diagnosis) was monitored over 22 years of follow-up, in relation to the number of elevated ISPs (i.e., in the 4th quartile). Subjects with myocardial infarction during follow-up were censored.

RESULTS

During the follow-up, 159 men were hospitalized due to HF. Baseline levels of all ISPs, except for haptoglobin, were significantly higher in men who developed HF. After adjustments for confounding factors, the hazard ratios (HR) of HF were 1.00 (reference), 1.7 (95% CI: 1.1-2.7), 2.0 (CI: 1.2-3.3) and 2.6 (CI: 1.6-4.1), respectively, in men with none, one, two and three or more ISPs in the 4th quartile (trend: p<0.001). Of the individual ISPs, fibrinogen, ceruloplasmin and alpha1-antitrypsin showed significant relationships with incidence of HF after adjustment for risk factors.

CONCLUSION

Plasma levels of inflammatory markers are associated with long-term incidence of hospitalizations due to HF in middle-aged men.

C-reactive protein, established risk factors and social inequalities in cardiovascular disease - the significance of absolute versus relative measures of disease

Background

The widespread use of relative scales in socioepidemiological studies has recently been criticized. The criticism is based mainly on the fact that the importance of different risk factors in explaining social inequalities in cardiovascular disease (CVD) varies, depending on which scale is used to measure social inequalities. The present study examines the importance of established risk factors, as opposed to low-grade inflammation, in explaining socioeconomic differences in the incidence of CVD, using both relative and absolute scales.

Methods

We obtained information on socioeconomic position (SEP), established risk factors (smoking, hypertension, and hyperlipidemia), and low-grade inflammation as measured by high-sensitive (hs) C-reactive protein (CRP) levels, in 4,268 Swedish men and women who participated in the Malmö Diet and Cancer Study (MDCS). Data on first cardiovascular events, i.e., stroke or coronary event (CE), was collected from regional and national registers. Social inequalities were measured in relative terms, i.e., as ratios between incidence rates in groups with lower and higher SEP, and also in absolute terms, i.e., as the absolute difference in incidence rates in groups with lower and higher SEP.

Results

Those with low SEP had a higher risk of future CVD. Adjustment for risk factors resulted in a rather small reduction in the relative socioeconomic gradient, namely 8% for CRP (≥ 3 mg/L) and 21% for established risk factors taken together. However, there was a reduction of 18% in the absolute socioeconomic gradient when looking at subjects with CRP-levels < 3 mg/L, and of 69% when looking at a low-risk population with no smoking, hypertension, or hyperlipidemia.

Conclusion

C-reactive protein and established risk factors all contribute to socioeconomic differences in CVD. However, conclusions on the importance of "modern" risk factors (here, CRP), as opposed to established risk factors, in the association between SEP and CVD depend on the scale on which social inequalities are measured. The one-sided use of the relative scale, without including a background of absolute levels of disease, and of what causes disease, can consequently prevent efforts to reduce established risk factors by giving priority to research and preventive programs looking in new directions.

Endothelial progenitor cells, endothelial dysfunction, inflammation, and oxidative stress in hypertension

With a prevalence in excess of 20%, hypertension is a common finding among Western adult populations. Hypertension is directly implicated in the pathophysiology of various cardiovascular disease states and is a significant contributor to ill health, leading to an excess of both morbidity and mortality. The etiology of hypertension has been explored in depth, but the pathophysiology is multifactorial, complex, and poorly understood. Recent interest has been directed toward investigating the purported role of the endothelium, which acts as an important regulator of vascular homeostasis. Endothelial dysfunction is now recognized to occur in hypertension, regardless of whether the etiology is essential or secondary to endocrine or renal processes. Nitric oxide (NO) is a volatile gas produced by endothelial cells that acts to maintain vascular tone. Reduced bioavailability of NO appears to be the key process through which endothelial dysfunction is manifested in hypertension. The result is of an imbalance of counteracting mechanisms, normally designed to maintain vascular homeostasis, leading to vasoconstriction and impaired vascular function. It has become increasingly apparent that these changes may be effected in response to enhanced oxidative stress, possibly as a result of systemic and localized inflammatory responses. This article provides an overview of endothelial dysfunction in hypertension and focuses on the purported role of oxidative stress and inflammation as the catalysts for this process.