Inflammation, immunity, and hypertension

Renal inflammatory markers during the onset of hypertension in spontaneously hypertensive rats

Early blockade of the renin-angiotensin system is successful in delaying the development of hypertension in spontaneously hypertensive rats (SHRs) and ameliorating organ damage by inhibition of the inflammatory response. In this study, we investigated the role of the angiotensin II type 1 receptor (AT1R) in the early renal inflammatory response in SHR. Blood pressure development and renal inflammatory markers were measured in 4-, 8- and 12-week-old SHR and age-matched Wistar Kyoto (WKY) rats. Separate groups of SHRs were transiently treated with the AT1R blocker losartan between 4 and 8 weeks of age. Urinary excretion of the renal injury markers osteopontin and neutrophil gelatinase-associated lipocalin increased in young SHR. Further, renal expression of inflammatory genes was also increased in young SHR. Losartan inhibited the increase of these inflammatory markers. In contrast, gene expression of the renal injury marker and T-cell inducer kidney injury molecule-1 (KIM-1) was reduced in 4-week-old SHR when compared with WKY. Similarly, the T-cell marker CD3 was significantly decreased in 4-week-old SHR. These effects were not antagonized by AT1R blockade. This study confirms the presence of an early renal inflammatory response in SHR that can be blocked by AT1R antagonism. In addition, it demonstrates that KIM-1 does not behave as a pure kidney injury marker in young SHR, but may reflect kidney maturation.

Angiotensin receptor agonistic autoantibodies and hypertension: preeclampsia and beyond

Hypertensive disorders are life-threatening diseases with high morbidity and mortality, affecting billions of individuals worldwide. A multitude of underlying conditions may contribute to hypertension, thus the need for a plethora of treatment options to identify the approach that best meets the needs of individual patients. A growing body of evidence indicates that (1) autoantibodies that bind to and activate the major angiotensin II type I (AT₁) receptor exist in the circulation of patients with hypertensive disorders, (2) these autoantibodies contribute to disease pathophysiology, (3) antibody titers correlate to the severity of the disease, and (4) efforts to block or remove these pathogenic autoantibodies have therapeutic potential. These autoantibodies, termed AT₁ agonistic autoantibodies have been extensively characterized in preeclampsia, a life-threatening hypertensive condition of pregnancy. As reviewed here, these autoantibodies cause symptoms of preeclampsia when injected into pregnant mice. Somewhat surprisingly, these auto antibodies also appear in 3 animal models of preeclampsia. However, the occurrence of AT₁ agonistic autoantibodies is not restricted to pregnancy. These autoantibodies are prevalent among kidney transplant recipients who develop severe transplant rejection and malignant hypertension during the first week after transplantation. AT₁ agonistic autoantibodies are also highly abundant among a group of patients with essential hypertension that are refractory to standard therapy. More recently these autoantibodies have been seen in patients with the autoimmune disease, systemic sclerosis. These 3 examples extend the clinical impact of AT₁ agonistic autoantibodies beyond pregnancy. Research reviewed here raises the intriguing possibility that preeclampsia and other hypertensive conditions are autoimmune diseases characterized by the presence of pathogenic autoantibodies that activate the major angiotensin receptor, AT₁. These pathogenic autoantibodies could serve as presymptomatic biomarkers and therapeutic targets, thereby providing improved medical management for these conditions.

Fimasartan, anti-hypertension drug, suppressed inducible nitric oxide synthase expressions via nuclear factor-kappa B and activator protein-1 inactivation

Since inhibition of angiotensin II type 1 (AT1) receptor reduces chronic inflammation associated with hypertension, we evaluated the anti-inflammatory potential and the underlying mechanism of fimasartan, a Korean Food and Drug Administration approved anti-hypertension drug, in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Fimasartan suppressed the expressions of inducible nitric oxide synthase (iNOS) by down-regulating its transcription, and subsequently inhibited the productions of nitric oxide (NO). In addition, fimasartan attenuated LPS-induced transcriptional and DNA-binding activities of nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1). These reductions were accompanied by parallel reductions in the nuclear translocation of NF-κB and AP-1. Taken together, our data suggest that fimasartan down-regulates the expression of the iNOS in macrophages via NF-κB and AP-1 inactivation.

Salt-sensitive hypertension in mitochondrial superoxide dismutase deficiency is associated with intra-renal oxidative stress and inflammation

BACKGROUND

Renal interstitial inflammation and oxidative stress are invariably present and play a key role in the pathogenesis of hypertension in experimental animals. Mitochondria are the major source of reactive oxygen species (ROS). ROS generated in the mitochondria are normally contained by the mitochondrial antioxidant system including manganese superoxide dismutase (MnSOD). We have previously shown that a high salt diet causes hypertension in MnSOD-deficient (MnSOD(+/-)) mice but not in wild-type mice. The present study was undertaken to determine the effect of a high salt diet on oxidative and inflammatory pathways in the kidneys of MnSOD(+/-) mice compared to the wild-type mice.

METHODS

Wild-type (MnSOD(+/+)) and MnSOD(+/-) mice were randomized to receive a regular or a high salt diet for 4 months. Tail arterial pressure was measured and timed urine collection was obtained. The animals were then euthanized and the kidneys were harvested and processed for histological examination and Western blot analyses.

RESULTS

In confirmation of our earlier study, a high salt diet resulted in a significant rise in arterial pressure and urinary albumin excretion in MnSOD(+/-) mice. This was accompanied by upregulation of NAD(P)H oxidase subunits, activation of nuclear factor kappa B, and elevation of PAI-1, iNOS, oxidized LDL receptor, and CD36 in the kidneys of the MnSOD(+/-) mice fed the high salt diet. In contrast, consumption of a high salt diet did not significantly alter blood pressure, urine protein excretion, or the measured oxidative and inflammatory mediators in the wild-type mice.

CONCLUSION

Salt-induced hypertension in MnSOD(+/-) mice is associated with activation of intra-renal inflammatory and ROS generating pathways.

Influence of genetic variations on levels of inflammatory markers of healthy subjects at baseline and one week after clopidogrel therapy; results of a preliminary study

We aimed to assess the association between the most common polymorphisms of cytochrome P450 (CYP) epoxygenases on the plasma levels of inflammatory markers in a population of healthy subjects. We also sought to determine whether CYP2C19*2 polymorphism is associated with the anti-inflammatory response to clopidogrel. In a population of 49 healthy young males, the baseline plasma levels of inflammatory markers including C-reactive protein, haptoglobin, orosomucoid acid, CD-40 were compared in carriers vs. non-carriers of the most frequent CYP epoxygenase polymorphisms: CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C8*2 and CYP2J2*7. Also, the variation of inflammatory markers from baseline to 7 days after administration of 75 mg per day of clopidogrel were compared in carriers vs. non-carriers of CYP2C19* allele and also in responders vs. hypo-responders to clopidogrel, determined by platelet reactivity tests. There was no significant association between epoxygenase polymorphisms and the baseline levels of inflammatory markers. Likewise, CYP2C19* allele was not associated with anti-inflammatory response to clopidogrel. Our findings did not support the notion that the genetic variations of CYP epoxygenases are associated with the level of inflammatory markers. Moreover, our results did not support the hypothesis that CYP2C19*2 polymorphism is associated with the variability in response to the anti-inflammatory properties of clopidogrel.

Primary hypertension in children and adolescents is an immuno-metabolic disease with hemodynamic consequences

With the rise in obesity epidemic primary hypertension (PH) is now one of the most common chronic diseases in adolescence. In contrast to hypertensive adults, hypertensive children usually are not exposed to other comorbidities such as diabetes, chronic kidney disease and atherosclerosis. Thus, PH in children and adolescents can be treated as the early stage of development of cardiovascular disease. There is increasing amount of data indicating that PH is not only hemodynamic phenomenon but a complex syndrome involving disturbed activity of sympathetic nervous system, metabolic abnormalities and activation of innate and adaptive immune system. We discuss results of the studies on clinical, metabolic and immunological phenotype of hypertensive children, associations between metabolic and immunological abnormalities with target organ damage and results of antihypertensive treatment.

Dysfunctional brain-bone marrow communication: a paradigm shift in the pathophysiology of hypertension

It is widely accepted that the pathophysiology of hypertension involves autonomic nervous system dysfunction, as well as a multitude of immune responses. However, the close interplay of these systems in the development and establishment of high blood pressure and its associated pathophysiology remains elusive and is the subject of extensive investigation. It has been proposed that an imbalance of the neuro-immune systems is a result of an enhancement of the "proinflammatory sympathetic" arm in conjunction with dampening of the "anti-inflammatory parasympathetic" arm of the autonomic nervous system. In addition to the neuronal modulation of the immune system, it is proposed that key inflammatory responses are relayed back to the central nervous system and alter the neuronal communication to the periphery. The overall objective of this review is to critically discuss recent advances in the understanding of autonomic immune modulation, and propose a unifying hypothesis underlying the mechanisms leading to the development and maintenance of hypertension, with particular emphasis on the bone marrow, as it is a crucial meeting point for neural, immune, and vascular networks.

Female SHR have greater blood pressure sensitivity and renal T cell infiltration following chronic NOS inhibition than males

Nitric oxide is a critical regulator of blood pressure (BP) and inflammation, and female spontaneously hypertensive rats (SHR) have higher renal nitric oxide bioavailability than males. We hypothesize that female SHR will have a greater rise in BP and renal T cell infiltration in response to nitric oxide synthase (NOS) inhibition than males. Both male and female SHR displayed a dose-dependent increase in BP to the nonspecific NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME: 2, 5, and 7 mg·kg(-1)·day(-1) for 4 days each); however, females exhibited a greater increase in BP than males. Treatment of male and female SHR with 7 mg·kg(-1)·day(-1) L-NAME for 2 wk significantly increased BP in both sexes; however, prior exposure to L-NAME only increased BP sensitivity to chronic NOS inhibition in females. L-NAME-induced hypertension increased renal T cell infiltration and indices of renal injury in both sexes, yet female SHR exhibited greater increases in Th17 cells and greater decreases in regulatory T cells than males. Chronic L-NAME was also associated with larger increases in renal cortical adhesion molecule expression in female SHR. The use of triple therapy to block L-NAME-mediated increases in BP attenuated L-NAME-induced increases in renal T cell counts and normalized adhesion molecule expression in SHR, suggesting that L-NAME-induced increases in renal T cells were dependent on both increases in BP and NOS inhibition. Our data suggest that NOS is critical in the ability of SHR, females in particular, to maintain BP and limit a pro-inflammatory renal T cell profile.

Immunosenescent CD8 + T Cells and C-X-C Chemokine Receptor Type 3 Chemokines Are Increased in Human Hypertension

The pathogenic role of T cells in hypertension has been documented well in recent animal studies. However, the existence of T-cell–driven inflammation in human hypertension has not been confirmed. Therefore, we undertook immunologic characterization of T cells from patients with hypertension and measured circulating levels of C-X-C chemokine receptor type 3 chemokines, which are well-known tissue-homing chemokines for T cells. We analyzed immunologic markers on T cells from patients with hypertension by multicolor flow cytometry. We then measured circulating levels of the C-X-C chemokine receptor type 3 chemokines, monokine induced by γ interferon (IFN), IFN γ–induced protein 10, and IFN-inducible T-cell α chemoattractant, in patients with hypertension and in age- and sex-matched control subjects by the cytometric bead array method. In addition, we examined histological features of IFN-inducible T-cell α chemoattractant expression from renal biopsy specimens of patients with hypertensive nephrosclerosis and control subjects. The total T-cell population from patients with hypertension showed an increased fraction of immunosenescent, proinflammatory, cytotoxic CD8 + T cells. Circulating levels of C-X-C chemokine receptor type 3 chemokines were significantly higher in patients with hypertension than in control subjects. Furthermore, immunohistochemical staining revealed increased expression of the T-cell chemokine, IFN-inducible T-cell α chemoattractant, in the proximal and distal tubules of patients with hypertensive nephrosclerosis. Immunosenescent CD8 + T cells and C-X-C chemokine receptor type 3 chemokines are increased in human hypertension, suggesting a role for T-cell–driven inflammation in hypertension. A more detailed characterization of CD8 + T cells may offer new opportunities for the prevention and treatment of human hypertension.

Reduced Macrophage-Dependent Inflammation Improves Endothelin-1–Induced Vascular Injury

Transgenic mice with endothelium-specific endothelin-1 (ET-1) overexpression exhibit endothelial dysfunction and vascular remodeling, oxidative stress, and inflammation. We previously observed that monocytes/macrophages play a role in angiotensin II, aldosterone, and deoxycorticosterone acetate/salt-induced vascular remodeling, oxidative stress, and inflammation using a model with reduced monocytes/macrophages, the osteopetrotic (Op) mouse, which has a mutation in the macrophage colony stimulating factor ( Csf1 ) gene. However, it is unknown whether monocytes/macrophages are implicated in adverse vascular effects of ET-1. We hypothesized that reduction in monocytes/macrophages would blunt ET-1–induced vascular injury. We performed a study on 4- to 6-month-old male mice with endothelium-specific ET-1 overexpression (eET-1), reduction in CSF1 ( Csf1 Op/+ ), or both (eET-1/ Csf1 Op/+ ), and their wild-type littermate control mice. There was no difference in systolic blood pressure between groups. Endothelial function and vascular structure were determined on a pressurized myograph. Endothelium-dependent relaxation in response to acetylcholine was similar in eET-1 and eET-1/ Csf1 Op/+ mice. Media:lumen ratio and media cross-sectional area were ≈1.5-fold greater in eET-1 than in wild-type mice ( P <0.05), which was not observed in mice deficient in CSF1. ET-1–induced oxidative stress measured by dihydroethidium staining ( P <0.05) and NADPH oxidase activity assessed with lucigenin chemiluminescence ( P <0.05) were blunted by CSF1 deficiency. ET-1 caused a 2.5-fold increase in monocyte/macrophage infiltration compared with wild-type mice ( P <0.001), which was blunted in the mice deficient in CSF1. Reduction of monocyte/macrophage-dependent inflammation in mice overexpressing ET-1 in endothelium results in reduced vascular remodeling and oxidative stress, providing evidence for a role of monocytes/macrophages and innate immunity in ET-1–induced vascular injury.

Prevention and endothelial therapy of coronary artery disease

Functional integrity of endothelial cells is an indicator and a prerequisite for vascular health and counteracts the development of atherosclerosis. This concept of 'endothelial therapy' was developed in the late 1990s as an approach to preserve or restore endothelial cell health given that 'the knowledge of the mechanisms involved in 'endothelial dysfunction' allows us to interfere specifically with pathogenic pathways at very early time points and to slow down the progression of disease'. In the present review, the principles underlying endothelial cell health will be discussed as well as the role of endothelial therapy as a preventive measure to reduce the prevalence of coronary artery disease or to delay disease progression in patients with chronic coronary artery disease. This article also highlights the importance of active participation, the need to reduce the number of future patients in view of the rising prevalence of childhood obesity, and the potential of endothelial therapy to improve survival, reduce disability and health costs, and to improve overall quality of life in patients at risk for or already diagnosed with coronary artery disease. The preventive and therapeutic approaches and considerations described herein can be applied by physicians, patients, parents, educators, health agencies, and political decision makers to help reducing the global cardiovascular disease burden in the decades to come.

TJ0711, a novel vasodilatory β-blocker, protects SHR rats against hypertension induced renal injury

Previous studies suggested that β-blockers with adjunctive α1-blocking activities warrant renoprotective function other than the therapeutic effect on hypertension. The current report is designed to dissect the role of TJ0711, a novel β-blocker with a 1:1 ratio for the β1/α1 blocking activities, in renoprotection in SHR rats. It was noted that TJ0711 possesses similar potency for control of blood pressure as that of Carvedilol. However, TJ0711 is much more potent in terms of protecting SHR rats against hypertension induced renal injury. Specifically, SHR rats treated with 20mg/kg/day of TJ0711 manifested significantly lower levels for urine albumin and total protein. In line with these result, TJ0711 treated rats displayed much less severe pathological changes in the kidneys. Mechanistic studies revealed that TJ0711 improves kidney perfusion during the course of hypertensive insult by enhancing eNOS expression through suppressing inflammatory cytokine secretion. TJ0711 also attenuates Vasohibin-1 expression to prevent HIF-1α from signal-induced degradation, and by which it promotes HO-1 expression to protect SHR rats against oxidative stress induced by hypertension in the kidneys. Together, our data suggest that TJ0711 possesses higher potency for renoprotection while manifesting the similar effect on hypertension therapy as Carvedilol.

Neurogenic hypertension: revelations from genome-wide gene expression profiling

There is now good evidence for a role of the sympathetic nervous system in the etiology of essential hypertension in humans. Although genetic variation is expected to underlie the elevated sympathetic outflow in this complex polygenic condition, only limited information has emerged from classic molecular genetic studies. Recently, progress has been made in understanding neurogenic aspects by determination of global alterations in gene expression in key brain regions of animal models of neurogenic hypertension. Such genome-wide expression studies in the hypothalamus and brainstem support roles for factors such as neuronal nitric oxide synthase, inflammation and reactive oxygen species. A role for non-coding RNAs such as microRNAs, and epigenetic alterations await exploration. Ongoing novel approaches should provide a better understanding of the processes responsible for the increased sympathetic outflow in animal models, as well as essential hypertension in humans. Such information may lead to better therapies for neurogenic hypertension in humans.

Variation in dietary salt intake induces coordinated dynamics of monocyte subsets and monocyte-platelet aggregates in humans: implications in end organ inflammation

BACKGROUND

Monocyte activation and tissue infiltration are quantitatively associated with high-salt intake induced target organ inflammation. We hypothesized that high-salt challenge would induce the expansion of CD14++CD16+ monocytes, one of the three monocyte subsets with a pro-inflammatory phenotype, that is associated with target organ inflammation in humans.

METHODOLOGY/PRINCIPAL FINDINGS

A dietary intervention study was performed in 20 healthy volunteers, starting with a 3-day usual diet and followed with a 7-day high-salt diet (≥15 g NaCl/day), and a 7-day low-salt diet (≤5 g NaCl/day). The amounts of three monocyte subsets ("classical" CD14++CD16-, "intermediate" CD14++CD16+ and "non-classical" CD14+CD16++) and their associations with monocyte-platelet aggregates (MPAs) were measured by flow cytometry. Blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) was used to evaluate renal hypoxia. Switching to a high-salt diet resulted in CD14++ monocyte activation and a rapid expansion of CD14++CD16+ subset and MPAs, with a reciprocal decrease in the percentages of CD14++CD16- and CD14+CD16++ subsets. In vitro study using purified CD14++ monocytes revealed that elevation in extracellular [Na(+)] could lead to CD14++CD16+ expansion via a ROS dependent manner. In addition, high-salt intake was associated with progressive hypoxia in the renal medulla (increased R2* signal) and enhanced urinary monocyte chemoattractant protein-1 (MCP-1) excretion, indicating a temporal and spatial correlation between CD14++CD16+ subset and renal inflammation. The above changes could be completely reversed by a low-salt diet, whereas blood pressure levels remained unchanged during dietary intervention.

CONCLUSIONS/SIGNIFICANCE

The present work demonstrates that short-term increases in dietary salt intake could induce the expansion of CD14++CD16+ monocytes, as well as an elevation of MPAs, which might be the underlying cellular basis of high-salt induced end organ inflammation and potential thromboembolic risk. In addition, this process seems largely unrelated to changes in blood pressure levels. This finding provides novel links between dietary salt intake, innate immunity and end organ inflammation.

Antioxidant-based therapies for angiotensin II-associated cardiovascular diseases

Cardiovascular diseases, including hypertension and heart failure, are associated with activation of the renin-angiotensin system (RAS) and increased circulating and tissue levels of ANG II, a primary effector peptide of the RAS. Through its actions on various cell types and organ systems, ANG II contributes to the pathogenesis of cardiovascular diseases by inducing cardiac and vascular hypertrophy, vasoconstriction, sodium and water reabsorption in kidneys, sympathoexcitation, and activation of the immune system. Cardiovascular research over the past 15-20 years has clearly implicated an important role for elevated levels of reactive oxygen species (ROS) in mediating these pathophysiological actions of ANG II. As such, the use of antioxidants, to reduce the elevated levels of ROS, as potential therapies for various ANG II-associated cardiovascular diseases has been intensely investigated. Although some antioxidant-based therapies have shown therapeutic impact in animal models of cardiovascular disease and in human patients, others have failed. In this review, we discuss the benefits and limitations of recent strategies, including gene therapy, dietary sources, low-molecular-weight free radical scavengers, polyethylene glycol conjugation, and nanomedicine-based technologies, which are designed to deliver antioxidants for the improved treatment of cardiovascular diseases. Although much work has been completed, additional research focusing on developing specific antioxidant molecules or proteins and identifying the ideal in vivo delivery system for such antioxidants is necessary before the use of antioxidant-based therapies for cardiovascular diseases become a clinical reality.

Immune and inflammatory role in renal disease

Chronic and acute renal diseases, irrespective of the initiating cause, have inflammation and immune system activation as a common underlying mechanism. The purpose of this review is to provide a broad overview of immune cells and inflammatory proteins that contribute to the pathogenesis of renal disease, and to discuss some of the physiological changes that occur in the kidney as a result of immune system activation. An overview of common forms of acute and chronic renal disease is provided, followed by a discussion of common therapies that have anti-inflammatory or immunosuppressive effects in the treatment of renal disease.

Impact of obesity on cardiovascular health

This review examines the impact of obesity on cardiovascular health. We will review first, relationship between obesity and hypertension. Second, we will describe obesity-related subclinical abnormalities in cardiovascular function and structure. Third, we will summarize evidence linking obesity to overt cardiovascular disease including coronary artery disease, congestive heart failure, stroke, arrhythmias and sudden cardiac death. Fourth, we will discuss the potential mechanisms underlying increased cardiovascular risk in obese subjects. Last, we will discuss contribution of sleep apnea to the link between obesity and cardiovascular disease. Despite recent progress in understanding epidemiologic and pathophysiological links between obesity and cardiovascular disease, several issues remain to be addressed in the future studies. There is a clear need to identify better markers of obesity-related subclinical cardiovascular damage. Furthermore, we should improve identification of obese subjects at highest cardiovascular risk.

Inflammation and hypertension: are there regional differences?

Hypertension is a chronic disease with global prevalence and incidence rapidly increasing in low and medium income countries. The surveillance of cardiovascular risk factors, such as hypertension, is a global health priority in order to estimate the burden and trends, to appropriately direct resources, and to measure the effect of interventions. We propose here that the adoption of Western lifestyles in low and middle incomes countries has dramatically increased the prevalence of abdominal obesity, which is the main source of proinflammatory cytokines, and that the vascular systemic inflammation produced by adipose tissue contributes to the development of hypertension. The concentration of proinflammatory cytokines is higher in the Latin American population than that reported in developed countries, suggesting a higher susceptibility to develop systemic low-degree inflammation at a given level of abdominal obesity. These particularities are important to be considered when planning resources for health care programs. Moreover, studying these singularities may provide a better understanding of the causes of the burden of cardiovascular risk factors and the remarkable variability in the prevalence of these medical conditions within and between countries.

Abnormal high-density lipoprotein induces endothelial dysfunction via activation of Toll-like receptor-2

Endothelial injury and dysfunction (ED) represent a link between cardiovascular risk factors promoting hypertension and atherosclerosis, the leading cause of death in Western populations. High-density lipoprotein (HDL) is considered antiatherogenic and known to prevent ED. Using HDL from children and adults with chronic kidney dysfunction (HDL(CKD)), a population with high cardiovascular risk, we have demonstrated that HDL(CKD) in contrast to HDL(Healthy) promoted endothelial superoxide production, substantially reduced nitric oxide (NO) bioavailability, and subsequently increased arterial blood pressure (ABP). We have identified symmetric dimethylarginine (SDMA) in HDL(CKD) that causes transformation from physiological HDL into an abnormal lipoprotein inducing ED. Furthermore, we report that HDL(CKD) reduced endothelial NO availability via toll-like receptor-2 (TLR-2), leading to impaired endothelial repair, increased proinflammatory activation, and ABP. These data demonstrate how SDMA can modify the HDL particle to mimic a damage-associated molecular pattern that activates TLR-2 via a TLR-1- or TLR-6-coreceptor-independent pathway, linking abnormal HDL to innate immunity, ED, and hypertension.

Irreversible renal damage after transient renin-angiotensin system stimulation: involvement of an AT1-receptor mediated immune response

Transient activation of the renin-angiotensin system (RAS) induces irreversible renal damage causing sustained elevation in blood pressure (BP) in Cyp1a1-Ren2 transgenic rats. In our current study we hypothesized that activation of the AT₁-receptor (AT₁R) leads to a T-cell response causing irreversible impairment of renal function and hypertension. Cyp1a1-Ren2 rats harbor a construct for activation of the RAS by indole-3-carbinol (I3C). Rats were fed a I3C diet between 4–8 weeks of age to induce hypertension. Next, I3C was withdrawn and rats were followed-up for another 12 weeks. Additional groups received losartan (20 mg/kg/day) or hydralazine (100 mg/kg/day) treatment between 4–8 weeks. Rats were placed for 24h in metabolic cages before determining BP at week 8, 12 and 20. At these ages, subsets of animals were sacrificed and the presence of kidney T-cell subpopulations was investigated by immunohistochemistry and molecular marker analysis. The development of sustained hypertension was completely prevented by losartan, whereas hydralazine only caused a partial decrease in BP. Markers of renal damage: KIM-1 and osteopontin were highly expressed in urine and kidney samples of I3C-treated rats, even until 20 weeks of age. Additionally, renal expression of regulatory-T cells (Tregs) was highly increased in I3C-treated rats, whereas the expression of T-helper 1 (Th1) cells demonstrated a strong decrease. Losartan prevented these effects completely, whereas hydralazine was unable to affect these changes. In young Cyp1a1-Ren2 rats AT₁R activation leads to induction of an immune response, causing a shift from Th1-cells to Tregs, contributing to the development of irreversible renal damage and hypertension.

Neuroimmune communication in hypertension and obesity: a new therapeutic angle?

Hypertension is an epidemic health concern and a major risk factor for the development of cardiovascular disease. Although there are available treatment strategies for hypertension, numerous hypertensive patients do not have their clinical symptoms under control and it is imperative that new avenues to treat or prevent high blood pressure in these patients are developed. It is well established that increases in sympathetic nervous system (SNS) outflow and enhanced renin-angiotensin system (RAS) activity are common features of hypertension and various pathological conditions that predispose individuals to hypertension. More recently, hypertension has also become recognized as an immune condition and accumulating evidence suggests that interactions between the RAS, SNS and immune systems play a role in blood pressure regulation. This review summarizes what is known about the interconnections between the RAS, SNS and immune systems in the neural regulation of blood pressure. Based on the reviewed studies, a model for RAS/neuroimmune interactions during hypertension is proposed and the therapeutic potential of targeting RAS/neuroimmune interactions in hypertensive patients is discussed. Special emphasis is placed on the applicability of the proposed model to obesity-related hypertension.

Impaired pressure natriuresis resulting in salt-sensitive hypertension is caused by tubulointerstitial immune cell infiltration in the kidney

Immune cell infiltration of the kidney is a constant feature in salt-sensitive hypertension (SSHTN). We evaluated the relationship between the renal inflammation and pressure natriuresis in the model of SSHTN that results from transient oral administration of N(ω)-nitro-L-arginine methyl ester (L-NAME). Pressure natriuresis was determined in Wistar rats that received 4 wk of a high-salt (4% NaCl) diet, starting 1 wk after stopping L-NAME, which was administered alone (SSHTN group, n = 17) or in association with mycophenolate mofetil (MMF; MMF group, n = 15). The administration of MMF in association with L-NAME is known to prevent the subsequent development of SSHTN. Control groups received a high (n = 12)- and normal (0.4%)-salt diet (n = 20). Rats with SSHTN had increased expression of inflammatory cytokines and oxidative stress. The severity of hypertension correlated directly (P < 0.0001) with the number of tubulointerstitial immune cells and angiotensin II-expressing cells. Pressure natriuresis was studied at renal arterial pressures (RAPs) of 90, 110, 130, and 150 mmHg. Glomerular filtration rate was similar and stable in all groups, and renal blood flow was decreased in the SSHTN group. Significantly decreased natriuresis (P < 0.05) was found in the SSHTN group at RAPs of 130 and 150 mmHg, and there was an inverse correlation (P < 0.01) between the urinary sodium excretion and the number of tubulointerstitial inflammatory cells (lymphocytes and macrophages) and cells expressing angiotensin II. We conclude that tubulointerstitial inflammation plays a key role in the impairment of pressure natriuresis that results in salt-dependent hypertension in this experimental model.

Markers of microbial translocation predict hypertension in HIV-infected individuals

OBJECTIVES

The aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV-infected individuals.

METHODS

In this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV-infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV-infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme-linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied.

RESULTS

In the HIV-infected patients [median (interquartile range) age 42 (32-46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10-unit increase in LPS (range 66-272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31-1.41) mmHg (P = 0.003).

CONCLUSIONS

As LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.

Activation of the renin-angiotensin system by a low-salt diet does not augment intratubular angiotensinogen and angiotensin II in rats

In angiotensin II (ANG II) infusion hypertension, there is an augmentation of intratubular angiotensinogen (AGT) and ANG II leading to increased urinary AGT and ANG II excretion rates associated with tissue injury. However, the changes in urinary AGT and ANG II excretion rates and markers of renal injury during physiologically induced stimulation of the renin-angiotensin system (RAS) by a low-salt diet remain unclear. Male Sprague-Dawley rats received a low-salt diet (0.03% NaCl; n = 6) and normal-salt diet (0.3% NaCl, n = 6) for 13 days. Low-salt diet rats had markedly higher plasma renin activity and plasma ANG II levels. Kidney cortex renin mRNA, kidney AGT mRNA, and AGT immunoreactivity were not different; however, medullary renin mRNA, kidney renin content, and kidney ANG II levels were significantly elevated by the low-salt diet. Kidney renin immunoreactivity was also markedly increased in juxtaglomerular apparati and in cortical and medullary collecting ducts. Urinary AGT excretion rates and urinary ANG II excretion rates were not augmented by the low-salt diet. The low-salt diet caused mild renal fibrosis in glomeruli and the tubulointerstitium, but no other signs of kidney injury were evident. These results indicate that, in contrast to the response in ANG II infusion hypertension, the elevated plasma and intrarenal ANG II levels caused by physiological stimulation of RAS are not reflected by increased urinary AGT or ANG II excretion rates or the development of renal injury.

The comparative effects of valsartan and amlodipine on vWf levels and N/L ratio in patients with newly diagnosed hypertension

High levels of circulating Von Willebrand factor (vWf) and increased neutrophil to lymphocyte (N/L) ratio may reflect vascular inflammation in hypertensive patients. In present study, we aimed to investigate the effects of valsartan as an angiotensin II receptor antagonist and amlodipine as a calcium channel blocker on the vWf levels and N/L ratio in patients with essential hypertension. Patients were randomized to one of the following intervention protocols: calcium channel blocker (amlodipine, 5-10 mg/day) as group A (n = 20 mean age = 51.85 ± 11.32 y) and angiotensine II receptor blocker (valsartan, 80-320 mg/day) as group B (n = 26 mean age = 49.12 ± 14.12 y). Endothelial dysfunction and vascular inflammation were evaluated with vWf levels and N/L ratio in hypertensive patients before treatment and after treatment in the 12th week. No statistically significant differences were found among the groups in terms of age, sex, and body mass index (BMI). There was a significant decrease in vWf levels (P < .001) and N/L ratio after treatment (P = .04, P < .001, respectively) in both the groups. Von Willebrand factor levels and N/L ratio are very important markers having a role in vascular inflammation and antihypertensive treatment with amlodipine and valsartan may improve cardiovascular outcomes by decreasing these biomarkers.

The carotid body as a putative therapeutic target for the treatment of neurogenic hypertension

In the spontaneously hypertensive (SH) rat, hyperoxic inactivation of the carotid body (CB) produces a rapid and pronounced fall in both arterial pressure and renal sympathetic nerve activity (RSA). Here we show that CB de-afferentation through carotid sinus nerve denervation (CSD) reduces the overactive sympathetic activity in SH rats, providing an effective antihypertensive treatment. We demonstrate that CSD lowers RSA chronically and that this is accompanied by a depressor response in SH but not normotensive rats. The drop in blood pressure is not dependent on renal nerve integrity but mechanistically accompanied by a resetting of the RSA-baroreflex function curve, sensitization of the cardiac baroreflex, changes in renal excretory function and reduced T-lymphocyte infiltration. We further show that combined with renal denervation, CSD remains effective, producing a summative response indicative of an independent mechanism. Our findings indicate that CB de-afferentation is an effective means for robust and sustained sympathoinhibition, which could translate to patients with neurogenic hypertension.

Immunosuppression preserves renal autoregulatory function and microvascular P2X(1) receptor reactivity in ANG II-hypertensive rats

Autoregulation is critical for protecting the kidney against arterial pressure elevation and is compromised in some forms of hypertension. Evidence indicates that activated lymphocytes contribute importantly to cardiovascular injury in hypertension. We hypothesized that activated lymphocytes contribute to renal vascular dysfunction by impairing autoregulation and P2X(1) receptor signaling in ANG II-infused hypertensive rats. Male Sprague-Dawley rats receiving ANG II infusion were treated with a lymphocyte proliferation inhibitor, mycophenolate mofetil (MMF) for 2 wk. Autoregulation was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. ANG II-treated rats exhibited impaired autoregulation. At the single vessel level, pressure-mediated afferent arteriolar vasoconstriction was significantly blunted (P < 0.05 vs. control rats). At the whole kidney level, renal blood flow passively decreased as renal perfusion pressure was reduced. MMF treatment did not alter the ANG II-induced hypertensive state; however, MMF did preserve autoregulation. The autoregulatory profiles in both in vitro or in vivo settings were similar to the responses from control rats despite persistent hypertension. Autoregulatory responses are linked to P2X(1) receptor activation. Accordingly, afferent arteriolar responses to ATP and the P2X(1) receptor agonist β,γ-methylene ATP were assessed. ATP- or β,γ-methylene ATP-induced vasoconstriction was significantly attenuated in ANG II-infused hypertensive rats but was normalized by MMF treatment. Moreover, MMF prevented elevation of plasma transforming growth factor-β1 concentration and lymphocyte and macrophage infiltration in ANG II-infused kidneys. These results suggest that anti-inflammatory treatment with MMF prevents lymphocyte infiltration and preserves autoregulation in ANG II-infused hypertensive rats, likely by normalizing P2X(1) receptor activation.

Interleukin-17 causes Rho-kinase-mediated endothelial dysfunction and hypertension

AIMS

Elevated levels of pro-inflammatory cytokine interleukin-17A (IL-17) are associated with hypertensive autoimmune diseases; however, the connection between IL-17 and hypertension is unknown. We hypothesized that IL-17 increases blood pressure by decreasing endothelial nitric oxide production.

METHODS AND RESULTS

Acute treatment of endothelial cells with IL-17 caused a significant increase in phosphorylation of the inhibitory endothelial nitric oxide (NO) synthase residue threonine 495 (eNOS Thr495). Of the kinases known to phosphorylate eNOS Thr495, only inhibition of Rho-kinase prevented the IL-17-induced increase. IL-17 caused a threefold increase in the Rho-kinase activator RhoA, and this was prevented by an IL-17 neutralizing antibody. In isolated mouse aortas, IL-17 significantly increased eNOS Thr495 phosphorylation, induced RhoA expression, and decreased NO-dependent relaxation responses, all of which were prevented by either an IL-17 neutralizing antibody or inhibition of Rho-kinase. In mice, IL-17 treatment for 1 week significantly increased systolic blood pressure and this was associated with decreased aortic NO-dependent relaxation responses, increased eNOS Thr495 phosphorylation, and increased RhoA expression. Inhibition of Rho-kinase prevented the hypertension caused by IL-17.

CONCLUSION

These data demonstrate that IL-17 activates RhoA/Rho-kinase leading to endothelial dysfunction and hypertension. Inhibitors of IL-17 or Rho-kinase may prove useful as anti-hypertensive drugs in IL-17-associated autoimmune diseases.

Role of the immune system in hypertension: modulation by dietary antioxidants

Hypertension is a major health problem worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease, and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role. Insulin resistance is a common feature of hypertension in both humans and animal models affecting glucose and lipid metabolism producing excess aldehydes including methylglyoxal. These aldehydes react with proteins to form conjugates called advanced glycation end products (AGEs). This alters protein structure and function and can affect vascular and immune cells leading to their activation and secretion of inflammatory cytokines. AGEs also act via receptors for advanced glycation end products on these cells altering the function of antioxidant and metabolic enzymes, and ion channels. This results in an increase in cytosolic free calcium, decrease in nitric oxide, endothelial dysfunction, oxidative stress, peripheral vascular resistance, and infiltration of vascular and kidney tissue with inflammatory cells leading to hypertension. Supplementation with dietary antioxidants including vitamins C, E, or B(6), thiols such as cysteine and lipoic acid, have been shown to lower blood pressure and plasma inflammatory cytokines in animal models and humans with essential hypertension. A well-balanced diet rich in antioxidants that includes vegetables, fruits, low fat dairy products, low salt, and includes whole grains, poultry, fish and nuts, lowers blood pressure and vascular inflammation. These antioxidants may achieve their antihypertensive and anti-inflammatory/immunomodulatory effects by reducing AGEs and improving insulin resistance and associated alterations. Dietary supplementation with antioxidants may be a beneficial, inexpensive, front-line alterative treatment modality for hypertension.

Effects of green tea supplementation on elements, total antioxidants, lipids, and glucose values in the serum of obese patients

The consumption of green tea has been associated with cardiovascular and metabolic diseases. There have been some studies on the influence of green tea on the mineral status of obese subjects, but they have not yielded conclusive results. The aim of the present study is to examine the effects of green tea extract on the mineral, body mass, lipid profile, glucose, and antioxidant status of obese patients. A randomized, double-blind, placebo-controlled study was conducted. Forty-six obese patients were randomly assigned to receive either 379 mg of green tea extract, or a placebo, daily for 3 months. At baseline, and after 3 months of treatment, the anthropometric parameters, blood pressure, and total antioxidant status were assessed, as were the levels of plasma lipids, glucose, calcium, magnesium, iron, zinc, and copper. We found that 3 months of green tea extract supplementation resulted in decreases in body mass index, waist circumference, and levels of total cholesterol, low-density cholesterol, and triglyceride. Increases in total antioxidant level and in zinc concentration in serum were also observed. Glucose and iron levels were lower in the green tea extract group than in the control, although HDL-cholesterol and magnesium were higher in the green tea extract group than in the placebo group. At baseline, a positive correlation was found between calcium and body mass index, as was a negative correlation between copper and triglycerides. After 3 months, a positive correlation between iron and body mass index and between magnesium and HDL-cholesterol, as well as a negative correlation between magnesium and glucose, were observed. The present findings demonstrate that green tea influences the body's mineral status. Moreover, the results of this study confirm the beneficial effects of green tea extract supplementation on body mass index, lipid profile, and total antioxidant status in patients with obesity.

The comparative effects of valsartan and amlodipine on vascular microinflammation in newly diagnosed hypertensive patients

Pentraxin 3 (PTX3) is a new candidate immunoinflammatory marker that has been reported to be associated with cardiometabolic risk factors. We aimed to investigate the effects of valsartan and amlodipine on the PTX3 and C-reactive protein (CRP) levels in patients with essential hypertension. Patients with a newly diagnosed essential hypertension were admitted to our internal medicine outpatient clinic. Patients were randomized to one of the following intervention protocols: calcium channel blocker (amlodipine, 5-10 mg/day) as group A (n = 22; mean age ± standard deviation [SD]: 52 ± 11 year) and angiotensine II receptor blocker (valsartan, 80-320 mg/day) as group B (n = 28; mean age ± SD: 50 ± 14 year). Endothelial dysfunction and systemic inflammation were evaluated with PTX3 and CRP. There was a significant decrease in the level of PTX3 after treatment in two groups (P < .05). Although there was a significant decrease in the level of CRP after treatment in amlodipine group, there was no significant decrease in the levels of PTX3 and CRP after treatment in two groups. There were no significant differences in the systolic and diastolic blood pressure reduction between the two treatment groups. In the treatment of hypertension, prior knowledge of the level of plasma PTX3 could be important in antihypertensive drug choice. C-reactive protein and PTX3 are the markers that have role in vascular inflammation and are found associated with the prognosis of cardiovascular outcomes in many trials. In our study, PTX and CRP levels were decreased when compared to baseline levels.

Helminth infection in populations undergoing epidemiological transition: a friend or foe?

Helminth infections are highly prevalent in developing countries, especially in rural areas. With gradual development, there is a transition from living conditions that are dominated by infection, poor sanitation, manual labor, and traditional diet to a situation where burden of infections is reduced, infrastructure is improved, sedentary lifestyle dominates, and processed food forms a large proportion of the calorie intake. The combinations of some of the changes in lifestyle and environment are expected to result in alteration of the landscape of diseases, which will become dominated by non-communicable disorders. Here we review how the major helminth infections affect a large proportion of the population in the developing world and discuss their impact on the immune system and the consequences of this for other infections which are co-endemic in the same areas. Furthermore, we address the issue of decreasing helminth infections in many parts of the world within the context of increasing inflammatory, metabolic, and cardiovascular diseases.

The role of tetrahydrobiopterin in inflammation and cardiovascular disease

The cofactor tetrahydrobiopterin (BH4) is required for nitric oxide (NO) production by all nitric oxide synthase (NOS) enzymes and is a key regulator of cellular redox signalling. When BH4 levels become limiting NOS enzymes become 'uncoupled' and produce superoxide rather than NO. Endothelial cell BH4 is required for the maintenance of vascular function through NO production, and reduced BH4 levels are associated with vascular dysfunction. Evidence increasingly points to important roles for BH4 and NOS enzymes in other vascular cell types. Leukocytes have a fundamental role in atherosclerosis, and new evidence points to a role in the control of hypertension. Leukocytes are a major site of iNOS expression, and the regulation of this isoform is another mechanism by which BH4 availability may modulate disease. This review provides an overview of BH4 control of NOS function in both endothelial cells and leukocytes in the context of vascular disease and current therapeutic evaluations.

Low nadir CD4 cell count predicts sustained hypertension in HIV-infected individuals

Hypertension is associated with cardiovascular disease in the human immunodeficiency virus (HIV)-infected population. The authors aimed to test the hypothesis whether advanced immunosuppression with low nadir CD4 lymphocyte cell count is a predictor of sustained hypertension in HIV-infected individuals. In a longitudinal study of an HIV cohort of 434 patients (43±11 years, 72% men, 71% Caucasians), standardized blood pressure was measured in duplicate during 3 clinical visits both at baseline and after 3.4±0.8 years. The lowest CD4 cell count in the individual history was recorded as nadir CD4. Both nadir CD4 cell count<50 cells/μL and duration of antiretroviral therapy (ART) were associated with sustained hypertension, and the highest proportion of hypertensive patients was observed in those who had both nadir CD4 cell count<50 cells/μL and prolonged ART duration. Nadir CD4 cell-count<50 cells/μL was an independent predictor of hypertension (adjusted odds ratio [OR], 2.48; 95% confidence interval [CI], 1.27-4.83), as was ART duration (adjusted OR, 1.13; 95% CI, 1.03-1.24). The predictive power of ART duration was more pronounced in patients with nadir CD4 cell count<50 cells/μL. Delaying ART initiation until a state of advanced immunosuppression might add to and even fuel the cardiovascular risk associated with ART.

Immune reactivity to heat shock protein 70 expressed in the kidney is cause of salt-sensitive hypertension

Hypertension affects one-third of the adult population of the world. The causes of hypertension are incompletely understood, but relative impairment of sodium excretion is central to its pathogenesis. Immune cell infiltration in the kidney is a constant finding in hypertension that in association with local angiotensin and oxidants causes a defect in sodium excretion. However, it is unclear if the T cell influx into the kidney responds to nonspecific chemokine cues or is due to antigen-driven immune attraction. We found that T cells in experimentally induced salt-driven hypertension present a CD4 clonal response to heat shock protein 70 (HSP70) that is overexpressed in the kidney. We used a highly preserved amino acid sequence within the HSP molecule to induce immune tolerance associated with the generation of IL-10 producing regulatory T cells. Immune tolerant rats to HSP70 developed minimal renal inflammation and were protected from the development of salt-sensitive hypertension. Adoptive transfer of T lymphocytes isolated from spleen of tolerized rats also reversed hypertension. HSP70 gene delivery to the renal vein of the kidneys of rats sensitized to HSP70 caused an increment in blood pressure in response to a high-salt diet. The HSP70 peptide used in this work induces a strong proliferative response in peripheral blood lymphocytes of patients with essential hypertension. These studies provide evidence that autoimmunity plays a role in salt-sensitive hypertension and identifies HSP70 expressed in the kidney as one key antigen. These findings raise the possibility of novel approaches to the treatment of this condition.

Brain-mediated dysregulation of the bone marrow activity in angiotensin II-induced hypertension

Oxidative stress in the brain is implicated in increased sympathetic drive, inflammatory status, and vascular dysfunctions, associated with development and establishment of hypertension. However, little is known about the mechanism of this impaired brain-vascular communication. Here, we tested the hypothesis that increased oxidative stress in the brain cardioregulatory areas, such as the paraventricular nucleus of the hypothalamus, is driven by mitochondrial reactive oxygen species and leads to increased inflammatory cells (ICs) and decreased/dysfunctional endothelial progenitor cells (EPCs), thereby compromising vasculature repair and accelerating hypertension. Chronic angiotensin II infusion resulted in elevated blood pressure and sympathetic vasomotor drive, decreased spontaneous baroreflex gain, and increased microglia activation in the paraventricular nucleus. This was associated with 46% decrease in bone marrow (BM)-derived EPCs and 250% increase in BM ICs, resulting in 5-fold decrease of EPC/IC ratio in the BM. Treatment with mitochondrial-targeted antioxidant, a scavenger of mitochondrial O(2)(-·), intracerebroventricularly but not subcutaneously attenuated angiotensin II-induced hypertension, decreased activation of microglia in the paraventricular nucleus, and normalized EPCs/ICs. This functional communication between the brain and BM was confirmed by retrograde neuronal labeling from the BM with green fluorescent protein-tagged pseudorabies virus. Administration of green fluorescent protein-tagged pseudorabies virus into the BM resulted in predominant labeling of paraventricular nucleus neurons within 3 days, with some fluorescence in the nucleus tractus solitarius, the rostral ventrolateral medulla, and subfornical organ. Taken together, these data demonstrate that inhibition of mitochondrial reactive oxygen species attenuates angiotensin II-induced hypertension and corrects the imbalance in EPCs/ICs in the BM. They suggest that an imbalance in vascular reparative and ICs may perpetuate vascular pathophysiology in this model of hypertension.

DBA-lectin reactivity defines mouse uterine natural killer cell subsets with biased gene expression

Endometrial decidualization, a process essential for blastocyst implantation in species with hemochorial placentation, is accompanied by an enormous but transient influx of natural killer (NK) cells. Mouse uterine NK (uNK) cell subsets have been defined by diameter and cytoplasmic granule number, reflecting stage of maturity, and by histochemical reactivity with Periodic Acid Schiff (PAS) reagent with or without co-reactivity with Dolichos biflorus agglutinin (DBA) lectin. We asked whether DBA- and DBA+ mouse uNK cells were equivalent using quantitative RT-PCR analyses of flow-separated, midpregnancy (Gestation Day [gd] 10) cells and immunohistochemistry. CD3E (CD3)-IL2RB (CD122)+DBA cells were identified as the dominant Ifng transcript source. Skewed IFNG production by uNK cell subsets was confirmed by analysis of uNK cells from eYFP-tagged IFNG-reporter mice. In contrast, CD3E-IL2RB+DBA+ uNK cells expressed genes compatible with significantly greater potential for IL22 synthesis, angiogenesis, and participation in regulation mediated by the renin-angiotensin system (RAS). CD3E-IL2RB+DBA+ cells were further divided into VEGFA+ and VEGFA- subsets. CD3E-IL2RB+DBA+ uNK cells but not CD3E-IL2RB+DBA- uNK cells arose from circulating, bone marrow-derived progenitor cells by gd6. These findings indicate the heterogeneous nature of mouse uNK cells and suggest that studies using only DBA+ uNK cells will give biased data that does not fully represent the uNK cell population.