Ang II Upregulation of the T-lymphocyte renin-angiotensin system is amplified by low-grade inflammation in human hypertension

Hypotensive drugs mitigate the high-sodium diet-induced pro-inflammatory activation of mouse macrophages in vivo

Nowadays, there is an increasing emphasis on the need to alleviate the chronic inflammatory response to effectively treat hypertension. However, there are still gaps in our understanding on how to achieve this. Therefore, research on interaction of antihypertensive drugs with the immune system is extremely interesting, since their therapeutic effect could partly result from amelioration of hypertension-related inflammation, in which macrophages seem to play a pivotal role. Thus, current comprehensive studies have investigated the impact of repeatedly administered hypotensive drugs (captopril, olmesartan, propranolol, carvedilol, amlodipine, verapamil) on macrophage functions in the innate and adaptive immunity, as well as if drug-induced effects are affected by a high-sodium diet (HSD), one of the key environmental risk factors of hypertension. Although the assayed medications increased the generation of reactive oxygen and nitrogen intermediates by macrophages from standard fed donors, they reversed HSD-induced enhancing effects on macrophage oxidative burst and secretion of pro-inflammatory cytokines. On the other hand, some drugs increased macrophage phagocytic activity and the expression of surface markers involved in antigen presentation, which translated into enhanced macrophage ability to activate B cells for antibody production. Moreover, the assayed medications augmented macrophage function and the effector phase of contact hypersensitivity reaction, but suppressed the sensitization phase of cell-mediated hypersensitivity under HSD conditions. Our current findings contribute to the recognition of mechanisms, by which excessive sodium intake affects macrophage immune activity in hypertensive individuals, and provide evidence that the assayed medications mitigate most of the HSD-induced adverse effects, suggesting their additional protective therapeutic activity.

The relationship between the systemic immune-inflammation index and reverse-dipper circadian pattern in newly diagnosed hypertensive patients

Although hypertension is considered high intravascular pressure, impairing circadian blood pressure (BP) has been shown to potentially contribute to poor clinical outcomes. Systemic immune-inflammation index (SII), based on platelet, neutrophil, and lymphocyte counts, has been established as a strong prognostic marker in cardiovascular disease. The role of inflammation in the pathogenesis of hypertension is a well-known issue and inflammatory markers are associated with BP variability. We aimed to investigate whether there is a relationship between circadian BP changes and SII in newly diagnosed hypertensive patients. The study population consisted of 196 newly diagnosed hypertensive patients without LVH. In total, 76 (38%) patients had a dipper BP pattern, 60 (31%) patients had a non-dipper BP pattern, and 60 (31%) patients had a reverse-dipper BP pattern. SII was calculated according to Multivariate logistic regression analysis revealed SII and HDL-C as an independent predictors of reverse-dipper circadian pattern in newly diagnosed hypertensive patients. The cut-off value of the SII for reverse-dipper hypertension in a ROC curve analysis was >639.73 with 63.3% sensitivity and 84.2% specificity. Our study showed that the SII level was higher in the reverse-dipper hypertension patient group than in the dipper and non-dipper hypertension groups. Furthermore, SII was an independent predictor of newly diagnosed reverse-dipper hypertensive patients. The high SII value in newly diagnosed hypertensive patients can be used as an early warning parameter to identify reverse-dipper hypertension patients.

Systemic inflammation markers and the prevalence of hypertension: A NHANES cross-sectional study

Systemic inflammation markers have been highlighted recently as related to cardiac and non-cardiac disorders. However, few studies have estimated pre-diagnostic associations between these markers and hypertension. In the National Health and Nutritional Examination Survey from 1999 to 2010, 22,290 adult participants were included for analysis. We assessed associations between four systemic inflammation markers based on blood cell counts: systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and hypertension prevalence in multivariate logistic regression analysis with odds ratio (OR) and 95% confidence interval (CI). To further explore their associations, subgroup and sensitivity analyses were performed. In continuous analyses, the ORs for hypertension prevalence per ln-transformed increment in SII and NLR were estimated at 1.115 and 1.087 (95% CI: 1.045-1.188; 1.008-1.173; respectively). Compared to those in the lowest tertiles, the hypertension risks for subjects in the highest SII and NLR tertiles were 1.20 and 1.11 times, respectively. Conversely, we found that PLR and LMR were negatively associated with hypertension prevalence in continuous analyses (1.060, 0.972-1.157; 0.926, 0.845-1.014; respectively), and the highest PLR and LMR tertiles (1.041, 0.959-1.129; 0.943, 0.866-1.028; respectively). Also, subgroup and sensitivity analyses indicated that SII had a greater correlation to hypertension. In conclusion, we find positive associations between SII and NLR and the prevalence of hypertension in this cross-sectional study. Our findings highlight that SII may be a superior systemic inflammation warning marker for hypertension.

SARS-CoV-2 Spike protein suppresses CTL-mediated killing by inhibiting immune synapse assembly

CTL-mediated killing of virally infected or malignant cells is orchestrated at the immune synapse (IS). We hypothesized that SARS-CoV-2 may target lytic IS assembly to escape elimination. We show that human CD8+ T cells upregulate the expression of ACE2, the Spike receptor, during differentiation to CTLs. CTL preincubation with the Wuhan or Omicron Spike variants inhibits IS assembly and function, as shown by defective synaptic accumulation of TCRs and tyrosine phosphoproteins as well as defective centrosome and lytic granule polarization to the IS, resulting in impaired target cell killing and cytokine production. These defects were reversed by anti-Spike antibodies interfering with ACE2 binding and reproduced by ACE2 engagement by angiotensin II or anti-ACE2 antibodies, but not by the ACE2 product Ang (1-7). IS defects were also observed ex vivo in CTLs from COVID-19 patients. These results highlight a new strategy of immune evasion by SARS-CoV-2 based on the Spike-dependent, ACE2-mediated targeting of the lytic IS to prevent elimination of infected cells.

T Cell-Based RAS Activity and Insulin Levels in Obese Subjects with Low Grade Inflammation

BACKGROUND

Obesity is a major contributor to inflammation and oxidative stress that are key underlying causes for insulin resistance (IR) and diabetes. Accumulated evidence suggest that RAS may serve as a strong link between IR and obesity. We investigated RAS activity in circulating T cells by obese subjects with and without angiotensin (Ang) II stimulation in presence or not of IR and of low-grade inflammation.

METHODS

We studied 29 obese and 10 healthy subjects. After T-lymphocytes isolation, mRNAs for angiotensin converting enzyme (ACE) and angiotensin 1-receptor (AT1-R) were quantified by reverse transcription polymerase chain reaction (RT-PCR). High-sensitivity C-reactive protein (hs-CRP), insulin and inflammatory cytokines serum levels, plasma renin activity (PRA) and ACE activity in cell pellet and supernatant, and angiotensin (Ang) II T cell content were also measured.

RESULTS

Under baseline conditions, RAS gene expressions, ACE activity and Ang II levels in T cells, but not PRA, of obese subjects with or without IR and with or without hs-CRP ≥3mg/dl were higher than in controls (p < 0.05). The increase in all parameters induced by Ang II was significantly higher in T cells from the obese subjects with hs-CRP≥3 mg/dl than in controls or in the obese subjects with hs-CRP<3 mg/dl. In the obese subjects with low grade inflammation and IR, the cytokine serum levels and T cells RAS gene expression was inversely correlated with insulin serum concentration.

CONCLUSIONS

Low grade inflammation amplifies the T cell RAS response to Ang II stimulation. T cell RAS gene expressions and serum levels of inflammatory cytokines were inversely related with insulin serum concentration. A protective role of insulin towards the development of inflammatory events can be hypothesized.

Can Systemic Immune-Inflammation Index Detect the Presence of Exxaggerated Morning Blood Pressure Surge in Newly Diagnosed Treatment-Naive Hypertensive Patients?

Background: The exaggerated morning blood pressure surge (MS) is associated with target organ damage and cardiovascular events. Systemic immune-inflammation index (SII) has been detected as a useful marker in tumors and cardiovascular diseases. The role of inflammation in the pathogenesis of hypertension is a well-known issue. We aimed to investigate whether there is an association between SII and exaggerated MS in newly diagnosed treatment-naive hypertensive patients.Material and Methods: In total, 343 newly diagnosed in clinical and 24-h ambulatory blood pressure (BP) monitoring treatment-naive hypertensive patients were included in this study. Morning surge was defined as the difference between morning BP, which was the mean of BP during 2 h after wake-up, and the lowest BP, which was the mean of three lowest BP during nighttime. A cutoff value of 52.1 mmHg was used to discriminate the high- and low value MS groups. SII was calculated based on neutrophil, platelet, and lymphocyte counts.Results: Neutrophil, platelet, SII, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) were higher, whereas lymphocyte counts were lower in the high-value MS than the low-value MS. These indices were all independently associated with exaggerated MS and SII was superior to all other indices for detecting the presence of exaggerated MS. SII was moderately correlated with morning BP surge (r: 0.489, p < 0.0001).Conclusion: SII was higher in patients with exaggerated MS and was independently associated with exaggerated MS. Furthermore, SII might be a better indicator than platelet, neutrophil, lymphocyte, NLR, and PLR for the presence of exaggerated MS.

Value of neutrophil-to-lymphocyte ratio as a marker of renal damage in patients with H-type hypertension

Aim: To explore the relationship between the neutrophil-to-lymphocyte ratio (NLR) and renal damage in patients with H-type hypertension. Materials & methods: A total of 618 patients between 2017 and 2019 were analyzed retrospectively. Results: NLR was significantly correlated with renal damage in hypertension patients. Appropriate cut-off value for NLR (2.247) was determined by receiver operating characteristic curve; linear regression analysis showed that NLR and estimated glomerular filtration rate, blood urea nitrogen/creatinine has a significant negative correlation in H-type hypertension group (p < 0.05); logistic regression analysis showed that the risk of renal damage increased by 10% for each 1 umol/l increase of homocysteine, and 51% for each 1.0 increase of NLR in H-type hypertension patients. Conclusion: NLR worth popularizing in prediction of renal damage in patients with H-type hypertension.

Neutrophil to Lymphocyte Ratio Is Increased and Associated With Left Ventricular Diastolic Function in Newly Diagnosed Essential Hypertension Children

Aim: Hypertension is associated with cardiac structural and functional changes, including left ventricular hypertrophy (LVH) and LV systolic dysfunction diastolic dysfunction. Neutrophil-to-lymphocyte ratio (NLR) is a novel inflammatory biomarker associated with cardiovascular diseases. The current study aimed to evaluate NLR in children with newly diagnosed essential hypertension and its relationship between blood pressure and cardiac changes. Methods and Subjects: Sixty-five children with newly diagnosed essential hypertension and 54 healthy children were included. Clinical characteristics, blood cell counts, and biochemical parameters were collected. LVH was assessed by calculation of LV mass index (LVMI), and LV systolic function was evaluated by measuring LV ejection fraction and fractional shortening. LV diastolic function was primarily assessed with E/E' ratio by Doppler and echocardiography. Results: The hypertension children had significantly higher LVMI and E/E' ratio than the controls, whereas there was no difference in LV systolic function between the two groups. The NLR was significantly higher in the hypertension group than the control group. Moreover, NLR was positively correlated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels in the hypertension group. Additionally, a significantly positive correlation between NLR and E/E' ratio was found in the hypertension group. However, NLR was not related to LVH and LV systolic function indicators in hypertension children. Conclusion: NLR is elevated in hypertension children, and it is associated positively with office blood pressure levels. Moreover, NLR may help assess LV diastolic function in hypertension children.

Role of the renin-angiotensin system in the development of severe COVID-19 in hypertensive patients

A new form of severe acute respiratory syndrome (SARS) caused by SARS-coronavirus 2 (CoV-2), called COVID-19, has become a global threat in 2020. The mortality rate from COVID-19 is high in hypertensive patients, making this association especially dangerous. There appears to be a consensus, despite the lack of experimental data, that angiotensin II (ANG II) is linked to the pathogenesis of COVID-19. This process may occur due to acquired deficiency of angiotensin-converting enzyme 2 (ACE2), resulting in reduced degradation of ANG II. Furthermore, ANG II has a critical role in the genesis and worsening of hypertension. In this context, the idea that there is a surge in the level of ANG II with COVID-19 infection, causing multiple organ injuries in hypertensive patients becomes attractive. However, the role of other components of the renin angiotensin system (RAS) in this scenario requires elucidation. The identification of other RAS components in COVID-19 hypertension may provide both diagnostic and therapeutic benefits. Here, we summarize the pathophysiologic contributions of different components of RAS in hypertension and their possible correlation with poor outcome observed in hypertensive patients with COVID-19.

Irbesartan may relieve renal injury by suppressing Th22 cells chemotaxis and infiltration in Ang II-induced hypertension

Angiotensin II (Ang II) as an important pathogenic factor, has been implicated in the pathogenesis of hypertension and associated renal injury, and inhibition of Ang II can reduce renal inflammation and exert renal protective effects. In the present study, we determine the infiltration of Th22 cells in kidney and serum IL-22 level in hypertensive renal injury, and explore the effects and mechanisms of a widely used angiotensin II type 1 receptor blocker irbesartan on Th22 cells infiltration and related renal injury. Hypertension was induced by administering 1.5 mg/kg Ang II subcutaneously daily in C57BL/6 mice for 28 days. The mice were additionally treated by irbesartan or amlodipine. Renal Th22 lymphocytes frequency was evaluated through flow cytometry, serum IL-22 was detected by ELISA, and renal histopathological changes were also detected. The levels of renal chemokines (CCL20, CCL22, CCL27) and serum proinflammatory factors (IL-1β, IL-6, TNF-α) were measured by ELISA. Renal expression of alpha-smooth muscle actin (α-SMA), Fibronectin (FN) and collagen I (Col I) were evaluated by western blot. Chemotaxis assay and co-culture assay were conducted to clarify the effect of irbesartan on Th22 cells chemotaxis and differentiation in vitro. Our results showed in Ang II-infused hypertension mice, irbesartan suppressed renal Th22 cells accumulation as well as CCL20, CCL22, CCL27 expression. Serum IL-22, IL-1β, IL-6 and TNF-α concentrations wasere also reduced, in addition to inhibited renal expression of α-SMA, FN and Col I. Irbesartan treatment lowered blood pressure, urinary protein and renal pathological damage. In vitro, irbesartan could abrogate the Th22 cells chemotaxis and differentiation, compared to control and amlodipine groups. Our study reveals a new pharmacological mechanism that irbesartan ameliorates inflammation and fibrosis in hypertensive renal injury induced by Ang II, maybe through inhibiting Th22 cells chemotaxis and infiltration, which provides a new theoretical basis and therapeutic target for hypertensive renal injury.

Immune mechanisms of hypertension

Hypertension affects 30% of adults and is the leading risk factor for heart attack and stroke. Traditionally, hypertension has been regarded as a disorder of two systems that are involved in the regulation of salt-water balance and cardiovascular function: the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS). However, current treatments that aim to limit the influence of the RAAS or SNS on blood pressure fail in ~40% of cases, which suggests that other mechanisms must be involved. This Review summarizes the clinical and experimental evidence supporting a contribution of immune mechanisms to the development of hypertension. In this context, we highlight the immune cell subsets that are postulated to either promote or protect against hypertension through modulation of cardiac output and/or peripheral vascular resistance. We conclude with an appraisal of knowledge gaps still to be addressed before immunomodulatory therapies might be applied to at least a subset of patients with hypertension.

Coexistence effect of hypertension and angiotensin II on the risk of coronary heart disease: a population-based prospective cohort study among Inner Mongolians in China

Objective: To investigate the coexistence effect of hypertension and angiotensin II on the risk of coronary heart disease based on a prospective study in an Inner Mongolian population of China. Methods: The participants were categorized into four subgroups according to hypertension status and median of angiotensin II level. Incident coronary heart disease (CHD) was defined as study outcome. A Cox proportional hazard model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) of CHD across the four subgroups after adjusting for important confounding factors. Results: During an average 9.2 years of follow-up, a total of 75 incident CHD cases were observed. The cumulative incidence rates of CHD among normotensives with angiotensin II ≤49 pg/mL, normotensives with angiotensin II >49 pg/mL, hypertensives with angiotensin II ≤49 pg/mL and hypertensives with angiotensin II >49 pg/mL were 1.76%, 1.50%, 4.71% and 5.62%, respectively (log-rank test, p < .001). Compared to the normotensives, the multivariable adjusted HRs (95% CI) of CHD with hypertensives and Ang II >49 pg/mL were 2.43 (1.41-4.17) and 1.30 (0.81-2.07), respectively. Furthermore, compared to normotensives with angiotensin II ≤49 pg/mL, the multivariate-adjusted HRs (95% CIs) of CHD for normotensives with angiotensin II >49 pg/mL, hypertensives with angiotensin II ≤49 pg/mL and hypertensives with angiotensin II >49 pg/mL were 1.33 (0.60-2.91), 2.35 (1.16-4.76) and 3.00 (1.52-5.92), respectively (p for trend <.05). The hypertensives with angiotensin II >49 pg/mL were at the highest risk of CHD. Conclusions: Hypertension not angiotensin II was an independent risk factor for incident CHD, but the coexistence of both hypertension and high angiotensin II level further increased risk of incident CHD among the Inner Mongolians.

T-Lymphocyte-Based Renin Angiotensin System in Obesity

BACKGROUND

Obesity can be associated with increased cardio-metabolic risk, but some subjects with obesity do not show metabolic impairment and escape this association. Low-grade inflammation (i.e., high sensitivity C-reactive protein [hsCRP] > 3 mg/dL) is associated with high cardiovascular risk in obesity. We investigated renin-angiotensin system (RAS) activity in cultured circulating T-cells in subjects with obesity with and without angiotensin II (Ang II) stimulation in the presence or absence of low-grade inflammation.

MATERIALS AND METHODS

We studied 18 subjects with obesity and 10 healthy subjects. After T-lymphocyte isolation, T-cell mRNAs for angiotensin converting enzyme (ACE) and AT1-receptor were quantified by reverse transcription polymerase chain reaction at baseline and after Ang II stimulation. hsCRP, plasma renin and ACE activity in the cell pellet and supernatant and Ang II T-cell content were also measured.

RESULTS

T-cell RAS in subjects with obesity with low-grade inflammation was more activated than in subjects with obesity without low-grade inflammation. The increase in RAS activation occurred both at baseline and after Ang II stimulation. Similarly, the release of ACE activity in the supernatant was significantly higher in subjects with obesity with hsCRP > 3 mg/dL than in subjects with hsCRP < 3 mg/dL and controls.

CONCLUSIONS

Circulating T-cell based RAS is activated in subjects with obesity independently of low-grade inflammation that amplifies the T-cell RAS response to Ang II stimulation.

Complete blood count-derived inflammatory markers in adolescents with primary arterial hypertension: a preliminary report

Aim of the study

The aim of our study was to evaluate selected inflammatory markers in children with untreated primary hypertension and to establish the relation between inflammatory markers and 24-hour ambulatory blood pressure monitoring (ABPM) and clinical and biochemical parameters.

Material and methods

In 54 children (15.12 ±2.02 years) with untreated primary hypertension, with excluded overt inflammation, we evaluated: neutrophils (NEU; 1000/μl), lymphocytes (LYM; 1000/μl), platelets (PLT; 1000/μl), mean platelet volume (MPV; fl), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), ABPM (OSCAR 2 SUNTECH), and selected clinical and biochemical parameters. The control group consisted of 20 healthy children (15.55 ±2.27 years).

Results

Children with primary hypertension had (p < 0.01) higher 24-hour systolic, diastolic and mean blood pressure, systolic and diastolic blood pressure loads, and pulse pressure. Hypertensive children did not differ in inflammatory indicators (NEU, LYM, PLT, MPV, NLR, PLR) from the control group. In 54 hypertensive children we found the following correlations: between office systolic and diastolic blood pressure and MPV (r = 0.35, p = 0.011, r = 0.36, p = 0.008), between 24-hour ambulatory mean arterial pressure Z-score and NLR (r = 0.30, p = 0.030), 24-hour systolic blood pressure load and NLR (r = 0.38, p = 0.005), plasma renin activity and neutrophil count, NLR, PLR (r = 0.47, p = 0.016, r = 0.64, p < 0.001, r = 0.42, p = 0.033), urinary albumin loss and neutrophil count, NLR (r = 0.46, p = 0.001 and r = 0.42, p = 0.003). Multivariate analysis revealed that office SBP Z-score was related to MPV (β = 0.35, p = 0.008) and albuminuria to neutrophil count (β = 0.62, p = 0.018).

Conclusions

In children with primary arterial hypertension there may be a relation between blood pressure, urinary albumin loss, and subclinical inflammation.

The association between mean platelet volume and inflammation in geriatric patients with emergency hypertension

Objectives

We aimed to investigate the role of inflammation parameters and platelet activation in geriatric patients with hypertension. Therefore, we compared the levels of those parameters in patients with hypertensive urgency and emergency. We also investigated the potential relationship between those parameters.

Methods

Ninety-six hypertensive (HT) patients (aged > 60) were included in the study in two groups: HT emergency (N = 48, group 1) and HT urgency (N = 48, group 2). Mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR) and high-sensitive C reactive protein (hs-CRP) were compared between those groups. Optimum cut-off levels of each parameter were determined by the use of Receiver operating characteristic (ROC) curve analysis. Pearson correlation test was used to examine the relationship between variables.

Results

The mean MPV and hs-CRP levels were significantly higher in patients with HT emergencies (both P < 0.001). Mean NLR was also significantly different between the two groups (P = 0.011). Pearson correlation analysis revealed a positive but weak correlation between the MPV and NLR (r = 0.245, P = 0.016), the hs-CRP level (r = 0.394, P < 0.001), and the WBC count (r = 0.362, P < 0.001).

Conclusion

Increased platelet activity and inflammation are associated with the end organ failure. Levels of MPV and other inflammatory parameters may be useful in the management of geriatric patients with HT.

Angiotensin receptor-binding molecule in leukocytes in association with the systemic and leukocyte inflammatory profile

BACKGROUND AND AIMS

The components of the renin-angiotensin system in leukocytes is involved in the pathophysiology of non-communicable diseases (NCDs), including hypertension, atherosclerosis and chronic kidney disease. Angiotensin II type 1 receptor (AT1R)-associated protein (ATRAP) is an AT1R-specific binding protein, and is able to inhibit the pathological activation of AT1R signaling in certain animal models of NCDs. The aim of the present study was to investigate the expression and regulation of ATRAP in leukocytes.

METHODS

Human leukocyte ATRAP mRNA was measured with droplet digital polymerase chain reaction system, and analyzed in relation to the clinical variables. We also examined the leukocyte cytokines mRNA in bone-marrow ATRAP-deficient and wild-type chimeric mice after injection of low-dose lipopolysaccharide.

RESULTS

The ATRAP mRNA was abundantly expressed in leukocytes, predominantly granulocytes and monocytes, of healthy subjects. In 86 outpatients with NCDs, leukocyte ATRAP mRNA levels correlated positively with granulocyte and monocyte counts and serum C-reactive protein levels. These positive relationships remained significant even after adjustment. Furthermore, the leukocyte ATRAP mRNA was significantly associated with the interleukin-1β, tumor necrosis factor-α and monocyte chemotactic protein-1 mRNA levels in leukocytes of NCDs patients. In addition, the leukocyte interleukin-1β mRNA level was significantly upregulated in bone marrow ATRAP-deficient chimeric mice in comparison to wild-type chimeric mice after injection of lipopolysaccharide.

CONCLUSIONS

These results suggest that leukocyte ATRAP is an emerging marker capable of reflecting the systemic and leukocyte inflammatory profile, and plays a role as an anti-inflammatory factor in the pathophysiology of NCDs.

Persistent and selective upregulation of renin-angiotensin system in circulating T lymphocytes in unstable angina

Introduction:

Unstable angina is associated with an acute systemic inflammatory reaction and circulating T lymphocytes are activated. We investigated whether in unstable angina with marked immune system activation a selective upregulation of the circulating T-cell renin–angiotensin system, modulated by angiotensin II, could occur.

Methods:

We studied 13 unstable angina patients, 10 patients with stable angina and 10 healthy subjects. After T-lymphocyte isolation, mRNAs for angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT1-R) were quantified at baseline and after angiotensin II stimulation. ACE activity in cell pellet and supernatant and angiotensin II cell content were measured.

Results:

Plasma renin activity was similar in controls, stable and unstable angina patients. At baseline ACE and AT1-R mRNA levels were higher (P<0.05) in T cells from unstable angina patients than in T cells from stable angina patients and controls, and further increased after angiotensin II addition to cultured T cells. ACE activity of unstable angina T cells was significantly higher than that of T cells from controls and stable angina patients. Only in T cells from unstable angina patients did angiotensin II stimulation cause the almost complete release of ACE activity in the supernatant.

Conclusions:

The circulating T-cell-based renin–angiotensin system from unstable angina patients was selectively upregulated. In vivo unstable angina T cells could locally increase angiotensin II concentration in tissues where they migrate independently of the circulating renin–angiotensin system.

The phosphoinositide-3 kinase signaling is involved in neuroinflammation in hypertensive rats

AIMS

It has been demonstrated that neuroinflammation is associated with cardiovascular dysfunction. The phosphoinositide-3 kinase (PI3K) signaling in the rostral ventrolateral medulla (RVLM), a key region for sympathetic outflow, is upregulated and contributes to increased blood pressure (BP) and sympathetic outflow in hypertension. This study was designed to determine the role of the PI3K signaling in neuroinflammation in the RVLM of hypertension.

METHODS

The normotensive WKY rats were performed by intracisternal infusion of lipopolysaccharide (LPS) or angiotensin II (Ang II) for inducing neuroinflammation. Elisa was used to determine the level of proinflammatory cytokines. Western blot was employed to detect the protein expression of PI3K signaling pathway. Gene silencing of PI3K p110δ subunit and overexpression of angiotensin-converting enzyme 2 (ACE2) were realized by injecting related lentivirus into the RVLM.

RESULTS

In the spontaneously hypertensive rats (SHR), the PI3K signaling in the RVLM was upregulated compared with WKY, gene silencing of PI3K in the RVLM significantly reduced BP and renal sympathetic nerve activity (RSNA), but also decreased the levels of proinflammatory cytokines. In the WKY rats, central infusion of LPS and Ang II significantly elevated BP and RSNA, but also increased the levels of proinflammatory cytokines and PI3K signaling activation in the RVLM. These changes in the Ang II-induced hypertension were effectively prevented by gene silencing of PI3K in the RVLM. Furthermore, overexpression of ACE2 in the RVLM significantly attenuated high BP and neuroinflammation, as well as decreased the activation of PI3K signaling in hypertensive rats.

CONCLUSION

This study suggests that the PI3K signaling in the RVLM is involved in neuroinflammation in hypertension and plays an important role in the renin-angiotensin system-mediated changes in neuroinflammation in the RVLM.

Primary hypertension is a disease of premature vascular aging associated with neuro-immuno-metabolic abnormalities

There is an increasing amount of data indicating that primary hypertension (PH) is not only a hemodynamic phenomenon but also a complex syndrome involving abnormal fat tissue distribution, over-activity of the sympathetic nervous system (SNS), metabolic abnormalities, and activation of the immune system. In children, PH usually presents with a typical phenotype of disturbed body composition, accelerated biological maturity, and subtle immunological and metabolic abnormalities. This stage of the disease is potentially reversible. However, long-lasting over-activity of the SNS and immuno-metabolic alterations usually lead to an irreversible stage of cardiovascular disease. We describe an intermediate phenotype of children with PH, showing that PH is associated with accelerated development, i.e., early premature aging of the immune, metabolic, and vascular systems. The associations and determinants of hypertensive organ damage, the principles of treatment, and the possibility of rejuvenation of the cardiovascular system are discussed.

Blood Neutrophil to Lymphocyte Ratio as a Predictor of Hypertension

BACKGROUND

Hypertension is a significant global public health challenge. Low-grade inflammation is known to facilitate the development of essential hypertension and target-organ hypertensive damage. Neutrophil to lymphocyte ratio (NLR) is a simple and reliable indicator of inflammation that may also be useful in the prediction of hypertension.

METHODS

Participants were recruited from Tianjin Medical University's General Hospital-Health Management Centre. A total of 28,850 initially hypertension-free subjects were followed from 2007 to 2013. Adjusted Cox proportional hazards regression models were used to assess relationships between NLR categories and incidence of hypertension.

RESULTS

During the ~6-year follow-up period (median duration of follow-up (interquartile range): 2.63 (2.58-2.68)), 1,824 subjects developed hypertension. The hazard ratios of hypertension incidence were evaluated in increasing NLR quintiles. Compared with participants with the lowest NLR levels, the multivariable-adjusted hazard ratios (95% confidence interval) of hypertension were related to increasing NLR quintiles and were as follows: 1.08 (0.92, 1.26), 0.97 (0.83, 1.14), 1.10 (0.94, 1.28), and 1.23 (1.06, 1.43), respectively (P for trend < 0.01). Similar results also were observed in the white blood cell and neutrophil counts, but not lymphocyte counts.

CONCLUSIONS

The study is the first to show the elevated NLR levels significantly correlate with an increased risk of developing hypertension. This result may be useful in elucidating the mechanism underlying the development of hypertension. New therapeutic approaches aimed at inflammation might be proposed to control hypertension and hypertensive damage.

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.

Protection of vascular endothelial cells injured by angiotensin II and hypoxia in vitro by Ginkgo biloba (Ginaton)

The objective of this study was to explore the protective effect and the possible mechanism of Ginkgo biloba extract (Ginaton) on human vascular endothelial cells (VECs) injured by angiotensin II (Ang-II) and hypoxia. The human aortic VECs were divided into different groups to observe the changes in endothelin (ET), calcium concentration ([Ca(2+)]i), and mitochondrial membrane potential (MMP). The results showed that Ginaton had inhibited ET secretion induced by hypoxia and Ang-II (P < .01). the protection offered by Ginaton at mid (10 mg/mL) and low (5 mg/mL) concentrations was obviously better than that offered at high concentration (25 mg/mL). The [Ca(2+)]i increased and MMP decreased significantly in both hypoxia group and Ang-II group (P < .01); however, the changes in [Ca(2+)]i and MMP could be meliorated by Ginaton. This study suggested that Ginaton could effectively protect VECs against injury, and the dose used clinically would rather be low than too high for getting better results.

Protective Effects of Ginaton on Vascular Endothelial Cells Injured by Angiotensin II and Hypoxia In Vitro

The objective of this study was to explore the protective effect and possible mechanism of Ginkgo biloba extract (Ginaton) on human vascular endothelial cells (VECs) injured by angiotensin II (Ang-II) and hypoxia. The human aortic VECs were divided into different groups to observe the changes in endothelin (ET), intracellular calcium concentration ([Ca2+]i), and mitochondrial membrane potential (MMP). The results showed that Ginaton had inhibited ET secretion induced by hypoxia and Ang-II ( P < .01); the protective effects of mid (10 mg/mL) and low concentrations (5 mg/mL) of Ginaton was obviously higher than that of the high concentration (25 mg/mL); [Ca2+]i increased and MMP decreased significantly in both the hypoxia and the Ang-II groups ( P < .01); however, the changes in [Ca2+]i and MMP could be meliorated by Ginaton. This study suggested that Ginaton could effectively protect VECs against injury, and lower dose would be used clinically rather than the higher dose for obtaining better results.

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.

Sensitization of slow pressor angiotensin II (Ang II)-initiated hypertension: induction of sensitization by prior Ang II treatment

Sensitization involving the central nervous system has been studied in many conditions but has received little attention in investigation of the pathogenesis of hypertension. Our experiments were initiated to determine whether angiotensin II (Ang II)-induced hypertension can be sensitized by prior Ang II treatment and the role of the brain renin-angiotensin-aldosterone system (RAAS) in this process. To demonstrate Ang II-induced sensitization, we used an experimental design of induction-delay-expression. Male rats were implanted for telemetered blood pressure (BP) recording. During induction (I), low doses of subcutaneous or intracerebroventricular Ang II were delivered for 1 week, and then the rats were rested for 1 week (delay [D]) to ensure that any exogenous Ang II was metabolized. After this, a second higher dose of Ang II was given subcutaneously for 2 weeks (expression [E]). During I and D, the low doses of Ang II had no sustained effects on BP. However, during E, the Ang II-induced BP increase was greater in the groups that had received low doses of Ang II during I in comparison to the group receiving saline during I. Central angiotensin type 1 receptor antagonist delivery blocked this sensitization. Brain tissue collected at the end of D and E showed increased mRNA expression of several RAAS components in key forebrain regions of sensitized rats. Fos-related antigen-like immunoreactivity was also increased at the end of E in the sensitized forebrain. These results indicate that subpressor doses of Ang II act on the brain to sensitize the hypertensive response to subsequent Ang II and that sensitization is associated with altered expression of RAAS components in forebrain cardiovascular control structures.