Alice Gavazzi

Pulsatile Hemodynamics and Microcirculation Evidence for a Close Relationship in Hypertensive Patients

The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure (r=0.36 and 0.31, P<0.001, respectively) and to central systolic and pulse pressure (r=0.44 and 0.42, P<0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity (r=0.45; P<0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index (r=0.33; P=0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections.The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure ( r =0.36 and 0.31, P <0.001, respectively) and to central systolic and pulse pressure ( r =0.44 and 0.42, P <0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity ( r =0.45; P <0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index ( r =0.33; P =0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections. # Novelty and Significance {#article-title-38}

Pulsatile Hemodynamics and MicrocirculationNovelty and Significance: Evidence for a Close Relationship in Hypertensive Patients

The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure (r=0.36 and 0.31, P<0.001, respectively) and to central systolic and pulse pressure (r=0.44 and 0.42, P<0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity (r=0.45; P<0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index (r=0.33; P=0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections.The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure ( r =0.36 and 0.31, P <0.001, respectively) and to central systolic and pulse pressure ( r =0.44 and 0.42, P <0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity ( r =0.45; P <0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index ( r =0.33; P =0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections. # Novelty and Significance {#article-title-38}

Immune Mechanisms in Hypertension

Low grade inflammation may have a key role in the pathogenesis of hypertension and cardiovascular disease. Several studies showed that both innate and adaptive immune systems may be involved, being T cells the most important players. Particularly, the balance between Th1 effector lymphocytes and Treg lymphocytes may be crucial for blood pressure elevation and related organ damage development. In the presence of a mild elevation of blood pressure, neo-antigens are produced. Activated Th1 cells may then contribute to the persistent elevation of blood pressure by affecting vasculature, kidney and perivascular fat. On the other hand, Tregs represent a lymphocyte subpopulation with an anti-inflammatory role, being their activity crucial for the maintenance of cardiovascular homeostasis. Indeed, Tregs were demonstrated to be able to protect from blood pressure elevation and from the development of organ damage, including micro and macrovascular alterations, in different animal models of genetic or experimental hypertension. In the vasculature, inflammation leads to vascular remodeling through cytokine activity, smooth muscle cell proliferation and oxidative stress. It is also known that a consistent part of ischemia-reperfusion-induced acute kidney injury is mediated by inflammatory infiltration and that Treg cell infusion have a protective role. Also the central nervous system has an important role in the maintenance of cardiovascular homeostasis. In conclusion, hypertension development involves chronic inflammatory process. Knowledge of cellular and molecular players in the progression of hypertension has dramatically improved in the last decade, by assessing the central role of innate and adaptive immunity cells and proinflammatory cytokines driving the development of target organ damage. The new concept of role of immunity, especially implicating T lymphocytes, will eventually allow discovery of new therapeutic targets that may improve outcomes in hypertension and cardiovascular or renal disease in humans and uncover an entirely novel approach in the treatment of hypertension and vascular disease.

Relationship Between Different Subpopulations of Circulating CD4+ T-lymphocytes and Microvascular Structural Alterations in Humans

BACKGROUND Different components of the immune system, including innate and adaptive immunity (T-effector lymphocytes and T-regulatory lymphocytes—TREGs) may be involved in the development of hypertension. In addition, it was demonstrated in animal models that TREGs may prevent angiotensin II-induced hypertension and vascular injury/inflammation. However, no data are presently available in humans about possible relationships between T-lymphocyte subtypes and microvascular structural alterations. METHODS For this purpose, in the present study, we enrolled 24 normotensive subjects and 12 hypertensive patients undergoing an elective surgical intervention. No sign of local or systemic inflammation was present. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph and the media to lumen ratio (M/L) was calculated. In addition, retinal arteriolar structure was evaluated noninvasively by scanning laser Doppler flowmetry. Capillary density in the nailfold, dorsum of the finger, and forearm were evaluated by videomicroscopy. A peripheral blood sample was obtained before surgery for assessment of T-lymphocyte subpopulations by flow cytometry. RESULTS Significant negative correlations were observed between indices of microvascular structure (M/L of subcutaneous small arteries and wall to lumen ratio of retinal arterioles) and circulating TREG lymphocytes. A direct correlation was observed between M/L of subcutaneous small arteries and circulating Th17 lymphocytes. In addition, total capillary density was correlated with a TREG effector memory subpopulation. CONCLUSION Our data suggest that some lymphocyte subpopulations may be related to microvascular remodeling, confirming previous animal data, and opening therapeutic possibilities.

Relationship between different subpopulations of circulating CD4+ T lymphocytes and microvascular or systemic oxidative stress in humans

Abstract Background and objective: Different components of the immune system, including innate and adaptive immunity (T effector lymphocytes and T regulatory lymphocytes – TREGs) may be involved in the development of hypertension, vascular injury and inflammation. However, no data are presently available in humans about possible relationships between T-lymphocyte subtypes and microvascular oxidative stress. Our objective was to investigate possible relationships between T-lymphocyte subtypes and systemic and microvascular oxidative stress in a population of normotensive subjects and hypertensive patients. Patients and methods: In the present study we enrolled 24 normotensive subjects and 12 hypertensive patients undergoing an elective surgical intervention. No sign of local or systemic inflammation was present. All patients underwent a biopsy of subcutaneous fat during surgery. A peripheral blood sample was obtained before surgery for assessment of T lymphocyte subpopulations by flow cytometry and circulating indices of oxidative stress. Results: A significant direct correlation was observed between Th1 lymphocytes and reactive oxygen species (ROS) production (mainly in microvessels). Additionally, significant inverse correlations were observed between ROS and total TREGs, or TREGs subtypes. Significant correlations were detected between circulating indices of oxidative stress/inflammation and indices of microvascular morphology/Th1 and Th17 lymphocytes. In addition, a significant inverse correlation was detected between TREGs in subcutaneous small vessels and C reactive protein. Conclusions: Our data suggest that TREG lymphocytes may be protective against microvascular damage, probably because of their anti-oxidant properties, while Th1–Th17 lymphocytes seem to exert an opposite effect, confirming an involvement of adaptive immune system in microvascular damage.

Pulsatile Hemodynamics and Microcirculation

The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure (r=0.36 and 0.31, P<0.001, respectively) and to central systolic and pulse pressure (r=0.44 and 0.42, P<0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity (r=0.45; P<0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index (r=0.33; P=0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections.The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure ( r =0.36 and 0.31, P <0.001, respectively) and to central systolic and pulse pressure ( r =0.44 and 0.42, P <0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity ( r =0.45; P <0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index ( r =0.33; P =0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections. # Novelty and Significance {#article-title-38}

[PP.21.05] RELATIONSHIP BETWEEN MICROVASCULAR STRUCTURE AND T REGULATORY LYMPHOCYTES OF SMALL RESISTANCE ARTERIES

Objective: Recently it has been demonstrated a role for adaptive immunity, particularly for T regulatory lymphocytes (Tregs), in the development of hypertension and in preventing of angiotensin II–induced vascular injury and inflammation in animal models (Barhoumi T et al, Hypertension 2011;57:469–476). However, no data are presently available in human beings about possible relationships between Tregs and microvascular structural alterations. Design and method: In the present study we enrolled 11 normotensive subjects and 8 hypertensive patients undergoing an election surgical intervention. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire myography and media to lumen ratio (M/L) was calculated. W/L of retinal arterioles was obtained by Scanning Laser Doppler Flowmetry. Functional (basal) and structural (total) microvascular density were studied by capillaroscopy before and after venous congestion. No sign of local or systemic inflammation was present in any subjects or patients. We extracted genomic DNA from small resistance arteries and analyzed methylation status of the FoxP3 gene promoter involved in Treg lymphocytes activation. Unmethylated FoxP3 has been demonstrated to be specific for Treg lymphocytes. A peripheral blood sample was obtained before surgery for routine chemistry Results: Results are summarized in the Table. Figure. No caption available. A significant positive correlation was detected between Tregs in small resistance arteries and basal, total and delta gain capillary density in the forearm, whereas no correlations were observed with small resistance artery M/L and retinal arteriole W/L. In addition, a significant inverse correlation was detected between Treg in subcutaneous small vessels and C reactive protein. Conclusions: Our data suggest that Treg lymphocytes detected in subcutaneous small resistance artery wall are related with capillary density and inversely related with inflammatory markers suggesting a protecting role of Treg also, probably, in terms of angiogenetic properties.

RELATIONSHIP BETWEEN MICROVASCULAR T REGULATORY LYMPHOCYTES AND CIRCULATING LYMPHOCYTES

Objective: Both innate and adaptive immune systems may contribute to the pathogenesis of cardiovascular disease and vascular remodeling through inflammation and oxidative stress. Particularly, the balance between Th1 effector lymphocytes (producing interferon-&ggr;), Th 17 (producing IL-17) and T regulatory (Treg) lymphocytes, which elicit an anti-inflammatory activity, may be crucial for blood pressure elevation and organ damage development, at least in experimental models. Tregs have been previously demonstrated to inversely correlate with subcutaneous small resistance artery media to lumen ratio (M/L) and retinal arteriole wall to lumen ratio (W/L) (unpublished data). Design and method: Therefore, we evaluated the possible relationship between Treg detected in small resistance arteries and circulating levels of Treg. We enrolled 11 normotensive subjects and 4 hypertensive patients undergoing an election surgical intervention (usually removal of adrenal gland for a non-producing adenoma). No sign of local or systemic inflammation was present in any subjects or patients. All patients underwent a biopsy of subcutaneous fat during surgery and small resistance arteries were isolated. We extracted genomic DNA from small resistance arteries and analyzed methylation status of the FoxP3 gene promoter involved in Treg lymphocytes activation. Unmethylated FoxP3 has been demonstrated to be specific for Treg lymphocytes. A peripheral blood sample was obtained before surgery for assessment of T lymphocyte subpopulations. Lymphocyte phenotype was evaluated by flow cytometry after 5 days in vitro activation in order to assess Th17 lymphocytes. Results: A significant positive correlation was detected between Treg in small resistance arteries and circulating levels of Treg (R = 0.42, p∼0.05) whereas an inverse correlation was observed between Th17 lymphocytes and Treg in small resistance arteries (R = -0.46, p < 0.05). Conclusions: Our data suggest that Treg lymphocytes detected in subcutaneous small resistance artery wall are related to circulating Treg which were previously observed to inversely correlate with subcutaneous small resistance artery media to lumen ratio and retinal arteriole wall to lumen ratio. This suggest that Treg may be protective against microvascular damage confirming an involvement of adaptive immune system on microvascular remodeling.

Aging and structural alterations of subcutaneous small resistance arteries in hypertensive patients

To cite this article: Carolina De Ciuceis, Claudia Rossini, Claudia Agabiti Rosei, Enzo Porteri, Alice Gavazzi, Stefano Caletti, Paola Pileri, Maria Antonietta Coschignano, Enrico Agabiti Rosei, Damiano Rizzoni* (2015) P2.1: AGING AND STRUCTURAL ALTERATIONS OF SUBCUTANEOUS SMALL RESISTANCE ARTERIES IN HYPERTENSIVE PATIENTS, Artery Research 12:C, 6–6, DOI: https://doi.org/10.1016/j.artres.2015.10.209

Pulsatile Hemodynamics and MicrocirculationNovelty and Significance

The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure (r=0.36 and 0.31, P<0.001, respectively) and to central systolic and pulse pressure (r=0.44 and 0.42, P<0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity (r=0.45; P<0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index (r=0.33; P=0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections.The possible relationships between indicators of small resistance artery structure and of arterial stiffness and central hemodynamics have not yet been evaluated. Aim of this study was to assess the relationship between indicators of large arteries stiffness, including carotido-femoral pulse wave velocity and of vascular alterations in small resistance arteries (media/lumen ratio, M/L) in patients with primary and secondary hypertension. In 73 patients (mean age, 53±14 years, 34 females, 25 with type 2 diabetes mellitus, 18 never treated) with essential (n=37) and secondary (n=36) hypertension, carotido-femoral pulse wave velocity was measured. In all patients, small resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M/L. Pulse wave analysis was performed in 67 patients. M/L ratio was significantly related to brachial systolic blood pressure and pulse pressure ( r =0.36 and 0.31, P <0.001, respectively) and to central systolic and pulse pressure ( r =0.44 and 0.42, P <0.001, respectively). A positive correlation was observed between M/L ratio and carotido-femoral pulse wave velocity ( r =0.45; P <0.001); this correlation remained statistically significant after adjustment for age and mean blood pressure. M/L ratio was also associated to aortic augmentation index ( r =0.33; P =0.008), and this correlations remained statistically significant after adjustment for potential confounders. In hypertensive patients, the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and possibly contribute to an increase in central pressure by increasing the magnitude of wave reflections. # Novelty and Significance {#article-title-38}