Maria Antonietta Coschignano

Changes in extracellular matrix in subcutaneous small resistance arteries of patients with essential hypertension

Abstract Background: In the development of hypertensive microvascular remodeling, a relevant role may be played by changes in extracellular matrix proteins. Aim of this study was the to evaluate some extracellular matrix components within the tunica media of subcutaneous small arteries in 9 normotensive subjects and 12 essential hypertensive patients, submitted to a biopsy of subcutaneous fat from the gluteal or the anterior abdominal region. Patients and Methods: Subcutaneous small resistance arteries were dissected and mounted on an isometric myograph, and the tunica media to internal lumen ratio was measured. In addition, fibronectin, laminin, transforming growth factor-beta-1 (TGF-β1) and emilin-1 contents within the tunica media were evaluated by immunofluorescence and relative immunomorphometrical analysis (immunopositivity % of area). The total collagen content and collagen subtypes within the tunica media were evaluated using both Sirius red staining (under polarized light) and immunofluorescence assay. Results: Normotensive controls had less total and type III collagen in respect with hypertensive patients. Fibronectin and TGF-β1 tunica media content was significantly greater in essential hypertensive patients, compared with normotensive controls, while laminin and emilin-1 tunica media content was lesser in essential hypertensive patients, compared with normotensive controls. A significant correlation was observed between fibronectin tunica media content and media to lumen ratio. Conclusions: Our results indicate that, in small resistance arteries of patients with essential hypertension, a relevant fibrosis may be detected; fibronectin and TGF-β1 tunica media content is increased, while laminin and emilin-1 content is decreased; these changes might be involved in the development of small resistance artery remodeling in humans.

Decreased circulating T regulatory lymphocytes in obese patients undergoing bariatric surgery

Objective It has been previously demonstrated that T lymphocytes may be involved in the development of hypertension and microvascular remodeling, and that circulating T effector lymphocytes may be increased in hypertension. In particular, Th1 and Th 17 lymphocytes may contribute to the progression of hypertension and microvascular damage while T-regulatory (Treg) lymphocytes seem to be protective in this regard. However, no data is available about patients with severe obesity, in which pronounced microvascular alterations were observed. Design and methods We have investigated 32 severely obese patients undergoing bariatric surgery, as well as 24 normotensive lean subjects and 12 hypertensive lean subjects undergoing an elective surgical intervention. A peripheral blood sample was obtained before surgery for assessment of CD4+ T lymphocyte subpopulations. Lymphocyte phenotype was evaluated by flow cytometry in order to assess T-effector and Treg lymphocytes. Results A marked reduction of several Treg subpopulations was observed in obese patients compared with controls, together with an increased in CD4+ effector memory T-effector cells. Conclusion In severely obese patients, Treg lymphocytes are clearly reduced and CD4+ effector memory cells are increased. It may be hypothesized that they might contribute to the development of marked microvascular alterations previously observed in these patients.

POOR CONCORDANCE BETWEEN NON-INVASIVE AND LOCALLY INVASIVE TECHNIQUES OF EVALUATION OF MICROVASCULAR MORPHOLOGY IN THE DETECTION OF HYPERTROPHIC REMODELING OF SMALL RESISTANCE ARTERIES

Objective: The evaluation of the morphological characteristics of small resistance arteries in human beings is not easy. The gold standard is generally considered to be the evaluation of the media to lumen ratio (MLR) of subcutaneous small vessels obtained by local biopsies and evaluated by wire or pressure micromyiography. However, non-invasive techniques for the evaluation of retinal arterioles were recently proposed, in particular two approaches seem to provide interesting information: scanning laser Doppler flowmetry (SLDF) and adaptive optics (AO); both of them provide an estimation of the wall to lumen ratio (WLR) of retinal arterioles, as well as of internal and external diameters and wall cross-sectional area. Design and method: In the present study we enrolled 12 normotensive subjects, 12 lean hypertensive patients (HP), 9 severely obese normotensive patients (ONP) and 8 severely obese hypertensive patients (OHP), undergoing an election surgical intervention. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire micromyography and the MLR was calculated. WLR of retinal arterioles was obtained by Scanning Laser Doppler Flowmetry and AO (SLDF, Heidelberg Engineering, Heidelberg, Germany and RTX-1, Imagine Eyes, Orsay, France). In hypertensive/obese patients the characteristics of microvascular remodeling were assessed by the calculation of the remodeling and growth indices, according to Heagerty AM et al, Hypertension 1993; 21:391–391). The remodeling index quantifies the proportion of the increase in the MLR or WLR that may be explained by a re-arrangement of the same amount of wall material around a narrowed lumen (eutrophic remodeling), while the growth index quantifies the contribution of vascular smooth muscle cell hypertrophy or hyperplasia (hypertrophic remodeling).When eutrophic remodeling is present, the remodeling index is close to 100%. Results: are reported in the Table. Figure. No caption available. Conclusions: Our data suggest that the three methodological approaches seems are not completely concordant in the detection of hypertrophic remodeling, since data provided are in relative poor agreement. The presence of a relevant proportion of hypertrophic remodeling in obese patients (Hypertension 2011; 58:29–36), observed with micromyographic approaches, is not always confirmed by non-invasive approaches.

REGRESSION OF RETINAL MICROVASCULAR ALTERATIONS IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH ABATACEPT, AN INHIBITOR OF LYMPHOCYTIC CO-STIMULATION

Objective: It has been previously demonstrated that T lymphocytes may be involved in the development of hypertension and microvascular remodeling, and that circulating T effector lymphocytes may be increased in hypertension (De Ciuceis C et al, Am J Hypertens 2017, 30:51–60; Itani HA et al. Hypertension 2016; 68:123–132). In particular, Th1 and Th 17 lymphocytes may contribute to the progression of hypertension and microvascular damage. Abatacept is a fusion protein composed of the Fc region of the immunoglobulin IgG1 fused to the extracellular domain of CTLA-4 that binds to the CD80 and CD86 molecule, and prevents activation of T cells, avoiding CD28 repetitive engagement. Abatacept is presently indicated for treatment of moderate to severe active rheumatoid arthritis in adults (aged 18 years or over) who have not had an adequate response to other drugs. The aim of our study was to non-invasively investigated morphological characteristics of retinal arterioles in patients with rheumatoid arthritis before and after treatment with abatacept. Design and method: In the present study we enrolled 5 patients with rheumatoid arthritis. The wall to lumen ratio (WLR) of retinal arterioles was measured by adaptive optics (RTX-1, Imagine Eyes, Orsay, France), a recently validated technique (De Ciuceis C, in press in J Hypertens) for non-invasive assessment of retinal arteriolar morphology, providing also an estimation of internal and external diameters and wall cross-sectional area. Morphological evaluations were performed at baseline, after 6 months and after 12 months of treatment Results: The results obtained are reported in the Table (* < 0.05, **p < 0.01 vs. baseline). Figure. No caption available. Conclusions: Our data suggest that a reduction in WLR, wall thickness and wall cross-sectional area was observed after treatment for 12 months with abatacept, thus suggesting the possibility to induce a regression of microvascular abnormalities through a modulation of the immune system.

Management of VEGF-Targeted Therapy-Induced Hypertension

Purpose of ReviewFrom a physiological point of view, VEGFs (vascular endothelial growth factors) and their receptors (VEGFR) play a critical role in vascular development angiogenesis, endothelial function, and vascular tone. On the pathological side, VEGF–VEGFR signaling may induce dysregulated angiogenesis, which contributes to the growth and to the spread of tumors, being essential for neoplastic proliferation and invasion.Recent FindingsPharmacological inhibition of VEGF–VEGFR is now a cornerstone in the treatment of many malignancies; however, treatment with VEGF inhibitors is commonly associated with an increase in blood pressure values. This side effect is strictly connected with the mechanism of action of these medications and might represent an index of therapy efficacy.SummaryThe optimal management of this form of hypertension is, at present, not clear. Calcium channel blockers and renin-angiotensin system inhibitors probably represent the most appropriate classes of hypertensive dugs for the treatment of this condition; however, no conclusive data are presently available.

[PP.09.17] REPRODUCIBILITY OF THE EVALUATION OF THE WALL TO LUMEN RATIO OF RETINAL ARTERIOLES WITH TWO DIFFERENT NON-INVASIVE APPROACHES: SCANNING LASER-DOPPLER FLOWMETRY AND ADAPTIVE OPTICS

Objective: The evaluation of the morphological characteristics of small resistance arteries in human beings in not easy. The gold standard is generally considered to be the evaluation of the media to lumen ratio of subcutaneous small vessels obtained by local biopsies and measured by wire or pressure micromyiography. However, non-invasive techniques for the evaluation of retinal arterioles were recently proposed, in particular two approaches seem to provide interesting information: scanning laser Doppler flowmetry and adaptive optics; both of them provide an estimation of the wall to lumen ratio (WLR) of retinal arterioles. The reproducibility of such measurements was previously stated to be acceptable (coefficient of variation <10% for SLDF, <4% for RTX-1), however, no direct comparison of the two techniques in the same population was previously performed. Design and method: Therefore, we evaluated 18 subjects and patients (10 normotensives, 8 hypertensives, 7/18 severely obese). In all of them an evaluation of the WLR of retinal arterioles was made by Scanning Laser Doppler Flowmetry (SLDF, Heidelberg Engineering, Heidelberg, Germany) and adaptive optics (RTX-1, Imagine Eyes, Orsay, France). The same operator evaluated the same acquired images in two different days (intra-observer variability), and two different operators evaluated the same images in the same day (inter-observer variability). Results: The results are reported in the Table (***p < 0.001). Variation coefficient of SLDF is much greater than that of AO. Figure. No caption available. Conclusions: It is clear how the reproducibility of the evaluation of the WLR with adaptive optics is far better, as compared with SLDF, since the variation coefficient are clearly lower. This may be important in terms of clinical evaluation of microvascular morphology in a clinical setting.

[OP.8C.03] COMPARISON BETWEEN THREE NON-INVASIVE TECHNIQUES OF EVALUATION MICROVASCULAR MORPHOLOGY VS. THE GOLD-STANDARD LOCALLY INVASIVE MICROMYOGRAPHY. PRELIMINARY DATA

Objective: The evaluation of the morphological characteristics of small resistance arteries in human beings in not easy. The gold standard is generally considered to be the evaluation of the media to lumen ratio (M/L) of subcutaneous small vessels obtained by local biopsies and evaluated by wire or pressure micromyiography. However, non-invasive techniques for the evaluation of retinal arterioles were recently proposed, in particular two approaches seem to provide interesting information: scanning laser Doppler flowmetry (SLDF) and adaptive optics (AO); both of them provide an estimation of the wall to lumen ratio (WLR) of retinal arterioles. A non-invasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. No direct comparison of the three non-invasive techniques in the same population was previously performed, in particular AO was never validated against micromyography. Design and method: In the present study we enrolled 12 normotensive subjects and 8 hypertensive patients undergoing an election surgical intervention; 11/20 were severely obese). All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire myography and the M/L was calculated. WLR of retinal arterioles was obtained by Scanning Laser Doppler Flowmetry and AO (SLDF, Heidelberg Engineering, Heidelberg, Germany and RTX-1, Imagine Eyes, Orsay, France). Functional (basal) and structural (total) microvascular density were evaluated by capillaroscopy (Videocap 3, DS Medica, Milan, Italy) before and after venous congestion. Results: The results are summarized in the Table (slope of the relation: p < 0.01 RTX-1 vs. SLDF). Figure. No caption available. Conclusions: Our data suggest that AO has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, since it is more closely correlated with the M/L of subcutaneous small arteries, considered a gold-standard approach but limited in its clinical application by the local invasiveness of the procedure.

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