Endogenous CGRP protects against neointimal hyperplasia following wire-induced vascular injury

信州大学博士（医学）・学位論文・平成25年3月31日授与（甲第942号）・楊 磊Neointimal hyperplasia is the primary lesion underlying atherosclerosis and restenosis after percutaneous coronary intervention. Calcitonin gene-related peptide (CGRP) is produced by alternative splicing of the primary transcript of the calcitonin/CGRP gene. Originally identified as a strongly vasodilatory neuropeptide, CGRP is now known to be a pleiotropic peptide widely distributed in various organs and tissues. Our aim was to investigate the possibility that CGRP acts as an endogenous vasoprotective molecule. We compared the effect of CGRP deficiency on neointimal formation after wire-induced vascular injury in wild-type and CGRP knockout (CGRP-/-) mice. We found that neointimal formation after vascular injury was markedly enhanced in CGRP-/- mice, which also showed a higher degree of oxidative stress, as indicated by reduced expression of nitric oxide synthase, increased expression of p47phox, and elevated levels of 4HNE, as well as greater infiltration of macrophages. In addition, CGRP-deficiency led to increased vascular smooth muscle cell (VSMC) proliferation within the neointima. By contrast, bone marrow-derived cells had little or no effect on neointimal formation in CGRP-/- mice. In vitro analysis showed that CGRP-treatment suppressed VSMC proliferation, migration, and ERK1/2 activity. These results clearly demonstrate that endogenous CGRP suppresses the oxidative stress and VSMC proliferation induced by vascular injury. As a vasoprotective molecule, CGRP could be an important therapeutic target in cardiovascular disease. (C) 2013 Elsevier Ltd. All rights reserved.ArticleJOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY. 59(0):55-66 (2013)journal articl

Vascular Endothelial Adrenomedullin-RAMP2 System Is Essential for Vascular Integrity and Organ Homeostasis

信州大学博士（医学）・学位論文・平成25年3月31日授与（甲第935号）・小山 晃英Background-Revealing the mechanisms underlying the functional integrity of the vascular system could make available novel therapeutic approaches. We previously showed that knocking out the widely expressed peptide adrenomedullin (AM) or receptor activity-modifying protein 2 (RAMP2), an AM-receptor accessory protein, causes vascular abnormalities and is embryonically lethal. Our aim was to investigate the function of the vascular AM-RAMP2 system directly. Methods and Results-We generated endothelial cell-specific RAMP2 and AM knockout mice (E-RAMP2(-/-) and E-AM(-/-)). Most E-RAMP2(-/-) mice died perinatally. In surviving adults, vasculitis occurred spontaneously. With aging, E-RAMP2(-/-) mice showed severe organ fibrosis with marked oxidative stress and accelerated vascular senescence. Later, liver cirrhosis, cardiac fibrosis, and hydronephrosis developed. We next used a line of drug-inducible E-RAMP2(-/-) mice (DI-E-RAMP2(-/-)) to induce RAMP2 deletion in adults, which enabled us to analyze the initial causes of the aforementioned vascular and organ damage. Early after the induction, pronounced edema with enhanced vascular leakage occurred. In vitro analysis revealed the vascular leakage to be caused by actin disarrangement and detachment of endothelial cells. We found that the AM-RAMP2 system regulates the Rac1-GTP/RhoA-GTP ratio and cortical actin formation and that a defect in this system causes the disruption of actin formation, leading to vascular and organ damage at the chronic stage after the gene deletion. Conclusions-Our findings show that the AM-RAMP2 system is a key determinant of vascular integrity and homeostasis from prenatal stages through adulthood. Furthermore, our models demonstrate how endothelial cells regulate vascular integrity and how their dysregulation leads to organ damage. (Circulation. 2013;127:842-853.)ArticleCIRCULATION. 127(7):842-853 (2013)journal articl

Endogenous CGRP protects against neointimal hyperplasia following wire-induced vascular injury

信州大学博士（医学）・学位論文・平成25年3月31日授与（甲第942号）・楊 磊Neointimal hyperplasia is the primary lesion underlying atherosclerosis and restenosis after percutaneous coronary intervention. Calcitonin gene-related peptide (CGRP) is produced by alternative splicing of the primary transcript of the calcitonin/CGRP gene. Originally identified as a strongly vasodilatory neuropeptide, CGRP is now known to be a pleiotropic peptide widely distributed in various organs and tissues. Our aim was to investigate the possibility that CGRP acts as an endogenous vasoprotective molecule. We compared the effect of CGRP deficiency on neointimal formation after wire-induced vascular injury in wild-type and CGRP knockout (CGRP-/-) mice. We found that neointimal formation after vascular injury was markedly enhanced in CGRP-/- mice, which also showed a higher degree of oxidative stress, as indicated by reduced expression of nitric oxide synthase, increased expression of p47phox, and elevated levels of 4HNE, as well as greater infiltration of macrophages. In addition, CGRP-deficiency led to increased vascular smooth muscle cell (VSMC) proliferation within the neointima. By contrast, bone marrow-derived cells had little or no effect on neointimal formation in CGRP-/- mice. In vitro analysis showed that CGRP-treatment suppressed VSMC proliferation, migration, and ERK1/2 activity. These results clearly demonstrate that endogenous CGRP suppresses the oxidative stress and VSMC proliferation induced by vascular injury. As a vasoprotective molecule, CGRP could be an important therapeutic target in cardiovascular disease. (C) 2013 Elsevier Ltd. All rights reserved.ArticleJOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY. 59(0):55-66 (2013)journal articl

SPECT measurement of regional cerebral blood flow, blood volume, and hematocrit in stroke

The clinical importance of measurement of the regional cerebral hemodynamics, using positron emission tomography (PET) or single-photon emission computed tomography (SPECT), is to ascertain the viability of the ischemic tissue or to predict the functional outcome after ischemic cerebral vascular diseases. Specifically, the following aspects may be considered important: I) to determine the state of the hemodynamics in regions of the brain identified from clinical signs and symptoms as ischemic or infarcted, 2) to determine whether the local flow is sufficient or at risk, 3) to estimate the prognosis with or without intervention and 4) to assess whether the risk of a second post-acute infarction has been reduced after treatment. In addition to investigations of the regional cerebral blood flow (CBF), there is now a growing interest in the role of the cerebral blood volume (CBV) and blood viscosity in the pathophysiology of cerebral ischemia. Recent studies have focused on the effectiveness of hemorheological approaches, including hemodilution ther­ apy, in the treatment of cerebral vascular diseases [1]. Employing PET, Gibbs et al. [2] and Powers et al. [3] suggested that the cerebral mean transit time derived from the ratio between CBF and CBV might serve as a sensitive parameter for estimating the circulatory reserve in the ischemic tissue. In the present study, SPECT was used to measure the regional CBF, CBV and cerebral hematocrit in normals and patients with occlusive cerebral vascular dis­ eases. Based on these three cerebral hemodynamic parameters, the regional patho­ physiology during the acute stages of cerebral infarction and of transient ischemic attack (TIA) was evaluated

Impact of the COVID-19 pandemic on migraine in Japan: a multicentre cross-sectional study

Abstract Objectives To assess the impacts of social situation changes due to the coronavirus disease 2019 (COVID-19) pandemic on headache-related disability and other symptoms in patients with migraine in Japan. Methods We conducted a multicentre, cross-sectional study including 659 outpatients with migraine diagnosed by headache specialists. The participants were asked about the impacts of the first wave of the COVID-19 pandemic on headache-related disability, headache days, headache intensity, stress, physical activity, hospital access and their work and home lives. For headache-related disability, the total Migraine Disability Assessment (MIDAS) score and part A and B scores were analysed. Multivariate stepwise linear regression analysis was performed to identify the clinical predictors of changes in the total MIDAS score before and during the COVID-19 pandemic. Logistic regression analysis was performed to determine the factors related to new-onset headache during the COVID-19 pandemic. Results Finally, 606 migraine patients (73 M/533 F; age, 45.2 ± 12.0 years) were included in the study, excluding those with incomplete data. Increased stress, substantial concern about COVID-19 and negative impacts of the first wave of the COVID-19 pandemic on daily life were reported in 56.8 %, 55.1 and 45.0 % of the participants, respectively. The total MIDAS and A and B scores did not significantly change after the first wave of the COVID-19 pandemic. New-onset headache, which was observed in 95 patients (15.7 %), was associated with younger age and worsened mood and sleep in the logistic regression analysis. The multivariate stepwise linear regression analysis of changes in the total MIDAS score before and during the first wave of COVID-19 pandemic identified worsened sleep, increased acute medication use, increased stress, medication shortages, comorbidities, the absence of an aura and new-onset headache were determinants of an increased total MIDAS score during the first wave of the COVID-19 pandemic. Conclusions In this multicentre study, clinical factors relevant to headache-related disability, such as new-onset headache, stress and sleep disturbances, were identified, highlighting the importance of symptom management in migraine patients during the first wave of the COVID-19 pandemic