The Role Of Angiogenesis-related Factors In The Pathogenesis Of Moyamoya Disease

Background:Moyamoya disease (MMD) is a kind of cerebrovascular disease characterized by the stenosis or occlusion in bilateral internal carotid artery ends and the formation of the abnormal vascular network in the skull base. It was reported by Japanese scholars firstly. For the feature of this abnormal vascular network on cerebral angiogram is shaped as "smoke", Japanese scholars in1967named the disease Moyamoya Disease which is the meaning of "smoke" in Japanese.With the obvious regional and ethnic characters, the high incidence of MMD happens in the yellow race in Asia. The highest incidence is in Japan followed by South Korea and some cases were reported in the west and Africa where the incidence is much lower than in Asia. The reported incidence of China is only limited to a few medical center in Beijing, Nanjing and the onset of the most patients are not included, so it is difficult to reflect the epidemiological characteristics of moyamoya disease in our country. But with the increasing awareness of the grassroots neurologist and the wide usage of TCCS, CTA, MRA, DSA, the diagnosis rate of MMD is also rising.Currently the etiology of moyamoya disease is still under the exploration and study. The high incidence in Japanese while low incidence in Caucasians and the epidemiological features that Hawaii Japanese incidence was significantly higher than other local ethnic reveal that moyamoya disease may occur with genetic. The study also found that the initial susceptibility gene for familial moyamoya disease, but only a part of moyamoya disease can be explained with the genetic factors. Moyamoya disease may be associated with chronic inflammation of the central nervous system, such as leptospirosis, Epstein-Barr virus infection and autoimmune related. Some studies suggest that the allergy immune injury cause directly moyamoya disease. In addition, the history of brain radiation exposure, cocaine may also have impacts on the occurrence of the disease.Moyamoya disease pathological changes of the internal carotid artery and its branches endometrial cell hyperplasia, thickening of blood vessels elastic buckling, thickening, fracture can occur with the progression of medial smooth muscle cell proliferation, degeneration, stenosis induced vascular lumen or occlusion. Past that the disease is limited to the internal carotid artery system, but further research found that the posterior cerebral artery, superficial temporal artery, middle meningeal artery, even in the coronary artery, pulmonary, renal arteries are very similar pathological changes. External carotid artery angiography showed stenosis in superficial temporal artery, middle meningeal artery within20%of the MMD patients so Moyamoya disease maybe a systemic disease conbained with some local factors (such as hemodynamic) in cerebral arterial circle.The hyperplasia of abnormal vascular network in skull base and disorder hemodynamic changes of MMD laid the hidden troubles for recurrent stroke which imaged cerebral hemorrhage or/and ischemia. Unlike the universal Asian adult phenotype, lower bleeding rate is a significant feature of Europe and the United States moyamoya disease. MMD clinical manifestations due to ischemia and bleeding involving the site performance of different common symptoms were: fatigue and sensory disturbances, dysarthria, headache, seizures, visual disturbances, syncope. Related case reports prompted rare symptoms of acute insanity, paroxysmal dyskinesia, and cortical blindness.Similar "smoke vascular" will appear in the part of the brain vessels in certain disease process and "Quasi-Moyamoya Disease" or "Moyamoya Syndrome" is defined different from the typical moyamoya disease. These diseases include atherosclerosis, autoimmune diseases, meningitis, brain tumor, neurofibromatosis type I, Down syndrome and later stage of cerebral radiotherapy, etc.So far there is no effective radical treatment for the disease and various surgical treatments are carried out in recent years, surgery purpose is mainly to establish collateral circulation, improve the supply. Surgical treatments of moyamoya disease mainly aim for intracranial vascular reconstructive approach, including straight joint reconstruction, indirect vascular remodeling and vascular remodeling three categories.The current study has found that certain growth factors played a certain role in the development process in vascular newborn and occlusion. The confirmed factors including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor-β1(TGF-β1), hepatocyte growth factor (HGF), granulocyte colony-stimulating factor (G-CSF), platelet-derived growth factor (PDGF), matrix metalloproteinases (MMPs), etc. The topics selected related angiogenesis factor as entry point to analysis the relationship within development and pathological stage of moyamoya disease so as to investigate the mechanisms of vascular changes in Moyamoya disease.Objective:As the representative angiogenic factors hypoxia inducible factor la (HIF-1α), angiopoietin (Ang) and interleukin (IL) play important regulatory roles in vascular endothelial cells and smooth muscle cell proliferation, migration and invasion so we speculate its relationship in moyamoya disease pathogenesis. Choosing angiogenesis factors such as hypoxia-inducible factor-la (HIF-la), angiopoietin-1(Ang-1), angiopoietin-2(Ang-2) and interleukin-8(IL-8), interleukin-10(IL-10) as an entry point, the subject analyzes the relationship between angiogenesis factors and development and pathological stage to explore mechanisms of vascular changes in Moyamoya disease.Methods:The cases were selected from the Neurosurgery Department in Wuhan General Hospital of Guangzhou Military Command (PLA Neurosurgery Institute) followed an audit included in admission, while healthy control persons from the outpatient physical examination center in Wuhan General Hospital of Guangzhou Military command. All selected patients take three-dimensional digital subtraction angiography (3D-DSA). The diagnosis in patients with cerebral angiography results as the "gold standard." Specific criteria contain①the stenosis or occlusion in the ends of the internal carotid artery (ICA) and/(or) the starting end of the middle cerebral artery (MCA), the anterior cerebral artery (ACA);②the visible abnormal vascular network in the base of brain;③lesions mentioned were bilateral. The selected healthy adults show no abnormality in blood, biochemical, electrocardiogram, chest X-ray, and transcranial Doppler ultrasound examinationsThe MMD patients should be excluded in the following conditions:①Combined with diseases such as autoimmune diseases, meningitis, brain tumor, a type of nerve fibers tumor, Down syndrome and cerebral radiotherapy which have been known as causes of the cerebrovascular lesion similar to "smoke blood vessels". This is to say, patients of the so-called "Quasi-of Moyamoya Disease" or "Moyamoya Syndrome";②Severe atherosclerosis, hypertension and heart lung and kidney dysfunction, contrast agent allergy cerebral angiography contraindications;③The patients and their families do not agree with cerebral angiography. MMD classification criteria with reference to the internationally widely-used Suzuki cerebral angiography staging this topic to reflect the distribution characteristics of the course of the disease, generally in line with the preliminary-term (including Suzuki stage1,2) The medium-term (including Suzuki stage3,4), late-term (including Suzuki stage5,6) be divided into subgroups.All patients admitted to hospital after a detailed medical history and strictly regulate the physical examination, and were in the hospital the day underwent head CT examination. All patients underwent transcranial color Doppler ultrasound. All patients were confirmed by DSA cerebral angiography diagnosed. For the healthy control group it is hard to check up with invasive3D-DSA. Fortunately the Doppler ultrasound operated by senior technician has the same diagnostic coincidence rate up to98%with DSA. The healthy control persons in this study take transcranial color Doppler ultrasound (TCCS) check as a non-invasive inspection items.All peripheral blood specimens are fasting when using yellow drying tube were collected about6ml and placed still for10minutes in room temperature and then centrifuged for10minutes in the speed of3000rev/min. The supernatant was collected, the serum samples for each subject stars installed and marked at-70℃for cryopreservation. Detection ELISA kit by the R&D, Inc.(USA) packing production of reagents. Determination:serum of Ang-1, Ang-2, HIF-la, IL-8, IL-10content expressed in ELISA (enzyme linked immunosorbent assay, ELISA) determination of its operations are in strict accordance with each Instructions executed in indicators ELISA kit.Application SPSS14.0software package for statistical analysis of the statistical indicators are presented as mean±standard deviation (X±S). The group first test of normality and homogeneity of variance test, qualified between the two groups were compared using t-test (Independent-sample T-test) among the three groups, the number of compared using analysis of variance (One-way ANOVA) between the two groups are compared with each other Least Significant Difference (LSD) method. Indicators used to compare between Spearman correlation analysis, statistically significant at P<0.05.Results:1. general comparison:MMD patients in this group included26patients,19males and7females;24cases of cerebral hemorrhage (including the ventricle, the lobes of the brain hemorrhage and subarachnoid hemorrhage), cerebral ischemia (including cerebral infarction and cerebral insufficiency) two cases;9cases in the preliminary-term (Suzuki of1,2),11cases in the medium-term (Suzuki of3,4),6cases in late-term (including Suzuki of5,6).2. Cytokines comparisons between MMD patients and the healthy control group: serum HIF-1α, Ang-1, Ang-2, IL-8, IL-10concentration are compared respectively, which only Ang-1, IL-8significant difference (P<0.05).3. Comparisons between different gender, type, stage groups:Between the two subgroups, which is divided according to sex or hemorrhagic and ischemic imaging, HIF-α, Ang-1, Ang-2, IL-8, IL-10concentration had no statistical difference (P>0.05). According to Suzuki stage, the above factors show no statistical difference between early, middle and late subgroups (P>0.05), but the early and middle stage of HIF-1α comparison within the group have statistical difference (P<0.05).4. The respective correlation analysis between the concentration of Ang-1、 Ang-2、HIF-1α、IL-8、IL-10and gender, type and stage only show the significant correlative relationship between gender and IL-8(P<0.05)although the relationship is not close (the correlation coefficient is less than0.5).Conclusion:1.As an important factor to maintain cardiovascular stability, the declining Ang-1may play an important role in moyamoya disease pathogenesis.2. The proinflammatory cytokine IL-8in moyamoya disease peripheral serum significantly increased, which may be by means of inflammatory mechanisms involved in the development and progression of MMD.3. Gender factors may be associated with the role of pro-inflammatory cytokines IL-8, but their correlation and mechanism remains to be further excavated.4. Based on the Suzuki cerebral angiography classification, HIF-la in the mid-staged (Suzuki stage3,4) MMD patients increased significantly, suggesting that HIF-1α may play an important role in the progress of peak stage in the abnormal vascular network in the base of the brain.