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dc.contributor.advisor권기환-
dc.contributor.author이지윤-
dc.creator이지윤-
dc.date.accessioned2021-01-25T16:30:44Z-
dc.date.available2021-01-25T16:30:44Z-
dc.date.issued2021-
dc.identifier.otherOAK-000000172911-
dc.identifier.urihttp://dcollection.ewha.ac.kr/common/orgView/000000172911en_US
dc.identifier.urihttps://dspace.ewha.ac.kr/handle/2015.oak/256207-
dc.description.abstractVascular endothelial cells (ECs) are exposed to fluid shear stress, which modulates vascular pathophysiology. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is crucial in endothelial dysfunction and atherosclerosis. This study elucidated the mechanism regulating LOX-1 expression in ECs by FSS. Human umbilical vein endothelial cells were exposed to laminar shear stress (LSS) of indicated intensities using a unidirectional steady flow, or to oscillatory shear stress (OSS) using a bidirectional disturbed flow. In vivo studies were performed in a mouse model of partial carotid ligation and human pulmonary artery sections. Within ECs, OSS upregulated LOX-1 expression, while LSS (20 dyne/cm2) downregulated it. It was confirmed that OSS-induced LOX-1 expression was suppressed when the mechanotransduction was inhibited by knockdown of mechanosensory complex. In addition, it was demonstrated that Kruppel-like factor 2 (KLF2) has an inhibitory role on OSS-induced LOX-1 expression. Next, activator protein-1 (AP-1) was determined as the key transcription factor inducing LOX-1 expression by OSS, which was inhibited by KLF2 overexpression. To explore whether the intensity of LSS affects LOX-1 expression, three different intensities (20, 60, and 120 dyne/cm2) of LSS were tested. Higher LOX-1 expression was observed in high shear stresses of 120 dyne/cm2 compared to 20 and 60 dyne/cm2, with OSS-like KLF2-AP-1 signaling patterns. Furthermore, ECs within disturbed flow regions showed upregulated LOX-1 expression in in vivo. In conclusion, LOX-1 expression on ECs is regulated via fluid shear stress depending on its intensity as well as pattern. Furthermore, this is mediated through the KLF2-AP1 pathway of mechanotransduction.;혈관내피세포 (ECs)는 혈관의 병태생리를 조절하는 혈류전단응력 (FSS)에 노출되어있다. 렉틴-유사 산화 저밀도 지질단백질 수용체-1 (LOX-1)은 혈관 내피세포의 기능장애와 동맥경화에서 중요한 역할을 한다고 알려져 있다. 본 연구에서는 혈관내피세포에서 FSS가 LOX-1의 발현을 조절하는 기전을 밝히고자 하였다. 세포 수준의 연구를 수행하기 위하여 인간탯줄정맥내피세포 (HUVECs)에 한 방향의 일정한 흐름을 갖는 층류 전단응력 (LSS) 또는 양방향으로 산란된 흐름을 갖는 진동 전단응력 (OSS)을 가하였다. 생체 내 연구는 부분목동맥결찰술을 이용한 마우스 모델과 사람 폐동맥 조직을 대상으로 수행하였다. 혈관내피세포 내에서, OSS는 LOX-1의 발현을 증가시킨 반면, LSS (20 dyne/cm2)는 LOX-1의 발현을 감소시켰다. 기계수용 복합체 유전자를 비활성화시켜 그 기능을 억제하였을 때에는, OSS에 의해 유도된 LOX-1의 발현이 감소함을 확인하였다. 또한, Krüppel-like factor 2 (KLF2)가 OSS에 의한 LOX-1 발현을 억제하는 역할을 하였다. 다음으로, activator protein-1 (AP-1)이 OSS에 의한 LOX-1 발현 유도에 중요한 전사인자로 작용하는데, 이 과정은 KLF2 과발현에 의해 억제되었다. LSS의 세기가 LOX-1 발현에 영향을 미치는지 확인하기 위해, HUVECs에 세 가지 다른 세기의 LSS (20, 60, 120 dyne/cm2)를 가하였다. 그 결과, 20, 60 dyne/cm2에 LSS에 비해 120 dyne/cm2에 해당하는 높은 세기의 LSS에서 LOX-1의 발현이 높게 나타났으며, 이 때에는 OSS와 같은 KLF2-AP-1 신호전달 양상이 동반되었다. 더 나아가 생체 내 연구를 통해 산란된 흐름이 있는 부위의 혈관내피세포에서 LOX-1의 발현이 증가되어있음을 확인하였다. 결론적으로, 혈관내피세포의 LOX-1 발현은 FSS의 패턴 뿐만 아니라 세기에 의해 조절된다. 그리고 이는 기계적 자극변환을 거쳐 KLF2-AP-1 경로를 통해 매개된다.-
dc.description.tableofcontentsΙ. Introduction 1 A. Fluid shear stress (FSS) in vascular endothelial cells (ECs) 1 B. Mechanotransduction via mechanosensory complex in ECs 4 C. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) 8 D. Pathological high shear stress (HSS) 12 E. Objective 17 ΙΙ. Materials and Methods 18 A. Cell culture and FSS experiment 18 B. Animal model of atherosclerosis induced by disturbed flow 19 C. Western blotting 19 D. Reverse Transcription and Real Time polymerase chain reaction 20 E. Quantification of oxLDL uptake by LOX-1 23 F. Small interference RNA transfection and genome overexpression 23 G. Dual Luciferase reporter assay 24 H. RNA isolation from ECs of the carotid artery 24 I. Immunofluorescence staining 25 J. Statistical analysis 26 ΙΙΙ. Results 27 A. FSS regulates LOX-1 expression in vascular ECs 27 B. FSS regulates LOX-1 expression in ECs through mechanosensory complex 30 C. KLF2 suppresses OSS-induced LOX-1 expression in ECs 33 D. Inhibition of AP-1 activity relieves OSS-induced LOX-1 expression in ECs 36 E. KLF2 inhibits LOX-1 expression by suppressing AP-1 activity induced by disturbed flow in ECs 38 F. High shear stress has an OSS-like role by inducing LOX-1 expression through the KLF2/AP-1 pathway in ECs 44 G. LOX-1 expression in ECs is upregulated in regions of pro-atherogenic disturbed flow in a model of partial carotid ligation 53 H. LOX-1 expression in ECs is upregulated in disturbed flow regions and branching points of human pulmonary artery 57 IV. Discussion 61 References 68 국문초록 80-
dc.formatapplication/pdf-
dc.format.extent3098490 bytes-
dc.languageeng-
dc.publisher이화여자대학교 의학전문대학원-
dc.subject.ddc610-
dc.titleFluid shear stress regulates the expression of Lectin-like oxidized low density lipoprotein receptor-1 via KLF2-AP-1 pathway depending on its intensity and pattern in endothelial cells-
dc.typeDoctoral Thesis-
dc.title.translated혈관내피세포 내 혈류전단응력의 패턴 및 세기에 따른 KLF2-AP-1 경로를 통한 렉틴-유사 산화 저밀도 지질단백질 수용체-1 발현 조절 메커니즘-
dc.format.pageix, 81 p.-
dc.identifier.thesisdegreeDoctor-
dc.identifier.major의학전문대학원 의학과-
dc.date.awarded2021. 2-
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