EGF로 유도된 사람 피부 세포의 transformation에서 14-3-3τ 의 역할

학위논문 (석사)-- 서울대학교 융합과학기술대학원 : 분자의학 및 바이오제약학과, 2014. 8. 서영준.14-3-3 단백질은 진화적으로 보존된 작은 단백질로서, 모든 진핵세포에서 발현되며, 다양한 세포 과정에 관여를 한다. 지금까지, 포유류 동물에서 β, γ, ε, ζ, η, σ, 그리고 τ의 7 가지 이성체가 존재함이 알려졌다. 14-3-3은 신호 전달을 조절하며 신호 전달의 단백질들의 이동을 도와주는 scaffold 단백질로서 작용을 한다. 그래서 14-3-3은 단백질-단백질 상호작용을 조절할 수 있다. 또한 14-3-3은 인산화된 Serine 또는 Threonine에 결합하려고 하는 성질을 가지고 있기 때문에 많은 세포내의 단백질들과 상호작용을 할 수가 있다. 최근에, 일부 14-3-3 이성체가 발암 과정 촉진 또는 억제 기능에 관여한다고 보고된 바 있으나, 14-3-3이 피부 암 발생에서 어떠한 역할을 하는지에 대한 연구는 아직 미비하다. 따라서 본 연구에서는 14-3-3τ 가 EGF로 유도된 사람 피부 세포의 transformation에 관여한다는 것을 밝히고자 하였다. Physiological 의미로서, 14-3-3τ가 knockdown 되면, HaCaT의 세포 증식과 EGF로 유도된 anchorage-independent transformation이 대조군과 비교하였을 때 억제됨을 확인하였다. 게다가, 14-3-3τ가 knockdown 된 경우에 EGF에 의한 CREB의 인산화가 감소하였고, c-Fos의 발현도 역시 억제되었다. 이 결과에 더하여, 본 연구에서는 14-3-3τ가 EGF로 유도된 사람 피부 세포의 transformation에 관여하는 분자적 기전도 조사하였다. 그 기전의 핵심으로 생각되는 부분은 14-3-3τ와 RSK2의 direct physical interaction으로, 여기에서 RSK2는 EGF로 유도된 사람 피부세포의 transformation에 중요하다고 알려져 있으며, CREB의 인산화에 직접적으로 관여하는 단백질이다. 그리고 RSK2에 14-3-3τ가 결합하는 데에 있어서 RSK2의 두 가지 Serine 잔기 (Ser325, Ser715)가 중요하다는 것 또한 증명하였다. 마지막으로는, EGF로 유도된 사람 피부세포의 transformation에서 14-3-3τ와 RSK2 상호작용의 physiological 의미도 확인하였다. 종합적으로, 본 연구는 14-3-3τ가 EGF로 유도된 사람 피부 세포의 transformation에서 RSK2와의 결합을 통해 발암 촉진제로서 작용할 수 있다는 점을 시사한다.The 14-3-3 proteins, a family of conserved regulatory molecules, are expressed in all eukaryotic cells and have seven isoforms (β, γ, ε, ζ, η, σ, and τ) known in mammals. 14-3-3s are scaffold proteins that control of the signal transduction, direct other proteins to restricted specific pathway by interacting with many cellular proteins as a result of their specific phospho-serine/phospho-threonine binding activity. Recently, some of 14-3-3 isoforms were suggested tumor enhancers or suppressors. However, the roles of 14-3-3s in skin carcinogenesis has not been well studied yet. Here, I suggest that 14-3-3τ is involved in epidermal growth factor (EGF) - induced transformation of human keratinocytes. Knockdown of 14-3-3τ inhibited anchorage-independent cell transformation and proliferation of HaCaT induced by EGF. Moreover, phosphorylation of CREB (cAMP response element-binding protein) and c-Fos expression induced by EGF was significantly suppressed by knockdown of 14-3-3τ. Furthermore, I revealed that 14-3-3τ directly binds with RSK2, a key regulator in EGF-induced skin cell transformation and direct kinase of CREB. Additionally I identified that Ser325 and Ser715 residues of RSK2 is important for interaction with 14-3-3τ. Taken together, these findings suggest that 14-3-3τ might have a role as a tumor inducer in EGF-induced transformation of human keratinocytes, through direct interaction with RSK2.Contents Abstract…………………………………………………………i Contents………………………………………………………iii List of Figures………………………………………………iv Introduction……………………………………………………1 Materials and Methods…………………………………………4 Results……………………………………………………………9 Discussion………………………………………………………28 References………………………………………………………30 Abstract (국문초록)…………………………………………33Maste

Clinical Features and Brain MRI Findings in Korean Patients with AGel Amyloidosis

Purpose: AGel amyloidosis is systemic amyloidosis caused by pathogenic variants in the GSN gene. In this study, we sought to characterize the clinical and brain magnetic resonance image (MRI) features of Korean patients with AGel amyloidosis. Materials and Methods: We examined 13 patients with AGel amyloidosis from three unrelated families. Brain MRIs were performed in eight patients and eight age-and sex-matched healthy controls. Therein, we analyzed gray and white matter content using voxel-based morphometry (VBM), tract-based spatial statistics (TBSS), and FreeSurfer. Results: The median age at examination was 73 (interquartile range: 64-76) years. The median age at onset of cutis laxa was 20 (interquartile range: 15-30) years. All patients over that age of 60 years had dysarthria, cutis laxa, dysphagia, and facial palsy. Two patients in their 30s had only mild cutis laxa. The median age at dysarthria onset was 66 (interquartile range: 63.5-70) years. Ophthalmoparesis was observed in three patients. No patient presented with muscle weakness of the limbs. Axial fluid-attenuated inversion recovery images of the brain showed no significant differences between the patient and control groups. Also, analysis of VBM, TBSS, and FreeSurfer revealed no significant differences in cortical thickness between patients and healthy controls at the corrected significance level. Conclusion: Our study outlines the clinical manifestations of prominent bulbar palsy and early-onset cutis laxa in 13 Korean patients with AGel amyloidosis and confirms that AGel amyloidosis mainly affects the peripheral nervous system rather than the central nervous system

Longitudinal follow-up of serum biomarkers in patients with neuromyelitis optica spectrum disorder

--------------------e-pub (22.1.12)---------------- Background: Recently, several serum biomarkers have been proposed in Neuromyelitis Optica Spectrum Disorders (NMOSD) to monitor disease activity. Objective: The objective of the study is to evaluate the longitudinal clinical value of serum biomarkers in patients with NMOSD. Methods: We prospectively recruited consecutive NMOSD patients with anti-aquaporin-4 antibody and obtained serum samples at enrollment, after 6?12?months of follow-up (main period), and at attacks. Using single-molecule array assays, we evaluated longitudinal changes of serum neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and GFAP/NfL levels. Results: Overall, 64 patients (58 women) were enrolled (age: 51?years, disease duration: 6.7?years) and 133 samples were obtained. Among patients who did not develop new attacks during the main period (n?=?62), serum levels of NfL, GFAP, and GFAP/NfL were significantly decreased over time in patients with attacks (<2?months) at enrollment (n?=?14 (23%)), whereas serum NfL and GFAP levels gradually increased in the others (n?=?48 (77%)). During the study, five (8%) patients developed new attacks; only serum GFAP levels increased consistently upon these events compared with baseline levels. To differentiate attacks from remissions, serum GFAP levels showed the largest area under the receiver operating characteristic curve (0.876, 95% confidence interval: 0.801?0.951). Conclusion: Among NfL, GFAP, and GFAP/NfL, serum GFAP might be the most appropriate for monitoring NMOSD longitudinally, which warrants future confirming studies