MK-801에 의한 행동민감화의 특성

학위논문(박사) -- 서울대학교대학원 : 의과대학 의학과, 2024. 2. 강웅구.Characteristics of MK-801-induced locomotor sensitization LI GANG Department of Medicine, Psychiatry Major The Graduate School Seoul National University Repeated administration of drugs of abuse leads to progressively greater behavioral responses; this phenomenon is referred to as behavioral sensitization. MK-801 blocks the N-methyl-D-aspartate (NMDA) receptor and elicits behavioral sensitization. Ketamine and phencyclidine, are also NMDA antagonists and have well-documented abuse potential. This study investigated the characteristics of MK-801-induced behavioral sensitization and found that it induced sensitization rapidly; only five consecutive treatments were required. The optimal dose for robust sensitization was also identified, which corresponded to the typical doses of abused NMDA antagonists (i.e., between the doses inducing antidepressant and anesthetic effects). Following MK-801-induced behavioral sensitization, changes were observed in the expression and/or phosphorylation of NMDA receptor subunits. While the expression of early growth response protein 1, which serves as a marker of neuronal activation, was affected by MK-801 sensitization, extracellular signal-regulated kinase phosphorylation was not associated with MK-801 treatment. Moreover, it was found that MK-801 sensitized rats show an increased locomotor response to cocaine and cocaine sensitized rats also show a potentiated locomotor response to MK-801. While clozapine prevented behavioral sensitization elicited by MK-801, haloperidol could not block the sensitization. The current study may lead to better understanding of MK-801 induced sensitization and suggest that drugs of abuse may have a common mechanism of action in addiction. Keywords: Behavioral sensitization; NMDA receptor; MK-801; cocaine; cortex; striatum; cross-sensitization Student Number: 2018-38747남용 약물의 반복투여는 점차 향상되는 행동반응을 일으키는데 이런 현상을 행동민감화 라고 한다. MK-801은 NMDA 수용체를 억제하는 작용이 있고 행동민감화를 일으킨다. Ketamine과 phencyclidine도 NMDA 수용체를 억제하는 작용이 있는 남용 약물이다. 본 연구에서는 MK-801에 의한 행동민감화의 특성을 연구하여 MK-801에 의한 행동민감화가 빠르게, 5번의 연속 투여로 일어나는 것을 관찰하였고 MK-801의 행동민감화를 일으키는 최적의 용량 (남용을 일으키는 용량이며 항우울작용과 마취작용을 일으키는 사이의 용량)을 찾아냈다. MK-801의 행동민감화가 일어나는 것을 관찰한 후 본 연구는 NMDA 수용체의 변화와 NMDA 수용체의 인산화 변화를 관찰하였다. 그리고 뉴런의 활성을 가늠하는 단백질인 Egr-1의 발현의 증가를 관찰하였고 ERK 단백질의 인산화에 변화가 없음을 관찰하였다. 이외에 MK-801의 행동민감화가 일어나는 시점에서 코카인과의 교차행동민감화와 코카인의 행동민감화가 일어나는 시점에서 MK-801과의 교차행동민감화를 증명하였다. Clozapine은 MK-801에 의한 행동민감화를 감소시키는 반면 haloperidol는 MK-801에 의한 행동민감화를 감소시키지 않았다. 본 연구는 MK-801에 의한 행동민감화의 특성을 이해하는데 도움을 주고 남용 약물의 작용과정에서 공통된 기전을 갖고 있음을 시사한다.Abstract ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ⅰ Table of Contents ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ⅲ List of Figures ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ⅳ List of abbreviations ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ⅶ Introduction ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․1 Materials and Methods ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․5 Results ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․16 Discussion ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․45 References ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․51 Abstract in Korean ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․61박

Hypomethylation of long interspersed element-1 is a prognostic factor in stage III or high-risk stage II colorectal cancers treated with adjuvant FOLFOX

학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2015. 2. 강경훈.Background: Hypomethylation of Long intersperse element-1 (L1) is considered a surrogate marker for a decrease in methylcytosine content in tumor cells. Tumoral L1 hypomethylation correlates worse clinical outcome in patients with gastric cancer or esophageal cancer. However, it remains unclear whether low L1 methylation is a prognostic marker in colorectal cancers (CRCs). We aimed to elucidate whether tumoral L1 hypomethylation may have a prognostic role in CRCs treated with adjuvant FOLFOX. Materials and methods: We analyzed a total of 427 resected cases of stage III or high-risk stage II CRC for their statuses in L1 methylation, CpG island methylator phenotype, microsatellite instability, and KRAS/BRAF mutation. L1 methylation was assayed by pyrosequencing. Results: L1 hypomethylation was closely associated with nodal metastasis but did not show any association with age of onset, gender, tumor subsite, tumor differentiation, mucinous histology, lymphatic emboli, venous invasion, perineural invasion, T stage, and KRAS/BRAF mutation. Multivariate analysis revealed that L1 hypomethylation as well as mucinous histology, T stage, N stage, lymphatic emboli and KRAS mutation was an independent prognostic parameter heralding poor prognosis. Conclusion:Tumoral L1 hypomethylation correlated independently with poor prognosis in patients with resectable CRC treated with adjuvant FOLFOX.Abstract i Contents iii List of tables ⅴ List of figures ⅵ Introduction 1 Material and Methods 5 Patients and tissue samples 5 Determination of MSI 6 KRAS and BRAF Mutation Analysis 7 DNA extraction and bisulfite modification 7 Analysis of methylation status of LINE-1 by pyrosequencing 8 Statistical analysis 9 Results 11 Pyrosequencing assay for L1 methylation status 11 Relationships between L1 methylation level and clinicopathological features 12 Survival 15 Discussion 20 References 25 Abstract in Korean 31Maste

Oct4/Sox2 과발현 지방유래중간엽줄기세포의 마우스 염증 모델에 미치는 영향

학위논문 (석사)-- 서울대학교 대학원 : 수의학과(수의내과학 전공), 2015. 8. 윤화영.Inflammation is part of a complex biological defense against harmful stimuli. When inflammatory cytokines are released, they induce redness, swelling, and heatmulti-organ failure is possibly the result of cytokine overexpression. The immune modulating effect of adipose tissue derived mesenchymal stem cells (ATMSCs) has been known to change the immune response by altering inflammatory cytokine secretion. In this study, we evaluated the anti-inflammatory effects of Oct4/Sox2 engineered mesenchymal stem cells using reverse transcription polymerase chain reaction (RT-PCR) and immunostaining, to confirm the successful transduction of Oct4/Sox2 in ATMSCs. GFP (control) and Oct4/Sox2-ATMSCs were cultured for 48 h and the supernatant (conditioned media) was collected to treat lipopolysaccharide (LPS)-induced Raw 264.7 cells (mouse macrophage-like cells). Subsequently, the levels of the inflammatory cytokines, Interleukin (IL)-2, IL-6, and IL-10 were determined using RT-PCR analysis. Comparison of GFP- and Oct4/Sox2-ATMSCs conditioned media-treatment and the LPS stimulated group revealed 2- and 5.8-fold reduction in IL-2 expression, respectively, and 1.08- and 1.68-fold reduction in IL-6 expression, respectively. Additionally, macrophages treated with GFP- and Oct4/Sox2-ATMSCs conditioned media expressed similar levels of IL-10. Mice were stimulated with LPS (20mg/kg) and were evaluated with a sick score based on symptoms such as, diarrhea, eye condition, and the condition of their fur. Compared to the phosphate buffer saline (PBS)-injected group with GFP and Oct4/Sox2-ATMSCs, the total sick score was reduced to 1.23- and 1.89-fold, while the survival rate was increased by 5.6% and 16.7%. These results suggest that Oct4/Sox2-ATMSCs have superior inflammatory modulation effects than GFP-ATMSCs. According to this result, the Oct4/Sox2-ATMSCs anti-inflammatory effect may be applied to a variety of inflammatory-related diseases in veterinary medicineContents 1. Introduction 1 2. Material and Methods 3 2.1. Cell culture 2.2. Animals 2.3. Oct4/Sox2 Lentivirus vector construction and transduction in human MSCs 2.4. Reverse transcription (RT)-PCR assay 2.5. Raw 264.7 cells was treated ATMSCs conditioned medium 2.6. LPS Induced systemic inflammatory mice model and Oct4/Sox2-ATMSCs administration 2.7. Statistical analysis 3. Results 8 3.1. Cell morphology 3.2. Oct4 and Sox2 overexpression in ATMSCs was transfected lentivirus. 3.3. Comparison of inflammatory cytokine mRNA expression level in GFP and Oct4/Sox2-ATMSCs 3.4. Effect of GFP- and Oct4/Sox2-ATMSCs conditioned media treatment Raw 264.7 cells 3.5. Evaluation of mouse sick score and survival rate 4. Discussion 11 5. Conclusion 15 References 26 국문초록 29Maste