https://scholar.dgist.ac.kr/handle/20.500.11750/11738 Sat, 04 Apr 2026 12:10:10 GMT 2026-04-04T12:10:10Z https://scholar.dgist.ac.kr/handle/20.500.11750/59909 Title: Erythropoietin-derived Non-erythropoietic Peptides Conferring Oxidative Stress Resistance to Keratinocytes and Fibroblasts Author(s): Han, Min Ae; Ashim, Janbolat; Ji, Youngheum; Kang, Eunho; Jeong, Minchan; Kim, Sung Jae; Yu, Wookyung; Kim, Jin Hae; Moon, Cheil; Lee, Chang-Hun Abstract: Erythropoietin (EPO) exerts tissue-protective effects; however, its erythropoietic activity limits broader use. Three EPO-derived peptides (ML1-C1/C2/C3) were designed from the C-helix of EPO to remove erythropoietic activity while retaining cell-protective activity. Circular dichroism and nuclear magnetic resonance spectroscopies were used to assess the solution structures of ML1-C1/C2/C3 peptides. The peptide activities for cytoprotection and growth support were assessed using skin-relevant cells, HaCaT cells and 3T3-L1 cells, which proposes an effect on skin epithelial keratinocytes and pre-adipocytic fibroblasts, respectively. Also, an erythroid-precursor cell line, TF-1, was used to evaluate the erythropoietic function of the three peptides. Spectroscopic analyses of ML1-C1/C2/C3 peptides revealed similar secondary structures and different flexibilities between the peptides. While ML1-C1 and ML1-C3 had highly flexible loop-like structures, ML1-C2 had less flexible loop-like structures. Also, their cellular effects vary in a cell type-dependent manner. The EPO-derived peptides can attenuate H2O2-induced loss of viability in HaCaT cells and 3T3-L1 cells. Under low-serum conditions, the three peptides promoted HaCaT proliferation, whereas only ML1-C1 improved 3T3-L1 proliferation. In TF-1 cells, none of the peptides increased cell viability or hemoglobin staining, whereas recombinant human EPO did, indicating the lack of erythropoietic activity of the peptides under experimental conditions. These findings support the potential of EPO-derived peptides as skin-protective agents and motivate future work for skin therapeutics or cosmetic purposes. https://scholar.dgist.ac.kr/handle/20.500.11750/59909 https://scholar.dgist.ac.kr/handle/20.500.11750/59293 Title: Structure and function of the keratin 17 tail domain associated with keratin intermediate filament organization Author(s): Yeom, Jiwoo; Lee, Sanghoon; Ko, Young Ho; Hong, Eunmi; Kim, Jin Hae; Coulombe, Pierre A.; Lee, Chang-Hun Abstract: Keratins are the largest subgroup of intermediate filament proteins, forming 10-nm filaments from type I/II heterodimers, and occur primarily in epithelial cells. Keratin 6 (K6; type II) and Keratin 17 (K17; type I) show a complex expression pattern that includes induction following stress and in several diseases, including carcinomas. K17 is being used as a biomarker for several types of cancer. K6 and K17 sequences are respectively highly homologous to K5 and K14, which are expressed in the progenitor compartment of epidermis and related epithelia. The mechanical support roles of the K6/K17 and K5/K14 pairing require 10 nm filament assembly and the subsequent lateral association of these filaments to form thicker bundles. Previous studies showed that the non-helical tail domain of K14 is dispensable for 10 nm filament assembly but essential to the bundling of K5/ K14 filaments. Whether the K6/K17 pairing undergoes bundling, and whether the tail domain of K17 plays a role, is unknown. Here, we use sedimentation assays and electron microscopy to show that, when paired with K6, tailless K17 forms filaments that do not readily bundle. Nuclear magnetic resonance analysis revealed that the isolated K17 tail domain is an intrinsically disordered region (IDR). Follow-up studies with mutant K17 tail constructs suggest that IDR-like tail domains of keratins can form a curved local structure required for bundling and interact dynamically with other regions of keratin filaments in a flexible and heterogeneous manner. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59293 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59292 Title: Differential Effects of Murine Stroke Models on Dopaminergic Neurons, Glial Responses, and Neurobehavioral Outcomes Author(s): Tabassum, Sidra; Hu, Heng; Wu, Silin; Huang, Shuning; Yang, Bosco Seong Kyu; Lee, Chang-Hun; Gusdon, Aaron W.; Ren, Xuefang S. Abstract: Stroke is a leading cause of disability worldwide, often resulting in persistent motor, cognitive, and emotional impairments. While the hippocampus and amygdala play critical roles in post-stroke behavioral changes, specific neuronal alterations and prolonged glial responses within these regions across different stroke types remain unclear. This study investigates the behavioral, neuronal, and glial effects of subarachnoid hemorrhage (SAH), transient middle cerebral artery occlusion (tMCAO), and photothrombotic stimulation (PTS) in mice. SAH and tMCAO models exhibited significant motor deficits, spatial and recognition memory impairments, and increased anxiety- and depressive-like behaviors, whereas the PTS model showed similar motor and cognitive impairments but lacked affective (anxiety- and depressive-like) behavioral changes. Immunohistochemical analysis revealed increased overlap of tyrosine hydroxylase (TH, a dopaminergic marker) process with NeuN (a neuronal marker) in the dentate gyrus (DG) of SAH and tMCAO mice, highlighting region-specific vulnerability to ischemic damage in the hippocampus. In the amygdala, elevated overlap of TH+ process with NeuN in SAH and tMCAO mice suggests enhanced dopaminergic involvement in emotional dysregulation. In contrast, the PTS model did not exhibit any changes in overlap of TH+ process with NeuN in either the hippocampus or amygdala, consistent with the absence of affective behavioral deficits. Additionally, SAH and tMCAO models exhibited persistent astrocytic and microglial activation in the amygdala, characterized by increased intensity and density without significant morphological changes, indicative of a chronic inflammatory response. The PTS model also showed increased microglial intensity and density without overt morphological changes, suggesting a more moderate, possibly subclinical inflammatory response. These findings highlight the differential effects of stroke models on behavior, neuronal populations, and glial responses in limbic regions. The pronounced dopaminergic and glial alterations in SAH and tMCAO may underlie post-stroke emotional and cognitive disturbances. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59292 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58150 Title: 구조 기반 단백질 설계와 구조생물학의 역할, 그리고 인공지능을 활용한 도구들 Author(s): 이창훈 Abstract: 단백질 설계는 자연계에 아직 존재하지 않지만 원하는 기능을 갖는 단백질을 창조하는 작업이다. 단백질에 대한 구조생물학 연구의 성과가 축적되면서, 과학자들은 1차 구조 (아미노산 서열)에 숨겨진 3차 구조 형성 (접힘)의 패턴을 어느 정도 예측할 수 있게 되었다. 특히, 인공지능, 머신러닝에 기반한 구조 예측 모델이 성공을 거두고, 원하는 기능의 단백질을 3차 구조에 기반하여 그 서열을 뽑아낼 수 있는 기술적 진보가 최근 3~4년 내에 급속하게 이루어졌다. 본 논문에서는 구조생물학이 단백질의 구조-기능 상관관계의 이해에 기여한 바를 정리하고, 이를 바탕으로 데이터 학습을 수행하면서 개발된 다양한 인공지능 도구들을 개괄적으로 설명하고자 한다. 특히, 피부장벽 항상성에 중요한 단백질은 3차 구조 및 4차 구조에 대한 정보가 상당히 부족한바, 인공지능 도구 및 구조생물학 도구를 적절한 작업 흐름으로 사용한다면 주요 단백질의 구조와 기능의 이해를 증진할 수 있다. 나아가 예측 구조와 신규 설계 단백질을 바탕으로 피부 장벽질병의 예방 및 치료에 도움이 되는 해결책을 마련할 수 있을 것이다. Wed, 31 May 2023 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/58150 2023-05-31T15:00:00Z