https://scholarworks.unist.ac.kr/handle/201301/7 2026-05-13T04:15:28Z https://scholarworks.unist.ac.kr/handle/201301/91666 Title: High-intensity irreversible electroporation targeting intracellular structures enhance tumor ablation in lung cancer models Author(s): Kim, Hong Bae; Youm, Jin Young; Yang, Joon-Mo; Sim, Sung Bo Abstract: This study aimed to optimize irreversible electroporation (IRE) parameters to enhance intracellular injury, specifically targeting nuclear and mitochondrial structures that are insufficiently affected by conventional protocols. To address limitations of standard 1000 similar to 2500 V/cm clinical settings, we experimentally and computationally evaluated both low- and high-electric-field conditions and identified pulse parameters capable of safely achieving electric field strengths exceeding 4,000 V/cm, values that remain below the predicted arcing threshold for our electrode configuration while permitting effective intracellular electroporation. In vitro studies using A549 lung cancer cells demonstrated that high-field IRE markedly intensified oxidative stress, resulting in a 30-fold increase in hydrogen peroxide production and pronounced disruption of mitochondrial membrane potential. Transmission electron microscopy further confirmed severe ultrastructural injury, including plasma membrane rupture, nuclear membrane deformation, and complete loss of mitochondrial cristae, culminating in irreversible cell death. In vivo experiments corroborated these findings: high-field IRE produced extensive and uniform tumor ablation, whereas conventional lower field strengths generated only localized and partial damage. These results indicate that elevating electric-field intensity in IRE protocols can overcome the inherent limitations of traditional approaches by reliably inducing intracellular organelle damage, suppressing cellular repair pathways, and enhancing overall ablation completeness. Further studies are warranted to evaluate long-term safety and therapeutic durability of high-field IRE in vivo. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91656 Title: Orai1 acts as a novel Ca2+ signal switch, balancing erythropoiesis through KLF1 regulation Author(s): Lee, Yoon Young; Koh, Hyebin; Kim, Jieun; Kim, Sun-Uk; Lee, Jong-Hee; Park, Chan Young Abstract: Terminal erythropoiesis, the final stage of red blood cell maturation, is orchestrated by erythropoietin (EPO) and the master transcription factor, Kruppel-like factor 1 (KLF1). Recent studies highlight the importance of Ca2+ signaling in erythroid maturation; however, the underlying mechanisms remain elusive. Here we identify Orai1 as a novel EPO-responsive Ca2+ channel in erythroid cells, serving as a dynamic regulatory toggle that modulates KLF1 transcription and facilitates distinct phases of erythroid maturation. During the early stages, EPO-activated Orai1 suppresses KLF1 transcription through Ca2+-dependent NFAT2 activation and promoter binding, pausing erythroid maturation. As maturation progresses, Orai1 expression decreases, transitioning KLF1 regulation to an EPO-STAT5 pathway, thereby maintaining KLF1 expression and promoting terminal erythropoiesis. Using HUDEP-2 cells, umbilical cord blood and human pluripotent stem cell-derived CD71(+) erythroblasts, we observed a progressive downregulation of Orai1 and reduction in intracellular Ca2+ levels during terminal maturation. The functional inactivation of Orai1 via R91W mutants and CRISPR-Cas9 knockout enhanced KLF1 expression, leading to increased erythroid-specific gene expression, accelerated erythroid maturation, higher levels of globin production and improved enucleation efficiency. This study unveils the EPO-Orai1-Ca2+-NFAT2-KLF1 axis as a critical regulatory checkpoint in erythropoiesis and highlights Orai1 downregulation as a potential strategy to enhance clinical red blood cell production by promoting erythrocyte maturation. 2026-02-28T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91647 Title: Prediction model for periodontitis stage based on the salivary microbiome Author(s): Lee, Jaewoong; Kim, Hyun-Joo; Kim, Eun-Hye; Kim, Seunghoon; Park, Byeongjun; Hong, Suji; Kang, Jihoon; Lee, Ju-Youn; Lee, Semin Abstract: This study aimed to characterize salivary microbiome compositions that can classify periodontal health and various stages of periodontitis. We collected saliva samples from 250 study subjects, including 100 periodontally healthy controls and 150 periodontitis patients in stages I/II/III. We performed 16S ribosomal RNA gene sequencing to characterize their salivary microbiomes. Alpha diversities show significant differences between healthy and periodontitis. Differentially abundant taxa were identified by ANCOM. Random forest machine learning models were used to classify each periodontitis stage based on the centered log-ratio of differentially abundant taxa. We identified 20 differentially abundant taxa among the groups in the salivary microbiomes of all groups. Among these differentially abundant taxa, Porphyromonas gingivalis and Actinomyces spp. are the most important taxa on the random forest model to classify the periodontitis statuses. Our random forest model classified multiple periodontitis statuses with an area-under-curve of 0.829 ± 0.124, sensitivity 0.884 ± 0.022, and specificity 0.652 ± 0.065. Moreover, because it can be difficult to diagnose in dentistry practice, we performed our classifier model to distinguish healthy or stage I, providing an area-under-curve of 0.736 ± 0.168, sensitivity 0.789 ± 0.102, and specificity 0.622 ± 0.196. Furthermore, our random forest model detected periodontitis patients from healthy individuals with an area-under-curve of 0.924 ± 0.088, sensitivity of 0.862 ± 0.175, and specificity of 0.921 ± 0.061. Finally, we evaluated our classification model with external data sets from Spanish and Portuguese subjects. Some evaluations showed a slight decrease, but it might be due to different salivary microbiome compositions from ethnicity. Significant differences were identified in the differentially abundant taxa among healthy controls and the various stages of periodontitis.IMPORTANCEPeriodontitis is a common but complex oral disease that can lead to tooth loss and contribute to systemic health issues. Early and accurate diagnosis is essential for effective intervention, yet traditional diagnostic methods often rely on invasive clinical assessments that may miss early signs. This study demonstrates that salivary microbiome profiles can be used to classify both periodontal health and multiple periodontitis stages using a machine learning approach. By identifying the 20 key microbial taxa, including Actinomyces spp., we developed a non-invasive predictive model with high diagnostic accuracy. Importantly, the model was also able to detect early-stage disease and performed well across external data sets, highlighting its potential for broader clinical application. These findings suggest that a salivary microbiome-based diagnostic tool may support more precise, accessible, and early diagnosis of periodontitis in dental disease management. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91639 Title: Mechanically Spatio-Chimeric Fibrin Assembly Enables Vascular-Integrated Muscle Reconstruction for Volumetric Muscle Loss Repair Author(s): Jung, Su Hyun; Kim, Minjun; Kim, Da-Yoon; Kim, Min Kyu; Lee, Sieun; Jin, Yoonhee; Kang, Joo H. Abstract: Volumetric muscle loss (VML), a severe injury involving irreversible loss of both muscle tissue and vasculature, poses a major barrier to the development of clinically viable muscle grafts. Functional restoration requires engineered constructs capable of reconstructing both contractile and vascular components that can functionally integrate with the host vasculature. Here, we introduce SPARC (spatio-chimeric, plasma-based, anisotropic, and shear-responsive construct), a mechanically bimodal fibrin hydrogel engineered via shear-guided assembly of plasma fibrin to recreate the structural and mechanical heterogeneity of native muscle. Controlled microfluidic shear generates aligned fibrillar bundles and a spatially graded bimodal stiffness architecture, establishing stiff, bundle-dense regions that favor myogenic differentiation and compliant regions that promote endothelial morphogenesis. When co-cultured with myoblasts and endothelial cells, the resulting anisotropic matrix directs spatially organized myogenic maturation and endothelial morphogenesis. In vivo evaluation in a murine VML model shows that vascularized muscle SPARC grafts restore muscle architecture and function, promoting neovascularization, myofiber regeneration, and enhanced motor recovery. Through its spatially mechano-programmed design, SPARC enables coordinated myogenic and endothelial organization within a single construct, establishing a scalable biofabrication strategy for functional repair of extensive muscle defects. 2026-03-31T15:00:00Z