Hyun-A Seong

Psoriasis and psoriatic arthritis (PsA) are systemic immune-mediated diseases, but the features that distinguish cutaneous-dominant psoriasis from musculoskeletal involvement remain unclear. We analyzed four core public cross-sectional datasets spanning whole-blood methylation, PBMC single-cell RNA sequencing summarized at the subject level, skin RNA sequencing, and purified CD4⁺ T-cell methylation, and used two additional public skin cohorts for external contextual checks to define a disease inflammatory response axis (DIR) and a contrast-resolved systemic state coordinate (CRS) representing systemic immune state variation associated with PsA. In whole-blood methylation, DIR primarily separated healthy controls from psoriasis, whereas CRS separated psoriasis from PsA with minimal correlation to DIR. In untreated-only PBMC single-cell reanalysis, CRS separated PsA from PsO; the source-defined PSX subgroup (joint pain without CASPAR-classified PsA) showed heterogeneous subject-level positioning, with above-band enrichment concentrated at the cell-type level. Cell-type-resolved analyses localized CRS-related shifts to T-cell, monocyte, B-cell, and regulatory compartments and identified multicompartment pathway state remodeling along the CRS continuum. In contrast, skin RNA sequencing mainly captured lesional inflammatory burden and showed only limited additional PsA-related separation within the same tissue state. These findings support a model in which PsA is distinguished from psoriasis by an additional systemic immune state axis rather than by skin inflammatory burden alone.

Psoriasis and psoriatic arthritis (PsA) are systemic immune-mediated diseases, but the features that distinguish cutaneous-dominant psoriasis from musculoskeletal involvement remain unclear. We analyzed four core public cross-sectional datasets spanning whole-blood methylation, PBMC single-cell RNA sequencing summarized at the subject level, skin RNA sequencing, and purified CD4+ T-cell methylation, and used two additional public skin cohorts for external contextual checks to define an inflammatory disease axis (DIR) and a contrast-resolved systemic-state coordinate (CRS) representing additional systemic immune-state variation associated with PsA. In whole-blood methylation, DIR primarily separated healthy controls from psoriasis, whereas CRS separated psoriasis from PsA with minimal correlation to DIR. In PBMC single-cell data, CRS was higher in PsA and in the source-defined PSX subgroup (joint pain without CASPAR-classified PsA) than in PsO. Cell-type-resolved analyses localized CRS-related shifts to CD8 naive T cells, NK cells, CD14 monocytes, and regulatory T cells and identified multicompartment pathway-state remodeling along the CRS continuum. In contrast, skin RNA sequencing mainly captured lesional inflammatory burden and showed only limited additional PsA-related separation within the same tissue state. These findings support a model in which PsA is distinguished from psoriasis by an additional systemic immune-state axis rather than by skin inflammatory burden alone.

Background/Objectives: Regulation of acute inflammatory responses is crucial for host mortality and morbidity induced by pathogens. The pathogenesis of acute respiratory distress syndrome (ARDS) and sepsis are associated with systemic inflammation. p38 MAPK is a crucial regulator of inflammatory responses and is a potential target for acute inflammatory diseases, including ARDS and sepsis. We investigated the therapeutic effects of the TAT-TN13 peptide (TN13) on severe inflammatory diseases, including ARDS and sepsis, in vivo. Methods: To establish the ARDS model, C57BL/6 mice were intranasally (i.n.) administered lipopolysaccharide (LPS; 5 mg/kg, 40 µL) to induce lung inflammation. As a positive control, dexamethasone (DEX; 0.2 mg/kg) was administered intraperitoneally (i.n.) 1 h post-LPS exposure. In the experimental groups, TN13 was administered intranasally (i.n.) at doses of 2.5 mg or 5 mg/kg at the same time point. In the LPS-induced sepsis model, mice received an intraperitoneal injection of LPS (20 mg/kg) to induce systemic inflammation. TN13 (25 mg/kg, i.p.) was administered 1 h after LPS treatment. Control mice received phosphate-buffered saline (PBS). Lung histopathology, inflammatory cell infiltration, cytokine levels, and survival rates were assessed to evaluate TN13 efficacy. Results: TN13 significantly reduced inflammatory cell recruitment and cytokine production in the lungs, thereby mitigating LPS-induced ARDS. In the sepsis model, TN13 treatment improved survival rates by suppressing inflammatory responses. Mechanistically, TN13 exerted its effects by inhibiting the p38 MAPK/NF-κB signaling pathway. Conclusions: These results collectively suggested that TN13 could be an effective treatment option for severe inflammatory diseases.

Conventional biochemical methods for studying cellular signaling cascades have relied on destructive cell disruption. In contrast, the live cell imaging of fluorescent-tagged transfected proteins offers a non-invasive approach to understanding signal transduction events. One strategy involves monitoring the phosphorylation-dependent shuttling of a fluorescent-labeled kinase between the nucleus and cytoplasm using nuclear localization, export signals, or both. In this paper, we introduce a simple method to visualize intracellular signal transduction in live cells by exploring the translocation properties of PKC from the cytoplasm to the membrane. We fused bait protein to PKC, allowing the bait (RFP-labeled) and target (GFP-labeled) proteins to co-translocate from the cytoplasm to the membrane. However, in non-interacting protein pairs, only the bait protein was translocated to the plasma membrane. To verify our approach, we examined the Raf–MEK–ERK signaling cascade (ERK pathway). We successfully visualized direct Raf1/MEK2 interaction and the KSR1-containing ternary complex (Raf1/MEK2/KSR1). However, the interaction between MEK and ERK was dependent on the presence of the KSR1 scaffold protein under our experimental conditions.

Conventional biochemical methods for studying cellular signaling cascades have relied on destructive cell disruption. In contrast, live cell imaging of fluorescent-tagged transfected proteins offers a non-invasive approach to understanding signal transduction events. One strategy involves monitoring the phosphorylation-dependent shuttling of a fluorescent-labeled kinase between the nucleus and cytoplasm using nuclear localization, export signals, or both. This paper introduces a simple method to visualize intracellular signal transduction in live cells by exploring the translocation properties of PKC from the cytoplasm to the membrane. We fused bait protein to PKC, allowing the bait (RFP-labeled) and target (GFP-labeled) proteins to co-translocate from the cytoplasm to the membrane. However, in non-interacting protein pairs, only the bait protein was translocated to the plasma membrane. To verify our approach, we examined the Raf–MEK–ERK signaling cascade (ERK pathway) and directly observed the Raf1/MEK2 interaction. We also identified ternary complexes containing the KSR1 scaffold protein. Additionally, the MEK/ERK interaction was dependent on the exogenous expression of KSR1.

Ginsenoside is the primary active substance of ginseng and has many pharmacological effects, such as anti-cancer, immune, regulating sugar and lipid metabolism, and antioxidant effects. It also protects the nervous and cardiovascular systems. This study analyzes the effects of thermal processing on the bioactivities of crude ginseng saponin. Heat treatment increased the contents of minor ginsenosides in crude saponins, such as Rg3, and heat-treated crude ginseng saponin (HGS) had better neuroprotective effects than non-treated crude saponin (NGS). HGS reduced glutamate-induced apoptosis and reactive oxygen species generation in pheochromocytoma 12 (PC12) cells, significantly more than NGS. HGS protected PC12 cells against glutamate-induced oxidative stress by upregulating Nrf2-mediated antioxidant signaling and downregulating MAPK-mediated apoptotic signaling. HGS has the potential for the prevention and treatment of neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease.

Four Korea-native wild vegetables belonging to the Allium genus (Allium tuberosum Rottl., Allium senescens L., Allium thunbergii G. Don., and Allium sacculiferum Maxim.) were investigated for their antioxidant and anti-obesity potential, in order to promote the utilization of wild edible plants for the development of potential new crops. In this study, we compared the antioxidant activity of the plant extracts by ABTS+ and DPPH scavenging method. We then compared the anti-adipogenic effects of the extracts in adipocytes. We quantified the phenolics in the extracts using high-performance liquid chromatography (HPLC) to identify the bioactive compounds. A. tuberosum and A. sacculiferum had a higher total phenolic content (19.0 ± 0.3 and 19.6 ± 0.7 mg GA/g extract, respectively) than A. senescens and A. thunbergii (16.0 ± 0.2 and 14.5 ± 0.7 mg GA/g extract). Caffeic acid, an antioxidant and anti-adipogenic compound, was detected in A. tuberosum and A. sacculiferum, but not in A. senescens and A. thunbergii. A. tuberosum, and A. sacculiferum showed superior antioxidative and anti-adipogenic activities compared to A. senescens and A. thunbergii. Therefore, A. tuberosum and A. sacculiferum, both of which contain antioxidant and anti-adipogenic phenolics, such as caffeic acid, present a therapeutic potential against obesity. Various phenolic compounds, which have been found to differ among Allium spp., may partially account for differences among the Allium spp. with respect to their antioxidant and anti-obesity effects.

As the central node between nutrition signaling input and the metabolic pathway, AMP-activated protein kinase (AMPK) is tightly regulated to maintain energy homeostasis. Subcellular compartmentalization of AMPK is one of the critical regulations that enables AMPK to access proper targets and generate appropriate responses to specific perturbations and different levels of stress. One of the characterized localization mechanisms is RanGTPase-driven CRM1 that recognizes the nuclear export sequence (NES) on the α subunit to translocate AMPK into the cytoplasm. Nuclear localization putatively employs RanGTPase-driven importin that might recognize the nuclear localization signal (NLS) present on the AMPKα2 kinase domain. Nucleo-cytoplasmic shuttling of AMPK is influenced by multiple factors, such as starvation, exercise, heat shock, oxidant, cell density, and circadian rhythm. Tissue-specific localization, which distributes AMPK trimers with different combinations, has also been shown to be vital in maintaining tissue-specific metabolism. Tissue-specific and subcellular distribution of AMPK might be attributed to differences in the expression of the subunit, the stabilization by protein regulators, tissue activity, and the localization of AMPK activators. Considering the importance of AMPK localization in coordinating signaling and metabolism, further research is due to fully elucidate the largely unknown complex mechanism underlying this regulation.

Coreopsis lanceolata L. is a perennial plant of the family Asteraceae, and its flower is known to contain flavonoids with various bioactivities. We evaluated the effect of Coreopsis lanceolata L. flower (CLF) extracts on H₂O₂-induced oxidative stress (OS) in neuronal cells and mouse neurons. The flowering part of CL was used as CLF1 (70% ethanol extract) and CLF2 (water extract), and 10 types of phenolic compounds were quantified using high-performance liquid chromatography. To evaluate the neuroprotective effects of CLF, the antioxidant activities of the extracts were measured, and the expression levels of antioxidant enzymes and proteins related to OS-induced apoptosis in neuronal cells and mouse neurons treated with the extracts were investigated. In the in vitro study, CLF ameliorated H₂O₂-induced oxidative stress and induced the expression of antioxidant enzymes in PC12 cells. Furthermore, CLF1 enhanced the expression of the Bcl-xL protein but reduced the expression of Bax and the cleavage of caspase-3. In the same manner, CLF1 showed neuroprotective effects against OS in vivo. Pretreatment with CLF1 (200 mg/kg) increased the Bcl-2 protein and decreased Bax compared with the 1-methyl-4-phenylpyridinium ion (MPP+)-treated C57BL/6 mice model group. Our results suggest that the protective effects of CLF1 on MPP+-induced apoptosis may be due to its anti-apoptotic activity, through regulating the expression of the Bcl-2 family. CLF1 exerts neuroprotective effects against OS-induced apoptosis in PC12 cells in a Parkinson’s disease model mouse. This effect may be attributable to the upregulation of Bcl-2 protein expression, downregulation of Bax expression, and inhibition of caspase-3 activation. These data indicate that CLF may provide therapeutic value for the treatment of progressive neurodegenerative diseases.