1.The Immunohistochemical Study of MAPKs Expression in Psoriatic Epidermis.
Sung Han KIM ; Jung Hun KO ; Kyu Cherl CHOI ; Byoung Soo CHUNG
Annals of Dermatology 2004;16(3):99-104
No abstract available.
Epidermis*
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Psoriasis
2.Age-dependent expression of ion channel genes in rat
Sung-Cherl JUNG ; Tong ZHOU ; Eun-A KO
The Korean Journal of Physiology and Pharmacology 2023;27(1):85-94
Ion channels regulate a large number of cellular functions and their functional role in many diseases makes them potential therapeutic targets. Given their diverse distribution across multiple organs, the roles of ion channels, particularly in age-associated transcriptomic changes in specific organs, are yet to be fully revealed.Using RNA-seq data, we investigated the rat transcriptomic profiles of ion channel genes across 11 organs/tissues and 4 developmental stages in both sexes of Fischer 344 rats and identify tissue-specific and age-dependent changes in ion channel gene expression. Organ-enriched ion channel genes were identified. In particular, the brain showed higher tissue-specificity of ion channel genes, including Gabrd, Gabra6, Gabrg2, Grin2a, and Grin2b. Notably, age-dependent changes in ion channel gene expression were prominently observed in the thymus, including in Aqp1, Clcn4, Hvcn1, Itpr1, Kcng2, Kcnj11, Kcnn3, and Trpm2. Our comprehensive study of ion channel gene expression will serve as a primary resource for biological studies of aging-related diseases caused by abnormal ion channel functions.
3.Prenatal Exposure to High Cortisol Induces ADHD-like Behaviors with Delay in Spatial Cognitive Functions during the Post-weaning Period in Rats
Sang-Chan JEON ; Hye-Ji KIM ; Eun-A KO ; Sung-Cherl JUNG
Experimental Neurobiology 2021;30(1):87-100
High levels of cortisol in blood are frequently observed in patients with major depressive disorders and increased cortisol level induces depressivelike symptoms in animal models. However, it is still unclear whether maternal cortisol level during pregnancy is a critical factor resulting in neuropsychiatric disorders in offspring. In this study, we increased cortisol level in rats by repetitively injecting corticosterone subcutaneously (Corti.Mom, 20 mg/kg/day) during pregnancy and evaluated the behavioral patterns of their pups (Corti.Pups) via forced swimming (FS), open field (OF), elevated plus maze (EPM) and Morris water maze (MWM) tests during the immediate post-weaning period (postnatal day 21 to 25). In results, corticosterone significantly increased plasma cortisol levels in both Corti.Moms and Corti.Pups. Unlike depressive animal models, Corti.Pups showed higher hyperactive behaviors in the FS and OF tests than normal pups (Nor.Pups) born from rats (Nor.Moms) treated with saline. Furthermore, Corti.Pups spent more time and traveled longer distance in the open arms of EPM test, exhibiting higher extremity. These patterns were consistent with behavioral symptoms observed in animal models of attention deficit hyperactivity disorder (ADHD), which is characterized by hyperactivity, impulsivity, and inattention. Additionally, Corti.Pups swam longer and farther to escape in MWM test, showing cognitive declines associated with attention deficit. Our findings provide evidence that maternal cortisol level during pregnancy may affect the neuroendocrine regulation and the brain development of offspring, resulting in heterogeneous developmental brain disorders such as ADHD.
4.Nobiletin Exhibits Neuroprotective Effects against Mitochondrial Complex I Inhibition via Regulating Apoptotic Signaling
Khulan AMARSANAA ; Hye-Ji KIM ; Eun-A KO ; Jaemin JO ; Sung-Cherl JUNG
Experimental Neurobiology 2021;30(1):73-86
Nobiletin, a polymethoxylated flavonoid found in citrus, has been studied because of its modulatory functions in cellular signaling cascades, and effects to prevent mitochondrial calcium overload and neuronal cell death. Particularly, we previously reported that nobiletin induced changes in the mitochondrial membrane potential through K + channel regulation, suggesting that nobiletin might exert neuroprotective effects via regulating mitochondrial functions associated with the electron transport chain (ETC) system. This study investigated whether nobiletin regulated mitochondrial dysfunction mediated by ETC system downregulation by inhibiting complex I (CI) and complex III (CIII) in pure mitochondria and the cortical neurons of rats. The results showed that nobiletin significantly reduced mitochondrial reactive oxygen species (ROS) production, inhibited apoptotic signaling, enhanced ATP production and then restored neuronal viability under conditions of CI inhibition, but not CIII inhibition.These effects were attributed to the downregulation of translocation of apoptosis-induced factor (AIF), and the upregulation of CI activity and the expression of antioxidant enzymes such as Nrf2 and HO-1. Together with our previous study, these results indicate that the neuroprotective effects of nobiletin under mitochondrial dysfunction may be associated with its function to activate antioxidant signaling cascades. Our findings suggest the possibility that nobiletin has therapeutic potential in treating oxidative neurological and neurodegenerative diseases mediated by mitochondrial dysfunction.
5.Sustained K+ Outward Currents are Sensitive to Intracellular Heteropodatoxin2 in CA1 Neurons of Organotypic Cultured Hippocampi of Rats.
The Korean Journal of Physiology and Pharmacology 2012;16(5):343-348
Blocking or regulating K+ channels is important for investigating neuronal functions in mammalian brains, because voltage-dependent K+ channels (Kv channels) play roles to regulate membrane excitabilities for synaptic and somatic processings in neurons. Although a number of toxins and chemicals are useful to change gating properties of Kv channels, specific effects of each toxin on a particular Kv subunit have not been sufficiently demonstrated in neurons yet. In this study, we tested electrophysiologically if heteropodatoxin2 (HpTX2), known as one of Kv4-specific toxins, might be effective on various K+ outward currents in CA1 neurons of organotypic hippocampal slices of rats. Using a nucleated-patch technique and a pre-pulse protocol in voltage-clamp mode, total K+ outward currents recorded in the soma of CA1 neurons were separated into two components, transient and sustained currents. The extracellular application of HpTX2 weakly but significantly reduced transient currents. However, when HpTX2 was added to internal solution, the significant reduction of amplitudes were observed in sustained currents but not in transient currents. This indicates the non-specificity of HpTX2 effects on Kv4 family. Compared with the effect of cytosolic 4-AP to block transient currents, it is possible that cytosolic HpTX2 is pharmacologically specific to sustained currents in CA1 neurons. These results suggest that distinctive actions of HpTX2 inside and outside of neurons are very efficient to selectively reduce specific K+ outward currents.
Animals
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Brain
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Carisoprodol
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Cytosol
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Humans
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Membranes
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Neurons
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Rats
6.Roles of PDGF/PDGFR signaling in various organs
Sung-Cherl JUNG ; Dawon KANG ; Eun-A KO
The Korean Journal of Physiology and Pharmacology 2025;29(2):139-155
Platelet-derived growth factors (PDGFs) ligands and their corresponding receptors, PDGF receptor (PDGFR)α and PDGFRβ, play a crucial role in controlling diverse biological functions, including cell growth, viability and migration. These growth factors bind to PDGFRs, which are receptor tyrosine kinases present on the surface of target cells. The interaction between PDGFs and PDGFRs induces receptor dimerization and subsequent activation through auto-phosphorylation, which in turn triggers a cascade of intracellular signaling pathways. PDGF/PDGFR signaling is essential for maintaining normal physiological functions, including tissue regeneration and growth. However, dysregulation of this signaling pathway leads to pathological conditions, including fibrosis, atherosclerosis, and cancer development in various organs. The pathological impact of PDGF/PDGFR signaling primarily stems from its capacity to promote excessive cell proliferation, enhanced migration, and increased extracellular matrix deposition, resulting in tissue overgrowth, scarring, and abnormal vessel formation. These processes are integral to the pathogenesis of fibrotic, neoplastic, and vascular disorders. Therefore, understanding these pathways is crucial for developing targeted treatments designed to inhibit PDGF/PDGFR signaling in these diseases. This review delves into the dual role of PDGF/PDGFR signaling in both physiological and pathophysiological contexts across different organs and provides insights into current pharmacological therapies designed to target the PDGF signaling pathway.
7.Transcriptomic Alteration in the Brain and Gut of Offspring Following Prenatal Exposure to Corticosterone
Eun-A KO ; Tong ZHOU ; Jae-Hong KO ; Sung-Cherl JUNG
Experimental Neurobiology 2025;34(1):9-19
Maternal stress during pregnancy can profoundly affect offspring health, increasing the risk of psychiatric disorders, metabolic diseases, and gastrointestinal problems. In this study, the effects of high prenatal corticosterone exposure on gene expression in the brain and small intestine of rat offspring were investigated via RNA-sequencing analysis. Pregnant rats were divided into two groups: Corti.Moms were injected with corticosterone daily, while Nor.Moms were given saline injections. Their offspring were labeled as Corti.Pups and Nor.Pups, respectively. The brain tissue analysis of Corti.Pups showed that the expression levels of the genes linked to neurodegenerative conditions increased and enhanced mitochondrial biogenesis, possibly due to higher ATP demands. The genes associated with calcium signaling pathways, neuroactive ligand-receptor interactions, and IgA production were also upregulated in the small intestine of Corti.pups. Conversely, the genes related to protein digestion, absorption, and serotonergic and dopaminergic synaptic activities were downregulated. These findings revealed that gene expression patterns in both the brain and intestinal smooth muscle of offspring prenatally exposed to corticosterone were substantially altered. Thus, this study provided valuable insights into the effects of prenatal stress on neurodevelopment and gut function.
8.Roles of PDGF/PDGFR signaling in various organs
Sung-Cherl JUNG ; Dawon KANG ; Eun-A KO
The Korean Journal of Physiology and Pharmacology 2025;29(2):139-155
Platelet-derived growth factors (PDGFs) ligands and their corresponding receptors, PDGF receptor (PDGFR)α and PDGFRβ, play a crucial role in controlling diverse biological functions, including cell growth, viability and migration. These growth factors bind to PDGFRs, which are receptor tyrosine kinases present on the surface of target cells. The interaction between PDGFs and PDGFRs induces receptor dimerization and subsequent activation through auto-phosphorylation, which in turn triggers a cascade of intracellular signaling pathways. PDGF/PDGFR signaling is essential for maintaining normal physiological functions, including tissue regeneration and growth. However, dysregulation of this signaling pathway leads to pathological conditions, including fibrosis, atherosclerosis, and cancer development in various organs. The pathological impact of PDGF/PDGFR signaling primarily stems from its capacity to promote excessive cell proliferation, enhanced migration, and increased extracellular matrix deposition, resulting in tissue overgrowth, scarring, and abnormal vessel formation. These processes are integral to the pathogenesis of fibrotic, neoplastic, and vascular disorders. Therefore, understanding these pathways is crucial for developing targeted treatments designed to inhibit PDGF/PDGFR signaling in these diseases. This review delves into the dual role of PDGF/PDGFR signaling in both physiological and pathophysiological contexts across different organs and provides insights into current pharmacological therapies designed to target the PDGF signaling pathway.
9.Roles of PDGF/PDGFR signaling in various organs
Sung-Cherl JUNG ; Dawon KANG ; Eun-A KO
The Korean Journal of Physiology and Pharmacology 2025;29(2):139-155
Platelet-derived growth factors (PDGFs) ligands and their corresponding receptors, PDGF receptor (PDGFR)α and PDGFRβ, play a crucial role in controlling diverse biological functions, including cell growth, viability and migration. These growth factors bind to PDGFRs, which are receptor tyrosine kinases present on the surface of target cells. The interaction between PDGFs and PDGFRs induces receptor dimerization and subsequent activation through auto-phosphorylation, which in turn triggers a cascade of intracellular signaling pathways. PDGF/PDGFR signaling is essential for maintaining normal physiological functions, including tissue regeneration and growth. However, dysregulation of this signaling pathway leads to pathological conditions, including fibrosis, atherosclerosis, and cancer development in various organs. The pathological impact of PDGF/PDGFR signaling primarily stems from its capacity to promote excessive cell proliferation, enhanced migration, and increased extracellular matrix deposition, resulting in tissue overgrowth, scarring, and abnormal vessel formation. These processes are integral to the pathogenesis of fibrotic, neoplastic, and vascular disorders. Therefore, understanding these pathways is crucial for developing targeted treatments designed to inhibit PDGF/PDGFR signaling in these diseases. This review delves into the dual role of PDGF/PDGFR signaling in both physiological and pathophysiological contexts across different organs and provides insights into current pharmacological therapies designed to target the PDGF signaling pathway.
10.Transcriptomic Alteration in the Brain and Gut of Offspring Following Prenatal Exposure to Corticosterone
Eun-A KO ; Tong ZHOU ; Jae-Hong KO ; Sung-Cherl JUNG
Experimental Neurobiology 2025;34(1):9-19
Maternal stress during pregnancy can profoundly affect offspring health, increasing the risk of psychiatric disorders, metabolic diseases, and gastrointestinal problems. In this study, the effects of high prenatal corticosterone exposure on gene expression in the brain and small intestine of rat offspring were investigated via RNA-sequencing analysis. Pregnant rats were divided into two groups: Corti.Moms were injected with corticosterone daily, while Nor.Moms were given saline injections. Their offspring were labeled as Corti.Pups and Nor.Pups, respectively. The brain tissue analysis of Corti.Pups showed that the expression levels of the genes linked to neurodegenerative conditions increased and enhanced mitochondrial biogenesis, possibly due to higher ATP demands. The genes associated with calcium signaling pathways, neuroactive ligand-receptor interactions, and IgA production were also upregulated in the small intestine of Corti.pups. Conversely, the genes related to protein digestion, absorption, and serotonergic and dopaminergic synaptic activities were downregulated. These findings revealed that gene expression patterns in both the brain and intestinal smooth muscle of offspring prenatally exposed to corticosterone were substantially altered. Thus, this study provided valuable insights into the effects of prenatal stress on neurodevelopment and gut function.