1.Effects of Vitamin D on Blood Pressure and Endothelial Function.
The Korean Journal of Physiology and Pharmacology 2013;17(5):385-392
Vitamin D deficiency is prevalent, primarily due to limited sun exposure, which may be observed in urban areas, or as a result of modern lifestyles. Common myths about vitamin D persist, including that it is mostly obtained from the diet and is only essential for bone and mineral homeostasis. Nonetheless, advances in biomedical science suggest that vitamin D is a hormone that is integral to numerous physiologic functions in most cells and tissues. Therefore, abnormal vitamin D levels may contribute to health disturbances. A number of recent reports on potential associations between vitamin D deficiency and cardiovascular disease have highlighted its role in this system. A focus over the previous decade has been to better understand the mechanisms behind vitamin D regulation and the pathophysiology associated with suboptimal vitamin D levels. Vitamin D deficiency is highly associated with the incidence of cardiovascular diseases, even when considering other well-known risk factors. In this process, the renin-angiotensin system is disrupted, and hypertension and endothelial dysfunction contribute to the risk of cardiovascular disease. Likewise, clinical outcomes upon the normalization of vitamin D levels have been investigated in different patient populations. It makes sense that vitamin D supplementation to improve vitamin D status among vitamin D-deficient individuals could be useful without requiring a sudden lifestyle change. This manuscript provides a brief overview of vitamin D metabolism and the vitamin D receptor. It also summarizes the current clinical research relating to vitamin D supplementation and its effects on hypertension and endothelial dysfunction in cardiovascular medicine.
Blood Pressure*
;
Calcitriol
;
Cardiovascular Diseases
;
Diet
;
Homeostasis
;
Humans
;
Hypertension
;
Incidence
;
Life Style
;
Receptors, Calcitriol
;
Renin-Angiotensin System
;
Risk Factors
;
Solar System
;
Vitamin D Deficiency
;
Vitamin D*
;
Vitamins
2.Imaging Findings of Neonatal Adrenal Disorders.
Hye Kyung YOON ; Bokyung Kim HAN ; Min Hee LEE
Journal of the Korean Radiological Society 1999;40(1):173-179
In newborn infants, normal adrenal glands are characterized by a relatively thin echogenic center surroundedby a thick, hypoechoic cortical rim as seen on ultrasound (US). Various disorders involving the neonatal adrenalgland include adrenal hemorrhage, hyperplasia, cyst, Wolman's disease, and congenital neuroblastoma. Adrenalhemorrhage is the most common cause of an adrenal mass in the neonate, though differentiation between adrenalhemorrhage and neuroblastoma is in many cases difficult. We describe characteristic US, CT and MR imaging findingsin neonates with various adrenal disorders.
Adrenal Glands
;
Hemorrhage
;
Humans
;
Hyperplasia
;
Infant, Newborn
;
Magnetic Resonance Imaging
;
Neuroblastoma
;
Ultrasonography
;
Wolman Disease
3.Imaging Findings of Neonatal Adrenal Disorders.
Hye Kyung YOON ; Bokyung Kim HAN ; Min Hee LEE
Journal of the Korean Radiological Society 1999;40(1):173-179
In newborn infants, normal adrenal glands are characterized by a relatively thin echogenic center surroundedby a thick, hypoechoic cortical rim as seen on ultrasound (US). Various disorders involving the neonatal adrenalgland include adrenal hemorrhage, hyperplasia, cyst, Wolman's disease, and congenital neuroblastoma. Adrenalhemorrhage is the most common cause of an adrenal mass in the neonate, though differentiation between adrenalhemorrhage and neuroblastoma is in many cases difficult. We describe characteristic US, CT and MR imaging findingsin neonates with various adrenal disorders.
Adrenal Glands
;
Hemorrhage
;
Humans
;
Hyperplasia
;
Infant, Newborn
;
Magnetic Resonance Imaging
;
Neuroblastoma
;
Ultrasonography
;
Wolman Disease
4.4-Aminopyridine Inhibits the Large-conductance Ca2+ -activated K+ Channel (BKCa) Currents in Rabbit Pulmonary Arterial Smooth Muscle Cells.
Young Min BAE ; Aeran KIM ; Bokyung KIM ; Sung Il CHO ; Junghwan KIM ; Yung E EARM
The Korean Journal of Physiology and Pharmacology 2003;7(1):25-28
Ion channel inhibitors are widely used for pharmacological discrimination between the different channel types as well as for determination of their functional role. In the present study, we tested the hypothesis that 4-aminopyridine (4-AP) could affect the large conductance Ca2+ -activated K+ channel (BKCa) currents using perforated-patch or cell-attached configuration of patch-clamp technique in the rabbit pulmonary arterial smooth muscle. Application of 4-AP reversibly inhibited the spontaneous transient outward currents (STOCs). The reversal potential and the sensitivity to charybdotoxin indicated that the STOCs were due to the activation of BKCa. The BKCa currents were recorded in single channel resolution under the cell-attached mode of patch-clamp technique for minimal perturbation of intracellular environment. Application of 4-AP also inhibited the single BKCa currents reversibly and dose-dependently. The membrane potential of rabbit pulmonary arterial smooth muscle cells showed spontaneous transient hyperpolarizations (STHPs), presumably due to the STOC activities, which was also inhibited by 4-AP. These results suggest that 4-AP can inhibit BKCa currents in the intact rabbit vascular smooth muscle. The use of 4-AP as a selective voltage-dependent K+ (KV) channel blocker in vascular smooth muscle, therefore, must be reevaluated.
4-Aminopyridine*
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Charybdotoxin
;
Discrimination (Psychology)
;
Ion Channels
;
Membrane Potentials
;
Muscle, Smooth*
;
Muscle, Smooth, Vascular
;
Myocytes, Smooth Muscle*
;
Patch-Clamp Techniques
;
Pulmonary Artery
5.Experimental development of the epigenomic library construction method to elucidate the epigenetic diversity and causal relationship between epigenome and transcriptome at a single-cell level
Kyunghyuk PARK ; Min Chul JEON ; Bokyung KIM ; Bukyoung CHA ; Jong-Il KIM
Genomics & Informatics 2022;20(1):e2-
The method of single-cell RNA sequencing has been rapidly developed, and numerous experiments have been conducted over the past decade. Their results allow us to recognize various subpopulations and rare cell states in tissues, tumors, and immune systems that are previously unidentified, and guide us to understand fundamental biological processes that determine cell identity based on single-cell gene expression profiles. However, it is still challenging to understand the principle of comprehensive gene regulation that determines the cell fate only with transcriptome, a consequential output of the gene expression program. To elucidate the mechanisms related to the origin and maintenance of comprehensive single-cell transcriptome, we require a corresponding single-cell epigenome, which is a differentiated information of each cell with an identical genome. This review deals with the current development of single-cell epigenomic library construction methods, including multi-omics tools with crucial factors and additional requirements in the future focusing on DNA methylation, chromatin accessibility, and histone post-translational modifications. The study of cellular differentiation and the disease occurrence at a single-cell level has taken the first step with single-cell transcriptome and is now taking the next step with single-cell epigenome.
6.Facilitation of serotonin-induced contraction of rat mesenteric artery by ketamine.
Sang Woong PARK ; Hyun Ju NOH ; Jung Min KIM ; Bokyung KIM ; Sung Il CHO ; Yoon Soo KIM ; Nam Sik WOO ; Sung Hun KIM ; Young Min BAE
The Korean Journal of Physiology and Pharmacology 2016;20(6):605-611
Ketamine is an anesthetic with hypertensive effects, which make it useful for patients at risk of shock. However, previous ex vivo studies reported vasodilatory actions of ketamine in isolated arteries. In this study, we reexamined the effects of ketamine on arterial tones in the presence and absence of physiological concentrations of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) by measuring the isometric tension of endothelium-denuded rat mesenteric arterial rings. Ketamine little affected the resting tone of control mesenteric arterial rings, but, in the presence of 5-HT (100~200 nM), ketamine (10~100 µM) markedly contracted the arterial rings. Ketamine did not contract arterial rings in the presence of NE (10 nM), indicating that the vasoconstrictive action of ketamine is 5-HT-dependent. The concentration-response curves (CRCs) of 5-HT were clearly shifted to the left in the presence of ketamine (30 µM), whereas the CRCs of NE were little affected by ketamine. The left shift of the 5-HT CRCs caused by ketamine was reversed with ketanserin, a competitive 5-HT(2A) receptor inhibitor, indicating that ketamine facilitated the activation of 5-HT(2A) receptors. Anpirtoline and BW723C86, selective agonists of 5-HT(1B) and 5-HT(2B) receptors, respectively, did not contract arterial rings in the absence or presence of ketamine. These results indicate that ketamine specifically enhances 5-HT(2A) receptor-mediated vasoconstriction and that it is vasoconstrictive in a clinical setting. The facilitative action of ketamine on 5-HT(2A) receptors should be considered in ketamine-induced hypertension as well as in the pathogenesis of diseases such as schizophrenia, wherein experimental animal models are frequently generated using ketamine.
Animals
;
Arteries
;
Blood Pressure
;
Humans
;
Hypertension
;
Ketamine*
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Ketanserin
;
Mesenteric Arteries*
;
Models, Animal
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Norepinephrine
;
Rats*
;
Receptor, Serotonin, 5-HT2A
;
Schizophrenia
;
Serotonin
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Shock
;
Vasoconstriction
7.Serotonin contracts the rat mesenteric artery by inhibiting 4-aminopyridine-sensitive Kv channels via the 5-HT2A receptor and Src tyrosine kinase.
Dong Jun SUNG ; Hyun Ju NOH ; Jae Gon KIM ; Sang Woong PARK ; Bokyung KIM ; Hana CHO ; Young Min BAE
Experimental & Molecular Medicine 2013;45(12):e67-
Serotonin (5-hydroxytryptamine (5-HT)) is a neurotransmitter that regulates a variety of functions in the nervous, gastrointestinal and cardiovascular systems. Despite such importance, 5-HT signaling pathways are not entirely clear. We demonstrated previously that 4-aminopyridine (4-AP)-sensitive voltage-gated K+ (Kv) channels determine the resting membrane potential of arterial smooth muscle cells and that the Kv channels are inhibited by 5-HT, which depolarizes the membranes. Therefore, we hypothesized that 5-HT contracts arteries by inhibiting Kv channels. Here we studied 5-HT signaling and the detailed role of Kv currents in rat mesenteric arteries using patch-clamp and isometric tension measurements. Our data showed that inhibiting 4-AP-sensitive Kv channels contracted arterial rings, whereas inhibiting Ca2+-activated K+, inward rectifier K+ and ATP-sensitive K+ channels had little effect on arterial contraction, indicating a central role of Kv channels in the regulation of resting arterial tone. 5-HT-induced arterial contraction decreased significantly in the presence of high KCl or the voltage-gated Ca2+ channel (VGCC) inhibitor nifedipine, indicating that membrane depolarization and the consequent activation of VGCCs mediate the 5-HT-induced vasoconstriction. The effects of 5-HT on Kv currents and arterial contraction were markedly prevented by the 5-HT2A receptor antagonists ketanserin and spiperone. Consistently, alpha-methyl 5-HT, a 5-HT2 receptor agonist, mimicked the 5-HT action on Kv channels. Pretreatment with a Src tyrosine kinase inhibitor, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine, prevented both the 5-HT-mediated vasoconstriction and Kv current inhibition. Our data suggest that 4-AP-sensitive Kv channels are the primary regulator of the resting tone in rat mesenteric arteries. 5-HT constricts the arteries by inhibiting Kv channels via the 5-HT2A receptor and Src tyrosine kinase pathway.
4-Aminopyridine/pharmacology
;
Action Potentials
;
Animals
;
Calcium Channel Blockers/pharmacology
;
Calcium Channels/metabolism
;
Cells, Cultured
;
Ketanserin/pharmacology
;
Male
;
Mesenteric Arteries/drug effects/*metabolism/physiology
;
Muscle Contraction
;
Muscle, Smooth, Vascular/cytology/drug effects/metabolism/physiology
;
Myocytes, Smooth Muscle/drug effects/metabolism/physiology
;
Nifedipine/pharmacology
;
Potassium Channel Blockers/pharmacology
;
Potassium Channels, Voltage-Gated/antagonists & inhibitors/*metabolism
;
Protein Kinase Inhibitors/pharmacology
;
Rats
;
Rats, Sprague-Dawley
;
Receptor, Serotonin, 5-HT2A/*metabolism
;
Serotonin/*pharmacology
;
Serotonin 5-HT2 Receptor Antagonists/pharmacology
;
Spiperone/pharmacology
;
*Vasoconstriction
;
src-Family Kinases/antagonists & inhibitors/*metabolism
8.Optimization of Large-Scale Expansion and Cryopreservation of Human Natural Killer Cells for Anti-Tumor Therapy.
Bokyung MIN ; Hana CHOI ; Jung Hyun HER ; Mi Young JUNG ; Hyo Jin KIM ; Mi young JUNG ; Eun Kyoung LEE ; Sung Yoo CHO ; Yu Kyeong HWANG ; Eui Cheol SHIN
Immune Network 2018;18(4):e31-
Allogeneic natural killer (NK) cell therapy is a potential therapeutic approach for a variety of solid tumors. We established an expansion method for large-scale production of highly purified and functionally active NK cells, as well as a freezing medium for the expanded NK cells. In the present study, we assessed the effect of cryopreservation on the expanded NK cells in regards to viability, phenotype, and anti-tumor activity. NK cells were enormously expanded (about 15,000-fold expansion) with high viability and purity by stimulating CD³⁺ T cell-depleted peripheral blood mononuclear cells (PBMCs) with irradiated autologous PBMCs in the presence of IL-2 and OKT3 for 3 weeks. Cell viability was slightly reduced after freezing and thawing, but cytotoxicity and cytokine secretion were not significantly different. In a xenograft mouse model of hepatocellular carcinoma cells, cryopreserved NK cells had slightly lower anti-tumor efficacy than freshly expanded NK cells, but this was overcome by a 2-fold increased dose of cryopreserved NK cells. In vivo antibody-dependent cell cytotoxicity (ADCC) activity of cryopreserved NK cells was also demonstrated in a SCID mouse model injected with Raji cells with rituximab co-administration. Therefore, we demonstrated that expanded/frozen NK cells maintain viability, phenotype, and anti-tumor activity immediately after thawing, indicating that expanded/frozen NK cells can provide ‘ready-to-use’ cell therapy for cancer patients.
Animals
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Antibody-Dependent Cell Cytotoxicity
;
Carcinoma, Hepatocellular
;
Cell Survival
;
Cell- and Tissue-Based Therapy
;
Cryopreservation*
;
Freezing
;
Heterografts
;
Humans*
;
Interleukin-2
;
Killer Cells, Natural*
;
Methods
;
Mice
;
Mice, SCID
;
Muromonab-CD3
;
Phenotype
;
Rituximab
9.p38 MAPK Participates in Muscle-Specific RING Finger 1-Mediated Atrophy in Cast-Immobilized Rat Gastrocnemius Muscle.
Junghwan KIM ; Kyung Jong WON ; Hwan Myung LEE ; Byong Yong HWANG ; Young Min BAE ; Whan Soo CHOI ; Hyuk SONG ; Ki Won LIM ; Chang Kwon LEE ; Bokyung KIM
The Korean Journal of Physiology and Pharmacology 2009;13(6):491-496
Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.
Aging
;
Animals
;
Atrophy
;
Bed Rest
;
Fingers
;
Imidazoles
;
Immobilization
;
Muscle, Skeletal
;
Muscles
;
Myoblasts
;
Myoblasts, Skeletal
;
p38 Mitogen-Activated Protein Kinases
;
Phosphorylation
;
Protein Kinases
;
Pyridines
;
Rats
;
RNA, Small Interfering
;
Space Flight
;
Starvation
;
Transfection
10.Protective effect of low-intensity treadmill exercise against acetylcholine-calcium chloride-induced atrial fibrillation in mice
Dong-Jun SUNG ; Yong-Kyun JEON ; Jaeil CHOI ; Bokyung KIM ; Shadi GOLPASANDI ; Sang Woong PARK ; Seung-Bum OH ; Young Min BAE
The Korean Journal of Physiology and Pharmacology 2022;26(5):313-323
Atrial fibrillation (AF) is the most common supraventricular arrhythmia, and it corresponds highly with exercise intensity. Here, we induced AF in mice using acetylcholine (ACh)-CaCl2 for 7 days and aimed to determine the appropriate exercise intensity (no, low, moderate, high) to protect against AF by running the mice at different intensities for 4 weeks before the AF induction by ACh-CaCl2 . We examined the AF-induced atrial remodeling using electrocardiogram, patch-clamp, and immunohistochemistry. After the AF induction, heart rate, % increase of heart rate, and heart weight/body weight ratio were significantly higher in all the four AF groups than in the normal control; highest in the high-ex AF and lowest in the low-ex (lower than the no-ex AF), which indicates that low-ex treated the AF. Consistent with these changes, G protein-gated inwardly rectifying K + currents, which were induced by ACh, increased in an exercise intensity-dependent manner and were lower in the low-ex AF than the no-ex AF. The peak level of Ca2+ current (at 0 mV) increased also in an exercise intensity-dependent manner and the inactivation time constants were shorter in all AF groups except for the low-ex AF group, in which the time constant was similar to that of the control. Finally, action potential duration was shorter in all the four AF groups than in the normal control; shortest in the high-ex AF and longest in the low-ex AF. Taken together, we conclude that low-intensity exercise protects the heart from AF, whereas high-intensity exercise might exacerbate AF.