Changes of Cytosolic Ca<SUP>2⁢</SUP> under Metabolic Inhibition in Isolated Rat Ventricular Myocytes

Sunghyun Kang,Nari Kim,Hyun Joo,Jae Boum Youm,Won Sun Park,Mohamed Warda,Hyungkyu Kim,Dang Van Cuong,Taeho Kim,Euiyong Kim,Jin Han 대한생리학회-대한약리학회 2005 The Korean Journal of Physiology & Pharmacology Vol.9 No.5

To characterize cytosolic Ca<SUP>2⁢</SUP> fluctuations under metabolic inhibition, rat ventricular myocytes were exposed to 200μM 2,4-dinitrophenol (DNP), and mitochondrial Ca<SUP>2⁢</SUP>, mitochondrial membrane potential (ΔΨ<SUB>m</SUB>), and cytosolic Ca<SUP>2⁢</SUP> were measured, using Rhod-2 AM, TMRE, and Fluo-4 AM fluorescent dyes, respectively, by Laser Scanning Confocal Microscopy (LSCM). Furthermore, the role of sarcolemmal Na<SUP>⁢</SUP>/Ca<SUP>2⁢</SUP> exchange (NCX) in cytosolic Ca<SUP>2⁢</SUP> efflux was studied in KB-R7943 and Na<SUP>⁢</SUP>-free normal Tyrode s solution (143 mM LiCl ). When DNP was applied to cells loaded with Fluo-4 AM, Fluo-4 AM fluorescence intensity initially increased by 70⁑10% within 70⁑10 s, and later by 400⁑200% at 850⁑46 s. Fluorescence intensity of both Rhod-2 AM and TMRE were initially decreased by DNP, coincident with the initial increase of Fluo-4 AM fluorescence intensity. When sarcoplasmic reticulum (SR) Ca<SUP>2⁢</SUP> was depleted by 1μM thapsigargin plus 10μM ryanodine, the initial increase of Fluo-4 AM fluorescence intensity was unaffected, however, the subsequent progressive increase was abolished. KB-R7943 delayed both the first and the second phases of cytosolic Ca<SUP>2⁢</SUP> overload, while Na<SUP>⁢</SUP>-free solution accelerated the second. The above results suggest that: 1) the initial rise in cytosolic Ca<SUP>2⁢</SUP> under DNP results from mitochondrial depolarization; 2) the secondary increase is caused by progressive Ca<SUP>2⁢</SUP> release from SR; 3) NCX plays an important role in transient cytosolic Ca<SUP>2⁢</SUP> shifts under metabolic inhibition with DNP.

The K<SUB>ATP</SUB> channel opener diazoxide attenuates mitochondrial Ca<SUP>2+</SUP> overload in rat ventricular myocytes

Sunghyun Kang(강성현),Nari Kim(김나리),Hyun Joo(주현),Jae boum Youm(염재범),Won sun Park(박원선),Dang Van Cuong,Hyoung kyu Kim(김형규),Teaho Kim(김태호),Tran Min Khoa,Vu Thi Thu,Hyunju Kim(김현주),Hyejin Moon(문혜진),Hyunsuk L 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.10

Verrucous carcinoma arising from a previous cystic lesion: a case report

Kang, Sunghyun,Leem, Dae Ho Korean Association of Maxillofacial Plastic and Re 2018 Maxillofacial Plastic Reconstructive Surgery Vol.40 No.-

Background: Verrucous carcinoma (VC) accounts for 1-10% of cases of squamous cell carcinoma (SCC) in the oral cavity, and 75% of VC occur in the oral cavity. Only 3% of primary intraosseous squamous cell carcinomas (PIOSCC), which means SCC occurring primarily in the bone, are VC. Verrucous carcinoma arising from odontogenic cysts (OC) is very rare, with only seven cases reported to date. Case presentation: This study reported a case of a patient who underwent partial maxillectomy and neck dissection for VC that occurred in the right anterior maxilla. The patient was admitted to the emergency department at our institution 8 years ago and showed cystic lesions in the anterior maxilla on facial computed tomography (CT) images. Treatment through other departments including assessment of laceration in the mental region and only suture was performed. This report highlights a very rare case of VC in the right anterior maxilla arising from a previous cystic lesion. Conclusions: Since PIOSCC can arise from OC, appropriate treatment of intraosseous cysts and regular radiologic evaluation are necesssary. Surgical exicision of the primary lesion without neck dissection can lead to good prognosis for patients with primary intraosseous verrucous carcinoma.

Cardiac Mitochondrial Inner Membrane Anion Channel during Ischemic-Reperfusion Injury

Kang, Sunghyun,Kim, Hyunggyu,Ko, Jaehong,Park, Won Sun,Mohamad Warda,Kim, Nari,Youm, Jae Boum,Han, Jin 이화여자대학교 세포신호전달연구센터 2008 고사리 세포신호전달 심포지움 Vol. No.10

Mitochondria are involved in oxidative phosphorylation, thermogenesis, reactive oxygen species. production, and intracellular Ca^(2+) homeostasis. Mitochondrial dysfunction during metabolic inhibition causes energy depletion and loss of cellular function and integrity, leading to cell death. Mitochondria possess a highly permeable outer membrane and an inner membrane that was originally thought to be relatively impermeable to ions to prevent dissipation of the electrochemical gradient for protons. Ion channels on the mitochondrial inner membrane influence membrane potential(ΔΨ_(m)) and cell function in specific ways that can be detrimental to cell survival. Mitochondrial K^(+) channels(mitoK_(Ca) and mitoK_(ATP)) are important determinants of resistance to ischemic damage and apoptosis, and may be clinically recruitable to prevent cardiac ischemic injury. In contrast, inner membrane anion channel(IMAC) initiates oscillations of mitochondrial redox and membrane potential, and thus might influence the overall function of the cell. In this study we recorded IMAC in cardiac mitochondrial inner membrane using nano patch-clamp techniques, and we tested whether IMAC confers protection against ischemic-reperfusion injury or not. We demonstrated that metabolic inhibition can trigger synchronized oscillations in ΔΨ_(m), ROS production, and mitochondrial redox potential. In the open-channel current-voltage curve, single channel currents with a full unitary conductance of 107 pS were often observed. DIDS, 4'-chlorodiazepham and PK11195 decreased the channel activity and prevented metabolic inhibition-induced ΔΨ_(m) loss. They also protected cardiac myocytes against ischemic-reperfusion injury. We are now trying to confirm the nature and molecular identity of the channel components. Our results suggest that IMAC is present in cardiac mitochondria and plays a role as key arbiters of cell life and death. Our studies may contribute to understanding the close relationship between mitochondrial ion channels, membrane potential, and the overall function of the cell. The ion channels should be present in all cell types containing mitochondria and the implications for normal as well as for pathophysiological cell function are universal.

Oral Synechia from the Lower Lip to Maxillary Alveolus: A Case Report

Sunghyun Kang,JinA Baek 대한구순구개열학회 2019 대한구순구개열학회지 Vol.22 No.2

Congenital maxillomandibular fusion is an extremely rare condition. To date, approximately 70 cases of oral synechia have been reported, and most of these involved palate-mouth floor, palate-tongue, or interalveolar synechiae. This study reported a very unique case of synechia in which the lower lip vermilion had split into two branches and formed a cordlike structure as it attached to an anterior maxillary alveolar cleft. In particular, the synechia was accompanied by a cleft lip and a lower lip pit, accentuating the rarity of the case. In this report, we analyzed the case based on the mechanisms of synechia development and related syndromes; in addition, we discussed the importance of the examinations, diagnosis, and treatment methods. Synechiae should be resolved as soon as possible, since they can severely restrict mouth opening and lead to problem with oral function, and its relation with the syndrome should be considered.

Phosphoproteomic analysis of neuronal cell death by glutamate-induced oxidative stress

Kang, Tae Hyuk,Bae, Kwang-Hee,Yu, Min-jung,Kim, Won-Kon,Hwang, Hyang-Ran,Jung, Hyeyun,Lee, Phil Young,Kang, Sunghyun,Yoon, Tae-Sung,Park, Sung Goo,Ryu, Seong Eon,Lee, Sang Chul WILEY-VCH Verlag 2007 Proteomics Vol.7 No.15

<P>Oxidative stress is one of the major causes of neuronal cell death in disorders such as perinatal hypoxia and ischemia. Protein phosphorylation is the most significant PTM of proteins and plays an important role in stress-induced signal transduction. Thus, the analysis of alternative protein phosphorylation states which occur during oxidative stress-induced cell death could provide valuable information regarding cell death. In this study, a reference phosphoproteome map of the mouse hippocampal cell line HT22 was constructed based on 125 spots that were identified by MALDI-TOF or LC-ESI-Q-TOF-MS analysis. In addition, proteins of HT22 cells at various stages of oxidative stress-induced cell death were separated by 2-DE and alterations in phosphoproteins were detected by Pro-Q Diamond staining. A total of 17 spots showing significant quantitative changes and seven newly appearing spots were identified after glutamate treatment. Splicing factor 2, peroxiredoxin 2, S100 calcium binding protein A11, and purine nucleoside phosphorylase were identified as up- or down-regulated proteins. CDC25A, caspase-8, and cyp51 protein appeared during oxidative stress-induced cell death. The data in this study from phosphoproteomic analysis provide a valuable resource for the understanding of HT22 cell death mechanisms mediated by oxidative stress.</P>

Probing DAMA/LIBRA data in the full parameter space of WIMP effective models of inelastic scattering

Kang, Sunghyun,Scopel, S.,Tomar, Gaurav American Physical Society 2019 Physical Review D Vol.99 No.10

No Rules in Color

Sunghyun Ryoo KANG 한국색채학회 2014 International Invitation Exhibition of Color Works Vol.2014 No.-

One Nation: Unification

SungHyun Ryoo KANG 한국색채학회 2015 International Invitation Exhibition of Color Works Vol.2015 No.-

선택적 자기표현, 자아존중감, 조직에 대한 소속감 관계 연구

강성현(Sunghyun Kang),신동희(Donghee Shin) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2

SNS를 통해 다양한 사람들이 실시간으로 의사소통하고 사회적인 관계를 형성하며 온라인상에서는 자신의 또 다른 정체성도 형성하게 된다. 온라인에서 많은 이용자들의 정체성을 파악하기 위해 다양한 정보들이 존재하지만, 개인 프로필에서의 정보들은 이용자를 대변해 주는 중요한 변인으로 작용한다. 프로필을 통해 자신의 지위를 알리거나 심리적인 상태를 암시할 수 있기 때문이고, 또한 이용자의 심리적인 상태가 자신의 SNS 프로필 정보를 구성하는 중요한 요인으로 영향을 미칠 수 있기도 하다. 본 연구는 세계적으로 가장 많은 가입자를 가지고 있는 SNS인 페이스 북을 통해, 이용자가 선택할 수 있는 29개의 프로필 정보 중에 어떤 정보를 선택적으로 표현했는지 중점을 둔다. 그리고 선택된 정보의 수준과 관련하여 자아존중감과 조직에 대한 소속감과 같은 이용자의 심리적인 상태가 어떠한 영향을 미치는지 연구했다. 연구 결과, 페이스 북에 나타나는 프로필 정보는 이용자의 심리적인 상태와 유의한 관계를 나타냈고, 이를 통해 온라인에서의 선택적 자기표현은 자신의 정체성과 마음을 간접적으로 알려주는 중요한 단서라는 것을 알 수 있다. While people communicate and form a relationship with others through the SNS, they also create their Avatar identities in online communities. Although there are numerous clues to infer the user"s identities from online profile such as picture and text, profile information on work and education is the salient factors for us to identify the psychological status of users. This study examines the user"s self-esteem and sense of belonging based on the profile information of 29 factors and their exposure levels. Our inquiry focuses on whether and how these information factors are influenced by human mind and psychological status. The result shows that user"s self-esteem and sense of belonging have significant effects on the profile information of facebook. The finding indicates that psychological beings give users to select profile information in other to form their online identities.