Calcium permeability of transient receptor potential canonical (TRPC) 4 channels measured by TRPC4-GCaMP6s

Ko, Juyeon,Myeong, Jongyun,Yang, Dongki,So, Insuk The Korean Society of Pharmacology 2017 The Korean Journal of Physiology & Pharmacology Vol.21 No.1

Conflicting evidence has been obtained regarding whether transient receptor potential cation channels (TRPC) are store-operated channels (SOCs) or receptor-operated channels (ROCs). Moreover, the Ca/Na permeability ratio differs depending on whether the current-voltage (I-V) curve has a doubly rectifying shape or inward rectifying shape. To investigate the calcium permeability of TRPC4 channels, we attached GCaMP6s to TRPC4 and simultaneously measured the current and calcium signals. A TRPC4 specific activator, (-)-englerin A, induced both current and calcium fluorescence with the similar time course. Muscarinic receptor stimulator, carbachol, also induced both current and calcium fluorescence with the similar time course. By forming heteromers with TRPC4, TRPC1 significantly reduced the inward current with outward rectifying I-V curve, which also caused the decrease of calcium fluorescence intensity. These results suggest that GCaMP6s attached to TRPC4 can detect slight calcium changes near TRPC4 channels. Consequently, TRPC4-GCaMP6s can be a useful tool for testing the calcium permeability of TRPC4 channels.

Negative self-regulation of transient receptor potential canonical 4 by the specific interaction with phospholipase C-δ1

Juyeon Ko,Jinhyeong Kim,Jongyun Myeong,Misun Kwak,서인석 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.2

Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4β is regulated by phospholipase C (PLC) signaling and is especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP2). In this study, we present the regulation mechanism of the TRPC4 channel with PIP2 hydrolysis which is mediated by a channel-bound PLCδ1 but not by the GqPCR signaling pathway. Our electrophysiological recordings demonstrate that the Ca2+ via an open TRPC4 channel activates PLCδ1 in the physiological range, and it causes the decrease of current amplitude. The existence of PLCδ1 accelerated PIP2 depletion when the channel was activated by an agonist. Interestingly, PLCδ1 mutants which have lost the ability to regulate PIP2 level failed to reduce the TRPC4 current amplitude. Our results demonstrate that TRPC4 self-regulates its activity by allowing Ca2+ ions into the cell and promoting the PIP2 hydrolyzing activity of PLCδ1.

Air pollution exposures and brain cortical thinning in adults: a longitudinal neuroimaging study

Juyeon Ko,Heeseon Jang,Changsoo Kim,Jaelim Cho 환경독성보건학회 2022 한국독성학회 심포지움 및 학술발표회 Vol.2022 No.10

Long lasting mesalazine-induced pancytopenia in a patient with ulcerative colitis

Ko, Juyeon,Song, Hyun Joo,Han, Sanghoon,Moon, Chiyoon Institute for Medical Science 2019 The Journal of Medicine and Life Science Vol.16 No.2

Inflammatory bowel disease (IBD) is an immune-mediated chronic inflammatory intestinal condition. With development of various treatment options for IBD, 5-aminosalicylic acid (5-ASA) agents became the drugs of choice due to high efficacy and low risk of complication, specifically effective at inducing and maintaining remission in ulcerative colitis(UC). Pancytopenia caused by 5-ASA agents, especially by mesalazine, has been rarely reported compared with azathioprine, which is commonly used for glucocorticoid-dependent IBD and known to have risk of bone marrow suppression. In the present report, we describe the case of a 57-year-old woman diagnosed with UC, who developed pancytopenia due to adverse effect of mesalazine after recovery from azathioprine-induced pancytopenia. After withdrawal of mesalazine, the laboratory values consistent with myelosuppression continued for 3 months while pancytopenia from azathioprine remained only for 2 weeks. Since pancytopenia can be fatal due to its risk of severe bleeding and infection, close monitoring of clinical presentation is important when starting mesalazine and laboratory data should be evaluated whenever the patients present related symptoms. Furthermore, we suggest that complete blood cell counts should be considered when resuming mesalazine following the development of pancytopenia from any cause, as routinely recommended for azathioprine use.

Identification of phospholipase Cβ downstream effect on transient receptor potential canonical 1/4, transient receptor potential canonical 1/5 channels

Ko, Juyeon,Myeong, Jongyun,Kwak, Misun,Jeon, Ju-Hong,So, Insuk The Korean Society of Pharmacology 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.5

$G{\alpha}_q$-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate ($PI(4,5)P_2$) depletion. When $PI(4,5)P_2$ depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon $G{\alpha}_q$-phospholipase $C{\beta}$ ($G{\alpha}_q-PLC{\beta}$) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in $PLC{\beta}$ activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by $Ca^{2+}$ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic $Ca^{2+}$ due to $Ca^{2+}$ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following $PI(4,5)P_2$ depletion.

Increased risk of developing cerebro-cardiovascular diseases in police officers: a nationwide retrospective cohort study

Ko Juyeon,Park Hyunji,Park Sungha,Kim Dae-Hee,조재림 대한고혈압학회 2024 Clinical Hypertension Vol.30 No.-

Police officers face an increased risk of developing cerebro-cardiovascular diseases (CVD). However, current literature lacks population-based cohort studies specifically focusing on this association. This study aimed to investigate the association between police officers and the risk of developing CVD compared with education officers, while accounting for socioeconomic and demographic factors.We used the Korean National Health Insurance Service data spanning from 2009 to 2020. In this population-based retrospective matched cohort study, we identified age, sex, and calendar years of job-enrollment–matched education officers for each police officer. This study evaluated the CVD occurrence, including acute myocardial infarction, ischemic stroke, and hemorrhagic stroke. Using multivariable Cox regression analysis, we determined the risk of developing CVD, expressed as a hazard ratio (HR) and 95% confidence interval (CI).Among 104,134 police officers and 104,134 education officers, 4,391(42.2%) cases and 3,631(34.9%) cases of CVD occurred, respectively. The mean ± standard deviation age was 38.4 ± 9.4 years in police officers and 38.6 ± 9.5 years in education officers. The proportion of men was 84.8 % in both groups. Police officers were significantly associated with a higher risk of developing CVD compared with education officers, with an adjusted HR of 1.15 (95% CI, 1.09–1.22). In addition, police officers had significantly higher risks for acute myocardial infarction (adjusted HR, 1.16; 95% CI, 1.06–1.26) and ischemic stroke (adjusted HR, 1.17; 95% CI, 1.09–1.25).The findings of our study highlight a significant increase in the risk of developing CVD among police officers, particularly among those aged 45 years and older and those with uncontrolled blood pressure compared to their education officer counterparts. Future cohort studies are required to confirm this association. Background Police ofcers face an increased risk of developing cerebro-cardiovascular diseases (CVD). However, current literature lacks population-based cohort studies specifcally focusing on this association. This study aimed to investigate the association between police ofcers and the risk of developing CVD compared with education ofc‑ ers, while accounting for socioeconomic and demographic factors. Methods We used the Korean National Health Insurance Service data spanning from 2009 to 2020. In this pop‑ ulation-based retrospective matched cohort study, we identifed age, sex, and calendar years of job-enrollment– matched education ofcers for each police ofcer. This study evaluated the CVD occurrence, including acute myocar‑ dial infarction, ischemic stroke, and hemorrhagic stroke. Using multivariable Cox regression analysis, we determined the risk of developing CVD, expressed as a hazard ratio (HR) and 95% confdence interval (CI). Results Among 104,134 police ofcers and 104,134 education ofcers, 4,391(42.2%) cases and 3,631(34.9%) cases of CVD occurred, respectively. The mean ± standard deviation age was 38.4 ± 9.4 years in police ofcers and 38.6 ± 9.5 years in education ofcers. The proportion of men was 84.8 % in both groups. Police ofcers were signifcantly associ‑ ated with a higher risk of developing CVD compared with education ofcers, with an adjusted HR of 1.15 (95% CI, 1.09–1.22). In addition, police ofcers had signifcantly higher risks for acute myocardial infarction (adjusted HR, 1.16; 95% CI, 1.06–1.26) and ischemic stroke (adjusted HR, 1.17; 95% CI, 1.09–1.25). Conclusions The fndings of our study highlight a signifcant increase in the risk of developing CVD among police ofcers, particularly among those aged 45 years and older and those with uncontrolled blood pressure compared to their education ofcer counterparts. Future cohort studies are required to confrm this association.

Identification of phospholipase C β downstream effect on transient receptor potential canonical 1/4, transient receptor potential canonical 1/5 channels

Juyeon Ko,Jongyun Myeong,Misun Kwak,Ju-Hong Jeon,Insuk So 대한약리학회 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.5

Gq-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P2) depletion. When PI(4,5)P2 depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon Gq-phospholipase C  (Gq-PLC) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in PLC activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by Ca2+ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic Ca2+ due to Ca2+ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following PI(4,5)P2 depletion.

Individualized Acupuncture for Symptom Relief in Functional Dyspepsia: A Randomized Controlled Trial

Ko, Seok-Jae,Kuo, Braden,Kim, Seul-Ki,Lee, Hyangsook,Kim, Jinsung,Han, Gajin,Kim, Juyeon,Kim, Song-Yi,Jang, Seungwon,Son, Jiyoung,Kim, Minji,Lee, Hyejung,Yeo, Inkwon,Joo, Kwang Ro,Park, Jae-Woo Mary Ann Liebert 2016 Journal of Alternative & Complementary Medicine Vol.22 No.12

디지털 홀로그램 압축으로 인한 수치 복원 영상의 화질 열화 분석

서주연(Juyeon Seo),고현석(Hyunsuk Ko) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

Availability of Tongue Diagnosis System for Assessing Tongue Coating Thickness in Patients with Functional Dyspepsia

Kim, Juyeon,Son, Jiyoung,Jang, Seungwon,Nam, Dong-Hyun,Han, Gajin,Yeo, Inkwon,Ko, Seok-Jae,Park, Jae-Woo,Ryu, Bongha,Kim, Jinsung Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>Tongue diagnosis is an important procedure in traditional Korean medicine (TKM). In particular, tongue coating thickness (TCT) is deemed to show the progression of the disease. However, conventional tongue diagnosis has limitations because of various external factors. Therefore, it is necessary to investigate the availability of tongue diagnosis system (TDS) in the assessment of TCT. This study has been designed as a prospective clinical trial involving 60 patients with functional dyspepsia. Tongue images will be obtained by TDS twice with a 30 min interval. The system will measure the percentage of TCT and classify it as either no coating, thin coating, or thick coating according to the existing diagnostic criteria. After finishing the collection of 60 patients' tongue images, TCT on the images will be simultaneously evaluated by the conventional method to establish the gold standard for assessing TCT by 5 well-trained clinicians. The evaluation will be repeated by the same clinicians after 2 weeks, but the order of the images will be changed. This trial is expected to provide clinical evidence for the availability of TDS as a diagnostic tool and to contribute to the standardization of the diagnosis system used in TKM. This trial is registered with ClinicalTrials.gov NCT01864837.</P>