1.Relationship between Arterial Stiffness and Physical Activity Level Assessed by International Physical Activity Questionnaireshort form (IPAQSF) in the Elderly
HyunJu LEE ; JiYeon GWAK ; HaYeon JUN ; EunKyung KIM
Korean Journal of Community Nutrition 2020;25(3):236-245
Objectives:
Cardiovascular disease is a major cause of death in the elderly in Korea. Increased arterial stiffness is linked to risk of cardiovascular disease and mortality. The purpose of this study was to investigate the relationship between arterial stiffness and physical activity in the elderly.
Methods:
A total of 209 older adults (110 men and 99 women) participated in this study. Arterial stiffness of subjects such as brachial–ankle pulse wave velocity (baPWV) and ankle brachial pressure index (ABI) was measured using a non-invasive vascular screening device (VP-1000 Plus, Omron, Kyoto, Japan). The interviewed Korean version of the international physical activity questionnaire short form (IPAQ-SF) was used to evaluate subject’s physical activity level and classify subjects as active or inactive group based on the time spent doing moderate to vigorous physical activity (MVPA).
Results:
The mean age of total subjects was 75.3 ± 5.6 years. There was no significant difference in sex distribution between the active group (39.7%) and inactive group (60.3%). The baPWV (1,758.1 ± 375.2cm /sec) of the active group was significantly lower than that (1,969.7 ± 372.3 cm/sec) of the inactive group (P < 0.05). There was a significant inverse association between time spent in MVPA and baPWV (r = -0.245, P < 0.01).
Conclusions
This study suggests that physical activity programs for older adults are needed to prevent arteriosclerosis.
2.Elucidating molecular mechanisms of acquired resistance to BRAF inhibitors in melanoma using a microfluidic device and deep sequencing
Jiyeon HAN ; Yeonjoo JUNG ; Yukyung JUN ; Sungsu PARK ; Sanghyuk LEE
Genomics & Informatics 2021;19(1):e2-
BRAF inhibitors (e.g., vemurafenib) are widely used to treat metastatic melanoma with the BRAF V600E mutation. The initial response is often dramatic, but treatment resistance leads to disease progression in the majority of cases. Although secondary mutations in the mitogen-activated protein kinase signaling pathway are known to be responsible for this phenomenon, the molecular mechanisms governing acquired resistance are not known in more than half of patients. Here we report a genome- and transcriptome-wide study investigating the molecular mechanisms of acquired resistance to BRAF inhibitors. A microfluidic chip with a concentration gradient of vemurafenib was utilized to rapidly obtain therapy-resistant clones from two melanoma cell lines with the BRAF V600E mutation (A375 and SK-MEL-28). Exome and transcriptome data were produced from 13 resistant clones and analyzed to identify secondary mutations and gene expression changes. Various mechanisms, including phenotype switching and metabolic reprogramming, have been determined to contribute to resistance development differently for each clone. The roles of microphthalmia-associated transcription factor, the master transcription factor in melanocyte differentiation/dedifferentiation, were highlighted in terms of phenotype switching. Our study provides an omics-based comprehensive overview of the molecular mechanisms governing acquired resistance to BRAF inhibitor therapy.
3.Elucidating molecular mechanisms of acquired resistance to BRAF inhibitors in melanoma using a microfluidic device and deep sequencing
Jiyeon HAN ; Yeonjoo JUNG ; Yukyung JUN ; Sungsu PARK ; Sanghyuk LEE
Genomics & Informatics 2021;19(1):e2-
BRAF inhibitors (e.g., vemurafenib) are widely used to treat metastatic melanoma with the BRAF V600E mutation. The initial response is often dramatic, but treatment resistance leads to disease progression in the majority of cases. Although secondary mutations in the mitogen-activated protein kinase signaling pathway are known to be responsible for this phenomenon, the molecular mechanisms governing acquired resistance are not known in more than half of patients. Here we report a genome- and transcriptome-wide study investigating the molecular mechanisms of acquired resistance to BRAF inhibitors. A microfluidic chip with a concentration gradient of vemurafenib was utilized to rapidly obtain therapy-resistant clones from two melanoma cell lines with the BRAF V600E mutation (A375 and SK-MEL-28). Exome and transcriptome data were produced from 13 resistant clones and analyzed to identify secondary mutations and gene expression changes. Various mechanisms, including phenotype switching and metabolic reprogramming, have been determined to contribute to resistance development differently for each clone. The roles of microphthalmia-associated transcription factor, the master transcription factor in melanocyte differentiation/dedifferentiation, were highlighted in terms of phenotype switching. Our study provides an omics-based comprehensive overview of the molecular mechanisms governing acquired resistance to BRAF inhibitor therapy.
4.Activation of the cGMP/Protein Kinase G Pathway by Nitric Oxide Can Decrease TRPV1 Activity in Cultured Rat Dorsal Root Ganglion Neurons.
Yunju JIN ; Jun KIM ; Jiyeon KWAK
The Korean Journal of Physiology and Pharmacology 2012;16(3):211-217
Recent studies have demonstrated that nitric oxide (NO) activates transient receptor potential vanilloid subtype 1 (TRPV1) via S-nitrosylation of the channel protein. NO also modulates various cellular functions via activation of the soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway and the direct modification of proteins. Thus, in the present study, we investigated whether NO could indirectly modulate the activity of TRPV1 via a cGMP/PKG-dependent pathway in cultured rat dorsal root ganglion (DRG) neurons. NO donors, sodium nitroprusside (SNP) and S-nitro-N-acetylpenicillamine (SNAP), decreased capsaicin-evoked currents (Icap). NO scavengers, hemoglobin and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO), prevented the inhibitory effect of SNP on Icap. Membrane-permeable cGMP analogs, 8-bromoguanosine 3', 5'-cyclic monophosphate (8bromo-cGMP) and 8-(4chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (8-pCPT-cGMP), and the guanylyl cyclase stimulator YC-1 mimicked the effect of SNP on Icap. The PKG inhibitor KT5823 prevented the inhibition of Icap by SNP. These results suggest that NO can downregulate the function of TRPV1 through activation of the cGMP/PKG pathway in peripheral sensory neurons.
Animals
;
Benzoates
;
Carbazoles
;
Cyclic GMP-Dependent Protein Kinases
;
Ganglia, Spinal
;
Guanosine
;
Guanylate Cyclase
;
Hemoglobins
;
Humans
;
Imidazoles
;
Neurons
;
Nitric Oxide
;
Nitroprusside
;
Penicillamine
;
Phosphotransferases
;
Proteins
;
Rats
;
Receptors, Cytoplasmic and Nuclear
;
Sensory Receptor Cells
;
Spinal Nerve Roots
;
Tissue Donors
5.Identification of neoantigens derived from alternative splicing and RNA modification
Genomics & Informatics 2019;17(3):e23-
The acquisition of somatic mutations is the most common event in cancer. Neoantigens expressed from genes with mutations acquired during carcinogenesis can be tumor-specific. Since the immune system recognizes tumor-specific peptides, they are potential targets for personalized neoantigen-based immunotherapy. However, the discovery of druggable neoantigens remains challenging, suggesting that a deeper understanding of the mechanism of neoantigen generation and better strategies to identify them will be required to realize the promise of neoantigen-based immunotherapy. Alternative splicing and RNA editing events are emerging mechanisms leading to neoantigen production. In this review, we outline recent work involving the large-scale screening of neoantigens produced by alternative splicing and RNA editing. We also describe strategies to predict and validate neoantigens from RNA sequencing data.
Alternative Splicing
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Carcinogenesis
;
Humans
;
Immune System
;
Immunotherapy
;
Mass Screening
;
Peptides
;
RNA Editing
;
RNA
;
Sequence Analysis, RNA
6.Spinal orexin A attenuates opioid-induced mechanical hypersensitivity in the rat
Dong-ho YOUN ; Jiyeon JUN ; Tae Wan KIM ; Kibeom PARK
The Korean Journal of Pain 2022;35(4):433-439
Background:
Repeated administration of opioid analgesics for pain treatment can produce paradoxical hyperalgesia via peripheral and/or central mechanisms. Thus, this study investigated whether spinally (centrally) administered orexin A attenuates opioid-induced hyperalgesia (OIH).
Methods:
[D-Ala2 , N-Me-Phe4 , Gly5 -ol]-enkephalin (DAMGO), a selective µ-opioid receptor agonist, was used to induce mechanical hypersensitivity and was administered intradermally (4 times, 1-hour intervals) on the rat hind paw dorsum. To determine whether post- or pretreatments with spinal orexin A, dynorphin A, and antidynorphin A were effective in OIH, the drugs were injected through an intrathecal catheter whose tip was positioned dorsally at the L3 segment of the spinal cord (5 µg for all). Mechanical hypersensitivity was assessed using von Frey monofilaments.
Results:
Repeated intradermal injections of DAMGO resulted in mechanical hypersensitivity in rats, lasting more than 8 days. Although the first intrathecal treatment of orexin A on the 6th day after DAMGO exposure did not show any significant effect on the mechanical threshold, the second (on the 8th day) significantly attenuated the DAMGO-induced mechanical hypersensitivity, which disappeared when the type 1 orexin receptor (OX1R) was blocked. However, intrathecal administration of dynorphin or an anti-dynorphin antibody (dynorphin antagonists) had no effect on DAMGO-induced hypersensitivity. Lastly, pretreatment with orexin A, dynorphin, or anti-dynorphin did not prevent DAMGO-induced mechanical hypersensitivity.
Conclusions
Spinal orexin A attenuates mechanical hyperalgesia induced by repetitive intradermal injections of DAMGO through OX1R. These data suggest that OIH can be potentially treated by activating the orexin A-OX1R pathway in the spinal dorsal horn.
7.Mechanism of Glutamate-inducedCa2+i Increase in Substantia Gelatinosa Neurons of Juvenile Rats.
Sung Jun JUNG ; Jeong Sook CHOI ; Jiyeon KWAK ; Jun KIM ; Jong Whan KIM ; Sang Jeong KIM
The Korean Journal of Physiology and Pharmacology 2003;7(2):53-58
The glutamate receptors (GluRs) are key receptors for modulatory synaptic events in the central nervous system. It has been reported that glutamate increases the intracellularCa (2+) concentration ([Ca2+]i) and induces cytotoxicity. In the present study, we investigated whether the glutamate-induced[Ca2+]i increase was associated with the activation of ionotropic (iGluR) and metabotropic GluRs (mGluR) in substantia gelatinosa neurons, using spinal cord slice of juvenile rats (10~21 day) .[Ca2+]i was measured using conventional imaging techniques, which was combined with whole-cell patch clamp recording by incorporating fura-2 in the patch pipette. At physiological concentration of extracellularCa (2+), the inward current and[Ca2+]i increase were induced by membrane depolarization and application of glutamate. Dose-response relationship with glutamate was observed in bothCa (2+) signal and inward current. The glutamate-induced[Ca2+]i increase at holding potential of 70 mV was blocked by CNQX, an AMPA receptor blocker, but not by AP-5, a NMDA receptor blocker. The glutamate-induced[Ca2+]i increase inCa (2+) free condition was not affected by iGluR blockers. A selective mGluR (group I) agonist, RS-3, 5-dihydroxyphenylglycine (DHPG), induced[Ca2+]i increase at holding potential of 70 mV in SG neurons. These findings suggest that the glutamate-induced[Ca2+]i increase is associated with AMPA-sensitive iGluR and group I mGluR in SG neurons of rats.
6-Cyano-7-nitroquinoxaline-2,3-dione
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Animals
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Central Nervous System
;
Fura-2
;
Glutamic Acid
;
Membranes
;
N-Methylaspartate
;
Neurons*
;
Rats*
;
Receptors, AMPA
;
Receptors, Glutamate
;
Receptors, Metabotropic Glutamate
;
Spinal Cord
;
Substantia Gelatinosa*
8.Prognostic Significance of BCL9 Expression in Hepatocellular Carcinoma.
Jiyeon HYEON ; Soomin AHN ; Jae Jun LEE ; Dae Hyun SONG ; Cheol Keun PARK
Korean Journal of Pathology 2013;47(2):130-136
BACKGROUND: BCL9 enhances beta-catenin-mediated transcriptional activity regardless of the mutational status of the Wnt signaling components and increases the cell proliferation, migration, invasion, and metastatic potential of tumor cells. The goal of this study was to elucidate the prognostic significance of BCL9 protein expression in hepatocellular carcinoma (HCC) patients. METHODS: We evaluated BCL9 protein expression by immunohistochemistry in tumor tissue from 288 primary HCC patients who underwent curative hepatectomy. The impact of BCL9 expression on the survival of the patients was analyzed. The median follow-up period was 97.1 months. RESULTS: Nuclear BCL9 protein expression was observed in 74 (25.7%) of the 288 HCCs. BCL9 expression was significantly associated with younger age (p=0.038), higher Edmondson grade (p=0.001), microvascular invasion (p=0.013), and intrahepatic metastasis (p=0.017). Based on univariate analyses, BCL9 expression showed an unfavorable influence on both disease-free survival (DFS, p=0.012) and disease-specific survival (DSS, p=0.032). Multivariate analyses revealed that higher Barcelona Clinic Liver Cancer stage was an independent predictor of both shorter DFS (p<0.001) and shorter DSS (p<0.001). BCL9 expression tended to be an independent predictor of shorter DFS (p=0.078). CONCLUSIONS: BCL9 protein expression might be a marker of shorter DFS in HCC patients after curative hepatectomy.
Carcinoma, Hepatocellular
;
Cell Proliferation
;
Disease-Free Survival
;
Follow-Up Studies
;
Hepatectomy
;
Humans
;
Immunohistochemistry
;
Liver Neoplasms
;
Multivariate Analysis
;
Neoplasm Metastasis
;
Recurrence
9.Cost-Benefit Analysis of Tafenoquine for Radical Cure of Plasmodium vivax Malaria in Korea
Jiyeon SUH ; Jung Ho KIM ; Jong-Dae KIM ; Changsoo KIM ; Jun Yong CHOI ; Jeehyun LEE ; Joon-Sup YEOM
Journal of Korean Medical Science 2022;37(27):e212-
Background:
Plasmodium vivax malaria has a persistent liver stage that causes relapse, and introducing tafenoquine to suppress relapse could aid in disease eradication. Therefore, we assessed the impact of tafenoquine introduction on P. vivax malaria incidence and performed a cost-benefit analysis from the payer’s perspective.
Methods:
We expanded the previously developed P. vivax malaria dynamic transmission model and calibrated it to weekly civilian malaria incidences in 2014–2018. Primaquine and tafenoquine scenarios were considered by assuming different relapse probabilities, and relapse and total P. vivax malaria cases were predicted over the next decade for each scenario. We then estimated the number of cases prevented by replacing primaquine with tafenoquine. The cost and benefit of introducing tafenoquine were obtained using medical expenditure from a nationwide database, and a cost-benefit analysis was conducted. A probabilistic sensitivity analysis was performed to assess the economic feasibility robustness of tafenoquine introduction under uncertainties of model parameters, costs, and benefits.
Results:
Under 0.04 primaquine relapse probability, the introduction of tafenoquine with relapse probability of 0.01 prevented 129 (12.27%) and 35 (77.78%) total and relapse cases, respectively, over the next decade. However, under the same relapse probability as primaquine, introducing tafenoquine had no additional preventative effect. The 14-day primaquine treatment cost was $3.71. The tafenoquine and the glucose-6-phosphate dehydrogenase rapid diagnostic testing cost $57.37 and $7.76, totaling $65.13. The average medical expenditure per malaria patient was estimated at $1444.79. The cost-benefit analysis results provided an incremental benefit-cost ratio (IBCR) from 0 to 3.21 as the tafenoquine relapse probability decreased from 0.04 to 0.01. The probabilistic sensitivity analysis showed an IBCR > 1, indicating that tafenoquine is beneficial, with a probability of 69.1%.
Conclusion
Tafenoquine could reduce P. vivax malaria incidence and medical costs and bring greater benefits than primaquine.
10.Association between Medical Costs and the ProVent Model in Patients Requiring Prolonged Mechanical Ventilation
Jiyeon ROH ; Myung Jun SHIN ; Eun Suk JEONG ; Kwangha LEE
Tuberculosis and Respiratory Diseases 2019;82(2):166-172
BACKGROUND:
The purpose of this study was to determine whether components of the ProVent model can predict the high medical costs in Korean patients requiring at least 21 days of mechanical ventilation (prolonged mechanical ventilation [PMV]).
METHODS:
Retrospective data from 302 patients (61.6% male; median age, 63.0 years) who had received PMV in the past 5 years were analyzed. To determine the relationship between medical cost per patient and components of the ProVent model, we collected the following data on day 21 of mechanical ventilation (MV): age, blood platelet count, requirement for hemodialysis, and requirement for vasopressors.
RESULTS:
The mortality rate in the intensive care unit (ICU) was 31.5%. The average medical costs per patient during ICU and total hospital (ICU and general ward) stay were 35,105 and 41,110 US dollars (USD), respectively. The following components of the ProVent model were associated with higher medical costs during ICU stay: age <50 years (average 42,731 USD vs. 33,710 USD, p=0.001), thrombocytopenia on day 21 of MV (36,237 USD vs. 34,783 USD, p=0.009), and requirement for hemodialysis on day 21 of MV (57,864 USD vs. 33,509 USD, p<0.001). As the number of these three components increased, a positive correlation was found betweeen medical costs and ICU stay based on the Pearson's correlation coefficient (γ) (γ=0.367, p<0.001).
CONCLUSION
The ProVent model can be used to predict high medical costs in PMV patients during ICU stay. The highest medical costs were for patients who required hemodialysis on day 21 of MV.