5 results on '"Chul-Hoon Kim"'
Search Results
2. Protocadherin 19 regulates axon guidance in the developing Xenopus retinotectal pathway
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Jane Jung, Jugeon Park, Sihyeon Park, Chul Hoon Kim, and Hosung Jung
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Pcdh19 ,Axon guidance ,Midline crossing ,Fasciculation ,Retinal ganglion cell ,Xenopus tropicalis ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Protocadherin 19 (Pcdh19) is a homophilic cell adhesion molecule and is involved in a variety of neuronal functions. Here, we tested whether Pcdh19 has a regulatory role in axon guidance using the developing Xenopus retinotectal system. We performed targeted microinjections of a translation blocking antisense morpholino oligonucleotide to knock down the expression of Pcdh19 selectively in the central nervous system. Knocking down Pcdh19 expression resulted in navigational errors of retinal ganglion cell (RGC) axons specifically at the optic chiasm. Instead of projecting to the contralateral optic tectum, RGC axons in the Pcdh19-depleted embryo misprojected ipsilaterally. Although incorrectly delivered into the ipsilateral brain hemisphere, these axons correctly reached the optic tectum. These data suggest that Pcdh19 has a critical role in preventing mixing of RGC axons originating from the opposite eyes at the optic chiasm, highlighting the importance of cell adhesion in bundling of RGC axons.
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- 2024
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3. Synergistic toxicity with copper contributes to NAT2-associated isoniazid toxicity
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Jihoon G. Yoon, Dong Geon Jang, Sung-Gyu Cho, Chaeyoung Lee, Shin Hye Noh, Soo Kyung Seo, Jung Woo Yu, Hyeon Woo Chung, KyeoRe Han, Soon Sung Kwon, Dai Hoon Han, Jaeseong Oh, In-Jin Jang, Sang-Hoon Kim, Young-Koo Jee, Hyun Lee, Dong Won Park, Jang Won Sohn, Ho Joo Yoon, Chul Hoon Kim, Jae Myun Lee, Sang-Heon Kim, and Min Goo Lee
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Medicine ,Biochemistry ,QD415-436 - Abstract
Abstract Anti-tuberculosis (AT) medications, including isoniazid (INH), can cause drug-induced liver injury (DILI), but the underlying mechanism remains unclear. In this study, we aimed to identify genetic factors that may increase the susceptibility of individuals to AT-DILI and to examine genetic interactions that may lead to isoniazid (INH)-induced hepatotoxicity. We performed a targeted sequencing analysis of 380 pharmacogenes in a discovery cohort of 112 patients (35 AT-DILI patients and 77 controls) receiving AT treatment for active tuberculosis. Pharmacogenome-wide association analysis was also conducted using 1048 population controls (Korea1K). NAT2 and ATP7B genotypes were analyzed in a replication cohort of 165 patients (37 AT-DILI patients and 128 controls) to validate the effects of both risk genotypes. NAT2 ultraslow acetylators (UAs) were found to have a greater risk of AT-DILI than other genotypes (odds ratio [OR] 5.6 [95% confidence interval; 2.5–13.2], P = 7.2 × 10−6). The presence of ATP7B gene 832R/R homozygosity (rs1061472) was found to co-occur with NAT2 UA in AT-DILI patients (P = 0.017) and to amplify the risk in NAT2 UA (OR 32.5 [4.5–1423], P = 7.5 × 10−6). In vitro experiments using human liver-derived cell lines (HepG2 and SNU387 cells) revealed toxic synergism between INH and Cu, which were strongly augmented in cells with defective NAT2 and ATP7B activity, leading to increased mitochondrial reactive oxygen species generation, mitochondrial dysfunction, DNA damage, and apoptosis. These findings link the co-occurrence of ATP7B and NAT2 genotypes to the risk of INH-induced hepatotoxicity, providing novel mechanistic insight into individual AT-DILI susceptibility. Yoon et al. showed that individuals who carry NAT2 UAs and ATP7B 832R/R genotypes are at increased risk of developing isoniazid hepatotoxicity, primarily due to the increased synergistic toxicity between isoniazid and copper, which exacerbates mitochondrial dysfunction-related apoptosis.
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- 2024
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4. Association of Muscle Mass Loss with Diabetes Development in Liver Transplantation Recipients
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Sejeong Lee, Minyoung Lee, Young-Eun Kim, Hae Kyung Kim, Sook Jung Lee, Jiwon Kim, Yurim Yang, Chul Hoon Kim, Hyangkyu Lee, Dong Jin Joo, Myoung Soo Kim, and Eun Seok Kang
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diabetes mellitus ,muscle, skeletal ,liver transplantation ,sarcopenia ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Background Post-transplant diabetes mellitus (PTDM) is one of the most significant complications after transplantation. Patients with end-stage liver diseases requiring transplantation are prone to sarcopenia, but the association between sarcopenia and PTDM remains to be elucidated. We aimed to investigate the effect of postoperative muscle mass loss on PTDM development. Methods A total of 500 patients who underwent liver transplantation at a tertiary care hospital between 2005 and 2020 were included. Skeletal muscle area at the level of the L3–L5 vertebrae was measured using computed tomography scans performed before and 1 year after the transplantation. The associations between the change in the muscle area after the transplantation and the incidence of PTDM was investigated using a Cox proportional hazard model. Results During the follow-up period (median, 4.9 years), PTDM occurred in 165 patients (33%). The muscle mass loss was greater in patients who developed PTDM than in those without PTDM. Muscle depletion significantly increased risk of developing PTDM after adjustment for other confounding factors (hazard ratio, 1.50; 95% confidence interval, 1.23 to 1.84; P=0.001). Of the 357 subjects who had muscle mass loss, 124 (34.7%) developed PTDM, whereas of the 143 patients in the muscle mass maintenance group, 41 (28.7%) developed PTDM. The cumulative incidence of PTDM was significantly higher in patients with muscle loss than in patients without muscle loss (P=0.034). Conclusion Muscle depletion after liver transplantation is associated with increased risk of PTDM development.
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- 2024
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5. Mosaicism-independent mechanisms contribute to Pcdh19-related epilepsy and repetitive behaviors in Xenopus.
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Jugeon Park, Eunee Lee, Chul Hoon Kim, Jiyeon Ohk, and Hosung Jung
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PEOPLE with epilepsy ,EPILEPSY ,XENOPUS ,X chromosome ,KNOCKOUT mice ,MEMBRANE proteins - Abstract
Protocadherin19 (PCDH19)-related epilepsy syndrome is a rare disorder characterized by early-onset epilepsy, intellectual disability, and autistic behaviors. PCDH19 is located on the X chromosome and encodes a calcium-dependent single-pass transmembrane protein, which regulates cell-to-cell adhesion through homophilic binding. In human, 90% of heterozygous females, containing PCDH19 wild-type and mutant cells due to random X inactivation, are affected, whereas mutant males, containing only mutant cells, are typically not. The current view, the cellular interference, is that the altered interactions between wild-type and mutant cells during development, rather than loss of function itself, are responsible. However, studies using Pcdh19 knockout mice showed that the complete loss of function also causes autism-like behaviors both in males and females, suggesting that other functions of PCDH19 may also contribute to pathogenesis. To address whether mosaicism is required for PCDH19-related epilepsy, we generated Xenopus tropicalis tadpoles with complete or mosaic loss of function by injecting antisense morpholino oligonucleotides into the blastomeres of neural lineage at different stages of development. We found that either mosaic or complete knockdown results in seizure-like behaviors, which could be rescued by antiseizure medication, and repetitive behaviors. Our results suggest that the loss of PCDH19 function itself, in addition to cellular interference, may also contribute to PCDH19-related epilepsy. [ABSTRACT FROM AUTHOR]
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- 2024
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