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3,212
result(s) for
"Lee, Yong Sun"
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كوريا في نصوص الدراسات الاجتماعية في المصادر التعليمية بالدول العربية
by
Lee, Chan-hee مؤلف
,
Son, Yong-t'aek مؤلف
,
Chung, Young sun مؤلف
in
التعليم كوريا الجنوبية
,
التعليم كوريا الجنوبية قرن 20
,
كوريا أحوال اجتماعية
2000
يتناول كتاب (كوريا في نصوص الدراسات الاجتماعية في المصادر التعليمية بالدول العربية) والذي قام بتحريره (د. لي تشان-هي) في حوالي (76) صفحة من القطع المتوسط موضوع (التعليم في كوريا الجنوبية) مستعرضا المحتويات التالية : مراجعة المحتويات الخاصة بكوريا في نصوص الدراسات الاجتماعية في الدول العربية، تقديم موضوعات متعلقة بالمجتمع الإسلامي في الكتب المدرسية الابتدائية والإعدادية.
A1AT dysregulation of metabolically stressed hepatocytes by Kupffer cells drives MASH and fibrosis
2025
Metabolic dysfunction-associated steatohepatitis (MASH) is associated with the activation of Kupffer cells (KCs) and hepatic stellate cells, at which point a metabolically stressed hepatocyte becomes integral to the progression of the disease. We observed a significant reduction in the level of alpha-1-antitrypsin (A1AT), a hepatocyte-derived secreted factor, in both patients with MASH and mice fed a fast-food diet (FFD). KC-mediated hepatic inflammation, most notably IL-1β, led to the transcriptional inhibition of A1AT by HNF4α. In quintuple
Serpina1a–e
knockout mice, ablation of A1AT worsened MASH through increased activity of proteinase 3 (PR3), a proinflammatory protease produced by F4/80
hi
/CD11b
low
/TIM4
−
/CCR2
+
monocyte-derived KCs (MoKCs). Conversely, A1AT restoration or PR3 inhibition mitigated MASH progression. A PR3-bound cytokine array identified IL-32 as a key factor associated with MASH. Combining
IL-32
with
SERPINA1
, the gene encoding A1AT, synergistically predicted patients at risk of MASH through univariate logistic regression analysis. Furthermore, in vivo overexpression of IL-32γ alleviated MASH induced by FFD. However, additional knockout of A1AT increased PR3 activity, consequently abolishing the anti-MASH effects of IL-32γ. Blocking PR3-mediated IL-32γ cleavage via the V104A mutation sustained its protective actions, while the PR3-cleaved C-terminal fragment activated KCs. Additionally, after cleavage, the antifibrogenic effect of IL-32γ is lost, resulting in a failure to prevent the activation of hepatic stellate cells. This study highlights the critical role of hepatocyte-derived A1AT in the PR3/IL-32γ axis during MASH development. Strategies to correct A1AT dysregulation, such as A1AT supplementation or PR3 inhibition with sivelestat, may offer protection against the development and progression of MASH and fibrosis.
Elevated hepatic IL-1β levels in MASH lead to the downregulation of A1AT via the transcription factor HNF4α, resulting in increased recruitment of proinflammatory MoKCs and heightened PR3 activity. PR3 cleaves IL-32γ, transforming it from an anti-inflammatory and antifibrogenic cytokine into a potent activator of KCs and failing to prevent HSC activation. This cascade amplifies liver inflammation and fibrosis, suggesting that targeting the A1AT/PR3/IL-32γ axis could be a strategy for treating MASH.
A1AT deficiency drives inflammation in metabolic liver disease
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major cause of liver failure worldwide. Researchers are trying to understand how it progresses to more severe conditions such as metabolic dysfunction-associated steatohepatitis (MASH). This study focuses on a protein called alpha-1-antitrypsin, which is important for liver health. The researchers used mice and human samples to study the role of A1AT in liver disease. They found that A1AT levels are lower in people and mice with MASLD, which leads to increased inflammation and liver damage. They also discovered that a protein called proteinase 3 becomes more active when A1AT is low, worsening the condition. By experimenting with mice, they showed that increasing A1AT or blocking PR3 can reduce liver damage. This suggests new treatment possibilities for MASH. The study concludes that targeting the A1AT/PR3 pathway could help manage liver disease progression.
This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.
Journal Article
Astaxanthin alleviated ethanol-induced liver injury by inhibition of oxidative stress and inflammatory responses via blocking of STAT3 activity
2018
Astaxanthin (AXT) is classified as a xanthophyll carotenoid compound which have broader functions including potent antioxidant, anti-inflammatory and neuroprotective properties. Considerable researches have demonstrated that AXT shows preventive and therapeutic properties against for Diabetes, Osteoarthritis and Rheumatoid Arthritis. However, the protective effect of AXT on liver disease has not yet been reported. In this study, we investigated effects of AXT on ethanol-induced liver injury in chronic plus binge alcohol feeding model. The hepatic steatosis and inflammation induced by ethanol administration were alleviated by AXT. Serum levels of aspartate transaminase and alanine transaminase were decreased in the livers of AXT administrated group. The ethanol-induced expression of cytochrome P450 2E1 (CYP2E1), pro-inflammatory proteins, cytokines, chemokines and reactive oxygen species (ROS) levels were also reduced in the livers of AXT administrated group. Moreover, ethanol-induced infiltration of neutrophils was decreased in the livers of AXT administrated group. Docking model and pull-down assay showed that AXT directly binds to the DNA binding site of STAT3. Moreover, AXT decreased STAT3 phosphorylation in the liver of AXT administration group. Therefore, these results suggest that AXT could prevent ethanol-induced hepatic injury via inhibition of oxidant and inflammatory responses via blocking of STAT3 activity.
Journal Article
Are We Studying Non-Coding RNAs Correctly? Lessons from nc886
2022
Non-coding RNAs (ncRNAs), such as microRNAs or long ncRNAs, have brought about a new paradigm in the regulation of gene expression. Sequencing technologies have detected transcripts with tremendous sensitivity and throughput and revealed that the majority of them lack protein-coding potential. Myriad articles have investigated numerous ncRNAs and many of them claim that ncRNAs play gene-regulatory roles. However, it is questionable whether all these articles draw conclusions through cautious gain- and loss-of function experiments whose design was reasonably based on an ncRNA’s correct identity and features. In this review, these issues are discussed with a regulatory ncRNA, nc886, as an example case to represent cautions and guidelines when studying ncRNAs.
Journal Article
IL-32γ Induced Autophagy Through Suppression of MET and mTOR Pathways in Liver Tumor Growth Inhibition
2024
Interleukin-32γ (IL-32γ) has diverse functions in various malignancies. In this study, we investigated the role of IL-32γ in autophagy induction in liver cancer cells and delineated the underlying mechanisms. We found that the increased IL-32γ expression inhibited the growth, cell cycle progression, and migration of HepG2 and Hep3B cell lines; it also decreased the expression of related proteins. Furthermore, the IL-32γ overexpression induced autophagy, as indicated by the number of puncta, the expression of LC3, and the expression of autophagy-related markers. The expression levels of LAMP1, a protein essential for autophagosome formation, and colocalization with LC3 also increased. Big data analysis revealed that the expression of MET, a well-known target of autophagy, and the expression of mTOR and mTOR-related proteins were decreased by the IL-32γ overexpression. The combination treatment of MET inhibitor, cabozantinib (2 µM), and IL-32γ overexpression further increased the number of puncta, the colocalization of LC3 and LAMP1, and the expression of autophagy-related proteins. In vivo, liver tumor growth was suppressed in the IL-32γ-overexpressing mouse model, and autophagy induction was confirmed by the increased expression of LC3 and LAMP1 and the decreased expression of autophagy pathway markers (MET and mTOR). Autophagy was also decreased in the liver tumor sample of human patients. ROC curve and spearman analysis revealed that the expression levels of LC3 and IL-32γ were significantly correlated in human tumor serum and tissues. Therefore, IL-32γ overexpression induced autophagy in liver tumors through the suppression of MET and mTOR pathways critical for tumor growth inhibition.
Journal Article
Involvement of Mitogen-Activated Protein Kinase Pathways in Expression of the Water Channel Protein Aquaporin-4 after Ischemia in Rat Cortical Astrocytes
by
Endo, Hidenori
,
Lee, Yong-Sun
,
Nito, Chikako
in
Animals
,
Animals, Newborn
,
Aquaporin 4 - metabolism
2012
Brain edema after ischemic brain injury is a key determinant of morbidity and mortality. Aquaporin-4 (AQP4) plays an important role in water transport in the central nervous system and is highly expressed in brain astrocytes. However, the AQP4 regulatory mechanisms are poorly understood. In this study, we investigated whether mitogen-activated protein kinases (MAPKs), which are involved in changes in osmolality, might mediate AQP4 expression in models of rat cortical astrocytes after ischemia. Increased levels of AQP4 in primary cultured astrocytes subjected to oxygen-glucose deprivation (OGD) and 2 h of reoxygenation were observed, after which they immediately decreased at 0 h of reoxygenation. Astrocytes exposed to OGD injury had significantly increased phosphorylation of three kinds of MAPKs. Treatment with SB203580, a selective p38 MAPK inhibitor, or SP600125, a selective c-Jun N-terminal kinase inhibitor, significantly attenuated the return of AQP4 to its normal level, and SB203580, but not SP600125, significantly decreased cell death. In an in vivo study, AQP4 expression was upregulated 1–3 days after reperfusion, which was consistent with the time course of p38 phosphorylation and activation, and decreased by the p38 inhibition after transient middle cerebral artery occlusion (MCAO). These results suggest that p38 MAPK may regulate AQP4 expression in cortical astrocytes after ischemic injury.
Journal Article
Editorial of Special Issue “Non-Coding RNAs in Pathogen-Host Interaction”
2021
Inter-personal genomic/epigenomic variations and the resulting differences in gene expression profiles determine the process of infection as well as its clinical manifestation. [...]understanding the complexity of host–pathogen interactions and their effect on gene expression is imperative to develop treatments and prevent future infectious diseases. A diverse range of viruses are discussed in this Special Issue, including enteroviruses, respiratory syncytial virus (RSV), Epstein–Barr virus (EBV), Rift valley fever virus, Japanese encephalitis virus, Zika virus, Hepatitis B virus (HBV), and Hepatitis C virus (HCV), all important pathogens. Choi, E.J.; Ren, J.; Zhang, K.; Wu, W.; Lee, Y.S.; Lee, I.; Bao, X. The Importance of AGO 1 and 4 in Post-Transcriptional Gene Regulatory Function of tRF5-GluCTC, an Respiratory Syncytial Virus-Induced tRNA-Derived RNA Fragment.
Journal Article
Identification and Functional Characterization of tRNA-derived RNA Fragments (tRFs) in Respiratory Syncytial Virus Infection
by
Wang, Qingrong
,
Lee, Inhan
,
Ren, Junping
in
Biosensing Techniques
,
Blotting, Northern
,
Bronchiolitis - genetics
2013
The discovery of small noncoding RNAs (sncRNAs) with regulatory functions is a recent breakthrough in biology. Among sncRNAs, microRNA (miRNA), derived from host or virus, has emerged as elements with high importance in control of viral replication and host responses. However, the expression pattern and functional aspects of other types of sncRNAs, following viral infection, are unexplored. In order to define expression patterns of sncRNAs, as well as to discover novel regulatory sncRNAs in response to viral infection, we applied deep sequencing to cells infected with human respiratory syncytial virus (RSV), the most common cause of bronchiolitis and pneumonia in babies. RSV infection leads to abundant production of transfer RNA (tRNA)-derived RNA Fragments (tRFs) that are ~30 nucleotides (nts) long and correspond to the 5′-half of mature tRNAs. At least one tRF, which is derived from tRNA-Glu-CTC, represses target mRNA in the cytoplasm and promotes RSV replication. This demonstrates that this tRF is not a random by-product of tRNA degradation but a functional molecule. The biogenesis of this tRF is also specific, as it is mediated by the endonuclease angiogenin (ANG), not by other nucleases. In summary, our study presents novel information on the induction of a functional tRF by viral infection.
Journal Article
The Versatile Roles of nc886, a Fascinating and Peculiar Regulatory Non-Coding RNA, in Cancer
2024
This review concerns nc886, a 101-nucleotide non-coding RNA (ncRNA). Because nc886 is transcribed by RNA polymerase III (Pol III) and contains a CpG island in its promoter region, its expression is regulated by several transcription factors and the DNA methylation status. These features drive nc886 expression in two opposing directions during tumorigenesis. The known function of nc886 is to bind to and modulate the activity of target proteins such as PKR, Dicer, and OAS1. By being differentially expressed during tumorigenesis and interacting with these proteins, nc886 plays a role in tumor surveillance, promotes or suppresses tumorigenesis, and influences the efficacy of cancer therapy. The multiple roles of nc886 have been well-documented in the literature. In this review, we have summarized this literature and critically discussed the roles and mechanisms of action of nc886 in various cancers.
Journal Article
Oxidative Stress and Neuronal Death/Survival Signaling in Cerebral Ischemia
2005
It has been demonstrated by numerous studies that apoptotic cell death pathways are implicated in ischemic cerebral injury in ischemia models in vivo. Experimental ischemia and reperfusion models, such as transient focal/global ischemia in rodents, have been thoroughly studied and the numerous reports suggest the involvement of cell survival/death signaling pathways in the pathogenesis of apoptotic cell death in ischemic lesions. In these models, reoxygenation during reperfusion provides oxygen as a substrate for numerous enzymatic oxidation reactions and for mitochondrial oxidative phosphorylation to produce adenosine triphosphate. Oxygen radicals, the products of these biochemical and physiological reactions, are known to damage cellular lipids, proteins, and nucleic acids and to initiate cell signaling pathways after cerebral ischemia. Genetic manipulation of intrinsic antioxidants and factors in the signaling pathways has provided substantial understanding of the mechanisms involved in cell death/survival signaling pathways and the role of oxygen radicals in ischemic cerebral injury. Future studies of these pathways could provide novel therapeutic strategies in clinical stroke.
Journal Article