Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
159
result(s) for
"Choi, Jong-Soon"
Sort by:
Gold nanozyme-based paper chip for colorimetric detection of mercury ions
by
Kwon, Joseph
,
Han, Kwi Nam
,
Choi, Jong-Soon
in
639/301/1005/1009
,
639/638/11/511
,
639/638/169/895
2017
In this study, we developed a facile gold nanozyme-based paper chip (AuNZ-PAD) for Hg
2+
detection. This device has the advantages of being simple, rapid, cost effective, sensitive, selective, high throughput, and applicable to onsite detection. The colorimetric mercury assay on the AuNZ-PAD is established based on the enzyme-like catalytic activity of gold nanoparticles promoted by the formation of Au–Hg amalgam, which is correlated to the intensity of the colorimetric response resulting from the catalytic reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) and H
2
O
2
. Highly sensitive and selective detection of Hg
2+
ions is achieved in both distilled and tap water samples, indicating the feasibility and applicability of our device for the determination of mercury pollution in real samples. Moreover, AuNZ-PAD analysis using a smartphone camera eliminates the need for expensive analytical equipment, thereby increasing the practicality of field monitoring of trace Hg
2+
compared with other sensing methods.
Journal Article
Three-dimensional paper-based slip device for one-step point-of-care testing
2016
In this study, we developed a new type of paper-based analytical device (PAD), the three-dimensional (3D) slip-PAD, to detect infectious human norovirus for global healthcare. The 3D configuration of the papers combined with a slip design provides unique features and versatility that overcome the limitations of fluidic manipulation and sensitivity in point-of-care (POC) tests. The assay can be carried out in a single step based on a moveable slip design, making it suitable for unskilled users. The 3D fluidic network developed by layered construction of wax-patterned papers provides different fluidic paths for the sequential delivery of multiple fluids without the need for peripheral equipment. The release and mixing of enhancement reagents on the device improved the sensitivity and detection limit. The assay results could be visualized by naked eye within 10 min, with subsequent amplification of the signal over time (<60 min). The device showed a broad dynamic range of detection and high sensitivity, with a detection limit of 9.5 × 10
4
copies ml
−1
for human norovirus. These results demonstrate that the 3D slip-PAD is a sensitive diagnostic assay for detecting human norovirus infection that is particularly suitable for POC testing in regions where resources are scarce.
Journal Article
FBXW7-mediated ERK3 degradation regulates the proliferation of lung cancer cells
2022
Extracellular signal-regulated kinase 3 (ERK3) is an atypical member of the mitogen-activated protein kinase (MAPK) family, members of which play essential roles in diverse cellular processes during carcinogenesis, including cell proliferation, differentiation, migration, and invasion. Unlike other MAPKs, ERK3 is an unstable protein with a short half-life. Although deubiquitination of ERK3 has been suggested to regulate the activity, its ubiquitination has not been described in the literature. Here, we report that FBXW7 (F-box and WD repeat domain-containing 7) acts as a ubiquitination E3 ligase for ERK3. Mammalian two-hybrid assay and immunoprecipitation results demonstrated that ERK3 is a novel binding partner of FBXW7. Furthermore, complex formation between ERK3 and the S-phase kinase-associated protein 1 (SKP1)-cullin 1-F-box protein (SCF) E3 ligase resulted in the destabilization of ERK3 via a ubiquitination-mediated proteasomal degradation pathway, and FBXW7 depletion restored ERK3 protein levels by inhibiting this ubiquitination. The interaction between ERK3 and FBXW7 was driven by binding between the C34D of ERK3, especially at Thr417 and Thr421, and the WD40 domain of FBXW7. A double mutant of ERK3 (Thr417 and Thr421 to alanine) abrogated FBXW7-mediated ubiquitination. Importantly, ERK3 knockdown inhibited the proliferation of lung cancer cells by regulating the G
1
/S-phase transition of the cell cycle. These results show that FBXW7-mediated ERK3 destabilization suppresses lung cancer cell proliferation in vitro.
Cancer: Controling the stability of a pro-proliferation protein
An enzymatic process that marks a cellular signaling protein for destruction may be a check against uncontrolled proliferation in some cancers. Prior studies have indicated that the ERK3 protein can influence essential functions like cell division and migration and that its effects are governed by its stability. Researchers led by Yong-Yeon Cho at The Catholic University of Korea, Bucheon-si, have now determined that an enzyme called FBXW7 controls ERK3 by tagging it with a modification that marks it for destruction. ERK3 has been linked to cancer, although the data have been contradictory as to whether it controls or promotes malignancy. The authors show that ERK3 can promote proliferation in cultured lung cancer cells and that this proliferation can be counteracted by FBXW7. However, ERK3’s general role in tumors is likely to be context-specific.
Journal Article
TDAG51 is a crucial regulator of maternal care and depressive-like behavior after parturition
by
Amarasekara, Dulshara Sachini
,
Lee, Nari
,
Park, Eui-Soon
in
Animals
,
Biochemistry
,
Biology and Life Sciences
2019
Postpartum depression is a severe emotional and mental disorder that involves maternal care defects and psychiatric illness. Postpartum depression is closely associated with a combination of physical changes and physiological stress during pregnancy or after parturition in stress-sensitive women. Although postpartum depression is relatively well known to have deleterious effects on the developing fetus, the influence of genetic risk factors on the development of postpartum depression remains unclear. In this study, we discovered a novel function of T cell death-associated gene 51 (TDAG51/PHLDA1) in the regulation of maternal and depressive-like behavior. After parturition, TDAG51-deficient dams showed impaired maternal behavior in pup retrieving, nursing and nest building tests. In contrast to the normal dams, the TDAG51-deficient dams also exhibited more sensitive depressive-like behaviors after parturition. Furthermore, changes in the expression levels of various maternal and depressive-like behavior-associated genes regulating neuroendocrine factor and monoamine neurotransmitter levels were observed in TDAG51-deficient postpartum brain tissues. These findings indicate that TDAG51 plays a protective role against maternal care defects and depressive-like behavior after parturition. Thus, TDAG51 is a maternal care-associated gene that functions as a crucial regulator of maternal and depressive-like behavior after parturition.
Journal Article
Novel electrochemical PMI marker biosensor based on quantum dot dissolution using a double-label strategy
2022
A novel and facile post-mortem interval (PMI) biosensor was fabricated using a double-label strategy to detect the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) biomarker. A monoclonal anti-GAPDH antibody was immobilized on a surface label containing cadmium selenide quantum dots (CdSe QDs) on a cysteamine graphene oxide (Cys-GO) self-assembled monolayer. Glucose oxidase (GOx) was used as a signal label to conjugate with GAPDH. GAPDH recognition was achieved through the dissolution of the surface-attached CdSe QDs by hydrogen peroxide generated through GAPDH-conjugated GOx-catalyzed
β
-glucose oxidation. To enhance sensitivity, a competitive interaction was introduced between free and conjugated GAPDH to the active site of the anti-GAPDH antibody. The electrochemical response due to CdSe dissolution decreased proportionally with the concentration of free GAPDH. Differential pulsed voltammetry was conducted to determine the analytical characteristics of the immunosensor, including the limit of detection, linear dynamic range, target selectivity, system stability, and applicability toward the analysis of real samples.
Journal Article
Systematic functional analysis of kinases in the fungal pathogen Cryptococcus neoformans
2016
Cryptococcus neoformans
is the leading cause of death by fungal meningoencephalitis; however, treatment options remain limited. Here we report the construction of 264 signature-tagged gene-deletion strains for 129 putative kinases, and examine their phenotypic traits under 30 distinct
in vitro
growth conditions and in two different hosts (insect larvae and mice). Clustering analysis of
in vitro
phenotypic traits indicates that several of these kinases have roles in known signalling pathways, and identifies hitherto uncharacterized signalling cascades. Virulence assays in the insect and mouse models provide evidence of pathogenicity-related roles for 63 kinases involved in the following biological categories: growth and cell cycle, nutrient metabolism, stress response and adaptation, cell signalling, cell polarity and morphology, vacuole trafficking, transfer RNA (tRNA) modification and other functions. Our study provides insights into the pathobiological signalling circuitry of
C. neoformans
and identifies potential anticryptococcal or antifungal drug targets.
Cryptococcus neoformans
is the leading cause of death by fungal meningoencephalitis. Here, the authors study the roles played by 129 putative kinases in the growth and virulence of
C. neoformans
, identifying potential targets for development of anticryptococcal drugs.
Journal Article
Anti‐growth and pro‐apoptotic effects of dasatinib on human oral cancer cells through multi‐targeted mechanisms
by
Jang, Byeong‐Churl
,
Park, Nam‐Sook
,
Park, Yu‐Kyung
in
Angiogenesis
,
Antibodies
,
Antineoplastic Agents - pharmacology
2021
Dasatinib is an inhibitor of Src that has anti‐tumour effects on many haematological and solid cancers. However, the anti‐tumour effects of dasatinib on human oral cancers remain unclear. In this study, we investigated the effects of dasatinib on different types of human oral cancer cells: the non‐tumorigenic YD‐8 and YD‐38 and the tumorigenic YD‐10B and HSC‐3 cells. Strikingly, dasatinib at 10 µM strongly suppressed the growth and induced apoptosis of YD‐38 cells and inhibited the phosphorylation of Src, EGFR, STAT‐3, STAT‐5, PKB and ERK‐1/2. In contrast, knockdown of Src blocked the phosphorylation of EGFR, STAT‐5, PKB and ERK‐1/2, but not STAT‐3, in YD‐38 cells. Dasatinib induced activation of the intrinsic caspase pathway, which was inhibited by z‐VAD‐fmk, a pan‐caspase inhibitor. Dasatinib also decreased Mcl‐1 expression and S6 phosphorylation while increased GRP78 expression and eIF‐2α phosphorylation in YD‐38 cells. In addition, to its direct effects on YD‐38 cells, dasatinib also exhibited anti‐angiogenic properties. Dasatinib‐treated YD‐38 or HUVEC showed reduced HIF‐1α expression and stability. Dasatinib alone or conditioned media from dasatinib‐treated YD‐38 cells inhibited HUVEC tube formation on Matrigel without affecting HUVEC viability. Importantly, dasatinib's anti‐growth, anti‐angiogenic and pro‐apoptotic effects were additionally seen in tumorigenic HSC‐3 cells. Together, these results demonstrate that dasatinib has strong anti‐growth, anti‐angiogenic and pro‐apoptotic effects on human oral cancer cells, which are mediated through the regulation of multiple targets, including Src, EGFR, STAT‐3, STAT‐5, PKB, ERK‐1/2, S6, eIF‐2α, GRP78, caspase‐9/3, Mcl‐1 and HIF‐1α.
Journal Article
Activation of PI3K, Akt, and ERK during early rotavirus infection leads to V-ATPase-dependent endosomal acidification required for uncoating
by
Kwon, Joseph
,
Soliman, Mahmoud
,
Kang, Mun-Il
in
1-Phosphatidylinositol 3-kinase
,
Acidification
,
Acids - metabolism
2018
The cellular PI3K/Akt and/or MEK/ERK signaling pathways mediate the entry process or endosomal acidification during infection of many viruses. However, their roles in the early infection events of group A rotaviruses (RVAs) have remained elusive. Here, we show that late-penetration (L-P) human DS-1 and bovine NCDV RVA strains stimulate these signaling pathways very early in the infection. Inhibition of both signaling pathways significantly reduced production of viral progeny due to blockage of virus particles in the late endosome, indicating that neither of the two signaling pathways is involved in virus trafficking. However, immunoprecipitation assays using antibodies specific for pPI3K, pAkt, pERK and the subunit E of the V-ATPase co-immunoprecipitated the V-ATPase in complex with pPI3K, pAkt, and pERK. Moreover, Duolink proximity ligation assay revealed direct association of the subunit E of the V-ATPase with the molecules pPI3K, pAkt, and pERK, indicating that both signaling pathways are involved in V-ATPase-dependent endosomal acidification. Acidic replenishment of the medium restored uncoating of the RVA strains in cells pretreated with inhibitors specific for both signaling pathways, confirming the above results. Isolated components of the outer capsid proteins, expressed as VP4-VP8* and VP4-VP5* domains, and VP7, activated the PI3K/Akt and MEK/ERK pathways. Furthermore, psoralen-UV-inactivated RVA and CsCl-purified RVA triple-layered particles triggered activation of the PI3K/Akt and MEK/ERK pathways, confirming the above results. Our data demonstrate that multistep binding of outer capsid proteins of L-P RVA strains with cell surface receptors phosphorylates PI3K, Akt, and ERK, which in turn directly interact with the subunit E of the V-ATPase to acidify the late endosome for uncoating of RVAs. This study provides a better understanding of the RVA-host interaction during viral uncoating, which is of importance for the development of strategies aiming at controlling or preventing RVA infections.
Journal Article
AZD1208, a pan‐Pim kinase inhibitor, inhibits adipogenesis and induces lipolysis in 3T3‐L1 adipocytes
by
Obiang‐Obounou, Brice Wilfried
,
Park, Yu‐Kyoung
,
Lee, Kyung‐Bok
in
3T3-L1 Cells
,
3T3‐L1
,
Adipocytes
2018
The proviral integration moloney murine leukaemia virus (Pim) kinases, consisting of Pim‐1, Pim‐2 and Pim‐3, are involved in the control of cell growth, metabolism and differentiation. Pim kinases are emerging as important mediators of adipocyte differentiation. AZD1208 is a pan‐Pim kinase inhibitor and is known for its anti‐cancer activity. In this study, we investigated the effect of AZD1208 on adipogenesis and lipolysis in 3T3‐L1 cells, a murine preadipocyte cell line. AZD1208 markedly suppressed lipid accumulation and reduced triglyceride contents in differentiating 3T3‐L1 cells, suggesting the drug's anti‐adipogenic effect. On mechanistic levels, AZD1208 reduced not only the expressions of CCAAT/enhancer‐binding protein‐α (C/EBP‐α), peroxisome proliferator‐activated receptor‐γ (PPAR‐γ), fatty acid synthase (FAS), acetyl‐CoA carboxylase (ACC) and perilipin A but also the phosphorylation of signal transducer and activator of transcription‐3 (STAT‐3) in differentiating 3T3‐L1 cells. Remarkably, AZD1208 increased cAMP‐activated protein kinase (AMPK) and LKB‐1 phosphorylation while decreased intracellular ATP contents in differentiating 3T3‐L1 cells. Furthermore, in differentiated 3T3‐L1 adipocytes, AZD1208 also partially promoted lipolysis and enhanced the phosphorylation of hormone‐sensitive lipase (HSL), a key lipolytic enzyme, indicating the drug's HSL‐dependent lipolysis. In summary, the findings show that AZD1208 has anti‐adipogenic and lipolytic effects on 3T3‐L1 adipocytes. These effects are mediated by the expression and/or phosphorylation levels of C/EBP‐α, PPAR‐γ, FAS, ACC, perilipin A, STAT‐3, AMPK and HSL.
Journal Article
Degradation of Kidney and Psoas Muscle Proteins as Indicators of Post-Mortem Interval in a Rat Model, with Use of Lateral Flow Technology
by
Hwang, Jeong Won
,
Jung, Hyo-Il
,
Lee, Dong-Gi
in
Abscess
,
AMP-activated protein kinase
,
Analysis
2016
We investigated potential protein markers of post-mortem interval (PMI) using rat kidney and psoas muscle. Tissue samples were taken at 12 h intervals for up to 96 h after death by suffocation. Expression levels of eight soluble proteins were analyzed by Western blotting. Degradation patterns of selected proteins were clearly divided into three groups: short-term, mid-term, and long-term PMI markers based on the half maximum intensity of intact protein expression. In kidney, glycogen synthase (GS) and glycogen synthase kinase-3β were degraded completely within 48 h making them short-term PMI markers. AMP-activated protein kinase α, caspase 3 and GS were short-term PMI markers in psoas muscle. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was a mid-term PMI marker in both tissues. Expression levels of the typical long-term PMI markers, p53 and β-catenin, were constant for at least 96 h post-mortem in both tissues. The degradation patterns of GS and caspase-3 were verified by immunohistochemistry in both tissues. GAPDH was chosen as a test PMI protein to perform a lateral flow assay (LFA). The presence of recombinant GAPDH was clearly detected in LFA and quantified in a concentration-dependent manner. These results suggest that LFA might be used to estimate PMI at a crime scene.
Journal Article