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  1. Article: MicroRNA-21 Plays Multiple Oncometabolic Roles in Colitis-Associated Carcinoma and Colorectal Cancer via the PI3K/AKT, STAT3, and PDCD4/TNF-α Signaling Pathways in Zebrafish.

    Lai, Chi-Yu / Yeh, Kun-Yun / Liu, Bi-Feng / Chang, Tzu-Ming / Chang, Chuan-Hsun / Liao, Yung-Feng / Liu, Yi-Wen / Her, Guor Mour

    Cancers

    2021  Volume 13, Issue 21

    Abstract: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Patients with inflammatory bowel disease (IBD) have a high risk of developing CRC. Inflammatory cytokines are regulated by complex gene networks and regulatory RNAs, ... ...

    Abstract Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Patients with inflammatory bowel disease (IBD) have a high risk of developing CRC. Inflammatory cytokines are regulated by complex gene networks and regulatory RNAs, especially microRNAs. MicroRNA-21 (miR-21) is amongst the most frequently upregulated microRNAs in inflammatory responses and cancer development. miR-21 has become a target for genetic and pharmacological regulation in various diseases. However, the association between inflammation and tumorigenesis in the gut is largely unknown. Hence, in this study, we generated a zebrafish model (ImiR-21) with inducible overexpression of miR-21 in the intestine. The results demonstrate that miR-21 can induce CRC or colitis-associated cancer (CAC) in ImiR-21 through the PI3K/AKT, PDCD4/TNF-α, and IL-6/STAT3 signaling network. miR-21 activated the PI3K/AKT and NF-κB signaling pathways, leading to initial inflammation; thereafter, miR-21 and TNF-α repressed PDCD4 and its tumor suppression activity. Eventually, active STAT3 stimulated a strong inflammatory response and activated the invasion/metastasis process of tumor cells. Hence, our findings indicate that miR-21 is critical for the development of CRC/CAC via the PI3K/AKT, STAT3, and PDCD4/TNF-α signaling networks.
    Language English
    Publishing date 2021-11-06
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527080-1
    ISSN 2072-6694
    ISSN 2072-6694
    DOI 10.3390/cancers13215565
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Critical Roles of Dual-Specificity Phosphatases in Neuronal Proteostasis and Neurological Diseases.

    Bhore, Noopur / Wang, Bo-Jeng / Chen, Yun-Wen / Liao, Yung-Feng

    International journal of molecular sciences

    2017  Volume 18, Issue 9

    Abstract: Protein homeostasis or proteostasis is a fundamental cellular property that encompasses the dynamic balancing of processes in the proteostasis network (PN). Such processes include protein synthesis, folding, and degradation in both non-stressed and ... ...

    Abstract Protein homeostasis or proteostasis is a fundamental cellular property that encompasses the dynamic balancing of processes in the proteostasis network (PN). Such processes include protein synthesis, folding, and degradation in both non-stressed and stressful conditions. The role of the PN in neurodegenerative disease is well-documented, where it is known to respond to changes in protein folding states or toxic gain-of-function protein aggregation. Dual-specificity phosphatases have recently emerged as important participants in maintaining balance within the PN, acting through modulation of cellular signaling pathways that are involved in neurodegeneration. In this review, we will summarize recent findings describing the roles of dual-specificity phosphatases in neurodegeneration and offer perspectives on future therapeutic directions.
    Language English
    Publishing date 2017-09-13
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms18091963
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: New Hydroxyquinoline-Based Derivatives as Potent Modulators of Amyloid-β Aggregations.

    Fu, Chin-Lan / Hsu, Li-Shin / Liao, Yung-Feng / Hu, Ming-Kuan

    Archiv der Pharmazie

    2016  Volume 349, Issue 5, Page(s) 327–341

    Abstract: Copper and zinc have been found to contribute to the burden of amyloid-β (Aβ) aggregations in neurodegenerative Alzheimer's disease (AD). Dysregulation of these metals leads to the generation of reactive oxygen species (ROS) and eventually results in ... ...

    Abstract Copper and zinc have been found to contribute to the burden of amyloid-β (Aβ) aggregations in neurodegenerative Alzheimer's disease (AD). Dysregulation of these metals leads to the generation of reactive oxygen species (ROS) and eventually results in oxidative damage and accumulation of the Aβ peptide, which are the key elements of the disease. Aiming to pursue the discovery of new modulators for the disease, we here rationally focused on conjugating the core hydroxyquinoline of the metal-protein attenuating compound PBT2 and the N-methylanilide analogous moiety of the Aβ imaging agent to build a new type of multi-target modulators of Aβ aggregations. We found that the N,N-dimethylanilinyl imines 7a, 8a, and the corresponding amines 7b, 8b exerted efficient inhibition of Cu(2+) - or Zn(2+) -induced Aβ aggregations and significant disassembly of metal-mediated Aβ aggregated fibrils. Further, 7a and 7b also exhibited significant ROC scavenging effects compared to PBT2. The results suggested that 7a and 7b are promising lead compounds for the development of a new therapy for AD.
    MeSH term(s) Amyloid beta-Peptides/chemistry ; Amyloid beta-Peptides/drug effects ; Amyloid beta-Peptides/metabolism ; Amyloid beta-Peptides/ultrastructure ; Chelating Agents/chemical synthesis ; Chelating Agents/pharmacology ; Chelating Agents/therapeutic use ; Clioquinol/analogs & derivatives ; Clioquinol/chemistry ; Clioquinol/pharmacology ; Clioquinol/therapeutic use ; Copper/adverse effects ; Hydroxyquinolines/chemical synthesis ; Hydroxyquinolines/chemistry ; Hydroxyquinolines/pharmacology ; Hydroxyquinolines/therapeutic use ; Protein Aggregation, Pathological/drug therapy ; Structure-Activity Relationship ; Zinc/adverse effects
    Chemical Substances Amyloid beta-Peptides ; Chelating Agents ; Hydroxyquinolines ; PBT2 compound ; Copper (789U1901C5) ; Clioquinol (7BHQ856EJ5) ; Zinc (J41CSQ7QDS)
    Language English
    Publishing date 2016-05
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 6381-2
    ISSN 1521-4184 ; 0365-6233 ; 1437-1014
    ISSN (online) 1521-4184
    ISSN 0365-6233 ; 1437-1014
    DOI 10.1002/ardp.201500453
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Calreticulin regulates MYCN expression to control neuronal differentiation and stemness of neuroblastoma.

    Lee, Andy Chi-Lung / Shih, Yu-Yin / Zhou, Fanfan / Chao, Tsi-Chian / Lee, Hsinyu / Liao, Yung-Feng / Hsu, Wen-Ming / Hong, Ji-Hong

    Journal of molecular medicine (Berlin, Germany)

    2019  Volume 97, Issue 3, Page(s) 325–339

    Abstract: Oncogenic N-MYC (MYCN) is widely used as a biomarker in clinics for neuroblastoma (NB) patients; nevertheless, mechanism that underlines MYCN regulation remains elusive. In the present study, we identified calreticulin (CRT) as a novel MYCN suppressor ... ...

    Abstract Oncogenic N-MYC (MYCN) is widely used as a biomarker in clinics for neuroblastoma (NB) patients; nevertheless, mechanism that underlines MYCN regulation remains elusive. In the present study, we identified calreticulin (CRT) as a novel MYCN suppressor that downregulated MYCN promoter activity and protein expression to modulate neuronal differentiation and stemness. Our data showed that CRT-mediated MYCN suppression led to increased neurite length and commensurate elevation in differentiation marker GAP-43. We examined effect of radiotherapy and discovered that ionizing radiation (IR) was able to augment CRT expression dose-dependently in NB. Interestingly, neuronal differentiation and neurosphere formation (NSF) of NB were not only co-modulated by IR and CRT but were also dependent on Ca
    MeSH term(s) Animals ; Calreticulin/metabolism ; Cell Line, Tumor ; Female ; Humans ; Mice, SCID ; N-Myc Proto-Oncogene Protein/genetics ; N-Myc Proto-Oncogene Protein/metabolism ; Neuroblastoma/metabolism ; Neuroblastoma/pathology ; Neuroblastoma/radiotherapy ; Neurogenesis ; Neurons/physiology ; Promoter Regions, Genetic ; Radiation, Ionizing
    Chemical Substances CALR protein, human ; Calreticulin ; MYCN protein, human ; N-Myc Proto-Oncogene Protein
    Language English
    Publishing date 2019-01-05
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1223802-8
    ISSN 1432-1440 ; 0946-2716
    ISSN (online) 1432-1440
    ISSN 0946-2716
    DOI 10.1007/s00109-018-1730-x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Dual-Specificity Phosphatase 15 (DUSP15) Modulates Notch Signaling by Enhancing the Stability of Notch Protein.

    Bhore, Noopur / Wang, Bo-Jeng / Wu, Po-Fan / Lee, Yen-Lurk / Chen, Yun-Wen / Hsu, Wen-Ming / Lee, Hsinyu / Huang, Yi-Shuian / Yang, Ding-I / Liao, Yung-Feng

    Molecular neurobiology

    2021  Volume 58, Issue 5, Page(s) 2204–2214

    Abstract: Dual-specificity phosphatases (DUSPs) comprise a unique group of enzymes that dephosphorylate signaling proteins at both phospho-serine/threonine and phospho-tyrosine residues. Since Notch signaling is an essential pathway for neuronal cell fate ... ...

    Abstract Dual-specificity phosphatases (DUSPs) comprise a unique group of enzymes that dephosphorylate signaling proteins at both phospho-serine/threonine and phospho-tyrosine residues. Since Notch signaling is an essential pathway for neuronal cell fate determination and development that is also upregulated in Alzheimer's disease tissues, we sought to explore whether and how DUSPs may impact Notch processing. Our results show that overexpression of DUSP15 concomitantly and dose-dependently increased the steady-state levels of recombinant Notch (extracellular domain-truncated Notch, NotchΔE) protein and its cleaved product, Notch intracellular domain (NICD). The overall ratio of NotchΔE to NICD was unchanged by overexpression of DUSP15, suggesting that the effect is independent of γ-secretase. Interestingly, overexpression of DUSP15 also dose-dependently increased phosphorylated ERK1/2. Phosphorylated ERK1/2 is known to be positively correlated with Notch protein level, and we found that DUSP15-mediated regulation of Notch was dependent on ERK1/2 activity. Together, our findings reveal the existence of a previously unidentified DUSP15-ERK1/2-Notch signaling axis, which could potentially play a role in neuronal differentiation and neurological disease.
    MeSH term(s) Amyloid Precursor Protein Secretases/metabolism ; Cell Differentiation/physiology ; Dual-Specificity Phosphatases/metabolism ; HEK293 Cells ; Humans ; Neurons/metabolism ; Phosphorylation ; Receptors, Notch/metabolism ; Signal Transduction/physiology
    Chemical Substances Receptors, Notch ; DUSP15 protein, human (EC 3.1.3.48) ; Dual-Specificity Phosphatases (EC 3.1.3.48) ; Amyloid Precursor Protein Secretases (EC 3.4.-)
    Language English
    Publishing date 2021-01-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 645020-9
    ISSN 1559-1182 ; 0893-7648
    ISSN (online) 1559-1182
    ISSN 0893-7648
    DOI 10.1007/s12035-020-02254-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Difluorophenylglycinols as new modulators of proteolytic processing of amyloid precursor proteins.

    Chen, Chia-Yu / Liao, Yung-Feng / Chang, Ming-Yun / Hu, Ming-Kuan

    Archiv der Pharmazie

    2014  Volume 347, Issue 3, Page(s) 161–173

    Abstract: Synthesis and evaluation of difluorophenylglycinols as new modulators of proteolytic processing of the amyloid-β precursor proteins for Alzheimer's therapies were described. A range of N-substituted (R)- and (S)-difluorophenylglycinols, structured on the ...

    Abstract Synthesis and evaluation of difluorophenylglycinols as new modulators of proteolytic processing of the amyloid-β precursor proteins for Alzheimer's therapies were described. A range of N-substituted (R)- and (S)-difluorophenylglycinols, structured on the amino alcohol framework, were explored by incorporating the arylsulfonyl moieties and various N-substituents. Evans' chiral auxiliary strategy was employed for the asymmetric synthesis of these enantiomeric difluorophenylglycinols. Compounds with effects on the γ-secretase inhibition and ERK-mediated signaling pathways were evaluated on cell-based assays. Among them, N-cyclopropylmethyl derivatives R-12c and R-13c showed modest γ-secretase inhibition as well as ERK-dependent activation.
    MeSH term(s) Alzheimer Disease/drug therapy ; Alzheimer Disease/enzymology ; Amyloid Precursor Protein Secretases/antagonists & inhibitors ; Amyloid Precursor Protein Secretases/genetics ; Amyloid Precursor Protein Secretases/metabolism ; Amyloid beta-Protein Precursor/metabolism ; Enzyme Activation ; Ethanolamines/chemical synthesis ; Ethanolamines/pharmacology ; Extracellular Signal-Regulated MAP Kinases/metabolism ; HEK293 Cells ; Humans ; Molecular Structure ; Protease Inhibitors/chemical synthesis ; Protease Inhibitors/pharmacology ; Proteolysis ; Signal Transduction/drug effects ; Structure-Activity Relationship ; Transfection
    Chemical Substances Amyloid beta-Protein Precursor ; Ethanolamines ; Protease Inhibitors ; N-phenylethanolamine (630DL2N96B) ; Extracellular Signal-Regulated MAP Kinases (EC 2.7.11.24) ; Amyloid Precursor Protein Secretases (EC 3.4.-)
    Language English
    Publishing date 2014-03
    Publishing country Germany
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 6381-2
    ISSN 1521-4184 ; 0365-6233 ; 1437-1014
    ISSN (online) 1521-4184
    ISSN 0365-6233 ; 1437-1014
    DOI 10.1002/ardp.201300283
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Quantitative Measurement of γ-Secretase-mediated Amyloid Precursor Protein and Notch Cleavage in Cell-based Luciferase Reporter Assay Platforms.

    Wang, Bo-Jeng / Wu, Pei-Yi / Chen, Yun-Wen / Chang, Yu-Tzu / Bhore, Noopur / Wu, Po-Fan / Liao, Yung-Feng

    Journal of visualized experiments : JoVE

    2018  , Issue 131

    Abstract: We have developed a pair of cell-based reporter gene assays to quantitatively measure γ-secretase cleavage of distinct substrates. This manuscript describes procedures that may be used to monitor γ-secretase-mediated cleavage of either APP-C99 or Notch, ... ...

    Abstract We have developed a pair of cell-based reporter gene assays to quantitatively measure γ-secretase cleavage of distinct substrates. This manuscript describes procedures that may be used to monitor γ-secretase-mediated cleavage of either APP-C99 or Notch, using a Gal4 promoter-driven firefly luciferase reporter system. These assays were established by stably co-transfecting HEK293 cells with the Gal4-driven luciferase reporter gene and either the Gal4/VP16-tagged C-terminal fragment of APP (APP-C99; CG cells), or the Gal4/VP16-tagged Notch-ΔE (NΔE; NG cells). Using these reporter assays in parallel, we have demonstrated that an ErbB2 inhibitor, CL-387,785, can preferentially suppress γ-secretase cleavage of APP-C99 in CG cells, but not NΔE in NG cells. The differential responses exhibited by the CG and NG cells, when treated with CL-387,785, represent a preferred characteristic for γ-secretase modulators, and these responses are in stark contrast to the pan-inhibition of γ-secretase induced by DAPT. Our studies provide direct evidence that γ-secretase activities toward different substrates can be differentiated in a cellular context. These new assays may therefore be useful tools in drug discovery for improved AD therapies.
    MeSH term(s) Amyloid Precursor Protein Secretases/analysis ; Amyloid Precursor Protein Secretases/metabolism ; Cell Differentiation/physiology ; HEK293 Cells ; Humans ; Luciferases, Firefly/chemistry ; Luciferases, Firefly/metabolism ; Receptors, Notch/metabolism ; Substrate Specificity ; Transfection
    Chemical Substances Receptors, Notch ; Luciferases, Firefly (EC 1.13.12.7) ; Amyloid Precursor Protein Secretases (EC 3.4.-)
    Language English
    Publishing date 2018-01-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Video-Audio Media
    ZDB-ID 2259946-0
    ISSN 1940-087X ; 1940-087X
    ISSN (online) 1940-087X
    ISSN 1940-087X
    DOI 10.3791/56795
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Phosphatidylinositol-4-phosphate 5-kinase type 1α attenuates Aβ production by promoting non-amyloidogenic processing of amyloid precursor protein.

    Wu, Po-Fan / Bhore, Noopur / Lee, Yen-Lurk / Chou, Ju-Yun / Chen, Yun-Wen / Wu, Pei-Yi / Hsu, Wen-Ming / Lee, Hsinyu / Huang, Yi-Shuian / Lu, Pei-Jung / Liao, Yung-Feng

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology

    2020  Volume 34, Issue 9, Page(s) 12127–12146

    Abstract: Alzheimer's disease (AD) is characterized by a chronic decline in cognitive function and is pathologically typified by cerebral deposition of amyloid-β peptide (Aβ). The production of Aβ is mediated by sequential proteolysis of amyloid precursor protein ( ...

    Abstract Alzheimer's disease (AD) is characterized by a chronic decline in cognitive function and is pathologically typified by cerebral deposition of amyloid-β peptide (Aβ). The production of Aβ is mediated by sequential proteolysis of amyloid precursor protein (APP) by β- and γ-secretases, and has been implicated as the essential determinant of AD pathology. Previous studies have demonstrated that the level of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] in the membrane may potentially modulate Aβ production. Given that PI(4,5)P2 is produced by type 1 phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks), we sought to determine whether the level of PIP5K type Iα (PIP5K1A) can affect production of Aβ by modulating the lipid composition of the membrane. Using a HEK-derived cell line that constitutively expresses yellow fluorescent protein-tagged APP (APP-YFP), we demonstrated that overexpression of PIP5K1A results in significant enhancement of non-amyloidogenic APP processing and a concomitant suppression of the amyloidogenic pathway, leading to a marked decrease in secreted Aβ. Consistently, cells overexpressing PIP5K1A exhibited a significant redistribution of APP-YFP from endosomal compartments to the cell surface. Our findings suggest that PIP5K1A may play a critical role in governing Aβ production by modulating membrane distribution of APP, and as such, the pathway may be a valuable therapeutic target for AD.
    MeSH term(s) Alzheimer Disease/genetics ; Alzheimer Disease/metabolism ; Alzheimer Disease/pathology ; Amyloid beta-Peptides/genetics ; Amyloid beta-Peptides/metabolism ; Animals ; HEK293 Cells ; Humans ; Phosphatidylinositol 4,5-Diphosphate/genetics ; Phosphatidylinositol 4,5-Diphosphate/metabolism ; Phosphotransferases (Alcohol Group Acceptor)/genetics ; Phosphotransferases (Alcohol Group Acceptor)/metabolism ; Rats
    Chemical Substances Amyloid beta-Peptides ; Phosphatidylinositol 4,5-Diphosphate ; Phosphotransferases (Alcohol Group Acceptor) (EC 2.7.1.-) ; 1-phosphatidylinositol-4-phosphate 5-kinase (EC 2.7.1.68)
    Language English
    Publishing date 2020-07-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 639186-2
    ISSN 1530-6860 ; 0892-6638
    ISSN (online) 1530-6860
    ISSN 0892-6638
    DOI 10.1096/fj.202000113R
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Equilibrative nucleoside transporter 1 inhibition rescues energy dysfunction and pathology in a model of tauopathy.

    Chang, Ching-Pang / Chang, Ya-Gin / Chuang, Pei-Yun / Nguyen, Thi Ngoc Anh / Wu, Kuo-Chen / Chou, Fang-Yi / Cheng, Sin-Jhong / Chen, Hui-Mei / Jin, Lee-Way / Carvalho, Kevin / Huin, Vincent / Buée, Luc / Liao, Yung-Feng / Lin, Chun-Jung / Blum, David / Chern, Yijuang

    Acta neuropathologica communications

    2021  Volume 9, Issue 1, Page(s) 112

    Abstract: Tau pathology is instrumental in the gradual loss of neuronal functions and cognitive decline in tauopathies, including Alzheimer's disease (AD). Earlier reports showed that adenosine metabolism is abnormal in the brain of AD patients while consequences ... ...

    Abstract Tau pathology is instrumental in the gradual loss of neuronal functions and cognitive decline in tauopathies, including Alzheimer's disease (AD). Earlier reports showed that adenosine metabolism is abnormal in the brain of AD patients while consequences remained ill-defined. Herein, we aimed at investigating whether manipulation of adenosine tone would impact Tau pathology, associated molecular alterations and subsequent neurodegeneration. We demonstrated that treatment with an inhibitor (J4) of equilibrative nucleoside transporter 1 (ENT1) exerted beneficial effects in a mouse model of Tauopathy. Treatment with J4 not only reduced Tau hyperphosphorylation but also rescued memory deficits, mitochondrial dysfunction, synaptic loss, and abnormal expression of immune-related gene signatures. These beneficial effects were particularly ascribed to the ability of J4 to suppress the overactivation of AMPK (an energy reduction sensor), suggesting that normalization of energy dysfunction mitigates neuronal dysfunctions in Tauopathy. Collectively, these data highlight that targeting adenosine metabolism is a novel strategy for tauopathies.
    MeSH term(s) Animals ; Brain/drug effects ; Brain/metabolism ; Brain/pathology ; Disease Models, Animal ; Equilibrative Nucleoside Transporter 1/antagonists & inhibitors ; Humans ; Mice ; Tauopathies/metabolism ; Tauopathies/pathology
    Chemical Substances Equilibrative Nucleoside Transporter 1
    Language English
    Publishing date 2021-06-22
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2715589-4
    ISSN 2051-5960 ; 2051-5960
    ISSN (online) 2051-5960
    ISSN 2051-5960
    DOI 10.1186/s40478-021-01213-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Quantitative measurement of γ-secretase-mediated amyloid precursor protein and notch cleavage in cell-based luciferase reporter assay platforms

    Wang, Bo-Jeng / Wu, Pei-Yi / Chen, Yun-Wen / Chang, Yu-Tzu / Bhore, Noopur / Wu, Po-Fan / Liao, Yung-Feng

    Journal of visualized experiments. 2018 Jan. 25, , no. 131

    2018  

    Abstract: We have developed a pair of cell-based reporter gene assays to quantitatively measure γ-secretase cleavage of distinct substrates. This manuscript describes procedures that may be used to monitor γ-secretase-mediated cleavage of either APP-C99 or Notch, ... ...

    Abstract We have developed a pair of cell-based reporter gene assays to quantitatively measure γ-secretase cleavage of distinct substrates. This manuscript describes procedures that may be used to monitor γ-secretase-mediated cleavage of either APP-C99 or Notch, using a Gal4 promoter-driven firefly luciferase reporter system. These assays were established by stably co-transfecting HEK293 cells with the Gal4-driven luciferase reporter gene and either the Gal4/VP16-tagged C-terminal fragment of APP (APP-C99; CG cells), or the Gal4/VP16-tagged Notch-ΔE (NΔE; NG cells). Using these reporter assays in parallel, we have demonstrated that an ErbB2 inhibitor, CL-387,785, can preferentially suppress γ-secretase cleavage of APP-C99 in CG cells, but not NΔE in NG cells. The differential responses exhibited by the CG and NG cells, when treated with CL-387,785, represent a preferred characteristic for γ-secretase modulators, and these responses are in stark contrast to the pan-inhibition of γ-secretase induced by DAPT. Our studies provide direct evidence that γ-secretase activities toward different substrates can be differentiated in a cellular context. These new assays may therefore be useful tools in drug discovery for improved AD therapies.
    Keywords amyloid ; drugs ; enzyme activity ; luciferase ; quantitative analysis ; reporter genes
    Language English
    Dates of publication 2018-0125
    Size p. e56795.
    Publishing place Journal of Visualized Experiments
    Document type Article
    ZDB-ID 2259946-0
    ISSN 1940-087X
    ISSN 1940-087X
    DOI 10.3791/56795
    Database NAL-Catalogue (AGRICOLA)

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