Wang C.-F.,Institute of Cellular and Organismic Biology |
Hsing H.-W.,Institute of Cellular and Organismic Biology |
Zhuang Z.-H.,Institute of Cellular and Organismic Biology |
Wen M.-H.,Institute of Cellular and Organismic Biology |
And 5 more authors.
Cell Reports | Year: 2017
Cortical neurons must be specified and make the correct connections during development. Here, we examine a mechanism initiating neuronal circuit formation in the barrel cortex, a circuit comprising thalamocortical axons (TCAs) and layer 4 (L4) neurons. When Lhx2 is selectively deleted in postmitotic cortical neurons using conditional knockout (cKO) mice, L4 neurons in the barrel cortex are initially specified but fail to form cellular barrels or develop polarized dendrites. In Lhx2 cKO mice, TCAs from the thalamic ventral posterior nucleus reach the barrel cortex but fail to further arborize to form barrels. Several activity-regulated genes and genes involved in regulating barrel formation are downregulated in the Lhx2 cKO somatosensory cortex. Among them, Btbd3, an activity-regulated gene controlling dendritic development, is a direct downstream target of Lhx2. We find that Lhx2 confers neuronal competency for activity-dependent dendritic development in L4 neurons by inducing the expression of Btbd3. © 2017 The Author(s)
Huang H.-P.,National Taiwan University Hospital |
Chen P.-H.,Institute of Cellular and Organismic Biology |
Chen P.-H.,A-Life Medical |
Hwu W.-L.,National Taiwan University Hospital |
And 13 more authors.
Human Molecular Genetics | Year: 2011
Pompe disease is caused by autosomal recessive mutations in the acid alpha-glucosidase (GAA) gene, which encodes GAA. Although enzyme replacement therapy has recently improved patient survival greatly, the results in skeletal muscles and for advanced disease are still not satisfactory. Here, we report the derivation of Pompe disease-induced pluripotent stem cells (PomD-iPSCs) from two patients with different GAA mutations and their potential for pathogenesis modeling, drug testing and disease marker identification. PomD-iPSCs maintained pluripotent features and had low GAA activity and high glycogen content. Cardiomyocyte-like cells (CMLCs) differentiated from PomD-iPSCs recapitulated the hallmark Pompe disease pathophysiological phenotypes, including high levels of glycogen and multiple ultrastructural aberrances. Drug rescue assessment showed that exposure of PomD-iPSC-derived CMLCs to recombinant human GAA reversed the major pathologic phenotypes. Furthermore, l-carnitine treatment reduced defective cellular respiration in the diseased cells. By comparative transcriptome analysis, we identified glycogen metabolism, lysosome and mitochondria-related marker genes whose expression robustly correlated with the therapeutic effect of drug treatment in PomD-iPSC-derived CMLCs. Collectively, these results demonstrate that PomD-iPSCs are a promising in vitro disease model for the development of novel therapeutic strategies for Pompe disease. © The Author 2011. Published by Oxford University Press. All rights reserved.
Kapoor A.,Institute of Cellular and Organismic Biology |
Kapoor A.,National Chung Hsing University |
Wang B.-J.,Institute of Cellular and Organismic Biology |
Wang B.-J.,National Taiwan University |
And 5 more authors.
ACS Chemical Neuroscience | Year: 2013
Retinoic acid (RA)-elicited signaling has been shown to play critical roles in development, organogenesis, and the immune response. RA regulates expression of Alzheimer's disease (AD)-related genes and attenuates amyloid pathology in a transgenic mouse model. In this study, we investigated whether RA can suppress the production of amyloid-β (Aβ) through direct inhibition of γ-secretase activity. We report that RA treatment of cells results in significant inhibition of γ-secretase-mediated processing of the amyloid precursor protein C-terminal fragment APP-C99, compared with DMSO-treated controls. RA-elicited signaling was found to significantly increase accumulation of APP-C99 and decrease production of secreted Aβ40. In addition, RA-induced inhibition of γ-secretase activity was found to be mediated through significant activation of extracellular signal-regulated kinases (ERK1/2). Treatment of cells with the specific ERK inhibitor PD98059 completely abolished RA-mediated inhibition of γ-secretase. Consistent with these findings, RA was observed to inhibit secretase-mediated proteolysis of full-length APP. Finally, we have established that RA inhibits γ-secretase through nuclear retinoic acid receptor-α (RARα) and retinoid X receptor-α (RXRα). Our findings provide a new mechanistic explanation for the neuroprotective role of RA in AD pathology and add to the previous data showing the importance of RA signaling as a target for AD therapy. © 2013 American Chemical Society.
PubMed | Chang Gung University, Institute of Biomedical science, National Taiwan University Hospital, Academia Sinica, Taiwan and 2 more.
Type: Journal Article | Journal: Human molecular genetics | Year: 2015
Huntingtons disease (HD) is an autosomal-dominant degenerative disease caused by a cytosine-adenine-guanine trinucleotide expansion in the Huntingtin (htt) gene. The most vulnerable brain areas to mutant HTT-evoked toxicity are the striatum and cortex. In spite of the extensive efforts that have been devoted to the characterization of HD pathogenesis, no disease-modifying therapy for HD is currently available. The A2A adenosine receptor (A2AR) is widely distributed in the brain, with the highest level observed in the striatum. We previously reported that stimulation of the A2AR triggers an anti-apoptotic effect in a rat neuron-like cell line (PC12). Using a transgenic mouse model (R6/2) of HD, we demonstrated that A2AR-selective agonists effectively ameliorate several major symptoms of HD. In the present study, we show that human iPSCs can be successfully induced to differentiate into DARPP32-positive, GABAergic neurons which express the A2AR in a similar manner to striatal medium spiny neurons. When compared with those derived from control subjects (CON-iPSCs), these HD-iPSC-derived neurons exhibited a higher DNA damage response, based on the observed expression of H2AX and elevated oxidative stress. This is a critical observation, because oxidative damage and abnormal DNA damage/repair have been reported in HD patients. Most importantly, stimulation of the A2AR using selective agonists reduced DNA damage and oxidative stress-induced apoptosis in HD-iPSC-derived neurons through a cAMP/PKA-dependent pathway. These findings support our hypothesis that human neurons derived from diseased iPSCs might serve as an important platform to investigate the beneficial effects and underlying mechanisms of A2AR drugs.
Chi J.R.,University of Taipei |
Chi J.R.,Institute of Cellular and Organismic Biology |
Chi J.R.,Food Industry Research and Development Institute |
Huang C.-W.,National Taiwan Ocean University |
And 2 more authors.
Journal of Aquaculture Research and Development | Year: 2014
Hybrid tilapia is a major aquaculture food fish species in developing countries. The development of molecular markers to characterize and trace tilapia species is necessary to improve tilapia quality and enhance the competitive advantage of the aquaculture industry. Microsatellite markers have been suggested to assist breeding, species identification, and traceability system for tilapia. We used six microsatellites markers located within growth-related genes to discriminate between several tilapia species. We found that a combination of two microsatellites markers located within the proximal promoter of the prolactin I (PRL I) gene, PRL I-MS01 and PRL I-MS02, were able to discriminate between five Oreochromis tilapia species (O. mossambicus, O. aureus, O. niloticus, O. hornorum and O. spilurus) and two O. niloticus strains that exhibit the distinctive growth traits. Furthermore, we found that PRL I-MS01 microsatellite marker was able to trace parental origin of hybrid tilapia. Thus, this marker is a potentially beneficial tool for a tilapia traceability system. We conclude that the GT tandem repeats in PRL I-MS01 and CA tandem repeats in PRL I-MS02 are useful genetic markers to characterize diverse tilapia species, assist in the genetic tracing and conventional breeding of superior strains and strengthen the management of the tilapia aquaculture industry. There was strong relationship between the cold and both temperature at death and cumulative degree hours represented by negative correlation coefficient for all tested fish. There was no correlation between cold tolerance and fish size for all tested fish. The cooling degree hours were significantly different between the selected and non-selected O. niloticus (P<0.005). The selected O. aureus exhibited greater cold tolerance than the non-selected and death began at 14.1°C, while non-selected occurred at 15.2°C. © 2014 Chi JR, et al.
Cheng C.-L.,National Taiwan Ocean University |
Huang S.-J.,National Taiwan University |
Wu C.-L.,Institute of Cellular and Organismic Biology |
Gong H.-Y.,National Taiwan Ocean University |
And 3 more authors.
Journal of Biomedical Science | Year: 2015
Background: Highly desaturated n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are synthesized by desaturases and elongase. They exert hepatoprotective effects to prevent alcoholic fatty liver syndrome or cholestatic liver injury. However, it is unclear how n-3 PUFAs improve immune function in liver. Vibrio vulnificus, a gram-negative bacterial pathogen, causes high mortality of aquaculture fishes upon infection. Humans can become infected with V. vulnificus through open wounds or by eating raw seafood, and such infections may result in systemic septicemia. Moreover, patients with liver diseases are vulnerable to infection, and are more likely than healthy persons to present with liver inflammation following infection. This study quantified n-3 PUFAs and their anti-bacterial effects in Fadsd6 and Elvol5a transgenic zebrafish. Results: Two transgenic zebrafish strains with strong liver specific expression of Fadsd6 and Elvol5a (driven by the zebrafish Fabp10 promoter) were established using the Tol2 system. Synthesis of n-3 PUFAs in these strains were increased by 2.5-fold as compared to wild type (Wt) fish. The survival rate in 24 h following challenge with V. vulnificus was 20 % in Wt, but 70 % in the transgenic strains. In addition, the bacteria counts in transgenic fish strains were significantly decreased. The expression levels of pro-inflammatory genes, such as TNF-aα, IL-1β, and NF-κB, were suppressed between 9 and 12 h after challenge. This study confirms the anti-bacterial function of n-3 PUFAs in a transgenic zebrafish model. Conclusions: Fadsd6 and Elvol5a transgenic zebrafish are more resistant to V. vulnificus infection, and enhance survival by diminishing the attendant inflammatory response. © 2015 Cheng et al.
PubMed | Institute of Cellular and Organismic Biology, Duke University, Academia Sinica, Taiwan and Taipei Medical University
Type: Journal Article | Journal: Proceedings of the National Academy of Sciences of the United States of America | Year: 2016
Topoisomerase 3 (Top3) can associate with the mediator protein Tudor domain-containing protein 3 (TDRD3) to participate in two gene expression processes of transcription and translation. Despite the apparent importance of TDRD3 in binding with Top3 and directing it to cellular compartments critical for gene expression, the biochemical mechanism of how TDRD3 can affect the functions of Top3 is not known. We report here sensitive biochemical assays for the activities of Top3 on DNA and RNA substrates in resolving topological entanglements and for the analysis of TDRD3 functions. TDRD3 stimulates the relaxation activity of Top3 on hypernegatively supercoiled DNA and changes the reaction from a distributive to a processive mode. Both supercoil retention assays and binding measurement by fluorescence anisotropy reveal a heretofore unknown preference for binding single-stranded nucleic acids over duplex. Whereas TDRD3 has a structure-specific binding preference, it does not discriminate between DNA and RNA. This unique property for binding with nucleic acids can have an important function in serving as a hub to form nucleoprotein complexes on DNA and RNA. To gain insight into the roles of Top3 on RNA metabolism, we designed an assay by annealing two single-stranded RNA circles with complementary sequences. Top3 is capable of converting two such single-stranded RNA circles into a double-stranded RNA circle, and this strand-annealing activity is enhanced by TDRD3. These results demonstrate that TDRD3 can enhance the biochemical activities of Top3 on both DNA and RNA substrates, in addition to its function of targeting Top3 to critical sites in subcellular compartments.
Yu C.-Y.,Institute of Cellular and Organismic Biology |
Kuo H.-C.,Institute of Cellular and Organismic Biology
Stem Cells | Year: 2016
The trans-spliced noncoding RNA RMST (tsRMST) is an emerging regulatory lncRNA in the human pluripotency circuit. Previously, we found that tsRMST represses lineage-specific transcription factors through the PRC2 complex and NANOG in human pluripotent stem cells (hESCs). Here, we demonstrate that tsRMST also modulates noncanonical Wnt signaling to suppress the epithelial-to-mesenchymal transition (EMT) and in vitro differentiation of embryonic stem cells (ESCs). Our results demonstrate that disruption of tsRMST expression in hESCs results in the upregulation of WNT5A, EMT, and lineage-specific genes/markers. Furthermore, we found that the PKC inhibitors Go6983 and Go6976 inhibited the effects of WNT5A, indicating that WNT5A promotes the EMT and in vitro differentiation although conventional and novel PKC activation in hESCs. Finally, we showed that either antiserum neutralization of WNT5A or Go6983 treatment in tsRMST knockdown cells decreased the expression of mesenchymal and lineage-specific markers. Together, these findings indicate that tsRMST regulates Wnt and EMT signaling pathways in hESCs by repressing WNT5A, which is a potential EMT inducer for promoting in vitro differentiation of hESCs through PKC activation. Our findings provide further insights into the role of trans-spliced RNA and WNT5A in hESC differentiation, in which EMT plays an important role. Stem Cells 2016. © 2016 AlphaMed Press.
Abe G.,Institute of Cellular and Organismic Biology |
Lee S.-H.,Institute of Cellular and Organismic Biology |
Chang M.,Institute of Cellular and Organismic Biology |
Liu S.-C.,Institute of Cellular and Organismic Biology |
And 2 more authors.
Nature Communications | Year: 2014
Twin-tail goldfish possess a bifurcated caudal axial skeleton. The scarcity of this trait in nature suggests that a rare mutation, which drastically altered the mechanisms underlying axial skeleton formation, may have occurred during goldfish domestication. However, little is known about the molecular development of twin-tail goldfish. Here we show that the bifurcated caudal skeleton arises from a mutation in the chordin gene, which affects embryonic dorsal-ventral (DV) patterning. We demonstrate that formation of the bifurcated caudal axial skeleton requires a stop-codon mutation in one of two recently duplicated chordin genes; this mutation may have occurred within approximately 600 years of domestication. We also report that the ventral tissues of the twin-tail strain are enlarged, and form the embryonic bifurcated fin fold. However, unlike previously described chordin-deficient embryos, this is not accompanied by a reduction in anterior-dorsal neural tissues. These results provide insight into large-scale evolution arising from artificial selection. © 2014 Macmillan Publishers Limited. All rights reserved.
PubMed | Institute of Cellular and Organismic Biology
Type: | Journal: American journal of physiology. Regulatory, integrative and comparative physiology | Year: 2017
This an editorial focus.