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Martí-Clúa J. 5-Bromo-2'-deoxyuridine labeling: historical perspectives, factors influencing the detection, toxicity, and its implications in the neurogenesis. Neural Regen Res 2024; 19:302-308. [PMID: 37488882 PMCID: PMC10503596 DOI: 10.4103/1673-5374.379038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/25/2023] [Accepted: 05/25/2023] [Indexed: 07/26/2023] Open
Abstract
The halopyrimidine 5-bromo-2'-deoxyuridine (BrdU) is an exogenous marker of DNA synthesis. Since the introduction of monoclonal antibodies against BrdU, an increasing number of methodologies have been used for the immunodetection of this synthesized bromine-tagged base analogue into replicating DNA. BrdU labeling is widely used for identifying neuron precursors and following their fate during the embryonic, perinatal, and adult neurogenesis in a variety of vertebrate species including birds, reptiles, and mammals. Due to BrdU toxicity, its incorporation into replicating DNA presents adverse consequences on the generation, survival, and settled patterns of cells. This may lead to false results and misinterpretation in the identification of proliferative neuroblasts. In this review, I will indicate the detrimental effects of this nucleoside during the development of the central nervous system, as well as the reliability of BrdU labeling to detect proliferating neuroblasts. Moreover, it will show factors influencing BrdU immunodetection and the contribution of this nucleoside to the study of prenatal, perinatal, and adult neurogenesis. Human adult neurogenesis will also be discussed. It is my hope that this review serves as a reference for those researchers who focused on detecting cells that are in the synthetic phase of the cell cycle.
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Affiliation(s)
- Joaquín Martí-Clúa
- Unidad de Citología e Histología. Departament de Biologia Cel·lular, de Fisiologia i d’Immunologia. Facultad de Biociencias. Institut de Neurociències. Universidad Autónoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Martí-Clúa J. Methods for Inferring Cell Cycle Parameters Using Thymidine Analogues. Biology (Basel) 2023; 12:885. [PMID: 37372169 DOI: 10.3390/biology12060885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/12/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023]
Abstract
Tritiated thymidine autoradiography, 5-bromo-2'-deoxyuridine (BrdU) 5-chloro-2'-deoxyuridine (CldU), 5-iodo-2'-deoxyuridine (IdU), and 5-ethynyl-2'-deoxyiridine (EdU) labeling have been used for identifying the fraction of cells undergoing the S-phase of the cell cycle and to follow the fate of these cells during the embryonic, perinatal, and adult life in several species of vertebrate. In this current review, I will discuss the dosage and times of exposition to the aforementioned thymidine analogues to label most of the cells undergoing the S-phase of the cell cycle. I will also show how to infer, in an asynchronous cell population, the duration of the G1, S, and G2 phases, as well as the growth fraction and the span of the whole cell cycle on the base of some labeling schemes involving a single administration, continuous nucleotide analogue delivery, and double labeling with two thymidine analogues. In this context, the choice of the optimal dose of BrdU, CldU, IdU, and EdU to label S-phase cells is a pivotal aspect to produce neither cytotoxic effects nor alter cell cycle progression. I hope that the information presented in this review can be of use as a reference for researchers involved in the genesis of tissues and organs.
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Affiliation(s)
- Joaquín Martí-Clúa
- Unidad de Citología e Histología, Departament de Biologia Cel·lular, de Fisiologia i d'Immunologia, Facultad de Biociencias, Institut de Neurociències, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
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3
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Abstract
5-Bromo-2′-deoxyuridine (BrdU) is a halogenated pyrimidine that can be incorporated into newly synthesized DNA during the S phase of the cell cycle. BrdU is widely used in fate-mapping studies of embryonic and adult neurogenesis to identify newborn neurons, however side effects on neural stem cells and their progeny have been reported. In vivo astrocyte-to-neuron (AtN) conversion is a new approach for generating newborn neurons by directly converting endogenous astrocytes into neurons. The BrdU-labeling strategy has been used to trace astrocyte-converted neurons, but whether BrdU has any effect on the AtN conversion is unknown. Here, while conducting a NeuroD1-mediated AtN conversion study using BrdU to label dividing reactive astrocytes following ischemic injury, we accidentally discovered that BrdU inhibited AtN conversion. We initially found a gradual reduction in BrdU-labeled astrocytes during NeuroD1-mediated AtN conversion in the mouse cortex. Although most NeuroD1-infected astrocytes were converted into neurons, the number of BrdU-labeled neurons was surprisingly low. To exclude the possibility that this BrdU inhibition was caused by the ischemic injury, we conducted an in vitro AtN conversion study by overexpressing NeuroD1 in cultured cortical astrocytes in the presence or absence of BrdU. Surprisingly, we also found a significantly lower conversion rate and a smaller number of converted neurons in the BrdU-treated group compared with the untreated group. These results revealed an unexpected inhibitory effect of BrdU on AtN conversion, suggesting more caution is needed when using BrdU in AtN conversion studies and in data interpretation.
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Affiliation(s)
- Tao Wang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Jian-Cheng Liao
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Xu Wang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Qing-Song Wang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Kai-Ying Wan
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Yi-Yi Yang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Qing He
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Jia-Xuan Zhang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Gong Chen
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
| | - Wen Li
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, Guangdong Province, China
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Somasundaram S, Satheesh V, Singh M, Anandhan S. A simple flow cytometry-based assay to study global methylation levels in onion, a non-model species. Physiol Mol Biol Plants 2021; 27:1859-1865. [PMID: 34539120 PMCID: PMC8405793 DOI: 10.1007/s12298-021-01047-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED DNA methylation is an important epigenetic mark and global methylation dynamics regulate plant developmental processes. Even though genome sequencing technologies have made DNA methylation studies easier, it is difficult in non-model species where genome information is not available. Therefore in this study, we developed a simple assay for analysing global methylation levels in plants by washless immunolabelling of unfixed nuclei using flow cytometry. Onion leaf tissue was used as a model system, and mean fluorescence intensity due to anti-5- methyl cytosine (5-mC) antibodies were used as a measure of global methylation levels. Among three nuclear isolation buffers evaluated, the highest nuclear yield with the low background was obtained with LB01. To maintain a balance between high DNA fluorescence value and low coefficient of variation of DNA peaks, 45 min of hydrolysis with 0.2 N hydrochloric acid was used for chromatin denaturation resulting in six-fold increase in 5-mC fluorescence compared to control. This method was used successfully to detect 5-Azacytidine induced DNA hypomethylation in onion leaf tissues. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-021-01047-6.
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Affiliation(s)
- Saravanakumar Somasundaram
- ICAR-Directorate of Onion and Garlic Research, Pune, 410505 India
- Present Address: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
| | - Viswanathan Satheesh
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Major Singh
- ICAR-Directorate of Onion and Garlic Research, Pune, 410505 India
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Martí-Clúa J. Incorporation of 5-Bromo-2'-deoxyuridine into DNA and Proliferative Behavior of Cerebellar Neuroblasts: All That Glitters Is Not Gold. Cells 2021; 10:cells10061453. [PMID: 34200598 PMCID: PMC8229392 DOI: 10.3390/cells10061453] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/06/2021] [Accepted: 06/07/2021] [Indexed: 12/27/2022] Open
Abstract
The synthetic halogenated pyrimidine analog, 5-bromo-2'-deoxyuridine (BrdU), is a marker of DNA synthesis. This exogenous nucleoside has generated important insights into the cellular mechanisms of the central nervous system development in a variety of animals including insects, birds, and mammals. Despite this, the detrimental effects of the incorporation of BrdU into DNA on proliferation and viability of different types of cells has been frequently neglected. This review will summarize and present the effects of a pulse of BrdU, at doses ranging from 25 to 300 µg/g, or repeated injections. The latter, following the method of the progressively delayed labeling comprehensive procedure. The prenatal and perinatal development of the cerebellum are studied. These current data have implications for the interpretation of the results obtained by this marker as an index of the generation, migration, and settled pattern of neurons in the developing central nervous system. Caution should be exercised when interpreting the results obtained using BrdU. This is particularly important when high or repeated doses of this agent are injected. I hope that this review sheds light on the effects of this toxic maker. It may be used as a reference for toxicologists and neurobiologists given the broad use of 5-bromo-2'-deoxyuridine to label dividing cells.
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Affiliation(s)
- Joaquín Martí-Clúa
- Unidad de Citología e Histología, Departament de Biologia Cellular, de Fisiologia i d'Immunologia, Facultad de Biociencias, Institut de Neurociències, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
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Rodríguez-Vázquez L, Martí J. Administration of 5-bromo-2'-deoxyuridine interferes with neuroblast proliferation and promotes apoptotic cell death in the rat cerebellar neuroepithelium. J Comp Neurol 2020; 529:1081-1096. [PMID: 32785933 DOI: 10.1002/cne.25005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/09/2020] [Accepted: 08/05/2020] [Indexed: 12/13/2022]
Abstract
The current study was conducted to assess whether a single administration of 5-bromo-2'-deoxyuridine (BrdU) interferes with cell proliferation and leads to the activation of apoptotic cellular events in the prenatal cerebellum. BrdU effects across a wide range of doses (25-300 μg/g b.w.) were analyzed using immunohistochemical and ultrastructural procedures. The pregnant rats were injected with BrdU at embryonic day 13, and their fetuses were sacrificed from 5 to 35 hr after exposure. The quantification of several parameters such as the density of mitotic figures, and BrdU and proliferating cell nuclear antigen (PCNA)-reactive cells showed that, in comparison with the saline injected rats, the administration of BrdU impairs the proliferative behavior of neuroepithelial cells. The above-mentioned parameters were significantly reduced in rats injected with 100 μg/g b.w. of BrdU. The reduction was more evident using 200 μg/g b.w. The most severe effects were found with 300 μg/g b.w. of BrdU. The present findings also revealed that high doses of BrdU lead to the activation of apoptotic cellular events as evidenced by both terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and immunohistochemistry for active caspase-3. In comparison with saline rats, many apoptotic cells were found in rats injected with 100 μg/g b.w. of BrdU. The number of dying cells increased with 200 μg/g b.w. The most important number of apoptotic cells were observed in animals injected with 300 μg/g b.w. of BrdU. Ultrastructural studies confirmed the presence of neuroblasts at different stages of apoptosis.
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Affiliation(s)
- Lucía Rodríguez-Vázquez
- Unidad de Citología e Histología, Departament de Biologia Cellular, de Fisiologia i d'Immunologia, Facultad de Biociencias, Institut de Neurociències, Universidad Autónoma de Barcelona, Barcelona, Spain
| | - Joaquín Martí
- Unidad de Citología e Histología, Departament de Biologia Cellular, de Fisiologia i d'Immunologia, Facultad de Biociencias, Institut de Neurociències, Universidad Autónoma de Barcelona, Barcelona, Spain
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7
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Rajashekaraiah R, Kumar PR, Prakash N, Rao GS, Devi VR, Metta M, Narayanaswamy HD, Swamy MN, Satyanarayan K, Rao S, Rathnamma D, Sahadev A, Sunilchandra U, Santhosh CR, Dhanalakshmi H, Kumar SN, Ruban SW, Kalmath GP, Gomes AR, Kumar KRA, Govindappa PK. Anticancer efficacy of 6-thioguanine loaded chitosan nanoparticles with or without curcumin. Int J Biol Macromol 2020; 148:704-714. [PMID: 31954127 DOI: 10.1016/j.ijbiomac.2020.01.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/12/2020] [Accepted: 01/12/2020] [Indexed: 12/14/2022]
Abstract
6-Thioguanine encapsulated chitosan nanoparticles (6-TG-CNPs) has formulated by the ionic-gelation method. Morphologically, the 6-TG-CNPs were spherical and showed mean size, PDI, zeta potential, and entrapment efficiency of 261.63 ± 6.01 nm, 0.34 ± 0.10, +15.97 ± 0.46 mV and 44.27%, respectively. The IR spectra confirmed the 6-TG complex with chitosan. The in vitro drug release profile of 6-TG-CNPs revealed an increase in sustained-release (91.40 ± 1.08% at 48 h) at pH 4.8 compared to less sustained-release (73.96 ± 1.12% at 48 h) at pH 7.4. The MTT assay was conducted on MCF-7 and PA-1 cell lines at 48 h incubation to determine % cell viability. The IC50 values of 6-TG, 6-TG-CNPs, and curcumin for MCF-7 were 23.09, 17.82, and 15.73 μM, respectively. Likewise, IC50 values of 6-TG, 6-TG-CNPs, and curcumin for PA-1 were 5.81, 3.92, and 12.89 μM, respectively. A combination of 6-TG-CNPs (IC25) with curcumin (IC25) on PA-1 and MCF-7 showed % cell viability of 43.67 ± 0.02 and 49.77 ± 0.05, respectively. The in vitro cytotoxicity potential in terms of % cell viability, early apoptosis, G2/M phase arrest, and DNA demethylating activity of 6-TG-CNPs alone and combination with curcumin proved to be more effective than that of 6-TG on PA-1 cells.
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Affiliation(s)
- Rashmi Rajashekaraiah
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India.
| | - P Ravi Kumar
- NTR College of Veterinary Science, Sri Venkateswara Veterinary University, Gannavaram 521102, Andhra Pradesh, India
| | - N Prakash
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - G Srinivasa Rao
- NTR College of Veterinary Science, Sri Venkateswara Veterinary University, Gannavaram 521102, Andhra Pradesh, India
| | - V Rama Devi
- NTR College of Veterinary Science, Sri Venkateswara Veterinary University, Gannavaram 521102, Andhra Pradesh, India
| | - M Metta
- NTR College of Veterinary Science, Sri Venkateswara Veterinary University, Gannavaram 521102, Andhra Pradesh, India
| | - H D Narayanaswamy
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - M Narayana Swamy
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - K Satyanarayan
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - Suguna Rao
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - D Rathnamma
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - A Sahadev
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - U Sunilchandra
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - C R Santhosh
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - H Dhanalakshmi
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - S Naveen Kumar
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - S Wilfred Ruban
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - G P Kalmath
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - A R Gomes
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - K R Anjan Kumar
- Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar 585401, Karnataka, India
| | - Prem Kumar Govindappa
- Department of Orthopaedics and Rehabilitation, Centre for Orthopaedic Research and Translational Science (CORTS), College of Medicine, The Pennsylvania State University, Hershey, PA 17033, USA
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Desai M, Han G, Li T, Ross MG. Programmed Epigenetic DNA Methylation-Mediated Reduced Neuroprogenitor Cell Proliferation and Differentiation in Small-for-Gestational-Age Offspring. Neuroscience 2019; 412:60-71. [PMID: 31153962 DOI: 10.1016/j.neuroscience.2019.05.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 05/01/2019] [Accepted: 05/22/2019] [Indexed: 12/28/2022]
Abstract
Small-for-gestational age (SGA) human newborns have an increased risk of hyperphagia and obesity, as well as a spectrum of neurologic and neurobehavioral abnormalities. We have shown that the SGA hypothalamic (appetite regulatory site) neuroprogenitor cells (NPCs) exhibit reduced proliferation and neuronal differentiation. DNA methylation (DNA methyltransferase; DNMT1) regulates neurogenesis by maintaining NPC proliferation and suppressing premature differentiation. Once differentiation ensues, DNMT1 preferentially promotes neuronal and inhibits astroglial fate. We hypothesized that the programmed dysfunction of NPC proliferation and differentiation in SGA offspring is epigenetically mediated via DNMT1. Pregnant rats received either ad libitum food (Control) or were 50% food-restricted to create SGA offspring. Primary hypothalamic NPCs from 1 day old SGA and Controls newborns were cultured and transfected with nonspecific or DNMT1-specific siRNA. NPC proliferation and protein expression of specific markers of NPC (nestin), neuroproliferative transcription factor (Hes1), neurons (Tuj1) and astrocytes (GFAP) were determined. Under basal conditions, SGA NPCs exhibited decreased DNMT1 and reduced proliferation and differentiation, as compared to Controls. In both SGA and Controls, DNMT1 siRNA in complete media inhibited NPC proliferation, consistent with reduced expression of nestin and Hes1. In differentiation media, DNMT1 siRNA decreased expression of Tuj1 but increased GFAP. In vivo data replicated these findings. In SGA offspring, impaired neurogenesis is epigenetically mediated, in part, via reduction in DNMT1 expression and suppression of Hes1 resulting in NPC differentiation. It is likely that the maturation of regions beyond the hypothalamus (e.g., cerebral cortex, hippocampus) may be impacted, contributing to poor cognitive and neurobehavioral competency in SGA offspring.
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Affiliation(s)
- Mina Desai
- Perinatal Research Laboratory, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Department of Obstetrics and Gynecology, Torrance, CA, USA; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
| | - Guang Han
- Perinatal Research Laboratory, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Department of Obstetrics and Gynecology, Torrance, CA, USA
| | - Tie Li
- Perinatal Research Laboratory, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Department of Obstetrics and Gynecology, Torrance, CA, USA
| | - Michael G Ross
- Perinatal Research Laboratory, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Department of Obstetrics and Gynecology, Torrance, CA, USA; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Department of Obstetrics and Gynecology, Charles R. Drew University, Los Angeles, CA, USA
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Hendrickson ML, Zutshi I, Wield A, Kalil RE. Nestin expression and in vivo proliferative potential of tanycytes and ependymal cells lining the walls of the third ventricle in the adult rat brain. Eur J Neurosci 2018; 47:284-293. [PMID: 29359828 DOI: 10.1111/ejn.13834] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 12/10/2017] [Accepted: 12/19/2017] [Indexed: 12/13/2022]
Abstract
There is a disagreement in the literature concerning the degree of proliferation of cells in the walls of the third ventricle (3rdV) under normal conditions in the adult mammalian brain. To address this issue, we mapped the cells expressing the neural stem/progenitor cell marker nestin along the entire rostrocaudal extent of the 3rdV in adult male rats and observed a complex distribution. Abundant nestin was present in tanycyte cell bodies and processes and also was observed in patches of ependymal cells as well as in isolated ependymal cells throughout the walls of the 3rdV. However, we observed very limited ependymal cell or tanycyte proliferation in normal adult rats as determined by bromodeoxyuridine (BrdU) incorporation or the expression of Ki-67. Moreover, fewer than 13% of the cells that were BrdU-positive (BrdU+) or Ki-67-positive (Ki-67+) expressed nestin. These observations stand in contrast to those made in the subventricular zone of the lateral ventricle (SVZ) and subgranular zone of the hippocampal formation (SGZ), where cell proliferation measured by BrdU incorporation or Ki-67 expression is observed frequently in cells that also express nestin. Thus, while ependymal cell or tanycyte cell proliferation can be promoted by the addition of mitogens, dietary modifications or other in vivo manipulations, the proliferation of ependymal cells and tanycytes in the walls of the 3rdV is very limited in the normal adult male rat brain.
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Affiliation(s)
- Michael L Hendrickson
- School of Medicine and Public Health, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, USA
| | - Ipshita Zutshi
- Graduate Program in Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Alyssa Wield
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Ronald E Kalil
- School of Medicine and Public Health, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, USA
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Çelik-Uzuner S, Li Y, Peters L, O’Neill C. Measurement of global DNA methylation levels by flow cytometry in mouse fibroblasts. In Vitro Cell Dev Biol Anim 2016; 53:1-6. [DOI: 10.1007/s11626-016-0075-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 07/22/2016] [Indexed: 01/09/2023]
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11
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Liu Z, Zhong G, Chai PC, Luo L, Liu S, Yang Y, Baeg GH, Cai Y. Coordinated niche-associated signals promote germline homeostasis in the Drosophila ovary. J Cell Biol 2016; 211:469-84. [PMID: 26504174 PMCID: PMC4621830 DOI: 10.1083/jcb.201503033] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Stem cell niches provide localized signaling molecules to promote stem cell fate and to suppress differentiation. The Drosophila melanogaster ovarian niche is established by several types of stromal cells, including terminal filament cells, cap cells, and escort cells (ECs). Here, we show that, in addition to its well-known function as a niche factor expressed in cap cells, the Drosophila transforming growth factor β molecule Decapentaplegic (Dpp) is expressed at a low level in ECs to maintain a pool of partially differentiated germline cells that may dedifferentiate to replenish germline stem cells upon their depletion under normal and stress conditions. Our study further reveals that the Dpp level in ECs is modulated by Hedgehog (Hh) ligands, which originate from both cap cells and ECs. We also demonstrate that Hh signaling exerts its function by suppressing Janus kinase/signal transducer activity, which promotes Dpp expression in ECs. Collectively, our data suggest a complex interplay of niche-associated signals that controls the development of a stem cell lineage.
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Affiliation(s)
- Zhong Liu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Guohua Zhong
- Laboratory of Insect Toxicology, South China Agriculture University, Guangzhou, PR China 510642
| | - Phing Chian Chai
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Lichao Luo
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Sen Liu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Ying Yang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Gyeong-Hun Baeg
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Yu Cai
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543
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12
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Kleiderman S, Sá JV, Teixeira AP, Brito C, Gutbier S, Evje LG, Hadera MG, Glaab E, Henry M, Sachinidis A, Alves PM, Sonnewald U, Leist M. Functional and phenotypic differences of pure populations of stem cell-derived astrocytes and neuronal precursor cells. Glia 2015; 64:695-715. [DOI: 10.1002/glia.22954] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Susanne Kleiderman
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - João V. Sá
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ana P. Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Catarina Brito
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Simon Gutbier
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - Lars G. Evje
- Department of Earth Science, University of Bergen; Allégaten 41 5007 Bergen Norway
| | - Mussie G. Hadera
- Department of Pharmacy; College of Health Sciences; Mekelle University, Tigray Ethiopia
| | - Enrico Glaab
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg; Belvaux L-4366 Luxembourg
| | - Margit Henry
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Agapios Sachinidis
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Paula M. Alves
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ursula Sonnewald
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; Copenhagen Denmark
- Department of Neuroscience; Norwegian University of Science and Technology; Faculty of Medicine; Trondheim Norway
| | - Marcel Leist
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
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Liyanage VRB, Zachariah RM, Davie JR, Rastegar M. Ethanol deregulates Mecp2/MeCP2 in differentiating neural stem cells via interplay between 5-methylcytosine and 5-hydroxymethylcytosine at the Mecp2 regulatory elements. Exp Neurol 2015; 265:102-17. [PMID: 25620416 DOI: 10.1016/j.expneurol.2015.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/23/2014] [Accepted: 01/18/2015] [Indexed: 11/29/2022]
Abstract
Methyl CpG Binding Protein 2 (MeCP2) is an important epigenetic factor in the brain. MeCP2 expression is affected by different environmental insults including alcohol exposure. Accumulating evidence supports the role of aberrant MeCP2 expression in ethanol exposure-induced neurological symptoms. However, the underlying molecular mechanisms of ethanol-induced MeCP2 deregulation remain elusive. To study the effect of ethanol on Mecp2/MeCP2 expression during neurodifferentiation, we established an in vitro model of ethanol exposure, using differentiating embryonic brain-derived neural stem cells (NSC). Previously, we demonstrated the impact of DNA methylation at the Mecp2 regulatory elements (REs) on Mecp2/MeCP2 expression in vitro and in vivo. Here, we studied whether altered DNA methylation at these REs is associated with the Mecp2/MeCP2 misexpression induced by ethanol. Binge-like and continuous ethanol exposure upregulated Mecp2/MeCP2, while ethanol withdrawal downregulated its expression. DNA methylation analysis by methylated DNA immunoprecipitation indicated that increased 5-hydroxymethylcytosine (5hmC) and decreased 5-methylcytosine (5mC) enrichment at specific REs were associated with upregulated Mecp2/MeCP2 following continuous ethanol exposure. The reduced Mecp2/MeCP2 expression upon ethanol withdrawal was associated with reduced 5hmC and increased 5mC enrichment at these REs. Moreover, ethanol altered global DNA methylation (5mC and 5hmC). Under the tested conditions, ethanol had minimal effects on NSC cell fate commitment, but caused changes in neuronal morphology and glial cell size. Taken together, our data represent an epigenetic mechanism for ethanol-mediated misexpression of Mecp2/MeCP2 in differentiating embryonic brain cells. We also show the potential role of DNA methylation and MeCP2 in alcohol-related neurological disorders, specifically Fetal Alcohol Spectrum Disorders.
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Affiliation(s)
- Vichithra Rasangi Batuwita Liyanage
- Regenerative Medicine Program, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada; Department of Biochemistry and Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
| | - Robby Mathew Zachariah
- Regenerative Medicine Program, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada; Department of Biochemistry and Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
| | - James Ronald Davie
- Department of Biochemistry and Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
| | - Mojgan Rastegar
- Regenerative Medicine Program, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada; Department of Biochemistry and Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
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Chen XS, Huang N, Michael N, Xiao L. Advancements in the Underlying Pathogenesis of Schizophrenia: Implications of DNA Methylation in Glial Cells. Front Cell Neurosci 2015; 9:451. [PMID: 26696822 PMCID: PMC4667081 DOI: 10.3389/fncel.2015.00451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 11/02/2015] [Indexed: 02/05/2023] Open
Abstract
Schizophrenia (SZ) is a chronic and severe mental illness for which currently there is no cure. At present, the exact molecular mechanism involved in the underlying pathogenesis of SZ is unknown. The disease is thought to be caused by a combination of genetic, biological, psychological, and environmental factors. Recent studies have shown that epigenetic regulation is involved in SZ pathology. Specifically, DNA methylation, one of the earliest found epigenetic modifications, has been extensively linked to modulation of neuronal function, leading to psychiatric disorders such as SZ. However, increasing evidence indicates that glial cells, especially dysfunctional oligodendrocytes undergo DNA methylation changes that contribute to the pathogenesis of SZ. This review primarily focuses on DNA methylation involved in glial dysfunctions in SZ. Clarifying this mechanism may lead to the development of new therapeutic interventional strategies for the treatment of SZ and other illnesses by correcting abnormal methylation in glial cells.
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Affiliation(s)
- Xing-Shu Chen
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Third Military Medical UniversityChongqing, China
| | - Nanxin Huang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Third Military Medical UniversityChongqing, China
| | - Namaka Michael
- College of Pharmacy and Medicine, Joint Laboratory of Biological Psychiatry Between Shantou University Medical College and the College of Medicine, University of ManitobaWinnipeg, MB, Canada
| | - Lan Xiao
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Third Military Medical UniversityChongqing, China
- *Correspondence: Lan Xiao
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Torroglosa A, Enguix-Riego MV, Fernández RM, Román-Rodriguez FJ, Moya-Jiménez MJ, de Agustín JC, Antiñolo G, Borrego S. Involvement of DNMT3B in the pathogenesis of Hirschsprung disease and its possible role as a regulator of neurogenesis in the human enteric nervous system. Genet Med 2014; 16:703-10. [PMID: 24577265 DOI: 10.1038/gim.2014.17] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/28/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Hirschsprung disease (OMIM 142623) is a neurocristopathy attributed to a failure of cell proliferation or migration and/or failure of the enteric precursors along the gut to differentiate during embryonic development. Although some genes involved in this pathology are well characterized, many aspects remain poorly understood. In this study, we aimed to identify novel genes implicated in the pathogenesis of Hirschsprung disease. METHODS We compared the expression patterns of genes involved in human stem cell pluripotency between enteric precursors from controls and Hirschsprung disease patients. We further evaluated the role of DNMT3B in the context of Hirschsprung disease by inmunocytochemistry, global DNA methylation assays, and mutational screening. RESULTS Seven differentially expressed genes were identified. We focused on DNMT3B, which encodes a DNA methyltransferase that performs de novo DNA methylation during embryonic development. DNMT3B mutational analysis in our Hirschsprung disease series revealed the presence of potentially pathogenic mutations (p.Gly25Arg, p.Arg190Cys, and p.Gly198Trp). CONCLUSION DNMT3B may be regulating enteric nervous system development through DNA methylation in the neural crest cells, suggesting that aberrant methylation patterns could have a relevant role in Hirschsprung disease. Moreover, the synergistic effect of mutations in both DNMT3B and other Hirschsprung disease-related genes may be contributing to a more severe phenotype in our Hirschsprung disease patients.
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Affiliation(s)
- Ana Torroglosa
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
| | - María Valle Enguix-Riego
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
| | - Raquel María Fernández
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
| | - Francisco José Román-Rodriguez
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
| | | | | | - Guillermo Antiñolo
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
| | - Salud Borrego
- 1] Department of Genetics, Reproduction, and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain [2] Centre for Biomedical Network Research on Rare Diseases, Seville, Spain
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Re A, Workman CT, Waldron L, Quattrone A, Brunak S. Lineage-specific interface proteins match up the cell cycle and differentiation in embryo stem cells. Stem Cell Res 2014; 13:316-28. [PMID: 25173649 DOI: 10.1016/j.scr.2014.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 07/25/2014] [Accepted: 07/26/2014] [Indexed: 11/25/2022] Open
Abstract
The shortage of molecular information on cell cycle changes along embryonic stem cell (ESC) differentiation prompts an in silico approach, which may provide a novel way to identify candidate genes or mechanisms acting in coordinating the two programs. We analyzed germ layer specific gene expression changes during the cell cycle and ESC differentiation by combining four human cell cycle transcriptome profiles with thirteen in vitro human ESC differentiation studies. To detect cross-talk mechanisms we then integrated the transcriptome data that displayed differential regulation with protein interaction data. A new class of non-transcriptionally regulated genes was identified, encoding proteins which interact systematically with proteins corresponding to genes regulated during the cell cycle or cell differentiation, and which therefore can be seen as interface proteins coordinating the two programs. Functional analysis gathered insights in fate-specific candidates of interface functionalities. The non-transcriptionally regulated interface proteins were found to be highly regulated by post-translational ubiquitylation modification, which may synchronize the transition between cell proliferation and differentiation in ESCs.
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Affiliation(s)
- Angela Re
- Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, Via delle Regole 101, I38123 Trento, Italy; Center for Biological Sequence Analysis, Technical University of Denmark, Kemitorvet, DK2800 Lyngby, Denmark
| | - Christopher T Workman
- Center for Biological Sequence Analysis, Technical University of Denmark, Kemitorvet, DK2800 Lyngby, Denmark
| | - Levi Waldron
- City University of New York School of Public Health, Hunter College, 2180 3rd Avenue, NY 10035, USA
| | - Alessandro Quattrone
- Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, Via delle Regole 101, I38123 Trento, Italy.
| | - Søren Brunak
- Center for Biological Sequence Analysis, Technical University of Denmark, Kemitorvet, DK2800 Lyngby, Denmark; Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, DK2200 Copenhagen, Denmark.
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Yang CW, Chou WC, Chen KH, Cheng AL, Mao IF, Chao HR, Chuang CY. Visualized gene network reveals the novel target transcripts Sox2 and Pax6 of neuronal development in trans-placental exposure to bisphenol A. PLoS One 2014; 9:e100576. [PMID: 25051057 DOI: 10.1371/journal.pone.0100576] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 05/26/2014] [Indexed: 12/12/2022] Open
Abstract
Background Bisphenol A (BPA) is a ubiquitous endocrine disrupting chemical in our daily life, and its health effect in response to prenatal exposure is still controversial. Early-life BPA exposure may impact brain development and contribute to childhood neurological disorders. The aim of the present study was to investigate molecular target genes of neuronal development in trans-placental exposure to BPA. Methodology A meta-analysis of three public microarray datasets was performed to screen for differentially expressed genes (DEGs) in exposure to BPA. The candidate genes of neuronal development were identified from gene ontology analysis in a reconstructed neuronal sub-network, and their gene expressions were determined using real-time PCR in 20 umbilical cord blood samples dichotomized into high and low BPA level groups upon the median 16.8 nM. Principal Findings Among 36 neuronal transcripts sorted from DAVID ontology clusters of 457 DEGs using the analysis of Bioconductor limma package, we found two neuronal genes, sex determining region Y-box 2 (Sox2) and paired box 6 (Pax6), had preferentially down-regulated expression (Bonferroni correction p-value <10−4 and log2-transformed fold change ≤−1.2) in response to BPA exposure. Fetal cord blood samples had the obviously attenuated gene expression of Sox2 and Pax6 in high BPA group referred to low BPA group. Visualized gene network of Cytoscape analysis showed that Sox2 and Pax6 which were contributed to neural precursor cell proliferation and neuronal differentiation might be down-regulated through sonic hedgehog (Shh), vascular endothelial growth factor A (VEGFA) and Notch signaling. Conclusions These results indicated that trans-placental BPA exposure down-regulated gene expression of Sox2 and Pax6 potentially underlying the adverse effect on childhood neuronal development.
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Liyanage VRB, Zachariah RM, Rastegar M. Decitabine alters the expression of Mecp2 isoforms via dynamic DNA methylation at the Mecp2 regulatory elements in neural stem cells. Mol Autism 2013; 4:46. [PMID: 24238559 PMCID: PMC3900258 DOI: 10.1186/2040-2392-4-46] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 10/01/2013] [Indexed: 01/01/2023] Open
Abstract
Background Aberrant MeCP2 expression in brain is associated with neurodevelopmental disorders including autism. In the brain of stressed mouse and autistic human patients, reduced MeCP2 expression is correlated with Mecp2/MECP2 promoter hypermethylation. Altered expression of MeCP2 isoforms (MeCP2E1 and MeCP2E2) is associated with neurological disorders, highlighting the importance of proper regulation of both isoforms. While known regulatory elements (REs) within the MECP2/Mecp2 promoter and intron 1 are involved in MECP2/Mecp2 regulation, Mecp2 isoform-specific regulatory mechanisms are unknown. We hypothesized that DNA methylation at these REs may impact the expression of Mecp2 isoforms. Methods We used a previously characterized in vitro differentiating neural stem cell (NSC) system to investigate the interplay between Mecp2 isoform-specific expression and DNA methylation at the Mecp2 REs. We studied altered expression of Mecp2 isoforms, affected by global DNA demethylation and remethylation, induced by exposure and withdrawal of decitabine (5-Aza-2′-deoxycytidine). Further, we performed correlation analysis between DNA methylation at the Mecp2 REs and the expression of Mecp2 isoforms after decitabine exposure and withdrawal. Results At different stages of NSC differentiation, Mecp2 isoforms showed reciprocal expression patterns associated with minor, but significant changes in DNA methylation at the Mecp2 REs. Decitabine treatment induced Mecp2e1/MeCP2E1 (but not Mecp2e2) expression at day (D) 2, associated with DNA demethylation at the Mecp2 REs. In contrast, decitabine withdrawal downregulated both Mecp2 isoforms to different extents at D8, without affecting DNA methylation at the Mecp2 REs. NSC cell fate commitment was minimally affected by decitabine under tested conditions. Expression of both isoforms negatively correlated with methylation at specific regions of the Mecp2 promoter, both at D2 and D8. The correlation between intron 1 methylation and Mecp2e1 (but not Mecp2e2) varied depending on the stage of NSC differentiation (D2: negative; D8: positive). Conclusions Our results show the correlation between the expression of Mecp2 isoforms and DNA methylation in differentiating NSC, providing insights on the potential role of DNA methylation at the Mecp2 REs in Mecp2 isoform-specific expression. The ability of decitabine to induce Mecp2e1/MeCP2E1, but not Mecp2e2 suggests differential sensitivity of Mecp2 isoforms to decitabine and is important for future drug therapies for autism.
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Affiliation(s)
| | | | - Mojgan Rastegar
- Regenerative Medicine Program, Department of Biochemistry and Medical Genetics, Faculty of Medicine, University of Manitoba, Rm, 627, Basic Medical Sciences Bldg,, 745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9, Canada.
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Kar S, Parbin S, Deb M, Shilpi A, Sengupta D, Rath SK, Rakshit M, Patra A, Patra SK. Epigenetic choreography of stem cells: the DNA demethylation episode of development. Cell Mol Life Sci 2013; 71:1017-32. [PMID: 24114325 DOI: 10.1007/s00018-013-1482-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/12/2013] [Accepted: 09/16/2013] [Indexed: 12/17/2022]
Abstract
Reversible DNA methylation is a fundamental epigenetic manipulator of the genomic information in eukaryotes. DNA demethylation plays a very significant role during embryonic development and stands out for its contribution in molecular reconfiguration during cellular differentiation for determining stem cell fate. DNA demethylation arbitrated extensive make-over of the genome via reprogramming in the early embryo results in stem cell plasticity followed by commitment to the principal cell lineages. This article attempts to highlight the sequential phases and hierarchical mode of DNA demethylation events during enactment of the molecular strategy for developmental transition. A comprehensive knowledge regarding the pattern of DNA demethylation during embryogenesis and organogenesis and study of the related lacunae will offer exciting avenues for future biomedical research and stem cell-based regenerative therapy.
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Affiliation(s)
- Swayamsiddha Kar
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
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Abstract
The semi-conservative nature of DNA replication has suggested that identical DNA molecules within chromatids are inherited by daughter cells after cell division. Numerous reports of non-random DNA segregation in prokaryotes and eukaryotes suggest that this is not always the case, and that epigenetic marks on chromatids, if not the individual DNA strands themselves, could have distinct signatures. Their selective distribution to daughter cells provides a novel mechanism for gene and cell fate regulation by segregating chromatids asymmetrically. Here we highlight some examples and potential mechanisms that can regulate this process. We propose that cellular asymmetry is inherently present during each cell division, and that it provides an opportunity during each cell cycle for moderating cell fates.
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Affiliation(s)
- Siham Yennek
- Institut Pasteur, Stem Cells & Development, Department of Developmental & Stem Cell Biology, CNRS URA 2578, 25 rue du Dr. Roux, Paris F-75015, France
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Abstract
During hippocampal development, the Cornus Ammonis (CA) and the dentate gyrus (DG) undergo waves of neurogenesis and neuronal migration and maturation independently. This stage is widely known to be vulnerable to environmental stresses, but its underlying mechanism is unclear. Alcohol exposure has been shown to alter the expression of genes that regulate the fate, survival, migration and differentiation of pyramidal and granule cells. Undermining this process might compromise hippocampal development underlying the learning and memory deficits known in Fetal Alcohol Spectrum Disorders (FASD). We have previously demonstrated that DNA methylation was programmed along with neural tube development. Here, we demonstrated that DNA methylation program (DMP) proceeded along with hippocampal neuronal differentiation and maturation, and how this DMP was affected by fetal alcohol exposure. C57BL/6 mice were treated with 4% v/v ethanol through a liquid diet along with pair-fed and chow-fed controls from gestation day (E) 7 to E16. We found that a characteristic DMP, including 5-methylcytidine (5mC), 5-hydroxylmethylcytidine (5hmC) and their binding proteins, led the hippocampal neuronal differentiation and maturation spatiotemporally as indicated by their phenotypic marks in the CA and DG pre- and post-natally. Alcohol hindered the acquisition and progression of methylation marks, and altered the chromatin translocation of these marks in the nucleus, which was correlated with developmental retardation.
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Affiliation(s)
- Yuanyuan Chen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | | | - Feng C. Zhou
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Liu TW, Ma ZG, Zhou Y, Xie JX. Transplantation of mouse CGR8 embryonic stem cells producing GDNF and TH protects against 6-hydroxydopamine neurotoxicity in the rat. Int J Biochem Cell Biol 2013; 45:1265-73. [PMID: 23535049 DOI: 10.1016/j.biocel.2013.03.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/02/2013] [Accepted: 03/17/2013] [Indexed: 01/17/2023]
Abstract
Embryonic stem cells (ESCs)-based therapies have been increasingly recognized as a potential tool to replace or support cells and their function damaged by the neurodegenerative process that underlies Parkinson's disease (PD). In this study, we implanted engineered mouse embryonic stem (ES) CGR8 cells, which stably co-express glial cell line-derived neurotrophic factor (GDNF) and tyrosine hydroxylase (TH), into striatum (Str) or both Str and substantia nigra (SN) of parkinsonian rats lesioned by 6-hydroxydopamine (6-OHDA). We found that cell transplantation into Str or both Str and SN rescued behavioral abnormalities and striatal DA depletion associated with 6-OHDA lesion. Our findings suggested that the profound functional impairment in nigrostriatal circuitry could be at least partially restored by ESCs-based expression of TH and GDNF, which may be developed into a useful tool for PD therapy.
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