1
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Huang J, Zhang J, Sun J, Gong M, Yuan Z. Exposure to polystyrene microplastics and perfluorooctane sulfonate disrupt the homeostasis of intact planarians and the growth of regenerating planarians. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171653. [PMID: 38485023 DOI: 10.1016/j.scitotenv.2024.171653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/17/2024]
Abstract
Microplastics (MPs) and perfluorinated compounds (PFAS) are widespread in the global ecosystem. MPs have the ability to adsorb organic contaminants such as perfluorooctane sulfonate (PFOS), leading to combined effects. The current work aims to explore the individual and combined toxicological effects of polystyrene (PS) and PFOS on the growth and nerves of the freshwater planarian (Dugesia japonica). The results showed that PS particles could adsorb PFOS. PS and PFOS impeded the regeneration of decapitated planarians eyespots, whereas the combined treatment increased the locomotor speed of intact planarians. PS and PFOS caused significant DNA damage, while co-treatment with different PS concentrations aggravated and attenuated DNA damage, respectively. Further studies at the molecular level have shown that PS and PFOS affect the proliferation and differentiation of neoblasts in both intact and regenerating planarians, alter the expression levels of neuronal genes, and impede the development of the nervous system. PS and PFOS not only disrupted the homeostasis of intact planarians, but also inhibited the regeneration of decapitated planarians. This study is the first to assess the multiple toxicity of PS and PFOS to planarians after combined exposure. It provides a basis for the environmental and human health risks of MPs and PFAS.
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Affiliation(s)
- Jinying Huang
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China
| | - Jianyong Zhang
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China
| | - Jingyi Sun
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China
| | - Mengxin Gong
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China
| | - Zuoqing Yuan
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China.
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2
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Wang S, Sun Y, Liu X, Guo Y, Huang Y, Zhang S, Tian Q. Meis1 Controls the Differentiation of Eye Progenitor Cells and the Formation of Posterior Poles during Planarian Regeneration. Int J Mol Sci 2023; 24:ijms24043505. [PMID: 36834910 PMCID: PMC9961902 DOI: 10.3390/ijms24043505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/21/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
As a member of TALE family, Meis1 has been proven to regulate cell proliferation and differentiation during cell fate commitment; however, the mechanism is still not fully understood. The planarian, which has an abundance of stem cells (neoblasts) responsible for regenerating any organ after injury, is an ideal model for studying the mechanisms of tissue identity determination. Here, we characterized a planarian homolog of Meis1 from the planarian Dugesia japonica. Importantly, we found that knockdown of DjMeis1 inhibits the differentiation of neoblasts into eye progenitor cells and results in an eyeless phenotype with normal central nervous system. Furthermore, we observed that DjMeis1 is required for the activation of Wnt signaling pathway by promoting the Djwnt1 expression during posterior regeneration. The silencing of DjMeis1 suppresses the expression of Djwnt1 and results in the inability to reconstruct posterior poles. In general, our findings indicated that DjMeis1 acts as a trigger for the activation of eye and tail regeneration by regulating the differentiation of eye progenitor cells and the formation of posterior poles, respectively.
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Affiliation(s)
- Shaocong Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yujia Sun
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaomai Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yajun Guo
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yongding Huang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Shoutao Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou 450046, China
- Correspondence: (S.Z.); (Q.T.)
| | - Qingnan Tian
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (S.Z.); (Q.T.)
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3
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Guo Y, Sun Y, Ma M, Huang Y, Zhang S, Tian Q. Djsnon, a downstream gene of Djfoxk1, is required for the regeneration of the planarian central nervous system. Biochem Biophys Res Commun 2023; 643:8-15. [PMID: 36584589 DOI: 10.1016/j.bbrc.2022.12.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/23/2022] [Indexed: 12/25/2022]
Abstract
Regulators of adult neurogenesis are crucial targets for neuronal repair. Freshwater planarians are ideal model systems for studying neuronal regeneration as they can regenerate their entire central nervous system (CNS) using pluripotent adult stem cells. Here, we identified Djfoxk1 in planarian Dugesia japonica to be required for planarian CNS regeneration. Knockdown of Djfoxk1 inhibits the regeneration of the cephalic ganglia, resulting in the failure of eye regeneration. By RNAi screening of Djfoxk1 downstream genes, we identified Djsnon as another regulator of planarian neuronal regeneration. Inhibition of Djsnon with RNA interference (RNAi) results in similar phenotypes caused by Djfoxk1 RNAi without affecting cell proliferation and wound healing. Our findings show that Djsnon as a downstream gene of Djfoxk1 regulates the regeneration of the planarian CNS.
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Affiliation(s)
- Yajun Guo
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yujia Sun
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Mengwen Ma
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yongding Huang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shoutao Zhang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China; Longhu Laboratory of Advanced Immunology, Zhengzhou, Henan, China.
| | - Qingnan Tian
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China.
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4
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Liu X, Sun Y, Wang S, Zhang S, Tian Q. Actin restricts cell proliferation and promotes differentiation during planarian regeneration. Biochem Biophys Res Commun 2023; 640:150-156. [PMID: 36508928 DOI: 10.1016/j.bbrc.2022.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 12/03/2022] [Indexed: 12/11/2022]
Abstract
Actin is an integral component of the cytoskeleton, which plays an important role in various fundamental cellular processes, such as affecting the polarity of embryonic cells during embryonic development in various model organisms. Meanwhile, previous studies have demonstrated that the polymerization of the actin cytoskeleton can affect cell migration, proliferation, and differentiation. Actin polymerization state regulated osteogenic differentiation and affected cell proliferation. However, the function of actin in regenerative biology has not been thoroughly elucidated. The planarian flatworm, which contains a large number of adult somatic stem cells (neoblasts), is an ideal model organism to study regenerative biology. Here, we identified a homolog of actin in planarian Dugesia japonica and found that RNAi targeting actin during planarian regeneration results in the formation of protrusions on the dorsal side, where the division of phospho-H3 mitotic cells is increased. In addition, a decrease in differentiation is observed in regenerating tissues after Djactin RNAi. These results indicate that Djactin functions in proliferation and differentiation control in planarian regeneration.
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Affiliation(s)
- Xiaomai Liu
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yujia Sun
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shaocong Wang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shoutao Zhang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China; Longhu Laboratory of Advanced Immunology, Zhengzhou, Henan, China.
| | - Qingnan Tian
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China.
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5
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An anti-inflammatory transcriptional cascade conserved from flies to humans. Cell Rep 2022; 41:111506. [DOI: 10.1016/j.celrep.2022.111506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/19/2022] [Accepted: 09/22/2022] [Indexed: 11/22/2022] Open
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6
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Wlodkowic D, Bownik A, Leitner C, Stengel D, Braunbeck T. Beyond the behavioural phenotype: Uncovering mechanistic foundations in aquatic eco-neurotoxicology. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154584. [PMID: 35306067 DOI: 10.1016/j.scitotenv.2022.154584] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
During the last decade, there has been an increase in awareness of how anthropogenic pollution can alter behavioural traits of diverse aquatic organisms. Apart from understanding profound ecological implications, alterations in neuro-behavioural indices have emerged as sensitive and physiologically integrative endpoints in chemical risk assessment. Accordingly, behavioural ecotoxicology and broader eco-neurotoxicology are becoming increasingly popular fields of research that span a plethora of fundamental laboratory experimentations as well as applied field-based studies. Despite mounting interest in aquatic behavioural ecotoxicology studies, there is, however, a considerable paucity in deciphering the mechanistic foundations underlying behavioural alterations upon exposure to pollutants. The behavioural phenotype is indeed the highest-level integrative neurobiological phenomenon, but at its core lie myriads of intertwined biochemical, cellular, and physiological processes. Therefore, the mechanisms that underlie changes in behavioural phenotypes can stem among others from dysregulation of neurotransmitter pathways, electrical signalling, and cell death of discrete cell populations in the central and peripheral nervous systems. They can, however, also be a result of toxicity to sensory organs and even metabolic dysfunctions. In this critical review, we outline why behavioural phenotyping should be the starting point that leads to actual discovery of fundamental mechanisms underlying actions of neurotoxic and neuromodulating contaminants. We highlight potential applications of the currently existing and emerging neurobiology and neurophysiology analytical strategies that should be embraced and more broadly adopted in behavioural ecotoxicology. Such strategies can provide new mechanistic discoveries instead of only observing the end sum phenotypic effects.
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Affiliation(s)
- Donald Wlodkowic
- The Neurotox Laboratory, School of Science, RMIT University, Melbourne, Australia.
| | - Adam Bownik
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences, Lublin, Poland
| | - Carola Leitner
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Daniel Stengel
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
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7
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Le D, Sabry Z, Chandra A, Kristan WB, Collins EMS, Kristan WB. Planarian fragments behave as whole animals. Curr Biol 2021; 31:5111-5117.e4. [PMID: 34624209 DOI: 10.1016/j.cub.2021.09.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/08/2021] [Accepted: 09/22/2021] [Indexed: 12/11/2022]
Abstract
Behavioral responses of freshwater planarians have been studied for over a century.1 In recent decades, behavior has been used as a readout to study planarian development and regeneration,2-6 wound healing,7,8 molecular evolution,4,9,10 neurotoxicology,11-13 and learning and memory.14-17The planarian nervous system is among the simplest of the bilaterally symmetric animals,18 with an anterior brain attached to two ventral nerve cords interconnected by multiple commissures. We found that, in response to mechanical and near-UV stimulation, head stimulation produces turning, tail stimulation produces contraction, and trunk stimulation produces midbody elongation in the planarian Dugesia japonica. When cut into two or three pieces, the anterior end of each headless piece switched its behavior to turning instead of elongation; i.e., it responded as though it were the head. In addition, posterior ends of the head and midbody pieces sometimes produced contraction instead of elongation. Thus, each severed piece acts like an intact animal, with each midbody region having nearly complete behavioral capabilities. These observations show that each midbody region reads the global state of the organism and adapts its response to incoming signals from the remaining tissue. Selective lateral incisions showed that the changes in behavior are not due to nonselective pain responses and that the ventral nerve cords and cross-connectives are responsible for coordinating local behaviors. Our findings highlight a fast functional reorganization of the planarian nervous system that complements the slower repairs provided by regeneration. This reorganization provides needed behavioral responses for survival as regeneration proceeds.
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Affiliation(s)
- Dylan Le
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Ziad Sabry
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
| | - Aarav Chandra
- The Bishop's School, 7607 La Jolla Boulevard, La Jolla, CA 92037, USA
| | - William B Kristan
- Department of Biological Sciences, California State University San Marcos, 333 South Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Eva-Maria S Collins
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA; Department of Physics and Astronomy, 500 College Avenue, Swarthmore College, Swarthmore, PA 19081, USA; Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA, USA.
| | - William B Kristan
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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8
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Zeng CW, Kamei Y, Shigenobu S, Sheu JC, Tsai HJ. Injury-induced Cavl-expressing cells at lesion rostral side play major roles in spinal cord regeneration. Open Biol 2021; 11:200304. [PMID: 33622104 PMCID: PMC8061693 DOI: 10.1098/rsob.200304] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The extent of cellular heterogeneity involved in neuronal regeneration after spinal cord injury (SCI) remains unclear. Therefore, we established stress-responsive transgenic zebrafish embryos with SCI. As a result, we found an SCI-induced cell population, termed SCI stress-responsive regenerating cells (SrRCs), essential for neuronal regeneration post-SCI. SrRCs were mostly composed of subtypes of radial glia (RGs-SrRCs) and neuron stem/progenitor cells (NSPCs-SrRCs) that are able to differentiate into neurons, and they formed a bridge across the lesion and connected with neighbouring undamaged motor neurons post-SCI. Compared to SrRCs at the caudal side of the SCI site (caudal-SrRCs), rostral-SrRCs participated more actively in neuronal regeneration. After RNA-seq analysis, we discovered that caveolin 1 (cav1) was significantly upregulated in rostral-SrRCs and that cav1 was responsible for the axonal regrowth and regenerative capability of rostral-SrRCs. Collectively, we define a specific SCI-induced cell population, SrRCs, involved in neuronal regeneration, demonstrate that rostral-SrRCs exhibit higher neuronal differentiation capability and prove that cav1 is predominantly expressed in rostral-SrRCs, playing a major role in neuronal regeneration after SCI.
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Affiliation(s)
- Chih-Wei Zeng
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan.,Liver Disease Prevention and Treatment Research Foundation, Taipei 10008, Taiwan
| | - Yasuhiro Kamei
- Spectrography and Bioimaging Facility, National Institute for Basic Biology (NIBB), National Institutes of Natural Sciences (NINS), Okazaki 444-8585, Japan.,Department of Basic Biology, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
| | - Shuji Shigenobu
- Department of Basic Biology, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan.,Functional Genomics Facility, NIBB, NINS, Okazaki 444-8585, Japan
| | - Jin-Chuan Sheu
- Liver Disease Prevention and Treatment Research Foundation, Taipei 10008, Taiwan
| | - Huai-Jen Tsai
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City 25245, Taiwan.,Department of Life Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
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9
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Hijioka M, Ikemoto Y, Fukao K, Inoue T, Kobayakawa T, Nishimura K, Takata K, Agata K, Kitamura Y. MEK/ERK Signaling Regulates Reconstitution of the Dopaminergic Nerve Circuit in the Planarian Dugesia japonica. Neurochem Res 2021; 47:2558-2567. [PMID: 33464445 DOI: 10.1007/s11064-020-03226-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/23/2020] [Accepted: 12/31/2020] [Indexed: 11/27/2022]
Abstract
Planarian Dugesia japonica is a flatworm that can autonomously regenerate its own body after an artificial amputation. A recent report showed the role of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathway in the head morphogenesis during the planarian regeneration process after amputation; however, neuron-specific regeneration mechanisms have not yet been reported. Here, whether MEK/ERK pathway was involved in the dopaminergic neuronal regeneration in planarians was investigated. Planarians regenerated their body within 14 days after amputation; however, the head region morphogenesis was inhibited by MEK inhibitor U0126 (3 or 10 μM). Furthermore, the number of planarian tyrosine hydroxylase (DjTH)-positive dopaminergic neurons in the regenerated head region was also decreased by U0126. The 6-hydroxydopamine (6-OHDA), a dopaminergic neurotoxin, can decrease the number of dopaminergic neurons; however, planarians can regenerate dopaminergic neurons after injecting 6-OHDA into the intestinal tract. MEK inhibitor PD98059 (30 μM) or U0126 (10 μM) significantly decreased dopaminergic neurons 5 days after the 6-OHDA injection. During the regeneration process of dopaminergic neurons, phosphorylated histone H3 (H3P)-positive stem cells known as "neoblasts" were increased in the head region; however, MEK inhibitors significantly decreased the number of H3P-positive neoblasts. These results suggested that dopaminergic neuronal regeneration in planarian was regulated by the MEK/ERK pathway.
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Affiliation(s)
- Masanori Hijioka
- Laboratory of Pharmacology and Neurobiology, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan.,Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8601, Japan
| | - Yusuke Ikemoto
- Laboratory of Pharmacology and Neurobiology, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kosuke Fukao
- Laboratory of Pharmacology and Neurobiology, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Takeshi Inoue
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-0031, Japan.,Division of Adaptation Physiology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, 683-8503, Japan
| | - Tatsuki Kobayakawa
- Laboratory of Pharmacology and Neurobiology, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kaneyasu Nishimura
- Division of Integrated Pharmaceutical Sciences, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Kazuyuki Takata
- Division of Integrated Pharmaceutical Sciences, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Kiyokazu Agata
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-0031, Japan.,National Institute for Basic Biology, National Institutes of Natural Science, 38 Nishigonaka, Myodaiji, Okazaki, 444-0867, Japan
| | - Yoshihisa Kitamura
- Laboratory of Pharmacology and Neurobiology, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan.
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10
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Auwal MA, Kashima M, Nishimura O, Hosoda K, Motoishi M, Kamimura A, Okumura A, Agata K, Umesono Y. Identification and characterization of a fibroblast growth factor gene in the planarian Dugesia japonica. Dev Growth Differ 2020; 62:527-539. [PMID: 33080046 DOI: 10.1111/dgd.12696] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/18/2020] [Accepted: 10/02/2020] [Indexed: 11/29/2022]
Abstract
Planarians belong to the phylum Platyhelminthes and can regenerate their missing body parts after injury via activation of somatic pluripotent stem cells called neoblasts. Previous studies suggested that fibroblast growth factor (FGF) signaling plays a crucial role in the regulation of head tissue differentiation during planarian regeneration. To date, however, no FGF homologues in the Platyhelminthes have been reported. Here, we used a planarian Dugesia japonica model and identified an fgf gene termed Djfgf, which encodes a putative secreted protein with a core FGF domain characteristic of the FGF8/17/18 subfamily in bilaterians. Using Xenopus embryos, we found that DjFGF has FGF activity as assayed by Xbra induction. We next examined Djfgf expression in non-regenerating intact and regenerating planarians. In intact planarians, Djfgf was expressed in the auricles in the head and the pharynx. In the early process of regeneration, Djfgf was transiently expressed in a subset of differentiated cells around wounds. Notably, Djfgf expression was highly induced in the process of head regeneration when compared to that in the tail regeneration. Furthermore, assays of head regeneration from tail fragments revealed that combinatorial actions of the anterior extracellular signal-regulated kinase (ERK) and posterior Wnt/ß-catenin signaling restricted Djfgf expression to a certain anterior body part. This is the region where neoblasts undergo active proliferation to give rise to their differentiating progeny in response to wounding. The data suggest the possibility that DjFGF may act as an anterior counterpart of posteriorly localized Wnt molecules and trigger neoblast responses involved in planarian head regeneration.
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Affiliation(s)
| | - Makoto Kashima
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Osamu Nishimura
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Kazutaka Hosoda
- Graduate School of Life Science, University of Hyogo, Kouto, Hyogo, Japan
| | - Minako Motoishi
- Graduate School of Life Science, University of Hyogo, Kouto, Hyogo, Japan
| | - Akifumi Kamimura
- Graduate School of Life Science, University of Hyogo, Kouto, Hyogo, Japan
| | - Akinori Okumura
- Graduate School of Life Science, University of Hyogo, Kouto, Hyogo, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.,Department of Life Science, Faculty of Science Graduate Course in Life Science, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, Kouto, Hyogo, Japan
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11
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Wang C, Peng R, Yuan X, Liu S, Xu S, Li Y, Zhang Z, Zeng M, Hu L, Zou F. Cellular and molecular responses-mediated by DjMEK1/2 are necessary for planarian regeneration. Int J Biol Macromol 2020; 164:3751-3761. [PMID: 32888997 DOI: 10.1016/j.ijbiomac.2020.08.209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 01/23/2023]
Abstract
The planarian flatworm is an ideal model to study the regeneration due to its robust regenerative ability. A variety of cellular response activities have been reported to be involved in the regeneration process, including the mitogen-activated protein kinase (MAPK) signaling. However, the mechanism of MAPK pathway in regenerative responses is still unclear. In this study, we employed the planarian, Dugesia japonica, as the model to investigate the function of MAP-extracellular signal-regulated kinase (MEK), an important component of MAPK signaling pathway, in the regeneration process. We found that MEK was required for the missing tissue response after several amputation and subsequent regeneration. MEK not only affected the size of blastema in the early stage of regeneration by regulating stem cell proliferation, but also determined the planarian's regeneration through balancing cell proliferation and apoptosis. In addition, the activation of Wnt pathway partially rescued regenerative defects induced by inhibition of MEK. Taken together, our results highlight a crucial role of MEK signaling in the planarian regeneration.
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Affiliation(s)
- Chao Wang
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Rui Peng
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Xieyong Yuan
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Shengpeng Liu
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Shutao Xu
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Yan Li
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Zhenhua Zhang
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Min Zeng
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Lanlin Hu
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China
| | - Fangdong Zou
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, PR China.
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12
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Dean MRP, Duncan EM. Laboratory Maintenance and Propagation of Freshwater Planarians. CURRENT PROTOCOLS IN MICROBIOLOGY 2020; 59:e120. [PMID: 33058563 PMCID: PMC7941200 DOI: 10.1002/cpmc.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Freshwater planarians are a powerful model organism for the study of animal regeneration, stem cell maintenance and differentiation, and the development and functions of several highly conserved complex tissues. At the same time, planarians are easy to maintain, inexpensive to propagate, and reasonably macroscopic (1 mm to 1 cm in length), making them excellent organisms to use in both complex academic research and hands-on teaching laboratories. Here, we provide a detailed description of how to maintain and propagate these incredibly versatile animals in any basic laboratory setting. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Salt solution preparation Basic Protocol 2: Cleaning planarian housing Basic Protocol 3: Food preparation Basic Protocol 4: Feeding planarians Basic Protocol 5: Expansion and amplification of colony.
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Affiliation(s)
- Makayla R P Dean
- Department of Biology, University of Kentucky, Lexington, Kentucky
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Zhang J, Shao X, Zhao B, Zhai L, Liu N, Gong F, Ma X, Pan X, Zhao B, Yuan Z, Zhang X. Neurotoxicity of perfluorooctanoic acid and post-exposure recovery due to blueberry anthocyanins in the planarians Dugesia japonica. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 263:114471. [PMID: 32268227 DOI: 10.1016/j.envpol.2020.114471] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 03/13/2020] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Perfluorooctanoic acid (PFOA) is a widely used synthetic industrial chemical which accumulates in ecosystems and organisms. Our study have investigated the neurobehavioral effects of PFOA and the alleviation effects of PFOA-induced neurotoxicity by blueberry anthocyanins (ANT) in Dugesia japonica. The planarians were exposed to PFOA and ANT for ten days. Researchs showed that exposure to PFOA affected locomotor behavior and ANT significantly alleviated the reduction in locomotion induced by PFOA. The regeneration of eyespots and auricles was suppressed by PFOA and was promoted by ANT. Following exposure to PFOA, acetylcholinesterase activity continually decreased and was unaffected in the ANT group, but was elevated after combined administration of PFOA and ANT. Oxidative DNA damage was found in planarians exposed to PFOA and was attenuated after administration of ANT by the alkaline comet assay. Concentrations of three neurotransmitters increased following exposure to PFOA and decreased after administration of ANT. Furthermore, ANT promoted and PFOA inhibited neuronal regeneration. DjotxA, DjotxB, DjFoxG, DjFoxD and Djnlg associated with neural processes were up-regulated following exposure to PFOA. Our findings indicate that PFOA is a neurotoxicant while ANT can attenuate these detrimental effects.
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Affiliation(s)
- Jianyong Zhang
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Xinxin Shao
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Baoying Zhao
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Liming Zhai
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Na Liu
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Fangbin Gong
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Xue Ma
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Xiaolu Pan
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Bosheng Zhao
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Zuoqing Yuan
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
| | - Xiufang Zhang
- School of Life Sciences, Shandong University of Technology, Zibo, Shandong, 255000, China.
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Miyamoto M, Hattori M, Hosoda K, Sawamoto M, Motoishi M, Hayashi T, Inoue T, Umesono Y. The pharyngeal nervous system orchestrates feeding behavior in planarians. SCIENCE ADVANCES 2020; 6:eaaz0882. [PMID: 32285000 PMCID: PMC7141820 DOI: 10.1126/sciadv.aaz0882] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 01/14/2020] [Indexed: 05/06/2023]
Abstract
Planarians exhibit traits of cephalization but are unique among bilaterians in that they ingest food by means of goal-directed movements of a trunk-positioned pharynx, following protrusion of the pharynx out of the body, raising the question of how planarians control such a complex set of body movements for achieving robust feeding. Here, we use the freshwater planarian Dugesia japonica to show that an isolated pharynx amputated from the planarian body self-directedly executes its entire sequence of feeding functions: food sensing, approach, decisions about ingestion, and intake. Gene-specific silencing experiments by RNA interference demonstrated that the pharyngeal nervous system (PhNS) is required not only for feeding functions of the pharynx itself but also for food-localization movements of individual animals, presumably via communication with the brain. These findings reveal an unexpected central role of the PhNS in the linkage between unique morphological phenotypes and feeding behavior in planarians.
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Affiliation(s)
- Mai Miyamoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Miki Hattori
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Kazutaka Hosoda
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Mika Sawamoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Minako Motoishi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Tetsutaro Hayashi
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Takeshi Inoue
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
- Corresponding author. (Y.U.); (T.I.)
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
- Corresponding author. (Y.U.); (T.I.)
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Meddeb E, Charni M, Ben Abdallah R, Raboudi F, Fattouch S. A molecular study of Tunisian populations of Dugesia sicula (Plathelminthes, Tricladida) through an identification of a set of genes. C R Biol 2019; 342:291-298. [PMID: 31786144 DOI: 10.1016/j.crvi.2019.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 10/30/2019] [Indexed: 10/25/2022]
Abstract
Cell regeneration is a natural repair of different types of tissue after an injury or a lesion, and is associated with asexual reproduction in some animals such as planarians. Its understanding and improvement could have repercussions for tissue repair and regeneration as far as humans are concerned. In this context, we have proceeded to an essential step, which is the identification of the genes involved in planarian regeneration in the model species. Dugesia sicula Lepori (D. sicula) is distributed around the Mediterranean Sea, and this population is found in most of Tunisian dams. The collection of identified genes is already known in other species. DjFoxG, DjPC2, DjotxA, and Cathepsin-D were identified by the PCR technique and their expression was confirmed by RT-PCR and in situ hybridization. DjFoxG gene, the FoxG1 homolog, is expressed throughout the planarian body, abundantly on stem cells. Consecutively, we choose a central nervous system (CNS) marker; the prohormone convertase 2 (DjPC2) gene. DjotxA was observed in the brain and especially in the region surrounding the eyes (visual cells). The regenerative cells of the gut of D. sicula were scored by the Cathepsin-D gene expression, which belongs to the aspartyl protease family. We found significant results through RT-PCR and In Situ Hybridization (ISH) techniques, confirming the expression of DjFoxG, DjPC2, DjotxA and Cathepsin-D genes in our specimens.
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Affiliation(s)
- Emna Meddeb
- Laboratory of Food and Molecular Biochemistry, National Institute of Applied Sciences and Technology (INSAT), University of Carthage, Zone Urbaine Nord, 1080 Tunis, Tunisia; Faculty of Sciences of Bizerte, University of Carthage, Tunis, Tunisia.
| | - Mohamed Charni
- Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, Tunisia; College of Sciences and Humanities of Dawadmi, Shaqra University, Shaqra, Kingdom of Saudi Arabia
| | - Rim Ben Abdallah
- Laboratory of Food and Molecular Biochemistry, National Institute of Applied Sciences and Technology (INSAT), University of Carthage, Zone Urbaine Nord, 1080 Tunis, Tunisia; Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Faten Raboudi
- ISAJC, Bir El Bey, University of Tunis, Tunis, Tunisia
| | - Sami Fattouch
- Laboratory of Food and Molecular Biochemistry, National Institute of Applied Sciences and Technology (INSAT), University of Carthage, Zone Urbaine Nord, 1080 Tunis, Tunisia
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Ivankovic M, Haneckova R, Thommen A, Grohme MA, Vila-Farré M, Werner S, Rink JC. Model systems for regeneration: planarians. Development 2019; 146:146/17/dev167684. [PMID: 31511248 DOI: 10.1242/dev.167684] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Planarians are a group of flatworms. Some planarian species have remarkable regenerative abilities, which involve abundant pluripotent adult stem cells. This makes these worms a powerful model system for understanding the molecular and evolutionary underpinnings of regeneration. By providing a succinct overview of planarian taxonomy, anatomy, available tools and the molecular orchestration of regeneration, this Primer aims to showcase both the unique assets and the questions that can be addressed with this model system.
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Affiliation(s)
- Mario Ivankovic
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Radmila Haneckova
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
| | - Albert Thommen
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Markus A Grohme
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Miquel Vila-Farré
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
| | - Steffen Werner
- FOM Institute AMOLF, Department of Systems Biology, Science Park 104, 1098 XG, Amsterdam, The Netherlands
| | - Jochen C Rink
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany .,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
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17
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Towards High-Throughput Chemobehavioural Phenomics in Neuropsychiatric Drug Discovery. Mar Drugs 2019; 17:md17060340. [PMID: 31174272 PMCID: PMC6627923 DOI: 10.3390/md17060340] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/19/2019] [Accepted: 06/01/2019] [Indexed: 12/11/2022] Open
Abstract
Identifying novel marine-derived neuroactive chemicals with therapeutic potential is difficult due to inherent complexities of the central nervous system (CNS), our limited understanding of the molecular foundations of neuro-psychiatric conditions, as well as the limited applications of effective high-throughput screening models that recapitulate functionalities of the intact CNS. Furthermore, nearly all neuro-modulating chemicals exhibit poorly characterized pleiotropic activities often referred to as polypharmacology. The latter renders conventional target-based in vitro screening approaches very difficult to accomplish. In this context, chemobehavioural phenotyping using innovative small organism models such as planarians and zebrafish represent powerful and highly integrative approaches to study the impact of new chemicals on central and peripheral nervous systems. In contrast to in vitro bioassays aimed predominantly at identification of chemicals acting on single targets, phenotypic chemobehavioural analysis allows for complex multi-target interactions to occur in combination with studies of polypharmacological effects of chemicals in a context of functional and intact milieu of the whole organism. In this review, we will outline recent advances in high-throughput chemobehavioural phenotyping and provide a future outlook on how those innovative methods can be utilized for rapidly screening and characterizing marine-derived compounds with prospective applications in neuropharmacology and psychosomatic medicine.
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Hosoda K, Motoishi M, Kunimoto T, Nishimura O, Hwang B, Kobayashi S, Yazawa S, Mochii M, Agata K, Umesono Y. Role of MEKK1 in the anterior-posterior patterning during planarian regeneration. Dev Growth Differ 2018; 60:341-353. [PMID: 29900546 DOI: 10.1111/dgd.12541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 11/29/2022]
Abstract
Planarians have established a unique body pattern along the anterior-posterior (AP) axis, which consists of at least four distinct body regions arranged in an anterior to posterior sequence: head, prepharyngeal, pharyngeal (containing a pharynx), and tail regions, and possess high regenerative ability. How they reconstruct the regional continuity in a head-to-tail sequence after amputation still remains unknown. We use as a model planarian Dugesia japonica head regeneration from tail fragments, which involves dynamic rearrangement of the body regionality of preexisting tail tissues along the AP axis, and show here that RNA interference of the gene D. japonica mek kinase 1 (Djmekk1) caused a significant anterior shift in the position of pharynx regeneration at the expense of the prepharyngeal region, while keeping the head region relatively constant in size, and accordingly led to development of a relatively longer tail region. Our data suggest that DjMEKK1 regulates anterior extracellular signal-regulated kinase (ERK) and posterior β-catenin signaling pathways in a positive and negative manner, respectively, to establish a proper balance resulting in the regeneration of planarian's scale-invariant trunk-to-tail patterns across individuals. Furthermore, we demonstrated that DjMEKK1 negatively modulates planarian β-catenin activity via its serine/threonine kinase domain, but not its PHD/RING finger domain, by testing secondary axis formation in Xenopus embryos. The data suggest that Djmekk1 plays an instructive role in the coordination between the establishment of the prepharyngeal region and posteriorizing of pharynx formation by balancing the two opposing morphogenetic signals along the AP axis during planarian regeneration.
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Affiliation(s)
- Kazutaka Hosoda
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.,Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
| | - Minako Motoishi
- Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
| | - Takuya Kunimoto
- Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
| | - Osamu Nishimura
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.,Phyloinformatics Unit, RIKEN Center for Life Science Technologies, Kobe, Japan
| | - Byulnim Hwang
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Sumire Kobayashi
- Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
| | - Shigenobu Yazawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.,Cellular and Structural Physiology Institute, Nagoya University, Nagoya, Japan
| | - Makoto Mochii
- Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.,Department of Life Science, Faculty of Science Graduate Course in Life Science, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, Kamigori-cho, Japan
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19
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Fields C, Levin M. Are Planaria Individuals? What Regenerative Biology is Telling Us About the Nature of Multicellularity. Evol Biol 2018. [DOI: 10.1007/s11692-018-9448-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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20
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Stamatis SA, Worsaae K, Garm A. Regeneration of the Rhopalium and the Rhopalial Nervous System in the Box Jellyfish Tripedalia cystophora. THE BIOLOGICAL BULLETIN 2018; 234:22-36. [PMID: 29694798 DOI: 10.1086/697071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cubozoans have the most intricate visual apparatus within Cnidaria. It comprises four identical sensory structures, the rhopalia, each of which holds six eyes of four morphological types. Two of these eyes are camera-type eyes that are, in many ways, similar to the vertebrate eye. The visual input is used to control complex behaviors, such as navigation and obstacle avoidance, and is processed by an elaborate rhopalial nervous system. Several studies have examined the rhopalial nervous system, which, despite a radial symmetric body plan, is bilaterally symmetrical, connecting the two sides of the rhopalium through commissures in an extensive neuropil. The four rhopalia are interconnected by a nerve ring situated in the oral margin of the bell, and together these structures constitute the cubozoan central nervous system. Cnidarians have excellent regenerative capabilities, enabling most species to regenerate large body areas or body parts, and some species can regenerate completely from just a few hundred cells. Here we test whether cubozoans are capable of regenerating the rhopalia, despite the complexity of the visual system and the rhopalial nervous system. The results show that the rhopalia are readily regrown after amputation and have developed most, if not all, neural elements within two weeks. Using electrophysiology, we investigated the functionality of the regrown rhopalia and found that they generated pacemaker signals and that the lens eyes showed a normal response to light. Our findings substantiate the amazing regenerative ability in Cnidaria by showing here the complex sensory system of Cubozoa, a model system proving to be highly applicable in studies of neurogenesis.
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Key Words
- CNS, central nervous system
- DAPI, 4′,6-diamidino-2-phenylindole
- EdU, 5-ethynyl-2′-deoxyuridine
- FMRF-LIR, FMRFamide-like immunoreactive
- I-cells, interstitial cells
- PFA, paraformaldehyde
- PNS, peripheral nervous system
- RF-LIR, RFamide-like immunoreactive
- RNS, rhopalial nervous system
- α-tubulin LIR, α-tubulin-like immunoreactions
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Umesono Y. Postembryonic Axis Formation in Planarians. DIVERSITY AND COMMONALITY IN ANIMALS 2018. [DOI: 10.1007/978-4-431-56609-0_33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Hattori M, Miyamoto M, Hosoda K, Umesono Y. Usefulness of multiple chalk-based food colorings for inducing better gene silencing by feeding RNA interference in planarians. Dev Growth Differ 2017; 60:76-81. [PMID: 29266402 DOI: 10.1111/dgd.12413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 11/29/2022]
Abstract
Planarians have become widely recognized as one of the major animal models for regeneration studies in invertebrates. To induce RNA interference (RNAi) by feeding in planarians, the widely accepted protocol is one in which animals undergo two or three feedings of food containing double-stranded RNA (dsRNA) plus visible food coloring (e.g., blood) for confirmation of feeding by individual animals. However, one possible problem is that incorporated food coloring is often retained within the gut for several days, which makes it difficult to confirm the success of each round of dsRNA feeding based on the difference of the color density within the gut before and after feeding. As a consequence, the difference of appetite levels among individuals undergoing dsRNA feeding leads to phenotypic variability among them due to insufficient knockdown. In our attempts to overcome this problem, we have developed a novel method for achieving robust confirmation of the success of dsRNA feeding in individuals fed multiple times by means of including a combination of three different colored chalks (pink, yellow and blue) as food coloring. Notably, we found that this method is superior to the conventional method for positively marking individuals that actively consumed the dsRNA-containing food during four times of once-daily feeding. Using these selected animals, we obtained stable and sufficiently strong RNAi-induced phenotypes. We termed this improved multi-colored chalk-spiked method of feeding RNAi "Candi" and propose its benefits for gene function analysis in planarians.
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Affiliation(s)
- Miki Hattori
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Mai Miyamoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Kazutaka Hosoda
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
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Wu S, Liu B, Yuan Z, Zhang X, Liu H, Pang Q, Zhao B. Planarian homolog of puromycin-sensitive aminopeptidase DjPsa is required for brain regeneration. INVERTEBRATE NEUROSCIENCE 2017; 17:3. [PMID: 28324191 DOI: 10.1007/s10158-017-0196-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/10/2017] [Indexed: 12/19/2022]
Abstract
Puromycin-sensitive aminopeptidase (PSA) belongs to the M1 zinc metallopeptidase family. PSA is the most abundant aminopeptidase in the brain and plays a role in the metabolism of neuropeptides including those involved in neurodegeneration. A cDNA DjPsa was identified from the planarian Dugesia japonica cDNA library. It contains a 639-bp open reading frame corresponding to a deduced protein of 212 amino acids. Whole mount in situ hybridization revealed that DjPsa is expressed in the brain and ventral nerve cords of intact and regenerating animals and demonstrates a tissue and stage-specific expression pattern of DjPsa in developing embryos and larvae. Knocking down DjPsa gene expression with RNA interference during planarian regeneration inhibits the brain reformation completely. The results suggest that DjPsa is required for planarian brain regeneration.
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Affiliation(s)
- Suge Wu
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China
| | - Bin Liu
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China
| | - Zuoqing Yuan
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China.,School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049, People's Republic of China
| | - Xiufang Zhang
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China.,School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049, People's Republic of China
| | - Hong Liu
- School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049, People's Republic of China
| | - Qiuxiang Pang
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China.,School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049, People's Republic of China
| | - Bosheng Zhao
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo, 255049, People's Republic of China. .,School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049, People's Republic of China.
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Proteomic Analysis Reveals the Contribution of TGFβ/Smad4 Signaling Pathway to Cell Differentiation During Planarian Tail Regeneration. Appl Biochem Biotechnol 2016; 182:529-545. [DOI: 10.1007/s12010-016-2342-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/24/2016] [Indexed: 02/06/2023]
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25
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Neuhof M, Levin M, Rechavi O. Vertically- and horizontally-transmitted memories - the fading boundaries between regeneration and inheritance in planaria. Biol Open 2016; 5:1177-88. [PMID: 27565761 PMCID: PMC5051648 DOI: 10.1242/bio.020149] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Weismann barrier postulates that genetic information passes only from the germline to the soma and not in reverse, thus providing an obstacle to the inheritance of acquired traits. Certain organisms such as planaria – flatworms that can reproduce through asymmetric fission – avoid the limitations of this barrier, thus blurring the distinction between the processes of inheritance and development. In this paper, we re-evaluate canonical ideas about the interaction between developmental, genetic and evolutionary processes through the lens of planaria. Biased distribution of epigenetic effects in asymmetrically produced parts of a regenerating organism could increase variation and therefore affect the species' evolution. The maintenance and fixing of somatic experiences, encoded via stable biochemical or physiological states, may contribute to evolutionary processes in the absence of classically defined generations. We discuss different mechanisms that could induce asymmetry between the two organisms that eventually develop from the regenerating parts, including one particularly fascinating source – the potential capacity of the brain to produce long-lasting epigenetic changes. Summary: In this hypothesis paper we re-evaluate canonical ideas about the interaction between developmental, genetic and evolutionary processes through the lens of planaria, an invertebrate model organism which challenges fundamental assumptions regarding reproduction.
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Affiliation(s)
- Moran Neuhof
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Michael Levin
- Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155, USA
| | - Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155, USA Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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Hosoda K, Morimoto M, Motoishi M, Nishimura O, Agata K, Umesono Y. Simple blood-feeding method for live imaging of gut tube remodeling in regenerating planarians. Dev Growth Differ 2016; 58:260-9. [PMID: 26948408 DOI: 10.1111/dgd.12270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/19/2016] [Accepted: 01/24/2016] [Indexed: 11/27/2022]
Abstract
Live cell imaging is a powerful technique to study cellular dynamics in vivo during animal development and regeneration. However, few live imaging methods have been reported for studying planarian regeneration. Here, we developed a simple method for steady visualization of gut tube remodeling during regeneration of a living freshwater planarian, Dugesia japonica. When planarians were fed blood several times, gut branches were well-visualized in living intact animals under normal bright-field illumination. Interestingly, tail fragments derived from these colored planarians enabled successive observation of the processes of the formation of a single anterior gut branch in the prepharyngeal region from the preexisting two posterior gut branches in the same living animals during head regeneration. Furthermore, we combined this method and RNA interference (RNAi) and thereby showed that a D. japonica raf-related gene (DjrafA) and mek-related gene (DjmekA) we identified both play a major role in the activation of extracellular signal-regulated kinase (ERK) signaling during planarian regeneration, as indicated by their RNAi-induced defects on gut tube remodeling in a time-saving initial screening using blood-feeding without immunohistochemical detection of the gut. Thus, this blood-feeding method is useful for live imaging of gut tube remodeling, and provides an advance for the field of regeneration study in planarians.
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Affiliation(s)
- Kazutaka Hosoda
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Mizuki Morimoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Minako Motoishi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Osamu Nishimura
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
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Ong TH, Romanova EV, Roberts-Galbraith RH, Yang N, Zimmerman TA, Collins JJ, Lee JE, Kelleher NL, Newmark PA, Sweedler JV. Mass Spectrometry Imaging and Identification of Peptides Associated with Cephalic Ganglia Regeneration in Schmidtea mediterranea. J Biol Chem 2016; 291:8109-20. [PMID: 26884331 PMCID: PMC4825013 DOI: 10.1074/jbc.m115.709196] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 12/21/2022] Open
Abstract
Tissue regeneration is a complex process that involves a mosaic of molecules that vary spatially and temporally. Insights into the chemical signaling underlying this process can be achieved with a multiplex and untargeted chemical imaging method such as mass spectrometry imaging (MSI), which can enablede novostudies of nervous system regeneration. A combination of MSI and multivariate statistics was used to differentiate peptide dynamics in the freshwater planarian flatwormSchmidtea mediterraneaat different time points during cephalic ganglia regeneration. A protocol was developed to makeS. mediterraneatissues amenable for MSI. MS ion images of planarian tissue sections allow changes in peptides and unknown compounds to be followed as a function of cephalic ganglia regeneration. In conjunction with fluorescence imaging, our results suggest that even though the cephalic ganglia structure is visible after 6 days of regeneration, the original chemical composition of these regenerated structures is regained only after 12 days. Differences were observed in many peptides, such as those derived from secreted peptide 4 and EYE53-1. Peptidomic analysis further identified multiple peptides from various known prohormones, histone proteins, and DNA- and RNA-binding proteins as being associated with the regeneration process. Mass spectrometry data also facilitated the identification of a new prohormone, which we have named secreted peptide prohormone 20 (SPP-20), and is up-regulated during regeneration in planarians.
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Affiliation(s)
- Ta-Hsuan Ong
- From the Department of Chemistry, and the Beckman Institute
| | | | - Rachel H Roberts-Galbraith
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ning Yang
- From the Department of Chemistry, and the Beckman Institute
| | | | - James J Collins
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ji Eun Lee
- From the Department of Chemistry, and the Beckman Institute
| | - Neil L Kelleher
- the Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60611
| | - Phillip A Newmark
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
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Mangel M, Bonsall MB, Aboobaker A. Feedback control in planarian stem cell systems. BMC SYSTEMS BIOLOGY 2016; 10:17. [PMID: 26873593 PMCID: PMC4752765 DOI: 10.1186/s12918-016-0261-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/29/2016] [Indexed: 01/10/2023]
Abstract
Background In planarian flatworms, the mechanisms underlying the activity of collectively pluripotent adult stem cells (neoblasts) and their descendants can now be studied from the level of the individual gene to the entire animal. Flatworms maintain startling developmental plasticity and regenerative capacity in response to variable nutrient conditions or injury. We develop a model for cell dynamics in such animals, assuming that fully differentiated cells exert feedback control on neoblast activity. Results Our model predicts a number of whole organism level and general cell biological and behaviours, some of which have been empirically observed or inferred in planarians and others that have not. As previously observed empirically we find: 1) a curvilinear relationship between external food and planarian steady state size; 2) the fraction of neoblasts in the steady state is constant regardless of planarian size; 3) a burst of controlled apoptosis during regeneration after amputation as the number of differentiated cells are adjusted towards their homeostatic/steady state level. In addition our model describes the following properties that can inform and be tested by future experiments: 4) the strength of feedback control from differentiated cells to neoblasts (i.e. the activity of the signalling system) and from neoblasts on themselves in relation to absolute number depends upon the level of food in the environment; 5) planarians adjust size when food level reduces initially through increased apoptosis and then through a reduction in neoblast self-renewal activity; 6) following wounding or excision of differentiated cells, different time scales characterize both recovery of size and the two feedback functions; 7) the temporal pattern of feedback controls differs noticeably during recovery from a removal or neoblasts or a removal of differentiated cells; 8) the signaling strength for apoptosis of differentiated cells depends upon both the absolute and relative deviations of the number of differentiated cells from their homeostatic level; and 9) planaria prioritize resource use for cell divisions. Conclusions We offer the first analytical framework for organizing experiments on planarian flatworm stem cell dynamics in a form that allows models to be compared with quantitative cell data based on underlying molecular mechanisms and thus facilitate the interplay between empirical studies and modeling. This framework is the foundation for studying cell migration during wound repair, the determination of homeostatic levels of differentiated cells by natural selection, and stochastic effects. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0261-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marc Mangel
- Department of Applied Mathematics and Statistics, University of California, Santa Cruz, 95064, CA, USA. .,Department of Biology, University of Bergen, Bergen, 9020, Norway.
| | | | - Aziz Aboobaker
- Department of Zoology, University of Oxford, Oxford, UK.
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Akiyama Y, Agata K, Inoue T. Spontaneous Behaviors and Wall-Curvature Lead to Apparent Wall Preference in Planarian. PLoS One 2015; 10:e0142214. [PMID: 26539715 PMCID: PMC4635015 DOI: 10.1371/journal.pone.0142214] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/19/2015] [Indexed: 12/05/2022] Open
Abstract
The planarian Dugesia japonica tends to stay near the walls of its breeding containers and experimental dishes in the laboratory, a phenomenon called “wall preference”. This behavior is thought to be important for environmental adaptation, such as hiding by planarians in nature. However, the mechanisms regulating wall-preference behavior are not well understood, since this behavior occurs in the absence of any particular stimulation. Here we show the mechanisms of wall-preference behavior. Surprisingly, planarian wall-preference behavior was also shown even by the head alone and by headless planarians. These results indicate that planarian “wall-preference” behavior only appears to be a “preference” behavior, and is actually an outcome of spontaneous behaviors, rather than of brain function. We found that in the absence of environmental cues planarians moved basically straight ahead until they reached a wall, and that after reaching a wall, they changed their direction of movement to one tangential to the wall, suggesting that this spontaneous behavior may play a critical role in the wall preference. When we tested another spontaneous behavior, the wigwag movement of the planarian head, using computer simulation with various wigwag angles and wigwag intervals, large wigwag angle and short wigwag interval reduced wall-preference behavior. This indicated that wigwag movement may determine the probability of staying near the wall or leaving the wall. Furthermore, in accord with this simulation, when we tested planarian wall-preference behavior using several assay fields with different curvature of the wall, we found that concavity and sharp curvature of walls negatively impacted wall preference by affecting the permissible angle of the wigwag movement. Together, these results indicate that planarian wall preference may be involuntarily caused by the combination of two spontaneous planarian behaviors: moving straight ahead until reaching a wall and then moving along it in the absence of environmental cues, and wigwag movements of the head.
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Affiliation(s)
- Yoshitaro Akiyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
| | - Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
- * E-mail:
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Loonen AJM, Ivanova SA. Circuits regulating pleasure and happiness: the evolution of reward-seeking and misery-fleeing behavioral mechanisms in vertebrates. Front Neurosci 2015; 9:394. [PMID: 26557051 PMCID: PMC4615821 DOI: 10.3389/fnins.2015.00394] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 10/07/2015] [Indexed: 12/21/2022] Open
Abstract
The very first free-moving animals in the oceans over 540 million years ago must have been able to obtain food, territory, and shelter, as well as reproduce. Therefore, they would have needed regulatory mechanisms to induce movements enabling achievement of these prerequisites for survival. It can be useful to consider these mechanisms in primitive chordates, which represent our earliest ancestors, to develop hypotheses addressing how these essential parts of human behavior are regulated and relate to more sophisticated behavioral manifestations such as mood. An animal comparable to lampreys was the earliest known vertebrate with a modern forebrain consisting of old and new cortical parts. Lampreys have a separate dorsal pallium, the forerunner of the most recently developed part of the cerebral cortex. In addition, the lamprey extrapyramidal system (EPS), which regulates movement, is modern. However, in lampreys and their putative forerunners, the hagfishes, the striatum, which is the input part of this EPS, probably corresponds to the human centromedial amygdala, which in higher vertebrates is part of a system mediating fear and anxiety. Both animals have well-developed nuclear habenulae, which are involved in several critical behaviors; in lampreys this system regulates the reward system that reinforces appetitive-seeking behavior or the avoidance system that reinforces flight behavior resulting from negative inputs. Lampreys also have a distinct glutamatergic nucleus, the so-called habenula-projection globus pallidus, which receives input from glutamatergic and GABAergic signals and gives output to the lateral habenula. Via this route, this nucleus influences midbrain monoaminergic nuclei and regulates the food acquisition system. These various structures involved in motor regulation in the lampreys may be conserved in humans and include two complementary mechanisms for reward reinforcement and avoidance behaviors. The first system is associated with experiencing pleasure and the second with happiness. The activities of these mechanisms are regulated by a tract running via the habenula to the upper brainstem. Identifying the human correlate of the lamprey habenula-projecting globus pallidus may help in elucidating the mechanism of the antidepressant effects of glutamatergic drugs.
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Affiliation(s)
- Anton J M Loonen
- Department of Pharmacy, Geestelijke GezondheidsZorg Westelijk Noord-Brabant Chair of Pharmacotherapy in Psychiatric Patients, University of Groningen Groningen, Netherlands ; Mental Health Institute Westelijk Noord-Brabant Halsteren, Netherlands
| | - Svetlana A Ivanova
- Molecular Biology and Biological Psychiatry, Mental Health Research Institute Tomsk, Russia ; Department of Ecology and Basic Safety, National Research Tomsk Polytechnic University Tomsk, Russia
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31
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Blackiston DJ, Shomrat T, Levin M. The stability of memories during brain remodeling: A perspective. Commun Integr Biol 2015; 8:e1073424. [PMID: 27066165 PMCID: PMC4802789 DOI: 10.1080/19420889.2015.1073424] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 07/13/2015] [Indexed: 01/10/2023] Open
Abstract
One of the most important features of the nervous system is memory: the ability to represent and store experiences, in a manner that alters behavior and cognition at future times when the original stimulus is no longer present. However, the brain is not always an anatomically stable structure: many animal species regenerate all or part of the brain after severe injury, or remodel their CNS toward a new configuration as part of their life cycle. This raises a fascinating question: what are the dynamics of memories during brain regeneration? Can stable memories remain intact when cellular turnover and spatial rearrangement modify the biological hardware within which experiences are stored? What can we learn from model species that exhibit both, regeneration and memory, with respect to robustness and stability requirements for long-term memories encoded in living tissues? In this Perspective, we discuss relevant data in regenerating planaria, metamorphosing insects, and hibernating ground squirrels. While much remains to be done to understand this remarkable process, molecular-level insight will have important implications for cognitive science, regenerative medicine of the brain, and the development of non-traditional computational media in synthetic bioengineering.
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Affiliation(s)
- Douglas J Blackiston
- Center for Regenerative and Developmental Biology and Department of Biology; Tufts University ; Medford, MA USA
| | - Tal Shomrat
- Department of Neurobiology; Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus; Jerusalem, Israel; School of Marine Sciences, Ruppin Academic Center; Michmoret, Israel
| | - Michael Levin
- Center for Regenerative and Developmental Biology and Department of Biology; Tufts University ; Medford, MA USA
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32
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Reactive Oxygen Species in Planarian Regeneration: An Upstream Necessity for Correct Patterning and Brain Formation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:392476. [PMID: 26180588 PMCID: PMC4477255 DOI: 10.1155/2015/392476] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 12/12/2022]
Abstract
Recent research highlighted the impact of ROS as upstream regulators of tissue regeneration. We investigated their role and targeted processes during the regeneration of different body structures using the planarian Schmidtea mediterranea, an organism capable of regenerating its entire body, including its brain. The amputation of head and tail compartments induces a ROS burst at the wound site independently of the orientation. Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis. ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process. Stem cell proliferation was not affected, as indicated by histone H3-P immunostaining, fluorescence-activated cell sorting (FACS), in situ hybridization of smedwi-1, and transcript levels of proliferation-related genes. We showed for the first time that ROS modulate both anterior and posterior regeneration in a context where regeneration is not limited to certain body structures. Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.
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33
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Identification and expression analysis of a Spsb gene in planarian Dugesia japonica. Gene 2015; 564:168-75. [DOI: 10.1016/j.gene.2015.03.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 03/02/2015] [Accepted: 03/14/2015] [Indexed: 11/22/2022]
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Hwang B, An Y, Agata K, Umesono Y. Two distinct roles of the yorkie/yap gene during homeostasis in the planarian Dugesia japonica. Dev Growth Differ 2015; 57:209-17. [PMID: 25708270 PMCID: PMC4415594 DOI: 10.1111/dgd.12195] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/18/2014] [Accepted: 12/21/2014] [Indexed: 12/21/2022]
Abstract
Adult planarians possess somatic pluripotent stem cells called neoblasts that give rise to all missing cell types during regeneration and homeostasis. Recent studies revealed that the Yorkie (Yki)/Yes-associated protein (YAP) transcriptional coactivator family plays an important role in the regulation of tissue growth during development and regeneration, and therefore we investigated the role of a planarian yki-related gene (termed Djyki) during regeneration and homeostasis of the freshwater planarian Dugesia japonica. We found that knockdown of the function of Djyki by RNA interference (RNAi) downregulated neoblast proliferation and caused regeneration defects after amputation. In addition, Djyki RNAi caused edema during homeostasis. These seemingly distinct defects induced by Djyki RNAi were rescued by simultaneous RNAi of a planarian mats-related gene (termed Djmats), suggesting an important role of Djmats in the negative regulation of Djyki, in accordance with the conservation of the functional relationship of these two genes during the course of evolution. Interestingly, Djyki RNAi did not prevent normal protonephridial structure, suggesting that Djyki RNAi induced the edema phenotype without affecting the excretory system. Further analyses revealed that increased expression of the D. japonica gene DjaquaporinA (DjaqpA), which belongs to a large gene family that encodes a water channel protein for the regulation of transcellular water flow, promoted the induction of edema, but not defects in neoblast dynamics, in Djyki(RNAi) animals. Thus, we conclude that Djyki plays two distinct roles in the regulation of active proliferation of stem cells and in osmotic water transport across the body surface in D. japonica.
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Affiliation(s)
- Byulnim Hwang
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto
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35
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Thermosensory signaling by TRPM is processed by brain serotonergic neurons to produce planarian thermotaxis. J Neurosci 2015; 34:15701-14. [PMID: 25411498 DOI: 10.1523/jneurosci.5379-13.2014] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
For most organisms, sensitive recognition of even slight changes in environmental temperature is essential for adjusting their behavioral strategies to ensure homeostasis and survival. However, much remains to be understood about the molecular and cellular processes that regulate thermosensation and the corresponding behavioral responses. Planarians display clear thermotaxis, although they have a relatively simple brain. Here, we devised a quantitative thermotaxis assay and unraveled a neural pathway involved in planarian thermotaxis by combinatory behavioral assays and RNAi analysis. We found that thermosensory neurons that expressed a planarian Dugesia japonica homolog of the Transient Receptor Potential Melastatin family a (DjTRPMa) gene were required for the thermotaxis. Interestingly, although these thermosensory neurons are distributed throughout their body, planarians with a dysfunctional brain due to regeneration-dependent conditional gene knockdown (Readyknock) of the synaptotagmin gene completely lost their thermotactic behavior. These results suggest that brain function is required as a central processor for the thermosensory response. Therefore, we investigated the type(s) of brain neurons involved in processing the thermal signals by gene knockdown of limiting enzymes for neurotransmitter biosynthesis in the brain. We found that serotonergic neurons with dendrites that were elongated toward DjTRPMa-expressing thermosensory neurons might be required for the processing of signals from thermosensory neurons that results in thermotaxis. These results suggest that serotonergic neurons in the brain may interact with thermosensory neurons activated by TRPM ion channels to produce thermotaxis in planarians.
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36
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Planarian myosin essential light chain is involved in the formation of brain lateral branches during regeneration. Mol Genet Genomics 2015; 290:1277-85. [PMID: 25585662 DOI: 10.1007/s00438-015-0990-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 01/06/2015] [Indexed: 10/24/2022]
Abstract
The myosin essential light chain (ELC) is a structure component of the actomyosin cross-bridge, however, the functions in the central nervous system (CNS) development and regeneration remain poorly understood. Planarian Dugesia japonica has revealed fundamental mechanisms and unique aspects of neuroscience and neuroregeneration. In this study, the cDNA DjElc, encoding a planarian essential light chain of myosin, was identified from the planarian Dugesia japonica cDNA library. It encodes a deduced protein with highly conserved functionally domains EF-Hand and Ca(2+) binding sites that shares significant similarity with other members of ELC. Whole mount in situ hybridization studies show that DjElc expressed in CNS during embryonic development and regeneration of adult planarians. Loss of function of DjElc by RNA interference during planarian regeneration inhibits brain lateral branches regeneration completely. In conclusion, these results demonstrated that DjElc is required for maintenance of neurons and neurite outgrowth, particularly for involving the brain later branch regeneration.
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37
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Schaible R, Sussman M, Kramer BH. Aging and potential for self-renewal: hydra living in the age of aging - a mini-review. Gerontology 2014; 60:548-56. [PMID: 25012456 DOI: 10.1159/000360397] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 02/06/2014] [Indexed: 11/19/2022] Open
Abstract
Hydra present an interesting deviation from typical life histories: they have an extensive capacity to regenerate and self-renew and seem to defy the aging process. Hydra have the ability to decouple the aging process from their life history and therefore provide us with a unique opportunity to gain insight into the aging process not only for basal hydrozoans but also for other species across the tree of life. We argue that under steady feeding and asexual reproduction Hydra species are able to escape aging as a result of high levels of cell proliferation and regenerative ability. We further highlight cellular processes for stem cell maintenance, such as the telomere dynamic, which prevent the accumulation of damage and protect against diseases and pathogens that mediate this condition. In addition, we discuss the causes of aging in other Hydra species.
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Affiliation(s)
- Ralf Schaible
- Max Planck Institute for Demographic Research, Rostock, Germany
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38
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Dong Z, Shi C, Zhang H, Dou H, Cheng F, Chen G, Liu D. The characteristics of sox gene in Dugesia japonica. Gene 2014; 544:177-83. [DOI: 10.1016/j.gene.2014.04.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 03/29/2014] [Accepted: 04/23/2014] [Indexed: 11/30/2022]
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39
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Petralia RS, Mattson MP, Yao PJ. Aging and longevity in the simplest animals and the quest for immortality. Ageing Res Rev 2014; 16:66-82. [PMID: 24910306 DOI: 10.1016/j.arr.2014.05.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 05/08/2014] [Accepted: 05/22/2014] [Indexed: 12/12/2022]
Abstract
Here we review the examples of great longevity and potential immortality in the earliest animal types and contrast and compare these to humans and other higher animals. We start by discussing aging in single-celled organisms such as yeast and ciliates, and the idea of the immortal cell clone. Then we describe how these cell clones could become organized into colonies of different cell types that lead to multicellular animal life. We survey aging and longevity in all of the basal metazoan groups including ctenophores (comb jellies), sponges, placozoans, cnidarians (hydras, jellyfish, corals and sea anemones) and myxozoans. Then we move to the simplest bilaterian animals (with a head, three body cell layers, and bilateral symmetry), the two phyla of flatworms. A key determinant of longevity and immortality in most of these simple animals is the large numbers of pluripotent stem cells that underlie the remarkable abilities of these animals to regenerate and rejuvenate themselves. Finally, we discuss briefly the evolution of the higher bilaterians and how longevity was reduced and immortality lost due to attainment of greater body complexity and cell cycle strategies that protect these complex organisms from developing tumors. We also briefly consider how the evolution of multiple aging-related mechanisms/pathways hinders our ability to understand and modify the aging process in higher organisms.
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40
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Chan JD, Agbedanu PN, Zamanian M, Gruba SM, Haynes CL, Day TA, Marchant JS. 'Death and axes': unexpected Ca²⁺ entry phenologs predict new anti-schistosomal agents. PLoS Pathog 2014; 10:e1003942. [PMID: 24586156 PMCID: PMC3930560 DOI: 10.1371/journal.ppat.1003942] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/06/2014] [Indexed: 11/19/2022] Open
Abstract
Schistosomiasis is a parasitic flatworm disease that infects 200 million people worldwide. The drug praziquantel (PZQ) is the mainstay therapy but the target of this drug remains ambiguous. While PZQ paralyses and kills parasitic schistosomes, in free-living planarians PZQ caused an unusual axis duplication during regeneration to yield two-headed animals. Here, we show that PZQ activation of a neuronal Ca2+ channel modulates opposing dopaminergic and serotonergic pathways to regulate ‘head’ structure formation. Surprisingly, compounds with efficacy for either bioaminergic network in planarians also displayed antischistosomal activity, and reciprocally, agents first identified as antischistocidal compounds caused bipolar regeneration in the planarian bioassay. These divergent outcomes (death versus axis duplication) result from the same Ca2+ entry mechanism, and comprise unexpected Ca2+ phenologs with meaningful predictive value. Surprisingly, basic research into axis patterning mechanisms provides an unexpected route for discovering novel antischistosomal agents. Schistosomiasis (Bilharzia) is one of the most burdensome parasitic worm infections, encumbering third world economies with an annual loss of several million disability-adjusted life years. The key treatment for schistosome infections is the drug praziquantel but the mechanism of action of this drug remains controversial hampering targeted development of next generation antischistosomal agents. Here we provide fresh insight into the signaling pathways engaged by PZQ, by resolving commonalities in the action of PZQ with the process of regenerative signaling in free-living planarian flatworms. A similar calcium-dependent network is engaged in both model systems, but with divergent phenotypic outcomes. This relationship provides predictive insight such that basic research on signaling pathways involved in tissue regeneration reveals novel drug leads for schistosomiasis, and reciprocally schistosomal drug screens reveal targets involved in regenerative signaling. We believe this phenology will be helpful for uncovering new antischistosomal drug targets by exploiting broader vulnerabilities within the PZQ interactome.
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Affiliation(s)
- John D. Chan
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Prince N. Agbedanu
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Mostafa Zamanian
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Sarah M. Gruba
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Christy L. Haynes
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Timothy A. Day
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Jonathan S. Marchant
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America
- The Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail:
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Prokai D, Nguyen T, Kamrowski K, Chandra A, Talamantes T, Baxter LR, Prokai L. An exploratory evaluation of tyrosine hydroxylase inhibition in planaria as a model for parkinsonism. Int J Mol Sci 2013; 14:23289-96. [PMID: 24287905 PMCID: PMC3876044 DOI: 10.3390/ijms141223289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 12/26/2022] Open
Abstract
Planaria are the simplest organisms with bilateral symmetry and a central nervous system (CNS) with cephalization; therefore, they could be useful as model organisms to investigate mechanistic aspects of parkinsonism and to screen potential therapeutic agents. Taking advantage of the organism’s anti-tropism towards light, we measured a significantly reduced locomotor velocity in planaria after exposure to 3-iodo-l-tyrosine, an inhibitor of tyrosine hydroxylase that is an enzyme catalyzing the first and rate-limiting step in the biosynthesis of catecholamines. A simple semi-automatic assay using videotaped experiments and subsequent evaluation by tracking software was also implemented to increase throughput. The dopaminergic regulation of locomotor velocity was confirmed by bromocriptine, a drug whose mechanisms of action to treat Parkinson’s disease is believed to be through the stimulation of nerves that control movement.
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Affiliation(s)
- David Prokai
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL 32611, USA; E-Mails: (D.P.); (L.R.B.)
| | - Thinh Nguyen
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; E-Mails: (T.N.); (K.K.); (A.C.); (T.T.)
| | - Kurt Kamrowski
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; E-Mails: (T.N.); (K.K.); (A.C.); (T.T.)
| | - Ashwin Chandra
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; E-Mails: (T.N.); (K.K.); (A.C.); (T.T.)
| | - Tatjana Talamantes
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; E-Mails: (T.N.); (K.K.); (A.C.); (T.T.)
| | - Lewis R. Baxter
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL 32611, USA; E-Mails: (D.P.); (L.R.B.)
| | - Laszlo Prokai
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; E-Mails: (T.N.); (K.K.); (A.C.); (T.T.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-817-735-2206; Fax: +1-817-735-2118
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März M, Seebeck F, Bartscherer K. A Pitx transcription factor controls the establishment and maintenance of the serotonergic lineage in planarians. Development 2013; 140:4499-509. [DOI: 10.1242/dev.100081] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In contrast to adult vertebrates, which have limited capacities for neurogenesis, adult planarians undergo constitutive cellular turnover during homeostasis and are even able to regenerate a whole brain after decapitation. This enormous plasticity derives from pluripotent stem cells residing in the planarian body in large numbers. It is still obscure how these stem cells are programmed for differentiation into specific cell lineages and how lineage identity is maintained. Here we identify a Pitx transcription factor of crucial importance for planarian regeneration. In addition to patterning defects that are co-dependent on the LIM homeobox transcription factor gene islet1, which is expressed with pitx at anterior and posterior regeneration poles, RNAi against pitx results in islet1-independent specific loss of serotonergic (SN) neurons during regeneration. Besides its expression in terminally differentiated SN neurons we found pitx in stem cell progeny committed to the SN fate. Also, intact pitx RNAi animals gradually lose SN markers, a phenotype that depends neither on increased apoptosis nor on stem cell-based turnover or transdifferentiation into other neurons. We propose that pitx is a terminal selector gene for SN neurons in planarians that controls not only their maturation but also their identity by regulating the expression of the Serotonin production and transport machinery. Finally, we made use of this function of pitx and compared the transcriptomes of regenerating planarians with and without functional SN neurons, identifying at least three new neuronal targets of Pitx.
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Affiliation(s)
- Martin März
- Max Planck Research Group Stem Cells and Regeneration, Max Planck Institute for Molecular Biomedicine, Von-Esmarch-Strasse 54, 48149 Münster, Germany
| | - Florian Seebeck
- Max Planck Research Group Stem Cells and Regeneration, Max Planck Institute for Molecular Biomedicine, Von-Esmarch-Strasse 54, 48149 Münster, Germany
| | - Kerstin Bartscherer
- Max Planck Research Group Stem Cells and Regeneration, Max Planck Institute for Molecular Biomedicine, Von-Esmarch-Strasse 54, 48149 Münster, Germany
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43
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Umesono Y, Tasaki J, Nishimura Y, Hrouda M, Kawaguchi E, Yazawa S, Nishimura O, Hosoda K, Inoue T, Agata K. The molecular logic for planarian regeneration along the anterior–posterior axis. Nature 2013; 500:73-6. [DOI: 10.1038/nature12359] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 06/07/2013] [Indexed: 12/25/2022]
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Shomrat T, Levin M. An automated training paradigm reveals long-term memory in planarians and its persistence through head regeneration. ACTA ACUST UNITED AC 2013; 216:3799-810. [PMID: 23821717 DOI: 10.1242/jeb.087809] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Planarian flatworms are a popular system for research into the molecular mechanisms that enable these complex organisms to regenerate their entire body, including the brain. Classical data suggest that they may also be capable of long-term memory. Thus, the planarian system may offer the unique opportunity to study brain regeneration and memory in the same animal. To establish a system for the investigation of the dynamics of memory in a regenerating brain, we developed a computerized training and testing paradigm that avoided the many issues that confounded previous, manual attempts to train planarians. We then used this new system to train flatworms in an environmental familiarization protocol. We show that worms exhibit environmental familiarization, and that this memory persists for at least 14 days - long enough for the brain to regenerate. We further show that trained, decapitated planarians exhibit evidence of memory retrieval in a savings paradigm after regenerating a new head. Our work establishes a foundation for objective, high-throughput assays in this molecularly tractable model system that will shed light on the fundamental interface between body patterning and stored memories. We propose planarians as key emerging model species for mechanistic investigations of the encoding of specific memories in biological tissues. Moreover, this system is lik ely to have important implications for the biomedicine of stem-cell-derived treatments of degenerative brain disorders in human adults.
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Affiliation(s)
- Tal Shomrat
- Biology Department and Tufts Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155, USA
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Elliott SA, Sánchez Alvarado A. The history and enduring contributions of planarians to the study of animal regeneration. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2013; 2:301-26. [PMID: 23799578 PMCID: PMC3694279 DOI: 10.1002/wdev.82] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Having an almost unlimited capacity to regenerate tissues lost to age and injury, planarians have long fascinated naturalists. In the Western hemisphere alone, their documented history spans more than 200 years. Planarians were described in the early 19th century as being 'immortal under the edge of the knife', and initial investigation of these remarkable animals was significantly influenced by studies of regeneration in other organisms and from the flourishing field of experimental embryology in the late 19th and early 20th centuries. This review strives to place the study of planarian regeneration into a broader historical context by focusing on the significance and evolution of knowledge in this field. It also synthesizes our current molecular understanding of the mechanisms of planarian regeneration uncovered since this animal's relatively recent entrance into the molecular-genetic age.
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Affiliation(s)
- Sarah A Elliott
- Howard Hughes Medical Institute and Stowers Institute for Medical Research, Kansas City, MO, USA.
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Perez Y, Rieger V, Martin E, Müller CHG, Harzsch S. Neurogenesis in an early protostome relative: progenitor cells in the ventral nerve center of chaetognath hatchlings are arranged in a highly organized geometrical pattern. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 320:179-93. [PMID: 23483730 DOI: 10.1002/jez.b.22493] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/29/2012] [Accepted: 01/23/2013] [Indexed: 01/08/2023]
Abstract
Emerging evidence suggests that Chaetognatha represent an evolutionary lineage that is the sister group to all other Protostomia thus promoting these animals as a pivotal model for our understanding of bilaterian evolutionary history. We have analyzed the proliferation of neuronal progenitor cells in the developing ventral nerve center (VNC) of Spadella cephaloptera hatchlings. To that end, for the first time in Chaetognatha, we performed in vivo incorporation experiments with the S-phase specific mitosis marker bromodeoxyuridine (BrdU). Our experiments provide evidence for a high level of mitotic activity in the VNC for ca. 3 days after hatching. Neurogenesis is carried by presumptive neuronal progenitor cells that cycle rapidly and most likely divide asymmetrically. These progenitors are arranged in a distinct grid-like geometrical pattern including about 35 transverse rows. Considering Chaetognaths to be an early offshoot of the protostome lineage we conclude that the presence of neuronal progenitor cells with asymmetric division seems to be a feature that is rooted deeply in the Metazoa. In the light of previous evidence indicating the presence of serially iterated peptidergic neurons with individual identities in the chaetognath VNC, we discuss if these neuronal progenitor cells give rise to distinct lineages. Furthermore, we evaluate the serially iterated arrangement of the progenitor cells in the light of evolution of segmentation.
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Affiliation(s)
- Yvan Perez
- Institut Méditerranéen de Biodiversité et d'Ecologie Evolution Genome Environment, IMBE-UMR CNRS 7263/IRD 237 Aix-Marseille Université/Centre St Charles, Marseille cedex 3, France
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Abstract
Planarians are members of the Platyhelminthes (flatworms). These animals have evolved a remarkable stem cell system. A single pluripotent adult stem cell type ("neoblast") gives rise to the entire range of cell types and organs in the planarian body plan, including a brain, digestive-, excretory-, sensory- and reproductive systems. Neoblasts are abundantly present throughout the mesenchyme and divide continuously. The resulting stream of progenitors and turnover of differentiated cells drive the rapid self-renewal of the entire animal within a matter of weeks. Planarians grow and literally de-grow ("shrink") by the food supply-dependent adjustment of organismal turnover rates, scaling body plan proportions over as much as a 50-fold size range. Their dynamic body architecture further allows astonishing regenerative abilities, including the regeneration of complete and perfectly proportioned animals even from tiny tissue remnants. Planarians as an experimental system, therefore, provide unique opportunities for addressing a spectrum of current problems in stem cell research, including the evolutionary conservation of pluripotency, the dynamic organization of differentiation lineages and the mechanisms underlying organismal stem cell homeostasis. The first part of this review focuses on the molecular biology of neoblasts as pluripotent stem cells. The second part examines the fascinating mechanistic and conceptual challenges posed by a stem cell system that epitomizes a universal design principle of biological systems: the dynamic steady state.
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Affiliation(s)
- Jochen C Rink
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
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The (real) neurogenic/gliogenic potential of the postnatal and adult brain parenchyma. ISRN NEUROSCIENCE 2013; 2013:354136. [PMID: 24967310 PMCID: PMC4045543 DOI: 10.1155/2013/354136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 01/08/2013] [Indexed: 11/17/2022]
Abstract
During the last two decades basic research in neuroscience has remarkably expanded due to the discovery of neural stem cells (NSCs) and adult neurogenesis in the mammalian central nervous system (CNS). The existence of such unexpected plasticity triggered hopes for alternative approaches to brain repair, yet deeper investigation showed that constitutive mammalian neurogenesis is restricted to two small "neurogenic sites" hosting NSCs as remnants of embryonic germinal layers and subserving homeostatic roles in specific neural systems. The fact that in other classes of vertebrates adult neurogenesis is widespread in the CNS and useful for brain repair sometimes creates misunderstandings about the real reparative potential in mammals. Nevertheless, in the mammalian CNS parenchyma, which is commonly considered as "nonneurogenic," some processes of gliogenesis and, to a lesser extent, neurogenesis also occur. This "parenchymal" cell genesis is highly heterogeneous as to the position, identity, and fate of the progenitors. In addition, even the regional outcomes are different. In this paper the heterogeneity of mammalian parenchymal neurogliogenesis will be addressed, also discussing the most common pitfalls and misunderstandings of this growing and promising research field.
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The stem cell system in demosponges: suggested involvement of two types of cells: archeocytes (active stem cells) and choanocytes (food-entrapping flagellated cells). Dev Genes Evol 2012; 223:23-38. [PMID: 23053625 DOI: 10.1007/s00427-012-0417-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 09/16/2012] [Indexed: 10/27/2022]
Abstract
Major questions about stem cell systems include what type(s) of stem cells are involved (unipotent/totipotent/pluripotent/multipotent stem cells) and how the self-renewal and differentiation of stem cells are regulated. Sponges, the sister group of all other animals and probably the earliest branching multicellular lineage of extant animals, are thought to possess totipotent stem cells. This review introduces what is known about the stem cells in sponges based on histological studies and also on recent molecular biological studies that have started to reveal the molecular and cellular mechanisms of the stem cell system in sponges (mainly in demosponges). The currently proposed model of the stem cell system in demosponges is described, and the possible applicability of this model to other classes of sponges is discussed. Finally, a possible scenario of the evolution of stem cells, including how migrating stem cells arose in the urmetazoan (the last common ancestor of metazoans) and the evolutionary origin of germ line cells in the urbilaterian (the last common ancestor of bilaterians), are discussed.
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Nishimura O, Hirao Y, Tarui H, Agata K. Comparative transcriptome analysis between planarian Dugesia japonica and other platyhelminth species. BMC Genomics 2012; 13:289. [PMID: 22747887 PMCID: PMC3507646 DOI: 10.1186/1471-2164-13-289] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 06/04/2012] [Indexed: 11/10/2022] Open
Abstract
Background Planarians are considered to be among the extant animals close to one of the earliest groups of organisms that acquired a central nervous system (CNS) during evolution. Planarians have a bilobed brain with nine lateral branches from which a variety of external signals are projected into different portions of the main lobes. Various interneurons process different signals to regulate behavior and learning/memory. Furthermore, planarians have robust regenerative ability and are attracting attention as a new model organism for the study of regeneration. Here we conducted large-scale EST analysis of the head region of the planarian Dugesia japonica to construct a database of the head-region transcriptome, and then performed comparative analyses among related species. Results A total of 54,752 high-quality EST reads were obtained from a head library of the planarian Dugesia japonica, and 13,167 unigene sequences were produced by de novo assembly. A new method devised here revealed that proteins related to metabolism and defense mechanisms have high flexibility of amino-acid substitutions within the planarian family. Eight-two CNS-development genes were found in the planarian (cf. C. elegans 3; chicken 129). Comparative analysis revealed that 91% of the planarian CNS-development genes could be mapped onto the schistosome genome, but one-third of these shared genes were not expressed in the schistosome. Conclusions We constructed a database that is a useful resource for comparative planarian transcriptome studies. Analysis comparing homologous genes between two planarian species showed that the potential of genes is important for accumulation of amino-acid substitutions. The presence of many CNS-development genes in our database supports the notion that the planarian has a fundamental brain with regard to evolution and development at not only the morphological/functional, but also the genomic, level. In addition, our results indicate that the planarian CNS-development genes already existed before the divergence of planarians and schistosomes from their common ancestor.
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Affiliation(s)
- Osamu Nishimura
- Department of Biophysics and Global COE Program, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
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