1
|
Kumar VS, Sivasubramanian S, Padmanabhan P, Anupama CP, Ramesh K, Gunasekaran P, Krishnasamy K, Kitambi SS. Etiological Profile and Clinico Epidemiological Patterns of Acute Encephalitis Syndrome in Tamil Nadu, India. J Glob Infect Dis 2023; 15:52-58. [PMID: 37469472 PMCID: PMC10353646 DOI: 10.4103/jgid.jgid_179_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/03/2022] [Accepted: 12/15/2022] [Indexed: 07/21/2023] Open
Abstract
Introduction Establishing the etiological cause of acute encephalitis syndrome (AES) is challenging due to the distinct distribution of various etiological agents. This study aims to determine the etiological profiles of both viruses and bacteria and their associated clinico-epidemiological features among the AES suspected cases in Tamil Nadu, India. Methods Samples of 5136 suspected AES cases from January 2016 to December 2020 (5 years) were subjected to the detection of etiological agents for AES through serological and molecular diagnosis methods. Further, the clinical profile, age- and gender-wise susceptibility of cases, co-infection with other AES etiological agents, and seasonality pattern with respect to various etiological agents were examined. Results AES positivity was established in 1480 cases (28.82%) among the 5136 suspected cases and the positivity for male and female groups were 57.77% and 42.23%, respectively. The pediatric group was found to be more susceptible than others. Among the etiological agents tested, the Japanese encephalitis virus (JEV) was the predominant followed by Cytomegalovirus, Herpes Simplex virus, Epstein-Barr virus, Varicella Zoster virus, and others. Co-infection with other AES etiological agents was observed in 3.5% of AES-positive cases. Seasonality was observed only for vector-borne diseases such as JEV, dengue virus, and West Nile virus infections in this study. Conclusion AES was found to be a significant burden for Tamil Nadu with a diverse etiological spectrum including both sporadic and outbreak forms. Overlapping clinical manifestations of AES agents necessitate the development of region-specific diagnostic algorithm with distinct etiological profiles for early detection and effective case management.
Collapse
Affiliation(s)
- Vijayan Senthil Kumar
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Srinivasan Sivasubramanian
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Padmapriya Padmanabhan
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Cherayi Padinjakare Anupama
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Kiruba Ramesh
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Palani Gunasekaran
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Kaveri Krishnasamy
- Department of Virology, State Viral Research and Diagnostic Laboratory, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Satish Srinivas Kitambi
- Department of Translational Sciences, Institute for Healthcare Education and Translational Sciences, Hyderabad, Telangana, India
| |
Collapse
|
2
|
Gopalan V, Chandran A, Arumugam K, Sundaram M, Velladurai S, Govindan K, Azhagesan N, Jeyavel P, Dhandapani P, Sivasubramanian S, Kitambi SS. Distribution and Functional Analyses of Mutations in Spike Protein and Phylogenic Diversity of SARS-CoV-2 Variants Emerged during the Year 2021 in India. J Glob Infect Dis 2023; 15:43-51. [PMID: 37469462 PMCID: PMC10353649 DOI: 10.4103/jgid.jgid_178_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/27/2022] [Accepted: 01/04/2023] [Indexed: 07/21/2023] Open
Abstract
Introduction Prolonged COVID-19 pandemic accelerates the emergence and transmissibility of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants through the accumulation of adaptive mutations. Particularly, adaptive mutations in spike (S) protein of SARS-CoV-2 leads to increased viral infectivity, severe morbidity and mortality, and immune evasion. This study focuses on the phylodynamic distribution of SARS-CoV-2 variants during the year 2021 in India besides analyzing the functional significance of mutations in S-protein of SARS-CoV-2 variants. Methods Whole genome of SARS-CoV-2 sequences (n = 87957) from the various parts of India over the period of January to December 2021 was retrieved from Global Initiative on Sharing All Influenza Data. All the S-protein sequences were subjected to clade analysis, variant calling, protein stability, immune escape potential, structural divergence, Furin cleavage efficiency, and phylogenetic analysis using various in silico tools. Results Delta variant belonging to 21A, 21I, and 21J clades was found to be predominant throughout the year 2021 though many variants were also present. A total of 4639 amino acid mutations were found in S-protein. D614G was the most predominant mutation in the S-protein followed by P681R, L452R, T19R, T478K, and D950N. The highest number of mutations was found in the N-terminal domain of S-protein. Mutations in the crucial sites of S-protein impacting pathogenicity, immunogenicity, and fusogenicity were identified. Intralineage diversity analysis showed that certain variants of SARS-CoV-2 possess high diversification. Conclusions The study has disclosed the distribution of various variants including the Delta, the predominant variant, in India throughout the year 2021. The study has identified mutations in S-protein of each SARS-CoV-2 variant that can significantly impact the virulence, immune evasion, increased transmissibility, high morbidity, and mortality. In addition, it is found that mutations acquired during each viral replication cycle introduce new sub-lineages as studied by intralineage diversity analysis.
Collapse
Affiliation(s)
- Vidya Gopalan
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Aswathi Chandran
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Kishore Arumugam
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Monisha Sundaram
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Selvakumar Velladurai
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Karthikeyan Govindan
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Nivetha Azhagesan
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Padmapriya Jeyavel
- Department of Virology, King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Prabu Dhandapani
- Department of Microbiology, Dr. ALM Post Graduate, Institute of Basic Medical Sciences, University of Madras, Chennai, Tamil Nadu, India
| | | | - Satish Srinivas Kitambi
- Department of Translational Sciences, Institute for Healthcare Education and Translational Sciences, Hyderabad, Telengana, India
| |
Collapse
|
3
|
Sivasubramanian S, Gopalan V, Ramesh K, Padmanabhan P, Mone K, Govindan K, Velladurai S, Dhandapani P, Krishnasamy K, Kitambi SS. Phylodynamic Pattern of Genetic Clusters, Paradigm Shift on Spatio-Temporal Distribution of Clades, and Impact of Spike Glycoprotein Mutations of SARS-CoV-2 Isolates from India. J Glob Infect Dis 2021; 13:164-171. [PMID: 35017872 PMCID: PMC8697821 DOI: 10.4103/jgid.jgid_97_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 09/22/2021] [Accepted: 10/04/2021] [Indexed: 11/18/2022] Open
Abstract
Introduction: The COVID-19 pandemic is associated with high morbidity and mortality, with the emergence of numerous variants. The dynamics of SARS-CoV-2 with respect to clade distribution is uneven, unpredictable and fast changing. Methods: Retrieving the complete genomes of SARS-CoV-2 from India and subjecting them to analysis on phylogenetic clade diversity, Spike (S) protein mutations and their functional consequences such as immune escape features and impact on infectivity. Whole genome of SARS-CoV-2 isolates (n = 4,326) deposited from India during the period from January 2020 to December 2020 is retrieved from Global Initiative on Sharing All Influenza Data (GISAID) and various analyses performed using in silico tools. Results: Notable clade dynamicity is observed indicating the emergence of diverse SARS-CoV-2 variants across the country. GR clade is predominant over the other clades and the distribution pattern of clades is uneven. D614G is the commonest and predominant mutation found among the S-protein followed by L54F. Mutation score prediction analyses reveal that there are several mutations in S-protein including the RBD and NTD regions that can influence the virulence of virus. Besides, mutations having immune escape features as well as impacting the immunogenicity and virulence through changes in the glycosylation patterns are identified. Conclusions: The study has revealed emergence of variants with shifting of clade dynamics within a year in India. It is shown uneven distribution of clades across the nation requiring timely deposition of SARS-CoV-2 sequences. Functional evaluation of mutations in S-protein reveals their significance in virulence, immune escape features and disease severity besides impacting therapeutics and prophylaxis.
Collapse
Affiliation(s)
- Srinivasan Sivasubramanian
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Vidya Gopalan
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Kiruba Ramesh
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Padmapriya Padmanabhan
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Kiruthiga Mone
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Karthikeyan Govindan
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Selvakumar Velladurai
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Prabu Dhandapani
- Department of Microbiology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai, Tamil Nadu, India
| | - Kaveri Krishnasamy
- Department of Virology, State Viral Research and Diagnostic Laboratory (VRDL), King Institute of Preventive Medicine and Research, Chennai, Tamil Nadu, India
| | - Satish Srinivas Kitambi
- Department of Translational Sciences, Institute for Healthcare Education and Translational Sciences, Hyderabad, Telengana, India
| |
Collapse
|
4
|
Kitambi SS, Toledo EM, Usoskin D, Wee S, Harisankar A, Svensson R, Sigmundsson K, Kalderén C, Niklasson M, Kundu S, Aranda S, Westermark B, Uhrbom L, Andäng M, Damberg P, Nelander S, Arenas E, Artursson P, Walfridsson J, Nilsson KF, Hammarström LGJ, Ernfors P. Retraction Notice to: Vulnerability of Glioblastoma Cells to Catastrophic Vacuolization and Death Induced by a Small Molecule. Cell 2017; 170:407. [PMID: 28709005 DOI: 10.1016/j.cell.2017.06.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
5
|
Dasari B, Fufa T, Aeluri M, Gaddam J, Deora GS, Gaunitz F, Kitambi SS, Arya P. Macrocyclic Toolbox from Epothilone Fragment Identifies a Compound Showing Molecular Interactions with Actin and Novel Promoters of Apoptosis in Patient-derived Brain Tumor Cells. ASIAN J ORG CHEM 2016. [DOI: 10.1002/ajoc.201600126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Bhanudas Dasari
- Dr. Reddy's Institute of Life Sciences (DRILS); University of Hyderabad, Campus; Hyderabad 500046 India
- Sai Advantium Pharma Ltd.; IKP Road Turkapally; Hyderabad 500078 India
| | - Temesgen Fufa
- Klinik und Poliklinik für Neurochirurgie; Universitätsklinikum Leipzig; Leipzig Germany
- Department of Microbiology and Tumor and Cell Biology; Karolinska Institutet; 17177 Stockholm Sweden
| | - Madhu Aeluri
- Dr. Reddy's Institute of Life Sciences (DRILS); University of Hyderabad, Campus; Hyderabad 500046 India
- GVK Biosciences, Nacharam; IDA Mallapur; Hyderabad 500076 India
| | - Jagan Gaddam
- Dr. Reddy's Institute of Life Sciences (DRILS); University of Hyderabad, Campus; Hyderabad 500046 India
| | - Girdhar Singh Deora
- School of Pharmacy; The University of Queensland; Brisbane QLD 4072 Australia
| | - Frank Gaunitz
- Klinik und Poliklinik für Neurochirurgie; Universitätsklinikum Leipzig; Leipzig Germany
| | - Satish Srinivas Kitambi
- Department of Microbiology and Tumor and Cell Biology; Karolinska Institutet; 17177 Stockholm Sweden
| | - Prabhat Arya
- Dr. Reddy's Institute of Life Sciences (DRILS); University of Hyderabad, Campus; Hyderabad 500046 India
| |
Collapse
|
6
|
Theofilopoulos S, Griffiths WJ, Crick PJ, Yang S, Meljon A, Ogundare M, Kitambi SS, Lockhart A, Tuschl K, Clayton PT, Morris AA, Martinez A, Reddy MA, Martinuzzi A, Bassi MT, Honda A, Mizuochi T, Kimura A, Nittono H, De Michele G, Carbone R, Criscuolo C, Yau JL, Seckl JR, Schüle R, Schöls L, Sailer AW, Kuhle J, Fraidakis MJ, Gustafsson JÅ, Steffensen KR, Björkhem I, Ernfors P, Sjövall J, Arenas E, Wang Y. Cholestenoic acids regulate motor neuron survival via liver X receptors. J Clin Invest 2014; 124:4829-42. [PMID: 25271621 DOI: 10.1172/jci68506] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 08/21/2014] [Indexed: 11/17/2022] Open
Abstract
Cholestenoic acids are formed as intermediates in metabolism of cholesterol to bile acids, and the biosynthetic enzymes that generate cholestenoic acids are expressed in the mammalian CNS. Here, we evaluated the cholestenoic acid profile of mammalian cerebrospinal fluid (CSF) and determined that specific cholestenoic acids activate the liver X receptors (LXRs), enhance islet-1 expression in zebrafish, and increase the number of oculomotor neurons in the developing mouse in vitro and in vivo. While 3β,7α-dihydroxycholest-5-en-26-oic acid (3β,7α-diHCA) promoted motor neuron survival in an LXR-dependent manner, 3β-hydroxy-7-oxocholest-5-en-26-oic acid (3βH,7O-CA) promoted maturation of precursors into islet-1+ cells. Unlike 3β,7α-diHCA and 3βH,7O-CA, 3β-hydroxycholest-5-en-26-oic acid (3β-HCA) caused motor neuron cell loss in mice. Mutations in CYP7B1 or CYP27A1, which encode enzymes involved in cholestenoic acid metabolism, result in different neurological diseases, hereditary spastic paresis type 5 (SPG5) and cerebrotendinous xanthomatosis (CTX), respectively. SPG5 is characterized by spastic paresis, and similar symptoms may occur in CTX. Analysis of CSF and plasma from patients with SPG5 revealed an excess of the toxic LXR ligand, 3β-HCA, while patients with CTX and SPG5 exhibited low levels of the survival-promoting LXR ligand 3β,7α-diHCA. Moreover, 3β,7α-diHCA prevented the loss of motor neurons induced by 3β-HCA in the developing mouse midbrain in vivo.Our results indicate that specific cholestenoic acids selectively work on motor neurons, via LXR, to regulate the balance between survival and death.
Collapse
|
7
|
Kitambi SS, Toledo EM, Usoskin D, Wee S, Harisankar A, Svensson R, Sigmundsson K, Kalderén C, Niklasson M, Kundu S, Aranda S, Westermark B, Uhrbom L, Andäng M, Damberg P, Nelander S, Arenas E, Artursson P, Walfridsson J, Forsberg Nilsson K, Hammarström LGJ, Ernfors P. RETRACTED: Vulnerability of glioblastoma cells to catastrophic vacuolization and death induced by a small molecule. Cell 2014; 157:313-328. [PMID: 24656405 DOI: 10.1016/j.cell.2014.02.021] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/18/2013] [Accepted: 02/06/2014] [Indexed: 12/25/2022]
Abstract
Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer with marginal life expectancy. Based on the assumption that GBM cells gain functions not necessarily involved in the cancerous process, patient-derived glioblastoma cells (GCs) were screened to identify cellular processes amenable for development of targeted treatments. The quinine-derivative NSC13316 reliably and selectively compromised viability. Synthetic chemical expansion reveals delicate structure-activity relationship and analogs with increased potency, termed Vacquinols. Vacquinols stimulate death by membrane ruffling, cell rounding, massive macropinocytic vacuole accumulation, ATP depletion, and cytoplasmic membrane rupture of GCs. The MAP kinase MKK4, identified by a shRNA screen, represents a critical signaling node. Vacquinol-1 displays excellent in vivo pharmacokinetics and brain exposure, attenuates disease progression, and prolongs survival in a GBM animal model. These results identify a vulnerability to massive vacuolization that can be targeted by small molecules and point to the possible exploitation of this process in the design of anticancer therapies.
Collapse
Affiliation(s)
- Satish Srinivas Kitambi
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Enrique M Toledo
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Dmitry Usoskin
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Shimei Wee
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Aditya Harisankar
- Department of Medicine, HERM, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Richard Svensson
- Department of Pharmacy, UDOPP, Chemical Biology Consortium Sweden, Uppsala University, 751 05 Uppsala, Sweden
| | - Kristmundur Sigmundsson
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine & Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Christina Kalderén
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine & Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Mia Niklasson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Soumi Kundu
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Sergi Aranda
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Bengt Westermark
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Lene Uhrbom
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Michael Andäng
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Peter Damberg
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Sven Nelander
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Ernest Arenas
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Per Artursson
- Department of Pharmacy, UDOPP, Chemical Biology Consortium Sweden, Uppsala University, 751 05 Uppsala, Sweden
| | - Julian Walfridsson
- Department of Medicine, HERM, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Karin Forsberg Nilsson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Lars G J Hammarström
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine & Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Patrik Ernfors
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden.
| |
Collapse
|
8
|
Abdelhady S, Kitambi SS, Lundin V, Aufschnaiter R, Sekyrova P, Sinha I, Lundgren KT, Castelo-Branco G, Linnarsson S, Wedlich-Söldner R, Teixeira A, Andäng M. Erg channel is critical in controlling cell volume during cell cycle in embryonic stem cells. PLoS One 2013; 8:e72409. [PMID: 23936540 PMCID: PMC3732234 DOI: 10.1371/journal.pone.0072409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 07/16/2013] [Indexed: 02/05/2023] Open
Abstract
The cell cycle progression in mouse embryonic stem cells (mESCs) is controlled by ion fluxes that alter cell volume [1]. This suggests that ion fluxes might control dynamic changes in morphology over the cell cycle, such as rounding up of the cell at mitosis. However, specific channels regulating such dynamic changes and the possible interactions with actomyosin complex have not been clearly identified. Following RNAseq transcriptome analysis of cell cycle sorted mESCs, we found that expression of the K+ ion channel Erg1 peaked in G1 cell cycle phase, which was confirmed by immunostaining. Inhibition of Erg channel activity caused loss of G1 phase cells via non-apoptotic cell death. Cells first lost the ability of membrane blebbing, a typical feature of cultured embryonic stem cells. Continued Erg inhibition further increased cell volume and the cell eventually ruptured. In addition, atomic force measurements on live cells revealed a decreased cortical stiffness after treatment, suggesting alterations in actomyosin organization. When the intracellular osmotic pressure was experimentally decreased by hypertonic solution or block of K+ ion import via the Na, K-ATPase, cell viability was restored and cells acquired normal volume and blebbing activity. Our results suggest that Erg channels have a critical function in K+ ion homeostasis of mESCs over the cell cycle, and that cell death following Erg inhibition is a consequence of the inability to regulate cell volume.
Collapse
Affiliation(s)
- Shaimaa Abdelhady
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Vanessa Lundin
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Roland Aufschnaiter
- Cellular Dynamics and Cell Patterning, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Petra Sekyrova
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Indranil Sinha
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kalle T. Lundgren
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- Department of Reconstructive Plastic Surgery, Karolinska University Hospital, Stockholm, Sweden
| | | | - Sten Linnarsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Roland Wedlich-Söldner
- Cellular Dynamics and Cell Patterning, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Ana Teixeira
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Michael Andäng
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
| |
Collapse
|
9
|
Reddy Guduru SK, Chamakuri S, Chandrasekar G, Kitambi SS, Arya P. Tetrahydroquinoline-derived macrocyclic toolbox: the discovery of antiangiogenesis agents in zebrafish assay. ACS Med Chem Lett 2013; 4:666-70. [PMID: 24900727 DOI: 10.1021/ml400026n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 05/24/2013] [Indexed: 02/06/2023] Open
Abstract
A novel approach to incorporate the macrocyclic rings onto the privileged substructure, i.e., tetrahydroquinoline scaffold, is developed. The presence of an amino acid-derived moiety in the macrocyclic skeleton provides an opportunity to modulate the nature of the chiral side chain. Further, evaluation in a zebrafish screen identified three active small molecules (2.5b, 3.2d, and 4.2) as antiangiogenesis agents at 2.5 μM.
Collapse
Affiliation(s)
- Shiva Krishna Reddy Guduru
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India
| | - Srinivas Chamakuri
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India
| | | | - Satish Srinivas Kitambi
- School of Life Sciences, Södertörns Högskola, Sweden
- Division of Molecular Neurobiology and Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Prabhat Arya
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India
| |
Collapse
|
10
|
Jogula S, Dasari B, Khatravath M, Chandrasekar G, Kitambi SS, Arya P. Building a Macrocyclic Toolbox fromC-Linked Carbohydrates Identifies Antiangiogenesis Agents from Zebrafish Assay. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300548] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
11
|
Aeluri M, Gaddam J, Trinath DVKS, Chandrasekar G, Kitambi SS, Arya P. An Intramolecular Heck Approach To Obtain 17-Membered Macrocyclic Diversity and the Identification of an Antiangiogenesis Agent from a Zebrafish Assay. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300408] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
12
|
Chamakuri S, Guduru SKR, Pamu S, Chandrasekar G, Kitambi SS, Arya P. A Modular Approach to Build Macrocyclic Diversity in Aminoindoline Scaffolds Identifies Antiangiogenesis Agents from a Zebrafish Assay. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300409] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
13
|
Dasari B, Jogula S, Borhade R, Balasubramanian S, Chandrasekar G, Kitambi SS, Arya P. Macrocyclic Glycohybrid Toolbox Identifies Novel Antiangiogenesis Agents from Zebrafish Assay. Org Lett 2013; 15:432-5. [DOI: 10.1021/ol3032297] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Bhanudas Dasari
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Srinivas Jogula
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Ramdas Borhade
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Sridhar Balasubramanian
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Gayathri Chandrasekar
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Satish Srinivas Kitambi
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Prabhat Arya
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition, Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| |
Collapse
|
14
|
Aeluri M, Pramanik C, Chetia L, Mallurwar NK, Balasubramanian S, Chandrasekar G, Kitambi SS, Arya P. 14-Membered Macrocyclic Ring-Derived Toolbox: The Identification of Small Molecule Inhibitors of Angiogenesis and Early Embryo Development in Zebrafish Assay. Org Lett 2013; 15:436-9. [DOI: 10.1021/ol3032126] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Madhu Aeluri
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Chinmoy Pramanik
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Lakshindra Chetia
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Naveen Kumar Mallurwar
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Sridhar Balasubramanian
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Gayathri Chandrasekar
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Satish Srinivas Kitambi
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Prabhat Arya
- Dr. Reddy’s Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India, School of Life Sciences, Södertörns Högskola, Sweden, and Department of Biosciences and Medical Nutrition and Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| |
Collapse
|
15
|
Kitambi SS, Nilsson ES, Sekyrova P, Ibarra C, Tekeoh GN, Andäng M, Ernfors P, Uhlén P. Small molecule screening platform for assessment of cardiovascular toxicity on adult zebrafish heart. BMC Physiol 2012; 12:3. [PMID: 22449203 PMCID: PMC3334682 DOI: 10.1186/1472-6793-12-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 03/26/2012] [Indexed: 01/27/2023]
Abstract
Background Cardiovascular toxicity is a major limiting factor in drug development and requires multiple cost-effective models to perform toxicological evaluation. Zebrafish is an excellent model for many developmental, toxicological and regenerative studies. Using approaches like morpholino knockdown and electrocardiogram, researchers have demonstrated physiological and functional similarities between zebrafish heart and human heart. The close resemblance of the genetic cascade governing heart development in zebrafish to that of humans has propelled the zebrafish system as a cost-effective model to conduct various genetic and pharmacological screens on developing embryos and larvae. The current report describes a methodology for rapid isolation of adult zebrafish heart, maintenance ex vivo, and a setup to perform quick small molecule throughput screening, including an in-house implemented analysis script. Results Adult zebrafish were anesthetized and after rapid decapitation the hearts were isolated. The short time required for isolation of hearts allows dissection of multiple fishes, thereby obtaining a large sample size. The simple protocol for ex vivo culture allowed maintaining the beating heart for several days. The in-house developed script and spectral analyses allowed the readouts to be presented either in time domain or in frequency domain. Taken together, the current report offers an efficient platform for performing cardiac drug testing and pharmacological screens. Conclusion The new methodology presents a fast, cost-effective, sensitive and reliable method for performing small molecule screening. The variety of readouts that can be obtained along with the in-house developed analyses script offers a powerful setup for performing cardiac toxicity evaluation by researchers from both academics and industry.
Collapse
Affiliation(s)
- Satish Srinivas Kitambi
- Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, Stockholm 17177, Sweden.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Adameyko I, Lallemend F, Furlan A, Zinin N, Aranda S, Kitambi SS, Blanchart A, Favaro R, Nicolis S, Lübke M, Müller T, Birchmeier C, Suter U, Zaitoun I, Takahashi Y, Ernfors P. Sox2 and Mitf cross-regulatory interactions consolidate progenitor and melanocyte lineages in the cranial neural crest. Development 2012; 139:397-410. [PMID: 22186729 DOI: 10.1242/dev.065581] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cellular origin and molecular mechanisms regulating pigmentation of head and neck are largely unknown. Melanocyte specification is controlled by the transcriptional activity of Mitf, but no general logic has emerged to explain how Mitf and progenitor transcriptional activities consolidate melanocyte and progenitor cell fates. We show that cranial melanocytes arise from at least two different cellular sources: initially from nerve-associated Schwann cell precursors (SCPs) and later from a cellular source that is independent of nerves. Unlike the midbrain-hindbrain cluster from which melanoblasts arise independently of nerves, a large center of melanocytes in and around cranial nerves IX-X is derived from SCPs, as shown by genetic cell-lineage tracing and analysis of ErbB3-null mutant mice. Conditional gain- and loss-of-function experiments show genetically that cell fates in the neural crest involve both the SRY transcription factor Sox2 and Mitf, which consolidate an SCP progenitor or melanocyte fate by cross-regulatory interactions. A gradual downregulation of Sox2 in progenitors during development permits the differentiation of both neural crest- and SCP-derived progenitors into melanocytes, and an initial small pool of nerve-associated melanoblasts expands in number and disperses under the control of endothelin receptor B (Ednrb) and Wnt5a signaling.
Collapse
Affiliation(s)
- Igor Adameyko
- Unit of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Stockholm, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Archer A, Srinivas Kitambi S, L. Hallgren S, Pedrelli M, Håkan Olsén K, Mode A, Gustafsson JÅ. The Liver X-Receptor (Lxr) Governs Lipid Homeostasis in Zebrafish during Development. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojemd.2012.24012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
18
|
Chandrasekar G, Arner A, Kitambi SS, Dahlman-Wright K, Lendahl MA. Developmental toxicity of the environmental pollutant 4-nonylphenol in zebrafish. Neurotoxicol Teratol 2011; 33:752-64. [PMID: 22002180 DOI: 10.1016/j.ntt.2011.09.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 09/23/2011] [Accepted: 09/29/2011] [Indexed: 10/17/2022]
Abstract
4-Nonylphenol (4-NP), an estrogen mimicking compound is produced by biodegradation of alkylethoxylates. It is well established that 4-NP can affect the development of aquatic animals by disrupting the endocrine signals. Here we show for the first time in zebrafish that 4-NP does not only target the neuroendocrine system but also the notochord and the muscle. The notochord malformation was first evident as distortions at 24hourspostfertilization (hpf) which within 24h appeared as kinks and herniations. The notochord phenotype was accompanied by reduced motility and impaired swimming behavior. Whole-mount in situ hybridization using chordamesoderm markers and electron microscopic analysis showed failure in the notochord differentiation and disruption of the perinotochordal basement membrane. Late larval stages of 4-NP treated embryos displayed abnormal mineralization, vertebral curvature, fusion of vertebral bodies and abnormal extension of haemal arches. The muscle structure and the maximal active force in isolated muscle preparations were similar between 4-NP exposed and of control embryos, suggesting that 4-NP did not induce major changes in striated muscle function. However, repeated electrical stimulation (>40Hz) of the 4-NP exposed larvae revealed an impaired relaxation between stimuli, possibly reflecting an alteration in the relaxant mechanisms (e.g. in cellular Ca(2+) removal) which could explain the abnormal swimming pattern exhibited by 4-NP exposed larvae. Additionally, we demonstrate that the expression levels of the stress hormone, corticotropin releasing hormonewere elevated in the brain following 4-NP treatment. We also observed a significant decrease in the transcript levels of luteinizing hormone b at early larval stages. Collectively, our results show that 4-NP is able to disrupt the notochord morphogenesis, muscle function and the neuroendocrine system. These data suggest that 4-NP enduringly affects the embryonic development in zebrafish and that this compound might exert these deleterious effects through diverse signaling pathways.
Collapse
Affiliation(s)
- Gayathri Chandrasekar
- Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge, Sweden
| | | | | | | | | |
Collapse
|
19
|
Abstract
The identification of normal and cancerous stem cells and the recent advances made in isolation and culture of stem cells have rapidly gained attention in the field of drug discovery and regenerative medicine. The prospect of performing screens aimed at proliferation, directed differentiation, and toxicity and efficacy studies using stem cells offers a reliable platform for the drug discovery process. Advances made in the generation of induced pluripotent stem cells from normal or diseased tissue serves as a platform to perform drug screens aimed at developing cell-based therapies against conditions like Parkinson’s disease and diabetes. This review discusses the application of stem cells and cancer stem cells in drug screening and their role in complementing, reducing, and replacing animal testing. In addition to this, target identification and major advances in the field of personalized medicine using induced pluripotent cells are also discussed.
Collapse
|
20
|
Kitambi SS, Hauptmann G. The zebrafish orphan nuclear receptor genes nr2e1 and nr2e3 are expressed in developing eye and forebrain. Gene Expr Patterns 2007; 7:521-8. [PMID: 17127102 DOI: 10.1016/j.modgep.2006.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 10/12/2006] [Accepted: 10/16/2006] [Indexed: 11/24/2022]
Abstract
Mammalian Nr2e1 (Tailless, Mtll or Tlx) and Nr2e3 (photoreceptor-specific nuclear receptor, Pnr) are highly related orphan nuclear receptors, that are expressed in eye and forebrain-derived structures. In this study, we analyzed the developmental expression patterns of zebrafish nr2e1 and nr2e3. RT-PCR analysis showed that nr2e1 and nr2e3 are both expressed during embryonic and post-embryonic development. To examine the spatial distribution of nr2e1 and nr2e3 during development whole-mount in situ hybridization was performed. At tailbud stage, initial nr2e1 expression was localized to the rostral brain rudiment anterior to pax2.1 and eng2 expression at the prospective midbrain-hindbrain boundary. During subsequent stages, nr2e1 became widely expressed in fore- and midbrain primordia, eye and olfactory placodes. At 24hpf, strong nr2e1 expression was detected in telencephalon, hypothalamus, dorsal thalamus, pretectum, midbrain tectum, and retina. At 2dpf, the initially widespread nr2e1 expression became more restricted to distinct regions within the fore- and midbrain and to the retinal ciliary margin, the germinal zone which gives rise to retina and presumptive iris. Expression of nr2e3 was exclusively found in the developing retina and epiphysis. In both structures, nr2e3 expression was found in photoreceptor cells. The developmental expression profile of zebrafish nr2e1 and nr2e3 is consistent with evolutionary conserved functions in eye and rostral brain structures.
Collapse
Affiliation(s)
- Satish Srinivas Kitambi
- School of Life Sciences, Södertörns University College, Department of Biosciences and Nutrition, Karolinska Institutet, Alfred Nobels Allé 3, 14152 Huddinge, Sweden
| | | |
Collapse
|