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Fukushima HCS, Bailone RL, Corrêa T, Janke H, De Aguiar LK, Setti PG, Borra RC. Zebrafish toxicological screening could aid Leishmaniosis drug discovery. Lab Anim Res 2021; 37:27. [PMID: 34530926 PMCID: PMC8444568 DOI: 10.1186/s42826-021-00104-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/05/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Recently a screen from a library of 1.8 million compounds identified in vitro a potent activity of the 2-aminobenzimidazoles series against Leishmania infantum, the etiological agent responsible by over 20.000 deaths each year. Several analogs were synthesized and in vitro tested through an optimization program, leading to a promising 2-aminobenzimidazoles derived compound (2amnbzl-d) that was progressed to in vivo mice studies. However, the not expected toxic effects prevented its progression to more advanced preclinical and clinical phases of drug development. Due to limitations of cell models in detecting whole organism complex interactions, 90% of the compounds submitted to pre-clinical tests are reproved. The use of Zebrafish embryo models could improve this rate, saving mammals, time and costs in the development of new drugs. To test this hypothesis, we compared 2amnbzl-d with two compounds with already established safety profile: carbamazepine and benznidazole, using an embryo Zebrafish platform based on acute toxicity, hepatotoxicity, neurotoxicity and cardiotoxicity assays (Pltf-AcHpNrCd). RESULTS Tests were performed blindly, and the results demonstrated the presence of lethal and teratogenic effects (CL50%: 14.8 µM; EC50%: 8.6 µM), hepatotoxic in concentrations above 7.5 µM and neurotoxic in embryos exposed to 15 µM of 2amnbzl-d. Nevertheless, benznidazole exposition showed no toxicity and only the 100 µM of carbamazepine induced a bradycardia. CONCLUSIONS Results using Pltf-AcHpNrCd with zebrafish reproduced that found in the toxicological tests with mammals to a portion of the costs and time of experimentation.
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Affiliation(s)
- Hirla Costa Silva Fukushima
- Center of Biological and Health Sciences, Federal University of Sao Carlos, Washington Luis Road km 235, Sao Carlos, 13565-905, Brazil.
| | - Ricardo Lacava Bailone
- Department of Federal Inspection Service, Ministry of Agriculture, Livestock and Supply of Brazil, Federal Inspection Service,, Treze de Maio, Street n°1558, Bela Vista, São Paulo, 01327-00, Brazil.,Department of Genetic and Evolution, Federal University of São Carlos, Washington Luis Road km 235, São Carlos, 13565-905, Brazil
| | - Tatiana Corrêa
- Department of Genetic and Evolution, Federal University of São Carlos, Washington Luis Road km 235, São Carlos, 13565-905, Brazil
| | - Helena Janke
- Department of Genetic and Evolution, Federal University of São Carlos, Washington Luis Road km 235, São Carlos, 13565-905, Brazil
| | - Luís Kluwe De Aguiar
- Department of Food Technology and Innovation, Harper Adams University, Edgmond, Newport, TF10 8NB, UK
| | - Princia Grejo Setti
- Department of Genetic and Evolution, Federal University of São Carlos, Washington Luis Road km 235, São Carlos, 13565-905, Brazil
| | - Ricardo Carneiro Borra
- Department of Genetic and Evolution, Federal University of São Carlos, Washington Luis Road km 235, São Carlos, 13565-905, Brazil
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González-Maciel A, Romero-Velázquez RM, Alfaro-Rodríguez A, Sanchez Aparicio P, Reynoso-Robles R. Prenatal exposure to oxcarbazepine increases hippocampal apoptosis in rat offspring. J Chem Neuroanat 2019; 103:101729. [PMID: 31794794 DOI: 10.1016/j.jchemneu.2019.101729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/29/2019] [Accepted: 11/29/2019] [Indexed: 01/18/2023]
Abstract
This study assessed apoptosis in the offspring of rats exposed to oxcarbazepine (OXC) from day 7 to 15 of gestation. Three groups of pregnant Wistar rats were used: 1) Control, treated with saline solution; 2) treated with 100 mg/kg OXC; 3) treated with 100 mg/kg of carbamazepine (CBZ, as a positive control for apoptosis); the route of administration was intragastric. Apoptosis was detected at three postnatal ages using the TUNEL technique in the CA1, and CA3 regions of the hippocampus and in the dentate gyrus (DG); neurogenesis was assessed in the DG using an antibody against doublecortin. The litter characteristics were recorded. OXC increased apoptosis in all regions (p < 0.01) at the three ages evaluated. Lamination disruption occurred in CA1 and CA3 due to the neuron absence and to ectopic neurons; there were also malformations in the dorsal lamina of the DG in 38% and 25% of the pups born from rats treated with OXC and CBZ respectively. CBZ also increased apoptosis. No clear effect on neurogenesis in the DG was observed. The size of the litter was smaller (p < 0.01) in the experimental groups. Nineteen-day OXC fetuses had low weight (p < 0.01), but 21 and 30 postnatal days old CBZ and OXC pups were overweight (p < 0.01). The results demonstrate that OXC administered during gestation is pro-apoptotic, alters the cytoarchitecture of the hippocampus, reduces litter size, and probably influences postnatal weight. We provide evidence of the proapoptotic effect of CBZ when administered early in gestation.
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Affiliation(s)
- A González-Maciel
- Laboratory of Cell and Tissue Morphology, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur No. 3700-C, Mexico City, C. P. 04530, Mexico.
| | - R M Romero-Velázquez
- Laboratory of Cell and Tissue Morphology, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur No. 3700-C, Mexico City, C. P. 04530, Mexico.
| | - A Alfaro-Rodríguez
- Division of Neurosciences, Instituto Nacional de Rehabilitación, "Luis Guillermo Ibarra Ibarra", Secretaría de Salud, Col. Arenal de Guadalupe, Mexico City, C.P. 14389, Mexico.
| | - P Sanchez Aparicio
- Faculty of Veterinary Medicine, Department of Pharmacology, Universidad Autónoma del Estado de México, Mexico
| | - R Reynoso-Robles
- Laboratory of Cell and Tissue Morphology, Instituto Nacional de Pediatría, Secretaría de Salud, Insurgentes Sur No. 3700-C, Mexico City, C. P. 04530, Mexico.
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Kohl A, Golan N, Cinnamon Y, Genin O, Chefetz B, Sela-Donenfeld D. A proof of concept study demonstrating that environmental levels of carbamazepine impair early stages of chick embryonic development. ENVIRONMENT INTERNATIONAL 2019; 129:583-594. [PMID: 31174146 DOI: 10.1016/j.envint.2019.03.064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 05/20/2023]
Abstract
Carbamazepine (CBZ) is an anticonvulsant drug used for epilepsy and other disorders. Prescription of CBZ during pregnancy increases the risk for congenital malformations. CBZ is ubiquitous in effluents and persistent during wastewater treatment. Thus, it is re-introduced into agricultural ecosystems upon irrigation with reclaimed wastewater. People consuming produce irrigated with reclaimed wastewater were found to be exposed to CBZ. However, environmental concentrations of CBZ (μgL-1) are magnitudes lower than its therapeutic levels (μgml-1), raising the question of whether and how environmental levels of CBZ affect embryonic development. The chick embryo is a powerful and highly sensitive amniotic model system that enables to assess environmental contaminants in the living organism. Since the chick embryonic development is highly similar to mammalians, yet, it develops in an egg, toxic effects can be directly analyzed in a well-controlled system without maternal influences. This research utilized the chick embryo to test whether CBZ is embryo-toxic by using morphological, cellular, molecular and imaging strategies. Three key embryonic stages were monitored: after blastulation (st.1HH), gastrulation/neurulation (st.8HH) and organogenesis (st.15HH). Here we demonstrate that environmental relevant concentrations of CBZ impair morphogenesis in a dose- and stage- dependent manner. Effects on gastrulation, neural tube closure, differentiation and proliferation were exhibited in early stages by exposing embryos to CBZ dose as low as 0.1μgL-1. Quantification of developmental progression revealed a significant difference in the total score obtained by CBZ-treated embryos compared to controls (up to 5-fold difference, p<0.05). Yet, defects were unnoticed as embryos passed gastrulation/neurulation. This study provides the first evidence for teratogenic effect of environmental-relevant concentrations of CBZ in amniotic embryos that impair early but not late stages of development. These findings call for in-depth risk analysis to ensure that the environmental presence of CBZ and other drugs is not causing irreversible ecological and public-health damages.
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Affiliation(s)
- Ayelet Kohl
- Koret School of Veterinary Medicine, Faculty of Agriculture, Food and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Naama Golan
- Department of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Yuval Cinnamon
- Department of Poultry and Aquaculture Sciences, Institute of Animal Science, Agricultural Research Organization - The Volcani Center, Rishon LeZiyon 7528809, Israel
| | - Olga Genin
- Department of Poultry and Aquaculture Sciences, Institute of Animal Science, Agricultural Research Organization - The Volcani Center, Rishon LeZiyon 7528809, Israel
| | - Benny Chefetz
- Department of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel.
| | - Dalit Sela-Donenfeld
- Koret School of Veterinary Medicine, Faculty of Agriculture, Food and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel.
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Jose M, Sreelatha HV, James MV, Arumughan S, Thomas SV. Teratogenic Effects of Carbamazepine in Mice. Ann Indian Acad Neurol 2017; 20:132-137. [PMID: 28615898 PMCID: PMC5470153 DOI: 10.4103/aian.aian_492_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Objectives: The aim of this study was to determine the teratogenic effects of carbamazepine (CBZ) in BALB/c mice. Materials and Methods: Mature female and male BALB/c mice (25–30 g) were used for all experiments. After standardization of administration and dose of CBZ, animals in the CBZ-treated groups (CBZ 450 mg/kg and 600 mg/kg) were fed on medicinal diet. The dams in the control group were mated on the same day as that of the CBZ-treated dams. After cesarean section (CS), fetal viability status and weights were recorded. Gross histopathological examination of fetuses was conducted to identify alterations in morphology and external or internal organs due to in utero exposure of CBZ. Results: Out of the nine female animals (three treated on CBZ 450 mg/kg, three treated on CBZ 600 mg/kg and three controls), seven were pregnant, and two (one each from the two CBZ-treated groups) were nonpregnant. All fetuses of the control group (n = 31) and CBZ 450 mg/kg treated group (n = 24) were live, but eight out of the twenty fetuses (40%) of CBZ 600 mg/kg treated group were dead at CS. The birth weight of the fetuses antenatally exposed to CBZ was drastically reduced (0.71 ± 0.06) when compared to control fetuses (1.67 ± 0.12) (P < 0.0001). All the fetuses of the CBZ-treated groups showed stunted physical development. Conclusion: Although oral administration of CBZ to mice is a convenient model to study the effect of CBZ to pregnancy, higher oral dose was associated with increased fetal loss. Some of the fetuses exposed to CBZ demonstrated structural abnormalities and low body weight.
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Affiliation(s)
- Manna Jose
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Harikrishnan Vijayakumar Sreelatha
- Division of Laboratory Animal Science, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Manjula Valiyamattathil James
- Department of Histopathology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Sabareeswaran Arumughan
- Department of Histopathology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Sanjeev Varghese Thomas
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
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Abstract
This chapter includes the aspects of carbamazepine. The drug is synthesized by the use of 5H-dibenz[b,f]azepine and phosgene followed by subsequent reaction with ammonia. Carbamazepine is generally used for the treatment of seizure disorders and neuropathic pain, it is also important as off-label for a second-line treatment for bipolar disorder and in combination with an antipsychotic in some cases of schizophrenia when treatment with a conventional antipsychotic alone has failed. Other uses may include attention deficit hyperactivity disorder, schizophrenia, phantom limb syndrome, complex regional pain syndrome, borderline personality disorder, and posttraumatic stress disorder. The chapter discusses the drug metabolism and pharmacokinetics and presents various methods of analysis of this drug such electrochemical analysis, spectroscopic analysis, and chromatographic techniques of separation. It also discusses its physical properties such as solubility characteristics, X-ray powder diffraction pattern, and thermal methods of analysis. The chapter is concluded with a discussion on its biological properties such as activity, toxicity, and safety.
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Beker van Woudenberg A, Snel C, Rijkmans E, de Groot D, Bouma M, Hermsen S, Piersma A, Menke A, Wolterbeek A. Zebrafish embryotoxicity test for developmental (neuro)toxicity: Demo case of an integrated screening approach system using anti-epileptic drugs. Reprod Toxicol 2014; 49:101-16. [DOI: 10.1016/j.reprotox.2014.07.082] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 07/14/2014] [Accepted: 07/31/2014] [Indexed: 01/26/2023]
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Andretta RR, Okada FK, Paccola CC, Stumpp T, de Oliva SU, Miraglia SM. Carbamazepine-exposure during gestation and lactation affects pubertal onset and spermatic parameters in male pubertal offspring. Reprod Toxicol 2014; 44:52-62. [DOI: 10.1016/j.reprotox.2013.09.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 09/24/2013] [Accepted: 09/25/2013] [Indexed: 11/25/2022]
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Hermsen SA, Pronk TE, van den Brandhof EJ, van der Ven LT, Piersma AH. Transcriptomic analysis in the developing zebrafish embryo after compound exposure: Individual gene expression and pathway regulation. Toxicol Appl Pharmacol 2013; 272:161-71. [DOI: 10.1016/j.taap.2013.05.037] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/01/2013] [Accepted: 05/22/2013] [Indexed: 11/15/2022]
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van den Brandhof EJ, Montforts M. Fish embryo toxicity of carbamazepine, diclofenac and metoprolol. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2010; 73:1862-6. [PMID: 20832863 DOI: 10.1016/j.ecoenv.2010.08.031] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 08/20/2010] [Accepted: 08/22/2010] [Indexed: 05/22/2023]
Abstract
Frequently measured pharmaceuticals in environmental samples were tested in fish embryo toxicity (FET) tests with Danio rerio, based on the draft OECD test protocol. In this FET test 2-h-old zebrafish embryos were exposed for 72 h to carbamazepine, diclofenac and metoprolol to observe effects on embryo mortality, gastrulation, somite formation, tail movement and detachment, pigmentation, heartbeat, malformation of head, otoliths and heart, scoliosis, deformity of yolk, and hatching success at 24, 48 and 72 h. We found specific effects on growth retardation above 30.6 mg/l for carbamazepine, on hatching, yolk sac and tail deformation above 1.5mg/l for diclofenac, and on scoliosis and growth retardation above 12.6 mg/l for metoprolol. Scoring all effect parameters, the 72-h-EC(50) values were: for carbamazepine 86.5mg/l, for diclofenac 5.3mg/l and for metoprolol 31.0mg/l (mean measured concentrations). In conclusion, our results for carbamazepine and metoprolol are in agreement with other findings for aquatic toxicity, and also fish embryos responded in much the same way as rat embryos did. For diclofenac, the FET test performs comparably to Early Life Stage testing.
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Afshar M, Moallem SA, Houshang Mohammadpour A, Shiravi A, Majid Jalalian S, Jafar Golalipour M. Teratogenic effects of carbamazepine on embryonic eye development in pregnant mice. Cutan Ocul Toxicol 2010; 29:10-5. [PMID: 19895254 DOI: 10.3109/15569520903380353] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Carbamazepine is an antiepileptic drug used widely for the treatment of epileptic seizures and neuropathic pain. Several malformations in humans, mainly neural tube defects, have been reported as a consequence of its use during pregnancy. The association between maternal use of carbamazepine and congenital eye malformations is not very well understood. OBJECTIVE The purpose of this study was to examine this association after intraperitoneal injection of carbamazepine during the period of organogenesis in mice. METHODS Balb/c timed-pregnant mice were divided into 4 experimental and control groups. Two experimental groups received daily intraperitoneal injections of 15 mg/kg (group I) or 30 mg/kg (group II) of carbamazepine on gestational days 6 to 15. Two control groups received normal saline or Tween 20 (polysorbate 20). Dams underwent Cesarean section on gestational day 18 and embryos were harvested. External examination for eye malformations, routine histological processing of malformed fetuses to study eye morphology, and skeletal staining were performed. RESULTS The mean weight and crown-rump of the fetuses in both experimental groups were significantly reduced compared with those of the control groups. Various malformations were detected such as brachygnathia, calvarial deformity, vertebral deformity, short tail, and brachydactyly. Premature opening of one or both eyes with mild to severe exophthalmos occurred in the 2 experimental groups. Deformed lens, retinal folds with undeveloped layers, and corneal folds with absence of surface epithelium were detected in both experimental groups. CONCLUSIONS This study, to the best of our knowledge, showed for the first time that intraperitoneal administration of carbamazepine at clinically comparable doses during organogenesis can induce several eye malformations in mice. The implication of these results needs to be considered when carbamazepine is administered during human pregnancy.
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Affiliation(s)
- Mohammad Afshar
- Department of Anatomy, Birjand University of Medical Sciences, Birjand, Iran
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Augustine-Rauch KA, Zhang QJ, Leonard JL, Chadderton A, Welsh MJ, Rami HK, Thompson M, Gaster L, Wier PJ. Evidence for a molecular mechanism of teratogenicity of SB-236057, a 5-HT1B receptor inverse agonist that alters axial formation. ACTA ACUST UNITED AC 2005; 70:789-807. [PMID: 15472891 DOI: 10.1002/bdra.20076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND SB-236057 is a potent skeletal teratogen in rodents and rabbits, producing axial and posterior somite malformations in cultured rat embryos. The compound shares some structural similarity to cyclopamine. METHODS M13 phage display was used to identify amino acid motifs with binding affinity to SB-236057. A 10 microM SB-236057 solution was administered to cultured day 9 postcoitus rat embryos and real-time PCR was conducted at 6 hr posttreatment to evaluate early transcriptional response of axial development genes. Whole-mount in situ hybridization of selected transcripts was conducted on embryos at 48 hr post-compound administration. The rat-enhancer of split protein 1 (r-esp1) expression-functional characterization was done by transcriptional expression and morpholino antisense approaches. RESULTS We identified several amino acid motifs that had high binding affinity to SB-236057-biotin conjugates, one with 100% sequence homology to a region of r-esp1, one of the Groucho homologs transcribed by the enhancer of split complex (En[spl]C). SB-236057 repressed expression of r-esp1 and members of the Notch-En[spl]C pathway. Goosecoid and HNF3-beta, both suspected to associate with Groucho proteins, were also responsive, although expression of another putative binding protein, engrailed-1 (en-1), and other en-1 pathway members was not affected. R-esp1 mRNA was localized along the axis and antisense inhibition produced similar somite malformations as SB-236057 did. At 48 hr post-SB-236057 or post-r-esp1 antisense administration, affected embryos demonstrated unchanged sonic hedgehog (shh) expression, however HNF3-beta expression was either absent, altered, or reduced. CONCLUSIONS We present experimental evidence that the mechanism of SB-236057 teratogenicity includes transcriptional alterations to the Notch1-En[spl] pathway. In addition, alterations in HNF3-beta expression were similar to those induced by cyclopamine. The relationships between r-esp1 with Notch1 and shh signaling pathways and potential mechanisms of SB-236057 teratogenicity are also discussed.
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Affiliation(s)
- Karen A Augustine-Rauch
- Department of Reproductive Toxicology, GlaxoSmithKline Pharmaceuticals, King of Prussia, Pennsylvania, USA.
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Hansen DK, Streck RD, Antony AC. Antisense modulation of the coding or regulatory sequence of the folate receptor (folate binding protein-1) in mouse embryos leads to neural tube defects. ACTA ACUST UNITED AC 2004; 67:475-87. [PMID: 14565618 DOI: 10.1002/bdra.10072] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Although folic acid decreases the incidence of neural tube defects (NTDs) in humans, the mechanism for this protection is unknown. We have employed antisense technology to alter expression of the gene for the folate receptor (folate binding protein-1 [Folbp1]) in mouse embryos cultured in vitro. METHODS Embryos were explanted on day 8 of gestation and cultured for 44 hr. Several oligodeoxyribonucleotides designed to modulate the coding region or a regulatory sequence in the 5'-untranslated region of Folbp1 were microinjected into the amniotic sac of embryos at the beginning of the culture period. RESULTS Two different antisense sequences to the 5' and 3' coding region in Folbp1 produced concentration-dependent increases in the number of embryos with NTDs. Coinjection of 5-methyltetrahydrofolate with these sequences decreased the frequency of abnormal embryos. A semi-quantitative RT-PCR technique used to measure the amount of Folbp1 mRNA in treated and control embryos confirmed that the mRNA level was decreased by treatment with the antisense sequences. An antisense oligodeoxyribonucleotide to a 17 base cis regulatory element also generated a concentration-dependent increase in the frequency of embryos with NTDs, and a decrease in the level of Folbp1 mRNA. CONCLUSIONS These results demonstrate that alterations in expression of Folbp1 by perturbing either the coding sequence or a critical regulatory cis-element can play a role in NTDs.
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Affiliation(s)
- Deborah K Hansen
- Division of Genetic and Reproductive Toxicology, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas 72079-9502, USA.
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Hansen DK, Grafton TF, Melnyk S, James SJ. Lack of embryotoxicity of homocysteine thiolactone in mouse embryos in vitro. Reprod Toxicol 2001; 15:239-44. [PMID: 11390167 DOI: 10.1016/s0890-6238(01)00133-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Recent work from humans and chick embryos has suggested that homocysteine may play a role in producing neural tube defects (NTDs). In an effort to determine if homocysteine is able to produce NTDs in mammalian embryos, mouse embryos were explanted on GD 8 and cultured for 44 h. When either homocysteine or homocysteine thiolactone was added to the culture medium, treated embryos developed as well as controls and had closed neural tubes. Homocysteine thiolactone was also microinjected into the amniotic sac of mouse embryos. Again, development proceeded normally with no significant increase in the number of embryos with open neural tubes at the end of the culture period. HPLC analysis of embryonic thiols 24 h after microinjection revealed a significant increase in embryonic cystathionine levels. These data suggest that homocysteine does not produce NTDs in mouse embryos cultured in vitro and that early organogenesis-stage embryos are able to metabolize homocysteine.
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Affiliation(s)
- D K Hansen
- Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079-9502, USA.
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Hansen DK, Barbee SA, Grafton TF, Gu Y, Streck RD. Antisense modulation of 5,10-methylenetetrahydrofolate reductase expression produces neural tube defects in mouse embryos. Reprod Toxicol 2001; 15:21-9. [PMID: 11137375 DOI: 10.1016/s0890-6238(00)00117-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The role of folate metabolism in producing neural tube defects (NTDs) in humans is unknown. In the current study, antisense oligodeoxyribonucleotide technology was utilized to disrupt normal expression of the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) in organogenesis-stage mouse embryos. Two different antisense probes were microinjected into the amniotic sac of gestation day (GD) 8 mouse embryos with PBS or scrambled sense oligodeoxyribonucleotides injected into control embryos. Concentration-dependent increases in the frequencies of embryos with NTDs were observed for both antisense sequences. The level of mRNA for MTHFR was decreased in embryos treated with the higher concentration of one antisense sequence, indicating that the sequence is able to decrease gene expression. 5-methyltetrahydrofolate, the product of the MTHFR reaction, was able to decrease the incidence of antisense-induced NTDs, but co-injection with L-methionine did not. These results suggest that reduced expression of MTHFR may play a role in producing NTDs.
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Affiliation(s)
- D K Hansen
- Division of Genetic and Reproductive Toxicology, Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd., 72079-9502, Jefferson, AR, USA.
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