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Veeraragavan S, Wan YW, Connolly DR, Hamilton SM, Ward CS, Soriano S, Pitcher MR, McGraw CM, Huang SG, Green JR, Yuva LA, Liang AJ, Neul JL, Yasui DH, LaSalle JM, Liu Z, Paylor R, Samaco RC. Loss of MeCP2 in the rat models regression, impaired sociability and transcriptional deficits of Rett syndrome. Hum Mol Genet 2016; 25:3284-3302. [PMID: 27365498 PMCID: PMC5179927 DOI: 10.1093/hmg/ddw178] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/18/2016] [Accepted: 06/08/2016] [Indexed: 01/31/2023] Open
Abstract
Mouse models of the transcriptional modulator Methyl-CpG-Binding Protein 2 (MeCP2) have advanced our understanding of Rett syndrome (RTT). RTT is a 'prototypical' neurodevelopmental disorder with many clinical features overlapping with other intellectual and developmental disabilities (IDD). Therapeutic interventions for RTT may therefore have broader applications. However, the reliance on the laboratory mouse to identify viable therapies for the human condition may present challenges in translating findings from the bench to the clinic. In addition, the need to identify outcome measures in well-chosen animal models is critical for preclinical trials. Here, we report that a novel Mecp2 rat model displays high face validity for modelling psychomotor regression of a learned skill, a deficit that has not been shown in Mecp2 mice. Juvenile play, a behavioural feature that is uniquely present in rats and not mice, is also impaired in female Mecp2 rats. Finally, we demonstrate that evaluating the molecular consequences of the loss of MeCP2 in both mouse and rat may result in higher predictive validity with respect to transcriptional changes in the human RTT brain. These data underscore the similarities and differences caused by the loss of MeCP2 among divergent rodent species which may have important implications for the treatment of individuals with disease-causing MECP2 mutations. Taken together, these findings demonstrate that the Mecp2 rat model is a complementary tool with unique features for the study of RTT and highlight the potential benefit of cross-species analyses in identifying potential disease-relevant preclinical outcome measures.
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Affiliation(s)
- Surabi Veeraragavan
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Ying-Wooi Wan
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Daniel R Connolly
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Christopher S Ward
- Department of Pediatrics, Section of Neurology
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sirena Soriano
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Meagan R Pitcher
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Christopher M McGraw
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sharon G Huang
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Lisa A Yuva
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Agnes J Liang
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Section of Neurology
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Dag H Yasui
- Rowe Program in Human Genetics, University of California Davis, Davis, CA, USA
| | - Janine M LaSalle
- Rowe Program in Human Genetics, University of California Davis, Davis, CA, USA
| | - Zhandong Liu
- Department of Pediatrics, Section of Neurology
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Rodney C Samaco
- Department of Molecular and Human Genetics
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
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Schaevitz L, Berger-Sweeney J, Ricceri L. One-carbon metabolism in neurodevelopmental disorders: using broad-based nutraceutics to treat cognitive deficits in complex spectrum disorders. Neurosci Biobehav Rev 2014; 46 Pt 2:270-84. [PMID: 24769289 DOI: 10.1016/j.neubiorev.2014.04.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 03/07/2014] [Accepted: 04/15/2014] [Indexed: 12/22/2022]
Abstract
Folate and choline, two nutrients involved in the one-carbon metabolic cycle, are intimately involved in regulating DNA integrity, synthesis, biogenic amine synthesis, and methylation. In this review, we discuss evidence that folate and choline play an important role in normal cognitive development, and that altered levels of these nutrients during periods of high neuronal proliferation and synaptogenesis can result in diminished cognitive function. We also discuss the use of these nutrients as therapeutic agents in a spectrum of developmental disorders in which intellectual disability is a prominent feature, such as in Fragile-X, Rett syndrome, Down syndrome, and Autism spectrum disorders. A survey of recent literature suggests that nutritional supplements have mild, but generally consistent, effects on improving cognition. Intervening with supplements earlier rather than later during development is more effective in improving cognitive outcomes. Given the mild improvements seen after treatments using nutrients alone, and the importance of the genetic profile of parents and offspring, we suggest that using nutraceutics early in development and in combination with other therapeutics are likely to have positive impacts on cognitive outcomes in a broad spectrum of complex neurodevelopmental disorders.
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Affiliation(s)
| | | | - Laura Ricceri
- Section of Neurotoxicology and Neuroendocrinology, Dept Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
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Ricceri L, De Filippis B, Fuso A, Laviola G. Cholinergic hypofunction in MeCP2-308 mice: Beneficial neurobehavioural effects of neonatal choline supplementation. Behav Brain Res 2011; 221:623-9. [DOI: 10.1016/j.bbr.2011.03.051] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 03/21/2011] [Accepted: 03/21/2011] [Indexed: 12/16/2022]
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Zeisel SH. The supply of choline is important for fetal progenitor cells. Semin Cell Dev Biol 2011; 22:624-8. [PMID: 21693194 DOI: 10.1016/j.semcdb.2011.06.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 06/06/2011] [Indexed: 01/08/2023]
Abstract
Fetal progenitor cells proliferate, migrate, differentiate and undergo apoptosis at specific times during fetal development. Choline is needed by these cells for membrane synthesis and for methylation. There is growing evidence that this nutrient also modulates epigenetic regulation of gene expression in both neuronal and endothelial progenitor cells, thereby modifying brain development. It is likely that these mechanisms explain why, in rodent models, maternal dietary intake of choline influences both angiogenesis and neurogenesis in fetal hippocampus, and results in life-long changes in memory function. This also may explain why women eating diets low in choline have a greater risk of having a baby with a birth defect. Choline is mainly found in foods that contain fat and cholesterol, and intake of such foods has diminished in response dietary advice from nutritionists and physicians. Forty years ago, diets commonly contained choline-rich foods but now women in the USA tend to eat diets low in choline content. Premenopausal women normally may require less choline in their diet than do men and postmenopausal women, because estrogen induces the gene for the enzyme catalyzing endogenous biosynthesis of the choline-containing phospholipid phosphatidylcholine. However, many women have a single nucleotide polymorphism (SNP) that blocks the induction of endogenous biosynthesis, thereby making them require more dietary choline. When these women eat diets low in choline, the supply of this nutrient to the fetus is likely to be inadequate, and may perturb progenitor cell proliferation, migration, differentiation and apoptosis.
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Affiliation(s)
- Steven H Zeisel
- Nutrition Research Institute, School of Public Health and School of Medicine, The University of North Carolina at Chapel Hill, Kannapolis, NC 28081, United States.
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