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Derycke S, Kéver L, Herten K, Van den Berge K, Van Steenberge M, Van Houdt J, Clement L, Poncin P, Parmentier E, Verheyen E. Neurogenomic Profiling Reveals Distinct Gene Expression Profiles Between Brain Parts That Are Consistent in Ophthalmotilapia Cichlids. Front Neurosci 2018; 12:136. [PMID: 29593484 PMCID: PMC5855355 DOI: 10.3389/fnins.2018.00136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 02/20/2018] [Indexed: 01/22/2023] Open
Abstract
The detection of external and internal cues alters gene expression in the brain which in turn may affect neural networks that underly behavioral responses. Previous studies have shown that gene expression profiles differ between major brain regions within individuals and between species with different morphologies, cognitive abilities and/or behaviors. A detailed description of gene expression in all macroanatomical brain regions and in species with similar morphologies and behaviors is however lacking. Here, we dissected the brain of two cichlid species into six macroanatomical regions. Ophthalmotilapia nasuta and O. ventralis have similar morphology and behavior and occasionally hybridize in the wild. We use 3′ mRNA sequencing and a stage-wise statistical testing procedure to identify differential gene expression between females that were kept in a social setting with other females. Our results show that gene expression differs substantially between all six brain parts within species: out of 11,577 assessed genes, 8,748 are differentially expressed (DE) in at least one brain part compared to the average expression of the other brain parts. At most 16% of these DE genes have |log2FC| significantly higher than two. Functional differences between brain parts were consistent between species. The majority (61–79%) of genes that are DE in a particular brain part were shared between both species. Only 32 genes show significant differences in fold change across brain parts between species. These genes are mainly linked to transport, transmembrane transport, transcription (and its regulation) and signal transduction. Moreover, statistical equivalence testing reveals that within each comparison, on average 89% of the genes show an equivalent fold change between both species. The pronounced differences in gene expression between brain parts and the conserved patterns between closely related species with similar morphologies and behavior suggest that unraveling the interactions between genes and behavior will benefit from neurogenomic profiling of distinct brain regions.
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Affiliation(s)
- Sofie Derycke
- Operational Direction Taxonomy and Phylogeny, Royal Belgian Institute for Natural Sciences, Brussels, Belgium.,Department of Biology, Ghent University, Ghent, Belgium
| | - Loic Kéver
- Laboratory of Functional and Evolutionary Morphology, University of Liège, Liège, Belgium.,Behavioural Biology Unit, Ethology and Animal Psychology, University of Liège, Liège, Belgium
| | - Koen Herten
- Department of Human Genetics, Genomics Core Facility, KU Leuven, Leuven, Belgium
| | - Koen Van den Berge
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium.,Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Maarten Van Steenberge
- Operational Direction Taxonomy and Phylogeny, Royal Belgian Institute for Natural Sciences, Brussels, Belgium.,Section Vertebrates, Ichthyology, Royal Museum for Central Africa, Tervuren, Belgium
| | - Jeroen Van Houdt
- Department of Human Genetics, Genomics Core Facility, KU Leuven, Leuven, Belgium
| | - Lieven Clement
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium.,Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Pascal Poncin
- Behavioural Biology Unit, Ethology and Animal Psychology, University of Liège, Liège, Belgium
| | - Eric Parmentier
- Laboratory of Functional and Evolutionary Morphology, University of Liège, Liège, Belgium
| | - Erik Verheyen
- Operational Direction Taxonomy and Phylogeny, Royal Belgian Institute for Natural Sciences, Brussels, Belgium
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Shin YJ, Park JH, Choi JS, Chun MH, Moon YW, Lee MY. Enhanced expression of the sweet taste receptors and alpha-gustducin in reactive astrocytes of the rat hippocampus following ischemic injury. Neurochem Res 2010; 35:1628-34. [PMID: 20596769 DOI: 10.1007/s11064-010-0223-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2010] [Indexed: 10/19/2022]
Abstract
The heterodimeric sweet taste receptors, T1R2 and T1R3, have recently been proposed to be associated with the brain glucose sensor. To identify whether sweet taste signaling is regulated in response to an ischemic injury inducing acute impairment of glucose metabolism, we investigated the spatiotemporal expression of the sweet taste receptors and their associated taste-specific G-protein α-gustducin in the rat hippocampus after ischemia. The expression profiles of both receptor subunits and α-gustducin shared overlapping expression patterns in sham-operated and ischemic hippocampi. Constitutive expression of both receptors and α-gustducin was localized in neurons of the pyramidal cell and granule cell layers, but their upregulation was detected in reactive astrocytes in ischemic hippocampi. Immunoblot analysis confirmed the immmunohistochemically determined temporal patterns of sweet-taste signaling proteins. These results suggest that the expression of sweet taste signaling proteins in astrocytes might be regulated in response to altered extracellular levels of glucose following an ischemic insult.
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Affiliation(s)
- Yoo-Jin Shin
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Abstract
Aquaporin 9 (AQP9) is a member of the aquaporin channel family involved in water flux through plasma membranes and exhibits the distinct feature of being also permeable to monocarboxylates, such as lactate, and various solutes, including glycerol, carbamides, purines, pyrimidines, and urea. AQP9 is constitutively expressed at high levels in the liver. In the brain under physiological conditions, AQP9 was first observed in tanycytes, and then in astrocytes. Only recently, its expression was also shown in neurons. Neurons expressing AQP9 are catecholaminergic and glucose sensitive. The expression of neuronal AQP9 can be negatively regulated by insulin and in diabetic animals an increase in AQP9 expression is observed in the catecholaminergic nuclei of the hindbrain, similar to the regulation of AQP9 by insulin in the liver. Furthermore, after transient brain ischemia, AQP9 expression is increased in astrocytes and its regulation may implicate the MAP-kinase pathways stimulated in such pathological conditions. Despite these new data, the exact role of AQP9 in the brain is still unclear. However, we may hypothesize that AQP9 is implicated in brain energy metabolism, as a neutral solute channel. AQP9 could facilitate the diffusion of lactate from the astrocyte to the neuron. In glucose sensitive neurons, diffusion of lactate and glycerol could stimulate these neurons in a similar manner to glucose and could regulate the energy balance. In pathological conditions, induction of AQP9 in astrocytes could participate in the clearance of excess lactate in the extracellular space. These hypotheses concerning the function of brain AQP9 are still speculative and open new areas of investigation.
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Affiliation(s)
- J Badaut
- Department of Neurosurgery, CHUV BH19-208, 1011 Lausanne, Switzerland.
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de Souza KB, Feoli AM, Krüger AH, de Souza MR, Perry CT, Rotta LN, Souza DO, Perry MLS. Effects of Undernutrition on Glycine Metabolism in the Cerebellum of Rats. ANNALS OF NUTRITION AND METABOLISM 2004; 48:246-50. [PMID: 15331883 DOI: 10.1159/000080458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Accepted: 03/30/2004] [Indexed: 11/19/2022]
Abstract
Undernutrition is a worldwide problem affecting millions of unborn and young children during the most vulnerable stages of brain development. Total restriction of protein during the perinatal period of life can alter the development of the mammalian fetus and have marked repercussions on development of the central nervous system (CNS). The brain is vulnerable to undernutrition with altered morphologic and biochemical maturation, leading to impaired functions. The focus of this study is to investigate [U-14C]glycine metabolism in undernourished rats submitted to pre- and postnatal protein deprivation (diet: 8% protein with and without addition of L-methionine; control group: 25% protein). Although undernutrition produced a reduction in cerebellar weight and alterations in the DNA concentration, the present study shows that glycine metabolism in this structure is partially protected because the undernourished group with L-methionine did not show modifications in glycine metabolism at all ages studied. However, L-methionine deficiency alters glycine metabolism at 7 and 21 days, but in the adult age both undernourished groups presented no differences in oxidation to CO2, conversion to lipids and incorporation into protein from glycine, compared to the control group.
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Affiliation(s)
- Karine B de Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde--UFRGS, Porto Alegre, Brazil
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Badaut J, Petit JM, Brunet JF, Magistretti PJ, Charriaut-Marlangue C, Regli L. Distribution of Aquaporin 9 in the adult rat brain: Preferential expression in catecholaminergic neurons and in glial cells. Neuroscience 2004; 128:27-38. [PMID: 15450351 DOI: 10.1016/j.neuroscience.2004.05.042] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2004] [Indexed: 11/26/2022]
Abstract
Aquaporin 9 (AQP9) is a recently cloned water channel that is permeable to monocarboxylate, glycerol and urea. In rat, AQP9 has been found in testis and liver as well as in brain where its expression has been initially shown in glial cells in forebrain. However, the expression of AQP9 has not been investigated in the brainstem. The purpose of this study is to describe the distribution of AQP9-immunoreactive cells throughout the adult rat brain using reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry. We performed immunolabeling on brain from animals perfused with fixative and we show that AQP9 is expressed (i) in astrocytes in the glia limitans, in the white matter and in glial cells of the cerebellum, (ii) in the endothelial cells of pial vessels, and (iii) in specific groups of neurons. The neuronal AQP9 expression was almost exclusively observed in catecholaminergic cells including the adrenergic, noradrenergic and dopaminergic groups, but not in other monoaminergic neurons such as serotonergic or histaminergic cells. A slight labeling was also observed in non-catecholaminergic neurons localized in the paraventricular nucleus of the hypothalamus. These results indicate that AQP9 has a unique brain distribution with a preferential localization in catecholaminergic nuclei known to be involved in many cerebral functions. While the presence of AQP9 in glia limitans and in endothelial cells of the pial vessels could be related to water transport through the blood-brain barrier, its expression in neuronal cells, not directly involved in the osmoregulation, suggests that brain AQP9 could also be used as a metabolite channel since lactate and glycerol can be energy substrates for neurons.
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Affiliation(s)
- J Badaut
- Département de Neurochirurgie, CHUV BH19-208, 1011 Lausanne, Switzerland.
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