Limits...
Brain fatty acid binding protein (Fabp7) is diurnally regulated in astrocytes and hippocampal granule cell precursors in adult rodent brain.

Gerstner JR, Bremer QZ, Vander Heyden WM, Lavaute TM, Yin JC, Landry CF - PLoS ONE (2008)

Bottom Line: This pattern of Fabp7 mRNA expression was confirmed using in situ hybridization and found to occur throughout the entire brain.Diurnal changes in Fabp7, however, were not found in postnatal day 6 brain, when astrocytes are not yet mature.Of clock or clock-regulated genes, the synchronized, global cycling pattern of Fabp7 expression is unique and implicates glial cells in the response or modulation of activity and/or circadian rhythms.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA.

ABSTRACT
Brain fatty acid binding protein (Fabp7), which is important in early nervous system development, is expressed in astrocytes and neuronal cell precursors in mature brain. We report here that levels of Fabp7 mRNA in adult murine brain change over a 24 hour period. Unlike Fabp5, a fatty acid binding protein that is expressed widely in various cell types within brain, RNA analysis revealed that Fabp7 mRNA levels were elevated during the light period and lower during dark in brain regions involved in sleep and activity mechanisms. This pattern of Fabp7 mRNA expression was confirmed using in situ hybridization and found to occur throughout the entire brain. Changes in the intracellular distribution of Fabp7 mRNA were also evident over a 24 hour period. Diurnal changes in Fabp7, however, were not found in postnatal day 6 brain, when astrocytes are not yet mature. In contrast, granule cell precursors of the subgranular zone of adult hippocampus did undergo diurnal changes in Fabp7 expression. These changes paralleled oscillations in Fabp7 mRNA throughout the brain suggesting that cell-coordinated signals likely control brain-wide Fabp7 mRNA expression. Immunoblots revealed that Fabp7 protein levels also underwent diurnal changes in abundance, with peak levels occurring in the dark period. Of clock or clock-regulated genes, the synchronized, global cycling pattern of Fabp7 expression is unique and implicates glial cells in the response or modulation of activity and/or circadian rhythms.

Show MeSH

Related in: MedlinePlus

The amount and distribution of Fabp7 mRNA in amygdala changes during the diurnal cycle.A) In situ hybridization of coronal tissue sections probed for Fabp7 mRNA at four diurnal time points. Top panels, phosphorimages of amygdala, bottom panels, dark field images of a different set of hybridized sections subjected to emulsion autoradiography. Higher levels of Fabp7 were evident during lights-on. B) Graphic representation of elevated Fabp7 mRNA levels during lights-on in basolateral and medial amygdala. Two-way ANOVA (p = 0.002). ***p<0.001, **p<0.01 vs. ZT18 (post-hoc t-test). Each value represents the average +/− S.E.M. N = 2–4 per time point. C) Sections processed for in situ hybridization for Fabp7 subjected to emulsion autoradiography. Dark field microscopy revealed a more dispersed labeling pattern at ZT 6 (C1) compared to ZT18 (C2). Higher magnification micrographs of Nissl counterstained sections indicated labeling over cells whose staining pattern was consistent with an astrocyte morphology and whose labeling pattern was more disperse at ZT6 (C3) compared to ZT18 (C4). Note that silver grain accumulation around cell nuclei was similar at the two time points (arrows in C3 and C4). Astrocytes stained with DIG-labeled riboprobe for Fabp7 (unstained astrocytic nuclei (n) are indicated) were also co-labeled for mRNA for the astrocyte protein, GFAP (silver grain accumulations). Unstained neuronal nuclei (N) are shown for reference. A representative tissue section subjected to immunohistochemistry with anti-Fabp7 antibodies is shown in C6. Note astrocytic processes emanating from stained cell somata. Bar in A = 400 µm; in C1,C2 = 100 µm; in C3,C4 = 20 µm; in C5 = 10 µm, C6 = 30 µm BLA, basolateral amygdala; MA, medial amygdala
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2238817&req=5

pone-0001631-g004: The amount and distribution of Fabp7 mRNA in amygdala changes during the diurnal cycle.A) In situ hybridization of coronal tissue sections probed for Fabp7 mRNA at four diurnal time points. Top panels, phosphorimages of amygdala, bottom panels, dark field images of a different set of hybridized sections subjected to emulsion autoradiography. Higher levels of Fabp7 were evident during lights-on. B) Graphic representation of elevated Fabp7 mRNA levels during lights-on in basolateral and medial amygdala. Two-way ANOVA (p = 0.002). ***p<0.001, **p<0.01 vs. ZT18 (post-hoc t-test). Each value represents the average +/− S.E.M. N = 2–4 per time point. C) Sections processed for in situ hybridization for Fabp7 subjected to emulsion autoradiography. Dark field microscopy revealed a more dispersed labeling pattern at ZT 6 (C1) compared to ZT18 (C2). Higher magnification micrographs of Nissl counterstained sections indicated labeling over cells whose staining pattern was consistent with an astrocyte morphology and whose labeling pattern was more disperse at ZT6 (C3) compared to ZT18 (C4). Note that silver grain accumulation around cell nuclei was similar at the two time points (arrows in C3 and C4). Astrocytes stained with DIG-labeled riboprobe for Fabp7 (unstained astrocytic nuclei (n) are indicated) were also co-labeled for mRNA for the astrocyte protein, GFAP (silver grain accumulations). Unstained neuronal nuclei (N) are shown for reference. A representative tissue section subjected to immunohistochemistry with anti-Fabp7 antibodies is shown in C6. Note astrocytic processes emanating from stained cell somata. Bar in A = 400 µm; in C1,C2 = 100 µm; in C3,C4 = 20 µm; in C5 = 10 µm, C6 = 30 µm BLA, basolateral amygdala; MA, medial amygdala

Mentions: Conceived and designed the experiments: JY CL JG TL. Performed the experiments: JG QB WV TL. Analyzed the data: CL JG QB. Wrote the paper: JY CL JG. Other: Jason Gerstner's primary supervisor: JV. Aided greatly in the progression of the work, the organization of critical experiments and the writing of the article: JV. Aided in the initial interpretation and analysis of results pertaining to the identification of the diurnal regulation of Fabp7 in mature brain: TL. Ran the Northern blots that lead to the initial observations and provided critical input on the progression of the work: TL JG. Isolated RNA used in many of the experiments outlined in the first part of the Results: WV. Aided in Northern blotting and data analysis: WV. Isolated all protein samples for immunoblotting and performed all immunoblot experiments: QB. Subjected the immunodata to statistical analysis, wrote the methods section pertaining to immunoblotting and aided in the writing of the Results section: QB. Aided in the in situ hybridization technique: QB. Performed the initial analysis that lead to the identification of the cycling of the gene in adult brain: JG. Performed many of the analyses including those listed in figure 1, 2, 4 and 5: JG. Contributed to many of the experiments outlined in the article: JG. Performed much of the in situ analysis and aided Mr. Gerstner in the generation of the figures: CL. Supervised, with Dr. Yin, the progression of the work: CL. Co-wrote the article: CL.


Brain fatty acid binding protein (Fabp7) is diurnally regulated in astrocytes and hippocampal granule cell precursors in adult rodent brain.

Gerstner JR, Bremer QZ, Vander Heyden WM, Lavaute TM, Yin JC, Landry CF - PLoS ONE (2008)

The amount and distribution of Fabp7 mRNA in amygdala changes during the diurnal cycle.A) In situ hybridization of coronal tissue sections probed for Fabp7 mRNA at four diurnal time points. Top panels, phosphorimages of amygdala, bottom panels, dark field images of a different set of hybridized sections subjected to emulsion autoradiography. Higher levels of Fabp7 were evident during lights-on. B) Graphic representation of elevated Fabp7 mRNA levels during lights-on in basolateral and medial amygdala. Two-way ANOVA (p = 0.002). ***p<0.001, **p<0.01 vs. ZT18 (post-hoc t-test). Each value represents the average +/− S.E.M. N = 2–4 per time point. C) Sections processed for in situ hybridization for Fabp7 subjected to emulsion autoradiography. Dark field microscopy revealed a more dispersed labeling pattern at ZT 6 (C1) compared to ZT18 (C2). Higher magnification micrographs of Nissl counterstained sections indicated labeling over cells whose staining pattern was consistent with an astrocyte morphology and whose labeling pattern was more disperse at ZT6 (C3) compared to ZT18 (C4). Note that silver grain accumulation around cell nuclei was similar at the two time points (arrows in C3 and C4). Astrocytes stained with DIG-labeled riboprobe for Fabp7 (unstained astrocytic nuclei (n) are indicated) were also co-labeled for mRNA for the astrocyte protein, GFAP (silver grain accumulations). Unstained neuronal nuclei (N) are shown for reference. A representative tissue section subjected to immunohistochemistry with anti-Fabp7 antibodies is shown in C6. Note astrocytic processes emanating from stained cell somata. Bar in A = 400 µm; in C1,C2 = 100 µm; in C3,C4 = 20 µm; in C5 = 10 µm, C6 = 30 µm BLA, basolateral amygdala; MA, medial amygdala
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2238817&req=5

pone-0001631-g004: The amount and distribution of Fabp7 mRNA in amygdala changes during the diurnal cycle.A) In situ hybridization of coronal tissue sections probed for Fabp7 mRNA at four diurnal time points. Top panels, phosphorimages of amygdala, bottom panels, dark field images of a different set of hybridized sections subjected to emulsion autoradiography. Higher levels of Fabp7 were evident during lights-on. B) Graphic representation of elevated Fabp7 mRNA levels during lights-on in basolateral and medial amygdala. Two-way ANOVA (p = 0.002). ***p<0.001, **p<0.01 vs. ZT18 (post-hoc t-test). Each value represents the average +/− S.E.M. N = 2–4 per time point. C) Sections processed for in situ hybridization for Fabp7 subjected to emulsion autoradiography. Dark field microscopy revealed a more dispersed labeling pattern at ZT 6 (C1) compared to ZT18 (C2). Higher magnification micrographs of Nissl counterstained sections indicated labeling over cells whose staining pattern was consistent with an astrocyte morphology and whose labeling pattern was more disperse at ZT6 (C3) compared to ZT18 (C4). Note that silver grain accumulation around cell nuclei was similar at the two time points (arrows in C3 and C4). Astrocytes stained with DIG-labeled riboprobe for Fabp7 (unstained astrocytic nuclei (n) are indicated) were also co-labeled for mRNA for the astrocyte protein, GFAP (silver grain accumulations). Unstained neuronal nuclei (N) are shown for reference. A representative tissue section subjected to immunohistochemistry with anti-Fabp7 antibodies is shown in C6. Note astrocytic processes emanating from stained cell somata. Bar in A = 400 µm; in C1,C2 = 100 µm; in C3,C4 = 20 µm; in C5 = 10 µm, C6 = 30 µm BLA, basolateral amygdala; MA, medial amygdala
Mentions: Conceived and designed the experiments: JY CL JG TL. Performed the experiments: JG QB WV TL. Analyzed the data: CL JG QB. Wrote the paper: JY CL JG. Other: Jason Gerstner's primary supervisor: JV. Aided greatly in the progression of the work, the organization of critical experiments and the writing of the article: JV. Aided in the initial interpretation and analysis of results pertaining to the identification of the diurnal regulation of Fabp7 in mature brain: TL. Ran the Northern blots that lead to the initial observations and provided critical input on the progression of the work: TL JG. Isolated RNA used in many of the experiments outlined in the first part of the Results: WV. Aided in Northern blotting and data analysis: WV. Isolated all protein samples for immunoblotting and performed all immunoblot experiments: QB. Subjected the immunodata to statistical analysis, wrote the methods section pertaining to immunoblotting and aided in the writing of the Results section: QB. Aided in the in situ hybridization technique: QB. Performed the initial analysis that lead to the identification of the cycling of the gene in adult brain: JG. Performed many of the analyses including those listed in figure 1, 2, 4 and 5: JG. Contributed to many of the experiments outlined in the article: JG. Performed much of the in situ analysis and aided Mr. Gerstner in the generation of the figures: CL. Supervised, with Dr. Yin, the progression of the work: CL. Co-wrote the article: CL.

Bottom Line: This pattern of Fabp7 mRNA expression was confirmed using in situ hybridization and found to occur throughout the entire brain.Diurnal changes in Fabp7, however, were not found in postnatal day 6 brain, when astrocytes are not yet mature.Of clock or clock-regulated genes, the synchronized, global cycling pattern of Fabp7 expression is unique and implicates glial cells in the response or modulation of activity and/or circadian rhythms.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA.

ABSTRACT
Brain fatty acid binding protein (Fabp7), which is important in early nervous system development, is expressed in astrocytes and neuronal cell precursors in mature brain. We report here that levels of Fabp7 mRNA in adult murine brain change over a 24 hour period. Unlike Fabp5, a fatty acid binding protein that is expressed widely in various cell types within brain, RNA analysis revealed that Fabp7 mRNA levels were elevated during the light period and lower during dark in brain regions involved in sleep and activity mechanisms. This pattern of Fabp7 mRNA expression was confirmed using in situ hybridization and found to occur throughout the entire brain. Changes in the intracellular distribution of Fabp7 mRNA were also evident over a 24 hour period. Diurnal changes in Fabp7, however, were not found in postnatal day 6 brain, when astrocytes are not yet mature. In contrast, granule cell precursors of the subgranular zone of adult hippocampus did undergo diurnal changes in Fabp7 expression. These changes paralleled oscillations in Fabp7 mRNA throughout the brain suggesting that cell-coordinated signals likely control brain-wide Fabp7 mRNA expression. Immunoblots revealed that Fabp7 protein levels also underwent diurnal changes in abundance, with peak levels occurring in the dark period. Of clock or clock-regulated genes, the synchronized, global cycling pattern of Fabp7 expression is unique and implicates glial cells in the response or modulation of activity and/or circadian rhythms.

Show MeSH
Related in: MedlinePlus