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miR-26a and miR-384-5p are required for LTP maintenance and spine enlargement.

Gu QH, Yu D, Hu Z, Liu X, Yang Y, Luo Y, Zhu J, Li Z - Nat Commun (2015)

Bottom Line: Long-term potentiation (LTP) is a form of synaptic plasticity that results in enhanced synaptic strength.Using bioinformatics, we also examine the global effects of miRNA transcriptome changes during LTP on gene expression and cellular activities.This study reveals a novel miRNA-mediated mechanism for gene-specific regulation of translation in LTP, identifies two miRNAs required for long-lasting synaptic and spine plasticity and presents a catalogue of candidate 'LTP miRNAs'.

View Article: PubMed Central - PubMed

Affiliation: Unit on Synapse Development and Plasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.

ABSTRACT
Long-term potentiation (LTP) is a form of synaptic plasticity that results in enhanced synaptic strength. It is associated with the formation and enlargement of dendritic spines-tiny protrusions accommodating excitatory synapses. Both LTP and spine remodelling are crucial for brain development, cognition and the pathophysiology of neurological disorders. The role of microRNAs (miRNAs) in the maintenance of LTP, however, is not well understood. Using next-generation sequencing to profile miRNA transcriptomes, we demonstrate that miR-26a and miR-384-5p specifically affect the maintenance, but not induction, of LTP and different stages of spine enlargement by regulating the expression of RSK3. Using bioinformatics, we also examine the global effects of miRNA transcriptome changes during LTP on gene expression and cellular activities. This study reveals a novel miRNA-mediated mechanism for gene-specific regulation of translation in LTP, identifies two miRNAs required for long-lasting synaptic and spine plasticity and presents a catalogue of candidate 'LTP miRNAs'.

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RSK3 mediates the effect of miR-26a and miR-384-5p on LTP.(a,b) Cultured hippocampal neurons were transfected with designated reporter constructs at DIV14 and fixed for image acquisition at DIV17; n=13–15 neurons for each group; data are presented as mean±s.e.m.; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; ***P<0.001; scale bar, 20 μm. (c–f) Cultured hippocampal slices were transduced with a designated lentivirus, unstimulated (c,d), sham-stimulated (e,f) or stimulated with high-frequency stimulation (HFS; e,f) and immunoblotted for RSK3; data are presented as mean±s.e.m.; n=4–5 slices for each condition; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; *P<0.05, ***P<0.001. (g–i) Cultured hippocampal slices were treated with vehicle or BI-D1870 or transduced with designated lentivirus, and stimulated for LTP induction; the fEPSP slope normalized to the baseline prior to stimulation was plotted as mean±s.e.m.; n=5–7 slices for each condition; one-way analysis of variance and Student's t-test are used for normally distributed data with equal variance, and Kruskal–Wallis and Mann–Whitney U-tests are used for non-normally distributed data with unequal variance for statistical analysis.
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f3: RSK3 mediates the effect of miR-26a and miR-384-5p on LTP.(a,b) Cultured hippocampal neurons were transfected with designated reporter constructs at DIV14 and fixed for image acquisition at DIV17; n=13–15 neurons for each group; data are presented as mean±s.e.m.; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; ***P<0.001; scale bar, 20 μm. (c–f) Cultured hippocampal slices were transduced with a designated lentivirus, unstimulated (c,d), sham-stimulated (e,f) or stimulated with high-frequency stimulation (HFS; e,f) and immunoblotted for RSK3; data are presented as mean±s.e.m.; n=4–5 slices for each condition; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; *P<0.05, ***P<0.001. (g–i) Cultured hippocampal slices were treated with vehicle or BI-D1870 or transduced with designated lentivirus, and stimulated for LTP induction; the fEPSP slope normalized to the baseline prior to stimulation was plotted as mean±s.e.m.; n=5–7 slices for each condition; one-way analysis of variance and Student's t-test are used for normally distributed data with equal variance, and Kruskal–Wallis and Mann–Whitney U-tests are used for non-normally distributed data with unequal variance for statistical analysis.

Mentions: We first tested whether RSK3 is a true target of miR-26a and miR-384-5p. We generated miR-26a and miR-384-5p reporter constructs by inserting the sequences surrounding their predicted binding sites in the 3′ UTR of RSK3 behind the destabilized mCherry gene. These reporter constructs were co-transfected with plasmids expressing miRNAs (along with enhanced green fluorescent protein (EGFP)) into cultured hippocampal neurons (DIV14). At 2∼3 days after transfection, in neurons co-transfected with the miR-26a or miR-384-5p constructs and their corresponding reporters, mCherry expression was significantly lower than in cells transfected with the EGFP and the miR-26a or miR-384-5p reporter (Fig. 3a,b; Supplementary Fig. 5). Deleting the miR-26a- and miR-384-5p-binding sites or mutating the sequence base-pairing with the seed region of miR-26a and miR-384-5p in the reporter construct abolished this effect (Fig. 3a,b; Supplementary Fig. 5). By contrast, miR-215, which is not predicted to bind to RSK3 mRNAs (TargetScan and miRanda) did not affect expression of the miR-26a and miR-384-5p reporters (Fig. 3a,b; Supplementary Fig. 5).


miR-26a and miR-384-5p are required for LTP maintenance and spine enlargement.

Gu QH, Yu D, Hu Z, Liu X, Yang Y, Luo Y, Zhu J, Li Z - Nat Commun (2015)

RSK3 mediates the effect of miR-26a and miR-384-5p on LTP.(a,b) Cultured hippocampal neurons were transfected with designated reporter constructs at DIV14 and fixed for image acquisition at DIV17; n=13–15 neurons for each group; data are presented as mean±s.e.m.; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; ***P<0.001; scale bar, 20 μm. (c–f) Cultured hippocampal slices were transduced with a designated lentivirus, unstimulated (c,d), sham-stimulated (e,f) or stimulated with high-frequency stimulation (HFS; e,f) and immunoblotted for RSK3; data are presented as mean±s.e.m.; n=4–5 slices for each condition; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; *P<0.05, ***P<0.001. (g–i) Cultured hippocampal slices were treated with vehicle or BI-D1870 or transduced with designated lentivirus, and stimulated for LTP induction; the fEPSP slope normalized to the baseline prior to stimulation was plotted as mean±s.e.m.; n=5–7 slices for each condition; one-way analysis of variance and Student's t-test are used for normally distributed data with equal variance, and Kruskal–Wallis and Mann–Whitney U-tests are used for non-normally distributed data with unequal variance for statistical analysis.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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f3: RSK3 mediates the effect of miR-26a and miR-384-5p on LTP.(a,b) Cultured hippocampal neurons were transfected with designated reporter constructs at DIV14 and fixed for image acquisition at DIV17; n=13–15 neurons for each group; data are presented as mean±s.e.m.; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; ***P<0.001; scale bar, 20 μm. (c–f) Cultured hippocampal slices were transduced with a designated lentivirus, unstimulated (c,d), sham-stimulated (e,f) or stimulated with high-frequency stimulation (HFS; e,f) and immunoblotted for RSK3; data are presented as mean±s.e.m.; n=4–5 slices for each condition; Kruskal–Wallis and Mann–Whitney U-tests are used for statistical analysis; *P<0.05, ***P<0.001. (g–i) Cultured hippocampal slices were treated with vehicle or BI-D1870 or transduced with designated lentivirus, and stimulated for LTP induction; the fEPSP slope normalized to the baseline prior to stimulation was plotted as mean±s.e.m.; n=5–7 slices for each condition; one-way analysis of variance and Student's t-test are used for normally distributed data with equal variance, and Kruskal–Wallis and Mann–Whitney U-tests are used for non-normally distributed data with unequal variance for statistical analysis.
Mentions: We first tested whether RSK3 is a true target of miR-26a and miR-384-5p. We generated miR-26a and miR-384-5p reporter constructs by inserting the sequences surrounding their predicted binding sites in the 3′ UTR of RSK3 behind the destabilized mCherry gene. These reporter constructs were co-transfected with plasmids expressing miRNAs (along with enhanced green fluorescent protein (EGFP)) into cultured hippocampal neurons (DIV14). At 2∼3 days after transfection, in neurons co-transfected with the miR-26a or miR-384-5p constructs and their corresponding reporters, mCherry expression was significantly lower than in cells transfected with the EGFP and the miR-26a or miR-384-5p reporter (Fig. 3a,b; Supplementary Fig. 5). Deleting the miR-26a- and miR-384-5p-binding sites or mutating the sequence base-pairing with the seed region of miR-26a and miR-384-5p in the reporter construct abolished this effect (Fig. 3a,b; Supplementary Fig. 5). By contrast, miR-215, which is not predicted to bind to RSK3 mRNAs (TargetScan and miRanda) did not affect expression of the miR-26a and miR-384-5p reporters (Fig. 3a,b; Supplementary Fig. 5).

Bottom Line: Long-term potentiation (LTP) is a form of synaptic plasticity that results in enhanced synaptic strength.Using bioinformatics, we also examine the global effects of miRNA transcriptome changes during LTP on gene expression and cellular activities.This study reveals a novel miRNA-mediated mechanism for gene-specific regulation of translation in LTP, identifies two miRNAs required for long-lasting synaptic and spine plasticity and presents a catalogue of candidate 'LTP miRNAs'.

View Article: PubMed Central - PubMed

Affiliation: Unit on Synapse Development and Plasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.

ABSTRACT
Long-term potentiation (LTP) is a form of synaptic plasticity that results in enhanced synaptic strength. It is associated with the formation and enlargement of dendritic spines-tiny protrusions accommodating excitatory synapses. Both LTP and spine remodelling are crucial for brain development, cognition and the pathophysiology of neurological disorders. The role of microRNAs (miRNAs) in the maintenance of LTP, however, is not well understood. Using next-generation sequencing to profile miRNA transcriptomes, we demonstrate that miR-26a and miR-384-5p specifically affect the maintenance, but not induction, of LTP and different stages of spine enlargement by regulating the expression of RSK3. Using bioinformatics, we also examine the global effects of miRNA transcriptome changes during LTP on gene expression and cellular activities. This study reveals a novel miRNA-mediated mechanism for gene-specific regulation of translation in LTP, identifies two miRNAs required for long-lasting synaptic and spine plasticity and presents a catalogue of candidate 'LTP miRNAs'.

Show MeSH
Related in: MedlinePlus