Limits...
The calcium-binding protein EFhd2 modulates synapse formation in vitro and is linked to human dementia.

Borger E, Herrmann A, Mann DA, Spires-Jones T, Gunn-Moore F - J. Neuropathol. Exp. Neurol. (2014)

Bottom Line: We show that EFhd2 is mainly a neuronal protein in the brain and is abundant in the forebrain.Using short hairpin RNA-mediated knockdown of EFhd2 expression in cultured cortical neurons, we demonstrate that loss of EFhd2 affects the number of synapses developed in vitro whereas it does not alter neurite outgrowth per se.Our data suggest that EFhd2 is involved in the control of synapse development and maintenance through means other than affecting neurite development.

View Article: PubMed Central - PubMed

Affiliation: From the School of Biology, University of St. Andrews, St. Andrews (EB, FG-M); Centre for Cognitive and Neural Systems and Euan MacDonald Centre, School of Biomedical Sciences, University of Edinburgh, Edinburgh (AH, TS-J); and Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford (DAM), United Kingdom.

ABSTRACT
EFhd2 is a calcium-binding adaptor protein that has been found to be associated with pathologically aggregated tau in the brain in Alzheimer disease and in a mouse model of frontotemporal dementia. EFhd2 has cell type-specific functions, including the modulation of intracellular calcium responses, actin dynamics, and microtubule transport. Here we report that EFhd2 protein and mRNA levels are reduced in human frontal cortex tissue affected by different types of dementia with and without tau pathology. We show that EFhd2 is mainly a neuronal protein in the brain and is abundant in the forebrain. Using short hairpin RNA-mediated knockdown of EFhd2 expression in cultured cortical neurons, we demonstrate that loss of EFhd2 affects the number of synapses developed in vitro whereas it does not alter neurite outgrowth per se. Our data suggest that EFhd2 is involved in the control of synapse development and maintenance through means other than affecting neurite development. The changes in expression levels observed in human dementias might, therefore, play a significant role in disease onset and progression of dementia, which is characterized by the loss of synapses.

Show MeSH

Related in: MedlinePlus

EFhd2 protein levels in the frontal cortex are reduced in patients with dementia without tauopathy. (A) Western blots showing EFhd2 protein levels in human frontal cortex (left) and hippocampal (right) tissue RIPA extracts from nondemented controls and individuals with frontotemporal lobar degeneration FTLD-TDP Type B. A sample from AD frontal cortex was run as a calibrator and phospho-tau–positive control on each gel. No calibrator sample was run for EFhd2 and actin detection in hippocampal samples because all samples were run on the same SDS-PAGE. Beta-actin was used as a loading control. (B) Quantification of EFhd2 protein bands by densitometry in frontal cortex samples. * p < 0.05 with all data points (left), *** p < 0.001 without encircled outlier (right), compared with control by t test. (C) Quantification of EFhd2 protein bands in samples from human hippocampus from nondemented controls and individuals with FTLD-TDP Type B.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4238966&req=5

Figure 3: EFhd2 protein levels in the frontal cortex are reduced in patients with dementia without tauopathy. (A) Western blots showing EFhd2 protein levels in human frontal cortex (left) and hippocampal (right) tissue RIPA extracts from nondemented controls and individuals with frontotemporal lobar degeneration FTLD-TDP Type B. A sample from AD frontal cortex was run as a calibrator and phospho-tau–positive control on each gel. No calibrator sample was run for EFhd2 and actin detection in hippocampal samples because all samples were run on the same SDS-PAGE. Beta-actin was used as a loading control. (B) Quantification of EFhd2 protein bands by densitometry in frontal cortex samples. * p < 0.05 with all data points (left), *** p < 0.001 without encircled outlier (right), compared with control by t test. (C) Quantification of EFhd2 protein bands in samples from human hippocampus from nondemented controls and individuals with FTLD-TDP Type B.

Mentions: We therefore asked if changes in EFhd2 protein expression are limited to dementias with tau pathology. To answer this question, EFhd2 protein abundance was compared between nondemented controls and cases with tau-negative FTLD (FTLD-TDP Type B). As in the previously studied tau-positive cases, significantly lower levels of EFhd2 protein were detected in the frontal cortex tissues in FTLD-TDB Type B cases when compared with nondemented controls (Fig. 3A, B). Again, no significant changes in EFhd2 levels could be detected in hippocampal tissues from the same cases (Fig. 3A, C). The absence of tau pathology was confirmed by Western blotting for tau phosphorylated at Ser-394/404 (PHF-1 epitope), which had clearly been detected in AD and FTLD-tau (Fig. 3A, bottom).


The calcium-binding protein EFhd2 modulates synapse formation in vitro and is linked to human dementia.

Borger E, Herrmann A, Mann DA, Spires-Jones T, Gunn-Moore F - J. Neuropathol. Exp. Neurol. (2014)

EFhd2 protein levels in the frontal cortex are reduced in patients with dementia without tauopathy. (A) Western blots showing EFhd2 protein levels in human frontal cortex (left) and hippocampal (right) tissue RIPA extracts from nondemented controls and individuals with frontotemporal lobar degeneration FTLD-TDP Type B. A sample from AD frontal cortex was run as a calibrator and phospho-tau–positive control on each gel. No calibrator sample was run for EFhd2 and actin detection in hippocampal samples because all samples were run on the same SDS-PAGE. Beta-actin was used as a loading control. (B) Quantification of EFhd2 protein bands by densitometry in frontal cortex samples. * p < 0.05 with all data points (left), *** p < 0.001 without encircled outlier (right), compared with control by t test. (C) Quantification of EFhd2 protein bands in samples from human hippocampus from nondemented controls and individuals with FTLD-TDP Type B.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4238966&req=5

Figure 3: EFhd2 protein levels in the frontal cortex are reduced in patients with dementia without tauopathy. (A) Western blots showing EFhd2 protein levels in human frontal cortex (left) and hippocampal (right) tissue RIPA extracts from nondemented controls and individuals with frontotemporal lobar degeneration FTLD-TDP Type B. A sample from AD frontal cortex was run as a calibrator and phospho-tau–positive control on each gel. No calibrator sample was run for EFhd2 and actin detection in hippocampal samples because all samples were run on the same SDS-PAGE. Beta-actin was used as a loading control. (B) Quantification of EFhd2 protein bands by densitometry in frontal cortex samples. * p < 0.05 with all data points (left), *** p < 0.001 without encircled outlier (right), compared with control by t test. (C) Quantification of EFhd2 protein bands in samples from human hippocampus from nondemented controls and individuals with FTLD-TDP Type B.
Mentions: We therefore asked if changes in EFhd2 protein expression are limited to dementias with tau pathology. To answer this question, EFhd2 protein abundance was compared between nondemented controls and cases with tau-negative FTLD (FTLD-TDP Type B). As in the previously studied tau-positive cases, significantly lower levels of EFhd2 protein were detected in the frontal cortex tissues in FTLD-TDB Type B cases when compared with nondemented controls (Fig. 3A, B). Again, no significant changes in EFhd2 levels could be detected in hippocampal tissues from the same cases (Fig. 3A, C). The absence of tau pathology was confirmed by Western blotting for tau phosphorylated at Ser-394/404 (PHF-1 epitope), which had clearly been detected in AD and FTLD-tau (Fig. 3A, bottom).

Bottom Line: We show that EFhd2 is mainly a neuronal protein in the brain and is abundant in the forebrain.Using short hairpin RNA-mediated knockdown of EFhd2 expression in cultured cortical neurons, we demonstrate that loss of EFhd2 affects the number of synapses developed in vitro whereas it does not alter neurite outgrowth per se.Our data suggest that EFhd2 is involved in the control of synapse development and maintenance through means other than affecting neurite development.

View Article: PubMed Central - PubMed

Affiliation: From the School of Biology, University of St. Andrews, St. Andrews (EB, FG-M); Centre for Cognitive and Neural Systems and Euan MacDonald Centre, School of Biomedical Sciences, University of Edinburgh, Edinburgh (AH, TS-J); and Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford (DAM), United Kingdom.

ABSTRACT
EFhd2 is a calcium-binding adaptor protein that has been found to be associated with pathologically aggregated tau in the brain in Alzheimer disease and in a mouse model of frontotemporal dementia. EFhd2 has cell type-specific functions, including the modulation of intracellular calcium responses, actin dynamics, and microtubule transport. Here we report that EFhd2 protein and mRNA levels are reduced in human frontal cortex tissue affected by different types of dementia with and without tau pathology. We show that EFhd2 is mainly a neuronal protein in the brain and is abundant in the forebrain. Using short hairpin RNA-mediated knockdown of EFhd2 expression in cultured cortical neurons, we demonstrate that loss of EFhd2 affects the number of synapses developed in vitro whereas it does not alter neurite outgrowth per se. Our data suggest that EFhd2 is involved in the control of synapse development and maintenance through means other than affecting neurite development. The changes in expression levels observed in human dementias might, therefore, play a significant role in disease onset and progression of dementia, which is characterized by the loss of synapses.

Show MeSH
Related in: MedlinePlus