Postnatal disruption of the disintegrin/metalloproteinase ADAM10 in brain causes epileptic seizures, learning deficits, altered spine morphology, and defective synaptic functions.

Abstract

The metalloproteinase ADAM10 is of importance for Notch-dependent cortical brain development. The protease is tightly linked with α-secretase activity toward the amyloid precursor protein (APP) substrate. Increasing ADAM10 activity is suggested as a therapy to prevent the production of the neurotoxic amyloid β (Aβ) peptide in Alzheimer's disease. To investigate the function of ADAM10 in postnatal brain, we generated Adam10 conditional knock-out (A10cKO) mice using a CaMKIIα-Cre deleter strain. The lack of ADAM10 protein expression was evident in the brain cortex leading to a reduced generation of sAPPα and increased levels of sAPPβ and endogenous Aβ peptides. The A10cKO mice are characterized by weight loss and increased mortality after weaning associated with seizures. Behavioral comparison of adult mice revealed that the loss of ADAM10 in the A10cKO mice resulted in decreased neuromotor abilities and reduced learning performance, which were associated with altered in vivo network activities in the hippocampal CA1 region and impaired synaptic function. Histological and ultrastructural analysis of ADAM10-depleted brain revealed astrogliosis, microglia activation, and impaired number and altered morphology of postsynaptic spine structures. A defect in spine morphology was further supported by a reduction of the expression of NMDA receptors subunit 2A and 2B. The reduced shedding of essential postsynaptic cell adhesion proteins such as N-Cadherin, Nectin-1, and APP may explain the postsynaptic defects and the impaired learning, altered network activity, and synaptic plasticity of the A10cKO mice. Our study reveals that ADAM10 is instrumental for synaptic and neuronal network function in the adult murine brain.

• Authors: Johannes Prox, Christian Bernreuther, Hermann Altmeppen, Jasper Grendel, Markus Glatzel, Rudi D'Hooge, Stijn Stroobants, Tariq Ahmed, Detlef Balschun, Michael Willem, Sven Lammich, Dirk Isbrandt, Michaela Schweizer, Katrien Horré, Bart De Strooper, Paul Saftig
• Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci) Vol. 33 Issue 32 Pg. 12915-28, 12928a (Aug 07 2013) ISSN: 1529-2401 [Electronic] United States
• PMID: 23926248 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amyloid beta-Protein Precursor
• Cadherins
• Cell Adhesion Molecules
• Membrane Proteins
• NR2B NMDA receptor
• Nectin1 protein, mouse
• Nectins
• Receptors, N-Methyl-D-Aspartate
• Calcium-Calmodulin-Dependent Protein Kinase Type 2
• Amyloid Precursor Protein Secretases
• ADAM Proteins
• ADAM10 Protein
• Adam10 protein, mouse
• N-methyl D-aspartate receptor subtype 2A

Topics

• ADAM Proteins (deficiency)
• ADAM10 Protein
• Amyloid Precursor Protein Secretases (deficiency)
• Amyloid beta-Protein Precursor (metabolism)
• Animals
• Animals, Newborn
• Brain (pathology, ultrastructure)
• Cadherins (metabolism)
• Calcium-Calmodulin-Dependent Protein Kinase Type 2 (genetics)
• Cell Adhesion Molecules (metabolism)
• Dendritic Spines (metabolism, pathology)
• Disease Models, Animal
• Epilepsy (genetics, pathology)
• Gene Expression Regulation, Developmental (genetics)
• Gliosis (genetics)
• Learning Disabilities (genetics, pathology)
• Membrane Proteins (deficiency)
• Mice
• Mice, Transgenic
• Nectins
• Receptors, N-Methyl-D-Aspartate (metabolism)
• Synapses (metabolism, pathology, ultrastructure)