Investigating The Role Of ADAM10on Glial Cells Development In Central Nervous System

The central nervous system, possessing highly sophisticated structure in mammals, plays complicated roles in preventing and curing diseases. In order to understand better about nervous system related deaeases, it is pivotal to study on the mechanism of the central nervous system development. ADAM10is a member of integrin metalloproteinase family and have metalloprotease, integrin-binding, intracellular signaling and cell adhesion activities. AD AM10are important for a secretase activity of proteins such as Notch, amyloid precursor protein (APP) and transforming growth factor a (TGFa), and can bind integrins. What’s more AD AM10has been shown to play important roles in the development of the nervous system, where it regulates proliferation, migration, differentiation and survival of various cells, as well as axonal growth and myelination.Central nervous system is mainly made up of two types of cells:neurons and glia cells. And glial cells are classified into several different types:astrocyte, oligodendrocyte, radial glial cell, ependymal cell and microglial cell. In quantity, the number of glial cells in brain is about10to50times as the number of neurons and glial cells account for about half the size of the brain, in which, neurons and glial cells wrap together closely, interval width20nm and they interact with each other closely. Glial cells have many functions, such as support and nutrition neurons, repair and regeneration of the nervous system, immune response, material metabolism and center, keeping stable on nerve cells extracellular K+concentration, enhancement the synapse formation, synaptic plasticity and improvement of synaptic transmission.In this study, we established the mouse model that Adam10gene was knocked out in GFAP-positive cells to complete the experimental purpose:exploring the role of ADAM10in regulating the nerve cell development in central nervous system.Methods:To build mouse model of Adam10gene was specific knocked out in GFAP-positive cells, Cre/LoxP system was applied. Mice genotype was identified by PCR. Western blot was used to test the expression of ADAM10. HE staining was observed to compare the test group with control group. Immunofluorescence staining was used to mark astrocytes, NG2cells, neurons to see whether knockout of Adam10influence the nerve cells development.Results:1. Western blot test showed ADAM10expression decreased in the knockout group. And PCR detected genotype of the mice. The phenotype of knockout group showed ataxia, thin body, hair loss et al.2. HE staining showed that the cerebral cortex structure was damaged in knockout mice and the cell layer disorder, larger ventricular cavity; hippocampus damage or loss.3. The expression of NeuN deceased in the brain where ADAM10is knocked out in GFAP-positive cells.4. GFAP immunofluorescence staining and Western blot showed that the GFAP expression increased in knockout group comparing with the control group.5. NG2immunofluorescence staining showed that there was no significance difference of NG2cells number in knockout mice and the control group. Western blot showed NG2expression didn’t change in knockout group.Conclusion:Adam10gene is knocked out in GFAP-positive cells, seriously affecting brain development, resulting in structure of cerebral cortex damage, cortical thinning and the cell layer disorder, lateral cavity expandation, even the missing of brain, damage or loss of hippocampus. That Adam10gene is knocked out in GFAP-positive cells reduced the number of cortical neurons.