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Integrin family of cell adhesion molecules in the injured brain: Regulation and cellular localization in the normal and regenerating mouse facial motor nucleus
Author(s) -
Kloss Christian U.A.,
Werner Alexander,
Klein Michael A.,
Shen Jun,
Menuz Karen,
Probst J. Chistoph,
Kreutzberg Georg W.,
Raivich Gennadij
Publication year - 1999
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/(sici)1096-9861(19990816)411:1<162::aid-cne12>3.0.co;2-w
Subject(s) - axotomy , microglia , integrin , biology , microbiology and biotechnology , cell adhesion molecule , protein subunit , integrin alpha m , neuroscience , central nervous system , inflammation , cell , immunology , gene , biochemistry
Integrins are a large family of heterodimeric glycoproteins that play a crucial role in cell adhesion during development, inflammation, and tissue repair. In the current study, we investigated the localization of different integrin subunits in the mouse facial motor nucleus and their regulation after transection of the facial nerve. In the normal mouse brain, there was clear immunoreactivity for α5‐, α6‐, and β1‐integrin subunits on blood vessel endothelia and for αM‐ and β2‐subunits on resting parenchymal microglia. Facial nerve transection led to an up‐regulation of the β1‐subunit on the axotomized neurons and an increase in the α4‐, α5‐, α6‐, β1‐, αM‐, αX‐, and β2‐subunits on the adjacent, activated microglia. Quantification of the microglial integrins revealed two different expression patterns. The subunits α5 and α6 showed a monophasic increase with a maximum at day 4, the αM‐subunit a biphasic regulation, with an early peak at day 1 and an elevated plateau between day 14 and 42. At day 14, there was also an influx of lymphocytes immunoreactive for the α4β1‐ and αLβ2‐integrins, which aggregated at sites of neural debris and phagocytotic microglia. This finding was accompanied by a significant increase of the α5β1‐integrin on blood vessel endothelia. In summary, facial axotomy is followed by a strong and cell‐type–specific expression of integrins on the affected neurons and on surrounding microglia, lymphocytes, and vascular endothelia. The presence of several, strikingly different temporal patterns suggests a selective involvement of these molecules in the different adhesive events during regeneration in the central nervous system. J. Comp. Neurol. 411:162–178, 1999. © 1999 Wiley‐Liss, Inc.