Differential expression of apolipoprotein d in human astroglial and oligodendroglial cells.
Apolipoprotein D (Apo D) is a secreted lipocalin in the nervous system that may be related to processes of reinnervation and regeneration. Under normal conditions, Apo D is present in the central nervous system in oligodendrocytes, astrocytes, and some scattered neurons. To elucidate the regional and cellular distribution of Apo D in normal human brain, we performed double immunohistochemistry for glial fibrillary acidic protein (GFAP) and Apo D in samples of postmortem human cerebral and cerebellar cortices. Most of the GFAP-positive cells in the gray matter had features of protoplasmic astrocytes and were mainly Apo D-positive. Apo D staining was mostly confined to the cell soma and proximal processes, whereas GFAP extended to a rich and extensive array of processes. The fibrous astrocytes in the white matter were immunoreactive for GFAP but not for Apo D. In the white matter, Apo D was mainly detected in oligodendrocytes and extracellularly in the neuropil. The results of the present study support a specific behavior for each astrocyte type. These findings suggest that Apo D expression may be cell-specific, depending on the particular tissue physiology at the time of examination.
Navarro
Ana
A
Departamento Morfología y Biología Celular, Facultad de Biología y Medicina, Universidad de Oviedo, Julián Clavería s/n, Oviedo 33006, Spain.
Del Valle
Eva
E
Tolivia
Jorge
J
D000328:Adult; D001053:Apolipoproteins / Q000096:biosynthesis*; D053399:Apolipoproteins D; D001253:Astrocytes / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009836:Oligodendroglia / Q000378:metabolism*
D001053:Apolipoproteins; D053399:Apolipoproteins D; D005904:Glial Fibrillary Acidic Protein