FABP7 expression in normal and stab-injured brain cortex and its role in astrocyte proliferation

• Published in: Histochemistry and cell biology Vol. 136; no. 5; pp. 501 - 513
• Main Authors: Sharifi, Kazem, Morihiro, Yusuke, Maekawa, Motoko, Yasumoto, Yuki, Hoshi, Hisae, Adachi, Yasuhiro, Sawada, Tomoo, Tokuda, Nobuko, Kondo, Hisatake, Yoshikawa, Takeo, Suzuki, Michiyasu, Owada, Yuji
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-11-2011; Springer Nature B.V
• Subjects: Animals; Animals, Newborn; Antigens - metabolism; Astrocytes; Astrocytes - metabolism; Astrocytes - pathology; Biochemistry; Biomedical and Life Sciences; Biomedicine; Brain; Brain damage; Cell Biology; Cell Proliferation; Cells, Cultured; Cellular biology; Cerebral Cortex - injuries; Cerebral Cortex - metabolism; Cortex; Data processing; Developmental Biology; Differentiation; Disease Models, Animal; Fatty acid-binding protein; Fatty Acid-Binding Protein 7; Fatty Acid-Binding Proteins - genetics; Fatty Acid-Binding Proteins - metabolism; Fatty acids; Fatty Acids, Omega-3 - metabolism; Gene Expression; Glial cells; Glial fibrillary acidic protein; Glial stem cells; Gliosis; Gliosis - metabolism; Gliosis - pathology; Homeostasis; Immunohistochemistry; Injuries; Lipid metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neural stem cells; Neural Stem Cells - metabolism; Neural Stem Cells - pathology; Oligodendroglia - metabolism; Oligodendroglia - pathology; Original Paper; Proteoglycans - metabolism; Western blotting; Wounds, Stab - genetics; Wounds, Stab - metabolism; Wounds, Stab - pathology; Reactive gliosis; Astrocyte; Oligodendrocyte progenitor cell; FABP7; Brain injury
• ISSN: 0948-6143; 1432-119X
• DOI: 10.1007/s00418-011-0865-4

Reactive gliosis, in which astrocytes as well as other types of glial cells undergo massive proliferation, is a common hallmark of all brain pathologies. Brain-type fatty acid-binding protein (FABP7) is abundantly expressed in neural stem cells and astrocytes of developing brain, suggesting its role in differentiation and/or proliferation of glial cells through regulation of lipid metabolism and/or signaling. However, the role of FABP7 in proliferation of glial cells during reactive gliosis is unknown. In this study, we examined the expression of FABP7 in mouse cortical stab injury model and also the phenotype of FABP7-KO mice in glial cell proliferation. Western blotting showed that FABP7 expression was increased significantly in the injured cortex compared with the contralateral side. By immunohistochemistry, FABP7 was localized to GFAP
+
astrocytes (21% of FABP7
+
cells) and NG2
+
oligodendrocyte progenitor cells (62%) in the normal cortex. In the injured cortex there was no change in the population of FABP7
+
/NG2
+
cells, while there was a significant increase in FABP7
+
/GFAP
+
cells. In the stab-injured cortex of FABP7-KO mice there was decrease in the total number of reactive astrocytes and in the number of BrdU
+
astrocytes compared with wild-type mice. Primary cultured astrocytes from FABP7-KO mice also showed a significant decrease in proliferation and omega-3 fatty acid incorporation compared with wild-type astrocytes. Overall, these data suggest that FABP7 is involved in the proliferation of astrocytes by controlling cellular fatty acid homeostasis.