Expression of thymosin beta4 mRNA by activated microglia in the denervated hippocampus.
Thymosin beta4 is a major actin-sequestering molecule. Here, we report a prominent upregulation of thymosin beta4 in the hippocampus following entorhinal deafferentation. Northern blotting displayed a transient increase of thymosin beta4 mRNA in the deafferented hippocampus by 1.8, 2.3, 1.3 and 1.1-fold of controls, respectively, at 1, 3, 7 and 15 days post-lesion. In-situ hybridization confirmed that the induction of thymosin beta4 mRNA specifically occurred in the entorhinally denervated zones of the hippocampus. The double labeling of in-situ hybridization for thymosin beta4 mRNA with isolectin B4 cytochemistry showed that isolectin B4-positive microglial cells are responsible for deafferentation-induced thymosin beta4 mRNA expression. The results suggest that thymosin beta4 may participate in the process of microglial activation, which is the earliest event in lesion-induced plasticity.
Dong
Jing-Hui
JH
Key Laboratory of Neurobiology, Shanghai Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences.
Ying
Guo-Xin
GX
Liu
Xin
X
Wang
Wen-Yuan
WY
Wang
Yan
Y
Ni
Zi-Mei
ZM
Zhou
Chang-Fu
CF
D000818:Animals; D015152:Blotting, Northern; D003714:Denervation; D018728:Entorhinal Cortex / Q000502:physiology; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D037102:Lectins; D017628:Microglia / Q000378:metabolism*; D009475:Neurons, Afferent / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013947:Thymosin / Q000096:biosynthesis*; D015854:Up-Regulation; D000099201:Thymosin beta(4)
D005904:Glial Fibrillary Acidic Protein; D037102:Lectins; D012333:RNA, Messenger; D013947:Thymosin; D000099201:Thymosin beta(4)