Altered expression of sphingosine kinase 1 and sphingosine-1-phosphate receptor 1 in mouse hippocampus after kainic acid treatment.
Kainic acid (KA) induces hippocampal cell death and astrocyte proliferation. There are reports that sphingosine kinase (SPHK)1 and sphingosine-1- phosphate (S1P) receptor 1 (S1P(1)) signaling axis controls astrocyte proliferation. Here we examined the temporal changes of SPHK1/S1P(1) in mouse hippocampus during KA-induced hippocampal cell death. Mice were killed at 2, 6, 24, or 48 h after KA (30 mg/kg) injection. There was an increase in Fluoro-Jade B-positive cells in the hippocampus of KA-treated mice with temporal changes of glial fibrillary acidic protein (GFAP) expression. The lowest level of SPHK1 protein expression was found 2h after KA treatment. Six hours after KA treatment, the expression of SPHK1 and S1P(1) proteins steadily increased in the hippocampus. In immunohistochemical analysis, SPHK1 and S1P(1) are more immunoreactive in astrocytes within the hippocampus of KA-treated mice than in hippocampus of control mice. These results indicate that SPHK1/S1P(1) signaling axis may play an important role in astrocytes proliferation during KA-induced excitotoxicity.
Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Biomedical Center (BK21), Gyeongsang National University School of Medicine, Jinju, Gyeongnam 660-751, Republic of Korea.
Dong Hoon
DH
Lee
Byeong Tak
BT
Jeon
Eun Ae
EA
Jeong
Joon Soo
JS
Kim
Yong Woon
YW
Cho
Hyun Joon
HJ
Kim
Sang Soo
SS
Kang
Gyeong Jae
GJ
Cho
Wan Sung
WS
Choi
Gu Seob
GS
Roh
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D019636:Neurodegenerative Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis*; D049349:Receptors, Lysosphingolipid / Q000096:biosynthesis*; D000099157:Sphingosine Kinase
D005904:Glial Fibrillary Acidic Protein; D007608:Kainic Acid; D009419:Nerve Tissue Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D049349:Receptors, Lysosphingolipid; D000099157:Sphingosine Kinase; C528900:glial fibrillary astrocytic protein, mouse