Enhanced expression of the sweet taste receptors and alpha-gustducin in reactive astrocytes of the rat hippocampus following ischemic injury.
The heterodimeric sweet taste receptors, T1R2 and T1R3, have recently been proposed to be associated with the brain glucose sensor. To identify whether sweet taste signaling is regulated in response to an ischemic injury inducing acute impairment of glucose metabolism, we investigated the spatiotemporal expression of the sweet taste receptors and their associated taste-specific G-protein α-gustducin in the rat hippocampus after ischemia. The expression profiles of both receptor subunits and α-gustducin shared overlapping expression patterns in sham-operated and ischemic hippocampi. Constitutive expression of both receptors and α-gustducin was localized in neurons of the pyramidal cell and granule cell layers, but their upregulation was detected in reactive astrocytes in ischemic hippocampi. Immunoblot analysis confirmed the immmunohistochemically determined temporal patterns of sweet-taste signaling proteins. These results suggest that the expression of sweet taste signaling proteins in astrocytes might be regulated in response to altered extracellular levels of glucose following an ischemic insult.
Shin
Yoo-Jin
YJ
Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Park
Joo-Hee
JH
Choi
Jeong-Sun
JS
Chun
Myung-Hoon
MH
Moon
Young Wha
YW
Lee
Mun-Yong
MY
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D015151:Immunoblotting; D007150:Immunohistochemistry; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000378:metabolism; D021122:Protein Subunits / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000096:biosynthesis*; D013649:Taste; D013997:Time Factors; D015293:Transducin / Q000096:biosynthesis*
D021122:Protein Subunits; D043562:Receptors, G-Protein-Coupled; C431926:taste receptors, type 1; C075192:gustducin; D015293:Transducin