GLUT8 is dispensable for embryonic development but influences hippocampal neurogenesis and heart function.
GLUT8 is a glucose transporter isoform expressed at high levels in testis; at intermediate levels in the brain, including the hippocampus; and at lower levels in the heart and several other tissues. GLUT8 is located in an intracellular compartment and does not appear to translocate to the cell surface, except in blastocysts, where insulin has been reported to induce its surface expression. Here, we generated mice with inactivation of the glut8 gene. We showed that expression of GLUT8 was not required for normal embryonic development and that glut8-/- mice had normal postnatal development, glucose homeostasis, and response to mild stress. Adult glut8-/- mice showed increased proliferation of hippocampal cells but no defect in memory acquisition and retention. Absence of GLUT8 from the heart did not alter heart size and morphology but led to an increase in P-wave duration, which was not associated with abnormal Nav1.5 Na+ channel or connexin expression. Thus, absence of GLUT8 expression in the mouse caused complex but mild physiological alterations.
Membrez
Mathieu
M
Institute of Physiology, University of Lausanne, Center for Integrative Genomics, Génopode Building, CH-1015 Lausanne, Switzerland.
Hummler
Edith
E
Beermann
Friedrich
F
Haefliger
Jacques-Antoine
JA
Savioz
Rebecca
R
Pedrazzini
Thierry
T
Thorens
Bernard
B
D000818:Animals; D001835:Body Weight; D049109:Cell Proliferation; D017630:Connexins / Q000235:genetics; D047108:Embryonic Development; D018390:Gene Targeting; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D051246:Glucose Transport Proteins, Facilitative / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D006321:Heart / Q000196:embryology / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000196:embryology*; D006706:Homeostasis / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009206:Myocardium / Q000166:cytology; D009929:Organ Size; D038081:Organogenesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015222:Sodium Channels / Q000235:genetics; D014981:Xenopus
D017630:Connexins; D051246:Glucose Transport Proteins, Facilitative; D012333:RNA, Messenger; C498628:Slc2a8 protein, mouse; D015222:Sodium Channels; C082920:connexin 45; D005947:Glucose