Expression of intracellular calcium channels and pumps after partial hepatectomy in rat.
Ca(2+) signals regulate many cellular functions, including proliferation. They are governed by the inositol 1,4,5-trisphosphate receptor (IP(3)R), the only intracellular hepatic Ca(2+) channel and by the endoplasmic reticulum Ca(2+) pumps, SERCA. To characterise their role in regeneration, expression of their isoforms was studied after 2/3 hepatectomy by real-time quantitative PCR, Western blot and binding studies. We found an early increase in the expression of the IP(3)R isoform 1 which contrasted with the decrease of the expression of the IP(3)R isoforms 2 and 3 and of SERCA3. This results in a transient switch between IP(3)R isoforms 1 and 2, IP(3)R isoform 1 becoming predominant before the first round of mitosis. Binding studies detected a 30% diminution of the IP(3)R population at 24 h. In conclusion, the Ca(2+) signalling machinery is regulated, after hepatectomy, by changes in expression of the IP(3)R and SERCA isoforms to adapt Ca(2+) signals to the regenerative state.
Magnino
F
F
Department of Clinical Pharmacology, University of Bern, Bern, Switzerland.
St-Pierre
M
M
Lüthi
M
M
Hilly
M
M
Mauger
J P
JP
Dufour
J F
JF
D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006498:Hepatectomy; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008099:Liver / Q000196:embryology / Q000378:metabolism / Q000502:physiology; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D013997:Time Factors
C506951:Atp2a3 protein, rat; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020033:Protein Isoforms; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium