Treatment with alpha-melanocyte stimulating hormone preserves calcium regulatory proteins in rat heart allografts.
Prevention of graft dysfunction is a major objective in transplantation medicine. Previous research on experimental heart transplantation indicated that treatment with the immunomodulatory peptide alpha-melanocyte stimulating hormone (alpha-MSH) improves histopathology, prolongs allograft survival, and reduces expression of the main tissue injury mediators. Because calcium-handling is critical in heart graft function, we determined the effects of transplantation injury and influences of alpha-MSH treatment on representative calcium regulatory proteins in rat heart allografts. Hearts from Brown Norway rats were transplanted heterotopically into MHC incompatible Lewis rats. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), protein kinase C epsilon (PKC epsilon), sarcoplasmic/endoplasmic reticulum calcium-ATPase 2 (SERCA2a), arrestin-beta1 (Arrb1), cholinergic receptor M2 (Chrm2), and inositol 1,4,5-triphosphate receptor 1 (InsP(3)R1) were examined in: (1) non-transplanted donor hearts; (2) allografts from saline-treated rats; and (3) allografts from rats treated with the synthetic alpha-MSH analog Nle4-DPhe7-alpha-MSH (NDP-alpha-MSH) (100 microg i.p. every 12h). Transplantation injury was associated with severe reduction in calcium regulatory protein transcription and expression level. NDP-alpha-MSH administration partly reversed inhibition of protein transcription and almost completely prevented protein loss. Finally, because certain effects of cyclic 3'-5'-adenosine monophosphate (cAMP) signaling on calcium handling in cardiac myocytes depend on activation of exchange protein directly activated by cAMP 1 (Epac1), we determined Epac1 mRNA and protein expression in heart allografts. Transplantation injury markedly reduced Epac1. NDP-alpha-MSH treatment significantly preserved both Epac1 protein and mRNA in the allografts. Administration of alpha-MSH or related melanocortins could reduce transplantation-induced dysfunction through protection of heart calcium regulatory proteins.
Colombo
Gualtiero
G
Center for Preclinical Investigation, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via F.Sforza 35, Milano 20122, Italy.
Sordi
Andrea
A
Lonati
Caterina
C
Carlin
Andrea
A
Turcatti
Flavia
F
Leonardi
Patrizia
P
Gatti
Stefano
S
Catania
Anna
A
D000818:Animals; D019390:Arrestins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics / Q000378:metabolism; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D006084:Graft Rejection / Q000188:drug therapy; D006085:Graft Survival / Q000187:drug effects; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D016027:Heart Transplantation / Q000379:methods*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D051744:Protein Kinase C-epsilon / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D011950:Receptors, Cholinergic / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000521:alpha-MSH / Q000494:pharmacology*; D000071559:beta-Arrestin 1; D000071557:beta-Arrestins
C000605253:ARRB1 protein, human; C000605256:Arrb1 protein, rat; D019390:Arrestins; D015220:Calcium Channels; D002135:Calcium-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D053496:Inositol 1,4,5-Trisphosphate Receptors; C488910:Itpr1 protein, rat; C116122:RAPGEF3 protein, human; D011950:Receptors, Cholinergic; D018160:Receptors, Cytoplasmic and Nuclear; D000071559:beta-Arrestin 1; D000071557:beta-Arrestins; D000521:alpha-MSH; D000242:Cyclic AMP; C497257:Prkce protein, rat; D051744:Protein Kinase C-epsilon; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium