title: Cardiotrophin-1: expression in experimental myocardial infarction and potential role in post-MI wound healing.
abstract: Cardiotrophin-1 (CT-1), a member of the IL-6 family of cytokines, has been shown to be elevated in the serum of patients with ischemic heart disease and valvular heart disease, and induces cardiomyocyte hypertrophy in vitro. We investigated expression of CT-1 in post-MI rat heart and the effect of CT-1 on cultured primary adult rat cardiac fibroblasts. Elevated CT-1 expression was observed in the infarct zone at 24 h and continued through 2, 4 and 8 weeks post-MI, compared to sham-operated animals. CT-1 induced rapid phosphorylation of Jak, Jak2, STAT1, STAT3, p42/44 MAPK and Akt in cultured adult cardiac fibroblasts. CT-1 induced cardiac fibroblast protein synthesis and proliferation. Protein and DNA synthesis were dependent on activation of Jak/STAT, MEK1/2, PI3K and Src pathways as evidenced by decreased 3H-leucine and 3H-thymidine incorporation after pretreatment with AG490, PD98059, LY294002 and genistein respectively. Furthermore, CT-1 treatment increased procollagen-1-carboxypropeptide (PICP) synthesis, a marker of mature collagen synthesis. CT-1 induced cell migration of rat cardiac fibroblasts. Our results suggest that CT-1, as expressed in post-MI heart, may play an important role in infarct scar formation and ongoing remodeling of the scar. CT-1 was able to initiate each of the processes considered important in the formation of infarct scar including cardiac fibroblast migration as well as fibroblast proliferation and collagen synthesis. Further work is required to determine factors that induce CT-1 expression and interplay with other mediators of cardiac infarct wound healing in the setting of acute cardiac ischemia and chronic post-MI heart failure.
authors.affiliation: Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Darren H
authors.initials: DH
authors.lastname: Freed
authors.forename: Michael C
authors.initials: MC
authors.lastname: Moon
authors.forename: Anna M
authors.initials: AM
authors.lastname: Borowiec
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Jones
authors.forename: Peter
authors.initials: P
authors.lastname: Zahradka
authors.forename: Ian M C
authors.initials: IM
authors.lastname: Dixon
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002455:Cell Division; D002465:Cell Movement; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis*; D004247:DNA / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009203:Myocardial Infarction / Q000378:metabolism*; D010766:Phosphorylation; D011347:Procollagen / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013997:Time Factors; D014945:Wound Healing
chemical_list: D016207:Cytokines; D004791:Enzyme Inhibitors; D015850:Interleukin-6; D011347:Procollagen; D003094:Collagen; D004247:DNA; C092073:cardiotrophin 1; D020928:Mitogen-Activated Protein Kinases