Difluoromethylornithine stimulates early cardiac commitment of mesenchymal stem cells in a model of mixed culture with cardiomyocytes.
The efficiency of in vitro mesenchymal stem cell (MSC) differentiation into the myocardial lineage is generally poor. In order to improve cardiac commitment, bone marrow GFP+MSCs obtained from transgenic rats were cultured with adult wild type rat cardiomyocytes for 5 days in the presence of difluoromethylornithine (DFMO), an inhibitor of polyamine synthesis and cell proliferation. The percentage of GFP+MSCs showing cardiac myofibril proteins (cMLC2, cTnI) was about threefold higher after DFMO addition (3%) relative to the untreated control (1%). Another set of experiments was performed with cardiomyocytes incubated for 1 day in the absence of glucose and serum and under hypoxic conditions (pO2 < 1%), in order to simulate severe ischemia. The percentage of cardiac committed GFP+MSCs was about 5% when cultured with the hypoxic/starved cardiomyocytes and further increased to 7% after DFMO addition. The contemporary presence of putrescine in DFMO-treated cells markedly blunted differentiation, while the cytostatic mitomycin C was not able to induce cardiac commitment. The involvement of histone acetylation in DFMO-induced differentiation was evidenced by the strong attenuation of cardiac commitment exerted by anacardic acid, an inhibitor of histone acetylase. Moreover, the percentage of acetylated histone H3 significantly increased in bone marrow MSCs obtained from wild type rats and treated with DFMO. These results suggest that polyamine depletion can represent a useful strategy to improve MSC differentiation into the cardiac lineage, especially in the presence of cardiomyocytes damaged by an ischemic environment.
Muscari
Claudio
C
Department of Biochemistry "G. Moruzzi", University of Bologna, Bologna, Italy. claudio.muscari@unibo.it
Bonafé
Francesca
F
Carboni
Marco
M
Govoni
Marco
M
Stanic
Ivana
I
Gamberini
Chiara
C
Ricci
Francesca
F
Tazzari
Pier Luigi
PL
Caldarera
Claudio Marcello
CM
Guarnieri
Carlo
C
D000107:Acetylation; D048729:Anacardic Acids / Q000494:pharmacology; D000818:Animals; D030801:Animals, Genetically Modified; D001854:Bone Marrow Cells / Q000166:cytology* / Q000502:physiology; D024722:Cardiac Myosins / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D015687:Cell Hypoxia; D019070:Cell Lineage; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D000518:Eflornithine / Q000494:pharmacology*; D006657:Histones / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D016685:Mitomycin / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000502:physiology; D018994:Myosin Light Chains / Q000378:metabolism; D011073:Polyamines / Q000494:pharmacology; D051381:Rats
D048729:Anacardic Acids; D006657:Histones; D018994:Myosin Light Chains; D011073:Polyamines; C107184:myosin light chain 2; C088115:anacardic acid; D016685:Mitomycin; D024722:Cardiac Myosins; D000518:Eflornithine