Impact of heart failure on the behavior of human neonatal stem cells in vitro.
BACKGROUND
Clinical cardiac cell therapy using autologous somatic stem cells is restricted by age and disease-associated impairment of stem cell function. Juvenile cells possibly represent a more potent alternative, but the impact of patient-related variables on such cell products is unknown. We therefore evaluated the behavior of neonatal cord blood mesenchymal stem cells (CB-MSC) in the presence of serum from patients with advanced heart failure (HF).


METHODS
Human serum was obtained from patients with severe HF (n = 21) and from healthy volunteers (n = 12). To confirm the systemic quality of HF in the sera, TNF-α and IL-6 were quantified. CB-MSC from healthy neonates were cultivated for up to 14 days in medium supplemented with 10% protein-normalized human HF or control serum or fetal calf serum (FCS).


RESULTS
All HF sera contained increased cytokine concentrations (IL-6, TNF-α). When exposed to HF serum, CB-MSC maintained basic MSC properties as confirmed by immunophenotyping and differentiation assays, but clonogenic cells were reduced in number and gave rise to substantially smaller colonies in the CFU-F assay. Cell cycle analysis pointed towards G1 arrest. CB-MSC metabolic activity and proliferation were significantly impaired for up to 3 days as measured by MTS turnover, BrdU incorporation and DAPI + nuclei counting. On day 5, however, CB-MSC growth kinetics approached control serum levels, though protein expression of cell cycle inhibitors (p21, p27), and apoptosis marker Caspase 3 remained elevated. Signal transduction included the stress and cytokine-induced JNK and ERK1/2 MAP kinase pathways.


CONCLUSIONS
Heart failure temporarily inhibits clonality and proliferation of "healthy" juvenile MSC in vitro. Further studies should address the in vivo and clinical relevance of this finding.
Berlin-Brandenburg Center for Regenerative Therapies, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. stamm@dhzb.de.
Kristin
K
Klose
Rajika
R
Roy
Andreja
A
Brodarac
Andreas
A
Kurtz
Andrea
A
Ode
Kyung-Sun
KS
Kang
Karen
K
Bieback
Yeong-Hoon
YH
Choi
Christof
C
Stamm
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002453:Cell Cycle; D049109:Cell Proliferation; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000097:blood; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005312:Fetal Blood / Q000166:cytology; D006333:Heart Failure / Q000097:blood / Q000473:pathology*; D006801:Humans; D007231:Infant, Newborn; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D044967:Serum / Q000378:metabolism; D015398:Signal Transduction; D055815:Young Adult
D015415:Biomarkers; D016207:Cytokines; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases