Abstract 16172: Human Umbilical Cord Blood Stem Cells Decrease Cardiac Fibrosis and Increase Vascularity and Cardiac Function in Cardiomyopathy
We investigated whether human umbilical cord blood mononuclear cells (HUCBC), which contain hematopoietic and mesenchymal stem cells, can limit the progressive congenital myocardial fibrosis and myopathy that occurs in TO2 hamsters. 25 TO2 1[[Unable to Display Character: &-]]month-old hamsters were treated with intramyocardial (IM) HUCBC, 4×106 in Isolyte, and 25 TO2 1[[Unable to Display Character: &-]]month-old hamsters were treated with IM Isolyte. F1B hamsters served as normal controls and received IM Isolyte. Echocardiograms were performed prior to and monthly after initial treatment for 6 months. Heart tissues were stained with hematoxylin and eosin and Masson’s Trichrome stains. In the normal F1B hamsters, LV fractional shortening (FS) and ejection fractions (EF) did not significantly decrease over 6 months. By contrast, in Isolyte-treated TO2 hamsters, FS decreased from 56.2±1.0% to 19.7±3.2% and EF decreased from 89.5±1.4% to 44.9±5.9% at 6 months (p<0.0001). The FS and EF in HUCBC-treated TO2 hamsters also progressively decreased over 6 months but the changes were more gradual, especially during the first month after HUCBC treatment when FS was 52.0±1.5% and EF was 89.5±1.4%, which was not significantly different from the F1B hamsters. Moreover, in the HUCBC-treated TO2 hamsters, the FS and EF were 20-30% greater than FS and EF in Isolyte treated TO2 hamsters at 3 and 5 months (p<0.01). Injection of HUCBC at 2 or 4 months of age in subsets of Isolyte-treated and also HUCBC treated TO2 hamsters increased the LV EF at 5 to 6 months of age by >36% in comparison with TO2 hamsters treated with only Isolyte or a single HUCBC injection at 1 month of age (p<0.01). In Isolyte-treated TO2 hamsters at 6-7 months, fibrosis involved 30.0 ± 5.0% of LV and 35.0 ± 5.0% of septum but fibrosis involved only 6.5 ± 2.3% of the LV and 6.3 ± 1.8% of septum in HUCBC treated hamsters (p < 0.05). The average number of blood vessels per myocardial microscopic field in HUCBC-treated hearts was 53.5 ± 0.8 versus 46.2 ± 3.0 in Isolyte-treated TO2 hearts (p<0.05).
Conclusion: HUCBC can limit fibrosis and increase heart function in TO2 hamsters with congenital cardiomyopathy.
- © 2012 by American Heart Association, Inc.