Abstract 183: Heart-Type Fatty Acid Binding Protein and C-Reactive Protein are Significantly up-Regulated in Bone Marrow-Derived Mesenchymal Stem Cells Under Hypoxic Conditions
Background: Cardiac injury markers, Heart-type fatty acid binding protein (FABP3) and C-reactive protein (CRP), are highly sensitive predictors of myocardial ischemia and necrosis. These proteins may stimulate endogenous stem cell to embark on the repair of injured myocardiocytes. Additionally FABP3 and CRP could be optimal markers to evaluate the form of hypoxia-preconditioned bone marrow derived stem cell (MSC) for the cell-based transplantation therapy to patients with ischemic heart diseases.
Methods: Eight swine and 5 human MSCs were cultured in DMEM with 1% FBS for 6, 24 and 48 hours (hr) in either standard (O2=20%, CO2=5%) or hypoxic (O2 = 1%, CO2=8%) conditions (H). CRP, FABP3 and other well-defined, hypoxic regulated genes HIF1A, VEGF, CXCR4, EGF and EGFR were examined using semi-quantitative rtPCR (qPCR), Antibody Array (Ray Biotech, Inc.) and Immunocytochemistry (IMC).
Results: Through qPCR, we identified that the expressions of CRP and FABP3 were significantly elevated (P=0.045) after 24hr culture with 1% oxygen and recovered rapidly to baseline expression level after 6hr of re-oxygenation. The CRP and FABP3 transcript regulated patterns were parallel to those of VEGF, HIF1A and CXCR4. CRP, EGF and EGFR proteins increased over one hundred folds in H MSCs after 24hrs in their respective extracellular medium; suggesting CRP and EGFs were secreted by oxygen starved MSCs. By IMC analysis, FABP3 was found localized in the cytoplasm and extracellular matrix of 24hr. MSCs. No signs of increased apoptosis were found in the 24hr. H MSCs by DAPI staining and PCR apoptotic analysis.
Conclusions: Our results demonstrate that CRP and FABP3 are extremely sensitive to hypoxia in bone marrow derived MSCs and are associated with the proliferation and differentiation processes of MSCs in hypoxic or ischemic condition.
- © 2010 by American Heart Association, Inc.