Purpose:
Recent studies have demonstrated corneal myofibroblast development from bone marrow-derived precursor cells (Barbosa et al., 2010; Saika et al., 2010) and shown that TGFβ is a key factor regulating myofibroblast development and maintaining myofibroblast viability in the cornea and other tissues (Flanders, 2004; Tandon et al., 2010). The purpose of this study was to test the hypothesis that mouse corneal stromal fibroblast (MSF) and bone marrow-derived cell (BMC) interactions augment corneal myofibroblast generation mediated by TGFβ.
Methods:
Mouse bone marrow derived cells (BMC) and mouse stromal fibroblast (MSF) were obtained from both green fluorescent protein (GFP)-expressing mice and normal BL6 control mice. Adherent BMC were isolated and co-cultured at a cell density of 1 X 105 cells/ml in co-culture MEM media with 15% FBS and L-Glu without any TGFβ. To study the juxtacrine interactions GFP+ BMC were co-cultured with GFP- MSF or GFP- BMC were co-cultured with GFP+ MSF. SMA and GFP expression were analyzed after 72 hours of co-culture. Each co-culture interaction was tested in three wells and the entire experiment was repeated three times to insure reproducibility.
Results:
In either co-culture experiment, transformation of the GFP+ precursor into GFP+ myofibroblasts was augmented by the presence of the other GFP- cell type. Thus, more SMA+GFP+ myofibroblasts were generated from GFP+ corneal fibroblasts when GFP- BMC were present in the co-cultures, and more SMA+GFP+ myofibroblasts were generated from GFP+ BMC when GFP- corneal fibroblasts were present in the co-cultures. (Table 1). In either co-culture, monoclonal anti-human LAP (TGF-β1) antibody and/or TGFβ type I receptor kinase inhibitor (LY) added to the co-culture inhibited the generation of SMA+ myofibroblasts.
Conclusions:
These data suggest that TGFβ modulates the generation of SMA+ myofibroblasts from either corneal fibroblast or bone marrow-derived cell precursors. Development of corneal myofibroblasts from either corneal fibroblast precursors or bone marrow-derived cell precursors in the presence of TGFβ is augmented by interaction with the other cell type. In situ experiments are in progress in chimeric mice to explore these cell-cell interactions in vivo.
Keywords: cornea: stroma and keratocytes • cornea: basic science • wound healing