Abstract
Purpose:
Because regenerative medicine offers great potential to the amelioration of glaucoma, we wished to characterize the similarities and differences between human trabecular meshwork (HTM) cells and human mesenchymal stem cells (hMSCs).
Methods:
HTM cells and hMSCs were characterized via flow cytometry. Using qPCR, expression of myoc, angptl7, sox2, pou5f1, and notch1 were determined both with and without dexamethasone. Immunosuppressive behavior of HTM cells and hMSCs was measured using T-cells activated using phytohaemagglutinin. T-cell proliferation was determined using BrdU incorporation and flow cytometry. Multipotency of HTM cells and hMSCs was determined using adipogenic and osteogenic differentiation media as well as aqueous humor. Alpha-smooth muscle actin (αSMA) expression was determined in HTM cells, hMSCs, and HTM tissue.
Results:
Both HTM and hMSCs expressed CD73, CD90, CD105, and CD146 but not CD31, CD34, and CD45 and had similar sox2, pou5f1, and notch1 levels. Both suppressed T-cell proliferation. However, HTM cells, but not hMSCs, had an upregulation of myoc and angptl7 in response to dexamethasone. Additionally, HTM cells did not differentiate into adipocytes or osteocytes. Culture of hMSCs in 20% aqueous humor induced alkaline phosphatase activity indicating the start to osteogenic differentiation. HTM cells in culture possessed high uniform expression of αSMA rather than the focal appearance in HTM tissue. There was limited expression of αSMA in hMSCs.
Conclusions:
HTM cells possess numerous similarities with hMSCs, but lack multipotency, one of the defining characteristics of stem cells. The hMSCs do not exhibit an increase in myocilin with dexamethasone treatment and only have limited expression of αSMA.
Keywords: 735 trabecular meshwork •
721 stem cells