Abstract
Purpose:
Adipose-derived stem cells (ADSCs) can be easily harvested using minimal invasive procedures and have multilineage potential. This study aims to induce ADSCs to differentiate into functional TM cells, which are suitable for cell-based therapy for glaucoma.
Methods:
Human ADSCs were obtained from the Adipose Stem Center (Drs. Kacey Marra and J. Peter Rubin) at University of Pittsburgh. ADSCs were induced by co-culturing with primary TM cells, extracellular matrix produced by TM cells, or TM cell conditioned medium. After 5-7 days, cells were either harvested for detection of gene expression and phagocytosis; or stimulated with 200 nM dexamethasone for another 7-9 days. Quantitative RT-PCR, western blotting and immunofluorescent staining were used to detect the changes of stem cell marker nestin and TM cell markers CHI3L1 and AQP1 as well as MYOC after induction and after dexamethasone stimulation. TM cell phagocytic function was evaluated by confocal microscopy and flow cytometry. ADSCs and TM cells were served as controls.
Results:
After induction, human ADSCs were able to express TM cell markers CHI3L1 and AQP1 with decreased or diminished expression of stem cell marker nestin. Induced ADSCs obtained phagocytic function with the ability to ingest inactivated pHrodo Staphylococcus aureus bioparticles, similar to primary TM cells. Co-culturing with TM cells is the most effective method for TM cell induction. After dexamethasone treatment, the expression of MYOC increased about 200-fold comparing to ADSCs. The increase of MYOC expression of ADSCs in response to dexamethasone is comparable to that of primary TM cells.
Conclusions:
Human ADSCs can be induced to differentiate into TM cells with phagocytic function and responsive to dexamethasone stimulation. This suggests a potential of using autologous ADSCs for glaucoma treatment. In vivo functional investigation is ongoing.