Human Adipose-derived Stem Cells Integrate into Normal Mouse Trabecular Meshwork

Abstract

Purpose : We have previously induced human adipose-derive stem cells (ADSCs) into trabecular meshwork cells (TMs) as a regenerative therapeutic candidate for glaucoma. This study aims to compare the effects of differentiated ADSCs and undifferentiated ADSCs after intracameral micro-injection into non-glaucomatous mouse eyes.

Methods : Human ADSCs were obtained from the Adipose Stem Center (Drs. Kacey Marra and J. Peter Rubin) at University of Pittsburgh. ADSCs were induced to differentiate into TM cells by culturing on extracellular matrix produced by TM cells in TM-conditioned media. After 14 days, both differentiated and undifferentiated ADSCs were collected and stained with membrane dye Vybrant DiO. Cells were then diluted at the density of 10,000 cells/µl in DMEM/F12, and 2µl of cells were injected at the speed of 0.22 µl/min into C57BL/6 mouse anterior chamber using a 5-µl capillary tube micropipette connected to a syringe pump. Sham injection and normal mice served as controls. Intraocular pressure (IOP) was measured at day 0, 3, 6, 10, 14, week 3, 4, 5, 6 using an iCare tonometer. Anterior chamber structure images were taken to observe inflammation outcome. Outflow facility was monitored using an ex vivo perfusion system to test the IOP-regulating function. Confocal microscopy on whole-mounts and cryosections was performed to detect the location of injected cells.

Results : At various time points post injection, there was no significant difference in IOP and outflow facility among each group. Anterior chamber structure in each group remained intact without visible vascularization or adhesion. Both differentiated and undifferentiated ADSCs homed to the TM region. The homed cells were viable and integrated into the cell layers of the original TM structure.

Conclusions : Both differentiated ADSCs with TM phenotype and undifferentiated ADSCs homed to the TM tissue and did not increase IOP after intracameral injection. Long-term effects on restoring trabecular meshwork function in glaucomatous animal models are needed for further investigation.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.