Abstract
Purpose :
To evaluate the efficacy of trabecular meshwork stem cell (SC) derived exosomes on trabecular meshwork (TM) cell survival under oxidative stress and wound healing in vitro as an attempt towards a cell free therapy for glaucoma.
Methods :
Exosomes were isolated from conditioned medium of human TM and TMSC cultures by ultracentrifugation and characterized by western blotting, nanoparticle tracking analysis (NTA) using NS300 and Transmission Electron Microscopy (TEM). Regenerative efficacy of the isolated exosomes was analyzed by in vitro wound healing assay. Anti-oxidant role of exosomes on TM cells exposed to oxidative stress was examined by MTT assay. TM and TMSC exosomes were also subjected to mass spectrometry to identify the protein cargo.
Results :
TM and TMSC exosomes expressed the exosomal markers syntenin, neuropilin and emilin. NTA analysis revealed the size of TM (150.7±20.03nm) and TMSC (137.7±11.9nm) exosomes to be within exosomal size range of 30-200nm. TEM images revealed the exosomes to be poly-dispersive and spherical in nature. In vitro wound healing assay indicated that the TMSC exosomes significantly increased the wound closure rate (96.47±2.95%) compared to control (75.80±4.62%) at 48 hours. In addition, the TMSC exosomes enhanced TM cell survival by 21.9% under oxidative stress compared to TM exosomes. Proteomic analysis of exosomes identified with high confidence 720 proteins in TMSC exosomes and 693 in TM exosomes. 43.3% of the proteins were common between TM and TMSC exosomes while 30.9% proteins were only found in TMSC exosomes and 25.8% proteins only in TM exosomes. Differential expression analysis showed high abundance of wound healing and anti-oxidant proteins in TMSC exosomes compared to TM exosomes.
Conclusions :
TMSC exosomes enhanced wound healing efficacy and their anti-oxidant potential indicating the possibility of developing a TMSC exosome based therapy for patients with primary open angle glaucoma.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.