Therapeutic effects of human adipose mesenchymal stem cells and their paracrine agents on sodium iodate induced retinal degeneration in rats

Aims: The degeneration of retinal neurons which occurs in many neurodegenerative diseases of retina such as retinitis pigmentosa and aged-related macular degeneration, is a progressive phenomenon and leads to permanent visual disability. Aside from their economic and social impact, those who suffer from these diseases have a poor quality of life due to the lack of cures. Researchers have turned to stem cell therapies as a potential solution to this global health crisis. Mesenchymal stem cells (MSCs) and their paracrine agents such as conditioned medium (CM) and exosomes (Exo) have been applied to treat different retinal disorders. This study compared the therapeutic effects of human adipose mesenchymal stem cells (hADSCs) and their secretome on an in vivo model of sodium iodate retinal neurodegeneration.

Main methods: We analyzed the expression of retinal cells' specific mRNAs by RT-PCR and proteins by immunostaining as well as performing visual cliff avoidance test as a functional evaluation technique. There were four therapeutic groups in this study: hADSC, hADSC-CM, hADSC-Exo and hADSC-Exo + CM.

Key findings: Although all groups showed different therapeutic effects on various retinal cells, the results of hADSC-CM were most striking, especially in terms of photoreceptor regeneration and retinal function.

Significance: The findings of present study demonstrated the different effects of MSC-based therapies on various retinal cells which could be helpful in designing more precise treatments that suit to each neurodegenerative disease mechanism and the cells involved. It also suggests that CM might be a better choice due to its multifactorial characteristic.