Exploring the Genotypic Differences Between Diabetic and Non-Diabetic Human Retinal Pigment Epithelial Cells
Kia Bayat1 , Leila Javanparast 2 , Mohammad Abolhoseini1 , Fatemeh Suri2 , Mozhgan Rezaei Kanavi1 *
- Ocular Tissue Engineering Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abstract: Investigating genotypic alterations in human retinal pigment epithelium (hRPE) can offer valuable insights into mechanisms underlying diabetic retinopathy (DR) and opens a therapeutic avenue for future treatment of DR. This study is the first investigation into the genotypic profile of diabetic hRPE cells.
Methods: Human donor eye globes were provided from Central Eye Bank of Iran and categorized into five groups including proliferative DR (PDR), moderate to severe non-proliferative DR (NPDR), mild NPDR, patients with diabetic mellitus without DR, and a healthy control group. Each group included three eye samples. Total RNA was extracted from hRPE cells and real-time RT-PCR was performed to evaluate the relative expression of eight reference genes (ABCA4, ABCA2, C3AR, C5AR, EI5A, NOX4, XBP1).
Results: NOX4 showed highest expression in PDR cases which was significantly different from healthy controls (p=0.005), patients with DM without DR (p=0.023), and mild NPDR cases (p=0.001). Additionally, samples with moderate to severe NPDR exhibited significantly higher expression compared to mild NPDR (p=0.017). The highest level of ABCA4 was also observed in PDR cases, exhibiting significant differences from moderate to severe NPDR cases (p=0.021) and healthy controls (p=0.006). Regarding XBP1the highest level was detected in PDR cases, which was significantly higher than healthy controls (p=0.024). Our analysis revealed no significant differences in the expression levels of C3aR, C5aR SLC2A1, ABCA2, and EIF5A levels across the five groups.
Conclusion: This report underscores the vital roles of oxidative stress, lipid metabolism, and ER stress in the development of DR, as demonstrated by higher expression of NOX4, ABCA4, and XBP1 in more advanced stages. Results of this study enhance our understanding of the pathological processes involved in DR. Additional in-depth studies on the mechanisms underlying RPE injury may offer new insights into the pathogenesis of DR and guide strategies for effective treatment.
