Compromised Barrier Function in Human Induced Pluripotent Stem-Cell-Derived Retinal Pigment Epithelial Cells from Type 2 Diabetic Patients

• Published in: International journal of molecular sciences Vol. 20; no. 15; p. 3773
• Main Authors: Kiamehr, Mostafa, Klettner, Alexa, Richert, Elisabeth, Koskela, Ali, Koistinen, Arto, Skottman, Heli, Kaarniranta, Kai, Aalto-Setälä, Katriina, Juuti-Uusitalo, Kati
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.08.2019; MDPI
• Subjects: Antioxidants; Autophagy; barrier function; Cell culture; Cell Line; Cells, Cultured; Cultivation; Diabetes; Diabetes mellitus; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - pathology; Diabetic retinopathy; diabetic retinopathy (DR); Diabetic Retinopathy - etiology; Diabetic Retinopathy - metabolism; Diabetic Retinopathy - pathology; Extracellular matrix; Fluorescent indicators; GA-binding protein; Gene expression; Glucose - metabolism; Growth factors; Humans; Hypoxia; induced pluripotent stem cells (hiPSC); Induced Pluripotent Stem Cells - metabolism; Induced Pluripotent Stem Cells - pathology; Inflammation; Inserts; Insulin; matrix metalloproteinase; Microtubule-associated protein 1; Morphology; Oxidants; Oxidative stress; Oxidizing agents; Patients; Permeability; Pluripotency; Polyethylene; Polyethylene terephthalate; Polymerase chain reaction; Proteins; Retina; retinal pigment epithelial cells; Retinal pigment epithelium; Retinal Pigment Epithelium - metabolism; Retinal Pigment Epithelium - pathology; Stem cell transplantation; Stem cells; Tightness; Tissue culture; type 2 diabetes; autophagy; type 2 diabetes; retinal pigment epithelial cells; matrix metalloproteinase; induced pluripotent stem cells (hiPSC); barrier function; diabetic retinopathy (DR)
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20153773

In diabetic patients, high blood glucose induces alterations in retinal function and can lead to visual impairment due to diabetic retinopathy. In immortalized retinal pigment epithelial (RPE) cultures, high glucose concentrations are shown to lead to impairment in epithelial barrier properties. For the first time, the induced pluripotent stem-cell-derived retinal pigment epithelium (hiPSC-RPE) cell lines derived from type 2 diabetics and healthy control patients were utilized to assess the effects of glucose concentration on the cellular functionality. We show that both type 2 diabetic and healthy control hiPSC-RPE lines differentiate and mature well, both in high and normal glucose concentrations, express RPE specific genes, secrete pigment epithelium derived factor, and form a polarized cell layer. Here, type 2 diabetic hiPSC-RPE cells had a decreased barrier function compared to controls. Added insulin increased the epithelial cell layer tightness in normal glucose concentrations, and the effect was more evident in type 2 diabetics than in healthy control hiPSC-RPE cells. In addition, the preliminary functionality assessments showed that type 2 diabetic hiPSC-RPE cells had attenuated autophagy detected via ubiquitin-binding protein p62/Sequestosome-1 (p62/SQSTM1) accumulation, and lowered pro- matrix metalloproteinase 2 (proMMP2) as well as increased pro-MMP9 secretion. These results suggest that the cellular ability to tolerate stress is possibly decreased in type 2 diabetic RPE cells.