MHC class II positive retinal pigment epithelial (RPE) cells can function as antigen-presenting cells for microbial superantigen

To gain further insights into the molecular basis of Sulforaphane (SF) mediated retinal pigment epithelial (RPE) 19 cell against oxidative stress, we investigated the effects of SF on the regulation of gene expression on a global scale and tested whether SF can endow RPE cells with the ability to resist apoptosis. The data revealed that after exposure to H2O2, RPE 19 cell viability was increased in the cells pretreated with SF compared to the cell not treated with SF. Microarray analysis revealed significant changes in the expression of 69 genes in RPE 19 cells after 6 hours of SF treatment. Based on the functional relevance, eight of the SF-responsive genes, that belong to antioxidant redox system, and inflammatory responsive factors were validated. The up-regulating translation of thioredoxin-1 (Trx1) and the nuclear translocation of Nuclear factor-like2 (Nrf2) were demonstrated by immunoblot analysis in SF treated RPE cells. Our data indicate that SF increases the ability of RPE 19 cell against oxidative stress through up-regulating antioxidative enzymes and down-regulating inflammatory mediators and chemokines. The results suggest that the antioxidant, SF, may be a valuable supplement for preventing and retarding the development of Age Related Macular Degeneration.

Download Full-text

Stratification of Antigen-presenting Cells within the Normal Cornea

Ophthalmology and Eye Diseases ◽

10.4137/oed.s2813 ◽

2009 ◽

Vol 1 ◽

pp. OED.S2813 ◽

Cited By ~ 44

Author(s):

Jared E. Knickelbein ◽

Simon C. Watkins ◽

Paul G. Mcmenamin ◽

Robert L. Hendricks

Keyword(s):

Bone Marrow ◽

Basement Membrane ◽

Mhc Class Ii ◽

Fluorescent Protein ◽

Antigen Presenting Cells ◽

Class Ii ◽

Apical Surface ◽

Bone Marrow Derived Cells ◽

Green Fluorescent ◽

Antigen Presenting

The composition and location of professional antigen presenting cells (APC) varies in different mucosal surfaces. The cornea, long considered an immune-privileged tissue devoid of APCs, is now known to host a heterogeneous network of bone marrow-derived cells. Here, we utilized transgenic mice that express enhanced green fluorescent protein (EGFP) from the CD 11c promoter (pCD11c) in conjunction with immunohistochemical staining to demonstrate an interesting stratification of APCs within non-inflamed murine corneas. pCD11c+ dendritic cells (DCs) reside in the basal epithelium, seemingly embedded in the basement membrane. Most DCs express MHC class II on at least some dendrites, which extend up to 50 μm in length and traverse up 20 μm tangentially towards the apical surface of the epithelium. The DC density diminishes from peripheral to central cornea. Beneath the DCs and adjacent to the stromal side of the basement membrane reside pCD11c–CD11b+ putative macrophages that express low levels of MHC class II. Finally, MHC class II–pCD11c–CD11b+ cells form a network throughout the remainder of the stroma. This highly reproducible stratification of bone marrow-derived cells is suggestive of a progression from an APC function at the exposed corneal surface to an innate immune barrier function deeper in the stroma.

Download Full-text

GEP100/ARF6 regulates VEGFR2 signaling to facilitate high-glucose-induced epithelial-mesenchymal transition and cell permeability in retinal pigment epithelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.00312.2018 ◽

2019 ◽

Vol 316 (6) ◽

pp. C782-C791 ◽

Cited By ~ 1

Author(s):

Zhi-Peng You ◽

Shan-Shan Chen ◽

Zhong-Yi Yang ◽

Shu-Rong Li ◽

Fan Xiong ◽

...

Keyword(s):

Cell Migration ◽

High Glucose ◽

Retinal Pigment Epithelial ◽

Epithelial Mesenchymal Transition ◽

Retinal Pigment ◽

Cell Permeability ◽

Mesenchymal Transition ◽

Rpe Cells ◽

Pigment Epithelial ◽

Vegfr2 Signaling

Cell permeability and epithelial-mesenchymal transition (EMT) were found to be enhanced in diabetic retinopathy, and the aim of this study was to investigate the underlying mechanism. ARPE-19 cell line or primary retinal pigment epithelial (RPE) cells were cultured under high or normal glucose conditions. Specific shRNAs were employed to knock down ADP-ribosylation factor 6 (ARF6), GEP100, or VEGF receptor 2 (VEGFR2) in ARPE-19 or primary RPE cells. Cell migration ability was measured using Transwell assay. Western blotting was used to measure indicated protein levels. RPE cells treated with high glucose showed increased cell migration, paracellular permeability, EMT, and expression of VEGF. Knockdown of VEGFR2 inhibited the high-glucose-induced effects on RPE cells via inactivation of ARF6 and MAPK pathways. Knockdown ARF6 or GEP100 led to inhibition of high-glucose-induced effects via inactivation of VEGFR2 pathway. Knockdown of ARF6, but not GEP100, decreased high-glucose-induced internalization of VEGFR2. High-glucose enhances EMT and cell permeability of RPE cells through activation of VEGFR2 and ARF6/GEP100 pathways, which form a positive feedback loop to maximize the activation of VEGF/VEGFR2 signaling.

Download Full-text

Hesperidin Prevents High Glucose-Induced Damage of Retinal Pigment Epithelial Cells

Planta Medica ◽

10.1055/a-0601-7020 ◽

2018 ◽

Vol 84 (14) ◽

pp. 1030-1037 ◽

Cited By ~ 5

Author(s):

Wayne Liu ◽

Shorong-Shii Liou ◽

Tang-Yao Hong ◽

I-Min Liu

Keyword(s):

High Glucose ◽

Retinal Pigment Epithelial ◽

Colorimetric Assay ◽

Retinal Pigment ◽

Retinal Pigment Epithelial Cells ◽

Antioxidant Enzyme Activities ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Rpe Cells ◽

Pigment Epithelial

AbstractThe present study aimed to determine whether hesperidin, a plant-based active flavanone found in citrus fruits, can prevent high glucose-induced retinal pigment epithelial (RPE) cell impairment. Cultured human RPE cells (ARPE-19) were exposed to a normal glucose concentration (5.5 mM) for 4 d and then soaked in either normal (5.5 mM) or high (33.3 mM) concentrations of D-glucose with or without different concentrations of hesperidin (10, 20, or 40 µM) for another 48 h. The survival rates of the cells were measured using a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction assay. With the help of a fluorescent probe, the intracellular production of reactive oxygen species (ROS) was evaluated. Colorimetric assay kits were used to assess the antioxidant enzyme activities, and western blotting was used to measure the expression of apoptosis-related protein. Hesperidin was effective in inhibiting high glucose-induced ROS production, preventing loss of cell viability, and promoting the endogenous antioxidant defense components, including glutathione peroxidase, superoxide dismutase, catalase, and glutathione, in a concentration-dependent manner. Furthermore, high glucose triggered cell apoptosis via the upregulation of caspase-9/3, enhancement of cytochrome c release into the cytosol, and subsequent interruption of the Bax/Bcl-2 balance. These detrimental effects were ameliorated by hesperidin in a concentration-dependent manner. We conclude that through the scavenging of ROS and modulation of the mitochondria-mediated apoptotic pathway, hesperidin may protect RPE cells from high glucose-induced injury and thus may be a candidate in preventing the visual impairment caused by diabetic retinopathy.

Download Full-text

Differential induction of gene expression by basic fibroblast growth factor and neuroD in cultured retinal pigment epithelial cells

Visual Neuroscience ◽

10.1017/s0952523800171172 ◽

2000 ◽

Vol 17 (2) ◽

pp. 157-164 ◽

Cited By ~ 16

Author(s):

RUN-TAO YAN ◽

SHU-ZHEN WANG

Keyword(s):

Gene Expression ◽

Growth Factor ◽

Fibroblast Growth Factor ◽

Basic Fibroblast Growth Factor ◽

Retinal Pigment Epithelial ◽

Retinal Pigment ◽

Fibroblast Growth ◽

Rpe Cells ◽

Pigment Epithelial ◽

Two Factors

Embryonic chick retinal pigment epithelial (RPE) cells can undergo transdifferentiation upon appropriate stimulation. For example, basic fibroblast growth factor (bFGF) induces intact RPE tissue younger than embryonic day 4.5 (E4.5) to transdifferentiate into a neural retina. NeuroD, a gene encoding a basic helix-loop–helix transcription factor, triggers de novo production of cells that resemble young photoreceptor cells morphologically and express general neuron markers (HNK-1/N-CAM and MAP2) and a photoreceptor-specific marker (visinin) from cell cultures of dissociated E6 RPE (Yan & Wang, 1998). The present study examined whether bFGF will lead to the same transdifferentiation phenomenon as neuroD when applied to dissociated, cultured E6 RPE cells, and whether interplay exists between the two factors under the culture conditions. Dissociated E6 RPE cells were cultured in the presence or absence of bFGF, and with or without the addition of retrovirus expressing neuroD. Gene expression was analyzed with immunocytochemistry and in situ hybridization. Unlike neuroD, bFGF did not induce the expression of visinin, or HNK-1/N-CAM and MAP2. However, bFGF elicited the expression of RA4 immunogenicity; yet, many of these RA4-positive cells lacked a neuronal morphology. Addition of bFGF to neuroD-expressing cultures did not alter the number of visinin-expressing cells; misexpression of neuroD in bFGF-treated cultures did not change the number of RA4-positive cells, suggesting the absence of interference or synergistic interaction between the two factors. Our data indicated that bFGF and neuroD induced the expression of different genes in cultured RPE cells.

Download Full-text