Project description:Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium, and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that this endothelial cell dropout is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat inactivated serum which lacks complement components. Cells exposed to complement components in human serum showed increased labeling with antibodies directed against the MAC, time and dose dependent cell death as assessed by lactate dehydrogenase assay, and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteases (MMPs) 3 and 9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5 depleted serum compared to C5 reconstitited serum. Increased levels of MMP9 were also determined using Western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells. RNA-Seq of RF/6A (cultured choroidal endothelial cells from Rhesus macaque) treated with either 50% heat-inactivated human serum ([CONTROL], n=3) or 50% normal human serum (active complement membrane attack complex [MAC], n=3)
Project description:Many diseases that affect the heart, brain, and even the eyes originate from vascular pathology, emphasizing the role of vascular regulation. In age-related macular degeneration (AMD), excessive growth of abnormal blood vessels in the eye (choroidal neovascularization) ultimately leads to detachment of retinal pigment epithelium and decreased vision, indicating the importance of choroidal neovascularization in the treatment of age-related diseases. The circadian clock in the mammalian retina regulates various retinal functions, enabling the retina to adapt to the light dark cycle. Emerging evidence suggests a link between circadian clock and retinopathy, but the causal relationship has not yet been determined.
Project description:The activity and survival of retinal photoreceptors depend on support functions performed by the retinal pigment epithelium (RPE) and on oxygen and nutrients delivered by blood vessels in the underlying choroid. By combining single cell and bulk RNA sequencing, we categorized mouse RPE/choroid cell types and characterized the tissue-specific transcriptomic features of choroidal endothelial cells. We found that choroidal endothelium adjacent to the RPE expresses high levels of Indian Hedgehog, and identified its downstream target as stromal GLI1+ mesenchymal stem cell-like cells. Genetic impairment of Hedgehog signaling in vivo induced significant loss of choroidal mast cells, as well as an altered inflammatory response and exacerbated visual function defects after retinal damage. Our studies reveal the cellular and molecular landscape of adult RPE/choroid and uncover a Hedgehog-regulated choroidal immunomodulatory signaling circuit. These results open new avenues for the study and treatment of retinal vascular diseases and choroid-related inflammatory blinding disorders.
Project description:Retinal pigment epithelial (RPE) cells and choroidal stromal fibroblast (CSF) were isolated from healthy human donor eyes. Cells were cultured and RNA extracted.
Project description:Retinitis Pigmentosa is a group of inherited eye disorders characterized by progressive degeneration of photoreceptor cells in the retina, leading to vision loss and eventual blindness. One of the known genetic mutations associated with RP is the c.6926A>C mutation in the RPE (retinal pigment epithelium) cells. The dataset involves multiple experimental approaches and cell types, providing a comprehensive understanding of the disease and potential corrective strategies.
Project description:The retinal pigment epithelium (RPE) provides vital support to photoreceptor cells and its dysfunction is associated with the onset and progression of age-related macular degeneration (AMD). Surgical provision of RPE cells may ameliorate AMD and thus it would be valuable to develop sources of patient-matched RPE cells for this application of regenerative medicine. We describe here the generation of functional RPE-like cells from fibroblasts that represent an important step toward that goal. We identified candidate master transcriptional regulators of RPEs using a novel computational method and then used these regulators to guide exploration of the transcriptional regulatory circuitry of RPE cells and to reprogram human fibroblasts into RPE-like cells. The RPE-like cells share key features with RPEs derived from healthy individuals, including morphology, gene expression and function, and thus represent a step toward the goal of generating patient-matched RPE cells for treatment of macular degeneration. Expression analysis was performed on induced retinal pigment epithelium-like cells.
Project description:Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the omega-3 fatty acid docosahexaenote (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier (BRB) or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine symporter expressed at the BRB. Microarrays were used to determine difference in gene expression between wild-type and Mfsd2a KO eye cups.