Suchergebnisse

Modelo animal; Medicina regenerativa; Retina ; Model animal; Medicina regenerativa; Retina ; Animal model; Regenerative medicine; Retina ; Background: The aim of this study was to test the feasibility and safety of subretinal transplantation of human induced pluripotent stem cell (hiPSC)-derived retinal pigment epithelium (RPE) cells into the healthy margins and within areas of degenerative retina in a swine model of geographic atrophy (GA). Methods: Well-delimited selective outer retinal damage was induced by subretinal injection of NaIO3 into one eye in minipigs (n = 10). Thirty days later, a suspension of hiPSC-derived RPE cells expressing green fluorescent protein was injected into the subretinal space, into the healthy margins, and within areas of degenerative retina. In vivo follow-up was performed by multimodal imaging. Post-mortem retinas were analyzed by immunohistochemistry and histology. Results: In vitro differentiated hiPSC-RPE cells showed a typical epithelial morphology, expressed RPE-related genes, and had phagocytic ability. Engrafted hiPSC-RPE cells were detected in 60% of the eyes, forming mature epithelium in healthy retina extending towards the border of the atrophy. Histological analysis revealed RPE interaction with host photoreceptors in the healthy retina. Engrafted cells in the atrophic zone were found in a patchy distribution but failed to form an epithelial-like layer. Conclusions: These results might support the use of hiPSC-RPE cells to treat atrophic GA by providing a housekeeping function to aid the overwhelmed remnant RPE, which might improve its survival and therefore slow down the progression of GA. ; This work was supported by Spanish Ministry of Science and Innovation (MICINN, RTI2018-095377-B-100), Instituto de Salud Carlos III ISCIII/FEDER (PRB2 PT13/0001/0041; TerCel RD16/0011/0024 and Oftared-RETICS RD16/0008), ERA-NET EuroNanoMed III/ISCIII (AC19/00080), the Catalan Government, AGAUR (2017-SGR-899), CERCA Programme/Generalitat de Catalunya, and by Fundació Carmen i Mª José Godó (Fundació CMJ Godó 2017).

Abstract
A major cause for childhood blindness worldwide is attributed to nutritional vitamin A deficiency. Surprisingly, the molecular basis of the ensuing retinal degeneration has not been well defined. Abundant expression of the retinoid transporter STRA6 in the retinal pigment epithelium (RPE) and homeostatic blood levels of retinol-binding protein delay vitamin A deprivation of the mouse eyes. Hence, genetic dissection of STRA6 makes mice susceptible to nutritional manipulation of ocular retinoid status. We performed RNA-seq analyses and complemented the data with tests of visual physiology, ocular morphology, and retinoid biochemistry to compare eyes with different vitamin A status. Mild ocular vitamin A deficiency decreased transcripts of photoreceptor transduction pathway-related genes and increased transcripts of oxidative stress pathways. The response was associated with impaired visual sensitivity and an accumulation of fluorescent debris in the retina. Severe vitamin A deficiency did not only impair visual perception but also decreased transcripts of genes encoding cell adhesion and cellular junction proteins. This response altered cell morphology, resulted in significant changes in transport pathways of small molecules, and compromised the barrier function of the RPE. Together, our analyses characterize the molecular events underlying nutritional blindness in a novel mouse model and indicate that breakdown of the outer blood–retinal barrier contributes to retinal degeneration and photoreceptor cell death in severe vitamin A deficiency.

Funding Information: Supported by Funda??o para a Ciência e Tecnologia (FCT) ? Portugal co-funded by FEDER under the PT2020 Partnership Agreement (to MCS, including project PTDC/MED-PAT/30385/2017, iNOVA4Health-UIDB/04462/2020, research infrastructure PPBI-POCI-01-0145-FEDER-022122, M-ERA.NET 2/0005/2016), Boehringer Ingelheim (to MCS), Fight for Sight UK (to MCS), Wellcome Trust grant number 212216/Z/18/Z/ (to CEF). MJH was funded by Moor-fields Eye Charity with the Bill Brown 1989 Charitable Trust PhD studentship 538158, MLS was funded by FCT-CEECIND/01536/2018, ACF was funded by FCT PhD studentship (PD/BD/135503/2018). This work was developed with the support from the research infrastructure PPBI-POCI-01-0145-FEDER-022122, co-financed by FCT (Portugal) and Lisboa2020, under the PORTUGAL2020 agreement (European Regional Development Fund) and this article is supported by the LYSOCIL project funded by the European Union?s Horizon 2020 programme under grant agreement No. 811087. Funding Information: Supported by Fundação para a Ciência e Tecnologia (FCT) – Portugal co-funded by FEDER under the PT2020 Partnership Agreement (to MCS, including project PTDC/MED-PAT/30385/2017, iNOVA4Health-UIDB/04462/2020, research infrastructure PPBI-POCI-01-0145-FEDER-022122, M-ERA.NET 2/0005/2016), Boehringer Ingelheim (to MCS), Fight for Sight UK (to MCS), Wellcome Trust grant number 212216/Z/18/Z/ (to CEF). MJH was funded by Moor-fields Eye Charity with the Bill Brown 1989 Charitable Trust PhD studentship 538158, MLS was funded by FCT-CEECIND/01536/2018, ACF was funded by FCT PhD studentship (PD/BD/135503/2018). This work was developed with the support from the research infrastructure PPBI-POCI-01-0145-FEDER-022122, co-financed by FCT (Portugal) and Lisboa2020, under the PORTUGAL2020 agreement (European Regional Development Fund) and this article is supported by the LYSOCIL project funded by the European Union's Horizon 2020 programme under grant agreement No. 811087. Publisher Copyright: Copyright 2021 The Authors ; PURPOSE. We aim to characterize the pathways required for autofluorescent granule (AFG) formation by RPE cells using cultured monolayers. METHODS. We fed RPE monolayers in culture with a single pulse of photoreceptor outer segments (POS). After 24 hours the cells started accumulating AFGs that were comparable to lipofuscin in vivo. Using this model, we used a variety of light and electron microscopical techniques, flow cytometry and Western blot to analyze the formation of AFGs. We also generated a mutant RPE line lacking cathepsin D by gene editing. RESULTS. AFGs seem to derive from incompletely digested POS-containing phagosomes and after 3 days are surrounded by a single membrane positive for lysosome markers. We show by various methods that lysosome-phagosome fusion is required for AFG formation, and that impairment of lysosomal pH or catalytic activity, particularly cathepsin D activity, enhances AF accumulation. CONCLUSIONS. We conclude that lysosomal dysfunction results in incomplete POS degradation and enhanced AFG accumulation. ; publishersversion ; published

Background Mutations in pre-mRNA splicing factor PRPF31 can lead to retinitis pigmentosa (RP). Although the exact disease mechanism remains unknown, it has been hypothesized that haploinsufficiency might be involved in the pathophysiology of the disease. Methods In this study, we have analyzed a mouse model containing the p.A216P mutation in Prpf31 gene. Results We found that mutant Prpf31 protein produces cytoplasmic aggregates in the retinal pigment epithelium and decreasing the protein levels of this splicing factor in the nucleus. Additionally, normal protein was recruited in insoluble aggregates when the mutant protein was overexpressed in vitro. In response to protein aggregation, Hspa4l is overexpressed. This member of the HSP70 family of chaperones might contribute to the correct folding and solubilization of the mutant protein, allowing its translocation to the nucleus. Conclusions Our data suggests that a mechanism haploinsufficiency and dominant-negative is involved in retinal degeneration due to mutations in PRPF31. HSP70 over-expression might be a new therapeutic target for the treatment of retinal degeneration due to PRPF31 mutations. ; This project has been financed through a) The ISCIII (Miguel Servet-I, 2015), co-financed by the European Regional Development Fund (ERDF), No CP15/00071. b) The European Union's Horizon 2020 research and innovation program, under grant agreement No 634479. c) Regional Ministry of Economy, Innovation and Science of the Junta de Andalucía, No P09-CTS-04967.

Abstract
Myopia, which prevalence is rapidly increasing, causes visual impairment; however, the onset mechanism of pathological axial length (AL) elongation remains unclear. A highly vascularized choroid between the retinal pigment epithelium (RPE) and sclera not only maintains physiological activities, but also contributes to ocular development and growth regulation. Vascular endothelial growth factor (VEGF) secreted from the RPE to the choroid is essential for retinal function and maintenance of the choriocapillaris. Herein, we demonstrated that the loss of VEGF secreted from the RPE caused abnormal choriocapillaris development and AL elongation, with features similar to those of the lens-induced myopia (LIM) mouse model, whereas VEGF overexpression by knocking-out von Hippel–Lindau (VHL) specific to the RPE expands the choriocapillaris and shortens the AL. Additionally, LDL Receptor Related Protein 2 (LRP2) deletion in the RPE downregulated VEGF expression and leads to pathological AL elongation. Furthermore, high-myopia patients without choriocapillaris demonstrated longer ALs than did those with preserved choriocapillaris. These results suggest that physiological secretion of VEGF from the RPE is required for proper AL development by maintaining the choriocapillaris. The pinpoint application of VEGF to the choriocapillaris may become a potential intervention for the prevention and treatment of axial myopia progression.

Background Mutations in pre-mRNA splicing factor PRPF31 can lead to retinitis pigmentosa (RP). Although the exact disease mechanism remains unknown, it has been hypothesized that haploinsufficiency might be involved in the pathophysiology of the disease. Methods In this study, we have analyzed a mouse model containing the p.A216P mutation in Prpf31 gene. Results We found that mutant Prpf31 protein produces cytoplasmic aggregates in the retinal pigment epithelium and decreasing the protein levels of this splicing factor in the nucleus. Additionally, normal protein was recruited in insoluble aggregates when the mutant protein was overexpressed in vitro. In response to protein aggregation, Hspa4l is overexpressed. This member of the HSP70 family of chaperones might contribute to the correct folding and solubilization of the mutant protein, allowing its translocation to the nucleus. Conclusions Our data suggests that a mechanism haploinsufficiency and dominant-negative is involved in retinal degeneration due to mutations in PRPF31. HSP70 over-expression might be a new therapeutic target for the treatment of retinal degeneration due to PRPF31 mutations. ; This project has been financed through a) The ISCIII (Miguel Servet-I, 2015), co-financed by the European Regional Development Fund (ERDF), No CP15/00071. b) The European Union's Horizon 2020 research and innovation program, under grant agreement No 634479. c) Regional Ministry of Economy, Innovation and Science of the Junta de Andalucía, No P09-CTS-04967. ; info:eu-repo/semantics/publishedVersion

Funding Information: The authors acknowledge Fundacao para a Ciencia e Tecnologia for funding (PD/BD/114251/2016 scholarship to D.F. Santos; EXPL-BIM-MEC-1433-2013; PTDC/BTM/ORG/28121/2017 grants to G.A.Silva) and iNOVA4Health ? UIDB/Multi/04462/2020, a program financially supported by Funda??o para a Ci?ncia e Tecnologia/Ministerio da Educacao e Ciencia through national funds and co-funded by FEDER under the PT2020 Partnership Agreement, is also acknowledged. C.N.S. also acknowledges the European Research Council (ERC) under the European Union?s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 804229. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. ; (Poly)phenol-derived metabolites are small molecules resulting from (poly)phenol metab-olization after ingestion that can be found in circulation. In the last decade, studies on the impact of (poly)phenol properties in health and cellular metabolism accumulated evidence that (poly)phenols are beneficial against human diseases. Diabetic retinopathy (DR) is characterized by inflammation and neovascularization and targeting these is of therapeutic interest. We aimed to study the effect of pyrogallol-O-sulfate (Pyr-s) metabolite in the expression of proteins involved in retinal glial acti-vation, neovascularization, and glucose transport. The expression of PEDF, VEGF, and GLUT-1 were analyzed upon pyrogallol-O-sulfate treatment in RPE cells under high glucose and hypoxia. To test its effect on a diabetic mouse model, Ins2Akita mice were subjected to a single intraocular injection of the metabolite and the expression of PEDF, VEGF, GLUT-1, Iba1, or GFAP measured in the neural retina and/or retinal pigment epithelium (RPE), two weeks after treatment. We observed a significant decrease in the expression of pro-angiogenic VEGF in RPE cells. Moreover, pyrogallol-O-sulfate significantly decreased the expression of microglial marker Iba1 in the diabetic retina at different stages of disease progression. These results highlight the potential pyrogallol-O-sulfate metabolite as a preventive approach towards DR progression, targeting molecules involved in both inflammation and neovascularization. ; publishersversion ; published

Liver cancer ranks in the top 10 most common malignancies for both mortality rate and incidence worldwide. Hepatocellular carcinoma (HCC) is the most common subtype of liver cancer. It has been reported that long non-coding RNA GABPB1 intronic transcript 1 (IT1) is downregulated in lung cancer and predicts poor survival. However, its role in live cancer remains unclear. Therefore, the present study aimed to investigate the role of GABPB1-IT1 in HCC. A total of 64 patients with HCC (40 males and 24 females; range, 43–67 years old; mean age=55.1±5.1 years) were enrolled at the 96604 Military Hospital of the Chinese People's Liberation Army between May 2012 and May 2014. The expression levels of GABPB1-IT1 and microRNA (miR)-93 in tumor and adjacent normal tissues were measured using quantitative PCR. A dual luciferase activity assay was performed to analyze the interaction between miR-93 and GABPB1-IT1. A Cell Counting Kit-8 assay was used to analyze the effect of miR transfection on the proliferation of SNU-398 cells. It was demonstrated that GABPB1-IT1 can interact with miR-93 in HCC cells, while overexpression of GABPB1-IT1 and miR-93 in HCC cells did not affect the expression of each other. GABPB1-IT1 was downregulated in HCC tissues compared with paired non-tumor tissues and predicted poor survival. Notably, overexpression of GABPB1-IT1 in HCC cells led to upregulation of pigment epithelium-derived factor (PEDF), a target of miR-93. In addition, overexpression of GABPB1-IT1 reduced the enhancing effects of miR-93 on HCC cell proliferation. Therefore, GABPB1-IT1 may upregulate PEDF through miR-93 to suppress cell proliferation in HCC.

Introduction: Retinal pigment epithelial detachments (PEDs) are characterized by separation between the RPE and the inner most aspect of Bruch's membrane. The space created by this separation is occupied by blood, serous exudate, drusenoid material, fibro vascular tissue or a combination. The symptoms of RPE detachment can be considered under Drustigata Rogas mentioned by Sushrutha. This is a case study of a 73year old male patient who was diagnosed with PED with Subretinal fluid in Right eye since 8 months. Materials and methods: The subject who approached Shalakya Tantra OPD of Government Ayurveda Medical College Bengaluru with symptoms of diminished vision for both near and far objects in right eye associated with flashes in front of eye since 8 months, patient underwent two courses of inpatient management, which included Ayurvedic oral medicines, and external therapies for the eyes (Kriyakalpa) and head. Results: Signs of improvement in visual acuity and optical coherence tomography (OCT) were observed at the end of both treatments. Conclusion: The main aim of management was to preserve and give a better quality of vision for the patient. The results indicate the potential of Ayurvedic treatments to manage and maintain vision in REP detachment.

Retina differentiation involves the acquisition of a precise layered arrangement, with RPE cells in the first layer in intimate contact with photoreceptors in the second layer. Here, we developed an in vitro coculture model, to test the hypothesis that RPE cells play a pivotal role in organizing the spatial structure of the retina. We cocultured rat retinal neurons with ARPE-19 epithelial cells under various experimental conditions. Strikingly, when seeded over RPE cells, photoreceptors attached to their apical surfaces and proceeded with their development, including the increased synthesis of rhodopsin. Conversely, when we seeded RPE cells over neurons, the RPE cells rapidly detached photoreceptors from their substrata and positioned themselves underneath, thus restoring the normal in vivo arrangement. Treatment with the metalloproteinase inhibitor TIMP-1 blocked this reorganization, suggesting the involvement of metalloproteinases in this process. Reorganization was highly selective for photoreceptors because 98% of photoreceptors but very few amacrine neurons were found to redistribute on top of RPE cells. Interestingly, RPE cells were much more efficient than other epithelial or nonepithelial cells in promoting this reorganization. RPE cells also promoted the growth of photoreceptor axons away from them. An additional factor that contributed to the distal arrangement of photoreceptor axons was the migration of photoreceptor cell bodies along their own neurites toward the RPE cells. Our results demonstrate that RPE and photoreceptor cells interact in vitro in very specific ways. They also show that in vitro studies may provide important insights into the process of pattern formation in the retina. ; Fil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina ; Fil: Buzzi, Edgardo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina ; Fil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina ; Fil: Rodriguez Boulan, Enrique. Cornell University; Estados Unidos ; Fil: Politi, Luis Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina

OBJECTIVES: Diabetes-associated retinal impairment has been implicated in diabetic retinopathy. Chronic hyperglycemia leads to disruption of tight junction and breakdown of blood retinal barrier. Eucalyptol is a natural organic essential oil and a monoterpenoid present in eucalyptus oil with anti-inflammatory, anti-diabetic and antioxidant properties. METHODS: Primary human retinal pigment epithelial cells (HRPEC) were cultured in media containing 33 mM glucose for 4 days in the presence of 1–20 μM eucalyptol. The in vivo animal study employed db/db mice orally administrated with 10 mg/kg eucalyptol. Cell lysates and mouse eye tissue extracts were prepared for Western blotting, in which antibodies of ZO-1, occludin, matrix metalloproteinase (MMP)-2 and MMP-9 were used. RESULTS: Eucalyptol enhanced epithelial induction of the tight junction proteins of ZO-1 and occludin reduced by glucose loading. Consistently, oral administration of eucalyptol to db/db mice augmented the eye tissue levels of these tight junction proteins. In addition, the induction of MMP-2 and MMP-9 involved in the degradation of extracellular matrix, was elevated by exposure of glucose to HRPEC, which was encumbered by eucalyptol in a dose-dependent manner. CONCLUSIONS: These results demonstrated that eucalyptol maintained transepithelial cells integrity and blood retinal barrier in diabetic eyes. Therefore, eucalyptol may be a potent retinoprotective agent combating diabetes-associated retinal malfunction. FUNDING SOURCES: This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (2017R1A6A3A04011473).