scholarly journals Inhibition of DUSP6 Activates Autophagy and Rescues the Retinal Pigment Epithelium in Sodium Iodate-Induced Retinal Degeneration Models In Vivo and In Vitro

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 159
Author(s):  
Hao-Yu Tsai ◽  
Henkie Isahwan Ahmad Mulyadi Lai ◽  
Zhang-Yuan Chen ◽  
Tai-Chi Lin ◽  
Winnie Khor ◽  
...  

Autophagy plays a protective role in the retinal pigment epithelium (RPE) by eliminating damaged organelles in response to reactive oxygen species (ROS). Dual-specificity protein phosphatase 6 (DUSP6), which belongs to the DUSP subfamily, works as a negative-feedback regulator of the extracellular signal-regulated kinase (ERK) pathway. However, the complex interplay between DUSP6 and autophagy induced by ROS in RPE is yet to be investigated. To investigate the relationship between DUSP6 and autophagy, we exposed the ARPE-19 cell line and C57BL/6N mice to sodium iodate (NaIO3) as an oxidative stress inducer. Our data showed that the inhibition of DUSP6 activity promotes autophagy flux through the ERK pathway via the upregulation of immunoblotting expression in ARPE-19 cells. Live imaging showed a significant increase in autophagic flux activities, which suggested the restoration autophagy after treatment with the DUSP6 inhibitor. Furthermore, the mouse RPE layer exhibited an irregular structure and abnormal deposits following NaIO3 injection. The retina layer was recovered after being treated with DUSP6 inhibitor; this suggests that DUSP6 inhibitor can rescue retinal damage by restoring the mouse retina’s autophagy flux. This study suggests that the upregulation of DUSP6 can cause autophagy flux malfunctions in the RPE. The DUSP6 inhibitor can restore autophagy induction, which may serve as a potential therapeutic approach for retinal degeneration disease.

2021 ◽  
Author(s):  
Jiang Shuang ◽  
Guo Yongpeng ◽  
Yi Ning ◽  
Li Hongdan ◽  
Liu Hua

AbstractObjectiveGlucose-regulated protein 78 (Grp78) has been regarded as a main member of the endoplasmic reticulum proteins, Grp78 could protect cells from apoptosis under stress conditions. However, whether Grp78 could protect retinal pigment epithelium (RPE) cells from oxidative injury and then protect retinas from morphological changes and functional abnormalities remain undetermined. Here, we try to explore the effect of Grp78 on retinal cell injury induced by sodium iodate in vivo and in vitro.MethodsTo investigate whether Grp78 has a protective effect on RPE injury in vitro, human retinal pigment epithelium (ARPE-19) cells were treated with sodium iodate. The cell proliferation, morphology, apoptosis and ROS production assays were detected. In vivo, We established sodium iodate-induced retinal injury model in mice by intravenous injection of sodium iodate into tail vein. After that, we examined the morphology and function of retina in mice by fundus photography, OCT and ERG. Finally, we removed the retina of mice for histological examination.ResultsGrp78 significantly inhibited sodium iodate-induced reactive oxygen species (ROS), and decreased apoptosis of RPE in vitro. Furthermore, Grp78 significantly decreased the apoptosis of retinal cells in vivo, resulting in the inhibition of morphological changes of retina, and improving the function of retina. The underlying mechanisms included inhibited caspase3 and Nos, and increased expression of Bcl2, thereby protecting RPE from SI-induced ROS and apoptosis.ConclusionGrp78 could reduce the injury of retinal cells induced by sodium iodate in vitro and in vivo. These findings suggested Grp78 may become a new therapeutic target for retinal injury in clinical practice.


1988 ◽  
Vol 91 (2) ◽  
pp. 303-312
Author(s):  
N.M. McKechnie ◽  
M. Boulton ◽  
H.L. Robey ◽  
F.J. Savage ◽  
I. Grierson

The cytoskeletal elements of normal (in situ) and cultured human retinal pigment epithelium (RPE) were studied by a variety of immunocytochemical techniques. Primary antibodies to vimentin and cytokeratins were used. Positive immunoreactivity for vimentin was obtained with in situ and cultured material. The pattern of reactivity obtained with antisera and monoclonals to cytokeratins was more complex. Cytokeratin immunoreactivity could be demonstrated in situ and in cultured cells. The pattern of cytokeratin expression was similar to that of simple or glandular epithelia. A monoclonal antibody that specifically recognizes cytokeratin 18 identified a population of cultured RPE cells that had particularly well-defined filamentous networks within their cytoplasm. Freshly isolated RPE was cytokeratin 18 negative by immunofluorescence, but upon culture cytokeratin 18 positive cells were identifiable. Cytokeratin 18 positive cells were identified in all RPE cultures (other than early primaries), regardless of passage number, age or sex of the donor. In post-confluent cultures cytokeratin 18 cells were identified growing over cytokeratin 18 negative cells, suggesting an association of cytokeratin 18 immunoreactivity with cell proliferation. Immunofluorescence studies of retinal scar tissue from two individuals revealed the presence of numerous cytokeratin 18 positive cells. These findings indicate that RPE cells can be identified by their cytokeratin immunoreactivity and that the overt expression of cytokeratin 18 may be associated with proliferation of human RPE both in vitro and in vivo.


2017 ◽  
Vol 117 (04) ◽  
pp. 750-757
Author(s):  
Xin Jia ◽  
Chen Zhao ◽  
Qishan Chen ◽  
Yuxiang Du ◽  
Lijuan Huang ◽  
...  

SummaryJunctional adhesion molecule-C (JAM-C) has been shown to play critical roles during development and in immune responses. However, its role in adult eyes under oxidative stress remains poorly understood. Here, we report that JAM-C is abundantly expressed in adult mouse retinae and choroids in vivo and in cultured retinal pigment epithelium (RPE) and photoreceptor cells in vitro. Importantly, both JAM-C expression and its membrane localisation are downregulated by H2O2-induced oxidative stress. Under H2O2-induced oxidative stress, JAM-C is critically required for the survival of human RPE cells. Indeed, loss of JAM-C by siRNA knockdown decreased RPE cell survival. Mechanistically, we show that JAM-C is required to maintain VEGFR2 expression in RPE cells, and VEGFR2 plays an important role in keeping the RPE cells viable since overexpression of VEGFR2 partially restored impaired RPE survival caused by JAM-C knockdown and increased RPE survival. We further show that JAM-C regulates VEGFR2 expression and, in turn, modulates p38 phosphorylation. Together, our data demonstrate that JAM-C plays an important role in maintaining VEGR2 expression to promote RPE cell survival under oxidative stress. Given the vital importance of RPE in the eye, approaches that can modulate JAM-C expression may have therapeutic values in treating diseases with impaired RPE survival.


2019 ◽  
Vol 11 (475) ◽  
pp. eaat5580 ◽  
Author(s):  
Ruchi Sharma ◽  
Vladimir Khristov ◽  
Aaron Rising ◽  
Balendu Shekhar Jha ◽  
Roba Dejene ◽  
...  

Considerable progress has been made in testing stem cell–derived retinal pigment epithelium (RPE) as a potential therapy for age-related macular degeneration (AMD). However, the recent reports of oncogenic mutations in induced pluripotent stem cells (iPSCs) underlie the need for robust manufacturing and functional validation of clinical-grade iPSC-derived RPE before transplantation. Here, we developed oncogenic mutation-free clinical-grade iPSCs from three AMD patients and differentiated them into clinical-grade iPSC-RPE patches on biodegradable scaffolds. Functional validation of clinical-grade iPSC-RPE patches revealed specific features that distinguished transplantable from nontransplantable patches. Compared to RPE cells in suspension, our biodegradable scaffold approach improved integration and functionality of RPE patches in rats and in a porcine laser-induced RPE injury model that mimics AMD-like eye conditions. Our results suggest that the in vitro and in vivo preclinical functional validation of iPSC-RPE patches developed here might ultimately be useful for evaluation and optimization of autologous iPSC-based therapies.


2002 ◽  
Author(s):  
Clemens Alt ◽  
Carsten Framme ◽  
Susanne Schnell ◽  
Georg Schuele ◽  
Ralf Brinkmann ◽  
...  

2006 ◽  
Vol 47 (9) ◽  
pp. 4098 ◽  
Author(s):  
Maria E. Marin-Castan~o ◽  
Gary E. Striker ◽  
Oscar Alcazar ◽  
Paola Catanuto ◽  
Diego G. Espinosa-Heidmann ◽  
...  

2021 ◽  
Vol 22 (6) ◽  
pp. 3237
Author(s):  
Masaaki Ishida ◽  
Sunao Sugita ◽  
Kenichi Makabe ◽  
Shota Fujii ◽  
Yoko Futatsugi ◽  
...  

Currently, retinal pigment epithelium (RPE) transplantation includes sheet and single-cell transplantation, the latter of which includes cell death and may be highly immunogenic, and there are some issues to be improved in single-cell transplantation. Y-27632 is an inhibitor of Rho-associated protein kinase (ROCK), the downstream kinase of Rho. We herein investigated the effect of Y-27632 in vitro on retinal pigment epithelium derived from induced pluripotent stem cells (iPS-RPE cells), and also its effects in vivo on the transplantation of iPS-RPE cell suspensions. As a result, the addition of Y-27632 in vitro showed suppression of apoptosis, promotion of cell adhesion, and higher proliferation and pigmentation of iPS-RPE cells. Y-27632 also increased the viability of the transplant without showing obvious retinal toxicity in human iPS-RPE transplantation into monkey subretinal space in vivo. Therefore, it is possible that ROCK inhibitors can improve the engraftment of iPS-RPE cell suspensions after transplantation.


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