scholarly journals Role of FGF and Hyaluronan in Choroidal Neovascularization in Sorsby Fundus Dystrophy

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 608
Author(s):  
Alyson Wolk ◽  
Dilara Hatipoglu ◽  
Alecia Cutler ◽  
Mariya Ali ◽  
Lestella Bell ◽  
...  

Sorsby’s fundus dystrophy (SFD) is an inherited blinding disorder caused by mutations in the tissue inhibitor of metalloproteinase-3 (TIMP3) gene. The SFD pathology of macular degeneration with subretinal deposits and choroidal neovascularization (CNV) closely resembles that of the more common age-related macular degeneration (AMD). The objective of this study was to gain further insight into the molecular mechanism(s) by which mutant TIMP3 induces CNV. In this study we demonstrate that hyaluronan (HA), a large glycosaminoglycan, is elevated in the plasma and retinal pigment epithelium (RPE)/choroid of patients with AMD. Mice carrying the S179C-TIMP3 mutation also showed increased plasma levels of HA as well as accumulation of HA around the RPE in the retina. Human RPE cells expressing the S179C-TIMP3 mutation accumulated HA apically, intracellularly and basally when cultured long-term compared with cells expressing wildtype TIMP3. We recently reported that RPE cells carrying the S179C-TIMP3 mutation have the propensity to induce angiogenesis via basic fibroblast growth factor (FGF-2). We now demonstrate that FGF-2 induces accumulation of HA in RPE cells. These results suggest that the TIMP3-MMP-FGF-2-HA axis may have an important role in the pathogenesis of CNV in SFD and possibly AMD.

2021 ◽  
Vol 76 (4) ◽  
pp. 384-393
Author(s):  
Vladimir V. Neroev ◽  
Marina V. Zueva ◽  
Natalia V. Neroeva ◽  
Ludmila A. Katargina ◽  
Oksana A. Losanova ◽  
...  

Background.Studies demonstrate the need for long-term follow-up of patients with wet age-related macular degeneration (AMD) treated with inhibitors of angiogenesis to monitor long-term vision outcomes and assess the safety of antiangiogenic therapy in relation to the risk of secondary geographic atrophy. Aims to determine the characteristic clinical and functional signs of secondary GA that developed against the background of wet AMD. Methods.In 22 patients (25 eyes) with wet AMD and 18 healthy subjects comparable in age and sex standard ophthalmological and instrumental studies were performed and photopic electroretinograms (ERGs) were recorded according to ISCEV standards, flicker-ERGs, multifocal ERGs and electrooculogram. Results.The appearance of the area of secondary atrophy against the background of wet AMD in eyes treated with inhibitors of angiogenesis is clinically indistinguishable from areas of geographic atrophy that developed as an outcome of dry AMD. The ERG-signs of secondary atrophy are described, which are similar to the biomarkers of primary atrophy and specifically differ from them. Secondary atrophy is characterized by the dependence of the increase in the b/a ratio on the atrophic area, reducing of the 8.3 Hz-flicker-ERG amplitude in the absence of 24 Hz-flicker ERG changes. In eyes with secondary atrophy, a significant decrease in the density of the multifocal ERG P1-peak was shown not only in the first hexagon but also in the parafoveal zone. The electrooculography results showed a sharper dark troughs decrease in with an increase in Ardens ratio in patients with secondary atrophya on the background of wet AMD, in contrast to the previously described changes in primary geographic atrophy. Conclusion.Comparison of the change in the b/a ratio with secondary atrophy area in patients with wet AMD may have clinical implications for assessing retinal dysfunction and predicting visual function. Secondary atrophy is associated with a pronounced inhibition of photoreceptor activity with better preservation of cone bipolar cells. The ERG and electrooculography data taking together indicate a more significant dysfunction of the retinal pigment epithelium in GA against the background of wet AMD and the associated deterioration of photoreceptor function than the changes characterizing primary geographic atrophy.


Choroidal neovascularization is defined as the formation of new blood vessels located between the retinal pigment epithelium and the Bruch's membrane. The neovascular structure is taken origin from the choroid, crosses the Bruch membrane, and affects the photoreceptors with RPE. It is most frequently observed in Age-Related Macular Degeneration and less frequently in other eye diseases. This review mentions choroidal neovascularization and its causes as a general.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jiangyuan Gao ◽  
Ruozhou Tom Liu ◽  
Sijia Cao ◽  
Jing Z. Cui ◽  
Aikun Wang ◽  
...  

Age-related macular degeneration (AMD) is the leading cause of legal blindness in the elderly in industrialized countries. AMD is a multifactorial disease influenced by both genetic and environmental risk factors. Progression of AMD is characterized by an increase in the number and size of drusen, extracellular deposits, which accumulate between the retinal pigment epithelium (RPE) and Bruch’s membrane (BM) in outer retina. The major pathways associated with its pathogenesis include oxidative stress and inflammation in the early stages of AMD. Little is known about the interactions among these mechanisms that drive the transition from early to late stages of AMD, such as geographic atrophy (GA) or choroidal neovascularization (CNV). As part of the innate immune system, inflammasome activation has been identified in RPE cells and proposed to be a causal factor for RPE dysfunction and degeneration. Here, we will first review the classic model of inflammasome activation, then discuss the potentials of AMD-related factors to activate the inflammasome in both nonocular immune cells and RPE cells, and finally introduce several novel mechanisms for regulating the inflammasome activity.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jakob Malsy ◽  
Andrea C Alvarado ◽  
Joseph O Lamontagne ◽  
Karin Strittmatter ◽  
Alexander G Marneros

NLRP3 inflammasome activation and complement-mediated inflammation have been implicated in promoting choroidal neovascularization (CNV) in age-related macular degeneration (AMD), but central questions regarding their contributions to AMD pathogenesis remain unanswered. Key open questions are (1) whether NLRP3 inflammasome activation mainly in retinal pigment epithelium (RPE) or rather in non-RPE cells promotes CNV, (2) whether inflammasome activation in CNV occurs via NLRP3 or also through NLRP3-independent mechanisms, and (3) whether complement activation induces inflammasome activation in CNV. Here we show in a neovascular AMD mouse model that NLRP3 inflammasome activation in non-RPE cells but not in RPE cells promotes CNV. We demonstrate that both NLRP3-dependent and NLRP3-independent inflammasome activation mechanisms induce CNV. Finally, we find that complement and inflammasomes promote CNV through independent mechanisms. Our findings uncover an unexpected role of non-NLRP3 inflammasomes for CNV and suggest that combination therapies targeting inflammasomes and complement may offer synergistic benefits to inhibit CNV.


2020 ◽  
Vol 21 (6) ◽  
pp. 1976 ◽  
Author(s):  
Iswariyaraja Sridevi Gurubaran ◽  
Johanna Viiri ◽  
Ali Koskela ◽  
Juha M.T. Hyttinen ◽  
Jussi J. Paterno ◽  
...  

Increased oxidative stress and mitochondrial damage are observed in protein aggregation diseases, such as age-related macular degeneration (AMD). We have recently reported elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in the retinal pigment epithelial cells (RPE) of the dry AMD-resembling NFE2L2/PGC1α double knockout (dKO) mouse model. Here, we provide evidence of a disturbance in the autolysosomal machinery handling mitochondrial clearance in the RPE cells of one-year-old NFE2L2/PGC1α-deficient mice. Confocal immunohistochemical analysis revealed an upregulation of autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as numerous mitophagy markers, such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN) together with damaged mitochondria. However, we detected no evidence of increased autolysosome formation in transmission electron micrographs or of colocalization of lysosomal marker LAMP2 (lysosome-associated membrane protein 2) and the mitochondrial marker ATP synthase β in confocal micrographs. Interestingly, we observed an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells together with autofluorescence aggregates. Our results reveal that there is at least a relative decrease of mitophagy in the RPE cells of NFE2L2/PGC1α dKO mice. This further supports the hypothesis that mitophagy is a putative therapy target in AMD-like pathology.


2019 ◽  
Vol 55 (2) ◽  
pp. 121-132
Author(s):  
Tea Čaljkušić-Mance ◽  
Ivan Brumini ◽  
Renata Gržetić-Lenac ◽  
Tamara Mišljenović-Vučerić ◽  
Zvjezdana Alpeza-Dunato

Senilna makularna degeneracija (engl. age-related macular degeneration; AMD) jedan je od najvažnijih uzroka gubitka centralnog vida kod starije populacije. Dijelimo je na „vlažnu” i „suhu” formu, ovisno o prisutnosti koroidne neovaskularizacije (engl. choroidal neovascularization; CNV). Do sada nijedna terapija nije potvrđena i odobrena za liječenje geografske atrofije (engl. geographic atrophy; GA), najtežeg oblika „suhog” AMD-a, jer nije bilo moguće popraviti oštećenja retinalnog pigmentnog epitela (engl. retinal pigment epithelium; RPE) i fotoreceptora. Liječenje se svodilo na pokušaje zaustavljanja progresije oboljenja i širenja geografske atrofije. Namjera ovog članka je prikazati podatke novijih dovršenih i tekućih kliničkih ispitivanja s naglaskom na mjesto djelovanja potencijalnih lijekova. Danas su nam dostupne brojne nove dijagnostičke metode koje nam omogućavaju bolje praćenje morfoloških promjena mrežnice, RPE-a i žilnice, kao i širenja područja atrofije. Oksidativni stres, kronična upala, insuficijentni koroidalni protok krvi te depoziti lipofuscina za koje se pretpostavlja da bi imali važniju ulogu u razvoju bolesti predstavljaju potencijalne mete za djelovanje lijekova. Velik je broj tekućih studija koje istražuju moguća rješenja, kao što su protuupalni i neuroprotektivni lijekovi te matične stanice, dok će samo neki od lijekova biti dostupni na tržištu i pružiti nadu pacijentima za očuvanje centralnog vida, pa ih je potrebno dugoročno pratiti. Uključiti treba i tretman ispodpražnim i mikropulsnim laserom koji je kod nekih oboljenja mrežnice pokazao određene rezultate u revitalizaciji tkiva, a koji koristimo i na našoj Klinici, te su prvi kratkoročni rezultati skromni ali ohrabrujući i zahtijevaju daljnje tretmane i praćenje.


Sign in / Sign up

Export Citation Format

Share Document