Case report: Sympathetic ophthalmia after vitrectomies in a patient with Von Hippel-Lindau syndrome.

Background: Sympathetic ophthalmia (SO) is a rare but sight-threatening uveitis, and most observations have been made after typical manifestations occur. This report focuses on the choroidal changes detected by multimodal imaging at the presymptomatic stage of SO, which is implicated in the early recognition of SO. Case presentation: A 21-year-old woman suffered from decreased vision in the right eye and was diagnosed with retinal capillary hemangioblastomas associated with Von Hippel-Lindau syndrome. The patient underwent two 23-G pars plana vitrectomies (PPVs), soon after which typical signs of SO manifested. SO resolved quickly after the oral administration of prednisone and remained stable during the follow-up of more than 1 year. The retrospective analysis revealed preexisting bilaterally increased choroidal thickness, dots of flow void on the choroid, and choriocapillaris en-face slabs in optical coherence tomography angiography (OCTA) after the first PPV, which were all reversed by corticosteroid treatment. Conclusion: The case report highlights the involvement of the choroid and choriocapillaris at the presymptomatic stage of SO after the first inciting event. Abnormally thickened choroid and flow void dots suggested that SO had started and an ensuing surgery would run the risk of exacerbating SO. OCTA scanning of both eyes should be ordered routinely for patients with a history of trauma or intraocular surgeries, especially before the next surgical intervention. The report also suggests that non-human leukocyte antigen gene variation may also regulate the progression of SO, which requires further laboratory investigations.

SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways.

BACKGROUND: Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS: In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS: We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS: These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.

MiR-375 mitigates retinal angiogenesis by depressing the JAK2/STAT3 pathway.

Aberrant neovascularization in the retina is an important threat to vision and closely related to several retinal diseases, such as wet form of age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. However, the pathogenesis remains largely unknown. MicroRNAs (miRNAs) have been demonstrated to play critical regulatory roles in angiogenesis. Therefore, we aimed to identify the key miRNAs that regulate retinal neovascularization and elucidate the potential underlying mechanisms. In the present study, we performed RNA sequencing of microRNAs in the retina and found that miR-375 was significantly downregulated in the retina of oxygen-induced retinopathy mice. In retinal microvascular endothelial cells (RMECs), overexpression of miR-375 inhibited cell proliferation and angiogenesis. Conversely, inhibition of miR-375 had the opposite effects. Moreover, our results showed that miR-375 negatively regulated the protein expression of JAK2 by inhibiting its translation. The promoting effects of anti-miR-375 on cell proliferation and angiogenesis were attenuated by an inhibitor of STAT3. These results indicate that miR-375 mitigates cell proliferation and angiogenesis, at least in part, through the JAK2/STAT3 pathway in RMECs, which implies an important underlying mechanism of retinal angiogenesis and provides potential therapeutic targets for retinal microangiopathy.

Ocular Manifestations in a Chinese Pedigree of Familial Amyloidotic Polyneuropathy Carrying the Transthyretin Mutation c.401A>G (p.Tyr134Cys)

Familial amyloid polyneuropathy (FAP) caused by a genetic mutation in transthyretin (TTR) is an autosomal dominant hereditary disease. The retrospective, observational case series study presents the ocular clinicopathological findings of five cases carrying the TTR mutation c.401A>G (p.Tyr134Cys). Multimodal retinal imaging and electrophysiological examination, Congo red staining and immunohistochemical analysis of specimens, and genetic analyses were performed. Cases 1 and 2 were symptomatic with vitreous and retinal amyloid deposition and poor visual recovery. Case 3 had a symptomatic vitreous haze in the left eye with good postoperative visual recovery. The right eye of case 3 and the eyes of cases 4 and 5 were asymptomatic. Thicker retinal nerve fiber layer, retinal venous tortuosity with prolonged arteriovenous passage time on fluorescein angiography and retinal dysfunction detected by multifocal electroretinogram occurred even in asymptomatic eyes. Moreover, the internal limiting membrane from patients with FAP was stained positive for Congo red and transforming growth factor-ß1. The results highlight the amyloid deposition of mutant TTR in the optic disc and retina, even in the asymptomatic stage. The deposited amyloid leads to increased resistance to venous return and retinal functional abnormalities. Therefore, careful follow-up of structural and functional changes in the retina is needed, even in asymptomatic patients with FAP.

Proinflammatory and angiogenesis-related cytokines in vitreous samples of highly myopic patients.

PURPOSE: To determine the concentrations of vitreous proinflammatory cytokines and angiogenesis-related growth cytokines in highly myopic (HM) patients and controls. METHODS: Vitreous humor (VH) was obtained from patients during vitrectomy for rhegmatogenous retinal detachment (RRD), myopic retinoschisis (MRS), idiopathic epiretinal membrane (ERM), or macular hole (MH). High myopia was defined as an axial length (AL) of ≥26.0 mm and a spherical equivalent refractive error more negative than -6.0 D. A multiplex fluorescent-bead-based immunoassay was employed to measure the levels of 29 designated cytokines. The results were compared across groups. RESULTS: Seventy-eight VH samples were collected from 78 patients (36 HM versus 42 controls). Vascular endothelial growth factor (VEGF) was significantly higher in the VH samples from HM patients than in those from the controls. Five inflammation-related factors, interferon γ (IFN-γ), interleukin 6 (IL6), IFN-γ-induced protein 10 (IP-10), eotaxin, and macrophage inflammatory protein 1α (MIP-1α), were significantly higher in the HM group than in the control group. The vitreous concentrations of well-known angiogenic growth factors monocyte chemoattractant protein 1 (MCP1) and IL5 were significantly elevated in the VH samples from HM patients. CONCLUSIONS: Proinflammatory cytokines and angiogenic growth factors were elevated in the VH of HM patients, suggesting that an elevated inflammatory status and higher levels of angiogenic factors are present in eyes with HM.

SHP-1 suppresses endotoxin-induced uveitis by inhibiting the TAK1/JNK pathway.

We investigated how Src-homology 2-domain phosphatase-1 (SHP-1) regulates the inflammatory response in endotoxin-induced uveitis (EIU), and the signalling pathways involved. One week after intravitreal injection of short hairpin RNA targeting SHP-1 or SHP-1 overexpression lentivirus in rats, we induced ocular inflammation with an intravitreal injection of lipopolysaccharide (LPS). We then assessed the extent of inflammation and performed full-field electroretinography. The concentrations and retinal expression of various inflammatory mediators were examined with enzyme-linked immunosorbent assays and Western blotting, respectively. SHP-1 overexpression and knockdown were induced in Müller cells to study the role of SHP-1 in the LPS-induced inflammatory response in vitro. Retinal SHP-1 expression was up-regulated by LPS. SHP-1 knockdown exacerbated LPS-induced retinal dysfunction and increased the levels of proinflammatory mediators in the retina, which was abrogated by a c-Jun N-terminal kinase (JNK) inhibitor (SP600125). SHP-1 overexpression had the opposite effects. In Müller cells, the LPS-induced inflammatory response was enhanced by SHP-1 knockdown and suppressed by SHP-1 overexpression. SHP-1 negatively regulated the activation of the transforming growth factor-ß-activated kinase-1 (TAK1)/JNK pathway, but not the nuclear factor-κB pathway. These results indicate that SHP-1 represses EIU, at least in part, by inhibiting the TAK1/JNK pathway and suggest that SHP-1 is a potential therapeutic target for uveitis.