Microvascular Changes in Pituitary Adenoma Correlate with Structural Measurements and Visual Field Loss.

Purpose: This study aimed to determine the relationship among microvascular changes, retinal nerve fiber layer (RNFL) thickness, and visual field loss in pituitary adenoma (PA) patients. Patients and Methods: Optic disc and macular vessel densities were measured, using optical coherence tomography angiography (OCTA) in the eyes from PA patients with radiographic chiasmal compression. Comparisons of retinal microvascular and structural parameters were conducted between PA patients and age/sex-matched healthy controls. The PA group was subdivided into PA with temporal visual field defects (perimetric PA) and PA without visual field defect (preperimetric PA) groups. The study determined correlation between microvascular parameters and optic nerve damage, including visual field and structural measurements. Subgroup analyses were performed to distinguish the different microcirculation characteristics of the perimetric PA eyes and preperimetric PA eyes. Results: Forty-five eyes from 40 PA patients and 24 eyes from 24 healthy controls were recruited prospectively. Eyes in the perimetric PA group had significantly decreased optic disc vessel density but slightly increased macular vessel density at superficial retinal capillary plexus (SCP) level. Eyes in the preperimetric PA group had significantly increased macular vessel density at SCP level. Optic disc vessel density was inversely correlated with visual field mean deviation and positively correlated with RNFL thickness. Conclusion: Significantly decreased optic disc vessel density in the perimetric stage but increased SCP macular vessel density in the preperimetric stage were found in PA patients. Our data suggest that increased SCP macular vessel density may serve as an early biomarker of preperimetric PA eyes, while decreased optic disc vessel density could be a late biomarker of perimetric PA eyes. Optic disc vessel density was correlated with RNFL thickness and visual field loss in PA eyes. OCTA is a useful tool to detect retinal microvascular changes and access the severity of neural impairments in chiasmal compression caused by PA.

Sleeve gastrectomy improved microvascular phenotypes from obesity cohort, detected with optical coherence tomography angiography.

AIMS: To examine how metabolic status is associated with microvascular phenotype and to identify variables associated with vascular remodeling after bariatric surgery, using noninvasive optical coherence tomography angiography (OCTA). METHODS: The study included 136 obese subjects scheduled for bariatric surgery and 52 normal-weight controls. Patients with obesity were divided into metabolically healthy obesity (MHO) and metabolic syndrome (MetS) groups according to the diagnosis criteria of the Chinese Diabetes Society. Retinal microvascular parameters were measured by OCTA, including superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel densities. Follow-ups were performed at the baseline and 6 months after bariatric surgery. RESULTS: Fovea SCP, average DCP, fovea DCP, parafovea DCP, and perifovea DCP vessel densities were significantly lower in the MetS group, compared to controls (19.91% vs. 22.49%, 51.60% vs. 54.20%, 36.64% vs. 39.14%, 56.24% vs. 57.65% and 52.59% vs. 55.58%, respectively, all p < .05). Parafovea SCP, average DCP, parafovea DCP, and perifovea DCP vessel densities significantly improved in patients with obesity 6 months after surgery, compared to baseline (54.21% vs. 52.97%, 54.43% vs. 50.95%, 58.29% vs. 55.54% and 55.76% vs. 51.82%, respectively, all p < .05). Multivariable analyses showed that baseline blood pressure and insulin were independent predictors of vessel density changes 6 months after surgery. CONCLUSIONS: Retinal microvascular impairment occurred mainly in MetS rather than MHO patients. Retinal microvascular phenotype improved 6 months after bariatric surgery and baseline blood pressure and insulin status may be key determinants. OCTA may be a reliable method to evaluate the microvascular complications associated with obesity.

ZD6474 attenuates TGF-ß1-induced fibrosis in human Tenon fibroblasts and inhibits neovascularization via AKT-mTOR signaling pathway.

PURPOSE: To investigate the anti-fibrotic effect of ZD6474 (a novel inhibitor of VEGF and EGF) in TGF-ß1 stimulated human Tenon's capsule fibroblasts (HTFs) and the anti-angiogenetic role in HUVECs, compared to that of mitomycin C (MMC). METHODS: The effects of ZD6474 on cell proliferation or migration in TGF-ß1-stimulated HTFs and HUVECs were determined, using CCK8 or wound healing assay, respectively. The typical markers of fibrosis in TGF-ß1-stimuated HTFs were detected, vimentin by immunofluorescence, α-SMA and snail by western blot. Tube formation was applied to validate the anti-angiogenesis effect in HUVECs following ZD6474 treatment. Furthermore, phosphorylated AKT and mTOR (p-AKT and p-mTOR) were evaluated, compared to the standardized total AKT and mTOR, using western blot. RESULTS: There was almost no decreased cell viability in HTFs following ZD6474 (≤ 1 µM/mL) treatment, but MMC (> 50 µg/mL) significantly impaired cell viability. ZD6474 significantly inhibited TGF-ß1-stimulated proliferation and migration in HTFs, compared to control group (**P < 0.01). ZD6474 also significantly attenuated the TGF-ß1-stimulated expression of vimentin, α-SMA and snail in HTFs. Tube formation was notably interrupted in HUVECs following ZD6474 treatment (**P < 0.01). P-AKT and p-mTOR were significantly decreased in response to ZD6474 treatment in TGF-ß1- induced HTFs and HUVECs. CONCLUSIONS: ZD6474 exerts anti-proliferation and anti-fibrotic effects in TGF-ß1-stimulated HTFs perhaps via regulating AKT-mTOR signaling pathway. ZD6474 also inhibited proliferation, migration and tube formation in HUVECs via the same signaling pathway. We concluded that ZD6474 may be potentially a novel agent in preventing bleb dysfunction following glaucoma filtration surgery (GFS).

Atorvastatin reduces IOP in ocular hypertension in vivo and suppresses ECM in trabecular meshwork perhaps via FGD4.

To explore the role of atorvastatin in regulating intraocular pressure (IOP) in glaucoma in vivo, and to investigate its related molecular pathway in vitro, an ocular hypertension model was generated by intravitreal injection of an adenoviral vector encoding transforming growth factor (TGF)­ß2 in the right eye of BALB/cJ mice, while the left was treated with an empty control adenovirus. To determine its anti­intraocular hypertension role, these induced hyper­IOP mice were gavaged with atorvastatin (20 mg/kg/day). Furthermore, extracellular matrix (ECM) factors were examined in the primary human trabecular meshwork (HTM) cells followed atorvastatin (0~200 µM) treatment in vitro. Whole genome microarray was employed to identify potential therapeutic target molecules associated with ECM regulation. Unilateral murine ocular hypertension was induced, via intravitreal injection of the adenoviral vector carrying the human TGF­ß2 gene (Ad.hTGF­ß2226/228), raising IOP from 12±1.6 to 32.3±0.7 mmHg (n=6, P<0.05) at day 15, which plateaued from day 15 to 30. Atorvastatin administration from day 15 to 30 decreased IOP from 32.3±0.7 to 15.4±1.1 mmHg (n=6, P<0.05) at day 30. Additionally, atorvastatin administration changed the morphology of cultured HTM cells from an elongated and adherent morphology into rounded, less elongated and less adherent cells, accompanied with suppressed expression of ECM. Gene Ontology and Genome analysis revealed that FGD4 (FYVE, RhoGEF and PH domain containing 4) might be a key factor contributing to these changes. Our data demonstrated that atorvastatin reduced TGF­ß2­induced ocular hypertension in vivo, perhaps via modifying cellular structure and decreasing ECM, using the FGD4 signaling pathway, as demonstrated in HTM cells. Our findings provide some useful information for the management of glaucoma, with statin therapy revealing a potential novel therapeutic pathway for glaucoma treatment.

CircDHDDS/miR-361-3p/WNT3A Axis Promotes the Development of Retinoblastoma by Regulating Proliferation, Cell Cycle, Migration, and Invasion of Retinoblastoma Cells.

Retinoblastoma (RB) is a common intraocular malignant tumor. The growing evidence has reported that circular RNAs (circRNAs) play critical roles in RB development. Therefore, the purpose of the study is to investigate the regulatory mechanism of circDHDDS in RB. The real-time quantitative polymerase chain reaction (RT-qPCR) assay was used to quantify the expression levels of circDHDDS, miR-361-3p, and WNT3A in RB tissues and cells (RPCs, Y-79, and WERI-Rb-1). The proliferation and cell cycle of RB cells were assessed by colony formation assay and flow cytometry assays, respectively. The migration and invasion of RB cells were measured by transwell assay. The protein expression levels of Nectin-3 (CD113), SOX2, Nanog, and WNT3A were measured by Western blot assay. The functional targets of circDHDDS and miR-361-3p were predicted by bioinformatics databases, and the dual-luciferase reporter assay was used to confirm the interaction relationship between miR-361-3p and circDHDDS or WNT3A. The functional role of circDHDDS silencing in vivo was evaluated by xenograft experiment. We found that circDHDDS was overexpressed in RB tissues and cells compared with normal retinas tissues and retinal pigment epithelial cells, correspondingly. Furthermore, silencing of circDHDDS impeded proliferation, migration, invasion, and induced cell cycle arrest in vitro, which were abolished by knockdown of miR-361-3p. The in vivo experiments also suggested that tumor growth was inhibited by knockdown of circDHDDS. Moreover, we also found that miR-361-3p specifically bound to WNT3A, and overexpression of miR-361-3p suppressed RB development by decreasing WNT3A expression. Summarily, circDHDDS, a molecule sponge of miR-361-3p, regulated the expression of WNT3A. Therefore, circDHDDS/miR-361-3p/WNT3A axis stimulated the development of RB by regulation of proliferation, cell cycle program, migration, and invasion of RB cells.

The role of TLR4/NF-κB signaling pathway in activated microglia of rats with chronic high intraocular pressure and vitro scratch injury-induced microglia.

Glaucoma is a kind of blind-causing disease with structural damages of optic nerve and defection of visual field. It is believed that the death of retinal ganglion cell (RGC) is a consequential event of over-reactive immune orchestral cells such as microglia. Previous evidences in animal and clinical studies show the innate immunity plays a pivotal role in neuro-inflammation of glaucoma. Toll-like receptor 4 (TLR4) is expressed on microglia and mediates many neuroinflammatory diseases. We aimed to explore the impacts of high intraocular pressure (IOP) on rat microglia in retina and the regulation of TLR4/NF-κB signaling pathway in scratched microglia cells. In our study, we successfully established chronic high IOP rat model by episcleral vein cauterization (EVC) which behaved like the chronic glaucoma. Besides, we set up an in vitro scratch-induced injury model in rat microglia cells. We found the level of activated microglia cells were significantly increased in the retina of chronic high IOP groups. Moreover, the inhibition of TLR4/NF-κB signaling pathway suppressed the expression of TLR4 protein and mRNA levels of P50, IL-6 and TNF-α. Our original study provided a theoretical basis on targeting TLR4/NF-κB to suppress pro-inflammatory factors releasing in activated microglia and it might be a good treatment target to prevent glaucoma from progressing.

Novel inflammatory cytokines (IL-36, 37, 38) in the aqueous humor from patients with chronic primary angle closure glaucoma.

Glaucoma eventually leads to optic nerve damage and vision loss without medical intervention. More than 50% of glaucoma caused blindness are attributed to primary angle closure glaucoma, particularly in Asians. It is reported that immune inflammation is involved in the progress of glaucoma. Increased inflammation cytokines are detected in the aqueous humor of chronic primary angle closure glaucoma (CPACG). IL-36, IL-37 and IL-38, are novel cytokines and are involved in many inflammatory diseases, including inflammatory bowel diseases and acute anterior uveitis, but the possible contributing role in the pathogenesis of CPACG is unclear. In our current study, increased IL-36, IL-37 and IL-38 were detected in the aqueous humor of CPACG compared with age-related cataract (ARC). Furthermore, a significant correlation was detected between mean deviation of visual field (MDVF) of CPACG and IL-36, IL-37 or IL-38, respectively. Our data suggest IL-36, IL-37 and IL-38 might contribute to the immunological mediated pathogenesis of CPACG, despite the eye being an immune-privileged organ under normal conditions. The precise underlying mechanism of these cytokines during the development of CPACG remains to be explored. Our findings may be useful in therapeutic targeting of specific pathology.

Diffusion Tensor Imaging Detects Microstructural Differences of Visual Pathway in Patients With Primary Open-Angle Glaucoma and Ocular Hypertension.

Ocular hypertension (OHT), the common situation in adult patients in the outpatients, occurs ∼5% worldwide. However, there are still some practical problems in differentiation of OHT with early primary open-angle glaucoma (POAG) using current standard methods. Application of high resolution diffusion tensor imaging (DTI) enables us to the differentiate axonal architecture of visual pathway between POAG and OHT subjects. Among 32 POAG patients recruited (15 OHT and 14 control subjects), 62.5% of glaucoma were in early stage for the current study. All subjects underwent ophthalmological assessments with standard automated perimetry and optical coherence tomography (OCT). DTI was applied to measure fraction anisotropy (FA) and mean diffusivity (MD) of optic tract (OT), lateral geniculate body (LGN) and optic radiation (OR) using voxel-based analysis. Our data demonstrated that FA values of bilateral OR in POAG were significantly lower in the right or left than that of OHT patients (left OR: 0.51 ± 0.04 vs. 0.54 ± 0.03, p < 0.05; right OR: 0.51 ± 0.05 vs. 0.54 ± 0.03, p < 0.05). In right LGN, MD values were higher in POAG patients compared with OHT subjects (9.81 ± 1.45 vs. 8.23 ± 0.62, p < 0.05). However, no significant difference of all of the DTI parameters was observed between OHT and control subjects. DTI parameters in POAG patients were positively correlated with morphological and functional measurements (p < 0.05). Vertical cup to disc ratio (VCDR) was correlated with ipsilateral FA of OT (p < 0.05), ipsilateral MD of OT (p < 0.05), ipsilateral MD of LGN (p < 0.05), and contralateral MD of OT (p < 0.05). Mean deviation of visual field (MDVF) was correlated with ipsilateral FA of OT (p < 0.05), ipsilateral MD of OT (p < 0.05), and ipsilateral FA of LGN (p < 0.05). Our study demonstrated that DTI can differentiate POAG from OHT subjects in optic pathway, particularly in early POAG, and DTI parameters can quantify the progression of POAG.