Proteomic investigation of neural stem cell to oligodendrocyte precursor cell differentiation reveals phosphorylation-dependent Dclk1 processing.

Oligodendrocytes are generated via a two-step mechanism from pluripotent neural stem cells (NSCs): after differentiation of NSCs to oligodendrocyte precursor/NG2 cells (OPCs), they further develop into mature oligodendrocytes. The first step of this differentiation process is only incompletely understood. In this study, we utilized the neurosphere assay to investigate NSC to OPC differentiation in a time course-dependent manner by mass spectrometry-based (phospho-) proteomics. We identify doublecortin-like kinase 1 (Dclk1) as one of the most prominently regulated proteins in both datasets, and show that it undergoes a gradual transition between its short/long isoform during NSC to OPC differentiation. This is regulated by phosphorylation of its SP-rich region, resulting in inhibition of proteolytic Dclk1 long cleavage, and therefore Dclk1 short generation. Through interactome analyses of different Dclk1 isoforms by proximity biotinylation, we characterize their individual putative interaction partners and substrates. All data are available via ProteomeXchange with identifier PXD040652.

Diagnostic value of intereye difference metrics for optic neuritis in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders.

BACKGROUND: The novel optic neuritis (ON) diagnostic criteria include intereye differences (IED) of optical coherence tomography (OCT) parameters. IED has proven valuable for ON diagnosis in multiple sclerosis but has not been evaluated in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders (AQP4+NMOSD). We evaluated the diagnostic accuracy of intereye absolute (IEAD) and percentage difference (IEPD) in AQP4+NMOSD after unilateral ON >6 months before OCT as compared with healthy controls (HC). METHODS: Twenty-eight AQP4+NMOSD after unilateral ON (NMOSD-ON), 62 HC and 45 AQP4+NMOSD without ON history (NMOSD-NON) were recruited by 13 centres as part of the international Collaborative Retrospective Study on retinal OCT in Neuromyelitis Optica study. Mean thickness of peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell and inner plexiform layer (GCIPL) were quantified by Spectralis spectral domain OCT. Threshold values of the ON diagnostic criteria (pRNFL: IEAD 5 µm, IEPD 5%; GCIPL: IEAD: 4 µm, IEPD: 4%) were evaluated using receiver operating characteristics and area under the curve (AUC) metrics. RESULTS: The discriminative power was high for NMOSD-ON versus HC for IEAD (pRNFL: AUC 0.95, specificity 82%, sensitivity 86%; GCIPL: AUC 0.93, specificity 98%, sensitivity 75%) and IEPD (pRNFL: AUC 0.96, specificity 87%, sensitivity 89%; GCIPL: AUC 0.94, specificity 96%, sensitivity 82%). The discriminative power was high/moderate for NMOSD-ON versus NMOSD-NON for IEAD (pRNFL: AUC 0.92, specificity 77%, sensitivity 86%; GCIP: AUC 0.87, specificity 85%, sensitivity 75%) and for IEPD (pRNFL: AUC 0.94, specificity 82%, sensitivity 89%; GCIP: AUC 0.88, specificity 82%, sensitivity 82%). CONCLUSIONS: Results support the validation of the IED metrics as OCT parameters of the novel diagnostic ON criteria in AQP4+NMOSD.

Pediatric Open Globe Injuries Caused by Firecrackers in a Tertiary Eye Care Hospital in Iran.

OBJECTIVE: The aim of the study is to determine characteristic features of open globe injuries caused by firecrackers among pediatric population. METHODS: In this retrospective cross-sectional chart review, medical records of children with ocular trauma who were hospitalized in Isfahan, Iran, during 2013-2017 were reviewed. We analyzed the collected data before and after propensity score (PS) matching. RESULTS: Of 396 pediatric patients with open globe injury, 22 injuries (5.9%) were caused by firecrackers. Hyphema, iris prolapse, and lens rupture were noted in 15 (68.18%), 10 (45.45%), and 2 (9.09) eyes, respectively. None of patients had endophthalmitis. The mean age of patients in firecracker group was higher and significant (11.86 ± 4.05 in firecracker vs 7.80 ± 4.68 in nonfirecracker, P < 0.001). Furthermore, most boys were in firecracker group (95.5%, P = 0.005). Patients in firecracker group resided more in urban areas (86.4%, P = 0.054) and had more intraocular foreign body (IOFB) in the eyes (40.9%, P < 0.001). After PS matching, patients in firecracker group had higher IOFB ( P = 0.008). In logistic regression models, patients with corneal lacerations had lower odds for long-time admission (≥4 days) than patients with both corneal and scleral lacerations in crude model (odds ratio, 0.35; 95% confidence interval, 0.17-0.69) and adjusted model (odds ratio, 0.37; 95% CI, 0.18 to 0.74). After PS matching, there was no significant association between risk factors and outcomes. CONCLUSIONS: The present study showed several differences between the pediatric open globe injuries caused by firecrackers and other mechanisms of injuries, including the age, sex, living place, presence of IOFB, and length of hospital stay.

Effect of treatment regimen of the rheumatoid arthritis patients on the risk of coronavirus disease 2019 by modulating the inflammatory mediators.

BACKGROUND: The therapeutic profile of the patients with rheumatoid arthritis (RA) commonly consists of immunosuppressive and anti-inflammatory compounds. Here in this research, we assessed the potential effect of drug treatment in the RA patients in increasing the risk of coronavirus disease 2019 (COVID-19) infection. METHODS: In this retrospective cross-sectional study, 200 subjects with RA were recruited. The treatment profile of the subjects for the past 6 months was collected. The COVID-19 diagnosis was implemented based on the standard molecular tests and clinical examinations. Serum concentration of cytokines was measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: It was detected that there was an increased risk of COVID-19 in RA subjects receiving Etanercept (OR = 3.51, 95% CI 1.19-10.30, P = 0.022). Concentrations of Interleukin (IL)-1ß, Interferon (IFN)-γ, Tumor necrosis factor (TNF)-α, IL-6, IL-17A, and IL-23 were significantly higher in the RA patients with COVID-19 relative to RA cases without COVID-19. In RA/COVID-19 cases receiving Etanercept, serum levels of TNF-α, IL-1ß, and IL-6 were significantly lower than RA/COVID-19 subjects without Etanercept therapy. CONCLUSIONS: It seems that Etanercept therapy in RA cases might increase proneness of the COVID-19 risk in these cases. The mechanism of this increased risk may stem from suppressing a protective immunity state in the RA cases.

Systemic isotretinoin therapy and central macular and choroidal thicknesses in acne vulgaris: is there any association?

PURPOSE: To investigate the effect of oral isotretinoin therapy on central macular thickness (CMT) thickness and choroidal thickness (CT) using optical coherence tomography (OCT). METHODS: CT and CMT thickness of 43 eyes were evaluated at baseline, the third, and sixth month of isotretinoin therapy by spectral-domain OCT. For assessment of CT, OCT measurements were obtained at the fovea with six additional measurements at adjacent locations (at 500-1000 µm temporal to the fovea and 500-1000 µm nasal to the fovea). RESULTS: Forty-three eyes from 43 patients with acne vulgaris, including 33 females (76.7%), who had a mean age of 24.81 ± 6.60 years, completed the study. The mean CMT was 231.49 ± 19.52 at the baseline and significantly decreased to 229.0 ± 19.57 (p = 0.02) and 229.28 ± 18.83 after three and six months, respectively (p < 0.03). The change in the macular thicknesses measured at four quadrants and choroidal thicknesses were not statistically significant during the study (p > 0.05). CONCLUSION: The result of our study demonstrated choroidal thickness change is not significant in patients with acne vulgaris after systemic isotretinoin therapy during six months of follow-up. The decreased CMT amount was 2.2 microns; even if statistically significant, this amount is clinically insignificant.

Astrocytic outer retinal layer thinning is not a feature in AQP4-IgG seropositive neuromyelitis optica spectrum disorders.

BACKGROUND: Patients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort. METHOD: 197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site. RESULTS: No significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere. CONCLUSION: The results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.

Diabetic retinopathy and corneal endothelial parameters: an analytical cross-sectional study.

BACKGROUND: To investigate the possible association of different pattern of diabetic retinopathy (DR) on corneal endothelium cells in type 2 diabetes mellitus patients. METHODS: In this descriptive-analytical cross-sectional study, corneal endothelium parameters including endothelial cell density (ECD), average cell size (AVG), coefficient of variation in cell size (CV), and hexagonality (Hex) were evaluated by non-contact specular microscopy. RESULTS: One hundred and thirty-four eyes of 134 diabetic patients including 77 females (57.5%) with a mean age of 61.03 ± 8.08 years were enrolled. The overall corneal parameters in diabetic patients with and without retinopathy were not significantly different (P > 0.05). There is a significant relationship between CV and the duration of the disease with age variable control (B = 0.369, p-value < 0.001). CONCLUSIONS: Corneal endothelial parameters were not associated with DM in patients without and with DR. There is a significant relationship between CV and the duration of the disease with age variable control.

Ocular delivery of sunitinib-loaded nanoparticles doped in tragacanthic acid hydrogel in treatment of diabetic retinopathy in rats.

OBJECTIVE: Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. This study aimed to compare the effect of sunitinib-loaded poly (glycerol sebacate) (PGS)/gelatin nanoparticles doped in an injectable hydrogel with bevacizumab as a standard treatment of DR. METHODS: The shear-sensitive hydrogel was prepared based on tragacanthic acid (TA) cross-linked with sodium acetate. DR was induced in rats by streptozotocin (STZ), and the animals were injected intravitreally a single dose of 20 µL sunitinib solution in three different concentrations (12.5, 25, and 50 µg/mL), sunitinib-loaded nanoparticles in hydrogel (413 µg/mL) and bevacizumab solution (6.25 mg/mL). The efficacy of the treatments was studied by histological and immunohisitological tests, angiogenesis, and optical coherence tomography (OCT). Vascular endothelial growth factor (VEGF) concentration was measured in the retina. RESULTS: The results revealed that 20 µL of sunitinib with the concentration of 25 µg/mL was effective in DR without any disruption in the retina or any other side effects. This dose was considered the therapeutic dose for nanoparticles. Sunitinib loaded PGS/gelatin nanoparticles that were incorporated in the injectable hydrogel were as effective as bevacizumab in controlling DR. Although sunitinib solution reduced VEGF production and neovascularization in the retina compared to the negative control group, it was not as suitable as the nanoparticles. TA-based hydrogel showed no toxicity on the normal retina, and the angiography and histologic studies confirmed the VEGF results.' CONCLUSIONS: Sunitinib nanoparticles doped in TA hydrogel may be an appropriate substitution of bevacizumab in the treatment of DR.

Evaluation of optical coherence tomography angiography parameters in patients treated with Hydroxychloroquine.

BACKGROUND: One of the major side effects of Hydroxychloroquine (HCQ) is retinopathy. The aim of this study was to evaluate the Optical coherence tomography angiography (OCTA) parameters in a group of patients who have Hydroxychloroquine-induced retinopathy based on Multifocal electroretinography (mfERG) with a group who do not have retinopathy. METHOD: This is a Cross-Sectional Study. In this study, patients with Rheumatoid arthritis (RA) or Systemic lupus erythematosus (SLE) who had been taking Hydroxychloroquine for at least 7 years were included. MfERG and OCTA imaging were performed for all patients. Patients were divided into Normal mfERG and Abnormal mfERG groups based on mfERG results. OCTA parameters were studied in these two groups. RESULT: Sixty-one patients (61 eyes) were included. Forty-one patients had SLE and 20 patients had RA. Forty patients (66.7%) had Abnormal mfERG. The mean vascular density (VD) in Superficial capillary plexus (SCP) layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). Mean VD in SCP layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). In RA subgroup, mean VD in SCP layer in PeriFovea region in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). Mean VD in deep capillary plexus (DCP) layer in Whole Image, Superior Hemi, Inferior Hemi, PeriFovea area in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). This discrepancy was also observed in the RA subgroup but not in the SLE subgroup. The mean of none of the parameters of foveal avascular zone (FAZ) (mm2), Flow Area of Outer Retina (mm2) and Flow Area of Choriocapillaris (mm2) were not statistically significant between the groups Abnormal mfERG and Normal mfERG. (p-value> 0.05). CONCLUSION: VD in the DCP layer decreased in abnormal mfERG patients compared to patients with normal mfERG. But it seems that VD in SCP layer, FAZ Area and Flow Area are similar in both groups. OCTA may be used as a non-invasive tool in the diagnosis of early stages of HCQ-induced retinopathy, especially in RA patients, but further studies are needed.

Targeted next generation sequencing reveals genetic defects underlying inherited retinal disease in Iranian families.

Purpose: Inherited retinal diseases (IRDs) are clinically and genetically heterogeneous showing progressive retinal cell death which results in vision loss. IRDs include a wide spectrum of disorders, such as retinitis pigmentosa (RP), Leber congenital amaurosis (LCA), cone-rod dystrophy (CRD), and Stargardt disease (STGD1). Methods: In this study, we performed targeted next-generation sequencing based on molecular inversion probes (MIPs) that allowed the sequence analysis of 108 IRD-associated genes in 50 Iranian IRD probands. Results: The sequencing and variant filtering led to the identification of putative pathogenic variants in 36 out of 50 (72%) probands. Among 36 unique variants, we identified 20 novel variants in 15 genes. Four out of 36 probands carry compound heterozygous variants, and 32 probands carry homozygous variants. Conclusions: Employing a cost-effective targeted next-generation sequencing procedure, we identified the genetic causes of different retinal disorders in the majority of Iranian families in this study.