NADPH and NAC synergistically inhibits chronic ocular hypertension-induced neurodegeneration and neuroinflammation through regulating p38/MAPK pathway and peroxidation.

Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by neurodegeneration and neuroinflammation with retinal NAD/NADP and GSH decline. Nicotinamide adenine dinucleotide (NAD)/NAD phosphate (NADP) and glutathione (GSH) are two redox reducers in neuronal and glial metabolism. However, therapeutic strategies targeting NAD/NADP or GSH do not exert ideal effects, and the underlying mechanisms are still poorly understood. We assessed morphological changes in retinal ganglion cells (RGCs), the affected neurons in glaucoma, and Müller cells, the major glial cells in the retina, as well as the levels of phosphorylated p38 (p-p38) and Caspase-3 in glaucoma patients. We constructed a modified chronic ocular hypertensive rat model and an oxygen-glucose deprivation (OGD) cell model. After applying NADPH and N-acetylcysteine (NAC), a precursor to cysteine, the rate-limiting substrate in GSH biosynthesis, to cells, apoptosis, axonal damage and peroxidation were reduced in the RGCs of the NAC group and p-p38 levels were decreased in the RGCs of the NADPH group, while in stimulated Müller cells cultured individually or cocultured with RGCs, gliosis and p38/MAPK, rather than JNK/MAPK, activation were inhibited. The results were more synergistic in the rat model, where either NADPH or NAC showed crossover effects on inhibiting peroxidation and p38/MAPK pathway activation. Moreover, the combination of NADPH and NAC ameliorated RGC electrophysiological function and prevented Müller cell gliosis to the greatest extent. These data illustrated conjoined mechanisms in glaucomatous RGC injury and Müller cell gliosis and suggested that NADPH and NAC collaborate as a neuroprotective and anti-inflammatory combination treatment for glaucoma and other underlying human neurodegenerative diseases.

Comparison Between Two Types of Viral-Induced Anterior Uveitis In Vitro and In Vivo: A Stronger Response in Herpes Simplex Virus Type 1 Than in Murine Cytomegalovirus.

Purpose: To observe the similarities and differences between herpes simplex virus type 1 (HSV-1) and murine cytomegalovirus (MCMV)-induced viral anterior uveitis (VAU), both in vitro and in vivo. Methods: Primary rat trabecular meshwork cells (RTMCs) were infected by HSV-1 or MCMV to clarify the pattern of virus replication and the effect on cells. In vivo, intracameral injection of HSV-1 or MCMV was performed to establish the VAU rat models. The clinical manifestation, intraocular pressure (IOP), histological characteristics, ultrastructural changes, and the expression of inflammatory cytokines in the anterior segment were observed and compared between these two types of VAU models. Results: Both viruses could infect the RTMCs but HSV-1 exhibited an earlier and greater cytopathic effect in vitro. In vivo, both VAU rats showed typical acute VAU signs, and the IOP elevation seemed to be correlated with the inflammatory progression. Histopathological findings and ultrastructural changes revealed tissue damage and cell infiltration in the anterior chamber angle. In both models, similar proinflammatory cytokines were upregulated. HSV-1 and MCMV viral particles were identified under transmission electron microscopy. Conclusions: HSV-1 and MCMV infection share certain similarities but have significant differences both in vitro and in vivo. HSV-1 usually has a stronger anterior segment inflammation with a longer duration compared with MCMV in VAU models. Our results provided a valuable animal model for investigating pathogenesis and exploring therapeutic strategies for clinical VAU.

Inhibition of cGAS-STING pathway alleviates neuroinflammation-induced retinal ganglion cell death after ischemia/reperfusion injury.

Acute glaucoma is a vision-threatening disease characterized by a sudden elevation in intraocular pressure (IOP), followed by retinal ganglion cell (RGC) death. Cytosolic double-stranded DNA (dsDNA)-a damage-associated molecular pattern (DAMP) that triggers inflammation and immune responses-has been implicated in the pathogenesis of IOP-induced RGC death, but the underlying mechanism is not entirely clear. In this study, we investigated the effect of the inflammatory cascade on dsDNA recognition and examined the neuroprotective effect of the cyclic GMP-AMP (cGAMP) synthase (cGAS) antagonist A151 on a retinal ischemia/reperfusion (RIR) mouse model. Our findings reveal a novel mechanism of microglia-induced neuroinflammation-mediated RGC death associated with glaucomatous vision loss. We found that RIR injury facilitated the release of dsDNA, which initiated inflammatory responses by activating cGAS-stimulator of interferon genes (STING) pathway. Correspondingly, elevated expressions of cGAS and STING were found in retinal samples from human glaucoma donors. Furthermore, we found that deletion or inhibition of cGAS or STING in microglia transfected with poly(dA:dT) specifically decreased microglia activation and inflammation response. We also observed that A151 treatment promoted poly(dA:dT)--stimulated changes in polarization from the M1 to the M2 phenotype in microglia. Subsequently, A151 administered to mice effectively inhibited the cGAS-STING pathway, absent in melanoma 2 (AIM2) inflammasome and pyroptosis-related molecules. Furthermore, A151 administration significantly reduced neuroinflammation, ameliorated RGC death and RGC-related reductions in visual function. These findings provide a unique perspective on glaucomatous neuropathogenesis and suggest cGAS as an underlying target of retinal inflammation to provide a potential therapeutic for acute glaucoma.

Development and material characteristics of glaucoma surgical implants.

Background: Glaucoma is the leading cause of irreversible blindness worldwide. The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment, and surgical management is one of the important methods for the treatment of glaucoma patients. Main text: In order to increase aqueous humor outflow and further reduce intraocular pressure, various drainage implants have been designed and applied in clinical practice. From initial Molteno, Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device, Paul glaucoma implant, EX-PRESS and the eyeWatch implant, to iStent, Hydrus, XEN, PreserFlo, Cypass, SOLX Gold Shunt, etc., glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances. Multitudinous materials have been used to produce these implants, from original silicone and porous polyethylene, to gelatin, stainless steel, SIBS, titanium, nitinol and even 24-carat gold. Moreover, the material geometry, size, rigidity, biocompatibility and mechanism (valved versus nonvalved) among these implants are markedly different. In this review, we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants, such as the eyeWatch and the new minimally invasive glaucoma surgery (MIGS) devices. Conclusions: Although different in design and materials, these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods, and improved the success rate and safety of glaucoma surgery significantly. However, all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Keratin8 Deficiency Aggravates Retinal Ganglion Cell Damage Under Acute Ocular Hypertension.

Purpose: Keratin 8/18 (KRT8/18), paired members of the intermediate filament family, have shown vital functions in regulating physiological activities more than supporting the mechanic strength for cells and organelles. However, the KRT8/18 presence in retinal ganglion cells (RGCs) and functions on neuroprotection in a mouse model of acute ocular hypertension (AOH) are unknown and worthy of exploration. Methods: We identified the existence of KRT8/18 in normal human and mouse retinas and primary RGCs. KRT8/18 levels were detected after AOH modeling. The adeno-associated virus (AAV) system was intravitreally used for selective KRT8 knockdown in RGCs. The histological changes, the loss and dysfunction of RGCs, and the gliosis in retinas were detected. The markers of cell apoptosis and MAPK pathways were investigated. Results: KRT8/18 existed in all retinal layers and was highly expressed in RGCs, and they increased after AOH induction. The KRT8 knockdown in RGCs caused no histopathological changes and RGC loss in retinas without AOH modeling. However, after the KRT8 deficiency, AOH significantly promoted the loss of whole retina and inner retina thickness, the reduction, apoptosis, and dysfunction of RGCs, and the glial activation. Besides, downregulated Bcl-2 and upregulated cleaved-Caspase 3 were found in the AOH retinas with KRT8 knockdown, which may be caused by the increased phosphorylation level of MAPK pathways (JNK, p38, and ERK). Conclusions: The KRT8 deficiency promoted RGC apoptosis and neurodegeneration by abnormal activation of MAPK pathways in AOH retinas. Targeting KRT8 may serve as a novel treatment for saving RCGs from glaucomatous injuries.

Comprehensive bioinformatics analysis revealed potential key genes and pathways underlying abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is a permanent, asymptomatic segmental dilatation of the abdominal aorta, with a high mortality risk upon rupture. Identification of potential key genes and pathways may help to develop curative drugs for AAA. We conducted RNA-seq on abdominal aortic tissues from both AAA patients and normal individuals as a control group. Integrated bioinformatic analysis was subsequently performed to comprehensively reveal potential key genes and pathways. A total of 1148 differential expressed genes (DEGs) (631 up-regulated and 517 down-regulated) were identified in our study. Gene Ontology (GO) analysis revealed enrichment in terms related to extracellular matrix organization, while KEGG analysis indicated enrichment in hematopoietic cell lineage and ECM-receptor interaction. Protein-protein interaction (PPI) network analysis revealed several candidate key genes, and differential expression of 6 key genes (CXCL8, CCL2, PTGS2, SELL, CCR7, and CXCL1) was validated by Gene Expression Omnibus (GEO) datasets. Receiver operating characteristic curve (ROC) analysis demonstrated these genes' high discriminatory ability between AAA and normal tissues. Immunohistochemistry indicated that several key genes were highly expressed in AAA tissues. Single-cell RNA sequencing revealed differential distribution patterns of these identified key genes among various cell types. 26 potential drugs linked to our key genes were found through DGIdb. Overall, our study provides a comprehensive evaluation of potential key genes and pathways in AAA, which could pave the way for the development of curative pharmacological therapies.

Inhibiting multiple forms of cell death optimizes ganglion cells survival after retinal ischemia reperfusion injury.

Progressive retinal ganglion cells (RGCs) death that triggered by retinal ischemia reperfusion (IR), leads to irreversible visual impairment and blindness, but our knowledge of post-IR neuronal death and related mechanisms is limited. In this study, we first demonstrated that apart from necroptosis, which occurs before apoptosis, ferroptosis, which is characterized by iron deposition and lipid peroxidation, is involved in the whole course of retinal IR in mice. Correspondingly, all three types of RGCs death were found in retina samples from human glaucoma donors. Further, inhibitors of apoptosis, necroptosis, and ferroptosis (z-VAD-FMK, Necrostatin-1, and Ferrostatin-1, respectively) all exhibited marked RGC protection against IR both in mice and primary cultured RGCs, with Ferrostatin-1 conferring the best therapeutic effect, suggesting ferroptosis plays a more prominent role in the process of RGC death. We also found that activated microglia, Müller cells, immune responses, and intracellular reactive oxygen species accumulation following IR were significantly mitigated after each inhibitor treatment, albeit to varying degrees. Moreover, Ferrostatin-1 in combination with z-VAD-FMK and Necrostatin-1 prevented IR-induced RGC death better than any inhibitor alone. These findings stand to advance our knowledge of the post-IR RGC death cascade and guide future therapy for RGC protection.

CO2 Laser-Assisted Sclerectomy Surgery Alone or Combined with Phacoemulsification in Primary Open-Angle Glaucoma: Comparison of 1-Year Outcomes.

INTRODUCTION: To compare 1-year outcomes of CO2 laser-assisted sclerectomy surgery (CLASS) alone or combined with phacoemulsification (CLASS + Phaco) in eyes with primary open-angle glaucoma (POAG). METHODS: This was a prospective, comparative, case series study. A total of 46 eyes with POAG underwent CLASS or CLASS + Phaco were followed up for 1 year. The primary outcomes included changes in intraocular pressure (IOP), medication and best corrected visual acuity (BCVA). The secondary outcomes were success rate, functional bleb, postoperative laser intervention and complications. RESULTS: CLASS alone resulted in a greater IOP reduction compared with CLASS + Phaco. BCVA improved remarkably in CLASS + Phaco group, but there was no difference in BCVA before and after CLASS. The number of antiglaucoma medications significantly decreased at 12 months postoperatively in both groups. Functional blebs were more commonly seen in the CLASS than combination group. The overall success rate was higher in the CLASS than CLASS + Phaco group at 1 year after surgery. The incidence of peripheral anterior synechiae (PAS) in CLASS + Phaco group was significantly lower than that of CLASS alone. CONCLUSION: CLASS alone achieved a greater IOP reduction, more common functional bleb formation and a higher success rate compared to CLASS combined with Phaco, while combination surgery yielded a better BCVA improvement and a lower PAS incidence than CLASS alone. Both surgical strategies have favorable safety and efficacy among POAG patients. Combined surgery could be a viable option for patients with co-existing POAG and cataract.

Corneal in vivo Confocal Microscopy for Assessment of Non-Neurological Autoimmune Diseases: A Meta-Analysis.

Purpose: This study aimed to evaluate the features of corneal nerve with in vivo confocal microscopy (IVCM) among patients with non-neurological autoimmune (NNAI) diseases. Methods: We systematically searched PubMed, Web of Science, and Cochrane Central Register of Controlled Trials for studies published until May 2021. The weighted mean differences (WMDs) of corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), tortuosity, reflectivity, and beadings per 100 µm with a 95% CI between NNAI and control group were analyzed using a random-effects model. Results: The results showed 37 studies involving collective totals of 1,423 patients and 1,059 healthy controls were ultimately included in this meta-analysis. The pooled results manifested significantly decreased CNFL (WMD: -3.94, 95% CI: -4.77--3.12), CNFD (WMD: -6.62, 95% CI: -8.4--4.85), and CNBD (WMD: -9.89, 95% CI: -14--5.79) in NNAI patients. In addition, the NNAI group showed more tortuous corneal nerve (WMD: 1.19, 95% CI:0.57-1.81). The comparison between NNAI patients and healthy controls in beadings per 100 µm corneal nerve length was inconsistent. No significant difference was found in the corneal nerve fiber reflectivity between NNAI and the control group (WMD: -0.21, 95% CI: -0.65-0.24, P = 0.361). Conclusions: The parameters and morphology of corneal nerves observed by IVCM proved to be different in NNAI patients from healthy controls, suggesting that IVCM may be a non-invasive technique for identification and surveillance of NNAI diseases.

Analysis of macular microvasculature with optical coherence tomography angiography for migraine: A systematic review and meta-analysis.

Objective: This study aimed to evaluate the features of macular microvasculature with optical coherence tomography angiography (OCTA) among migraine patients. Methods: We systematically searched PubMed, Web of Science, Embase, and Cochrane Library for studies that evaluated the macular microvasculature of migraine patients. The weighted mean differences (WMDs) of the foveal avascular zone (FAZ), foveal superficial capillary plexus (SCP) vessel density (VD), parafoveal SCP VD, foveal deep capillary plexus (DCP) VD, and parafoveal DCP VD with 95% confidence intervals (CIs) among migraine with aura (MA) group, migraine without aura (MO) group, and healthy controls (HC) group were analyzed using a random-effect model. P < 0.05 was considered significant in statistical analyses. Publication bias was assessed using funnel plots and statistical tests (Egger's test and Begg's test). Results: Nine studies covering 675 individuals were enrolled in this meta-analysis ultimately. The FAZ of MA patients was not significantly different from HC (WMD = 0.04, 95% CI -0.00 to 0.09). However, the FAZ of MA was significantly larger than that of HC after correction of publication bias by trim and fill method (WMD = 1.03, 95% CI 0.99 to 1.08). The FAZ of MO patients was similar to that of HC (WMD = 0.03, 95% CI -0.00 to 0.07), while smaller than that of MA patients (WMD = 0.05, 95% CI 0.01 to 0.09). VD of the SCP, either in the foveal or parafoveal area, was not significantly different among the three groups. As for DCP, VD in MA patients was lower when compared with HC in the parafovea (WMD = -1.20, 95% CI -1.88 to -0.51). Conclusions: We found that there was a larger FAZ in MA compared with HC after adjusting for publication bias. The FAZ in MO was not significantly different from that in HC, but significantly lower than that in MA. There was no significant difference in either foveal or parafoveal VD of SCP among MA, MO, and HC participants, while the parafoveal VD of the DCP in MA was lower than that of the HC.