A 3D Model of Human Trabecular Meshwork for the Research Study of Glaucoma

Magnetic-Guided Delivery of Antisense Oligonucleotides for Targeted Transduction in Multiple Retinal Explant and Organoid Models

Antisense oligonucleotide (ASO) therapy holds promise in gene therapy but faces challenges due to poor delivery efficiency and limited evaluation models. This investigation employs magnetic nanoparticles (MNPs) to augment the delivery efficiency of ASOs. It assesses their distribution and therapeutic efficacy across various models, including retinal explants from mice and macaques or human retinal and inner ear organoids. Retinal explants from both mice and monkeys are methodically arranged to expose the ganglion cell layer (GCL) or the photoreceptor layer (PL). MNPs markedly enhanced the penetration and targeting of ASOs, resulting in a 60% accumulation in the GCL or 72% in the photoreceptors. Furthermore, an in vitro biomimetic model of the neuroretina-RPE/choroid-sclera complex is developed to examine ASO distribution under dynamic flow conditions. Moreover, the utilization of MNP-assisted ASO-Cy3 markedly enhanced transfection efficiency within human retinal and inner ear organoids, resulting in an increase in positively transfected cells to 60% and 70%, respectively. Here, for the first time, an MNP-explant-organoid platform is carried out for the promotion of ASO transfection efficiency, therapeutic screening and targeted delivery. This development paves the way for investigating novel gene therapy strategies targeting retinal diseases.

Risk factors for self-reports of diagnosed cataracts among older adults in Poland

PURPOSE

The aim of our study was to investigate sociodemographic factors, comorbidities and health behaviors associated with self-reported diagnosed cataracts in a large, nationally representative population of older adults in Poland, aged 60 and older.

PATIENT AND METHODS

An analysis was conducted using a survey of 5956 participants in the nationally representative PolSenior2 study conducted between 2018 and 2019. Multiple logistic regression analysis was used to evaluate the associations between self-reports of diagnosed cataracts and sociodemographic factors, health behaviors, and comorbidities.

RESULTS

According to the final multivariable model, the odds ratio (OR) of self-reported cataract diagnosis was 1.71 times greater for women than for men. Additionally, the odds increased significantly with age, with 70-79-year-olds having 3.38 times greater odds, 80-89-year-olds having 8.08 times greater odds, and those aged 90 years and older having 10.76 times greater odds than did the reference group (60-69 years old). The prevalence of self-reported diagnosed cataracts was found to be 1.47 times greater among individuals with diabetes, 1.20 times greater among those with hypertension, and 1.25 times greater among tobacco users than among their respective counterparts. Additionally, rural dwellers exhibited a lower risk of self-reported cataracts (OR = 0.63).

CONCLUSION

Our study revealed a positive relationship between several demographic and health factors-namely, older age, female sex, urban residence, hypertension, diabetes, and smoking-and an elevated risk of self-reports of diagnosed cataracts.

Application of Single Cell Type-Derived Spheroids Generated by Using a Hanging Drop Culture Technique in Various In Vitro Disease Models: A Narrow Review

Cell culture methods are indispensable strategies for studies in biological sciences and for drug discovery and testing. Most cell cultures have been developed using two-dimensional (2D) culture methods, but three-dimensional (3D) culture techniques enable the establishment of in vitro models that replicate various pathogenic conditions and they provide valuable insights into the pathophysiology of various diseases as well as more precise results in tests for drug efficacy. However, one difficulty in the use of 3D cultures is selection of the appropriate 3D cell culture technique for the study purpose among the various techniques ranging from the simplest single cell type-derived spheroid culture to the more sophisticated organoid cultures. In the simplest single cell type-derived spheroid cultures, there are also various scaffold-assisted methods such as hydrogel-assisted cultures, biofilm-assisted cultures, particle-assisted cultures, and magnet particle-assisted cultures, as well as non-assisted methods, such as static suspension cultures, floating cultures, and hanging drop cultures. Since each method can be differently influenced by various factors such as gravity force, buoyant force, centrifugal force, and magnetic force, in addition to non-physiological scaffolds, each method has its own advantages and disadvantages, and the methods have different suitable applications. We have been focusing on the use of a hanging drop culture method for modeling various non-cancerous and cancerous diseases because this technique is affected only by gravity force and buoyant force and is thus the simplest method among the various single cell type-derived spheroid culture methods. We have found that the biological natures of spheroids generated even by the simplest method of hanging drop cultures are completely different from those of 2D cultured cells. In this review, we focus on the biological aspects of single cell type-derived spheroid culture and its applications in in vitro models for various diseases.

Artificial Trabecular Meshwork Structure Combining Melt Electrowriting and Solution Electrospinning

The human trabecular meshwork (HTM) is responsible for regulating intraocular pressure (IOP) by means of gradient porosity. Changes in its physical properties, like increases in stiffness or alterations in the extracellular matrix (ECM), are associated with increases in the IOP, which is the primary cause of glaucoma. The complexity of its structure limits the engineered models to one-layered and simple approaches, which do not accurately replicate the biological and physiological cues related to glaucoma. Here, a combination of melt electrowriting (MEW) and solution electrospinning (SE) is explored as a biofabrication technique used to produce a gradient porous scaffold that mimics the multi-layered structure of the native HTM. Polycaprolactone (PCL) constructs with a height of 20-710 µm and fiber diameters of 0.7-37.5 µm were fabricated. After mechanical characterization, primary human trabecular meshwork cells (HTMCs) were seeded over the scaffolds within the subsequent 14-21 days. In order to validate the system's responsiveness, cells were treated with dexamethasone (Dex) and the rho inhibitor Netarsudil (Net). Scanning electron microscopy and immunochemistry staining were performed to evaluate the expected morphological changes caused by the drugs. Cells in the engineered membranes exhibited an HTMC-like morphology and a correct drug response. Although this work demonstrates the utility of combining MEW and SE in reconstructing complex morphological features like the HTM, new geometries and dimensions should be tested, and future works need to be directed towards perfusion studies.

Antioxidative effects of ghrelin on human trabecular meshwork cells

Glaucoma is a group of neurodegenerative diseases characterized by loss of retinal ganglion cells and visual field defects and is one of the major causes of irreversible blindness worldwide. Primary open-angle glaucoma (POAG) is one of the classifications of glaucoma. Oxidative stress in trabecular reticulated cells is one of the possible mechanisms of the development of glaucoma. At present, there is still a lack of effective methods to treat glaucoma. Ghrelin is characterized by its wide distribution and high potency and has anti-inflammatory, antioxidant, and anti-apoptotic effects, which may be beneficial in the treatment of glaucoma. In this study, we investigated whether ghrelin can protect human trabecular meshwork cells (HTMCs) from oxidative damage induced by hydrogen peroxide (H2O2), as well as the possible mechanism of action. CCK8 and flow cytometry results revealed that treatment of HTMCs with ghrelin showed a dose-dependent protective effect against H2O2-induced damage. Ghrelin significantly decreased the rate of apoptosis and levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the level of superoxide dismutase (SOD) and catalase (CAT) in HTMCs. The difference was statistically significant compared with the H2O2 group. Ghrelin activated Nrf2/HO-1/NQO-1 signaling pathways and decreased HIF-1α level in H2O2-injured HTMCs as shown on qPCR and Western blot. In conclusion, ghrelin can protect HTMCs from oxidative damage induced by H2O2 and reduce apoptosis in HTMCs, which can be a new approach to treating POAG. The underlying therapeutic mechanism may be related to Nrf2/HO-1/NQO-1 signaling pathways and HIF-1α.

An Overview of Current Glaucomatous Trabecular Meshwork Models

PURPOSE

To provide an overview of the existing alternative models for studying trabecular meshwork (TM).

METHODS

Literature review.

RESULTS

The TM is a complex tissue that regulates aqueous humor outflow from the eye. Dysfunction of the TM is a major contributor to the pathogenesis of open-angle glaucoma, a leading cause of irreversible blindness worldwide. The TM is a porous structure composed of trabecular meshwork cells (TMC) within a multi-layered extracellular matrix (ECM). Although dysregulation of the outflow throughout the TM represents the first step in the disease process, the underlying mechanisms of TM degeneration associate cell loss and accumulation of ECM, but remain incompletely understood, and drugs targeting the TM are limited. Therefore, experimental models of glaucomatous trabeculopathy are necessary for preclinical screening, to advance research on this disease's pathophysiology, and to develop new therapeutic strategies targeting the TM. Traditional animal models have been used extensively, albeit with inherent limitations, including ethical concerns and limited translatability to humans. Consequently, there has been an increasing focus on developing alternative in vitro models to study the TM. Recent advancements in three-dimensional cell culture and tissue engineering are still in their early stages and do not yet fully reflect the complexity of the outflow pathway. However, they have shown promise in reducing reliance on animal experimentation in certain aspects of glaucoma research.

CONCLUSION

This review provides an overview of the existing alternative models for studying TM and their potential for advancing research on the pathophysiology of open-angle glaucoma and developing new therapeutic strategies.

Nanofibrous PCL-Based Human Trabecular Meshwork for Aqueous Humor Outflow Studies

Primary open-angle glaucoma is characterized by the progressive degeneration of the optic nerve, with the high intraocular pressure (IOP) being one of the main risk factors. The human trabecular meshwork (HTM), specifically the juxtacanalicular tissue (JCT), is responsible for placing resistance to the aqueous humor (AH) outflow and the resulting IOP control. Currently, the lack of a proper in vitro JCT model and the complexity of three-dimensional models impede advances in understanding the relationship between AH outflow and HTM degeneration. Therefore, we design an in vitro JCT model using a polycaprolactone (PCL) nanofibrous scaffold, which supports cells to recapitulate the functional JCT morphology and allow the study of outflow physiology. Mechanical and morphological characterizations of the electrospun membranes were performed, and human trabecular meshwork cells were seeded over the scaffolds. The engineered JCT was characterized by scanning electron microscopy, quantitative real-time polymerase chain reaction, and immunochemistry assays staining HTM cell markers and proteins. A pressure-sensitive perfusion system was constructed and used for the investigation of the outflow facility of the polymeric scaffold treated with dexamethasone (a glucocorticoid) and netarsudil (a novel IOP lowering the rho inhibitor). Cells in the in vitro model exhibited an HTM-like morphology, expression of myocilin, fibronectin, and collagen IV, genetic expression, outflow characteristics, and drug responsiveness. Altogether, the present work develops an in vitro JCT model to better understand HTM cell biology and the relationship between the AH outflow and the HTM and allow further drug screening of pharmacological agents that affect the trabecular outflow facility.

Through the Smoke: An In-Depth Review on Cigarette Smoking and Its Impact on Ocular Health

Smoking is a widespread and pervasive habit, impacting health across various care settings, including acute care, subacute care, home-based care, and long-term care. Smoking is a serious global public health concern that has been related to many chronic diseases. However, the effect of smoking on eye disorders has been less studied. Cigarette smoke contains a complex mixture of harmful constituents, including nicotine and toxic chemicals, which permeate the bloodstream, affecting ocular tissues. The oxidative stress and inflammation induced by smoking are central to its detrimental effects on ocular health. Age-related macular degeneration (AMD), a leading cause of vision loss, exhibits a strong association with smoking. Research consistently demonstrates that smokers face a heightened risk of both early and advanced AMD. Cataracts, another prevalent ocular condition, develop earlier and progress more rapidly in smokers. The oxidative stress on the lens and reduced antioxidants among smokers contribute to the increased severity of cataracts. Moreover, the health of the eyes may be compromised by smoking-related chemicals that reduce blood flow and/or hasten thrombus formation in ocular capillaries thus increasing the chance of acquiring glaucoma, cataracts, AMD, and Graves' eye disease. Beyond individual health concerns, the societal implications of smoking on ocular health are substantial, including increased healthcare costs and diminished quality of life for affected individuals. Understanding the underlying mechanisms can provide insights into potential therapeutic interventions for preventing and managing smoking-related ocular damage. Given the global prevalence of smoking, raising awareness about the ocular risks associated with smoking is crucial for promoting eye health. The review underscores the urgent need for comprehensive anti-smoking initiatives and smoking cessation programs to alleviate the burden of ocular diseases associated with smoking.

iPSCs-Based Therapy for Trabecular Meshwork

The trabecular meshwork (TM) of the eye serves as an essential tissue in controlling aqueous humor (AH) outflow and intraocular pressure (IOP) homeostasis. However, dysfunctional TM cells and/or decreased TM cellularity is become a critical pathogenic cause for primary open-angle glaucoma (POAG). Consequently, it is particularly valuable to investigate TM characteristics, which, in turn, facilitates the development of new treatments for POAG. Since 2006, the advancement in induced pluripotent stem cells (iPSCs) provides a new tool to (1) model the TM in vitro and (2) regenerate degenerative TM in POAG. In this context, we first summarize the current approaches to induce the differentiation of TM-like cells from iPSCs and compare iPSC-derived TM models to the conventional in vitro TM models. The efficacy of iPSC-derived TM cells for TM regeneration in POAG models is also discussed. Through these approaches, iPSCs are becoming essential tools in glaucoma modeling and for developing personalized treatments for TM regeneration.

Technological advances in ocular trabecular meshwork in vitro models for glaucoma research

Glaucoma is the leading cause of irreversible blindness worldwide and is characterized by the progressive degeneration of the optic nerve. Intraocular pressure (IOP), which is considered to be the main risk factor for glaucoma development, builds up in response to the resistance (resistance to what?) provided by the trabecular meshwork (TM) to aqueous humor (AH) outflow. Although the TM and its relationship to AH outflow have remained at the forefront of scientific interest, researchers remain uncertain regarding which mechanisms drive the deterioration of the TM. Current tissue-engineering fabrication techniques have come up with promising approaches to successfully recreate the TM. Nonetheless, more accurate models are needed to understand the factors that make glaucoma arise. In this review, we provide a chronological evaluation of the technological milestones that have taken place in the field of glaucoma research, and we conduct a comprehensive comparison of available TM fabrication technologies. Additionally, we also discuss AH perfusion platforms, since they are essential for the validation of these scaffolds, as well as pressure-outflow relationship studies and the discovery of new IOP-reduction therapies.