Stem cell transplantation rescued a primary open-angle glaucoma mouse model

Trabecular Meshwork Regeneration for Glaucoma Treatment Using Stem Cell-Derived Trophic Factors

Glaucoma is one of the leading causes of irreversible blindness. Stem cell therapy has shown promise in the treatment of primary open-angle glaucoma in animal models. Stem cell-free therapy using stem cell-derived trophic factors might be in demand in patients with high-risk conditions or religious restrictions. In this chapter, we describe methods for trabecular meshwork stem cell (TMSC) cultivation, secretome harvesting, and protein isolation, as well as assays to ensure the health of TMSC post-secretome harvesting and for secretome periocular injection into mice for therapeutic purposes.

Trabecular Meshwork Stem Cells for Glaucoma Treatment

Elevated intraocular pressure (IOP) is the most important risk factor for primary open-angle glaucoma (POAG) and currently is the only effective treatment target for glaucoma to prevent vision loss. In POAG patients, the trabecular meshwork (TM) cellularity is reduced which might be the main pathologic reason for the conventional outflow pathway dysfunction leading to elevated IOP. Stem cell-based therapy has been shown promising to reduce IOP and preserve retinal ganglion cells and their function in animal models. In this chapter, we describe the method details on TM stem cell cultivation and identification; induction for differentiation into different cell types, including differentiation to TM cell responsiveness to dexamethasone treatment with phagocytic function; and transplantation into mouse anterior chamber for therapeutic purposes.

Anesthetic effects on electrophysiological responses across the visual pathway

Anesthetics are widely used in electrophysiological tests to assess retinal and visual system functions to avoid experimental errors caused by movement and stress in experimental animals. To determine the most suitable anesthetic for visual electrophysiological tests, excluding ketamine and chloral hydrate due to regulatory and side effect concerns, this study investigated the effects of ethyl carbamate (EC), avertin (AR), and pentobarbital sodium (PS) on visual signal conduction in the retina and primary visual cortex. Assessments included flash electroretinogram (FERG), pattern electroretinogram (PERG), pattern visual evoked potentials (PVEP), and flash visual evoked potentials (FVEP), FERG and FVEP were used to evaluate the responses of the retina and visual cortex to flash stimuli, respectively, while PERG and PVEP assessed responses to pattern stimuli. The research showed that AR demonstrates the least disruption to the visual signal pathway, as evidenced by consistently high characteristic peaks in the AR group across various tests. In contrast, mice given EC exhibited the lowest peak values in both FERG and FVEP, while subjects anesthetized with PS showed suppressed oscillatory potentials and PERG responses. Notably, substantial PVEP characteristic peaks were observed only in mice anesthetized with AR. Consequently, among the three anesthetics tested, AR is the most suitable for visual electrophysiological studies.

iPSC-derived cells stimulate ABCG2+/NES+ endogenous trabecular meshwork cell proliferation and tissue regeneration

A major risk factor for glaucoma, the first leading cause of irreversible blindness worldwide, is the decellularisation of the trabecular meshwork (TM) in the conventional outflow pathway. Stem cell-based therapy, particularly the utilisation of induced pluripotent stem cells (iPSCs), presents an enticing potential for tissue regeneration and intraocular pressure (IOP) maintenance in glaucoma. We have previously observed that differentiated iPSCs can stimulate endogenous cell proliferation in the TM, a pivotal factor in TM regeneration and aqueous humour outflow restoration. In this study, we investigated the response of TM cells in vivo after interacting with iPSC-derived cells and identified two subpopulations responsible for this relatively long-term tissue regeneration: ATP Binding Cassette Subfamily G Member 2 (ABCG2)-positive cells and Nestin (NES)-positive cells. We further uncovered that alterations of these responsive cells are linked to ageing and different glaucoma etiologies, suggesting that ABCG2+ subpopulation decellularization could serve as a potential risk factor for TM decellularization in glaucoma. Taken together, our findings illustrated the proliferative subpopulations in the conventional outflow pathway when stimulated with iPSC-derived cells and defined them as TM precursors, which may be applied to develop novel therapeutic approaches for glaucoma.

Magnetically Steered Cell Therapy For Functional Restoration Of Intraocular Pressure Control In Open-Angle Glaucoma

Trabecular meshwork (TM) cell therapy has been proposed as a next-generation treatment for elevated intraocular pressure (IOP) in glaucoma, the most common cause of irreversible blindness. Using a magnetic cell steering technique with excellent efficiency and tissue-specific targeting, we delivered two types of cells into a mouse model of glaucoma: either human adipose-derived mesenchymal stem cells (hAMSCs) or induced pluripotent cell derivatives (iPSC-TM cells). We observed a 4.5 [3.1, 6.0] mmHg or 27% reduction in intraocular pressure (IOP) for nine months after a single dose of only 1500 magnetically-steered hAMSCs, associated with restoration of function to the conventional outflow pathway, as judged by increased outflow facility and TM cellularity. iPSC-TM cells were also effective, but less so, showing only a 1.9 [0.4, 3.3] mmHg or 13% IOP reduction and increased risk of tumorigenicity. In both cases, injected cells remained detectable in the iridocorneal angle three weeks post-transplantation. Based on the locations of the delivered cells, the mechanism of IOP lowering is most likely paracrine signaling. We conclude that magnetically-steered hAMSC cell therapy has potential for long-term treatment of ocular hypertension in glaucoma.

One Sentence Summary

A novel magnetic cell therapy provided effective intraocular pressure control in a mouse model of glaucoma, motivating future translational studies.

Regenerative treatment of ophthalmic diseases with stem cells: Principles, progress, and challenges

Background

Degenerate eye disorders, such as glaucoma, cataracts and age-related macular degeneration (AMD), are prevalent causes of blindness and visual impairment worldwide. Other eye disorders, including limbal stem cell deficiency (LSCD), dry eye diseases (DED), and retinitis pigmentosa (RP), result in symptoms such as ocular discomfort and impaired visual function, significantly impacting quality of life. Traditional therapies are limited, primarily focus on delaying disease progression, while emerging stem cell therapy directly targets ocular tissues, aiming to restore ocular function by reconstructing ocular tissue.

Main text

The utilization of stem cells for the treatment of diverse degenerative ocular diseases is becoming increasingly significant, owing to the regenerative and malleable properties of stem cells and their functional cells. Currently, stem cell therapy for ophthalmopathy involves various cell types, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), and retinal progenitor cells (RPCs). In the current article, we will review the current progress regarding the utilization of stem cells for the regeneration of ocular tissue covering key eye tissues from the cornea to the retina. These therapies aim to address the loss of functional cells, restore damaged ocular tissue and or in a paracrine-mediated manner. We also provide an overview of the ocular disorders that stem cell therapy is targeting, as well as the difficulties and opportunities in this field.

Conclusions

Stem cells can not only promote tissue regeneration but also release exosomes to mitigate inflammation and provide neuroprotection, making stem cell therapy emerge as a promising approach for treating a wide range of eye disorders through multiple mechanisms.

Intraocular pressure across the lifespan of Tg-MYOCY437H mice

Transgenic C57BL/6 mice expressing human myocilinY437 (Tg-MYOCY437H) are a well-established model for primary open-angle glaucoma (POAG). While the reduced trabecular meshwork (TM) cellularity due to severe endoplasmic reticulum (ER) stress has been characterized as the etiology of this model, there is a limited understanding of how glaucomatous phenotypes evolve over the lifespan of Tg-MyocY437H mice. In this study, we compiled the model's intraocular pressure (IOP) data recorded in our laboratory from 2017 to 2023 and selected representative eyes to measure the outflow facility (Cr), a critical parameter indicating the condition of the conventional TM pathway. We found that Tg-MYOCY437H mice aged 4-12 months exhibited significantly higher IOPs than age-matched C57BL/6 mice. Notably, a decline in IOP was observed in Tg-MYOCY437H mice at 17-24 months of age, a phenomenon not attributable to the gene dosage of mutant myocilin. Measurements of the Cr of Tg-MYOCY437H mice indicated that the age-related IOP reduction was not a result of ongoing TM damage. Instead, Hematoxylin and Eosin staining, immunohistochemistry analysis, and transmission electron microscopic examination revealed that this reduction might be induced by degenerations of the non-pigmented epithelium in the ciliary body of aged Tg-MYOCY437H mice. Overall, our findings provide a comprehensive profile of mutant myocilin-induced ocular changes over the Tg-MYOCY437H mouse lifespan and suggest a specific temporal window of elevated IOP that may be ideal for experimental purposes.

Future directions of glaucoma treatment: emerging gene, neuroprotection, nanomedicine, stem cell, and vascular therapies

PURPOSE OF REVIEW

The aim of this article is to summarize current research on novel gene, stem cell, neuroprotective, nanomedicine, and vascular therapies for glaucoma.

RECENT FINDINGS

Gene therapy using viral vectors and siRNA have been shown to reduce intraocular pressure by altering outflow and production of aqueous humor, to reduce postsurgical fibrosis with few adverse effects, and to increase retinal ganglion cell (RGC) survival in animal studies. Stem cells may treat glaucoma by replacing or stimulating proliferation of trabecular meshwork cells, thus restoring outflow facility. Stem cells can also serve a neuroprotective effect by differentiating into RGCs or preventing RGC loss via secretion of growth factors. Other developing neuroprotective glaucoma treatments which can prevent RGC death include nicotinamide, the NT-501 implant which secretes ciliary neurotrophic factor, and a Fas-L inhibitor which are now being tested in clinical trials. Recent studies on vascular therapy for glaucoma have focused on the ability of Rho Kinase inhibitors and dronabinol to increase ocular blood flow.

SUMMARY

Many novel stem cell, gene, neuroprotective, nanomedicine, and vascular therapies have shown promise in preclinical studies, but further clinical trials are needed to demonstrate safety and efficacy in human glaucomatous eyes. Although likely many years off, future glaucoma therapy may take a multifaceted approach.

Genetic rodent models of glaucoma in representing disease phenotype and insights into the pathogenesis

Genetic rodent models are widely used in glaucoma related research. With vast amount of information revealed by human studies about genetic correlations with glaucoma, use of these models is relevant and required. In this review, we discuss the glaucoma endophenotypes and importance of their representation in an experimental animal model. Mice and rats are the most popular animal species used as genetic models due to ease of genetic manipulations in these animal species as well as the availability of their genomic information. With technological advances, induction of glaucoma related genetic mutations commonly observed in human is possible to achieve in rodents in a desirable manner. This approach helps to study the pathobiology of the disease process with the background of genetic abnormalities, reveals potential therapeutic targets and gives an opportunity to test newer therapeutic options. Various genetic manipulation leading to appearance of human relevant endophenotypes in rodents indicate their relevance in glaucoma pathology and the utility of these rodent models for exploring various aspects of the disease related to targeted mutation. The molecular pathways involved in the pathophysiology of glaucoma leading to elevated intraocular pressure and the disease hallmark, apoptosis of retinal ganglion cells and optic nerve degeneration, have been extensively explored in genetic rodent models. In this review, we discuss the consequences of various genetic manipulations based on the primary site of pathology in the anterior or the posterior segment. We discuss how these genetic manipulations produce features in rodents that can be considered a close representation of disease phenotype in human. We also highlight several molecular mechanisms revealed by using genetic rodent models of glaucoma including those involved in increased aqueous outflow resistance, loss of retinal ganglion cells and optic neuropathy. Lastly, we discuss the limitations of the use of genetic rodent models in glaucoma related research.

Posterior corneoscleral limbus: Architecture, stem cells, and clinical implications

The limbus is a transition from the cornea to conjunctiva and sclera. In human eyes, this thin strip has a rich variation of tissue structures and composition, typifying a change from scleral irregularity and opacity to corneal regularity and transparency; a variation from richly vascularized conjunctiva and sclera to avascular cornea; the neural passage and drainage of aqueous humor. The limbal stroma is enriched with circular fibres running parallel to the corneal circumference, giving its unique role in absorbing small pressure changes to maintain corneal curvature and refractivity. It contains specific niches housing different types of stem cells for the corneal epithelium, stromal keratocytes, corneal endothelium, and trabecular meshwork. This truly reflects the important roles of the limbus in ocular physiology, and the limbal functionality is crucial for corneal health and the entire visual system. Since the anterior limbus containing epithelial structures and limbal epithelial stem cells has been extensively reviewed, this article is focused on the posterior limbus. We have discussed the structural organization and cellular components of the region beneath the limbal epithelium, the characteristics of stem cell types: namely corneal stromal stem cells, endothelial progenitors and trabecular meshwork stem cells, and recent advances leading to the emergence of potential cell therapy options to replenish their respective mature cell types and to correct defects causing corneal abnormalities. We have reviewed different clinical disorders associated with defects of the posterior limbus and summarized the available preclinical and clinical evidence about the developing topic of cell-based therapy for corneal disorders.

Improved magnetic delivery of cells to the trabecular meshwork in mice

Glaucoma is the leading cause of irreversible blindness worldwide and its most prevalent subtype is primary open angle glaucoma (POAG). One pathological change in POAG is loss of cells in the trabecular meshwork (TM), which is thought to contribute to ocular hypertension and has thus motivated development of cell-based therapies to refunctionalize the TM. TM cell therapy has shown promise in intraocular pressure (IOP) control, but existing cell delivery techniques suffer from poor delivery efficiency. We employed a novel magnetic delivery technique to reduce the unwanted side effects of off-target cell delivery. Mesenchymal stem cells (MSCs) were labeled with superparamagnetic iron oxide nanoparticles (SPIONs) and after intracameral injection were magnetically steered towards the TM using a focused magnetic apparatus ("point magnet"). This technique delivered the cells significantly closer to the TM at higher quantities and with more circumferential uniformity compared to either unlabeled cells or those delivered using a "ring magnet" technique. We conclude that our point magnet cell delivery technique can improve the efficiency of TM cell therapy and in doing so, potentially increase the therapeutic benefits and lower the risk of complications such as tumorigenicity and immunogenicity.

Recreating the Trabecular Outflow Tissue on Implantable, Micropatterned, Ultrathin, Porous Polycaprolactone Scaffolds

Glaucoma, where increased intraocular pressure (IOP) leads to damage to the optic nerve and loss of sight, is amongst the foremost causes of irreversible blindness worldwide. In primary open angle glaucoma, the increased IOP is a result of the malfunctioning human trabecular meshwork (HTM) cells' inability to properly regulate the outflow of aqueous humor from the eye. A potential future treatment for glaucoma is to replace damaged HTM cells with a tissue-engineered substitute, thus restoring proper fluid outflow. Polycaprolactone (PCL) is a versatile, biodegradable, and implantable material that is widely used for cell culture and tissue engineering. In this work, PCL scaffolds were lithographically fabricated using a sacrificial process to produce submicron-thick scaffolds with openings of specific sizes and shapes (e.g., grid, hexagonal pattern). The HTM cell growth on gelatin-coated PCL scaffolds was assessed by scanning electron microscopy, tetrazolium metabolic activity assay, and cytoskeletal organization of F-actin. Expression of HTM-specific markers and ECM deposition were assessed by immunocytochemistry and qPCR analysis. Gelatin-coated, micropatterned, ultrathin, porous PCL scaffolds with a grid pattern supported proper HTM cell growth, cytoskeleton organization, HTM-marker expression, and ECM deposition, demonstrating the feasibility of using these PCL scaffolds to tissue-engineer implantable, healthy ocular outflow tissue.

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.

A novel glaucoma approach: Stem cell regeneration of the trabecular meshwork

Glaucoma is the leading cause of global irreversible blindness, necessitating research for new, more efficacious treatment options than currently exist. Trabecular meshwork (TM) cells play an important role in the maintenance and function of the aqueous outflow pathway, and studies have found that there is decreased cellularity of the TM in glaucoma. Regeneration of the TM with stem cells has been proposed as a novel therapeutic option by several reports over the last few decades. Stem cells have the capacity for self-renewal and the potential to differentiate into adult functional cells. Several types of stem cells have been investigated in ocular regenerative medicine: tissue specific stem cells, embryonic stem cells, induced pluripotent stem cells, and adult mesenchymal stem cells. These cells have been used in various glaucoma animal models and ex vivo models and have shown success in IOP homeostasis and TM cellularity restoration. They have also demonstrated stability without serious side effects for a significant period of time. Based on current knowledge of TM pathology in glaucoma and existing literature regarding stem cell regeneration of this tissue, we propose a human clinical study as the next step in understanding this potentially revolutionary treatment paradigm. The ability to protect and replace TM cells in glaucomatous eyes could change the field forever.

Differential Retinal Ganglion Cell Vulnerability, A Critical Clue for the Identification of Neuroprotective Genes in Glaucoma

Retinal ganglion cells (RGCs) are the neurons in the retina which directly project to the brain and transmit visual information along the optic nerve. Glaucoma, one of the leading causes of blindness, is characterized by elevated intraocular pressure (IOP) and degeneration of the optic nerve, which is followed by RGC death. Currently, there are no clinical therapeutic drugs or molecular interventions that prevent RGC death outside of IOP reduction. In order to overcome these major barriers, an increased number of studies have utilized the following combined analytical methods: well-established rodent models of glaucoma including optic nerve injury models and transcriptomic gene expression profiling, resulting in the successful identification of molecules and signaling pathways relevant to RGC protection. In this review, we present a comprehensive overview of pathological features in a variety of animal models of glaucoma and top differentially expressed genes (DEGs) depending on disease progression, RGC subtypes, retinal regions or animal species. By comparing top DEGs among those different transcriptome profiles, we discuss whether commonly listed DEGs could be defined as potential novel therapeutic targets in glaucoma, which will facilitate development of future therapeutic neuroprotective strategies for treatments of human patients in glaucoma.

Magnetic Nano-Platform Enhanced iPSC-Derived Trabecular Meshwork Delivery and Tracking Efficiency

Purpose

Transplantation of stem cells to remodel the trabecular meshwork (TM) has become a new option for restoring aqueous humor dynamics and intraocular pressure homeostasis in glaucoma. In this study, we aimed to design a nanoparticle to label induced pluripotent stem cell (iPSC)-derived TM and improve the delivery accuracy and in vivo tracking efficiency.

Methods

PLGA-SPIO-Cypate (PSC) NPs were designed with polylactic acid-glycolic acid (PLGA) polymers as the backbone, superparamagnetic iron oxide (SPIO) nanoparticles, and near-infrared (NIR) dye cypate. In vitro assessment of cytotoxicity, iron content after NPs labeling, and the dual-model monitor was performed on mouse iPSC-derived TM (miPSC-TM) cells, as well as immortalized and primary human TM cells. Cell function after labeling, the delivery accuracy, in vivo tracking efficiency, and its effect on lowering IOP were evaluated following miPSC-TM transplantation in mice.

Results

Initial in vitro experiments showed that a single-time nanoparticles incubation was sufficient to label iPSC-derived TM and was not related to any change in both cell viability and fate. Subsequent in vivo evaluation revealed that the use of this nanoparticle not only improves the delivery accuracy of the transplanted cells in live animals but also benefits the dual-model tracking in the long term. More importantly, the use of the magnet triggers a temporary enhancement in the effectiveness of cell-based therapy in alleviating the pathologies associated with glaucoma.

Conclusion

This study provided a promising approach for enhancing both the delivery and in vivo tracking efficiency of the transplanted cells, which facilitates the clinical translation of stem cell-based therapy for glaucoma.

Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms

Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.

Replacement of the Trabecular Meshwork Cells-A Way Ahead in IOP Control?

Glaucoma is one of the leading causes of vision loss worldwide, characterised with irreversible optic nerve damage and progressive vision loss. Primary open-angle glaucoma (POAG) is a subset of glaucoma, characterised by normal anterior chamber angle and raised intraocular pressure (IOP). Reducing IOP is the main modifiable factor in the treatment of POAG, and the trabecular meshwork (TM) is the primary site of aqueous humour outflow (AH) and the resistance to outflow. The structure and the composition of the TM are key to its function in regulating AH outflow. Dysfunction and loss of the TM cells found in the natural ageing process and more so in POAG can cause abnormal extracellular matrix (ECM) accumulation, increased TM stiffness, and increased IOP. Therefore, repair or regeneration of TM's structure and function is considered as a potential treatment for POAG. Cell transplantation is an attractive option to repopulate the TM cells in POAG, but to develop a cell replacement approach, various challenges are still to be addressed. The choice of cell replacement covers autologous or allogenic approaches, which led to investigations into TM progenitor cells, induced pluripotent stem cells (iPSCs), and mesenchymal stem cells (MSCs) as potential stem cell source candidates. However, the potential plasticity and the lack of definitive cell markers for the progenitor and the TM cell population compound the biological challenge. Morphological and differential gene expression of TM cells located within different regions of the TM may give rise to different cell replacement or regenerative approaches. As such, this review describes the different approaches taken to date investigating different cell sources and their differing cell isolation and differentiation methodologies. In addition, we highlighted how these approaches were evaluated in different animal and ex vivo model systems and the potential of these methods in future POAG treatment.

Cell-Based Therapies for Trabecular Meshwork Regeneration to Treat Glaucoma

Glaucoma is clinically characterized by elevated intraocular pressure (IOP) that leads to retinal ganglion cell (RGC) and optic nerve damage, and eventually blindness if left untreated. Even in normal pressure glaucoma patients, a reduction of IOP is currently the only effective way to prevent blindness, by either increasing aqueous humor outflow or decreasing aqueous humor production. The trabecular meshwork (TM) and the adjacent Schlemm’s canal inner wall play a key role in regulating IOP by providing resistance when aqueous humor drains through the tissue. TM dysfunction seen in glaucoma, through reduced cellularity, abnormal extracellular matrix accumulation, and increased stiffness, contributes to elevated IOP, but current therapies do not target the TM tissue. Stem cell transplantation for regeneration and re-functionalization of damaged TM has shown promise in providing a more direct and effective therapy for glaucoma. In this review, we describe the use of different types of stem cells for TM regeneration in glaucoma models, the mechanisms of regeneration, and the potential for glaucoma treatment using autologous stem cell transplantation.

iPSC-Derived Trabecular Meshwork Cells Stimulate Endogenous TM Cell Division Through Gap Junction in a Mouse Model of Glaucoma

Purpose

Decreased trabecular meshwork (TM) cellularity has been implicated as a major reason for TM dysfunction and aqueous humor (AH) outflow abnormalities in primary open angle glaucoma. We previously found that transplantation of induced pluripotent stem cell (iPSC)-derived TM cells can restore TM function and stimulate endogenous TM cell division. The goal of the present study is to investigate whether signaling via gap junctions is involved in this process.

Methods

Differentiated iPSCs were characterized morphologically, transcriptionally, and immunohistochemically. After purification, iPSC-TM were co-cultured with mouse TM (MTM) cells to mimic the transplantation procedure. Through the pharmacological antagonists and short hairpin RNA (shRNA) technique, the gap junction function in iPSC-based therapy was determined.

Results

In the co-culture system, iPSC-TM increase MTM cell division as well as transfer of Ca2+ to MTM. This effect was blocked by treatment with the gap junction inhibitors carbenoxolone (CBX) or flufenamic acid (FFA). The shRNA mediated knock down of connexin 43 (Cx43) expression in iPSC-TM also results in decreased Ca2+ transfer and lower MTM proliferation rates. In vivo, Cx43 downregulation in transplanted iPSC-TM weakened their regenerative role in an Ad5.myocilinY437H mouse model of glaucoma. Mice receiving these cells exhibited lower TM cellularity and higher intraocular pressure (IOP) than those receiving unmodified iPSC-TM.

Conclusions

Our findings reveal a crucial role of gap junction, especially Cx43, in iPSC-based TM regeneration, and provides insights to enhance the regenerative effect of iPSCs in glaucoma therapy.