Rho-associated kinase inhibitors: A novel glaucoma therapy

Discovery of Dual ROCK1/2 Inhibitors from Nocardiopsis sp. under Metal Stress

Rho-associated protein kinase (ROCK) inhibitors are promising therapeutic agents for reducing elevated intraocular pressure in patients with glaucoma. We explored new ROCK inhibitors derived from bioactive metabolites produced by microbes, specifically cryptic metabolites from Nocardiopsis sp. MCY7, using a liquid chromatography-mass spectrometry-based chemical analysis approach integrated with metal stress-driven isolation. This strategy led to the identification of two previously undescribed linear peptides, nocarnickelamides A and B (1 and 2), and an unreported cittilin derivative, cittilin C (3). The planar structures of 1-3 were elucidated using UV spectroscopy, high-resolution mass spectrometry, and nuclear magnetic resonance. The absolute configurations of 1 and 2 were assigned using the advanced Marfey's method. Biological assays demonstrated that nocarnickelamides (1 and 2) exhibited dual inhibitory activity against ROCK1 (IC50 29.8 and 14.9 μM, respectively) and ROCK2 (IC50 27.0 and 21.9 μM, respectively), with molecular simulations suggesting binding to the ATP-binding site. In human trabecular meshwork cells, 2 significantly inhibited the activation of ROCK-regulated cytoskeletal contraction markers such as the myosin light chain. Nocarnickelamide B (2) is a novel dual ROCK1/2 inhibitor and a potential pharmacophore for designing new therapeutic agents to reduce intraocular pressure in glaucoma.

Dysregulation of septin cytoskeletal organization in the trabecular meshwork contributes to ocular hypertension

Ocular hypertension, believed to result partly from increased contractile activity, cell adhesive interactions, and stiffness within the trabecular meshwork (TM), is a major risk factor for glaucoma, a leading cause of blindness. However, the identity of molecular mechanisms governing organization of actomyosin and cell adhesive interactions in the TM remains limited. Based on our previous findings, in which proteomics analyses revealed elevated levels of septins, including septin-9 in human TM cells treated with the ocular hypertensive agent dexamethasone, here, we evaluated the effects of septin-9 overexpression, deficiency, and pharmacological targeting in TM cells. These studies demonstrated a profound impact on actomyosin organization, cell adhesion, contraction, and phagocytosis. Overexpression raised intraocular pressure (IOP) in mice, while inhibition increased cell permeability. In addition, we replicated a significant association between a common variant (rs9038) in SEPT9 with IOP in the Genetic Epidemiology Research on Adult Healthy and Aging (GERA) cohort. Collectively, these data reveal a link between dysregulated septin cytoskeletal organization in the TM and increased IOP, likely due to enhanced cell contraction, adhesive interactions, and fibrotic activity. This suggests that targeting the septin cytoskeleton could offer a novel approach for lowering IOP in patients with glaucoma.

Ocular effects of Rho kinase (ROCK) inhibition: a systematic review

Topical therapies targeting Rho-associated protein kinase (ROCK) signalling, including netarsudil (Rhopressa®) and ripasudil (Glanatec®), have become widely adopted as part of standard clinical practice to lower intraocular pressure (IOP) in patients with ocular hypertension or glaucoma. Given the pleiotropic roles of ROCK signalling, ROCK inhibition has the potential to cause unintended ocular side effects beyond IOP lowering in other substructures of the eye, both beneficial and deleterious. Additional experience and observation of patients treated with this class of medications have uncovered both new side effects not reported in the initial clinical trials, as well as potential benefits that have inspired off-label uses and that have been the topic of numerous clinical studies, case series, case reports, and translational studies. Here, we performed a comprehensive systematic review and identified 170 studies describing ocular effects of ROCK inhibition. In addition to describing well-established ocular effects associated with inhibition of ROCK signalling, such as conjunctival hyperaemia, corneal verticillata, and reticular corneal epithelial oedema, we also highlight other effects, such as corneal haemorrhages, changes in corneal contour, anterior subcapsular opacities, contact dermatitis, punctal stenosis, and eyelid wound dehiscence, which have been described in case series and case reports. Finally, we evaluated studies describing potential novel applications of ROCK inhibition for treating disorders affecting the cornea, the retina, and the optic nerve, finding strong evidence in support of a beneficial effect of ROCK inhibitors on corneal oedema due to corneal endothelial cell dysfunction. The other potential applications require further research.

Endothelial Rho kinase controls blood vessel integrity and angiogenesis

Background

The Rho kinases 1 and 2 (ROCK1/2) are serine-threonine specific protein kinases that control actin cytoskeleton dynamics. They are expressed in all cells throughout the body, including cardiomyocytes, smooth muscle cells and endothelial cells, and intimately involved in cardiovascular health and disease. Pharmacological ROCK inhibition is beneficial in mouse models of hypertension, atherosclerosis, and neointimal thickening that display overactivated ROCK. However, the consequences of endothelial ROCK signaling deficiency in vivo remain unknown. To address this issue, we analyzed endothelial cell (EC) specific ROCK1 and 2 deletions.

Methods

We generated Cdh5-CreERT2 driven, tamoxifen inducible loss of function alleles of ROCK1 and ROCK2 and analyzed mouse survival and vascular defects through cellular, biochemical, and molecular biology approaches.

Results

We observed that postnatal or adult loss of endothelial ROCK1 and 2 was lethal within a week. Mice succumbed to multi-organ hemorrhage that occurred because of loss of vascular integrity. ECs displayed deficient cytoskeletal actin polymerization that prevented focal adhesion formation and disrupted junctional integrity. Retinal sprouting angiogenesis was also perturbed, as sprouting vessels exhibited lack of polymerized actin and defective lumen formation. In a three-dimensional endothelial sprouting assay, combined knockdown of ROCK1/2 or knockdown or ROCK2 but not ROCK1 led to reduced sprouting, lumenization and cell polarization defects caused by defective actin and altered VE-cadherin dynamics. The isoform specific role of endothelial ROCK2 correlated with ROCK2 substrate specificity for FAK and LIMK. By analyzing single and three allele mutants we show that one intact allele of ROCK2 is sufficient to maintain vascular integrity in vivo.

Conclusion

Endothelial ROCK1 and 2 maintain junctional integrity and ensure proper angiogenesis and lumen formation. The presence of one allele of ROCK2 is sufficient to maintain vascular growth and integrity. These data indicate the need of careful consideration for the use of ROCK inhibitors in disease settings.

Glaucoma: Current and New Therapeutic Approaches

Glaucoma is identified by the loss of retinal ganglion cells (RGCs). The primary approach to managing glaucoma is to control intraocular pressure (IOP). Lately, there has been an increasing focus on neuroprotective therapies for glaucoma because of the limited effectiveness of standard methods in reducing IOP and preventing ongoing vision deterioration in certain glaucoma patients. Various drug-based techniques with neuroprotective properties have demonstrated the ability to decrease the mortality of retinal ganglion cells. This study will analyze the currently recommended drug-based techniques for neuroprotection in the prospective treatment of glaucoma.

The ROCK inhibitor netarsudil in the treatment of corneal endothelial decompensation caused by corneal endotheliitis: A case report and literature review

Proper hydration and the clarity of the cornea are maintained through the crucial function of the corneal endothelium. Inflammation of the corneal endothelium, known as endotheliitis, can disrupt endothelial function, resulting in alterations to vision. Corneal endotheliitis is characterised by corneal oedema, the presence of keratic precipitates, inflammation within the anterior chamber, and occasionally, limbal injection, neovascularisation, and the concurrent or overlapping presence of uveitis. The aetiology of this condition is diverse, predominantly viral, but it may also be drug-induced, result from bacterial or fungal infections, be associated with systemic diseases and procedures, or remain idiopathic with no identifiable cause. To date, no standardised protocol for the treatment of this ocular disease exists, and in severe cases, corneal transplantation may be required. A 31-year-old male was transferred to our hospital for the management of corneal endothelial decompensation resulting from corneal endotheliitis. Hormonal therapy and antiviral medications proved ineffective, rendering the patient a candidate for corneal transplantation. As a final measure, treatment with the ROCK inhibitor netarsudil was initiated. The patient demonstrated significant improvement in symptoms, and the inflammation was successfully managed after nine months. In this study, a novel approach employing ROCK inhibitor therapy was utilised for the treatment of corneal endotheliitis, leading to marked recovery during patient follow-up. This case report represents the inaugural application of the ROCK inhibitor netarsudil in managing corneal endothelial decompensation attributed to corneal endotheliitis. These findings suggest that this method warrants consideration as a potential novel treatment option for similar conditions.

CRISPR-CasRx-mediated disruption of Aqp1/Adrb2/Rock1/Rock2 genes reduces intraocular pressure and retinal ganglion cell damage in mice

Glaucoma affects approximately 80 million individuals worldwide, a condition for which current treatment options are inadequate. The primary risk factor for glaucoma is elevated intraocular pressure. Intraocular pressure is determined by the balance between the secretion and outflow of aqueous humor. Here we show that using the RNA interference tool CasRx based on shH10 adenovirus-associated virus can reduce the expression of the aqueous humor circulation related genes Rock1 and Rock2, as well as aquaporin 1 and β2 adrenergic receptor in female mice. This significantly reduced intraocular pressure in female mice and provided protection to the retina ganglion cells, ultimately delaying disease progression. In addition, we elucidated the mechanisms by which the knockdown of Rock1 and Rock2, or aquaporin 1 and β2 adrenergic receptor in female mice, reduces the intraocular pressure and secures the retina ganglion cells by single-cell sequencing.

Development of Cell Culture Platforms for Study of Trabecular Meshwork Cells and Glaucoma Development

BACKGROUND

Various cell culture platforms that could display native environmental cue-mimicking stimuli were developed, and effects of environmental cues on cell behaviors were studied with the cell culture platforms. Likewise, various cell culture platforms mimicking native trabecular meshwork (TM) composed of juxtacanalicular, corneoscleral and uveal meshwork located in internal scleral sulcus were used to study effects of environmental cues and/or drug treatments on TM cells and glaucoma development. Glaucoma is a disease that could cause blindness, and cause of glaucoma is not clearly identified yet. It appears that aqueous humor (AH) outflow resistance increased by damages on pathway of AH outflow can elevate intraocular pressure (IOP). These overall possibly contribute to development of glaucoma.

METHODS

For the study of glaucoma, static and dynamic cell culture platforms were developed. Particularly, the dynamic platforms exploiting AH outflow-mimicking perfusion or increased IOP-mimicking increased pressure were used to study how perfusion or increased pressure could affect TM cells. Overall, potential mechanisms of glaucoma development, TM structures and compositions, TM cell culture platform types and researches on TM cells and glaucoma development with the platforms were described in this review.

RESULTS AND CONCLUSION

This will be useful to improve researches on TM cells and develop enhanced therapies targeting glaucoma.

Aqueous humor as eye lymph: A crossroad between venous and lymphatic system

Aqueous humor (AQH) is a transparent fluid with characteristics similar to those of the interstitial fluid, which fills the eyeball posterior and anterior chambers and circulates in them from the sites of production to those of drainage. The AQH volume and pressure homeostasis is essential for the trophism of the ocular avascular tissues and their normal structure and function. Different AQH outflow pathways exist, including a main pathway, quite well defined anatomically and referred to as the conventional pathway, and some accessory pathways, more recently described and still not fully morphofunctionally understood, generically referred to as unconventional pathways. The conventional pathway is based on the existence of a series of conduits starting with the trabecular meshwork and Schlemm's Canal and continuing with a system of intrascleral and episcleral venules, which are tributaries to veins of the anterior segment of the eyeball. The unconventional pathways are mainly represented by the uveoscleral pathway, in which AQH flows through clefts, interstitial conduits located in the ciliary body and sclera, and then merges into the aforementioned intrascleral and episcleral venules. A further unconventional pathway, the lymphatic pathway, has been supported by the demonstration of lymphatic microvessels in the limbal sclera and, possibly, in the uvea (ciliary body, choroid) as well as by the ocular glymphatic channels, present in the neural retina and optic nerve. It follows that AQH may be drained from the eyeball through blood vessels (TM-SC pathway, US pathway) or lymphatic vessels (lymphatic pathway), and the different pathways may integrate or compensate for each other, optimizing the AQH drainage. The present review aims to define the state-of-the-art concerning the structural organization and the functional anatomy of all the AQH outflow pathways. Particular attention is paid to examining the regulatory mechanisms active in each of them. The new data on the anatomy and physiology of AQH outflow pathways is the key to understanding the pathophysiology of AQH outflow disorders and could open the way for novel approaches to their treatment.

The Specific ROCK2 Inhibitor KD025 Alleviates Glycolysis through Modulating STAT3-, CSTA- and S1PR3-Linked Signaling in Human Trabecular Meshwork Cells

To investigate the biological significance of Rho-associated coiled-coil-containing protein kinase (ROCK) 2 in the human trabecular meshwork (HTM), changes in both metabolic phenotype and gene expression patterns against a specific ROCK2 inhibitor KD025 were assessed in planar-cultured HTM cells. A seahorse real-time ATP rate assay revealed that administration of KD025 significantly suppressed glycolytic ATP production rate and increased mitochondrial ATP production rate in HTM cells. RNA sequencing analysis revealed that 380 down-regulated and 602 up-regulated differentially expressed genes (DEGs) were identified in HTM cells treated with KD025 compared with those that were untreated. Gene ontology analysis revealed that DEGs were more frequently related to the plasma membrane, extracellular components and integral cellular components among cellular components, and related to signaling receptor binding and activity and protein heterodimerization activity among molecular functions. Ingenuity Pathway Analysis (IPA) revealed that the detected DEGs were associated with basic cellular biological and physiological properties, including cellular movement, development, growth, proliferation, signaling and interaction, all of which are associated with cellular metabolism. Furthermore, the upstream regulator analysis and causal network analysis estimated IL-6, STAT3, CSTA and S1PR3 as possible regulators. Current findings herein indicate that ROCK2 mediates the IL-6/STAT3-, CSTA- and S1PR3-linked signaling related to basic biological activities such as glycolysis in HTM cells.

The Application of Rho Kinase Inhibitors in the Management of Glaucoma

Glaucoma is a chronic neurodegenerative disease that poses a significant threat of irreversible blindness worldwide. Current treatments for glaucoma focus on reducing intraocular pressure (IOP), which is the only modifiable risk factor. Traditional anti-glaucomatous agents, including carbonic anhydrase inhibitors, beta-blockers, alpha-2 agonists, and prostaglandin analogs, work by either improving uveoscleral outflow or reducing aqueous humor production. Rho kinase (ROCK) inhibitors represent a novel class of anti-glaucomatous drugs that have emerged from bench to bedside in the past decade, offering multifunctional characteristics. Unlike conventional medications, ROCK inhibitors directly target the trabecular meshwork outflow pathway. This review aims to discuss the mechanism of ROCK inhibitors in reducing IOP, providing neuroprotection, and preventing fibrosis. We also highlight recent studies and clinical trials evaluating the efficacy and safety of ROCK inhibitors, compare them with other clinical anti-glaucomatous medications, and outline future prospects for ROCK inhibitors in glaucoma treatment.

High throughput functional profiling of genes at intraocular pressure loci reveals distinct networks for glaucoma

INTRODUCTION

Primary open angle glaucoma (POAG) is a leading cause of blindness globally. Characterized by progressive retinal ganglion cell degeneration, the precise pathogenesis remains unknown. Genome-wide association studies (GWAS) have uncovered many genetic variants associated with elevated intraocular pressure (IOP), one of the key risk factors for POAG. We aimed to identify genetic and morphological variation that can be attributed to trabecular meshwork cell (TMC) dysfunction and raised IOP in POAG.

METHODS

62 genes across 55 loci were knocked-out in a primary human TMC line. Each knockout group, including five non-targeting control groups, underwent single-cell RNA-sequencing (scRNA-seq) for differentially-expressed gene (DEG) analysis. Multiplexed fluorescence coupled with CellProfiler image analysis allowed for single-cell morphological profiling.

RESULTS

Many gene knockouts invoked DEGs relating to matrix metalloproteinases and interferon-induced proteins. We have prioritized genes at four loci of interest to identify gene knockouts that may contribute to the pathogenesis of POAG, including ANGPTL2, LMX1B, CAV1, and KREMEN1. Three genetic networks of gene knockouts with similar transcriptomic profiles were identified, suggesting a synergistic function in trabecular meshwork cell physiology. TEK knockout caused significant upregulation of nuclear granularity on morphological analysis, while knockout of TRIOBP, TMCO1 and PLEKHA7 increased granularity and intensity of actin and the cell-membrane.

CONCLUSION

High-throughput analysis of cellular structure and function through multiplex fluorescent single-cell analysis and scRNA-seq assays enabled the direct study of genetic perturbations at the single-cell resolution. This work provides a framework for investigating the role of genes in the pathogenesis of glaucoma and heterogenous diseases with a strong genetic basis.

Axonal protection by combination of ripasudil and brimonidine with upregulation of p-AMPK in TNF-induced optic nerve degeneration

PURPOSE

The ROCK inhibitor ripasudil hydrochloride hydrate was shown to have axonal protective effects in TNF-induced optic nerve degeneration. The α2-adrenoreceptor agonist brimonidine was also shown to exert axonal protection. The current study aimed to elucidate whether additive axonal protection was achieved by the simultaneous injection of ripasudil and brimonidine and examine the association with AMPK activation.

METHODS

Intravitreal administration was performed in the following groups: PBS, TNF, or TNF with ripasudil, with brimonidine, or with a combination of ripasudil and brimonidine. Axon numbers were counted to evaluate the effects against axon loss. Immunoblot analysis was performed to examine phosphorylated AMPK expression in optic nerves, and immunohistochemical analysis was performed to evaluate the expression levels of p-AMPK and neurofilament in the optic nerve.

RESULTS

Both ripasudil alone or brimonidine alone resulted in significant neuroprotection against TNF-induced axon loss. The combination of ripasudil and brimonidine showed additive protective effects. Combined ripasudil and brimonidine plus TNF significantly upregulated p-AMPK levels in the optic nerve compared with the TNF groups. Immunohistochemical analysis revealed that p-AMPK is present in axons and enhanced by combination therapy.

CONCLUSION

The combination of ripasudil and brimonidine may have additive protective effects compared with single-agent treatment alone. These protective effects may be at least partially associated with AMPK activation.

Influence of the calcium voltage-gated channel auxiliary subunit (CACNA2D1) absence on intraocular pressure in mice

The etiology of elevated intraocular pressure (IOP), a major risk factor for glaucoma (optic nerve atrophy), is poorly understood despite continued efforts. Although the gene variant of CACNA2D1 (encoding α2δ1), a calcium voltage-gated channel auxiliary subunit, has been reported to be associated with primary open-angle glaucoma, and the pharmacological mitigation of α2δ1 activity by pregabalin lowers IOP, the cellular basis for α2δ1 role in the modulation of IOP remains unclear. Our recent findings reveled readily detectable levels of α2δ1 and its ligand thrombospondin in the cytoskeletome fraction of human trabecular meshwork (TM) cells. To understand the direct role of α2δ1 in the modulation of IOP, we evaluated α2δ1 null mice for changes in IOP and found a moderate (∼10%) but significant decrease in IOP compared to littermate wild type control mice. Additionally, to gain cellular insights into α2δ1 antagonist (pregabalin) induced IOP changes, we assessed pregabalin's effects on human TM cell actin cytoskeletal organization and cell adhesive interactions in comparison with a Rho kinase inhibitor (Y27632), a known ocular hypotensive agent. Unlike Y27632, pregabalin did not have overt effects on cell morphology, actin cytoskeletal organization, or cell adhesion in human TM cells. These results reveal a modest but significant decrease in IOP in α2δ1 deficient mice, and this response appears to be not associated with the contractile and cell adhesive characteristics of TM cells based on the findings of pregabalin effects on isolated TM cells. Therefore, the mechanism by which pregabalin lowers IOP remains elusive.

Rho-Kinase Inhibitors as Emerging Targets for Glaucoma Therapy

Glaucoma, the leading cause of irreversible blindness worldwide, is a chronic and progressive optic neuropathy characterized by damage to the optic and retinal nerve fiber layers, which can lead to permanent loss of peripheral or central vision. Reduction of intraocular pressure (IOP) is the only known modifiable risk factor for preventing and treating glaucoma. Rho kinase (ROCK) inhibitors are a new class of glaucoma drugs with a novel mechanism of action and good safety profile. They exert neuroprotective effects, act on the trabecular tissue, increase the outflow of aqueous humor, and reduce intraocular pressure. However, they also cause local adverse reactions, including common conjunctival congestion and subconjunctival bleeding; however, most are self-limiting and temporary. Netarsudil (0.02%), a ROCK inhibitor, relaxes the trabecular meshwork, increases the outflow of aqueous humor, reduces scleral venous pressure, and directly decreases IOP. Conjunctival congestion can be reduced if netarsudil is administered at night. The combination of these medications is always more effective than the single drug. Ripasudil (0.4%), another ROCK inhibitor, also lowers IOP; however, conjunctival hyperemia is the most common adverse drug reaction. The purpose of this review is to summarize the effects and adverse reactions of ROCK inhibitors in the experimental trial stage and in clinical treatment in recent years, providing suggestions for future clinical drug use, and research and development to reduce the side effects of these drugs, maximize the potential for reducing IOP, and improve the therapeutic effect.

Design, Synthesis, and Biological Evaluation of an Orally Bioavailable, Potent, and Selective ROCK2 Inhibitor for Psoriasis Treatment

Psoriasis, a prevalent chronic skin disorder, remains a significant therapeutic obstacle. This study centers on rho-associated coiled-coil-containing kinase2 (ROCK2) as an advantageous target for treating psoriasis and identifies five potent and selective ROCK2 inhibitors (A31-35). Notably, A32-35 outperform KD025 in ROCK2/ROCK1 selectivity by up to 216-fold. Among these candidates, A31 emerged as an exceedingly promising molecule, showcasing remarkable inhibitory potency (IC50 = 3.7 ± 0.8 nM), 19-fold ROCK2/ROCK1 selectivity, and favorable pharmacokinetics. Insights from the binding mode study further underscored the pivotal role of interactions with Phe103 on the P-loop in determining the selectivity between ROCK1 and ROCK2. In an imiquimod-induced psoriasis-like mouse model, oral administration of A31 notably ameliorated symptoms by targeting the IL-23/Th17 axis. Based on these compelling findings, A31 was selected as a highly promising compound for further investigation as a potential treatment for psoriasis.

ROCK Inhibitors in Corneal Diseases and Glaucoma-A Comprehensive Review of These Emerging Drugs

Rho kinase (ROCK) inhibitors have gained significant attention as emerging novel treatment options in the field of ophthalmology in recent years. The evidence supporting their efficacy in glaucoma and corneal pathology includes both in vitro and clinical studies. Among the available options, ripasudil and netarsudil have emerged as the leading ROCK inhibitors, and some countries have approved these therapeutic options as treatments for glaucoma. Various dosing regimens have been studied, including monotherapy and combination therapy, especially for patients with secondary glaucoma who are already on multiple medications. Another rising application of ROCK inhibitors includes their use as an adjunct in surgical procedures such as Descemetorhexis Without Endothelial Keratoplasty (DWEK), Descemet Stripping Only (DSO) to accelerate visual recovery, glaucoma surgeries to reduce scarring process and allow better intraocular pressure (IOP) control, or after complicated anterior segment surgery to treat corneal oedema. This article provides a comprehensive overview of the existing literature in the field, offering recommendations for prescribing ROCK inhibitors and also discussing patient selection, drug efficacy, and possible adverse effects.

Effects of Ripasudil, a Rho-Kinase Inhibitor, on Scar Formation in a Mouse Model of Filtration Surgery

PURPOSE

Glaucoma is a leading cause of blindness worldwide. Characteristic changes occur in the optic nerve and visual field of patients with glaucoma; optic nerve damage can be mitigated by lowering intraocular pressure. Treatment modalities include drugs and lasers; filtration surgery is necessary for patients with insufficient intraocular pressure reduction. Scar formation often contributes to glaucoma filtration surgery failure by increasing fibroblast proliferation and activation. Here, we examined the effects of ripasudil, a Rho-associated protein kinase (ROCK) inhibitor, on postoperative scar formation in human Tenon's fibroblasts.

METHODS

Collagen gel contraction assays were used to compare contractility activity among ripasudil and other anti-glaucoma drugs. The effect of Ripasudil in combination with other anti-glaucoma drugs and transforming growth factor-β (TGF-β), latanoprost and timolol-induce contractions were also tested in this study. Immunofluorescence and Western blotting were used to study the expression of factors relating scarring formation.

RESULTS

Ripasudil inhibited contraction in collagen gel assay and reduced α-smooth muscle actin (SMA) and vimentin (scar formation-related factors) expression, which was inversely promoted by latanoprost, timolol or TGF-β. Ripasudil also inhibited contraction on TGF-β, latanoprost and timolol-induced contraction. Furthermore, we investigated the effects of ripasudil on postoperative scarring in a mouse model; ripasudil suppressed postoperative scar formation by altering the expression of α-SMA and vimentin.

CONCLUSIONS

These results suggest that ripasudil, ROCK inhibitor may inhibit excessive fibrosis after glaucoma filtering surgery vis inhibition the transdifferentiation of tenon fibroblast into myofibroblast and may have a potential effect as anti-scarring for glaucoma filtration surgery.

Connective tissue growth factor: Role in trabecular meshwork remodeling and intraocular pressure lowering

Connective tissue growth factor (CTGF) is a distinct signaling molecule modulating many physiological and pathophysiological processes. This protein is upregulated in numerous fibrotic diseases that involve extracellular matrix (ECM) remodeling. It mediates the downstream effects of transforming growth factor beta (TGF-β) and is regulated via TGF-β SMAD-dependent and SMAD-independent signaling routes. Targeting CTGF instead of its upstream regulator TGF-β avoids the consequences of interfering with the pleotropic effects of TGF-β. Both CTGF and its upstream mediator, TGF-β, have been linked with the pathophysiology of glaucomatous optic neuropathy due to their involvement in the regulation of ECM homeostasis. The excessive expression of these growth factors is associated with glaucoma pathogenesis via elevation of the intraocular pressure (IOP), the most important risk factor for glaucoma. The raised in the IOP is due to dysregulation of ECM turnover resulting in excessive ECM deposition at the site of aqueous humor outflow. It is therefore believed that CTGF could be a potential therapeutic target in glaucoma therapy. This review highlights the CTGF biology and structure, its regulation and signaling, its association with the pathophysiology of glaucoma, and its potential role as a therapeutic target in glaucoma management.

Mendelian Randomization and Transcriptome-Wide Association Analysis Identified Genes That Were Pleiotropically Associated with Intraocular Pressure

BACKGROUND

Intraocular pressure (IOP) is a major modifiable risk factor for glaucoma. However, the mechanisms underlying the controlling of IOP remain to be elucidated.

OBJECTIVE

To prioritize genes that are pleiotropically associated with IOP.

METHODS

We adopted a two-sample Mendelian randomization method, named summary-based Mendelian randomization (SMR), to examine the pleiotropic effect of gene expression on IOP. The SMR analyses were based on summarized data from a genome-wide association study (GWAS) on IOP. We conducted separate SMR analyses using Genotype-Tissue Expression (GTEx) and Consortium for the Architecture of Gene Expression (CAGE) expression quantitative trait loci (eQTL) data. Additionally, we performed a transcriptome-wide association study (TWAS) to identify genes whose cis-regulated expression levels were associated with IOP.

RESULTS

We identified 19 and 25 genes showing pleiotropic association with IOP using the GTEx and CAGE eQTL data, respectively. RP11-259G18.3 (P_SMR = 2.66 × 10^-6), KANSL1-AS1 (P_SMR = 2.78 × 10^-6), and RP11-259G18.2 (P_SMR = 2.91 × 10^-6) were the top three genes using the GTEx eQTL data. LRRC37A4 (P_SMR = 1.19 × 10^-5), MGC57346 (P_SMR = 1.19 × 10^-5), and RNF167 (P_SMR = 1.53 × 10^-5) were the top three genes using the CAGE eQTL data. Most of the identified genes were found in or near the 17q21.31 genomic region. Additionally, our TWAS analysis identified 18 significant genes whose expression was associated with IOP. Of these, 12 and 4 were also identified by the SMR analysis using the GTEx and CAGE eQTL data, respectively.

CONCLUSIONS

Our findings suggest that the 17q21.31 genomic region may play a critical role in the regulation of IOP.

Addition of ROCK Inhibitors Alleviates Prostaglandin-Induced Inhibition of Adipogenesis in 3T3L-1 Spheroids

To elucidate the additive effects of the ROCK inhibitors (ROCK-i), ripasudil (Rip) and Y27632 on bimatoprost acid (BIM-A), a prostaglandin analog (PG), on adipose tissue, two- and three-dimensional (2D or 3D) cultures of 3T3-L1 cells, the most well characterized cells in the field of lipid research, were used. The cells were subjected to a variety of analyses including lipid staining, real-time cellular metabolic analysis, the mRNA expressions of genes related to adipogenesis and extracellular matrices (ECMs) as well as the sizes and physical properties of the 3D spheroids by a micro-squeezer. BIM-A induced strong inhibitory effects on most of the adipogenesis-related changes in the 2D and 3D cultured 3T3-L1 cells, including (1) the enlargement and softening of the 3D spheroids, (2) a dramatic enhancement in lipid staining and the expression of adipogenesis-related genes, and (3) a decrease in mitochondrial and glycolytic metabolic function. By adding ROCK-i to the BIM-A, most of these BIM-A-induced effects were cancelled. The collective findings reported herein suggest that ROCK-i eliminated the PG-induced suppression of adipogenesis in the 3T3-L1 cells, accompanied by the formation of enlarged 3D spheroids. Such effects of adding ROCK-i to a PG in preadipocytes on cellular properties appear to be associated with the suppression of PG-induced adverse effects, and provide additional insight into our understanding of lipid-related research.

ROCK2 Inhibition: A Futuristic Approach for the Management of Alzheimer's Disease

Neurons depend on mitochondrial functions for membrane excitability, neurotransmission, and plasticity.Mitochondrialdynamicsare important for neural cell maintenance. To maintain mitochondrial homeostasis, lysosomes remove dysfunctionalmitochondria through mitophagy. Mitophagy promotes mitochondrial turnover and prevents the accumulation of dysfunctional mitochondria. In many neurodegenerative diseases (NDDs), including Alzheimer's disease (AD), mitophagy is disrupted in neurons.Mitophagy is regulated by several proteins; recently,Rho-associated coiled-coil containing protein kinase 2 (ROCK2) has been suggested to negatively regulate the Parkin-dependent mitophagy pathway.Thus, ROCK2inhibitionmay bea promising therapyfor NDDs. This review summarizesthe mitophagy pathway, the role of ROCK2in Parkin-dependentmitophagyregulation,and mitophagy impairment in the pathology of AD. We further discuss different ROCK inhibitors (synthetic drugs, natural compounds,and genetherapy-based approaches)and examine their effects on triggering neuronal growth and neuroprotection in AD and other NDDs. This comprehensive overview of the role of ROCK in mitophagy inhibition provides a possible explanation for the significance of ROCK inhibitors in the therapeutic management of AD and other NDDs.

Identification of Nitric Oxide-Donating Ripasudil Derivatives with Intraocular Pressure Lowering and Retinal Ganglion Cell Protection Activities

Based on the synergistic therapeutic effect of nitric oxide (NO) and Rho-associated protein kinase (ROCK) inhibitors on glaucoma, a new group of NO-donating ripasudil derivatives RNO-1-RNO-6 was designed, synthesized, and biologically evaluated. The results demonstrated that the most active compound RNO-6 maintained potent ROCK inhibitory and NO releasing abilities, reversibly depolymerized F-actin, and suppressed mitochondrial respiration in human trabecular meshwork (HTM) cells. Topical administration of RNO-6 (0.26%) in chronic ocular hypertension glaucoma mice exhibited significant IOP lowering and visual function and retinal ganglion cell (RGC) protection activities, superior to an equal molar dose of ripasudil. RNO-6 could be a promising agent for glaucoma or ocular hypertension, warranting further investigation.

Early Postoperative Effect of Ripasudil Hydrochloride After Trabeculectomy on Secondary Glaucoma: A Randomized Controlled Trial

Purpose:

To evaluate the effect of Rho-associated kinase inhibitor (ripasudil hydrochloride hydrate; ripasudil) eye drops on postoperative intraocular pressure (IOP) after trabeculectomy in eyes with uveitic glaucoma.

Design:

This was a prospective, observational, controlled, and randomized study.

Methods:

Sixteen eyes of 16 patients with uveitic glaucoma who underwent trabeculectomy without mitomycin C were randomly treated without ripasudil (8 eyes) and with ripasudil (8 eyes). Postoperative IOP and surgical outcomes 3 months after surgery were compared between the two groups.

Results:

No patient discontinued treatment due to the lack of efficacy or adverse effects of ripasudil during the 3-month study period in the ripasudil group. The mean IOP (mmHg) in the control and ripasudil groups were 42.5 ± 9.8 mmHg /43.9 ± 11.7 mmHg (p = 0.82) at baseline, 14.3 ± 4.9 mmHg /9.0 ± 3.7 mmHg (p = 0.04) at 1 week, 16.3 ± 4.2 mmHg /10.6 ± 3.0 mmHg (p = 0.01) at 1 month, and 16.0 ± 3.4 mmHg /12.5 ± 2.3 mmHg (p = 0.04) at 3 months. The number of laser suture lysis procedures (2.0 ± 0.5 vs 0.4 ± 0.7), the rate of bleb revision by needling (50.0% vs 0.0%), and the mean number of antiglaucoma medications (1.6 ± 1.5 vs. 0.1 ± 0.3) after trabeculectomy were higher in the control group than in the ripasudil group (all p < 0.05). A multivariate analysis showed that the IOP reduction rate at 3 months after surgery was associated with the use of ripasudil and baseline IOP (all p < 0.05).

Conclusion:

This study demonstrated the therapeutic efficacy, safety, and tolerability of ripasudil for 3 months postoperatively. Ripasudil may effectively reduce postoperative IOP and increase the success rate of trabeculectomy in patients with uveitic glaucoma.

Brimonidine Modulates the ROCK1 Signaling Effects on Adipogenic Differentiation in 2D and 3D 3T3-L1 Cells

The additive effects of an α2-adrenergic agonist, brimonidine (BRI), on the pan-ROCK inhibitor (ROCK-i), ripasudil (Rip), and the ROCK2-I, KD025, on adipogenic differentiation (DIF+) were examined using two- or three-dimension (2D or 3D) cultures of 3T3-L1 cells. The following analyses were carried out: (1) lipid staining (2D and 3D), (2) real-time measurements of cellular metabolism (2D), (3) mRNA expression of DIF+ related genes and extracellular matrix molecules (ECMs) including collagen (Col)-1, -4, and -6, and fibronectin (Fn), and (4) the sizes and physical properties of the 3D spheroids. The findings indicate that DIF+ induced (1) a substantial enhancement in lipid staining and enhanced expression of the Pparγ and Fabp4 genes, (2) significantly larger and softer 3D spheroids, and (3) down-regulation of Col1 and Fn and up-regulation of Col4 and Col6 genes. Treatment with Rip alone caused a significant enhancement in adipogenesis of both the 2D and 3D cultured 3T3-L1 cells and in the physical properties of the 3D spheroids; these effects were substantially inhibited by BRI, and the effects induced by BRI or KD025 were not insignificant. These collective findings indicate that the addition of BRI inhibited the Rip-induced enhancement of DIF+ in 3T3-L1 cells, presumably by modulating ROCK1 signaling.

A Review of Selective Laser Trabeculoplasty: "The Hype Is Real"

Presently, there is no efficacious treatment for glaucomatous optic neuropathy; the current treatment is focused on lowering intraocular pressure (IOP). Studies have demonstrated the safety and efficacy of selective laser trabeculoplasty (SLT) in reducing the IOP in eyes with open-angle (OAG) glaucoma or ocular hypertension (OH). Moreover, the European Glaucoma Society has instated SLT as the first-line or adjunctive treatment in OAG or OH, reiterating its clinical significance. In this review, we outline the old and the new roles of SLT, with an emphasis on clinical practice, and look further into its renewed appeal and future developments.

Human Trabecular Meshwork (HTM) Cells Treated with TGF-β2 or Dexamethasone Respond to Compression Stress in Different Manners

To characterize our recently established in vitro glaucomatous human trabecular meshwork (HTM) models using dexamethasone (DEX)- or TGF-β2-treated HTM cells, (1) two-dimensional (2D) cultured HTM cells were characterized by means of the real-time cellular metabolism analysis using a Seahorse analyzer, and (2) the effects of mechanical compression stresses toward the three-dimensional (3D) HTM spheroids were evaluated by analyzing the gene expression of several ECM proteins, inflammatory cytokines, and ER stress-related factors of those 3D HTM spheroid models. The results indicated that (1) the real-time cellular metabolism analysis indicated that TGF-β2 significantly induced an energy shift from mitochondrial oxidative phosphorylation (OXPHOS) into glycolysis, and DEX induced similar but lesser effects. In contrast, ROCK2 inhibition by KD025 caused a substantial reverse energy shift from glycolysis into OXPHOS. (2) Upon direct compression stresses toward the untreated control 3D HTM spheroids, a bimodal fluctuation of the mRNA expressions of ECM proteins was observed for 60 min, that is, initial significant upregulation (0–10 min) and subsequent downregulation (10–30 min) followed by another upregulation (30–60 min); those of inflammatory cytokines and ER stress-related factors were also bimodally changed. However, such compression stresses for 30 min toward TGF-β2- or DEX-treated 3D HTM spheroids induced downregulation of most of those of inflammatory cytokines and ER stress-related factors in addition to upregulation of COL1 and downregulation of FN. The findings presented herein indicate that (1) OXPHOS of the HTM cells was decreased or increased by TGF-β2 or DEX stimulation or ROCK2 inhibition, and (2) mechanical compression stresses toward 3D HTM spheroids may replicate acute, subacute, and chronic HTM models affected by elevated intraocular pressures.

Glucocorticoids Preferentially Influence Expression of Nucleoskeletal Actin Network and Cell Adhesive Proteins in Human Trabecular Meshwork Cells

Clinical use of glucocorticoids is associated with increased intraocular pressure (IOP), a major risk factor for glaucoma. Glucocorticoids have been reported to induce changes in actin cytoskeletal organization, cell adhesion, extracellular matrix, fibrogenic activity, and mechanical properties of trabecular meshwork (TM) tissue, which plays a crucial role in aqueous humor dynamics and IOP homeostasis. However, we have a limited understanding of the molecular underpinnings regulating these myriad processes in TM cells. To understand how proteins, including cytoskeletal and cell adhesion proteins that are recognized to shuttle between the cytosolic and nuclear regions, influence gene expression and other cellular activities, we used proteomic analysis to characterize the nuclear protein fraction of dexamethasone (Dex) treated human TM cells. Treatment of human TM cells with Dex for 1, 5, or 7 days led to consistent increases (by ≥ two-fold) in the levels of various actin cytoskeletal regulatory, cell adhesive, and vesicle trafficking proteins. Increases (≥two-fold) were also observed in levels of Wnt signaling regulator (glypican-4), actin-binding chromatin modulator (BRG1) and nuclear actin filament depolymerizing protein (MICAL2; microtubule-associated monooxygenase, calponin and LIM domain containing), together with a decrease in tissue plasminogen activator. These changes were independently further confirmed by immunoblotting analysis. Interestingly, deficiency of BRG1 expression blunted the Dex-induced increases in the levels of some of these proteins in TM cells. In summary, these findings indicate that the widely recognized changes in actin cytoskeletal and cell adhesive attributes of TM cells by glucocorticoids involve actin regulated BRG1 chromatin remodeling, nuclear MICAL2, and glypican-4 regulated Wnt signaling upstream of the serum response factor/myocardin controlled transcriptional activity.

Response to netarsudil in goniotomy-treated eyes and goniotomy-naïve eyes: a pilot study

PURPOSE

To compare the intraocular pressure (IOP)-lowering effects of netarsudil on goniotomy-treated eyes versus goniotomy-naïve control eyes.

METHODS

Retrospective cohort study of 70 eyes from 49 adult glaucoma patients treated with netarsudil. Thirty-five eyes received sectoral goniotomy using Kahook Dual Blade (KDB) combined with cataract surgery with minimum of 3 months prior to netarsudil treatment. Thirty-five eyes in the control cohort received only cataract surgery prior to netarsudil. Primary outcome was treatment success, defined as ≥ 20% decrease in IOP at minimum 1 month follow-up. Secondary outcome measures included percent of IOP reduction, adverse effects of medication, medication discontinuation rate, and relationship between KDB goniotomy response and netarsudil response.

RESULTS

Eighty-three percent of KDB-treated eyes achieved netarsudil treatment success compared to 54% of control eyes (P = .012). IOP reduction was 30.3 ± 16.2% (IQR 21-38%) in KDB-treated eyes and 19.4 ± 12.4% (IQR 9.2-30.8) in control eyes (P = .007). History of prior KDB increased the likelihood of success to netarsudil treatment compared to eyes without prior KDB, regardless of surgical response to KDB (odds ratio 4.51, 95% CI 1.34-15.14, P = .015). The overall rate of adverse effects of netarsudil was 42%, most commonly reported as conjunctival hyperemia, allergy, and blurred vision.

CONCLUSIONS

Netarsudil had a greater IOP-lowering effect in eyes treated with prior goniotomy and may serve as a promising adjunctive ocular hypotensive agent to further reduce IOP in eyes with prior goniotomy.

Sovesudil (locally acting rho kinase inhibitor) for the treatment of normal-tension glaucoma: the randomized phase II study

PURPOSE

To evaluate ocular hypotensive efficacy and the safety of sovesudil (formally known as PHP-201), a novel Rho-associated protein kinase (ROCK) inhibitor, in patients with normal-tension glaucoma (NTG).

DESIGN

Multicentre, prospective, double-masked, randomized, placebo-controlled, parallel clinical study.

METHODS

Patients with NTG (unmedicated baseline IOP ≤ 21 mmHg) were randomized in 3 groups and treated with sovesudil in concentrations of 0.25% and 0.5%, or with a placebo three times daily (TID) for 4 weeks. The primary end-point was the mean diurnal IOP change from the baseline at week 4. Safety was recorded over a 4-week treatment period and the following 2-week observation period.

RESULTS

A total of 119 patients were included in the primary efficacy analysis. The mean diurnal IOP change from the baseline at week 4 was -1.56 mmHg for the high-dose group, -1.10 mmHg for the low-dose group and -0.65 mmHg for the placebo group. The difference between the high-dose and the placebo groups was -0.91 mmHg (95% confidence intervals: -1.73, -0.09). 0.5% sovesudil TID met the criteria for superiority to the placebo. The most frequent ocular adverse event among sovesudil-treated patients was conjunctival hyperaemia (24.4% for the high-dose and 17.5% for the low-dose group) and predominately classified as mild.

CONCLUSIONS

Sovesudil 0.25% and 0.5% TID showed statistically significant IOP-lowering effects and 0.5% concentration's IOP-lowering effects met the superiority criteria in comparison with the placebo at week 4. Sovesudil was well tolerated with mild adverse events including relatively low incidence of conjunctival hyperaemia in patients with NTG.

ANGPTL7 is transcriptionally regulated by SP1 and modulates glucocorticoid-induced cross-linked actin networks in trabecular meshwork cells via the RhoA/ROCK pathway

Glaucoma is one of the leading causes of worldwide irreversible blindness. Lowering elevated intraocular pressure (IOP) is currently the only effective approach for controlling the progress of glaucoma. Angiopoietin-like 7 (ANGPTL7) takes a key part in elevated outflow resistance of aqueous humor in dysfunctional trabecular meshwork (TM), along with the formation of cross-linked actin networks (CLANs), leading to high IOP. In this study, we explored the role of the ANGPTL7 signaling pathway in CLAN formation. We detected the expression of ANGPTL7 in cultured primary TM cells treated with dexamethasone (DEX) and ethanol as a control using qRT-PCR and western blotting. Actin filaments were revealed by phalloidin staining. ANGPTL7 short hairpin RNA (shRNA) was applied to TM cells to examine the effect of ANGPTL7 on DEX-induced CLAN formation. Western blotting was used to assess the effect of ANGPTL7 on the RhoA/Rho-associated kinase (Rho-kinase/ROCK) signaling pathway. Bioinformatics, dual-luciferase reporter assays, and chromatin immunoprecipitation were employed to identify the transcription factors of ANGPTL7. Transcription factor specificity protein 1 (SP1) overexpression and silencing were performed to determine their roles in the modulation of ANGPTL7 expression. We found DEX-induced ANGPTL7 expression and stress fiber rearrangement in TM cells. ANGPTL7 knockdown effectively inhibited the formation of CLANs. Moreover, it was involved in the regulation of the RhoA/ROCK signaling pathway, further affecting DEX-induced CLAN formation. SP1 was identified as a transcription factor of ANGPTL7 which regulated ANGPTL7 level to mediate CLAN formation through the RhoA/ROCK signaling pathway. This study contributes to revealing the molecular mechanisms of ANGPTL7 in CLAN formation, which is involved in TM dysfunction and glaucoma pathogenesis.

Axonal Protection by Netarsudil, a ROCK Inhibitor, Is Linked to an AMPK-Autophagy Pathway in TNF-Induced Optic Nerve Degeneration

Purpose

Netarsudil, a Rho kinase inhibitor with norepinephrine transport inhibitory effect, lowers intraocular pressure, however, its effect on axon damage remains to be elucidated. The aim of the current study was to investigate the effect of netarsudil on TNF-induced axon loss and to examine whether it affects phosphorylated-AMP-activated kinase (p-AMPK) and autophagy in the optic nerve.

Methods

Intravitreal administration of TNF or TNF with netarsudil was carried out on rats and quantification of axon number was determined. Electron microscopy determined autophagosome numbers. Localization of p-AMPK expression was examined by immunohistochemistry. The changes in p62, LC3-II, and p-AMPK levels were estimated in the optic nerve by immunoblot analysis. The effect of an AMPK activator A769662 or an AMPK inhibitor dorsomorphin on axon number was evaluated.

Results

Morphometric analysis revealed apparent protection by netarsudil against TNF-induced axon degeneration. Netarsudil increased autophagosome numbers inside axons. Netarsudil treatment significantly upregulated optic nerve LC3-II levels in both the TNF-treated eyes and the control eyes. Increased p62 protein level induced by TNF was significantly ameliorated by netarsudil. The netarsudil administration alone lessened p62 levels. Netarsudil significantly upregulated the optic nerve p-AMPK levels. A769662 exhibited obvious axonal protection against TNF-induced damage. A769662 treatment upregulated LC3-II levels and the increment of p62 level induced by TNF was significantly ameliorated by A769662. Immunohistochemical analysis revealed that p-AMPK is present in axons. Netarsudil-mediated axonal protection was significantly suppressed by dorsomorphin administration.

Conclusions

Netarsudil upregulated p-AMPK and autophagy. Netarsudil-mediated axonal protection may be associated with upregulated p-AMPK.

Exploring the therapeutic promise of targeting Rho kinase in rheumatoid arthritis

Rheumatoid arthritis (RA) is a prevalent systemic autoimmune disease caused by dysregulated inflammatory reactions, T lymphocyte invasion into the joints, and articular thickening. Immune cells, primarily tumor necrosis factor-alpha (TNF-α) and chemokines (interleukin or IL-1), which are predominantly generated by activated macrophages cells, have also been involved with the pathogenesis of rheumatoid arthritis. Rho GTPases are integral factors of biochemical cascades utilized by antigens, and also by cellular receptors, cytokines, and chemokines, to modulate inflammatory reactions, according to growing data. The Rho family is a group of G proteins that govern a variety of biological and physiological activities such as mobility, actin stress fiber production, growth, and polarity. Research suggests that the Rho A and Rho-associated coiled-coil kinase (ROCK) regulatory cascade could be essential in several autoimmune conditions, including RA. ROCK is activated in the synovial of rheumatoid arthritis patients, while the blocking of ROCK with fasudil could also decrease IL-6, TNF-α, and IL-1. This review covers current developments in understanding the overactivation of Rho enzyme activity in RA suppressed by ROCK inhibitors which can be utilized for the treatment of autoimmune disease. We offer an outline of the function of ROCK inhibitors in immune cells and discuss findings which emphasize the rising participation of this category of kinases within the pathological process of autoimmune disorders. Assuming the potential ability of ROCK as a therapeutic, we define approaches that might be used to inhibit Rho kinase activity in rheumatoid disorders.

Pan-ROCK and ROCK2 Inhibitors Affect Dexamethasone-Treated 2D- and 3D-Cultured Human Trabecular Meshwork (HTM) Cells in Opposite Manners

Effects of a pan-ROCK-inhibitor, ripasudil (Rip), and a ROCK2 inhibitor, KD025 on dexamethasone (DEX)-treated human trabecular meshwork (HTM) cells as a model of steroid-induced glaucoma were investigated. In the presence of Rip or KD025, DEX-treated HTM cells were subjected to permeability analysis of 2D monolayer by transendothelial electrical resistance (TEER) and FITC–dextran permeability, physical properties, size and stiffness analysis (3D), and qPCR of extracellular matrix (ECM), and their modulators. DEX resulted in a significant increase in the permeability, as well as a large and stiff 3D spheroid, and those effects were inhibited by Rip. In contrast, KD025 exerted opposite effects on the physical properties (down-sizing and softening). Furthermore, DEX induced several changes of gene expressions of ECM and their modulators were also modulated differently by Rip and KD025. The present findings indicate that Rip and KD025 induced opposite effects toward 2D and 3D cell cultures of DEX-treated HTM cells.

ROCK inhibitors modulate the physical properties and adipogenesis of 3D spheroids of human orbital fibroblasts in different manners

To elucidate the pharmacological effects of Rho-associated coiled-coil containing protein kinase inhibitors (ROCK-is), ripasudil (Rip), Y27632, and KD025, on human orbital fatty tissue, the human orbital fibroblasts (HOFs) were three-dimensional (3D) cultured for 12 days. The effects of ROCK-is on the physical properties of the 3D-cultured HOF spheroids, including their sizes and physical stiffness, their adipogenesis by lipid staining, and the mRNA expression of adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) including collagen (COL) 1, 4, and 6, and fibronectin were analyzed. A significant increase in the sizes, physical stiffness, lipid staining, and mRNA expression of adipogenesis-related genes, COL4 and COL6, and a decrease in COL1 expression were observed with adipogenesis (DIF+). In the presence of ROCK-is, such DIF+-induced effects were differently modulated as follows: (1) the sizes were not affected or significantly enhanced by Rip, Y27632, or KD025, (2) the physical stiffness was significantly decreased in Rip and Y27632, but was substantially increased in KD025, (3) the lipid staining was further enhanced or significantly suppressed by Rip, Y27632, or KD025, and both PPARγ and AP2 expression were significantly downregulated or upregulated by KD025 or Rip, and (4) Rip upregulated the expression of COL4, Y27632 upregulated the expression of COL1, COL4, and COL6, and KD025 upregulated the expression of COL1 and COL4. This study indicates that ROCK-is significantly and differently modulate physical properties of the 3D HOF spheroids as well as their adipogenesis.

Addition of ROCK inhibitors to prostaglandin derivative (PG) synergistically affects adipogenesis of the 3D spheroids of human orbital fibroblasts (HOFs)

To study the additive effects of Rho-associated coiled-coil containing protein kinase inhibitors, ripasudil (Rip) to bimatoprost acid (BIM-A) on orbital adipose tissue, three-dimensional (3D) cultures of human orbital fibroblasts (HOFs) were prepared and the physical properties including the 3D spheroid size and stiffness, lipid staining by BODIPY and the mRNA expression of adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) including collagen (COL)1, 4 and 6, and fibronectin (FN) were analyzed. Adipogenesis (DIF+) induced (1) enlargement and increasing stiffness of the 3D HOFs spheroid, (2) increased lipid staining, the expression of adipogenesis-related gene expressions, and (3) the down-regulation of COL1 and FN and up-regulation of COL4 and COL6. In the presence of BIM-A, (1) such DIF+-induced changes in 3D spheroid size and stiffness were significantly inhibited or enhanced, respectively, (2) the lipid staining and its related gene expressions were significantly down-regulated, and (3) the expression of COL1 and COL6 were up-regulated. By the addition of Rip to BIM-A, the above BIM-A-induced effects were all inhibited, except for the up-regulation of COL6 and FN expression, that is, enlarging and decreasing stiffness, enhancement of lipid staining and its related gene expression, and down-regulation of COL1 expression. Our present study indicates that Rip significantly suppressed BIM-A-induced effects toward 3D HOFs spheroids.

Establishment of appropriate glaucoma models using dexamethasone or TGFβ2 treated three-dimension (3D) cultured human trabecular meshwork (HTM) cells

To establish appropriate ex vivo models for a glaucomatous trabecular meshwork (TM), two-dimensional (2D) and three-dimensional (3D) cultures of human trabecular meshwork cells (HTM) were prepared in the presence of 250 nM dexamethasone (DEX) or 5 ng/mL TGFβ2, and characterized by the following analyses; transendothelial electrical resistance (TEER) measurements, FITC dextran permeability, scanning electron microscopy and the expression of the extracellular matrix (ECM) including collagen (COL)1, 4 and 6, and fibronectin (FN), α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase (TIMP)1–4, and matrix metalloproteinase (MMP)2, 9 and 14. DEX and TGFβ2 both caused a significant increase or decrease in the TEER values and FITC dextran permeability. During the 3D spheroid culture, DEX or TGFβ2 induced a mild and significant down-sizing and an increase in stiffness, respectively. TGFβ2 induced a significant up-regulation of COL1 and 4, FN, α-SMA, and MMP 2 and 14 (2D) or COL1 and 6, and TIMP2 and 3 (3D), and DEX induced a significant up-regulation of FN (3D) and TIMP4 (2D and 3D). The findings presented herein indicate that DEX or TGFβ2 resulted in mild and severe down-sized and stiff 3D HTM spheroids, respectively, thus making them viable in vitro HTM models for steroid-induced and primary open angle glaucoma.

Design, synthesis, and biological evaluation of urea-based ROCK2 inhibitors

A series of urea-based ROCK2 inhibitors were design and synthesized. The inhibitory activity on ROCK2 was screened by enzyme-linked immunosorbent assay (ELISA). The study results showed that the urea derivatives exhibited certain ROCK2 inhibitory activity. The most potent compound 10p showed ROCK2 inhibitory activity with the IC₅₀  value of 0.03 μM. A preliminary structure-activity relationship was then summarized. The molecular docking studies showed that further optimization needs to conduct to obtain more potent ROCK inhibitors.

Diverse effects of pan-ROCK and ROCK2 inhibitors on 2 D and 3D cultured human trabecular meshwork (HTM) cells treated with TGFβ2

A pan-ROCK-inhibitor, ripasudil (Rip), and a ROCK2 inhibitor, KD025, were used To study the effects of Rho-associated coiled-coil containing protein kinase (ROCK)1 and 2 on two-dimensional (2D) and three-dimensional (3D) cultures of a TGFβ2-treated human trabecular meshwork (HTM) cells. In the presence of 5 ng/mL TGFβ2, the effects of these inhibitors were characterized by transendothelial electrical resistance (TEER), FITC-dextran permeability, and the size and stiffness of 3D sphenoids, the expression of extracellular matrix (ECM) including collagen1, 4 and 6, and fibronectin, α-smooth muscle actin, a tissue inhibitor of metalloproteinase (TIMP)1–4, and matrix metalloproteinase (MMP)2, 9 and 14. TGFβ2 caused a significant increase in the TEER values, and decrease in FITC-dextran permeability, as well as a decrease in the sizes and stiffness of the 3D sphenoids. In the presence of ROCK inhibitors, the TGFβ2-induced effects of the TEER and FITC-dextran permeability were inhibited, especially by KD025. Rip induced a significant increase in sizes and a decrease in the stiffness of the TGFβ2-treated 3D sphenoids, although the effects of KD025 were weaker. Gene expressions of most of the ECMs, TIMP2 and MMP9 of 2D and 3D HTM cells were significantly up-regulated by TGFβ2. Those were significantly and differently modulated by Rip or KD025.

The ROCK Inhibitor Ripasudil Shows an Endothelial Protective Effect in Patients With Low Corneal Endothelial Cell Density After Cataract Surgery

Purpose

In the field of regenerative medicine, Rho kinase inhibitors (ROCK inhibitors) show a protective effect on the corneal endothelium and promote effective healing in acute surgical wounds. In this study, we investigated the effectiveness of eyedrops containing ripasudil, a ROCK inhibitor approved in Japan for therapeutic use for glaucoma.

Methods

In this retrospective observational study, 13 glaucoma patients (16 eyes) were treated with 0.4% ripasudil eyedrops twice a day after cataract surgery. The control group comprised 13 patients (17 eyes). The averaged corneal endothelial cell density from one central and four paracentral points was <1500/mm2 (range, 527 to 1439/mm2).

Results

The mean rate of increase in the thinnest corneal thickness one week after surgery was 1.25% in the ripasudil group, which was significantly lower than the 5.97% increase observed in the control group (P = 0.0037). The mean endothelial cell density loss 90 to 120 days after surgery, excluding bullous keratopathy patients for whom measurements were not possible was -4.5% in the ripasudil group, which was significantly lower than in control group (14.1%; P = 0.0003).

Conclusions

The results suggest that ripasudil may help maintain corneal endothelial functional integrity and reduce cell loss after cataract surgery in patients with low corneal endothelial cell density, suggesting that it may be more broadly useful for protection of the corneal endothelium after intraocular surgery.

Translational Relevance

The clinically approved ROCK inhibitor ripasudil formulated as an eye drop for glaucoma has a corneal endothelial protective effect in cataract surgery for patients with low corneal endothelial cell density.

Xeno- and Feeder-Free Differentiation of Human iPSCs to Trabecular Meshwork-Like Cells by Recombinant Cytokines

Purpose

Stem cell-based therapy has the potential to become one approach to regenerate the damaged trabecular meshwork (TM) in glaucoma. Co-culture of induced pluripotent stem cells (iPSCs) with human TM cells has been a successful approach to generate autologous TM resembling cells. However, the differentiated cells generated using this approach are still problematic for clinical usage. This study aimed to develop a clinically applicable strategy for generating TM-like cells from iPSCs.

Methods

Highly expressed receptors during iPSC differentiation were identified by AutoSOME, Gene Ontology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. The recombinant cytokines that bind to these receptors were used to generate a new differentiation protocol. The resultant TM-like cells were characterized morphologically, immunohistochemically, and transcriptionally.

Results

We first determined two stages of iPSC differentiation and identified highly expressed receptors associated with the differentiation at each stage. The expression of these receptors was further confirmed by RT-PCR analysis. Exposure to the recombinant cytokines that bind to these receptors, including transforming growth factor beta 1, nerve growth factor beta, erythropoietin, prostaglandin F2 alpha, and epidermal growth factor, can efficiently differentiate iPSCs into TM-like cells, which express TM biomarkers and can form dexamethasone-inducible CLANs.

Conclusions

We successfully generated a xeno- and feeder-free differentiation protocol with recombinant cytokines to generate the TM progenitor and TM-like cells from human iPSCs.

Translational Relevance

The new approach minimizes the risks from contamination and also improves the differentiation efficiency and consistency, which are particularly crucial for clinical use of stem cells in glaucoma treatment.

Genetic Risk and Phenotype Correlation of Primary Open-Angle Glaucoma Based on Rho-Kinase Gene Polymorphisms

Rho-associated coiled-coil kinase (ROCK) signaling can affect glaucoma risk by regulating trabecular meshwork outflow. We investigated the effect of ROCK gene polymorphism on the risks of primary open-angle glaucoma (POAG) and POAG-related phenotypes including intraocular pressure (IOP) in a Korean population. A total of 24 single-nucleotide polymorphisms (SNPs) from ROCK1 and ROCK2 were selected and genotyped for 363 POAG patients and 213 healthy controls. Among the 363 POAG patients, 282 were normal-tension glaucoma (NTG, baseline IOP ≤ 21 mmHg) and 81 were high-tension glaucoma (HTG, baseline IOP > 21 mmHg). The SNPs rs288979, rs1006881, rs35996865, rs10083915, and rs11873284 in ROCK1 (tagged to each other, r² = 1) were nominally associated with risk of HTG (OR = 0.52, p = 0.045). However, there were no SNPs that were significantly associated with the risk of NTG. In the genotype-phenotype correlation analysis, the SNPs rs2230773 and rs3771106 in ROCK2 were significantly correlated with central corneal thickness (CCT)-adjusted IOP (p = 0.024) and axial length (AXL; p = 0.024), respectively. The present data implicated the role of ROCK in POAG development, and as such, can serve as a good reference for upcoming Rho/ROCK-pathway-related studies on POAG.

Physiologic Consequences of Caveolin-1 Ablation in Conventional Outflow Endothelia

Purpose

Polymorphisms at the caveolin-1/2 locus are associated with glaucoma and IOP risk and deletion of caveolin-1 (Cav1) in mice elevates IOP and reduces outflow facility. However, the specific location/cell type responsible for Cav1-dependent regulation of IOP is unclear. We hypothesized that endothelial Cav1 in the conventional outflow (CO) pathway regulate IOP via endothelial nitric oxide synthase (eNOS) signaling.

Methods

We created a mouse with targeted deletion of Cav1 in endothelial cells (Cav1ΔEC) and evaluated IOP, outflow facility, outflow pathway distal vascular morphology, eNOS phosphorylation, and tyrosine nitration of iridocorneal angle tissues by Western blotting.

Results

Endothelial deletion of Cav1 resulted in significantly elevated IOP versus wild-type mice but not a concomitant decrease in outflow facility. Endothelial Cav1 deficiency did not alter the trabecular meshwork or Schlemm's canal morphology, suggesting that the effects observed were not due to developmental deformities. Endothelial Cav1 deletion resulted in eNOS hyperactivity, modestly increased protein nitration, and significant enlargement of the drainage vessels distal to Schlemm's canal. L-Nitro-arginine methyl ester treatment reduced outflow in Cav1ΔEC but not wild-type mice and had no effect on the size of drainage vessels. Endothelin-1 treatment decrease the outflow and drainage vessel size in both wild-type and Cav1ΔEC mice.

Conclusions

Our results suggest that hyperactive eNOS signaling in the CO pathway of both Cav1ΔEC and global Cav1 knockout mice results in chronic dilation of distal CO vessels and protein nitration, but that Cav1 expression in the trabecular meshwork is sufficient to rescue CO defects reported in global Cav1 knockout mice.

Responsiveness to ripasudil may be a potential outcome marker for selective laser trabeculoplasty in patients with primary open-angle glaucoma

We examined responsiveness to ripasudil as a potential factor for predicting the effect of selective laser trabeculoplasty (SLT) when performed for primary open-angle glaucoma (POAG). A total of 70 eyes with no history of glaucoma surgery underwent SLT between January 2015 and June 2019. Patients were divided into two groups, with an intraocular pressure (IOP) decrease of 15% or more due to ripasudil administration before SLT defined as the effective group, while an IOP decrease of less than 15% was defined as the non-effective group. Kaplan–Meier survival analysis was performed. A Cox proportional hazards model assessed the influence of baseline factors on the success. Of the 70 eyes evaluated, treatments were effective in 22 and non-effective in 48. Postoperatively, both groups exhibited IOP reductions for up to 24 months. Success ratios at 12 and 24 months after SLT were 43.5% and 18.5% in the effective versus 24.9% and 9.3% in the non-effective group, which were significantly higher in the effective group (P = 0.03). Presence of a ripasudil effective eye (P = 0.03) was associated with treatment success. Responsiveness to ripasudil may be useful in predicting the therapeutic effect of SLT.

ROCK inhibitors enhance the production of large lipid-enriched 3D organoids of 3T3-L1 cells

Since the recent discovery of prostaglandin-associated peri-orbitopathy, a great deal of interest has developed concerning the side effects of anti-glaucoma medications toward periocular fatty tissue, especially their adipogenesis. Two- or three-dimension (2D or 3D) cultures of the 3T3-L1 cells were employed to elucidate the effects of the Rho-associated coiled-coil containing protein kinase inhibitor (ROCK-i) the anti-glaucoma drug, Ripasudil, and other ROCK-i, such as Y27632 on adipogenesis. Ultrastructure by electron microscopy and physical stiffness measurements by a micro-squeezer demonstrated the 3D organoids had essentially matured during the 7-day culture. The effects of ROCK-i on 3D organoid sizes, lipid staining, the mRNA expression of adipogenesis related genes, Pparγ, Cebpa and Leptin, and extracellular matrix (ECM) including collagen (COL) 1, 4 and 6, and fibronectin, and physical stiffness were then conducted. Upon adipogenesis, the sizes, lipid staining and mRNA expressions of adipogenesis related genes, Col 4 and Col 6 were dramatically increased, and were further enhanced by ROCK-i. Micro-squeezer analysis demonstrated that adipogenesis resulted in a marked less stiffed 3D organoid and this was further enhanced by ROCK-i. Our present study indicates that ROCK-i significantly enhanced the production of large lipid-enriched 3T3-L1 3D organoids.

Additive Intraocular Pressure-Lowering Effects of a Novel Selective EP2 Receptor Agonist, Omidenepag Isopropyl, Combined with Existing Antiglaucoma Agents in Conscious Ocular Normotensive Monkeys

Purpose: To investigate the intraocular pressure (IOP)-lowering effects of omidenepag isopropyl (OMDI), a potent and highly selective prostanoid EP2 receptor agonist, as a potential first-line ocular hypotensive agent when combined with existing antiglaucoma agents in conscious ocular normotensive monkeys. Methods: Male cynomolgus monkeys were examined under conscious conditions. OMDI ophthalmic solution alone was topically applied to an eye or combined with other ophthalmic solutions at 5-min intervals. The contralateral eye was left untreated. IOP was measured before and at 2, 4, 6, and 8 h after instillation. Results: Topical application of OMDI to the eye resulted in statistically significant IOP reduction, which lasted for at least 6 h. The IOP-lowering effects of OMDI concomitantly administered with any of the tested antiglaucoma agents (timolol, brinzolamide, netarsudil, ripasudil, and brimonidine) were greater than those of OMDI alone. Furthermore, these enhanced IOP responses to their concomitant use were statistically significant compared with those of the tested antiglaucoma agents alone. Any combination of OMDI with the tested agents did not lead to serious abnormalities either systemically or locally in the eye. Conclusions: We demonstrated that OMDI has additive IOP-lowering effects when administered in combination with various antiglaucoma agents, namely, β-adrenergic antagonist, carbonic anhydrase inhibitor, Rho-associated coiled-coil containing protein kinase inhibitors, and α2-adrenergic agonist. These results suggest that OMDI provides additional clinical benefits because of its unique mechanisms of action when combination therapy is required.

Effects of Ripasudil on Open-Angle Glaucoma after Circumferential Suture Trabeculotomy Ab Interno

We evaluated the effects of ripasudil on the distal aqueous outflow tract in patients with open-angle glaucoma (OAG) who underwent a 360° suture trabeculotomy ab interno followed by ripasudil treatment beginning 1 month postoperatively. We compared 27 of these patients, by using propensity score analysis, with 27 patients in a matched control group who had no ripasudil treatment. We assessed the changes in the mean intraocular pressure (IOP) and the relationship between the IOP changes and background factors. All eyes had a complete 360° Schlemm’s canal incision and phacoemulsification. The mean IOP at 1 and 3 months after ripasudil administration were significantly reduced by −1.7 ± 1.9 mmHg (p < 0.0001) and −1.3 ± 2.3 mmHg (p = 0.0081) in the ripasudil group, respectively, but IOP in the control group was not significantly reduced. The IOP reduction was significantly associated with the IOP before ripasudil treatment (p < 0.001). In conclusion, the use of ripasudil for patients with OAG after circumferential incision of the Schlemm’s canal produced significant IOP reductions. Ripasudil may affect the distal outflow tract, thereby leading to the IOP reduction.

VIP Induces Changes in the F-/G-Actin Ratio of Schlemm's Canal Endothelium via LRRK2 Transcriptional Regulation

Purpose

A previous study reported that vasoactive intestinal peptide (VIP) can regulate the cytoskeleton of Schlemm's canal (SC) endothelium and expand the SC lumen in a rat glaucoma model. In this study, we aimed to investigate the molecular mechanism of VIP on cytoskeleton regulation.

Methods

During in vivo experiments in rats, leucine-rich repeat kinase 2 (LRRK2) expression and the ratio of F-actin to G-actin (F-/G-actin) surrounding SC were examined by immunofluorescence after the application of VIP. For in vitro experiments in human umbilical vein endothelial cells, both quantitative PCR (qPCR) and western blotting were performed to evaluate Sp1 and LRRK2 expression after the application of VIP (and Sp1/LRRK2 inhibitor). In addition, the F-/G-actin ratio was examined by both immunofluorescence and western blotting after the application of VIP (and LRRK2 inhibitor).

Results

VIP induced increases in the expression of LRRK2 both in vivo and in vitro and the nuclear translocation of Sp1 in vitro. The application of Sp1 inhibitor abolished the increase in LRRK2 expression induced by VIP in vitro. In addition, VIP changed the F-/G-actin ratio, and this effect was abolished by the LRRK2 inhibitor both in vivo and in vitro.

Conclusions

VIP increased the expression of LRRK2, and this regulation was due to the nuclear translocation of Sp1. VIP further changed the F-/G-actin ratio and regulated the balance between the stabilization and destabilization of the F-actin architecture. This study elucidates a novel mechanism by which VIP regulates the actin cytoskeleton of SC endothelium via the Sp1–LRRK2 pathway, suggesting a potential novel treatment strategy for glaucoma.

CD151 Alleviates Early Blood-Brain Barrier Dysfunction After Experimental Focal Brain Ischemia in Rats

Preservation of the blood-brain barrier (BBB) function is a potential protective strategy against cerebral ischemic injuries. CD151 has a beneficial effect in maintaining vascular stability and plays a role in pro-angiogenesis. Both vascular stability and angiogenesis can affect BBB function. Therefore, we aimed to examine the action of CD151 in regulating BBB permeability after cerebral ischemic injury in the present study. Using a transient focal cerebral ischemia (tFCI) rat model, we established that CD151 overexpression in the brain mitigated the leakage of endogenous IgG at 6-24 h after tFCI in vivo. Moreover, we found that CD151 can decrease the diffusion of macromolecules through monolayer brain microvessel endothelial cells (BMVECs) after glucose and oxygen deprivation (OGD)-reoxygenation in vitro. Furthermore, overexpression of CD151 in BMVECs suppressed OGD-reoxygenation-induced F-actin formation and RhoA activity. However, while preserving BBB integrity after tFCI, CD151 overexpression did not affect the post-stroke outcomes. Taken together, the present study demonstrated that CD151 overexpression in the brain protects BBB permeability at early phase after tFCI. CD151 may be a potential target for early BBB protection in ischemic stroke.

ROCK inhibitors beneficially alter the spatial configuration of TGFβ2-treated 3D organoids from a human trabecular meshwork (HTM)

To elucidate molecular pharmacology of Rho-associated coiled-coil containing protein kinase inhibitors (ROCK-i, Ripasudil and Y27632) on their efficiency for aqueous outflow, 2D or 3D cultures of a human trabecular meshwork (HTM) were prepared in the presence of TGFβ2. Those were examined by transendothelial electrical resistance (TEER, 2D), electronic microscopy (EM, 2D and 3D), expression of the extracellular matrix (ECM) including collagen1 (COL1), COL4 and COL6, and fibronectin (FN) by immunolabeling and/or quantitative PCR (3D), and solidity of 3D organoids by a micro-squeezer. TGFβ2 significantly increased the TEER values in 2D cultures, and the ECM expression indicated that the 3D organoids assumed a more densely packed shape. ROCK-i greatly reduced the TGFβ2-induced enhancement of TEER and the immunolabeled ECM expression of the 3D organoids. In contrast, the mRNA expression of COL1 was increased, and those of COL4 and FN were unchanged. EM revealed that TGFβ2 caused the HTM cells to become more compact and abundant ECM deposits within the 3D organoids were observed. These were significantly inhibited by ROCK-i. The dense solids caused by the presence of TGFβ2 were significantly suppressed by ROCK-i. Current study indicates that ROCK-i cause beneficial effects toward the spatial configuration of TGFβ2-induced HTM 3D organoids.