The stimulatory effect of ROCK inhibitor on bovine corneal endothelial cells

ROCK Inhibitors as an Alternative Therapy for Corneal Grafting: A Systematic Review

Currently, corneal blindness is affecting >10 million individuals worldwide, and there is a significant unmet medical need because only 1.5% of transplantation needs are met globally due to a lack of high-quality grafts. In light of this global health disaster, researchers are developing corneal substitutes that can resemble the human cornea in vivo and replace human donor tissue. Thus, this review examines ROCK (Rho-associated coiled-coil containing protein kinases) inhibitors as a potential corneal wound-healing (CWH) therapy by reviewing the existing clinical and nonclinical findings. The systematic review was done from PubMed, Scopus, Web of Science, and Google Scholar for CWH, corneal injury, corneal endothelial wound healing, ROCK inhibitors, Fasudil, Netarsudil, Ripasudil, Y-27632, clinical trial, clinical study, case series, case reports, preclinical study, in vivo, and in vitro studies. After removing duplicates, all downloaded articles were examined. The literature search included the data till January 2023. This review summarized the results of ROCK inhibitors in clinical and preclinical trials. In a clinical trial, various ROCK inhibitors improved CWH in individuals with open-angle glaucoma, cataract, iris cyst, ocular hypertension, and other ocular diseases. ROCK inhibitors also improved ocular wound healing by increasing cell adhesion, migration, and proliferation in vitro and in vivo. ROCK inhibitors have antifibrotic, antiangiogenic, anti-inflammatory, and antiapoptotic characteristics in CWH, according to the existing research. ROCK inhibitors were effective topical treatments for corneal infections. Ripasudil, Y-27632, H-1152, Y-39983, and AMA0526 are a few new ROCK inhibitors that may help CWH and replace human donor tissue.

Effects of Y-27632, a Rho-associated Kinase Inhibitor, on Human Corneal Endothelial Cells Cultured by Isolating Human Corneal Endothelial Progenitor Cells

CONCLUSIONS

Y-27632 enabled the isolation and expansion of HCEPs. It also enhanced the proliferation, viability, and migration of differentiated HCEPs.

METHODS

HCEPs were isolated and expanded in a medium with and without 10μM Y-27632, and then differentiated into HCECs in a medium with fetal bovine serum. The characteristics of HCEPs and differentiated HCEPs were confirmed by immunofluorescence staining. The proliferation, viability, morphology, and wound-healing ability of differentiated HCEPs were assessed in the presence of different concentrations of Y-27632.

PURPOSE

Human corneal endothelial progenitor cells (HCEPs), which has been selectively isolated and differentiated into human corneal endothelial cells (HCECs), are crucial for repairing corneal endothelial damage. In this study, we evaluated the roles of a Rho-assisted kinase (ROCK) inhibitor, Y-27632, on the isolation and expansion of HCEPs, and assessed the in vitro effects of different concentrations of Y-27632 on the differentiated HCEPs.

RESULTS

Y-27632 enabled the isolation and expansion of HCEPs from the corneal endothelium. The differentiated HCEPs showed an optimal increase in proliferation and survival in the presence of 10μM Y-27632. As the concentration of Y-27632 increased, differentiated HCEPs became elongated, and actin filaments were redistributed to the periphery of cells. Y-27632 also caused a concentration-dependent enhancement in the wound-healing ability of differentiated HCEPs.

Experimental design of a culture approach for corneal endothelial cells of New Zealand white rabbit

The harvesting of corneal endothelial cells (CEC) has received special attention due to its potential as a therapy for corneal blindness. The main challenges are related to the culture media formulation, cellular density at the primary isolation, and the number of passages in which CEC can retain their functional characteristics. To alternate different media formulations to harvest CEC has an impact on the cellular yield and morphology. Therefore, we analyzed four different sequences of growth factor-supplemented Stimulatory (S) and non-supplemented Quiescent (Q) media, upon passages to find the optimal S-Q culture sequence. We assessed cell yield, morphology, procollagen I production, Na⁺/K⁺-ATPase function, and the expression of ZO-1 and Na⁺/K⁺-ATPase. Our results show SQSQ and SQQQ sequences with a balance between an improved cell yield and hexagonal morphology rate. CEC cultured in the SQQQ sequence produced procollagen I, showed Na⁺/K⁺-ATPase function, and expression of ZO-1 and Na⁺/K⁺-ATPase. Our study sets a culture approach to guarantee CEC expansion, as well as functionality for their potential use in tissue engineering and in vivo analyses. Thus, the alternation of S and Q media improves CEC culture. SQQQ sequence demonstrated CEC proliferation and lower the cost implied in SQSQ sequences. We discarded the use of pituitary extract and ROCK inhibitors as essential for CEC proliferation.

Targeting non-muscle myosin II promotes corneal endothelial migration through regulating lamellipodial dynamics

Corneal endothelial cell (CEC) dysfunction causes corneal edema that may lead to blindness. In addition to corneal transplantation, simple descemetorhexis has been proposed to treat centrally located disease with adequate peripheral cell reserve, but promoting the centripetal migration of CECs is pivotal to this strategy. Here, we show that targeting non-muscle myosin II (NMII) activity by Y27632, a ROCK inhibitor, or blebbistatin, a selective NMII inhibitor, promotes directional migration of CECs and accelerates in vitro wound healing. The lamellipodial protrusion persistence is increased, and actin retrograde flow is decreased after NMII inhibition. Counteracting lamellipodial protrusion by actin-related protein 2/3 (ARP2/3) inhibitor abolishes this migration-promoting effect. Although both Y27632 and blebbistatin accelerate wound healing, cell junctional integrity and barrier function are better preserved after blebbistatin treatment, leading to more rapid corneal deturgescence in rabbit corneal endothelial wounding model. Our findings indicate that NMII is a promising therapeutic target in the treatment of CEC dysfunction. KEY MESSAGES: NMII inhibition promotes directional migration and wound healing of CECs in vitro. Lamellipodial protrusion persistence is increased after NMII inhibition. Selective NMII inhibitor preserves junctional integrity better than ROCK inhibitor. Selective NMII inhibitor accelerates corneal deturgescence after wounding in vivo.

Characterization of the iPSC-derived conditioned medium that promotes the growth of bovine corneal endothelial cells

Corneal endothelial cells (CECs) maintain corneal transparency and visual acuity. However, the limited proliferative capability of these cells in vitro has prompted researchers to find efficient culturing techniques for them. The aim of our study was to evaluate the use of conditioned medium (CM) obtained from induced pluripotent stem cells (iPSCs) as a source for the effective proliferation of bovine CECs (B-CECs). In our study, the proliferative ability of B-CECs was moderately enhanced when the cells were grown in 25% iPSC conditioned medium (iPSC-CM). Additionally, hexagonal cell morphology was maintained until passage 4, as opposed to the irregular and enlarged shape observed in control corneal endothelial medium (CEM). B-CECs in both the 25% iPSC-CM and CEM groups expressed and Na+-K+-ATPase. The gene expression levels of NIFK, Na+-K+-ATPase, Col4A and Col8A and the percentage of cells entering S and G2 phases were higher in the iPSC-CM group. The number of apoptotic cells also decreased in the iPSC-CM group. In comparison to the control cultures, iPSC-CM facilitated cell migration, and these cells showed better barrier functions after several passages. The mechanism of cell proliferation mediated by iPSC-CM was also investigated, and phosphorylation of Akt was observed in B-CECs after exposure to iPSC-CM and showed sustained phosphorylation induced for up to 180 min in iPSC-CM. Our findings indicate that iPSC-CM may employ PI3-kinase signaling in regulating cell cycle progression, which can lead to enhanced cellular proliferation. Effective component analysis of the CM showed that in the iPSC-CM group, the expression of activin-A was significantly increased. If activin-A is added as a supplement, it could help to maintain the morphology of the cells, similar to that of CM. Hence, we conclude that activin-A is one of the effective components of CM in promoting cell proliferation and maintaining cell morphology.

From DMEK to Corneal Endothelial Cell Therapy: Technical and Biological Aspects

The main treatment available for restoration of the corneal endothelium is keratoplasty and DMEK provides faster visual recovery and better postoperative visual acuity when compared to DSAEK. However, the technical challenges related to this technique and the steep technical learning curve seem to prevent the overcoming of DSAEK in favor of DMEK. Furthermore, the outcome of lamellar keratoplasty techniques is influenced by problems related to corneal grafting tissue availability, management, and quality. On the other hand, improvements in the field of cell engineering have opened the way for the use of stem cells-derived corneal endothelial cells with regenerative intent. In this overview, latest findings in endothelial cell engineering are reported, and perspectives of clinical application of mesenchymal stem cells for corneal endothelial replacement and regeneration are evaluated.

Rho-kinase inhibitor Y-27632 facilitates the proliferation, migration and pluripotency of human periodontal ligament stem cells

The selective in vitro expansion and differentiation of multipotent stem cells are critical steps in cell-based regenerative therapies, while technical challenges have limited cell yield and thus affected the success of these potential treatments. The Rho GTPases and downstream Rho kinases are central regulators of cytoskeletal dynamics during cell cycle and determine the balance between stem cells self-renewal, lineage commitment and apoptosis. Trans-4-[(1R)-aminoethyl]-N-(4-pyridinyl)cylohexanecarboxamidedihydrochloride (Y-27632), Rho-associated kinase (ROCK) inhibitor, involves various cellular functions that include actin cytoskeleton organization, cell adhesion, cell motility and anti-apoptosis. Here, human periodontal ligament stem cells (PDLSCs) were isolated by limiting dilution method. Cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU) labelling assay, cell apoptosis assay, cell migration assay, wound-healing assay, alkaline phosphatase (ALP) activity assay, Alizarin Red S staining, Oil Red O staining, quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the effects of Y-27632 on the proliferation, apoptosis, migration, stemness, osteogenic and adipogenic differentiation of PDLSCs. Afterwards, Western blot analysis was performed to elucidate the mechanism of cell proliferation. The results indicated that Y-27632 significantly promoted cell proliferation, chemotaxis, wound healing, fat droplets formation and pluripotency, while inhibited ALP activity and mineral deposition. Furthermore, Y-27632 induced PDLSCs proliferation through extracellular-signal-regulated kinase (ERK) signalling cascade. Therefore, control of Rho-kinase activity may enhance the efficiency of stem cell-based treatments for periodontal diseases and the strategy may have the potential to promote periodontal tissue regeneration by facilitating the chemotaxis of PDLSCs to the injured site, and then enhancing the proliferation of these cells and maintaining their pluripotency.

A Surgical Cryoprobe for Targeted Transcorneal Freezing and Endothelial Cell Removal

Purpose

To examine the effects of transcorneal freezing using a new cryoprobe designed for corneal endothelial surgery.

Methods

A freezing console employing nitrous oxide as a cryogen was used to cool a series of different cryoprobe tip designs made of silver for high thermal conductivity. In vitro studies were conducted on 426 porcine corneas, followed by preliminary in vivo investigations on three rabbit corneas.

Results

The corneal epithelium was destroyed by transcorneal freezing, as expected; however, the epithelial basement membrane remained intact. Reproducible endothelial damage was optimally achieved using a 3.4 mm diameter cryoprobe with a concave tip profile. Stromal edema was seen in the pre-Descemet's area 24 hrs postfreeze injury, but this had been resolved by 10 days postfreeze. A normal collagen fibril structure was seen 1 month postfreeze, concurrent with endothelial cell repopulation.

Conclusions

Transcorneal freezing induces transient posterior stromal edema and some residual deep stromal haze but leaves the epithelial basement membrane intact, which is likely to be important for corneal re-epithelialization. Localized destruction of the endothelial monolayer was achieved in a consistent manner with a 3.4 mm diameter/concave profile cryoprobe and represents a potentially useful approach to remove dysfunctional corneal endothelial cells from corneas with endothelial dysfunction.

In vitro biomimetic platforms featuring a perfusion system and 3D spheroid culture promote the construction of tissue-engineered corneal endothelial layers

Corneal endothelial cells (CECs) are very important for the maintenance of corneal transparency. However, in vitro, CECs display limited proliferation and loss of phenotype via endothelial to mesenchymal transformation (EMT) and cellular senescence. In this study, we demonstrate that continuous supplementary nutrition using a perfusion culture bioreactor and three-dimensional (3D) spheroid culture can be used to improve CEC expansion in culture and to construct a tissue-engineered CEC layer. Compared with static culture, perfusion-derived CECs exhibited an increased proliferative ability as well as formed close cell-cell contact junctions and numerous surface microvilli. We also demonstrated that the CEC spheroid culture significantly down-regulated gene expression of the proliferation marker Ki67 and EMT-related markers Vimentin and α-SMA, whereas the gene expression level of the CEC marker ATP1A1 was significantly up-regulated. Furthermore, use of the perfusion system in conjunction with a spheroid culture on decellularized corneal scaffolds and collagen sheets promoted the generation of CEC monolayers as well as neo-synthesized ECM formation. This study also confirmed that a CEC spheroid culture on a curved collagen sheet with controlled physiological intraocular pressure could generate a CEC monolayer. Thus, our results show that the use of a perfusion system and 3D spheroid culture can promote CEC expansion and the construction of tissue-engineered corneal endothelial layers in vitro.

In Vivo Functionality of a Corneal Endothelium Transplanted by Cell-Injection Therapy in a Feline Model

PURPOSE

To evaluate the functionality of a corneal endothelium reconstituted by injection of corneal endothelial cells (CEC) in the anterior chamber of a feline model.

METHODS

We operated the right eyes of 16 animals. Eight underwent central endothelial scraping and injection with 2 × 10(5) (n = 4) or 1 × 10(6) (n = 4) feline CEC supplemented with Y-27632 and labeled with 3,3'-Dioctadecyl-5,5'-Di(4-Sulfophenyl)Oxacarbocyanine (SP-DiOC18[3] or DiOC). After total endothelial scraping, two eyes were injected with 1 × 10(6) labeled CEC and Y-27632. The central (n = 3) or entire (n = 3) endothelium was scraped in six eyes followed by Y-27632 injection without CEC. Subjects were positioned eyes down for 3 hours. Outcomes included graft transparency, pachymetry, CEC morphometry, histology, electron microscopy, and function and wound healing-related protein immunostaining.

RESULTS

Postoperatively, corneas grafted with 2 × 10(5) CEC and centrally scraped controls displayed the best transparency and pachymetry. Corneas grafted with 1 × 10(6) CEC yielded intermediate results. Entirely scraped controls remained hazy and thick. Histopathology revealed a confluent endothelial monolayer expressing sodium-potassium adenosine triphosphatase (Na(+)/K(+)-ATPase) and zonula occludens-1 (ZO-1) in corneas grafted with 2 × 10(5) CEC and centrally scraped controls, a nonuniform endothelial multilayer without expression of functional proteins in centrally scraped corneas grafted with 1 × 10(6) CEC, and a nonfunctional fibrotic endothelium in entirely scraped grafts and controls. Expression of DiOC in grafts was scarce.

CONCLUSIONS

Injected CEC contributed little to the incompletely functional endothelium of grafted corneas. Y-27632 injection without CEC following scraping reconstituted the healthiest endothelium. Further studies investigating the therapeutic effect of Y-27632 alone are needed to validate these conclusions.

PAC1R agonist maxadilan enhances hADSC viability and neural differentiation potential

Pituitary adenylate cyclase‐activating polypeptide (PACAP) is a structurally endogenous peptide with many biological roles. However, little is known about its presence or effects in human adipose‐derived stem cells (hADSCs). In this study, the expression of PACAP type I receptor (PAC1R) was first confirmed in hADSCs. Maxadilan, a specific agonist of PAC1R, could increase hADSC proliferation as determined by Cell Counting Kit‐8 and cell cycle analysis and promote migration as shown in wound‐healing assays. Maxadilan also showed anti‐apoptotic activity in hADSCs against serum withdrawal‐induced apoptosis based on Annexin V/propidium iodide analysis and mitochondrial membrane potential assays. The anti‐apoptotic effects of maxadilan correlated with the down‐regulation of Cleaved Caspase 3 and Caspase 9 as well as up‐regulation of Bcl‐2. The chemical neural differentiation potential could be enhanced by maxadilan as indicated through quantitative PCR, Western blot and cell morphology analysis. Moreover, cytokine neural redifferentiation of hADSCs treated with maxadilan acquired stronger neuron‐like functions with higher voltage‐dependent tetrodotoxin‐sensitive sodium currents, higher outward potassium currents and partial electrical impulses as determined using whole‐cell patch clamp recordings. Maxadilan up‐regulated the Wnt/β‐catenin signalling pathway associated with dimer‐dependent activity of PAC1R, promoting cell viability that was inhibited by XAV939, and it also activated the protein kinase A (PKA) signalling pathway associated with ligand‐dependent activity of PAC1R, enhancing cell viability and neural differentiation potential that was inhibited by H‐89. In summary, these results demonstrated that PAC1R is present in hADSCs, and maxadilan could enhance hADSC viability and neural differentiation potential in neural differentiation medium.

The effects of Rho-associated kinase inhibitor Y-27632 on primary human corneal endothelial cells propagated using a dual media approach

The global shortage of donor corneas has garnered extensive interest in the development of graft alternatives suitable for endothelial keratoplasty using cultivated primary human corneal endothelial cells (CECs). We have recently described a dual media approach for the propagation of human CECs. In this work, we characterize the effects of a Rho-kinase inhibitor Y-27632 on the cultivation of CECs propagated using the dual media culture system. Seventy donor corneas deemed unsuitable for transplantation were procured for this study. We assessed the use of Y-27632 for its effect at each stage of the cell culture process, specifically for cell attachment, cell proliferation, and during both regular passaging and cryopreservation. Lastly, comparison of donor-matched CEC-cultures expanded with or without Y-27632 was also performed. Our results showed that Y-27632 significantly improved the attachment and proliferation of primary CECs. A non-significant pro-survival effect was detected during regular cellular passage when CECs were pre-treated with Y-27632, an effect that became more evident during cryopreservation. Our study showed that the inclusion of Y-27632 was beneficial for the propagation of primary CECs expanded via the dual media approach, and was able to increase overall cell yield by between 1.96 to 3.36 fold.

The effects of ROCK inhibitor Y-27632 on injectable spheroids of bovine corneal endothelial cells

The spheroids of 3-dimensional culture and Rho-associated kinase (ROCK) inhibitor Y-27632 have shown many advantages for the promotion of cellular viability and proliferation. The objective of this study was to investigate the effect of Y-27632 on the growth and injectability of bovine corneal endothelial cells (B-CECs) maintained in vitro as spheroid cultures. Immunofluorescence staining showed that Y-27632 did not alter the cell type specificity of B-CECs, but it significantly enhanced B-CEC spherical viability and proliferation by a Live/Dead assay, 5-ethynyl-2'-deoxyuridine (EdU) labeling assay, and Cell Counting Kit-8 (CCK-8) assay. The uniform B-CEC spheroids could easily form in multiwall agarose micromolds and had a higher stemness potential than single B-CECs. Injectable B-CEC spheroids were able to form monolayer growth, and polygonal B-CECs completely covered culture plates or Descemet's membrane of decellularized corneas under inverted microscopy and scanning electron microscopy (SEM). B-CEC spheroids were generated from agarose microwells on day 1 and then adherent culture with Y-27632 for day 5. However, small B-CEC spheroids still existed on culture plates or decellularized corneas when B-CEC spheroids were cultured in the same condition except for absence of Y-27632. Our findings that CEC spheroids with Y-27632 are injectable in vitro have important implications for the favorable treatment of CEC deficiency.