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Abstract Age-related macular degeneration (AMD) is associated with the dysfunction and degeneration of retinal pigment epithelium (RPE) cells. Here, we examined how the formation and expansions of cell clusters are regulated by the differentiation of the RPE cells. In this study, ARPE-19 cells were cultivated in standard or differentiation media, i.e., without or with nicotinamide, to evaluate the spreading of cell clusters specified with differentiated cell phenotypes. Mitochondria membrane potential (MMP) and the distribution of the RPE cell clusters was also monitored with or without rotenone, a mitochondrial electron transport chain (ETC) complex I inhibitor. Cultured ARPE-19 cells generated scattered cell clusters composed mostly of smaller size cells expressing the differentiation markers mouse anti-cellular retinaldehyde–binding protein (CRALBP) and Bestrophin only in differentiation medium. After the increase of the number of clusters, the clusters appeared to paracellularly merge, resulting in expansion of the area occupied by the clusters. Of note, the cells within the clusters selectively had high MMP and were in accordance with the expression of RPE differentiation markers. Rotenone repressed the formation of the clusters and decreased intracellular MMP. The above results suggest that clustering of RPE cells with functional mitochondria plays a pivotal role in RPE cell differentiation process and the ETC complex I inhibition greatly influences the composition of RPE cells that are degenerated or differentiation disposed.

Purpose: The purpose of the study was to clarify the interplay between metabolites and microRNAs (miRs) in the aqueous humor (AqH) of bullous keratopathy (BK) patients to retain human corneal endothelium (HCE) integrity. Design: Prospective, comparative, observational study. Participants: A total of 55 patients with BK and 31 patients with cataract (Cat) as control. Methods: A biostatic analysis of miRs and metabolites in the AqH, hierarchical clustering, and a least absolute shrinkage and selection operator (Lasso) analysis were employed. The miR levels in AqH of BK (n = 18) and Cat (n = 8) patients were determined using 3D-Gene human miR chips. Hierarchical clusters of metabolites detected by liquid chromatography–mass spectrometry or gas chromatography–mass spectrometry in AqH specimens from 2 disease groups, BK (total n = 55) and Cat (total n = 31), were analyzed twice to confirm the reproducibility. The analytical procedure applied for investigating the association between metabolites and miRs in AqH was the exploratory data analysis of biostatistics to avoid any kind of prejudice. This research procedure includes a heat-map, cluster analysis, feature extraction techniques by principal component analysis, and a regression analysis method by Lasso. The cellular and released miR levels were validated using reverse transcription polymerase chain reaction and mitochondria membrane potential was assessed to determine the functional features of the released miRs. Main Outcome Measures: Identification of interacting metabolites and miRs in AqH attenuating HCE degeneration. Results: The metabolites that decreased in the AqH of BK patients revealed that 3-hydroxyisobutyric acid (HIB), 2-aminobutyric acid (AB) and branched-chain amino acids, and serine were categorized into the same cluster by hierarchical clustering of metabolites. The positive association of HIB with miR-34a-5p was confirmed (P = 0.018), and the Lasso analysis identified the interplay between miR-34a-5p and HIB, between miR-24-3p and AB, and between miR-34c-5p and serine (P = 0.041, 0.027, and 0.009, respectively). 3-hydroxyisobutyric acid upregulated the cellular miR-34a expression, mitochondrial membrane potential, and release of miR-184 in dedifferentiated cultured HCE cells. Conclusions: Metabolites and miRs in AqH may synchronize in ensuring the integrity of the HCE to maintain efficient dehydration from the stroma. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Abstract This study aims to clarify the immunogenicity in acquired and innate immune responses of cultured human corneal endothelial cells (hCECs) applied for cell injection therapy, a newly established modality for corneal endothelium failures. Thirty-four patients with corneal endothelial failure received injection of allogeneic hCEC suspension into anterior chamber. No sign of immunological rejection was observed in all 34 patients during the 5–8 years postoperative follow-up period. Cell injection therapy was successful in 2 patients treated for endothelial failure after penetrating keratoplasty and one patient with Descemet membrane stripping automated endothelial keratoplasty failure. ELISPOT assays performed in allo-mixed lymphocyte reaction to the alloantigen identical to that on the injected hCECs, elicited sparse IFN-γ-specific spots in the peripheral blood mononuclear cells of patients who received hCEC injection. The therapy generated simple and smooth graft-host junctions without wound stress. The injection of C57BL/6 CECs into the anterior chamber of BALB/c mice, which rejected C57BL/6 corneas 6 weeks ago, induced no sign of inflammatory reactions after the second challenge of alloantigen. Collectively, injection of the hCEC cell suspension in the aqueous humor induces immune tolerance that contributes to the survival of the reconstituted endothelium.

Abstract This study aimed to uncover the mechanism responsible for the clinical efficacy of cell injection therapy with fully differentiated cultured cells. Analysis of polarized expression of ion transporters on cultured human corneal endothelial cells (CECs) subpopulations (SPs) was performed. The intracellular pH (pHi) between two CEC SPs, distinct in the proportion of differentiated cells, was measured, and the association with mitochondrial respiration homeostasis was investigated. The effects of the ion transporter inhibition by their selective inhibitors or siRNA transfection were also explored. Na+/K+-ATPase, Aquaporin 1, SLC4A11, NBCe1, NHE1 as transporters, and ZO-1, were all selectively expressed in differentiated SPs, but were almost null in the cell-state-transitioned SPs. We also confirmed that the pHi of CEC SPs affected their mitochondrial respiration by modulating the expression of these ion transporters via inhibitors or siRNA transfection. Ion and water transporters might participate in the maintenance of pHi and mitochondria homeostasis in differentiated SPs, which may contribute, combined with integral barrier functions, to efficient water efflux. The differences in intracellular pH between the two SPs is attributed to variations in the expression profile of specific ion transporters and mitochondrial functions, which may associate with the efficacy of the SPs in cell injection therapy.

Objective: The objective of the study was to reveal the presence of cellular interplay through extracellular vesicle (EV) microRNAs (miRs), to dampen the vicious cycle to degenerate human corneal endothelium (HCE) tissues. Design: Prospective, comparative, observational study. Methods: The miR levels in neonate-derived corneal tissues, in the aqueous humor (AqH) of bullous keratoplasty and cataract patients, as well as in the culture supernatant (CS) and EV of cultured human corneal endothelial cells (hCECs), were determined using 3D-Gene human miR chips and then validated using the real-time polymerase chain reaction. The extracellularly released miRs were profiled after the forced downregulation of cellular miR-34a, either by an miR-34a inhibitor or exposure to H2O2. The senescence-associated secretory phenotypes and mitochondrial membrane potential (MMP) were assessed to determine the functional features of the released miRs. Main Outcome Measures: Identification of functional miRs attenuating HCE degeneration. Results: The miRs in AqH were classified into 2 groups: expression in 1 group was significantly reduced in neonate-derived tissues, whereas that in the other group remained almost constant, independent of aging. The miR-34a and -29 families were typical in the former group, whereas miR-184 and -24-3p were typical in the latter. Additionally, a larger amount of the latter miRs was detected in AqH compared with those of the former miRs. There was also a greater abundance of miR-184 and -24-3p in hCECs, EV, and CS in fully mature CD44−/dull hCEC, leading to sufficient clinical tissue regenerative capacity in cell injection therapy. The repression of cellular miR-34a, either due to miR-34a inhibitors or exposure to oxidative stress, unexpectedly resulted in the elevated release of miR-184 and -24-3p. Secretions of VEGF, interleukin 6, monocyte chemotactic protein-1, and MMP were all repressed in both mature CD44−/dull and degenerated CD44+++ hCEC, transfected with an miR-184 mimic. Conclusions: The elevated release of miR-184 into AqH may constitute cellular interplay that prevents the aggravation of HCE degeneration induced by oxidative stress, thereby sustaining tissue homeostasis in HCE.

Abstract This study investigated the pathophysiological features of pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD) by analysing and comparing cytokine profiles in aqueous humour (AH) collected from 18 PNV, 18 nAMD and 11 control patients. Responses to intravitreal injection of aflibercept were also analysed in the PNV and nAMD groups. In the PNV group, vascular endothelial growth factor (VEGF)-A was significantly lower than in the nAMD group (p = 0.03) but was almost identical to that in the control group (p = 0.86). The nAMD group showed positive correlations between interleukin (IL)-6 and IL-8 (r = 0.78, p

Corneal endothelial dysfunctions occurring in patients with Fuchs' endothelial corneal dystrophy, pseudoexfoliation syndrome, corneal endotheliitis, and surgically induced corneal endothelial damage cause blindness due to the loss of endothelial function that maintains corneal transparency. Transplantation of cultivated corneal endothelial cells (CECs) has been researched to repair endothelial dysfunction in animal models, though the in vitro expansion of human CECs (HCECs) is a pivotal practical issue. In this study we established an optimum condition for the cultivation of HCECs. When exposed to culture conditions, both primate and human CECs showed two distinct phenotypes: contact-inhibited polygonal monolayer and fibroblastic phenotypes. The use of SB431542, a selective inhibitor of the transforming growth factor-beta (TGF-β) receptor, counteracted the fibroblastic phenotypes to the normal contact-inhibited monolayer, and these polygonal cells maintained endothelial physiological functions. Expression of ZO-1 and Na(+)/K(+)-ATPase maintained their subcellular localization at the plasma membrane. Furthermore, expression of type I collagen and fibronectin was greatly reduced. This present study may prove to be the substantial protocol to provide the efficient in vitro expansion of HCECs with an inhibitor to the TGF-β receptor, and may ultimately provide clinicians with a new therapeutic modality in regenerative medicine for the treatment of corneal endothelial dysfunctions.