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Purpose: This study investigated the protective effect of probucol on Müller cells exposed to high glucose conditions and examined potential mechanisms of action. Methods: Primary human retinal Müller cells were incubated with high glucose (HG, 35 mM) in the present or absence of different concentrations of probucol for 24 h. Cell viability was determined using the CCK-8 method. Mitochondrial membrane potential (MMP) was measured using JC-1 staining and cell cycle by flow cytometry. The expression of nuclear factor E2-related factor 2 (Nrf2), glutamate–cysteine ligase catalytic subunit, and p62 was quantified using quantitative polymerase chain reaction and western blot. Results: We found that HG inhibited cell proliferation, arrested cell cycle, and increased MMP in human Müller cells. Probucol activated the Nrf2/p62 pathway and upregulated the anti-apoptotic protein, Bcl2, and attenuated HG-mediated damage in Müller cells. Conclusions: Our results suggest that probucol may protect Müller cells from HG-induced damage through enhancing the Nrf2/p62 signaling pathway. [ABSTRACT FROM AUTHOR]

Aging is a risk factor for multiple retinal degeneration diseases. Entraining brain gamma oscillations with gamma-flicker light (γFL) has been confirmed to coordinate pathological changes in several Alzheimer's disease mouse models and aged mice. However, the direct effect of γFL on retinal aging remains unknown. We assessed retinal senescence-associated beta-galactosidase (β-gal) and autofluorescence in 20-month-old mice and found reduced β-gal-positive cells in the inner retina and diminished lipofuscin accumulation around retinal vessels after 6 days of γFL. In immunofluorescence, γFL was further demonstrated to ameliorate aging-related retinal changes, including a decline in microtubule-associated protein 1 light chain 3 beta expression, an increase in complement C3 activity, and an imbalance between the anti-oxidant factor catalase and pro-oxidant factor carboxymethyl lysine. Moreover, we found that γFL can increase the expression of activating transcription factor 4 (ATF4) in the inner retina, while revealing a decrease of ATF4 expression in the inner retina and positive expression in the outer segment of photoreceptor and RPE layer for aged mice. Western blotting was then used to confirm the immunofluorescence results. After mRNA sequencing (NCBI Sequence Read Archive database: PRJNA748184), we found several main mechanistic clues, including mitochondrial function and chaperone-mediated protein folding. Furthermore, we extended γFL to aged Apoe−/− mice and showed that 1-m γFL treatment even improved the structures of retinal-pigment-epithelium basal infolding and Bruch's membrane. Overall, γFL can orchestrate various pathological characteristics of retinal aging in mice and might be a noninvasive, convenient, and tissue-specific therapeutic strategy for retinal aging. [ABSTRACT FROM AUTHOR]

Human adipose-derived stem cells (hASCs) become an appealing source for regenerative medicine. However, with the multi-passage or cryopreservation for large-scale growth procedures in terms of preclinical and clinical purposes, hASCs often reveal defective cell viability, which is a major obstacle for cell therapy. In our study, the effects of induced pluripotent stem cells-derived conditioned medium (iPS-CM) on the proliferation and anti-apoptosis in hASCs were investigated. hASCs at passage 1 were identified by the analysis of typical surface antigens with flow cytometry assay and adipogenic and osteogenic differentiation. The effect of iPS-CM on the proliferation in hASCs was analyzed by cell cycle assay and Ki67/P27 quantitative polymerase chain reaction analysis. The effect of iPS-CM on the anti-apoptosis of hASCs irradiated by 468 J/m of ultraviolet C was investigated by annexin v/propidium iodide analysis, mitochondrial membrane potential assay, intracellular reactive oxygen species assay, Western blotting and caspase activity assays. The effect of iPS-CM on the surface antigen expressions of hASCs was analyzed using flow cytometry assay. The levels of Activin A and bFGF in culture supernatant of hASCs with different treatments were also detected by enzyme-linked immunosorbent assay. iPS-CM promoted proliferation and inhibited apoptosis of hASCs. This discovery demonstrates that iPS-CM might be used as one of the available means to overcome the propagation obstacle for hASCs and make for large-scale growth procedures in terms of preclinical and clinical purposes. [ABSTRACT FROM AUTHOR]

Phenotype transformation of corneal keratocyte to myofibroblast plays an important role in the wound healing process of cornea and TGFβ is considered to be the most important mediator to induce myofibroblast trans-differentiation. Peroxisome proliferator-activated receptors-γ (PPAR-γ) activation has been proved to exert anti-fibrotic effect in many tissues. In this study, we investigated the effect of PPAR-γ agonist, pioglitazone, on myofibroblast transformation, extracellular matrix production and cell proliferation. The results showed pioglitazone inhibited the TGFβ-driven myofibroblast differentiation, as determined by F-actin fluorescence staining, α-smooth muscle actin-specific immunocytochemistry and western blot analysis. Pioglitazone also potently attenuated TGFβ induced type I collagen and fibronectin mRNA and protein production. Moreover, pioglitazone showed inhibitory effect on TGFβ induced cell proliferation. The irreversible PPAR-γ antagonist GW9662, partially reversed the inhibition of collagen I and fibronectin expression but not myofibroblast transformation, suggesting both PPAR-γ dependent and PPAR-γ independent mechanisms were involved in the action of pioglitazone. Therefore, our study indicates pioglitazone has a potential application in therapy of corneal fibrosis and PPAR-γ might be a promising therapy target. [ABSTRACT FROM AUTHOR]