Publications by authors named "Sze Wan Shan"

Secretion of melatonin, a natural hormone whose receptors are present in the ciliary epithelium, displays diurnal variation in the aqueous humor (AH), potentially contributing to the regulation of intraocular pressure. This study aimed to determine the effects of melatonin on AH secretion in porcine ciliary epithelium. The addition of 100 µM melatonin to both sides of the epithelium significantly increased the short-circuit current (Isc) by ~40%.

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Elevated intraocular pressure (IOP) is a major risk factor for glaucoma that results from impeded fluid drainage. The increase in outflow resistance is caused by trabecular meshwork (TM) cell dysfunction and excessive extracellular matrix (ECM) deposition. Baicalein (Ba) is a natural flavonoid and has been shown to regulate cell contraction, fluid secretion, and ECM remodeling in various cell types, suggesting the potential significance of regulating outflow resistance and IOP.

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Gene expression of the chick retina was examined during the early development of lens-induced myopia (LIM) using whole transcriptome sequencing. Monocular treatment of the right eyes with -10 diopter (D) lenses was performed on newly born chicks for one day (LIM-24) or two days (LIM-48), while the contralateral eyes without lenses served as controls. Myopia development was confirmed by demonstrating significant elongation of the optical axis in lens-treated eyes compared to untreated control eyes.

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In age-related macular degeneration (AMD), hydroquinone (HQ)-induced oxidative damage in retinal pigment epithelium (RPE) is believed to be an early event contributing to dysregulation of inflammatory cytokines and vascular endothelial growth factor (VEGF) homeostasis. However, the roles of antioxidant mechanisms, such as autophagy and the ubiquitin-proteasome system, in modulating HQ-induced oxidative damage in RPE is not well-understood. This study utilized an in-vitro AMD model involving the incubation of human RPE cells (ARPE-19) with HQ.

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Rho-kinase (ROCK) inhibitors, a novel class of anti-glaucoma agents, act by increasing the aqueous humor outflow through the conventional trabecular meshwork pathway. However, the downstream signaling consequences of the ROCK inhibitor are not completely understood. Our data show that Y39983, a selective ROCK inhibitor, could induce filamentous actin remodeling, reduced cell motility (as measured by cell migration), and transepithelial resistance in primary human TM (hTM) cells.

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Myopia is a common ocular disorder with significant alterations in the anterior ocular structure, including the cornea. The cell biophysical phenotype has been proposed to reflect the state of various diseases. However, the biophysical properties of corneal cells have not been characterized during myopia progression and their relationship with myopia remains unknown.

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Our previous research showed that increased phosphorylation of connexin (Cx)36 indicated extended  coupling of AII amacrine cells (ACs) in the rod-dominant mouse myopic retina. This research will determine whether phosphorylation at serine 276 of Cx35-containing gap junctions increased in the myopic chicken, whose retina is cone-dominant. Refractive errors and ocular biometric dimensions of 7-days-old chickens were determined following 12 h and 7 days induction of myopia by a -10D lens.

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Trehalose is a natural dietary molecule that has shown antiaging and neuroprotective effects in several animal models of neurodegenerative diseases. The role of trehalose in the management of age-related macular degeneration (AMD) is yet to be investigated and whether trehalose could be a remedy for the treatment of diseases linked to oxidative stress and NRF2 dysregulation. Here, we showed that incubation of human retinal pigment epithelial (RPE) cells with trehalose enhanced the mRNA and protein expressions of TFEB, autophagy genes and , as well as protein expressions of macroautophagy markers, LC3B and p62/SQTM1, and the chaperone-mediated autophagy (CMA) receptor LAMP2.

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Rho-associated coiled coil-forming protein kinase (ROCK) inhibitors represent a novel class of anti-glaucoma drugs because of their ocular hypotensive effects. However, the underlying mechanisms responsible for lowering intraocular pressure (IOP) are not completely clear. The protein profile changes in primary human trabecular meshwork (TM) cells after two days treatment with a ROCK inhibitor were studied using label-free SWATH acquisition.

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Myopia, the most common cause of impaired vision, may induce sight- threatening diseases or ocular complications due to axial elongation. The exact mechanisms underlying myopia development have received much attention and understanding of these is necessary for clinical prevention or therapeutics. In this study, quantitative proteomics using Isotope Coded Protein Label (ICPL) was applied to identify differentially regulated proteins in the retinas of myopic chicks and, from their presence, infer the possible pathogenesis of excessive ocular elongation.

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Myopia is generally regarded as a failure of normal emmetropization process, however, its underlying molecular mechanisms are unclear. Retinal protein profile changes using integrated SWATH and MRM-HR MS were studied in guinea pigs at 3- and 21-days of age, where the axial elongation was significantly detected. Differential proteins expressions were identified, and related to pathways which are important in postnatal development in retina, proliferation, breakdown of glycogen-energy and visual phototransduction.

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Purpose: Gap junctions provide a conduit between the intracellular fluids of the pigmented (PE) and non-pigmented (NPE) ciliary epithelial cells, and are therefore critical in the secretion of the aqueous humor (AH). However, opinions differ concerning the connexin (Cx) composition of the gap junctions. Therefore, we aimed to characterize the expression of Cx in the porcine ciliary epithelium (CE), a favorable model for humans; and determine the contribution of the highest expressed Cx to AH secretion.

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Unlabelled: Myopia is generally regarded as a failure of normal emmetropization process, however, its underlying molecular mechanisms are unclear. To investigate the retinal protein profile changes during emmetropization, we studied differential protein expressions of ocular growth in young guinea pigs at 3 and 21 days old respectively, when significant axial elongation was detected (P < 0.001, n = 10).

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The molecular pathophysiology of corticosteroid-induced ocular hypertension (CIH) is not well understood. To determine the biological mechanisms of CIH, this study investigated protein expression profiles of human trabecular meshwork (hTM) cells in response to dexamethasone and prednisolone treatment. Both discovery-based sequential windowed data independent acquisition of the total high-resolution mass spectra (SWATH-MS) and targeted based high resolution multiple reaction monitoring (MRM-HR) confirmation were applied using a hybrid quadrupole-time-of-flight mass spectrometer.

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Myopia and astigmatism, two common refractive errors frequently co-exist, are affecting vision at all working distances in the affected populations worldwide. Eyeballs having these refractive errors are known to exhibit abnormal eye shape at the anterior and posterior eye segments, but whether the outer coats of these abnormal eyeballs, cornea anteriorly and sclera posteriorly, are regulated by region-specific molecular mechanism remains unclear. Here we presented the changes in mRNA expression levels of three genes (MMP2, TIMP2, and TGFB2), all known to participate in extracellular matrix organization, at five regions of the cornea and sclera in chickens developing high myopia and astigmatism induced by form deprivation.

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Purpose: Apolipoprotein A1 (ApoA1) has been shown to inhibit myopia development in chicks, but the underlying biological mechanism remains unknown. Because ApoA1 interacts with cyclic adenosine monophosphate (cAMP) in many cellular systems, we examined whether this interaction is important in myopia development.

Methods: The nonmetabolizable cAMP analogue 8-Bromo-cAMP (8-Br-cAMP) was administered intravitreally to the right eyes of 8-day old chicks for 4 consecutive days.

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Steatosis is a pivotal event in the initiation and progression of nonalcoholic fatty liver disease (NAFLD) which can be driven by peroxisome proliferator-activated receptor-α (PPAR-α) dysregulation. Through examining the effect of PPAR-α on fatty liver development, we found that PPAR-α is a target of miR-17-5p. Transgenic mice expressing miR-17 developed fatty liver and produced higher levels of triglyceride and cholesterol but lower levels of PPAR-α.

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Background: Elevated levels of nitric oxide (NO(•) ), a pro-oxidant that has been associated with numerous retinal diseases, have been implicated in experimental glaucoma models. This study investigated the oxidative effects of sodium nitroprusside (SNP), a nitric oxide donor, on the retinal lipids and proteins and evaluated the potential protective effects of glutathione (GSH).

Methods: Porcine retinal homogenates were incubated with 0, 1, 2, 3, 4 and 5 μm SNP.

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We aimed to investigate the role of miR-17 in cardiac matrix remodeling following myocardial infarction (MI). Using real-time PCR, we quantified endogenous miR-17 in infarcted mouse hearts. Compared with related microRNAs, miR-17 was up-regulated most dramatically: 3.

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MicroRNAs are known to play regulatory roles in gene expression associated with cancer development. We analyzed levels of the microRNA miR-24 in patients with breast carcinoma and found that miR-24 was higher in breast carcinoma samples than in benign breast tissues. We generated constructs expressing miR-24 and studied its functions using both in vitro and in vivo techniques.

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To study the physiological role of a single microRNA (miRNA), we generated transgenic mice expressing the miRNA precursor miR-17 and found that the mature miR-17-5p and the passenger strand miR-17-3p were abundantly expressed. We showed that mature miR-17-5p and passenger strand miR-17-3p could synergistically induce the development of hepatocellular carcinoma. The mature miR-17-5p exerted this function by repressing the expression of PTEN.

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MicroRNAs are short noncoding RNAs that are implicated in cell self- renewal and cancer development. We show that miR-378 is up-regulated in human cancers and found that tumor cells transfected with miR-378 acquired properties of tumor stem cells, including cell self-renewal. Overexpression of miR-378 enhanced cell survival and colony formation.

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Overexpression of EGFR and versican has been reported in association with breast cancers. Considered oncogenic, these molecules may be attractive therapeutic targets. Possessing anti-apoptotic and drug resistant properties, overexpression of these molecules is accompanied by selective sensitization to the process of apoptosis.

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Background: Experimental evidence has shown that myopic and hyperopic optical defocus induces thickening and thinning of the choroids, respectively, moving the retina forward and backward toward the plane of focus; however, the underlying mechanism of this phenomenon remains elusive. It has been hypothesised that the change in choroidal thickness might be elicited by the alteration of ion and fluid transport across the retinal pigment epithelium (RPE). Therefore, the aims of the present study were to determine the content of specific Cl(-) transporter/channel mRNA and proteins in chick RPE in a normal, untreated state and in lens-induced myopia.

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