Prdx6 Regulates Nlrp3 Inflammasome Activation-Driven Inflammatory Response in Lens Epithelial Cells.

The continuum of antioxidant response dysregulation in aging/oxidative stress-driven Nlrp3 inflammasome activation-mediated inflammatory response is associated with age-related diseases. Peroxiredoxin (Prdx) 6 is a key antioxidant that provides cytoprotection by regulating redox homeostasis. Herein, using lens epithelial cells (LECs) derived from the targeted inactivation of Prdx6 gene and aging lenses, we present molecular evidence that Prdx6-deficiency causes oxidative-driven Nlrp3 inflammasome activation, resulting in pyroptosis in aging/redox active cells wherein Prdx6 availability offsets the inflammatory process. We observed that Prdx6-/- and aging LECs harboring accumulated reactive oxygen species (ROS) showed augmented activation of Nlrp3 and bioactive inflammatory components, like Caspase-1, IL-1ß, ASC and Gasdermin-D. Similar to lipopolysaccharide treatment, oxidative exposure led to further ROS amplification with increased activation of the Nlrp3 inflammasome pathway. Mechanistically, we found that oxidative stress enhanced Kruppel-like factor 9 (Klf9) expression in aging/Prdx6-/- mLECs, leading to a Klf9-dependent increase in Nlrp3 transcription, while the elimination of ROS by the delivery of Prdx6 or by silencing Klf9 prevented the inflammatory response. Altogether, our data identify the biological significance of Prdx6 as an intrinsic checkpoint for regulating the cellular health of aging or redox active LECs and provide opportunities to develop antioxidant-based therapeutic(s) to prevent oxidative/aging-related diseases linked to aberrant Nlrp3 inflammasome activation.

Acute cataract by a high-intensity focused ultrasound procedure: a case report.

BACKGROUND: We report a case of acute onset of cataract after eyelid rejuvenation tightening with intense focused ultrasound (IFUS) treatment without using a protection device. CASE PRESENTATION: A 47-year-old female patient presented at the outpatient clinic with blurred vision in her left eye immediately after undergoing an eyelid tightening procedure, using IFUS, seven days prior. The patient had decreased vision in her left eye, caused by an acute cataract with several drop-like opacities and a rosette-like posterior subcapsular cataract. One month after her first visit, the patient's visual acuity in her left eye decreased to 20/630. A Swept-Source Anterior Segment optical coherence tomography confirmed that the posterior capsule was not ruptured. The patient underwent uneventful phacoemulsification cataract surgery with intraocular lens implantation, which resulted in full visual recovery. CONCLUSIONS: This case emphasized the need to evaluate possible ocular side effects, resulting from periocular IFUS without a protection device, including severe cataract requiring surgery.

Positive dysphotopsia after intrascleral intraocular lens fixation: a case report.

BACKGROUND: Positive dysphotopsia is a symptom caused by the reflection of incident light through the pupil at the inner surface of the intraocular lens (IOL) edge after cataract surgery and is perceived as an abnormal arcuate or radiating photopic image at night or indoors with a light source. Although positive dysphotopsia is one of the most important symptoms that affect patients after cataract surgery, it is still not well known even among ophthalmologists. Positive dysphotopsia as the cause of patient complaint following intraocular surgery other than cataract surgery has not been identified. CASE PRESENTATION: A 52-year-old man underwent IOL extraction and intrascleral IOL fixation for bilateral IOL subluxation at another hospital. The right eye had good subjective visibility, but the patient noticed symptoms of light sources appearing divided into multiple lights indoors after surgery in the left eye. Because the cause of the symptoms could not be identified, the patient visited our department. At the time of his first visit, the corrected visual acuity in both eyes was good, and ocular findings in eye position, motility, intraocular pressure, and fundus were within normal limits. The elongated holes of peripheral iridectomy (PI) created during previous intrascleral IOL fixation were observed to be approximately 2 mm in length on the nasal side in both eyes. The PI hole in the right eye was covered by the optics of the IOL, whereas the edge of the IOL overlapped the center of the PI hole in the left eye. Accordingly, we concluded that the abnormal photopic image in the left eye was caused by positive dysphotopsia, in which light passing through the PI hole was reflected by the edge of the IOL. We attempted surgical closure of the PI hole, resulting in the complete disappearance of positive dysphotopsia. CONCLUSIONS: A PI hole created during intrascleral IOL fixation may cause postoperative positive dysphotopsia depending on the position of the IOL edge. Thus, surgeons should be aware of the importance of the size and location of the PI hole when creating it during surgery.

Relative gene expression analysis of human pterygium tissues and UV radiation-evoked gene expression patterns in corneal and conjunctival cells.

A sight threatening, pterygium is a common ocular surface disorders identified by fibrovascular growth of the cornea and induced by variety of stress factors, like ultraviolet (UV) exposure. However, the genes involved in the etiopathogenesis of this disease is not well studied. Herein, we identified the gene expression pattern of pterygium and examined the expression of pterygium-related genes in UV-B-induced human primary cultured corneal epithelial cells (HCEpCs), telomerase immortalized human corneal epithelial (hTCEpi), primary conjunctival fibroblast (HConFs) and primary pterygium fibroblast cells (HPFCs). A careful analysis revealed that the expression of 10 genes was significantly modulated (by > 10-fold). Keratin 24 (KRT24) and matrix metalloproteinase 9 (MMP-9) were dramatically upregulated by 49.446- and 24.214-fold, respectively. Intriguingly, UV-B exposure (50 J/m2) induced the upregulation of the expressions of MMP-9 in corneal epithelial cells such as HCEpCs and hTCEpi. Furthermore, UV-B exposure (100 and/or 200 J/m2) induced the upregulation of the expressions of MMP-9 in fibroblast such as HConFs and HPFCs. The exposure of HCEpCs to 100 and 200 J/m2 UV-B induced significant expressions of KRT24 mRNA. Nevertheless, no expression of KRT24 mRNA was detected in HConFs and HPFCs. The findings provide evidence that the progression of pterygium may involve the modulation of extracellular matrix-related genes and vasculature development and the up-regulation of KRT24 and MMP-9 by UV stress. UV radiation may promote the modulation of these pterygium-related genes and induce the initiation and progression of human pterygium.

Roles of TGF ß and FGF Signals in the Lens: Tropomyosin Regulation for Posterior Capsule Opacity.

Transforming growth factor (TGF) ß and fibroblast growth factor (FGF) 2 are related to the development of posterior capsule opacification (PCO) after lens extraction surgery and other processes of epithelial⁻mesenchymal transition (EMT). Oxidative stress seems to activate TGF ß1 largely through reactive oxygen species (ROS) production, which in turn alters the transcription of several survival genes, including lens epithelium-cell derived growth factor (LEDGF). Higher ROS levels attenuate LEDGF function, leading to down-regulation of peroxiredoxin 6 (Prdx6). TGF ß is regulated by ROS in Prdx6 knock-out lens epithelial cells (LECs) and induces the up-regulation of tropomyosins (Tpms) 1/2, and EMT of LECs. Mouse and rat PCO are accompanied by elevated expression of Tpm2. Further, the expression of Tpm1/2 is induced by TGF ß2 in LECs. Importantly, we previously showed that TGF ß2 and FGF2 play regulatory roles in LECs in a contrasting manner. An injury-induced EMT of a mouse lens as a PCO model was attenuated in the absence of Tpm2. In this review, we present findings regarding the roles of TGF ß and FGF2 in the differential regulation of EMT in the lens. Tpms may be associated with TGF ß2- and FGF2-related EMT and PCO development.

Ginkgolic Acid Rescues Lens Epithelial Cells from Injury Caused by Redox Regulated-Aberrant Sumoylation Signaling by Reviving Prdx6 and Sp1 Expression and Activities.

Sumoylation is a downstream effector of aging/oxidative stress; excess oxidative stress leads to dysregulation of a specificity protein1 (Sp1) and its target genes, such as Peroxiredoxin 6 (Prdx6), resulting in cellular damage. To cope with oxidative stress, cells rely on a signaling pathway involving redox-sensitive genes. Herein, we examined the therapeutic efficacy of the small molecule Ginkgolic acid (GA), a Sumoylation antagonist, to disrupt aberrant Sumoylation signaling in human and mouse lens epithelial cells (LECs) facing oxidative stress or aberrantly expressing Sumo1 (small ubiquitin-like modifier). We found that GA globally reduced aberrant Sumoylation of proteins. In contrast, Betulinic acid (BA), a Sumoylation agonist, augmented the process. GA increased Sp1 and Prdx6 expression by disrupting the Sumoylation signaling, while BA repressed the expression of both molecules. In vitro DNA binding, transactivation, Sumoylation and expression assays revealed that GA enhanced Sp1 binding to GC-boxes in the Prdx6 promoter and upregulated its transcription. Cell viability and intracellular redox status assays showed that LECs pretreated with GA gained resistance against oxidative stress-driven aberrant Sumoylation signaling. Overall, our study revealed an unprecedented role for GA in LECs and provided new mechanistic insights into the use of GA in rescuing LECs from aging/oxidative stress-evoked dysregulation of Sp1/Prdx6 protective molecules.

FGF2 antagonizes aberrant TGFß regulation of tropomyosin: role for posterior capsule opacity.

Transforming growth factor (TGF) ß2 and fibroblast growth factor (FGF) 2 are involved in regulation of posterior capsule opacification (PCO) and other processes of epithelial-mesenchymal transition (EMT) such as cancer progression, wound healing and tissue fibrosis as well as normal embryonic development. We previously used an in vivo rodent PCO model to show the expression of tropomyosin (Tpm) 1/2 was aberrantly up-regulated in remodelling the actin cytoskeleton during EMT. In this in vitro study, we show the Tpms family of cytoskeleton proteins are involved in regulating and stabilizing actin microfilaments (F-actin) and are induced by TGFß2 during EMT in lens epithelial cells (LECs). Importantly, we found TGFß2 and FGF2 played contrasting roles. Stress fibre formation and up-regulation of α-smooth muscle actin (αSMA) induced by TGFß2 could be reversed by Tpm1/2 knock-down by siRNA. Expression of Tpm1/2 and stress fibre formation induced by TGFß2 could be reversed by FGF2. Furthermore, FGF2 delivery to TGFß-treated LECs perturbed EMT by reactivating the mitogen-activated protein kinase (MAPK)/ extracellular signal-regulated kinase (ERK) pathway and subsequently enhanced EMT. Conversely, MEK inhibitor (PD98059) abated the FGF2-mediated Tpm1/2 and αSMA suppression. However, we found that normal LECs which underwent EMT showed enhanced migration in response to combined TGFß and FGF2 stimulation. These findings may help clarify the mechanism reprogramming the actin cytoskeleton during morphogenetic EMT cell proliferation and fibre regeneration in PCO. We propose that understanding the physiological link between levels of FGF2, Tpm1/2 expression and TGFßs-driven EMT orchestration may provide clue(s) to develop therapeutic strategies to treat PCO based on Tpm1/2.

Upregulation of multiple signaling pathways by Dock5 deletion in epithelial cells.

Purpose: Rupture of lens cataract (RLC) is a hereditary mouse model that shows spontaneous rupture of the lens at the posterior pole at 45-100 days of age. The responsible gene for this phenotype was identified as Dock5, a guanine nucleotide exchange factor for small GTPase Rac1. This study was performed to elucidate the pathway initiating this phenotype. Methods: We examined the RNA expression by microarray in lens epithelial cells (LECs) from wild-type and RLC mice at the pre-rupture age of 21 days. We applied the list of altered genes to an Ingenuity Pathway Analysis (IPA) to predict the pathways that are altered upon dedicator of cytokinesis-5 (Dock5) protein loss. The activation status of the predicted pathways was examined by western blotting in the cultured epithelial cells treated with a Dock5 inhibitor. Results: The highest-scored network was "Antimicrobial Response, Inflammatory Response, Dermatological Diseases and Conditions." In that network, it is predicted that extracellular signal-regulated kinase (Erk) is activated in LECs from RLC mice. Our test confirmed that Erk was more phosphorylated in the LECs at the equator in both Dock5-knockout mice and RLC mice. In an in vitro experiment of the cultured epithelial cells, the inhibition of Dock5 activity significantly induced Erk activation. It was also confirmed that Akt (cellular homolog of murine thymoma virus akt8 oncogene, also called protein kinase B) and nuclear factor-kappa B (NFκB), predicted to be the key molecules in two other high-scoring networks by IPA, were activated upon Dock5 inhibition in the cultured epithelial cells. Conclusions: Dock5 participates in epithelial cell maintenance by regulating gene expression.

Delivery of a protein transduction domain-mediated Prdx6 protein ameliorates oxidative stress-induced injury in human and mouse neuronal cells.

Oxidative stress or reduced expression of naturally occurring antioxidants during aging has been identified as a major culprit in neuronal cell/tissue degeneration. Peroxiredoxin (Prdx) 6, a protective protein with GSH peroxidase and acidic calcium-independent phospholipase A2 activities, acts as a rheostat in regulating cellular physiology by clearing reactive oxygen species (ROS) and thereby optimizing gene regulation. We found that under stress, the neuronal cells displayed reduced expression of Prdx6 protein and mRNA with increased levels of ROS, and the cells subsequently underwent apoptosis. Using Prdx6 fused to TAT transduction domain, we showed evidence that Prdx6 was internalized in human brain cortical neuronal cells, HCN-2, and mouse hippocampal cells, HT22. The cells transduced with Prdx6 conferred resistance against the oxidative stress inducers paraquat, H2O2, and glutamate. Furthermore, Prdx6 delivery ameliorated damage to neuronal cells by optimizing ROS levels and overstimulation of NF-κB. Intriguingly, transduction of Prdx6 increased the expression of endogenous Prdx6, suggesting that protection against oxidative stress was mediated by both extrinsic and intrinsic Prdx6. The results demonstrate that Prdx6 expression is critical to protecting oxidative stress-evoked neuronal cell death. We propose that local or systemic application of Prdx6 can be an effective means of delaying/postponing neuronal degeneration.

The use of ultrasonography in education for undergraduate nursing students: A literature review.

AIM: The incorporation of ultrasonography into nursing practice is becoming more common, but how ultrasonography is used or applied in nursing student education is still unclear. This study aimed to review and synthesize relevant literature on the use of ultrasonography in education for undergraduate nursing students. METHODS: An electronic literature search was conducted in June 2022 (updated in June 2023) using MEDLINE, CINAHL, Scopus, and Ichushi-Web databases. Two researchers independently screened/assessed the eligibility of the studies, synthesized extracted data using a narrative synthesis (due to anticipated heterogeneity across studies), and evaluated the methodological quality of quantitative studies using the Medical Education Research Study Quality Instrument. RESULTS: Thirteen peer-reviewed articles were included in the review. All of the studies were conducted in high-income countries, and the majority of them employed an uncontrolled single-group design. Ultrasonography was used mainly for visualizing the vascular system to improve students' puncture skills, but it was also used with various other applications. The included studies were predominantly of moderate quality and heterogeneous, but all of them reported at least some benefits in nursing student education, such as enhancing knowledge and understanding of subcutaneous anatomical structures, and improving confidence in and/or skills of venipuncture and other visualization/assessment methods. CONCLUSIONS: This review provides a broad perspective and highlights the potential use of ultrasonography in education for undergraduate nursing students. Further research is needed to develop standardized teaching methods/curriculum and competency assessments in order to ensure minimum competency standards for students and to improve clinical outcomes for patients.

DNA methylation as an epigenetic mechanism in the regulation of LEDGF expression and biological response in aging and oxidative stress.

The physiological quantum of stress-inducible transcriptional protein, Lens Epithelium-Derived Growth Factor (LEDGF), is vital for the maintenance of cellular physiology. Erratic epigenetic reprogramming in response to oxidative stress or with advancing age is found to be a major cause in the gene silencing, leading to pathobiologies. Using aging human (h) eye lens/lens epithelial cells (LECs) coupled with redox-active Peroxiredoxin 6 (Prdx6)-deficient (Prdx6-/-) mLECs as model systems, herein, we showed that in aging/oxidative stress, the human LEDGF gene was regulated by unique methylation patterns of CGs nucleotides within and around the Sp1 binding site(s) of CpG island of the LEDGF promoter (-170 to -27nts). The process caused the repression of LEDGF and its target, Hsp27, resulting in reactive oxygen species (ROS) amplification and cellular insults. This phenomenon was opposed to the unmethylated promoter in LECs. Clinically, we observed that the loss of LEDGF in the Prdx6-/- mLECs or aging lenses/LECs, correlating with increased expression of DNMT1, DNMT3a, and DNMT3b along with the methyl CpG binding protein 2 (MeCP2). Upon oxidative stress, the expression of these molecules was increased with the dramatic reduction in LEDGF expression. While demethylating agent, 5-Aza deoxycytidine (5-AzaC) transposed the aberrant methylation status, and revived LEDGF and Hsp27 expression. Mechanistically, the chloramphenicol acetyltransferase (CAT) reporter gene driven by the LEDGF promoter (-170/ + 35) and ChIP assays uncovered that 5-AzaC acted on GC/Sp1 sites to release LEDGF transcription. The data argued, for the first time, that de novo methylation of CGs around and within Sp1 sites of the CpG island directly disrupted Sp1 activity, which ensued in LEDGF repression and its biological functions. The findings should improve our understanding of cellular insults-associated with aberrant DNMTs-mediated LEDGF's activity, and can offer strategies for therapeutic intervention to halt aging/oxidative stress-induced abnormalities.

Progressive hyperopic refractive changes after posterior capsule tear following blunt ocular trauma.

Purpose: To describe the mechanism of progressive hyperopia and its management in the long-term course of traumatic cataract with a posterior capsule tear (PCT) following blunt ocular trauma. Observation: A 37-year-old woman presented with blurry vision and photophobia after being hit in the right eye by a slipper. She was found to have PCT with the formation of a traumatic cataract with emmetropia (0 diopters [D]). Three years after the injury, a broader hyperopic change of +8.0 D was found in the patient at her first visit to our clinic. Optical coherence tomography (OCT) analysis of the anterior segment of the eye revealed damage to the posterior capsule and cataracts due to disorganization of the lens fibers and liquefaction of the lens. Femtosecond laser-associated cataract surgery was performed for anterior capsulotomy and segmentation of the nucleus without further enlargement of the PCT, facilitating the placement of a capsular tension ring segment and a multifocal intra ocular lens (IOL) in the capsular bag. At 1-month post-operation, her uncorrected visual acuity was 20/20 in the right eye, with a well-centered IOL. Conclusions and Importance: Isolated PCT due to blunt trauma is rare, and there have been no reports of progressive hyperopia after three years of follow-up. In such cases, the lens may liquefy, resulting in decreased refraction and significant hyperopia.

Prediction of low-addition segmented refractive intraocular lens position and deviation using anterior-segment optical coherence tomography.

This study aimed to develop and analyze the accuracy of predictive formulae for postoperative anterior chamber depth, tilt, and decentration of low-added-segment refractive intraocular lenses. This single-center, retrospective, observational study included the right eyes of 96 patients (mean age: 72.43 ± 6.58 years), who underwent a cataract surgery with implantation of a low-added segmented refractive intraocular lens at the Medical University Hospital between July 2019 and January 2021, and were followed up for more than 1 month postoperatively. The participants were divided into an estimation group to create a prediction formula and a validation group to verify the accuracy of the formula. Anterior segment optical coherence tomography (CASIA 2, Tomey Corporation, Japan) and swept-source optical coherence tomography biometry (IOL Master 700, Carl Zeiss Meditec AG) were used to measure the anterior ocular components. A predictive formula was devised for postoperative anterior chamber depth, intraocular lens tilt, and intraocular lens decentration (p <0.01) in the estimation group. A significant positive correlation was observed between the estimated values calculated using the prediction formula and the measured values for postoperative anterior chamber depth (r = 0.792), amount of intraocular lens tilt (r = 0.610), direction of intraocular lens tilt (r = 0.668), and amount of intraocular lens decentration (r = 0.431) (p < 0.01) in the validation group. In conclusion, our findings reveal that predicting the position of the low-added segmented refractive intraocular lens enables the prognosis of postoperative refractive values with a greater accuracy in determining the intraocular lens adaptation.

Curcumin abates hypoxia-induced oxidative stress based-ER stress-mediated cell death in mouse hippocampal cells (HT22) by controlling Prdx6 and NF-κB regulation.

Oxidative stress and endoplasmic reticulum (ER) stress are emerging as crucial events in the etiopathology of many neurodegenerative diseases. While the neuroprotective contributions of the dietary compound curcumin has been recognized, the molecular mechanisms underlying curcumin's neuroprotection under oxidative and ER stresses remains elusive. Herein, we show that curcumin protects HT22 from oxidative and ER stresses evoked by the hypoxia (1% O(2) or CoCl(2) treatment) by enhancing peroxiredoxin 6 (Prdx6) expression. Cells exposed to CoCl(2) displayed reduced expression of Prdx6 with higher reactive oxygen species (ROS) expression and activation of NF-κB with IκB phosphorylation. When NF-κB activity was blocked by using SN50, an inhibitor of NF-κB, or cells treated with curcumin, the repression of Prdx6 expression was restored, suggesting the involvement of NF-κB in modulating Prdx6 expression. These cells were enriched with an accumulation of ER stress proteins, C/EBP homologous protein (CHOP), GRP/78, and calreticulin, and had activated states of caspases 12, 9, and 3. Reinforced expression of Prdx6 in HT22 cells by curcumin reestablished survival signaling by reducing propagation of ROS and blunting ER stress signaling. Intriguingly, knockdown of Prdx6 by antisense revealed that loss of Prdx6 contributed to cell death by sustaining enhanced levels of ER stress-responsive proapoptotic proteins, which was due to elevated ROS production, suggesting that Prdx6 deficiency is a cause of initiation of ROS-mediated ER stress-induced apoptosis. We propose that using curcumin to reinforce the naturally occurring Prdx6 expression and attenuate ROS-based ER stress and NF-κB-mediated aberrant signaling improves cell survival and may provide an avenue to treat and/or postpone diseases associated with ROS or ER stress.

Dynamic and differential regulation in the microRNA expression in the developing and mature cataractous rat lens.

Recent evidence supports a role for microRNAs (miRNAs) in regulating gene expression, and alterations in gene expression are known to affect cells involved in the development of ageing disorders. Using developing rat lens epithelial cells (LECs), we profiled the expression of miRNAs by a microarray-based approach. Few gene expression changes known to be involved in pathogenesis or cytoprotection were uniquely influenced by miRNA expression. Most miRNAs increased or decreased in abundance (let 7b, let 7c, miR29a, miR29c, miR126 and miR551b) in LECs/lenses during late embryonic and post-natal development and in cataract. Among them, miR29a, miR29c and miR126 were dramatically decreased in cataractous LECs from Shumiya Cataract Rats (SCRs). Specifically, the cytoskeleton remodelling genes tropomyosin (Tm) 1α and 2ß, which have been implicated in the initiation of pathophysiology, were targets of miR29c and were over-stimulated as demonstrated by inhibitor experiments. In transfection experiments, increasing the level of miR29c caused a corresponding decrease in the expression of Tm1α and 2ß, suggesting that miR29c may regulate the translation of Tm1α and 2ß. 3'UTR luciferase activity of Tm1α, not 2ß, was significantly decreased in miR29c-transfected mouse LECs. These findings demonstrate changes in miRNAs expression, and target molecules have potential as diagnostic indicators of ageing and as a foundation of miR-based therapeutics for age-related diseases.

Elevated tropomyosin expression is associated with epithelial-mesenchymal transition of lens epithelial cells.

Injury to lens epithelial cells (LECs) leads to epithelial-mesenchymal transition (EMT) with resultant fibrosis. The tropomyosin (Tpm) family of cytoskeleton proteins is involved in regulating and stabilizing actin microfilaments. Aberrant expression of Tpms leads to abnormal morphological changes with disintegration of epithelial integrity. The EMT of LECs has been proposed as a major cause of posterior capsule opacification (PCO) after cataract surgery. Using in vivo rodent PCO and human cataractous LECs, we demonstrated that the aberrant expression of rat Tpm and human Tpm1α/2ß suggested their association in remodelling of the actin cytoskeleton during EMT of LECs. Expression analysis from abnormally growing LECs after lens extraction revealed elevated expression of α-smooth muscle actin (α-SMA), a marker for EMT. Importantly, these cells displayed increased expression of Tpm1α/2ß following EMT/PCO formation. Expression of Tpm1α/2ß was up-regulated in LECs isolated from cataractous lenses of Shumiya Cataract Rats (SCRs), compared with non-cataractous lenses. Also, LECs from human patients with nuclear cataract and anterior subcapsular fibrosis (ASF) displayed significantly increased expression of Tpm2ß mRNA, suggesting that similar signalling invokes the expression of these molecules in LECs of cataractous SCR and human lenses. EMT was observed in LECs overexpressed with Tpm1α/2ß, as evidenced by increased expression of α-SMA. These conditions were correlated with remodelling of actin filaments, possibly leading to EMT/PCO and ASF. The present findings may help clarify the condition of the actin cytoskeleton during morphogenetic EMT, and may contribute to development of Tpm-based inhibitors for postponing PCO and cataractogenesis.

Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response.

A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.

Function of mitochondrial cytochrome c oxidase is enhanced in human lens epithelial cells at high temperatures.

Enhancement of density via human lens epithelium (HLE) cell proliferation is the underlying cause of nuclear cataracts. Moreover, our previous epidemiological study demonstrated that the risk of nuclear cataract development is significantly higher under elevated environmental temperatures compared with under lower temperatures. The present study investigated the relationship between temperature and cell proliferation in terms of mitochondrial function, which is a nuclear cataract­inducing risk factor, using two different HLE cell lines, SRA01/04 and immortalized human lens epithelial cells NY2 (iHLEC­NY2). Cell proliferation was significantly enhanced under the high­temperature condition (37.5˚C) in both cell lines. The cell growth levels of SRA01/04 and iHLEC­NY2 cells cultured at 37.5˚C were 1.20­ and 1.16­fold those in the low­temperature cultures (35.0˚C), respectively. Moreover, the levels of cytochrome c oxidase mRNA (mitochondrial genome, cytochrome c oxidase­1­3) and its activity in SRA01/04 and iHLEC­NY2 cells cultured at 37.5˚C were higher compared with those in cells cultured at 35.0˚C. In addition, adenosine­5'­triphosphate (ATP) levels in SRA01/04 and iHLEC­NY2 cells were also significantly higher at 37.5˚C compared with those at 35.0˚C. By contrast, no significant differences in Na+/K+­ATPase or Ca2+­ATPase activities were observed between HLE cells cultured at 35.0 and 37.5˚C. These results suggested that expression of the mitochondrial genome was enhanced in high­temperature culture, resulting in a sufficient ATP content and cell proliferation for lens opacity. Therefore, elevated environmental temperatures may increase the risk of nuclear cataracts caused by HLE cell proliferation via mitochondrial activation.

Orientation of the intermediate-vision zone of rotationally asymmetric multifocal intraocular lenses and photic phenomena.

PURPOSE: To evaluate the association between the orientation of the intermediate-vision zone and postoperative photic phenomena in eyes implanted with rotationally asymmetric multifocal intraocular lenses with + 1.5 diopters near addition. STUDY DESIGN: Retrospective comparative case series. METHODS: We performed the photic phenomena test (PPT) to quantitatively evaluate photic phenomena at 1-3 months after cataract surgery with Lentis Comfort LS-313 MF15 or Lentis Comfort Toric LS-313 MF15T insertion (Oculentis; Santen Pharmaceutical). In cases of bilateral surgeries, only the right eye was included in the analysis. We also conducted a questionnaire survey about the photic phenomena. RESULTS: The study included 96 eyes from 96 patients. The intermediate-vision zones of 44, 19, 19, and 14 eyes were fixed in the inferior, superior, nasal, and temporal directions, respectively. The measured PPT values for halo, glare, and starburst were equivalent in all the fixed directions. Eighty-four eyes (87.5%) perceived a triangle-shaped halo, and the direction of fixation for the intermediate-vision zone and the extension direction of this photic phenomenon were consistent in 94.0% of the eyes. Less than 10% of the patients responded "moderate" or "severe" for the triangle-shaped halo, glare, and starburst in fixed directions with low frequency in the questionnaire. CONCLUSION: No qualitative or quantitative difference was found in photic phenomena in eyes implanted with the LS-313 MF15 or the MF15T regardless of the fixation direction. Our study revealed that many patients were aware of a triangle-shaped halo extending in the direction of the intermediate-vision zone.

Association of nuclear cataract prevalence with UV radiation and heat load in lens of older people -five city study.

Epidemiological studies have reported that the frequency of nuclear cataracts (NUCs) is high among the elderly and in tropical countries. Ultraviolet (UV) irradiation and lens temperature are considered as key physical contributors, although their precise quantification is difficult. The aim of this study is to investigate the association of NUC prevalence with UV irradiation and heat load. First, we assessed the lens temperature using thermodynamic modeling considering the thermophysiological response. We then conducted a multivariate linear regression analysis for the epidemiological analysis of NUC prevalence across five cities. A strong correlation was observed between NUC prevalence and the combined effects of UV irradiation and cumulative equivalent minutes at 43 °C (CEM43°C) derived from the computed lens temperature (adjusted R2 = 0.933, p < 0.0001). Heat load significantly contributed to the prevalence at 52%, surpassing the contributions of UV irradiation (31%) and the decline in DNA repair capacity in the lens (17%). These results suggested that both UV radiation and heat load are associated with NUC, with heat load contributing more. Our findings provided important implications for future interventions, particularly in the context of global warming.