BCLA CLEAR presbyopia: Management with scleral techniques, lens softening, pharmaceutical and nutritional therapies.

The aging eye undergoes the same progressive crosslinking which occurs throughout the body, resulting in increased rigidity of ocular connective tissues including the lens and the sclera which impact ocular functions. This offers the potential for a scleral treatment that is based on restoring normal biomechanical movements. Laser Scleral Microporation is a laser therapy that evaporates fractional areas of crosslinked tissues in the sclera, reducing ocular rigidity over critical anatomical zones of the accommodation apparatus, restoring the natural dynamic range of focus of the eye. Although controversial and challenged, an alternative theory for presbyopia is Schachar's theory that suggests a reduction in the space between the ciliary processes and the crystalline lens. Widening of this space with expansion bands has been shown to aid near vision in people with presbyopia, a technique that has been used in the past but seems to be obsolete now. The use of drugs has been used in the treatment of presbyopia, either to cause pupil miosis to increase depth of focus, or an alteration in refractive error (to induce myopia in one eye to create monovision). Drugs and laser ablation of the crystalline lens have been used with the aim of softening the hardened lens. Poor nutrition and excess exposure to ultraviolet light have been implicated in the onset of presbyopia. Dietary nutritional supplements, lifestyle changes have also been shown to improve accommodation and the question arises whether these could be harnessed in a treatment for presbyopia as well.

Biologically Relevant Laminin-511 Moderates the Derivation and Proliferation of Human Lens Epithelial Stem/Progenitor-Like Cells.

Purpose: The role of specific extracellular matrix (ECM) molecules in lens cell development and regeneration is poorly understood, as appropriate cellular models are lacking. Here, a laminin-based lens cell in vitro induction system was developed to study the role of laminin in human lens epithelial stem/progenitor cell (LES/PC) development. Methods: The human embryonic stem cell-based lens induction system followed a three-stage protocol. The expression profile of laminins during lens induction was screened, and laminin-511 (LN511) was tested as a candidate substitute. LN511 induction system cellular and molecular features, including induction efficiency, transcription factor expression related to different lens development stages, ECM alterations, and Hippo/YAP signaling, were evaluated. Results: LAMA5, LAMB1, and LAMC1 were highly expressed around the time of LES/PC derivation. We chose LN511 (product of LAMA5, LAMB1, and LAMC1) and found that it considerably enhanced lens cell induction efficiency, compared to that in Matrigel-coated culture, as more and larger lentoid bodies were detected. Notably, LES/PC induction efficiency improved by promoting lens specification-related transcription factor expression and cell proliferation. Transcriptome analysis revealed that compared to those with Matrigel, ECM accumulation and cell adhesion were downregulated in the LN511 system. Hippo/YAP signaling was hypoactive during LES/P-like cell generation, and small molecule inhibitors of YAP/TAZ activity upregulated LES/PC marker expression and promoted the efficiency of LES/P-like cell derivation. Conclusions: The laminin isoform LN511 is a reliable substitute for the LES/P-like cell induction system, and LN511-YAP acted as efficient modulators of LES/PC derivation; this contributes to knowledge of the role of the ECM in human lens development.

The impact of lutein-loaded poly(lactic-co-glycolic acid) nanoparticles following topical application: An in vitro and in vivo study.

Antioxidant therapies are of interest in the prevention and management of ocular disorders such as cataracts. Although an active area of interest, topical therapy with antioxidants for the treatment of cataracts is complicated by multiple ocular anatomical barriers, product stability, and solubility. Entrapment and delivery of antioxidants with poly(lactic-co-glycolic acid) nanoparticles is a possible solution to these challenges, however, little is known regarding their effects in vitro or in vivo. Our first aim was to investigate the impact of blank and lutein loaded PLGA nanoparticles on viability and development of reactive oxygen species in lens epithelial cells in vitro. Photo-oxidative stress was induced by ultraviolet light exposure with cell viability and reactive oxygen species monitored. Next, an in vivo, selenite model was utilized to induce cataract formation in rodents. Eyes were treated topically with both free lutein and lutein loaded nanoparticles (LNP) at varying concentrations. Eyes were monitored for the development of anterior segment changes and cataract formation. The ability of nanodelivered lutein to reach the anterior segment of the eye was evaluated by liquid chromatography coupled to mass spectrometry of aqueous humor samples and liquid chromatography coupled to tandem mass spectrometry (targeted LC-MS/MS) of lenses. LNP had a minimal impact on the viability of lens epithelial cells during the short exposure timeframe (24 h) and at concentrations < 0.2 µg LNP/µl. A significant reduction in the development of reactive oxygen species was also noted. Animals treated with LNPs at an equivalent lutein concentration of 1,278 µg /mL showed the greatest reduction in cataract scores. Lutein delivery to the anterior segment was confirmed through evaluation of aqueous humor and lens sample evaluation. Topical treatment was not associated with the development of secondary keratitis or anterior uveitis when applied once daily for one week. LNPs may be an effective in the treatment of cataracts.

Hyaluronic acid-mediated epithelial-mesenchymal transition of human lens epithelial cells via CD44 and TGF-ß2.

PURPOSE: The epithelial-mesenchymal transition of human lens epithelial cells plays a role in posterior capsule opacification, a fibrotic process that leads to a common type of cataract. Hyaluronic acid has been implicated in this fibrosis. Studies have investigated the role of transforming growth factor (TGF)-ß2 in epithelial-mesenchymal transition. However, the role of TGF-ß2 in hyaluronic acid-mediated fibrosis of lens epithelial cell remains unknown. We here examined the role of TGF-ß2 in the hyaluronic acid-mediated epithelial-mesenchymal transition of lens epithelial cells. METHODS: Cultured human lens epithelial cells (HLEB3) were infected with CD44-siRNA by using the Lipofectamine 3000 transfection reagent. The CCK-8 kit was used to measure cell viability, and the scratch assay was used to determine cell migration. Cell oxidative stress was analyzed in a dichloro-dihydro-fluorescein diacetate assay and by using a flow cytometer. The TGF-ß2 level in HLEB3 cells was examined through immunohistochemical staining. The TGF-ß2 protein level was determined through western blotting. mRNA expression levels were determined through quantitative real-time polymerase chain reaction. RESULTS: Treatment with hyaluronic acid (1.0 µM, 24 h) increased the epithelial-mesenchymal transition of HLEB3 cells. The increase in TGF-ß2 levels corresponded to an increase in CD44 levels in the culture medium. However, blocking the CD44 function significantly reduced the TGF-ß2-mediated epithelial-mesenchymal transition response of HLEB3 cells. CONCLUSIONS: Our study showed that both CD44 and TGF-ß2 are critical contributors to the hyaluronic acid-mediated epithelial-mesenchymal transition of lens epithelial cells, and that TGF-ß2 in epithelial-mesenchymal transition is regulated by CD44. These results suggest that CD44 could be used as a target for preventing hyaluronic acid-induced posterior capsule opacification. Our findings suggest that CD44/TGF-ß2 is crucial for the hyaluronic acid-induced epithelial-mesenchymal transition of lens epithelial cells.

Impact and Correction of an Anterior Phakic Intraocular Lens on Swept-Source Optical Coherence Tomography Biometry.

PURPOSE: To evaluate the impact of anterior chamber phakic intraocular lens (pIOL) on swept-source optical coherence tomography (SS-OCT) biometric measurements and IOL power calculation. METHODS: This retrospective analysis of 67 eyes of 49 patients with previous anterior chamber pIOL implantation analyzed the accuracy of automatic segmentation of the anterior surface of the crystalline lens and its impact on anterior chamber depth (ACD, measured from epithelium to lens), lens thickness measurements, and IOL power calculation. The sample was divided into two groups: correct detection of the anterior surface of the crystalline lens and inaccurate detection. Segmentation of eyes from the inaccurate detection group was manually corrected and ACD and lens thickness were calculated using ImageJ software. IOL power was calculated using 7 formulas for both measurements. RESULTS: The anterior surface of the crystalline lens was mis-identified in 13 (19.4%) eyes. ACD was underestimated (Δ -0.85 ± 0.33 mm, P < .001) and lens thickness was overestimated (Δ +0.81 ± 0.25 mm, P < .001). Manual correction changed the target spherical equivalent only in the Haigis formula (P = .009). After correction for segmentation bias, the Pearl DGS, Cooke K6, and EVO 2.0 formulas showed the lowest prediction error, with the Pearl DGS showing greatest accuracy within ±1.00 diopters of prediction error range (81.0%). CONCLUSIONS: SS-OCT biometry misidentifies the anterior surface of the crystalline lens in a significant proportion, resulting in significant IOL power calculation error in the Haigis formula. Manual proofing of segmentation is mandatory in every patient with anterior chamber pIOL implantation. After correct segmentation, the Pearl DGS, Cooke K6, and EVO seem to be the best formulas. [J Refract Surg. 2024;40(8):e562-e568.].

A role for YAP/FOXM1/Nrf2 axis in oxidative stress and apoptosis of cataract induced by UVB irradiation.

This study aims to investigate the hypothesis that Yes-associated protein (YAP) significantly regulates antioxidant potential and anti-apoptosis in UVB-induced cataract by exploring the underlying molecular mechanisms. To investigate the association between YAP and cataract, various experimental techniques were employed, including cell viability assessment, Annexin V FITC/PI assay, measurement of ROS production, RT-PCR, Western blot assay, and Immunoprecipitation. UVB exposure on human lens epithelium cells (HLECs) reduced total and nuclear YAP protein expression, increased cleaved/pro-caspase 3 ratios, decreased cell viability, and elevated ROS levels compared to controls. Similar Western blot results were observed in in vivo experiments involving UVB-treated mice. YAP knockdown in vitro demonstrated a decrease in the protein expression of FOXM1, Nrf2, and HO-1, which correlated with the mRNA expression, accompanied by an increase in cell apoptosis, caspase 3 activation, and the release of ROS. Conversely, YAP overexpression mitigated these effects induced by UVB irradiation. Immunoprecipitation revealed a FOXM1-YAP interaction. Notably, inhibiting FOXM1 decreased Nrf2 and HO-1, activating caspase 3. Additionally, administering the ROS inhibitor N-acetyl-L-cysteine (NAC) effectively mitigated the apoptotic effects induced by oxidative stress from UVB irradiation, rescuing the protein expression levels of YAP, FOXM1, Nrf2, and HO-1. The initial findings of our study demonstrate the existence of a feedback loop involving YAP, FOXM1, Nrf2, and ROS that significantly influences the cell apoptosis in HLECs under UVB-induced oxidative stress.

Post-traumatic lens absorption with an intact lens capsule.

A 29-year-old man presented with longstanding, stable, unilateral vision loss in the setting of a remote paintball injury. His examination was notable for a sensory exotropia as well as multiple foci of posterior synechiae, segments of white lenticular material and islands of lenticular cells within a grossly intact capsule, and severe zonular compromise in the affected eye. The majority of the nuclear lens material was absent. The patient was diagnosed with post-traumatic lens absorption and underwent synechialysis, capsulotomy, excision of remnant lenticular material, and placement of a sulcus lens, with significant improvement in visual acuity and ocular alignment following surgery. Our report uniquely highlights identification of a Soemmering's ring in an absorbed lens in the presence of an intact anterior and posterior capsule as well as successful refractive and sensorimotor outcomes following surgical repair despite delay in treatment of many years.

A case of accidental into-the-lens dexamethasone implant: watching or removing?

BACKGROUND: To report a case of cataract surgery in unintentional Ozurdex (Allergan, Inc., Irvine, California, USA) injection into the lens. CASE PRESENTATION: A 82-years old man reporting decreased visual acuity in his right eye came to our Ophthalmology service. Due to the clinical history, and on the basis of ophthalmoscopic and imaging examinations diabetic macular edema was diagnosed. Thus, intravitreal dexamethasone implant was scheduled and therefore performed. The following day Ozurdex appeared to be located into the lens. After careful evaluation and strict follow up examinations, due to the risks associated with the presence of the implant into the lens, phacoemulsification with Ozurdex removal and intraocular lens (IOL) implantation was scheduled and performed. CONCLUSIONS: In this case report we reported the surgical management of accidental into-the lens dexamethasone implant carefully taking into account the dexamethasone pharmacokinetic.

Influence of Ocular Biometric Parameters on Intraocular Lens Position: A Prospective Cohort Study.

PURPOSE: To assess the influence of ocular biometric parameters on intraocular lens (IOL) tilt and decentration after cataract surgery. METHODS: Patients scheduled for cataract surgery were screened for inclusion in this prospective cohort study. Tilt and decentration of the crystalline lens and IOL were measured using the CASIA2 (Tomey). Anterior chamber depth (ACD), lens thickness (LT), and axial length (AL) were preoperatively measured by the IOLMaster 700 (Carl Zeiss Meditec AG). Multivariate regression analysis was performed to assess the influence of ocular biometric parameters on IOL tilt and decentration after cataract surgery. RESULTS: In total, 191 eyes of 120 patients were included. Age was positively correlated with IOL tilt, whereas ACD and AL were negatively correlated with IOL tilt. A strong positive correlation was found between preoperative crystalline lenses and postoperative IOLs in tilt magnitude (r = 0.769, P < .001) and tilt direction (r = 0.688, P < .001). A positive correlation was found between preoperative and postoperative lens decentration magnitude and decentration direction. Greater postoperative IOL tilt and decentration were significantly associated with greater preoperative crystalline lens tilt (P < .001) and decentration (P = .027). CONCLUSIONS: IOL tilt was greater in older patients. Shorter AL and shallower ACD contributed to greater IOL tilt. The tilt and decentration of the IOL will be greater in patients with greater tilt and decentration of the crystalline lens. [J Refract Surg. 2024;40(7):e438-e444.].

Optimizing Mouse Primary Lens Epithelial Cell Culture: A Comprehensive Guide to Trypsinization.

Lens epithelial cells (LECs) play multiple important roles in maintaining the homeostasis and normal function of the lens. LECs determine lens growth, development, size, and transparency. Conversely, dysfunctional LECs can lead to cataract formation and posterior capsule opacification (PCO). Consequently, establishing a robust primary LEC culture system is important to researchers engaged in lens development, biochemistry, cataract therapeutics, and PCO prevention. However, cultivating primary LECs has long presented challenges due to their limited availability, slow proliferation rate, and delicate nature. This study addresses these hurdles by presenting a comprehensive protocol for primary LEC culture. The protocol encompasses essential steps such as the formulation of an optimized culture medium, precise isolation of lens capsules, trypsinization techniques, subculture procedures, harvest protocols, and guidelines for storage and shipment. Throughout the culture process, cell morphology was monitored using phase-contrast microscopy. To confirm the authenticity of the cultured LECs, immunofluorescence assays were conducted to detect the presence and subcellular distribution of critical lens proteins, namely αA- and γ-crystallins. This detailed protocol equips researchers with a valuable resource for cultivating and characterizing primary LECs, enabling advancements in our comprehension of lens biology and the development of therapeutic strategies for lens-related disorders.

A Transcriptomics Analysis of the Regulation of Lens Fiber Cell Differentiation in the Absence of FGFRs and PTEN.

Adding 50% vitreous humor to the media surrounding lens explants induces fiber cell differentiation and a significant immune/inflammatory response. While Fgfr loss blocks differentiation in lens epithelial explants, this blockage is partially reversed by deleting Pten. To investigate the functions of the Fgfrs and Pten during lens fiber cell differentiation, we utilized a lens epithelial explant system and conducted RNA sequencing on vitreous humor-exposed explants lacking Fgfrs, or Pten or both Fgfrs and Pten. We found that Fgfr loss impairs both vitreous-induced differentiation and inflammation while the additional loss of Pten restores these responses. Furthermore, transcriptomic analysis suggested that PDGFR-signaling in FGFR-deficient explants is required to mediate the rescue of vitreous-induced fiber differentiation in explants lacking both Fgfrs and Pten. The blockage of ß-crystallin induction in explants lacking both Fgfrs and Pten in the presence of a PDGFR inhibitor supports this hypothesis. Our findings demonstrate that a wide array of genes associated with fiber cell differentiation are downstream of FGFR-signaling and that the vitreous-induced immune responses also depend on FGFR-signaling. Our data also demonstrate that many of the vitreous-induced gene-expression changes in Fgfr-deficient explants are rescued in explants lacking both Fgfrs and Pten.

SP1 promotes high glucose-induced lens epithelial cell viability, migration and epithelial-mesenchymal transition via regulating FGF7 and PI3K/AKT pathway.

BACKGROUND: Diabetic cataract (DC) is a common complication of diabetes and its etiology and progression are multi-factorial. In this study, the roles of specific protein 1 (SP1) and fibroblast growth factor 7 (FGF7) in DC development were explored. METHODS: DC cell model was established by treating SRA01/04 cells with high glucose (HG). MTT assay was conducted to evaluate cell viability. Transwell assay and wound-healing assay were performed to assess cell migration and invasion. Western blot assay and qRT-PCR assay were conducted to measure the expression of N-cadherin, E-cadherin, Collagen I, Fibronectin, SP1 and FGF7 expression. CHIP assay and dual-luciferase reporter assay were conducted to analyze the combination between FGF7 and SP1. RESULTS: FGF7 was upregulated in DC patients and HG-induced SRA01/04 cells. HG treatment promoted SRA01/04 cell viability, migration, invasion and epithelial-mesenchymal transition (EMT), while FGF7 knockdown abated the effects. Transcription factor SP1 activated the transcription level of FGF7 and SP1 overexpression aggravated HG-induced SRA01/04 cell injury. SP1 silencing repressed HG-induced SRA01/04 cell viability, migration, invasion and EMT, but these effects were ameliorated by upregulating FGF7. Additionally, SP1 knockdown inhibited the PI3K/AKT pathway by regulating the transcription level of FGF7. CONCLUSION: Transcription factor SP1 activated the transcription level of FGF7 and the PI3K/AKT pathway to regulate HG-induced SRA01/04 cell viability, migration, invasion and EMT.

Lens autophagy protein ATG16L1: a potential target for cataract treatment.

Rationale: Cataract is the leading cause of blindness and low vision worldwide, yet its pathological mechanism is not fully understood. Although macroautophagy/autophagy is recognized as essential for lens homeostasis and has shown potential in alleviating cataracts, its precise mechanism remains unclear. Uncovering the molecular details of autophagy in the lens could provide targeted therapeutic interventions alongside surgery. Methods: We monitored autophagic activities in the lens and identified the key autophagy protein ATG16L1 by immunofluorescence staining, Western blotting, and transmission electron microscopy. The regulatory mechanism of ATG16L1 ubiquitination was analyzed by co-immunoprecipitation and Western blotting. We used the crystal structure of E3 ligase gigaxonin and conducted the docking screening of a chemical library. The effect of the identified compound riboflavin was tested in vitro in cells and in vivo animal models. Results: We used HLE cells and connexin 50 (cx50)-deficient cataract zebrafish model and confirmed that ATG16L1 was crucial for lens autophagy. Stabilizing ATG16L1 by attenuating its ubiquitination-dependent degradation could promote autophagy activity and relieve cataract phenotype in cx50-deficient zebrafish. Mechanistically, the interaction between E3 ligase gigaxonin and ATG16L1 was weakened during this process. Leveraging these mechanisms, we identified riboflavin, an E3 ubiquitin ligase-targeting drug, which suppressed ATG16L1 ubiquitination, promoted autophagy, and ultimately alleviated the cataract phenotype in autophagy-related models. Conclusions: Our study identified an unrecognized mechanism of cataractogenesis involving ATG16L1 ubiquitination in autophagy regulation, offering new insights for treating cataracts.

GDF-15 Attenuates the Epithelium-Mesenchymal Transition and Alleviates TGFß2-Induced Lens Opacity.

Purpose: We sought to evaluate the efficacy of growth differentiation factor (GDF)-15 treatment for suppressing epithelial-mesenchymal transition (EMT) and alleviating transforming growth factor ß2 (TGFß2)-induced lens opacity. Methods: To test whether GDF-15 is a molecule that prevents EMT, we pretreated the culture with GDF-15 in neural progenitor cells, retinal pigment epithelial cells, and lens epithelial cells and then treated with factors that promote EMT, GDF-11, and TGFß2, respectively. To further investigate the efficacy of GDF-15 on alleviating lens opacity, we used mouse lens explant culture to mimic secondary cataracts. We pretreated the lens culture with GDF-15 and then added TGFß2 to develop lens opacity (n = 3 for each group). Western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to measure EMT protein and gene expression, respectively. Results: In cell culture, GDF-15 pretreatment significantly attenuated EMT marker expression in cultured cells induced by treatment with GDF-11 or TGFß2. In the lens explant culture, GDF-15 pretreatment also reduced mouse lens opacity induced by exposure to TGFß2. Conclusions: Our results indicate that GDF-15 could alleviate TGFß2-induced EMT and is a potential therapeutic agent to slow or prevent posterior capsular opacification (PCO) progression after cataract surgery. Translational Relevance: Cataracts are the leading cause of blindness worldwide, with the only current treatment involving surgical removal of the lens and replacement with an artificial lens. However, PCO, also known as secondary cataract, is a common complication after cataract surgery. The development of an adjuvant that slows the progression of PCO will be beneficial to the field of anterior complications.

Construction and Identification of a Novel Mice Model of Microphthalmia.

Purpose: Microphthalmia is a rare developmental eye disease that affects 1 in 7000 births. Currently, there is no cure for this condition. This study aimed to construct a stable mouse model of microphthalmia, thus providing a new tool for the study of the etiology of microphthalmia. Methods: The Hedgehog signaling pathway plays a crucial role in eye development. One of the key mechanisms of the Sonic Hedgehog signaling is the strong transcriptional activation ability of GLI3, a major mediator of this pathway. This study used CRISPR/Cas9 system to construct a novel TgGli3Ki/Ki lens-specific over-expression mouse line. To identify the ocular characteristics of this line, quantitative PCR, Western blot, hematoxylin and eosin staining, immunofluorescent staining, and RNA-seq were performed on the ocular tissues of this line and normal mice. Results: The TgGli3Ki/Ki lens-specific over-expression mouse model exhibits the ocular phenotype of microphthalmia. In the TgGli3Ki/Ki mouse, Gli3 is over-expressed in the lens, and the size of the eyeball and lens is significantly smaller than the normal one. RNA-seq analysis using the lens and the retina samples from TgGli3Ki/Ki and normal mice indicates that the phototransduction pathway is ectopically activated in the lens. Immunofluorescent staining of the lens samples confirmed this activation. Conclusions: The TgGli3Ki/Ki mouse model consistently manifests the stereotypical microphthalmia phenotype across generations, making it an excellent tool for studying this severe eye disease. Translational Relevance: This study developed a novel animal model to facilitate clinical research on microphthalmia.

Through the Cat-Map Gateway: A Brief History of Cataract Genetics.

Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.

Mir-204-5p alleviates mitochondrial dysfunction by targeting IGFBP5 in diabetic cataract.

BACKGROUND: Cataract contributes to visual impairment worldwide, and diabetes mellitus accelerates the formation and progression of cataract. Here we found that the expression level of miR-204-5p was diminished in the lens epithelium with anterior lens capsule of cataract patients compared to normal donors, and decreased more obviously in those of diabetic cataract (DC) patients. However, the contribution and mechanism of miR-204-5p during DC development remain elusive. METHODS AND RESULT: The mitochondrial membrane potential (MMP) was reduced in the lens epithelium with anterior lens capsule of DC patients and the H2O2-induced human lens epithelial cell (HLEC) cataract model, suggesting impaired mitochondrial functional capacity. Consistently, miR-204-5p knockdown by the specific inhibitor also attenuated the MMP in HLECs. Using bioinformatics and a luciferase assay, further by immunofluorescence staining and Western blot, we identified IGFBP5, an insulin-like growth factor binding protein, as a direct target of miR-204-5p in HLECs. IGFBP5 expression was upregulated in the lens epithelium with anterior lens capsule of DC patients and in the HLEC cataract model, and IGFBP5 knockdown could reverse the mitochondrial dysfunction in the HLEC cataract model. CONCLUSIONS: Our results demonstrate that miR-204-5p maintains mitochondrial functional integrity through repressing IGFBP5, and reveal IGFBP5 may be a new therapeutic target and prognostic factor for DC.

Qiju Dihuang Pill protects the lens epithelial cells via alleviating cuproptosis in diabetic cataract.

ETHNOPHARMACOLOGICAL RELEVANCE: Qiju Dihuang Pill (QDP) is a traditional Chinese medicine prescription for the treatment of eye diseases. Novel literature reports that copper-induced cell death, called as cuproptosis, is a copper-dependent and differs distinctly from other types of cell death. AIM OF THE STUDY: The present study aims to investigate whether QDP could protect lens epithelial cells via alleviating copper-induced death in diabetic cataract. MATERIALS AND METHODS: The different concentration of QDP medicated serum was administrated on high glucose (HG)-induced human lens epithelial cells (HLECs). The copper concentration was tested using Elabscience Copper Assay kit. The proliferation was detected using CCK-8 and EdU assays. The molecular binding was identified using RIP-PCR and luciferase reporter assay. RESULTS: Results indicated that HG culture condition triggered the copper concentration and repressed the proliferation of HLECs. Then, the elesclomol-Cu (Es-Cu) administration up-regulated the copper concentration and inhibited the proliferation, and cuproptosis inhibitor tetrathiomolybdate (TTM) could specifically reverse the consequence. QDP treatment reduced the copper concentration and cuproptosis-related genes (SLC31A1, FDX1). MeRIP-Seq and RIP-PCR confirmed that QDP reduced the stability of SLC31A1 mRNA through m6A modified site, and copper actually synergized the molecular binding efficiency. Rescue assay verified the role of QDP and SLC31A1 on HLECs' cuproptosis characteristic. CONCLUSION: This research identified the protective role of QDP on HG-induced HLECs in DC through decreasing m6A/SLC31A1-mediated cuproptosis in DC. This finding provides novel insights into mechanisms for QDP and sheds light on the multifaceted role of traditional prescription on DC.

Ascorbic acid export from human donor lenses: Is the lens a source of ascorbic acid in the ocular humors?

In previous work, we have shown that the lens acts a reservoir of the antioxidant glutathione (GSH), capable of exporting this antioxidant into the ocular humors and potentially protecting the tissues of the eye that interface with these humors from oxidative stress. In this study, we have extended this work by examining whether the lens acts as a source of ascorbic acid (AsA) to maintain the high levels of AsA known to be present in the ocular humors either by the direct export of AsA into the humors and/or by functioning as a recycling site for AsA, via the direct uptake of oxidised ascorbate (DHA) from the humors, its regeneration to AsA in the lens and then its subsequent export back into the humors. To test this, human lenses of varying ages were cultured for 1 h under hypoxic conditions and AsA/DHA levels measured in the media and in the lens. Human lenses were also cultured in compartmentalised chambers to determine whether efflux of AsA/DHA occurs at the anterior or posterior surface. Immunohistochemistry was performed on human donor lenses and sections labelled with antibodies against GLUT1, a putative DHA uptake transporter. Vitreous humor was collected from patients undergoing vitrectomy who either had a natural clear lens, an artificial intraocular implant (IOL) or a cataractous lens, and AsA/DHA and GSH and oxidised GSH (GSSG) measured. We found that cultured human donor lenses released both AsA and DHA into the media. Culturing of lenses in a compartmentalised chamber revealed that AsA and DHA efflux occurs at both surfaces, with relatively equal amounts of AsA and DHA released from each surface. The posterior surface of the lens was shown to express the GLUT1 transporter. Analysis of vitreous samples from patients undergoing vitrectomy revealed that vitreous GSH and AsA levels were similar between the natural lens group, IOL and cataractous lens group. Taken together, while human donor lenses were shown to export AsA and DHA into the surrounding media, the amount of AsA and DHA released from donor lenses was low and not sufficient to sustain the high levels of total AsA normally present in the humors. This suggests that although the lens is not the main source for maintaining high levels of AsA in the ocular humors, the lens may help to support local AsA levels close to the lens.