Challenges in cataract surgery after penetrating keratoplasty managed using femtosecond laser: A series of 3 case reports.

INTRODUCTION: Cataract surgery in patients after penetrating keratoplasty (PKP) is often challenging because of changes in corneal structure induced by PKP and primary corneal disease. Femtosecond laser-assisted cataract surgery offers several advantages over conventional phacoemulsification, and has been widely used in complicated cataract surgery. CASE REPORT: We report the use of femtosecond laser-assisted cataract surgery in 3 challenging cases after penetrating keratoplasty. Case 1 involved a patient with hard nuclear grade IV° cataract. After surgery, his corrected distance visual acuity (CDVA) improved from 20/400 to 20/25, and the endothelial cell loss (ECL) % was 12.05 % at 3 months postoperatively. The rotation of the toric IOL in Case 1 was 2°. Case 2 involved a patient with severe nuclear cataract and an endothelial cell density of 837 cells/mm2. After surgery, the CDVA improved from 20/100 to 20/40. The ECL% was 4.06% at 1 week postoperatively. Case 3 was a 91-year-old woman with a short axis length of 21.35 mm and an endothelial cell density number of 1238 cells/mm2. After surgery, the CDVA improved from light perception to 20/133, and the ECL% was 26.09% at 1 week postoperatively; ECL% was 2.67% at 1 month post-operation. The corneal grafts were transparent. CONCLUSION: Femtosecond laser-assisted cataract surgery seems to be an effective, predictable, and safe approach for challenging patients after PKP, and improves visual recovery and optimal refractive outcomes.

Appraising the Effects of Metabolic Traits on the Risk of Glaucoma: A Mendelian Randomization Study.

Metabolic traits are associated with the risk of developing glaucoma in observational studies. To assess whether theses associations reflect causality, we conducted a Mendelian randomization (MR) study. Our study included up to 20,906 glaucoma cases and 438,188 controls. Genetic instruments associated with the concerned 11 exposures at the genome-wide significance level were selected from corresponding genome-wide association studies. Summary-level data for glaucoma were obtained from the UK Biobank, the GERA study, and the FinnGen consortium. Univariable and multivariable MR analyses were conducted separately in two populations. Our results showed that higher genetic liability to type 2 diabetes (T2D) was causally and independently associated with an increased risk of glaucoma (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.06-1.16; p = 4.4 × 10-6). The association for T2D persisted after multivariable adjustment. In addition, higher genetically predicted systolic blood pressure (SBP), fasting glucose (FG), and HbA1c, were also suggestively associated with glaucoma risk. The OR was 1.08 (95% CI, 1.01-1.16; p = 0.035) for SBP, 1.24 (95% CI, 1.05-1.47; p = 0.011) for FG, and 1.28 (95% CI, 1.01-1.61; p = 0.039) for HbA1c. No evidence was observed to support the causal effects of body mass index and blood lipids for glaucoma. This study suggests a causal role for diabetes, as well as possible roles for higher SBP, FG, and HbA1c in the development of glaucoma. Further validation is needed to assess the potential of these risk factors as pharmacological targets for glaucoma prevention.

Comparative visual outcomes of EDOF intraocular lens with FLACS vs conventional phacoemulsification.

PURPOSE: To investigate the visual quality after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS) with the implantation of an extended depth-of-focus (EDOF) intraocular lens (IOL) TECNIS Symfony. SETTING: Eye Center, the Second Affiliated Hospital of Zhejiang University, Zhejiang, China. DESIGN: Prospective cohort study. METHODS: Patients were given the option to choose FLACS or CPS and were implanted with a TECNIS Symfony. Main outcome measures were postoperative examinations that included defocus curves, contrast sensitivity (CS), optic path difference aberrometry scan, anterior segment photography, and questionnaires. RESULTS: 261 patients (261 eyes) were enrolled. The circularity index of FLACS was more precise than that of CPS ( P = .001). FLACS demonstrated a significantly lower IOL decentration ( P = .011) and IOL tilt ( P = .009). FLACS presented a significantly lower total aberration ( P < .001), higher-order aberrations (HOAs) ( P = .001), coma ( P = .001), and spherical aberration ( P < .001). With IOL decentration of more than 0.40 mm, total internal aberration ( P = .023) and HOAs ( P = .045) were significantly deteriorated. As for defocus curve, FLACS was better at -1.00 diopter ( P < .01). The FLACS group achieved higher CS at 6 to 18 cycles per degree under glare condition ( P < .05). With regard to photic phenomena, the FLACS group received better outcomes ( P < .05). CONCLUSIONS: With the implantation of an EDOF IOL, FLACS could precisely control the shape and size of the capsulotomy and induce a significantly better-centered IOL, leading to higher visual performance compared with CPS.

The impact of the COVID-19 pandemic on the mental health and academic performance of medical postgraduates.

Background: The Coronavirus disease 2019 (COVID-19) has presented a major challenge to the health, economic, and social sectors of the entire world. This study aimed to investigate the mental health and academic performance of medical postgraduates during the COVID-19 pandemic in China. Methods: A cross-sectional online survey was conducted from March 20 to April 20, 2022 at the Zhejiang University School of Medicine in China. The questionnaire consisted of three parts: general information, mental health and academic performance. Mental health outcomes were assessed according to the Generalized Anxiety Scale (GAD-7) and the Patient Health Questionnaire-9 Scale (PHQ-9). Results: A total of 153 valid questionnaires were obtained. Of the medical postgraduates in this study, (1) 41.8% had no anxiety symptoms. In addition, 51.0% had mild anxiety symptoms during the COVID-19 pandemic. None of the participants had a severe anxiety or depression disorder; (2) Females experienced significantly more symptoms in mental health measure scores than the males (P < 0.01); (3) 78.4% believed that the COVID-19 pandemic had varying degrees of impact on their academics. Doctoral postgraduates showed greater academic stress, and they were more worried about not meeting graduation standards than the master's postgraduates (P < 0.05). There were no significant differences between the surgical postgraduates and internal postgraduates in either mental health or academic performance. Conclusions: Our study found that the COVID-19 pandemic has had a mild impact on the mental health and academic performance of medical postgraduates in China. Females experienced significantly more symptoms on mental health measure scores than the males. Doctoral postgraduates showed greater academic stress than the master's postgraduates. There is uncertainty regarding how long this COVID-19 situation will persist and increasing recognition that there may be periods of recurrence in the future. We need more active curricular innovation and transformation to maintain and improve medical postgraduates' mental health and academic performance.

Exosomes-loaded thermosensitive hydrogels for corneal epithelium and stroma regeneration.

Corneal damage forms scar tissue and manifests as permanent corneal opacity, which is the main cause of visual impairment caused by corneal diseases. To treat these diseases, herein, we developed a novel approach based on the exosome derived from induced pluripotent stem cell-derived mesenchymal stem cells (iPSC-MSCs) combined with a thermosensitive hydrogel, which reduces scar formation and accelerates the healing process. We found that a thermosensitive chitosan-based hydrogels (CHI hydrogel) sustained-release iPSC-MSC exosomes can effectively promote the repair of damaged corneal epithelium and stromal layer, downregulating mRNA expression coding for the three most enriched collagens (collagen type I alpha 1, collagen type V alpha 1 and collagen type V alpha 2) in corneal stroma and reducing scar formation in vivo. Furthermore, iPSC-MSCs secrete exosomes that contain miR-432-5p, which suppresses translocation-associated membrane protein 2 (TRAM2), a vital modulator of the collagen biosynthesis in the corneal stromal stem cells to avert the deposition of extracellular matrix (ECM). Our findings indicate that iPSC-MSCs secrete miRNA-containing exosomes to promote corneal epithelium and stroma regeneration, and that miR-432-5p can prevent ECM deposition via a mechanism most probably linked to direct repression of its target gene TRAM2. Overall, our exosomes-based thermosensitive CHI hydrogel, is a promising technology for clinical therapy of various corneal diseases.

Modeling congenital cataract in vitro using patient-specific induced pluripotent stem cells.

Congenital cataracts are the leading cause of childhood blindness. To date, surgical removal of cataracts is the only established treatment, but surgery is associated with multiple complications, which often lead to visual impairment. Therefore, mechanistic studies and drug-candidate screening have been intrigued by the aims of developing novel therapeutic strategies. However, these studies have been hampered by a lack of an appropriate human-disease model of congenital cataracts. Herein, we report the establishment of a human congenital cataract in vitro model through differentiation of patient-specific induced pluripotent stem cells (iPSCs) into regenerated lenses. The regenerated lenses derived from patient-specific iPSCs with known causative mutations of congenital cataracts (CRYBB2 [p. P24T] and CRYGD [p. Q155X]) showed obvious opacification that closely resembled that seen in patients' cataracts in terms of opacification severity and disease course accordingly, as compared with lentoid bodies (LBs) derived from healthy individuals. Increased protein aggregation and decreased protein solubility corresponding to the patients' cataract severity were observed in the patient-specific LBs and were attenuated by lanosterol treatment. Taken together, the in vitro model described herein, which recapitulates patient-specific clinical manifestations of congenital cataracts and protein aggregation in patient-specific LBs, provides a robust system for research on the pathological mechanisms of cataracts and screening of drug candidates for cataract treatment.

Quality of Life in Patients with ß-thalassemia Major: Short-term and Long-term Effects After Haematopoietic Stem Cell Transplantation.

BACKGROUND: Allogeneic haematopoietic stem cell transplantation (ALLO-HSCT) is a potentially curative approach to treat ß-thalassemia major (ß-TM). OBJECTIVE AND METHODS: To assess the quality of life (QOL) of patients with ß-TM after ALLO-HSCT, we searched PubMed, Embase, Web of Science, and MEDLINE for articles on the quality of life (QOL) of patients with ß-TM from 1 Feb 2020 to 31 Mar 2020. RESULTS: Our review revealed that the QOL of patients with ß-TM after ALLO-HSCT from a sibling donor is higher than that of patients that received blood infusion and iron-chelating therapy. Survivors of ALLO-HSCT have a QOL as good as that of a healthy population and the ability to return to normal life. However, studies thus far are limited to investigations with a few patients with ß-TM who received ALLO-HSCT of the bone marrow (BM) from a sibling donor or related donor. Graft vs. host disease, patient age, gender, sexual desire, health condition, psychological state, financial and employment stress, and social support contributed to a worse QOL after ALLO-HSCT. Medicine usage, physical therapy, and psychological intervention may help improve the decline in QOL related to ALLO-HSCT in patients with ß-TM. CONCLUSION: Doctors and nurses must focus on implementing medicine usage, physical therapy, and psychological intervention to improve the decline in QOL related to ALLO-HSCT.

Transcriptomic profiling of human corneal epithelial cells exposed to airborne fine particulate matter (PM2.5).

PURPOSE: To explore the molecular mechanisms of PM2.5-induced dysfunction in human corneal epithelial cells (HCECs) and the potential role of the plasminogen activator inhibitor type-2 (PAI-2) in PM2.5-induced autophagy in vitro and in vivo. METHODS: RNA-Seq was performed to identify the differentially expressed genes (DEGs) in PM2.5-exposed HCECs compared to unexposed condition, followed by validation via real-time PCR (qRT-PCR). Corneal fluorescein staining and tear secretion were assessed in the PM2.5-exposed rat model. The expression of PAI-2 and autophagy-related markers were examined via immunoblotting, immunofluorescence staining and/or qRT-PCR in PM2.5-exposed or unexposed HCECs and rat corneas. PAI-2-knockdown HCECs were generated to study PAI-2's role in the PM2.5-induced autophagy in HCECs. RESULTS: A total of 434 DEGs-240 up-regulated and 194 down-regulated-were identified in PM2.5-exposed HCECs rather than unexposed HCECs. The expression of a few genes related to proliferation, inflammation, and aryl hydrocarbon stimulation were significantly altered by PM2.5 exposure. PAI-2 expression was up-regulated in PM2.5-exposed HCECs, sharing a similar fluctuation trend with autophagy-related markers LC3B II and BECN1 according to various exposure periods. Moreover, PAI-2 knockdown significantly suppressed the expression of LC3B and BECN1 in PM2.5-exposed HCECs. The corneal fluorescein staining was enhanced and tear secretion was significantly reduced in PM2.5-exposed rat eyes. PAI-2 expression was also increased in PM2.5-exposed rat corneas, together with the up-regulation of several autophagy-related markers. CONCLUSION: The present study identified the altered expression of hundreds of genes in PM2.5-exposed HCECs, which suggests the importance of PM2.5 for cornea health. The involvement of PAI-2 was discovered in the PM2.5-induced autophagy in HCECs as well as likely in rat corneas, which implied that PAI-2 may become a potential target of clinical treatment of PM2.5-associated ocular surface diseases.

Multiple cytokine analyses of aqueous humor from the patients with retinitis pigmentosa.

PURPOSE: Cataracts are the most common eye complications of retinitis pigmentosa (RP). This study aimed to investigate the cytokine profiles of the aqueous humor of RP with cataracts. METHODS: The aqueous humor was collected from RP eyes with cataract (RP group, n = 20) and age-related cataract eyes (ARC group, n = 20) during cataract surgery. The levels of 37 mediators were measured with multiplex fluorescent bead-based immunoassay and compared across groups. The correlation among chemokines, growth factors, and cytokines was analyzed with Spearman's rank correlation coefficient. RESULTS: Twelve cytokines (IL-1α, IL-1ß, IL-4, IL-10, TNF-α, IFN-γ, EGF, GM-CSF, PDGF-AB/BB, TGF-α, BMP-9, and E-selection) were below the limit of detection, and the detection rate of IL-6 was significantly higher in RP group than in the ARC group (P < 0.01). Compared with those in the control group, the aqueous humor levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-(IL-)8, interferon gamma-induced protein (IP)-10, hepatocyte growth factor (HGF), platelet-derived growth factor AA (PDGF-AA), matrix metalloproteinase-2 (MMP-2), MMP3, MMP-7, MMP-8, plasminogen activator inhibitor-1 (PAI-1), and thrombospondin-2 (TSP-2) in the RP group increased significantly (P < 0.01). A lower level of BMP-4 in the aqueous humor was observed in the RP patients than in the controls (P < 0.05). CONCLUSIONS: Significantly increased levels of PDGF-AA, MMP2, MMP3, MMP-7, MMP-8, PAI-1, and TSP-2 and lower levels of BMP-4 were found in the aqueous humor of RP patients. This result indicates a disturbance of the extracellular matrix (ECM) and cytokines in RP patients and suggests a possible role of these cytokines in the pathogenesis of capsular contraction syndrome (CCS) in RP patients.

Opacification of lentoid bodies derived from human induced pluripotent stem cells is accelerated by hydrogen peroxide and involves protein aggregation.

Despite the recent breakthrough in cataract drug development, further improvements have been limited by the lack of human in vitro cataract disease models. This study, therefore, aims to generate a qualified cataract disease model. Mature lentoid bodies (LBs) on Day 25 (D25), which were differentiated from human induced pluripotent stem cells (iPSCs) using the "fried egg" method, were continually culturing (control) or extra treated with either ultraviolet (UV) radiation or hydrogen peroxide (H2 O2 ). The LBs' shape alteration and opacity were examined using light microscopy and mean gray value evaluation. Their structure and crystallin expression were examined using immunofluorescence and transmission electron microscopy (TEM). Real-time polymerase chain reaction and western blot were used to investigate the potential role of autophagy in cloudy LBs. Mature LBs became cloudy with time which was accelerated by H2 O2 . Immunofluorescence examinations and TEM showed that the H2 O2 -treated and control LBs had similar shapes, lens capsule, and monolayer lens epithelial cell (LEC) structures. However, we were unable to do further assessment of the UV-treated LBs as the structures of LBs were easily damaged when treated with UV radiation. Cells containing aggregated protein (αA-crystallin and αB-crystallin) puncta were more abundant in the H2 O2 -treated LBs as compared with control LBs. Moreover, LC3B expression decreased with age in anterior lens capsules obtained from age-related cataracts (ARCs) patients as compared with LC3B levels in primary LECs, which is consistent with that LC3B expression in LBs was lower on D45 than on D25. Our study found that human iPSCs-derived LBs became cloudy with time which was accompanied by protein aggregation, and this phenomenon was accelerated by H2 O2 , suggesting that LBs with extending culture may serve as a human model for in vitro ARCs.

Cytokine profiling reveals increased serum inflammatory cytokines in idiopathic choroidal neovascularization.

BACKGROUND: The exact pathogenesis of idiopathic choroidal neovascularization (ICNV) remains unclear. Cytokine-mediated inflammation has been thought to be involved in the pathophysiology of ICNV. The purpose of this study was to investigate serum cytokine profiles in patients with ICNV and to explore the relationship between serum cytokine levels and ICNV severity. METHODS: This case-control study was conducted in 32 ICNV patients and 30 healthy volunteers. Clinical and demographic information was obtained from the medical data platform and the serum was analysed with a multiplex assay to determine the levels of seven cytokines: interleukin (IL)-2, IL-10, IL-15, IL-17, basic fibroblast growth factor (basic FGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF). RESULTS: Serum levels of IL-2, IL-10, IL-17, basic FGF, and VEGF were elevated in ICNV patients compared to controls. Serum GM-CSF levels were positively related to central retinal thickness, and serum IL-17 levels were positively related to CNV lesion area. CONCLUSION: Serum inflammatory cytokines were significantly elevated in ICNV patients compared to controls. This suggests that systemic inflammation may play a critical role in the physiopathology of ICNV.

Impacts of air pollution on dry eye disease among residents in Hangzhou, China: A case-crossover study.

The purpose of this study is to investigate the potential associations between air pollution and dry eye disease (DED). Data of outdoor air pollutants and meteorology as well as outpatient visits for DED were collected. A time-stratified case-crossover approach was used to analyze the associations between ambient air pollutants and outpatient visits for DED. Among the 5062 DED patients studied, 65.45% were female and 34.55% were male. In the single-pollutant model, significant associations were observed between an increase of 10 µg/m3 in the concentrations of fine-particulate matter with a median aerometric diameter of less than 10 µm (PM10), fine-particulate matter with a median aerometric diameter of less than 2.5 µm (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) and outpatient visits for DED. These results were consistent with those of the multipollutant model. The strongest associations between air pollutants and patient visits were observed during the cold season and in patients aged 21-40. The significant association between air pollutants (PM10, PM2.5, SO2, NO2, and CO) and DED outpatient visits indicates the importance of increased environmental protection.

A New Long Noncoding RNA ALB Regulates Autophagy by Enhancing the Transformation of LC3BI to LC3BII during Human Lens Development.

Autophagy is essential in lens organelle degradation. This study aimed to seek potential autophagy-associated long noncoding RNAs (lncRNAs) and their relative mechanisms in human lens development using the "fried egg" lentoid body (LB) generation system. The expression pattern of LC3B in differentiating LBs was similar to that in developing a mouse lens in vivo. Among the massive lncRNAs expressed with a significant difference between induced pluripotent stem cells (iPSCs) and LBs, lncRNA affecting LC3B (ALB), which was predicted to have a co-relationship with the autophagy marker LC3B, was highly expressed in differentiating lens fibers in LBs. This result was consistent with its high expression in human embryonic lenses compared to those in embryonic stem cells (ESCs). Furthermore, lncRNA ALB knockdown resulted in the downregulation of LC3BII at the protein level, therefore inhibiting the autophagy process in human lens epithelial cells (HLECs). Our results identify lncRNA ALB, a potential autophagy regulator in organelle degradation during human lens development, highlighting the importance of lncRNAs in lens development.

Clinical evaluation of corneal changes after phacoemulsification in diabetic and non-diabetic cataract patients, a systematic review and meta-analysis.

Corneal endothelium morphological abnormalities result in fluid imbalance, stromal swelling, and loss of transparency, thus impairing visual function. Recently, growing number of studies have focused on diabetic corneal abnormalities after cataract surgery and its comparison with non-diabetic patients, the results remain conflicting. Thus, to evaluate the effect of phacoemulsification on the corneal properties in diabetic and non-diabetic patients, prospective studies were comprehensively searched through PubMed, EMBASE, and Cochrane databases updated to Jan 2017. A meta-analysis of the 13 identified studies was performed using weighted mean difference (WMD) and 95% confidence interval (CI). For the dynamic changes between preoperative and postoperative values, significant differences were identified between the two groups in endothelial cell density (ECD) and hexagon cells (HC%) at 1 day, 1 week, 1 month, and 3 months postoperatively, in central corneal thickness (CCT) at 1 month postoperatively, and in coefficient variation (CV) at 1 week and 1 month postoperatively. However, no significant differences were observed in CCT at 1 day, 1 week and 3 months postoperatively or in CV at 1 day and 3 months postoperatively. Diabetic corneas are more vulnerable to stress and trauma, resulting in greater morphological abnormalities and longer recovery time.

Air pollution and outpatient visits for conjunctivitis: A case-crossover study in Hangzhou, China.

BACKGROUND: Conjunctivitis, one of the most common ocular surface diseases, can be caused by many factors. OBJECTIVES: The objective of this study was to investigate the potential association between conjunctivitis and air pollutants. MATERIALS AND METHODS: Data of 9737 outpatient visits for conjunctivitis from July 1, 2014 to June 30, 2016 were obtained from the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China. The data were linked to data on the concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), and fine particulate matter with a median aerometric diameter of less than 10 and 2.5 µm (PM10 and PM2.5, respectively), which were obtained from the Environmental Protection Department of Zhejiang Province. A time-stratified case-crossover study design and conditional logistic regression were applied to analyze the association between air pollutants and outpatient visits for conjunctivitis. RESULTS: A 10 µg/m3 increase in PM10, PM2.5, SO2, NO2, and CO concentrations on the same day as the hospital visit or on lag days before the hospital visit date was associated with outpatient visits for conjunctivitis. The strongest association was observed between SO2 and conjunctivitis patients aged 2-5 years. Variation occurs between warm and cold seasons, between genders, and among different age groups. CONCLUSIONS: Our study provided evidence that outpatient visits for conjunctivitis were significantly associated with air pollution in Hangzhou, China.

Thermosensitive chitosan-based hydrogels releasing stromal cell derived factor-1 alpha recruit MSC for corneal epithelium regeneration.

Corneal epithelium integrity depends on continuous self-renewing of epithelium and connections between adjacent cells or between the cells and the basement membrane. Self-renewing epithelium cells mainly arise from the continuous proliferation and differentiation of the basal layer and limbal stem cells. The aim of the present study was to generate a bioactive, thermosensitive chitosan-gelatin hydrogel (CHI hydrogel) by incorporating exogenous recombinant human stromal cell-derived factor-1 alpha (SDF-1 alpha) for corneal epithelium regeneration. The exogenous SDF-1 alpha could enhance the stem cells proliferation, chemotaxis and migration, and the expression levels of related genes were significantly elevated in LESCs and mesenchymal stem cells (MSCs) in vitro. Moreover, the MSCs promoted the proliferation and maintained the corneal fate of the LESCs. The rat alkali injury model was used for in vivo study. The injured eyes were covered with CHI hydrogel alone or rhSDF-1 alpha-loaded CHI hydrogel. All rats were followed for 13days. Histological examination showed that the SDF-1 alpha/CHI hydrogel complex group had a nearly normal thickness; moreover, it was also found that this group could upregulate the expression of some genes and had more ΔNp63-positive cells. The SDF-1 alpha/CHI hydrogel complex group had a more tightly arranged epithelium compared with the control group using transmission electron microscopy (TEM). The mechanism for this may have involved the activation of stem cell homing and the secretion of growth factors via the SDF-1/CXCR4 chemokine axis. Therefore, SDF-1 alpha/CHI hydrogel complexes could provide a new idea for the clinical application. STATEMENT OF SIGNIFICANCE: The clarity of cornea is important for normal vision. The loss or dysfunction of LESCs leads to the impairment of corneal epithelium. The complete regeneration of corneal epithelium has not been achieved. Our study demonstrated that the incorporation of rhSDF-1 alpha with CHI hydrogel accelerated corneal epithelium reconstruction with more native structural and functional properties. The mechanism may involve in inducing proliferation and migration of the LESCs and MSCs to the injury site via the SDF-1/CXCR4 chemokine axis. Therefore, SDF-1 alpha/CHI hydrogel complexes could be a practical application for clinical therapy.

Airborne particulate matter (PM2.5) triggers autophagy in human corneal epithelial cell line.

PURPOSE: To investigate particulate matter (PM2.5)-induced damage to human corneal epithelial cells (HCECs) and to determine the underlying mechanisms. METHODS: HCECs were exposed to PM2.5 at a series of concentrations for various periods. Cell viability was measured by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell proliferation was evaluated via 5-ethynyl-2'-deoxyuridine (EdU) analysis, while autophagy was determined by immunofluorescence and Western blot. RESULTS: PM2.5-induced cell damage of HCECs occurred in a time- and dose-dependent manner. Decreased cell viability and proliferation as well as increased apoptosis were observed in HCECs after PM2.5 exposure for 24 h. Autophagy in HCECs was slightly inhibited in the early stage (before 4 h) of exposure but significantly activated in the late stage (after 24 h), as evidenced by a decrease in the former and increase in the latter of the expression of the autophagy-associated markers LC3B, ATG5, and BECN1. Interestingly, rapamycin, an autophagy activator, attenuated early-stage but aggravated late-stage PM2.5-induced cell damage, suggesting that the role of autophagy in HCECs may change over time during PM2.5 exposure. In addition, in the early stage, the expression of LC3B and ATG5 increased in cells co-treated with rapamycin and PM2.5 compared to rapamycin-only or PM2.5-only treated cells, suggesting that autophagy may benefit cell viability after PM2.5 exposure. CONCLUSIONS: The results indicate the potential role of autophagy in the treatment of PM2.5-induced ocular corneal diseases and provide direct evidence for the cytotoxicity, possibly involving an autophagic process, of PM2.5 in HCECs.

Proliferative Effects of Histamine on Primary Human Pterygium Fibroblasts.

Purpose. It has been confirmed that inflammatory cytokines are involved in the progression of pterygium. Histamine can enhance proliferation and migration of many cells. Therefore, we intend to investigate the proliferative and migratory effects of histamine on primary culture of human pterygium fibroblasts (HPFs). Methods. Pterygium and conjunctiva samples were obtained from surgery, and toluidine blue staining was used to identify mast cells. 3-[4, 5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was performed to evaluate the proliferative rate of HPFs and human conjunctival fibroblasts (HCFs); ki67 expression was also measured by immunofluorescence analysis. Histamine receptor-1 (H1R) antagonist (Diphenhydramine Hydrochloride) and histamine receptor-2 (H2R) antagonist (Nizatidine) were added to figure out which receptor was involved. Wound healing model was used to evaluate the migratory ability of HPFs. Results. The numbers of total mast cells and degranulated mast cells were both higher in pterygium than in conjunctiva. Histamine had a proliferative effect on both HPFs and HCFs, the effective concentration (10 µmol/L) on HPFs was lower than on HCFs (100 µmol/L), and the effect could be blocked by H1R antagonist. Histamine showed no migratory effect on HPFs. Conclusion. Histamine may play an important role in the proliferation of HPFs and act through H1R.

Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue.

The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations.

Effects of senescent lens epithelial cells on the severity of age-related cortical cataract in humans: A case-control study.

The aging of lens progenitor cell has been repeatedly proposed to play a key role in age-related cataracts (ARCs), but the mechanism is far from being understood. The present study aims to investigate the relationship between aging of lens progenitor/epithelial cells and the 4 subtypes of ARCs in humans.Lens capsules, which were collected from ARC patients during surgery, were divided into 3 groups according to the age of patients (50-60, 60-80, and >80 years). The expressions of lens progenitor cell-related markers Sox2, Abcg2, and Ki67 were first examined in human lens epithelial cells (HLECs) in situ. Then, the percentage of senescent and SA-ß-gal HLECs isolated from lens capsules were quantified. Finally, the potential relationships between the percentage of senescent (and SA-ß-gal) HLECs and the severity of ARCs were analyzed.Ki67, Sox2, and Abcg2 HLECs in lens capsules were clearly more abundant in young people than in patients older than 50 years, and they were almost absent in patients older than 60 years. The percentage of primary HLECs with aging morphology increased with age, consistent with the results of SA-ß-gal primary HLECs. Only cortical cataract classification was found to be strongly related to the percentage of SA-ß-gal and senescent HLECs.Our study gave the initial evidence on the dynamical change of lens stem/progenitor cells in human lens capsule with age and suggested that lens progenitor/epithelial cell aging is important in the severity of cortical cataracts.