PAX6/CXCL14 regulatory axis promotes the repair of corneal injury by enhancing corneal epithelial cell proliferation.

BACKGROUND: Corneal injuries, often leading to severe vision loss or blindness, have traditionally been treated with the belief that limbal stem cells (LSCs) are essential for repair and homeostasis, while central corneal epithelial cells (CCECs) were thought incapable of such repair. However, our research reveals that CCECs can fully heal and maintain the homeostasis of injured corneas in rats, even without LSCs. We discovered that CXCL14, under PAX6's influence, significantly boosts the stemness, proliferation, and migration of CCECs, facilitating corneal wound healing and homeostasis. This finding introduces CXCL14 as a promising new drug target for corneal injury treatment. METHODS: To investigate the PAX6/CXCL14 regulatory axis's role in CCECs wound healing, we cultured human corneal epithelial cell lines with either increased or decreased expression of PAX6 and CXCL14 using adenovirus transfection in vitro. Techniques such as coimmunoprecipitation, chromatin immunoprecipitation, immunofluorescence staining, western blot, real-time PCR, cell colony formation, and cell cycle analysis were employed to validate the axis's function. In vivo, a rat corneal epithelial injury model was developed to further confirm the PAX6/CXCL14 axis's mechanism in repairing corneal damage and maintaining corneal homeostasis, as well as to assess the potential of CXCL14 protein as a therapeutic agent for corneal injuries. RESULTS: Our study reveals that CCECs naturally express high levels of CXCL14, which is significantly upregulated by PAX6 following corneal damage. We identified SDC1 as CXCL14's receptor, whose engagement activates the NF-κB pathway to stimulate corneal repair by enhancing the stemness, proliferative, and migratory capacities of CCECs. Moreover, our research underscores CXCL14's therapeutic promise for corneal injuries, showing that recombinant CXCL14 effectively accelerates corneal healing in rat models. CONCLUSION: CCECs play a critical and independent role in the repair of corneal injuries and the maintenance of corneal homeostasis, distinct from that of LSCs. The PAX6/CXCL14 regulatory axis is pivotal in this process. Additionally, our research demonstrates that the important function of CXCL14 in corneal repair endows it with the potential to be developed into a novel therapeutic agent for treating corneal injuries.

Changes in Corneal Morphology with Age in Asian Population: A Multicenter Study of 30,618 Cases.

INTRODUCTION: To evaluate normal reference ranges for corneal morphological parameters and investigate age-related changes in these parameters in Asian subjects with healthy eyes in order to provide reference data for preoperative evaluation of corneal refractive surgery and the early differential diagnosis of subclinical and asymptomatic keratoconus. METHODS: This cross-sectional, multicenter, observational study was conducted in five provinces of China, from January 2014 through October 2019. It is a retrospective analysis. Examiner-blinded clinical measurements were performed after stratification of the subjects into the following age groups: < 18, 18-30, 31-40, 41-50. We evaluated 30,618 healthy eyes of Chinese subjects who exhibited a normal corneal morphology, had no history of eye surgery or trauma, stopped wearing soft contact lenses for at least 2 weeks (rigid contact lenses for at least 4 weeks), and underwent topographic studies for both eyes on the same day. RESULTS: While the anterior and posterior corneal curvatures (K1 and K2) increased with age, corneal astigmatism of the anterior and posterior surfaces (ΔK) and central, minimum, and overall corneal thicknesses decreased with age. Age-related decrease of the overall corneal thickness was more obvious toward the periphery. The anterior and posterior corneal surface heights exhibited a decrease and an increase, respectively. Both index of height asymmetry (IHA) and index of vertical asymmetry (IVA) exhibited an increase with age. CONCLUSIONS: The cornea exhibits overall thinning with age and gradually changes from a flat ellipse to an elongated ellipse in Asian individuals with healthy eyes. However, the anterior and posterior surfaces become smoother with age. Owing to the very large number of cases, these small differences are statistically significant. The results obtained are consistent with the hypothesis that a normal cornea seems to withstand quite well the effect of IOP, external pressures, and the natural cross-linking.

Distribution and Trends in Corneal Thickness Parameters in a Large Population-Based Multicenter Study of Young Chinese Adults.

Purpose: The purpose of this study was to characterize corneal thickness from multiple regions and determine accurate reference values in young adults for diagnosis and treatment. Methods: This cross-sectional observational study was conducted from January 2008 through October 2016 using examiner-blinded clinical measurements and included 37,375 healthy eyes from young adults who exhibited normal corneal morphology, had no history of eye surgery or trauma, had stopped wearing soft contact lenses for ≥2 weeks (rigid contact lenses for ≥4 weeks), and had undergone topographies of both eyes on same day. Keratoconus and subclinical keratoconus were excluded. This multicenter study was conducted in four provinces of China: Tianjin, Shandong, Hubei, and Xinjiang. Results: Central corneal, corneal vertex, and thinnest corneal thicknesses were higher in eyes from Hubei than other provinces. The left eye was thicker than the right in patients from Shandong, Tianjin, and Hubei, but not Xinjiang. Overall corneal thickness was higher in eyes from Hubei than from other provinces. Changing trend of the whole-cornea thickness in eyes from Xinjiang differed from eyes from other provinces. Trends in maximum and minimum axial for change of corneal thickness were similar between eyes from Hubei and Xinjiang and between Shandong and Tianjin. Conclusions: Corneal thickness differs among eyes from different regions. Corneal thickness parameters are influenced by ethnicity and geographical location, as increasing proximity to the equator was related to increasing corneal thickness. Design of refractive surgery and diagnosis of related diseases in patients of a certain area should be based on reference values from its population.

MiR-497 Suppresses YAP1 and Inhibits Tumor Growth in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: To investigate the expression, clinical significance and the cellular effects of miR-497 in non-small cell lung cancer (NSCLC). METHODS: NSCLC cells were transiently transfected with miR-497 mimics or siRNA to up-regulate or down-regulate expression. Quantitative real-time PCR (qRT-PCR) was used to detect the mRNA level of miR-497. Luciferase assays, colony formation assays and BrdU incorporation assays were performed to identify the targets and role of miR-497 in NSCLC cells. Finally, the abundance of miR-497 was analyzed in a total of 51 NSCLC specimens. RESULTS: The transcript levels of miR-497 were significantly decreased in NSCLC tissue (25/30; 83.3%). Low miR-497 levels in tumor tissue correlated with advanced pT stage. Additionally, miR-497 transcript levels correlated with overall survival of NSCLC patients (n = 51, p = 0.022). Overexpression of miR-497 inhibited the proliferation of NSCLC cell and down-regulation of miR-497 resulted in elevated NSCLC growth. Exogenous over-expression of YAP1 partially eliminated miR-497-induced cell growth. CONCLUSION: miR-497 plays an important role in inhibiting the proliferation of NSCLC by targeting YAP1. Our results suggest that miR-497 is a potential therapeutic target in treating patients with NSCLC.

Wnt2 promotes non-small cell lung cancer progression by activating WNT/ß-catenin pathway.

BACKGROUND: Wnt2 is overexpressed and able to promote tumorigenesis in many types of cancer. However, its expression and role in lung cancer has not been well clarified yet. In this study, we aims to investigate the expression pattern, clinical significance and the underlying molecular mechanism of Wnt2 in non-small lung cancer (NSCLC). METHODS: Immunohistochemical staining and ELISA assays were applied to detect Wnt2 level in tumor tissue and serum. EDU incorporation assays and colony formation assays were used to evaluate the growth-promoting effect of Wnt2 in vitro. Then we performed western blot and immunofluorescence assays to detect the activation of WNT signaling pathway. Finally mice engrafted with NSCLC tumor cells were used to assess the role of Wnt2 in vivo. RESULTS: Immunohistochemical staining consisting of 264 NSCLC tumor tissues showed that a high level of Wnt2 was associated with a poor overall survival (OS) and relapse-free survival (RFS) of NSCLC patients (P = 0.002 and 0.0005, respectively). Multivariate analysis presented that Wnt2 level in tumor tissue was an independent prognostic factor (P = 0.049 for OS and P = 0.002 for RFS, respectively). Furthermore, ELISA assays for 181 individuals (116 NSCLC and 65 controls) revealed that serum Wnt2 levels in adenocarcinoma was significantly higher than that in healthy volunteers (P < 0.0001). In vitro H460 cell line stably overexpressing Wnt2 showed enhanced growth activity than the control cells whereas knockdown of Wnt2 by siRNA in H1299 cells resulted in decreased growth activity. Additionally, Wnt2 level in tumor tissues was significantly associated with Ki-67 level (rs: 0.316; P < 0.0001). Immunofluorescence and Western blot assays detected the translocation of ß-catenin from cytoplasm into nucleus, which indicated that Wnt2 probably promotes proliferation by activating WNT/ß-catenin pathway. In vivo H460 cells expressing exogenous Wnt2 showed increased growth-promoting effect in Balb/c nude mice than control cells. CONCLUSIONS: The present study for the first time suggested that Wnt2 was both a prognostic and a diagnostic biomarker for NSCLC. Tumor-derived Wnt2 can promote growth activity of NSCLC cells through activating WNT/ß-catenin signaling pathway.

Biocompatibility of helicoidal multilamellar arginine-glycine-aspartic acid-functionalized silk biomaterials in a rabbit corneal model.

Silk proteins represent a unique choice in the selection of biomaterials that can be used for corneal tissue engineering and regenerative medical applications. We implanted helicoidal multilamellar arginine-glycine-aspartic acid-functionalized silk biomaterials into the corneal stroma of rabbits, and evaluated its biocompatibility. The corneal tissue was examined after routine hematoxylin-eosin staining, immunofluorescence for collagen I and III, and fibronectin, and scanning electron microscopy. The silk films maintained their integrity and transparency over the 180-day experimental period without causing immunogenic and neovascular responses or degradation of the rabbit corneal stroma. Collagen I increased, whereas Collagen III and fibronectin initially increased and then gradually decreased. The extracellular matrix deposited on the surface of the silk films, tightly adhered to the biomaterial. We have shown this kind of silk film graft has suitable biocompatibility with the corneal stroma and is an initial step for clinical trials to evaluate this material as a transplant biomaterial for keratoplasty tissue constructs.