Effect of PKH-26-labeled exosomes derived from bone marrow mesenchymal stem cells on corneal epithelium regeneration in diabetic mice.

Background: It is known that bone marrow mesenchymal stem cells (BM-MSCs) could speed up the regeneration of diabetic corneal epithelium. To investigate the effect of exosomes derived from mouse BM-MSCs on corneal epithelium regeneration in diabetic mice. Methods: Diabetic mouse models were established using streptozotocin (STZ), and their central corneal epithelium was scratched under a microscope. The diabetic mice were randomly divided into three groups: the control group was injected with subconjunctival phosphate buffer saline; the exosomes group was treated with a subconjunctival injection of exosomes derived from BM-MSCs; and the BM-MSCs group was treated with a subconjunctival injection of BM-MSCs. The corneal epithelium repair rates in the three groups were compared, and the distribution of the exosomes derived from BM-MSCs labeled with PKH-26 was observed by immunofluorescence. Hematoxylin-eosin staining of the corneal tissue was observed 72 h after the treatments in the three groups. Results: The diabetic mice were successfully established by a blood glucose level >16.7 mmol/L after 8 weeks. The corneal epithelium healing rates in experimental groups 1 and 2 were significantly higher than those of the control group at 24, 48, and 72 h (P<0.05). However, there was no significant difference in the corneal epithelial healing rate between experimental groups 1 and 2 (P>0.05). The exosomes derived from BM-MSCs were found in the superficial corneal stroma in experimental groups 1 and 2, with the majority of the exosomes distributed in the limbal epithelium at the edge of the injury area. The proliferation of corneal epithelial cells in experimental groups 1 and 2 was more obvious than that in the control group. Conclusions: The exosomes derived from BM-MSCs labeled with PKH-26 significantly promoted the repair of corneal epithelial injury in diabetic mice. These exosomes might be a substitute for BM-MSCs in the repair of diabetic keratopathy, suggesting a new idea for the repair of diabetic keratopathy with "cell-free" stem cell therapy, which will require a clinical study.

Construction of a Promising Tumor-Infiltrating CD8+ T Cells Gene Signature to Improve Prediction of the Prognosis and Immune Response of Uveal Melanoma.

BACKGROUND: CD8+ T cells work as a key effector of adaptive immunity and are closely associated with immune response for killing tumor cells. It is crucial to understand the role of tumor-infiltrating CD8+ T cells in uveal melanoma (UM) to predict the prognosis and response to immunotherapy. MATERIALS AND METHODS: Single-cell transcriptomes of UM with immune-related genes were combined to screen the CD8+ T-cell-associated immune-related genes (CDIRGs) for subsequent analysis. Next, a prognostic gene signature referred to tumor-infiltrating CD8+ T cells was constructed and validated in several UM bulk RNA sequencing datasets. The risk score of UM patients was calculated and classified into high- or low-risk subgroup. The prognostic value of risk score was estimated by using multivariate Cox analysis and Kaplan-Meier survival analysis. Moreover, the potential ability of gene signature for predicting immunotherapy response was further explored. RESULTS: In total, 202 CDIRGs were screened out from the single-cell RNA sequencing of GSE139829. Next, a gene signature containing three CDIRGs (IFNGR1, ANXA6, and TANK) was identified, which was considered as an independent prognostic indicator to robustly predict overall survival (OS) and metastasis-free survival (MFS) of UM. In addition, the UM patients were classified into high- and low-risk subgroups with different clinical characteristics, distinct CD8+ T-cell immune infiltration, and immunotherapy response. Gene set enrichment analysis (GSEA) showed that immune pathways such as allograft rejection, inflammatory response, interferon alpha and gamma response, and antigen processing and presentation were all positively activated in low-risk phenotype. CONCLUSION: Our work gives an inspiration to explain the limited response for the current immune checkpoint inhibitors to UM. Besides, we constructed a novel gene signature to predict prognosis and immunotherapy responses, which may be regarded as a promising therapeutic target.

Regulation of Apoptosis by miR-122 in Pterygium via Targeting Bcl-w.

PURPOSE: To identify the differently expressed micro (mi) RNAs in pterygium compared with normal conjunctiva and investigate the potential role of miRNAs in the pathogenesis of pterygium. METHODS: With microRNA microarray and quantitative RT-PCR, we identified that microRNA-122 (miR-122) was significantly decreased in pterygium tissue. We detected the expression of Bcl-w, a predicted target of miR-122, in both pterygium and normal conjunctiva, as well as its correlation with the expression of miR-122. Pterygium epithelial cells were isolated and cultured, and transfected with miR-122 mimic or miR-122 inhibitor to change the miR-122 levels. The regulation of Bcl-w expression by miR-122 was examined with luciferase activity assay, quantitative (q) RT-PCR, and Western blot. The effect of the miR-122 on the apoptosis of cultured pterygium epithelial cells was investigated with TUNEL staining and caspase activity assay. RESULTS: We found the expression of Bcl-w, with an inverse correlation with the expression of miR-122, was significantly increased in pterygium, especially in the superficial layer of epithelium. In cultured pterygium epithelial cells, miR-122 could specifically combine with Bcl-w mRNA, and negatively regulated the expression of Bcl-w. Suppression of miR-122 could reduce apoptosis and caspase activity in pterygium epithelial cell treated with TNFα/cycloheximide (CHX), and this effect was abolished by inhibition of the expression of Bcl-w with specific siRNA. CONCLUSIONS: Decreased expression of miR-122 in pterygium might result in abnormal cell apoptosis via its regulation of the expression of Bcl-w, and subsequently contribute to the development of pterygium.

Comparison of Visual Quality after Implantation of Big Bag and Akreos Adapt Intraocular Lenses in Patients with High Myopia.

PURPOSE: To compare vision quality following phacoemulsification cataract extraction and implantation of a Big Bag or Akreos Adapt intraocular lens (IOL) in patients diagnosed with high myopia complicated with cataract. METHODS: This was a randomized prospective control study. The patients with high myopia. complicated with cataract, with axial length ≥ 28 mm, and corneal astigmatism ≤ 1D were enrolled and randomly divided into the Big Bag and Akreos Adapt IOL groups. All patients underwent phacoemulsification cataract extraction and lens implantation. At 3 months after surgery, intraocular high-order aberration was measured by a Tracey-iTrace wavefront aberrometer at a pupil diameter of 5 mm in an absolutely dark room and statistically compared between two groups. The images of the anterior segment of eyes were photographed with a Scheimpflug camera using Penta-cam three-dimensional anterior segment analyzer. The tilt and decentration of the IOL were calculated by Image-pro plus 6.0 imaging analysis software and statistically compared between two groups. RESULTS: In total, 127 patients (127 eyes), including 52 males and 75 females, were enrolled in this study. The total high-order aberration and coma in the Akreos Adapt group (59 eyes) were significantly higher compared with those in the Big Bag (P < 0.05). The clover and spherical aberration did not differ between the two groups (P > 0.05). The horizontal and vertical decentration were significantly smaller in the Big Bag lens group than in the Akreos Adapt group (both P < 0.05), whereas the tilt of IOL did not significantly differ between the two groups (P > 0.05). CONCLUSION: Both Big Bag and Akreos Adapt IOLs possess relatively good intraocular stability implanted in patients with high myopia. Compared with the Akreos Adapt IOL, the Big Bag IOL presents with smaller intraocular high-order aberration. Coma is the major difference between the two groups.

Clinical efficacy of toric orthokeratology in myopic adolescent with moderate to high astigmatism.

PURPOSE: To observe the efficacy of toric design orthokera- tology (ortho-k) for correcting myopia and astigmatism in myopic adolescents with moderate to high astigmatism. METHODS: This was a self-controlled clinical study. Twenty-four subjects (42 eyes) aged 9 to 16 years with myopia of 2.50-6.00 D complicated with rule astigmatism of 1.50-3.50 D were fitted with Lucid Night Toric Ortho-k Lenses (LUCID,KO- REA). The changes in uncorrected visual acuity (UCVA), spherical degree, refraction, axial length (AL), and corneal status were assessed at baseline, 1 night, 1 week, 1 month, 3 months, 6 months, and 1 year after the commencement of ortho-k lens wear. RESULTS: The success rate of the first lens fit was 92.8%. The UCVA after ortho-k wearing was improved significantly compared to the baseline during each visit (all P < 0.01), and became stable 1 month after ortho-k. The manifest myopia was significantly reduced from (-3.41 ± 1.27) D to (-0.41 ± 0.37) D by toric ortho-k and the degree of astigmatism from (-1.81 ± 0.53)D to (-0.41 ± 0.39) D after 1 month of lens wear (P < 0.01). The mean AL was (24.47 ± 0.91) mm at baseline, which did not significantly differ from (24.49 ± 0.87) mm and (24.48 ± 0.94) mm after 6 months and 1 year, respectively, of lens wear (both P > 0.05). Grade 1 corneal staining was observed at 1 week (23.8%), 1 month (21.4%), and 1 year (16.7%) following lens wear, and was improved by lens cleaning, discontinuing lens wear, and moistening the cornea with eye drops. No severe adverse events were reported. CONCLUSION: The toric ortho-k lens was effective and safe for correction of low to moderate myopia in children with moderate to high astigmatism. The lens also effectively controlled axial length elongation during 1 year of observation. However, the long-term efficacy remains to be elucidated.

[Combining application burst and occlude mode in the treatment of hard nucleus cataract during phacoemulisification].

PURPOSE: To investigate the effect of combined burst and occlude mode in the treatment of hard nucleus cataract during phacoemulisification. METHODS: Phacoemulisification with combined burst and occlude mode were performed in forty-eight eyes with senile cataracts with nucleus density at grade III-V. RESULTS: First day after operation, the uncorrected visual acuity in 25 eyes were from 0.3 to 0.8 (52.08%), and 4 eyes is better than 0.9 (8.34%). One week later, the visual acuity in 30 eyes has reached to 0.3-0.8 (62.25%), and 11 eyes were better than 0.9 (22.92%). The average effective time was (15 +/- 2.50) seconds for grade III nucleus, (35 +/- 5.33) seconds for grade IV nucleus, and (57 +/- 9.12) seconds for grade V nucleus. CONCLUSIONS: Phacoemulsification with burst and occlude mode was very effective in the treatment of hard nucleus cataract, and was safer. It can decrease phaco power and has little side effect on the ocular tissues.