Proteomic analysis of posterior capsular plaques in congenital unilateral cataract

Characteristic cytokine profile of the aqueous humor in eyes with congenital cataract and pre-existing posterior capsule dysfunction

Objectives

To investigate the characteristic cytokine profile of the aqueous humor in eyes with congenital cataract and pre-existing posterior capsule dysfunction (PCD).

Methods

In this cross-sectional study, the enrolled eyes with congenital cataract and PCD were included in the PCD group, while those with an intact posterior capsule were included in the control group. Demographic data and biometric parameters were recorded. The levels of 17 inflammatory factors in the aqueous humor collected from the enrolled eyes were detected using Luminex xMAP technology, and intergroup differences in the collected data were analyzed.

Results

The PCD group comprised 41 eyes from 31 patients with congenital cataract and PCD, whereas the control group comprised 42 eyes from 27 patients with congenital cataract and an intact posterior capsule. Lens thickness was significantly thinner in the PCD group than in the control group. However, the levels of monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-β2 (TGF-β2), and vascular endothelial growth factor (VEGF) were significantly higher in the PCD group than in the control group. Multivariate logistic regression confirmed that lens thickness and TGF-β2 level were independent risk factors for PCD.

Conclusion

A thinner lens thickness in eyes with congenital cataract and PCD could serve as a biometric feature of these eyes. The higher levels of MCP-1, TGF-β2, and VEGF in eyes with PCD indicated a change in their intraocular inflammatory microenvironment, which possibly led to cataract progression. Lens thickness and TGF-β2 level are independent risk factors for PCD.

Interfering Hsa_circRNA_0060640 Suppresses TGF-β2-Induced Proliferation, Motility and EMT in Human Lens Epithelium Cells by Targeting miR-214-3p and Collagen Type I alpha2 Chain

BACKGROUND

Circular RNA (circRNA) is a novel star factor in the research of ocular diseases including cataract and the most common postoperative complication posterior capsule opacification (PCO). Hsa_circRNA_0060640 (circ_0060640) is an age-related cataract-related circRNA. However, its role in cataractogenesis is unrevealed yet.

METHODS

PCO in vitro model was established in human lens epithelium cells (hLECs) induced by transforming growth factor-beta2 (TGF-β2). RNA and protein expressions were respectively detected by quantitative PCR and western blotting. Direct interaction between two RNAs was predicted by Starbase tool and confirmed by dual-luciferase reporter assay. MTS and EdU assays measured cell proliferation; Transwell, starch wound and western blotting assays evaluated cell motility and epithelial-mesenchymal transition (EMT).

RESULTS

Circ_0060640 expression is higher in anterior lens capsule tissues from human cataractous eyes and TGF-β2-stimulated hLECs cells line SRA01/04. RNA interference of circ_0060640 could prevent SRA01/04 cells from TGF-β2-induced cell proliferation, migration and invasion, accompanied with decreased N-cadherin and α-smooth muscle actin and increased E-cadherin. Mechanistically, circ_0060640 directly controls microRNA (miR)-214-3p expression and then regulates gene expression of collagen type I alpha2 chain (COL1A2). Notably, COL1A2 inhibition is underlying the protective role of circ_0060640 silencing and miR-214-3p ectopic expression in TGF-β2-stimulated SRA01/04 cells.

CONCLUSION

Circ_0060640 is a novel cataract-related gene and its silencing could block TGF-β2-evoked hLECs proliferation, motility and EMT in vitro via targeting miR-214-3p-COL1A2 axis. Therefore, targeting circ_0060640 via RNA interference might be a treatment strategy for PCO development.

The importance of the epithelial fibre cell interface to lens regeneration in an in vivo rat model and in a human bag-in-the-lens (BiL) sample

Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI.

Congenital cataract - clinical and morphological aspects

Congenital cataract is one of the main causes of blindness in newborns and children. According to the World Health Organization (WHO), there are about 14 million children suffering from congenital cataract. Our study is based on 82 children, males – 46 (56.1%) and females – 36 (43.9%), with congenital cataract operated in the same ophthalmological centre in Bucharest, Romania. Of the 82 patients, 49 (59.76%) had bilateral cataract and 33 (40.24%) unilateral cataract. Clinically, the most frequent was the total cataract, followed by lamellar, nuclear and cerulean. We employed nine surgical approaches in our patients, depending on the type of intraocular lens (IOL). Morphologically, obvious changes were rendered evident at the level of anterior and posterior capsules, as well as subcapsular.