Naoki Yamamoto

TRPV1, which is widely expressed throughout the body, is a non-selective cation channel activated by capsaicin. We previously reported that TRPV1 activation suppressed TGFβ2-induced epithelial-mesenchymal transition (EMT) by inhibiting Epidermal Growth Factor Receptor (EGFR) phosphorylation in lens epithelial cells (Sugiyama et al., 2021). However, the detailed molecular mechanism remains unclear. In this study, we focused on the calpain-protein tyrosine phosphatase (PTP) pathway to elucidate the detailed mechanism underlying TRPV1-induced EMT suppression. Calpain and PTP inhibitors mitigated the suppressive effect of capsaicin on TGFβ2-induced EMT in vitro and ex vivo. Finally, we shown that CalpainS1 and PTPN9 overexpression abrogated the effect of capsaicin on EMT in lens epithelial cells. Our findings indicate that calpain and PTP proteins are good candidates for preventing EMT after cataract surgery.

Background and Objectives: Posterior chamber phakic implantable contact lenses (Phakic-ICL) are widely used for refractive correction due to their efficacy and safety, including minimal corneal endothelial cell loss. The Collamer-based EVO+ Visian implantable contact lens (ICL), manufactured from Collamer, which is a blend of collagen and hydroxyethyl methacrylate (HEMA), has demonstrated excellent long-term biocompatibility and optical clarity. Recently, hydrophilic acrylic Phakic-ICLs, such as the Implantable Phakic Contact Lens (IPCL), have been introduced. This study investigated the material differences among Phakic-ICLs and their interaction with fibronectin (FN), which has been reported to adhere to intraocular lens (IOL) surfaces following implantation. The aim was to compare Collamer, IPCL, and LENTIS lenses (used as control) in terms of FN distribution and cell adhesion using a small number of explanted Phakic-ICLs. Materials and Methods: Three lens types were analyzed: a Collamer Phakic-ICL (EVO+ Visian ICL), a hydrophilic acrylic IPCL, and a hydrophilic acrylic phakic-IOL (LENTIS). FN distribution and cell adhesion were evaluated across different regions of each lens. An in vitro FN-coating experiment was conducted to assess its effect on cell adhesion. Results: All lenses demonstrated minimal FN deposition and cellular adhesion in the central optical zone. A thin FN film was observed on the haptics of Collamer lenses, while FN adhesion was weaker or absent on IPCL and LENTIS surfaces. Following FN coating, Collamer lenses supported more uniform FN film formation; however, this did not significantly enhance cell adhesion. Conclusions: Collamer, which contains collagen, promotes FN film formation. Although FN film formation was enhanced, the low cell-adhesive properties of HEMA resulted in minimal cell adhesion even with FN presence. This characteristic may contribute to the long-term transparency and biocompatibility observed clinically. In contrast, hydrophilic acrylic materials used in IPCL and LENTIS demonstrated limited FN interaction. These material differences may influence extracellular matrix protein deposition and biocompatibility in clinical settings, warranting further investigation.

The study aimed to investigate whether eosinophil major basic protein (MBP), which is linked to cataract formation due to lens epithelial cell (LEC) damage in atopic dermatitis (AD), is associated with intraocular lens (IOL) dislocation. This retrospective observational study was conducted at a Medical University Hospital and included 22 eyes (10 AD, 12 non-AD [NAD]) that underwent IOL explantation and fixation. Surgeries were conducted to extract the intraocular lens capsule for morphological evaluations. Quantitative analysis of the MBP staining was conducted using the staining area ratio (SAR) gap. MBP staining was negative in all cases for both the lens capsule and LEC. The SAR gap in Soemmering's ring was significantly higher in the AD group (14.3 ± 8.7%) than in the NAD group (1.1 ± 1.1%) (p = 0.0037). In contrast, the SAR gap for fibrous metaplasia showed no significant difference between the AD (8.3 ± 13.2%) and NAD (6.5 ± 12.3%) groups (p = 0.75). Six cases of fibrous metaplasia, including those in the NAD group, showed SAR gaps equal to or greater than those in the positive control group, with five classified as low-density fibrosis (LDF). While Soemmering's rings in AD cases demonstrated greater MBP immunoreactivity than NAD controls, both groups exhibited MBP-positive fibrous metaplasia specimens.