PhD Scientific Days 2022

Molecular Sciences II.

Fluvoxamine Reduces Fibrotic Changes in Trabecular Meshwork Cells

Text of the abstract

Introduction
Trabecular meshwork (TM) is the main pathway for aqueous humor drainage from the eye. The fibrotic-like remodeling of the actin cytoskeleton in TM cells results in altered stiffness and impaired outflow which are the primary cause of increased intraocular pressure (IOP) leading to glaucoma. Thus, cytoskeletal-disrupting drugs could be a novel therapeutic approach to lower IOP. Recently, we proved that fluvoxamine (FLU), a specific Sigma-1 receptor agonist is antifibrotic in the kidney.

Aims
We investigated whether FLU is effective in the prevention of cytoskeletal rearrangement and in vitro TM fibrosis in primary mouse- (MsTM) and non-glaucomatous human TM cells (HTM5).

Methods
Immunocytochemistry and Western blot were used to detect S1R on HTM5 and on MsTM cells. Primary MsTM cells from wild type (WT) and S1R knock-out (KO) mice and HTM5 cells were treated for 24h with 20 ng/mL platelet-derived growth factor (PDGF) combined with 10 µM of FLU. Cell proliferation was determined by thiazolyl blue tetrazolium bromide assay and cell migration was measured by scratch assay, and F-actin was visualized by phalloidin staining and detected with fluorescent microscope.

Results
S1R is present both in primary MsTM and HTM5 cells and is localized in the endoplasmic reticulum. Cell proliferation, migration and cytoskeletal rearrangement were induced by PDGF. FLU treatment ameliorated or even prevented the PDGF induced changes in all assays. Furthermore, upon PDGF treatment the integrated density of phalloidin staining increased with 19.73% in primary KO MsTM cells compared to WT and the formation of F-actin bundles and actin clumps was more pronounced in the absence of S1R suggesting its protective role in TM fibrosis.

Conclusions
FLU effectively reduces profibrotic factor-induced cytoskeletal rearrangement and cell proliferation of TM cells. Therefore one can speculate that it might lead to lower outflow resistance also in animals and it could be an IOP-lowering drug candidate for glaucoma.

Funding
OTKA- K135398, LP2021-3/2021, TKP2021-EGA-24, 2020-4.1.1.-TKP2020-6183169273

medveczki.timea@gmail.com
Semmelweis University, Károly Rácz Doctoral School of Clinical Medicine
Supervisors: Dr. Andrea Fekete, Dr. Judit Hodrea