Abstract
Objective: Acrolein is a highly reactive aldehyde that covalently binds to cellular macromolecules and subsequently modulates cellular function. Our previous study demonstrated that acrolein induces glial cell migration, a pathological hallmark of diabetic retinopathy; however, the detailed cellular mechanism remains unclear. The purpose of this study was to investigate the role of acrolein in retinal glial cell migration by focusing on rho-associated coiled-coil-containing protein kinases (ROCKs).Methods: Immunofluorescence staining for ROCK isoforms was performed using sections of fibrovascular tissue obtained from the eyes of patients with proliferative diabetic retinopathy (PDR). Rat retinal Müller glial cell line, TR-MUL5, was stimulated with acrolein and the levels of ROCK1 were evaluated using real-time PCR and western blotting. Phosphorylation of the myosin-binding subunit of myosin light chain phosphatase [myosin phosphatase target subunit 1, (MYPT1)] and myosin light chain 2 (MLC2) was assessed. The cell migration rate of TR-MUL5 cells exposed to acrolein and/or ripasudil, a non-selective ROCK inhibitor, was measured using the Oris cell migration assay.Results: ROCK isoforms, ROCK1 and ROCK2, were positively stained in the cytosol of glial cells in fibrovascular tissues. In TR-MUL5 cells, the mRNA expression level of Rock1, but not Rock2, was increased following acrolein stimulation. In line with the PCR data, western blotting showed increase in ROCK1 and cleaved ROCK1 protein in TR-MUL5 cells stimulated with acrolein. N-acetylcysteine (NAC) suppressed acrolein-associated Rock1 upregulation in TR-MUL5 cells. Acrolein augmented the phosphorylation of MYPT1 and MLC2 and increased the cell migration rate of TR-MUL5 cells, both of which were abrogated by ripasudil.Conclusions: Our study demonstrated that ROCK1 mediates the migration of retinal glial cells promoted by the unsaturated aldehyde acrolein.
Highlights
Diabetic retinopathy (DR) is one of the leading causes of blindness worldwide [1]
We explored the regulatory mechanisms responsible for Müller glial cell migration induced by the unsaturated aldehyde acrolein, especially focusing on Rho-associated coiled-coil-containing protein kinases (ROCKs)
Immunofluorescence staining was performed to determine the localization of ROCKs in fibrovascular tissues obtained from patients with proliferative diabetic retinopathy (PDR)
Summary
Pathological neovascularization due to retinal ischemia causes the formation of fibrovascular tissues at the vitreoretinal surface, which is a hallmark of proliferative diabetic retinopathy (PDR). Müller glial cells, which provide homeostatic, metabolic, and functional support to neurons, can become activated upon pathogenic stimuli [3] and migrate toward the vitreoretinal surface in the diabetic retina [4]. We previously investigated the triggers that facilitate the migratory response of Müller glial cells and found that acrolein, an unsaturated aldehyde, was one of the causative factors [7]. A growing body of evidence explicitly suggests that acrolein is one of the trigger stimuli for glial cell migration in the diabetic retina and plays a role in the cell motility mechanism
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
