June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Mechanical Control of AGE/RAGE Signaling in Retinal Vascular Inflammation
Author Affiliations & Notes
  • Sathishkumar Chandrakumar
    Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States
    Ophthalmology, Doheny Eye Institute, Los Angeles, California, United States
  • Irene Santiago Tierno
    Molecular, Cellular, and Integrative Physiology Interdepartmental PhD Program, University of California Los Angeles, Los Angeles, California, United States
    Ophthalmology, Doheny Eye Institute, Los Angeles, California, United States
  • Nikolaos Matisioudis
    Ophthalmology, Doheny Eye Institute, Los Angeles, California, United States
  • Mahesh Agarwal
    Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States
    Ophthalmology, Doheny Eye Institute, Los Angeles, California, United States
  • Kaustabh Ghosh
    Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States
    Ophthalmology, Doheny Eye Institute, Los Angeles, California, United States
  • Footnotes
    Commercial Relationships   Sathishkumar Chandrakumar, None; Irene Santiago Tierno, None; Nikolaos Matisioudis, None; Mahesh Agarwal, None; Kaustabh Ghosh, None
  • Footnotes
    Support  NIH 1R01EY028242
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 3028. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Sathishkumar Chandrakumar, Irene Santiago Tierno, Nikolaos Matisioudis, Mahesh Agarwal, Kaustabh Ghosh; Mechanical Control of AGE/RAGE Signaling in Retinal Vascular Inflammation. Invest. Ophthalmol. Vis. Sci. 2021;62(8):3028.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Advanced glycation end products (AGEs) promote retinal endothelial cell (EC) activation, a hallmark of early diabetic retinopathy (DR). We recently reported that lysyl oxidase (LOX)-dependent subendothelial matrix stiffening mediates the inflammatory effect of AGEs on retinal ECs. Yet, precisely how matrix stiffening promotes AGE-mediated retinal EC activation remains unknown. Addressing this question is the main objective of this study.

Methods : Human retinal endothelial cells (HRECs) were treated with methylglyoxal (MGO, 10µM) for 10 days. AGE (MG-H1) and RAGE levels were measured by ELISA and western blotting (WB), respectively while EC activation was determined by ICAM-1 expression (WB) and monocyte-EC adhesion. LOX expression and collagen IV (Col IV) deposition were assessed by WB and immunofluorescence, respectively, while the stiffness of decellularized matrix was measured using atomic force microscope. The direct effect of matrix stiffness on RAGE and ICAM1 mRNA was assessed by plating the fresh ECs on decellularized matrices. Finally, the role of LOX and RAGE in AGE-mediated effects was confirmed by adding LOX inhibitor BAPN and RAGE-antagonist in these studies.

Results : Our findings revealed that MGO-treated HRECs exhibit significant increase in AGE formation (MG-H1, p<0.001), RAGE (p<0.01), and ICAM-1 (p<0.01) expression while simultaneously increasing LOX, Col IV deposition, and matrix stiffness. Importantly, inhibition of LOX-dependent matrix stiffening suppressed the AGE-induced ICAM-1 expression/clustering (p<0.0001) and monocyte-EC adhesion (p<0.0001). Crucially, we found that inhibiting LOX-dependent matrix stiffness blocks the inflammatory effects of AGEs by decreasing RAGE expression. Finally, pharmacological inhibition of RAGE prevented AGE-induced LOX expression (p<0.001). Collectively, these studies indicate that although RAGE signaling is upstream of LOX-dependent matrix stiffness, the latter feeds back to regulate RAGE expression. Ongoing in vivo studies aim to confirm the role of LOX-dependent vascular stiffening in controlling RAGE-mediated retinal vascular inflammation in diabetes.

Conclusions : These findings reveal a previously unknown and potentially crucial role of LOX-dependent vascular stiffening in AGE/RAGE signaling and associated retinal EC activation and provide the basis to examine this pathway as a novel anti-inflammatory strategy for effective DR management.

This is a 2021 ARVO Annual Meeting abstract.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×