Pericyte Migration in Diabetes and Quiescence
Creators: name: Corliss, Bruce A.
name: Ray, H. Clifton
name: Doty, Richard
name: Mathews, Corbin
name: Fitzgerald, Kathleen
name: Shariff, Hamzah
name: Prince, Remi
name: Petchul, Shannan
name: Kelly-Goss, Molly
name: Yates, Paul A.
name: Peirce, Shayn M.
Publisher: name: Zenodo
Year: 2018
Subjects: pericyte
diabetes
retina

description: Oral presentation at 2018 Biomedical Engineering Society Annual Meeting. <strong>Title</strong>: Pericyte Migration in Diabetes and Quiescence <strong>Authors</strong>: Bruce A. Corliss<sup>1</sup>, Howard C. Ray<sup>1</sup>, Kathleen Fitzgerald<sup>1</sup>, Hamzah Shariff<sup>1</sup>, Remi Prince<sup>1</sup>, Shannan Petchul<sup>1</sup>, Molly Kelly-Goss<sup>1</sup>, Paul Yates<sup>1,2</sup>, Shayn M. Peirce<sup>1</sup> 1Department of Biomedical Engineering, 2Department of Ophthalmometry, UVA School of Medicine, University of Virginia. <strong>Introduction</strong>: Diabetic retinopathy threatens the vision of over a third of diabetic patients1 , and treatments have limited effectiveness in the clinic. Progression of the disease is associated with dropout of pericytes (PCs), a cell type that wraps around and stabilizes the microvasculature that leads to dramatic dysfunction of the vessel network2 . We present evidence that prior to pericyte dropout, PC migration off-vessel is enriched in diabetes, and show that this transition to an “off vessel pericyte” (OVPC) can occur in as little as 20 minutes. Preventing PC dissociation from the vascular network could prevent PC dropout and downstream dysfunction, including increased vascular permeability, capillary dropout paired with pathological neovascularization, and uncontrolled fibrosis of the tissue3 . Materials and Methods: A lineage tracing mouse model, Myh11-CreERT ROSA26 STOP-floxed tdTomato (Myh11-TOM), treated with tomaxifen at 6-8 weeks of age, was used to trace the lineage of pericytes. For the live imaging, mice were anesthetized with isoflurane and perfused with IB4 lectin via a retro-orbital injection, and the limbal vessels were imaged continuously with a confocal point-scanning microscope (Nikon TE-2000, 10X objective). For the immunostaining, tissue was processed as done previously4 , and incubated overnight in primary antibodies: NG2 (pericyte), CD31 (endothelial cell), collagen-IV (PC and EC extracellular matrix), and anti-RFP (Myh11 lineaged cells). Secondary antibodies were applied, samples washed, and then the deep vasculature of the retina imaged (20X objective for cell counts, 60X objective for single cell examination). <strong>Results and Discussion</strong>: OVPCs are of Myh11 in lineage, a marker shared exclusively between PCs and smooth muscle cells (Fig 1A). Live timelapse reveals that Myh11 lineaged PCs can migrate off vessel in quiescent conditions (Fig 1B,C). In STZ induced diabetes and using NG2 as a PC marker, enriched OVPC density is observed compared to vehicle control at 7 days (33.2% increase, p=8.2E-4) and 14 days (39.2% increase, p=4.5E9) post injection, while insulin treatment partially reduces fraction of OVPCs (30.6% decrease from STZ, p=1.2e6), with opposite trends for the fraction of on vessel pericytes (Fig 1E) and no change in NG2+ cells at day 14 (Fig 1F, p=0.28). <strong>Figure 1</strong>: In Myh11-TOM mouse model, OVPCs share Myh11 lineage with PCs (red, star) in the retina microvasculature (A) and can migrate on and off vessel (green) in a timelapse of limbal vessels (green) (B,C) (scale bar 15 um). In the retina, after STZ-induced diabetes, fraction of (D) PCs, (E) OVPCs, and (F) total NG2+ cell count, with STZtreated (red), vehicle (blue), and STZ with insulin (green) (N=8). Conclusions: Pericyte and capillary dropout take months to manifest in STZ-induced diabetes5 : we demonstrate that perivascular remodeling occurs within mere days of hyperglycemic stimulus. Furthermore, we show, for the first time, that pericytes are capable of migration in the adult microvasculature. While this phenomena has been hypothesized and pericyte dysfunction is accepted to play a key role in the pathogenesis of diabetic retinopathy, this data demonstrates that the vasculature acutely and transiently remodels in response to blood sugar, and modulating this process could lead to preventing downstream vascular pathologies associated with diabetes. <strong>References</strong>: (1) Lee, R.. Eye Vis(Lond), 2015, 2:17. (2) Ikram, M.K.. Diab. Care, 2013, 35 750-759. (3) ParsonsWingerter, P. IOVS, 2010, 51(1) 498-507. (4) Hughes, S. IOVS, 2004, 45 2795-2806 (5) Chou, J. Adv Med Biol 2015, 801, 669-675.