Gyrid Nygaard from Firestein Lab, UC San Diego, USA, the Lonza CytoSMART Lab for scratch assay

Gyrid Nygaard, Firestein Lab, Division of Rheumatology, Allergy & Immunology, UC San Diego






Effect of Platelet-derived Growth Factor on Synoviocyte Migration

Research Interest

Rheumatoid arthritis (RA) is a chronic immune-mediated disease characterized by joint inflammation and destruction of cartilage and bone. Normal fibroblast-like synoviocytes (FLS), which form the intimal lining layer in the synovium, produce key factors necessary for joint lubrication and function. However, the synovial environment in RA “transforms” FLS into an aggressive phenotype, marked by synovitis and increased production of proinflammatory cytokines such as IL-6 and matrix metalloproteases. FLS then invade into the extracellular matrix to destroy cartilage and bone. In the Firestein lab, we study the mechanisms that promote this aggressive phenotype to identify potential therapeutic targets in RA. We can evaluate the effects of knocking down a target gene or chemical inhibitors on FLS migration by using scratch assays.

The Experiment

FLS were plated in 6 well plates and a scratch was made in the monolayer. After washing, the cells were incubated with various concentrations of platelet-derived growth factor (PDGF). The  CytoSMART™ System was then set up to monitor cell migration for 24 hours.

Video of scratch assay cell culture of Normal fibroblast-like synoviocytes recorded with CytoSMART™ Lux 10X Device
 Graph showing increasing scratch closure with increasing PDGF concentrations


Video of scratch assay of Normal fibroblast-like synoviocytes in the presence of PDGF recorded with the CytoSMART™ Lux 10X Device (Snapshot interval: 5 minutes).              Quantitative analysis of scratch closure after 24 hours in response to increasing PDGF concentrations recorded with the CytoSMART™ System. The scratch area at 0 hours (A) is compared with the size of the scratch area in the wells receiving treatment (B, C and D) after 24 hours. The area covered for each well are then quantified using the ImageJ software.           


The time-lapse video taken with the CytoSMART™ System allows us to study the effect of variables such as cytokines, small-molecule inhibitors and disease on synoviocyte migration and invasion.  


Find out more about research in the Firestein lab.