WISTAR VS SPRAGUE-DAWLEY: THE INFLUENCE OF RAT STRAIN ON SCHWANN CELL ISOLATION
Schwann cell is associated with axon by forming either myelin sheath or Remak bundles. Studies on Schwann cell biology usually employ primary culture as an experimental model that is established by isolating Schwann cells from rodent nerves. This study was to compare whether Wistar and Sprague-Dawley strains can influence Schwann cell isolation from the sciatic nerve tissue using the D-valine selective media method. Sciatic nerve tissue was dissected and the epineurium with blood vessels was stripped off. The tissue was teased and then incubated in either 0.05% (w/v) or 1% (w/v) type I collagenase for 90 minutes and 60 minutes, respectively. The digested tissue was filtered, washed, and centrifuged. The cell pellet was resuspended and finally plated in laminin/poly-L-lysine coated well plate. Schwann cell growth was observed weekly until day 28 and images were captured using an inverted microscope. Stronger enzymatic digestion resulted with significant fibroblast contamination in both strains, leading to unsuccessful Schwann cell isolation. Schwann cell growth derived from low enzymatic digestion was comparable between both strains but beyond 21-day, Sprague-Dawley culture was observed to be overtaken by fibroblasts. Furthermore, Sprague-Dawley Schwann cells assumed a differentiated phenotype, greatly reducing their proliferative capacity and eventually fibroblast growth surpassed Schwann cell growth. Wistar Schwann cells managed to outgrowth fibroblasts because they maintained proliferative phenotype. Meanwhile, Wistar fibroblasts were generally at the state of senescence. Although some Sprague-Dawley fibroblasts appeared to be senescent, presence of proliferating cells, typically possess small, elongated morphology was evident. Due to this, Schwann cells were able to thrive in Wistar culture whilst fibroblasts eventually managed to outgrow Schwann cell in Sprague-Dawley culture. In summary, isolating Schwann cell from Wistar rat was comparatively superior to that from Sprague-Dawley rat using D-valine selective media technique.