Topographical regulation of primary cilia orientation and length in mesenchymal stem cells

摘要

IntroductionThe role of the primary cilia in directing the differentiationof mesenchymal stem cells (MSCs) has recently beendemonstrated in response to chemical cues. In additionthere is increasing evidence for the role of the primarycilia in sensing environmental cues. The purpose of thisstudy was to test the hypothesis that surface topography,which regulates MSC differentiation, influences primarycilia structure and function.MethodsGrooved topographical surfaces were produced by hotembossing a quartz stamp into the polymer polycaprolactone(PCL) and then coating in fibronectin (10ug/ml) topromote even cell attachment. MSCs were cultured for 1and 3 days in basal media (a-MEM + 10% FBS) followedby 24 hours culture in serum free media on either grooved(540nm deep) or planar surfaces. Cells were fixed andstained with acetylated a-tubulin to label the primary ciliawhich were visualised using confocal microscopy.ResultsMSCs and their primary cilia were observed to orientateparallel to the grooves. In addition primary cilia lengthwas found to be significantly different (p<0.005) betweenthe two surfaces with mean lengths 3.1μm and 2.6μm forcells on grooved and planar surfaces respectively.DiscussionThe mechanism for cilia alignment in response to topographyis unclear but is unlikely to be mediated by alignmentof the extracellular matrix as suggested in tissue.These changes in primary cilia structure may be involvedin mediating stem cell differentiation and other changes incell function associated with the topographical cues.