Focal adhesion kinase knockdown modulates the response of human corneal epithelial cells to topographic cues.
A rapidly expanding literature broadly documents the impact of biophysical cues on cellular behaviors. In spite of increasing research efforts in this field, the underlying signaling processes are poorly understood. One of the candidate molecules for being involved in mechanotransduction is focal adhesion kinase (FAK). To examine the role of FAK in the response of immortalized human corneal epithelial (hTCEpi) cells to topographic cues, FAK was depleted by siRNA transfection. Contrary to expectations, FAK knockdown resulted in an enhanced response with a greater number of hTCEpi cells aligned to the long axis of anisotropically ordered surface ridges and grooves. Both underlying topographic features and FAK depletion modulated the migration of corneal epithelial cells. The impact of FAK knockdown on both migration and alignment varied depending on the topographic cues to which the cells were exposed, with the most significant change observed on the biologically relevant size scale (400nm). Additionally, a change in expression of genes encoding perinuclear Nesprins 1 and 2 (SYNE1, 2) was observed in response to topographic cues. SYNE1/2 expression was also altered by FAK depletion, suggesting that these proteins might represent a link between cytosolic and nuclear signaling processes. The data presented here have relevance to our understanding of the fundamental processes involved in corneal cell behavior to topographic cues. These results highlight the importance of incorporating biophysical cues in the conduction of in vitro studies and into the design and fabrication of implantable prosthetics.
Department of Surgical and Radiological Sciences, School of Veterinary Medicine, One Shields Avenue, University of California Davis, Davis, CA 95616, USA.
Britta
B
Dreier
Vijaya Krishna
VK
Raghunathan
Paul
P
Russell
Christopher J
CJ
Murphy
D002461:Cell Line, Transformed; D002465:Cell Movement; D003598:Cytoskeletal Proteins; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1; D005786:Gene Expression Regulation / Q000235:genetics; D055785:Gene Knockdown Techniques; D006801:Humans; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics; D019736:Prostheses and Implants; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014162:Transfection / Q000379:methods
D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C415465:SYNE1 protein, human; C485904:SYNE2 protein, human; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human