X-Message-Number: 25970 Date: Sun, 3 Apr 2005 21:34:47 -0700 (PDT) From: Doug Skrecky <> Subject: physicists zero in on aging with an atomic force microscope Physics in Medicine and Biology January 2005 50(1): 81-92 Human epithelial cells increase their rigidity with ageing in vitro: direct measurements Abstract. The decrease in elasticity of epithelial tissues with ageing contributes to many human diseases. This change was previously attributed to increased crosslinking of extracellular matrix proteins. Here we show that individual human epithelial cells also become significantly more rigid during ageing in vitro. Using atomic force microscopy (AFM), we found that the Young's modulus of viable cells was consistently increased two- to four-fold in older versus younger cells. Direct visualization of the cytoskeleton using a novel method involving the AFM suggested that increased rigidity of ageing cells was due to a higher density of cytoskeletal fibres. Our results identify a unique mechanism that might contribute to the age-related loss of elasticity in epithelial tissues. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=25970