tendon is covered by a basement membrane epithelium that is required for cell retention and the prevention of adhesion formation腱覆盖所需的基底膜上皮细胞保留和预防粘连的形成.pdfVIP

Tendon Is Covered by a Basement Membrane Epithelium That Is Required for Cell Retention and the Prevention of Adhesion Formation 1 1,2 3 1 2 Susan H. Taylor , Sarah Al-Youha , Tom Van Agtmael , Yinhui Lu , Jason Wong , Duncan A. 2 1 McGrouther , Karl E. Kadler * 1 Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom, 2 Plastic and Reconstructive Surgery Research, Faculty of Medicine and Human Sciences, University of Manchester, Manchester, United Kingdom, 3 Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom Abstract The ability of tendons to glide smoothly during muscle contraction is impaired after injury by fibrous adhesions that form between the damaged tendon surface and surrounding tissues. To understand how adhesions form we incubated excised tendons in fibrin gels (to mimic the homeostatic environment at the injury site) and assessed cell migration. We noticed cells exiting the tendon from only the cut ends. Furthermore, treatment of the tendon with trypsin resulted in cell extravagation from the shaft of the tendons. Electron microscopy and immunolocalisation studies showed that the tendons are covered by a novel cell layer in which a collagen type IV/laminin basement membrane (BM) overlies a keratinised epithelium. PCR and western blot analyses confirmed the expression of laminin b1 in surface cells, only. To evaluate the cell retentive properties of the BM in vivo we examined the tendons of the Col4a1+/Svc mouse that is heterozygous for a G-to-A transition in the Col4a1 gene that p