一项新研究发现，一个在血小板和肠道内壁细胞发炎研究中很有了解的粘附分子JAM-C也帮助封闭周围神经的关键绝缘。在没有JAM-C的小鼠中，这个髓绝缘鞘退化，小鼠表现出神经传出放电故障、肌肉无力、比正常步子短的步姿等，Christoph Scheiermann和同事说。JAM-C看来封闭Schwann细胞之间关键缝隙的绝缘，Schwann细胞产生包在神经细胞周围的髓鞘。虽然没有JAM-C 的人类细胞也是失去它们的髓绝缘鞘，但是研究人员说，还需要有更多的研究来确定这个粘附分子是否在脱髓鞘疾病（比如多发性硬化症）中起部分的作用。
原始出处:
Science 30 November 2007:
Vol. 318. no. 5855, pp. 1472 - 1475
DOI: 10.1126/science.1149276
Expression and Function of Junctional Adhesion Molecule-C in Myelinated Peripheral Nerves
Christoph Scheiermann,1,2 Paolo Meda,3 Michel Aurrand-Lions,4 Rime Madani,3 Yiangos Yiangou,5 Peter Coffey,6 Thomas E. Salt,6 Dominique Ducrest-Gay,3 Dorothée Caille,3 Owain Howell,7 Richard Reynolds,7 Alexander Lobrinus,3 Ralf H. Adams,8 Alan S. L. Yu,9 Praveen Anand,5 Beat A. Imhof,3* Sussan Nourshargh1,2*
JAM-C is an adhesion molecule that is expressed on cells within the vascular compartment and epithelial cells and, to date, has been largely studied in the context of inflammatory events. Using immunolabeling procedures in conjunction with confocal and electron microscopy, we show here that JAM-C is also expressed in peripheral nerves and that this expression is localized to Schwann cells at junctions between adjoining myelin end loops. Sciatic nerves from JAM-C–deficient [having the JAM-C gene knocked out (KO)] mice exhibited loss of integrity of the myelin sheath and defective nerve conduction as indicated by morphological and electrophysiological studies, respectively. In addition, behavioral tests showed motor abnormalities in the KO animals. JAM-C was also expressed in human sural nerves with an expression profile similar to that seen in mice. These results demonstrate that JAM-C is a component of the autotypic junctional attachments of Schwann cells and plays an important role in maintaining the integrity and function of myelinated peripheral nerves.
1 National Heart and Lung Institute, Imperial College London, London, UK.
2 William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, UK.
3 Centre Medical Universitaire (CMU), Medical Faculty, University of Geneva, Geneva, Switzerland.
4 INSERM UMR 599, Institut Paoli-Calmettes, Marseille, France.
5 Peripheral Neuropathy Unit, Division of Neurosciences and Mental Health, Imperial College London, London, UK.
6 Institute of Ophthalmology, University College London, London, UK.
7 Department of Cellular and Molecular Neuroscience, Division of Neurosciences and Mental Health, Imperial College London, London, UK.
8 London Research Institute, Cancer Research UK, London, UK.
9 Nephrology Division, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: s.nourshargh@qmul.ac.uk
