We examined the localization of neurofascin (NF) in the sciatic nerve of rat. In the myelinated fibers, neurofascin localizes strongly in the nodal axolemma except the small central cleft and also expresses in the paranodes, and weakly in the Schmidt-Lanterman incisures. In the paranodes, NF localizes around the axolemma and it expresses in the apposing membrane of paranodal loops. Axoplasm, compact myelin and cytoplasm of Schwann cell do not express NF at all. In the Schmidt-Lanterman incisures, NF is expressed weakly along the Schwann cell membrane. We propose that neurofascin may be a plasmalemmal integral protein of Schwann cell in the paranode and plays some important roles for the maintenance of axo-glial junctions at the paranode. It may also have some roles for maintaining the structure of Schmidt-Lanterman incisure and have some relations with proteins localizing in the node.
Animals ; Cell Adhesion Molecules/*analysis/physiology ; Fluorescent Antibody Technique ; Microscopy, Immunoelectron ; Nerve Growth Factors/*analysis/physiology ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/*chemistry/ultrastructure

OBJECTIVETo culture interleukin-1beta (IL-1beta)-activated Schwann cells (SCs) with human hair keratins (HHKs) for artificial nerve bridge construction.

METHODSSCs purified by primary culture with or without IL-1beta activation were cultured with HHKs decorated by extracellular matrix (ECM), and the artificial nerve bridge was implanted into the defect of rat sciatic nerve. The morphology of the SCs cultured with HHKs was monitored by inverted microscope, scanning electron microscope and evaluated by immunocytochemical staining, and the expression of nerve growth factor (NGF) in the sciatic nerve was observed by in situ hybridization.

RESULTSActivated SCs showed better ability to adhere to the HHKs and grew well. The HHKs component in the artificial nerve bridge underwent degradation in the sciatic nerve defect after 3 to 4 weeks, and IL-1beta activation resulted in enhanced NGF expression in the SCs.

CONCLUSIONThe constructed artificial nerve bridge by three-dimensional culture of IL-1beta-activiated SCs with HHKs decorated by ECM promotes the repair of sciatic nerve defects and accelerates sciatic nerve regeneration.

Animals ; Animals, Newborn ; Axons ; physiology ; Cell Culture Techniques ; Cell Movement ; physiology ; Cells, Cultured ; Hair ; chemistry ; Humans ; Interleukin-1beta ; pharmacology ; Keratins ; pharmacology ; Microscopy, Electron, Scanning ; Nerve Growth Factor ; biosynthesis ; Nerve Regeneration ; drug effects ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; drug effects ; metabolism ; ultrastructure ; Sciatic Nerve ; injuries ; physiopathology ; surgery ; Tissue Engineering ; methods