Abstract
Lysophosphatidylcholine (LPC)-induced demyelination is a versatile animal model that is frequently used to identify and examine molecular pathways of demyelination and remyelination in the central (CNS) and peripheral nervous system (PNS). However, identification of focally demyelinated lesion had been difficult and usually required tissue fixation, sectioning and histological analysis. Recently, a method for labeling and identification of demyelinated lesions in the CNS by intraperitoneal injection of neutral red (NR) dye was developed. However, it remained unknown whether NR can be used to label demyelinated lesions in PNS. In this study, we generated LPC-induced demyelination in sciatic nerve of mice, and demonstrated that the demyelinated lesions at the site of LPC injection were readily detectable at 7 days postlesion (dpl) by macroscopic observation of NR labeling. Moreover, NR staining gradually decreased from 7 to 21 dpl over the course of remyelination. Electron microscopy analysis of NR-labeled sciatic nerves at 7 dpl confirmed demyelination and myelin debris in lesions. Furthermore, fluorescence microscopy showed NR co-labeling with activated macrophages and Schwann cells in the PNS lesions. Together, NR labeling is a straightforward method that allows the macroscopic detection of demyelinated lesions in sciatic nerves after LPC injection.
Highlights
Abbreviations dpl Days post lesion chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) Chronic inflammatory demyelinating polyradiculoneuropathy electron microscopy (EM) Electron microscopy Iba[1] Inonized calcium binding adapter molecule inducible nitric oxide synthase (iNOS) Inducible nitric oxide synthase i.p
We found that neutral red (NR) was readily detectable on the injured sciatic nerve, corresponding to the site of LPC injection at 7 dpl macroscopically or by light microscopy, and no NR labeling was observed on the contralateral nerve (Fig. 1b)
These results suggest that NR incorporated into the site of sciatic nerve injury, and the labeling gradually decreased over the course of peripheral nervous system (PNS) repair
Summary
Abbreviations dpl Days post lesion CIDP Chronic inflammatory demyelinating polyradiculoneuropathy EM Electron microscopy Iba[1] Inonized calcium binding adapter molecule iNOS Inducible nitric oxide synthase i.p. HDAC2 is reported as a negative regulator after PNS nerve injury via inhibition of c-Jun and delay the regeneration[12,13] Transcription factor, such as STAT3 and c-Jun have the role of repair and maintenance for Schwann cells[14]. Single intraperitoneal (i.p) injection of NR before sacrifice allowed the detection of demyelinated lesions in the mouse CNS in vivo It remained unknown if the NR labeling method would be applicable to demyelination models of the PNS, and if the tissues with NR labeling could be used for subsequent ultrastructural analyses. We observed NR co-labeling with activated macrophages and a subpopulation of Schwann cells in lesions These results suggest that NR injection is a simple and powerful method to detect the lesions in demyelination animal models, and potentially applicable to the wide range of analyses in peripheral demyelinating disease models
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
