Abstract
Molecular mechanisms of myelin removal by macrophages were explored by examining the immunophenotypes of macrophages following injury of rat sciatic nerve, using a combined method of immunohistochemistry and confocal laser microscopy. In the crush injury model, the involvement in myelin clearance of a cytoplasmic antigen specific for monocytes/macrophages, ED1, was evident. The obvious recruitment of ED1-immunoreactive (-ir) cells was detected first at the crush injury site and then in the distal stump within which Wallerian degeneration had occurred. Double labelling revealed that the ED1-ir cells, except for monocyte-like round cells, always phagocytosed myelin basic protein-ir myelin debris. On the other hand, the expression of ED2, a surface antigen specific for resident macrophages, was significantly different; ED2-ir cells also increased while myelin removal was progressing from day 3 to day 7, but only some of the cells were engaged in myelin phagocytosis. The poor capacity of myelin phagocytosis by ED2-ir cells was supported by the transection model, in which the proximal stump was ligated to suppress regeneration. ED2 may be involved in events other than myelin removal, providing a local environment conducive to axonal regeneration. Our findings thus seem to suggest that ED1 is one of the most reliable markers for cells carrying out myelin phagocytosis, whereas ED2 may participate in entirely different functions. The expression of complement receptor type 3, OX42, was similar to that of ED1 in terms of the swift recruitment of immunopositive cells, their distribution with close association to myelin debris and their high phagocytotic capacity. This supports previously reported in vitro evidence that myelin phagocytosis by macrophages may be complement-mediated.
| Original language | English |
|---|---|
| Pages (from-to) | 685-695 |
| Number of pages | 11 |
| Journal | Journal of Neurocytology |
| Volume | 28 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Dec 1 1999 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Anatomy
- Neuroscience(all)
- Histology
- Cell Biology
Cite this
Differential response of macrophage subpopulations to myelin degradation in the injured rat sciatic nerve. / Hirata, K.; Mitoma, H.; Ueno, N.; He, J. W.; Kawabuchi, M.
In: Journal of Neurocytology, Vol. 28, No. 8, 01.12.1999, p. 685-695.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Differential response of macrophage subpopulations to myelin degradation in the injured rat sciatic nerve
AU - Hirata, K.
AU - Mitoma, H.
AU - Ueno, N.
AU - He, J. W.
AU - Kawabuchi, M.
PY - 1999/12/1
Y1 - 1999/12/1
N2 - Molecular mechanisms of myelin removal by macrophages were explored by examining the immunophenotypes of macrophages following injury of rat sciatic nerve, using a combined method of immunohistochemistry and confocal laser microscopy. In the crush injury model, the involvement in myelin clearance of a cytoplasmic antigen specific for monocytes/macrophages, ED1, was evident. The obvious recruitment of ED1-immunoreactive (-ir) cells was detected first at the crush injury site and then in the distal stump within which Wallerian degeneration had occurred. Double labelling revealed that the ED1-ir cells, except for monocyte-like round cells, always phagocytosed myelin basic protein-ir myelin debris. On the other hand, the expression of ED2, a surface antigen specific for resident macrophages, was significantly different; ED2-ir cells also increased while myelin removal was progressing from day 3 to day 7, but only some of the cells were engaged in myelin phagocytosis. The poor capacity of myelin phagocytosis by ED2-ir cells was supported by the transection model, in which the proximal stump was ligated to suppress regeneration. ED2 may be involved in events other than myelin removal, providing a local environment conducive to axonal regeneration. Our findings thus seem to suggest that ED1 is one of the most reliable markers for cells carrying out myelin phagocytosis, whereas ED2 may participate in entirely different functions. The expression of complement receptor type 3, OX42, was similar to that of ED1 in terms of the swift recruitment of immunopositive cells, their distribution with close association to myelin debris and their high phagocytotic capacity. This supports previously reported in vitro evidence that myelin phagocytosis by macrophages may be complement-mediated.
AB - Molecular mechanisms of myelin removal by macrophages were explored by examining the immunophenotypes of macrophages following injury of rat sciatic nerve, using a combined method of immunohistochemistry and confocal laser microscopy. In the crush injury model, the involvement in myelin clearance of a cytoplasmic antigen specific for monocytes/macrophages, ED1, was evident. The obvious recruitment of ED1-immunoreactive (-ir) cells was detected first at the crush injury site and then in the distal stump within which Wallerian degeneration had occurred. Double labelling revealed that the ED1-ir cells, except for monocyte-like round cells, always phagocytosed myelin basic protein-ir myelin debris. On the other hand, the expression of ED2, a surface antigen specific for resident macrophages, was significantly different; ED2-ir cells also increased while myelin removal was progressing from day 3 to day 7, but only some of the cells were engaged in myelin phagocytosis. The poor capacity of myelin phagocytosis by ED2-ir cells was supported by the transection model, in which the proximal stump was ligated to suppress regeneration. ED2 may be involved in events other than myelin removal, providing a local environment conducive to axonal regeneration. Our findings thus seem to suggest that ED1 is one of the most reliable markers for cells carrying out myelin phagocytosis, whereas ED2 may participate in entirely different functions. The expression of complement receptor type 3, OX42, was similar to that of ED1 in terms of the swift recruitment of immunopositive cells, their distribution with close association to myelin debris and their high phagocytotic capacity. This supports previously reported in vitro evidence that myelin phagocytosis by macrophages may be complement-mediated.
UR - http://www.scopus.com/inward/record.url?scp=0033298542&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033298542&partnerID=8YFLogxK
U2 - 10.1023/A:1007012916530
DO - 10.1023/A:1007012916530
M3 - Article
C2 - 10851347
AN - SCOPUS:0033298542
VL - 28
SP - 685
EP - 695
JO - Journal of Neurocytology
JF - Journal of Neurocytology
SN - 0300-4864
IS - 8
ER -