Different apoptotic reactions of dorsal root ganglion A- and B-cells after sciatic nerve axotomy: effect of p75 neurotrophin receptor / 中华医学杂志(英文版)
Chinese Medical Journal
;
(24): 2695-2700, 2010.
Article
in English
| WPRIM
| ID: wpr-285762
ABSTRACT
<p><b>BACKGROUND</b>By unbiased stereological methods, we have observed preferential dorsal root ganglion (DRG) B-cell loss in rodents after nerve injury, and caspase-3 activation and cell loss were related to the present of p75 receptor (p75(NTR)). We hypothesized that DRG B-cells express higher levels of pro-apoptotic proteins as compared to A-cells and the expressions of pro-apoptotic proteins can be reduced by depletion of p75(NTR). This study aimed to identify the p75(NTR) involved apoptotic pathway in DRG neurons after nerve injury.</p><p><b>METHODS</b>The p75(NTR) knockout mice (p75-/-) and wildtype Balb/C mice (p75+/+) were used in this study. The expressions of pro-apoptotic proteins, c-Jun-N-terminal kinase (JNK), c-jun and p38 in DRG were evaluated with immunohistochemistry 2 and 7 days following unilateral sciatic nerve transection. In addition, extra-cellular related kinase (ERK), a transducer of survival signals, was also tested with immunohistochemistry and Western blotting methods in these animal models.</p><p><b>RESULTS</b>Phosphorylated JNK (P-JNK) and phosphorylated p38 (P-p38) were mainly located in small B-cells, whereas phosphorylated c-jun (P-c-jun) was located in both A- and B-cells. Phosphorylated ERK (P-ERK) was located in both B-cells and satellite cells. Axotomy dramatically increased the expressions of P-JNK and P-c-jun (paired t-test), with no influence on the expressions of P-p38 and P-ERK. Furthermore, the increase of P-JNK in p75+/+ mice 2 days after nerve axotomy was approximately 2.2-folds of that in p75-/- mice (P = 0.001, unpaired t-test).</p><p><b>CONCLUSION</b>p75(NTR)-dependent JNK-caspase-3 pathway is involved in DRG B-cell loss after nerve injury and JNK is not the unique upstream of c-jun activation.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Physiology
/
Sciatic Nerve
/
General Surgery
/
Immunohistochemistry
/
Blotting, Western
/
Receptors, Nerve Growth Factor
/
Apoptosis
/
Mice, Knockout
/
Axotomy
/
Cell Biology
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
Chinese Medical Journal
Year:
2010
Type:
Article
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