Wang L, Long M, Wang M, Peng S, Chen G, Zhou J, Ou C. Trigeminal neuralgia causes neurodegeneration in rats associated with upregulation of the CD95/CD95L pathway.
Mol Pain 2021;
16:1744806920908092. [PMID:
32013712 PMCID:
PMC7054737 DOI:
10.1177/1744806920908092]
[Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Objectives
To explore the effects of trigeminal neuralgia on neurodegeneration
in rats and the underlining mechanism.
Methods
Sixty adult male Sprague Dawley rats were divided randomly into
Chronic Constriction Injury of the Rat’s Infraorbital Nerve
(ION-CCI) group and sham group (n = 30). Right
suborbital nerve was ligated in ION-CCI group to establish a
trigeminal neuralgia model. In sham group, suborbital nerve was
exposed without ligation. Pain thresholds were measured before
surgery and 1, 7, 15, and 30 days after surgery
(n = 10). Morris water maze tests
(n = 10) were conducted at 1, 15, and
30 days after surgery to evaluate the changes in learning and
memory ability of rats. At 5, 19, and 34 days after surgery,
serum S100β protein concentration and hippocampal Aβ1-42 protein
expression were detected by enzyme-linked immunosorbent assay;
total tau protein expression was detected by Western blotting;
changes of neurons in hippocampus were observed by Nissl
staining; and the expression of ser404p-tau, cluster
of differentiation (CD)95, CD95L, and cleaved caspase-3 proteins
was detected by immunofluorescence and Western blotting.
Results
Hyperalgesia occurred in ION-CCI group, and mechanical pain
threshold decreased significantly
(P < 0.05). On the 15th and 30th days after
surgery, ION-CCI group showed lower learning and memory ability
than sham group (P < 0.05). Serum S100β
protein concentration, hippocampal A β1-42, and
ser404p-tau protein expression increased in the
ION-CCI group 19 and 34 days after surgery
(P < 0.05), hippocampal CD95 expression
increased in the ION-CCI group after surgery
(P < 0.05), hippocampal CD95L expression
increased at 19 and 34 days after surgery
(P < 0.05), and cleaved caspase-3 expression
increased at 5 and 19 days after surgery
(P < 0.05). Nissl bodies in ION-CCI group
decreased significantly at 15 days after surgery. The expression
of cleaved caspase-3 protein in ION-CCI group was positively
correlated with the expression of CD95 and CD95L
(P < 0.05).
Conclusions
Trigeminal neuralgia may lead to neuronal inflammation and neuronal
apoptosis associated with upregulation of CD95/CD95L expression,
thus causing neurodegeneration.
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