Objective

2

To observe the effects of wheat-grain moxibustion on autophagy and endoplasmic reticulum stress (ERS) in the spinal cord and nerve root tissues of rats with cervical spondylotic radiculopathy (CSR)

and to explore the potential mechanisms by which wheat-grain moxibustion alleviates neuropathic pain in CSR.

Methods

2

Forty-eight SPF-grade SD rats were randomly divided into a sham operation group

a model group

a wheat-grain moxibustion group

and a wheat-grain moxibustion + 3-methyladenine (3MA) group

with 12 rats in each group. The CSR model was established in the model group

the wheat-grain moxibustion group

and the wheat-grain moxibustion + 3MA group using the spinal canal insertion method. From the third day after successful modeling

the wheat-grain moxibustion group received wheat-grain moxibustion at "Dazhui" (GV 14)

once daily

six cones each session. The wheat-grain moxibustion + 3MA group received intraperitoneal injection of 3MA (2.5 mg/kg)

followed by the same wheat-grain moxibustion intervention as the wheat-grain moxibustion group. Interventions were performed once daily for seven consecutive days. The gait disturbance scores and peripheral nerve mechanical pain thresholds were observed before and after the intervention. Western blot was used to detect the expression of ERS apoptosis factors C/EBP-homologous protein (CHOP) and Caspase-12

as well as autophagy substrate P62 in spinal cord and nerve root tissues. Transmission electron microscopy was used to observe autophagosomes and cellular ultrastructure in spinal cord and nerve root tissues.

Results

2

After modeling

compared with the sham operation group

gait disturbance scores were increased (

P

<

0.05) and peripheral nerve mechanical pain thresholds were decreased (

P

<

0.05) in the model group

the wheat-grain moxibustion group

and the wheat-grain moxibustion + 3MA group. After intervention

compared with the sham operation group

gait disturbance scores were increased (

P

<

0.05) and peripheral nerve mechanical pain thresholds were decreased (

P

<

0.05) in the model group; compared with the model group

gait disturbance score was decreased (

P

<

0.05) and peripheral nerve mechanical pain threshold was increased (

P

<

0.05) in the wheat-grain moxibustion and the wheat-grain moxibustion + 3MA group; compared with the wheat-grain moxibustion + 3MA group

gait disturbance score was decreased (

P

<

0.05) and peripheral nerve mechanical pain threshold was increased (

P

<

0.05) in the wheat-grain moxibustion group. Compared with the sham operation group

the expression of CHOP and Caspase-12 proteins in spinal cord and ner

ve root tissues was increased in the model group (

P

<

0.05); compared with the model group and the wheat-grain moxibustion + 3MA group

the expression of CHOP

Caspase-12

and P62 proteins in spinal cord and nerve root tissues was decreased in the wheat-grain moxibustion group (

P

<

0.05). Compared with the model group and the wheat-grain moxibustion + 3MA group

the number of autophagosomes in spinal cord and nerve root tissues was increased in the wheat-grain moxibustion group

and the cellular ultrastructure was clear and intact

similar to the sham operation group.

Conclusion

2

Wheat-grain moxibustion at "Dazhui" (GV 14) could effectively alleviate neuropathic pain in CSR model rats. The analgesic mechanism may be related to promoting autophagy

inhibiting ERS

reducing ERS-mediated apoptosis

and repairing damaged nerves.