Autophagy protects neurons against facial nerve injury in rats / 中国组织工程研究

BACKGROUND:After peripheral facial nerve injury,glial cell-derived neurotrophic factor(GDNF)can play a protective role in facial neurons.It has been found that GDNF can regulate the level of autophagy through mammalian target of rapamycin(mTOR),but it is unclear whether it can regulate facial neurons through the adenylate-activated protein kinase/Unc-51-like kinase 1(AMPK/ULK1)signaling pathway after facial nerve injury. OBJECTIVE:To establish a facial nerve injury model in Sprague-Dawley rats and explore the role of autophagy in facial nerve regeneration and the mechanism by which the GDNF/AMPK/ULK1 signaling pathway promotes facial nerve repair after injury. METHODS:Seventy-two Sprague-Dawley rats were randomly divided into sham group,model group and autophagy inhibitor 3-methyladenine(3-MA)group,with 24 rats in each group.Only the main trunk of the facial nerve was exposed in the sham group,while the remaining two groups were modeled for the compression injury of the facial nerve trunk.After successful modeling,the model group was given intraperitoneal injection of normal saline(15 mg/kg),and the 3-MA group was given intraperitoneal injection of 3-MA(15 mg/kg),both once daily for 7 days.The rats in each group were scored on the Simone 10-point behavioral scale at 1,4,7,14,21 and 28 days after surgery.Nissl staining was performed to observe the morphology and number of facial neuron cells at 7,14,21,and 28 days.The expression levels of p-AMPK,p-ULK1,Beclin1 and GDNF in the facial neuron tissues of rats were detected by western blot assay. RESULTS AND CONCLUSION:Behavioral scoring showed that the improvement of facial paralysis symptoms in the 3-MA group was worse and later than that in the model group(P<0.05).Nissl staining showed that the morphology and number of Nissl bodies in facial neurons in the 3-MA group recovered poorly and the number was less than that in the model group(P<0.05).Western blot detection results showed that the expression of p-AMPK and Beclin1 in the model group was higher than that in the 3-MA group and the sham group(P<0.05).The protein expression of p-ULK1 in the model group was lower than that in the 3-MA group and the sham group(P<0.05).To conclude,autophagy inhibitor delays nerve repair after facial nerve injury,which may be related to down-regulation of GDNF expression,inactivation of AMPK,and phosphorylation of ULK1,thereby inhibiting neuronal autophagy levels.

To repair defects of facial skin and tissue with the axial flap / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the clinical repair value of facial skin and tissue defect caused by tumour, trauma and infection with the axial flap.@*METHOD@#The clinical data of 38 patients with facial skin and tissue defect were analyzed retrospectively. All of them were repaired by the axial flap.@*RESULT@#The axial flap was alive in all patients, and all incision healed in the first stage. All patients had a satisfied result after the second stage of flap surgery.@*CONCLUSION@#The method of the axial flap in face can be clinically applied in the facial skin and tissue defects caused by tumour, trauma injury and infection. Because the axial flap cotained named blood vessel, the survival rate of it is high.

Expression of neuronal cadherin and placental cadherin in facial motoneurons after facial nerve injury / 中国组织工程研究

BACKGROUND:Peripheral facial nerve injury first involves the retrograde reactions of central nervous system axons, and nerve regeneration wil depend on the survival and functional status of neuronal cel bodies. OBJECTIVE:To explore the expression of neuronal cadherin and placental cadherin in facial nuclei after facial nerve injury. METHODS:New Zealand white rabbits were randomly divided into model group (n=48) and control group (n=8). In the model group, every eight rabbits were used to carry out the test respectively at 1, 4, 7, 14, 21 days after the model of facial nerve injury (right side) was established. SP and real-time quantitative PCR methods were taken to test the expression of neuronal cadherin and placental cadherin in the facial nerve nucleus at mRNA and RESULTS AND CONCLUSION:The control group had neuronal cadherin-and placental cadherin-positive neurons. In the model group, neuronal cadherin and placental cadherin positively expressed in the facial motorneurons (right side), and their expressions were peaked at 14 days. Compared with the control group, the mRNA expression of neuronal cadherin in the facial motorneurons was increased significantly at 4-28 days after injury;the mRNA expression of placental cadherin in the facial motorneurons was decreased significantly at 1 day after injury, and then increased significantly at 7-28 days. It is suggested that the expression of neuronal cadherin and placental cadherin is positive in the early stage of facial nerve injury, and the expression of placental cadherin is always present, while the expression of neuronal cadherin relatively lasts for a short time. After facial nerve injury, the expression of neuronal cadherin and placental cadherin in the facial nerve nucleus is both increased, which indicates that the facial nerve regeneration may be related to the high expression of adhesion molecules.