OBJECTIVE:To investigate the regulatory mechanism of the c-Jun N-terminal protein kinase(JNK)signaling pathway in substantia nigra(SN) dopaminergic neurons inflammation and apoptosis, and the neuroprotective effect of...OBJECTIVE:To investigate the regulatory mechanism of the c-Jun N-terminal protein kinase(JNK)signaling pathway in substantia nigra(SN) dopaminergic neurons inflammation and apoptosis, and the neuroprotective effect of Zishenpingchan granules in mice with Parkinson's disease(PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).METHODS:PD model mice were established by intraperitoneally injecting MPTP.Sixty mice were divided into a model group, Traditional Chinese Medicine(TCM) group and control group.The mice of the TCM group were administered Zishenpingchan granules 7 days before PD induction.Seven days after PD induction, we examined locomotor activity,and performed the rotarod test and swimming test,to evaluate limb movement function.Furthermore,we used immunohistochemistry and western blotting to examine the expression of tyrosine hydroxylase(TH), cyclooxygenase-2(Cox-2), caspase-3 and p-JNK.The terminal deoxynucleotidyl transferase mediated d UTP nick end labeling(TUNEL) method was used to examine neuron apoptosis in the SN.RESULTS:Compared with the control group, the mean score of locomotor activity, rotarod test and swimming test was significantly lower in the model group(P < 0.05); the TH-positive neuron expression was significantly decreased in the SN pars compacta(SNpc); the protein expression levels of Cox-2,caspase-3 and p-JNK was obviously increased; and the number of TUNEL-positive neurons in the SN was increased(P < 0.01).Compared with the model group, the mean score of neurobehavioral tests in the TCM group was obviously higher, the loss of TH-positive neurons ignificantly decreased, the protein expression levels of Cox-2, caspase-3 and p-JNK obviously decreased, and the number of TUNEL-positive neurons in the SN clearly decreased(P < 0.01).CONCLUSION:The JNK pathway plays an important role in the regulation of inflammation and apoptosis in nigral cells in PD mice.TCM can suppress the over-activation of the JNK pathway in the SN, and alleviate the inflammatory response in nigral cells and dopaminergic neuron apoptosis in PD mice.展开更多
基金Supported by the Natural Science Foundation of China(Effect of Dopamine D1/D2 Receptor-MAPK/ERK Signal Transduction in PD Levodopa-induced Dyskinesias with Shudi Pingchan Tang,No.81302926)the National Natural Science Foundation of China(Study on Inhibiting the Abnormal Aggregation and Misfolding of α-synuclein and Prevention of Parkinson's Disease with Shudipingchan Prescription,No.81673726)the National Clinical Research Base of Traditional Chinese Medicine Practitioners Program(Study on Inhibiting the Abnormal Aggregation and Misfolding of α-synuclein and Prevention of Parkinson's Disease with Acteoside,No.LYTD-34)
文摘OBJECTIVE:To investigate the regulatory mechanism of the c-Jun N-terminal protein kinase(JNK)signaling pathway in substantia nigra(SN) dopaminergic neurons inflammation and apoptosis, and the neuroprotective effect of Zishenpingchan granules in mice with Parkinson's disease(PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).METHODS:PD model mice were established by intraperitoneally injecting MPTP.Sixty mice were divided into a model group, Traditional Chinese Medicine(TCM) group and control group.The mice of the TCM group were administered Zishenpingchan granules 7 days before PD induction.Seven days after PD induction, we examined locomotor activity,and performed the rotarod test and swimming test,to evaluate limb movement function.Furthermore,we used immunohistochemistry and western blotting to examine the expression of tyrosine hydroxylase(TH), cyclooxygenase-2(Cox-2), caspase-3 and p-JNK.The terminal deoxynucleotidyl transferase mediated d UTP nick end labeling(TUNEL) method was used to examine neuron apoptosis in the SN.RESULTS:Compared with the control group, the mean score of locomotor activity, rotarod test and swimming test was significantly lower in the model group(P < 0.05); the TH-positive neuron expression was significantly decreased in the SN pars compacta(SNpc); the protein expression levels of Cox-2,caspase-3 and p-JNK was obviously increased; and the number of TUNEL-positive neurons in the SN was increased(P < 0.01).Compared with the model group, the mean score of neurobehavioral tests in the TCM group was obviously higher, the loss of TH-positive neurons ignificantly decreased, the protein expression levels of Cox-2, caspase-3 and p-JNK obviously decreased, and the number of TUNEL-positive neurons in the SN clearly decreased(P < 0.01).CONCLUSION:The JNK pathway plays an important role in the regulation of inflammation and apoptosis in nigral cells in PD mice.TCM can suppress the over-activation of the JNK pathway in the SN, and alleviate the inflammatory response in nigral cells and dopaminergic neuron apoptosis in PD mice.