The cortical and striatal gene expression profile of 100 hz electroacupuncture treatment in 6-hydroxydopamine-induced Parkinson's disease model.

Electroacupuncture (EA), especially high-frequency EA, has frequently been used as an alternative therapy for Parkinson disease (PD) and is reportedly effective for alleviating motor symptoms in patients and PD models. However, the molecular mechanism underlying its effectiveness is not completely understood. To implement a full-scale search for the targets of 100 Hz EA, we selected rat models treated with 6-hydroxydopamine into the unilateral MFB, which mimic end-stage PD. High-throughput microarray analysis was then used to uncover the regulated targets in the cortex and striatum after 4-week EA treatment. In the differentially regulated transcripts, the proportion of recovered expression profiles in the genes, the functional categories of targets in different profiles, and the affected pathways were analyzed. Our results suggested that the recovery of homeostasis in the transcript network and many regulated functional clusters in the cortex and striatum after EA treatment may contribute to the behavioral improvement of PD rats.

Therapeutic strategies for Parkinson's disease: the ancient meets the future--traditional Chinese herbal medicine, electroacupuncture, gene therapy and stem cells.

In China, it has been estimated that there are more than 2.0 million people suffering from Parkinson's disease, which is currently becoming one of the most common chronic neurodegenerative disorders during recent years. For many years, scientists have struggled to find new therapeutic approaches for this disease. Since 1994, our research group led by Drs. Ji-Sheng Han and Xiao-Min Wang of Neuroscience Research Institute, Peking University has developed several prospective treatment strategies for the disease. These studies cover the traditional Chinese medicine-herbal formula or acupuncture, and modern technologies such as gene therapy or stem cell replacement therapy, and have achieved some original results. It hopes that these data may be beneficial for the research development and for the future clinical utility for treatment of Parkinson's disease.

Triptolide, a Chinese herbal extract, protects dopaminergic neurons from inflammation-mediated damage through inhibition of microglial activation.

Mounting lines of evidence have suggested that brain inflammation participates in the pathogenesis of Parkinson's disease. Triptolide is one of the major active components of Chinese herb Tripterygium wilfordii Hook F, which possesses potent anti-inflammatory and immunosuppressive properties. We found that triptolide concentration-dependently attenuated the lipopolysaccharide (LPS)-induced decrease in [3H]dopamine uptake and loss of tyrosine hydroxylase-immunoreactive neurons in primary mesencephalic neuron/glia mixed culture. Triptolide also blocked LPS-induced activation of microglia and excessive production of TNFalpha and NO. Our data suggests that triptolide may protect dopaminergic neurons from LPS-induced injury and its efficiency in inhibiting microglia activation may underlie the mechanism.

Long-term high-frequency electro-acupuncture stimulation prevents neuronal degeneration and up-regulates BDNF mRNA in the substantia nigra and ventral tegmental area following medial forebrain bundle axotomy.

Electroacupuncture (EA) has been used in China for many years to treat Parkinson's disease (PD) with reportedly effective results. However, the physiological and biological mechanism behind its effectiveness is still unknown. In the present study, different frequencies of chronic EA stimulation (0, 2, 100 Hz) were tested in a partially lesioned rat model of PD which was induced by transection of the medial forebrain bundle (MFB). After 24 sessions of EA stimulation (28 days after MFB transection), dopaminergic neurons in the ventral midbrain were examined by immunohistochemical staining, and brain-derived neurotrophic factor (BDNF) mRNA levels in ventral midbrain were measured by in situ hybridization. The results show a marked decrease of dopaminergic neurons on the lesioned side of the substantia nigra (SN) comparing with the unlesioned side. Zero Hz and 2 Hz EA stimulation had no effect on the disappearance of dopaminergic neurons. However, after 100 Hz EA, about 60% of the tyrosine hydroxylase (TH)-positive neurons remained on the lesioned side of the SN. In addition, levels of BDNF mRNA in the SN and ventral tegmental area (VTA) of the lesioned side were significantly increased in the 100 Hz EA group, but unchanged in the 0 and 2 Hz groups. Our results suggest that long-term high-frequency EA is effective in halting the degeneration of dopaminergic neurons in the SN and up-regulating the levels of BDNF mRNA in the subfields of the ventral midbrain. Activation of endogenous neurotrophins by EA may be involved in the regeneration of the injured dopaminergic neurons, which may underlie the effectiveness of EA in the treatment of PD.

Electro-acupuncture improves behavior and upregulates GDNF mRNA in MFB transected rats.

Low and high frequency electro-acupuncture (EA) stimulation was used in rats that had been lesioned by medial forebrain bundle transection. Behavioral tests showed that both low and high frequency EA stimulation significantly reduced the amphetamine-induced rotation 2 weeks after the lesion but only high frequency EA improved the rotational behavior at 4 weeks. Analysis of the dopamine content in the striatum did not show any significant change after EA. In situ hybridization showed that high frequency EA stimulation up-regulated the glial cell line-derived neurotrophic factor (GDNF) mRNA in both sides of the globus pallidus, while low frequency EA only affected the unlesioned side. It suggests that the retrograde nourishment of GDNF to the dopaminergic neurons and the balanced activity of different nuclei in the basal ganglia circuit after EA may contribute to the behavioral improvement in these rats, which might be the factors that underlie the effectiveness of EA in the treatment of Parkinson's disease.

Neurotrophic and neuroprotective effects of tripchlorolide, an extract of Chinese herb Tripterygium wilfordii Hook F, on dopaminergic neurons.

It has been reported recently that the immunosuppressant FK506 produced neurotrophic and neuroprotective effects on dopaminergic neurons in vitro and in vivo. We investigated whether tripchlorolide, an immunosuppressive extract of Chinese herb Tripterygium wilfordii Hook F, could exert similar neurotrophic and neuroprotective effects similar to those of FK506. It was found that tripchlorolide promoted axonal elongation and protected dopaminergic neurons from a neurotoxic lesion induced by 1-methyl-4-phenylpyridinium ion (MPP+) at concentrations of as low as 10(-12) to 10(-8) M. In situ hybridization study revealed that tripchlorolide stimulated brain-derived neurotrophic factor (BDNF) mRNA expression. In vivo administration of tripchlorolide (1 microg/kg, ip) for 28 days effectively attenuated the rotational behavior challenged by D-amphetamine in the model rats by transection of the medial forebrain bundle. In addition, tripchlorolide treatment (0.5 or 1 microg/kg/day for 28 days) increased the survival of dopaminergic neurons in substantia nigra pars compacta by 50 and 67%, respectively. Moreover, tripchlorolide markedly prevented the decrease in amount of dopamine in the striatum of model rats. Taken together, our data provide the first evidence that tripchlorolide acts as a neuroprotective molecule that rescues MPP+ or axotomy-induced degeneration of dopaminergic neurons, which may imply its therapeutic potential for Parkinson's disease. The underlying mechanism may be relevant to its neurotrophic effect and its efficacy in stimulating the expression of BDNF.

Electro-acupuncture stimulation protects dopaminergic neurons from inflammation-mediated damage in medial forebrain bundle-transected rats.

Through producing a variety of cytotoxic factors upon activation, microglia are believed to participate in the mediation of neurodegeneration. Intervention against microglial activation may therefore exert a neuroprotective effect. Our previous study has shown that the electro-acupuncture (EA) stimulation at 100 Hz can protect axotomized dopaminergic neurons from degeneration. To explore the underlying mechanism, the effects of 100 Hz EA stimulation on medial forebrain bundle (MFB) axotomy-induced microglial activation were investigated. Complement receptor 3 (CR3) immunohistochemical staining revealed that 24 sessions of 100 Hz EA stimulation (28 days after MFB transection) significantly inhibited the activation of microglia in the substantia nigra pars compacta (SNpc) induced by MFB transection. Moreover, 100 Hz EA stimulation obviously inhibited the upregulation of the levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA in the ventral midbrains in MFB-transected rats, as revealed by reverse transcriptase polymerase chain reaction (RT-PCR). ED1 immunohistochemical staining showed that a large number of macrophages appeared in the substantia nigra (SN) 14 days after MFB transection. The number of macrophages decreased by 47% in the rats that received 12 sessions of EA simulation after MFB transection. These data indicate that the neuroprotective role of 100 Hz EA stimulation on dopaminergic neurons in MFB-transected rats is likely to be mediated by suppressing axotomy-induced inflammatory responses. Taken together with our previous results, this study suggests that the neuroprotective effect of EA on the dopaminergic neurons may stem from the collaboration of its anti-inflammatory and neurotrophic actions.