Oscillation-Specific Nodal Differences in Parkinson's Disease Patients with Anxiety.

Background: Parkinson's disease (PD) is a common neurodegenerative disorder that is predominantly known for its motor symptoms but is also accompanied by non-motor symptoms, including anxiety. Objective: The underlying neurobiological substrates and brain network changes associated with comorbid anxiety in PD require further exploration. Methods: An analysis of oscillation-specific nodal properties in patients with and without anxiety was conducted using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory. We used a band-pass filtering approach to differentiate oscillatory frequency bands for subsequent functional connectivity (FC) and graph analyses. Results: The study included 68 non-anxiety PD (naPD) patients, 62 anxiety PD (aPD) patients, and 64 healthy controls (NC). Analyses of nodal betweenness centrality (BC), degree centrality (DC), and efficiency were conducted across multiple frequency bands. The findings indicated no significant differences in BC among naPD, aPD, and NC within the 0.01-0.08 Hz frequency range. However, we observed a specific reduction in BC at narrower frequency ranges in aPD patients, as well as differing patterns of change in DC and efficiency, which are believed to reflect the neurophysiological bases of anxiety symptoms in PD. Conclusions: Differential oscillation-specific nodal characteristics have been identified in PD patients with anxiety, suggesting potential dysregulations in brain network dynamics. These findings emphasize the complexity of brain network alterations in anxiety-associated PD and identify oscillatory frequencies as potential biomarkers. The study highlights the importance of considering oscillatory frequency bands in the analysis of brain network changes.

Functional Connectivity and Anxiety Improvement After Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease.

Background: Anxiety is one of the most common and disturbing non-motor symptoms of Parkinson's disease (PD). However, few studies have explored the relationship between functional connectivity (FC) and the rate of anxiety improvement after subthalamic nucleus deep brain stimulation (STN-DBS). Therefore, in this study, we aimed to explore the correlation between FC and the rate of anxiety improvement in patients with PD who underwent STN-DBS. Methods: The resting-state functional magnetic resonance imaging (rs-fMRI) data of 62 patients with anxious PD (aPD), 68 patients with PD without anxiety (naPD), and 64 healthy controls (HCs) were analyzed according to FC. Intergroup comparison and correlation analyses of anxiety improvement rates were performed. Results: The HC, aPD and naPD groups of zFCs were then used for the ANOVA test, and the results were FDR-corrected. There were 24 significant differences in FCs between the three groups. Post tests were conducted between groups found that 15 significantly different FCs were observed between the naPD and aPD groups. In addition, the two FCs in patients with aPD were significantly correlated with the rate of improvement in anxiety. Conclusion: We found that the two FCs in patients with aPD (olfactory cortex and inferior frontal gyrus [IFG] pars orbitalis; inferior temporal gyrus and posterior orbital gyrus) were significantly correlated with the rate of improvement in anxiety. Our study may help us understand the underlying mechanisms by which STN-DBS improves anxiety in PD patients and identify more effective treatment strategies.

Relationship between serum uric acid levels and the outcome of STN-DBS in Parkinson's disease.

BACKGROUND: Uric acid is a natural antioxidant and it has been shown that low levels of uric acid may be a risk factor for the development of Parkinson's disease. We aimed to investigate the relationship between uric acid and improvement of motor symptoms in patients with Parkinson's disease after subthalamic nucleus deep brain stimulation. METHODS: We analyzed the correlation between serum uric acid levels in 64 patients with Parkinson's disease and the rate of improvement of motor symptoms 2 years after subthalamic nucleus deep brain stimulation. RESULTS: A non-linear correlation was observed between uric acid levels and the rate of motor symptom improvement after subthalamic nucleus deep brain stimulation, during both the drug-off and drug-on periods. CONCLUSIONS: Uric acid is positively associated with the rate of motor symptom improvement in subthalamic nucleus deep brain stimulation within a certain range.

Development and Validation of a Prediction Model for Anxiety Improvement after Deep Brain Stimulation for Parkinson Disease.

BACKGROUND: Parkinson's disease (PD) represents one of the most frequently seen neurodegenerative disorders, while anxiety accounts for its non-motor symptom (NMS), and it has greatly affected the life quality of PD cases. Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) can effectively treat PD. This study aimed to develop a clinical prediction model for the anxiety improvement rate achieved in PD patients receiving STN-DBS. METHODS: The present work retrospectively enrolled 103 PD cases undergoing STN-DBS. Patients were followed up for 1 year after surgery to analyze the improvement in HAMA scores. Univariate and multivariate logistic regression were conducted to select factors affecting the Hamilton Anxiety Scale (HAMA) improvement. A nomogram was established to predict the likelihood of achieving anxiety improvement. Receiver operating characteristic (ROC) curve analysis, decision curve analysis (DCA), and calibration curve analysis were conducted to verify nomogram performance. RESULTS: The mean improvement in HAMA score was 23.9% in 103 patients; among them, 68.9% had improved anxiety, 25.2% had worsened (Preop) anxiety, and 5.8% had no significant change in anxiety. Education years, UPDRS-III preoperative score, and HAMA preoperative score were independent risk factors for anxiety improvement. The nomogram-predicted values were consistent with real probabilities. CONCLUSIONS: Collectively, a nomogram is built in the present work for predicting anxiety improvement probability in PD patients 1 year after STN-DBS. The model is valuable for determining expected anxiety improvement in PD patients undergoing STN-DBS.

Prediction of STN-DBS for Parkinson's disease by uric acid-related brain function connectivity: A machine learning study based on resting state function MRI.

Introduction: Parkinson's disease (PD) is a neurodegenerative disorder characterized by dyskinesia and is closely related to oxidative stress. Uric acid (UA) is a natural antioxidant found in the body. Previous studies have shown that UA has played an important role in the development and development of PD and is an important biomarker. Subthalamic nucleus deep brain stimulation (STN-DBS) is a common treatment for PD. Methods: Based on resting state function MRI (rs-fMRI), the relationship between UA-related brain function connectivity (FC) and STN-DBS outcomes in PD patients was studied. We use UA and DC values from different brain regions to build the FC characteristics and then use the SVR model to predict the outcome of the operation. Results: The results show that PD patients with UA-related FCs are closely related to STN-DBS efficacy and can be used to predict prognosis. A machine learning model based on UA-related FC was successfully developed for PD patients. Discussion: The two biomarkers, UA and rs-fMRI, were combined to predict the prognosis of STN-DBS in treating PD. Neurosurgeons are provided with effective tools to screen the best candidate and predict the prognosis of the patient.

α-Synuclein as a Target for Metallo-Anti-Neurodegenerative Agents.

The unique thermodynamic and kinetic coordination chemistry of ruthenium allows it to modulate key adverse aggregation and membrane interactions of α-synuclein (α-syn) associated with Parkinson's disease. We show that the low-toxic RuIII complex trans-[ImH][RuCl4 (Me2 SO)(Im)] (NAMI-A) has dual inhibitory effects on both aggregation and membrane interactions of α-syn with submicromolar affinity, and disassembles pre-formed fibrils. NAMI-A abolishes the cytotoxicity of α-syn towards neuronal cells and mitigates neurodegeneration and motor impairments in a rat model of Parkinson's. Multinuclear NMR and MS analyses show that NAMI-A binds to residues involved in protein aggregation and membrane binding. NMR studies reveal the key steps in pro-drug activation and the effect of activated NAMI-A species on protein folding. Our findings provide a new basis for designing ruthenium complexes which could mitigate α-syn-induced Parkinson's pathology differently from organic agents.

Nomogram for Predicting Depression Improvement after Deep Brain Stimulation for Parkinson's Disease.

BACKGROUND: Parkinson's disease is a common neurodegenerative disease, with depression being a common non-motor symptom. Bilateral subthalamic nucleus deep brain stimulation is an effective method for the treatment of Parkinson's disease. Thus, this study aimed to establish a nomogram of the possibility of achieving a better depression improvement rate after subthalamic nucleus deep brain stimulation in patients with Parkinson's disease. METHODS: We retrospectively analyzed 103 patients with Parkinson's disease who underwent subthalamic nucleus deep brain stimulation and were followed up for the improvement of their Hamilton Depression scale scores 1 year postoperatively. Univariate and multivariate logistic regression analyses were used to select factors affecting the improvement rate of depression. A nomogram was then developed to predict the possibility of achieving better depression improvement. Furthermore, the discrimination and fitting performance was evaluated using a calibration diagram, receiver operating characteristics, and decision curve analysis. RESULTS: The mean and median improvement rates of Hamilton Depression scores were 13.1 and 33.3%, respectively. Among the 103 patients, 70.8% had an improved depression, 23.3% had a worsened depression, and 5.8% remained unchanged. Logistic multivariate regression analysis showed that age, preoperative Parkinson's Disease Questionnaire, Hamilton Anxiety, and Hamilton Depression scores were independent factors for the possibility of achieving a better depression improvement rate. Based on these results, a nomogram model was developed. The nomogram had a C-index of 0.78 (95% confidence interval: 0.69-0.87) and an area under the receiver operating characteristics of 0.78 (95% confidence interval: 0.69-0.87). The calibration plot and decision curve analysis further demonstrated goodness-of-fit between the nomogram predictions and actual observations. CONCLUSION: We developed a nomogram to predict the possibility of achieving good depression improvement 1 year after subthalamic nucleus deep brain stimulation in patients with Parkinson's disease, which showed a certain value in judging the expected depression improvement of these patients.

Nomogram to Predict Cognitive State Improvement after Deep Brain Stimulation for Parkinson's Disease.

PURPOSE: Parkinson's disease (PD) is a common neurodegenerative disease, for which cognitive impairment is a non-motor symptom (NMS). Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for PD. This study established a nomogram to predict cognitive improvement rate after STN-DBS in PD patients. METHODS: We retrospectively analyzed 103 PD patients who underwent STN-DBS. Patients were followed up to measure improvement in MoCA scores one year after surgery. Univariate and multivariate logistic regression analyses were used to identify factors affecting improvement in cognitive status. A nomogram was developed to predict this factor. The discrimination and fitting performance were evaluated by receiver operating characteristics (ROC) analysis, calibration diagram, and decision curve analysis (DCA). RESULTS: Among 103 patients, the mean improvement rate of the MoCA score was 37.3% and the median improvement rate was 27.3%, of which 64% improved cognition, 27% worsened cognition, and 8.7% remained unchanged. Logistic multivariate regression analysis showed that years of education, UPDRSIII drug use, MoCA Preop, and MMSE Preop scores were independent factors affecting the cognitive improvement rate. A nomogram model was subsequently developed. The C-index of the nomogram was 0.98 (95%CI, 0.97-1.00), and the area under the ROC was 0.98 (95%CI 0.97-1.00). The calibration plot and DCA demonstrated the goodness-of-fit between nomogram predictions and actual observations. CONCLUSION: Our nomogram could effectively predict the possibility of achieving good cognitive improvement one year after STN-DBS in patients with PD. This model has value in judging the expected cognitive improvement of patients with PD undergoing STN-DBS.

A New Application of Functional Zonal Image Reconstruction in Programming for Parkinson's Disease Treated Using Subthalamic Nucleus-Deep Brain Stimulation.

Objective: Programming plays an important role in the outcome of deep brain stimulation (DBS) for Parkinson's disease (PD). This study introduced a new application for functional zonal image reconstruction in programming. Methods: Follow-up outcomes were retrospectively compared, including first programming time, number of discomfort episodes during programming, and total number of programming sessions between patients who underwent image-reconstruction-guided programming and those who underwent conventional programming. Data from 142 PD patients who underwent subthalamic nucleus (STN)-DBS between January 2017 and June 2019 were retrospectively analyzed. There were 75 conventional programs and 67 image reconstruction-guided programs. Results: At 1-year follow-up, there was no significant difference in the rate of stimulus improvement or superposition improvement between the two groups. However, patients who underwent image reconstruction-guided programming were significantly better at the first programming time, number of discomfort episodes during programming, and total number of programming sessions than those who underwent conventional programming. Conclusion: Imaging-guided programming of directional DBS leads was possible and led to reduced programming time and reduced patient side effects compared with conventional programming.

Bilateral Globus Pallidus Interna Combined With Subthalamic Nucleus Variable Frequency Deep Brain Stimulation in the Treatment of Young-Onset Parkinson's Disease With Refractory Dyskinesia: A Case Report.

Background: Main motor characteristics in Parkinson's disease (PD) include bradykinesia, rigidity, and tremors. With the development of neuromodulation techniques, it has become possible to use deep brain stimulation (DBS) to control the symptoms of PD. However, since the subthalamic nucleus(STN) and globus pallidus interna (GPi) DBS have their own advantages and disadvantages, it is difficult to control symptoms of the patients. It is essential to find new stimulation methods. Case Presentation: A 33-year-old male PD patient with onset at the age of 12 years. The onset of the disease is presented with bradykinesia and progressively developed severe choreic dyskinesia with the use of medications. We then performed a thorough evaluation of the patient and decided to perform bilateral globus pallidus interna combined with subthalamic nucleus variable frequency DBS (bSGC-DBS) implantation, and after 2 years of follow-up the patient's bradykinesia and dyskinesia symptoms and quality of life improved significantly. Conclusions: This is the first case of bSCG-DBS in a PD patient with refractory dyskinesia, and the first report of encouraging results from this clinical condition. This important finding explores multi-electrode and multi-target stimulation for the treatment of dystonia disorders.

Application of multimodal MRI and radiologic features for stereotactic brain biopsy: insights from a series of 208 patients.

OBJECTIVES: We reviewed our institutional experience during a 10-year period for improvement of safety and efficacy of stereotactic biopsy procedures. METHODS: We performed a retrospective review of inpatient summaries, stereotactic worksheets and radiologic investigations of 208 consecutive patients, who underwent MRI-guided stereotactic biopsies between March 2010 and March 2020. RESULTS: The overall diagnostic yield was 96.2%. CT-confirmed intracranial hemorrhage occurred in 17 patients (8.2%), and the overall mortality rate was 0.5%. Combined MRS and PWI helped target selection in 27 cases (13.0%), the diagnostic yield was 100%. The results of the regression analysis revealed that non-diagnostic biopsy specimen significantly correlated with the cystic trait (p<.01) and edema of lesions (p<.05). Enhancement (p<.01) is shown to be an important factor for obtaining a diagnostic biopsy. Furthermore, the edema trait of lesions (p<.01) showed the important factors of hemorrhage. CONCLUSIONS: The radiological features of lesions and use of the most suitable MRI sequences during biopsy planning are recommended ways to improve the diagnostic yield and safety of this technique.

In vivo detection of metabolic changes in the striatum of proteasomal inhibition-induced Parkinson's disease in rats using proton MR spectroscopy at 9.4 T.

Purpose: Parkinson's disease is a progressive disorder. To investigate the biochemical alterations in the striatum of rats with different stages of Parkinson's disease induced by proteasomal inhibition, we quantified neurochemical profiles of the striatum using proton magnetic resonance spectroscopyusing 9.4 T ultra-high field imaging.Methods: In this study, 10 µg/2 µl lactacystin, a selective proteasome inhibitor, was unilaterally injected stereotaxically into the left substantia nigra pars compacta of rats. An equal volume of saline was injected into the same region and side in the control group. Changes in motor behaviour were observed. The morphological changes of tyrosine hydroxylase-positive cells in substantia nigra pars compacta were visualized using immunohistochemistry. Tyrosine hydroxylase-positive nerve fibers were quantified. Alterations of N-acetylaspartate, choline, creatine, taurine in the different stages of Parkinson's disease rats were detected using proton magnetic resonance spectroscopy.Results: Application of in vivo 1H magnetic resonance spectroscopy was repeated in both the six Parkinson's disease rats and the six control rats across three time points during the first, second and fourth weekend after administration. In Parkinson's disease rats, increased N-acetylaspartate and decreased taurine concentrations were observed in the left striatum at the first week after administration. The increased N-acetylaspartate and choline concentrations were observed at the second weekend. At the fourth weekend, increased creatine concentrations in the left side were observed, while other metabolites were not significantly changed.Conclusions: Neurochemical alterations occurred in the striatum during different stages of the Parkinson's disease model in rats. Also, 9.4 T 1H magnetic resonance spectroscopy may be a useful tool for elucidating the progression of Parkinson's disease through the variation of these metabolites.

Retractorless Surgery for Giant Vestibular Schwannomas via the Retrosigmoid Approach.

BACKGROUND: A fixed retractor is routinely used during surgery for vestibular schwannoma to maintain the surgical corridor; however, brain injuries can be caused by use of retractors. The aim of this study was to present strategies for retractorless surgery for giant vestibular schwannomas and compare retractorless surgery with traditional retractor-assisted surgery to illustrate feasibility and potentially superiority of retractorless surgery. METHODS: Clinical data of 61 patients with giant (≥4 cm diameter) vestibular schwannomas undergoing craniotomy were retrospectively analyzed. Patients were divided into 2 cohorts: 1) 35 patients with traditional retractor surgery performed between June 2016 and July 2017; 2) 26 patients with retractorless surgery performed between June 2016 and July 2018. Duration of operation, intraoperative blood loss, extent of resection, rate of retention of facial nerve function, postoperative brain injury rate, intracranial infection rate, hospitalization time, and grade of facial nerve function were compared between the 2 groups. RESULTS: The incidence of postoperative brain injury was 3.84% in the retractorless surgery group, which was significantly lower compared with the traditional retractor surgery group (22.86%) (P < 0.05). No significant differences were found regarding the other characteristics compared. CONCLUSIONS: Through appropriate comprehensive measures, retractorless surgery for giant vestibular schwannomas is an achievable goal. This procedure can reduce the incidence of postoperative brain injury with satisfactory tumor resection.

How does conserved dopamine neurotrophic factor protect against and rescue neurodegeneration of PC12 cells?

Conserved dopamine neurotrophic factor protects and rescues dopaminergic neurodegeneration induced by 6-hydroxydopamine in vivo, but its potential value in treating Parkinson's disease remains controversial. Here, we used the proteasome inhibitors lactacystin and MG132 to induce neurodegeneration of PC12 cells. Afterwards, conserved dopamine neurotrophic factor was administrated as a therapeutic factor, both pretreatment and posttreatment. Our results showed that (1) conserved dopamine neurotrophic factor enhanced lactacystin/MG132-induced cell viability and morphology, and attenuated alpha-synuclein accumulation in differentiated PC12 cells. (2) Enzyme linked immunosorbent assay showed up-regulated 26S proteasomal activity in MG132-induced PC12 cells after pre- and posttreatment with conserved dopamine neurotrophic factor. Similarly, 26S proteasome activity was upregulated in lactacystin-induced PC12 cells pretreated with conserved dopamine neurotrophic factor. (3) With regard proteolytic enzymes (specifically, glutamyl peptide hydrolase, chymotrypsin, and trypsin), glutamyl peptide hydrolase activity was up-regulated in lactacystin/MG132-administered PC12 cells after pre- and posttreatment with conserved dopamine neurotrophic factor. However, upregulation of chymotrypsin activity was only observed in MG132-administered PC12 cells pretreated with conserved dopamine neurotrophic factor. There was no change in trypsin expression. We conclude that conserved dopamine neurotrophic factor develops its neurotrophic effects by modulating proteasomal activities, and thereby protects and rescues PC12 cells against neurodegeneration.

Combined pretreatment with torrefaction and washing using torrefaction liquid products to yield upgraded biomass and pyrolysis products.

This study presented an approach to upgrade biomass and pyrolysis products using a process based on torrefaction liquid washing combined with torrefaction pretreatment. The torrefaction of cotton stalk was first conducted at 250°C for 30min and then the resulting torrefaction liquid products were collected and reused to wash cottonstalk. The pyrolysis of the original and pretreated cotton stalk was performed at 500°C for 15min in a fixed-bed reactor. The results indicated that the combined pretreatment obviously reduced the metallic species in cotton stalk, decreased the water and acids contents while promoted phenols in bio-oil, declined the ash content in biochar, as well as improved the heating value of non-condensable gas. Overall, the combined pretreatment did not only allow to reuse the liquid products issued from torrefaction pretreatment but also improved the quality of biomass and the pyrolysis products, making it a novel promising pretreatment method.

Protective and reversal effects of conserved dopamine neurotrophic factor on PC12 cells following 6-hydroxydopamine administration.

Conserved dopamine neurotrophic factor (CDNF), a member of the mammalian mesencephalic astrocyte-derived neurotrophic factor family of conserved secreted factors, has been reported to protect and rescue dopaminergic neurons in vivo. PC12 pheochromocytoma cells are widely used as a cell model for Parkinson's disease (PD) for experimental studies. In the present study, PC12 cells were induced using 6-hydroxydopamine (6-OHDA) to mimic PD, which was used to investigate the protective and reversal effects of CDNF against PD in vitro. Cell growth was assessed using an MTT assay, the rate of cell apoptosis was detected using flow cytometry and the apoptotic morphology of cells was observed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining. Pre-treatment of PC12 cells with CDNF (50, 100 and 200 nM) prior to exposure to 100 µM 6-OHDA for 24 h, resulted in a significant increase in cell viability compared with that of 6-OHDA only-treated cells, with cell survival rates of 46.6, 54.7 and 69.6%, respectively. In addition, PC12 cells were treated with CDNF (50, 100 and 200 nM) following 6-OHDA administration, which resulted in cell survival rates of 47.7, 57.6 and 57.5%, respectively. Flow cytometric and TUNEL staining analyses revealed that CDNF exhibited significant dose-dependent protective and reversal effects on the apoptotic rate of PC12 cells following 6-OHDA treatment. In conclusion, the results of the present study showed that CDNF exhibited neuroprotective and reversal effects on the 6-OHDA-induced apoptosis of PC12 cells in a dose-dependent manner.

Effects of engineered conserved dopamine neurotrophic factor-expressing bone marrow stromal cells on dopaminergic neurons following 6-OHDA administrations.

Numerous lines of evidence previously indicated that conserved dopamine neurotrophic factor (CDNF) has potential therapeutic value for Parkinson's disease (PD); however, this hypothesis remains controversial. In the present study, the therapeutic effects of engineered CDNF-expressing bone marrow stromal cells (CDNF-BMSCs) on dopaminergic (DA) neurons were evaluated in vivo. CDNF-BMSCs and control BMSCs were transplanted into the rat striatum and one week later, 6-hydroxydopamine (6-OHDA) was administered to induce neurotoxicity. It was discovered that intrastriatal transplantation of CDNF-BMSCs significantly reduced 6-OHDA-induced neurotoxicity in DA neurons with regard to behavioral recovery and tyrosine hydroxylase levels in the substantia nigra and striatum. These data therefore indicated that transplantation of engineered CDNF-BMSCs into the striatum may present a beneficial strategy for the treatment of PD.

Effects of CDNF on 6-OHDA-induced apoptosis in PC12 cells via modulation of Bcl-2/Bax and caspase-3 activation.

Progressive dopamine neuron degeneration in the substantia nigra pars compacta is considered the most prominent pathological characteristic of Parkinson's disease (PD). Currently, there is no cure, but only the capability to relieve the symptoms of PD. The conserved dopamine neurotrophic factor (CDNF) protects and rescues dopamine neurons in vivo. However, the molecular function of CDNF in PD remains unclear. In present study, we investigated the role and intrinsic mechanism of CDNF in preventing and reversing rat pheochromocytoma (PC12) cells from apoptosis induced by 6-hydroxydopamine (6-OHDA). We demonstrate that 6-OHDA induces cell death in PC12 cells, but that CDNF attenuates this effect in a dose-dependent manner. Further study shows that upregulation of the Bcl-2/Bax ratio and downregulation of caspase-3 activity are observed in a dose-dependent manner upon pre-treatment or post-treatment with CDNF, suggesting a pathway of regulation of apoptosis by CDNF. These data demonstrate that CDNF prevents the apoptosis of PC12 cells induced by 6-OHDA by modulating Bcl-2/Bax and caspase-3 activation.

Does neurotrophic factor benefit to PD therapy via co-function with ubiquitin-proteasome system?

Parkinson's disease (PD) is a common progressive neurodegenerative disorder whose core symptoms are tremor, bradykinesia, rigidity, and postural instability. Currently available treatment of PD is mainly based on dopamine replacement strategy to provide relief of motor symptoms, but cannot halt or reverse the degenerative processes of disease. Considerable in vitro and in vivo studies have found that neurotrophic factor (NTF) has neuroprotective or even neurorestorative properties on dopaminergic (DA) system, promoting them become promising candidates for the treatment of PD. However, the precise mechanism of NTF's effect in PD remains to be elucidated. Though the etiopathogenesis of PD has remained elusive, recently, compelling evidence has converged to suggest that failure of the ubiquitin-proteasome system (UPS) to degrade unwanted proteins may underlie nigralstrital degeneration and Lewy body (LB) formation which occurs in PD. In support of this, proteasome inhibitor has been successfully induced a PD modal both in vivo and in vitro. Many NTFs have been proved to possess definitely a therapy effect in a PD animal modal. Whether NTF can co-function with UPS that accomplishes the aim to protect and reserve dopaminergic neurons' function from neurotoxicity injury induced by proteasome inhibitor? If this hypothesis could be confirmed, it will represent a valuable advancement in the study of PD. Moreover, investigation of the functional link between UPS and NTF should also provide useful information for understanding the pathogenesis of PD.

The analysis of differential induction of hsp70 in the related cerebral domains and nerve fibers of rats after proteasome inhibiton.

BACKGROUND: Parkinson's disease (PD) is popularly called "proteins conformation disease". Heat shock proteins (Hsps) are essential molecular chaperones that handle abnormal protein conformations. The hsp70 family, in particular, represents the most highly conserved molecular chaperones. They constitute a central part of a Ubiquitous-chaperone system. PURPOSE: In the present study, we tested if the induction of hsp70 after proteasome inhibition follows a differential pattern in the related cerebral domains and nerve fibers of rats. METHODS: We used RT-PCR, stereotactic delivery method and immunohistochemical analysis as the molecular tools of investigation. RESULTS: With regard to cerebral domains, the induction of hsp70 exhibited regionality and time-dependence. The intensity of hsp70 expression varied as follows: hippocampus > substantia nigra > frontal lobe > olfactory tract, especially following the order: CA3 > CA2 > CA1 in hippocampus. As for the nerve fibers, it was interesting to find that hsp70 induction was prominent in corpus striatum of lactacystin-treated rats, however hsp70 induction was not observed in the corpus callosum. CONCLUSION: Our study shows the differential induction of hsp70 in Dopamine (DA) nerve fibers and cerebral-association fibers, indicating that hsp70 could protect extrapyramidal system (corpus striatum), not pyramidal system (corpus callosum).