Treatment of Parkinson's disease in the advanced stage

Effects of latroeggtoxin-VI on dopamine and α-synuclein in PC12 cells and the implications for Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is characterized by death of dopaminergic neurons leading to dopamine deficiency, excessive α-synuclein facilitating Lewy body formation, etc. Latroeggtoxin-VI (LETX-VI), a proteinaceous neurotoxin discovered from the eggs of spider L. tredecimguttatus, was previously found to promote the synthesis and release of PC12 cells, showing a great potential as a drug candidate for PD. However, the relevant mechanisms have not been understood completely. The present study explored the mechanism underlying the effects of LETX-VI on dopamine and α-synuclein of PC12 cells and the implications for PD.

RESULTS

After PC12 cells were treated with LETX-VI, the level of dopamine was significantly increased in a dose-dependent way within a certain range of concentrations. Further mechanism analysis showed that LETX-VI upregulated the expression of tyrosine hydroxylase (TH) and L-dopa decarboxylase to enhance the biosynthesis of dopamine, and downregulated that of monoamine oxidase B to reduce the degradation of dopamine. At the same time, LETX-VI promoted the transport and release of dopamine through modulating the abundance and/or posttranslational modification of vesicular monoamine transporter 2 (VMAT2) and dopamine transporter (DAT). While the level of dopamine was increased by LETX-VI treatment, α-synuclein content was reduced by the spider toxin. α-Synuclein overexpression significantly decreased the dopamine level and LETX-VI efficiently alleviated the inhibitory action of excessive α-synuclein on dopamine. In the MPTP-induced mouse model of PD, application of LETX-VI ameliorated parkinsonian behaviors of the mice, and reduced the magnitude of MPTP-induced α-synuclein upregulation and TH downregulation. In addition, LETX-VI displayed neuroprotective effects by inhibiting MPTP-induced decrease in the numbers of TH-positive and Nissl-stained neurons in mouse brain tissues.

CONCLUSIONS

All the results demonstrate that LETX-VI promotes the synthesis and release of dopamine in PC12 cells via multiple mechanisms including preventing abnormal α-synuclein accumulation, showing implications in the prevention and treatment of PD.

Neuroprotective Effects of Probucol against Rotenone-Induced Toxicity via Suppression of Reactive Oxygen Species Production in SH-SY5Y Cells

Probucol is a hyperlipidemic drug with antioxidant properties. It has been reported to prevent mitochondrial dysfunction, reduce oxidative stress, and suppress neurotoxicity in neurodegenerative disease models, including Parkinson's disease models. However, the molecular mechanisms underlying the neuroprotective effects of probucol have been not examined yet. Thus, in this study, we investigated whether probucol can alleviate the effects of a mitochondrial complex I inhibitor, rotenone, on a human neuroblastoma cell line (SH-SY5Y). We evaluated the cell viability and cytotoxicity and apoptosis rates of SH-SY5Y cells treated with rotenone and probucol or edaravone, a known free-radical scavenger. Subsequently, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) levels in the cells were evaluated to determine the effects of probucol on mitochondrial function. We found that rotenone caused cytotoxicity, cell apoptosis, and mitochondrial dysfunction, enhanced ROS generation, and impaired MMP. However, probucol could inhibit this rotenone-induced decrease in cell viability, MMP loss, intracellular ROS generation, and apoptosis. These results suggest that probucol exerts neuroprotective effects via MMP stabilization and the inhibition of ROS generation. Additionally, this effect of probucol was equal to or greater than and more persistent than that of edaravone. Thus, we believe probucol may be a promising drug for the treatment of neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases.

Anxiety, depression, and worries in advanced Parkinson disease during COVID-19 pandemic

Background

The psychological impact of the COVID-19 outbreak and lockdown on frail populations with advanced Parkinson disease (APD) and their caregivers may present with peculiar features and require specific interventions.

Methods

We enrolled here 100 APD patients and 60 caregivers. Seventy-four patients were treated with device-aided therapies (DAT) and 26 with standard medical treatment (SMT). Through a telephonic interview, subjects underwent the Hospital Anxiety and Depression Scale (HADS-A; HADS-D), and an ad hoc questionnaire to explore thoughts and emotions related to the pandemic.

Results

Depression was observed in 35% of APD patients and anxiety in 39%, with a significant reduction of the latter after the lockdown (p= 0.023). We found a significant correlation between the type of therapy and the HADS-A score (p= 0.004). Patients’ main worries were as follows: a possible higher risk of COVID-19 infection (25%), interruption of non-pharmacological treatments (35%), interruption of outpatient clinics (38%), PD complications related to COVID-19 (47%). Patients treated with DAT manifested worries about device-related issues and risk for caregivers’ infection. The 40% of caregivers showed anxiety, while the 21.7% of them showed depression.

Conclusion

Our study reveals a higher prevalence of anxiety and the presence of peculiar worries and needs in APD patients during the pandemic alongside psychological sequelae of their caregivers. These findings are important for neurologists and healthcare services to foster strategies for the management of psychological distress in both patients and caregivers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05286-z.

Patient preference of device-based treatment of Parkinson's disease

INTRODUCTION

Subthalamic nucleus deep brain stimulation (STN-DBS), continuous subcutaneous apomorphine infusion (APO), and levodopa-carbidopa intestinal gel infusion (LCIG) are treatments used to treat severe motor fluctuations and dyskinesia in patients with advanced levodopa responsive Parkinson's disease (PD), who can no longer be managed with available combinations of oral medications. This study aims to evaluate patient choice of one of three device-based treatment methods.

METHODS

A total of 58 patients clinically diagnosed with PD were included in the study. Eligibility for device-based treatment of PD patients with motor symptoms despite optimal medical treatment was assessed based on Hoehn & Yahr Stages, and Unified Parkinson's Disease Rating Scale-Part III. All three device-based treatment methods were thoroughly explained with on-hand demonstrations. Preferences and reasons for choice were recorded.

RESULTS

Nineteen patients were ineligible for STN-DBS due to neurological causes. A total of 23 patients preferred STN-DBS, 23 preferred APO, and only one patient preferred LCIG. Thirteen patients preferred to continue oral medical treatment, while two patients positively approached both STN-DBS and APO.

CONCLUSION

The most common reason patients declined STN-DBS and LCIG was concerned about the surgical operation, while the most common reason APO was declined was its frequent administration of the injection. While STN-DBS was preferred by younger, less severe patients, APO was preferred by older patients who had a longer duration of disease.

Opicapone Efficacy and Tolerability in Parkinson's Disease Patients Reporting Insufficient Benefit/Failure of Entacapone

BACKGROUND

Opicapone, a recently introduced catechol-o-methyl transferase (COMT) inhibitor has the advantage of being administered once daily, and has pharmacokinetic data to indicate it offers a greater degree of COMT inhibition than entacapone. Although trial data indicate it is non-inferior to entacapone, there are no data to indicate whether it offers any clinical advantages.

METHODS

In this audit, we present data from 57 individuals prescribed opicapone at the National Hospital for Neurology and Neurosurgery, Queen Square who had either not tolerated or reported insufficient benefit following previous prescription of entacapone.

RESULTS

A total of 20 of 57 patients switched directly from entacapone to opicapone ("entacapone switchers") whereas 37 of 57 patients had previously discontinued entacapone because of lack of benefit or adverse events ("entacapone failures"). A total of 21 of 57 (37%) patients stopped opicapone prior to 6 months. A total of 7 of 20 (35%) "entacapone switchers" experienced adverse events with opicapone of which 5 stopped the drug prior to the 6 month evaluation of efficacy. A total of 23 of 37 (62%) "entacapone failures" reported adverse events of which 16 stopped the drug. Among 36 of 57 (63%) patients who continued to use opicapone at 6 months, there was an improvement in OFF time of ~2 hours per day as measured by interview.

CONCLUSIONS

We conclude that opicapone can be an effective additional treatment for wearing off in Parkinson's disease (PD) in a subgroup of patients. The use of opicapone in our cohort with prior entacapone exposure, however, was associated with higher rates of adverse effects and treatment discontinuation than reported in published trial data of COMT inhibitor naïve patients.

Apomorphine in the treatment of Parkinson's disease: a review

Optimizing idiopathic Parkinson's disease treatment is a challenging, multifaceted and continuous process with direct impact on patients' quality of life. The basic tenet of this task entails tailored therapy, allowing for optimal motor function with the fewest adverse effects. Apomorphine, a dopamine agonist used as rescue therapy for patients with motor fluctuations, with potential positive effects on nonmotor symptoms, is the only antiparkinsonian agent whose capacity to control motor symptoms is comparable to that of levodopa. Subcutaneous administration, either as an intermittent injection or as continuous infusion, appears to be the most effective and tolerable route. This review summarizes the historical background, structure, mechanism of action, indications, contraindications and side effects, compares apomorphine infusion therapy with other treatments, such as oral therapy, deep brain stimulation and continuous enteral infusion of levodopa/carbidopa gel, and gives practical instructions on how to initiate treatment.

Complex therapies for advanced Parkinson's disease: what is the role of doctor-patient communication?

OBJECTIVES

Communication processes play a key role in the patient-doctor relationship. Few studies have considered communicative processes in advanced Parkinson's disease (PD), and in particular in the phase of proposing complex therapies (CT). Therefore, we explored the role of communication and patient-doctor relationship in the transition phase to CT for advanced PD, analysing satisfaction, factors influencing the relationship and patients' unmet needs.

MATERIALS AND METHODS

Twenty-four PD patients (mean age 61.7 ± 8.8 years; mean disease duration 12 ± 4.8 years) eligible for deep brain stimulation or infusion therapies were submitted to a semi-structured interview aimed to investigate communication-related cognitions, feelings and behaviours concerning PD and the possible transition towards CT. The Patient-Doctor Relationship Questionnaire (PDRQ-9) was administered along with neuropsychological and behavioural screening tests.

RESULTS

All patients discussed the possible transition to CT with a neurologist. A high degree of satisfaction about the relationship with the neurologist was revealed (mean PDRQ-9 score 37.3 ± 7.3). The communication not only aroused feelings of fear (11/24 patients) and concern (15/24 patients), but also fostered the hope for motor improvement (15/24 patients). Half the patients (12/24) wanted to receive more information about CT after communication.

CONCLUSIONS

This pilot study highlights the importance of doctor-patient communication in PD when facing the transition to CT. Trust in the physician emerged as a key point in favour of the therapeutic alliance. Neurologists should carefully consider patients' reactions and preferences for eliciting collaboration and treatment adherence, favouring a patient-centred standard of care.

Generation of functional dopaminergic neurons from human spermatogonial stem cells to rescue parkinsonian phenotypes

Background

Recent progress in the induced generation of dopaminergic (DA) neurons from different types of stem cells or reprogrammed somatic cells holds tremendous potential for the treatment of Parkinson’s disease (PD). However, the lack of a reliable source for cell replacement therapy remains a major limitation in the treatment of human neurological disorders. Additionally, the current protocols for in vitro differentiation or cell reprogramming to generate human DA neurons are laborious, time-consuming, and expensive, and efficient conversion of human spermatogonial stem cells (hSSCs) to functional DA neurons has not yet been achieved.

Methods

Primary hSSCs from testicular tissues of patients were exposed to an improved induction system, which consisted mainly of olfactory ensheathing cell conditioned culture medium (OECCM) and a set of defined cell-extrinsic factors and small molecules. Morphological changes were assessed, along with the expression of various DA neuron phenotypic markers (e.g., Tuj-1, TH, Nurr1, DAT) and several critical pro-DA neurogenesis effectors (e.g., EN-1, Pitx3, Foxa2, Lmx1a, Lmx1b, and OTX2). In addition, transcriptome analysis was used to further evaluate the genetic similarity between the artificially differentiated DA neurons and genuine ones. Concomitantly, the functional properties of converted DA neurons including synapse formation, dopamine release, electrophysiological activity, and neuron-specific Ca²⁺ signaling images were determined. Finally, hSSCs in the early stage of induction were evaluated for survival, differentiation, migration, tumorigenicity in the mouse striatum, and improvement of functional deficits in MPTP-induced PD animals.

Results

The hSSC-derived neurons not only acquired neuronal morphological features but also expressed various phenotypic genes and protein characteristic of DA neurons and several effectors critical for pro-DA neurogenesis. Strikingly, as the period of induction was prolonged, expression of the critical molecules for DA neuron epigenetic status gradually increased while hSSC-specific markers sharply decreased. After 3 weeks of induction, the transdifferentiation efficiency reached 21%. In addition, hierarchical clustering analysis showed that the differentiated DA neurons closely resembled genuine ones. Furthermore, the hSSC-derived neurons gained sophisticated functional properties of wild-type DA neurons, and pro-induced hSSCs efficiently survived, migrated, and differentiated into DA neurons without tumorigenesis after transplantation into mouse striatum, leading to improvement of functional deficits in PD animals.

Conclusions

The results showed that, using the present improved straightforward approach, hSSCs could acquire DA neuron morphological features and functional properties and rescue parkinsonian phenotypes. Our strategy for the conversion of hSSCs into DA neurons is very efficient and thus may provide an alternative approach suitable for clinical cell therapy to treat neurodegenerative diseases including PD.

Factors to Consider in the Selection of Dopamine Agonists for Older Persons with Parkinson's Disease

Dopamine agonists (DAs) are frequently used in the management of Parkinson's disease (PD), a complex multisystem disorder influenced substantially by age-related factors. Over 80% of PD patients present after age 60 years and may have clinical features exacerbated by age-related comorbidities or decline in physiological compensatory mechanisms. Pharmacotherapy for motor symptoms in older persons is more likely to involve exclusive use of levodopa combined with a peripheral decarboxylase inhibitor throughout the course of the illness. Non-ergot DAs, such as pramipexole, rotigotine and ropinirole, may be used as de novo monotherapy for the control of motor symptoms in older persons, although they are less efficacious than levodopa therapy. DAs may also be considered as adjunct therapy in older persons when motor symptoms are no longer adequately controlled by levodopa or when motor fluctuations and dyskinesia appear. DAs may be used cautiously in older persons with cognitive impairment and orthostatic hypotension but should be avoided when there is a history or risk of psychosis or impulse control disorders.

Duodenal Levodopa Infusion for Long-Term Deep Brain Stimulation-Refractory Symptoms in Advanced Parkinson Disease

OBJECTIVES

This study assesses the effect of levodopa/carbidopa intestinal infusion gel (LCIIG) as an additional treatment in patients with advanced idiopathic Parkinson disease (PD) previously treated with deep brain stimulation (DBS).

METHODS

Prospective study of advanced PD patients, satisfactorily treated with bilateral DBS of the subthalamic nucleus, who had developed refractory symptoms and LCIIG was added. Controls were advanced PD patients treated with LCIIG. Measurements included the Unified Parkinson Disease Rating Scale (UPDRS)-III and the UPDRS axial compound.

RESULTS

There were 19 patients in the DBS-LCIIG therapy group and 21 in the control group. The DBS-LCIIG patients were younger and had disease duration longer than controls. The median time from DBS to gastrostomy was 7.8 years (range, 2-12 years). In both study groups, the mean scores of the UPDRS-III and UPDRS axial subscales improved significantly after LCIIG treatment (DBS-LCIIG group: UPDRS-III, 62.0 [15.7] vs 30.9 [12.1]; UPDRS axial, 24.7 [4.9] vs 10.2 [2.7]; P < 0.0005 for all comparisons). There were no differences in adverse events between the groups. In the follow-up of the DBS-LCIIG group. 5 patients discontinued DBS-LCIIG therapy and returned to DBS, 5 discontinued DBS and were maintained with LCIIG, and the remaining 9 continued with DBS-LCIIG therapy. Mean time until discontinuation in the double DBS-LCIIG group was 891 days. The main risk factors for discontinuation were age at the beginning of LCIIG and severity of the UPDRS axial subscale.

CONCLUSIONS

Levodopa/carbidopa intestinal infusion gel therapy may be a valuable option in selected patients with advanced PD who develop refractory symptoms after long-term subthalamic nucleus-DBS.

Can suitable candidates for levodopa/carbidopa intestinal gel therapy be identified using current evidence?

Advanced Parkinson's disease (APD) is characterized by increased functional disability, caused by motor complications, the presence of axial symptoms, and emergent disease- and drug-related non-motor symptoms. One of the advanced therapies available is intrajejunal infusion of levodopa/carbidopa intestinal gel (LCIG); however, patient selection for this treatment is sometimes difficult, particularly because of overlapping indications with other alternatives. In recent years, strong evidence has supported the use of LCIG in treating motor fluctuations associated with APD, and several clinical studies provide emerging evidence for additional benefits of LCIG treatment in certain patients. This article provides an overview of the published literature on the benefits, limitations, and drawbacks of LCIG in relation to PD symptoms, the psychosocial impact of the disease, and the quality of life of patients, with the aim of determining candidates for whom treatment with LCIG would be beneficial. According to current evidence, patients with APD (defined as inability to achieve optimal control of the disease with conventional oral treatment), a relatively well-preserved cognitive-behavioral status, and good family/caregiver would count as suitable candidates for LCIG treatment. Contraindications in the opinion of the authors are severe dementia and active psychosis.

Glucose-6-phosphatase-α participates in dopaminergic differentiation

OBJECTIVE

 Induction of dopaminergic (DA) differentiation is a cell-based therapy for Parkinson's disease (PD). Here, we explore the key factors of DA differentiation with a focus on glucose-6-phosphatase (G6Pase), a marker enzyme for the endoplasmic reticulum (ER) associated with cell differentiation.

METHODS

 We cultured SH-SY5Y human neuroblastoma cells, a model system for PD research, and added glial cell-derived neurotrophic factor (GDNF; 25, 50, or 100 ng/ml) to stimulate differentiation. Subsequently, several methods, such as microRNA/mRNA microarrays, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to detect target genes and proteins respectively.

RESULTS

 Light microscopy revealed that 50 ng/ml GDNF most effectively induced DA differentiation. MicroRNA/mRNA microarrays identified that G6PC mRNA was significantly upregulated, which might be influenced by three downregulated microRNAs. Follow-up qRT-PCR results were consistent with the microarray findings, and western blots also supported the results.

DISCUSSION

Taken together, our results demonstrate that G6PC, a subunit of G6Pase, participates in DA differentiation. Our findings may contribute to provide a foundation for the research on the mechanism of DA differentiation as well as cell-based therapy for PD.

Regulation of human GDNF gene expression in nigral dopaminergic neurons using a new doxycycline-regulated NTS-polyplex nanoparticle system

The human glial-cell derived neurotrophic factor (hGDNF) gene transfer by neurotensin (NTS)-polyplex nanoparticles functionally restores the dopamine nigrostriatal system in experimental Parkinson's disease models. However, high levels of sustained expression of GDNF eventually can cause harmful effects. Herein, we report an improved NTS-polyplex nanoparticle system that enables regulation of hGDNF expression within dopaminergic neurons. We constructed NTS-polyplex nanoparticles containing a single bifunctional plasmid that codes for the reverse tetracycline-controlled transactivator advanced (rtTA-Adv) under the control of NBRE3x promoter, and for hGDNF under the control of tetracycline-response element (TRE). Another bifunctional plasmid contained the enhanced green fluorescent protein (GFP) gene. Transient transfection experiments in N1E-115-Nurr1 cells showed that doxycycline (100 ng/mL) activates hGDNF and GFP expression. Doxycycline (5 mg/kg, i.p.) administration in rats activated hGDNF expression only in transfected dopaminergic neurons, whereas doxycycline withdrawal silenced transgene expression. Our results offer a specific doxycycline-regulated system suitable for nanomedicine-based treatment of Parkinson's disease.

Current Pharmaceutical Treatments and Alternative Therapies of Parkinson's Disease

Over the decades, pharmaceutical treatments, particularly dopaminergic (DAergic) drugs have been considered as the main therapy against motor symptoms of Parkinson's disease (PD). It is proposed that DAergic drugs in combination with other medications, such as monoamine oxidase type B inhibitors, catechol-O-methyl transferase inhibitors, anticholinergics and other newly developed non-DAergic drugs can make a better control of motor symptoms or alleviate levodopa-induced motor complications. Moreover, non-motor symptoms of PD, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances caused by intrinsic PD pathology or drug-induced side effects, are gaining increasing attention and urgently need to be taken care of due to their impact on quality of life. Currently, neuroprotective therapies have been investigated extensively in pre-clinical studies, and some of them have been subjected to clinical trials. Furthermore, non-pharmaceutical treatments, including deep brain stimulation (DBS), gene therapy, cell replacement therapy and some complementary managements, such as Tai chi, Yoga, traditional herbs and molecular targeted therapies have also been considered as effective alternative therapies to classical pharmaceutics. This review will provide us updated information regarding the current drugs and non-drugs therapies for PD.

Technology-aided leisure and communication: Opportunities for persons with advanced Parkinson's disease

OBJECTIVE

This study investigated whether simple technology-aided programs could be used to promote leisure and communication engagement in three persons with advanced Parkinson's disease.

METHOD

The programs included music and video options, which were combined with (a) text messaging and telephone calls for the first participant, (b) verbal statements/requests, text messaging, and reading for the second participant, and (c) verbal statements/requests and prayers for the third participant. The participants could activate those options via hand movement or vocal emission and specific microswitches.

RESULTS

All three participants were successful in activating the options available. The mean cumulative frequencies of option activations were about five per 15-min session for the first two participants and about four per 10-min session for the third participant.

CONCLUSION

The results were considered encouraging and relevant given the limited amount of evidence available on helping persons with advanced Parkinson's disease with leisure and communication.

Parkinson's Disease and development of levodopa induced motor complications: Influence of baseline features and first medical approach

Background

The introduction of levodopa in clinical practice represents a hallmark in the treatment of the neurodegenerative disease, Parkinson's Disease. However, levodopa induced motor complications, namely dyskinesias and motor fluctuations, develop in the majority of Parkinson's Disease patients.

Objective

to identify which Parkinson's Disease's, patient's and therapeutics' initial features are more associated with dyskinesias or motor fluctuations development.

Methods

Patients with diagnosed Parkinson's Disease attending neurology outpatient clinic at Centro Hospitalar São João were selected. For this observational study, data was retrospectively collected from patient's clinical records. A survival analysis model with univariate and multivariate regression analysis was used.

Results

87 patients with a mean of 72 ± 9.7 years were included. After a median follow-up of 6 (range 1-17) years, 35.6% patients developed dyskinesias; and with a median of 5 (range 1-16) years, 32.2% developed motor fluctuations. After multivariate analysis, the akinesia/rigidity subtype was found to have a higher risk of dyskinesias and motor fluctuations development. Age of onset ≤50 years was associated with motor fluctuations development.

Conclusion

In conclusion, our results suggest that Parkinson's Disease patients' initial characteristics, such as subtype or age of onset, are independently associated with the development of motor complications.

Neuroprotective Effect of Coptis chinensis in MPP+ and MPTP-Induced Parkinson’s Disease Models

The rhizome of Coptis chinensis is commonly used in traditional Chinese medicine alone or in combination with other herbs to treat diseases characterized by causing oxidative stress including inflammatory diseases, diabetes mellitus and neurodegenerative diseases. In particular, there is emerging evidence that Coptis chinensis is effective in the treatment of neurodegenerative diseases associated with oxidative stress. Hence, the aim of this study was to investigate the neuroprotective effect of Coptis chinensis in vitro and in vivo using MPP[Formula: see text] and MPTP models of Parkinson’s disease. MPP[Formula: see text] treated human SH-SY5Y neuroblastoma cells were used as a cell model of Parkinson’s disease. A 24[Formula: see text]h pre-treatment of the cells with the watery extract of Coptis chinensis significantly increased cell viability, as well as the intracellular ATP concentration and attenuated apoptosis compared to the MPP[Formula: see text] control. Further experiments with the main alkaloids of Coptidis chinensis, berberine, coptisine, jaterorrhizine and palmatine revealed that berberine and coptisine were the main active compounds responsible for the observed neuroprotective effect. However, the full extract of Coptis chinensis was more effective than the tested single alkaloids. In the MPTP-induced animal model of Parkinson’s disease, Coptis chinensis dose-dependently improved motor functions and increased tyrosine hydroxylase-positive neurons in the substantia nigra compared to the MPTP control. Based on the results of this work, Coptis chinensis and its main alkaloids could be considered potential candidates for the development of new treatment options for Parkinson’s disease.

Betaine protects cerebellum from oxidative stress following levodopa and benserazide administration in rats

OBJECTIVES

The aim of the present study was to evaluate antioxidant and methyl donor effects of betaine in cerebellum following levodopa and benserazide administration in rats.

MATERIALS AND METHODS

Sprague-Dawley male rats were treated with levodopa (LD), betaine (Bet), levodopa plus betaine (LD/Bet), levodopa plus benserazide (LD/Ben), levodopa plus betaine-benserazide (LD/Bet-Ben), and the controls with vehicle for 10 consecutive days, orally.

RESULTS

Treatment of rats with LD and benserazide significantly increased total homocysteine in plasma of the LD/Ben group when compared to the other groups. Lipid peroxidation of cerebellum increased significantly in LD-treated rats when compared to the other groups. In contrast, glutathione peroxidase activity and glutathione content in cerebellum were significantly higher in the betaine-treated rats when compared to the LD and LD/Ben groups. Serum dopamine concentration increased significantly in LD-treated rats in comparison with the LD/Ben group. LD/Bet-treated rats also demonstrated significantly higher dopamine levels when compared to the LD/Ben group.

CONCLUSION

We observed valuable effects of Bet in combination with LD and benserazide, which routinely were used for Parkinson's disease (PD) treatment, in experimentally-induced oxidative stress and hyperhomocysteinemia in rats. Therefore, it seems that Bet is a vital and promising agent regarding PD for future clinical trials in humans.

Altered cytotoxicity of ROS-inducing compounds by sodium pyruvate in cell culture medium depends on the location of ROS generation

Induction of oxidative stress by drugs and other xenobiotics is an important mechanism of cytotoxicity. However, in vitro studies on the relationship between oxidative stress and cytotoxicity in cultured cells is frequently complicated by the fact that cell culture medium components affect reactive oxygen species (ROS) exposures in ways that vary with the mode of ROS production. The objectives of this study were to first determine the mode of ROS induction by certain model compounds when they are applied to cultured cells, and then to determine how ROS induction and cytotoxicity were affected by the ROS-quenching medium component pyruvate. Three compounds, eseroline, benserazide, and pyrogallol induced H₂O₂ in cell culture media independent of cells. However, another compound, menadione, induced H₂O₂ in a manner largely dependent on the MDA-MB-231 breast cancer cells used in this study, which is consistent with its known mechanism of inducing ROS through intracellular redox cycling. 1 mM pyruvate, as well as catalase, reduced the H₂O₂ in culture wells with each ROS inducer tested but it only reduced the cytotoxicity of cell-independent inducers. It reduced the cytotoxicity of benserazide and pyrogallol >10-fold and of eseroline about 2.5-fold, but had no effect on menadione cytotoxicity. From this data, it was concluded that depending on the mechanism of ROS induction, whether intra- or extracellular, a ROS-quenching medium component such as pyruvate will differentially affect the net ROS-induction and cytotoxicity of a test compound.

Beneficial antioxidant properties of betaine against oxidative stress mediated by levodopa/benserazide in the brain of rats

The present study was designed to evaluate antioxidant effects of betaine in the brain following administration of levodopa and benserazide, which are routinely used in the treatment of Parkinson's disease. Sprague-Dawley male rats were divided into levodopa (LD), Betaine (Bet.), levodopa plus betaine (LD/Bet.), levodopa plus benserazide (LD/Ben.), levodopa plus betaine-benserazide (LD/Bet.-Ben.) and control groups. The experimental groups received LD 300 mg/kg, Bet. 1.5 % w/w of the total diet, Ben. 75 mg/kg and distilled water to controls for 10 consecutive days, orally. The concentration of plasma total homocysteine significantly increased in LD/Ben.-treated rats when compared to the other groups. Brain glutathione peroxidase (GPx) activity and glutathione content both elevated with betaine treatment in LD/Bet. and LD/Bet.-Ben groups. Superoxide dismutase activity was also higher in controls and betaine-treated rats in comparison with LD and LD/Ben. groups. Likewise, catalase activity significantly increased in control and betaine groups when compared to LD- and LD/Ben.-treated rats. In contrast, brain lipid peroxidation significantly increased in response to LD and LD/Ben.

TREATMENTS

Regarding metabolism of LD in peripheral tissues, serumic dopamine concentration significantly increased in LD-treated rats in comparison with LD/Ben. group. The present results show beneficial antioxidant and methyl donor properties of betaine versus oxidative stress and hyperhomocysteinemia induced by levodopa and benserazide in an animal model.

Berberine chloride pretreatment exhibits neuroprotective effect against 6-hydroxydopamine-induced neuronal insult in rat

Parkinson's disease (PD) is a rather common movement disorder as a result of the degeneration of dopaminergic neurons within the substantianigra. Current treatments for PD afford symptomatic relief with no prevention of disease progression. Due to the neuroprotective and anti-apoptotic potential of the isoquinoline alkaloid berberine (BBR), this study was conducted to assess whether BBR pretreatment could attenuate behavioral and neuronal derangement in 6-hydroxydopamine (6-OHDA)-induced model of PD in the rat. Unilateral intrastriatal 6-OHDA-lesioned rats received BBR at doses of 25 and/or 50 mg/kg (i.p.) three times at an interval of 24 h, started 2 days before the surgery. After 1 week, apomorphine caused significant contralateral rotations and a significant reduction in the number of Nissl-stained and tyrosine-hydroxylase (TH)-positive neurons on the left side of the substantianigra. BBR pretreatment at a dose of 50 mg/kg significantly reduced rotations and prevented loss of TH-positive neurons. These results indicate pre-lesion administration of BBR could protect against 6-OHDA toxicity and this may be of benefit besides other available therapies in PD.

Eryptosis as a marker of Parkinson's disease

A major trend in recent Parkinson's disease (PD) research is the investigation of biological markers that could help in identifying at-risk individuals or to track disease progression and response to therapies. Central to this is the knowledge that inflammation is a known hallmark of PD and of many other degenerative diseases. In the current work, we focus on inflammatory signalling in PD, using a systems approach that allows us to look at the disease in a more holistic way. We discuss cyclooxygenases, prostaglandins, thromboxanes and also iron in PD. These particular signalling molecules are involved in PD pathophysiology, but are also very important in an aberrant coagulation/hematology system. We present and discuss a hypothesis regarding the possible interaction of these aberrant signalling molecules implicated in PD, and suggest that these molecules may affect the erythrocytes of PD patients. This would be observable as changes in the morphology of the RBCs and of PD patients relative to healthy controls. We then show that the RBCs of PD patients are indeed rather dramatically deranged in their morphology, exhibiting eryptosis (a kind of programmed cell death). This morphological indicator may have useful diagnostic and prognostic significance.

Is X-linked methyl-CpG binding protein 2 a new target for the treatment of Parkinson's disease

X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson's disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson's disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell (SH-SY5Y cells) injury as a cell model of Parkinson's disease. The 6-hydroxydopamine (50 μmol/L) treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson's disease.

Brain-specific delivery of dopamine mediated by n,n-dimethyl amino group for the treatment of Parkinson's disease

Parkinson's disease (PD) has become one of the most deadly diseases due to a lack of effective treatment. Herein, N-3,4-bis(pivaloyloxy)dopamine-3-(dimethylamino)propanamide (PDDP), a brain-specific derivative of dopamine, was designed and synthesized, which consists of a brain targeted ligand, N,N-dimethyl amino group, and two dipivaloyloxy groups for lipophilic modification. PDDP was investigated both in vitro and in vivo by comparing with L-DOPA and another derivative (BPD) without N,N-dimethyl amino group. PDDP showed a more pronounced accumulation in mouse brain microvascular endothelial cells (bEnd.3) than BPD via an active transport process. The increased cellular uptake of PDDP was proven to be mediated by putative pyrilamine cationic transporters. Following intravenous administration, the concentration of PDDP in the brain was 269.28-fold and 6.41-fold higher than that of L-DOPA and BPD at 5 min, respectively. Additionally, PDDP effectively attenuated the striatum lesion caused by 6-hydroxydopamine (6-OHDA) in rats. More importantly, PDDP presented antioxidant and antiapoptotic effects on 6-OHDA-induced toxicity in human neuroblastoma cells (SH-SY5Y). Thus, N,N-dimethyl amino group-based PDDP represents an effective and safe treatment for PD.

Astrocytic modulation of blood brain barrier: perspectives on Parkinson's disease

The blood–brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson’s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson’s disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

Carnosine exerts neuroprotective effect against 6-hydroxydopamine toxicity in hemiparkinsonian rat

Parkinson's disease (PD) is the second most common disorder of the central nervous system due to the degeneration of mesencephalic dopaminergic neurons. Current treatments for PD have a symptomatic relief strategy with no prevention of disease progression. Due to the neuroprotective and antiapoptotic potential of the natural dipeptide carnosine, this study was conducted to assess its beneficial effect in 6-hydroxydopamine (6-OHDA)-induced model of PD in rat. Unilateral intrastriatal 6-OHDA-lesioned rats received i.p. carnosine at a dose of 250 mg/kg twice at an interval of 24 h, which started presurgery. Apomorphine caused contralateral rotations, a significant reduction in the number of Nissl-stained neurons on the left side of the substantia nigra, and increased apoptosis was observed with enhanced oxidative stress burden in 6-OHDA-lesioned rats. Carnosine pretreatment significantly reduced rotations, attenuated apoptosis, and restored malondialdehyde and nitrite content and catalase activity with no significant effect on reduced glutathione (GSH). These results indicate that prelesion administration of carnosine could exert neuroprotection against 6-OHDA toxicity, and this may be of benefit in patients with early PD.

Efficacy and safety of Tai Chi for Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

Background and Objective

In Parkinson's disease (PD), wearing off and side effects of long-term medication and complications pose challenges for neurologists. Although Tai Chi is beneficial for many illnesses, its efficacy for PD remains uncertain. The purpose of this review was to evaluate the efficacy and safety of Tai Chi for PD.

Methods

Randomized controlled trials (RCTs) of Tai Chi for PD were electronically searched by the end of December 2013 and identified by two independent reviewers. The tool from the Cochrane Handbook 5.1 was used to assess the risk of bias. A standard meta-analysis was performed using RevMan 5.2 software.

Results

Ten trials with PD of mild-to-moderate severity were included in the review, and nine trials (n = 409) were included in the meta-analysis. The risk of bias was generally high in the blinding of participants and personnel. Improvements in the Unified Parkinson's Disease Rating Scale Part III (mean difference (MD) −4.34, 95% confidence interval (CI) −6.67–−2.01), Berg Balance Scale (MD: 4.25, 95% CI: 2.83–5.66), functional reach test (MD: 3.89, 95% CI: 1.73–6.04), Timed Up and Go test (MD: −0.75, 95% CI: −1.30–−0.21), stride length (standardized MD: 0.56, 95% CI: 0.03–1.09), health-related quality of life (standardized MD: −1.10, 95% CI: −1.81–−0.39) and reduction of falls were greater after interventions with Tai Chi plus medication. Satisfaction and safety were high. Intervention with Tai Chi alone was more effective for only a few balance and mobility outcomes.

Conclusions

Tai Chi performed with medication resulted in promising gains in mobility and balance, and it was safe and popular among PD patients at an early stage of the disease. This provides a new evidence for PD management. More RCTs with larger sample size that carefully address blinding and prudently select outcomes are needed. PROSPERO registration number CRD42013004989.

Unwanted effects and interaction of intrajejunal levodopa/carbidopa administration

INTRODUCTION

Levodopa is the most effective treatment for Parkinson's disease. After a number of years on treatment, fluctuations and dyskinesias may develop. Hence, invasive treatment measures are often needed (escalation therapy).

AREAS COVERED

Twenty years ago, a levodopa/carbidopa intestinal gel (LCIG) that can be infused directly into the jejunum was developed. This provides for continuous dopaminergic stimulation. For the past 10 years, LCIG has been licensed in some countries and its marketing approval is pending in the USA. It is endowed with very good efficacy, and in studies, it has proven to be superior to oral drug treatment. Continuous dopaminergic stimulation is also assured, and fluctuations and dyskinesias are significantly reduced. However, this technique involves an invasive procedure with percutaneous endoscopic gastrostomy and attendant surgical and postsurgical complications. Besides, there are problems related to the pump and tube. Vitamin deficiency and polyneuropathies are other drawbacks.

EXPERT OPINION

LCIG is a beneficial and very useful treatment option as escalation therapy for Parkinson's disease. While the side effects are not insignificant, they are justifiable in view of the severity of the disease. Attention must be paid, in particular, to malabsorption, with monitoring at baseline and in the course of treatment.

Exercise Guidelines for Patients With Parkinson’s Disease

Parkinson’s disease (PD) is a progressive neurological condition with no known cure. This disease progression is characterized by severe motor degeneration that often limits functional mobility during gross motor skills common in activities of daily living, work, and recreation. Exercise programs have been shown to slow symptom onset and lessen the progression of PD, helping to improve quality of life of individuals with this condition. This article provides an overview of recent studies addressing the impact of exercise programs on individuals with PD, and also provides home health care professions with suggestions for exercise program implementation within this clinical population.

An animal model mimicking pedunculopontine nucleus cholinergic degeneration in Parkinson's disease

A rostral brainstem structure, the pedunculopontine nucleus (PPN), is severely affected by Parkinson's disease (PD) pathology and is regarded a promising target for therapeutic deep-brain stimulation (DBS). However, understanding the PPN's role in PD and assessing the potential of DBS are hampered by the lack of a suitable model of PPN degeneration. Rats were rendered Parkinsonian through a unilateral substantia nigra pars compacta (SNpc) stereotaxic injection of the proteasome inhibitor Lactacystin, to investigate whether the lesion's pathological effects spread to impact the integrity of PPN cholinergic neurons which are affected in PD. At 5 weeks post-surgery, stereological analysis revealed that the lesion caused a 48 % loss of dopaminergic SNpc neurons and a 61 % loss of PPN cholinergic neurons, accompanied by substantial somatic hypotrophy in the remaining cholinergic neurons. Magnetic resonance imaging revealed T2 signal hyper-/hypointensity in the PPN of the injected hemisphere, respectively at weeks 3 and 5 post-lesion. Moreover, isolated PPN cholinergic neurons revealed no significant alterations in key autophagy mRNA levels, suggesting that autophagy-related mechanisms fail to protect the PPN against Lactacystin-induced cellular changes. Hence, the current results suggest that the Lactacystin PD model offers a suitable model for investigating the role of the PPN in PD.