miR-335 Targets LRRK2 and Mitigates Inflammation in Parkinson's Disease

Parkinson’s disease (PD) is mainly driven by dopaminergic neuronal degeneration in the substantia nigra pars compacta accompanied by chronic neuroinflammation. Despite being mainly sporadic, approximately 10% of all cases are defined as heritable forms of PD, with mutations in the leucine-rich repeat kinase (LRRK2) gene being the most frequent known cause of familial PD. MicroRNAs (miRNAs or miRs), including miR-335, are frequently deregulated in neurodegenerative diseases, such as PD. Here, we aimed to dissect the protective role of miR-335 during inflammation and/or neurodegenerative events in experimental models of PD. Our results showed that miR-335 is significantly downregulated in different PD-mimicking conditions, including BV2 microglia cells stimulated with lipopolysaccharide (LPS) and/or overexpressing wild-type LRRK2. Importantly, these results were confirmed in serum of mice injected with 1-methyl-1-4-phenyl-1,2,3,6-tetrahydripyridine hydrochloride (MPTP), and further validated in patients with idiopathic PD (iPD) and those harboring mutations in LRRK2 (LRRK2-PD), thus corroborating potential clinical relevance. Mechanistically, miR-335 directly targeted LRRK2 mRNA. In the BV2 and N9 microglia cell lines, miR-335 strongly counteracted LPS-induced proinflammatory gene expression, and downregulated receptor interacting protein 1 (RIP1) and RIP3, two important players of necroptotic and inflammatory signaling pathways. Further, miR-335 inhibited LPS-mediated ERK1/2 activation. LRRK2-Wt-induced proinflammatory gene expression was also significantly reduced by miR-335 overexpression. Finally, in SH-SY5Y neuroblastoma cells, miR-335 decreased the expression of pro-inflammatory genes triggered by α-synuclein. In conclusion, we revealed novel roles for miR-335 in both microglia and neuronal cells that strongly halt the effects of classical inflammatory stimuli or LRRK2-Wt overexpression, thus attenuating chronic neuroinflammation.

Patients and Health Professional's Perspective of Functional Mobility in Parkinson's Disease

Background: Functional mobility (FM) is the person's ability to move to accomplish daily living tasks and activities. FM limitations are common in Parkinson's disease, increase with disease progression, and can be highly disabling. Although several studies in Parkinson's disease (PD) field use this concept, only recently, a formal definition has been proposed.

Objective: We aimed to explore patient's and health professional's perspectives of FM in PD.

Methods: A focus group methodology has been used. Four focus groups, with a total of 10 patients and 10 health professionals, were performed. Six patients were early stage and four advanced stage. The health professional's group was composed of five neurologists and five physiotherapists. The suitability of the new concept, the impact of FM limitations in PD patient's daily routine, and the potential benefit of walking aids have been discussed.

Results: All participants were able to provide a spontaneous definition of FM, matching with the proposed concept. All agreed that PD affects patient's FM, increasing the limitations with disease progression, and with the existence of a serious prejudice with walking aids that hinders its use. Early-stage patient's perspective seems to be more in line with neurologist's perspective, while the views of advanced-stage patients were closer to physiotherapist's views.

Conclusion: FM concept was considered as intuitive and useful. FM limitations have an important physical and social impact in the advanced stage of the disease. Although patients and health professionals acknowledge walking aid's benefit improving patient's FM, the prejudice associated with this type of tools limits its recommendation and use.

Circulating Inflammatory miRNAs Associated with Parkinson's Disease Pathophysiology

Parkinson’s disease (PD) is the second most common neurodegenerative disease worldwide, being largely characterized by motor features. MicroRNAs (miRNAs) are small non-coding RNAs, whose deregulation has been associated with neurodegeneration in PD. In this study, miRNAs targeting cell death and/or inflammation pathways were selected and their expression compared in the serum of PD patients and healthy controls. We used two independent cohorts (discovery and validation) of 20 idiopathic PD patients (iPD) and 20 healthy controls each. We also analyzed an additional group of 45 patients with a mutation in the leucine-rich repeat kinase 2 (LRRK2) gene (LRRK2-PD). miRNA expression was determined using Taqman qRT-PCR and their performance to discriminate between groups was assessed by receiver operating characteristic (ROC) curve analysis. We found miR-146a, miR-335-3p, and miR-335-5p downregulated in iPD and LRRK2-PD patients versus controls in both cohorts. In addition, miR-155 was upregulated in LRRK2-PD compared to iPD patients showing an appropriate value of area under the ROC curve (AUC 0.80) to discriminate between the two groups. In conclusion, our study identified a panel of inflammatory related miRNAs differentially expressed between PD patients and healthy controls that highlight key pathophysiological processes and may contribute to improve disease diagnosis.

Correction: Gene Expression Differences in Peripheral Blood of Parkinson's Disease Patients with Distinct Progression Profiles

[This corrects the article DOI: 10.1371/journal.pone.0157852.].

Disability in Activities of Daily Living and Severity of Dyskinesias Determine the Handicap of Parkinson's Disease Patients in Advanced Stage Selected to DBS

BACKGROUND

There is scarce data on the level of handicap in Parkinson's disease (PD) and none in advanced stage PD.

OBJECTIVE

To assess the handicap in advanced stage PD patients with disabling levodopa-induced motor complications selected to deep brain stimulation (DBS).

METHODS

Data was prospectively recorded during routine evaluation for DBS. Handicap was measured using London Handicap Scale (LHS) (0 = maximal handicap; 1 = no handicap). Disease severity was evaluated using the Hoehn & Yahr scale and the UPDRS/MDS-UPDRS, during off and on after a supra-maximal dose of levodopa. Schwab and England Scale (S&E) was scored in off and on. Dyskinesias were scored using the modified Abnormal Involuntary Movement Scale (mAIMS). Results concern cross-sectional assessment before DBS.

RESULTS

100 PD patients (mean age 61 (±7.6); mean disease duration 12.20 (±4.6) years) were included. Median score of motor MDS-UPDRS was 54 in off and 25 in on. Mean total LHS score was 0.56 (±0.14). Patients were handicapped in several domains with a wide range of severity. Physical Independence and Social Integration were the most affected domains. Determinants of total LHS score were MDS-UPDRS part II off (β= -0.271; p = 0.020), S&E on (β= 0.264; p = 0.005) and off (β= 0.226; p = 0.020), and mAIMS on (β= -0.183; p = 0.042) scores (R2  = 29.6%).

CONCLUSIONS

We were able to use handicap to measure overall health condition in advanced stage PD. Patients were moderately to highly handicapped and this was strongly determined by disability in ADL and dyskinesias. Change in handicap may be a good patient-centred outcome to assess efficiency of DBS.

Gene Expression Differences in Peripheral Blood of Parkinson's Disease Patients with Distinct Progression Profiles

The prognosis of neurodegenerative disorders is clinically challenging due to the inexistence of established biomarkers for predicting disease progression. Here, we performed an exploratory cross-sectional, case-control study aimed at determining whether gene expression differences in peripheral blood may be used as a signature of Parkinson’s disease (PD) progression, thereby shedding light into potential molecular mechanisms underlying disease development. We compared transcriptional profiles in the blood from 34 PD patients who developed postural instability within ten years with those of 33 patients who did not develop postural instability within this time frame. Our study identified >200 differentially expressed genes between the two groups. The expression of several of the genes identified was previously found deregulated in animal models of PD and in PD patients. Relevant genes were selected for validation by real-time PCR in a subset of patients. The genes validated were linked to nucleic acid metabolism, mitochondria, immune response and intracellular-transport. Interestingly, we also found deregulation of these genes in a dopaminergic cell model of PD, a simple paradigm that can now be used to further dissect the role of these molecular players on dopaminergic cell loss. Altogether, our study provides preliminary evidence that expression changes in specific groups of genes and pathways, detected in peripheral blood samples, may be correlated with differential PD progression. Our exploratory study suggests that peripheral gene expression profiling may prove valuable for assisting in prediction of PD prognosis, and identifies novel culprits possibly involved in dopaminergic cell death. Given the exploratory nature of our study, further investigations using independent, well-characterized cohorts will be essential in order to validate our candidates as predictors of PD prognosis and to definitively confirm the value of gene expression analysis in aiding patient stratification and therapeutic intervention.

Espresso Coffee for the Treatment of Somnolence in Parkinson's Disease: Results of n-of-1 Trials

There is limited information available concerning the treatment of daytime somnolence associated with Parkinson’s disease (PD); the most frequently applied therapeutic strategies include decreasing the dose of dopamine agonists or adding potential wake-promoting agents. There is recent data from a placebo-controlled trial concluding on a non-significant trend in favor of caffeine. We aimed to evaluate the efficacy of espresso-coffee in the treatment of daytime somnolence in PD. To evaluate the efficacy of espresso-coffee in the treatment of daytime somnolence in PD, we have conducted multiple single-patient (n-of-1) clinical trials comparing regular espresso coffee to decaffeinated coffee in PD patients presenting moderate to severe daytime somnolence defined as an Epworth Sleepiness Scale score >9. Each single-patient (n-of-1) trial included a sequence of three crossovers (two treatment periods separated by two days of washout). Four patients were included in the studies and three completed the three pairs of treatment periods. In two of the four patients, espresso coffee was considered beneficial. This study concludes that multiple single patient trials are feasible in PD and suggests that espresso-coffee may have a beneficial effect on daytime somnolence in some patients. These results cannot be generalized beyond the patients included in these trials.

Substantia nigra neuromelanin magnetic resonance imaging in de novo Parkinson's disease patients

BACKGROUND

Depigmentation of the substantia nigra (SN) and locus coeruleus (LC) is a conspicuous pathological feature of Parkinson's disease (PD) and is related to the loss of neuromelanin, whose paramagnetic properties result in high signal on specific T1-weighted magnetic resonance imaging (MRI). Recent studies have suggested that neuromelanin decrease in the SN and LC of PD patients may emerge as a possible diagnostic biomarker. The SN neuromelanin signal in de novo and early stage PD patients was studied to assess its diagnostic accuracy. This is the first study based on a semi-automated MRI analysis of the neuromelanin signal in de novo PD patients.

METHODS

The inclusion criteria were untreated de novo PD and a 2-5 year disease duration; in addition, age matched healthy controls were enrolled. These were studied with a high-resolution T1-weighted MRI sequence at 3 T to visualize neuromelanin. The primary outcome was SN high signal area, length and neuromelanin/midbrain ratio obtained with semi-automated methods.

RESULTS

A total of 12 de novo PD patients and 10 PD patients with a 2-5 year disease duration were evaluated. The area, length of the SN T1 high signal and the SN neuromelanin/midbrain ratio were markedly decreased in the PD groups compared with age-matched controls, with a substantial overlap between the two PD groups.

CONCLUSIONS

Neuromelanin-sensitive MRI techniques can discriminate PD patients from healthy individuals with high sensitivity and specificity. Our findings are consistent with recent findings showing that PD neuromelanin changes remain stable during the course of the disease.

Subthalamic deep brain stimulation effects on odor identification in Parkinson's disease

BACKGROUND AND PURPOSE

Olfactory dysfunction is common in Parkinson's disease (PD) and it is one of the earliest non-motor symptoms. A few studies have suggested that deep brain stimulation of the subthalamic nucleus (STN-DBS) could improve olfactory function. Our aim was to evaluate the acute effect of bilateral STN-DBS on a commonly used smell test in PD patients.

METHODS

Fifteen PD patients who underwent bilateral STN-DBS and 15 controls were recruited. Patients and controls were tested for odor identification.

RESULTS

No statistical differences were documented between ON and OFF STN-DBS acute stimulation concerning olfaction. Controls presented a better performance for olfactory identification than patients.

CONCLUSIONS

Our exploratory study did not support that bilateral STN-DBS could have an acute effect on olfactory function in PD patients.

[Health-economic burden of Parkinson's disease in Portugal: a cohort study]

INTRODUCTION

Parkinson's disease (PD) is a common neurodegenerative disorder with a considerable socioeconomic burden. Health-economic evaluations of PD in the Southern European countries are limited.

AIM

To evaluate the costs of PD in an outpatient cohort in Portugal.

PATIENTS AND METHODS

49 consecutive PD patients were recruited at the neurological outpatient clinic of the University of Lisbon between October 2004 and December 2005. Clinical status was evaluated using the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stages. Costs were assessed from the societal perspective using health-economic questionnaires. Human capital approach was used to estimate indirect costs. Health-related quality of life was evaluated by means of the EQ-5D.

RESULTS

Direct costs were 2,717 euros (95% CI = 1,147-3,351) per patient for a six-month period. Main contributors to the direct costs included drugs (544 euros; 95% CI = 426-6,940) and hospitalizations (690 euros; 95% CI = 229-1,944). Indirect costs amounted to 850 euros (95% CI = 397-1,529), whereas patient expenditures constituted 12% of direct costs. Assistance by family and other relatives played a major role. In general, costs were lower than in other Western countries.

CONCLUSIONS

The economic burden of PD in Portugal is considerable. Important cost components include medications and hospitalizations. More research is needed in order to describe a comprehensive health service patterns in Portugal and to guide health policy decisions more effectively.

Flunitrazepam in combination with alcohol engenders high levels of aggression in mice and rats

RATIONALE

Higher doses of benzodiazepines and alcohol induce sedation and sleep; however, in low to moderate doses these drugs can increase aggressive behavior.

OBJECTIVES

To assess firstly the effects of ethanol, secondly the effects of flunitrazepam, a so-called club drug, and thirdly the effects of flunitrazepam plus alcohol on aggression in mice and rats.

METHODS

Exhaustive behavioral records of confrontations between a male resident and a male intruder were obtained twice a week, using CF-1 mice and Wistar rats. The salient aggressive and non-aggressive elements in the resident's repertoire were analyzed. Initially, the effects of ethanol (1.0g/kg), and secondly flunitrazepam (0; 0.01; 0.1; and 0.3mg/kg) were determined in all mice and rats; subsequently, flunitrazepam or vehicle, given intraperitoneally (0; 0.01; 0.1; and 0.3mg/kg) was administered plus ethanol 1.0g/kg or vehicle via gavage.

RESULTS

The most significant finding is the escalation of aggression after a moderate dose of ethanol, and a low dose of flunitrazepam. The largest increase in aggressive behavior occurred after combined flunitrazepam plus ethanol treatment in mice and rats.

CONCLUSIONS

Ethanol can heighten aggressive behavior and flunitrazepam further increases this effect in male mice and rats.

5-HT(1B) receptors, ventral orbitofrontal cortex, and aggressive behavior in mice

RATIONALE

Systemic injections of 5-HT(1B) receptor agonists have been shown to have specific anti-aggressive effects in aggressive individuals. One site of action for these drugs is the 5-HT(1B) receptors in the ventral orbitofrontal cortex (VO PFC), an area that has been implicated in the inhibitory control of behavior and is a terminal region for 5-HT projections.

OBJECTIVE

To assess the anti-aggressive effects of the 5-HT(1B) receptor agonist CP-94,253 when microinjected into the VO PFC (0.1, 0.56, and 1.0 microg/0.2 microl) or into the infralimbic prefrontal cortex (IL PFC; 1.0 microg/0.2 microl) in separate groups of aggressive resident male mice. To confirm the 5-HT(1B) receptor as the critical site of action for the anti-aggressive effects, the 5-HT(1B/D) antagonist GR-127,935 was microinjected at 10.0 microg/0.2 microl into the VO PFC. After recovery from surgery, the anti-aggressive effects of microinjected CP-94,253 were studied during 5-min resident-intruder confrontations that were recorded and analyzed.

RESULTS

Microinjections of CP-94,253 (0.56 and 1.0 microg/0.2 microl) dose-dependently reduced the frequency of attack bites and sideways threats. This effect was behaviorally specific because non-aggressive motor activities were not significantly altered by the drug. In the IL vmPFC or in an area lateral to the VO PFC, CP-94,253 (1.0 microg/0.2 microl) did not have significant behavioral effects.

CONCLUSIONS

The results highlight the 5-HT(1B) receptors in the VO PFC as a particularly important site for the inhibition of species-typical aggressive behavior in male mice.

[Botulinum toxin for the treatment of pain syndromes]

Although botulinum toxin (BoNT) is being used for therapeutic purposes for more than 20 years, the list of potential new indications continues to increase and includes various pain syndromes. The pain relief experienced by patients with dystonia and spasticity from intramuscular BoNT injections suggested that other chronic skeletal-muscles pain conditions may also benefit. BoNT inhibits the release of acetylcholine at the neuromuscular junction thereby reducing striatal muscle contractions and the proposed analgesic property was initially attributed to muscular relaxation. A specific analgesic BoNT effect is difficult to conclude from studies where pain is conditioned by other associated symptoms like dystonia, muscle contraction or spasticity. One alternative is to critically appraise clinical trials where BoNT was studied as the active intervention and pain evaluated as an outcome. From this analysis there is convincing evidence for the effectiveness of BoNT in the treatment of pain associated with cervical dystonia. For all other pain syndromes there have been relatively few, small sized, placebo-controlled studies (myofascial pain syndrome, chronic neck and low back pain, piriformis syndrome and fibromyalgia) and the results of these studies have been contradictory or non conclusive. To establish the analgesic properties of BoNT there is a need for appropriately designed, exploratory randomized controlled studies in well accepted human models of nociceptive or neuropathic pain. This does not exclude the subsequent need to conduct pragmatic trials to evaluate the effectiveness of BoNT in conditions where the improvement of pain or any associated clinical sign or symptom may be of clinical relevance.

The European Multiple System Atrophy-Study Group (EMSA-SG)

Introduction. The European Multiple System Atrophy-Study Group (EMSA-SG) is an academic network comprising 23 centers across Europe and Israel that has constituted itself already in January 1999. This international forum of established experts under the guidance of the University Hospital of Innsbruck as coordinating center is supported by the 5th framework program of the European Union since March 2001 (QLK6-CT-2000-00661). Objectives. Primary goals of the network include (1) a central Registry for European multiple system atrophy (MSA) patients, (2) a decentralized DNA Bank, (3) the development and validation of the novel Unified MSA Rating Scale (UMSARS), (4) the conduction of a Natural History Study (NHS), and (5) the planning or implementation of interventional therapeutic trials. Methods. The EMSA-SG Registry is a computerized data bank localized at the coordinating centre in Innsbruck collecting diagnostic and therapeutic data of MSA patients. Blood samples of patients and controls are recruited into the DNA Bank. The UMSARS is a novel specific rating instrument that has been developed and validated by the EMSA-SG. The NHS comprises assessments of basic anthropometric data as well as a range of scales including the UMSARS, Unified Parkinson's Disease Rating Scale (UPDRS), measures of global disability, Red Flag list, MMSE (Mini Mental State Examination), quality of live measures, i.e. EuroQoL 5D (EQ-5D) and Medical Outcome Study Short Form (SF-36) as well as the Beck Depression Inventory (BDI). In a subgroup of patients dysautonomic features are recorded in detail using the Queen Square Cardiovascular Autonomic Function Test Battery, the Composite Autonomic Symptom Scale (COMPASS) and measurements of residual urinary volume. Most of these measures are repeated at 6-monthly follow up visits for a total study period of 24 months. Surrogate markers of the disease progression are identified by the EMSA-SG using magnetic resonance and diffusion weighted imaging (MRI and DWI, respectively). Results. 412 patients have been recruited into the Registry so far. Probable MSA-P was the most common diagnosis (49% of cases). 507 patients donated DNA for research. 131 patients have been recruited into the NHS. There was a rapid deterioration of the motor disorder (in particular akinesia) by 26.1% of the UMSARS II, and - to a lesser degree - of activities of daily living by 16.8% of the UMSARS I in relation to the respective baseline scores. Motor progression was associated with low motor or global disability as well as low akinesia or cerebellar subscores at baseline. Mental function did not deteriorate during this short follow up period. Conclusion. For the first time, prospective data concerning disease progression are available. Such data about the natural history and prognosis of MSA as well as surrogate markers of disease process allow planning and implementation of multi-centre phase II/III neuroprotective intervention trials within the next years more effectively. Indeed, a trial on growth hormone in MSA has just been completed, and another on minocycline will be completed by the end of this year.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part IV]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this fourth article (the last in a series), we present the prevention and management of tricyclic antidepressant overdose (in the three previous articles--published in previous issues of the Revista--we discussed the epidemiological aspects as well as the clinical presentation and the diagnosis, and the prognosis). Note: this is the fourth and last article on the cardiac toxicity of tricyclic antidepressant overdose.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part III]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this third (of four) articles, the prognosis of tryciclic antidepressant overdose is presented (in the two previous articles--published in previous issues of the Revista--we discussed the epidemiological aspects as well as the clinical presentation and the diagnosis). In the remaining paper we will present its management, and prevention. Note: this is the third of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the final article will be presented in the October issue of the Revista.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part II]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this second (of four) articles, the clinical presentation and diagnosis of tricyclic antidepressant overdose are presented (in the first article--published in the previous issue of the Journal--we discussed the epidemiological aspects). In the remaining two papers we will present its management, prognosis and prevention. NOTE: This is the second of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the next two articles will be presented in the September and October issues of the Revista.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature. Part I]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present the paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this first (of four) articles, the epidemiology tricyclic antidepressant overdose is presented. In the remaining three papers we will present its clinical presentation, diagnosis, treatment, prognosis and prevention. Note: this is the first of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the next three articles will be presented in the July, August and September issues of the RPC.

The neural correlates of verb and noun processing. A PET study

The hypothesis that categorical information, distinguishing among word classes, such as nouns, verbs, etc., is an organizational principle of lexical knowledge in the brain, is supported by the observation of aphasic subjects who are selectively impaired in the processing of nouns and verbs. The study of lesion location in these patients has suggested that the left temporal lobe plays a crucial role in processing nouns, while the left frontal lobe is necessary for verbs. To delineate the brain areas involved in the processing of different word classes, we used PET to measure regional cerebral activity during tasks requiring reading of concrete and abstract nouns and verbs for lexical decision. These tasks activated an extensive network of brain areas, mostly in the left frontal and temporal cortex, which represents the neural correlate of single word processing. Some left hemispheric areas, including the dorsolateral frontal and lateral temporal cortex, were activated only by verbs, while there were no brain areas more active in response to nouns. Furthermore, the comparison of abstract and concrete words indicated that abstract word processing was associated with selective activations (right temporal pole and amygdala, bilateral inferior frontal cortex), while no brain areas were more active in response to concrete words. There were no significant interaction effects between word class and concreteness. Taken together, these findings are compatible with the view that lexical-semantic processing of words is mediated by an extensive, predominantly left hemispheric network of brain structures. Additional brain activations appear to be related to specific semantic content, or, in the case of verbs, may be associated with the automatic access of syntactic information.