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1.
J Relig Health ; 62(6): 4177-4191, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37099054

ABSTRACT

Spirituality and religious beliefs are important for coping with medical conditions. The dopaminergic system is involved in reward behavior, and its dysfunction in Parkinson Disease (PD) raises questions about religiosity and spirituality in people with PD. This study examines the association between levels of spirituality and religiosity and the severity of PD motor and non-motor symptoms. The secondary aim investigates the perceived impact of PD diagnosis on spirituality and religiosity. This was a cross-sectional analysis of demographic, physical, mental, and spirituality and religiosity status in patients with PD recruited for the Health Outcomes Measurement (HOME) Study at the University of Maryland Parkinson Disease and Movement Disorders Center, Baltimore, USA. Spirituality and religiosity were assessed using the Spiritual Well-being Scale, and the World Health Organization Quality of Life Spiritual Religious and Personal Belief field-test instrument. The sample size was 85 PD patients. The mean age (standard deviation) was 65.5 (9.4) years and 67.1% were male. Higher levels of spirituality and religiosity were associated with younger age, sex (female), less education, religious affiliation (Christian), and mental health status. After adjusting for age, education, gender, race, marital status, religion, physical health, mental health, and comorbidity, only anxiety was associated with all of the spirituality/religiosity assessments. The majority of patients reported no change in their religious or spiritual beliefs following diagnosis. Greater spirituality and religiosity were associated with less anxiety. Also, younger women with PD showed higher levels of spirituality and religiosity. Longitudinal studies on more diverse populations are needed.


Subject(s)
Parkinson Disease , Spirituality , Humans , Male , Female , Aged , Quality of Life , Cross-Sectional Studies , Religion , Christianity
2.
Neurol Genet ; 8(4): e200002, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35747619

ABSTRACT

Background and Objectives: Genetic variants affect both Parkinson disease (PD) risk and manifestations. Although genetic information is of potential interest to patients and clinicians, genetic testing is rarely performed during routine PD clinical care. The goal of this study was to examine interest in comprehensive genetic testing among patients with PD and document reactions to possible findings from genome sequencing in 2 academic movement disorder clinics. Methods: In 203 subjects with PD (age = 63 years, 67% male), genome sequencing was performed and filtered using a custom panel, including 49 genes associated with PD, parkinsonism, or related disorders, as well as a 90-variant PD genetic risk score. Based on the results, 231 patients (age = 67 years, 63% male) were surveyed on interest in genetic testing and responses to vignettes covering (1) familial risk of PD (LRRK2); (2) risk of PD dementia (GBA); (3) PD genetic risk score; and (4) secondary, medically actionable variants (BRCA1). Results: Genome sequencing revealed a LRRK2 variant in 3% and a GBA risk variant in 10% of our clinical sample. The genetic risk score was normally distributed, identifying 41 subjects with a high risk of PD. Medically actionable findings were discovered in 2 subjects (1%). In our survey, the majority (82%) responded that they would share a LRRK2 variant with relatives. Most registered unchanged or increased interest in testing when confronted with a potential risk for dementia or medically actionable findings, and most (75%) expressed interest in learning their PD genetic risk score. Discussion: Our results highlight broad interest in comprehensive genetic testing among patients with PD and may facilitate integration of genome sequencing in clinical practice.

3.
Parkinsons Dis ; 2022: 5535826, 2022.
Article in English | MEDLINE | ID: mdl-35585902

ABSTRACT

Background: The American Academy of Neurology Parkinson Disease (PD) quality measures include an annual diagnostic review. Objective: To investigate the frequency and pattern of changes in diagnoses between PD and other causes of parkinsonism. Methods: This prospective longitudinal cohort study included consented patients diagnosed with PD at least once and a minimum of two times at the Movement Disorders Center between 2002 and 2017. Movement disorder specialists confirmed and documented diagnoses at every visit. Longitudinal changes in diagnoses were identified across visits. Results: Of 1567 patients with parkinsonism, 174 had non-PD parkinsonism with no change over time. Of 1393 patients diagnosed with PD at least once, 94% (N = 1308) had no change of diagnosis over time and 6% (N = 85) had a change of diagnosis including PD ⟷ drug-induced parkinsonism (DIP) (27.1%), PD ⟷ multiple system atrophy (MSA) (20.0%), PD ⟷ progressive supranuclear palsy (PSP) (18.8%), PD ⟷ Lewy body dementia (DLB) (16.5%), PD⟷ vascular parkinsonism (9.4%), more than two diagnoses (4.7%), and PD ⟷ corticobasal syndrome (CBS) (3.5%). The direction of diagnostic switches was as follows: PD ⟶ other parkinsonism diseases (36.5%), other parkinsonism diseases ⟶ PD (31.8%), and 31.8% of multiple switches. There were no significant differences in duration of follow-up, age at first visit, gender, race, marital status, education, income, cognition, or employment between the stable and unstable groups. Diagnostic change was associated with greater PD severity and greater medical comorbidity. Conclusion: Over a 15-year period, movement disorder specialists changed their clinical diagnosis of PD in 6% of patients. The most common diagnostic switches, to or from PD, were DIP, MSA, PSP, and DLB. This study describes routine clinical diagnostic patterns in the absence of pathologic confirmation. The presence of diverse diagnostic changes over time underscores the value of confirming PD diagnosis.

4.
J Parkinsons Dis ; 11(4): 1995-2003, 2021.
Article in English | MEDLINE | ID: mdl-34366371

ABSTRACT

BACKGROUND: Cognitive impairment (CI) is common in Parkinson's disease (PD) and an important cause of disability. Screening facilitates early detection of CI and has implications for management. Preclinical disability is when patients have functional limitations but maintain independence through compensatory measures. OBJECTIVE: The objective of this study was to investigate the relationship between scores on the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) with levels of PD severity and disability. METHODS: PD patients (n = 2,234) in a large observational study were stratified by disease severity, based on Total Unified Parkinson's Disease Rating Scale (Total UPDRS) and Hoehn and Yahr (HY) stage. Using MMSE (n = 1,184) or MoCA (n = 1,050) and basic (ADL) and instrumental activities of daily living (IADL) scales for disability, linear regression analysis examined associations between cognitive status and disability. RESULTS: Cognition and disability were highly correlated, with the strongest correlation between IADL and MoCA. Only 16.0% of mean MMSE scores were below threshold for CI (28) and only in advanced PD (Total UPDRS 60+, HY≥3). MoCA scores fell below CI threshold (26) in 66.2% of the sample and earlier in disease (Total UPDRS 30+, HY≥2), corresponding with impairments in ADLs. CONCLUSION: In a large clinical dataset, a small fraction of MMSE scores fell below cutoff for CI, reinforcing that MMSE is an insensitive screening tool in PD. MoCA scores indicated CI earlier in disease and coincided with disability. This study shows that MoCA, but not MMSE is sensitive to the emergence of early cognitive impairment in PD and correlates with the concomitant onset of disability.


Subject(s)
Cognitive Dysfunction , Mental Status and Dementia Tests , Parkinson Disease , Activities of Daily Living , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/etiology , Humans , Neuropsychological Tests , Parkinson Disease/complications , Parkinson Disease/diagnosis , Severity of Illness Index
5.
Parkinsonism Relat Disord ; 83: 31-36, 2021 02.
Article in English | MEDLINE | ID: mdl-33465545

ABSTRACT

INTRODUCTION: Parkinson disease (PD) has been associated with both weight loss and gain in different stages of the disease. Our study aimed to determine the prevalence and associations with weight change over two years based on 3% and 5% weight change. METHODS: In this longitudinal analysis, weight at baseline and follow-up was used to classify patients into groups of weight loss, stable, and weight gain. Differences between these groups at baseline and then with change over time were tested. RESULTS: The sample was 668 patients with mean(SD) age 66.1(10) and disease duration 5.3(5.4) years. Using 3% weight change criteria: 32.6% lost, 23.1% gained, and 55.7% had stable weight. Using 5% criteria: 22.6% lost, 15.7% gained, and 61.7% had stable weight. Age was associated with both 3% and 5% change in weight. Other associations with 5% weight change were disease duration, Total and Motor Unified Parkinson's Disease Rating Scale, Older Americans Resource and Services disability, and Hoehn & Yahr staging. The effects of 3% weight loss on Motor UPDRS, IADLs, and depression, and the effects of 5% weight loss on IADLs remained statistically significant when controlling for baseline differences in age, levodopa use, and Total UPDRS. CONCLUSION: PD patients are more likely to experience 3% than 5% weight change and this lower threshold of weight change was associated with greater disease severity and disability over time. Attention to more subtle weight change may help identify those at greater risk of disability.


Subject(s)
Parkinson Disease/physiopathology , Weight Gain/physiology , Weight Loss/physiology , Aged , Cross-Sectional Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , Retrospective Studies , Severity of Illness Index
6.
J Pediatric Infect Dis Soc ; 9(5): 626-629, 2020 Nov 10.
Article in English | MEDLINE | ID: mdl-33038241

ABSTRACT

Children in pediatric long-term care (LTC) facilities are commonly infected with respiratory tract viruses as they have many high-risk co-morbidities and require significant interactions with the healthcare team. From previous studies, we know that infected staff can often be the source of transmission of infection to the children. If instituted quickly, infection control practices can help mitigate the spread of infection. We will describe how Sunshine Children's Home and Rehabilitation Center responded to federal and state infection control and prevention mandates in LTC for COVID-19. We will report our practice changes, staff and resident screening, and testing results as well as outcomes of the COVID-19-infected cases. The outcomes for COVID-19 infection among pediatric LTC staff and residents are in stark contrast to the data available for the adult providers and residents in adult nursing homes. Implementation and change in infection control practices and procedures resulted in much fewer cases of COVID-19 infection in our pediatric LTC residents.


Subject(s)
Clinical Laboratory Techniques , Coronavirus Infections/prevention & control , Infection Control/methods , Long-Term Care , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Residential Facilities/organization & administration , Adolescent , Betacoronavirus , COVID-19 , COVID-19 Testing , Child , Child, Preschool , Clinical Laboratory Techniques/statistics & numerical data , Coronavirus Infections/diagnosis , Humans , Infant , Infectious Disease Transmission, Professional-to-Patient , Male , New York , SARS-CoV-2 , Young Adult
7.
J Parkinsons Dis ; 10(s1): S49-S56, 2020.
Article in English | MEDLINE | ID: mdl-32741840

ABSTRACT

Parkinson's disease (PD) is a movement disorder with many symptoms responsive to treatment with dopamine agonists, anti-cholinergics and the dopamine precursor, levodopa. The cardinal features of PD include tremor, rigidity, bradykinesia, and postural instability. There also are non-motor features that include sleep disorders, cognitive and affective dysfunction, hyposmia, pain and dysautonomia (constipation, bloating, orthostasis, urinary symptoms, sexual dysfunction, dysphagia). Among these non-motor features are signs and symptoms of visual system impairment that range from subtle examination findings to those causing severe disability. In this review we describe common PD-related abnormalities in the visual system, how they present, and potential treatments.


Subject(s)
Disease Management , Parkinson Disease/complications , Parkinson Disease/therapy , Vision Disorders/etiology , Vision Disorders/therapy , Dopamine Agonists/therapeutic use , Hallucinations/etiology , Hallucinations/physiopathology , Hallucinations/therapy , Humans , Oculomotor Nerve Diseases/etiology , Oculomotor Nerve Diseases/physiopathology , Oculomotor Nerve Diseases/therapy , Parkinson Disease/physiopathology , Retinal Diseases/etiology , Retinal Diseases/physiopathology , Retinal Diseases/therapy , Vision Disorders/physiopathology
8.
Med Clin North Am ; 103(2): 337-350, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30704685

ABSTRACT

The diagnosis of Parkinson disease (PD) is based on the presence of bradykinesia and either resting tremor or rigidity and there should be no features from the history or examination to suggest an alternative cause of parkinsonism. In addition to the motor manifestations of PD, there is a long list of nonmotor symptoms, several of which occur before motor signs and are considered "prodromal" PD. These are classified as neuropsychiatric, autonomic, sleep, and sensory. There are many medical options for the treatment of PD but levodopa remains the mainstay. Deep brain stimulation and other advanced therapies are also available.


Subject(s)
Antiparkinson Agents/therapeutic use , Levodopa/therapeutic use , Parkinson Disease , Deep Brain Stimulation , Diagnosis, Differential , Humans , Hypokinesia/etiology , Parkinson Disease/complications , Parkinson Disease/diagnosis , Parkinson Disease/drug therapy , Parkinson Disease/therapy , Tremor/etiology
9.
Curr Treat Options Neurol ; 20(8): 30, 2018 Jun 23.
Article in English | MEDLINE | ID: mdl-29936554

ABSTRACT

PURPOSE OF REVIEW: This article discusses visual disorders in both Parkinson disease (PD) and other Parkinsonian disorders. It is organized largely by the anatomical site of pathology and emphasizes practical treatments. Targeted treatment options include medications, surgery, occupational, and physical therapies as well as optical aids. RECENT FINDINGS: The causes of visual complaints in Parkinson disease and other similar disorders are being more clearly identified. A new medication approved specifically to treat hallucinations in PD now is available. There is increased understanding of the important role that an ophthalmologist can play in the care of these patients. Finally, research and therapeutic development are unmet needs in accessing and treating visual complaints in PD and Parkinsonian disorders. A better understanding of Parkinson-related visual complaints and of available treatment options is important to optimize patient safety and quality of life. Vision impairment leads to difficulties in many common activities including reading, ambulating, and driving. Falls and injuries, made more likely because of impaired vision, result in an early loss of independence. Awareness of the problem, patient education, ophthalmologic care, selected therapeutics, physical therapy, and occupational therapy are crucial to maximizing quality of life in these patients.

10.
Elife ; 4: e06828, 2015 Apr 02.
Article in English | MEDLINE | ID: mdl-25838128

ABSTRACT

RET can be activated in cis or trans by its co-receptors and ligands in vitro, but the physiological roles of trans signaling are unclear. Rapidly adapting (RA) mechanoreceptors in dorsal root ganglia (DRGs) express Ret and the co-receptor Gfrα2 and depend on Ret for survival and central projection growth. Here, we show that Ret and Gfrα2 null mice display comparable early central projection deficits, but Gfrα2 null RA mechanoreceptors recover later. Loss of Gfrα1, the co-receptor implicated in activating RET in trans, causes no significant central projection or cell survival deficit, but Gfrα1;Gfrα2 double nulls phenocopy Ret nulls. Finally, we demonstrate that GFRα1 produced by neighboring DRG neurons activates RET in RA mechanoreceptors. Taken together, our results suggest that trans and cis RET signaling could function in the same developmental process and that the availability of both forms of activation likely enhances but not diversifies outcomes of RET signaling.


Subject(s)
Ganglia, Spinal/metabolism , Glial Cell Line-Derived Neurotrophic Factor Receptors/genetics , Mechanoreceptors/metabolism , Mechanotransduction, Cellular , Proto-Oncogene Proteins c-ret/genetics , Animals , Cell Survival , Embryo, Mammalian , Ganglia, Spinal/cytology , Ganglia, Spinal/growth & development , Gene Expression Regulation, Developmental , Glial Cell Line-Derived Neurotrophic Factor Receptors/deficiency , Mechanoreceptors/cytology , Mice , Mice, Knockout , Morphogenesis/genetics , Neurturin/deficiency , Neurturin/genetics , Proto-Oncogene Proteins c-ret/deficiency
11.
J Neurosci ; 33(13): 5773-84, 2013 Mar 27.
Article in English | MEDLINE | ID: mdl-23536090

ABSTRACT

Ubiquitous classical (typical) calpains, calpain-1 and calpain-2, are Ca(+2)-dependent cysteine proteases, which have been associated with numerous physiological and pathological cellular functions. However, a clear understanding of the role of calpains in the CNS has been hampered by the lack of appropriate deletion paradigms in the brain. In this study, we describe a unique model of conditional deletion of both calpain-1 and calpain-2 activities in mouse brain, which more definitively assesses the role of these ubiquitous proteases in brain development/function and pathology. Surprisingly, we show that these calpains are not critical for gross CNS development. However, calpain-1/calpain-2 loss leads to reduced dendritic branching complexity and spine density deficits associated with major deterioration in hippocampal long-term potentiation and spatial memory. Moreover, calpain-1/calpain-2-deficient neurons were significantly resistant to injury induced by excitotoxic stress or mitochondrial toxicity. Examination of downstream target showed that the conversion of the Cdk5 activator, p35, to pathogenic p25 form, occurred only in the presence of calpain and that it played a major role in calpain-mediated neuronal death. These findings unequivocally establish two central roles of calpain-1/calpain-2 in CNS function in plasticity and neuronal death.


Subject(s)
Brain Injuries/metabolism , Brain Injuries/pathology , Brain , Calpain/deficiency , Long-Term Potentiation/physiology , 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacology , Age Factors , Analysis of Variance , Animals , Animals, Newborn , Biophysics , Brain/embryology , Brain/growth & development , Brain/pathology , Brain Injuries/chemically induced , Brain Injuries/physiopathology , Bromodeoxyuridine/metabolism , Cell Death/drug effects , Cell Death/genetics , Dendrites/metabolism , Dendrites/pathology , Dendrites/ultrastructure , Disease Models, Animal , Electric Stimulation , Embryo, Mammalian , Evoked Potentials/drug effects , Evoked Potentials/physiology , Excitatory Amino Acid Agonists/pharmacology , Excitatory Postsynaptic Potentials/drug effects , Excitatory Postsynaptic Potentials/genetics , Female , Gene Expression Regulation, Developmental/genetics , Green Fluorescent Proteins/genetics , Hippocampus/cytology , In Vitro Techniques , Intermediate Filament Proteins/genetics , Intermediate Filament Proteins/metabolism , Long-Term Potentiation/genetics , Male , Maze Learning/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , N-Methylaspartate/pharmacology , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Nestin , Neurons/cytology , Neurons/metabolism , Patch-Clamp Techniques , Phosphotransferases , Psychomotor Performance , RNA, Messenger/metabolism , Silver Staining , Transfection
12.
J Neurosci ; 32(46): 16503-9, 2012 Nov 14.
Article in English | MEDLINE | ID: mdl-23152632

ABSTRACT

Parkinson's disease (PD) is a progressive neurodegenerative disease caused by the interaction of genetic and environmental factors. However, the etiology of PD remains largely unknown. Macroautophagy is known to play an essential role in the degradation of abnormal proteins and organelles. Furthermore, the loss of autophagy-related (Atg) genes results in neurodegeneration and abnormal protein accumulation. Since these are also pathologic features of Parkinson's disease, the conditional impairment of autophagy may lead to improved animal models for the study of PD. Using transgenic mice expressing Cre recombinase under the control of either the dopamine transporter or the engrailed-1 promoters, we generated mice with the conditional deletion of Atg7 in the dopamine neurons of the substantia nigra pars compacta, other regions of the midbrain, and also the hindbrain. This conditional impairment of autophagy results in the age-related loss of dopaminergic neurons and corresponding loss of striatal dopamine, the accumulation of low-molecular-weight α-synuclein, and the presence of ubiquitinated protein aggregates, recapitulating many of the pathologic features of PD. These conditional knock-out animals provide insight into the process of autophagy in Parkinson's disease pathology.


Subject(s)
Autophagy/physiology , Parkinson Disease/pathology , Animals , Autophagy-Related Protein 7 , Blotting, Western , Cell Count , Chromatography, High Pressure Liquid , Disease Models, Animal , Dopamine/metabolism , Dopaminergic Neurons/physiology , Dynactin Complex , Electrochemistry , Gene Deletion , Immunohistochemistry , Mice , Mice, Knockout , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Neostriatum/metabolism , Neurotransmitter Agents/metabolism , Parkinson Disease/metabolism , Polyubiquitin/metabolism , Ubiquitin/metabolism , alpha-Synuclein/metabolism
13.
Stem Cells ; 30(4): 732-40, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22232066

ABSTRACT

Maintaining adequate numbers of spermatogonial stem cells is required for the production of the millions of sperm required for male fertility. To date, however, the mechanisms that regulate the size of this pool in the adult are poorly defined. Glial cell line-derived neurotrophic factor (GDNF) is required for establishing this pool in the prepubertal animal, but its in vivo function in the normal adult testis has never been examined directly. We used a chemical-genetic approach to address this issue. We generated mice carrying a single amino acid mutation (V805A) in Ret, the kinase subunit of the GDNF receptor. This mutation does not affect normal GDNF signaling but renders it susceptible to inhibition by the ATP competitive inhibitor, NA-PP1. When GDNF signaling was blocked in adults for 11 days, only a few cells remained that expressed the stem spermatogonial markers, Gfrα1 and Zbtb16, and testicular Ret mRNA content was reduced markedly. These decreases were associated with depletion of functional stem spermatogonia; some were lost when GDNF signaling was inhibited for only 2 days while others survived for up to 11 days. However, when signaling was restored, the remaining stem cells proliferated, initiating tissue restoration. In conclusion, these results provide the first direct proof that GDNF acutely regulates the number of spermatogonial stem cells in the normal adult testis. Additionally, these results demonstrate different sensitivities among subpopulation of these stem cells to inhibition of GDNF signaling.


Subject(s)
Aging/physiology , Cell Differentiation , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Signal Transduction , Spermatogonia/cytology , Stem Cells/cytology , Stem Cells/metabolism , Amino Acid Substitution/genetics , Animals , Biomarkers/metabolism , Male , Mice , Proto-Oncogene Proteins c-ret/metabolism , Spermatogonia/metabolism , Testis/cytology , Testis/metabolism
14.
J Clin Invest ; 121(7): 2684-92, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21701068

ABSTRACT

The popular media and personal anecdotes are rich with examples of stress-induced eating of calorically dense "comfort foods." Such behavioral reactions likely contribute to the increased prevalence of obesity in humans experiencing chronic stress or atypical depression. However, the molecular substrates and neurocircuits controlling the complex behaviors responsible for stress-based eating remain mostly unknown, and few animal models have been described for probing the mechanisms orchestrating this response. Here, we describe a system in which food-reward behavior, assessed using a conditioned place preference (CPP) task, is monitored in mice after exposure to chronic social defeat stress (CSDS), a model of prolonged psychosocial stress, featuring aspects of major depression and posttraumatic stress disorder. Under this regime, CSDS increased both CPP for and intake of high-fat diet, and stress-induced food-reward behavior was dependent on signaling by the peptide hormone ghrelin. Also, signaling specifically in catecholaminergic neurons mediated not only ghrelin's orexigenic, antidepressant-like, and food-reward behavioral effects, but also was sufficient to mediate stress-induced food-reward behavior. Thus, this mouse model has allowed us to ascribe a role for ghrelin-engaged catecholaminergic neurons in stress-induced eating.


Subject(s)
Behavior, Animal/physiology , Feeding Behavior/physiology , Food , Ghrelin/metabolism , Reward , Stress, Psychological , Animals , Conditioning, Psychological , Eating/physiology , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurons/metabolism , Receptors, Ghrelin/genetics , Receptors, Ghrelin/metabolism , Social Dominance
15.
Mov Disord ; 26(11): 2107-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21714006

ABSTRACT

BACKGROUND: Focal hand dystonia may be task specific, as is the case with writer's cramp. In early stages, task specificity can be so specific that it may be mistaken for a psychogenic movement disorder. METHODS: We describe 4 patients who showed extreme task specificity in writer's cramp. They initially only had problems writing either a single letter or number. Although they were largely thought to be psychogenic, they progressed to typical writer's cramp. CONCLUSIONS: Early recognition of this condition may provide an opportunity for early initiation of treatment.


Subject(s)
Dystonic Disorders/diagnosis , Hand/physiopathology , Handwriting , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Muscle Cramp , Sensitivity and Specificity
16.
17.
J Neurosci ; 29(45): 14057-65, 2009 Nov 11.
Article in English | MEDLINE | ID: mdl-19906954

ABSTRACT

Ghrelin targets the hypothalamus to regulate food intake and adiposity. Endogenous ghrelin receptors [growth hormone secretagogue receptor (GHSR)] are also present in extrahypothalamic sites where they promote circuit activity associated with learning and memory, and reward seeking behavior. Here, we show that the substantia nigra pars compacta (SNpc), a brain region where dopamine (DA) cell degeneration leads to Parkinson's disease (PD), expresses GHSR. Ghrelin binds to SNpc cells, electrically activates SNpc DA neurons, increases tyrosine hydroxylase mRNA and increases DA concentration in the dorsal striatum. Exogenous ghrelin administration decreased SNpc DA cell loss and restricted striatal dopamine loss after 1-methyl-4-phenyl-1,2,5,6 tetrahydropyridine (MPTP) treatment. Genetic ablation of ghrelin or the ghrelin receptor (GHSR) increased SNpc DA cell loss and lowered striatal dopamine levels after MPTP treatment, an effect that was reversed by selective reactivation of GHSR in catecholaminergic neurons. Ghrelin-induced neuroprotection was dependent on the mitochondrial redox state via uncoupling protein 2 (UCP2)-dependent alterations in mitochondrial respiration, reactive oxygen species production, and biogenesis. Together, our data reveal that peripheral ghrelin plays an important role in the maintenance and protection of normal nigrostriatal dopamine function by activating UCP2-dependent mitochondrial mechanisms. These studies support ghrelin as a novel therapeutic strategy to combat neurodegeneration, loss of appetite and body weight associated with PD. Finally, we discuss the potential implications of these studies on the link between obesity and neurodegeneration.


Subject(s)
Corpus Striatum/physiology , Dopamine/metabolism , Ghrelin/metabolism , Ion Channels/metabolism , Mitochondria/physiology , Mitochondrial Proteins/metabolism , Substantia Nigra/physiology , Acyl Coenzyme A/metabolism , Animals , Cell Death/physiology , Corpus Striatum/drug effects , Ghrelin/genetics , Ion Channels/genetics , MPTP Poisoning , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Mitochondria/drug effects , Mitochondrial Proteins/genetics , RNA, Messenger/metabolism , Receptors, Ghrelin/genetics , Receptors, Ghrelin/metabolism , Substantia Nigra/drug effects , Tyrosine 3-Monooxygenase/metabolism , Uncoupling Protein 2
18.
Proc Natl Acad Sci U S A ; 106(12): 4900-5, 2009 Mar 24.
Article in English | MEDLINE | ID: mdl-19273858

ABSTRACT

Inhibitors of apoptosis (IAPs) are a family of highly-conserved proteins that regulate cell survival through binding to caspases, the final executioners of apoptosis. X-linked IAP (XIAP) is the most widely expressed IAP and plays an important function in regulating cell survival. XIAP contains 3 baculoviral IAP repeats (BIRs) followed by a RING finger domain at the C terminal. The BIR domains of XIAP possess anticaspase activities, whereas the RING finger domain enables XIAP to function as an E3 ubiquitin ligase in the ubiquitin and proteasomal system. Our previous study showed that parkin, a protein that is important for the survival of dopaminergic neurons in Parkinson's disease (PD), is S-nitrosylated both in vitro and in vivo in PD patients. S-nitrosylation of parkin compromises its ubiquitin E3 ligase activity and its protective function, which suggests that nitrosative stress is an important factor in regulating neuronal survival during the pathogenesis of PD. In this study we show that XIAP is S-nitrosylated in vitro and in vivo in an animal model of PD and in PD patients. Nitric oxide modifies mainly cysteine residues within the BIR domains. In contrast to parkin, S-nitrosylation of XIAP does not affect its E3 ligase activity, but instead directly compromises its anticaspase-3 and antiapoptotic function. Our results confirm that nitrosative stress contributes to PD pathogenesis through the impairment of prosurvival proteins such as parkin and XIAP through different mechanisms, indicating that abnormal S-nitrosylation plays an important role in the process of neurodegeneration.


Subject(s)
Neurons/metabolism , Neurons/pathology , Nitroso Compounds/metabolism , Parkinson Disease/metabolism , Parkinson Disease/pathology , X-Linked Inhibitor of Apoptosis Protein/metabolism , Animals , Apoptosis , Caspase Inhibitors , Cell Survival , Cytoprotection , Disease Models, Animal , Enzyme Activation , Humans , Mice , Neurons/enzymology , Nitric Oxide/metabolism , Protein Multimerization , Protein Structure, Tertiary , Ubiquitin-Protein Ligases/metabolism
19.
Neuron ; 54(5): 739-54, 2007 Jun 07.
Article in English | MEDLINE | ID: mdl-17553423

ABSTRACT

NGF controls survival, differentiation, and target innervation of both peptidergic and nonpeptidergic DRG sensory neurons. The common receptor for GDNF family ligands, Ret, is highly expressed in nonpeptidergic neurons, but its function during development of these neurons is unclear. Here, we show that expression of Ret and its coreceptors GFRalpha1 and GFRalpha2 is dependent on NGF. GFR/Ret signaling, in turn, autoregulates expression of both GFRalpha1 and GFRalpha2 and promotes expression of TrpA1, MrgA1, MrgA3, and MrgB4, acquisition of normal neuronal size, axonal innervation of the epidermis, and postnatal extinction of the NGF receptor TrkA. Moreover, NGF controls expression of several other genes characteristic of nonpeptidergic neurons, such as TrpC3, TrpM8, MrgD, and the transcription factor Runx1, via a Ret-independent signaling pathway. These findings support a model in which NGF controls maturation of nonpeptidergic DRG neurons through a combination of GFR/Ret-dependent and -independent signaling pathways.


Subject(s)
Cell Differentiation/physiology , Ganglia, Spinal/embryology , Nerve Growth Factor/metabolism , Neurons, Afferent/metabolism , Nociceptors/embryology , Proto-Oncogene Proteins c-ret/metabolism , Animals , Ganglia, Spinal/cytology , Ganglia, Spinal/metabolism , Gene Expression Regulation, Developmental/physiology , Glial Cell Line-Derived Neurotrophic Factor Receptors/metabolism , Ion Channels/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Neurons, Afferent/cytology , Nociceptors/cytology , Nociceptors/metabolism , Organ Culture Techniques , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/physiology , Transcription Factors/metabolism
20.
Ann Neurol ; 60(5): 557-569, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17120249

ABSTRACT

OBJECTIVE: The PARK8 gene responsible for late-onset autosomal dominant Parkinson's disease encodes a large novel protein of unknown biological function termed leucine-rich repeat kinase 2 (LRRK2). The studies herein explore the localization of LRRK2 in the mammalian brain. METHODS: Polyclonal antibodies generated against the amino or carboxy termini of LRRK2 were used to examine the biochemical, subcellular, and immunohistochemical distribution of LRRK2. RESULTS: LRRK2 is detected in rat brain as an approximate 280kDa protein by Western blot analysis. Subcellular fractionation demonstrates the presence of LRRK2 in microsomal, synaptic vesicle-enriched and synaptosomal cytosolic fractions from rat brain, as well as the mitochondrial outer membrane. Immunohistochemical analysis of rat and human brain tissue and primary rat cortical neurons, with LRRK2-specific antibodies, shows widespread neuronal-specific labeling localized exclusively to punctate structures within perikarya, dendrites, and axons. Confocal colocalization analysis of primary cortical neurons shows partial yet significant overlap of LRRK2 immunoreactivity with markers specific for mitochondria and lysosomes. Furthermore, ultrastructural analysis in rodent basal ganglia detects LRRK2 immunoreactivity associated with membranous and vesicular intracellular structures, including lysosomes, endosomes, transport vesicles, and mitochondria. INTERPRETATION: The association of LRRK2 with a variety of membrane and vesicular structures, membrane-bound organelles, and microtubules suggests an affinity of LRRK2 for lipids or lipid-associated proteins and may suggest a potential role in the biogenesis and/or regulation of vesicular and membranous intracellular structures within the mammalian brain.


Subject(s)
Brain/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , R-SNARE Proteins/genetics , R-SNARE Proteins/metabolism , Animals , Antibody Affinity , Biological Transport , Blotting, Western , Brain/cytology , Humans , Immunohistochemistry , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 , Mice , Neurons/metabolism , Rats , Subcellular Fractions/metabolism
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