scholarly journals Substantia nigra ferric overload and neuromelanin loss in Parkinson's disease measured with 7T MRI

2021 ◽  
Author(s):  
Catarina Rua ◽  
Claire O'Callaghan ◽  
Rong Ye ◽  
Frank Hubert Hezemans ◽  
Luca Passamonti ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
High Resolution ◽  
Substantia Nigra ◽  
Clinical Severity ◽  
7 Tesla ◽  
Control Group ◽  
Healthy Controls ◽  
Iron Loading ◽  
Weighted Sequence

Background: Vulnerability of the substantia nigra dopaminergic neurons in Parkinson's disease is associated with ferric overload, leading to neurodegeneration with cognitive and motor decline. Here, we quantify iron and neuromelanin-related markers in vivo using ultra-high field 7-Tesla MRI, and examine the clinical correlates of these imaging assessments. Methods: Twenty-five people with mild-to-moderate Parkinson's disease and twenty-six healthy controls underwent high-resolution imaging at 7-Tesla with a T2*-weighted sequence (measuring susceptibility-χ and R2*, sensitive to iron) and a magnetization transfer-weighted sequence (MT-w, sensitive to neuromelanin). From an independent control group (N=29), we created study-specific regions-of-interest for five neuromelanin- and/or iron-rich subregions within the substantia nigra. Mean R2*, susceptibility-χ and their ratio, as well as the MT-w contrast-to-noise ratio (MT-CNR) were extracted from these regions and compared between groups. We then tested the relationships between these imaging metrics and clinical severity. Results: People with Parkinson's disease showed a significant ~50% reduction in MT-CNR compared to healthy controls. They also showed a 1.2-fold increase in ferric iron loading (elevation of the ΔR2*/Δχ ratio from 0.19±0.058ms/ppm to 0.22±0.059ms/ppm) in an area of the substantia nigra identified as having both high neuromelanin and susceptibility MRI signal in healthy controls. In this region, the ferric-to-ferrous iron loading was associated with disease duration (β=0.0072, pFDR=0.048) and cognitive impairment (β=-0.0115, pFDR=0.048). Conclusions: T2*-weighted and MT-weighted high-resolution 7T imaging markers identified neurochemical consequences of Parkinson's disease, in overlapping but not-identical regions. These changes correlated with non-motor symptoms.

Ultrasound imaging of vagus nerves in patients with Parkinson's disease

2021 ◽  
Author(s):  
AO Chechetkin ◽  
AN Moskalenko ◽  
EYu Fedotova ◽  
SN Illarioshkin
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
High Resolution ◽  
Substantia Nigra ◽  
Ultrasound Imaging ◽  
Inverse Correlation ◽  
Control Group ◽  
Vagus Nerves ◽  
Multisystem Disorder ◽  
Cross Sectional

Parkinson’s disease (PD) is a neurodegenerative multisystem disorder characterized by pathologic α-synuclein aggregation affecting, among other things, vagal fibers. The aim of this study was to investigate the cross-sectional area (CSA) of the vagus nerve (VN) in patients with PD using ultrasound imaging. The study was conducted in 32 patients with PD (15 men and 17 women; mean age 58 ± 10 years) and 32 healthy controls comparable with the main group in terms of sex and age. All study participants underwent ultrasound examination of the VN using a high-resolution transducer. Left VN CSA was significantly smaller in patients with PD than in the control group (1.78 ± 0.52 mm2 vs 2.11 ± 0.41 mm2; р = 0.007). A similar result was obtained for right VN CSA at the trend level. ROC analysis demonstrated that the threshold CSA value of < 2.10 mm2 for the left VN has low diagnostic sensivity (59%) for VN atrophy in patients with PD. Right VN CSA was significantly larger than left VN CSA in both groups (p < 0.001). The analysis of the PD group did not reveal any associations between VN CSA and age, duration and stage of the disease, motor (UPDRS III) and non-motor (NMSQ) scores. Patients with akinetic-rigid form of PD had smaller left VN CSA than patients with the mixed form of the disease (р < 0.05). A moderate inverse correlation was established between left VN CSA and the area of substantia nigra hyperechogenicity on both sides (р < 0.04); for the right VN a similar correlation was established at the trend level. High-resolution ultrasound of patients with PD demonstrated atrophy of the VN and the association of VN CSA with the clinical form of the disease and the ultrasound features of the substantia nigra.

scholarly journals Prefrontal and hippocampal atrophy using 7-tesla magnetic resonance imaging in patients with Parkinson’s disease

2021 ◽  
Vol 10 (2) ◽  
pp. 205846012098809
Author(s):  
Byeong H Oh ◽  
Hyeong C Moon ◽  
Aryun Kim ◽  
Hyeon J Kim ◽  
Chae J Cheong ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Magnetic Resonance ◽  
7 Tesla ◽  
Cortical Atrophy ◽  
Automated Segmentation ◽  
Healthy Controls ◽  
Segmentation Method ◽  
Resonance Imaging

Background The pathology of Parkinson’s disease leads to morphological changes in brain structure. Currently, the progressive changes in gray matter volume that occur with time and are specific to patients with Parkinson’s disease, compared to healthy controls, remain unclear. High-tesla magnetic resonance imaging might be useful in differentiating neurological disorders by brain cortical changes. Purpose We aimed to investigate patterns in gray matter changes in patients with Parkinson’s disease by using an automated segmentation method with 7-tesla magnetic resonance imaging. Material and Methods High-resolution T1-weighted 7 tesla magnetic resonance imaging volumes of 24 hemispheres were acquired from 12 Parkinson’s disease patients and 12 age- and sex-matched healthy controls with median ages of 64.5 (range, 41–82) years and 60.5 (range, 25–74) years, respectively. Subgroup analysis was performed according to whether axial motor symptoms were present in the Parkinson’s disease patients. Cortical volume, cortical thickness, and subcortical volume were measured using a high-resolution image processing technique based on the Desikan-Killiany-Tourville atlas and an automated segmentation method (FreeSurfer version 6.0). Results After cortical reconstruction, in 7 tesla magnetic resonance imaging volume segmental analysis, compared with the healthy controls, the Parkinson’s disease patients showed global cortical atrophy, mostly in the prefrontal area (rostral middle frontal, superior frontal, inferior parietal lobule, medial orbitofrontal, rostral anterior cingulate area), and subcortical volume atrophy in limbic/paralimbic areas (fusiform, hippocampus, amygdala). Conclusion We first demonstrated that 7 tesla magnetic resonance imaging detects structural abnormalities in Parkinson’s disease patients compared to healthy controls using an automated segmentation method. Compared with the healthy controls, the Parkinson’s disease patients showed global prefrontal cortical atrophy and hippocampal area atrophy.

Parkinson's disease and convergence insufficiency: a mini-review

2021 ◽  
Vol 1 (3) ◽  
pp. 108-111
Author(s):  
Mashael Al-Namaeh
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clinical Trials ◽  
Control Group ◽  
Healthy Controls ◽  
Inclusion Criteria ◽  
Medline Search ◽  
Convergence Insufficiency ◽  
Eye Examination ◽  
The Relationship

Background: A key manifestation of Parkinson’s disease (PD) is visual impairment. Cognitive impairment has been found to overlap with convergence insufficiency (CI) in patients with PD and is associated with significantly greater near point convergence (NPC) distance. Difficulty in reading and diplopia were the most common symptoms of CI in PD. The prevalence of CI is greater among patients with PD. Therefore, this study aimed to assess the relationship between PD and CI. Methods: Studies that had included data on CI, NPC, or both were selected by searching PubMed/MEDLINE and clinicaltrails.gov, without any timeline or language limitation. The following terms were used in PubMed/MEDLINE search: ‘Clinical Trials’, ‘Parkinson’s Disease’, and ‘Convergence Insufficiency’. For clinical trials.gov database, the terms ‘Parkinson’s Disease’, ‘Convergence Insufficiency’, and ‘Completed Studies’ were used. Only those studies with control subjects were included. PubMed/MEDLINE search yielded 1,563 articles, but no article was found in the clinical trails.gov search. Twelve articles met the inclusion criteria, among which nine articles were selected as they had data on CI or NPC distance (cm), and PD.   Results: Overall, there were 1,563 articles; among them, 12 articles met the inclusion criteria. Nine articles were selected based on their data concerning CI or NPC distance (cm) and PD. Relative to the control group, the PD group had high CI. In addition, PD group showed increase in NPC distance than the control group. Conclusions: These data suggest that the patients with PD had an increased likelihood of developing CI visual symptoms, and increased NPC distance than healthy controls. These findings indicate that regular eye examination is very important for patients with PD.

Mildronate as a Regulator of Protein Expression in a Rat Model of Parkinson’s Disease

Medicina ◽  
2011 ◽  
Vol 47 (10) ◽  
pp. 79 ◽  
Author(s):  
Sergejs Isajevs ◽  
Darja Isajeva ◽  
Ulrika Beitnere ◽  
Baiba Jansone ◽  
Ivars Kalvinsh ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Growth Factor ◽  
Substantia Nigra ◽  
Rat Model ◽  
Control Group ◽  
Western Blot Assay ◽  
Neural Cell Adhesion ◽  
6 Hydroxydopamine ◽  
Cardioprotective Drug

Background. Mildronate (3-[2,2,2-trimethylhydrazinium] propionate dihydrate) traditionally is a well-known cardioprotective drug. However, our recent studies convincingly demonstrated its neuroprotective properties. The aim of the present study was to evaluate the influence of mildronate on the expression of proteins that are involved in the differentiation and survival of the nigrostriatal dopaminergic neurons in the rat model of Parkinson’s disease (PD). The following biomarkers were used: heat shock protein 70 (Hsp70, a molecular chaperone), glial cell line-derived nerve growth factor (GDNF, a growth factor promoting neuronal differentiation, regeneration, and survival), and neural cell adhesion molecule (NCAM). Material and Methods. PD was modeled by 6-hydroxydopamine (6-OHDA) unilateral intrastriatal injection in rats. Mildronate was administered at doses of 10, 20, and 50 mg/kg for 2 weeks intraperitoneally before 6-OHDA injection. Rat brains were dissected on day 28 after discontinuation of mildronate injections. The expression of biomarkers was assessed immunohistochemically and by Western blot assay. Results. 6-OHDA decreased the expression of Hsp70 and GDNF in the lesioned striatum and substantia nigra, whereas in mildronate-pretreated (20 and 50 mg/kg) rats, the expression of Hsp70 and GDNF was close to the control group values. NCAM expression also was decreased by 6-OHDA in the striatum and it was totally protected by mildronate at a dose of 50 mg/kg. In contrast, in the substantia nigra, 6-OHDA increased the expression of NCAM, while mildronate pretreatment (20 and 50 mg/kg) reversed the 6-OHDA-induced overexpression of NCAM close to the control values. Conclusion. The obtained data showed that mildronate was capable to regulate the expression of proteins that play a role in the homeostasis of neuro-glial processes.

scholarly journals miR-185 and SEPT5 Genes May Contribute to Parkinson’s Disease Pathophysiology

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Arman Rahimmi ◽  
Ilaria Peluso ◽  
Aref Rajabi ◽  
Kambiz Hassanzadeh
Keyword(s):  
Gene Expression ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Chromosomal Location ◽  
Gene Expression Pattern ◽  
Control Group ◽  
Significant Difference

There are still unknown mechanisms involved in the development of Parkinson’s disease (PD), which elucidating them can assist in developing efficient therapies. Recently, studies showed that genes located on the human chromosomal location 22q11.2 might be involved in the development of PD. Therefore, the present study was designed to evaluate the role of two genes located on the chromosomal location (miR-185 and SEPT5), which were the most probable candidates based on our bibliography. In vivo and in vitro models of PD were developed using male Wistar rats and SHSY-5Y cell line, respectively. The expression levels of miR-185, SEPT5, LRRK2, and PARK2 genes were measured at a mRNA level in dopaminergic areas of rats’ brains and SHSY-5Y cells using the SYBR Green Real-Time PCR Method. Additionally, the effect of inhibition on the genes or their products on cell viability and gene expression pattern in SHSY-5Y cells was investigated. The level of miR-185 gene expression was significantly decreased in the substantia nigra (SN) and striatum (ST) of the rotenone-treated group (control group) compared to the healthy normal group (P<0.05). In addition, there was a significant difference in the expression of SEPT5 gene (P<0.05) in the substantia nigra between two studied groups. The results of an in vitro study showed no significant change in the expression of the genes; however, the inhibition on miR-185 gene expression led to the increase in LRRK2 gene expression in SHSY-5Y cells. The inhibition on LRRK2 protein also decreased the cellular toxicity effect of rotenone on SHSY-5Y cells. The results suggested the protective role of miR-185 gene in preventing the development of PD.

scholarly journals Diffusion Kurtosis Imaging of Substantia Nigra Is a Sensitive Method for Early Diagnosis and Disease Evaluation in Parkinson’s Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Guohua Zhang ◽  
Yuhu Zhang ◽  
Chengguo Zhang ◽  
Yukai Wang ◽  
Guixian Ma ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Rating Scale ◽  
Diffusion Tensor ◽  
Diffusion Kurtosis Imaging ◽  
Healthy Controls ◽  
Potential Biomarker ◽  
Diffusion Kurtosis ◽  
Sensitive Method

Background.To diagnose Parkinson disease (PD) in an early stage and accurately evaluate severity, it is important to develop a sensitive method for detecting structural changes in the substantia nigra (SN).Method.Seventy-two untreated patients with early PD and 72 healthy controls underwent diffusion tensor and diffusion kurtosis imaging. Regions of interest were drawn in the rostral, middle, and caudal SN by two blinded and independent raters. Mean kurtosis (MK) and fractional anisotropy in the SN were compared between the groups. Receiver operating characteristic (ROC) and Spearman correlation analyses were used to compare the diagnostic accuracy and correlate imaging findings with Hoehn-Yahr (H-Y) staging and part III of the Unified Parkinson’s Disease Rating Scale (UPDRS-III).Result.MK in the SN was increased significantly in PD patients compared with healthy controls. The area under the ROC curve was 0.976 for MK in the SN (sensitivity, 0.944; specificity, 0.917). MK in the SN had a positive correlation with H-Y staging and UPDRS-III scores.Conclusion.Diffusion kurtosis imaging is a sensitive method for PD diagnosis and severity evaluation. MK in the SN is a potential biomarker for imaging studies of early PD that can be widely used in clinic.

High resolution magnetic susceptibility mapping of the substantia nigra in Parkinson's disease

2011 ◽  
Vol 35 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Ashley K. Lotfipour ◽  
Samuel Wharton ◽  
Stefan T. Schwarz ◽  
V. Gontu ◽  
Andreas Schäfer ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Magnetic Susceptibility ◽  
High Resolution ◽  
Substantia Nigra ◽  
Susceptibility Mapping

scholarly journals Polyomic Analyses of Dopaminergic Neurons Isolated From Human Substantia Nigra in Parkinson’s Disease: An Exploratory Study.

2021 ◽  
Author(s):  
Affif ZACCARIA ◽  
Paola Antinori Malaspina ◽  
Virginie Licker ◽  
Enikö Kovari ◽  
Johannes A Lobrinus ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Protein Expression ◽  
Differential Expression ◽  
Exploratory Study ◽  
Substantia Nigra Pars Compacta ◽  
Control Group ◽  
Gene And Protein Expression ◽  
And Control

Abstract Background Dopaminergic (DA) neurons of the substantia nigra pars compacta (SNpc) selectively and progressively degenerate in Parkinson’s disease (PD). Until now, molecular analyses of DA neurons in PD have been limited to genomic and transcriptomic approaches, whereas, to the best of our knowledge, no proteomic or combined polyomic study examining the protein profile of these neurons, is currently available. Methods In this exploratory study, we used laser microdissection to extract DA neurons from 10 human SNpc samples obtained at autopsy in PD patients and control subjects. Extracted RNA and proteins were identified by RNA sequencing and nano-LC-MS/MS, respectively, and the differential expression between the PD and control group was assessed. Results Qualitative analyses confirmed that the microdissection protocol preserves the integrity of our samples and offers access to specific molecular pathways. This polyomic analysis highlighted differential expression of 52 genes and 33 proteins, including molecules of interest already known to be dysregulated in PD, such as LRP2, PNMT, CXCR4, MAOA and CBLN1 genes, or the Aldehyde dehydrogenase 1 protein. On the other hand, despite the same samples were used for both analyses, correlation between RNA and protein expression was low, as exemplified by the CST3 gene encoding for the cystatin C protein. Conclusion This is the first exploratory study analyzing both gene and protein expression of LMD-dissected DA neurons from SNpc in PD. Although correlation between RNA and protein expressions was limited, this polyomic study provides an extensive and integrated overview of molecular changes identified in the PD SNpc and may offer novel insights into specific pathological processes at work in PD degeneration.

scholarly journals Multiomic Analyses of Dopaminergic Neurons Isolated from Human Substantia Nigra in Parkinson’s Disease: A Descriptive and Exploratory Study

2021 ◽  
Author(s):  
Affif Zaccaria ◽  
Paola Antinori ◽  
Virginie Licker ◽  
Enikö Kövari ◽  
Johannes A. Lobrinus ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Protein Expression ◽  
Differential Expression ◽  
Dopaminergic Neurons ◽  
Exploratory Study ◽  
Control Group ◽  
Gene And Protein Expression ◽  
And Control

AbstractDopaminergic neurons (DA) of the substantia nigra pars compacta (SNpc) selectively and progressively degenerate in Parkinson’s disease (PD). Until now, molecular analyses of DA in PD have been limited to genomic or transcriptomic approaches, whereas, to the best of our knowledge, no proteomic or combined multiomic study examining the protein profile of these neurons is currently available. In this exploratory study, we used laser capture microdissection to extract regions from DA in 10 human SNpc obtained at autopsy in PD patients and control subjects. Extracted RNA and proteins were identified by RNA sequencing and nanoliquid chromatography–mass spectrometry, respectively, and the differential expression between PD and control group was assessed. Qualitative analyses confirmed that the microdissection protocol preserves the integrity of our samples and offers access to specific molecular pathways. This multiomic analysis highlighted differential expression of 52 genes and 33 proteins, including molecules of interest already known to be dysregulated in PD, such as LRP2, PNMT, CXCR4, MAOA and CBLN1 genes, or the Aldehyde dehydrogenase 1 protein. On the other hand, despite the same samples were used for both analyses, correlation between RNA and protein expression was low, as exemplified by the CST3 gene encoding for the cystatin C protein. This is the first exploratory study analyzing both gene and protein expression of laser-dissected neuronal parts from SNpc in PD. Data are available via ProteomeXchange with identifier PXD024748 and via GEO with identifier GSE 169755.

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