scholarly journals Akkermansia muciniphila secretome promotes α-synuclein aggregation in enteroendocrine cells

2021 ◽  
Author(s):  
Dionísio Pedro Amorim Neto ◽  
Beatriz Pelegrini Bosque ◽  
João Vitor Pereira de Godoy ◽  
Paulla Vieira Rodrigues ◽  
Dario Donoso Meneses ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Calcium Release ◽  
Ryanodine Receptors ◽  
Enteroendocrine Cells ◽  
Ros Generation ◽  
List Type ◽  
Functional Link ◽  
Akkermansia Muciniphila ◽  
Intracellular Ca

ABSTRACTThe notion that the gut microbiota play a role in neurodevelopment, behavior and outcome of neurodegenerative disorders is recently taking place. A number of studies have consistently reported a greater abundance of Akkermansia muciniphila in Parkinson’s disease (PD) fecal samples. Nevertheless, a functional link between A.muciniphila and sporadic PD remained unexplored. Here, we investigated whether A.muciniphila secretome could initiate the misfolding process of α-synuclein (αSyn) in enteroendocrine cells (EECs), which are part of the gut epithelium and possess many neuron-like properties. We found that A.muciniphila secretome is directly modulated by mucin, induces intracellular calcium (Ca2+) release, and causes increased mitochondrial Ca2+ uptake in EECs, which in turn leads to production of reactive oxygen species (ROS) and αSyn aggregation. However, these events were efficiently inhibited once we buffered mitochondrial Ca2+. Thereby, these molecular insights provided here offer evidence that bacterial secretome is capable of inducing αSyn aggregation in enteroendocrine cells.SYNOPSIS FIGURE DESCRIPTIONThe secretome isolated from the commensal gut bacterium Akkermansia muciniphila triggers intracellular Ca2+ signaling in enteroendocrine cells, leading to increased mitochondrial Ca2+ uptake. Mitochondrial Ca2+ overload leads to ROS generation culminating with αSyn phosphorylation and aggregation (left panel). All these events were inhibited once mitochondrial Ca2+ is buffered (right panel).Gram-negative gut bacterium Akkermansia muciniphila is consistently found more abundant in Parkinson’s disease patients.Akkermansia muciniphila protein secretome composition is directly modulated by mucin and induces an IP3-independent endoplasmic reticulum (ER)-calcium release in enteroendocrine cells.This Ca2+ release is triggered by direct activation of Ryanodine Receptors leading to increased mitochondrial Ca2+ uptake.Mitochondrial Ca2+ overload leads to ROS generation culminating with αSyn aggregation.Buffering mitochondrial Ca2+ efficiently inhibits A.muciniphila-induced αSyn aggregation in enteroendocrine cells.

scholarly journals IPSC-derived midbrain astrocytes from Parkinson’s disease patients carrying pathogenic SNCA mutations exhibit alpha-synuclein aggregation, mitochondrial fragmentation and excess calcium release

2020 ◽  
Author(s):  
Peter A. Barbuti ◽  
Paul Antony ◽  
Gabriella Novak ◽  
Simone B. Larsen ◽  
Clara Berenguer-Escuder ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Calcium Release ◽  
Cytosolic Calcium ◽  
Alpha Synuclein ◽  
List Type ◽  
Cellular Model ◽  
Functional Impairments ◽  
Mitochondrial Fragmentation ◽  
Serum Free

AbstractParkinson’s disease (PD) is characterized by the loss of A9 midbrain dopaminergic neurons and the accumulation of alpha-synuclein aggregates in remaining neurons. Many studies of the molecular and cellular basis of neurodegeneration in PD have made use of iPSC-derived neurons from patients with familial PD mutations. However, approximately half of the cells in the brain are glia, and their role facilitating neurodegeneration is unclear. We developed a novel serum-free protocol to generate midbrain astrocytes from patient-derived iPSCs harbouring the pathogenic p.A30P, p.A53T mutations in SNCA, as well as duplication and triplication of the SNCA locus. In our cellular model, aggregates of alpha-synuclein occurred only within the GFAP+ astrocytes carrying the pathogenic SNCA mutations. Assessment of spontaneous cytosolic calcium (Ca2+) release using Fluo4 revealed that SNCA mutant astrocytes released excess Ca2+ compared to controls. Unbiased evaluation of 3D mitochondrial morphometric parameters showed that these SNCA mutant astrocytes had increased mitochondrial fragmentation and decreased mitochondrial connectivity compared to controls, and reduced mitochondrial bioenergetic function. This comprehensive assessment of different pathogenic SNCA mutations derived from PD patients using the same cellular model enabled assessment of the mutation effect, showing that p.A53T and triplication astrocytes were the most severely affected. Together, our results indicate that astrocytes harbouring the familial PD mutations in SNCA are dysfunctional, suggesting a contributory role for dysfunctional astrocytes in the disease mechanism and pathogenesis of PD.Table of Contents ImageMain PointsWe used a novel serum-free protocol to generate midbrain-specific functional astrocytes from Parkinson’s disease patients carrying pathological mutations in SNCAPatient-derived astrocytes show morphological and functional impairments

scholarly journals Sex-related effects on diabetes-induced alterations in calcium release in the rat heart

2007 ◽  
Vol 293 (6) ◽  
pp. H3584-H3592 ◽  
Author(s):  
Nazmi Yaras ◽  
Erkan Tuncay ◽  
Nuhan Purali ◽  
Babur Sahinoglu ◽  
Guy Vassort ◽  
...  
Keyword(s):  
Calcium Release ◽  
Binding Protein ◽  
Ryanodine Receptors ◽  
Left Ventricular ◽  
Adult Rats ◽  
Fk506 Binding Protein ◽  
Pressure Development ◽  
Spatiotemporal Parameters ◽  
Intracellular Ca ◽  
Developed Pressure

The present study was designed to determine whether the properties of local Ca2+ release and its related regulatory mechanisms might provide insight into the role of sex differences in heart functions of control and streptozotocin-induced diabetic adult rats. Left ventricular developed pressure, the rates of pressure development and decay (±dP/d t), basal intracellular Ca2+ level ([Ca2+]i), and spatiotemporal parameters of [Ca2+]i transients were found to be similar in male and female control rats. However, spatiotemporal parameters of Ca2+ sparks in cardiomyocytes isolated from control females were significantly larger and slower than those in control males. Diabetes reduced left ventricular developed pressure to a lower extent in females than in males, and the diabetes-induced depressions in both +dP/d t and −dP/d t were less in females than in males. Diabetes elicited a smaller reduction in the amplitude of [Ca2+]i transients in females than in males, a smaller reduction in sarcoplasmic reticulum-Ca2+ load, and less increase in basal [Ca2+]i. Similarly, the elementary Ca2+ events and their control proteins were clearly different in both sexes, and these differences were more marked in diabetes. Diabetes-induced depression of the Ca2+ spark amplitude was significantly less in females than in matched males. Levels of cardiac ryanodine receptors (RyR2) and FK506-binding protein 12.6 in control females were significantly higher than those shown in control males. Diabetes induced less RyR2 phosphorylation and FK506-binding protein 12.6 unbinding in females. Moreover, total and free sulfhydryl groups were significantly less reduced, and PKC levels were less increased, in diabetic females than in diabetic males. The present data related to local Ca2+ release and its related proteins describe some of the mechanisms that may underlie sex-related differences accounting for females to have less frequent development of cardiac diseases.

scholarly journals WED 131 Evaluating the clinical utility of the parkinson’s kinetigraph (PKG)

2018 ◽  
Vol 89 (10) ◽  
pp. A15.1-A15 ◽  
Author(s):  
Lewis Hutchinson ◽  
Thea Dominey ◽  
Emma Pearson ◽  
Fiona Murphy ◽  
Lucy Bell ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Treatment Recommendations ◽  
Healthcare Sector ◽  
Patient Questionnaire ◽  
List Type ◽  
Patient Acceptability ◽  
P4 Medicine ◽  
Remote Management ◽  
Centered Care

ObjectiveTo evaluate the utility of the Parkinson’s Kinetigraph (PKG™) in the remote management of Parkinson’s disease (PD).BackgroundThere is a movement in Parkinson’s care from a clinic-based model1 to P4 medicine, meaning medicine that is predictive, preventive, personalised and participatory.2 The development of wearable technology provides an opportunity to monitor patients remotely, and deliver targeted care. The PKG™ is a wrist-worn device that objectively measures Parkinson’s symptoms.AimTo evaluate the utility of the PKG™ in managing PD patients remotely, and the perception of service users.MethodPKG™ data were collated in real time. Patient acceptability data were collated via a patient questionnaire (n=61).ResultsBetween July 2015 and January 2018, 216 PKGs were performed. A variety of symptoms were identified, including different types of ‘OFF’ times (wearing off (25%), delayed on (6%) no drug response (8%)) and non-motor complications (fragmented sleep (33%) and daytime somnolence (21%)), with subsequent treatment recommendations being made. Patient acceptability of the PKG™ was high, 81% of patients being satisfied not having to travel for clinic appointments.ConclusionsThe PKG™ facilitated remote treatment recommendations. Remote management was acceptable to patients. Future evaluations will evaluate patient outcome.References. van der Eijk M, Nijhuis FAP, Faber MJ, Bloem BR. Moving from physician-centered care towards patient-centered care for Parkinson’s disease patients. Parkinsonism Relat Disord [Internet]. Elsevier; 1 November 2013;19(11):923–7. Available from: https://www.sciencedirect.com/science/article/pii/S1353802013001697?_rdoc=1&_fmt=high&_origin=gateway&_docanchor=&md5=b8429449ccfc9c30159a5f9aeaa92ffb [cited 2018 February 6]. P4 medicine: how systems medicine will transform the healthcare sector and society. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4204402/pdf/nihms532619.pdf [cited 2018 April 6]

scholarly journals Strain- and age-dependent features of the nigro-striatal circuit in three common laboratory mouse strains, C57BL/6J, A/J, and DBA/2J - Implications for Parkinson’s disease modeling

2020 ◽  
Author(s):  
Mélanie H. Thomas ◽  
Mona Karout ◽  
Beatriz Pardo Rodriguez ◽  
Yujuan Gui ◽  
Christian Jaeger ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Brain ◽  
Dopaminergic Neurons ◽  
Mouse Strains ◽  
List Type ◽  
Background Strain ◽  
Age Related ◽  
Health And Disease ◽  
Over Time

AbstractMouse models have been instrumental in understanding genetic determinants of aging and its crucial role in neurodegenerative diseases. However, few studies have analyzed the evolution of the mouse brain over time at baseline. Furthermore, mouse brain studies are commonly conducted on the C57BL/6 strain, limiting the analysis to a specific genetic background. In Parkinson’s disease, the gradual demise of nigral dopaminergic neurons mainly contributes to the motor symptoms. Interestingly, a decline of the dopaminergic neuron function and integrity is also a characteristic of physiological aging in some species. Age-related nigro-striatal features have never been studied in mice of different genetic backgrounds. In this study, we analyze the morphological features in the striatum of three common mouse strains, C57BL/6J, A/J, and DBA/2J at 3-, 9- and 15 months of age. By measuring dopaminergic markers, we uncover age-related changes that differ between strains and evolve dynamically over time. Overall, our results highlight the importance of considering background strain and age when studying the murine nigro-striatal circuit in health and disease.HighlightsStudy of the integrity of the nigro-striatal circuit in C57BL/6J, A/J, and DBA/2J at different agesAge related evolution of essential features of nigral dopaminergic neurons differ between strainsConsider background strain and age is crutial to study the nigrostriatal circuit in health and disease

scholarly journals The Neuro-Protective Effects of the TSPO Ligands CB86 and CB204 on 6-OHDA-Induced PC12 Cell Death as an In Vitro Model for Parkinson’s Disease

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1183
Author(s):  
Sheelu Monga ◽  
Nunzio Denora ◽  
Valentino Laquintana ◽  
Rami Yashaev ◽  
Abraham Weizman ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Neurodegenerative Disorder ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
The Impact

Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is characterized by the degeneration of dopaminergic neurons in substantia nigra (SN). Oxidative stress or reactive oxygen species (ROS) generation was suggested to play a role in this specific type of neurodegeneration. Therapeutic options which can target and counteract ROS generation may be of benefit. TSPO ligands are known to counteract with neuro-inflammation, ROS generation, apoptosis, and necrosis. In the current study, we investigated an in vitro cellular PD model by the assessment of 6-hydroxydopamine (6-OHDA, 80 µM)-induced PC12 neurotoxicity. Simultaneously to the exposure of the cells to 6-OHDA, we added the TSPO ligands CB86 and CB204 (25 µM each) and assessed the impact on several markers of cell death. The two ligands normalized significantly (57% and 52% respectively, from 44%; whereas the control was 68%) cell proliferation at different time points from 0–24 h. Additionally, we evaluated the effect of these two TSPO ligands on necrosis using propidium iodide (PI) staining and found that the ligands inhibited significantly the 6-OHDA-induced necrosis. As compared to control, the red count was increased up to 57-fold whereas CB86 and CB204 inhibited to 2.7-fold and 3.2-fold respectively. Necrosis was also analyzed by LDH assay which showed significant effect. Both assays demonstrated similar potent anti-necrotic effect of the two TSPO ligands. Reactive oxygen species (ROS) generation induced by 6-OHDA was also inhibited by the two TSPO ligand up to 1.3 and 1.5-fold respectively, as compared to 6-OHDA group. CB86 and CB204 inhibited also normalized the cell viability up to 1.8-fold after the exposure to 6-OHDA, as assessed by XTT assay. The two TSPO ligands also inhibited apoptosis significantly (1.3-fold for both) as assessed by apopxin green staining. In summary, it appears that the two TSPO ligands CB86 and CB204 can suppress cell death of PC12 induced by 6-OHDA. The results may be relevant to the use of these two TSPO ligands as therapeutic option neurodegenerative diseases like PD.

scholarly journals Neuroprotective Effects of Cuscutae Semen in a Mouse Model of Parkinson’s Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Minsook Ye ◽  
Seul gi Lee ◽  
Eun Sook Chung ◽  
Su-jin Lim ◽  
Won Seob Kim ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Glutathione Peroxidase ◽  
Pc12 Cells ◽  
Statistical Significance ◽  
Inhibitory Effect ◽  
Ros Generation ◽  
Neuroprotective Effects ◽  
Differentiated Pc12 Cells

Parkinson’s disease (PD) is a neurodegenerative movement disorder that is characterized by the progressive degeneration of the dopaminergic (DA) pathway. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes damage to the DA neurons, and 1-4-methyl-4-phenylpyridinium (MPP+) causes cell death in differentiated PC12 cells that is similar to the degeneration that occurs in PD. Moreover, MPTP treatment increases the activity of the brain’s immune cells, reactive oxygen species- (ROS-) generating processes, and glutathione peroxidase. We recently reported that Cuscutae Semen (CS), a widely used traditional herbal medicine, increases cell viability in a yeast model of PD. In the present study, we examined the inhibitory effect of CS on the neurotoxicity of MPTP in mice and on the MPP+-induced cell death in differentiated PC12 cells. The MPTP-induced loss of nigral DA neurons was partly inhibited by CS-mediated decreases in ROS generation. The activation of microglia was slightly inhibited by CS, although this effect did not reach statistical significance. Furthermore, CS may reduce the MPP+ toxicity in PC12 cells by suppressing glutathione peroxidase activation. These results suggest that CS may be beneficial for the treatment of neurodegenerative diseases such as PD.

A model of graded calcium release and L-type Ca2+ channel inactivation in cardiac muscle

2004 ◽  
Vol 286 (3) ◽  
pp. H1154-H1169 ◽  
Author(s):  
Vladimir E. Bondarenko ◽  
Glenna C. L. Bett ◽  
Randall L. Rasmusson
Keyword(s):  
Molecular Mechanisms ◽  
Calcium Release ◽  
Ventricular Myocytes ◽  
Ryanodine Receptors ◽  
Quantitative Description ◽  
Channel Current ◽  
Channel Inactivation ◽  
Transmembrane Voltage ◽  
Intracellular Ca ◽  
Junctional Sarcoplasmic Reticulum

We have developed a model of Ca2+ handling in ferret ventricular myocytes. This model includes a novel L-type Ca2+ channel, detailed intracellular Ca2+ movements, and graded Ca2+-induced Ca2+ release (CICR). The model successfully reproduces data from voltage-clamp experiments, including voltage- and time-dependent changes in intracellular Ca2+ concentration ([Ca2+]i), L-type Ca2+ channel current ( ICaL) inactivation and recovery kinetics, and Ca2+ sparks. The development of graded CICR is critically dependent on spatial heterogeneity and the physical arrangement of calcium channels in opposition to ryanodine-sensitive release channels. The model contains spatially distinct subsystems representing the subsarcolemmal regions where the junctional sarcoplasmic reticulum (SR) abuts the T-tubular membrane and where the L-type Ca2+ channels and SR ryanodine receptors (RyRs) are localized. There are eight different types of subsystems in our model, with between one and eight L-type Ca2+ channels distributed binomially. This model exhibits graded CICR and provides a quantitative description of Ca2+ dynamics not requiring Monte-Carlo simulations. Activation of RyRs and release of Ca2+ from the SR depend critically on Ca2+ entry through L-type Ca2+ channels. In turn, Ca2+ channel inactivation is critically dependent on the release of stored intracellular Ca2+. Inactivation of ICaL depends on both transmembrane voltage and local [Ca2+]i near the channel, which results in distinctive inactivation properties. The molecular mechanisms underlying many ICaL gating properties are unclear, but [Ca2+]i dynamics clearly play a fundamental role.

scholarly journals 035 Valproate-induced parkinsonism ‘an early warning’: case reports and review of literature

2019 ◽  
Vol 90 (e7) ◽  
pp. A12.2-A12
Author(s):  
Shoaib Dal ◽  
Scott Whyte
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Case Reports ◽  
The Elderly ◽  
Time Frame ◽  
List Type ◽  
Review Of The Literature ◽  
Hand Tremor ◽  
Wheel Rigidity

IntroductionWe describe two cases of valproate-induced parkinsonism, where the parkinsonian features develop after commencing valproate (VPA), in a time frame and manner well described by previous publications.1 In contrast to the published literature, that has short duration of follow-up, we have had a prolonged follow-up of these two cases, who initially improved on ceasing valproate, but then after a period progressed again, with the development of levodopa-responsive asymmetrical Parkinson’s disease.2Cases67 years old man, on VPA 500 mg twice a day for seizures since 2008, developed new rest, re-emergent left hand tremor and hypomimia in 2012. Within months, the parkinsonism progressed to decremental bradykinesia, cog-wheel rigidity and hypophonia. The symptoms initially improved with changing VPA to levetiracetam; however, the disease reappeared after 6 months and although levodopa-responsive, it has been progressive since then.88 years old man, on VPA 700 mg twice a day for seizures since 2010, developed upper limb decremental bradykinesia, cog-wheel rigidity, camptocormia and rest, re-emergent tremor in hands in 2011. The parkinsonism improved significantly with cessation of VPA; however, the disease re-emerged after 2 years and has been progressive since then.ConclusionVPA may be responsible for unmasking underlying subclinical parkinsonism and these patients represent an earlier onset of Parkinson’s disease related to VPA exposure, rather than a purely drug related parkinsonian dysfunction. These cases also highlight the importance of long-term follow up in VPA-induced parkinsonism. These observations are an important consideration for clinicians treating patients with parkinsonian features secondary to VPA exposure.ReferencesBrugger F, Bhatia KP, Besag FM. Valproate-associated parkinsonism: a critical review of the literature. CNS Drugs 2016;30(6):527–540.Mahmoud F, Tampi RR. Valproic acid-induced parkinsonism in the elderly: a comprehensive review of the literature. Am J Geriatr Pharmacother 2011;9(6):405–412.

scholarly journals Antioxidative Effects of Carrot-Derived Nanovesicles in Cardiomyoblast and Neuroblastoma Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1203
Author(s):  
Do Kyung Kim ◽  
Won Jong Rhee
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neuroblastoma Cells ◽  
Size Exclusion ◽  
Drug Candidate ◽  
Ros Generation ◽  
High Concentration ◽  
Antioxidative Function

Oxidative stress is implicated in many diseases, including cardiovascular and neurodegenerative diseases. Because an increased level of oxidative stress causes apoptosis, it is necessary to inhibit cellular responses to oxidative stress. In this study, Carex, a nanovesicle from carrot, was isolated and investigated as a novel biomaterial with antioxidative function in cardiomyoblasts and neuroblastoma cells. A high concentration of nanovesicles was purified from carrots, using size-exclusion chromatography in combination with ultrafiltration. The characterization of Carex demonstrated that it had properties similar to those of extracellular vesicles. Carex showed low cytotoxicity in both H9C2 cardiomyoblasts and SH-SY5Y neuroblastoma cells, when a high level of Carex was delivered to the cells. Carex was further investigated for its antioxidative and apoptotic effects, and it significantly inhibited ROS generation and apoptosis in vitro in myocardial infarction and Parkinson’s disease models. Carex inhibited the reduction of antioxidative molecule expression, including Nrf-2, HO-1, and NQO-1, in both models. Considering its antioxidative function and high production yield, Carex is a potential drug candidate for the treatment of myocardial infarction as well as Parkinson’s disease. Thus, the results demonstrated in this study will contribute to an exploration of a novel drug, using nanovesicles from plants, including carrots.

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