The Bacterial Amyloids Phenol Soluble Modulins from Staphylococcus aureus Catalyze Alpha-Synuclein Aggregation

Aggregated α-synuclein (α-syn) is the main constituent of Lewy bodies, which are a pathological hallmark of Parkinson’s disease (PD). Environmental factors are thought to be potential triggers capable of initiating the aggregation of the otherwise monomeric α-syn. Braak’s seminal work redirected attention to the intestine and recent reports of dysbiosis have highlighted the potential causative role of the microbiome in the initiation of pathology of PD. Staphylococcus aureus is a bacterium carried by 30–70% of the general population. It has been shown to produce functional amyloids, called phenol soluble modulins (PSMαs). Here, we studied the kinetics of α-syn aggregation under quiescent conditions in the presence or absence of four different PSMα peptides and observed a remarkable shortening of the lag phase in their presence. Whereas pure α-syn monomer did not aggregate up to 450 h after initiation of the experiment in neither neutral nor mildly acidic buffer, the addition of different PSMα peptides resulted in an almost immediate increase in the Thioflavin T (ThT) fluorescence. Despite similar peptide sequences, the different PSMα peptides displayed distinct effects on the kinetics of α-syn aggregation. Kinetic analyses of the data suggest that all four peptides catalyze α-syn aggregation through heterogeneous primary nucleation. The immunogold electron microscopic analyses showed that the aggregates were fibrillar and composed of α-syn. In addition of the co-aggregated materials to a cell model expressing the A53T α-syn variant fused to GFP was found to catalyze α-syn aggregation and phosphorylation in the cells. Our results provide evidence of a potential trigger of synucleinopathies and could have implications for the prevention of the diseases.

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The bacterial amyloids phenol soluble modulins from Staphylococcus aureus catalyze alpha-synuclein aggregation

10.1101/2021.03.10.434765 ◽

2021 ◽

Author(s):

Caroline Haikal ◽

Lei Ortigosa ◽

Katja Bernfur ◽

Alexander Svanbergsson ◽

Sara Linse ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Lag Phase ◽

Causative Role ◽

Potential Trigger ◽

Underlying Mechanisms ◽

Functional Amyloids ◽

Alpha Synuclein Aggregation ◽

Kinetics Of

AbstractAggregated α-synuclein (α-syn) is the main constituent of Lewy bodies, the main pathological hallmark of Parkinson’s disease (PD). Environmental factors are thought to be potential triggers capable of initiating the aggregation of the otherwise monomeric α-syn. Braak’s seminal work redirected attention to the intestine and recent reports of dysbiosis have highlighted the potential causative role that the microbiome might play in the pathology of PD. Staphylococcus aureus is a bacterium carried by 30-70% of the general population. It has been shown to produce functional amyloids, called Phenol Soluble Modulins (PSMαs). Here, we studied the kinetics of α-syn aggregation under quiescent conditions in the presence or absence of four different PSMα peptides and observed a remarkable shortening of the lag phase in their presence. Whereas pure α-syn monomer did not aggregate up to 450 h after initiation of the experiment in neither neutral nor mildly acidic buffer, the addition of different PSMα peptides resulted in an almost immediate increase in the Thioflavin T (ThT) fluorescence. Despite similar peptide sequences, the different PSMα peptides displayed distinct effects on the kinetics of α-syn aggregation. Kinetic analyses of the data suggest that while all four peptides catalyze α-syn aggregation, the underlying mechanisms might differ with a model of nucleation and elongation fitting the α-syn aggregation induced by PSMα2 but not PSMα1. The results of immunogold TEM imply that the aggregates are fibrillar and composed of α-syn. Addition of the co-aggregated materials to HEK cells expressing the A53T α-syn variant fused to GFP was found to catalyze α-syn aggregation and phosphorylation in the cells. Our results provide evidence of a potential trigger of synucleinopathies and could have implications for the prevention of the diseases.

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Alpha-Synuclein aggregates are excluded from Calbindin-D28k positive neurons in Dementia with Lewy Bodies, a unilateral rotenone mouse model and a cell model using SH-SY5Y neuroblastoma cells

Frontiers in Cellular Neuroscience ◽

10.3389/conf.fncel.2016.36.00077 ◽

2016 ◽

Vol 10 ◽

Author(s):

Rcom-H'Cheo-Gauthier Alexandre ◽

Meedeniya Adrian ◽

Pountney Dean

Keyword(s):

Mouse Model ◽

Dementia With Lewy Bodies ◽

Cell Model ◽

Neuroblastoma Cells ◽

Lewy Bodies ◽

Alpha Synuclein ◽

A Cell ◽

Calbindin D28k

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Treating Parkinson’s Disease with Antibodies: Previous Studies and Future Directions

Journal of Parkinson s Disease ◽

10.3233/jpd-202221 ◽

2020 ◽

pp. 1-22

Author(s):

Anne-Marie Castonguay ◽

Claude Gravel ◽

Martin Lévesque

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Neurodegenerative Disorder ◽

Passive Immunization ◽

Lewy Bodies ◽

Gene Mutations ◽

Alpha Synuclein ◽

Multiple Sources ◽

Immunization Strategies ◽

A Cell

Parkinson’s disease is a neurodegenerative disorder mainly characterized by the degeneration of dopaminergic neurons in the substantia nigra. Degenerating neurons contain abnormal aggregates called Lewy bodies, that are predominantly composed of the misfolded and/or mutated alpha-synuclein protein. Post-translational modifications, cellular stress, inflammation and gene mutations are thought to trigger its pathological misfolding and aggregation. With alpha-synuclein pathology being strongly associated with dopaminergic neuronal toxicity, strategies aimed to reduce its burden are expected to be beneficial in slowing disease progression. Moreover, multiple sources of evidence suggest a cell-to-cell transmission of pathological alpha-synuclein in a prion-like manner. Therefore, antibodies targeting extra- or intracellular alpha-synuclein could be efficient in limiting the aggregation and transmission. Several active and passive immunization strategies have been explored to target alpha-synuclein. Here, we summarize immunotherapeutic approaches that were tested in pre-clinical or clinical studies in the last two decades in an attempt to treat Parkinson’s disease.

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Microbiome, Parkinson’s Disease and Molecular Mimicry

Cells ◽

10.3390/cells8030222 ◽

2019 ◽

Vol 8 (3) ◽

pp. 222 ◽

Cited By ~ 13

Author(s):

Fabiana Miraglia ◽

Emanuela Colla

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Molecular Mimicry ◽

Current Knowledge ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Causative Role ◽

Olfactory Bulbs ◽

Host Interactions ◽

Aggregation Propensity

Parkinson’s Disease (PD) is typically classified as a neurodegenerative disease affecting the motor system. Recent evidence, however, has uncovered the presence of Lewy bodies in locations outside the CNS, in direct contact with the external environment, including the olfactory bulbs and the enteric nervous system. This, combined with the ability of alpha-synuclein (αS) to propagate in a prion-like manner, has supported the hypothesis that the resident microbial community, commonly referred to as microbiota, might play a causative role in the development of PD. In this article, we will be reviewing current knowledge on the importance of the microbiota in PD pathology, concentrating our investigation on mechanisms of microbiota-host interactions that might become harmful and favor the onset of PD. Such processes, which include the secretion of bacterial amyloid proteins or other metabolites, may influence the aggregation propensity of αS directly or indirectly, for example by favoring a pro-inflammatory environment in the gut. Thus, while the development of PD has not yet being associated with a unique microbial species, more data will be necessary to examine potential harmful interactions between the microbiota and the host, and to understand their relevance in PD pathogenesis.

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Different structures and pathologies of alpha-synuclein fibrils derived from preclinical and postmortem patients of Parkinson's disease

10.1101/2021.11.02.467019 ◽

2021 ◽

Author(s):

Yun Fan ◽

Yunpeng Sun ◽

Wenbo Yu ◽

Youqi Tao ◽

Wencheng Xia ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cerebrospinal Fluid ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Electron Microscopic ◽

Lewy Neurites ◽

The Difference ◽

A Minor

alpha-Synuclein (alpha-syn) fibrillar aggregates are the major component of Lewy bodies and Lewy neurites presenting as the pathology hallmark of Parkinson's disease (PD). Studies have shown that alpha-syn is potential to form different conformational fibrils associated with different synucleinopathies, but whether the conformation of alpha-syn fibrils changes in different phases of related diseases is to be explored. Here, we amplified alpha-syn aggregates from the cerebrospinal fluid (CSF) of preclinical (pre-PD) and late-stage postmortem PD (post-PD) patients. Our results show that compared to the CSF of pre-PD, that of post-PD is markedly stronger in seeding in vitro alpha-syn aggregation, and the amplified fibrils are more potent in inducing endogenous alpha-syn aggregation in neurons. Cryo-electron microscopic structures further reveal that the difference between the pre-PD- and post-PD-derived fibrils lies on a minor polymorph which in the pre-PD fibrils is morphologically straight, while in the post-PD fibrils represents a single protofilament assembled by a distinctive conformation of alpha-syn. Our work demonstrates structural and pathological differences between pre-PD and post-PD alpha-syn aggregation and suggests potential alteration of alpha-syn fibrils during the progression of PD clinical phases.

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Doxycycline inhibits α-synuclein-associated pathologies in vitro and in vivo

10.1101/2020.11.06.371229 ◽

2020 ◽

Author(s):

Antonio Dominguez-Meijide ◽

Valeria Parrales ◽

Eftychia Vasili ◽

Florencia González-Lizárraga ◽

Annekatrin König ◽

...

Keyword(s):

Lewy Bodies ◽

Alpha Synuclein ◽

Oxygen Species ◽

Additional Mechanism ◽

Neuroprotective Effects ◽

Free System ◽

Doxycycline Treatment ◽

A Cell

AbstractParkinson’s disease (PD) and dementia with Lewy bodies (DLB) are neurodegenerative disorders characterized by the misfolding and aggregation of alpha-synuclein (aSyn). Doxycycline, a tetracyclic antibiotic shows neuroprotective effects, initially proposed to be due to its anti-inflammatory properties. More recently, an additional mechanism by which doxycycline may exert its neuroprotective effects has been proposed as it has been shown that it inhibits amyloid aggregation. Here, we studied the effects of doxycycline on aSyn aggregation in vivo, in vitro and in a cell free system using real-time quaking induced conversion (RT-QuiC). Our results show that doxycycline decreases the number and size of aSyn aggregates in cells. In addition, doxycycline inhibits the aggregation and seeding of recombinant aSyn, and attenuates the production of mitochondrial-derived reactive oxygen species. Finally, we found doxycycline induces a cellular redistribution of the aggregates in an animal model of PD that is associated with a recovery of dopaminergic function. In summary, we provide strong evidence that doxycycline treatment may be an effective strategy against synucleinopathies.

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Modulating Kinetics of the Amyloid-Like Aggregation of S. aureus Phenol-Soluble Modulins by Changes in pH

Microorganisms ◽

10.3390/microorganisms9010117 ◽

2021 ◽

Vol 9 (1) ◽

pp. 117

Author(s):

Masihuz Zaman ◽

Maria Andreasen

Keyword(s):

Staphylococcus Aureus ◽

Clear Correlation ◽

Aggregation Kinetics ◽

Ph Values ◽

Fibril Structure ◽

Lag Times ◽

Functional Amyloids ◽

Important Basis ◽

Kinetics Of ◽

Microscopic Techniques

The pathogen Staphylococcus aureus is recognized as one of the most frequent causes of biofilm-associated infections. The recently identified phenol-soluble modulin (PSM) peptides act as the key molecular effectors of staphylococcal biofilm maturation and promote the formation of an aggregated fibril structure. The aim of this study was to evaluate the effect of various pH values on the formation of functional amyloids of individual PSM peptides. Here, we combined a range of biophysical, chemical kinetics and microscopic techniques to address the structure and aggregation mechanism of individual PSMs under different conditions. We established that there is a pH-induced switch in PSM aggregation kinetics. Different lag times and growth of fibrils were observed, which indicates that there was no clear correlation between the rates of fibril elongation among different PSMs. This finding confirms that pH can modulate the aggregation properties of these peptides and suggest a deeper understanding of the formation of aggregates, which represents an important basis for strategies to interfere and might help in reducing the risk of biofilm-related infections.

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Dendritic cells of the human epidermis: immuno-electron microscopic studies of la antigen reactivity

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084090 ◽

1978 ◽

Vol 36 (2) ◽

pp. 644-645

Author(s):

G. Rowden ◽

M. G. Lewis ◽

T. M. Phillips

Keyword(s):

Dendritic Cells ◽

Langerhans Cells ◽

Cell Types ◽

Cell Type ◽

Electron Microscopic ◽

La Antigen ◽

Microscopic Studies ◽

A Cell ◽

C3 Receptors ◽

Antigen Reactivity

Langerhans cells of mammalian stratified squamous epithelial have proven to be an enigma since their discovery in 1868. These dendritic suprabasal cells have been considered as related to melanocytes either as effete cells, or as post divisional products. Although grafting experiments seemed to demonstrate the independence of the cell types, much confusion still exists. The presence in the epidermis of a cell type with morphological features seemingly shared by melanocytes and Langerhans cells has been especially troublesome. This so called "indeterminate", or " -dendritic cell" lacks both Langerhans cells granules and melanosomes, yet it is clearly not a keratinocyte. Suggestions have been made that it is related to either Langerhans cells or melanocyte. Recent studies have unequivocally demonstrated that Langerhans cells are independent cells with immune function. They display Fc and C3 receptors on their surface as well as la (immune region associated) antigens.

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