DNAJB6b is Downregulated in Synucleinopathies

Background: α-synuclein (α-syn) aggregation contributes to the progression of multiple neurodegenerative diseases. We recently found that the isoform b of the co-chaperone DNAJB6 is a strong suppressor of a-syn aggregation in vivo and in vitro. However, nothing is known about the role of the endogenous isoform b of DNAJB6 (DNAJB6b) in health and disease, due to lack of specific antibodies. Objective: Here we generated a novel anti-DNAJB6b antibody to analyze the localization and expression this isoform in cells, in tissue and in clinical material. Methods: To address this we used immunocytochemistry, immunohistochemistry, as well as a novel quantitative DNAJB6 specific ELISA method. Results: The endogenous protein is mainly expressed in the cytoplasm and in neurites in vitro, where it is found more in dendrites than in axons. We further verified in vivo that DNAJB6b is expressed in the dopaminergic neurons of the substantia nigra pars compacta (SNpc), which is a neuronal subpopulation highly sensitive to α-syn aggregation, that degenerate to a large extend in patients with Parkinson’s disease (PD) and multiple system atrophy (MSA). When we analyzed the expression levels of DNAJB6b in brain material from PD and MSA patients, we found a downregulation of DNAJB6b by use of ELISA based quantification. Interestingly, this was also true when analyzing tissue from patients with progressive supranuclear palsy, a taupathic atypical parkinsonian disorder. However, the total level of DNAJB6 was upregulated in these three diseases, which may indicate an upregulation of the other major isoform of DNAJB6, DNAJB6a. Conclusion: This study shows that DNAJB6b is downregulated in several different neurodegenerative diseases, which makes it an interesting target to further investigate in relation to amyloid protein aggregation and disease progression.

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Serum interspecies differences in metabolic pathways of bradykinin and [des-Arg9]BK: influence of enalaprilat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1996.271.4.h1340 ◽

1996 ◽

Vol 271 (4) ◽

pp. H1340-H1347 ◽

Cited By ~ 17

Author(s):

A. Decarie ◽

P. Raymond ◽

N. Gervais ◽

R. Couture ◽

A. Adam

Keyword(s):

Metabolic Pathways ◽

Neutral Endopeptidase ◽

Thrombin Inhibitor ◽

Rat Serum ◽

Highly Sensitive ◽

Significant Difference ◽

Hydrolysis Of

Among the different enzymes responsible for the metabolism of bradykinin (BK), three peptidases look relevant in vivo: kininase I (KI), which transforms BK into its active metabolite, [des-Arg9]BK; kininase II (KII); and neutral endopeptidase, which inactivate BK and [des-Arg9]BK. The in vitro incubation of BK and [des-Arg9]BK in the serum of four species with or without enalaprilat and the quantification of the immunoreactivity of both peptides at different time intervals allowed the measurement of the kinetic parameters characterizing their metabolic pathways. Highly sensitive chemiluminescent enzyme immunoassays were used to measure the residual concentrations of BK and [des-Arg9]BK. Half-life (t1/2) of BK showed significant difference among species: rats (10 +/- 1 s) = dogs (13 +/- 1 s) < rabbits (31 +/- 1 s) < humans (49 +/- 2 s). t1/2 values of [des-Arg9]BK were also species dependent: rats (96 +/- 6 s) < < rabbits (314 +/- 6 s) = dogs (323 +/- 11 s) = humans (325 +/- 12 s). Enalaprilat significantly prevented the rapid BK and [des-Arg9]BK degradation in all species except that of [des-Arg9]BK in rat serum. Relative amount of BK hydrolyzed by serum KII was given as follows: rabbits (93.7 +/- 14.8%) = rats (83.6 +/- 6.7%) = humans (76.0 +/- 7.5%) > dogs (50.0 +/- 3.9%). Its importance in the hydrolysis of [des-Arg9]BK was 5.2 +/- 0.5% in rats < < 33.9 +/- 1.5% in humans < 52.0 +/- 1.1% in rabbits < 65.1 +/- 3.4% in dogs. The participation of serum KI in the transformation of BK into [des-Arg9]BK was dogs (67.2 +/- 5.3%) > > humans (3.4 +/- 1.2%) = rabbits (1.8 +/- 0.2%) = rats (1.4 +/- 0.3%). Finally, no significant difference on t1/2 values for BK and [des-Arg9]BK could be demonstrated between serum and plasma treated with either sodium citrate or a thrombin inhibitor. These results revealed striking species differences in the serum metabolism of kinins that could address at least partially some of the controversial data related to the cardioprotective role of kinins.

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Role of Bordetella O Antigen in Respiratory Tract Infection

Infection and Immunity ◽

10.1128/iai.71.1.86-94.2003 ◽

2003 ◽

Vol 71 (1) ◽

pp. 86-94 ◽

Cited By ~ 46

Author(s):

Valorie C. Burns ◽

Elizabeth J. Pishko ◽

Andrew Preston ◽

Duncan J. Maskell ◽

Eric T. Harvill

Keyword(s):

Tract Infection ◽

Respiratory Tract ◽

Respiratory Tract Infection ◽

Human Pathogen ◽

O Antigen ◽

Highly Sensitive ◽

Major Surface

ABSTRACT Lipopolysaccharide (LPS), as the major surface molecule of gram-negative bacteria, interacts with the host in complex ways, both inducing and protecting against aspects of inflammatory and adaptive immunity. The membrane-distal repeated carbohydrate structure of LPS, the O antigen, can prevent antibody functions and may vary as a mechanism of immune evasion. Genes of the wbm locus are required for the assembly of O antigen on the animal pathogen Bordetella bronchiseptica and the human pathogen B. parapertussis. However, the important human pathogen B. pertussis lacks these genes and a number of in vitro and in vivo characteristics associated with O antigen in other organisms. To determine the specific functions of O antigen in these closely related Bordetella subspecies, we compared wbm deletion (Δwbm) mutants of B. bronchiseptica and B. parapertussis in a variety of assays relevant to natural respiratory tract infection. Complement was not activated or depleted by wild-type bordetellae expressing O antigen, but both Δwbm mutants activated complement and were highly sensitive to complement-mediated killing in vitro. Although the O-antigen structures appear to be substantially similar, the two mutants differed strikingly in their defects within the respiratory tract. The B. parapertussis Δwbm mutant was severely defective in colonization of the tracheas and lungs of mice, while the B. bronchiseptica Δwbm mutant showed almost no defect. While in vitro characteristics such as serum resistance may be attributable to O antigen directly, the role of O antigen during infection appears to be more complex, possibly involving factors differing among the closely related bordetellae or different interactions between each one and its host.

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DEMONSTRATION OF Cl-INHIBITOR COMPLEXES IN PLASMA BY HIGHLY SENSITIVE RADIOIMMUNOASSAYS USING A MONOCLONAL ANTIBODY AGAINST A NEODETERMINANT ON COMPLEXED Cl-INHIBITOR

10.1055/s-0038-1642902 ◽

1987 ◽

Author(s):

J H Nuijens ◽

C C M Huijbregets ◽

L G Thijs ◽

C E Hack

Keyword(s):

Monoclonal Antibody ◽

Contact System ◽

Factor Xii ◽

Optimal Conditions ◽

Spleen Cells ◽

Highly Sensitive ◽

Factor Xiia

Levels of factor XIIa- and kallikrein-Cl inhibitor (Cl-Inh) complexes in plasma reflect activation of the contact system in vivo. Here, we report the development of radioimmunoassays (RIAs) for these complexes using a monoclonal antibody (mAb K0K12) that reacts with a neodeterminant exposed on Cl-Inh after interaction with proteases. mAb K0K12 was obtained by a fusion experiment with spleen cells of a mouse hyperimmunized with Cl-Inh complexes.Experiments with purified Cl-Inh incubated with either Cls or elastase revealed that the determinant for mAb KOK12 is exposed on complexed as well as proteolytically inactivated (modified) Cl-Inh.Radioimmunoassays (RIAs) for the detection of factor Xlla-Cl-Inh and kallikrein-Cl-Inh complexes were performed as follows: mAb K0K12 was coupled to Sepharose and incubated with the sample to be tested. Binding of Cl-Inh complexes was detected by a subsequent incubation with 125I-antibodies against factor XII or (pre)kallikrein.With these RIAs, activation of 0.1% of factor XII or prekal-likrein in plasma is easily detected.Optimal conditions for blood sampling and processing were established, i.e. conditions that prevented any in vitro activation of factor XII and prekallikrein. Levels of factor XIIa-Cl-Inh and kallikrein-Cl-Inh complexes in plasma samples from normal donors were less than 0.1 U/ml (100 U/ml is the maximal amount of Cl-Inh complexes generated in pooled plasma by DXS). Considerably higher, and fluctuating levels were observed in patients with diseases such as septicaemia. These highly sensitive RIAs will facilitate studies concerning the role of the contact system in human pathophysiology.

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Role of Vitamin E and the Orexin System in Neuroprotection

Brain Sciences ◽

10.3390/brainsci11081098 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1098

Author(s):

Maria Ester La Torre ◽

Ines Villano ◽

Marcellino Monda ◽

Antonietta Messina ◽

Giuseppe Cibelli ◽

...

Keyword(s):

Vitamin E ◽

Neurodegenerative Diseases ◽

Antioxidant Properties ◽

Phenotypic Change ◽

The Central Nervous System ◽

Specific Receptors

Microglia are the first line of defense at the level of the central nervous system (CNS). Phenotypic change in microglia can be regulated by various factors, including the orexin system. Neuroinflammation is an inflammatory process mediated by cytokines, by the lack of interaction of specific receptors such as the OX2-OX2R complex, caused by systemic tissue damage or, more often, associated with direct damage to the CNS. Chronic activation of microglia could lead to long-term neurodegenerative diseases. This review aims to explore how tocopherol (vitamin E) and the orexin system may play a role in the prevention and treatment of microglia inflammation and, consequently, in neurodegenerative diseases thanks to its antioxidant properties. The results of animal and in vitro studies provide evidence to support the use of tocopherol for a reduction in microglia inflammation as well as a greater activation of the orexinergic system. Although there is much in vivo and in vitro evidence of vitamin E antioxidant and protective abilities, there are still conflicting results for its use as a treatment for neurodegenerative diseases that speculate that vitamin E, under certain conditions or genetic predispositions, can be pro-oxidant and harmful.

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Epigenetics in Neurodegenerative Diseases: The Role of Histone Deacetylases

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527317666181004155136 ◽

2019 ◽

Vol 18 (1) ◽

pp. 11-18 ◽

Cited By ~ 12

Author(s):

Sorabh Sharma ◽

K.C. Sarathlal ◽

Rajeev Taliyan

Keyword(s):

Neurodegenerative Diseases ◽

Histone Acetylation ◽

Histone Deacetylases ◽

Hdac Inhibitors ◽

Beneficial Effects ◽

In Vivo Animal Models ◽

Preclinical And Clinical Studies

Background & Objective: Imbalance in histone acetylation levels and consequently the dysfunction in transcription are associated with a wide variety of neurodegenerative diseases. Histone proteins acetylation and deacetylation is carried out by two opposite acting enzymes, histone acetyltransferases and histone deacetylases (HDACs), respectively. In-vitro and in-vivo animal models of neurodegenerative diseases and post mortem brains of patients have been reported overexpressed level of HDACs. In recent past numerous studies have indicated that HDAC inhibitors (HDACIs) might be a promising class of therapeutic agents for treating these devastating diseases. HDACs being a part of repressive complexes, the outcome of their inhibition has been attributed to enhanced gene expression due to heightened histone acetylation. Beneficial effects of HDACIs has been explored both in preclinical and clinical studies of these diseases. Thus, their screening as future therapeutics for neurodegenerative diseases has been widely explored. Conclusion: In this review, we focus on the putative role of HDACs in neurodegeneration and further discuss their potential as a new therapeutic avenue for treating neurodegenerative diseases.

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LRRK2 interacts with the vacuolar-type H+-ATPase pump a1 subunit to regulate lysosomal function

Human Molecular Genetics ◽

10.1093/hmg/ddz088 ◽

2019 ◽

Vol 28 (16) ◽

pp. 2696-2710 ◽

Cited By ~ 24

Author(s):

Rebecca Wallings ◽

Natalie Connor-Robson ◽

Richard Wade-Martins

Keyword(s):

Critical Role ◽

Substantia Nigra Pars Compacta ◽

Cellular Mechanisms ◽

Genomic Locus ◽

Lysosomal Dysfunction ◽

Lrrk2 G2019s ◽

Lrrk2 Kinase

Abstract Lysosomal dysfunction lies at the centre of the cellular mechanisms underlying Parkinson’s disease although the precise underlying mechanisms remain unknown. We investigated the role of leucine-rich repeat kinase 2 (LRRK2) on lysosome biology and the autophagy pathway in primary neurons expressing the human LRRK2-G2019S or LRKK2-R1441C mutant or the human wild-type (hWT-LRRK2) genomic locus. The expression of LRRK2-G2019S or hWT-LRRK2 inhibited autophagosome production, whereas LRRK2-R1441C induced a decrease in autophagosome/lysosome fusion and increased lysosomal pH. In vivo data from the cortex and substantia nigra pars compacta of aged LRRK2 transgenic animals revealed alterations in autophagosome puncta number reflecting those phenotypes seen in vitro. Using the two selective and potent LRRK2 kinase inhibitors, MLi-2 and PF-06447475, we demonstrated that the LRRK2-R1441C-mediated decrease in autolysosome maturation is not dependent on LRRK2 kinase activity. We showed that hWT-LRRK2 and LRRK2-G2019S bind to the a1 subunit of vATPase, which is abolished by the LRRK2-R1441C mutation, leading to a decrease in a1 protein and cellular mislocalization. Modulation of lysosomal zinc increased vATPase a1 protein levels and rescued the LRRK2-R1441C-mediated cellular phenotypes. Our work defines a novel interaction between the LRRK2 protein and the vATPase a1 subunit and demonstrates a mode of action by which drugs may rescue lysosomal dysfunction. These results demonstrate the importance of LRRK2 in lysosomal biology, as well as the critical role of the lysosome in PD.

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POSCAbilities: The Application of the Prion Organotypic Slice Culture Assay to Neurodegenerative Disease Research

Biomolecules ◽

10.3390/biom10071079 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1079

Author(s):

Hailey Pineau ◽

Valerie Sim

Keyword(s):

Neurodegenerative Diseases ◽

Prion Diseases ◽

In Vitro Models ◽

Slice Culture ◽

Advantages And Disadvantages ◽

Organotypic Slice Culture ◽

Drug Treatments

Prion diseases are fatal, transmissible neurodegenerative disorders whose pathogenesis is driven by the misfolding, self-templating and cell-to-cell spread of the prion protein. Other neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and Huntington’s disease, share some of these prion-like features, with different aggregation-prone proteins. Consequently, researchers have begun to apply prion-specific techniques, like the prion organotypic slice culture assay (POSCA), to these disorders. In this review we explore the ways in which the prion phenomenon has been used in organotypic cultures to study neurodegenerative diseases from the perspective of protein aggregation and spreading, strain propagation, the role of glia in pathogenesis, and efficacy of drug treatments. We also present an overview of the advantages and disadvantages of this culture system compared to in vivo and in vitro models and provide suggestions for new directions.

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Netrin 1-Mediated Role of the Substantia Nigra Pars Compacta and Ventral Tegmental Area in the Guidance of the Medial Habenular Axons

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.682067 ◽

2021 ◽

Vol 9 ◽

Author(s):

Verónica Company ◽

Abraham Andreu-Cervera ◽

M. Pilar Madrigal ◽

Belén Andrés ◽

Francisca Almagro-García ◽

...

Keyword(s):

Substantia Nigra ◽

Ventral Tegmental Area ◽

Dopaminergic Neurons ◽

Functional Organization ◽

Substantia Nigra Pars Compacta ◽

Fasciculus Retroflexus ◽

Ventral Tegmental

The fasciculus retroflexus is an important fascicle that mediates reward-related behaviors and is associated with different psychiatric diseases. It is the main habenular efference and constitutes a link between forebrain regions, the midbrain, and the rostral hindbrain. The proper functional organization of habenular circuitry requires complex molecular programs to control the wiring of the habenula during development. However, the mechanisms guiding the habenular axons toward their targets remain mostly unknown. Here, we demonstrate the role of the mesodiencephalic dopaminergic neurons (substantia nigra pars compacta and ventral tegmental area) as an intermediate target for the correct medial habenular axons navigation along the anteroposterior axis. These neuronal populations are distributed along the anteroposterior trajectory of these axons in the mesodiencephalic basal plate. Using in vitro and in vivo experiments, we determined that this navigation is the result of netrin 1 attraction generated by the mesodiencephalic dopaminergic neurons. This attraction is mediated by the receptor deleted in colorectal cancer (DCC), which is strongly expressed in the medial habenular axons. The increment in our knowledge on the fasciculus retroflexus trajectory guidance mechanisms opens the possibility of analyzing if its alteration in mental health patients could account for some of their symptoms.

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Influence of the microenvironment on the modulation of the host response by the typhoid toxin

10.1101/2020.06.04.133686 ◽

2020 ◽

Author(s):

Océane C.B. Martin ◽

Deborah Butter ◽

Eleni Paparouna ◽

Sofia D.P. Theodorou ◽

Maria M. Haykal ◽

...

Keyword(s):

Dna Damage ◽

Intestinal Inflammation ◽

Inflammatory Conditions ◽

Damage Response ◽

Health And Disease ◽

Inflammatory Bowel ◽

Typhoid Toxin

SummaryBacterial genotoxins cause DNA damage in eukaryotic cells, resulting in activation of the DNA damage response (DDR) in vitro. These toxins are produced by Gram negative bacteria, enriched in the microbiota of Inflammatory Bowel Disease (IBD) and colorectal cancer (CRC) patients. However, their role in infection remains poorly characterized. We have addressed the role of the typhoid toxin in the modulation of the host-microbial interaction in health and disease.Infection with a genotoxigenic Salmonella protected mice from intestinal inflammation. The toxin-induced DNA damage caused senescence in vivo, which was uncoupled from the inflammatory response, and associated with the maintenance of an anti-inflammatory environment. This effect was lost when infection occurred in mice suffering from inflammatory conditions that mimic Ulcerative Colitis, a form of IBD.These data highlight a complex context-dependent crosstalk between bacterial genotoxins-induced DDR and the host immune response, underlining an unexpected role for bacterial genotoxins.

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The role of mycotoxins in neurodegenerative diseases: current state of the art and future perspectives of research

Biological Chemistry ◽

10.1515/hsz-2021-0214 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Vu Thu Thuy Nguyen ◽

Svenja König ◽

Simone Eggert ◽

Kristina Endres ◽

Stefan Kins

Keyword(s):

Neurodegenerative Diseases ◽

Research Field ◽

Model Systems ◽

Fungal Metabolites ◽

Future Perspectives ◽

Adverse Health Effects ◽

Current State

Abstract Mycotoxins are fungal metabolites that can cause various diseases in humans and animals. The adverse health effects of mycotoxins such as liver failure, immune deficiency, and cancer are well-described. However, growing evidence suggests an additional link between these fungal metabolites and neurodegenerative diseases. Despite the wealth of these initial reports, reliable conclusions are still constrained by limited access to human patients and availability of suitable cell or animal model systems. This review summarizes knowledge on mycotoxins associated with neurodegenerative diseases and the assumed underlying pathophysiological mechanisms. The limitations of the common in vivo and in vitro experiments to identify the role of mycotoxins in neurotoxicity and thereby in neurodegenerative diseases are elucidated and possible future perspectives to further evolve this research field are presented.

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