Aluminium co-localises with Biondi ring tangles in Parkinson's disease and epilepsy.

Aluminium is known to accumulate in neuropathological hallmarks. However, such has only tentatively been suggested in Biondi ring tangles. Owing to their intracellular and filamentous structure rich in ß-pleated sheets, Biondi ring tangles might attract the adventitious binding of aluminium in regions of the blood-cerebrospinal fluid barrier. The study's objective was to establish whether aluminium co-localises with Biondi ring tangles in the brains of Parkinson's disease donors versus a donor that went on to develop late-onset epilepsy. Herein, we have performed immunohistochemistry for phosphorylated tau, complemented with aluminium-specific fluorescence microscopy in the choroid plexus of Parkinson's disease donors and in a donor that developed late-onset epilepsy. Aluminium co-localises with lipid-rich Biondi ring tangles in the choroid plexus. While Biondi ring tangles are not composed of phosphorylated tau, the latter is identified in nuclei of choroidal cells where aluminium and Biondi ring tangles are co-located. Although Biondi ring tangles are considered artefacts in imaging studies using positron emission tomography, their ability to bind aluminium and then release it upon their subsequent rupture and escape from choroidal cells may allow for a mechanism that may propagate for aluminium toxicity in vivo.

Update on the Inactivation Procedures for the Vaccine Development Prospects of a New Highly Virulent RGNNV Isolate.

Viral nervous necrosis (VNN) caused by the nervous necrosis virus (NNV) affects a broad range of primarily marine fish species, with mass mortality rates often seen among larvae and juveniles. Its genetic diversification may hinder the effective implementation of preventive measures such as vaccines. The present study describes different inactivation procedures for developing an inactivated vaccine against a new NNV isolate confirmed to possess deadly effects upon the European seabass (Dicentrarchus labrax), an important Mediterranean farmed fish species that is highly susceptible to this disease. First, an NNV isolate from seabass adults diagnosed with VNN was rescued and the sequences of its two genome segments (RNA1 and RNA2) were classified into the red-spotted grouper NNV (RGNNV) genotype, closely clustering to the highly pathogenic 283.2009 isolate. The testing of different inactivation procedures revealed that the virus particles of this isolate showed a marked resistance to heat (for at least 60 °C for 120 min with and without 1% BSA) but that they were fully inactivated by 3 mJ/cm2 UV-C irradiation and 24 h 0.2% formalin treatment, which stood out as promising NNV-inactivation procedures for potential vaccine candidates. Therefore, these procedures are feasible, effective, and rapid response strategies for VNN control in aquaculture.

Aluminum and Tau in Neurofibrillary Tangles in Familial Alzheimer's Disease.

BACKGROUND: Familial Alzheimer's disease (fAD) is driven by genetic predispositions affecting the expression and metabolism of the amyloid-ß protein precursor. Aluminum is a non-essential yet biologically-reactive metal implicated in the etiology of AD. Recent research has identified aluminum intricately and unequivocally associated with amyloid-ß in senile plaques and, more tentatively, co-deposited with neuropil-like threads in the brains of a Colombian cohort of donors with fAD. OBJECTIVE: Herein, we have assessed the co-localization of aluminum to immunolabelled phosphorylated tau to probe the potential preferential binding of aluminum to senile plaques or neurofibrillary tangles in the same Colombian kindred. METHODS: Herein, we have performed phosphorylated tau-specific immunolabelling followed by aluminum-specific fluorescence microscopy of the identical brain tissue sections via a sequential labelling method. RESULTS: Aluminum was co-localized with immunoreactive phosphorylated tau in the brains of donors with fAD. While aluminum was predominantly co-located to neurofibrillary tangles in the temporal cortex, aluminum was more frequently co-deposited with cortical senile plaques. CONCLUSION: These data suggest that the co-deposition of aluminum with amyloid-ß precedes that with neurofibrillary tangles. Extracellularly deposited amyloid-ß may also be more immediately available to bind aluminum versus intracellular aggregates of tau. Therapeutic approaches to reduce tau have demonstrated the amelioration of its synergistic interactions with amyloid-ß, ultimately reducing tau pathology and reducing neuronal loss. These data support the intricate associations of aluminum in the neuropathology of fAD, of which its subsequent reduction may further therapeutic benefits observed in ongoing clinical trials in vivo.

CERTL reduces C16 ceramide, amyloid-ß levels, and inflammation in a model of Alzheimer's disease.

BACKGROUND: Dysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-ß (Aß) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain. METHODS: A plasmid expressing CERTL, the long isoform of CERTs, was used to study the interaction of CERTL with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERTL protein was employed to study interaction of CERTL with amyloid-ß (Aß), Aß aggregation process in presence of CERTL, and the resulting changes in Aß toxicity in neuroblastoma cells. CERTL was overexpressed in neurons by adeno-associated virus (AAV) in a mouse model of familial AD (5xFAD). Ten weeks after transduction, animals were challenged with behavior tests for memory, anxiety, and locomotion. At week 12, brains were investigated for sphingolipid levels by mass spectrometry, plaques, and neuroinflammation by immunohistochemistry, gene expression, and/or immunoassay. RESULTS: Here, we report that CERTL binds to APP, modifies Aß aggregation, and reduces Aß neurotoxicity in vitro. Furthermore, we show that intracortical injection of AAV, mediating the expression of CERTL, decreases levels of ceramide d18:1/16:0 and increases sphingomyelin levels in the brain of male 5xFAD mice. CERTL in vivo over-expression has a mild effect on animal locomotion, decreases Aß formation, and modulates microglia by decreasing their pro-inflammatory phenotype. CONCLUSION: Our results demonstrate a crucial role of CERTL in regulating ceramide levels in the brain, in amyloid plaque formation and neuroinflammation, thereby opening research avenues for therapeutic targets of AD and other neurodegenerative diseases.

Aluminum and Neurofibrillary Tangle Co-Localization in Familial Alzheimer's Disease and Related Neurological Disorders.

BACKGROUND: Protein misfolding disorders are frequently implicated in neurodegenerative conditions. Familial Alzheimer's disease (fAD) is an early-onset and aggressive form of Alzheimer's disease (AD), driven through autosomal dominant mutations in genes encoding the amyloid precursor protein and presenilins 1 and 2. The incidence of epilepsy is higher in AD patients with shared neuropathological hallmarks in both disease states, including the formation of neurofibrillary tangles. Similarly, in Parkinson's disease, dementia onset is known to follow neurofibrillary tangle deposition. OBJECTIVE: Human exposure to aluminum has been linked to the etiology of neurodegenerative conditions and recent studies have demonstrated a high level of co-localization between amyloid-ß and aluminum in fAD. In contrast, in a donor exposed to high levels of aluminum later developing late-onset epilepsy, aluminum and neurofibrillary tangles were found to deposit independently. Herein, we sought to identify aluminum and neurofibrillary tangles in fAD, Parkinson's disease, and epilepsy donors. METHODS: Aluminum-specific fluorescence microscopy was used to identify aluminum in neurofibrillary tangles in human brain tissue. RESULTS: We observed aluminum and neurofibrillary-like tangles in identical cells in all respective disease states. Co-deposition varied across brain regions, with aluminum and neurofibrillary tangles depositing in different cellular locations of the same cell. CONCLUSION: Neurofibrillary tangle deposition closely follows cognitive-decline, and in epilepsy, tau phosphorylation associates with increased mossy fiber sprouting and seizure onset. Therefore, the presence of aluminum in these cells may exacerbate the accumulation and misfolding of amyloidogenic proteins including hyperphosphorylated tau in fAD, epilepsy, and Parkinson's disease.

Imaging of aluminium and amyloid ß in neurodegenerative disease.

OBJECTIVES: Recent research has confirmed the presence of aluminium in human brain tissue. Quantitative analyses suggest increased brain aluminium content in a number of neurodegenerative diseases including familial Alzheimer's disease, congophilic amyloid angiopathy, epilepsy and autism. Complementary aluminium-specific fluorescence microscopy identifies the location of aluminium in human brain tissue and demonstrates significant differences in distribution between diseases. Herein we combine these approaches in investigating associations between aluminium in human brain tissue and specific disease-associated neuropathologies. METHODS: We have used aluminium-specific fluorescence microscopy, Congo red staining using light and polarised light and thioflavin S fluorescence microscopy on serial sections of brain tissues to identify co-localisation of aluminium and amyloid ß and tau neuropathology. RESULTS: A combination of light, polarised and fluorescence microscopy demonstrates an intimate relationship between aluminium and amyloid ß in familial Alzheimer's disease but not in other conditions and diseases, such as congophilic amyloid angiopathy and autism. We demonstrate preliminary evidence of amyloid ß pathology, including associations with vasculature and parenchymal tissues, in autism in tissues heavily loaded with aluminium. CONCLUSION: We suggest that complementary aluminium-specific fluorescence microscopy may reveal important information about the putative toxicity of aluminium in neurodegenerative and neurodevelopmental disorders.

Self-plasticized, lumogallion-based fluorescent optical sensor for the determination of aluminium (III) with ultra-low detection limits.

Aluminium-selective ion optical sensor based on covalently attached lumogallion methacrylate was synthesized and investigated in this study. Lumogallion based derivatives were copolymerized with various methacrylate monomers via a simple one step free radical polymerization to produce a "self-plasticized" copolymer. We demonstrate that covalently attached lumogallion moieties provide adequate functionality to the optical film thus achieving a very simple, one component sensing membrane. Fluorescence experiments demonstrated excellent sensitivity towards aluminium (III) ions with the detection limits found at 4.8 × 10-12 M. Furthermore, proposed sensor displays high selectivity towards aluminium over a number of biologically relevant cations. Moreover, the synthesized copolymer was used for the fabrication of nanoparticles that exhibit strong fluorescence upon contact with aluminium (III) ions. It is anticipated that lumogallion-based copolymers may form the basis for the development of highly sensitive and robust aluminium selective sensors capable of in situ measurements.

Aluminum and Amyloid-ß in Familial Alzheimer's Disease.

Genetic predispositions associated with metabolism of the amyloid-ß protein precursor underlie familial Alzheimer's disease; a form of dementia characterized by early disease onset and elevated levels of cortical amyloid-ß. Human exposure to aluminum is linked to the etiology of Alzheimer's disease and recent research measured a high content of aluminum in brain tissue in familial Alzheimer's disease. To elaborate upon this finding, we have obtained brain tissues from a Colombian cohort of donors with familial Alzheimer's disease. We have used established methods to measure the aluminum content of these tissues and we have compared the data with a recently measured dataset for control brain tissues. We report significantly higher levels of aluminum in brain tissues in donors with familial Alzheimer's disease than in control tissues from donors without neurological impairment or neurodegeneration. We have used aluminum-specific fluorescence microscopy along with complementary imaging for amyloid-ß to demonstrate a very high degree of co-localization of these two risk factors in brain tissue in familial Alzheimer's disease. Aluminum and amyloid-ß were co-located in senile plaques as well as vasculature, the latter resembling cerebral amyloid angiopathy. Aluminum was also found separately from amyloid-ß in intracellular compartments including glia and neuronal axons. The research has identified an arguably unique association between high brain aluminum content and amyloid-ß and allows postulation that genetic predispositions defining familial Alzheimer's disease underlie this relationship.

Detection of aluminum in lumbar spinal cord of sheep subcutaneously inoculated with aluminum-hydroxide containing products.

The use of vaccines containing aluminum (Al) adjuvants is widespread in ovine production. Al adjuvants induce an effective immune-response but lead to the formation of post-vaccination granulomas from which Al can disseminate. This work aims to study the accumulation of Al in the central nervous system of sheep subcutaneously inoculated with Al-hydroxide containing products. Lumbar spinal cord and parietal lobe from 21 animals inoculated with 19 doses of Vaccine (n = 7), Adjuvant-only (n = 7) or phosphate-buffered saline as Control (n = 7) were analyzed with transversely heated graphite furnace atomic absorption spectroscopy and lumogallion staining for Al analytical measurements and Al tisular localization respectively. In the lumbar spinal cord, Al median content was higher in both the Adjuvant-only and Vaccine group (p = .001) compared with the Control group. Animals of the Adjuvant-only group showed the higher individual measurements in the lumbar spinal cord (14.36 µg/g and 7.83 µg/g). In the parietal lobe, Al median content tended to be higher in the Adjuvant-only group compared with Control group (p = .074). Except for three replicates of the Adjuvant-only group, Al content was always below 1 µg/g. In the lumbar spinal cord, lumogallion-reactive Al deposits were more abundant in the gray matter than in the white matter in both Vaccine (p = .034) and Adjuvant-only groups (p = .017) and Al deposits were mostly associated with glial-like cells (p = .042). In the parietal lobe, few Al deposits, which were sometimes related to blood vessels, were found. In sheep, Al-hydroxide adjuvants inoculated in the subcutaneous tissue selectively accumulate in the lumbar spinal cord.

The interaction of aluminium-based adjuvants with THP-1 macrophages in vitro: Implications for cellular survival and systemic translocation.

Within clinical vaccinations, recombinant antigens are routinely entrapped inside or adsorbed onto the surface of aluminium salts in order to increase their immunological potency in vivo. The efficacy of these immunisations is highly dependent upon the recognition and uptake of these complexes by professional phagocytes and their subsequent delivery to the draining lymph nodes for further immunological processing. While monocytes have been shown to internalise aluminium adjuvants and their adsorbates, the role of macrophages in this respect has not been fully established. Furthermore, this study explored the interaction of THP-1 macrophages with aluminium-based adjuvants (ABAs) and how this relationship influenced the survival of such cells in vitro. THP-1 macrophages were exposed to low concentrations of ABAs (1.7 µg/mL Al) for a maximum of seven days. ABA uptake was determined using lumogallion staining and cell viability by both DAPI (4',6-diamidino-2-phenylindole) staining and LDH (lactate dehydrogenase) assay. Evidence of ABA particle loading was identified within cells at early junctures following treatment and appeared to be quite prolific (>90% cells positive for Al signal after 24 h). Total sample viability (% LDH release) in treated samples was predominantly similar to untreated cells and low levels of cellular death were consistently observed in populations positive for Al uptake. It can thus be concluded that aluminium salts can persist for some time within the intracellular environment of these cells without adversely affecting their viability. These results imply that macrophages may play a role in the systemic translocation of ABAs once administered in the form of an inoculation.

Correction to: Unequivocal imaging of aluminium in human cells and tissues by an improved method using morin.

After publication of our article, it has come to our attention that our Conflict of Interest statement should read.

Correction to: Aluminium in human brain tissue: how much is too much?

The authors declare.

Unequivocal imaging of aluminium in human cells and tissues by an improved method using morin.

Aluminium is biologically reactive and its ability to potentiate the immune response has driven its inclusion in both veterinary and human vaccines. Consequently, the need for unequivocal visualisation of aluminium in vivo has created a focused research effort to establish fluorescent molecular probes for this purpose. The most commonly used direct fluorescent labels for the detection of aluminium are morin (2',3,4',5,7-pentahydroxyflavone) and lumogallion [4-chloro-3-(2,4-dihydroxyphenylazo)-2-hydroxybenzene-1-sulphonic acid]. While the former has gained popularity in the detection of aluminium in plants and predominantly within root tips, the latter boasts greater sensitivity and selectivity for the detection of aluminium in human cells and tissues. Herein, we have developed a simplified morin staining protocol using the autofluorescence quenching agent, Sudan Black B. This modified protocol improves tissue morphology and increases analytical sensitivity, which allows intracellular aluminium to be detected in monocytes and when co-localised with senile plaques in human brain tissue of donors diagnosed with familial Alzheimer's disease. Overall, our results demonstrate a simple approach to minimise false positives in the use of morin to unequivocally detect aluminium in vivo.

Aluminium in human brain tissue: how much is too much?

A burgeoning body of research confirms and affirms the presence of aluminium in human brain tissue. Recently, the first data on aluminium content of brain tissue from donors with diagnoses of familial Alzheimer's disease, autism spectrum disorder, multiple sclerosis and epilepsy have been published. Quantitative data are supported by aluminium-specific fluorescence microscopy identifying the locations of aluminium in human brain tissue. The challenge in the future will be to confirm or refute the role played by brain aluminium intoxication in human neurodegenerative disease.

Aluminium in Brain Tissue in Epilepsy: A Case Report from Camelford.

(1) Introduction: Human exposure to aluminium is a burgeoning problem. In 1988, the population of the Cornish town of Camelford was exposed to exceedingly high levels of aluminium in their potable water supply. Herein we provide evidence that aluminium played a role in the death of a Camelford resident following development of late-onset epilepsy. (2) Case summary: We have measured the aluminium content of brain tissue in this individual and demonstrated significant accumulations of aluminium in the hippocampus (4.35 (2.80) µg/g dry wt.) and the occipital lobe (2.22 (2.23) µg/g dry wt., mean, SD, n = 5), the latter being associated with abnormal calcifications. Aluminium-specific fluorescence microscopy confirmed the presence of aluminium in both of these tissues and made the consistent observation of aluminium-loaded glial cells in close proximity to aluminium-rich cell/neuronal debris. These observations support an inflammatory component in this case of late-onset epilepsy. Congo red failed to identify any amyloid deposits in any tissue while thioflavin S showed extensive extracellular and intracellular tau pathologies. (3) Discussion: We present the first data showing aluminium in brain tissue in epilepsy and suggest, in light of complementary evidence from scientific literature, the first evidence that aluminium played a role in the advent of this case of late-onset adult epilepsy.

Intracellular Aluminium in Inflammatory and Glial Cells in Cerebral Amyloid Angiopathy: A Case Report.

(1) Introduction: In 2006, we reported on very high levels of aluminium in brain tissue in an unusual case of cerebral amyloid angiopathy (CAA). The individual concerned had been exposed to extremely high levels of aluminium in their potable water due to a notorious pollution incident in Camelford, Cornwall, in the United Kingdom. The recent development of aluminium-specific fluorescence microscopy has now allowed for the location of aluminium in this brain to be identified. (2) Case Summary: We used aluminium-specific fluorescence microscopy in parallel with Congo red staining and polarised light to identify the location of aluminium and amyloid in brain tissue from an individual who had died from a rare and unusual case of CAA. Aluminium was almost exclusively intracellular and predominantly in inflammatory and glial cells including microglia, astrocytes, lymphocytes and cells lining the choroid plexus. Complementary staining with Congo red demonstrated that aluminium and amyloid were not co-located in these tissues. (3) Discussion: The observation of predominantly intracellular aluminium in these tissues was novel and something similar has only previously been observed in cases of autism. The results suggest a strong inflammatory component in this case and support a role for aluminium in this rare and unusual case of CAA.

Granulomas Following Subcutaneous Injection With Aluminum Adjuvant-Containing Products in Sheep.

The use of vaccines including aluminum (Al)-based adjuvants is widespread among small ruminants and other animals. They are associated with the appearance of transient injection site nodules corresponding to granulomas. This study aims to characterize the morphology of these granulomas, to understand the role of the Al adjuvant in their genesis, and to establish the presence of the metal in regional lymph nodes. A total of 84 male neutered lambs were selected and divided into 3 treatment groups of 28 animals each: (1) vaccine (containing Al-based adjuvant), (2) adjuvant-only, and (3) control. A total of 19 subcutaneous injections were performed in a time frame of 15 months. Granulomas and regional lymph nodes were evaluated by clinicopathological means. All of the vaccine and 92.3% of the adjuvant-only lambs presented injection-site granulomas; the granulomas were more numerous in the group administered the vaccine. Bacterial culture in granulomas was always negative. Histologically, granulomas in the vaccine group presented a higher degree of severity. Al was specifically identified by lumogallion staining in granulomas and lymph nodes. Al median content was significantly higher ( P < .001) in the lymph nodes of the vaccine group (82.65 µg/g) compared with both adjuvant-only (2.53 µg/g) and control groups (0.96 µg/g). Scanning transmission electron microscopy demonstrated aggregates of Al within macrophages in vaccine and adjuvant-only groups. In these two groups, Al-based adjuvants induce persistent, sterile, subcutaneous granulomas with macrophage-driven translocation of Al to regional lymph nodes. Local translocation of Al may induce further accumulation in distant tissues and be related to the appearance of systemic signs.

Unraveling the enigma: elucidating the relationship between the physicochemical properties of aluminium-based adjuvants and their immunological mechanisms of action.

Aluminium salts are by far the most commonly used adjuvants in vaccines. There are only two aluminium salts which are used in clinically-approved vaccines, Alhydrogel® and AdjuPhos®, while the novel aluminium adjuvant used in Gardasil® is a sulphated version of the latter. We have investigated the physicochemical properties of these two aluminium adjuvants and specifically in milieus approximating to both vaccine vehicles and the composition of injection sites. Additionally we have used a monocytic cell line to establish the relationship between their physicochemical properties and their internalisation and cytotoxicity. We emphasise that aluminium adjuvants used in clinically approved vaccines are chemically and biologically dissimilar with concomitantly potentially distinct roles in vaccine-related adverse events.

Aluminium in Brain Tissue in Multiple Sclerosis.

Multiple sclerosis (MS) is a devastating and debilitating neurodegenerative disease of unknown cause. A consensus suggests the involvement of both genetic and environmental factors of which the latter may involve human exposure to aluminium. There are no data on the content and distribution of aluminium in human brain tissue in MS. The aluminium content of brain tissue from 14 donors with a diagnosis of MS was determined by transversely heated graphite furnace atomic absorption spectrometry. The location of aluminium in the brain tissue of two donors was investigated by aluminium-specific fluorescence microscopy. The aluminium content of brain tissue in MS was universally high with many tissues bearing concentrations in excess of 10 µg/g dry wt. (10 ppm) and some exceeding 50 ppm. There were no statistically significant relationships between brain lobes, donor age or donor gender. Aluminium-specific fluorescence successfully identified aluminium in brain tissue in both intracellular and extracellular locations. The association of aluminium with corpora amylacea suggests a role for aluminium in neurodegeneration in MS.