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1.
Front Neurosci ; 18: 1376282, 2024.
Article in English | MEDLINE | ID: mdl-38686331

ABSTRACT

Migraine is one of the world's most debilitating disorders, and it has recently been shown that changes in the retina can be a potential biomarker for the disease. These changes can be detected by optical coherence tomography (OCT), which measures retinal thickness, and optical coherence tomography angiography (OCTA), which measures vessel density. We searched the databases Google Scholar, ProQuest, Scopus, and Web of Science for studies in English using OCT and OCTA in migraineurs, using the search terms "optical coherence tomography," "OCT," "optical coherence tomography angiography," "OCTA" and "migraine." We found 73 primary studies, 11 reviews, and 8 meta-analyses pertaining to OCT and OCTA findings in migraineurs. They showed that migraineurs had reduced retinal thickness (via OCT), retinal vessel density, and greater foveal avascular zone area (via OCTA) than controls. OCTA changes reflect a perfusion compromise occurring in migraineurs as opposed to in healthy controls. OCT and OCTA deficits were worse in migraine-with-aura and chronic migraine than in migraine-without-aura and episodic migraine. Certain areas of the eye, such as the fovea, may be more vulnerable to these perfusion changes than other parts. Direct comparison between study findings is difficult because of the heterogeneity between the studies in terms of both methodology and analysis. Moreover, as almost all case-control studies were cross-sectional, more longitudinal cohort studies are needed to determine cause and effect between migraine pathophysiology and OCT/OCTA findings. Current evidence suggests both OCT and OCTA may serve as retinal markers for migraineurs, and further research in this field will hopefully enable us to better understand the vascular changes associated with migraine, perhaps also providing a new diagnostic and therapeutic biomarker.

2.
Neurotherapeutics ; 20(4): 1198-1214, 2023 07.
Article in English | MEDLINE | ID: mdl-37226029

ABSTRACT

Increased expression of the voltage-gated potassium channel Kv1.3 in activated microglia, and the subsequent release of pro-inflammatory mediators, are closely associated with the progression of Alzheimer's disease (AD). Studies have shown that reducing neuroinflammation through the non-selective blockade of microglial Kv1.3 has the potential to improve cognitive function in mouse models of familial AD. We have previously demonstrated that a potent and highly-selective peptide blocker of Kv1.3, HsTX1[R14A], not only entered the brain parenchyma after peripheral administration in a lipopolysaccharide (LPS)-induced mouse model of inflammation, but also significantly reduced pro-inflammatory mediator release from activated microglia. In this study, we show that microglial expression of Kv1.3 is increased in senescence accelerated mice (SAMP8), an animal model of sporadic AD, and that subcutaneous dosing of HsTX1[R14A] (1 mg/kg) every other day for 8 weeks provided a robust improvement in cognitive deficits in SAMP8 mice. The effect of HsTX1[R14A] on the whole brain was assessed using transcriptomics, which revealed that the expression of genes associated with inflammation, neuron differentiation, synapse function, learning and memory were altered by HsTX1[R14A] treatment. Further study is required to investigate whether these changes are downstream effects of microglial Kv1.3 blockade or a result of alternative mechanisms, including any potential effect of Kv1.3 blockade on other brain cell types. Nonetheless, these results collectively demonstrate the cognitive benefits of Kv1.3 blockade with HsTX1[R14A] in a mouse model of sporadic AD, demonstrating its potential as a therapeutic candidate for this neurodegenerative disease.


Subject(s)
Alzheimer Disease , Neurodegenerative Diseases , Mice , Animals , Peptides/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Disease Models, Animal , Inflammation , Cognition
3.
J Alzheimers Dis ; 93(2): 653-664, 2023.
Article in English | MEDLINE | ID: mdl-37066906

ABSTRACT

BACKGROUND: Obesity is linked to a higher incidence of Alzheimer's disease (AD). Studies show that plasma amyloid-ß (Aß) dyshomeostasis, particularly low 42/40 ratio indicates a heightened risk for developing AD. However, the relationship between body mass index (BMI) and circulating plasma Aß has not been extensively studied. OBJECTIVE: We hypothesized that people with a high BMI have altered plasma Aß homeostasis compared with people with a lower BMI. We also tested whether reducing BMI by calorie-restriction could normalize plasma concentrations of Aß. METHODS: Plasma concentrations of Aß40, Aß42, and Aß42/40 ratio were measured in 106 participants with BMIs classified as lean, overweight, or obese. From this cohort, twelve participants with overweight or obese BMIs entered a 12-week calorie-restriction weight loss program. We then tested whether decreasing BMI affected plasma Aß concentrations. RESULTS: Plasma Aß42/40 ratio was 17.54% lower in participants with an obese BMI compared to lean participants (p < 0.0001), and 11.76% lower compared to participants with an overweight BMI (p < 0.0001). The weight loss regimen decreased BMI by an average of 4.02% (p = 0.0005) and was associated with a 6.5% decrease in plasma Aß40 (p = 0.0425). However, weight loss showed negligible correlations with plasma Aß40, Aß42, and Aß42/40 ratio. CONCLUSION: Obesity is associated with aberrant plasma Aß homeostasis which may be associated with an increased risk for AD. Weight loss appears to lower Aß40, but large-scale longitudinal studies in addition to molecular studies are required to elucidate the underlying mechanisms of how obesity and weight loss influence plasma Aß homeostasis.


Subject(s)
Amyloid beta-Peptides , Overweight , Humans , Alzheimer Disease , Amyloid beta-Peptides/blood , Biomarkers , Body Mass Index , Obesity/blood , Obesity/complications , Overweight/blood , Overweight/complications , Peptide Fragments
4.
Front Endocrinol (Lausanne) ; 14: 1127481, 2023.
Article in English | MEDLINE | ID: mdl-36875491

ABSTRACT

There is increasing evidence of a positive association of type 2 diabetes with Alzheimer's disease (AD), the most prevalent form of dementia. Suggested pathways include cerebral vascular dysfunction; central insulin resistance, or exaggerated brain abundance of potentially cytotoxic amyloid-ß (Aß), a hallmark feature of AD. However, contemporary studies find that Aß is secreted in the periphery by lipogenic organs and secreted as nascent triglyceride-rich lipoproteins (TRL's). Pre-clinical models show that exaggerated abundance in blood of TRL-Aß compromises blood-brain barrier (BBB) integrity, resulting in extravasation of the TRL-Aß moiety to brain parenchyme, neurovascular inflammation and neuronal degeneration concomitant with cognitive decline. Inhibiting secretion of TRL-Aß by peripheral lipogenic organs attenuates the early-AD phenotype indicated in animal models, consistent with causality. Poorly controlled type 2 diabetes commonly features hypertriglyceridemia because of exaggerated TRL secretion and reduced rates of catabolism. Alzheimer's in diabetes may therefore be a consequence of heightened abundance in blood of lipoprotein-Aß and accelerated breakdown of the BBB. This review reconciles the prevailing dogma of amyloid associated cytotoxicity as a primary risk factor in late-onset AD, with substantial evidence of a microvascular axis for dementia-in-diabetes. Consideration of potentially relevant pharmacotherapies to treat insulin resistance, dyslipidaemia and by extension plasma amyloidemia in type 2 diabetes are discussed.


Subject(s)
Alzheimer Disease , Autoimmune Diseases , Diabetes Mellitus, Type 2 , Insulin Resistance , Animals , Amyloidogenic Proteins , Lipoproteins , Amyloid beta-Peptides
5.
BMC Neurol ; 23(1): 122, 2023 Mar 27.
Article in English | MEDLINE | ID: mdl-36973718

ABSTRACT

BACKGROUND: Migraine is a common and distressing neurological condition characterised by recurrent throbbing headaches, nausea and heightened sensitivity to light and sound. Accumulating evidence suggests that cerebral arteries dilate during migraine, causing distal microvessels to constrict, which could activate nociceptors and cause onset of headache pain. If so, preventing or attenuating chronic microvascular constriction, and promoting a dilatory phenotype, may reduce frequency and/or severity of migraines. The primary aim of the L-Arginine and Aged Garlic Extract (LARGE) trial is to investigate whether oral treatment with dietary nutraceuticals, L-arginine and aged garlic extract (AGE), both systemic vasodilatory agents, will alleviate migraine frequency, duration and severity in adults with chronic frequent episodic migraines. METHODS: The study is a randomised double-blind placebo-controlled phase-II single-site clinical trial conducted in Perth, Australia. The target sample is to recruit 240 participants diagnosed with chronic frequent episodic migraines between 18 and 80 years of age. Participants will be randomised to one of four treatment groups for 14 weeks (placebo induction for 2 weeks, followed by 12 weeks on one of the respective treatment arms): placebo, L-arginine, AGE, or a combination of L-arginine and AGE. The doses of L-arginine and AGE are 1.5 g and 1 g daily, respectively. The primary outcome is to assess migraine response using change in migraine frequency and intensity between baseline and 12 weeks. Secondary outcomes include the impact of L-arginine and/or AGE on photosensitivity, retinal vessel changes, and blood biomarker concentrations of vascular tone, following a 12-week intervention. DISCUSSION: The protocol describes the oral administration of 2 nutraceutical-based interventions as possible prophylactic treatments for chronic frequent episodic migraines, with potential for direct clinical translation of outcomes. Potential limitations of the study include the fixed-dose design of each treatment arm and that in vivo neuroimaging methods, such as magnetic resonance imaging (MRI), will not be conducted to determine putative cerebro-vasodilatory changes to coincide with the outcome measures. Dose-response studies may be indicated. TRIAL REGISTRATION: The trial was retrospectively registered with the Australian New Zealand Clinical Trials Registry ACTRN12621001476820 (Universal Trial Number: U1111-1268-1117) on 04/08/2021. This is protocol version 1, submitted on 25/11/2022.


Subject(s)
Garlic , Migraine Disorders , Treatment Outcome , Australia/epidemiology , Migraine Disorders/drug therapy , Migraine Disorders/prevention & control , Migraine Disorders/diagnosis , Headache , Double-Blind Method , Randomized Controlled Trials as Topic , Clinical Trials, Phase II as Topic
6.
Front Pain Res (Lausanne) ; 3: 1057830, 2022.
Article in English | MEDLINE | ID: mdl-36466216

ABSTRACT

Endometriosis is a complex and potentially debilitating condition that has major impact on quality of life. There is emerging evidence that biological compounds found in garlic (Allium sativum) may be effective for attenuating endometrial pain. Suggested mechanisms for efficacy include modulation of inflammation and potent antioxidant effects. Aged-garlic-extract (AGE) is a centuries old process describing ethanolic extracts of garlic bulbs for 12-20 months. The AGE formulation realised contains a complex array of stabilised biologics with significant immunomodulatory effects relevant to inflammatory conditions. This perspective article puts forward a hypothesis that AGE should be considered as a prophylactic to manage endometrial pain.

8.
BMJ Open ; 12(2): e058826, 2022 Feb 21.
Article in English | MEDLINE | ID: mdl-35190446

ABSTRACT

INTRODUCTION: Preclinical, clinical and epidemiological studies support the hypothesis that aberrant systemic metabolism of amyloid beta (Aß) in the peripheral circulation is causally related to the development of Alzheimer's disease (AD). Specifically, recent studies suggest that increased plasma concentrations of lipoprotein-Aß compromise the brain microvasculature, resulting in extravasation and retention of the lipoprotein-Aß moiety. The latter results in an inflammatory response and neurodegeneration ensues. Probucol, a historic cholesterol-lowering drug, has been shown in murine models to suppress lipoprotein-Aß secretion, concomitant with maintaining blood-brain-barrier function, suppressing neurovascular inflammation and supporting cognitive function. This protocol details the probucol in Alzheimer's study, a drug intervention trial investigating if probucol has potential to attenuate cognitive decline, delay brain atrophy and reduce cerebral amyloid burden in patients with mild-to-moderate AD. METHODS AND ANALYSIS: The study is a phase II, randomised, placebo-controlled, double-blind single-site clinical trial held in Perth, Australia. The target sample is 314 participants with mild-to-moderate AD. Participants will be recruited and randomised (1:1) to a 104-week intervention consisting of placebo induction for 2 weeks followed by 102 weeks of probucol (Lorelco) or placebo. The primary outcome is changed in cognitive performance determined via the Alzheimer's Disease Assessment Scales-Cognitive Subscale test between baseline and 104 weeks. Secondary outcomes measures will be the change in brain structure and function, cerebral amyloid load, quality of life, and the safety and tolerability of Lorelco, after a 104week intervention. ETHICS AND DISSEMINATION: The study has been approved by the Bellberry Limited Human Research Ethics Committee (approval number: HREC2019-11-1063; Version 4, 6 October 2021). Informed consent will be obtained from participants prior to any study procedures being performed. The investigator group will disseminate study findings through peer-reviewed publications, key conferences and local stakeholder events. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12621000726853).


Subject(s)
Alzheimer Disease , Probucol , Amyloid beta-Peptides/metabolism , Animals , Australia , Clinical Trials, Phase II as Topic , Cognition , Double-Blind Method , Humans , Mice , Probucol/pharmacology , Probucol/therapeutic use , Quality of Life , Randomized Controlled Trials as Topic , Treatment Outcome
9.
Curr Opin Endocrinol Diabetes Obes ; 29(2): 101-105, 2022 04 01.
Article in English | MEDLINE | ID: mdl-34845160

ABSTRACT

PURPOSE OF REVIEW: To summarize recent findings considering type II diabetes, or metabolic syndrome dyslipidaemia with risk for Alzheimer's disease. RECENT FINDINGS: Population, genetic, clinical and preclinical studies support the hypothesis of increased risk for Alzheimer's disease in type 2 diabetes mellitus. The mechanisms are unclear. However, recent studies suggest that aberrations in the peripheral metabolism of triglyceride-rich-lipoproteins compromise the brain microvasculature. SUMMARY: We review the literature of prediabetic metabolic syndrome and type 2 diabetes mellitus as a risk factor for Alzheimer's disease. We focus on a potential association with aberrations in the systemic metabolism of triglyceride-rich-lipoproteins reported over 18 months.


Subject(s)
Alzheimer Disease , Diabetes Mellitus, Type 2 , Hyperlipidemias , Hypertriglyceridemia , Metabolic Syndrome , Alzheimer Disease/complications , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Humans , Hyperlipidemias/complications , Hypertriglyceridemia/complications , Lipoproteins/metabolism , Metabolic Syndrome/complications , Triglycerides
11.
Nutr Neurosci ; 25(11): 2398-2407, 2022 Nov.
Article in English | MEDLINE | ID: mdl-34549671

ABSTRACT

Background: The ingestion of combinatory Alcohol Mixed with Energy Drink (AMED) beverages continues to increase markedly, particularly among young adults. Some studies suggest detrimental health effects related to the combination of alcohol with energy drink formulations; however, the consumption of AMED has not been investigated in context of the cerebral microvasculature or neuroinflammation. We hypothesized that cerebral capillary integrity and glial cells are particularly vulnerable to the combination of AMED.Methods:12-week old wild-type C57BL/6J mice were orally gavaged with either vehicle (water), alcohol (vodka), an energy drink (MotherTM), or a combination AMED, daily for five days. Thereafter, mice were sacrificed, blood alcohol concentrations were analysed and cryosections of brain specimens were subjected to confocal immunofluorescent analysis for measures of cerebral capillary integrity via immunoglobulin G (IgG), and markers of neuroinflammation, ionized-calcium-binding-adaptor-molecule 1 (Iba1) and Glial-Fibrillary-Acidic-Protein (GFAP). Proinflammatory cytokines, IL-2, IL-17A, IFN-ϒ, and anti-inflammatory cytokines, IL-4, IL-6 and IL-10, were also measured in serum.Results: Consistent with previous studies, cerebral capillary dysfunction and astroglial cell activation were markedly greater in the alcohol-only group (AO); however, the AO-induced effects were profoundly attenuated with the AMED combination. Mice maintained on AO and AMED interventions exhibited a moderate increase in microglial recruitment. There were no significant changes in pro-inflammatory nor anti-inflammatory cytokines in ED or AMED treated mice.Conclusion: This study suggests that paradoxically the acute detrimental effects of alcohol on cerebral capillary integrity and astrogliosis are counteracted with the co-provision of an ED, rich in caffeine and taurine and containing B-group vitamins.


Subject(s)
Energy Drinks , Mice , Animals , Neuroinflammatory Diseases , Alcohol Drinking/psychology , Mice, Inbred C57BL , Ethanol , Cytokines
12.
Eur J Clin Nutr ; 76(2): 317-319, 2022 02.
Article in English | MEDLINE | ID: mdl-34302129

ABSTRACT

A 74-year-old female subject with suboptimal management of episodic tension headache was treated with a daily dose of 1.5 g L-arginine and 1.2 g aged garlic extract (AGE). The aim of the intervention was to promote vasodilation of parenchymal cerebral blood vessels. Within 6 weeks of commencing treatment, her self-reported symptoms improved markedly and were sustained at 2 years following commencement. We propose that the putative beneficial effect of L-arginine and AGE in this patient is because of the well-established systemic vasodilatory effects of L-arginine and aged garlic extract. On the hypothesis that migraine is precipitated by cerebral microvascular constriction, we recommend a double-blind randomised controlled trial to clinically test this hypothesis in migraine patients.


Subject(s)
Garlic , Tension-Type Headache , Aged , Arginine/pharmacology , Arginine/therapeutic use , Dietary Supplements , Double-Blind Method , Female , Humans , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Tension-Type Headache/drug therapy , Treatment Outcome
13.
Nutrients ; 13(12)2021 Nov 26.
Article in English | MEDLINE | ID: mdl-34959820

ABSTRACT

Brown adipose tissue (BAT) activation is associated with increased energy expenditure by inducing non-shivering thermogenesis. The ingestion of a milk fat globule membrane (MFGM) supplement and a high calorie diet are reported gateways into BAT activation. However, little is known about the effect of the MFGM and high calorie diets on BAT volume. To gain insight into this, mice were maintained on a high-fat (HF) or low-fat (LF) diet in conjunction with either full-cream (FC) or skim bovine dairy milk (BDM). After being maintained on their respective diets for 13 weeks, their body composition, including BAT volume, was measured using X-ray microtomography. A high calorie diet resulted in an increase in the BAT volume and mice consuming an HF diet in conjunction with FC BDM had a significantly greater BAT volume than all the other groups. Conversely, mice consuming an HF diet in addition to skim milk had a lower BAT volume compared to the HF control. The data presented suggest that the consumption of a high calorie diet in conjunction with FC BDM increases the BAT volume in wild-type mice. This study may provide valuable insight into future studies investigating BAT volume and BAT activity in relation to environmental factors, including diet.


Subject(s)
Adipose Tissue, Brown/drug effects , Body Composition/drug effects , Eating/drug effects , Glycolipids/administration & dosage , Glycoproteins/administration & dosage , Milk/chemistry , Animals , Cattle , Diet, Fat-Restricted/methods , Diet, High-Fat/methods , Lipid Droplets , Lipids/administration & dosage , Mice , Thermogenesis/drug effects
14.
PLoS Biol ; 19(9): e3001358, 2021 09.
Article in English | MEDLINE | ID: mdl-34520451

ABSTRACT

Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippocampal-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides/biosynthesis , Hepatocytes/metabolism , Amyloid beta-Peptides/genetics , Animals , Blood-Brain Barrier/pathology , Brain/blood supply , Capillaries/pathology , Disease Models, Animal , Humans , Inflammation , Learning , Lipoproteins/metabolism , Male , Mice, Transgenic , Nerve Degeneration
15.
Pharmaceutics ; 13(8)2021 Aug 08.
Article in English | MEDLINE | ID: mdl-34452184

ABSTRACT

Probucol (PB) is a highly lipophilic drug with potential protective effects on pancreatic ß-cells from inflammation and oxidation. PB has poor bioavailability and solubility, and despite many attempts, significant improvement in antidiabetic effects or absorption has yet to be discovered. Recently, the role of bile acids has been established in significant drug formulation stabilisation effects and as cell-penetrating agents. Promising results in pharmaceutical formulation studies on drug stability and release patterns when lithocholic acid (LCA) is conjugated with PB and sodium alginate (SA) have been demonstrated. Thus, this study aimed to develop and characterise PB microcapsules incorporating LCA and examine the biological effects of the microcapsules in vitro and in vivo. PB/LCA microcapsules were prepared using an encapsulation method, ionic gelation vibrational jet flow technology. LCA incorporation in PB microcapsules showed positive effects on ß-cells with improved insulin release, antioxidant activity, and PB intracellular uptake. Diabetic mice gavaged LCA-PB microcapsules showed a significant reduction in diabetes signs and symptoms, better survival rate, reduced blood glucose levels, and pro-inflammatory cytokines, with an increase PB level in blood and tissues suggesting a potential therapy for treating diabetes mellitus.

16.
PLoS One ; 16(6): e0243858, 2021.
Article in English | MEDLINE | ID: mdl-34138862

ABSTRACT

BACKGROUND: Cannabidiol (CBD) confers therapeutic effects in some neurological disorders via modulation of inflammatory, oxidative and cell-signalling pathways. However, CBD is lipophilic and highly photooxidative with low oral bioavailability in plasma and brain. In this study, we aimed to design and test a CBD microencapsulation method as a drug delivery strategy to improve the absorption of CBD. Additionally, we evaluated the brain uptake of CBD capsules when administered alongside capsules containing a permeation-modifying bile acid, deoxycholic acid (DCA). METHODS: Microcapsules containing either CBD or DCA were formed using the ionic gelation method with 1.5% sodium alginate formulations and 100 mM calcium chloride. C57BL/6J wild type mice randomly assigned to three treatment groups (3-4 mice per group) were administered CBD in the following preparations: 1) CBD capsules, 2) CBD capsules + DCA capsules and 3) naked CBD oil (control). To assess the short-term bioavailability of CBD, plasma and brain samples were collected at 0.3, 1 and 3 hours post administration and CBD levels were analysed with liquid chromatography mass spectrometer. RESULTS: We produced spherical capsules at 400 ± 50 µm in size. The CBD capsules were calculated to have a drug loading of 2% and an encapsulation efficiency of 23%. Mice that received CBD capsules + DCA capsules showed a 40% and 47% increase in CBD plasma concentration compared to mice on CBD capsules and naked CBD oil, respectively. Furthermore, the CBD capsules + DCA capsules group showed a 48% and 25% increase in CBD brain concentration compared to mice on CBD capsules and naked CBD oil, respectively. In mice treated with CBD capsules + DCA capsules, the brain CBD concentration peaked at 0.3 hours with a 300% increased availability compared to CBD capsules and naked CBD oil groups, which peaked at 1 hour after administration. CONCLUSIONS: The microencapsulation method combined with a permeation enhancer, DCA increased the short-term bioavailability of CBD in plasma and brain.


Subject(s)
Alginates/chemistry , Cannabidiol/chemistry , Cannabidiol/pharmacokinetics , Deoxycholic Acid/administration & dosage , Drug Carriers/chemistry , Administration, Oral , Animals , Biological Availability , Cannabidiol/administration & dosage , Capsules , Male , Mice
17.
Yakugaku Zasshi ; 141(6): 835-842, 2021.
Article in Japanese | MEDLINE | ID: mdl-34078791

ABSTRACT

Dementia has no cure and is an international health crisis. In addition to the immeasurable loss of QOL caused by dementia, the global economic cost is predicted to reach $2 trillion (USD) by 2030. Although much remains unknown about the biochemical pathways driving cognitive decline and memory loss during dementia, metals have been implicated in neurodegenerative disease. For example, total levels of Fe and Cu increase, which has been proposed to drive oxidative stress; and Fe, Cu, and Zn can bind amyloid-ß, catalysing aggregation and formation of amyloid plaques. Unfortunately, despite these known facets through which metal ions may induce pathology, studies in greater detail have been hampered by a lack of microscopy methods to directly visualise metal ions, and their chemical form, within brain cells. Herein we report the use of synchrotron X-ray fluorescence microscopy to simultaneously image Fe, Cu, and Zn within neurons in ex vivo brain tissue sections. Using animal models of dementia, we now demonstrate for the first time that despite global increases in brain metal content and metal ion accumulation within amyloid plaques, key brain regions may also become metal ion deficient. Such deficiency could contribute to cognitive decline because of the essential roles metal ions play in neurotransmitter synthesis and energy metabolism. These recent findings are discussed in the context of memory loss, and the impact that metal ion dis-homeostasis may have on diagnostic and therapeutic development.


Subject(s)
Dementia/etiology , Dementia/metabolism , Hippocampus/metabolism , Metals/metabolism , Amyloid beta-Peptides/metabolism , Animals , Copper/metabolism , Dementia/psychology , Disease Models, Animal , Energy Metabolism , Humans , Ions , Iron/metabolism , Memory , Mice , Microscopy, Fluorescence , Neurotransmitter Agents/metabolism , Protein Binding , Proteostasis Deficiencies/etiology , Zinc/metabolism
18.
Front Neurosci ; 15: 617221, 2021.
Article in English | MEDLINE | ID: mdl-33935625

ABSTRACT

BACKGROUND: An increase in blood brain barrier permeability commonly precedes neuro-inflammation and cognitive impairment in models of dementia. Common methods to estimate capillary permeability have potential confounders, or require laborious and subjective semi-manual analysis. NEW METHOD: Here we used snap frozen mouse and rat brain sections that were double-immunofluorescent labeled for immunoglobulin G (IgG; plasma protein) and laminin-α4 (capillary basement membrane). A Machine Learning Image Analysis program (Zeiss ZEN Intellisis) was trained to recognize and segment laminin-α4 to equivocally identify blood vessels in large sets of images. An IgG subclass based on a threshold intensity was segmented and quantitated only in extravascular regions. The residual parenchymal IgG fluorescence is indicative of blood-to-brain extravasation of IgG and was accurately quantitated. RESULTS: Automated machine-learning and threshold based segmentation of only parenchymal IgG extravasation accentuates otherwise indistinct capillary permeability, particularly frequent in minor BBB leakage. Comparison with Existing Methods: Large datasets can be processed and analyzed quickly and robustly to provide an overview of vascular permeability throughout the brain. All human bias or ambiguity involved in classifying and measuring leakage is removed. CONCLUSION: Here we describe a fast and precise method of visualizing and quantitating BBB permeability in mouse and rat brain tissue, while avoiding the confounding influence of unphysiological conditions such as perfusion and eliminating any human related bias from analysis.

19.
Front Nutr ; 8: 668514, 2021.
Article in English | MEDLINE | ID: mdl-34012975

ABSTRACT

Energy drinks containing significant quantities of caffeine and sugar are increasingly consumed, particularly by adolescents and young adults. Chronic ingestion of energy drinks may potentially regulate vascular risk factors. This study investigated the effects of chronic ingestion of energy drinks on blood-brain barrier (BBB) integrity and neuroinflammation. Male C57BL/6J mice were maintained on water (control), MotherTM (ED), sugar-free MotherTM (sfED), or Coca ColaTM soft drink (SD) for 13 weeks. The BBB integrity and neuroinflammation were analyzed with semi-quantitative immunofluorescent microscopy. Blood pressure, plasma inflammatory cytokine levels and blood glucose were also considered. Following 13 weeks of intervention, mice treated with ED, sfED, and SD showed significant disruption of BBB. However, marked neuroinflammation was observed only in sfED group mice. The consumption of ED and sfED significantly altered the blood pressure and plasma concentrations of inflammatory cytokines, TNF-a, IL-4, IL-6, and IL-10, and both increased plasma glucose. Correlation analyses showed significant associations between BBB dysfunction and hypotension, hyperglycaemia and cytokine dyshomeostasis. The intake of energy drink, particularly the sugar free formulation, may compromise the integrity of BBB and induce neuroinflammation via hypotension, hyperglycaemia and inflammatory pathways.

20.
Nutrients ; 13(4)2021 Apr 06.
Article in English | MEDLINE | ID: mdl-33917297

ABSTRACT

Energy drinks containing significant quantities of caffeine, taurine and sugar are increasingly consumed, particularly by adolescents and young adults. The putative effects of chronic ingestion of either standard energy drink, MotherTM (ED), or its sugar-free formulation (sfED) on metabolic syndrome were determined in wild-type C57BL/6J mice, in comparison to a soft drink, Coca-Cola (SD), a Western-styled diet enriched in saturated fatty acids (SFA), and a combination of SFA + ED. Following 13 weeks of intervention, mice treated with ED were hyperglycaemic and hypertriglyceridaemic, indicating higher triglyceride glucose index, which was similar to the mice maintained on SD. Surprisingly, the mice maintained on sfED also showed signs of insulin resistance with hyperglycaemia, hypertriglyceridaemia, and greater triglyceride glucose index, comparable to the ED group mice. In addition, the ED mice had greater adiposity primarily due to the increase in white adipose tissue, although the body weight was comparable to the control mice receiving only water. The mice maintained on SFA diet exhibited significantly greater weight gain, body fat, cholesterol and insulin, whilst blood glucose and triglyceride concentrations remained comparable to the control mice. Collectively, these data suggest that the consumption of both standard and sugar-free forms of energy drinks induces metabolic syndrome, particularly insulin resistance.


Subject(s)
Carbonated Beverages/adverse effects , Diet, Western/adverse effects , Energy Drinks/adverse effects , Metabolic Syndrome/etiology , Adipose Tissue, White/physiopathology , Adiposity/physiology , Animals , Blood Glucose/analysis , Body Weight , Disease Models, Animal , Fatty Acids/administration & dosage , Fatty Acids/adverse effects , Humans , Male , Metabolic Syndrome/blood , Metabolic Syndrome/diagnosis , Metabolic Syndrome/physiopathology , Mice , Mice, Inbred C57BL , Sweetening Agents/adverse effects , Triglycerides/blood
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