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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.
Transl Neurodegener ; 13(1): 6, 2024 01 22.
Article in English | MEDLINE | ID: mdl-38247000

ABSTRACT

Neurodegenerative disorders present complex pathologies characterized by various interconnected factors, including the aggregation of misfolded proteins, oxidative stress, neuroinflammation and compromised blood-brain barrier (BBB) integrity. Addressing such multifaceted pathways necessitates the development of multi-target therapeutic strategies. Emerging research indicates that probucol, a historic lipid-lowering medication, offers substantial potential in the realm of neurodegenerative disease prevention and treatment. Preclinical investigations have unveiled multifaceted cellular effects of probucol, showcasing its remarkable antioxidative and anti-inflammatory properties, its ability to fortify the BBB and its direct influence on neural preservation and adaptability. These diverse effects collectively translate into enhancements in both motor and cognitive functions. This review provides a comprehensive overview of recent findings highlighting the efficacy of probucol and probucol-related compounds in the context of various neurodegenerative conditions, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and cognitive impairment associated with diabetes.


Subject(s)
Alzheimer Disease , Neurodegenerative Diseases , Parkinson Disease , Humans , Neurodegenerative Diseases/drug therapy , Probucol/therapeutic use , Blood-Brain Barrier
3.
Front Endocrinol (Lausanne) ; 14: 1224418, 2023.
Article in English | MEDLINE | ID: mdl-37850093

ABSTRACT

Introduction: Type 2 diabetes (T2D) is associated with chronic inflammation and neurovascular changes that lead to functional impairment and atrophy in neural-derived tissue. A reduction in retinal thickness is an early indicator of diabetic retinopathy (DR), with progressive loss of neuroglia corresponding to DR severity. The brain undergoes similar pathophysiological events as the retina, which contribute to T2D-related cognitive decline. Methods: This study explored the relationship between retinal thinning and cognitive decline in the LepR db/db model of T2D. Diabetic db/db and non-diabetic db/+ mice aged 14 and 28 weeks underwent cognitive testing in short and long-term memory domains and in vivo retinal imaging using optical coherence tomography (OCT), followed by plasma metabolic measures and ex vivo quantification of neuroinflammation, oxidative stress and microvascular leakage. Results: At 28 weeks, mice exhibited retinal thinning in the ganglion cell complex and inner nuclear layer, concomitant with diabetic insulin resistance, memory deficits, increased expression of inflammation markers and cerebrovascular leakage. Interestingly, alterations in retinal thickness at both experimental timepoints were correlated with cognitive decline and elevated immune response in the brain and retina. Discussion: These results suggest that changes in retinal thickness quantified with in vivo OCT imaging may be an indicator of diabetic cognitive dysfunction and neuroinflammation.


Subject(s)
Cognitive Dysfunction , Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Diabetic Retinopathy , Mice , Animals , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnostic imaging , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/diagnostic imaging , Diabetes Mellitus, Experimental/metabolism , Neuroinflammatory Diseases , Blood-Brain Barrier/metabolism , Retina , Diabetic Retinopathy/metabolism , Inflammation/diagnostic imaging , Inflammation/metabolism , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/etiology , Cognitive Dysfunction/metabolism
4.
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
5.
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
6.
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
7.
Genes Nutr ; 18(1): 2, 2023 Feb 25.
Article in English | MEDLINE | ID: mdl-36841786

ABSTRACT

Alzheimer's disease (AD) is a progressive neurodegenerative disorder pathologically characterized by brain parenchymal abundance of amyloid-beta (Aß) and the accumulation of lipofuscin material that is rich in neutral lipids. However, the mechanisms for aetiology of AD are presently not established. There is increasing evidence that metabolism of lipoprotein-Aß in blood is associated with AD risk, via a microvascular axis that features breakdown of the blood-brain barrier, extravasation of lipoprotein-Aß to brain parenchyme and thereafter heightened inflammation. A peripheral lipoprotein-Aß/capillary axis for AD reconciles alternate hypotheses for a vascular, or amyloid origin of disease, with amyloidosis being probably consequential. Dietary fats may markedly influence the plasma abundance of lipoprotein-Aß and by extension AD risk. Similarly, apolipoprotein E (Apo E) serves as the primary ligand by which lipoproteins are cleared from plasma via high-affinity receptors, for binding to extracellular matrices and thereafter for uptake of lipoprotein-Aß via resident inflammatory cells. The epsilon APOE ε4 isoform, a major risk factor for AD, is associated with delayed catabolism of lipoproteins and by extension may increase AD risk due to increased exposure to circulating lipoprotein-Aß and microvascular corruption.

8.
Anal Bioanal Chem ; 415(7): 1357-1369, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36705732

ABSTRACT

Despite its critical role in neurodevelopment and brain function, vitamin D (vit-D) homeostasis, metabolism, and kinetics within the central nervous system remain largely undetermined. Thus, it is of critical importance to establish an accurate, highly sensitive, and reproducible method to quantitate vit-D in brain tissue. Here, we present a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method and for the first time, demonstrate detection of seven major vit-D metabolites in brain tissues of C57BL/6J wild-type mice, namely 1,25(OH)2D3, 3-epi-1,25(OH)2D3, 1,25(OH)2D2, 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 24,25(OH)2D2. Chromatographic separation was achieved on a pentaflurophenyl column with 3 mM ammonium formate water/methanol [A] and 3 mM ammonium formate methanol/isopropanol [B] mobile phase components. Detection was by positive ion electrospray tandem mass spectrometry with the EVOQ elite triple quadrupole mass spectrometer with an Advance ultra-high-performance liquid chromatograph and online extraction system. Calibration standards of each metabolite prepared in brain matrices were used to validate the detection range, precision, accuracy, and recovery. Isotopically labelled analogues, 1,25(OH)2D3-d3, 25(OH)D3-c5, and 24,25(OH)2D3-d6, served as the internal standards for the closest molecular-related metabolite in all measurements. Standards between 1 fg/mL and 10 ng/mL were injected with a resulting linear range between 0.001 and 1 ng, with an LLOD and LLOQ of 1 pg/mL and 12.5 pg/mL, respectively. The intra-/inter-day precision and accuracy for measuring brain vit-D metabolites ranged between 0.12-11.53% and 0.28-9.11%, respectively. Recovery in acetonitrile ranged between 99.09 and 106.92% for all metabolites. Collectively, the sensitivity and efficiency of our method supersedes previously reported protocols used to measure vit-D and to our knowledge, the first protocol to reveal the abundance of 25(OH)D2, 1,25(OH)D2, and 24,25(OH)2D2, in brain tissue of any species. This technique may be important in supporting the future advancement of pre-clinical research into the function of vit-D in neurophysiological and neuropsychiatric disorders, and neurodegeneration.


Subject(s)
Methanol , Tandem Mass Spectrometry , Animals , Mice , Chromatography, Liquid/methods , Tandem Mass Spectrometry/methods , Mice, Inbred C57BL , Vitamin D , Vitamins , Brain
9.
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.

10.
Analyst ; 147(23): 5274-5282, 2022 Nov 21.
Article in English | MEDLINE | ID: mdl-36346247

ABSTRACT

Magnetic resonance imaging (MRI) is the gold standard method to study brain anatomy in vivo. Using MRI, subtle alterations to white matter structures in the brain are observed prior to cognitive decline associated with the ageing process, and neurodegenerative diseases such as Alzheimer's disease. Detection of such alterations provides hope for early clinical diagnosis. While MRI is essential to detect subtle alterations to brain structure in vivo, the technique is less suited to study and image the distribution of biochemical markers within specific brain structures. Consequently, the chemical changes that drive, or are associated with MRI-detectable alterations to white matter are not well understood. Herein, we describe (to the best of our knowledge) the first application of a complementary imaging approach that incorporates in vivo MRI with ex vivo Fourier transform infrared (FTIR) spectroscopic imaging on the same brain tissue. The combined workflow is used to detect and associate markers of altered biochemistry (FTIR) with anatomical changes to brain white matter (MRI). We have applied this combination of techniques to the senescence accelerated murine prone strain 8 (SAMP8) mouse model (n = 6 animals in each group, analysed across two ageing time points, 6 and 12 months). The results have demonstrated alterations to lipid composition and markers of disturbed metabolism during ageing are associated with loss of white matter volume.


Subject(s)
White Matter , Animals , Mice , White Matter/diagnostic imaging , White Matter/metabolism , White Matter/pathology , Brain Chemistry , Fourier Analysis , Spectroscopy, Fourier Transform Infrared , Brain/diagnostic imaging , Brain/pathology , Magnetic Resonance Imaging/methods , Aging , Neuroimaging
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
Pharm Res ; 38(9): 1477-1484, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34480263

ABSTRACT

The evidence shows that individuals with type-1 diabetes mellitus (T1DM) are at greater risk of accelerated cognitive impairment and dementia. Although, to date the mechanisms are largely unknown. An emerging body of literature indicates that dysfunction of cerebral neurovascular network and plasma dyshomeostasis of soluble amyloid-ß in association with impaired lipid metabolism are central to the onset and progression of cognitive deficits and dementia. However, the latter has not been extensively considered in T1DM. Therefore, in this review, we summarised the literature concerning altered lipid metabolism and cerebrovascular function in T1DM as an implication for potential pathways leading to cognitive decline and dementia.


Subject(s)
Cerebrovascular Disorders/metabolism , Cerebrovascular Disorders/pathology , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/pathology , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/pathology , Glucose/metabolism , Amyloid , Animals , Humans , Lipid Metabolism/physiology
18.
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
19.
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
20.
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.

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