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1.
Sci Adv ; 10(2): eadi8287, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38198537

ABSTRACT

Parkinson's disease (PD) is characterized pathologically by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Whether cell types beyond DA neurons in the SN show vulnerability in PD remains unclear. Through transcriptomic profiling of 315,867 high-quality single nuclei in the SN from individuals with and without PD, we identified cell clusters representing various neuron types, glia, endothelial cells, pericytes, fibroblasts, and T cells and investigated cell type-dependent alterations in gene expression in PD. Notably, a unique neuron cluster marked by the expression of RIT2, a PD risk gene, also displayed vulnerability in PD. We validated RIT2-enriched neurons in midbrain organoids and the mouse SN. Our results demonstrated distinct transcriptomic signatures of the RIT2-enriched neurons in the human SN and implicated reduced RIT2 expression in the pathogenesis of PD. Our study sheds light on the diversity of cell types, including DA neurons, in the SN and the complexity of molecular and cellular changes associated with PD pathogenesis.


Subject(s)
Endothelial Cells , Parkinson Disease , Humans , Animals , Mice , Parkinson Disease/genetics , Substantia Nigra , Dopaminergic Neurons , Neuroglia
2.
Front Aging Neurosci ; 14: 1019942, 2022.
Article in English | MEDLINE | ID: mdl-36583187

ABSTRACT

Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disease affecting approximately 50 million people worldwide. It is estimated to reach 152 million by the year 2050. AD is the fifth leading cause of death among Americans age 65 and older. In spite of the significant burden the disease imposes upon patients, their families, our society, and our healthcare system, there is currently no cure for AD. The existing approved therapies only temporarily alleviate some of the disease's symptoms, but are unable to modulate the onset and/or progression of the disease. Our failure in developing a cure for AD is attributable, in part, to the multifactorial complexity underlying AD pathophysiology. Nonetheless, the lack of successful pharmacological approaches has led to the consideration of alternative strategies that may help delay the onset and progression of AD. There is increasing recognition that certain dietary and nutrition factors may play important roles in protecting against select key AD pathologies. Consistent with this, select nutraceuticals and phytochemical compounds have demonstrated anti-amyloidogenic, antioxidative, anti-inflammatory, and neurotrophic properties and as such, could serve as lead candidates for further novel AD therapeutic developments. Here we summarize some of the more promising dietary phytochemicals, particularly polyphenols that have been shown to positively modulate some of the important AD pathogenesis aspects, such as reducing ß-amyloid plaques and neurofibrillary tangles formation, AD-induced oxidative stress, neuroinflammation, and synapse loss. We also discuss the recent development of potential contribution of gut microbiome in dietary polyphenol function.

4.
Mol Neurodegener ; 17(1): 17, 2022 03 02.
Article in English | MEDLINE | ID: mdl-35236372

ABSTRACT

Alzheimer's disease (AD) is the most common form of dementia, characterized by progressive cognitive impairment and neurodegeneration. Extensive clinical and genomic studies have revealed biomarkers, risk factors, pathways, and targets of AD in the past decade. However, the exact molecular basis of AD development and progression remains elusive. The emerging single-cell sequencing technology can potentially provide cell-level insights into the disease. Here we systematically review the state-of-the-art bioinformatics approaches to analyze single-cell sequencing data and their applications to AD in 14 major directions, including 1) quality control and normalization, 2) dimension reduction and feature extraction, 3) cell clustering analysis, 4) cell type inference and annotation, 5) differential expression, 6) trajectory inference, 7) copy number variation analysis, 8) integration of single-cell multi-omics, 9) epigenomic analysis, 10) gene network inference, 11) prioritization of cell subpopulations, 12) integrative analysis of human and mouse sc-RNA-seq data, 13) spatial transcriptomics, and 14) comparison of single cell AD mouse model studies and single cell human AD studies. We also address challenges in using human postmortem and mouse tissues and outline future developments in single cell sequencing data analysis. Importantly, we have implemented our recommended workflow for each major analytic direction and applied them to a large single nucleus RNA-sequencing (snRNA-seq) dataset in AD. Key analytic results are reported while the scripts and the data are shared with the research community through  GitHub. In summary, this comprehensive review provides insights into various approaches to analyze single cell sequencing data and offers specific guidelines for study design and a variety of analytic directions. The review and the accompanied software tools will serve as a valuable resource for studying cellular and molecular mechanisms of AD, other diseases, or biological systems at the single cell level.


Subject(s)
Alzheimer Disease , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Animals , Computational Biology , DNA Copy Number Variations , Data Analysis , Mice , Single-Cell Analysis/methods
5.
J Infect Chemother ; 28(1): 6-9, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34702637

ABSTRACT

EPIDEMIOLOGY AND PATHOGENESIS: Urinary tract infection (UTI) in patients with neurogenic bladder causes significant morbidity and mortality. DIAGNOSIS: UTI in neurogenic bladder causes atypical symptomatology. Urine tests are pivotal in confirming or excluding UTI, and in guiding appropriate antibiotic treatment. TREATMENT: 1. Symptomatic UTI warrants appropriate antibiotic treatment with reference to culture results and local antibiotic resistance patterns. Asymptomatic bacteriuria should not be treated, and antibiotic prophylaxis is generally not recommended.2. Adequate bladder drainage is essential in reducing the occurrence of urinary tract infections.3. Recurrent UTI in neurogenic bladder may necessitate the treatment of neurogenic detrusor overactivity and the restoration of low bladder pressure during bladder storage and voiding by drugs or surgery.


Subject(s)
Bacteriuria , Sexually Transmitted Diseases , Urinary Bladder, Neurogenic , Urinary Tract Infections , Anti-Bacterial Agents/therapeutic use , Bacteriuria/drug therapy , Humans , Urinary Tract Infections/drug therapy
6.
Life Sci ; 292: 119797, 2022 Mar 01.
Article in English | MEDLINE | ID: mdl-34237311

ABSTRACT

AIMS: We investigated whether the consumption of Concord grape juice (CGJ) was associated with increased bioavailability of serum metabolites and their potential impact on cognitive performance in Veterans with Gulf War Illness (GWI). MAIN METHODS: Twenty-six veterans were selected from a cohort of 36 enrolled in a 24-week randomized, double-blind, Phase I/IIA clinical trial exploring whether the consumption of Concord grape juice (CGJ) was tolerable and safe in Veterans with GWI and improved cognitive function and fatigue. These 26 veterans were selected based on their completion of the entire 24-week protocol and documented adherence to the study beverage ≥80%. Differences in serum metabolite levels between CGJ and placebo at midpoint and endpoint were evaluated using two-way repeated measures ANOVA with post hoc Sidak's multiple comparison test. Bivariate correlations to assess for possible relationships between change in serum metabolite levels and change in cognitive function as measured by the Halstead Category Test-Russell Revised Version (RCAT) were also conducted. KEY FINDINGS: Seventy-six metabolites were identified and quantified in this study, with three (cyanidin-glucuronide, me-cyanidin-glucuronide, and me-malvidin-glucuronide) found to be significantly higher (p < 0.05) in the CGJ group compared to placebo at 24 weeks. Significant associations between changes in cognitive function and changes in serum levels of epicatechin-sulphate (r = 0.48, p = 0.01) and petunidin-glucuronide (r = 0.53, p < 0.01) from baseline to 24 weeks were also observed. SIGNIFICANCE: Our data suggest that dietary supplementation with CGJ is associated with increased bioavailability of specific phenolic metabolites, some of which may be correlated with cognitive performance.


Subject(s)
Cognition/drug effects , Dietary Supplements/analysis , Persian Gulf Syndrome/drug therapy , Polyphenols , Biological Availability , Female , Humans , Male , Middle Aged , Polyphenols/pharmacokinetics , Polyphenols/pharmacology , Veterans , Vitis/metabolism
8.
Asia Pac J Clin Oncol ; 17 Suppl 3: 48-54, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33860643

ABSTRACT

AIM: In response to the fast-developing coronavirus disease 2019 (COVID-19) pandemic, special arrangement and coordination are urgently required in the interdisciplinary care of patients across different medical specialties. This article provides recommendations on the management of different stages of localized or metastatic prostate cancer (PC) amid this pandemic. METHODS: The Hong Kong Urological Association and Hong Kong Society of Uro-oncology formed a joint discussion panel, which consisted of six urologists and six clinical oncologists with extensive experience in the public and private sectors. Following an evidence-based approach, the latest relevant publications were searched and reviewed, before proceeding to a structured discussion of relevant clinical issues. RESULTS: The joint panel provided recommendations for PC management during the pandemic, in terms of general considerations, diagnostic procedures, different disease stages, treatment modules, patient support, and interdisciplinary collaboration. The overall goal was to minimize the risk of infection while avoiding unnecessary delays and compromises in management outcomes. Practical issues during the pandemic were addressed such as the use of invasive diagnostic procedures, robotic-assisted laparoscopic prostatectomy, hypofractionated radiotherapy, and prolonged androgen deprivation therapy. The recommendations were explicated in the context of Hong Kong, a highly populated international city, in relation to the latest international guidelines and evidence. CONCLUSION: A range of recommendations on the management of PC patients during the COVID-19 pandemic was developed. Urologists, oncologists, and physicians treating PC patients may refer to them as practical guidance.


Subject(s)
COVID-19/epidemiology , Prostatic Neoplasms/therapy , SARS-CoV-2 , Androgen Antagonists/therapeutic use , Hong Kong/epidemiology , Humans , Male , Medical Oncology , Prostatectomy , Prostatic Neoplasms/pathology , Societies, Medical
9.
Asia Pac J Clin Oncol ; 17 Suppl 3: 12-26, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33860645

ABSTRACT

BACKGROUND: To update the Hong Kong Urological Association-Hong Kong Society of Uro-Oncology consensus statements on the management of advanced prostate cancer, the same panelists as in the previous consensus panel held a series of meetings to discuss updated clinical evidence and experiences. METHODS: The previous consensus statements were retained, deleted, or revised, and new statements were added. At the final meeting, all statements were reviewed and amended as appropriate, followed by panel voting. RESULTS: There were significant changes and additions to the previous consensus statements, primarily driven by the advances in androgen receptor signaling inhibitors, treatment sequencing in metastatic castration-resistant prostate cancer, and increasing recognition of oligometastatic prostate cancer since the introduction of prostate-specific membrane antigen positron emission tomography. In this update, a total of 59 consensus statements were accepted and established. CONCLUSIONS: The consensus panel updated consensus statements on the management of advanced prostate cancer, aiming to allow physicians in the region to keep abreast of the recent evidence on optimal clinical practices.


Subject(s)
Prostatic Neoplasms/therapy , Urology/methods , History, 21st Century , Hong Kong , Humans , Male , Prostatic Neoplasms/pathology
10.
Sci Adv ; 7(2)2021 01.
Article in English | MEDLINE | ID: mdl-33523961

ABSTRACT

Alzheimer's disease (AD), the most common form of dementia, is recognized as a heterogeneous disease with diverse pathophysiologic mechanisms. In this study, we interrogate the molecular heterogeneity of AD by analyzing 1543 transcriptomes across five brain regions in two AD cohorts using an integrative network approach. We identify three major molecular subtypes of AD corresponding to different combinations of multiple dysregulated pathways, such as susceptibility to tau-mediated neurodegeneration, amyloid-ß neuroinflammation, synaptic signaling, immune activity, mitochondria organization, and myelination. Multiscale network analysis reveals subtype-specific drivers such as GABRB2, LRP10, MSN, PLP1, and ATP6V1A We further demonstrate that variations between existing AD mouse models recapitulate a certain degree of subtype heterogeneity, which may partially explain why a vast majority of drugs that succeeded in specific mouse models do not align with generalized human trials across all AD subtypes. Therefore, subtyping patients with AD is a critical step toward precision medicine for this devastating disease.


Subject(s)
Alzheimer Disease , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Brain/metabolism , Humans , Mice , RNA/metabolism , Sequence Analysis, RNA , tau Proteins/metabolism
11.
Neuron ; 109(2): 257-272.e14, 2021 01 20.
Article in English | MEDLINE | ID: mdl-33238137

ABSTRACT

To identify the molecular mechanisms and novel therapeutic targets of late-onset Alzheimer's Disease (LOAD), we performed an integrative network analysis of multi-omics profiling of four cortical areas across 364 donors with varying cognitive and neuropathological phenotypes. Our analyses revealed thousands of molecular changes and uncovered neuronal gene subnetworks as the most dysregulated in LOAD. ATP6V1A was identified as a key regulator of a top-ranked neuronal subnetwork, and its role in disease-related processes was evaluated through CRISPR-based manipulation in human induced pluripotent stem cell-derived neurons and RNAi-based knockdown in Drosophila models. Neuronal impairment and neurodegeneration caused by ATP6V1A deficit were improved by a repositioned compound, NCH-51. This study provides not only a global landscape but also detailed signaling circuits of complex molecular interactions in key brain regions affected by LOAD, and the resulting network models will serve as a blueprint for developing next-generation therapeutic agents against LOAD.


Subject(s)
Alzheimer Disease/genetics , Alzheimer Disease/therapy , Brain/physiology , Databases, Genetic , Gene Regulatory Networks/physiology , Signal Transduction/physiology , Alzheimer Disease/pathology , Animals , Animals, Genetically Modified , Brain/pathology , Databases, Genetic/trends , Drosophila melanogaster , Female , Humans , Induced Pluripotent Stem Cells/physiology , Male , Sequence Analysis, RNA/methods
12.
Front Neurosci ; 14: 398, 2020.
Article in English | MEDLINE | ID: mdl-32431588

ABSTRACT

Misfolding, aggregation and deposition of α-synuclein (α-syn) are major pathologic characteristics of Parkinson's disease (PD) and the related synucleinopathy, multiple system atrophy (MSA). The spread of α-syn pathology across brain regions is thought to play a key role in the onset and progression of clinical phenotypes. Thus, there is increasing interest in developing strategies that target and attenuate α-syn aggregation and spread. Recent studies of brain-penetrating polyphenolic acids, namely, 3-hydroxybenzoic acid (3-HBA), 3,4-dihydroxybenzoic acid (3,4-diHBA), and 3-(3-hydroxyphenyl)propionic acid (3-HPPA) that are derived from gut microbiota metabolism of dietary polyphenols, show in vitro ability to effectively modulate α-syn misfolding, oligomerization, and mediate aggregated α-syn neurotoxicity. Here we investigate whether 3-HBA, 4-hydroxybenzoic acid (4-HBA), 3,4-diHBA, or 3-HPPA interfere with α-syn spreading in a cell-based system. Using HEK293 cells overexpressing α-syn-A53T-CFP/YFP, we assessed α-syn seeding activity using Fluorescence Resonance Energy Transfer (FRET) to detect and quantify α-syn aggregation. We demonstrated that 3-HPPA, 3,4-diHBA, 3-HBA, and 4-HBA significantly attenuated intracellular α-syn seeding aggregation. To determine whether our compounds could inhibit brain-derived seeding activity, we utilized insoluble α-syn extracted from post-mortem MSA or PD brain specimens. We found that 3-HPPA effectively attenuated MSA-induced aggregation of monomer into high molecular weight aggregates capable of inducing intracellular aggregation. Outcomes from our studies suggest interactions between gut microbiome and certain dietary factors may form the basis for effective therapies that modulate pathologic α-syn propagation. Collectively, our findings provide the basis for future developments of probiotic, prebiotic, or synbiotic approaches for modulating the onset and/or progression of α-synucleinopathies.

13.
Article in English | MEDLINE | ID: mdl-32438639

ABSTRACT

Approximately 30 percent of U.S. veterans deployed during the Gulf War (1990-1991) have been diagnosed with Gulf War Illness (GWI), a chronic multi-symptom disorder without widely available specific treatments. We investigated whether the consumption of Concord grape juice (CGJ), rich in anti-inflammatory flavonoids, would be tolerated and safe in individuals with GWI and explored improvement in cognitive function and fatigue. Thirty-six veterans with GWI enrolled in a 24-week randomized, double-blind, Phase I/IIA clinical trial to explore safety, tolerability, and feasibility of 16 ounces daily of commercially available CGJ compared to placebo. Participants completed neurocognitive tests and self-reported surveys at baseline, 12 and 24 weeks. Thirty-one participants (86%) completed the study; no dropouts were related to side effects. Thirty participants (83%) documented ≥80% adherence. There were no statistically significant unadjusted differences between CGJ and placebo groups in change in efficacy measures from baseline to endpoint. We employed general linear regression models controlling for baseline differences between groups which indicated statistically significant improvement in the Halstead Category Test-Russell Revised Version (RCAT) at endpoint in the CGJ group compared to placebo (8.4 points, p = 0.04). Other measures of cognitive functioning did not indicate significant improvements in the adjusted analyses (p-values: 0.09-0.32), nor did the fatigue variable (p = 0.67). CGJ was safe and well-tolerated by veterans with GWI. Our data suggest high tolerability and potential benefit from CGJ in veterans with GWI and can be used to inform future studies of efficacy.


Subject(s)
Dietary Supplements , Persian Gulf Syndrome , Veterans , Vitis , Cognition Disorders/therapy , Double-Blind Method , Fatigue/therapy , Female , Gulf War , Humans , Male , Middle Aged , Persian Gulf Syndrome/therapy
16.
Asia Pac J Clin Oncol ; 15 Suppl 6: 8-13, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31642191

ABSTRACT

AIM: The 2017 Advanced Prostate Cancer Consensus Conference (APCCC) convened an international multidisciplinary panel to vote on controversial issues in the management of advanced prostate cancer (APC). We aimed to compare their conclusions with the opinions of local specialists and explore the practicability of international recommendations in the healthcare setting in Hong Kong. METHODS: Urologists and clinical oncologists practicing in Hong Kong were invited to complete a survey based on the original APCCC 2017 questionnaire and recently published trials in APC. A joint committee of expert key opinion leaders was convened to discuss and analyze the voting differences between local specialists and the APCCC 2017 panel. RESULTS: The respondents constituted 21% (28/132) of registered urologists and 21% (31/146) of clinical oncologists in Hong Kong. Discrepancies in three key areas were identified as being the most timely for this analysis: (a) management of metastatic hormone-sensitive/naïve prostate cancer; (b) management of metastatic castration-resistant prostate cancer; and (c) treatment monitoring and initiation of androgen-deprivation therapy. Fears of toxicity and intolerance among patients and physicians (especially urologists) may be driving the relative underuse of chemotherapy in multiple APC patient groups in Hong Kong. Local patients can face long wait times and limited access to contemporary imaging modalities compared with other developed countries. CONCLUSION: Increased collaborative efforts by urologists and clinical oncologists could ensure that patients gain wider access to the latest diagnostic, treatment and monitoring modalities for APC in Hong Kong.


Subject(s)
Practice Guidelines as Topic/standards , Practice Patterns, Physicians'/standards , Prostatic Neoplasms/therapy , Surveys and Questionnaires , Androgen Antagonists/therapeutic use , Antineoplastic Agents/therapeutic use , Combined Modality Therapy , Consensus , Disease Management , Hong Kong/epidemiology , Humans , Male , Prostatectomy , Prostatic Neoplasms/epidemiology , Radiotherapy
17.
PLoS One ; 14(10): e0223435, 2019.
Article in English | MEDLINE | ID: mdl-31577822

ABSTRACT

Developing effective therapies for back pain associated with intervertebral disc (IVD) degeneration is a research priority since it is a major socioeconomic burden and current conservative and surgical treatments have limited success. Polyphenols are naturally occurring compounds in plant-derived foods and beverages, and evidence suggests dietary supplementation with select polyphenol preparations can modulate diverse neurological and painful disorders. This study tested whether supplementation with a select standardized Bioactive-Dietary-Polyphenol-Preparation (BDPP) may alleviate pain symptoms associated with IVD degeneration. Painful IVD degeneration was surgically induced in skeletally-mature rats by intradiscal saline injection into three consecutive lumbar IVDs. Injured rats were given normal or BDPP-supplemented drinking water. In-vivo hindpaw mechanical allodynia and IVD height were assessed weekly for 6 weeks following injury. Spinal column, dorsal-root-ganglion (DRG) and serum were collected at 1 and 6 weeks post-operative (post-op) for analyses of IVD-related mechanical and biological pathogenic processes. Dietary BDPP significantly alleviated the typical behavioral sensitivity associated with surgical procedures and IVD degeneration, but did not modulate IVD degeneration nor changes of pro-inflammatory cytokine levels in IVD. Gene expression analyses suggested BDPP might have an immunomodulatory effect in attenuating the expression of pro-inflammatory cytokines in DRGs. This study supports the idea that dietary supplementation with BDPP has potential to alleviate IVD degeneration-related pain, and further investigations are warranted to identify the mechanisms of action of dietary BDPP.


Subject(s)
Back Pain/etiology , Dietary Supplements , Intervertebral Disc Degeneration/complications , Pain Management , Polyphenols/administration & dosage , Animals , Back Pain/diagnosis , Back Pain/drug therapy , Back Pain/physiopathology , Behavior, Animal , Biomarkers , Cytokines/genetics , Cytokines/metabolism , Disease Models, Animal , Ganglia, Spinal/metabolism , Hyperalgesia/etiology , Hyperalgesia/metabolism , Hyperalgesia/physiopathology , Inflammation Mediators/metabolism , Low Back Pain/diagnosis , Low Back Pain/drug therapy , Low Back Pain/etiology , Low Back Pain/physiopathology , Male , Pain Management/methods , Pain Measurement , Radiography , Rats
18.
Sci Rep ; 9(1): 3546, 2019 03 05.
Article in English | MEDLINE | ID: mdl-30837576

ABSTRACT

Dietary polyphenols promote memory in models of sleep deprivation (SD), stress, and neurodegeneration. The biological properties of dietary polyphenols greatly depend upon the bioavailability of their phenolic metabolites derivatives, which are modulated by gut microbiota. We recently demonstrated that supplementation with grape-derived bioactive dietary polyphenol preparation (BDPP) improves SD-induced cognitive impairment. This study examined the role of the gut microbiota in the ability of BDPP to prevent memory impairment in response to SD. C57BL6/J mice, treated with antibiotics mix (ABX) or BDPP or both, were sleep-deprived at the end of a fear conditioning training session and fear memory was assessed the next day. Gut microbiota composition was analyzed in fecal samples and BDPP-driven phenolic acid metabolites extraction was measured in plasma. We report that the beneficial effect of BDPP on memory in SD is attenuated by ABX-induced dysbiosis. We identified specific communities of fecal microbiota that are associated with the bioavailability of BDPP-derived phenolic acids, which in turn, are associated with memory promotion. These results suggest the gut microbiota composition significantly affects the bioavailability of phenolic acids that drive the dietary polyphenols' cognitive resilience property. Our findings provide a preclinical model with which to test the causal association of gut microbiota-polyphenols, with the ultimate goal of potential developing dietary polyphenols for the prevention/treatment of cognitive impairment.


Subject(s)
Cognition/drug effects , Diet , Gastrointestinal Microbiome , Hydroxybenzoates/pharmacokinetics , Polyphenols/pharmacology , Animals , Biological Availability , Gastrointestinal Microbiome/drug effects , Male , Memory/drug effects , Mice , Mice, Inbred C57BL
19.
BJU Int ; 124(2): 221-241, 2019 08.
Article in English | MEDLINE | ID: mdl-30653801

ABSTRACT

OBJECTIVE: To formulate consensus statements to facilitate physician management strategies for patients with clinically localized prostate cancer (PCa) in Hong Kong by jointly convening a panel of 12 experts from the two local professional organizations representing PCa specialists, who had previously established consensus statements on the management of metastatic PCa for the locality. METHODS: Through a series of meetings, the panellists discussed their clinical experience and the published evidence regarding various areas of the management of localized PCa, then drafted consensus statements. At the final meeting, each drafted statement was voted on by every panellist based on its practicability of recommendation in the locality. RESULTS: A total of 76 consensus statements were ultimately accepted and established by panel voting. CONCLUSION: Derived from the recent evidence and major overseas guidelines, along with local clinical experience and practicability, the consensus statements were aimed to serve as a practical reference for physicians in Hong Kong for the management of localized PCa.


Subject(s)
Prostatic Neoplasms/pathology , Prostatic Neoplasms/therapy , Consensus , Hong Kong , Humans , Male , Prostatic Neoplasms/diagnostic imaging
20.
J Nutr Biochem ; 64: 170-181, 2019 02.
Article in English | MEDLINE | ID: mdl-30530257

ABSTRACT

The intestinal microbiota actively converts dietary flavanols into phenolic acids, some of which are bioavailable in vivo and may promote resilience to select neurological disorders by interfering with key pathologic mechanisms. Since every person harbors a unique set of gut bacteria, we investigated the influence of the gut microbiota's interpersonal heterogeneity on the production and bioavailability of flavonoid metabolites that may interfere with the misfolding of alpha (α)-synuclein, a process that plays a central role in Parkinson's disease and other α-synucleinopathies. We generated two experimental groups of humanized gnotobiotic mice with compositionally diverse gut bacteria and orally treated the mice with a flavanol-rich preparation (FRP). The two gnotobiotic mouse groups exhibited distinct differences in the generation and bioavailability of FRP-derived microbial phenolic acid metabolites that have bioactivity towards interfering with α-synuclein misfolding or inflammation. We also demonstrated that these bioactive phenolic acids are effective in modulating the development and progression of motor dysfunction in a Drosophila model of α-synucleinopathy. Lastly, through in vitro bacterial fermentation studies, we identified select bacteria that are capable of supporting the generation of these bioavailable and bioactive phenolic acids. Outcomes from our studies provide a better understanding of how interpersonal heterogeneity in the gut microbiota differentially modulates the efficacy of dietary flavanols to protect against select pathologic mechanisms. Collectively, our findings provide the basis for future developments of probiotic, prebiotic, or synbiotic approaches for modulating the onset and/or progression of α-synucleinopathies and other neurological disorders involving protein misfolding and/or inflammation.


Subject(s)
Gastrointestinal Microbiome/physiology , Polyphenols/pharmacokinetics , Synucleinopathies/metabolism , alpha-Synuclein/metabolism , alpha-Synuclein/toxicity , Animals , Animals, Genetically Modified , Biological Availability , Brain/drug effects , Brain/metabolism , Brain/pathology , Disease Models, Animal , Drosophila , Female , Humans , Male , Mice, Inbred C57BL , Parkinson Disease/metabolism , Parkinson Disease/pathology , Polyphenols/metabolism , Protein Aggregation, Pathological/metabolism , Protein Folding , Specific Pathogen-Free Organisms , Synucleinopathies/pathology , alpha-Synuclein/chemistry , alpha-Synuclein/genetics
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