The role of mitochondrial dysfunction in Alzheimer's disease: A potential pathway to treatment
BACKGROUND:Alzheimer's disease (AD) is the most prevalent form of dementia worldwide and is characterized by progressive memory loss and cognitive impairment. Our understanding of AD pathogenesis is limited and no effective disease-modifying treatment is available. Mitochondria are cytoplasmic organelles critical to the homeostatic regulation of glucose and energy in the cell. METHODS:Mitochondrial abnormalities are found early in the course of AD and dysfunctional mitochondria are involved in AD progression. The resulting respiratory chain impairment, neuronal apoptosis, and generation of reactive oxygen species are highly damaging to neurons. Restoration of mitochondrial function may provide a novel therapeutic strategy for AD. RESULTS:This review discusses the specifics of mitochondrial fragmentation, imbalances in fission and fusion, and DNA damage seen in AD and the contribution of compromised mitochondrial activity to AD etiopathogenesis. It explores how an understanding of the processes underlying mitochondrial failure may lead to urgently needed treatment innovations. It considers individual mitochondrial proteins that have emerged as promising drug targets and evaluates neuroprotective agents that could improve the functional state of mitochondria in the setting of AD. CONCLUSIONS:There is great promise in exploring original approaches to preserving mitochondrial viability as a means to achieve breakthroughs in treating AD.
Cognitive changes mediated by adenosine receptor blockade in a resveratrol-treated atherosclerosis-prone lupus mouse model
Background and aim: Resveratrol is a bioactive molecule used in dietary supplements and herbal medicines and consumed worldwide. Prior work showed that resveratrol's anti-atherogenic properties are mediated in part through the adenosine A2A receptor. The present study explores the potential contribution of adenosine A2A receptor activation to neuroprotective action of resveratrol on cognitive deficits in a model of atherosclerosis-prone systemic lupus erythematosus. Experimental procedure: Using behavioral analysis (open field, static rod, novel object recognition) and QRT-PCR, this study measured working memory, anxiety, motor coordination, and expression of mRNA in the brain. Results and conclusion: Data indicate that resveratrol increases working memory, on average but not statistically, and shows a trend towards improved motor coordination (p = 0.07) in atherosclerosis-prone lupus mice. Additionally, resveratrol tends to increase mRNA levels of SIRT1, decrease vascular endothelial growth factor and CX3CL1 mRNA in the hippocampus. Istradefylline, an adenosine A2A receptor antagonist, antagonizes the effects of resveratrol on working memory (p = 0.04) and the expression of SIRT1 (p = 0.03), vascular endothelial growth factor (p = 0.04), and CX3CL1 (p = 0.03) in the hippocampus. This study demonstrates that resveratrol could potentially be a therapeutic candidate in the modulation of cognitive dysfunction in neuropsychiatric lupus, especially motor incoordination. Further human studies, as well as optimization of resveratrol administration, could confirm whether resveratrol may be an additional resource available to reduce the burden of cognitive impairment associated with lupus. Additionally, further studies need to address the role of A2A blockade in cognitive function among the autoimmune population. Section: 3. Dietary therapy/nutrients supplements. Taxonomy (classification by EVISE): autoimmunity, inflammation, neurology.
Absence of COVID-19 Disease Among Chronically Ventilated Nursing Home Patients
OBJECTIVE:To describe the experience of COVID-19 disease among chronically ventilated and nonventilated nursing home patients living in 3 separate nursing homes. DESIGN:Observational study of death, respiratory illness and COVID-19 polymerase chain reaction (PCR) results among residents and staff during nursing home outbreaks inÂ 2020. SETTING AND PARTICIPANTS:93 chronically ventilated nursing home patients and 1151 nonventilated patients living among 3 separate nursing homes on Long Island, New York, as of March 15, 2020. Illness, PCR results, and antibody studies among staff are also reported. MEASUREMENTS:Data were collected on death rate among chronically ventilated and nonventilated patients between March 15 and May 15, 2020, compared to the same time in 2019; prevalence of PCR positivity among ventilated and nonventilated patients in 2020; reported illness, PCR positivity, and antibody among staff. RESULTS:Total numbers of deaths among chronically ventilated nursing home patients during this time frame were similar to the analogous period 1Â year earlier (9 of 93 in 2020 vs 8 of 100 in 2019, PÂ = .8), whereas deaths among nonventilated patients were greatly increased (214 of 1151 in 2020 vs 55 of 1189 in 2019, P < .001). No ventilated patient deaths were clinically judged to be COVID-19 related. No clusters of COVID-19 illness could be demonstrated among ventilated patients. Surveillance PCR testing of ventilator patients failed to reveal COVID-19 positivity (none of 84 ventilator patients vs 81 of 971 nonventilator patients, P < .002). Illness and evidence of COVID-19 infection was demonstrated among staff working both in nonventilator and in ventilator units. CONCLUSIONS AND IMPLICATIONS:COVID-19 infection resulted in illness and death among nonventilated nursing home residents as well as among staff. This was not observed among chronically ventilated patients. The mechanics of chronic ventilation appears to protect chronically ventilated patients from COVID-19 disease.
Post-acute care nursing home deaths in the COVID era: Potential for attribution bias [Letter]
Alzheimer Disease Clinical Trials Targeting Amyloid: Lessons Learned From Success in Mice and Failure in Humans
BACKGROUND:The goal of slowing or halting the development of Alzheimer disease (AD) has resulted in the huge allocation of resources by academic institutions and pharmaceutical companies to the development of new treatments. The etiology of AD is elusive, but the aggregation of amyloid-Î² and tau peptide and oxidative processes are considered critical pathologic mechanisms. The failure of drugs with multiple mechanisms to meet efficacy outcomes has caused several companies to decide not to pursue further AD studies and has left the field essentially where it has been for the past 15 years. Efforts are underway to develop biomarkers for detection and monitoring of AD using genetic, imaging, and biochemical technology, but this is of minimal use if no intervention can be offered. REVIEW SUMMARY/RESULTS:In this review, we consider the natural progression of AD and how it continues despite present attempts to modify the amyloid-related machinery to alter the disease trajectory. We describe the mechanisms and approaches to AD treatment targeting amyloid, including both passive and active immunotherapy as well as inhibitors of enzymes in the amyloidogenic pathway. CONCLUSION/CONCLUSIONS:Lessons learned from clinical trials of amyloid reduction strategies may prove crucial for the leap forward toward novel therapeutic targets to treat AD.
Effect of oxytocin on lipid accumulation under inflammatory conditions in human macrophages
INTRODUCTION AND AIMS/OBJECTIVE:Oxytocin (OT) is a neuropeptide hormone secreted by the posterior pituitary gland. Deficits in OT action have been observed in patients with behavioral and mood disorders, some of which correlate with an increased risk of cardiovascular disease (CVD). Recent research has revealed a wider systemic role that OT plays in inflammatory modulation and development of atherosclerotic plaques. This study investigated the role that OT plays in cholesterol transport and foam cell formation in LPS-stimulated THP-1 human macrophages. METHODS:THP-1 differentiated macrophages were treated with media, LPS (100â€¯ng/ml), LPSâ€¯+â€¯OT (10 pM), or LPSâ€¯+â€¯OT (100 pM). Changes in gene expression and protein levels of cholesterol transporters were analyzed by real time quantitative PCR (RT-qPCR) and Western blot, while ox-LDL uptake and cholesterol efflux capacity were evaluated with fluorometric assays. RESULTS:RT-qPCR analysis revealed a significant increase in ABCG1 gene expression upon OTâ€¯+â€¯LPS treatment, compared to LPS alone (pâ€¯=â€¯0.0081), with Western blotting supporting the increase in expression of the ABCG1 protein. Analysis of ox-LDL uptake showed a significantly lower fluorescent value in LPSâ€¯+â€¯OT (100pM) -treated cells when compared to LPS alone (pâ€¯<â€¯0.0001). While not statistically significant (pâ€¯=â€¯0.06), cholesterol efflux capacity increased with LPSâ€¯+â€¯OT treatment. CONCLUSION/CONCLUSIONS:We demonstrate here that OT can attenuate LPS-mediated lipid accumulation in THP-1 macrophages. These findings support the hypothesis that OT could be used to reduce pro-inflammatory and potentially atherogenic changes observed in patients with heightened CVD risk. This study suggests further exploration of OT effects on monocyte and macrophage cholesterol handling in vivo.
Alzheimer's disease: many failed trials, so where do we go from here?
Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with relentlessly progressive cognitive impairment and memory loss. AD pathology proceeds for decades before cognitive deficits become clinically apparent, opening a window for preventative therapy. Imbalance of clearance and buildup of amyloid Î² and phosphorylated tau proteins in the central nervous system is believed to contribute to AD pathogenesis. However, multiple clinical trials of treatments aimed at averting accumulation of these proteins have yielded little success, and there is still no disease-modifying intervention. Here, we discuss current knowledge of AD pathology and treatment with an emphasis on emerging biomarkers and treatment strategies.
When Asymptomatic Bacteriuria is not Asymptomatic or "Pseudo-Urinary Tract Infection" [Letter]
THE EFFECT OF B-HYDROXYBUTYRATE ON HUMAN MICROGLIA: IMPLICATIONS FOR THE KETOGENIC DIET IN NEURODEGENERATIVE DISORDERS [Meeting Abstract]
MICROGLIA IN A HYPERGLYCEMIC ENVIRONMENT PROMOTE ALZHEIMER'S DISEASE-LIKE PATHOLOGY THROUGH CHOLINGERGIC SYNAPTIC DYSFUNCTION AND INCREASED AMYLOID B PRODUCTION [Meeting Abstract]