Oxidative stress and neurodegeneration

Intranasal therapies for neonatal hypoxic-ischemic encephalopathy: Systematic review, synthesis, and implications for global accessibility to care

Neonatal hypoxic-ischemic encephalopathy (HIE) is the leading cause of neurodevelopmental morbidity in term infants worldwide. Incidence of HIE is highest in low and middle-income communities with minimal access to neonatal intensive care and an underdeveloped infrastructure for advanced neurologic interventions. Moreover, therapeutic hypothermia, standard of care for HIE in high resourced settings, is shown to be ineffective in low and middle-income communities. With their low cost, ease of administration, and capacity to potently target the central nervous system, intranasal therapies pose a unique opportunity to be a more globally accessible treatment for neonatal HIE. Intranasal experimental therapeutics have been studied in both rodent and piglet models, but no intranasal therapeutics for neonatal HIE have undergone human clinical trials. Additional research must be done to expand the array of treatments available for use as intranasal therapies for neonatal HIE thus improving the neurologic outcomes of infants worldwide.

The Association Between Cardiovascular Disease and Dementia: A Review of Trends in Epidemiology, Risk Factors, Pathophysiologic Mechanisms, and Clinical Implications

With increases in life expectancy and the size of the aging population, cognitive decline and neurodegenerative pathologies are expected to increase in the next few decades. Age-related increases in risk for dementia and cardiovascular disease have been researched widely. Epidemiology trends reveal a predicted increase of neurodegenerative disease to more than 65 million by 2030 in the United States. There are several risk factors for the development of cardiovascular disease that have been widely studied for their impact on dementia; such as: diabetes, hypertension, and hyperlipidemia. Several pathophysiologic mechanisms exist by which cardiovascular disease could impact dementia including cerebral hypoperfusion, reactive oxidative species, and increased cleavage of amyloid precursor protein into amyloid beta plaques and accumulation of neurofibrillary tangles. Emerging evidence also suggests that treatment of cardiovascular disease risk factors could reduce the risk of dementia development. In this review, we seek to examine the relationship between cardiovascular disease and dementia by examining epidemiologic trends, common risk factors, pathophysiologic mechanisms and implications for clinical management.

The Role of the Neural Exposome as a Novel Strategy to Identify and Mitigate Health Inequities in Alzheimer's Disease and Related Dementias

With the continuous increase of the elderly population, there is an urgency to understand and develop relevant treatments for Alzheimer's disease and related dementias (ADRD). In tandem with this, the prevalence of health inequities continues to rise as disadvantaged communities fail to be included in mainstream research. The neural exposome poses as a relevant mechanistic approach and tool for investigating ADRD onset, progression, and pathology as it accounts for several different factors: exogenous, endogenous, and behavioral. Consequently, through the neural exposome, health inequities can be addressed in ADRD research. In this paper, we address how the neural exposome relates to ADRD by contributing to the discourse through defining how the neural exposome can be developed as a tool in accordance with machine learning. Through this, machine learning can allow for developing a greater insight into the application of transferring and making sense of experimental mouse models exposed to health inequities and potentially relate it to humans. The overall goal moving beyond this paper is to define a multitude of potential factors that can increase the risk of ADRD onset and integrate them to create an interdisciplinary approach to the study of ADRD and subsequently translate the findings to clinical research.

Perineuronal nets as regulators of parvalbumin interneuron function: Factors implicated in their formation and degradation

The brain extracellular matrix (ECM) has garnered increasing attention as a fundamental component of brain function in a predominantly "neuron-centric" paradigm. Particularly, the perineuronal nets (PNNs), a specialized net-like structure formed by ECM aggregates, play significant roles in brain development and physiology. PNNs enwrap synaptic junctions in various brain regions, precisely balancing new synaptic formation and long-term stabilization, and are highly dynamic entities that change in response to environmental stimuli, especially during the neurodevelopmental period. They are found mainly surrounding parvalbumin (PV)-expressing GABAergic interneurons, being proposed to promote PV interneuron maturation and protect them against oxidative stress and neurotoxic agents. This structural and functional proximity underscores the crucial role of PNNs in modulating PV interneuron function, which is critical for the excitatory/inhibitory balance and, consequently, higher-level behaviours. This review delves into the molecular underpinnings governing PNNs formation and degradation, elucidating their functional interactions with PV interneurons. In the broader physiological context and brain-related disorders, we also explore their intricate relationship with other molecules, such as reactive oxygen species and metalloproteinases, as well as glial cells. Additionally, we discuss potential therapeutic strategies for modulating PNNs in brain disorders.

Neurodegeneration, oxidative stress and lipid metabolism plasma biomarkers to differentiate Parkinson's disease from atypical parkinsonian syndromes

INTRODUCTION

The identification of blood biomarkers appears to be a means of improving diagnosis accuracy in Parkinson's disease (PD) and atypical parkinsonian syndromes (APS). We, therefore, evaluate the performance of neurodegeneration, oxidative stress and lipid metabolism plasma biomarkers to distinguish PD from APS.

METHODS

This was a monocentric study with a cross-sectional design. Plasma levels and discriminating power of neurofilament light chain (NFL), malondialdehyde (MDA) and 24S-Hydroxycholesterol (24S-HC) were assessed in patients with clinical diagnoses of PD or APS.

RESULTS

In total, 32 PD cases and 15 APS cases were included. Mean disease durations were 4.75 years in PD group and 4.2 years in APS group. Plasma levels of NFL, MDA and 24S-HC differed significantly between the APS and PD groups (P=0.003; P=0.009; P=0.032, respectively). NFL, MDA and 24S-HC discriminated between PD and APS (AUC=0.76688; AUC=0.7375; AUC=0.6958, respectively). APS diagnosis significantly increased with MDA level≥23.628nmol/mL (OR: 8.67, P=0.001), NFL level≥47.2pg/mL (OR: 11.92, P<0.001) or 24S-HC level≤33.4pmol/mL (OR: 6.17, P=0.008). APS diagnosis considerably increased with the combination of NFL and MDA levels beyond cutoff values (OR: 30.67, P<0.001). Finally, the combination of NFL and 24S-HC levels, or MDA and 24S-HC levels, or all three biomarkers' levels beyond cutoff values systematically classified patients in the APS group.

CONCLUSION

Our results suggest that 24S-HC and especially MDA and NFL could be helpful for differentiating PD from APS. Further studies will be needed to reproduce our findings on larger, prospective cohorts of patients with parkinsonism evolving for less than 3 years.

N-Acetylcysteine Suppresses Microglial Inflammation and Induces Mortality Dose-Dependently via Tumor Necrosis Factor-α Signaling

N-acetylcysteine (NAC) is an antioxidant that prevents tumor necrosis factor (TNF)-α-induced cell death, but it also acts as a pro-oxidant, promoting reactive oxygen species independent apoptosis. Although there is plausible preclinical evidence for the use of NAC in the treatment of psychiatric disorders, deleterious side effects are still of concern. Microglia, key innate immune cells in the brain, play an important role in inflammation in psychiatric disorders. This study aimed to investigate the beneficial and deleterious effects of NAC on microglia and stress-induced behavior abnormalities in mice, and its association with microglial TNF-α and nitric oxide (NO) production. The microglial cell line MG6 was stimulated by Escherichia coli lipopolysaccharide (LPS) using NAC at varying concentrations for 24 h. NAC inhibited LPS-induced TNF-α and NO synthesis, whereas high concentrations (≥30 mM) caused MG6 mortality. Intraperitoneal injections of NAC did not ameliorate stress-induced behavioral abnormalities in mice, but high-doses induced microglial mortality. Furthermore, NAC-induced mortality was alleviated in microglial TNF-α-deficient mice and human primary M2 microglia. Our findings provide ample evidence for the use of NAC as a modulating agent of inflammation in the brain. The risk of side effects from NAC on TNF-α remains unclear and merits further mechanistic investigations.

Hypertension and hyperhomocysteinemia as modifiable risk factors for Alzheimer's disease and dementia: New evidence, potential therapeutic strategies, and biomarkers

This review summarizes recent evidence on how mid-life hypertension, hyperhomocysteinemia (HHcy) and blood pressure variability, as well as late-life hypotension, exacerbate Alzheimer's disease (AD) and dementia risk. Intriguingly, HHcy also increases the risk for hypertension, revealing the importance of understanding the relationship between comorbid cardiovascular risk factors. Hypertension-induced dementia presents more evidently in women, highlighting the relevance of sex differences in the impact of cardiovascular risk. We summarize each major antihypertensive drug class's effects on cognitive impairment and AD pathology, revealing how carbonic anhydrase inhibitors, diuretics modulating cerebral blood flow, have recently gained preclinical evidence as promising treatment against AD. We also report novel vascular biomarkers for AD and dementia risk, highlighting those associated with hypertension and HHcy. Importantly, we propose that future studies should consider hypertension and HHcy as potential contributors to cognitive impairment, and that uncovering the underlying molecular mechanisms and biomarkers would aid in the identification of preventive strategies.

Homocysteine - A predictor for five year-mortality in patients with subjective cognitive decline, mild cognitive impairment and Alzheimer's dementia

BACKGROUND

Subjective Cognitive Decline (SCD) and Mild Cognitive Impairment (MCI) are preclinical stages of Alzheimer's Disease (AD), which is the most common entity of dementia. Homocysteine is an amino acid in the methionine cycle, and many studies revealed a significant association between elevated homocysteine serum levels and the progression of dementia. The primary objective of this retrospective study was to investigate whether elevated homocysteine serum levels could be associated with mortality and neuropsychological test results in individuals suffering from SCD, MCI or AD.

METHODS

This study is a single-center explorative retrospective data analysis with 976 data protocols from the Memory Outpatient's Clinic of the Medical University of Vienna included. All patients underwent a neurological examination, a laboratory blood test, and neuropsychological testing to establish a diagnosis of either SCD, MCI, or AD. Data was evaluated by Kaplan-Meier functions, factor analysis, and binary logistic regression models.

RESULTS

Patients with AD showed significantly higher mean homocysteine levels (SCD 12.15 ± 4.71, MCI 12.80 ± 4.81, AD 15.0 ± 6.44 μmol/L) compared to those with SCD and MCI (p ≤ .001). The mean age of patients with AD (75.2 ± 7.8) was significantly older at the time of testing than of patients with MCI (69.1 ± 9.6) or SCD (66.8 ± 9.3). Since homocysteine levels increase with age, this could be a possible explanation for the higher levels of AD patients. The age at death did not differ significantly between all diagnostic subgroups, resulting in the shortest survival times for AD patients. Homocysteine levels were negatively associated with in Mini-Mental State Examination (MMSE) and Neuropsyhcological Test Battery Vienna (NTBV) factors F1-F4 (F1 = attention, F2 = memory, F3 = executive functions, F4 = naming/verbal comprehension). Moreover, higher homocysteine levels significantly predicted shorter five-year survival in the logistic regression models, even after adjusting for age, diagnostic subgroups, sex, years of education and results of neuropsychological testing.

CONCLUSION

The results of this study suggest that homocysteine levels are independently associated with impaired cognitive function and increased five-year mortality.

Autonomic nervous system and cardiac neuro-signaling pathway modulation in cardiovascular disorders and Alzheimer's disease

The heart is a functional syncytium controlled by a delicate and sophisticated balance ensured by the tight coordination of its several cell subpopulations. Accordingly, cardiomyocytes together with the surrounding microenvironment participate in the heart tissue homeostasis. In the right atrium, the sinoatrial nodal cells regulate the cardiac impulse propagation through cardiomyocytes, thus ensuring the maintenance of the electric network in the heart tissue. Notably, the central nervous system (CNS) modulates the cardiac rhythm through the two limbs of the autonomic nervous system (ANS): the parasympathetic and sympathetic compartments. The autonomic nervous system exerts non-voluntary effects on different peripheral organs. The main neuromodulator of the Sympathetic Nervous System (SNS) is norepinephrine, while the principal neurotransmitter of the Parasympathetic Nervous System (PNS) is acetylcholine. Through these two main neurohormones, the ANS can gradually regulate cardiac, vascular, visceral, and glandular functions by turning on one of its two branches (adrenergic and/or cholinergic), which exert opposite effects on targeted organs. Besides these neuromodulators, the cardiac nervous system is ruled by specific neuropeptides (neurotrophic factors) that help to preserve innervation homeostasis through the myocardial layers (from epicardium to endocardium). Interestingly, the dysregulation of this neuro-signaling pathway may expose the cardiac tissue to severe disorders of different etiology and nature. Specifically, a maladaptive remodeling of the cardiac nervous system may culminate in a progressive loss of neurotrophins, thus leading to severe myocardial denervation, as observed in different cardiometabolic and neurodegenerative diseases (myocardial infarction, heart failure, Alzheimer's disease). This review analyzes the current knowledge on the pathophysiological processes involved in cardiac nervous system impairment from the perspectives of both cardiac disorders and a widely diffused and devastating neurodegenerative disorder, Alzheimer's disease, proposing a relationship between neurodegeneration, loss of neurotrophic factors, and cardiac nervous system impairment. This overview is conducive to a more comprehensive understanding of the process of cardiac neuro-signaling dysfunction, while bringing to light potential therapeutic scenarios to correct or delay the adverse cardiovascular remodeling, thus improving the cardiac prognosis and quality of life in patients with heart or neurodegenerative disorders.

Cerebral amyloid angiopathy-related cardiac injury: Focus on cardiac cell death

Cerebral amyloid angiopathy (CAA) is a kind of disease in which amyloid β (Aβ) and other amyloid protein deposits in the cerebral cortex and the small blood vessels of the brain, causing cerebrovascular and brain parenchymal damage. CAA patients are often accompanied by cardiac injury, involving Aβ, tau and transthyroxine amyloid (ATTR). Aβ is the main injury factor of CAA, which can accelerate the formation of coronary artery atherosclerosis, aortic valve osteogenesis calcification and cardiomyocytes basophilic degeneration. In the early stage of CAA (pre-stroke), the accompanying locus coeruleus (LC) amyloidosis, vasculitis and circulating Aβ will induce first hit to the heart. When the CAA progresses to an advanced stage and causes a cerebral hemorrhage, the hemorrhage leads to autonomic nervous function disturbance, catecholamine surges, and systemic inflammation reaction, which can deal the second hit to the heart. Based on the brain-heart axis, CAA and its associated cardiac injury can create a vicious cycle that accelerates the progression of each other.

Neuropharmacological Study on Capsaicin in Scopolamine-injected Mice

AIM

To evaluate the potential beneficial role of Capsaicin in cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice.

BACKGROUND

Capsaicin is the chief phenolic component present in red chili and is responsible for its pungent and spicy flavor. It affects TRPV1 channels in nociceptive sensory neurons and is present in the hippocampus, and hypothalamus of the brains of rodents and humans.

OBJECTIVE

The main objective is to investigate the effective role of capsaicin in attenuating cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice and examine the feasible mechanisms.

METHODS

Various doses of capsaicin (5, 10, and 20 mg/kg) were given orally to mice daily for 7 consecutive days after the administration of scopolamine. Various behavioral tests (motor coordination, locomotor counts, hole board test) and biochemical assay (Pro-inflammatory cytokines, catalase, lipid peroxidation, nitrite, reduced glutathione, and superoxide dismutase), mitochondrial complex (I, II, III, and IV) enzyme activities, and mitochondrial permeability transition were evaluated in the distinct regions of the brain.

RESULTS

Scopolamine-treated mice showed a considerable reduction in the entries and duration in the light zone as well as in open arms of the elevated plus maze. Interestingly, capsaicin at different doses reversed the anxiety, depressive-like behaviors, and learning and memory impairment effects of scopolamine. Scopolamine-administered mice demonstrated substantially increased pro-inflammatory cytokines levels, impaired mitochondrial enzyme complex activities, and increased oxidative damage compared to the normal control group. Capsaicin treatment reinstated the reduced lipid peroxidation, nitric oxide, catalase, superoxide dismutase, reduced glutathione activity, decreasing pro-inflammatory cytokines and restoring mitochondrial complex enzyme activities (I, II, III, and IV) as well as mitochondrial permeability. Moreover, the IL-1β level was restored at a dose of capsaicin (10 and 20 mg/kg) only. Capsaicin reduced the scopolamine-induced acetylcholinesterase activity, thereby raising the acetylcholine concentration in the hippocampal tissues of mice. Preservation of neuronal cell morphology was also confirmed by capsaicin in histological studies. From the above experimental results, capsaicin at a dose of 10 mg/kg, p.o. for seven consecutive days was found to be the most effective dose.

CONCLUSION

The experiential neuroprotective effect of capsaicin through the restoration of mitochondrial functions, antioxidant effects, and modulation of pro-inflammatory cytokines makes it a promising candidate for further drug development through clinical setup.

Brain tissue oxygen dynamics while mimicking the functional deficiency of interneurons

The dynamic interaction between excitatory and inhibitory activity in the brain is known as excitatory-inhibitory balance (EIB). A significant shift in EIB toward excitation has been observed in numerous pathological states and diseases, such as autism or epilepsy, where interneurons may be dysfunctional. The consequences of this on neurovascular interactions remains to be elucidated. Specifically, it is not known if there is an elevated metabolic consumption of oxygen due to increased excitatory activity. To investigate this, we administered microinjections of picrotoxin, a gamma aminobutyric acid (GABA) antagonist, to the rabbit cortex in the awake state to mimic the functional deficiency of GABAergic interneurons. This caused an observable shift in EIB toward excitation without the induction of seizures. We used chronically implanted electrodes to measure both neuronal activity and brain tissue oxygen concentrations (PO₂) simultaneously and in the same location. Using a high-frequency recording rate for PO₂, we were able to detect two important phenomena, (1) the shift in EIB led to a change in the power spectra of PO₂ fluctuations, such that higher frequencies (8-15 cycles per minute) were suppressed and (2) there were brief periods (dips with a duration of less than 100 ms associated with neuronal bursts) when PO₂ dropped below 10 mmHg, which we defined as the threshold for hypoxia. The dips were followed by an overshoot, which indicates either a rapid vascular response or decrease in oxygen consumption. Our results point to the essential role of interneurons in brain tissue oxygen regulation in the resting state.

The role of neuroimmune and inflammation in pediatric uremia-induced neuropathy

Uremic neuropathy in children encompasses a wide range of central nervous system (CNS), peripheral nervous system (PNS), autonomic nervous system (ANS), and psychological abnormalities, which is associated with progressive renal dysfunction. Clinically, the diagnosis of uremic neuropathy in children is often made retrospectively when symptoms improve after dialysis or transplantation, due to there is no defining signs or laboratory and imaging findings. These neurological disorders consequently result in increased morbidity and mortality among children population, making uremia an urgent public health problem worldwide. In this review, we discuss the epidemiology, potential mechanisms, possible treatments, and the shortcomings of current research of uremic neuropathy in children. Mechanistically, the uremic neuropathy may be caused by retention of uremic solutes, increased oxidative stress, neurotransmitter imbalance, and disturbance of the blood-brain barrier (BBB). Neuroimmune, including the change of inflammatory factors and immune cells, may also play a crucial role in the progression of uremic neuropathy. Different from the invasive treatment of dialysis and kidney transplantation, intervention in neuroimmune and targeted anti-inflammatory therapy may provide a new insight for the treatment of uremia.

Increased plasma trimethylamine-N-oxide levels are associated with mild cognitive impairment in high cardiovascular risk elderly population

Trimethylamine-N-oxide (TMAO) has been shown to be associated with cardiovascular (CV) disease and cognitive impairment. The association between early stages of cognitive impairment and TMAO in a high CV risk population has not been previously investigated. This study aimed to investigate the association between the plasma TMAO level and cognitive function in a population with a high risk of CV disease. Participants at a high risk of CV were included. The cognition was evaluated using the Montreal Cognitive Assessment. A score lower than 25 out of 30 was used to indicate mild cognitive impairment (MCI). Blood samples of all participants (n = 233) were collected to measure the plasma levels of TMAO and other metabolic parameters, including fasting blood sugar and lipid profiles. Logistic regression was used to evaluate the association between MCI and high plasma TMAO levels, adjusted for confounding factors. Of 233 patients, the mean age of patients in this study was 64 years old (SD 8.4). The median TMAO level was 4.31 μM (IQR 3.95). The high TMAO level was an independent risk factor of MCI (aOR 2.36, 95% CI 1.02 to 5.47; p 0.046), when adjusted for age, gender, health care service scheme, smoking history, metabolic syndrome, and history of established CV events. The high TMAO level was associated with MCI, after adjustment for potential confounding factors. These findings demonstrate that plasma TMAO levels can serve for target prediction as an independent risk factor for MCI in this population.

Harnessing the Power of Purple Sweet Potato Color and Myo-Inositol to Treat Classic Galactosemia

Classic Galactosemia (CG) is a devastating inborn error of the metabolism caused by mutations in the GALT gene encoding the enzyme galactose-1 phosphate uridylyltransferase in galactose metabolism. Severe complications of CG include neurological impairments, growth restriction, cognitive delays, and, for most females, primary ovarian insufficiency. The absence of the GALT enzyme leads to an accumulation of aberrant galactose metabolites, which are assumed to be responsible for the sequelae. There is no treatment besides the restriction of dietary galactose, which does not halt the development of the complications; thus, additional treatments are sorely needed. Supplements have been used in other inborn errors of metabolism but are not part of the therapeutic regimen for CG. The goal of this study was to test two generally recognized as safe supplements (purple sweet potato color (PSPC) and myo-inositol (MI)) that may impact cellular pathways contributing to the complications in CG. Our group uses a GalT gene-trapped mouse model to study the pathophysiology in CG, which phenocopy many of the complications. Here we report the ability of PSPC to ameliorate dysregulation in the ovary, brain, and liver of our mutant mice as well as positive results of MI supplementation in the ovary and brain.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

A review on neurodegenerative diseases associated with oxidative stress and mitochondria

Alzheimer's disease, Parkinson's disease, and other neurological diseases afflict people of all ages. Neuronal loss and cognitive dysfunction are common symptoms of these disorders. Overproduction of reactive oxygen species has been demonstrated to aggravate disease progression in previous investigations (ROS). Because of the large quantities of polyunsaturated fatty acids in their membranes and their fast oxygen consumption rate, neurons are especially susceptible to oxidative damage. The molecular aetiology of neurodegeneration produced by changes in redox balance has not yet been established. New antioxidants have shown considerable potential in modifying disease characteristics. For the treatment of Alzheimer's disease and other neurodegenerative illnesses such as Parkinson's disease, ALS and spinocerebellar ataxia and Huntington's disease, antioxidant-based therapies are examined extensively in the literature.

PrPSc Inhibition and Cellular Protection of DBL on a Prion-Infected Cultured Cell via Multiple Pathways

Prion diseases are kinds of fatal neurodegenerative diseases without effective therapeutic and prophylactic tools currently. In this study, the inhibition of PrP^Sc propagation and cellular protectivity of 3,4-dihydroxybenzalacetone (DBL), a small catechol-containing compound isolated and purified from the ethanol extract of Inonotus obliquus, upon a prion-infected cell line SMB-S15 were evaluated. Western blots showed that after incubation with 10 μM of DBL for 14 days, the level of PrP^Sc in SMB-S15 cells was significantly decreased. Meanwhile, the levels of ROS and hydrogen peroxide were decreased with a dose-dependent manner, whereas the levels of some antioxidant factors, such as HO-1, GCLC and GCLM, were significantly increased. The activities of total glutathione and SOD were up-regulated. DBL-treated SMB-S15 cells also showed the up-regulation of UPR-related proteins, including PERK, IRE1α, ATF6 and GRP78, and activation of autophagy system. Furthermore, the SIRT3 abnormalities caused by prion infection were relieved by DBL treatment. On the contrary, these comprehensive changes were not significantly noticed in the normal partner cell line SMB-PS under the same experimental condition. Those data indicate that treatment of DBL on prion-infected cells can reduce PrP^Sc level, activate UPR and autophagy system and meanwhile relieve intracellular oxidative stress, endoplasmic reticulum stress and mitochondrial dysfunction by raising the levels of multiple antioxidant factors. The PrP^Sc inhibition and protective effectiveness of DBL upon the prion-infected cells in vitro make it worthy of further study.

Associations of ARHGAP26 Polymorphisms with Alzheimer's Disease and Cardiovascular Disease

The Rho GTPase activating protein 26 (ARHGAP26) gene has been reported to be associated with neuropsychiatric diseases and neurodegenerative diseases including Parkinson's disease. We examined whether the ARHGAP26 gene is associated with Alzheimer's disease (AD) and/or cardiovascular disease (CVD). Multivariable logistic regression model was used to examine the associations of 154 single nucleotide polymorphisms (SNPs) within the ARHGAP26 gene with AD and CVD using the Alzheimer's Disease Neuroimaging Initiative 1 (ADNI-1) cohort. Fourteen SNPs were associated with AD (top SNP rs3776362 with p = 3.43 × 10^-3), while 37 SNPs revealed associations with CVD (top SNP rs415235 with p = 2.06 × 10^-4). Interestingly, 13 SNPs were associated with both AD and CVD. SNP rs3776362 was associated with CVD, Functional Activities Questionnaire (FAQ), and Clinical Dementia Rating Sum of Boxes (CDR-SB). A replication study using a Caribbean Hispanics sample showed that 17 SNPs revealed associations with AD, and 12 SNPs were associated with CVD. The third sample using a family-based study design showed that 9 SNPs were associated with AD, and 3 SNPs were associated with CVD. SNP rs6836509 within the ARHGAP10 gene (an important paralogon of ARHGAP26) was associated with AD and cerebrospinal fluid total tau (t-tau) level in the ADNI sample. Several SNPs were functionally important using the RegulomeDB, while a number of SNPs were associated with significant expression quantitative trait loci (eQTLs) using Genotype-Tissue Expression (GTEx) databases. In conclusion, genetic variants within ARHGAP26 were associated with AD and CVD. These findings add important new insights into the potentially shared pathogenesis of AD and CVD.

Late-Life Obesity Associated with Tau Pathology in Cognitively Normal Individuals: The CABLE Study

BACKGROUND

Existed evidence suggests that midlife obesity increases the risk of Alzheimer's disease (AD), while there is an inverse association between AD and obesity in late life. However, the underlying metabolic changes of AD pathological proteins attributed to obesity in two life stages were not clear.

OBJECTIVE

To investigate the associations of obesity types and obesity indices with AD biomarkers in cerebrospinal fluid (CSF) in different life stages.

METHODS

We recruited 1,051 cognitively normal individuals (61.94±10.29 years, 59.66%male) from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study with CSF detections for amyloid-β 42 (Aβ 42), total-tau (T-tau), and phosphorylated tau (P-tau). We utilized body mass index, waist circumference, waist-to-height ratio, and metabolic risk factors to determine human obesity types. Multiple linear models and interaction analyses were run to assess the impacts of obesity on AD biomarkers.

RESULTS

The metabolically unhealthy obesity or healthy obesity might exert a reduced tau pathology burden (p <  0.05). Individuals with overweight, general obesity, and central obesity presented lower levels of tau-related proteins in CSF than normal controls (p <  0.05). Specially, for late-life individuals, higher levels of obesity indices were associated with a lower load of tau pathology as measured by CSF T-tau and T-tau/Aβ 42 (p <  0.05). No similar significant associations were observed in midlife.

CONCLUSION

Collectively, late-life general and central obesity seems to be associated with the reduced load of tau pathology, which further consolidates the favorable influence of obesity in specific life courses for AD prevention.

Early Development of the GABAergic System and the Associated Risks of Neonatal Anesthesia

Human and animal studies have elucidated the apparent neurodevelopmental effects resulting from neonatal anesthesia. Observations of learning and behavioral deficits in children, who were exposed to anesthesia early in development, have instigated a flurry of studies that have predominantly utilized animal models to further interrogate the mechanisms of neonatal anesthesia-induced neurotoxicity. Specifically, while neonatal anesthesia has demonstrated its propensity to affect multiple cell types in the brain, it has shown to have a particularly detrimental effect on the gamma aminobutyric acid (GABA)ergic system, which contributes to the observed learning and behavioral deficits. The damage to GABAergic neurons, resulting from neonatal anesthesia, seems to involve structure-specific changes in excitatory-inhibitory balance and neurovascular coupling, which manifest following a significant interval after neonatal anesthesia exposure. Thus, to better understand how neonatal anesthesia affects the GABAergic system, we first review the early development of the GABAergic system in various structures that have been the focus of neonatal anesthesia research. This is followed by an explanation that, due to the prolonged developmental curve of the GABAergic system, the entirety of the negative effects of neonatal anesthesia on learning and behavior in children are not immediately evident, but instead take a substantial amount of time (years) to fully develop. In order to address these concerns going forward, we subsequently offer a variety of in vivo methods which can be used to record these delayed effects.

Dietary Antioxidants in Age-Related Macular Degeneration and Glaucoma

Age-related macular degeneration (AMD) and glaucoma are ophthalmic neurodegenerative diseases responsible for irreversible vision loss in the world population. Only a few therapies can be used to slow down the progression of these diseases and there are no available treatment strategies for reversing the degeneration of the neural retina. In AMD, the pathological process causes the malfunction and damage of the retinal pigmented epithelium and photoreceptors in the macula. In glaucoma, damage of the retinal ganglion cells and their axons is observed and treatment strategies are limited to intraocular pressure lowering. Therefore, other prophylactic and/or therapeutic methods are needed. Oxidative stress is involved in the neurodegenerative process accompanying both AMD and glaucoma; therefore, the use of antioxidant agents would clearly be beneficial, which is supported by the decreased prevalence and progression of AMD in patients adherent to a diet naturally rich in antioxidants. Dietary antioxidants are easily available and their use is based on the natural route of administration. Many preclinical studies both in vitro and using animal models of retinal degeneration showed the efficacy of dietary antioxidants, which was further proved in clinical trials. Resveratrol is beneficial both in AMD and glaucoma animal models, but confirmed only among AMD patients. For AMD, carotenoids and omega-3 fatty acids were also proved to be sufficient in preventing neurodegeneration. For glaucoma, coenzyme Q10 and alpha-lipoic acid showed efficacy for decreasing retinal ganglion cell loss and inhibiting the accompanying destructive processes. Interestingly, the benefits of vitamins, especially vitamin E was not confirmed, neither in preclinical nor in clinical studies.

The Conspicuous Link between Ear, Brain and Heart-Could Neurotrophin-Treatment of Age-Related Hearing Loss Help Prevent Alzheimer's Disease and Associated Amyloid Cardiomyopathy?

Alzheimer's disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction and cognitive decline. While the deposition of amyloid β peptide (Aβ) and the formation of neurofibrillary tangles (NFTs) are the pathological hallmarks of AD-affected brains, the majority of cases exhibits a combination of comorbidities that ultimately lead to multi-organ failure. Of particular interest, it can be demonstrated that Aβ pathology is present in the hearts of patients with AD, while the formation of NFT in the auditory system can be detected much earlier than the onset of symptoms. Progressive hearing impairment may beget social isolation and accelerate cognitive decline and increase the risk of developing dementia. The current review discusses the concept of a brain-ear-heart axis by which Aβ and NFT inhibition could be achieved through targeted supplementation of neurotrophic factors to the cochlea and the brain. Such amyloid inhibition might also indirectly affect amyloid accumulation in the heart, thus reducing the risk of developing AD-associated amyloid cardiomyopathy and cardiovascular disease.

Deficiency of optineurin enhances osteoclast differentiation by attenuating the NRF2-mediated antioxidant response

Abnormally increased resorption contributes to bone degenerative diseases such as Paget's disease of bone (PDB) through unclear mechanisms. Recently, the optineurin (OPTN) gene has been implicated in PDB, and global OPTN knockout mice (Optn^-/-) were shown to exhibit increased formation of osteoclasts (osteoclastogenesis). Growing evidence, including our own, has demonstrated that intracellular reactive oxygen species (ROS) stimulated by receptor activator of nuclear factor kappa-B ligand (RANKL) can act as signaling molecules to promote osteoclastogenesis. Here, we report that OPTN interacts with nuclear factor erythroid-derived factor 2-related factor 2 (NRF2), the master regulator of the antioxidant response, defining a pathway through which RANKL-induced ROS could be regulated for osteoclastogenesis. In this study, monocytes from Optn^-/- and wild-type (Optn^+/+) mice were utilized to differentiate into osteoclasts, and both qRT-PCR and tartrate-resistant acid phosphatase (TRAP) staining showed that the Optn^-/- monocytes exhibited enhanced osteoclastogenesis compared to the Optn^+/+ cells. CellROX^® staining, qRT-PCR, and Western blotting indicated that OPTN deficiency reduced the basal expression of Nrf2, inhibited the expression of NRF2-responsive antioxidants, and increased basal and RANKL-induced intracellular ROS levels, leading to enhanced osteoclastogenesis. Coimmunoprecipitation (co-IP) showed direct interaction, and immunofluorescence staining showed perinuclear colocalization of the OPTN-NRF2 granular structures during differentiation. Finally, curcumin and the other NRF2 activators attenuated the hyperactive osteoclastogenesis induced by OPTN deficiency. Collectively, our findings reveal a novel OPTN-mediated mechanism for regulating the NRF2-mediated antioxidant response in osteoclasts and extend the therapeutic potential of OPTN in the aging process resulting from ROS-triggered oxidative stress, which is associated with PDB and many other degenerative diseases.

The impact of sex and gender on heart-brain axis dysfunction: current concepts and novel perspectives

The heart-brain axis (HBA) recapitulates all the circuits that regulate bidirectional flow of communication between heart and brain. Several mechanisms may underlie the interdependent relationship involving heterogeneous tissues at rest and during specific target organ injury such as myocardial infarction, heart failure, arrhythmia, stroke, mood disorders, or dementia. In-depth translational studies of the HBA dysfunction under single-organ injury should include both male and female animals to develop sex- and gender-oriented prevention, diagnosis, and treatment strategies. Indeed, sex and gender are determining factors as females and males exhibit significant differences in terms of susceptibility to risk factors, age of onset, severity of symptoms, and outcome. Despite most studies having focused on the male population, we have conducted a careful appraisal of the literature investigating HBA in females. In particular, we have (i) analyzed sex-related heart and brain illnesses, (ii) recapitulated the most significant studies simultaneously conducted on cardio- and cerebro-vascular systems in female populations, and (iii) hypothesized future perspectives for the development of a gender-based approach to HBA dysfunction. Although sex- and gender-oriented research is at its infancy, the impact of sex on HBA dysfunction is opening unexpected new avenues for managing the health of female subjects exposed to risk of lifestyle multi-organ disease.

Inhibitory Effect of (2R)-4-(4-hydroxyphenyl)-2-butanol 2-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside on RANKL-Induced Osteoclast Differentiation and ROS Generation in Macrophages

In bone homeostasis, bone loss due to excessive osteoclasts and inflammation or osteolysis in the bone formation process cause bone diseases such as osteoporosis. Suppressing the accompanying oxidative stress such as ROS in this process is an important treatment strategy for bone disease. Therefore, in this study, the effect of (2R)-4-(4-hydroxyphenyl)-2-butanol 2-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (BAG), an arylbutanoid glycoside isolated from Betula platyphylla var. japonica was investigated in RANKL-induced RAW264.7 cells and LPS-stimulated MC3E3-T1 cells. BAG inhibited the activity of TRAP, an important marker of osteoclast differentiation and F-actin ring formation, which has osteospecific structure. In addition, the protein and gene levels were suppressed of integrin β3 and CCL4, which play an important role in the osteoclast-induced bone resorption and migration of osteoclasts, and inhibited the production of ROS and restored the expression of antioxidant enzymes such as SOD and CAT lost by RANKL. The inhibitory effect of BAG on osteoclast differentiation and ROS production appears to be due to the inhibition of MAPKs phosphorylation and NF-κβ translocation, which play a major role in osteoclast differentiation. In addition, BAG inhibited ROS generated by LPS and effectively restores the mineralization of lost osteoblasts, thereby showing the effect of bone formation in the inflammatory situation accompanying bone loss by excessive osteoclasts, suggesting its potential as a new natural product-derived bone disease treatment.

N-Acetylcysteine Attenuates the Anxiety-Like Behavior and Spatial Cognition Impairment Induced by Doxorubicin and Cyclophosphamide Combination Treatment in Rats

BACKGROUND

Cancer patients can suffer from psychological and cognitive disorders after chemotherapy, which influence quality of life.

OBJECTIVE

Oxidative stress may contribute to the psychological and cognitive disorders induced in rats by chemotherapy. In the present study, we examined the effects of N-acetylcysteine, an anti-oxidant, on anxiety-like behavior and cognitive impairment in rats treated with a combination of doxorubicin and cyclophosphamide.

METHODS

Rats were intraperitoneally injected with doxorubicin and cyclophosphamide once a week for 2 weeks. The light-dark test and the novel location recognition test were used to assess anxiety-like behavior and spatial cognition, respectively. The rats' hippocampal levels of glutathione (GSH) and glutathione disulfide (GSSG) were measured using a GSSG/GSH quantification kit.

RESULTS

Combined treatment with doxorubicin and cyclophosphamide produced anxiety-like behavior and cognitive impairment in rats. N-acetylcysteine reversed the anxiety-like behavior and inhibition of novel location recognition induced by the combination treatment. Furthermore, the combination of doxorubicin and cyclophosphamide significantly reduced the rats' hippocampal GSH/GSSG ratios. N-acetylcysteine reversed the reduction in the GSH/GSSG ratio seen in the doxorubicin and cyclophosphamide-treated rats.

CONCLUSION

These results suggest that N-acetylcysteine inhibits doxorubicin and cyclophosphamide-induced anxiety-like behavior and cognitive impairment by reducing oxidative stress in the hippocampus.

Exploring neurodegenerative disorders using a novel integrated model of cerebral transport: Initial results

The neurovascular unit (NVU) underlines the complex and symbiotic relationship between brain cells and the cerebral vasculature, and dictates the need to consider both neurodegenerative and cerebrovascular diseases under the same mechanistic umbrella. Importantly, unlike peripheral organs, the brain was thought not to contain a dedicated lymphatics system. The glymphatic system concept (a portmanteau of glia and lymphatic) has further emphasized the importance of cerebrospinal fluid transport and emphasized its role as a mechanism for waste removal from the central nervous system. In this work, we outline a novel multiporoelastic solver which is embedded within a high precision, subject specific workflow that allows for the co-existence of a multitude of interconnected compartments with varying properties (multiple-network poroelastic theory, or MPET), that allow for the physiologically accurate representation of perfused brain tissue. This novel numerical template is based on a six-compartment MPET system (6-MPET) and is implemented through an in-house finite element code. The latter utilises the specificity of a high throughput imaging pipeline (which has been extended to incorporate the regional variation of mechanical properties) and blood flow variability model developed as part of the VPH-DARE@IT research platform. To exemplify the capability of this large-scale consolidated pipeline, a cognitively healthy subject is used to acquire novel, biomechanistically inspired biomarkers relating to primary and derivative variables of the 6-MPET system. These biomarkers are shown to capture the sophisticated nature of the NVU and the glymphatic system, paving the way for a potential route in deconvoluting the complexity associated with the likely interdependence of neurodegenerative and cerebrovascular diseases. The present study is the first, to the best of our knowledge, that casts and implements the 6-MPET equations in a 3D anatomically accurate brain geometry.

Heart and Brain: Complex Relationships for Left Ventricular Dysfunction

PURPOSE OF REVIEW

This review summarizes the evidence for the established vascular/hypoperfusion model and explores the new hypothesis that configures the heart/brain axis as an organ system where similar pathogenic mechanisms exploit physiological and pathological changes.

RECENT FINDINGS

Although associated by common risk factors, similar epidemiological stratification and common triggers (including inflammation, oxidative stress, and hypoxia), heart failure and Alzheimer's disease have been, for long time, viewed as pathogenically separate illnesses. The silos began to be broken down with the awareness that vascular dysfunction, and loss of cardiac perfusion pump power, trigger biochemical changes, contributing to the typical hallmark of Alzheimer's disease (AD)-the accumulation of Aβ plaques and hyperphosphorylated Tau tangles. Compromised blood flow to the brain becomes the paradigm for the "heart-to-head" connection. Compelling evidence of common genetic variants, biochemical characteristics, and the accumulation of Aβ outside the brain suggests a common pathogenesis for heart failure (HF) and AD. These new findings represent just the beginning of the understanding the complex connection between AD and HF requiring further studies and interdisciplinary approaches. Altogether, the current evidence briefly summarized in this review, highlight a closer and complex relationship between heart failure and Alzheimer's that goes beyond the vascular/perfusion hypothesis. Genetic and biochemical evidence begin to suggest common pathogenic mechanisms between the two diseases involving a systemic defect in the folding of protein or a seeding at distance of the misfolded proteins from one organ to the other.

Alzheimer's Disease and Cardiovascular Disease: A Particular Association

Methods

This review is based on the material obtained via MEDLINE (PubMed), EMBASE, and Clinical Trials databases, from January 1980 until May 2019. The search term used was "Alzheimer's disease," combined with "cardiovascular disease," "hypertension," "dyslipidaemia," "diabetes mellitus," "atrial fibrillation," "coronary artery disease," "heart valve disease," and "heart failure." Out of the 1,328 papers initially retrieved, 431 duplicates and 216 records in languages other than English were removed. Among the 681 remaining studies, 98 were included in our research material on the basis of the following inclusion criteria: (a) the community-based studies; (b) using standardized diagnostic criteria; (c) reporting raw prevalence data; (d) with separate reported data for sex and age classes.

Results

While AD and CVD alone may be considered deleterious to health, the study of their combination constitutes a clinical challenge. Further research will help to clarify the real impact of vascular factors on these diseases. It may be hypothesized that there are various mechanisms underlying the association between AD and CVD, the main ones being hypoperfusion and emboli, atherosclerosis, and the fact that, in both the heart and brain of AD patients, amyloid deposits may be present, thus causing damage to these organs.

Conclusions

AD and CVD are frequently associated. Further studies are needed in order to understand the effect of CVD and its risk factors on AD in order to better comprehend the effects of subclinical and clinical CVD on the brain. Finally, we need to clarify the impact of the underlying hypothesized mechanisms of this association and to investigate gender issues.

Natural Antioxidant Anthocyanins-A Hidden Therapeutic Candidate in Metabolic Disorders with Major Focus in Neurodegeneration

All over the world, metabolic syndrome constitutes severe health problems. Multiple factors have been reported in the pathogenesis of metabolic syndrome. Metabolic disorders result in reactive oxygen species (ROS) induced oxidative stress, playing a vital role in the development and pathogenesis of major health issues, including neurological disorders Alzheimer's disease (AD) Parkinson's disease (PD). Considerable increasing evidence indicates the substantial contribution of ROS-induced oxidative stress in neurodegenerative diseases. An imbalanced metabolism results in a defective antioxidant defense system, free radicals causing inflammation, cellular apoptosis, and tissue damage. Due to the annual increase in financial and social burdens, in addition to the adverse effects associated with available synthetic agents, treatment diversion from synthetic to natural approaches has occurred. Antioxidants are now being considered as convincing therapeutic agents against various neurodegenerative disorders. Therefore, medicinal herbs and fruits currently receive substantially more attention as commercial sources of antioxidants. In this review, we argue that ROS-targeted therapeutic interventions with naturally occurring antioxidant flavonoid, anthocyanin, and anthocyanin-loaded nanoparticles might be the ultimate treatment against devastating illnesses. Furthermore, we elucidate the hidden potential of the neuroprotective role of anthocyanins and anthocyanin-loaded nanoparticles in AD and PD neuropathies, which lack sufficient attention compared with other polyphenols, despite their strong antioxidant potential. Moreover, we address the need for future research studies of native anthocyanins and nano-based-anthocyanins, which will be helpful in developing anthocyanin treatments as therapeutic mitochondrial antioxidant drug-like regimens to delay or prevent the progression of neurodegenerative diseases, such as AD and PD.

CDDO-Me, Sulforaphane and tBHQ attenuate the RANKL-induced osteoclast differentiation via activating the NRF2-mediated antioxidant response

Metabolic bone diseases are global public health concerns and are primarily caused by uncontrolled osteoclast (OC) formation and activation. During OC differentiation, intracellular reactive oxygen species (ROS) stimulated by receptor activator of nuclear factor kappa-B ligand (RANKL) can serve as the signaling molecules to promote osteoclastic genes expression. Nuclear factor erythroid-2 related factor 2 (NRF2), a master mediator of cellular antioxidant response, also plays a critical role in OC differentiation through the regulation of redox homeostasis. In this study, we investigated the effects of three NRF2 inducers on osteoclastogenesis, including Bardoxolone methyl (CDDO-Me), Sulforaphane (SFN), and tert-butylhydroquinone (tBHQ). By treating RAW cells with three compounds, we found that NRF2 was activated and its downstream antioxidant genes were upregulated, and the RANKL-induced intracellular ROS production and osteoclastogenesis were impaired. Additionally, the expression of nuclear factor of activated T cells c1 (NFATC1), C-FOS and tumor necrosis factor alpha (TNFα) were inhibited after acute exposures (6 h) to the three compounds. Furthermore, suppressed the expression of osteoclast differentiation-associated genes, tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), matrix metalloproteinase-9 (MMP-9) and dendritic cell-specific transmembrane protein (DC-STAMP) were observed after prolonged exposures (5 days) to the compounds. Taken together, these results suggest that CDDO-Me, SFN and tBHQ attenuate RANKL-induced osteoclastogenesis via activation of NRF2-mediated antioxidant response. Among these compounds, relatively low concentrations of CDDO-Me showed stronger active and inhibitory effects on antioxidant response and osteoclastogenesis, respectively.

Getting to the Heart of Alzheimer Disease

In a somewhat narrow diagnostic lens, Alzheimer disease (AD) has been considered a brain-specific disease characterized by the presence of Aβ (β-amyloid) plaques and tau neural fibrillary tangles and neural inflammation; these pathologies lead to neuronal death and consequently clinical symptoms, such as memory loss, confusion, and impaired cognitive function. However, for decades, researchers have noticed a link between various cardiovascular abnormalities and AD-such as heart failure, coronary artery disease, atrial fibrillation, and vasculopathy. A considerable volume of work has pointed at this head to heart connection, focusing mainly on associations between cerebral hypoperfusion and neuronal degradation. However, new evidence of a possible systemic or metastatic profile to AD calls for further analysis of this connection. Aβ aggregations-biochemically and structurally akin to those found in the typical AD pathology-are now known to be present in the hearts of individuals with idiopathic dilated cardiomyopathy, as well as the hearts of patients with AD. These findings suggest a potential systemic profile of proteinopathies and a new hypothesis for the link between peripheral and central symptoms of heart failure and AD. Herein, we provide an overview of the cardiovascular links to Alzheimer disease.

Protection of Taurine Against PFOS-Induced Neurotoxicity in PC12 Cells

As a new member of persistent organic pollutants, the potent neurotoxicity of perfluorooctane sulfonates (PFOS) found in epidemiological studies and laboratory research has drawn increasing attention around the world. Previous studies showed that apoptosis driven by oxidative stress and autophagy were both observed in PFOS-induced toxicity. Taurine has been demonstrated to exert potent protections against oxidative stress as an efficient antioxidant. Whether taurine could protect against the PFOS neurotoxicity is not known. In the present study, PC12 cells were treated with several concentrations of PFOS (31.25, 250 μM) for 24 h. 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was applied to assess the cell viability. DCFH-DA detector was used to explore the production of ROS. Caspase 3 activity was used to reflect the possible apoptosis pathway. The lyso-tracker red dying was invited to evaluate the autophagy. Our data showed that taurine could significantly reverse the decreased viability and the increased ROS production in PC12 cells treated with PFOS. Moreover, the increased autophagy and apoptosis elicited by PFOS in PC12 cells could also be attenuated by taurine. Collectively, our results indicate that taurine may be an effective antioxidant in fighting against PFOS cytotoxicity and therefore could potentially serve as a preventative and therapeutic agent for environmental pollution-related toxicities.

In Vitro Anti-Cholinesterase and Antioxidant Activity of Extracts of Moringa oleifera Plants from Rivers State, Niger Delta, Nigeria

This study evaluated Moringa oleifera extracts from two locations in Niger Delta for in vitro anti-cholinesterase and antioxidant activities. Methanolic, aqueous and ethanolic extracts of Moringa oleifera were evaluated for inhibition of acetylcholinesterase (AChE) activity, antioxidant properties, and total phenolic and flavonoid contents using standard procedures. M. oleifera extracts possessed significant and concentration dependent AChE inhibitory activity for methanolic, aqueous, and ethanolic extracts. For the most potent extracts, the percentage AChE inhibition/IC₅₀ (µg/mL) values were Moringa oleifera root methanolic extracts (MORME): ~80%/0.00845; Moringa oleifera root ethanolic extract 1 (MOREE1): ~90%/0.0563; Moringa oleifera root ethanolic extract 2 (MOREE2): ~70%/0.00175; and Moringa oleifera bark ethanolic extract (MOBEE): ~70%/0.0173. The descending order of AChE inhibitory potency of plant parts were: root > bark > leaf > flowers > seed. All M. oleifera methanolic extracts at a concentration of 1000 µg/mL displayed significant (p < 0.05–0.001) DPPH radical scavenging activity, with values of ~20–50% of that of ascorbic acid. The total phenolic content and total flavonoid content (TPC/TFC) of MORME, Moringa Oju bark methanolic extract (MOBME), MOREE1, MOREE2 and Moringa leaf ethanolic leaf extract (MLEE) were (287/254), (212/113), (223/185), (203/343) and (201/102) mg gallic acid equivalents/g and quercetin equivalents/g, respectively. There was an inverse correlation between plant extract AChE inhibition and total phenolic (p < 0.0001) and total flavonoid contents (p < 0.0012). In summary, this study revealed 5 of 19 extracts of M. oleifera that have potent in vitro anti-cholinesterase and antioxidant activities.

Evolvability of Amyloidogenic Proteins in Human Brain

Currently, the physiological roles of amyloidogenic proteins (APs) in human brain, such as amyloid-β and α-synuclein, are elusive. Given that many APs arose by gene duplication and have been resistant against the pressures of natural selection, APs may be associated with some functions that are advantageous for survival of offspring. Nonetheless, evolvability is the sole physiological quality of APs that has been characterized in microorganisms such as yeast. Since yeast and human brain may share similar strategies in coping with diverse range of critical environmental stresses, the objective of this paper was to discuss the potential role of evolvability of APs in aging-associated neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease. Given the heterogeneity of APs in terms of structure and cytotoxicity, it is argued that APs might be involved in preconditioning against diverse stresses in human brain. It is further speculated that these stress-related APs, most likely protofibrillar forms, might be transmitted to offspring via the germline, conferring preconditioning against forthcoming stresses. Thus, APs might represent a vehicle for the inheritance of the acquired characteristics against environmental stresses. Curiously, such a characteristic of APs is reminiscent of Charles Darwin's 'gemmules', imagined molecules of heritability described in his pangenesis theory. We propose that evolvability might be a physiological function of APs during the reproductive stage and neurodegenerative diseases could be a by-product effect manifested later in aging. Collectively, our evolvability hypothesis may play a complementary role in the pathophysiology of APs with the conventional amyloid cascade hypothesis.

Lessons learned from protein aggregation: toward technological and biomedical applications

The close relationship between protein aggregation and neurodegenerative diseases has been the driving force behind the renewed interest in a field where biophysics, neurobiology and nanotechnology converge in the study of the aggregate state. On one hand, knowledge of the molecular principles that govern the processes of protein aggregation has a direct impact on the design of new drugs for high-incidence pathologies that currently can only be treated palliatively. On the other hand, exploiting the benefits of protein aggregation in the design of new nanomaterials could have a strong impact on biotechnology. Here we review the contributions of our research group on novel neuroprotective strategies developed using a purely biophysical approach. First, we examine how doxycycline, a well-known and innocuous antibiotic, can reshape α-synuclein oligomers into non-toxic high-molecular-weight species with decreased ability to destabilize biological membranes, affect cell viability and form additional toxic species. This mechanism can be exploited to diminish the toxicity of α-synuclein oligomers in Parkinson's disease. Second, we discuss a novel function in proteostasis for extracellular glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in combination with a specific glycosaminoglycan (GAG) present in the extracellular matrix. GAPDH, by changing its quaternary structure from a tetramer to protofibrillar assembly, can kidnap toxic species of α-synuclein, and thereby interfere with the spreading of the disease. Finally, we review a brighter side of protein aggregation, that of exploiting the physicochemical advantages of amyloid aggregates as nanomaterials. For this, we designed a new generation of insoluble biocatalysts based on the binding of photo-immobilized enzymes onto hybrid protein:GAG amyloid nanofibrils. These new nanomaterials can be easily functionalized by attaching different enzymes through dityrosine covalent bonds.

Aβ Amyloid Pathology Affects the Hearts of Patients With Alzheimer's Disease: Mind the Heart

BACKGROUND

Individually, heart failure (HF) and Alzheimer's disease (AD) are severe threats to population health, and their potential coexistence is an alarming prospect. In addition to sharing analogous epidemiological and genetic profiles, biochemical characteristics, and common triggers, the authors recently recognized common molecular and pathological features between the 2 conditions. Whereas cognitive impairment has been linked to HF through perfusion defects, angiopathy, and inflammation, whether patients with AD present with myocardial dysfunction, and if the 2 conditions bear a common pathogenesis as neglected siblings are unknown.

OBJECTIVES

Here, the authors investigated whether amyloid beta (Aβ) protein aggregates are present in the hearts of patients with a primary diagnosis of AD, affecting myocardial function.

METHODS

The authors examined myocardial function in a retrospective cross-sectional study from a cohort of AD patients and age-matched controls. Imaging and proteomics approaches were used to identify and quantify Aβ deposits in AD heart and brain specimens compared with controls. Cell shortening and calcium transients were measured on isolated adult cardiomyocytes.

RESULTS

Echocardiographic measurements of myocardial function suggest that patients with AD present with an anticipated diastolic dysfunction. As in the brain, Aβ₄₀ and Aβ₄₂ are present in the heart, and their expression is increased in AD.

CONCLUSIONS

Here, the authors provide the first report of the presence of compromised myocardial function and intramyocardial deposits of Aβ in AD patients. The findings depict a novel biological framework in which AD may be viewed either as a systemic disease or as a metastatic disorder leading to heart, and possibly multiorgan failure. AD and HF are both debilitating and life-threatening conditions, affecting enormous patient populations. Our findings underline a previously dismissed problem of a magnitude that will require new diagnostic approaches and treatments for brain and heart disease, and their combination.

Increase of cytosolic phospholipase A2 as hydrolytic enzyme of phospholipids and autism cognitive, social and sensory dysfunction severity

BACKGROUND

Autism is neurodevelopmental disorder that is characterized by developmental, behavioral, social and sensory abnormalities. Researchers have focused in last years in immunological alteration and inflammation as a hot subject in autism field. This work aims to study the alteration in phospholipids (PE, PS, and PC) together with the change in cPLA2 concentration as the main phospholipid hydrolytic enzyme in autistic patients compared to control. It was also extended to find a correlation between these biomarkers and severity of autism measured as childhood autism rating scale (CARS), Social responsiveness scale (SRS), and Short sensory profile (SSP).

METHODS

Phospholipids (PE, PS, PC) and cPLA2 as biochemical parameters were determined in the plasma of 48 Saudi autistic male patients, categorized as mild-moderate and severe as indicated by their Childhood Autism Rating Scale (CARS), social responsiveness scale (SRS) and short sensory profile (SSP) and compared to 40 age- and gender-matched control samples.

RESULTS

The reported data demonstrate significantly lower levels of PE, PS, and PC together with a significant increase in cPLA2. While association between severity of autism and impaired phospholipid concentration was completely lacked, an association between cPLA2 and impaired sensory processing was observed.

CONCLUSIONS

The impaired phospholipid level and remarkable increased in cPLA2 concentration asserted their roles in the etiology of autism. Receiver operating characteristic analysis together with predictiveness diagrams proved that the measured parameters could be used as predictive biomarkers of clinical symptoms and provide significant guidance for future therapeutic strategy to re-establish physiological homeostasis.

Brain Anatomy in Latino Farmworkers Exposed to Pesticides and Nicotine

OBJECTIVE

Migrant tobacco farmworkers experience regular occupational exposure to pesticides and nicotine. The present study was designed to determine whether there are differences in brain anatomy between Latino farmworkers and non-farmworkers.

METHODS

Magnetic resonance brain images were compared between farmworkers and non-farmworkers. In addition, blood cholinesterase activity and urinary cotinine levels were also used to identify associations with pesticide and nicotine exposure.

RESULTS

Farmworkers had greater gray matter signal in putamen and cerebellum, and lower gray matter signal in frontal and temporal lobes. Urinary cotinine was associated with the observed differences in brain anatomy, but blood cholinesterase activity was not.

CONCLUSIONS

Nicotine exposure was associated with neuroanatomical differences between Latino farmworkers and non-farmworkers. Future studies are needed to differentiate iron deposition from brain atrophy and to further assess the potential role of nicotine and pesticide exposure.

Cu,Zn-SOD deficiency induces the accumulation of hepatic collagen

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic diseases, and results in the development of fibrosis. Oxidative stress is thought to be one of the underlying causes of NAFLD. Copper/zinc superoxide dismutase (SOD1) is a primary antioxidative enzyme that scavenges superoxide anion radicals. Although SOD1 knockout (KO) mice have been reported to develop fatty livers, it is not known whether this lack of SOD1 leads to the development of fibrosis. Since the accumulation of collagen typically precedes liver fibrosis, we assessed the balance between the synthesis and degradation of collagen in liver tissue from SOD1 KO mice. We found a higher accumulation of collagen in the livers of SOD1 KO mice compared to wild type mice. The level of expression of HSP47, a chaperone of collagen, and a tissue inhibitor (TIMP1) of matrix metalloproteinases (a collagen degradating enzyme) was also increased in SOD1 KO mice livers. These results indicate that collagen synthesis is increased but that its degradation is inhibited in SOD1 KO mice livers. Moreover, SOD1 KO mice liver sections were extensively modified by advanced glycation end products (AGEs), which suggest that collagen in SOD1 KO mice liver might be also modified with AGEs and then would be more resistant to the action of collagen degrading enzymes. These findings clearly show that oxidative stress plays an important role in the progression of liver fibrosis.

Enhanced Phospholipase A2 Group 3 Expression by Oxidative Stress Decreases the Insulin-Degrading Enzyme

Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD) model mice showed decreased insulin-degrading enzyme (IDE) levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa^-/-) mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa^-/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3); Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa^-/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD.

Defining the Relationships Among Retinal Function, Layer Thickness and Visual Behavior During Oxidative Stress-Induced Retinal Degeneration

PURPOSE

The purpose of this study was to identify how changes in retinal structure and function correlate with visual deficits during increasing amounts of retinal degeneration.

MATERIALS AND METHODS

Retinal degeneration was induced in adult mice by subretinal injections of paraquat (PQ) (0.2-1 mM). Retinal anatomy and photoreceptor layer thickness were quantified by histology and optical coherence tomography (OCT), retinal function was measured using electroretinography (ERG), and visual behavior were measured by optokinetic tracking, at 1 to 3 week post-injury.

RESULTS

Photoreceptor layer structure, function and visual behavior declined at a linear rate over time following PQ-induced degeneration, with the correlations between outcome measures being lowest at mild injury levels and increasing with injury severity. Overall reductions in visual acuity were highly correlated with declines in retinal thickness (r(2) = 0.78) and function (r(2) = 0.67) and retinal thickness correlated with photoreceptor function (r(2) = 0.72). ERG a-wave scotopic amplitudes showed a stronger correspondence to retinal structure and visual behavior than b-waves.

CONCLUSIONS

Measurements of photoreceptor loss at the structural and functional levels showed good correspondence with degeneration-associated changes in visual behavior after oxidative stress injury. The results provide new insight about the relative kinetics of measurements of retinal degeneration induced by oxidative stress, which could guide the choice of optimal outcome measurements for other retinal diseases.