Impact of air pollutants on oxidative stress in common autophagy-mediated aging diseases

From Inhalation to Neurodegeneration: Air Pollution as a Modifiable Risk Factor for Alzheimer's Disease

Air pollution, a growing concern for public health, has been linked to various respiratory and cardiovascular diseases. Emerging evidence also suggests a link between exposure to air pollutants and neurodegenerative diseases, particularly Alzheimer's disease (AD). This review explores the composition and sources of air pollutants, including particulate matter, gases, persistent organic pollutants, and heavy metals. The pathophysiology of AD is briefly discussed, highlighting the role of beta-amyloid plaques, neurofibrillary tangles, and genetic factors. This article also examines how air pollutants reach the brain and exert their detrimental effects, delving into the neurotoxicity of air pollutants. The molecular mechanisms linking air pollution to neurodegeneration are explored in detail, focusing on oxidative stress, neuroinflammation, and protein aggregation. Preclinical studies, including in vitro experiments and animal models, provide evidence for the direct effects of pollutants on neuronal cells, glial cells, and the blood-brain barrier. Epidemiological studies have reported associations between exposure to air pollution and an increased risk of AD and cognitive decline. The growing body of evidence supporting air pollution as a modifiable risk factor for AD underscores the importance of considering environmental factors in the etiology and progression of neurodegenerative diseases, in the face of worsening global air quality.

Global challenges in aging: insights from comparative biology and one health

The well-being of wildlife populations, ecosystem health, and human health are interlinked, and preserving wildlife is crucial for sustaining healthy ecosystems. Wildlife numbers, and in particular avian populations, have steeply declined over the past century, associated with anthropogenic factors originating from industry, urbanization, changing land use, habitat loss, pollution, emerging diseases, and climate change. All these factors combine to exert increasing stress and impair health for both humans and wildlife, with diminished metabolic, immune, and reproductive function, deteriorating overall health, and reduced longevity. The "toxic aging coin" suggests that these stressors may have dual impacts on aging-they can accelerate the aging process, and older individuals may struggle to cope with pollutants compared to younger ones. These responses are reflected in the health and productivity of individuals, and at a larger scale, the health and ability of populations to withstand disturbances. To understand the potential risk to health over the lifespan, it is important to articulate some of these global challenges and consider both their impacts on aging populations and on the aging process. In this review, we use the toxic aging coin and One Health conceptual frameworks to examine the interconnected health of humans, wildlife, and ecosystems. This exploration aims to develop proactive approaches for optimizing wildlife and human health.

Particulate matter exposure and neurodegenerative diseases: A comprehensive update on toxicity and mechanisms

Exposure to particulate matter (PM) has been associated with a range of health impacts, including neurological abnormalities that affect neurodevelopment, neuroplasticity, and behavior. Recently, there has been growing interest in investigating the possible relationship between PM exposure and the onset and progression of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. However, the precise mechanism by which PM affects neurodegeneration is still unclear, even though several epidemiological and animal model studies have provided mechanistic insights. This article presents a review of the current research on the neurotoxicity of PM and its impact on neurodegenerative diseases. This review summarizes findings from epidemiological and animal model studies collected through searches in Google Scholar, PubMed, Web of Science, and Scopus. This review paper also discusses the reported effects of PM exposure on the central nervous system and highlights research gaps and future directions. The information presented in this review may inform public health policies aimed at reducing PM exposure and may contribute to the development of new treatments for neurodegenerative diseases. Further mechanistic and therapeutic research will be needed to fully understand the relationship between PM exposure and neurodegenerative diseases.

Impact of Global Climate Change on Pulmonary Health: Susceptible and Vulnerable Populations

As fossil fuel combustion continues to power the global economy, the rate of climate change is accelerating, causing severe respiratory health impacts and large disparities in the degree of human suffering. Hotter and drier climates lead to longer and more severe wildland fire seasons, impairing air quality around the globe. Hotter temperatures lead to higher amounts of ozone and particles, causing the exacerbation of chronic respiratory diseases and premature mortality. Longer pollen seasons and higher pollen concentrations provoke allergic airway diseases. In arid regions, accelerated land degradation and desertification are promoting dust pollution and impairing food production and nutritional content that are essential to respiratory health. Extreme weather events and flooding impede healthcare delivery and can lead to poor indoor air quality due to mold overgrowth. Climate and human activities that harm the environment and ecosystem may also affect the emergence and spread of viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and associated morbidity and mortality exacerbated by air pollution. Children and elderly individuals are more susceptible to the adverse health effects of climate change. Geographical and socioeconomic circumstances, together with a decreased capacity to adapt, collectively increase vulnerability to the adverse effects of climate change. Successful mitigation of anthropogenic climate change is dependent on the commitment of energy-intensive nations to manage greenhouse gas emissions, as well as societal support and response to aggravating factors. In this review, we focus on the respiratory health impacts of global climate change, with an emphasis on susceptible and vulnerable populations and low- and middle-income countries.

The coupling of graphene, graphitic carbon nitride and cellulose to fabricate zinc oxide-based sensors and their enhanced activity towards air pollutant nitrogen dioxide

It is desirable but challenging to sense toxic nitrogen dioxide (NO₂) for it has become one of the most prominent air pollutants. Zinc oxide-based gas sensors are known to detect NO₂ gas efficiently, however, the sensing mechanism and involved intermediates structures remain underexplored. In the work, a series of sensitive materials, including zinc oxide (ZnO) and its composites ZnO/X [X = Cel (cellulose), CN (g-C₃N₄) and Gr (graphene)] have been comprehensively examined by density functional theory. It is found that ZnO favors adsorbing NO₂ over ambient O₂, and produces nitrate intermediates; and H₂O is chemically held by zinc oxide, in line with the non-negligible impact of humidity on the sensitivity. Of the formed composites, ZnO/Gr exhibits the best NO₂ gas-sensing performance, which is proved by the calculated thermodynamics and geometrical/electronic structures of reactants, intermediates and products. The interfacial interaction has been elaborated on for composites (ZnO/X) as well as their complexes (ZnO- and ZnO/X-adsorbates). The current study well explains experimental findings and opens up a way to design and unearth novel NO₂ sensing materials.

Redox Regulatory Changes of Circadian Rhythm by the Environmental Risk Factors Traffic Noise and Air Pollution

Significance: Risk factors in the environment such as air pollution and traffic noise contribute to the development of chronic noncommunicable diseases. Recent Advances: Epidemiological data suggest that air pollution and traffic noise are associated with a higher risk for cardiovascular, metabolic, and mental disease, including hypertension, heart failure, myocardial infarction, diabetes, arrhythmia, stroke, neurodegeneration, depression, and anxiety disorders, mainly by activation of stress hormone signaling, inflammation, and oxidative stress. Critical Issues: We here provide an in-depth review on the impact of the environmental risk factors air pollution and traffic noise exposure (components of the external exposome) on cardiovascular health, with special emphasis on the role of environmentally triggered oxidative stress and dysregulation of the circadian clock. Also, a general introduction on the contribution of circadian rhythms to cardiovascular health and disease as well as a detailed mechanistic discussion of redox regulatory pathways of the circadian clock system is provided. Future Directions: Finally, we discuss the potential of preventive strategies or "chrono" therapy for cardioprotection. Antioxid. Redox Signal. 37, 679-703.

Effects of Air Pollution on Cellular Senescence and Skin Aging

The human skin is exposed daily to different environmental factors such as air pollutants and ultraviolet (UV) light. Air pollution is considered a harmful environmental risk to human skin and is known to promote aging and inflammation of this tissue, leading to the onset of skin disorders and to the appearance of wrinkles and pigmentation issues. Besides this, components of air pollution can interact synergistically with ultraviolet light and increase the impact of damage to the skin. However, little is known about the modulation of air pollution on cellular senescence in skin cells and how this can contribute to skin aging. In this review, we are summarizing the current state of knowledge about air pollution components, their involvement in the processes of cellular senescence and skin aging, as well as the current therapeutic and cosmetic interventions proposed to prevent or mitigate the effects of air pollution in the skin.

Comprehensive Review Regarding Mercury Poisoning and Its Complex Involvement in Alzheimer's Disease

Mercury (Hg) is considered one of the most widespread toxic environmental pollutants, which seems to have multiple effects on organisms even at low concentrations. It has a critical role in many health problems with harmful consequences, with Hg primarily targeting the brain and its components, such as the central nervous system (CNS). Hg exposure was associated with numerous CNS disorders that frequently trigger Alzheimer's disease (AD). Patients with AD have higher concentrations of Hg in blood and brain tissue. This paper aims to emphasize a correlation between Hg and AD based on the known literature in the occupational field. The outcome shows that all these concerning elements could get attributed to Hg. However, recent studies did not investigate the molecular level of Hg exposure in AD. The present review highlights the interactions between Hg and AD in neuronal degenerations, apoptosis, autophagy, oxidative stress (OS), mitochondrial malfunctions, gastrointestinal (GI) microflora, infertility and altering gene expression.

Bisphenol S exposure induces cytotoxicity in mouse Leydig cells

Bisphenol S (BPS), an increasingly used alternative to bisphenol A, has been linked to testosterone deficiency and male reproductive dysfunction in laboratory animals. This study aimed to examine the cytotoxicity of BPS exposure to Leydig cells and to investigate its possible mechanisms. After treatment with BPS (100, 200 and 400 μM) for 48 h in vitro, TM3 mouse Leydig cells exhibited a dose-dependent decrease in the viability. Furthermore, BPS challenge triggered oxidative stress manifested by compromised activities of superoxide dismutase and catalase with exaggerated formation of reactive oxygen species. Especially, BPS exposure resulted in augmented mitochondrial permeability transition pore opening, dissipated mitochondrial membrane potential and reduced ATP generation, along with an altered energy metabolism. Moreover, BPS stimulation enhanced BAX expression and caspase-3 activity and inhibited BCL-2 expression. In addition, BPS-treated TM3 cells showed an accumulation of autophagic vacuoles, together with increased Beclin1 and P62 expression and elevated LC3B-II/LC3B-I ratio. These results demonstrated that in vitro exposure to BPS exerted cytotoxicity to TM3 Leydig cells through inducing oxidative stress, mitochondrial impairment, autophagic disturbance and apoptosis.

Particulate Air Pollution and Risk of Neuropsychiatric Outcomes. What We Breathe, Swallow, and Put on Our Skin Matters

We appraise newly accumulated evidence of the impact of particle pollution on the brain, the portals of entry, the neural damage mechanisms, and ultimately the neurological and psychiatric outcomes statistically associated with exposures. PM pollution comes from natural and anthropogenic sources such as fossil fuel combustion, engineered nanoparticles (NP ≤ 100 nm), wildfires, and wood burning. We are all constantly exposed during normal daily activities to some level of particle pollution of various sizes-PM_2.5 (≤2.5 µm), ultrafine PM (UFP ≤ 100 nm), or NPs. Inhalation, ingestion, and dermal absorption are key portals of entry. Selected literature provides context for the US Environmental Protection Agency (US EPA) ambient air quality standards, the conclusions of an Independent Particulate Matter Review Panel, the importance of internal combustion emissions, and evidence suggesting UFPs/NPs cross biological barriers and reach the brain. NPs produce oxidative stress and neuroinflammation, neurovascular unit, mitochondrial, endoplasmic reticulum and DNA damage, protein aggregation and misfolding, and other effects. Exposure to ambient PM_2.5 concentrations at or below current US standards can increase the risk for TIAs, ischemic and hemorrhagic stroke, cognitive deficits, dementia, and Alzheimer's and Parkinson's diseases. Residing in a highly polluted megacity is associated with Alzheimer neuropathology hallmarks in 99.5% of residents between 11 months and ≤40 y. PD risk and aggravation are linked to air pollution and exposure to diesel exhaust increases ALS risk. Overall, the literature supports that particle pollution contributes to targeted neurological and psychiatric outcomes and highlights the complexity of the pathophysiologic mechanisms and the marked differences in pollution profiles inducing neural damage. Factors such as emission source intensity, genetics, nutrition, comorbidities, and others also play a role. PM_2.5 is a threat for neurological and psychiatric diseases. Thus, future research should address specifically the potential role of UFPs/NPs in inducing neural damage.

Health disparities: Intracellular consequences of social determinants of health

Health disparities exist dependent on socioeconomic status, living conditions, race/ethnicity, diet, and exposures to environmental pollutants. Herein, the various exposures contributing to a person's exposome are collectively considered social determinants of health (SDOH), and the SDOH-exposome impacts health more than health care. This review discusses the extent of evidence of the physiologic consequences of these exposures at the intracellular level. We consider how the SDOH-exposome, which captures how individuals live, work and age, induces cell processes that modulate a conceptual "redox rheostat." Like an electrical resistor, the SDOH-exposome, along with genetic predisposition and age, regulate reductive and oxidative (redox) stress circuits and thereby stimulate inflammation. Regardless of the source of the SDOH-exposome that induces chronic inflammation and immunosenescence, the outcome influences cardiometabolic diseases, cancers, infections, sepsis, neurodegeneration and autoimmune diseases. The endogenous redox rheostat is connected with regulatory molecules such as NAD⁺/NADH and SIRT1 that drive redox pathways. In addition to these intracellular and mitochondrial processes, we discuss how the SDOH-exposome can influence the balance between metabolism and regulation of immune responsiveness involving the two main molecular drivers of inflammation, the NLRP3 inflammasome and NF-κB induction. Mitochondrial and inflammasome activities play key roles in mediating defenses against pathogens and controlling inflammation before diverse cell death pathways are induced. Specifically, pyroptosis, cell death by inflammation, is intimately associated with common disease outcomes that are influenced by the SDOH-exposome. Redox influences on immunometabolism including protein cysteines and ion fluxes are discussed regarding health outcomes. In summary, this review presents a translational research perspective, with evidence from in vitro and in vivo models as well as clinical and epidemiological studies, to outline the intracellular consequences of the SDOH-exposome that drive health disparities in patients and populations. The relevance of this conceptual and theoretical model considering the SARS-CoV-2 pandemic are highlighted. Finally, the case of asthma is presented as a chronic condition that is modified by adverse SDOH exposures and is manifested through the dysregulation of immune cell redox regulatory processes we highlight in this review.

The pathogenesis of age-related macular degeneration is not inflammatory mediated but is instead due to immunosenescence-related failure of tissue repair

A natural consequence of everyday tissue metabolism is cell injury or stress. This injury activates a canonical immune-mediated inflammatory response in order to achieve tissue repair so that homeostasis is maintained. With aging there is increased tissue injury and therefore increasing demands placed on an immune system, which itself is aging (immunosenescence). Thus, the increased reparative demands are reflected by an increased inflammatory load both locally and systemically. Eventually, if the reparative demands are excessive, the aging immune system is overwhelmed and disease ensues. In the macula this age-related failure in repair gives rise to age-related macular degeneration (AMD). The hypothesis proposed herein is therefore, that AMD is due to age-related failure of tissue repair and the chronic inflammation associated with this failure ('inflammaging') is both a surrogate and biomarker of this reparative failure and not in itself the primary cause of disease. Such a hypothesis can be applied to all the diseases of aging and by extension suggests that effective therapies should be aimed at facilitating repair through immunotherapy, possibly and perhaps controversially, through the promotion of inflammation rather than the current approach of its inhibition (anti-inflammatory strategies), the latter which can ultimately only hinder the repair process and thereby lead to the persistence of disease.

Accurate, Low Cost PM2.5 Measurements Demonstrate the Large Spatial Variation in Wood Smoke Pollution in Regional Australia and Improve Modeling and Estimates of Health Costs

The accuracy and utility of low-cost PM2.5 sensors was evaluated for measuring spatial variation and modeling population exposure to PM2.5 pollution from domestic wood-heating (DWH) in Armidale, a regional town in New South Wales (NSW), Australia, to obtain estimates of health costs and mortality. Eleven ‘PurpleAir’ (PA) monitors were deployed, including five located part of the time at the NSW government station (NSWGov) to derive calibration equations. Calibrated PA PM2.5 were almost identical to the NSWGov tapered element oscillating microbalance (TEOM) and Armidale Regional Council’s 2017 DustTrak measurements. Spatial variation was substantial. National air quality standards were exceeded 32 times from May–August 2018 at NSWGov and 63 times in one residential area. Wood heater use by about 50% of households increased estimated annual PM2.5 exposure by over eight micrograms per cubic meter, suggesting increased mortality of about 10% and health costs of thousands of dollars per wood heater per year. Accurate real-time community-based monitoring can improve estimates of exposure and avoid bias in estimating dose-response relationships. Efforts over the past decade to reduce wood smoke pollution proved ineffective, perhaps partly because some residents do not understand the health impacts or costs of wood-heating. Real-time Internet displays can increase awareness of DWH and bushfire pollution and encourage governments to develop effective policies to protect public health, as recommended by several recent studies in which wood smoke was identified as a major source of health-hazardous air pollution.

Lysosomes, Autophagy, and Hormesis in Cell Physiology, Pathology, and Age-Related Disease

Autophagy has been strongly linked with hormesis, however, it is only relatively recently that the mechanistic basis underlying this association has begun to emerge. Lysosomal autophagy is a group of processes that degrade proteins, protein aggregates, membranes, organelles, segregated regions of cytoplasm, and even parts of the nucleus in eukaryotic cells. These degradative processes are evolutionarily very ancient and provide a survival capability for cells that are stressed or injured. Autophagy and autophagic dysfunction have been linked with many aspects of cell physiology and pathology in disease processes; and there is now intense interest in identifying various therapeutic strategies involving its regulation. The main regulatory pathway for augmented autophagy is the mechanistic target of rapamycin (mTOR) cell signaling, although other pathways can be involved, such as 5'-adenosine monophosphate-activated protein kinase. Mechanistic target of rapamycin is a key player in the many highly interconnected intracellular signaling pathways and is responsible for the control of cell growth among other processes. Inhibition of mTOR (specifically dephosphorylation of mTOR complex 1) triggers augmented autophagy and the search is on the find inhibitors that can induce hormetic responses that may be suitable for treating many diseases, including many cancers, type 2 diabetes, and age-related neurodegenerative conditions.

Anti-oxidative hormetic effects of cellular autophagy induced by nutrient deprivation in a molluscan animal model

This investigation using a molluscan animal model tested the hypothesis that experimentally induced lysosomal autophagy protects against oxidative cell injury. Induction of augmented lysosomal autophagy has previously been implicated in this protective process. Four treatment groups of blue mussels (Mytilus galloprovincialis) were used: Group 1 (fed - control), Group 2 (fasted), Group 3 (copper + fed) and Group 4 (copper + fasted). Groups 2 and 4 were fasted in order to trigger autophagy; and samples of hepatopancreas (liver analogue or digestive gland) from all 4 groups were taken at 3, 6 and 15 days. Treatment with copper provided a positive reference for oxidative stress: Groups 3 and 4 were treated with copper (10 μg Cu²⁺/animal/day) for three days only. Oxidative damage and cellular injury in hepatopancreatic digestive cells was found to decrease in Group 2 (fasted) compared to Group 1 (fed - control). Group 3 (fed + copper) showed clear evidence of oxidative stress and cell injury, as well as induction of antioxidant activities. Group 4 (copper + fasted) had a reduced uptake of copper and toxicity of copper was also reduced, compared with Group 3. It was concluded that augmented autophagy had a hormetic cytoprotective anti-oxidant effect.

Oxidative stress, lysosomal damage and dysfunctional autophagy in molluscan hepatopancreas (digestive gland) induced by chemical contaminants

Autophagy is a highly conserved evolutionary survival or defence process that enables cells and organisms to survive periods of environmental stress by breaking down cellular organelles and macromolecules in autolysosomes to provide a supply of nutrients for cell maintenance. However, autophagy is also a part of normal cellular physiology that facilitates the turnover of cellular constituents under normal conditions: it can be readily augmented by mild environmental stress; but becomes dysfunctional with severe oxidative stress leading to cellular pathology. The molluscan hepatopancreas or digestive gland provides a versatile and environmentally relevant model to investigate lysosomal autophagy and stress-induced dysfunctional autophagy. This latter process has been implicated in many animal and human disease conditions, including degenerative and neurodegenerative diseases, as well as obesity related conditions. Many environmental pollutants have also been found to induce dysfunctional autophagy in molluscan hepatopancreatic digestive cells, and in this study, the marine blue mussel Mytilus galloprovincialis was exposed for 7 days to: 0.1 μM, 1 μM and 10 μM concentrations of fluoranthene and phenanthrene (PAHs); chlorpyrifos and malathion (organophosphorus compounds); atrazine (triazine herbicide); copper (transition metal) and dodecylbenzene sulphonic acid (LAS, surfactant). The marine snail or periwinkle, Littorina littorea, was also exposed to phenanthrene, chlorpyrifos and copper. Indices of oxidative stress, cell injury and dysfunctional autophagy were measured (i.e., lysosomal membrane stability, protein carbonyls, lipofuscin, and lysosomal accumulation of lipid or lipidosis). Evidence of oxidative stress, based on the elevation of lipofuscin and protein carbonyls, was found for all compounds tested; with chlorpyrifos being the most toxic to both species. Dysfunctional autophagy was induced by all of the compounds tested in both species, except for atrazine in mussels. This failure of normal autophagy was consistently associated with oxidative stress. Autophagic dysfunction is an important emerging feature in the aetiology of many disease conditions in animals and humans; and an explanatory conceptual mechanistic model has been developed for dysregulation of autophagy in response to oxidative stress.

Altered Features of Vimentin-containing Cells in Cerebrum of Tg(SOD1*G93A)1Gur Mice: A Preliminary Study on Cerebrum Endogenous Neural Precursor Cells in Amyotrophic Lateral Sclerosis

Vimentin-containing cells (VCCs) are potential neural precursor cells in central nervous systems, Thus, we studied the alteration of VCCs proliferation, differentiation and migration in the cerebrum during different stages of Tg(SOD1*G93A)1Gur mice. It aims to search potential ways regulating the proliferation, differentiation and migration of endogenous VCCs, to enhance their neural repair function and to cure or prevent from the development of ALS. We observed and analyzed the proliferation, differentiation and migration of VCCs in different anatomic regions and cell types of cerebrum at different stages including the pre-onset (60-70 days), onset (90-100 days) and progression (120-130 days) of wild-type (WT) and Tg(SOD1*G93A)1Gur mice using the fluorescent immunohistochemical technology. Results showed that VCCs in the cerebrum were mostly distributed in the ventricular system, periventricular structures, the hippocampus and the cerebral cortex in WT mice. VCCs significantly reduced in the motor cortex and the cingulate cortex in Tg(SOD1*G93A)1Gur mice. All vimentin expressed in the extranuclear and almost all VCCs were astrocytes in WT mice and Tg(SOD1*G93A)1Gur mice. There were no significant difference in the number of Brdu and nestin positive cells in left and right brains of WT mice and Tg(SOD1*G93A)1Gur mice in the period of 60-130 days. Our data suggested that there existed extensively NPCs in the cerebrum of adult mice. In ALS-like Tg(SOD1*G93A)1Gur mice, VCCs in the motor cortex, the olfactory cortex and the cingulate cortex showed that no any proliferation and redistribution in neural cells of VCCs in the cerebrum occurred in all stages of ALS, might migrate to damaged regions.

Association between ambient air pollution and Parkinson's disease: Systematic review and meta-analysis

Air pollution has been evaluated as a possible risk factor for Parkinson's disease (PD), but, the present results are inconsistent and have not been combined. We performed a systematic review and meta-analysis to estimate the association between long-term exposure to ambient air pollution and PD, given the nature of disease etiology. A total of 10 studies were identified by searching Web of Science, Science Direct, and PubMed before October 2017. We found a significantly increased risk of PD with 10 parts per billion (ppb) increase in nitrogen oxides (NO_x) exposure (relative risk (RR) = 1.06; 95% confidence interval (CI): 1.04, 1.09). The pooled RR for the association between carbon monoxide (CO) exposure, 1 parts per million (ppm) increment, and the risk of PD was 1.65 (95% CI: 1.10, 2.48). The pooled RRs for the association between nitrogen dioxide (NO₂) and ozone (O₃) exposure per 1 ppb increment, and the risk of PD were 1.01 (95% CI: 1.00, 1.03) and 1.01 (95% CI: 1.00, 1.02), respectively. There was a significant heterogeneity in the meta-analysis for fine particulate matter (PM_2.5), NO₂, sulfur dioxide (SO₂), and CO. We concluded that NO₂, NO_x, CO and O₃ exposure were associated with an increased risk of PD, although there is high risk of bias. The dose-response effects evaluated by high-quality studies are needed. Researches should be expanded to low- and/or middle- income countries where indoor and outdoor air pollution are high. CAPSULE: Long-term exposure to ambient NO₂, NO_x, CO and O₃ can increase the risk of Parkinson's disease.

Repetitive transcranial magnetic stimulation improves cognitive function of Alzheimer's disease patients

Repetitive transcranial magnetic stimulation (rTMS) acts as a kind of widely-applied and non-invasive method in the intervention of some neurological disorders. This prospective, randomized, double-blind, placebo-controlled trial investigates the effect of rTMS on 30 cases of Alzheimer’s disease (AD) participants, who were classified into mild and moderate groups. Neuropsychological tests were carried out using the AD Assessment Scale-cognitive subscale (ADAS-cog), Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and World Health Organization University of California-Los Angeles, Auditory Verbal Learning Test (WHO-UCLA AVLT) before, immediately after, and 6 weeks after the intervention. In this work, data from 30 AD patients revealed that there was no obvious interaction effect of time-by-group. The ADAS-cog, MMSE and WHO-UCLA AVLT score in the rTMS group was significantly improved compared with baselines at 6 weeks after treatment (all p<0.05). Meanwhile, MoCA scores were also obviously ameliorated in the mild AD patients with rTMS. Besides, subgroup analysis showed that the effect of rTMS on the memory and language of mild AD patients was superior to those of moderate AD patients. In conclusion, our findings suggested that repetitive transcranial magnetic stimulation improves cognitive function, memory and language level of AD patients, especially in the mild stage of AD. Thus, rTMS can be recommended as a promising adjuvant therapy combined with cholinesterase inhibitors at the mild stage of AD patients.

A general neurologist's perspective on the urgent need to apply resilience thinking to the prevention and treatment of Alzheimer's disease

The goal of this article was to look at the problem of Alzheimer's disease (AD) through the lens of a socioecological resilience-thinking framework to help expand our view of the prevention and treatment of AD. This serious and complex public health problem requires a holistic systems approach. We present the view that resilience thinking, a theoretical framework that offers multidisciplinary approaches in ecology and natural resource management to solve environmental problems, can be applied to the prevention and treatment of AD. Resilience thinking explains a natural process that occurs in all complex systems in response to stressful challenges. The brain is a complex system, much like an ecosystem, and AD is a disturbance (allostatic overload) within the ecosystem of the brain. Resilience thinking gives us guidance, direction, and ideas about how to comprehensively prevent and treat AD and tackle the AD epidemic.

Autophagy couteracts weight gain, lipotoxicity and pancreatic β-cell death upon hypercaloric pro-diabetic regimens

In the last years, autophagy has been revealed as an essential pathway for multiple biological processes and physiological functions. As a catabolic route, autophagy regulation by nutrient availability has been evolutionarily conserved from yeast to mammals. On one hand, autophagy induction by starvation is associated with a significant loss in body weight in mice. Here, we demonstrate that both genetic and pharmacological inhibition of the autophagy process compromise weight loss induced by starvation. Moreover, autophagic potential also impacts on weight gain induced by distinct hypercaloric regimens. Atg4b-deficient mice, which show limited autophagic competence, exhibit a major increase in body weight in response to distinct obesity-associated metabolic challenges. This response is characterized by the presence of larger adipocytes in visceral fat tissue, increased hepatic steatosis, as well as reduced glucose tolerance and attenuated insulin responses. Similarly, autophagy-deficient mice are more vulnerable to experimentally induced type-I diabetes, showing an increased susceptibility to acute streptozotocin administration. Notably, pharmacological stimulation of autophagy in wild-type mice by spermidine reduced both weight gain and obesity-associated alterations upon hypercaloric regimens. Altogether, these results indicate that systemic autophagic activity influences the resilience of the organism to weight gain induced by high-calorie diets, as well as to the obesity-associated features of both type-1 and type-2 diabetes.

Protein oxidation and degradation caused by particulate matter

Particulate matter (PM) modulates the expression of autophagy; however, the role of selective autophagy by PM remains unclear. The objective of this study was to determine the underlying mechanisms in protein oxidation and degradation caused by PM. Human epithelial A549 cells were exposed to diesel exhaust particles (DEPs), urban dust (UD), and carbon black (CB; control particles). Cell survival and proliferation were significantly reduced by DEPs and UD in A549 cells. First, benzo(a)pyrene diolepoxide (BPDE) protein adduct was caused by DEPs at 150 μg/ml. Methionine oxidation (MetO) of human albumin proteins was induced by DEPs, UD, and CB; however, the protein repair mechanism that converts MetO back to methionine by methionine sulfoxide reductases A (MSRA) and B3 (MSRB3) was activated by DEPs and inhibited by UD, suggesting that oxidized protein was accumulating in cells. As to the degradation of oxidized proteins, proteasome and autophagy activation was induced by CB with ubiquitin accumulation, whereas proteasome and autophagy activation was induced by DEPs without ubiquitin accumulation. The results suggest that CB-induced protein degradation may be via an ubiquitin-dependent autophagy pathway, whereas DEP-induced protein degradation may be via an ubiquitin-independent autophagy pathway. A distinct proteotoxic effect may depend on the physicochemistry of PM.

Paget's disease of bone: an osteoimmunological disorder?

Osteoimmunology represents a large area of research resulting from the cross talk between bone and immune systems. Many cytokines and signaling cascades are involved in the field of osteoimmunology, originating from various cell types. The RANK/receptor activator of nuclear factor Kappa-B ligand (RANKL)/osteoprotegerin (OPG) signaling has a pivotal role in osteoimmunology, in addition to proinflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1, IL-6, and IL-17. Clinically, osteoimmunological disorders, such as rheumatoid arthritis, osteoporosis, and periodontitis, should be classified according to their pattern of osteoimmunological serum biomarkers. Paget’s disease of bone is a common metabolic bone disorder, resulting from an excessively increased bone resorption coupled with aberrant bone formation. With the exception of the cellular responses to measles virus nucleocapsid protein and the interferon-gamma signature, the exact role of the immune system in Paget’s disease of bone is not well understood. The cytokine profiles, such as the increased levels of IL-6 and the interferon-gamma signature observed in this disease, are also very similar to those observed in other osteoimmunological disorders. As a potential osteoimmunological disorder, the treatment of Paget’s disease of bone may also benefit from progress made in targeted therapies, in particular for receptor activator of nuclear factor Kappa-B ligand and IL-6 signaling inhibition.