VEGF overexpression in the astroglial cells of rat brainstem following ozone exposure

Genome-wide profiling of long non-coding RNA following ozone exposure: a randomized, controlled exposure trial

BACKGROUND

Exposure to ambient ozone has been associated with extrapulmonary health, but the underlying mechanisms remain to be understood. LncRNAs are involved in the regulation of gene expression, but their regulatory mechanisms in ozone-related health effects are scarcely explored.

OBJECTIVE

To investigate genome-wide lncRNA changes after short-term ozone exposure and their regulatory roles in ozone exposure and gene expression.

METHOD

We conducted a randomized, crossover, controlled exposure trial in 32 healthy college students in Shanghai, China. Each participant received both 200-ppb ozone exposure and filtered air exposure for two hours in a random order with a 14-day washout period. Blood samples were collected after each exposure and used for lncRNA sequencing. Differentially expressed lncRNAs between the two exposures were identified using orthogonal partial least squares discriminant analysis and linear regression analysis. LncRNAs-targeted mRNAs were mapped and subjected to enrichment analyses. We also constructed lncRNA-miRNA-mRNA networks.

RESULTS

A total of 90 lncRNAs were differentially expressed after exposure to ozone, with 49 up-regulated and 41 down-regulated. Enrichment analyses suggested that these dysregulated lncRNAs were involved in a variety of biological processes, including those related to oxidative stress, inflammation response, and cell proliferation, development, and differentiation. Multiple pathways such as IL-17 signaling, NF-kB signaling, and Rho GTPases signaling were also enriched. Furthermore, the lncRNA-miRNA-mRNA network revealed that specific lncRNAs may regulate the expression of inflammation- and angiogenesis-related genes by interacting with miRNAs, such as NEAT1/hsa-miR-500a-3p/SIGLEC8, NEAT1/hsa-miR-6835-3p/SLC16A14, OIP5-AS1/miR-183-5p/EGR1, and SNHG25/hsa-miR-663a/FOSB axes.

CONCLUSION

This study characterized a thorough profile of human lncRNAs following short-term ozone exposure and suggested the regulatory roles of these lncRNAs in ozone-induced inflammatory responses and angiogenesis, providing novel epigenetic insights into the mechanisms of the health effects of ozone exposure.

Ozone Therapy for Breast Cancer: An Integrative Literature Review

Breast cancer is the most prevalent form of cancer in women. Despite significant advances in conventional treatment, additional safer complementary treatment options are needed. Recently, ozone therapy has been considered as a type of medical adjunctive treatment that could inhibit cancer cell survival and reduce chemoresistance. However, only a few studies have been conducted on its use in breast cancer, and the optimal dosage and time of administration are unknown. Currently, preclinical studies suggest that ozone alone or in combination with chemotherapy is an effective method for inhibiting breast cancer cell growth. However, rather than investigating the effects of ozone as an antitumor therapy, current clinical trials have generally assessed its effect as an adjunctive therapy for reducing chemotherapy-induced side effects, increasing oxygen tension, normalizing blood flow, restoring blood lymphocytes more rapidly, and reducing fatigue symptoms. In this article, the use of ozone as a medical adjunctive treatment for breast cancer and its role in integrative therapy are summarized and discussed.

Ozonated saline intradermal injection: promising therapy for accelerated cutaneous wound healing in diabetic rats

Introduction

The use of ozonized water is gaining importance in medicine due to its effects on hyperglycemia and wound healing mechanisms.

Methods

This experiment was conducted to assess the impacts of intradermal administration of ozonated water on acute skin wound healing in a diabetic rat model. Sixty-four adult male Wistar rats were randomly divided into two groups: an ozonated water group (O3W) and a control group (CG). Experimental diabetes was chemically induced in the rats by the intraperitoneal administration of 60 mg/kg streptozotocin. One week later, full-thickness skin surgical wounds (1 cm2) were created between the two shoulders of the rats under general anesthesia. The wounds were then daily irrigated with normal saline (CG) or intradermally injected with 1 mL of ozonated water at 10 mg/L O3W. Wound healing was evaluated through macroscopic analysis, measuring wound size, diameter, and percentage of contraction rate before wounding and at 3, 7, 9, 12, 14, 18, 21, 24, and 28 days post-wounding. On days 7, 14, 21, and 28 after induction of the wounds, the body weights and blood glucose levels of rats (8 per group) were measured before the rats were euthanized. Moreover, the morphological structure of the tissue, vascular endothelial and transforming growth factor (VEGF and TGF) affinity and gene expression were examined.

Results

The O3W group had significantly lower blood glucose levels and wound size and gained body weight. Additionally, epithelial vascularization, stromal edema, TGF, and VEGF gene expression significantly improved in the O3W group.

Discussion

Therefore, ozonated water has the potential to enhance and promote cutaneous wound healing in diabetic rats.

Effects of ambient fine particulates, nitrogen dioxide, and ozone on maturation of functional brain networks across early adolescence

BACKGROUND

Air pollution is linked to neurodevelopmental delays, but its association with longitudinal changes in brain network development has yet to be investigated. We aimed to characterize the effect of PM2.5, O3, and NO2 exposure at ages 9-10 years on changes in functional connectivity (FC) over a 2-year follow-up period, with a focus on the salience (SN), frontoparietal (FPN), and default-mode (DMN) brain networks as well as the amygdala and hippocampus given their importance in emotional and cognitive functioning.

METHODS

A sample of children (N = 9,497; with 1-2 scans each for a total of 13,824 scans; 45.6% with two brain scans) from the Adolescent Brain Cognitive Development (ABCD) Study® were included. Annual averages of pollutant concentrations were assigned to the child's primary residential address using an ensemble-based exposure modeling approach. Resting-state functional MRI was collected on 3T MRI scanners. First, developmental linear mixed-effect models were performed to characterize typical FC development within our sample. Next, single- and multi-pollutant linear mixed-effect models were constructed to examine the association between exposure and intra-network, inter-network, and subcortical-to-network FC change over time, adjusting for sex, race/ethnicity, income, parental education, handedness, scanner type, and motion.

RESULTS

Developmental profiles of FC over the 2-year follow-up included intra-network integration within the DMN and FPN as well as inter-network integration between the SN-FPN; along with intra-network segregation in the SN as well as subcortical-to-network segregation more broadly. Higher PM2.5 exposure resulted in greater inter-network and subcortical-to-network FC over time. In contrast, higher O3 concentrations resulted in greater intra-network, but less subcortical-to-network FC over time. Lastly, higher NO2 exposure led to less inter-network and subcortical-to-network FC over the 2-year follow-up period.

CONCLUSION

Taken together, PM2.5, O3, and NO2 exposure in childhood relate to distinct changes in patterns of network maturation over time. This is the first study to show outdoor ambient air pollution during childhood is linked to longitudinal changes in brain network connectivity development.

Ozone therapy for high-grade glioma: an overview

High-grade gliomas (grades III and IV) are highly malignant and aggressive brain tumors that present significant treatment challenges. Despite advances in surgery, chemotherapy, and radiation therapy, the prognosis for patients with glioma remains poor, with a median overall survival (mOS) range of 9-12 months. Therefore, exploring new and effective therapeutic strategies to improve glioma prognosis is of utmost importance and ozone therapy is a viable option. Ozone therapy has been used in various cancers, such as colon, breast, and lung, yielding significant results in preclinical studies and clinical trials. Only a few studies have been conducted on gliomas. Furthermore, since the metabolism of brain cells involves aerobic glycolysis, ozone therapy may improve the oxygen condition and enhance glioma radiation treatment. However, understanding the correct ozone dosage and optimal time of administration remains challenging. Herein, we hypothesize that ozone therapy should be more effective in gliomas compared with other tumors. This study provides an overview of the use of ozone therapy in high-grade glioma, including mechanisms of action, preclinical data, and clinical evidence.

Affective disorder and brain alterations in children and adolescents exposed to outdoor air pollution

BACKGROUND

Childhood and adolescence are critical periods for the development of the brain. However, a limited number of studies have explored how air pollution may associate with affective symptoms in youth.

METHODS

We performed a comprehensive review of the existing research on the associations between outdoor air pollution and affective disorders, suicidality, and the evidence for brain changes in youth. PRISMA guidelines were followed and PubMed, Embase, Web of Science, Cochrane Library, and PsychINFO databases were searched from their inception to June 2022.

RESULTS

From 2123 search records, 28 papers were identified as being relevant for studying the association between air pollution and affective disorders (n = 14), suicide (n = 5), and neuroimaging-based evidence of brain alterations (n = 9). The exposure levels and neuropsychological performance measures were highly heterogeneous and confounders including traffic-related noise, indoor air pollution, and social stressors were not consistently considered. Notwithstanding, 10 out of the 14 papers provide evidence that air pollution is associated with increased risk of depression symptoms, and 4 out of 5 papers provide evidence that air pollution might trigger suicidal attempts and behaviors. Besides, 5 neuroimaging studies revealed decreased gray-matter volume in the Cortico-Striato-Thalamo-Cortical neurocircuitry, and two found white matter hyperintensities in the prefrontal lobe.

CONCLUSIONS

Outdoor air pollution is associated with increased risks of affective disorders and suicide in youth, and there is evidence for associated structural and functional brain abnormalities. Future studies should determine the specific effects of each air pollutant, the critical exposure levels, and population susceptibility.

Impact of ground-level ozone exposure on sleep quality and electroencephalogram patterns at different time scales

Ozone exposure is associated with various adverse health outcomes, but its impact on sleep quality is uncertain. Here we assessed the causal effect of long-term (yearly and monthly) exposure to ozone on nocturnal workday sleep time in a national representative sample from the China Family Panel Study, using a difference-in-differences approach. We further followed ninety healthy Chinese young adults four times in four seasons from September 2020 to June 2021, measured their daily sleep architecture using accelerometers, ascertained daily ozone exposure, recorded 5-min eye-closed resting-state electroencephalogram (EEG) signals at the last day of each one-week-long measurement session, and explored the effect of ozone exposure on objectively-measured sleep architecture. In the national sample, we found that every 1 interquartile range (IQR) μg/m³ increase in yearly and monthly ozone exposure was causally associated with 7.31 (p = 0.0039) and 4.19 (p = 0.040) minutes decline in nocturnal workday sleep time; the dose-response curve represented a quasi-linear pattern with no safety threshold, and plateaued at higher concentrations. In the small-scale study with objectively-measured sleep architecture, we found that every 1 IQR μg/m³ increase in the weekly ozone exposure was associated with 5.33 min decrease in night-time total sleep time (p = 0.031), 1.63 percentage points decrease in sleep efficiency (p < 0.001), 1.99 min increase in sleep latency (p = 0.0070), and 5.34 min increase in wake after sleep onset time (p = 0.0016) in a quasi-linear pattern. Notably, we found the accumulating trend of ozone exposure on sleep quality during both the short-term and long-term periods. We also found that short-term ozone exposure was associated with altered EEG patterns, mediated by sleep quality. This study indicates that long-term and short-term ozone exposures have negative and accumulating impacts on sleep quality and might impair brain functioning. More hidden health burdens of ozone are worth exploring.

Perspectives of ozone induced neuropathology and memory decline in Alzheimer's disease: A systematic review of preclinical evidences

This systematic review aims to discover the plausible mechanism of Ozone in A.D., to boost translational research. The main focus of our review lies in understanding the effects of ozone pollution on the human brain and causing degenerative disease. Owing to the number of works carried out as preclinical evidence in association with oxidative stress and Alzheimer's disease and the lack of systematic review or meta-analysis prompted us to initiate a study on Alzheimer's risk due to ground-level ozone. We found relevant studies from PubMed, ScienceDirect, Proquest, DOAJ, and Scopus, narrowing to animal studies and the English language without any time limit. The searches will be re-run before the final analysis. This work was registered in Prospero with Reg ID CRD42022319360, followed the PRISMA-P framework, and followed the PICO approach involving Population, Intervention/Exposure, Comparison, and Outcomes data. Bibliographic details of 16 included studies were studied for Exposure dose of ozone, duration, exposure, and frequency with control and exposure groups. Primary and secondary outcomes were assessed based on pathology significance, and results were significant in inducing Alzheimer-like pathology by ozone. In conclusion, ozone altered oxidative stress, metabolic pathway, and amyloid plaque accumulation besides endothelial stress response involving mitochondria as the critical factor in ATP degeneration, caspase pathway, and neuronal damage. Thus, ozone is a criteria pollutant to be focused on in mitigating Alzheimer's Disease pathology.

Individual exposure to urban air pollution and its correlation with placental angiogenic markers in the first trimester of pregnancy, in São Paulo, Brazil

Pollution of the atmosphere is known that may lead to adverse obstetric outcomes, including fetal growth restriction, gestational hypertension, and preeclampsia. Such disorders are correlated with imbalances in angiogenic factors, which may also be involved in the pathological mechanism as the pollutants impact placental and maternal physiology. In the first trimester of gestation, this study assessed the outcomes of personal maternal short period exposure to air pollution on soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PLGF) of pregnant women blood concentrations. This was a cross-sectional study, held in the city of São Paulo, Brazil, and conducted with low-risk pregnant women, who carried personal passive nitrogen dioxide (NO2) and ozone (O3) monitors for about a few days preceding the ultrasound evaluation, and on this day, the venous blood sample was collected to measure the angiogenic factors sFlt1 and PLGF and their ratio (sFlt1/PLGF) by enzyme-linked immunosorbent assay (ELISA). By means of multiple regression models, the effect of the studied pollutants on the log-transformed concentrations of the angiogenic factors was evaluated. One hundred thirty-one patients were included. The log of the sFlt1/PLGF ratio increased with rising NO2 levels (p = 0.021 and beta = 0.206), and the log of the PLGF concentration showed a negative correlation with NO2 (p = 0.008 and beta = - 0.234). NO2, an indicator of the levels of primary air pollutants, presented significant positive correlation with an increased sFlt1/PLGF ratio and diminished PLGF levels, which may reflect an antiangiogenic state generated by air pollution exposure.

Ozonized solutions favor the repair of experimentally induced skin wounds in rats

ABSTRACT: This study aimed to evaluate and compare the effects of ozonized solutions on tissue wound repair in rats. Treatments consisted of ozonized water (GA), 0.9% sodium chloride (GCL), ozonized oil (GO), and 0.2% allantoin cream (GAL). The morphometric evaluation showed that wounds of the GA group presented a higher degree of retraction (p<0.05) at three and eight days of treatment (37.96 and 84.81%, respectively). Picrosirius red staining showed that groups GA and GO presented higher deposition (p<0.05) of type I collagen at 15 and 22 days of treatment, respectively. The neovascularization was higher in wounds of group GO on days 3, 8, and 15 (p<0.05), with higher VEGF immunostaining. (p<0.05). Thus, ozonized water enhances wound retraction and assists in the maturation and remodeling phase, while ozonized oil promotes higher neovascularization during tissue repair and higher deposition of type I collagen from the third week of treatment.

Association between ozone air pollution levels and hospitalizations for depression in Taipei: a time-stratified case-crossover study

Epidemiologic studies reported an association between exposure to ambient air pollutants and increased mortality rate attributed to suicide and suicide attempts. The investigation sought to determine whether there is an association between short-term ambient ozone (O₃) level exposure and daily hospital admissions for depression in Taipei from 2009 to 2013 using a time-stratified case-crossover design. In our single-pollutant model (with no adjustment for other pollutants), the % increase in daily hospital admissions for depression was 12% on warm days and 30% on cool days, per interquartile range (IQR) rise in O₃ levels, respectively. Ozone levels were significantly correlated with daily number of depression admissions both on warm and cool days. In our two-pollutant models, O₃ levels remained significant after adjusting for other air pollutants, including particulate matter (PM₁₀, PM_2.5), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO) both on warm and cool days. Although O₃ levels tended to be higher on warm days, admissions for depression were higher on cool days, suggesting that the relationship between O₃ concentrations and depression may be affected by temperature. Further study is needed to better understand these findings.

Astrocytes in the nucleus of the solitary tract: Contributions to neural circuits controlling physiology

The nucleus of the solitary tract (NTS) is the primary brainstem centre for the integration of physiological information from the periphery transmitted via the vagus nerve. In turn, the NTS feeds into downstream circuits regulating physiological parameters. Astrocytes are glial cells which have key roles in maintaining CNS tissue homeostasis and regulating neuronal communication. Recently an increasing number of studies have implicated astrocytes in the regulation of synaptic transmission and physiology. This review aims to highlight evidence for a role for astrocytes in the functions of the NTS. Astrocytes maintain and modulate NTS synaptic transmission contributing to the control of diverse physiological systems namely cardiovascular, respiratory, glucoregulatory, and gastrointestinal. In addition, it appears these cells may have a role in central control of feeding behaviour. As such these cells are a key component of signal processing and physiological control by the NTS.

Mitochondrial Bioenergetics in Brain Following Ozone Exposure in Rats Maintained on Coconut, Fish and Olive Oil-Rich Diets

Dietary supplementation with omega-3 and omega-6 fatty acids offer cardioprotection against air pollution, but these protections have not been established in the brain. We tested whether diets rich in omega-3 or -6 fatty acids offered neuroprotective benefits, by measuring mitochondrial complex enzyme I, II and IV activities and oxidative stress measures in the frontal cortex, cerebellum, hypothalamus, and hippocampus of male rats that were fed either a normal diet, or a diet enriched with fish oil olive oil, or coconut oil followed by exposure to either filtered air or ozone (0.8 ppm) for 4 h/day for 2 days. Results show that mitochondrial complex I enzyme activity was significantly decreased in the cerebellum, hypothalamus and hippocampus by diets. Complex II enzyme activity was significantly lower in frontal cortex and cerebellum of rats maintained on all test diets. Complex IV enzyme activity was significantly lower in the frontal cortex, hypothalamus and hippocampus of animals maintained on fish oil. Ozone exposure decreased complex I and II activity in the cerebellum of rats maintained on the normal diet, an effect blocked by diet treatments. While diet and ozone have no apparent influence on endogenous reactive oxygen species production, they do affect antioxidant levels in the brain. Fish oil was the only diet that ozone exposure did not alter. Microglial morphology and GFAP immunoreactivity were assessed across diet groups; results indicated that fish oil consistently decreased reactive microglia in the hypothalamus and hippocampus. These results indicate that acute ozone exposure alters mitochondrial bioenergetics in brain and co-treatment with omega-6 and omega-3 fatty acids alleviate some adverse effects within the brain.

Air pollutants and daily number of admissions to psychiatric emergency services: evidence for detrimental mental health effects of ozone

AIMS

Aim of the current study is to investigate the associations between daily levels of air pollutants (particulate matter, ozone, carbon monoxide, nitrogen dioxide) and daily admissions for mental disorders to the emergency department of two general hospitals in Umbria region (Italy).

METHODS

We collected data about daily admissions to psychiatric emergency services of two general hospitals, air pollutants' levels and meteorological data for the time period 1 January 2015 until 31 December 2016. We assessed the impact of an increase in air pollutants on the number of daily admissions using a time-series econometric framework.

RESULTS

A total of 1860 emergency department admissions for mental disorders were identified. We observed a statistically significant impact of ozone levels on daily admissions. The estimated coefficient of O3 is statistically significant at the 1% level. All other pollutants were not significantly associated with the number of daily admissions.

CONCLUSIONS

Short-term exposure to ozone may be associated with increased psychiatric emergency services admissions. Findings add to previous literature on existing evidence for air pollution to have an impact on mental health. Ozone may be considered a potential environmental risk factor for impaired mental health.

Mechanisms of pathophysiology of blood vessels in patients with multiple sclerosis treated with ozone therapy: a systematic review

Multiple sclerosis (MS) defines as an intricate disease with numerous pathophysiological processes, including: inflammation, demyelination, oxidative stress, axonal damage, and repair mechanisms that interfere in this disease and highly related to the pathogenesis of MS. In parallel, recent studies have shown that the ozone administration could be very useful in treating neurological disorders and inflammatory and degenerative neurological diseases. In this review, we examine the recent literature on the pathophysiology of blood vessels in patients with multiple sclerosis treated with ozone therapy. (www.actabiomedica.it)

Ambient ozone exposure and depressive symptoms in adolescents: Results of the GINIplus and LISA birth cohorts

BACKGROUND

Depression has been associated with air pollution, as reported by animal and epidemiological studies. However, the relationship between ozone exposure and depression, especially among adolescents, is scarcely investigated.

OBJECTIVES

The study aimed to analyze associations between ozone exposure and depressive symptoms among German adolescents.

METHODS

The analyses were based on 2827 adolescents aged 15 from Munich and Wesel areas of the GINIplus and LISA birth cohorts. The depressive symptoms were assessed by the Depression Screener for Teenagers (DesTeen). Long-term ozone exposure was estimated by optimal interpolation techniques and assigned to home addresses. Nitrogen dioxide (NO₂) and particulate matter with an aerodynamic diameter < 10 µm (PM₁₀) were assessed by land use regression models. For short-term exposure, maximum 8-h averages of ozone and daily average concentrations of NO₂ and PM₁₀ from the background monitoring sites 0 (same day), 1, 2, 3, and 7 days prior to depressive symptoms assessment were adopted. The cross-sectional analyses were conducted by adjusted logistic regression models controlling for residuals of NO₂ and PM₁₀, and covariates identified by a directed acyclic graph.

RESULTS

The prevalence of depressive symptoms ranged from 10.9% to 13.8% depending on regions. Overall, long- and short-term exposure to ozone were not statistically significantly associated with depressive symptoms. However, subgroup analysis showed inconsistent significant protective associations for short-term exposure to ozone lag 0 day (same day) and depressive symptoms in Wesel (OR = 0.76, 95% CI: (0.59, 0.98)), but not in Munich (OR = 1.00, 95% CI: (0.83, 1.21)).

CONCLUSIONS

Our study does not support the hypothesis that ambient ozone exposure might increase the prevalence of depressive symptoms in German adolescents. Nevertheless, due to a lack of similar studies, these results need to be replicated in other samples.

Ozone Atmospheric Pollution and Alzheimer's Disease: From Epidemiological Facts to Molecular Mechanisms

Atmospheric pollution is a well-known environmental hazard, especially in developing countries where millions of people are exposed to airborne pollutant levels above safety standards. Accordingly, several epidemiological and animal studies confirmed its role in respiratory and cardiovascular pathologies and identified a strong link between ambient air pollution exposure and adverse health outcomes such as hospitalization and mortality. More recently, the potential deleterious effect of air pollution inhalation on the central nervous system was also investigated and mounting evidence supports a link between air pollution exposure and neurodegenerative pathologies, especially Alzheimer's disease (AD). The focus of this review is to highlight the possible link between ozone air pollution exposure and AD incidence. This review's approach will go from observational and epidemiological facts to the proposal of molecular mechanisms. First, epidemiological and postmortem human study data concerning residents of ozone-severely polluted megacities will be presented and discussed. Then, the more particular role of ozone air pollution in AD pathology will be described and evidenced by toxicological studies in rat or mouse with ozone pollution exposure only. The experimental paradigms used to reproduce in rodent the human exposure to ozone air pollution will be described. Finally, current insights into the molecular mechanisms through which ozone inhalation can affect the brain and play a role in AD development or progression will be recapitulated.

Ambient ozone exposure and mental health: A systematic review of epidemiological studies

BACKGROUND

An increasing number of studies have suggested adverse effects of air pollution on mental health. Given the potentially negative impacts of ozone exposure on the immune and nervous system driven from animal experiments, ozone might also affect mental health. However, no systematic synthesis of the relevant literature has been conducted yet. This paper reviews the studies that assessed the link between ozone exposure and mental health thus far.

METHODS

We followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA). PubMed, Web of Science, and EMBASE were systematically searched for epidemiological studies on ambient ozone exposure and mental or behavioral disorders according to the International Classification of Disease. The period was from January 1st, 1960 to December 14st, 2017. We evaluated the risk of bias by the Office of Health Assessment and Translation (OHAT) Approach and Navigation Guide for each included study.

RESULTS

The keyword search yielded 567 results. 31 papers met the selection criteria and were included in the review. We found only inconclusive evidence that ozone affects autism spectrum disorders, impairment of cognitive functions and dementia, depression, and suicide. The large heterogeneity of study designs, outcome definitions and study quality in general prevented us from conducting meta-analyses.

CONCLUSIONS

Current evidence for an association between ambient ozone exposure and mental health outcomes is inconclusive and further high quality studies are needed to assess any potential links given the strong biologic plausibility.

Lung transcriptional profiling: insights into the mechanisms of ozone-induced pulmonary injury in Wistar Kyoto rats

Acute ozone-induced pulmonary injury and inflammation are well characterized in rats; however, mechanistic understanding of the pathways involved is limited. We hypothesized that acute exposure of healthy rats to ozone will cause transcriptional alterations, and comprehensive analysis of these changes will allow us to better understand the mechanism of pulmonary injury and inflammation. Male Wistar Kyoto rats (10-12 week) were exposed to air, or ozone (0.25, 0.5 or 1.0 ppm) for 4 h and pulmonary injury and inflammation were assessed at 0-h or 20-h (n = 8/group). Lung gene expression profiling was assessed at 0-h (air and 1.0 ppm ozone, n = 3-4/group). At 20-h bronchoalveolar lavage, fluid protein and neutrophils increased at 1 ppm ozone. Numerous genes involved in acute inflammatory response were up-regulated along with changes in genes involved in cell adhesion and migration, steroid metabolism, apoptosis, cell cycle control and cell growth. A number of NRF2 target genes were also induced after ozone exposure. Based on expression changes, Rela, SP1 and TP3-mediated signaling were identified to be mediating downstream changes. Remarkable changes in the processes of endocytosis provide the insight that ozone-induced lung injury and inflammation are likely initiated by changes in cell membrane components and receptors likely from oxidatively modified lung lining lipids and proteins. In conclusion, ozone-induced injury and inflammation are preceded by changes in gene targets for cell adhesion/migration, apoptosis, cell cycle control and growth regulated by Rela, SP1 and TP53, likely mediated by the process of endocytosis and altered steroid receptor signaling.

Associations of maternal personal exposure to air pollution on fetal weight and fetoplacental Doppler: A prospective cohort study

We determined the influence of maternal air pollution exposure during each trimester of pregnancy on fetal and birth weight and fetoplacental hemodynamics. In total, 366 women with singleton pregnancies were prospectively followed in the city of São Paulo, Brazil. Nitrogen dioxide (NO2) and ozone (O3) were measured during each trimester using passive personal samplers. We evaluated fetal weight and Doppler velocimetry data from the umbilical, middle cerebral, and uterine arteries in the 3rd trimester, and birth weight. Multivariate analysis was performed, controlling for known determinants of fetal weight. Exposure to higher levels of O3 during the 2nd trimester was associated with higher umbilical artery pulsatility indices (PIs) [p=0.013; beta=0.017: standard error (SE)=0.007]. Exposure to higher levels of O3 during the 3rd trimester was associated with lower umbilical artery PIs (p=0.011; beta=-0.021; SE=0.008). Our results suggest that in the environment of São Paulo, O3 may affects placental vascular resistance.

Astrocytes as new targets to improve cognitive functions

Astrocytes are now viewed as key elements of brain wiring as well as neuronal communication. Indeed, they not only bridge the gap between metabolic supplies by blood vessels and neurons, but also allow fine control of neurotransmission by providing appropriate signaling molecules and insulation through a tight enwrapping of synapses. Recognition that astroglia is essential to neuronal communication is nevertheless fairly recent and the large body of evidence dissecting such role has focused on the synaptic level by identifying neuro- and gliotransmitters uptaken and released at synaptic or extrasynaptic sites. Yet, more integrated research deciphering the impact of astroglial functions on neuronal network activity have led to the reasonable assumption that the role of astrocytes in supervising synaptic activity translates in influencing neuronal processing and cognitive functions. Several investigations using recent genetic tools now support this notion by showing that inactivating or boosting astroglial function directly affects cognitive abilities. Accordingly, brain diseases resulting in impaired cognitive functions have seen their physiopathological mechanisms revisited in light of this primary protagonist of brain processing. We here provide a review of the current knowledge on the role of astrocytes in cognition and in several brain diseases including neurodegenerative disorders, psychiatric illnesses, as well as other conditions such as epilepsy. Potential astroglial therapeutic targets are also discussed.

Ozone Therapy in Ethidium Bromide-Induced Demyelination in Rats: Possible Protective Effect

Multiple sclerosis, an autoimmune inflammatory disease of the central nervous system, is characterized by excessive demyelination. The study aimed to investigate the possible protective effect of ozone (O3) therapy in ethidium bromide (EB)-induced demyelination in rats either alone or in combination with corticosteroids in order to decrease the dose of steroid therapy. Rats were divided into Group (1) normal control rats received saline, Group (2) Sham-operated rats received saline, Group (3) Sham-operated rats received vehicle (oxygen), Group (4) EB-treated rats received EB, Group (5) EB-treated rats received O3, Group (6) EB-treated rats received methylprednisolone (MP), and Group (7) EB-treated rats received half the dose of MP concomitant with O3. EB-treated rats showed a significant increase in the number of footfalls in the grid walk test, decreased brain GSH, and paraoxonase-1 enzyme activity, whereas brain MDA, TNF-α, IL-1β, INF-γ, Cox-2 immunoreactivity, and p53 protein levels were increased. A significant decline in brain serotonin, dopamine, norepinephrine, and MBP immunoreactivity was also reported. Significant improvement of the above-mentioned parameters was demonstrated with the administration of either MP or O3, whereas best amelioration was achieved by combining half the dose of MP with ozone.

Ozone promotes regeneration by regulating the inflammatory response in zebrafish

Ozone is thought to advance wound healing by inhibiting inflammation, but the mechanism of this phenomenon has not been determined. Although the zebrafish is often used in regeneration experiments, there has been no report of zebrafish treated with ozonated water. We successfully established a zebrafish model of ozonated water treatment and demonstrate that ozonated water stimulates the regeneration of the zebrafish caudal fin, its mechanism, and time dependence. The growth rate of the caudal fin and the number of neutrophils migrating to the caudal fin wound after resection were higher in the experimental (ozonated) group than in the control group, preliminarily confirming that ozone-promoted regeneration is related to the stimulation of an early inflammatory response by ozone. Ozone modulated the expression of tumor necrosis factor-α (TNF-α) in two ways by regulating interleukin 10 (IL-10) expression. Therefore, ozone promotes tissue regeneration by regulating the inflammatory pathways. This effect of ozone in an experimental zebrafish model is demonstrated for the first time, confirming its promotion of wound healing and the mechanism of its effect in tissue regeneration. These results will open up new directions for ozone and regeneration research.

The effects of ozone exposure and associated injury mechanisms on the central nervous system

Ozone (O3) is a component of photochemical smog, which is a major air pollutant and demonstrates properties that are harmful to health because of the toxic properties that are inherent to its powerful oxidizing capabilities. Environmental O3 exposure is associated with many symptoms related to respiratory disorders, which include loss of lung function, exacerbation of asthma, airway damage, and lung inflammation. The effects of O3 are not restricted to the respiratory system or function - adverse effects within the central nervous system (CNS) such as decreased cognitive response, decrease in motor activity, headaches, disturbances in the sleep-wake cycle, neuronal dysfunctions, cell degeneration, and neurochemical alterations have also been described; furthermore, it has also been proposed that O3 could have epigenetic effects. O3 exposure induces the reactive chemical species in the lungs, but the short half-life of these chemical species has led some authors to attribute the injurious mechanisms observed within the lungs to inflammatory processes. However, the damage to the CNS induced by O3 exposure is not well understood. In this review, the basic mechanisms of inflammation and activation of the immune system by O3 exposure are described and the potential mechanisms of damage, which include neuroinflammation and oxidative stress, and the signs and symptoms of disturbances within the CNS caused by environmental O3 exposure are discussed.

The adverse effects of air pollution on the nervous system

Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health.

Vascular endothelial growth factor is upregulated by L-dopa in the parkinsonian brain: implications for the development of dyskinesia

Angiogenesis and increased permeability of the blood-brain barrier have been reported to occur in animal models of Parkinson's disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood-brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson's disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson's disease.

Ozone inhalation activates stress-responsive regions of the CNS

Ozone (O(3)), a major component of air pollution, has considerable impact on public health. Besides the well-described respiratory tract inflammation and dysfunctions, there is accumulating evidence indicating that O(3) exposure affects brain functions. However, the mechanisms through which O(3) exerts toxic effects on the brain remain poorly understood. This work aimed at precisely characterizing CNS neuronal activation after O(3) inhalation using Fos staining in adult rat. We showed that, together with lung inflammation, O(3) exposure caused a sustained time- and dose-dependent neuronal activation in the dorsolateral regions of the nucleus tractus solitarius overlapping terminal fields of lung afferents running in vagus nerves. Furthermore, we highlighted neuronal activation in interconnected central structures such as the caudal ventrolateral medulla, the parabrachial nucleus, the central nucleus of the amygdala, the bed nucleus of the stria terminalis and the paraventricular hypothalamic nucleus. In contrast, we did not detect any neuronal activation in the thoracic spinal cord where lung afferents running in spinal nerves terminate. Overall, our results demonstrate that O(3) challenge evokes a lung inflammation that induces the activation of nucleus tractus solitarius neurons through the vagus nerves and promotes neuronal activation in stress-responsive regions of the CNS.

Air pollution: mechanisms of neuroinflammation and CNS disease

Air pollution has been implicated as a chronic source of neuroinflammation and reactive oxygen species (ROS) that produce neuropathology and central nervous system (CNS) disease. Stroke incidence and Alzheimer's and Parkinson's disease pathology are linked to air pollution. Recent reports reveal that air pollution components reach the brain; systemic effects that impact lung and cardiovascular disease also impinge upon CNS health. While mechanisms driving air pollution-induced CNS pathology are poorly understood, new evidence suggests that microglial activation and changes in the blood-brain barrier are key components. Here we summarize recent findings detailing the mechanisms through which air pollution reaches the brain and activates the resident innate immune response to become a chronic source of pro-inflammatory factors and ROS, culminating in CNS disease.