Polluted Air Exposure Compromises Corneal Immunity and Exacerbates Inflammation in Acute Herpes Simplex Keratitis

Regulation of inflammatory cytokines and activation of PI3K/Akt pathway by Yiqi Jiedu Formula in recurrent Herpes Simplex Keratitis: Experimental and network pharmacology evidence

OBJECTIVE

This study investigates the therapeutic effects of the Yiqi Jiedu (YQJD) formula on Herpes Simplex Keratitis (HSK) induced by herpes simplex virus type 1 (HSV-1) and elucidates its mechanisms of action through experimental and network pharmacology approaches.

METHODS

Active ingredients of the YQJD formula were identified using UPLC-HRMS. Network pharmacology was employed to predict shared targets between YQJD and HSK, focusing on the PI3K/Akt signaling pathway. Molecular docking was performed to assess the interaction between key ingredients and targets. In vivo, an HSK mouse model was used to evaluate the YQJD formula's impact on corneal lesions and inflammatory factors. In vitro, human corneal epithelial cells (HCECs) were infected with HSV-1 to assess the formula's effect on IL-4 expression.

RESULTS

UPLC-HRMS identified 34 compounds in YQJD, with Isovitexin and Formononetin exhibiting high oral bioavailability. Network analysis revealed 97 intersecting targets, implicating the PI3K/Akt pathway in YQJD's mechanism. Molecular docking showed strong affinities between IL-4, IL-6, and YQJD compounds. In vivo, YQJD significantly improved corneal lesions and modulated the expression of IL-4, IL-6, and AKT. In vitro, YQJD-containing serum regulated IL-4 expression in HCECs post-HSV-1 infection.

CONCLUSION

The YQJD formula ameliorates Herpes Simplex Keratitis by regulating inflammatory cytokines and activating the PI3K/Akt pathway, offering a potential therapeutic strategy for HSK.

The Impact of Air Temperature and Pollution on Admissions for Acute Ophthalmic Inflammation at the Emergency Eye Department in Katowice, Poland, from 2011 to 2023

Purpose

To determine if significant correlations occur between recorded values for a) annual temperature, b) air pollution levels, and the prevalence of acute ophthalmic inflammation among patients attending an eye emergency department in an urban setting between 2011 and 2023.

Patients and Methods

A data bank of cases that attended an eye emergency unit (Medical University of Silesia, Katowice, Poland) between 1/1/2011 and 31/12/2023 was accessed. Cases were classified into inflammatory or noninflammatory ophthalmic groups. The former were then subdivided into subgroups for blepharitis, orbital inflammation, lacrimal system inflammation, conjunctivitis, scleritis, keratitis, uveitis with retinitis, endophthalmitis, and optic neuritis. Data on local temperatures and air pollution levels were obtained from available official publications.

Results

Reporting key results (p < 0.05).Total attending the emergency unit increased from 8,172 to 14,261 (8854 during pandemic lockdown in 2020), prevalence of all acute ophthalmic inflammation (y) decreased from 64.70% to 55.40% and prevalence of conjunctivitis within this group decreased from 53.96% to 36.23%.Annual average (±SD) temperature (x, °C) in Silesia increased from 8.33°C (±9.18°) in 2010 to 10.64°C (±6.83°C) in 2020 (paired t-test, p = 0.04). Curvi-linear regression revealed, y = 1.915x3-55.624x2+534.09x-1631.2, (n = 10, r2= 0.489).Prevalence of conjunctivitis was directly correlated with atmospheric concentrations of sulphur dioxide, carbon monoxide and particulate matter in suspended dust with a diameter≤10 microns.After factoring all cases of conjunctivitis, a) prevalence of endophthalmitis, uveitis with retinitis, and scleritis were negatively correlated with temperature, b) atmospheric concentrations of certain pollutants were positively correlated with the prevalence of endophthalmitis, uveitis with retinitis, scleritis and keratitis; and negatively correlated with the prevalence of orbital and lacrimal inflammation, blepharitis, and optic neuritis.

Conclusion

Air pollutants and temperature are linked to the prevalence of certain acute ophthalmic inflammations. Some correlations are negative suggesting some protection against the development of certain conditions. However, negative correlational effects do not necessarily imply negative causal effects.

Polychlorinated Biphenyls Induce Cytotoxicity and Inflammation in an In Vitro Model of an Ocular Barrier

Polychlorinated biphenyls (PCBs) are heterogeneous, synthetic, and widespread organochlorine compounds, and are one of the persistent organic pollutants present in improperly dumped waste and electronic equipment (e-waste), with a high bioaccumulation potential. In this study, the toxicity of Aroclor 1254 (a mixture of commercial PCBs) in human corneal epithelial cells (HCEpiCs), in an in vitro model of an ocular barrier, was evaluated. Aroclor 1254 (0.1-10 μg/mL) reduced cell viability, trans-endothelial electric resistance (TEER) and cell migration. Moreover, it induced an inflammatory response, as indicated by the increase in cPLA2 activity, PGE2 production, phosphorylation of ERK 1/2 and p-38, and release of inflammatory cytokines. Aroclor 1254 can damage corneal cells, compromising the integrity of the eye's outermost barrier. This damage may facilitate the occurrence of infectious processes that are physiologically prevented by the corneal barrier.

Impact of particulate matter and air pollution on ocular surface disease: A systematic review of preclinical and clinical evidence

PURPOSE

Exposure to particulate matter (PM) and air pollution has been implicated in the etiology of ocular surface diseases (OSD). The purpose of this systematic review is to evaluate and synthesize peer-reviewed literature on the impact of PM exposure on the ocular surface, integrating results from preclinical in vitro and in vivo studies with clinical findings to provide a comprehensive understanding of molecular mechanisms, physiological effects, clinical implications, and potential therapies to target acute and chronic PM-induced ocular toxicity.

METHODS

A systematic literature search was performed using PubMed and EMBASE over the period from 2009 to 2024 following the recommendations for the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. 102 studies were identified that met the inclusion/exclusion criteria. All studies were assessed for the risk of bias and qualitative data were analyzed.

RESULTS

Preclinical studies using models of corneal and conjunctival cells found that exposure to PM and similar air pollutants resulted in apoptosis, primarily via inflammatory and oxidative stress pathways as well as allergic and immune responses. Animal models resulted in phenotypes reminiscent of that of dry eye disease, presenting with reduced tear volumes and ocular surface damage. These results were corroborated by clinical studies, which reported that patients commonly presented with symptoms of itching, burning, and irritation, and ocular surface signs correlated with a diagnosis of dry eye disease, conjunctivitis, and allergic eye disease.

CONCLUSIONS

This systematic review provides a comprehensive summary of our current understanding of PM exposure on the ocular surface, highlighting the correlation between exposure to PM and ocular surface dysfunction.

Uncovering the impact and mechanisms of air pollution on eye and ear health in China

Increasing air pollution could undermine human health, but the causal link between air pollution and eye and ear health has not been well-studied. Based on four-week-level records of eye and ear health over 1991-2015 provided by the China Health and Nutrition Survey, we estimate the causal effect of air pollution on eye and ear health. Using two-stage least squares estimation, we find that eye or ear disease possibility rises 1.48% for a 10 μg/m3 increase in four-week average PM2.5 concentration. The impacts can last about 28 weeks and will be insignificant afterward. Females, individuals aged 60 years and over, with high exposure environments, relatively poor economic foundations, and low knowledge levels are more vulnerable to such negative influences. Behavioral channels like more smoking activities and less sleeping activities could partly explain this detrimental effect. Our findings enlighten how to minimize the impact of air pollution and protect public health.

The impact of population influx on infectious diseases - from the mediating effect of polluted air transmission

The global population influx during the COVID-19 pandemic poses significant challenges to public health, making the prevention and control of infectious diseases a pressing concern. This paper aims to examine the impact of population influx on the spread of infectious diseases, with a specific emphasis on the mediating role of air pollution in this process. A theoretical analysis is conducted to explore the relationship between population influx, air pollution, and infectious diseases. Additionally, we establish a series of econometric models and employ various empirical tests and analytical techniques, including mediation effect test, threshold effect test, and systematic GMM test, to evaluate our hypotheses. The results indicate that: (1) Population influx directly and indirectly impacts infectious diseases. Specifically, population influx not only directly elevates the risk of infectious diseases, but also indirectly increases the incidence rate of infectious diseases by intensifying air pollution. (2) The impact of population inflow on infectious diseases exhibits regional heterogeneity. Compared to central and western China, the eastern regions exhibit a significantly higher risk of infectious diseases, exceeding the national average. (3) External factors influence the relationship between population influx and infectious diseases differently. Personal income and medical resources both help mitigate the risk of infectious diseases due to population influx, with medical resources having a more substantial effect. Contrary to expectations, abundant educational resources have not reduced the risk, instead, they have exacerbated the risk associated with population influx. This paper provides a scientific basis for formulating effective strategies for the prevention and control of infectious diseases.

Impact of Airborne Exposure to PM10 Increases Susceptibility to P. aeruginosa Infection

The effects of exposure to airborne particulate matter with a size of 10 μm or less (PM10) on C57BL/6 mouse corneas, their response to Pseudomonas aeruginosa (PA) infection, and the protective effects of SKQ1 were determined. C57BL/6 mouse corneas receiving PBS or SKQ1 were exposed to control (air) or PM10 for 2 weeks, infected, and the disease was documented by clinical score, PMN quantitation, bacterial plate count, RT-PCR and Western blot. PBS-treated, PM10-exposed corneas did not differ at 1 day postinfection (dpi), but exhibited earlier (3 dpi) corneal thinning compared to controls. By 3 dpi, PM10 significantly increased corneal mRNA levels of several pro-inflammatory cytokines, but decreased IL-10, NQO1, GR1, GPX4, and Nrf2 over control. SKQ1 reversed these effects and Western blot selectively confirmed the RT-PCR results. PM10 resulted in higher viable bacterial plate counts at 1 and 3 dpi, but SKQ1 reduced them at 3 dpi. PM10 significantly increased MPO in the cornea at 3 dpi and was reduced by SKQ1. SKQ1, used as an adjunctive treatment to moxifloxacin, was not significantly different from moxifloxacin alone. Exposure to PM10 increased the susceptibility of C57BL/6 to PA infection; SKQ1 significantly reversed these effects, but was not effective as an adjunctive treatment.

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Urban Particulate Matter Triggers Meibomian Gland Dysfunction

Purpose

The meibomian gland (MG), as the largest modified sebaceous gland, is potentially damaged by urban particulate matter (UPM) based on epidemiological evidence, but the specific experimental mechanisms remain unknown. This study investigated the effects of UPM on MG dysfunction (MGD) in rodent models.

Methods

Female C57BL/6J mice received eye drops containing UPM suspension or PBS for 14 days. The proliferative capacity and progenitor of MG were evaluated by immunofluorescence. Cell apoptosis was confirmed by TUNEL assay, along with the analysis of caspase family expression. Lipid accumulation was visualized by Oil Red O staining and LipidTox staining. Ductal hyperkeratinization, neutrophil infiltration, and pyroptosis activation were detected through immunostaining. The relative gene expression and signaling pathway activation were determined by Western blot analysis.

Results

Administration of UPM caused MGD-like clinical signs, manifested as distinct corneal epithelial erosion, increased MG orifice occlusion, and glandular dropout. UPM exposure significantly induced progenitor loss, cellular apoptosis, and lipogenic disorder in MG, by reducing P63/Lrig1 expression and increasing cleaved caspase-8, -9, and -3 and meibum lipogenic protein (HMGCR/SREBP-1) expression. UPM-treated mice exhibited ductal hyperkeratinization and neutrophil recruitment. Simultaneously, pyroptosis was motivated, as indicated by the heightened expression of NLRP3 and the cleavage of caspase-1 and -4 and gasdermin D, as well as the increase in IL-1β and IL-18 downstream. The underlying pathological mechanisms of UPM involve the phosphorylation of mitogen-activated protein kinase and nuclear factor-κB.

Conclusions

These results provided direct evidence for the toxicity of UPM in MG. UPM-induced activation of pyroptosis and mitogen-activated protein kinase/nuclear factor-κB signaling pathway might account for the inflammatory MGD.

Loss of TRPM8 Exacerbate Herpes Simplex Keratitis Infection in Mice by Promoting the Infiltration of CD11b+ Ly6G+ Cells and Increasing the Viral Load in the Cornea

Purpose

To reveal the role of transient receptor potential cation subfamily M member 8 (TRPM8) channels in herpes simplex keratitis (HSK).

Methods

HSK models were established using TRPM8 knockout (TRPM8-/-) mice and their wild-type (WT) littermates. The infected corneas were graded and harvested to evaluate the mRNA levels of inflammatory factors through quantitative real-time polymerase chain reaction (RT-PCR), as well as the infiltration of inflammatory cells through immunofluorescence staining and flow cytometry. Viral titers were determined by plaque assay and absolute quantitative method. RNA-sequencing was conducted to elucidate the transcriptome of corneal epithelium in response to TRPM8 knockout after infection. The anti-inflammatory effect of TRPM8 agonist menthol was documented via subconjunctival administration.

Results

Compared to their wild-type counterparts, TRPM8-deficient mice exhibited exacerbated infection symptoms and thicker corneas in HSK models. Infection in TRPM8-deficient mice resulted in significant lymphocyte infiltration, primarily consisting of Ly6G+ CD11b+ cells. Additionally, TRPM8-deficient mice displayed increased levels of corneal viral titers after infection, along with decreased expression of interferon-stimulated genes (ISGs). Subconjunctival administration of menthol effectively alleviated infection-induced symptoms and Ly6G+ CD11b+ cell infiltration in herpes simplex virus type 1 (HSV-1)-treated mice.

Conclusions

TRPM8 promoted host resistance to HSV-1 infection by suppressing the accumulation of Ly6G+ CD11b+ cells and virus replication. These findings suggest that targeting TRPM8 could be valuable for therapeutic interventions against HSV-1 infections.

PM10 and Pseudomonas aeruginosa: effects on corneal epithelium

Purpose

In vivo data indicate that mouse corneas exposed to PM10 showed early perforation and thinning after infection with Pseudomonas aeruginosa. To understand the mechanisms underlying this finding, we tested the effects of PM10 and the mitochondria targeted anti-oxidant SKQ1 in immortalized human corneal epithelial cells (HCET) that were challenged with Pseudomonas aeruginosa strain 19660.

Methods

Mouse corneas were infected with strain 19660 after a 2 week whole-body exposure to PM10 or control air and assessed by clinical scores, slit lamp photography and western blot. HCET were exposed to 100μg/ml PM10 for 24h before challenge with strain 19660 (MOI 20). A subset of cells were pre-treated with 50nM SKQ1 for 1h before PM10 exposure. Phase contrast microscopy was used to study cell morphology, cell viability was measured by an MTT assay, and ROS by DCFH-DA. Levels of pro-inflammatory markers and anti-oxidant enzymes were evaluated by RT-PCR, western blot and ELISA. Reduced glutathione (GSH) and malondialdehyde (MDA) levels were evaluated by assay kits.

Results

In vivo, whole body exposure to PM10 vs. control air exposed mouse corneas showed early perforation and/or corneal thinning at 3 days post infection, accompanied by increased TNF-α and decreased SOD2 protein levels. In vitro, PM10 induced a dose dependent reduction in cell viability of HCET and significantly increased mRNA levels of pro-inflammatory molecules compared to control. Exposure to PM10 before bacterial challenge further amplified the reduction in cell viability and GSH levels. Furthermore, PM10 exposure also exacerbated the increase in MDA and ROS levels and phase contrast microscopy revealed more rounded cells after strain 19660 challenge. PM10 exposure also further increased the mRNA and protein levels of pro-inflammatory molecules, while anti-inflammatory IL-10 was decreased. SKQ1 reversed the rounded cell morphology observed by phase contrast microscopy, increased levels of MDA, ROS and pro-inflammatory molecules, and restored IL-10.

Conclusions

PM10 induces decreased cell viability, oxidative stress and inflammation in HCET and has an additive effect upon bacterial challenge. SKQ1 protects against oxidative stress and inflammation induced by PM10 after bacterial challenge by reversing these effects. The findings provide insight into mechanisms underlying early perforation and thinning observed in infected corneas of PM10 exposed mice.

Therapeutic Potential of Biochanin A in Herpes Simplex Keratitis

Herpes simplex keratitis (HSK) is a blinding eye disease that is initiated by the herpes simplex virus type 1 (HSV-1). Resistance to acyclovir (ACV) and the side effects of corticosteroid drugs have become concerning issues, so it is crucial to develop new antivirals for treating HSK. In this study, we report that biochanin A (BCA), a naturally occurring flavonoid compound, provides multifaceted protective effects with anti-viral, anti-inflammatory, anti-oxidative stress and anti-apoptotic activities to alleviate HSK. The results show that BCA significantly inhibited HSV-1 replication in vitro and further proved that BCA principally influenced the early stage of virus infection. We reveal that BCA downregulated the expression of pro-inflammatory factors triggered by HSV-1, including TNF-α, RANTES, IL-1β and IL-6. Furthermore, BCA treatment alleviated oxidative stress and apoptotic arising from HSV-1 infection. Lastly, we induced HSK in male C57BL/6 mice and treated them with either BCA or phosphate buffer solution (PBS) eye drops. We observed the ocular surface lesions; determined the virus load in the tear fluid, corneas as well as trigeminal ganglions (TGs); and detected the levels of inflammation and apoptosis in the corneas simultaneously. These results show that BCA inhibits HSV-1 and alleviates the corneal lesion degree. Our study illustrates that BCA is a promising therapeutic approach for application in treating HSK.

A retrospective study of air quality associated with teratogenic pathogen screening in women of reproductive age in southern China

Adverse pregnancy outcomes are associated with a poor ambient atmospheric environment. Infections by teratogenic pathogens such as cytomegalovirus (CMV) and herpes simplex virus (HSV) are the main cause of the worse pregnant outcomes. However, environmental factors governing these infections are uncertain and epidemiological studies are limited. An epidemiological study on relationships between air pollutants and antibodies against teratogenic pathogens will be explored. In total, 5475 women of childbearing age were enrolled in the study between January 2018 and December 2019 in a hospital in Shantou, China. Antibodies against pathogens were measured by electrochemical luminescence. Everyday air quality data, concerning particulate matter (PM), sulfur dioxide (SO2), nitrogen dioxide (NO2), and other parameters, were acquired from a government web site, and the relationships between them were evaluated with nonparametric and multivariate linear regression analyses. Not only titers of herpes simplex virus HSV(I+II) IgGs in spring, but also titers of cytomegalovirus IgG (CMV IgG) and HSV I IgG in autumn, both had positive associations with concentrations of SO2. When PM2.5 or PM10 exposure is elevated, HSV(I+II) IgGs, TOX IgM should be paid more attention in spring or summer. Air pollution may be crucial for teratogenic pathogen infections. This study highlights air pollution could increase the risk of teratogenic pathogen infection, implying stronger measures should be taken to protect air environment and screenings of associated antibody should be strengthened in different season.

The effect of social determinants of health on severity of microbial keratitis presentation at a tertiary eye care hospital in Southern India

Purpose

Understanding the association between social determinants of health (SDoHs) and microbial keratitis (MK) can inform underlying risk for patients and identify risk factors associated with worse disease, such as presenting visual acuity (VA) and time to initial presentation.

Methods

This was a cross-sectional study was conducted with patients presenting with MK to the cornea clinic at a tertiary care hospital in Madurai, India. Patient demographics, SDoH survey responses, geographic pollution, and clinical features at presentation were collected. Descriptive statistics, univariate analysis, multi-variable linear regression models, and Poisson regression models were utilized.

Results

There were 51 patients evaluated. The mean age was 51.2 years (SD = 13.3); 33.3% were female and 55% did not visit a vision center (VC) prior to presenting to the clinic. The median presenting logarithm of the minimum angle of resolution (logMAR) VA was 1.1 [Snellen 20/240, inter-quartile range (IQR) = 20/80 to 20/4000]. The median time to presentation was 7 days (IQR = 4.5 to 10). The average particulate matter 2.5 (PM2.5) concentration, a measure of air pollution, for the districts from which the patients traveled was 24.3 μg/m3 (SD = 1.6). Age- and sex-adjusted linear regression and Poisson regression results showed that higher levels of PM2.5 were associated with 0.28 worse presenting logMAR VA (Snellen 2.8 lines, P = 0.002). Patients who did not visit a VC had a 100% longer time to presentation compared to those who did (incidence rate ratio = 2.0, 95% confidence interval = 1.3-3.0, P = 0.001).

Conclusion

Patient SDoH and environmental exposures can impact MK presentation. Understanding SDoH is important for public health and policy implications to mitigate eye health disparities in India.

Airborne Exposure of the Cornea to PM10 Induces Oxidative Stress and Disrupts Nrf2 Mediated Anti-Oxidant Defenses

The purpose of this study is to test the effects of whole-body animal exposure to airborne particulate matter (PM) with an aerodynamic diameter of <10 μm (PM10) in the mouse cornea and in vitro. C57BL/6 mice were exposed to control or 500 µg/m3 PM10 for 2 weeks. In vivo, reduced glutathione (GSH) and malondialdehyde (MDA) were analyzed. RT-PCR and ELISA evaluated levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and inflammatory markers. SKQ1, a novel mitochondrial antioxidant, was applied topically and GSH, MDA and Nrf2 levels were tested. In vitro, cells were treated with PM10 ± SKQ1 and cell viability, MDA, mitochondrial ROS, ATP and Nrf2 protein were tested. In vivo, PM10 vs. control exposure significantly reduced GSH, corneal thickness and increased MDA levels. PM10-exposed corneas showed significantly higher mRNA levels for downstream targets, pro-inflammatory molecules and reduced Nrf2 protein. In PM10-exposed corneas, SKQ1 restored GSH and Nrf2 levels and lowered MDA. In vitro, PM10 reduced cell viability, Nrf2 protein, and ATP, and increased MDA, and mitochondrial ROS; while SKQ1 reversed these effects. Whole-body PM10 exposure triggers oxidative stress, disrupting the Nrf2 pathway. SKQ1 reverses these deleterious effects in vivo and in vitro, suggesting applicability to humans.

Effects of air pollution on myopia: an update on clinical evidence and biological mechanisms

Myopia is one of the most common forms of refractive eye disease and considered as a worldwide pandemic experienced by half of the global population by 2050. During the past several decades, myopia has become a leading cause of visual impairment, whereas several factors are believed to be associated with its occurrence and development. In terms of environmental factors, air pollution has gained more attention in recent years, as exposure to ambient air pollution seems to increase peripheral hyperopia defocus, affect the dopamine pathways, and cause retinal ischemia. In this review, we highlight epidemiological evidence and potential biological mechanisms that may link exposure to air pollutants to myopia. A thorough understanding of these mechanisms is a key for establishing and implementing targeting strategies. Regulatory efforts to control air pollution through effective policies and limit individual exposure to preventable risks are required in reducing this global public health burden.

A critical review on air pollutant exposure and age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of visual impairments and blindness worldwide in the elderly and its incidence strongly increases with ages. The etiology of AMD is complex and attributed to the genetic modifiers, environmental factors and gene-environment interactions. Recently, the impacts of air pollution on the development of eye diseases have become the new area of focus, and disordered air exposure combined with inadequate health management has caused problems for the eye health, such as dry eye, glaucoma, and retinopathy, while its specific role in the occurrence of AMD is still not well understood. In order to summarize the progress of this research field, we performed a critical review to summarize the epidemiological and mechanism evidence on the association between air pollutants exposure and AMD. This review documented that exposure to air pollutants will accelerate or worsen the morbidity and prevalence of AMD. Air pollutants exposure may change the homeostasis, interfere with the inflammatory response, and take direct action on the lipid metabolism and oxidative stress in the macula. More attention should be given to understanding the impact of ambient air pollution on AMD worldwide.

Smoke and the eyes: A review of the harmful effects of wildfire smoke and air pollution on the ocular surface

Wildfires are occurring worldwide with greater frequency and intensity. Wildfires, as well as other sources of air pollution including environmental tobacco smoke, household biomass combustion, agricultural burning, and vehicular emissions, release large amounts of toxic substances into the atmosphere. The ocular surface is constantly exposed to the ambient air and is hence vulnerable to damage from air pollutants. This review describes the detrimental effects of wildfire smoke and air pollution on the ocular surface and resultant signs and symptoms. The latest relevant evidence is synthesised and critically evaluated. A mechanism for the pathophysiology of ocular surface damage will be proposed considering the existing literature on respiratory effects of air pollution. Current strategies to reduce human exposure to air pollutants are discussed and specific possible approaches to protect the ocular surface and manage air pollution induced ocular surface damage are suggested. Further avenues of research are suggested to understand how acute and chronic air pollution exposure affects the ocular surface including the short and long-term implications.

Chronic exposure to polluted urban air aggravates myocardial infarction by impaired cardiac mitochondrial function and dynamics

Air pollution exposure positively correlates with increased cardiovascular morbidity and mortality rates, mainly due to myocardial infarction (MI). Herein, we aimed to study the metabolic mechanisms underlying this association, focusing on the evaluation of cardiac mitochondrial function and dynamics, together with its impact over MI progression. An initial time course study was performed in BALB/c mice breathing filtered air (FA) or urban air (UA) in whole-body exposure chambers located in Buenos Aires City downtown for up to 16 weeks (n = 8 per group and time point). After 12 weeks, lung inflammatory cell recruitment was evident in UA-exposed mice. Interestingly, impaired redox metabolism, characterized by decreased lung SOD activity and increased GSSG levels and NOX activity, precede local inflammation in this group. At this selected time point, additional mice were exposed to FA or UA (n = 12 per group) and alveolar macrophage PM uptake and nitric oxide (NO) production was observed in UA-exposed mice, together with increased pro-inflammatory cytokine levels (TNF-α and IL-6) in BAL and plasma. Consequently, impaired heart tissue oxygen metabolism and altered mitochondrial ultrastructure and function were observed in UA-exposed mice after 12 weeks, characterized by decreased active state respiration and ATP production rates, and enhanced mitochondrial H₂O₂ production. Moreover, disturbed cardiac mitochondrial dynamics was detected in this group. This scenario led to a significant increase in the area of infarcted tissue following myocardial ischemia reperfusion injury in vivo, from 43 ± 3% of the area at risk in mice breathing FA to 66 ± 4% in UA-exposed mice (n = 6 per group, p < 0.01), together with a sustained increase in LVEDP during myocardial reperfusion. Taken together, our data unravel cardiac mitochondrial mechanisms that contribute to the understanding of the adverse health effects of urban air pollution exposure, and ultimately highlight the importance of considering environmental factors in the development of cardiovascular diseases.