RESUMO
Human papillomaviruses (HPVs) infect keratinocytes of stratified epithelia. Long-term persistence of infection is a critical risk factor for the development of HPV-induced malignancies. Through the actions of its oncogenes, HPV evades host immune responses to facilitate its productive life cycle. In this work, we discovered a previously unknown function of the HPV16 E5 oncoprotein in the suppression of interferon (IFN) responses. This suppression is focused on keratinocyte-specific IFN-κ and is mediated through E5-induced changes in growth factor signaling pathways, as identified through phosphoproteomics analysis. The loss of E5 in keratinocytes maintaining the complete HPV16 genome results in the derepression of IFNK transcription and subsequent JAK/STAT-dependent upregulation of several IFN-stimulated genes (ISGs) at both the mRNA and protein levels. We also established a link between the loss of E5 and the subsequent loss of genome maintenance and stability, resulting in increased genome integration.IMPORTANCE Persistent human papillomavirus infections can cause a variety of significant cancers. The ability of HPV to persist depends on evasion of the host immune system. In this study, we show that the HPV16 E5 protein can suppress an important aspect of the host immune response. In addition, we find that the E5 protein is important for helping the virus avoid integration into the host genome, which is a frequent step along the pathway to cancer development.
Assuntos
Genoma Viral , Papillomavirus Humano 16/metabolismo , Interferon Tipo I/metabolismo , Queratinócitos , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus , Plasmídeos/metabolismo , Transdução de Sinais , Linhagem Celular , Instabilidade Genômica , Papillomavirus Humano 16/genética , Humanos , Interferon Tipo I/genética , Queratinócitos/metabolismo , Queratinócitos/patologia , Queratinócitos/virologia , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Plasmídeos/genéticaRESUMO
Autism spectrum disorder (ASD) has been hypothesized to be a result of the interplay between genetic predisposition and increased vulnerability to early environmental insults. Mitochondrial dysfunctions appear also involved in ASD pathophysiology, but the mechanisms by which such alterations develop are not completely understood. Here, we analyzed ASD primary fibroblasts by measuring mitochondrial bioenergetics, ultrastructural and dynamic parameters to investigate the hypothesis that defects in these pathways could be interconnected phenomena responsible or consequence for the redox imbalance observed in ASD. High levels of 4-hydroxynonenal protein adducts together with increased NADPH (nicotinamide adenine dinucleotide phosphateoxidase) activity and mitochondrial superoxide production coupled with a compromised antioxidant response guided by a defective Nuclear Factor Erythroid 2-Related Factor 2 pathway confirmed an unbalanced redox homeostasis in ASD. Moreover, ASD fibroblasts showed overactive mitochondrial bioenergetics associated with atypical morphology and altered expression of mitochondrial electron transport chain complexes and dynamics-regulating factors. We suggest that many of the changes observed in mitochondria could represent compensatory mechanisms by which ASD cells try to adapt to altered energy demand, possibly resulting from a chronic oxinflammatory status.
Assuntos
Transtorno do Espectro Autista/patologia , Metabolismo Energético , Fibroblastos/patologia , Mitocôndrias/patologia , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Estresse Oxidativo , Adolescente , Adulto , Transtorno do Espectro Autista/metabolismo , Estudos de Casos e Controles , Criança , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Mitocôndrias/metabolismo , Adulto JovemRESUMO
Human papillomaviruses (HPVs) infect squamous epithelia and cause several important cancers. Immune evasion is critical for viral persistence. Fibroblasts in the stromal microenvironment provide growth signals and cytokines that are required for proper epithelial differentiation, maintenance, and immune responses and are critical in the development of many cancers. In this study, we examined the role of epithelial-stromal interactions in the HPV16 life cycle using organotypic (raft) cultures as a model. Rafts were created using uninfected human foreskin keratinocytes (HFKs) and HFKs containing either wild-type HPV16 or HPV16 with a stop mutation to prevent the expression of the viral oncogene E5. Microarray analysis revealed significant changes in gene expression patterns in the stroma in response to HPV16, some of which were E5 dependent. Interferon (IFN)-stimulated genes (ISGs) and extracellular matrix remodeling genes were suppressed, the most prominent pathways affected. STAT1, IFNAR1, IRF3, and IRF7 were knocked down in stromal fibroblasts using lentiviral short hairpin RNA (shRNA) transduction. HPV late gene expression and viral copy number in the epithelium were increased when the stromal IFN pathway was disrupted, indicating that the stroma helps control the late phase of the HPV life cycle in the epithelium. Increased late gene expression correlated with increased late keratinocyte differentiation but not decreased IFN signaling in the epithelium. These studies show HPV16 has a paracrine effect on stromal innate immunity, reveal a new role for E5 as a stromal innate immune suppressor, and suggest that stromal IFN signaling may influence keratinocyte differentiation.IMPORTANCE The persistence of high-risk human papillomavirus (HPV) infections is the key risk factor for developing HPV-associated cancers. The ability of HPV to evade host immunity is a critical component of its ability to persist. The environment surrounding a tumor is increasingly understood to be critical in cancer development, including immune evasion. Our studies show that HPV can suppress the expression of immune-related genes in neighboring fibroblasts in a three-dimensional (3D) model of human epithelium. This finding is significant, because it indicates that HPV can control innate immunity not only in the infected cell but also in the microenvironment. In addition, the ability of HPV to regulate stromal gene expression depends in part on the viral oncogene E5, revealing a new function for this protein as an immune evasion factor.
Assuntos
Interações Hospedeiro-Patógeno , Papillomavirus Humano 16/crescimento & desenvolvimento , Papillomavirus Humano 16/imunologia , Evasão da Resposta Imune , Imunidade Inata , Fatores Imunológicos/antagonistas & inibidores , Interferons/antagonistas & inibidores , Células Cultivadas , Fibroblastos/imunologia , Fibroblastos/virologia , Perfilação da Expressão Gênica , Humanos , Queratinócitos/imunologia , Queratinócitos/virologia , Modelos Biológicos , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Transdução de SinaisRESUMO
Krev interaction trapped protein 1 (KRIT1) is a scaffold protein known to form functional complexes with distinct proteins, including Malcavernin, PDCD10, Rap1 and others. It appears involved in several cellular signaling pathways and exerts a protective role against inflammation and oxidative stress. KRIT1 has been studied as a regulator of endothelial cell functions and represents a determinant in the pathogenesis of Cerebral Cavernous Malformation (CCM), a cerebrovascular disease characterized by the formation of clusters of abnormally dilated and leaky blood capillaries, which predispose to seizures, neurological deficits and intracerebral hemorrhage. Although KRIT1 is ubiquitously expressed, few studies have described its involvement in pathologies other than CCM including cancer. Cutaneous melanoma represents the most fatal skin cancer due to its high metastatic propensity. Despite the numerous efforts made to define the signaling pathways activated during melanoma progression, the molecular mechanisms at the basis of melanoma growth, phenotype plasticity and resistance to therapies are still under investigation.
Assuntos
Proteína KRIT1/metabolismo , Melanoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Núcleo Celular/metabolismo , Proliferação de Células/genética , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes/métodos , Humanos , Proteína KRIT1/genética , Masculino , Melanócitos/metabolismo , Melanoma/patologia , Pessoa de Meia-Idade , beta Catenina/metabolismoRESUMO
Psoriasis is a skin disease characterized by abnormal keratinocyte proliferation and inflammation. Currently, there are no cures for this disease, so the goal of treatment is to decrease inflammation and slow down the associated rapid cell growth and shedding. Recent advances have led to the usage of phosphodiesterase 4 (PDE4) inhibitors for treatment of this condition. For example, apremilast is an oral, selective PDE4 inhibitor that is able to reduce skin inflammation and is Food and Drug Administration (FDA)-approved to treat adults with moderate to severe psoriasis and/or psoriatic arthritis. However, common target-related adverse events, including diarrhea, nausea, headache, and insomnia limit the usage of this drug. To circumvent these effects, the usage of PDE4 inhibitors specifically designed for topical treatment, such as CHF6001, may combine local anti-inflammatory activity with limited systemic exposure, improving tolerability. In this study, we showed that CHF6001, currently undergoing clinical development for COPD, suppresses human keratinocyte proliferation as assessed via BrdU incorporation. We also observed decreased re-epithelialization in a scratch-wound model after CHF6001 treatment. At the molecular level, CHF6001 inhibited translocation of phosphorylated NF-κB subunit p65, promoting loss of nuclear cyclin D1 accumulation and an increase of cell cycle inhibitor p21. Furthermore, CHF6001 decreased oxidative stress, measured by assessing lipid peroxidation (4-HNE adduct formation), through the inactivation of the NADPH oxidase. These results suggest that CHF6001 has the potential to treat skin disorders associated with hyperproliferative keratinocytes, such as psoriasis by targeting oxidative stress, abnormal re-epithelization, and inflammation.
Assuntos
Proliferação de Células/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Sulfonamidas/farmacologia , para-Aminobenzoatos/farmacologia , Aldeídos/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ciclina D1/metabolismo , Humanos , NADPH Oxidases/metabolismo , Inibidores da Fosfodiesterase 4/toxicidade , Psoríase/tratamento farmacológico , Sulfonamidas/toxicidade , Fator de Transcrição RelA/metabolismo , para-Aminobenzoatos/toxicidadeRESUMO
Alkaptonuria (AKU) is a rare metabolic disease correlated with the deficiency of homogentisate 1,2-dioxygenase and leading to an accumulation of the metabolite homogentisic acid (HGA) which can be subjected to oxidation and polymerization reactions. These events are considered a trigger for the induction of oxidative stress in AKU but, despite the large description of an altered redox status, the underlying pathogenetic processes are still unstudied. In the present study, we investigated the molecular mechanisms responsible for the oxidative damage present in an osteoblast-based cellular model of AKU. Bone, in fact, is largely affected in AKU patients: severe osteoclastic resorption, osteoporosis, even for pediatric cases, and an altered rate of remodeling biomarkers have been reported. In our AKU osteoblast cell model, we found a clear altered redox homeostasis, determined by elevated hydrogen peroxide (H2O2) levels and 4HNE protein adducts formation. These findings were correlated with increased NADPH oxidase (NOX) activity and altered mitochondrial respiration. In addition, we observed a decreased activity of superoxide dismutase (SOD) and reduced levels of thioredoxin (TRX) that parallel the decreased Nrf2-DNA binding. Overall, our results reveal that HGA is able to alter the cellular redox homeostasis by modulating the endogenous ROS production via NOX activation and mitochondrial dysfunctions and impair the cellular response mechanism. These findings can be useful for understanding the pathophysiology of AKU, not yet well studied in bones, but which is an important source of comorbidities that affect the life quality of the patients.
Assuntos
Alcaptonúria/metabolismo , Homeostase/fisiologia , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Ácido Homogentísico/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , NADPH Oxidases/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Osteoblastos/citologia , Oxirredução , Estresse Oxidativo/fisiologia , Transdução de Sinais , Superóxido Dismutase/metabolismo , Tiorredoxinas/metabolismoRESUMO
Inflammasomes are multiprotein signaling platforms of the innate immune system that detect markers of physiological stress and promote the maturation of caspase-1 and interleukin 1 beta (IL-1ß), IL-18, and gasdermin D. This randomized, cross-over trial investigated the influence of 2-week mixed flavonoid (FLAV) versus placebo (PL) supplementation on inflammasome activation and IL-1ß and IL-18 production after 75-km cycling in 22 cyclists (42 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr postexercise (176 ± 5.4 min, 73.4 ± 2.0 %VO2max). The supplement (678 mg FLAVs) included quercetin, green tea catechins, and bilberry anthocyanins. The pattern of change in the plasma levels of the inflammasome adaptor oligomer ASC (apoptosis-associated speck-like protein containing caspase recruitment domain) was different between the FLAV and PL trials, with the FLAV ASC levels 52% lower (Cohen's d = 1.06) than PL immediately following 75-km cycling (interaction effect, p = .012). The plasma IL-1ß levels in FLAV were significantly lower than PL (23-42%; Cohen's d = 0.293-0.644) throughout 21 hr of recovery (interaction effect, p = .004). The change in plasma gasdermin D levels were lower immediately postexercise in FLAV versus PL (15% contrast, p = .023; Cohen's d = 0.450). The patterns of change in plasma IL-18 and IL-37 did not differ between the FLAV and PL trials (interaction effects, p = .388, .716, respectively). These data indicate that 2-week FLAV ingestion mitigated inflammasome activation, with a corresponding decrease in IL-1ß release in cyclists after a 75-km cycling time trial. The data from this study support the strategy of ingesting high amounts of FLAV to mitigate postexercise inflammation.
RESUMO
This double-blinded, placebo controlled, randomized crossover trial investigated the influence of 2-week mixed flavonoid versus placebo supplementation on oxinflammation markers after a 75-km cycling time trial in 22 cyclists (42.3 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr post 75-km cycling (176 ± 5.4 min, 73.4 ±2.0% maximal oxygen consumption). The supplement provided 678-mg flavonoids with quercetin (200 mg), green tea catechins (368 mg, 180-mg epigallocatechin gallate), and anthocyanins (128 mg) from bilberry extract, with caffeine, vitamin C, and omega-3 fatty acids added as adjuvants. Blood samples were analyzed for blood leukocyte counts, oxinflammation biomarkers, including 4-hydroxynonenal, protein carbonyls, and peripheral blood mononuclear mRNA expression for cyclooxygenease-2 and glutathione peroxidase. Each of the blood biomarkers was elevated postexercise (time effects, all ps < .01), with lower plasma levels for 4-hydroxynonenal (at 21-hr postexercise) in flavonoid versus placebo (interaction effect, p = .008). Although elevated postexercise, no trial differences for the neutrophil/lymphocyte ratio (p = .539) or peripheral blood mononuclear mRNA expression for cyclooxygenease-2 (p = .322) or glutathione peroxidase (p = .839) were shown. Flavonoid supplementation prior to intensive exercise decreased plasma peroxidation and oxidative damage, as determined by 4-hydroxynonenal. Postexercise increases were similar between the flavonoid and placebo trials for peripheral blood mononuclear mRNA expression for cyclooxygenease-2 and the nuclear factor erythroid 2-related factor 2 related gene glutathione peroxidase (NFE2L2). The data support the strategy of flavonoid supplementation to mitigate postexercise oxidative stress in endurance athletes.
RESUMO
Persistent high-risk human papillomavirus (HPV) infection is the major causal factor in cervical and other anogenital cancers. Because there are currently no therapeutics capable of preventing neoplastic progression of HPV infections, understanding the mechanisms of HPV-mediated persistence, including immune evasion, is a major research priority. The multifunctional growth factor transforming growth factor beta (TGFß) has been shown to inhibit expression of early viral transcripts from cells harboring integrated HPV genomes or cells infected with retroviruses expressing HPV oncoproteins. However, the mechanism of TGFß-induced inhibition has not been fully defined. In this study, we have observed a previously uncharacterized ability of TGFß to repress the differentiation-induced upregulation of late HPV16 gene expression. In addition, interferon kappa (IFN-κ), a keratinocyte-specific, constitutively expressed cytokine suppressed by differentiation, can be transcriptionally induced by TGFß1. TGFß-mediated IFN-κ transcription only occurs in cells containing HPV16, and this is due to TGFß1-mediated reversal of HPV-induced methylation of the IFN-κ promoter through active DNA demethylation mediated by thymine DNA glycosylase (TDG). This novel interaction between growth factor and innate immune signaling may shed light on the mechanisms of HPV persistence and how the virus manipulates both immune and growth factor signaling to promote its life cycle.IMPORTANCE Persistent infection by high-risk HPVs is the primary risk factor for development of HPV-induced cancers. Persistence involves viral evasion of the immune response, including the IFN response. HPV is also known to suppress TGFß signaling, which inhibits viral gene expression. Here, we show that the TGFß and IFN pathways are interrelated in the context of HPV16 infection through the upregulation of IFN-κ by TGFß. The ability of TGFß to induce IFN-κ promoter demethylation and transcriptional activation provides a new explanation for why HPV has evolved mechanisms to inhibit TGFß in infected cells.
Assuntos
Metilação de DNA , Regulação Viral da Expressão Gênica , Papillomavirus Humano 16/metabolismo , Interferon Tipo I/metabolismo , Queratinócitos/metabolismo , Infecções por Papillomavirus/metabolismo , Regiões Promotoras Genéticas , Ativação Transcricional , Fator de Crescimento Transformador beta/metabolismo , Humanos , Queratinócitos/patologia , Queratinócitos/virologia , Infecções por Papillomavirus/patologiaRESUMO
BACKGROUND: The main functions of the skin are to protect against environmental insults and prevent water loss, which are performed by the complex lipid- and protein matrix present in the outermost layers of the epithelium. The lipidome of these outer layers is mainly composed of ceramides, fatty acids, and cholesterol, which regulates keratinocyte differentiation and skin barrier function. SR-B1 is a multifunctional scavenger receptor that is best known for facilitating uptake of cholesterol from HDL particles in the liver, but it is also expressed in the skin. OBJECTIVE: To determine the role of SR-B1 in keratinocyte differentiation. METHODS: We investigated the relationship between SR-B1 and keratinocyte differentiation using a physiologically relevant model, organotypic skin equivalents (SEs), wherein SR-B1 was knocked down via siRNA transfection. To assess effects of SR-B1 knockdown on keratinocyte differentiation, we performed hematoxylin/eosin staining, RT-PCR, western blotting, and immunohistochemistry. We also examined the effect of SR-B1 knockdown on lipid production by performing Oil Red O staining and thin layer chromatography. RESULTS: SR-B1 knockdown resulted in decreased lipid levels in SEs, specifically ceramides, and in decreased transcript levels of LDLR, PPAR-α and PPAR-γ, which are factors involved in regulating ceramide synthesis. In addition, filaggrin levels increased in SR-B1 KD tissues, but neither keratin 14 nor keratin 10 were affected. CONCLUSION: We conclude that one of the main functions of SR-B1 in the skin is to regulate ceramide levels and thereby maintain the barrier function of the skin, resulting in the protection of cutaneous tissues from outdoor insults.
Assuntos
Diferenciação Celular/fisiologia , Homeostase , Queratinócitos/citologia , Metabolismo dos Lipídeos , Receptores Depuradores Classe B/fisiologia , Pele/metabolismo , Células Cultivadas , Proteínas Filagrinas , Regulação da Expressão Gênica , Humanos , Metabolismo dos Lipídeos/genética , Receptores Depuradores Classe B/genética , Pele/citologiaRESUMO
Food-derived bioactive peptides (BAPs) obtained from edible insect-protein hold multiple activities promising the potential to target complex pathological mechanisms responsible for chronic health conditions such as hypertension development. In this study, enzymatic protein hydrolysates from non-mulberry edible silkworm Antheraea assama (Muga) and Philosomia ricini (Eri) pupae, specifically Alcalase (A. assama) and Papain (P. ricini) hydrolysates obtained after 60 and 240 min, exhibited the highest ACE-inhibitory and antioxidant properties. The hydrolysates' fractions (<3, 3-10 and >10 kDa), specifically Alc_M60min_F3 (≤3 kDa) and Pap_E240min_F3 (≤3 kDa), showed the highest antioxidant and ACE-inhibitory activities, respectively. Further RP-HPLC purified sub-fractions F4 and F6 showed the highest ACE inhibition as well as potent anti-oxinflammatory activities in lipopolysaccharide (LPS)-treated endothelial cells. Indeed, F4 and F6 ACE-inhibitory peptide fractions were effective in preventing p65 nuclear translocation after 3 h of LPS stimulation along with the inhibition of p38 MAPK phosphorylation in HUVEC cells. In addition, pretreatment with F4 and F6 ACE-inhibitory peptide fractions significantly prevented the LPS-induced upregulation of COX-2 expression and IL-1ß secretion, while the expression of NRF2 (nuclear factor erythroid 2-related factor 2)-regulated enzymes such as HO-1 and NQO1 was induced by both peptide fractions. The derived peptides from edible pupae protein hydrolysates have potentialities to be explored as nutritional approaches against hypertension and related cardiovascular diseases.
Assuntos
Bombyx , Hipertensão , Animais , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Antioxidantes/farmacologia , Hidrolisados de Proteína/farmacologia , Pupa , Células Endoteliais , Lipopolissacarídeos , Peptídeos/farmacologia , HidróliseRESUMO
Exposure to air pollutants has been previously associated with respiratory viral infections, including influenza, measles, mumps, rhinovirus, and respiratory syncytial virus. Epidemiological studies have also suggested that air pollution exposure is associated with increased cases of SARS-CoV-2 infection and COVID-19-associated mortality, although the molecular mechanisms by which pollutant exposure affects viral infection and pathogenesis of COVID-19 remain unknown. In this review, we suggest potential molecular mechanisms that could account for this association. We have focused on the potential effect of exposure to nitrogen dioxide (NO2 ), ozone (O3 ), and particulate matter (PM) since there are studies investigating how exposure to these pollutants affects the life cycle of other viruses. We have concluded that pollutant exposure may affect different stages of the viral life cycle, including inhibition of mucociliary clearance, alteration of viral receptors and proteases required for entry, changes to antiviral interferon production and viral replication, changes in viral assembly mediated by autophagy, prevention of uptake by macrophages, and promotion of viral spread by increasing epithelial permeability. We believe that exposure to pollutants skews adaptive immune responses toward bacterial/allergic immune responses, as opposed to antiviral responses. Exposure to air pollutants could also predispose exposed populations toward developing COIVD-19-associated immunopathology, enhancing virus-induced tissue inflammation and damage.
Assuntos
Poluição do Ar/efeitos adversos , COVID-19/etiologia , Pandemias , SARS-CoV-2 , Imunidade Adaptativa , Poluentes Atmosféricos/efeitos adversos , COVID-19/imunologia , COVID-19/virologia , Interações entre Hospedeiro e Microrganismos , Humanos , Imunidade Inata , Modelos Biológicos , Material Particulado/efeitos adversos , Receptores Virais/fisiologia , Sistema Respiratório/fisiopatologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Receptores Toll-Like/fisiologia , Internalização do Vírus , Replicação ViralRESUMO
SUMMARY: Exposure to air pollutants has been now associated with detrimental effects on a variety of organs, including the heart, lungs, GI tract, and brain. However, recently it has become clear that pollutant exposure can also promote the development/exacerbation of a variety of skin conditions, including premature aging, psoriasis, acne, and atopic dermatitis. Although the molecular mechanisms by which pollutant exposure results in these cutaneous pathological manifestations, it has been noticed that an inflammatory status is a common denominator of all those skin conditions. For this reason, recently, the activation of a cytosolic multiprotein complex involved in inflammatory responses (the inflammasome) that could promote the maturation of proinflammatory cytokines interleukin-1ß and interleukin-18 has been hypothesized to play a key role in pollution-induced skin damage. In this review, we summarize and propose the cutaneous inflammasome as a novel target of pollutant exposure and the eventual usage of inflammasome inhibitor as new technologies to counteract pollution-induced skin damage. Possibly, the ability to inhibit the inflammasome activation could prevent cutaneous inflammaging and ameliorate the health and appearance of the skin.
Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Dermatite/imunologia , Inflamassomos/imunologia , Pele/patologia , Animais , Dermatite/patologia , Dermatite/prevenção & controle , Modelos Animais de Doenças , Exposição Ambiental/efeitos adversos , Furanos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Humanos , Indenos , Inflamassomos/antagonistas & inibidores , Inflamassomos/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Nitrilas/farmacologia , Nitrilas/uso terapêutico , Pele/efeitos dos fármacos , Pele/imunologia , Envelhecimento da Pele/imunologia , Sulfonamidas , Sulfonas/farmacologia , Sulfonas/uso terapêuticoRESUMO
Ozone (O3) exposure has been reported to contribute to various cutaneous inflammatory conditions, such as eczema, psoriasis, rush etc. via a redox-inflammatory pathway. O3 is too reactive to penetrate cutaneous tissue; it interacts with lipids present in the outermost layer of skin, resulting in formation of oxidized molecules and hydrogen peroxide (H2O2). Interestingly, several inflammatory skin pathologies demonstrate altered levels of antimicrobial peptides (AMPs). These small, cationic peptides are found in various cells, including keratinocytes, eccrine gland cells, and seboctyes. Classically, AMPs function as antimicrobial agents. Recent studies indicate that AMPs also play roles in inflammation, angiogenesis, and wound healing. Since altered levels of AMPs have been detected in pollution-associated skin pathologies, we hypothesized that exposure to O3 could affect the levels of AMPs in the skin. We examined levels of AMPs using qRT-PCR, Western blotting, and immunofluorescence in vitro (human keratinocytes), ex vivo (human skin explants), and in vivo (human volunteer subjects exposed to O3) and observed increased levels of all the measured AMPs upon O3 exposure. In addition, in vitro studies have confirmed the redox regulation of AMPs in keratinocytes. This novel finding suggests that targeting AMPs could be a possible defensive strategy to combat pollution-associated skin conditions.
Assuntos
Peróxido de Hidrogênio , Dermatopatias , Humanos , Queratinócitos , Proteínas Citotóxicas Formadoras de Poros , PeleRESUMO
Air pollution represents one of the main risks for both environment and human health. The rapid urbanization has been leading to a continuous release of harmful manmade substances into the atmosphere which are associated to the exacerbation of several pathologies. The skin is the main barrier of our body against the external environment and it is the main target for the outdoor stressors. Among the pollutants, Ozone (O3) is one of the most toxic, able to initiate oxidative reactions and activate inflammatory response, leading to the onset of several skin conditions. Moreover, skin is daily subjected to the activity of Ultraviolet Radiation which are well known to induce harmful cutaneous effects including skin aging and sunburn. Even though both UV and O3 are able to affect the skin homeostasis, very few studies have investigated their possible additive effect. Therefore, in this study we evaluated the effect of the combined exposure of O3 and UV in inducing skin damage, by exposing human skin explants to UV alone or in combination with O3 for 4-days. Markers related to inflammation, redox homeostasis and tissue structure were analyzed. Our results demonstrated that O3 is able to amplify the UV induced skin oxinflammation markers.
Assuntos
Ozônio/toxicidade , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Proteínas Filagrinas , Humanos , Mediadores da Inflamação/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Pele/metabolismo , Pele/patologia , Proteínas de Junções Íntimas/metabolismo , Técnicas de Cultura de TecidosRESUMO
The skin is the main interface between the body and the environment, providing a biological barrier against an array of chemical and physical pollutants (e.g., ultraviolet light, ozone, etc.). Exposure of the skin to these outdoor stressors generates reactive oxygen species (ROS), which can overwhelm the skin's endogenous defense systems (e.g., catalase, vitamins C and E, etc.), resulting in premature skin aging due to the induction of DNA damage, mitochondrial damage, lipid peroxidation, activation of inflammatory signaling pathways, and formation of protein adducts. In this review, we discuss how topical application of antioxidants, including vitamins C and E, carotenoids, resveratrol, and pycnogenol, can be combined with dietary supplementation of these antioxidant compounds in addition to probiotics and essential minerals to protect against outdoor stressor-induced skin damage, including the damage associated with aging.
Assuntos
Fenômenos Fisiológicos da Pele , Antioxidantes/metabolismo , Humanos , Espécies Reativas de Oxigênio/metabolismoRESUMO
The lungs are one the main organs exposed to environmental pollutants, such as tropospheric ozone (O3) and particulate matter (PM), which induce lung pathologies through similar mechanisms, resulting in altered redox homeostasis and inflammation. Although numerous studies have investigated the effects of these pollutants in the respiratory tract, there are only a few evidences that have evaluated the combined effects of outdoor stressors, despite the fact that humans are consistently exposed to more pollutants simultaneously. In this study, we wanted to investigate whether exposure to PM and O3 could have an additive, noxious effect in lung epithelial cells by measuring oxidative damage and the activity of redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2) which is a master regulator of cellular antioxidant defenses. First, we measured the cytotoxic effects of O3 and PM individually and in combination. We observed that both pollutants alone increased LDH release 24 h post-exposure. Interestingly, we did observe via TEM that combined exposure to O3 and PM resulted in increased cellular penetration of PM particles. Furthermore, we found that levels of 4-hydroxy-nonenal (4HNE), a marker of oxidative damage, significantly increased 24 h post-exposure, in response to the combined pollutants. In addition, we observed increased levels of Nrf2, in response to the combined pollutants vs. either pollutant, although this effect was not followed by the increase in Nrf2-responsive genes expression HO1, SOD1, GPX, or GR nor enzymatic activity. Despite these observations, our study suggests that O3 exposure facilitate the cellular penetration of the particles leading to an increased oxidative damage, and additive defensive response.
Assuntos
Poluentes Atmosféricos/análise , Fator 2 Relacionado a NF-E2 , Células Epiteliais/efeitos dos fármacos , Humanos , Oxirredução , Estresse Oxidativo , Material Particulado/análiseRESUMO
Significance: Oxidative stress and oxidative damage are central hypothetical mechanisms for the adverse effects of airborne particulate matter (PM). Activation of inflammatory cells capable of generating reactive oxygen and nitrogen species is another proposed damage pathway. Understanding the interplay between these responses can help us understand the adverse health effects attributed to breathing polluted air. Recent Advances: The consequences of PM exposure on different organs are oxidative damage, decreased function, and inflammation, which can lead to the development/exacerbation of proinflammatory disorders. Mitochondrial damage is also an important event in PM-induced cytotoxicity. Critical Issues: Reactive oxygen species (ROS) are generated during phagocytosis of the particles, leading to enhancement of oxidative stress and triggering the inflammatory response. The activation of inflammatory signaling pathways results in the release of cytokines and other mediators, which can further induce ROS production by activating endogenous enzymes, leading to a positive feedback loop, which can aggravate the effects triggered by PM exposure. Future Directions: Further research is required to elucidate the exact mechanisms by which PM exposure results in adverse health effects, in terms of the relationship between the redox responses triggered by the presence of the particles and the inflammation observed in the different organs, so the development/exacerbation of PM-associated health problems can be prevented.
Assuntos
Suscetibilidade a Doenças , Inflamação/etiologia , Inflamação/metabolismo , Oxirredução , Estresse Oxidativo , Material Particulado/efeitos adversos , Poluição do Ar/efeitos adversos , Animais , Citocinas/metabolismo , Humanos , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Several pollutants have been shown to affect skin physiology, among which ozone (O3) is one of the most toxic. Prolonged exposure to O3 leads to increased oxidative damage and cutaneous inflammation. The correlation between O3 exposure and inflammatory cutaneous conditions (atopic dermatitis, psoriasis, acne and eczema) has been already suggested, although the mechanism involved is still unclear. In the last few decades, a new multiprotein complex, the inflammasome, has been discovered and linked to tissue inflammation, including inflammatory skin conditions. The inflammasome activates inflammatory responses and contributes to the maturation of cytokines such as interleukin 1ß (IL-1ß) and interleukin 18. This complex is also responsive to reactive oxygen species (ROS), which plays a role in triggering the activation of the complex. On this basis it is possible hypothesize that the activation of the inflammasome could be the link between the inflammatory skin conditions associated to O3 exposure. In the present work, the ability of O3 to induce inflammasome activation was determined in different skin models, ranging from 2D (human keratinocytes) to 3D models in vitro and ex vivo. Results clearly showed that O3 exposure increased both transcript and protein levels of the main inflammasome complex, such as ASC and caspase-1. Furthermore, by using both immunofluorescence and an ASC oligomerization assay the formation of the complex was determined together with increased secreted levels of both IL-18 and IL-1ß. Of note is that H2O2 and to a less extent 4HNE (both considered the main mediators of O3 interaction with cellular membranes) were also able to activate skin inflammasome while the use of catalase prevents the activation. This study demonstrated that O3 can activate cutaneous inflammasome in a redox dependent manner suggesting a possible role of this new pathway in pollution induced inflammatory skin conditions.
Assuntos
Inflamassomos , Ozônio , Caspase 1/metabolismo , Humanos , Peróxido de Hidrogênio , Inflamassomos/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Oxirredução , Ozônio/toxicidade , Espécies Reativas de OxigênioRESUMO
The skin is one of the main organs exposed to airborne particulate matter (PM), which may contain various pollutants linked to a wide range of adverse health endpoints. In the present work, we analyzed the proinflammatory and oxidative effects of some PM components leading to inflammatory responses, cell proliferation or cell death. We investigated four redox-active chemicals, such as Cu (II) metal and quinones generated from polycyclic aromatic hydrocarbons (PAHs), i.e., 9,10 phenanthrenequinone and isomers 1,2 and 1,4 naphthoquinone. We performed in vitro biological tests on human keratinocyte (HaCaT) cells and also acellular assays based on the oxidation of dithiothreitol and ascorbic acid, antioxidants to assess the oxidative potential (OP). We found that treated keratinocytes showed increased activation of the redox-sensitive transcription factor NFκB and increased transcript levels of the NFκB-dependent gene IL8. Moreover, the treatment with Cu(II) and quinones increased the activities and the expression of genes involved in the redox response, SOD1 and GPX, suggesting that PM components induced cellular damage due to redox imbalances. Finally, we found alteration of the mitochondrial ultrastructure and increased apoptosis after 24â¯h of treatment. The results presented suggest that all of the analyzed pollutant components are able to modulate similar signal transduction pathways, resulting in activation of inflammatory processes in the skin, followed by oxidative damage. Altogether these observations indicate that exposure of skin to air pollutants modifies the redox equilibrium of keratinocytes, which could explain the increased skin damage observed in populations that live in high-pollution cities.