RESUMO
OBJECTIVE: The present study evaluated the association of psychological distress and radiation exposure as a work-related stressor with mitochondrial function in health care professionals. METHODS: Health care professionals at a regional hospital in Italy were evaluated for physical health and psychological measures using self-report questionnaires (n = 41; mean age = 47.6 [13.1] years; 66% women). In a second sample, individuals exposed to elevated levels of ionizing radiation (IR; likely effective dose exceeding 6 mSv/y; n = 63, mean age = 45.8 [8.8] years; 62% women) were compared with health care workers with low IR (n = 57; mean age = 47.2 [9.5] years; 65% women) because exposure to a toxic agent might act as a (work-related) stressor. Associations were examined between psychological factors (12-item General Health Questionnaire, Perceived Stress Scale), work ability (Work Ability Index), and IR exposure at the workplace with markers of mitochondrial function, including mitochondrial redox activity, mitochondrial membrane potential, mitochondrial DNA (mtDNA) copy number, biogenesis, and mtDNA damage response measured from peripheral blood mononuclear cells. RESULTS: All participants were in good physical health. Individuals reporting high levels of psychological distress showed lower mitochondrial biogenesis as indicated by peroxisome proliferator-activated receptor-γ coactivator 1-α and lower nuclear factor erythroid 2-related factor 2 (NRF2) expression (2.5 [1.0] versus 1.0 [0.9] relative expression [rel exp], p = .035, and 31.5 [5.0] versus 19.4 [6.9] rel exp, p = .013, respectively). However, exposure to toxic agents (IR) was primarily associated with mitochondrial metabolism and reduced mtDNA integrity. Participants with IR exposure displayed higher mitochondrial redox activity (4480 [1202] mean fluorescence intensity [MFI]/min versus 3376 [983] MFI/min, p < .001) and lower mitochondrial membrane potential (0.89 [0.09] MFI versus 0.95 [0.11] MFI, p = .001), and reduced mtDNA integrity (1.18 [0.21] rel exp versus 3.48 [1.57] rel exp, p < .001) compared with nonexposed individuals. CONCLUSIONS: This study supports the notion that psychological distress and potential stressors related to toxic agents might influence various aspects of mitochondrial biology, and that chronic stress exposure can lead to molecular and functional recalibrations among mitochondria.
Assuntos
Leucócitos Mononucleares , Angústia Psicológica , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Feminino , Pessoal de Saúde , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismoRESUMO
Alzheimer's disease (AD), the most prevalent neurodegenerative disease in the growing population of elderly people, is still lacking minimally-invasive circulating biomarkers that could facilitate the diagnosis and the monitoring of disease progression. MicroRNAs (miRNAs) are emerging as tissue-specific and/or circulating biomarkers of several age-related diseases, but evidence on AD is still not conclusive. Since a systemic pro-inflammatory status was associated with an increased risk of AD development and progression, we focused our investigation on a subset of miRNAs modulating the inflammatory process, namely inflamma-miRNAs. The expression of inflamma-miR-17-5p, -21-5p, -126-3p, and -146a-5p was analyzed in plasma samples from 116 patients with AD compared with 41 age-matched healthy control (HC) subjects. MiR-17-5p, miR-21-5p, and miR-126-3p plasma levels were significantly increased in AD patients compared to HC. Importantly, a strong inverse relationship was observed between miR-21-5p and miR-126-3p, and the cognitive impairment, assessed by Mini-Mental State Examination (MMSE). Notably, miR-126-3p was able to discriminate between mild and severe cognitive impairment. Overall, our results reinforce the hypothesis that circulating inflamma-miRNAs could be assessed as minimally invasive tools associated with the development and progression of cognitive impairment in AD.
RESUMO
MiR-222 and miR-126 are associated with asbestos exposure and the ensuing malignancy, but the mechanism(s) of their regulation remain unclear. We evaluated the mechanism by which asbestos regulates miR-222 and miR-126 expression in the context of cancer etiology. An 'in vitro' model of carcinogen-induced cell transformation was used based on exposing bronchial epithelium BEAS-2B cells to three different carcinogens including asbestos. Involvement of the EGFR pathway and the role of epigenetics have been investigated in carcinogen-transformed cells and in malignant mesothelioma, a neoplastic disease associated with asbestos exposure. Increased expression of miR-222 and miR-126 were found in asbestos-transformed cells, but not in cells exposed to arsenic and chrome. Asbestos-mediated activation of the EGFR pathway and macrophages-induced inflammation resulted in miR-222 upregulation, which was reversed by EGFR inhibition. Conversely, asbestos-induced miR-126 expression was affected neither by EGFR modulation nor inflammation. Rather than methylation of the miR-126 host gene EGFL7, epigenetic mechanism involving DNMT1- and PARP1-mediated chromatin remodeling was found to upregulate of miR-126 in asbestos-exposed cells, while miR-126 was downregulated in malignant cells. Analysis of MM tissue supported the role of PARP1 in miR-126 regulation. Therefore, activation of the EGFR pathway and the PARP1-mediated epigenetic regulation both play a role in asbestos-induced miRNA expression, associated with in asbestos-induced carcinogenesis and tumor progression.
Assuntos
Amianto/efeitos adversos , Carcinógenos/química , Neoplasias Pulmonares/genética , Mesotelioma/genética , MicroRNAs/metabolismo , Idoso , Humanos , Neoplasias Pulmonares/patologia , Masculino , Mesotelioma/patologia , Mesotelioma MalignoRESUMO
Asbestos exposure leads to epigenetic and epigenomic modifications that, in association with ROS-induced DNA damage, contribute to cancer onset. Few miRNAs epigenetically regulated in MM have been described in literature; miR-126, however, is one of them, and its expression is regulated by epigenetic mechanisms. Asbestos exposure induces early changes in the miRNAs, which are reversibly expressed as protective species, and their inability to reverse reflects the inability of the cells to restore the physiological miRNA levels despite the cessation of carcinogen exposure. Changes in miRNA expression, which results from genetic/epigenetic changes during tumor formation and evolution, can be detected in fluids and used as cancer biomarkers. This article has reviewed the epigenetic mechanisms involved in miRNA expression in MM, focusing on their role as biomarkers of early diagnosis and therapeutic effects.
RESUMO
MiR-126 has been shown to suppress malignant mesothelioma (MM) by targeting cancer-related genes without inducing toxicity or histopathological changes. Exosomes provide the opportunity to deliver therapeutic cargo to cancer stroma. Here, a tumour stromal model composed of endothelial cells (HUVECs), fibroblasts (IMR-90â¯cells), non-malignant mesothelial cells (Met-5A cells) and MM cells (H28 and MM-B1 cells) was used. The cells were treated with exosomes from HUVECs carrying endogenous (exo-HUVEC) and enriched miR-126 (exo-HUVECmiR-126), and the uptake/turnover of exosomes; miR-126 distribution within the stroma; and effect of miR-126 on cell signalling, angiogenesis and cell proliferation were evaluated. Based on the sensitivity of MM cells to exo-HUVEC miR-126 treatment, miR-126 was distributed differently across stromal cells. The reduced miR-126 content in fibroblasts in favour of endothelial cells reduced angiogenesis and suppressed cell growth in an miR-126-sensitive environment. Conversely, the accumulation of miR-126 in fibroblasts and the reduced level of miR-126 in endothelial cells induced tube formation in an miR-126-resistant environment via VEGF/EGFL7 upregulation and IRS1-mediated cell proliferation. These findings suggest that transfer of miR-126 via HUVEC-derived exosomes represents a novel strategy to inhibit angiogenesis and cell growth in MM.
Assuntos
Comunicação Celular/fisiologia , Exossomos/metabolismo , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , MicroRNAs/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Carcinogênese/metabolismo , Células Cultivadas , Família de Proteínas EGF/metabolismo , Fibroblastos/metabolismo , Humanos , Mesotelioma Maligno , Transdução de Sinais/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
BACKGROUND: Altered miRNA expression is an early event upon exposure to occupational/environmental carcinogens; thus, identification of a novel asbestos-related profile of miRNAs able to distinguish asbestos-induced cancer from cancer with different etiology can be useful for diagnosis. We therefore performed a study to identify miRNAs associated with asbestos-induced malignancies. METHODS: Four groups of patients were included in the study, including patients with asbestos-related (NSCLCAsb) and asbestos-unrelated non-small cell lung cancer (NSCLC) or with malignant pleural mesothelioma (MPM), and disease-free subjects (CTRL). The selected miRNAs were evaluated in asbestos-exposed population. RESULTS: Four serum miRNAs, that is miR-126, miR-205, miR-222, and miR-520g, were found to be implicated in asbestos-related malignant diseases. Notably, increased expression of miR-126 and miR-222 were found in asbestos-exposed subjects, and both miRNAs are involved in major pathways linked to cancer development. Epigenetic changes and cancer-stroma cross-talk could induce repression of miR-126 to facilitate tumor formation, angiogenesis, and invasion. CONCLUSIONS: This study indicates that miRNAs are potentially involved in asbestos-related malignancies, and their expression outlines mechanism(s) whereby miRNAs may be involved in an asbestos-induced pathogenesis. IMPACT: The discovery of a miRNA panel for asbestos-related malignancies would impact on occupational compensation and may be utilized for screening asbestos-exposed populations.
Assuntos
Amianto/toxicidade , Carcinoma Pulmonar de Células não Pequenas/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Mesotelioma/induzido quimicamente , MicroRNAs/sangue , Idoso , Biomarcadores Tumorais/sangue , Carcinógenos/toxicidade , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Mesotelioma Maligno , MicroRNAs/genética , Pessoa de Meia-Idade , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Intestinal-type sinonasal adenocarcinomas (ITACs) are aggressive malignancies related to wood dust and leather exposure. ITACs are generally associated with advanced stage at presentation due to the insidious growth pattern and non-specific symptoms. Therefore, biomarkers that can detect the switch from the benign disease to malignancy are needed. Essential for tumour growth, angiogenesis is an important step in tumour development and progression. This process is strictly regulated, and MiR-126 considered its master modulator. METHODS: We have investigated MiR-126 levels in ITACs and compared them to benign sinonasal lesions, such as sinonasal-inverted papillomas (SIPs) and inflammatory polyps (NIPs). The tumour-suppressive functions of MiR-126 were also evaluated. RESULTS: We found that MiR-126 can significantly distinguish malignancy from benign nasal forms. The low levels of MiR-126 in ITACs point to its role in tumour progression. In this context, restoration of MiR-126 induced metabolic changes, and inhibited cell growth and the tumorigenic potential of MNSC cells. CONCLUSIONS: We report that MiR-126 delivered via exosomes from endothelial cells promotes anti-tumour responses. This paracrine transfer of MiRs may represent a new approach towards MiR-based therapy.
Assuntos
Adenocarcinoma/genética , MicroRNAs/genética , Neoplasias Nasais/genética , Neoplasias dos Seios Paranasais/genética , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Adulto , Idoso , Biomarcadores Tumorais/genética , Proliferação de Células/genética , Exossomos/genética , Exossomos/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Queratina-20/genética , Masculino , MicroRNAs/administração & dosagem , Pessoa de Meia-Idade , Neovascularização Patológica/genética , Neovascularização Patológica/terapia , Neoplasias Nasais/patologia , Neoplasias Nasais/terapia , Neoplasias dos Seios Paranasais/patologia , Neoplasias dos Seios Paranasais/terapia , Madeira/efeitos adversosRESUMO
OBJECTIVE: Medical personnel using radiation for diagnosis and therapeutic purposes are potentially at risk of cancer development. In this study, the effect of ionising radiation (IR) exposure was evaluated as DNA damage response (DDR) in the circulating cells of occupationally exposed subjects. METHODS: The study population consisted of IR-exposed workers included both in group B (effective dose ranging between 0.04 and 6 mSv/year) and group A (probable effective dose exceeding 6 mSv/year), and the control group consisted of healthy individuals who had never been occupationally exposed to IR or other known carcinogenic agents. DNA damage (single-strand breaks, oxidised purine and pyrimidine bases) and DNA repair (t1/2, half time to repair DNA damage, amount of repaired DNA and DNA repair activity) were measured in lymphocytes using the comet assay. To evaluate the influence of IR doses and genetic predisposition to cancer, the enrolled population was stratified according to IR exposure level and family history of cancer. RESULTS: Increased DNA repair activity was found in IR-exposed group, and only subjects highly exposed to IR doses accumulated DNA damage in their circulating cells, thus supporting the hypothesis of 'radiation hormesis'. A significant increase in DNA damage accumulation and a reduced 8-oxoguanine glycosylase 1-dependent DNA repair activity were found in IR-exposed subjects with cancer cases across their family. CONCLUSION: Our results indicate that chronic exposure to a low dose of IR in occupational settings induces DDR in exposed subjects and may be mutagenic in workers with family history of cancer, suggesting that periodic surveillance might be advisable, along with exposure monitoring.
Assuntos
Dano ao DNA , Exposição Ocupacional/efeitos adversos , Radiação Ionizante , Adulto , Análise de Variância , Estudos de Casos e Controles , Reparo do DNA , Relação Dose-Resposta à Radiação , Feminino , Predisposição Genética para Doença , Pessoal de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/etiologia , Neoplasias/genéticaRESUMO
Pesticides, including herbicides, insecticides and fungicides, are widely used in intensive agriculture. Recently, the long-term effects of pesticide exposure were found to be associated with many diseases. In this study, we evaluated the long-term effect of low-level exposure to a mixture of pesticides on DNA damage response (DDR) in relation to individual detoxifying variability. A residential population chronically exposed to pesticides was enrolled, biological/environmental pesticide levels; paroxonase 1 (PON-1) activity and 192 Q/R polymorphism and DDR were evaluated at three different periods of pesticide exposure. OGG1-dependent DNA repair activity was decreased in relation to pesticide exposure. The increase of DNA lesions and pesticide levels in the intensive pesticide-spraying period was independent on PON-1 activity. Next, human bronchial epithelial and neuronal cells were used as a model for in vitro evaluation of the mechanistic effect of pesticides. Pesticides induced mitochondrial dysfunction leading to ROS formation. ROS from mitochondria induced DNA damage, which in turn induced OGG1-dependent DNA repair activity through 8-oxoguanine DNA glycosylase 1 (OGG1) expression and activation. Even though OGG1 was overexpressed, an inhibition of its activity, associated with DNA lesion accumulation, was found at prolonged pesticide-exposure. A post-translational regulation of OGG1 by pesticide may be postulated. Taken together, long-term exposure to low-levels of pesticides affects DDR resulting in accumulation of DNA lesions that eventually may lead to cancer or neurological disorders.
Assuntos
Dano ao DNA/efeitos dos fármacos , DNA Glicosilases/genética , Praguicidas/toxicidade , Adolescente , Adulto , Arildialquilfosfatase/metabolismo , Linhagem Celular , Reparo do DNA/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Polimorfismo Genético , Espécies Reativas de Oxigênio/metabolismo , Adulto JovemRESUMO
It was reported recently that allyl isothiocyanate (AITC) could inhibit various types of cancer cell growth. In the present study, we further investigated whether AITC could inhibit the growth of human breast cancer cells. Unexpectedly, we found that AITC did not inhibit, rather slightly promoted, the proliferation of MDA-MB-231 breast cancer cells, although it did have inhibitory effect on MCF-7 breast cancer cells. Cytofluorimetric analysis revealed that AITC (10 µM) did not induce apoptosis and cell cycle arrest in MDA-MB-231 cells. In addition, AITC significantly (p < 0.05) increased the expression of BCL-2 and mTOR genes and Beclin-1 protein in MDA-MB-231 cells. No significant changes in expression of PRKAA1 and PER2 genes, Caspase-8, Caspase-9, PARP, p-mTOR, and NF-κB p65 proteins were observed in these AITC-treated cells. Importantly, AITC displayed cytotoxic effect on MCF-10A human breast epithelial cell line. These observations suggest that AITC may not have inhibitory activity in MDA-MB-231 breast cancer cells. This in vitro study warrants more preclinical and clinical studies on the beneficial and harmful effects of AITC in healthy and cancer cells.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Isotiocianatos/uso terapêutico , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Isotiocianatos/farmacologia , Proteínas de Neoplasias/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Lung cancer is one of the leading causes of cancer-related deaths. It is diagnosed mostly at the locally advanced or metastatic stage. Recently, micro RNAs (miRs) and their distribution in circulation have been implicated in physiological and pathological processes. In this study, miR-126 was evaluated in serum, exosome and exosome-free serum fractions in non-small cell lung cancer (NSCLC) patients at early and advanced stages, and compared with healthy controls. Down-regulation of miR-126 was found in serum of advanced stage NSCLC patients. In healthy controls, circulating miR-126 was equally distributed between exosomes and exosome-free serum fractions. Conversely, in both early and advanced stage NSCLC patients, miR-126 was mainly present in exosomes. Different fractions of miR-126 in circulation may reflect different conditions during tumour formation. Incubation of exosomes from early and advanced NSCLC patients induced blood vessel formation and malignant transformation in human bronchial epithelial cells. On the other hand, exosome-enriched miR-126 from normal endothelial cells inhibited cell growth and induces loss of malignancy of NSCLC cells. These findings suggest a role of exo-miRs in the modulation of the NSCLC microenvironmental niche. Exosome-delivered miRs thus hold a substantial promise as a diagnostics biomarker as well as a personalized therapeutic modality.
Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , MicroRNA Circulante/sangue , Exossomos/metabolismo , Neoplasias Pulmonares/sangue , MicroRNAs/sangue , RNA Neoplásico/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/patologia , Exossomos/patologia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Microambiente TumoralRESUMO
SCOPE: Glyphosate (GLY) and organophosphorus insecticides such as chlorpyrifos (CPF) may cause DNA damage and cancer in exposed individuals through mitochondrial dysfunction. Polyphenols ubiquitously present in fruits and vegetables, have been viewed as antioxidant molecules, but also influence mitochondrial homeostasis. Here, honey containing polyphenol compounds was evaluated for its potential protective effect on pesticide-induced genotoxicity. METHODS AND RESULTS: Honey extracts from four floral organic sources were evaluated for their polyphenol content, antioxidant activity, and potential protective effects on pesticide-related mitochondrial destabilization, reactive oxygen and nitrogen species formation, and DNA damage response in human bronchial epithelial and neuronal cells. The protective effect of honey was, then evaluated in a residential population chronically exposed to pesticides. The four honey types showed a different polyphenol profile associated with a different antioxidant power. The pesticide-induced mitochondrial dysfunction parallels ROS formation from mitochondria (mtROS) and consequent DNA damage. Honey extracts efficiently inhibited pesticide-induced mtROS formation, and reduced DNA damage by upregulation of DNA repair through NFR2. Honey supplementation enhanced DNA repair activity in a residential population chronically exposed to pesticides, which resulted in a marked reduction of pesticide-induced DNA lesions. CONCLUSION: These results provide new insight regarding the effect of honey containing polyphenols on pesticide-induced DNA damage response.
Assuntos
Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Mel , Praguicidas/toxicidade , Adolescente , Adulto , Antioxidantes/análise , Estudos de Casos e Controles , Linhagem Celular , Reparo do DNA/fisiologia , Suplementos Nutricionais , Exposição Ambiental/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Feminino , Mel/análise , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/efeitos dos fármacos , Polifenóis/análise , Testes de Toxicidade CrônicaRESUMO
The circadian biological clock is essentially based on the light/dark cycle. Some people working with shift schedules cannot adjust their sleep/wake cycle to the light/dark cycle, and this may result in alterations of the circadian biological clock. This study explored the circadian biological clock of shift and daytime nurses using non-invasive methods. Peripheral skin temperature, cortisol and melatonin levels in saliva, and Per2 expression in pubic hair follicle cells were investigated for 24 h after a day off. Significant differences were observed in peripheral skin temperature and cortisol levels between shift and daytime nurses. No differences in melatonin levels were obtained. Per2 maximum values were significantly different between the two groups. Shift nurses exhibited lower circadian variations compared to daytime nurses, and this may indicate an adjustment of the circadian biological clock to continuous shift schedules. Non-invasive procedures, such as peripheral skin temperature measurement, determination of cortisol and melatonin in saliva, and analysis of clock genes in hair follicle cells, may be effective approaches to extensively study the circadian clock in shift workers.
Assuntos
Relógios Circadianos/fisiologia , Adulto , Demografia , Expressão Gênica , Folículo Piloso/metabolismo , Humanos , Hidrocortisona/metabolismo , Melatonina/metabolismo , Enfermeiras e Enfermeiros , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Saliva/metabolismo , Temperatura Cutânea , Fatores de TempoRESUMO
Autophagy favors both cell survival and cancer suppression, and increasing evidence reveals that microRNAs (MIRs) regulate autophagy. Previously we reported that MIR126 is downregulated in malignant mesothelioma (MM). Therefore, we investigated the role of MIR126 in the regulation of cell metabolism and autophagy in MM models. We report that MIR126 induces autophagic flux in MM cells by downregulating insulin receptor substrate-1 (IRS1) and disrupting the IRS1 signaling pathway. This was specific to MM cells, and was not observed in non-malignant cells of mesothelial origin or in MM cells expressing MIR126-insensitive IRS1 transcript. The MIR126 effect on autophagy in MM cells was recapitulated by IRS1 silencing, and antagonized by IRS1 overexpression or antisense MIR126 treatment. The MIR126-induced loss of IRS1 suppressed glucose uptake, leading to energy deprivation and AMPK-dependent phosphorylation of ULK1. In addition, MIR126 stimulated lipid droplet accumulation in a hypoxia-inducible factor-1α (HIF1α)-dependent manner. MIR126 also reduced pyruvate dehydrogenase kinase (PDK) and acetyl-CoA-citrate lyase (ACL) expression, leading to the accumulation of cytosolic citrate and paradoxical inhibition of pyruvate dehydrogenase (PDH) activity. Simultaneous pharmacological and genetic intervention with PDK and ACL activity phenocopied the effects of MIR126. This suggests that in MM MIR126 initiates a metabolic program leading to high autophagic flux and HIF1α stabilization, incompatible with tumor progression of MM. Consistently, MIR126-expressing MM cells injected into immunocompromised mice failed to progress beyond the initial stage of tumor formation, showing that increased autophagy has a protective role in MM.