RESUMEN
Manganese (Mn)-induced pulmonary toxicity and the underlying molecular mechanisms remain largely enigmatic. Further, in recent years, microRNAs (miRNAs) have emerged as regulators of several pollutants-mediated toxicity. In this context, our study aimed at elucidating whether miRNAs are involved in manganese (II) chloride (MnCl2) (Mn2+)-induced cytotoxicity in lung epithelial cells. Growth inhibition of Mn2+ towards normal human bronchial epithelial (BEAS-2B) and adenocarcinomic human alveolar basal epithelial (A549) cells was analyzed by MTT assay following 24 or 48 h treatment. Reactive oxygen species (ROS) generation, mitochondrial membrane potential (ΔΨm), cell cycle arrest, and apoptosis were evaluated by flow cytometry. RT-qPCR and Western blot were performed to analyze the expression of cyclins, anti-oxidant genes, and miRNAs. We used small RNA sequencing to investigate Mn2+-induced changes in miRNA expression patterns. In both cell lines, Mn2+ treatment inhibited growth in a dose-dependent manner. Further, compared with vehicle-treated cells, Mn2+ (250 µM) treatment induced ROS generation, cell cycle arrest, apoptosis, and decreased ΔΨm as well as altered the expression of cyclins and anti-oxidant genes. Sequencing data revealed that totally 296 miRNAs were differentially expressed in Mn2+-treated cells. Among them, miR-221-3p was one of the topmost down-regulated miRNAs in Mn2+-treated cells. We further confirmed this association in A549 cells. In addition, transient transfection was performed to study gain-of-function experiments. Forced expression of miR-221-3p significantly improved cell viability and reduced Mn2+-induced cell cycle arrest and apoptosis in BEAS-2B cells. In conclusion, miR-221-3p may be the most likely target that accounts for the cytotoxicity of Mn2+-exposed lung epithelial cells.
Asunto(s)
Apoptosis , Células Epiteliales , Pulmón , MicroARNs , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Células A549 , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Apoptosis/efectos de los fármacos , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Compuestos de Manganeso , Manganeso/toxicidad , Línea Celular , Cloruros/toxicidad , Puntos de Control del Ciclo Celular/efectos de los fármacos , Relación Dosis-Respuesta a DrogaRESUMEN
Arsenic (As), a highly toxic metalloid, which causes environmental lung diseases and affects millions of people worldwide. Respiratory epithelial cells are essential for maintaining lung homeostasis, aberrant epithelial damage and death due to exposure to a wide range of environmental pollutants, which are considered to be the initial trigger for many pulmonary diseases. Accumulating evidence has shown that microRNAs (miRNAs) appear to be important players in various normal physiological and pathological processes. Therefore, the present study was carried out to examine the cytotoxic effects of a trivalent form of As (As3+) in normal human bronchial (BEAS-2B) and adenocarcinoma alveolar basal (A549) epithelial cells and the role of miR-195-5p. Further, we also explored the protective effects of a natural dietary polyphenol tannic acid (TA). As3+ (1 µM) treatment in BEAS-2B cells for 24 h induced cytotoxicity by decreasing the cell viability, mitochondrial membrane potential (ΔΨm) and inducing reactive oxygen species (ROS) generation, lipid peroxidation (LPO), cell cycle arrest, and apoptosis, which was associated with a significantly higher level of miR-195-5p expression compared with vehicle control. Forced expression of miR-195-5p alone suppressed cell survival, ΔΨm, regulated cell cycle distribution and induced ROS generation in BEAS-2B cells. As expected, miR-195-5p inhibition effectively rescued BEAS-2B cells from As3+-mediated toxicity, confirming the involvement of miR-195-5p in the cytotoxic effects of As3+. Further, TA pre-treatment expressively alleviated As3+-induced toxicity by suppressing ROS production, miR-195-5p expression, and increasing ΔΨm. These in vitro results indicate that miR-195-5p may be useful as a therapeutic target for treating As3+ toxicity.
Asunto(s)
Antineoplásicos , Arsénico , MicroARNs , Polifenoles , Humanos , Arsénico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , MicroARNs/metabolismo , Células Epiteliales , Pulmón/metabolismo , Apoptosis , Antineoplásicos/farmacologíaRESUMEN
Respiratory illnesses impose a significant health burden and cause deaths worldwide. Despite many advanced strategies to improve patient outcomes, they are often less effective. There is still considerable room for improvement in the treatment of various respiratory diseases. In recent years, alternative medicinal agents derived from food plants have shown better beneficial effects against a wide variety of disease models, including cancer. In this regard, kaempferol (KMF) and its derivatives are the most commonly found dietary flavonols. They have been found to exhibit protective effects on multiple chronic diseases like diabetes, fibrosis, and so on. A few recent articles have reviewed the pharmacological actions of KMF in cancer, central nervous system diseases, and chronic inflammatory diseases. However, there is no comprehensive review that exists regarding the beneficial effects of KMF and its derivatives on both malignant- and non-malignant respiratory diseases. Many experimental studies reveal that KMF and its derivatives are helpful in managing a wide range of respiratory diseases, including acute lung injury, fibrosis, asthma, cancer, and chronic obstructive pulmonary disease, and their underlying molecular mechanisms. In addition, we also discussed the chemistry and sources, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties, methods to enhance bioavailability, as well as our perspective on future research with KMF and its derivatives.
Asunto(s)
Neoplasias , Enfermedades Respiratorias , Humanos , Quempferoles/farmacología , Enfermedades Respiratorias/tratamiento farmacológico , Neoplasias/tratamiento farmacológico , Modelos Teóricos , FibrosisRESUMEN
BACKGROUND: The transforming growth factor-beta1 (TGF-ß1)-induced epithelial-tomesenchymal transition (EMT) has a crucial effect on the progression and metastasis of lung cancer cells. OBJECTIVE: The purpose of this study was to investigate whether microRNA (miR)-16 can suppress TGF-ß1-induced EMT and proliferation in human lung adenocarcinoma cell line (A549). METHODS: Quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-16. The hallmarks of EMT were assessed by RT-qPCR, Western blotting, and cell proliferation assay. A bioinformatics tool was used to identify the putative target of miR-16. The activation of TGF-ß1/Smad3 signaling was analysed using Western blotting. RESULTS: Our results showed that miR-16 expression was significantly down-regulated by TGF-ß1 in A549 cells. Moreover, agomir of miR-16 suppressed TGF-ß1-induced EMT and cell proliferation. Computational algorithms predicted that the 3'-untranslated regions (3'-UTRs) of Smad3 are direct targets of miR-16. In addition, miR-16 mimic was found to inhibit the TGF-ß1-induced activation of the TGF-ß1/Smad3 pathway, suggesting that miR-16 may function partly through regulating Smad3. CONCLUSION: Our results demonstrated that overexpression of miR-16 suppressed the expression and activation of Smad3, and ultimately inhibited TGF-ß1-induced EMT and proliferation in A549 cells. The present findings support further investigation of the anti-cancer effect of miR-16 in animal models of lung cancer to validate the therapeutic potential.
Asunto(s)
Adenocarcinoma del Pulmón , Transición Epitelial-Mesenquimal , Neoplasias Pulmonares , MicroARNs , Humanos , Adenocarcinoma del Pulmón/genética , Movimiento Celular , Transición Epitelial-Mesenquimal/genética , Neoplasias Pulmonares/patología , MicroARNs/genética , Factor de Crecimiento Transformador beta1/farmacología , Células A549RESUMEN
Arsenic (As), a toxic metalloid, primarily originates from both natural and anthropogenic activities. Reports suggested that millions of people globally exposed to high levels of naturally occurring As compounds via inhalation and ingestion. There is evidence that As is a well-known lung carcinogen. However, there has been relatively little evidence suggesting its non-malignant lung effects. This review comprehensively summarises current experimental and clinical studies implicating the association of As exposure and the development of several non-malignant lung diseases. Experimental studies provided evidence that As exposure induces redox imbalance, apoptosis, inflammatory response, epithelial-to-mesenchymal transition (EMT), and affected normal lung development through alteration of the components of intracellular signaling cascades. In addition, we also discuss the sources and possible mechanisms of As influx and efflux in the lung. Finally, current experimental studies on treatment strategies using phytochemicals and our perspective on future research with As are also discussed.