40 research outputs found
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Mitochondrial Stress Response in Neural Stem Cells Exposed to Electronic Cigarettes.
Stem cells provide a sensitive model to study exposure to toxicants, such as cigarette smoke. Electronic cigarettes (ECs) are popular nicotine delivery devices, often targeted to youth and pregnant mothers. However, little is known about how chemicals in ECs might affect neural stem cells, and in particular their mitochondria, organelles that maintain cell functionality and health. Here we show that the mechanism underlying EC-induced stem cell toxicity is stress-induced mitochondrial hyperfusion (SIMH), a transient survival response accompanied by increased mitochondrial oxidative stress. We identify SIMH as a survival response to nicotine, now widely available in EC refill fluids and in pure form for do-it-yourself EC products. These observed mitochondrial alterations combined with autophagy dysfunction to clear damaged mitochondria could lead to faulty stem cell populations, accelerate cellular aging, and lead to acquired mitochondriopathies. Any nicotine-containing product may likewise stress stem cells with long-term repercussions for users and passively exposed individuals. VIDEO ABSTRACT
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Intraperitoneal administration of Telmisartan prevents postsurgical adhesion band formation
Background
Angiotensin II receptor blockers (ARBs) have a potential role in reducing inflammation and fibrosis. We have integrated systems and molecular biology approaches to investigate the therapeutic potential of ARBs in preventing postsurgical adhesion band formation.
Material and methods
we have followed the ARRIVE guidelines point by point during experimental studies. Telmisartan (1 and 9 mg/kg), valsartan (1 and 9 mg/kg), and losartan (1 and 10 mg/kg) were administered intraperitoneally in different groups of male albino Wistar rat. After 7 d of treatment, macroscopic evidence and score of fibrotic bands based on scaling methods was performed. Moreover, the anti-inflammatory and antifibrosis effects of telmisartan on reduction of fibrotic bands were investigated by using histopathology, ELISA, and real-time polymerase chain reaction methods.
Results
Telmisartan, but not losartan or valsartan, prevented the frequency as well as the stability of adhesion bands. Telmisartan appears to elicit anti-inflammatory responses by attenuating submucosal edema, suppressing proinflammatory cytokines, decreasing proinflammatory cell infiltration, and inhibiting oxidative stress at the site of peritoneal surgery. We also showed that telmisartan prevents fibrotic adhesion band formation by reducing excessive collagen deposition and suppression of profibrotic genes expression at the peritoneum adhesion tissues.
Conclusions
These results support the potential application of telmisartan in preventing postsurgical adhesion band formation by inhibiting key pathologic responses of inflammation and fibrosis in postsurgery patients
Epithelial-to-mesenchymal transition of A549 lung cancer cells exposed to electronic cigarettes.
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Decoding the Molecular Mechanisms Underlying Electronic Cigarette Toxicity in Lung, Cancer and Stem Cells
Electronic cigarettes (ECs), popular nicotine-delivery devices, have emerged as potential health hazards. ECs contain nicotine, flavor chemicals, and solvents used to generate aerosols. The purpose of my dissertation was to develop bioassays and video bioinformatics tools to characterize effects of disposable-style ECs on cultured lung cells, stem cells, and cancer cells. A screening method was developed to identify toxic EC products and evaluate their modes of action (MOAs). StemCellQC software can assess the health of pluripotent embryonic stem cell (ESC) colonies and extract data on dynamic processes such as cell proliferation, spreading, migration, and cell death. MitoMo software was developed to assess mitochondrial (important and sensitive organelles) health parameters such as mitophagy, morphology, dynamics, membrane potential, oxidative stress, calcium levels, and mtDNA nucleoids. A two-tiered screen was performed to identify harmful EC products. Based on tier 1 assays, two brands were identified for further investigation. In tier 2 assays, Greensmoke exposure led to a decrease in growth rate, cytoskeletal depolymerization, adhesion defects, oxidation of mitochondrial proteins, and eventual apoptosis. Vuse exposure produced an epithelial-to-mesenchymal transition (EMT) and increased α-smooth muscle actin, a fibrosis biomarker. It also caused loss of cell-to-cell junctions, migratory behavior, internalization of junctional stabilizers E-cadherin and P120-catenin, and nuclear translocation of β-catenin (dual role as a transcription factor for EMT). EMT is the initial step enabling metastasis of cancer cells, which is a concern for former smokers with a pre-existing lung tumor. Fibrosis, epithelial cell disruption, and oxidative damage can lead to chronic lung diseases. The effects of ECs were studied on neural stem cells (NSCs) as an in vitro model for early development, since ECs are often targeted to youth and pregnant mothers, raising developmental risks. The high nicotine content in Vuse caused oxidative stress, autophagy defects, and a stress-induced mitochondrial hyperfusion (SIMH). Exposure to Vuse aerosols also led to upregulation and desensitization of nicotinic acetylcholine receptors (nAChRs). These findings are critical considering that nicotine is now widely available in EC products. Mitochondrial damage, oxidative stress and autophagy dysfunction can cause faulty stem cell populations, which may accelerate aging and lead to cancer, diabetes, neurodegenerative disorders
Evaluating Cell Processes, Quality, and Biomarkers in Pluripotent Stem Cells Using Video Bioinformatics.
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Automated spatio-temporal analysis of dendritic spines and related protein dynamics.
Cofilin and other Actin-regulating proteins are essential in regulating the shape of dendritic spines, which are sites of neuronal communications in the brain, and their malfunctions are implicated in neurodegeneration related to aging. The analysis of cofilin motility in dendritic spines using fluorescence video-microscopy may allow for the discovery of its effects on synaptic functions. To date, the flow of cofilin has not been analyzed by automatic means. This paper presents Dendrite Protein Analysis (DendritePA), a novel automated pattern recognition software to analyze protein trafficking in neurons. Using spatiotemporal information present in multichannel fluorescence videos, the DendritePA generates a temporal maximum intensity projection that enhances the signal-to-noise ratio of important biological structures, segments and tracks dendritic spines, estimates the density of proteins in spines, and analyzes the flux of proteins through the dendrite/spine boundary. The motion of a dendritic spine is used to generate spine energy images, which are used to automatically classify the shape of common dendritic spines such as stubby, mushroom, or thin. By tracking dendritic spines over time and using their intensity profiles, the system can analyze the flux patterns of cofilin and other fluorescently stained proteins. The cofilin flux patterns are found to correlate with the dynamic changes in dendritic spine shapes. Our results also have shown that the activation of cofilin using genetic manipulations leads to immature spines while its inhibition results in an increase in mature spines
Automated spatio-temporal analysis of dendritic spines and related protein dynamics.
Cofilin and other Actin-regulating proteins are essential in regulating the shape of dendritic spines, which are sites of neuronal communications in the brain, and their malfunctions are implicated in neurodegeneration related to aging. The analysis of cofilin motility in dendritic spines using fluorescence video-microscopy may allow for the discovery of its effects on synaptic functions. To date, the flow of cofilin has not been analyzed by automatic means. This paper presents Dendrite Protein Analysis (DendritePA), a novel automated pattern recognition software to analyze protein trafficking in neurons. Using spatiotemporal information present in multichannel fluorescence videos, the DendritePA generates a temporal maximum intensity projection that enhances the signal-to-noise ratio of important biological structures, segments and tracks dendritic spines, estimates the density of proteins in spines, and analyzes the flux of proteins through the dendrite/spine boundary. The motion of a dendritic spine is used to generate spine energy images, which are used to automatically classify the shape of common dendritic spines such as stubby, mushroom, or thin. By tracking dendritic spines over time and using their intensity profiles, the system can analyze the flux patterns of cofilin and other fluorescently stained proteins. The cofilin flux patterns are found to correlate with the dynamic changes in dendritic spine shapes. Our results also have shown that the activation of cofilin using genetic manipulations leads to immature spines while its inhibition results in an increase in mature spines
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Epithelial-to-mesenchymal transition of A549 lung cancer cells exposed to electronic cigarettes.
ObjectivesEpithelial-to-mesenchymal transition (EMT) is the initial step enabling the metastasis of cancer cells, which often leads to death. Although smoking is a major risk factor for lung cancer, there is still widespread use of conventional cigarettes. Recently, the tobacco industry has been transformed by the introduction of electronic cigarettes (ECs), which have lower levels of carcinogens and may provide a safer alternative. Here, we investigate the ability of EC liquids and aerosols to induce an EMT in A549 lung cancer cells.Materials and methodsHuman adenocarcinoma alveolar basal epithelial cells (A549) were exposed to EC liquids and aerosols from a popular product for 3-8 days. Live cell imaging, EMT biomarker analysis, and machine learning/image processing algorithms were used to characterize changes associated with EMT.ResultsLong-term exposure of A549 cells to menthol or tobacco-flavored EC liquids or aerosols induced an EMT that was characterized by acquisition of a fibroblast-like morphology, loss of cell-to-cell junctions, internalization of E-cadherin, increased motility, and upregulation of other EMT markers. The EMT was concurrent with plasma membrane to nuclear translocation of active β-catenin.ConclusionThis is the first known study to show an EMT of lung cancer cells during exposure to EC products. Because an EMT is an initial step leading to metastasis, an intractable problem that often leads to patient death, this critical finding has significant implications for former or heavy cigarette smokers who are using EC and may be at risk for lung cancer or who may already have a lung tumor