Cellular respiration: replicating in vivo systems biology for in vitro exploration of human exposome, microbiome, and disease pathogenesis biomarkers

2016 ◽  
Vol 10 (1) ◽  
pp. 010201 ◽  
Author(s):  
Joachim D Pleil
2009 ◽  
Vol 296 (4) ◽  
pp. L657-L665 ◽  
Author(s):  
Mohammad Abolhassani ◽  
Adeline Guais ◽  
Philippe Chaumet-Riffaud ◽  
Annie J. Sasco ◽  
Laurent Schwartz

The aim of this study was to assess whether one of the most common poisons of cellular respiration, i.e., carbon dioxide, is proinflammatory. CO2 is naturally present in the atmosphere at the level of 0.038% and involved in numerous cellular biochemical reactions. We analyzed in vitro the inflammation response induced by exposure to CO2 for 48 h (0–20% with a constant O2 concentration of 21%). In vivo mice were submitted to increasing concentrations of CO2 (0, 5, 10, and 15% with a constant O2 concentration of 21%) for 1 h. The exposure to concentrations above 5% of CO2 resulted in the increased transcription (RNase protection assay) and secretion (ELISA) of proinflammatory cytokines [macrophage inflammatory protein-1α (MIP-1α), MIP-1β, MIP-2, IL-8, IL-6, monocyte chemoattractant protein-1, and regulated upon activation, normal T cell expressed, and, presumably, secreted (RANTES)] by epithelial cell lines HT-29 or A549 and primary pulmonary cells retrieved from the exposed mice. Lung inflammation was also demonstrated in vivo by mucin 5AC-enhanced production and airway hyperreactivity induction. This response was mostly mediated by the nuclear translocation of p65 NF-κB, itself a consequence of protein phosphatase 2A (PP2A) activation. Short inhibiting RNAs (siRNAs) targeted toward PP2Ac reversed the effect of carbon dioxide, i.e., disrupted the NF-κB activation and the proinflammatory cytokine secretion. In conclusion, this study strongly suggests that exposure to carbon dioxide may be more toxic than previously thought. This may be relevant for carcinogenic effects of combustion products.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S30-S31
Author(s):  
Gabriel Suarez ◽  
Bo Liu ◽  
Jeremy Herzog ◽  
Ryan Sartor

Abstract Sulfur metabolism is emerging as a signature of IBD gut microbiota. Overrepresentation of sulfur-reducing bacteria (SRB) in IBD results in SRB-derived epithelial toxic H2S production that can overwhelm the body’s detoxification capacity, leading to impaired cellular respiration by inhibiting oxygen binding to mitochondrial cytochrome-c-oxidase. Butyrate potently inhibits SRBs and H2S, yet IBD patients have reduced short chain fatty acid (SCFA) production. More critically, H2S blocks butyrate oxidation, the primary energy source of colonocytes; butyrate oxidation deficiency is a defining characteristic of IBD. Since cysteine is the preferred substrate for H2S production by SRBs, a cysteine-rich environment provided by either a high protein diet or local intestinal mucus degradation promotes ideal conditions for SRB establishment and proliferation. SRBs can catabolize other sulfur-containing compounds critical for immune homeostasis and cellular health, such as taurine-conjugated bile acids and the “master antioxidant” glutathione, leading to further toxic H2S production. However, the molecular underpinnings of sulfur metabolism by specific bacterial genera is understudied in IBD. Results: Using a combination of in-vivo and in-vitro screening to detect the relative induction of interleukin 10 (IL-10) and interferon g (IFNg) by 19 resident bacterial strains isolated from a healthy human donor, we identified 4 bacterial strains that induce a low IL-10/IFNg ratio. These 4 strains (low group), but not 3 bacterial strains that induce a high IL-10/IFNg ratio, induce colitis in selectively colonized gnotobiotic Il10-/- mice (Fig.1A). Two of these 4 disease-inducing strains, Clostridium perfringens (A12) and Clostridium bolteae (B6), produce high concentrations of H2S in monoassociated mice (Fig.1B). In-vitro H2S production by these strains is dependent on cysteine (Fig.1C). C. perfringens and C. bolteae each induce colitis in monoassociated Il10-/- mice (Fig.1D). We are dissecting the sulfur metabolic pathways in C. perfringens and C. bolteae and their contribution to inflammatory processes by interrupting key genes predicted to contribute to H2S production, cysteine catabolism and bile acid metabolism. We will use these mutants in both in-vitro and in-vivo Il10 -/- gnotobiotic mice models to characterize their metabolic and inflammatory profiles. We have created several mutants using Targetron gene editing, including the dissimilatory sulfate reductase (Δdsr), a putative sulfonate membrane transporter (ΔssuA), anaerobic sulfite reductase (ΔasrA) and bile salt hydrolase (Δbsh). Conclusions: H2S producing bacterial strains can induce experimental colitis. Our planned mechanistic studies will determine the metabolic routes for H2S production by specific aggressive bacteria to guide novel therapeutic or dietary interventions to improve IBD prognosis.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1694
Author(s):  
Emmanuel Twumasi Osei ◽  
Steven Booth ◽  
Tillie-Louise Hackett

As the lung develops, epithelial-mesenchymal crosstalk is essential for the developmental processes that drive cell proliferation, differentiation, and extracellular matrix (ECM) production within the lung epithelial-mesenchymal trophic unit (EMTU). In asthma, a number of the lung EMTU developmental signals have been associated with airway inflammation and remodeling, which has led to the hypothesis that aberrant activation of the asthmatic EMTU may lead to disease pathogenesis. Monoculture studies have aided in the understanding of the altered phenotype of airway epithelial and mesenchymal cells and their contribution to the pathogenesis of asthma. However, 3-dimensional (3D) co-culture models are needed to enable the study of epithelial-mesenchymal crosstalk in the setting of the in vivo environment. In this review, we summarize studies using 3D co-culture models to assess how defective epithelial-mesenchymal communication contributes to chronic airway inflammation and remodeling within the asthmatic EMTU.


2003 ◽  
Vol 284 (2) ◽  
pp. C528-C534 ◽  
Author(s):  
Shiuhyang Kuo ◽  
Ann L. Chokas ◽  
Richard J. Rogers ◽  
Harry S. Nick

Manganese superoxide dismutase (MnSOD) is a critical antioxidant enzyme that protects against superoxide anion generated as a consequence of normal cellular respiration, as well as during the inflammatory response. By employing dimethyl sulfate in vivo footprinting, we have previously identified ten basal protein binding sites within the MnSODpromoter. On the basis of consensus sequence comparison and in vitro footprinting data, one would predict that Sp1 might occupy five of these binding sites. To address these findings in the context of the nucleoprotein environment, we first utilized chromatin immunoprecipitation (ChIP) to demonstrate the nuclear association of Sp1 with the MnSOD promoter region. To identify the precise location of Sp1 binding, we have modified the original protein position identification with nuclease tail (PIN*POINT) methodology, providing an approach to establish both the identity and binding occupancy of Sp1 in the context of the endogenous MnSOD promoter. These data, coupled with site-directed mutagenesis, demonstrate the functional importance of two of the Sp1 binding sites in the stimulus-specific regulation of MnSOD gene expression. We feel that the combination of ChIP and PIN*POINT analysis allows unequivocal identification and localization of protein/DNA interactions in vivo, specifically the demonstration of Sp1 with the MnSODpromoter.


2016 ◽  
Vol 13 (117) ◽  
pp. 20151046 ◽  
Author(s):  
Fei He ◽  
Ettore Murabito ◽  
Hans V. Westerhoff

Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out through in silico theoretical studies with the aim to guide and complement further in vitro and in vivo experimental efforts. Clearly, what counts is the result in vivo , not only in terms of maximal productivity but also robustness against environmental perturbations. Engineering an organism towards an increased production flux, however, often compromises that robustness. In this contribution, we review and investigate how various analytical approaches used in metabolic engineering and synthetic biology are related to concepts developed by systems and control engineering. While trade-offs between production optimality and cellular robustness have already been studied diagnostically and statically, the dynamics also matter. Integration of the dynamic design aspects of control engineering with the more diagnostic aspects of metabolic, hierarchical control and regulation analysis is leading to the new, conceptual and operational framework required for the design of robust and productive dynamic pathways.


2017 ◽  
Author(s):  
Alyssa D. Schwartz ◽  
Lauren E. Barney ◽  
Lauren E. Jansen ◽  
Thuy V. Nguyen ◽  
Christopher L. Hall ◽  
...  

TOC FigureDrug response screening, gene expression, and kinome signaling were combined across biomaterial platforms to combat adaptive resistance to sorafenib.Insight BoxWe combined biomaterial platforms, drug screening, and systems biology to identify mechanisms of extracellular matrix-mediated adaptive resistance to RTK-targeted cancer therapies. Drug response was significantly varied across biomaterials with altered stiffness, dimensionality, and cell-cell contacts, and kinome reprogramming was responsible for these differences in drug sensitivity. Screening across many platforms and applying a systems biology analysis were necessary to identify MEK phosphorylation as the key factor associated with variation in drug response. This method uncovered the combination therapy of sorafenib with a MEK inhibitor, which decreased viability on and within biomaterials in vitro, but was not captured by screening on tissue culture plastic alone. This combination therapy also reduced tumor burden in vivo, and revealed a promising approach for combating adaptive drug resistance.AbstractTraditional drug screening methods lack features of the tumor microenvironment that contribute to resistance. Most studies examine cell response in a single biomaterial platform in depth, leaving a gap in understanding how extracellular signals such as stiffness, dimensionality, and cell-cell contacts act independently or are integrated within a cell to affect either drug sensitivity or resistance. This is critically important, as adaptive resistance is mediated, at least in part, by the extracellular matrix (ECM) of the tumor microenvironment. We developed an approach to screen drug responses in cells cultured on 2D and in 3D biomaterial environments to explore how key features of ECM mediate drug response. This approach uncovered that cells on 2D hydrogels and spheroids encapsulated in 3D hydrogels were less responsive to receptor tyrosine kinase (RTK)-targeting drugs sorafenib and lapatinib, but not cytotoxic drugs, compared to single cells in hydrogels and cells on plastic. We found that transcriptomic differences between these in vitro models and tumor xenografts did not reveal mechanisms of ECM-mediated resistance to sorafenib. However, a systems biology analysis of phospho-kinome data uncovered that variation in MEK phosphorylation was associated with RTK-targeted drug resistance. Using sorafenib as a model drug, we found that co-administration with a MEK inhibitor decreased ECM-mediated resistance in vitro and reduced in vivo tumor burden compared to sorafenib alone. In sum, we provide a novel strategy for identifying and overcoming ECM-mediated resistance mechanisms by performing drug screening, phospho-kinome analysis, and systems biology across multiple biomaterial environments.


2019 ◽  
Author(s):  
Obada Abouassali ◽  
Mengmeng Chang ◽  
Michelle Reiser ◽  
Manasa Kanithi ◽  
Ravi Soni ◽  
...  

ABSTRACTBackgroundTobacco cigarette smoking is on the decline, but the usage of electronic nicotine delivery systems (ENDS) is gaining popularity, specifically in the teen and young adult age groups. While the cardiac toxicity of tobacco cigarette smoking has been widely studied and is well established, the possible cardiac toxicity of ENDS products and their design characteristics, such as added flavorings, are largely underexplored. Vaping, a form of electronic nicotine delivery, uses “e-liquid” to generate “e-vapor”, a smoke-like aerosolized mixture of nicotine and flavors. Here, we tested the hypothesis that vaping results in cardiac electrophysiological instability and arrhythmogenesis. We thus investigated how e-liquids with different flavors affect cardiac in-vitro and in-vivo toxicity, in cell culture and in animals.MethodsThree e-liquids with vanilla, cinnamon or fruit flavors were studied. We quantified apoptosis and oxygen consumption rate in HL-1 cells cultured with e-vapors extracts. In human iPSC derived ventricular cardiomyocytes (hiPSC-CM) cultured with e-vapor extract, beating frequency and repolarization duration were measured using multiple electrode arrays (MEA). Mass spectrometry (GC-MS) was used to analyze the composition of the e-vapors. Telemetric ECGs were obtained in freely moving C57BL/6J mice exposed to vanilla flavored e-vapor for 10 weeks and heart rate variability was analyzed (HRV). In-vivo inducibility of ventricular tachycardia as well as optical mapping of voltage in isolated Langendorff-perfused hearts were also carried out.ResultsE-vapor caused a dose dependent increase in toxicity in Hl-1 myocytes and e-vapors containing vanilla and cinnamon flavorings, as indicated by GC-MS, were more toxic, and inhibited cellular respiration more than the fruit flavored e-vapor. In hiPSC-CM cultured with 25% cinnamon flavored e-vapor for 24 hours, beating frequency increased, and the field potential duration significantly increased compared to air control. Inhalation exposure to vanilla flavored e-vapor for 10 weeks caused significant effects on HRV. Additionally, inducible VT was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the exposed mice compared to controlConclusionThe widely popular flavored ENDS are not harm free, and they show potential toxicity to the heart, in-vitro, and in vivo. Further studies are needed to further assess their cardiac safety profile, and long-term health effects.


2017 ◽  
Vol 41 (5) ◽  
pp. 1801-1829 ◽  
Author(s):  
Antônio F. Silva-filho ◽  
Wanessa L.B. Sena ◽  
Luiza R.A. Lima ◽  
Lidiane V.N. Carvalho ◽  
Michelly C. Pereira ◽  
...  

Post-translational and co-translational enzymatic addition of glycans (glycosylation) to proteins, lipids, and other carbohydrates, is a powerful regulator of the molecular machinery involved in cell cycle, adhesion, invasion, and signal transduction, and is usually seen in both in vivo and in vitro cancer models. Glycosyltransferases can alter the glycosylation pattern of normal cells, subsequently leading to the establishment and progression of several diseases, including cancer. Furthermore, a growing amount of research has shown that different oxygen tensions, mainly hypoxia, leads to a markedly altered glycosylation, resulting in altered glycan-receptor interactions. Alteration of intracellular glucose metabolism, from aerobic cellular respiration to anaerobic glycolysis, inhibition of integrin 3α1β translocation to the plasma membrane, decreased 1,2-fucosylation of cell-surface glycans, and galectin overexpression are some consequences of the hypoxic tumor microenvironment. Additionally, increased expression of gangliosides carrying N-glycolyl sialic acid can also be significantly affected by hypoxia. For all these reasons, it is possible to realize that hypoxia strongly alters glycobiologic events within tumors, leading to changes in their behavior. This review aims to analyze the complexity and importance of glycoconjugates and their molecular interaction network in the hypoxic context of many solid tumors.


2021 ◽  
Author(s):  
Florencia Cidre-Aranaz ◽  
Jing Li ◽  
Tilman L. B. Hölting ◽  
Martin F. Orth ◽  
Roland Imle ◽  
...  

ABSTRACTIdentification of cancer stemness genes is crucial to understanding the underlying biology of therapy resistance, relapse, and metastasis. Ewing sarcoma (EwS) is the second most common bone tumor in children and adolescents. It is a highly aggressive cancer associated with a dismal survival rate (<30%) for patients with metastatic disease at diagnosis (∼25% of cases). Hence, deciphering the underlying mechanisms of metastasis is imperative. EwS tumors are characterized by a remarkably ‘silent’ genome with a single driver mutation generating an oncogenic fusion transcription factor (EWSR1-ETS). Thus, EwS constitutes an ideal model to study how perturbation of a transcriptional network by a dominant oncogene can mediate metastasis, even though canonical metastasis-associated genes are not mutated.Here, through the implementation of an integrative systems biology approach, we identified transcription factor 7 like 1 (TCF7L1, alias TCF3) as a prognostically-relevant and EWSR1-ETS suppressed determinant of metastasis in EwS. We demonstrated that conditional TCF7L1 re-expression significantly reduces EwS single-cell migration, invasion and anchorage-independent growth in 3D assays in vitro, and tumorigenesis in vivo mediated by its DNA binding domain. In primary EwS tumors as well as in functional orthotopic in vivo models, low TCF7L1 expression was associated with pro-metastatic gene signatures and a much higher migratory and metastatic capacity of EwS cells, which correlated with poor outcome of EwS patients.Collectively, our findings establish TCF7L1 as a major regulator of metastasis in EwS, which may be utilized as a prognostic biomarker and open inroads to future therapeutic intervention.


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