Environmental chemical burden in metabolic tissues and systemic biological pathways in adolescent bariatric surgery patients: A pilot untargeted metabolomic approach
Project description:BackgroundAdvances in untargeted metabolomic technologies have great potential for insight into adverse metabolic effects underlying exposure to environmental chemicals. However, important challenges need to be addressed, including how biological response corresponds to the environmental chemical burden in different target tissues.AimWe performed a pilot study using state-of-the-art ultra-high-resolution mass spectrometry (UHRMS) to characterize the burden of lipophilic persistent organic pollutants (POPs) in metabolic tissues and associated alterations in the plasma metabolome.MethodsWe studied 11 adolescents with severe obesity at the time of bariatric surgery. We measured 18 POPs that can act as endocrine and metabolic disruptors (i.e. 2 dioxins, 11 organochlorine compounds [OCs] and 5 polybrominated diphenyl ethers [PBDEs]) in visceral and subcutaneous abdominal adipose tissue (vAT and sAT), and liver samples using gas chromatography with UHRMS. Biological pathways were evaluated by measuring the plasma metabolome using high-resolution metabolomics. Network and pathway enrichment analysis assessed correlations between the tissue-specific burden of three frequently detected POPs (i.e. p,p'-dichlorodiphenyldichloroethene [DDE], hexachlorobenzene [HCB] and PBDE-47) and plasma metabolic pathways.ResultsConcentrations of 4 OCs and 3 PBDEs were quantifiable in at least one metabolic tissue for > 80% of participants. All POPs had the highest median concentrations in adipose tissue, especially sAT, except for PBDE-154, which had comparable average concentrations across all tissues. Pathway analysis showed high correlations between tissue-specific POPs and metabolic alterations in pathways of amino acid metabolism, lipid and fatty acid metabolism, and carbohydrate metabolism.ConclusionsMost of the measured POPs appear to accumulate preferentially in adipose tissue compared to liver. Findings of plasma metabolic pathways potentially associated with tissue-specific POPs concentrations merit further investigation in larger populations.
Project description:Material stability and dissolution in aqueous media are key issues to address in the development of a new nanomaterial intended for technological application. Dissolution phenomena affect biological and environmental persistence; fate, transport, and biokinetics; device and product stability; and toxicity pathways and mechanisms. This article shows that MoS2 nanosheets are thermodynamically and kinetically unstable to O2-oxidation under ambient conditions in a variety of aqueous media. The oxidation is accompanied by nanosheet degradation and release of soluble molybdenum and sulfur species, and generates protons that can colloidally destabilize the remaining sheets. The oxidation kinetics are pH-dependent, and a kinetic law is developed for use in biokinetic and environmental fate modeling. MoS2 nanosheets fabricated by chemical exfoliation with n-butyl-lithium are a mixture of 1T (primary) and 2H (secondary) phases and oxidize rapidly with a typical half-life of 1-30 days. Ultrasonically exfoliated sheets are in pure 2H phase, and oxidize much more slowly. Cytotoxicity experiments on MoS2 nanosheets and molybdate ion controls reveal the relative roles of the nanosheet and soluble fractions in the biological response. These results indicate that MoS2 nanosheets will not show long-term persistence in living systems and oxic natural waters, with important implications for biomedical applications and environmental risk.
Project description:The molecular background of mitochondrial dysfunction in adipose tissue of morbidly obese individuals and bariatric surgery-induced changes in adipose mitochondrial function remain incompletely understood. To evaluate the mechanisms behind the surgery-induced changes and differences between morbidly obese subjects and nonobese controls, we performed a LC-MS/MS proteomics analysis of abdominal subcutaneous (SAT) and visceral adipose tissue samples (VAT) collected from the bariatric surgery, SAT samples collected 6 months after surgery, and control SAT and VAT samples collected from baseline.
Project description:BackgroundAssignment of chemical compounds to biological pathways is a crucial step to understand the relationship between the chemical repertory of an organism and its biology. Protein sequence profiles are very successful in capturing the main structural and functional features of a protein family, and can be used to assign new members to it based on matching of their sequences against these profiles. In this work, we extend this idea to chemical compounds, constructing a profile-inspired model for a set of related metabolites (those in the same biological pathway), based on a fragment-based vectorial representation of their chemical structures.ResultsWe use this representation to predict the biological pathway of a chemical compound with good overall accuracy (AUC 0.74-0.90 depending on the database tested), and analyzed some factors that affect performance. The approach, which is compared with equivalent methods, can in addition detect those molecular fragments characteristic of a pathway.ConclusionsThe method is available as a graphical interactive web server http://csbg.cnb.csic.es/iFragMent .
Project description:IntroductionObesity is associated with low-grade systemic inflammation. The "inflammome" is a network layout of the inflammatory pattern. The systemic inflammome of obesity has not been described as yet. We hypothesized that it can be significantly worsened by smoking and other comorbidities frequently associated with obesity, and ameliorated by bariatric surgery (BS). Besides, whether or not these changes are mirrored in the lungs is unknown, but obesity is often associated with pulmonary inflammation and bronchial hyperresponsiveness.ObjectivesWe sought to: (1) describe the systemic inflammome of morbid obesity; (2) investigate the effects of sex, smoking, sleep apnea syndrome, metabolic syndrome and BS upon this systemic inflammome; and, (3) determine their interplay with pulmonary inflammation.MethodsWe studied 129 morbidly obese patients (96 females; age 46 ± 12 years; body mass index [BMI], 46 ± 6 kg/m2) before and one year after BS, and 20 healthy, never-smokers, (43 ± 7 years), with normal BMI and spirometry.ResultsBefore BS, compared with controls, all obese subjects displayed a strong and coordinated (inflammome) systemic inflammatory response (adiponectin, C-reactive protein, interleukin (IL)-8, IL-10, leptin, soluble tumor necrosis factor-receptor 1(sTNF-R1), and 8-isoprostane). This inflammome was not modified by sex, smoking, or coexistence of obstructive sleep apnea and/or metabolic syndrome. By contrast, it was significantly ameliorated, albeit not completely abolished, after BS. Finally, obese subjects had evidence of pulmonary inflammation (exhaled condensate) that also decreased after BS.ConclusionsThe systemic inflammome of morbid obesity is independent of sex, smoking status and/or comorbidities, it is significantly reduced by BS and mirrored in the lungs.
Project description:Obesity is a chronic, multifactorial disease which is linked to a number of adverse endocrinological and metabolic conditions. Currently, bariatric surgery is one of the most effective treatments for individuals diagnosed with severe obesity. However, the current indications for bariatric surgery are based on inadequate metrics (i.e., BMI) which do not account for the complexity of the disease, nor the heterogeneity among the patient population. Moreover, there is a lack of understanding with respect to the biological underpinnings that influence successful and sustained weight loss post-bariatric surgery. Studies have implicated age and pre-surgery body weight as two factors that are associated with favorable patient outcomes. Still, there is an urgent medical need to identify other potential factors that could improve the specificity of candidate selection and better inform the treatment plan of patients with obesity. In this report, we present and describe the cohort of the DECON pilot project, a multicenter study which aims to identify predictive biomarkers of successful weight loss after bariatric surgery.