Structural basis for RAD18 regulation by MAGEA4 and its implications for RING ubiquitin ligase binding by MAGE family proteins.

MAGEA4 is a cancer-testis antigen primarily expressed in the testes but aberrantly overexpressed in several cancers. MAGEA4 interacts with the RING ubiquitin ligase RAD18 and activates trans-lesion DNA synthesis (TLS), potentially favouring tumour evolution. Here, we employed NMR and AlphaFold2 (AF) to elucidate the interaction mode between RAD18 and MAGEA4, and reveal that the RAD6-binding domain (R6BD) of RAD18 occupies a groove in the C-terminal winged-helix subdomain of MAGEA4. We found that MAGEA4 partially displaces RAD6 from the RAD18 R6BD and inhibits degradative RAD18 autoubiquitination, which could be countered by a competing peptide of the RAD18 R6BD. AlphaFold2 and cross-linking mass spectrometry (XL-MS) also revealed an evolutionary invariant intramolecular interaction between the catalytic RING and the DNA-binding SAP domains of RAD18, which is essential for PCNA mono-ubiquitination. Using interaction proteomics, we found that another Type-I MAGE, MAGE-C2, interacts with the RING ubiquitin ligase TRIM28 in a manner similar to the MAGEA4/RAD18 complex, suggesting that the MAGEA4 peptide-binding groove also serves as a ligase-binding cleft in other type-I MAGEs. Our data provide new insights into the mechanism and regulation of RAD18-mediated PCNA mono-ubiquitination.

Assembly and comparative genome analysis of a Patagonian Aureobasidium pullulans isolate reveals unexpected intraspecific variation.

Aureobasidium pullulans is a yeast-like fungus with remarkable phenotypic plasticity widely studied for its importance for the pharmaceutical and food industries. So far, genomic studies with strains from all over the world suggest they constitute a genetically unstructured population, with no association by habitat. However, the mechanisms by which this genome supports so many phenotypic permutations are still poorly understood. Recent works have shown the importance of sequencing yeast genomes from extreme environments to increase the repertoire of phenotypic diversity of unconventional yeasts. In this study, we present the genomic draft of A. pullulans strain from a Patagonian yeast diversity hotspot, re-evaluate its taxonomic classification based on taxogenomic approaches, and annotate its genome with high-depth transcriptomic data. Our analysis suggests this isolate could be considered a novel variant at an early stage of the speciation process. The discovery of divergent strains in a genomically homogeneous group, such as A. pullulans, can be valuable in understanding the evolution of the species. The identification and characterization of new variants will not only allow finding unique traits of biotechnological importance, but also optimize the choice of strains whose phenotypes will be characterized, providing new elements to explore questions about plasticity and adaptation.

Machine Learning Approximations to Predict Epigenetic Age Acceleration in Stroke Patients.

Age acceleration (Age-A) is a useful tool that is able to predict a broad range of health outcomes. It is necessary to determine DNA methylation levels to estimate it, and it is known that Age-A is influenced by environmental, lifestyle, and vascular risk factors (VRF). The aim of this study is to estimate the contribution of these easily measurable factors to Age-A in patients with cerebrovascular disease (CVD), using different machine learning (ML) approximations, and try to find a more accessible model able to predict Age-A. We studied a CVD cohort of 952 patients with information about VRF, lifestyle habits, and target organ damage. We estimated Age-A using Hannum's epigenetic clock, and trained six different models to predict Age-A: a conventional linear regression model, four ML models (elastic net regression (EN), K-Nearest neighbors, random forest, and support vector machine models), and one deep learning approximation (multilayer perceptron (MLP) model). The best-performing models were EN and MLP; although, the predictive capability was modest (R2 0.358 and 0.378, respectively). In conclusion, our results support the influence of these factors on Age-A; although, they were not enough to explain most of its variability.

Surgical management of suspected gallbladder cancer: The role of intraoperative frozen section for diagnostic confirmation.

BACKGROUND: Preoperative diagnosis for suspected gallbladder cancers is challenging, with a risk of overtreating benign disease, for example, xanthogranulomatous cholecystitis, with radical cholecystectomies. We retrospectively evaluated the surgeon's intraoperative assessment alone, and with the addition of intraoperative frozen sections, for suspected gallbladder cancers from a tertiary hepatobiliary multidisciplinary team (MDT). METHODS: MDT patients with complex gallbladder disease were included. Collated data included demographics, MDT discussion, operative details, and patient outcomes. RESULTS: A total of 454 patients with complex gallbladder disease were reviewed, 48 (10.6%) were offered radical surgery for suspected cancer. Twenty-five underwent frozen section that led to radical surgery in 6 (25%). All frozen sections were congruent with final histopathology but doubled the operating time (p < 0.0001). Both the surgeon's subjective and additional frozen section's objective assessment, allowed for de-escalation of unnecessary radical surgery, comparing favourably to a 13.0% cancer diagnosis among radical surgery historically. CONCLUSIONS: The MDT process was highly sensitive in identifying gallbladder cancers but lacked specificity. The surgeon's intraoperative assessment is paramount in suspected cancers, and deescalated unnecessary radical surgery. Intraoperative frozen section was a safe and viable adjunct at a cost of resources and operative time.

A scoring system for predicting malignancy in intraductal papillary mucinous neoplasms of the pancreas: a multicenter EUROPEAN validation.

PURPOSE: A preoperative estimate of the risk of malignancy for intraductal papillary mucinous neoplasms (IPMN) is important. The present study carries out an external validation of the Shin score in a European multicenter cohort. METHODS: An observational multicenter European study from 2010 to 2015. All consecutive patients undergoing surgery for IPMN at 35 hospitals with histological-confirmed IPMN were included. RESULTS: A total of 567 patients were included. The score was significantly associated with the presence of malignancy (p < 0.001). In all, 64% of the patients with benign IPMN had a Shin score < 3 and 57% of those with a diagnosis of malignancy had a score ≥ 3. The relative risk (RR) with a Shin score of 3 was 1.37 (95% CI: 1.07-1.77), with a sensitivity of 57.1% and specificity of 64.4%. CONCLUSION: Patients with a Shin score ≤ 1 should undergo surveillance, while patients with a score ≥ 4 should undergo surgery. Treatment of patients with Shin scores of 2 or 3 should be individualized because these scores cannot accurately predict malignancy of IPMNs. This score should not be the only criterion and should be applied in accordance with agreed clinical guidelines.

DisProt: intrinsic protein disorder annotation in 2020.

The Database of Protein Disorder (DisProt, URL: https://disprot.org) provides manually curated annotations of intrinsically disordered proteins from the literature. Here we report recent developments with DisProt (version 8), including the doubling of protein entries, a new disorder ontology, improvements of the annotation format and a completely new website. The website includes a redesigned graphical interface, a better search engine, a clearer API for programmatic access and a new annotation interface that integrates text mining technologies. The new entry format provides a greater flexibility, simplifies maintenance and allows the capture of more information from the literature. The new disorder ontology has been formalized and made interoperable by adopting the OWL format, as well as its structure and term definitions have been improved. The new annotation interface has made the curation process faster and more effective. We recently showed that new DisProt annotations can be effectively used to train and validate disorder predictors. We believe the growth of DisProt will accelerate, contributing to the improvement of function and disorder predictors and therefore to illuminate the 'dark' proteome.

Genetics and Epigenetics of Spontaneous Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is a complex and heterogeneous disease, and there is no effective treatment. Spontaneous ICH represents the final manifestation of different types of cerebral small vessel disease, usually categorized as: lobar (mostly related to cerebral amyloid angiopathy) and nonlobar (hypertension-related vasculopathy) ICH. Accurate phenotyping aims to reflect these biological differences in the underlying mechanisms and has been demonstrated to be crucial to the success of genetic studies in this field. This review summarizes how current knowledge on genetics and epigenetics of this devastating stroke subtype are contributing to improve the understanding of ICH pathophysiology and their potential role in developing therapeutic strategies.

Analysis of predictors of mortality after surgical and non-surgical management in proximal humerus fractures.

BACKGROUND: Proximal humerus fractures are one of the main osteoporotic fractures. Choosing between conservative or surgical treatment is a controversial topic in the literature, as is the functional impact. The main aim of our study was to analyse whether patient comorbidities should influence the final therapeutic decision for these fractures. MATERIAL AND METHODS: We collected data from 638 patients with proximal humerus fractures. The main variable collected was exitus. We also collected the following data: age, gender, type of fracture, laterality, type of treatment, production mechanism, comorbidities and the Charlson comorbidity index (CCI) for each patient. The therapeutic indication used the criteria established by the Upper Limb Unit in our centre. We performed chi-square tests, Fischer's exact tests and Student's t-tests to compare the variables. We used the Kaplan-Meier method to analyse both the overall and disease-specific survival rates. We employed the Cox regression model to analyse factors associated with mortality. RESULTS: Patients with a CCI greater than 5 showed greater mortality (HR = 3.83; p < 0.001) than those with a CCI lower than 5. Within the patients who underwent surgery, those with a CCI higher than 5 had an increased mortality rate (HR = 22.6; p < 0.001) compared with those with a CCI lower than 5. Within the patients who received conservative treatment, those with a CCI over 5 showed greater mortality (HR = 3.64; p < 0.001) than those with a CCI under 5. CONCLUSIONS: Patients with proximal humerus fractures and associated comorbidities (CCI > 5) presented higher mortality than healthier patients. This mortality risk was greater in patients with comorbidities if surgical treatment was indicated rather than conservative treatment. Patient's comorbidities should be a fundamental parameter when planning the therapeutic strategy. LEVEL OF EVIDENCE: Level 3.

The reactions of hydropersulfides (RSSH) with myoglobin.

Hydropersulfides are reported to be good biological reductants, superior to thiols and akin to selenols. As such, they have been previously shown to reduce metalloproteins such as ferric myoglobin and ferric cytochrome c to their ferrous forms under conditions where little or no reduction from corresponding thiols is observed. Not surprisingly, the reduction of ferric myoglobin to ferrous myoglobin under aerobic conditions results in the generation of oxymyoglobin (dioxygen bound ferrous myoglobin). Previous studies have demonstrated that oxymyoglobin can also act as an oxidant with highly reducing species such as hydroxylamine and ascorbate. Considering the reducing properties of hydropersulfides, it is possible that they can also react with oxymyoglobin similarly to hydroxylamine or ascorbate. Herein, this reaction is examined and indeed hydropersulfides are found to react with oxymyoglobin similarly to other reducing species leading to a fleeting ferric myoglobin which is rapidly reduced to the ferrous form also by hydropersulfide.

Cysteine Trisulfide Protects E. coli from Electrophile-Induced Death through the Generation of Cysteine Hydropersulfide.

Hydropersulfide and polysulfide species have recently been shown to elicit a wide variety of biological and physiological responses. In this study, we examine the effects of cysteine trisulfide (Cys-SSS-Cys; also known as thiocystine) treatment on E. coli. Previous studies in mammalian cells have shown that Cys-SSS-Cys treatment results in protection from the electrophiles. Here, we show that the protective effect of Cys-SSS-Cys treatment against electrophile-induced cell death is conserved in E. coli. This protection correlates with the rapid generation of cysteine hydropersulfide (Cys-SSH) in the culture media. We go on to demonstrate that an exogenous phosphatase expressed in E. coli, containing only a single catalytic cysteine, is protected from electrophile-induced inactivation in the presence of hydropersulfides. These data together demonstrate that E. coli can utilize Cys-SSS-Cys to generate Cys-SSH and that the Cys-SSH can protect cellular thiols from reactivity with the electrophiles.

The Underlying Mechanism of HNO Production by the Myoglobin-Mediated Oxidation of Hydroxylamine.

Azanone (HNO, nitroxyl) is a highly reactive molecule that, in the past few years, has drawn significant interest because of its pharmacological properties. However, the understanding of how, when, and where endogenous HNO is produced remains a matter of discussion. In this study, we examined the ability of myoglobin to produce HNO via the peroxidation of hydroxylamine with H2O2 using both experimental and computational approaches. The production of HNO was confirmed using an azanone selective electrochemical method and by the detection of N2O using FTIR. The catalytic capacity of myoglobin was characterized by the determination of the turnover number. The reaction kinetics of the hydroxylamine peroxidation were studied by both electrochemical and UV-vis methods. Further evidence about the reaction mechanism was obtained by EPR spectroscopy. Additionally, quantum mechanical/molecular mechanics experiments were performed to calculate the energy barrier for HNO production and to gain insight into the reaction mechanism. Our results confirm that myoglobin produces HNO via the peroxidation of hydroxylamine with a great catalytic capacity. In addition, our mechanistic study allows us to state that the Mb ferryl state is the most likely intermediate that reacts with hydroxylamine, yielding important evidence for endogenous HNO generation.

"Am I doing this wrong?" Breastfeeding mothers' use of an online forum.

As mothers seek out information around breastfeeding, many are turning to online message boards, listservs, or social media for advice. Babycenter.com, a parenting website with widespread use, hosts a Breastfeeding Support and Help community forum with over 140,000 users and more than one million conversation threads. The purpose of this study is to examine this online support forum to understand the information seeking and sharing practices of its users. We extracted a total of 258 original posts and 1,445 corresponding comments from Babycenter.com's breastfeeding forum posted over a 10-day period. Using content analysis, we coded the posts into 15 categories reflective of the types of information users were seeking. We then randomly selected 45 conversation threads across the most popular categories to further understand how users were sharing information. The most popular breastfeeding topics for which users sought out information included feeding challenges, supply issues, feeding schedule and duration, pumping, physical health, excretion issues, storing milk, nipple issues, and general breastfeeding questions. Participants elicited information from others using interviewing questions and built consensus around issues by agreeing with previous posts. They shared their knowledge and personal breastfeeding experiences and also provided encouragement to continue breastfeeding and overcome challenges. Online support forums are actively being used by breastfeeding mothers seeking information from others with similar experiences. This presents an important resource for breastfeeding mothers and may, therefore, be an important component of future breastfeeding interventions.

Serelaxin (recombinant human relaxin-2) treatment affects the endogenous synthesis of long chain poly-unsaturated fatty acids and induces substantial alterations of lipidome and metabolome profiles in rat cardiac tissue.

BACKGROUND AND PURPOSE: Recombinant human relaxin-2, serelaxin, is being proved as a novel drug with therapeutic efficacy in some cardiovascular diseases, especially heart failure, a disease whose physiopathology and course are firmly correlated with important alterations in cardiac metabolism. The aim of our present work was to investigate changes in the cardiac metabolome following relaxin-2 treatment. EXPERIMENTAL APPROACH: Sprague-Dawley rats were treated with human recombinant relaxin-2 using osmotic minipumps at a dose of 0.4 mg/kg/day for 2 weeks. Body composition was measured with a nuclear magnetic resonance imaging system seven days after surgery and on the final day of the experiment. The last two days of treatment, respiratory quotient, locomotor activity and energy expenditure were measured with a calorimetric system. The plasma levels of relaxin-2, total cholesterol, high- and low- density lipoproteins (HDL, LDL), triglycerides and the hepatic enzymes glutamic-pyruvic transaminase (GTP) and gamma-glutamyltransferase (GGT) levels were analyzed. The metabolic profiling of both atria from relaxin-2-treated and control rats was carried out using two separate ultra-high performance liquid chromatography (UHPLC)-Time of Flight-MS based platforms analyzing methanol and chloroform/methanol extracts combined with a UHPLC-single quadrupole-MS based platform used to analyze aminoacids and with a methanol/water extract platform that covered polar metabolites. Identified ion features in the methanol extract platform included fatty acids, acyl carnitines, bile acids, monoacylglycerophospholipids, monoetherglycerophospholipids, free sphingoid bases, and oxidized fatty acids. The chloroform / methanol extract platform provided coverage over glycerolipids, cholesterol esters, sphingolipids, diacylglycerophospholipids, and acyl-ether-glycerophospholipids. Gene expression levels of the adipokines adiponectin, leptin and nesfatin-1 in visceral adipose tissue and cardiac gene expression levels of key enzymes of desaturation and elongation of n-6 and n-3 PUFAs were assessed by Real Time-PCR. KEY RESULTS: Twenty-eight metabolites out of three hundred sixty-two were significantly altered by human relaxin-2. These included fifteen glycerophospholipids: three phosphatidylethanolamines (PE) and twelve phosphatidylcholines (PC); eight sphingolipids: three ceramides (Cer) and five sphingomyelins (SM); and also five aminoacids and one carboxylic acid. Interestingly, the majority of changes correspond to lipid classes, twelve of them polyunsaturated diacylglycerophosphatidylcholines with long acyl chains, containing mainly docosahexaenoic acid (22:6) and arachidonic acid (20:4). Atrial levels of Elovl5 (Elongation of very long chain fatty acids protein 5), Fads1 (Δ5-fatty acid desaturase) and Fads2 (Δ6-fatty acid desaturase), key enzymes of elongation and desaturation of n-6 and n-3 PUFAs like arachidonic acid and DHA, respectively, were significantly increased by relaxin-2 treatment. Atrial tissues from rats treated with relaxin-2 showed a significant increase in the mRNA levels of Srebf1, a transcription factor that activates the gene expression of Elovl5, Fads1 and Fads2. The treatment with relaxin-2 significantly decreased the visceral fat mRNA expression levels of adiponectin, leptin and nesfatin-1, adipokines known to exert an important influence on the regulation of cardiovascular function. CONCLUSION AND IMPLICATIONS: Serelaxin (human recombinant relaxin-2) treatment induces significant changes in cardiac major components of the membrane lipid bilayer such as glycerophospholipids and sphingolipids, known to have structural roles but also very relevant regulatory effects in cardiac function. Serelaxin induced also modifications in several aminoacids of high influence in cardiac energy metabolism regulation. Our results highlight the need to further understand the role of relaxin-2 in the regulation of cardiac energy metabolism, in the context of the therapeutic strategies for the treatment of cardiometabolic pathologies as heart failure.

Exposure to biomass smoke is associated with an increased expression of circulating miRNA-126 and miRNA-155 in Mexican women: a pilot study.

Household air pollution has been associated as a risk factor for cardiovascular diseases (CVD). Therefore, the aim of this study was to assess the expression of vascular inflammation regulators miR-126 and miR-155 in plasma from women that cook with wood and women that cook with liquid petroleum gas (LPG). A cumulative index of exposure to smoke (CIES) was estimated, urinary 1-hydroxypyrene (1-OHP) levels were quantified and miRNAs expression levels were determined by quantitative real-time PCR (qRT-PCR). Biochemical clinical parameters were also evaluated. The average values for CIES and 1-OHP were 140 ± 86.8 hours-years (12.0-270 hours-years) and 0.52 ± 0.45 µmol/mol creatinine, respectively. miR-126 and miR-155 expression levels were significantly higher (p < 0.01) in the wood users compared to LPG users. Besides, we found a significant association (p < 0.01) between miR-126 and miR-155 expression levels and CIES and urinary 1-OHP concentrations. These results contribute to the current evidence about the cardiovascular risk related to biomass smoke exposure, from an epigenetic level.

HNO Is Produced by the Reaction of NO with Thiols.

Azanone (nitroxyl, HNO) is a highly reactive compound whose biological role is still a matter of debate. One possible route for its formation is NO reduction by biological reductants. These reactions have been historically discarded due to the negative redox potential for the NO,H+/HNO couple. However, the NO to HNO conversion mediated by vitamins C, E, and aromatic alcohols has been recently shown to be feasible from a chemical standpoint. Based on these precedents, we decided to study the reaction of NO with thiols as potential sources of HNO. Using two complementary approaches, trapping by a Mn porphyrin and an HNO electrochemical sensor, we found that under anaerobic conditions aliphatic and aromatic thiols (as well as selenols) are able to convert NO to HNO, albeit at different rates. Further mechanistic analysis using ab initio methods shows that the reaction between NO and the thiol produces a free radical adduct RSNOH•, which reacts with a second NO molecule to produce HNO and a nitrosothiol. The nitrosothiol intermediate reacts further with RSH to produce a second molecule of HNO and RSSR, as previously reported.

Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications.

Human indoleamine 2,3-dioxygenase catalyzes the oxidative cleavage of tryptophan to N-formyl kynurenine, the initial and rate-limiting step in the kynurenine pathway. Additionally, this enzyme has been identified as a possible target for cancer therapy. A 20-amino acid protein segment (the JK loop), which connects the J and K helices, was not resolved in the reported hIDO crystal structure. Previous studies have shown that this loop undergoes structural rearrangement upon substrate binding. In this work, we apply a combination of replica exchange molecular dynamics simulations and site-directed mutagenesis experiments to characterize the structure and dynamics of this protein region. Our simulations show that the JK loop can be divided into two regions: the first region (JK loop(C)) displays specific and well-defined conformations and is within hydrogen bonding distance of the substrate, while the second region (JK loop(N)) is highly disordered and exposed to the solvent. The peculiar flexible nature of JK loop(N) suggests that it may function as a target for post-translational modifications and/or a mediator for protein-protein interactions. In contrast, hydrogen bonding interactions are observed between the substrate and Thr379 in the highly conserved "GTGG" motif of JK loop(C), thereby anchoring JK loop(C) in a closed conformation, which secures the appropriate substrate binding mode for catalysis. Site-directed mutagenesis experiments confirm the key role of this residue, highlighting the importance of the JK loop(C) conformation in regulating the enzymatic activity. Furthermore, the existence of the partially and totally open conformations in the substrate-free form suggests a role of JK loop(C) in controlling substrate and product dynamics.

Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (< LOD) to 215 ng/g lipid, with a mean total PBDEs level of 29.5 ± 53.0 ng/g lipid (geometric mean ± standard deviation). The mean total PCBs level in the study participants was 29.0 ± 10.5 ng/g lipid (range 4.50-50.0 ng/g lipid). The mean concentration of total DDT (DDT + DDE) was 11.9 ± 6.70 ng/g lipid (range 3.00-26.0 ng/g lipid). The mean 1-OHP levels was 1.2 ± 1.1 µmol/mol creatinine (range

Persistent Organic Pollutants and Heavy Metal Concentrations in Soil from the Metropolitan Area of Monterrey, Nuevo Leon, Mexico.

The purpose of this study was to assess the levels of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDE), and four heavy metals (arsenic, cadmium, and lead) in outdoor surface soils (50 samples) collected from the metropolitan area of Monterrey in Mexico. Total PBDEs levels ranged from 1.80 to 127 µg/kg, with mean total PBDEs level of 14.2 ± 21.5 µg/kg (geometric mean ± standard deviation). For PCBs, the mean total level in the studied soils was 23.5 ± 20.2 µg/kg (range 4.0-65.5 µg/kg). An important finding in our study was that all soil samples (100%) had detectable levels of the metabolite p,p'-DDE. Moreover, the mean total DDT level (∑p'p-DDT and p'p-DDE) was approximately 132 ± 175 µg/kg. The mean levels for arsenic, cadmium, and lead in soil were 5.30 ± 1.35 (range 1.55-7.85) mg/kg, 2.20 ± 1.20 (range 0.65-6.40) mg/kg, and 455 ± 204 (range 224-1230) mg/kg, respectively. Our study has several limitations, the most notable of which is the small sample of soils evaluated. However, this screening study provided concentration data for the occurrence of POPs and four heavy metals in soil from the metropolitan area of Monterrey, Nuevo Leon, Mexico, and taking into consideration that soil is an important pathway of exposure for people, a biomonitoring program for the surveillance of the general population in the metropolitan area of Monterrey, Nuevo Leon is deemed necessary.

Polybrominated diphenyl ethers (PBDEs) concentration in soil from San Luis Potosi, Mexico: levels and ecological and human health risk characterization.

The aim of this study was to assess the levels of polybrominated diphenyl ethers (PBDEs) in soils from the city of San Luis Potosi in Mexico and perform an ecological and human health risk characterization. In order to confirm the presence of PBDEs, outdoor surface soil samples were collected and the concentrations of PBDEs in urban, industrial, agricultural, and brick kiln industry areas were determined. The mean total PBDEs levels obtained in the study sites were 25.0 ± 39.5 µg/kg (geometric mean ± standard deviation) in the brick kiln industry zone; 34.5 ± 36.0 µg/kg in the urban zone; 8.00 ± 7.10 µg/kg in the industrial zone and 16.6 ± 15.3 µg/kg in the agricultural zone. The ecological and human health risk characterization showed relatively low-hazard quotient values. However, the moderately high PBDEs levels found in soils highlight the necessity to establish a systematic monitoring process for PBDEs in environmental and biological samples.