Project description:This study was conducted to explore the serum methylome of precancerous lesions belonging to the serrated pathway of colorectal carcinogenesis in a prospective multicentre cohort. Individuals were grouped into five main categories: (i) serrated adenocarcinoma (SAC), (ii) high-risk serrated polyps (HR-SP) comprising traditional serrated adenomas (TSA), sessile serrated lesions (SSL), and serrated polyps (SP) with dysplasia or ≥ 10 mm; (iii) high-risk hyperplastic polyps (HR-HP), defined as HP ≥ 10 mm; (iv) low-risk serrated lesions (LR-SL) including SP without dysplasia < 10 mm and HP < 10 mm; and (v) healthy individuals with no colorectal findings (NCF). First, epigenome-wide methylation levels were quantified in pooled cfDNA samples to characterize the differential methylation profile between no serrated neoplasia (NSN: NCF and LR-SL) and high-risk serrated lesions (HR-SL: HR-HP and HR-SP); concordance with tissue methylation levels was assessed using external datasets. Then, the pathway-specific cfDNA methylation signature was evaluated together with cfDNA pools from the conventional CRC pathway. cfDNA was extracted from serum samples and methylation measurements were assessed with the Infinium MethylationEPIC BeadChip. Data was mainly preprocessed and analyzed with R/Bioconductor packages.
Project description:Selective serotonin reuptake inhibitor (SSRI) antidepressants are the mainstay treatment for the 10-20% of pregnant and postpartum women who suffer major depression, but the effects of SSRIs on their children’s developing brain and later emotional health are poorly understood. SSRI use during pregnancy can elicit antidepressant withdrawal in newborns and increase toddlers’ anxiety and social avoidance. In rodents, perinatal SSRI exposure increases adult depression- and anxiety-like behavior, although certain individuals are more vulnerable to these effects than others. Our study establishes a rodent model of individual differences in susceptibility to perinatal SSRI exposure, utilizing selectively-bred Low Responder (LR) and High Responder (HR) rats that were previously bred for high versus low behavioral response to novelty. Pregnant HR/LR females were chronically treated with the SSRI paroxetine (10 mg/kg/day p.o.) to examine its effects on offspring’s emotional behavior and gene expression in the developing brain. Paroxetine treatment had minimal effect on HR/LR dams’ pregnancy outcomes or maternal behavior. We found that LR offspring, naturally prone to an inhibited/anxious temperament, were susceptible to behavioral abnormalities associated with perinatal SSRI exposure (which exacerbated their Forced Swim Test immobility), while high risk-taking HR offspring were resistant. Microarray studies revealed robust perinatal SSRI-induced gene expression changes in the developing LR hippocampus and amygdala (postnatal days 7-21), including transcripts involved in neurogenesis, synaptic vesicle components, and energy metabolism. These results highlight the LR/HR model as a useful tool to explore the neurobiology of individual differences in susceptibility to perinatal SSRI exposure.
Project description:Individual differences in human temperament can increase the risk of psychiatric disorders like depression and anxiety. Our laboratory utilized a rat model of temperamental differences to assess neurodevelopmental factors underlying emotional behavior differences. Rats selectively bred for low novelty exploration (Low Responders, LR) display high levels of anxiety- and depression-like behavior compared to High Novelty Responder (HR) rats. Using transcriptome profiling, the present study uncovered vast gene expression differences in the early postnatal HR versus LR limbic brain, including changes in genes involved in cellular metabolism. These data led us to hypothesize that rats prone to high (versus low) anxiety/depression-like behavior exhibit distinct patterns of brain metabolism during the first weeks of life, which may reflect disparate patterns of synaptogenesis and brain circuit development. All samples were generated from Sprague-Dawley male rats selectively bred for high novelty response (HRs) or low novelty response (LRs).
Project description:The study searched for the correlates of vaccine protection against furunculosis. After pathogen challenge of vaccinated (V) and unvaccinated (N) fish, hepatic gene expression was compared in salmon with high resistance (HR, individual samples) and low resistance (LR, pooled samples) Two-condition experiment - vaccinated and unvaccinated salmon, HR vs. LR livers. Biological replicates (HR): 6 vaccinated, 5 unvaccinated, pooled samples of LR were used as reference. One replicate per array.
Project description:We used microarrays to investigate gene expression changes in leukemic cells from Pax5+/- mice treated with antibiotics. Precursor B cell acute lymphoblastic leukemia (pB-ALL), the most common type of childhood leukemia, is frequently characterized by the cooperation of a genetic predisposition acquired in utero and secondary oncogenic events taking place only in a fraction of predisposed children after birth. Although predisposition can be detected at birth, it is currently unknown which factors determine the development of overt leukemia in genetic carriers and how this can be potentially prevented. Experimental studies have shown that infectious stimuli promote disease onset in genetically predisposed mice. Here, we analyzed the impact of the microbiome on leukemogenesis in a mouse model (Pax5+/- mice) that faithfully mimicks genetic predisposition and leukemogenesis of human pB-ALL related to the synergy of genetic predisposition and exposure to a natural infectious environment. Employing 16S rRNA sequencing and machine learning we can accurately predict a distinct gut microbiome which is determined by a specific constitutional genetic variant. Deprivation of the gut microbiome by antibiotic treatment enhanced pB-ALL development in Pax5+/- predisposed (63% vs. 22%) but not in wildtype mice (0%). This finding was observed in the presence but also -to a lesser extent- in the absence of a natural, infectious environment (48%). The composition of the gut microbiome constitutes a biomarker signature and allows to identify specifically those Pax5+/- mice that developed leukemia. This indicates that the gut microbiome can be used to identify carriers at risk to develop leukemia and to reduce this risk by early-life interventions.
Project description:Neuroblastoma (NB) is the most common extracranial solid tumor during infancy, causing up to 10% of mortality in children. NB shows notable heterogeneity with regard to histology and clinical behavior, ranging from low-risk localized tumors (LR-NB) to high-risk disease (HR-NB), characterized by aggressive metastatic phenotype, resistance to treatment, and fatal relapse occurrence. Risk stratification demands high accuracy, as it will determine the therapeutic treatment. However, the current therapeutic stratification, based on clinical and molecular risk factors, does not allow to discriminate among patients with similar clinical-pathological parameters who receive the same treatment despite showing markedly different clinical courses. The need of novel diagnostic molecular tools in oncology has led to increasing interest in liquid biopsies as a source of biomarkers, as they provide a minimally invasive method. Body fluids are a source of exosomes, nanosized extracellular vesicles that can drive tumor growth and chemoresistance. We previously identified exosomal microRNAs (exo-miRNA) indicative of HR-NB patient sensitivity/resistance to chemotherapy. As exosomes from cancer patients carry proteins that reflect the surface and cytoplasm content of parental cancer cells, including immunosuppressive molecules known to be associated with cancer progression and/or response to therapy, we extended our study to the exosomal proteins (Exo-prot).The purpose of the study is to identify Exo-prot that (i) are specifically expressed in NB patients and (ii) are associated with tumor phenotype and disease stage, in order to improve risk stratification and refine diagnosis.We isolated exosomes from plasma specimens of 24 HR-NB patients and 24 LR-NB patients at diagnosis and of 24 age-matched healthy controls (CTRL). Exo-prot expression was measured by liquid chromatography-mass spectrometry. Missing value distribution and differential expression analysis (performed with two different imputation methods) were applied to identify the most relevant Exo-prot. ROC analysis assessed the diagnostic value of the identified Exo-prot. We demonstrated that NB patients have a different Exo-prot expression profile compared to CTRL. The deregulated Exo-prot in NB specimens act mainly in tumor-associated pathways and build a strictly connected network. Furthermore, HR-NB patients show a different Exo-miR expression profile compared to LR-NB subjects, with the modulation of molecules involved in cell migration, proliferation and metastasis. Importantly, we show that NCAM, NCL, LUM and VASP have a diagnostic value in discriminating NB patients from CTRL; while MYH9, FN1, CALR, AKAP12 and, with a lower performance, LTBP1 can differentiate HR-NB and LR-NB patients with high accuracy. We demonstrated that Exo-prot deregulated in NB vs CTRL subjects and in HR-NB vs LR-NB patients contribute to NB tumor development and to the aggressive metastatic NB phenotype, respectively. We identified Exo-prot with significant diagnostic value for NB patients and able to efficiently identify the HR-NB subset of patients, which can be employed to improve risk stratification. Our results highlight the applicability of Exo-prot evaluation for integrating NB diagnosis and risk assessment.
Project description:Abstract: Many mouse models of neurological disease use the tetracycline transactivator (tTA) system to control transgene expression by oral treatment with the broad-spectrum antibiotic doxycycline. Antibiotic treatment used for transgene control might have undesirable systemic effects, including the potential to affect immune responses in the brain via changes in the gut microbiome. Recent work has shown that an antibiotic cocktail to perturb the gut microbiome can suppress microglial reactivity to brain amyloidosis in transgenic mouse models of Alzheimer's disease based on controlled overexpression of the amyloid precursor protein (APP). Here we assessed the impact of chronic low dose doxycycline on gut microbiome diversity and neuroimmune response to systemic LPS challenge in a tTA-regulated model of Alzheimer's amyloidosis. We show that doxycycline decreased microbiome diversity in both APP transgenic and wild-type mice and that these changes persisted long after drug withdrawal. Despite this change in microbiome composition, dox treatment had minimal effect on transcriptional signatures in the brain, both at baseline and following acute LPS challenge. Our findings suggest that central neuroinflammatory responses may be less affected by dox at doses needed for transgene control than by antibiotic cocktail at doses used for microbiome manipulation.
Project description:In chronic phase chronic myeloid leukemia (CP-CML) patients treated with frontline imatinib, failure to achieve early molecular response (EMR failure: BCR-ABL1 >10% (IS) at 3 months) is predictive of inferior outcomes. Identifying patients at high-risk of EMR failure at diagnosis provides an opportunity to intensify frontline therapy and potentially avoid EMR failure. We studied blood samples from 96 CP-CML patients at diagnosis and identified 365 genes that were aberrantly expressed in 13 patients who subsequently failed to achieve EMR, with a gene signature significantly enriched for stem cell phenotype (e.g. Myc, b-catenin, Hoxa9/Meis1), cell cycle, and reduced immune response pathways. We selected a 17-gene panel to predict EMR failure and validated this signature on an independent patient cohort. Patients classified as high-risk with our gene expression signature (HR-GES) exhibited significantly higher rates of EMR failure compared to low-risk (LR-GES) patients (78% vs 5%; p<0.0001) with an overall accuracy of 93%. Furthermore, HR-GES patients who received frontline nilotinib had a relatively low rate of EMR failure (10%). However HR-GES patients still had inferior deep molecular response achievement rate by 24 months compared to LR-GES patients. This novel multi-gene signature may be useful for selecting patients at high risk of EMR failure on standard therapy, who may benefit from trials of more potent kinase inhibitors or other experimental approaches.
Project description:The gut microbiome is a malleable microbial community that can remodel in response to various factors, including diet, and contribute to the development of several chronic diseases, including atherosclerosis. We devised an in vitro screening protocol of the mouse gut microbiome to discover molecules that can selectively modify bacterial growth. This approach was used to identify cyclic D,L-α-peptides that remodeled the Western diet (WD) gut microbiome toward the low-fat-diet microbiome state. Daily oral administration of the peptides in WD-fed LDLr-/- mice reduced plasma total cholesterol levels and atherosclerotic plaques. Depletion of the microbiome with antibiotics abrogated these effects. Peptide treatment reprogrammed the microbiome transcriptome, suppressed the production of pro-inflammatory cytokines (including interleukin-6, tumor necrosis factor-α and interleukin-1β), rebalanced levels of short-chain fatty acids and bile acids, improved gut barrier integrity and increased intestinal T regulatory cells. Directed chemical manipulation provides an additional tool for deciphering the chemical biology of the gut microbiome and might advance microbiome-targeted therapeutics.
Project description:The gut microbiome plays an important role in normal immune function and has been implicated in several autoimmune disorders. Here we use high-throughput 16S rRNA sequencing to investigate the gut microbiome in subjects with multiple sclerosis (MS, n=61) and healthy controls (n=43). Alterations in the gut microbiome in MS include increases in the genera Methanobrevibacter and Akkermansia and decreases in Butyricimonas, and correlate with variations in the expression of genes involved in dendritic cell maturation, interferon signaling and NF-kB signaling pathways in circulating T cells and monocytes. Patients on disease-modifying treatment show increased abundances of the genera Prevotella and Sutterella, and decreased Sarcina, compared to untreated patients. MS patients of a second cohort show elevated breath methane compared to controls, consistent with our observation of increased gut Methanobrevibacter in MS in the first cohort. Further study is required to assess whether the observed alterations in the gut microbiome play a role in, or are a consequence of, MS pathogenesis.