13 research outputs found

    Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5-hydroxymethylcytosine in the amygdala

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    AIMS: One potential risk factor for posttraumatic stress disorder (PTSD) involves the low activity (short; s) allelic variant of the serotonin transporter-linked polymorphic region (5-HTTLPR), possibly due to reduced prefrontal control over the amygdala. Evidence shows that DNA methylation/demethylation is crucial for fear extinction in these brain areas and is associated with neuronal activation marker c-Fos expression. We hypothesized that impaired fear extinction in serotonin transporter knockout (5-HTT-/- ) rats is related to changes in DNA (de) methylation and c-Fos expression in the prefrontal cortex (PFC) and/or amygdala. METHODS: 5-HTT-/- and 5-HTT+/+ rats were subjected to fear extinction. 2 hours after the extinction session, the overall levels of DNA methylation (5-mC), demethylation (5-hmC), and c-Fos in fear extinction and nonfear extinction rats were measured by immunohistochemistry. RESULTS: 5-HTT-/- rats displayed decreased fear extinction. This was associated with reduced c-Fos activity in the infralimbic PFC. In the central nucleus of the amygdala, c-Fos immunoreactivity was increased in the fear extinction group compared to the no-fear extinction group, regardless of genotype. 5-hmC levels were unaltered in the PFC, but reduced in the amygdala of nonextinction 5-HTT-/- rats compared to nonextinction wild-type rats, which caught up to wild-type levels during fear extinction. 5-mC levels were stable in central amygdala in both wild-type and 5-HTT-/- extinction rats. Finally, c-Fos and 5-mC levels were correlated with the prelimbic PFC, but not amygdala. CONCLUSIONS: In the amygdala, DNA demethylation, independent from c-Fos activation, may contribute to individual differences in risk for PTSD, as conferred by the 5-HTTLPR s-allele

    Diabetes Mellitus and Increased Tuberculosis Susceptibility: The Role of Short-Chain Fatty Acids

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    Type 2 diabetes mellitus confers a threefold increased risk for tuberculosis, but the underlying immunological mechanisms are still largely unknown. Possible mediators of this increased susceptibility are short-chain fatty acids, levels of which have been shown to be altered in individuals with diabetes. We examined the influence of physiological concentrations of butyrate on cytokine responses to Mycobacterium tuberculosis (Mtb) in human peripheral blood mononuclear cells (PBMCs). Butyrate decreased Mtb-induced proinflammatory cytokine responses, while it increased production of IL-10. This anti-inflammatory effect was independent of butyrate's well-characterised inhibition of HDAC activity and was not accompanied by changes in Toll-like receptor signalling pathways, the eicosanoid pathway, or cellular metabolism. In contrast blocking IL-10 activity reversed the effects of butyrate on Mtb-induced inflammation. Alteration of the gut microbiota, thereby increasing butyrate concentrations, can reduce insulin resistance and obesity, but further studies are needed to determine how this affects susceptibility to tuberculosis

    Quantification and localization of oncogenic receptor tyrosine kinase variant transcripts using molecular inversion probes

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    Contains fulltext : 191423.pdf (publisher's version ) (Open Access

    Patients with type 1 diabetes mellitus have impaired IL-1 beta production in response to Mycobacterium tuberculosis

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    Contains fulltext : 183988.pdf (publisher's version ) (Open Access

    ACLY (ATP Citrate Lyase) Mediates Radioresistance in Head and Neck Squamous Cell Carcinomas and is a Novel Predictive Radiotherapy Biomarker

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    Contains fulltext : 215253.pdf (publisher's version ) (Open Access)Radiotherapy is an important treatment modality of head and neck squamous cell carcinomas (HNSCC). Multiple links have been described between the metabolic activity of tumors and their clinical outcome. Here we test the hypothesis that metabolic features determine radiosensitivity, explaining the relationship between metabolism and clinical outcome. Radiosensitivity of 14 human HNSCC cell lines was determined using colony forming assays and the expression profile of approximately 200 metabolic and cancer-related genes was generated using targeted RNA sequencing by single molecule molecular inversion probes. Results: Correlation between radiosensitivity data and expression profiles yielded 18 genes associated with radiosensitivity or radioresistance, of which adenosine triphosphate (ATP) citrate lyase (ACLY) was of particular interest. Pharmacological inhibition of ACLY caused an impairment of DNA damage repair, specifically homologous recombination, and lead to radiosensitization in HNSCC cell lines. Examination of a The Cancer Genome Atlas (TCGA) cohort of HNSCC patients revealed that high expression of ACLY was predictive for radiotherapy failure, as it was only associated with poor overall survival in patients who received radiotherapy (hazard ratio of 2.00, 95% CI: 1.12-3.55; p = 0.0184). These data were further validated in an independent cohort of HNSCC patients treated with chemoradiation. Furthermore, patients with poor locoregional control after radiotherapy have significantly higher nuclear ACLY protein levels. Together, we here show that ACLY affects DNA damage repair, and is a predictive factor for radiotherapy outcome in HNSCC

    RNA-based high-risk HPV genotyping and identification of high-risk HPV transcriptional activity in cervical tissues

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    Contains fulltext : 218234.pdf (Publisher’s version ) (Closed access)Nearly all cervical cancers are initiated by a persistent infection with one of the high-risk human papillomaviruses (high-risk HPV). High-risk HPV DNA testing is highly sensitive but cannot distinguish between active, productive infections and dormant infections or merely deposited virus. A solution for this shortcoming may be the detection of transcriptional activity of viral oncogenes instead of mere presence of high-risk HPVs. In this study, fresh-frozen cervical tissues (n = 22) were subjected to high-risk HPV DNA detection using the line probe assay and to targeted RNA next-generation sequencing using single-molecule molecular inversion probes. Targeted RNA sequencing was applied for (1) RNA-based genotyping of high-risk HPV, giving information on specific HPV-subtype (2) discrimination of E2, E6, and E7 transcripts and (3) discovery of possible non-HPV cancer biomarkers. Data were analyzed using computational biology. Targeted RNA sequencing enabled reliable genotyping of high-risk HPV subtypes and allowed quantitative detection of E2, E6, and E7 viral gene expression, thereby discriminating cervical lesions from normal cervical tissues. Moreover, targeted RNA sequencing identified possible cervical cancer biomarkers other than high-risk HPV. Interestingly, targeted RNA sequencing also provided high-quality transcription profiles from cervical scrape samples, even after 1 week of dry storage or storage in Preservcyt fixative. This proof of concept study shows that targeted RNA sequencing can be used for high-risk HPV genotyping and simultaneous detection of high-risk HPV gene activity. Future studies are warranted to investigate the potential of targeted RNA sequencing for risk assessment for the development of cervical lesions, based on molecular analysis of cervical scrapes

    Mapping actionable pathways and mutations in brain tumours using targeted RNA next generation sequencing

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    Contains fulltext : 214227.pdf (publisher's version ) (Open Access)Many biology-based precision drugs are available that neutralize aberrant molecular pathways in cancer. Molecular heterogeneity and the lack of reliable companion diagnostic biomarkers for many drugs makes targeted treatment of cancer inaccurate for many individuals. Identifying actionable hyperactive biological pathways in individual cancers may improve this situation.To achieve this we applied a novel targeted RNA next generation sequencing (t/RNA-NGS) technique to surgically obtained glioma tissues. The test combines mutation detection with analysis of biological pathway activities that are involved in tumour behavior in many cancer types (e.g. tyrosine kinase signaling, angiogenesis signaling, immune response, metabolism), via quantitative measurement of transcript levels and splice variants of hundreds of genes. We here present proof of concept that the technique, which uses molecular inversion probes, generates a histology-independent molecular diagnosis and identifies classifiers that are strongly associated with conventional histopathology diagnoses and even with patient prognosis. The test not only confirmed known glioma-associated molecular aberrations but also identified aberrant expression levels of actionable genes and mutations that have so far been considered not to be associated with glioma, opening up the possibility of drug repurposing for individual patients. Its cost-effectiveness makes t/RNA-NGS to an attractive instrument to aid oncologists in therapy decision making
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