Project description:We exposed two groups of green frog tadpoles that differed in their microbiome composition to heat stress or control conditions. We subsequently used RNAseq to profile gene expression in their gut to understand how the microbiome impacts host responses to heat.
Project description:Environmental stress, such as oxidative or heat stress, induces the activation of the heat shock response
(HSR) and leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular
chaperones to maintain cellular proteostasis. Controlled by highly intricate regulatory mechanisms,
having stress-induced activation and feedback regulations with multiple partners, the HSR is still
incompletely understood. In this context, we propose a minimal molecular model for the gene
regulatory network of the HSR that reproduces quantitatively different heat shock experiments both
on heat shock factor 1 (HSF1) and HSPs activities. This model, which is based on chemical kinetics
laws, is kept with a low dimensionality without altering the biological interpretation of the model
dynamics. This simplistic model highlights the titration of HSF1 by chaperones as the guiding line of
the network. Moreover, by a steady states analysis of the network, three different temperature stress
regimes appear: normal, acute, and chronic, where normal stress corresponds to pseudo thermal
adaption. The protein triage that governs the fate of damaged proteins or the different stress regimes
are consequences of the titration mechanism. The simplicity of the present model is of interest in
order to study detailed modelling of cross regulation between the HSR and other major genetic
networks like the cell cycle or the circadian clock.
Sivéry, A., Courtade, E., Thommen, Q. (2016). A minimal titration model of the mammalian dynamical heat shock response. Physical biology, 13(6), 066008.
2022-01-25 | MODEL2201210001 | BioModels
Project description:Heat stress affects fecal microbiome of primiparous sows
| PRJNA560987 | ENA
Project description:Microbiome characterization of Galaxea fascicularis under heat stress
Project description:Opioid analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit long term use. In the current study using a chronic morphine-murine model a longitudinal approach was undertaken to investigate the role of morphine modulation of gut microbiome as a mechanism contributing to the negative consequences associated with opioids use. The results revealed a significant shift in the gut microbiome and metabolome within 24 hours following morphine treatment when compared to placebo. Morphine induced gut microbial dysbiosis exhibited distinct characteristic signatures profiles including significant increase in communities associated with pathogenic function, decrease in communities associated with stress tolerance. Collectively, these results reveal opioids-induced distinct alteration of gut microbiome, may contribute to opioids-induced pathogenesis. Therapeutics directed at these targets may prolong the efficacy long term opioid use with fewer side effects.
Project description:Korean peninsular weather is rapidly becoming subtropical due to global warming. In summer 2018, South Korea experienced the highest temperatures since the meteorological observations recorded in 1907. Heat stress has a negative effect on Holstein cows, the most popular breed of dairy cattle in South Korea, which is susceptible to heat. To examine physiological changes in dairy cows under heat stress conditions, we analyzed the profiles circulating microRNAs isolated from whole blood samples collected under heat stress and non-heat stress conditions using small RNA sequencing. We compared the expression profiles in lactating cows under heat stress and non-heat stress conditions to understand the regulation of biological processes in heat-stressed cows. Moreover, we measured several heat stress indicators, such as rectal temperature, milk yield, average daily gain, and progesterone concentration. All these assessments showed that pregnant cows were more susceptible to heat stress than non-pregnant cows. Particularly, progesterone concentrations known to have maternal warming effects were at similar levels in non-pregnant cows but significantly increased in pregnant cows under heat stress conditions. The differentially expressed miRNAs and their putative target genes were analyzed in pregnant cows. Interestingly, we found that differentially expressed miRNAs (bta-miR-146b, bta-miR-20b, bta-miR-29d-3p, bta-miR-1246) specifically targeted progesterone biosynthesis (StAR) and the function of corpus luteum-related genes (CCL11, XCL), suggesting that pregnant cows with elevated progesterone concentrations are more susceptible to heat stress. In addition, we found the differential expression of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) in both pregnant and non-pregnant cows under heat stress conditions. In target gene prediction and gene set enrichment analysis, these miRNAs were found to be associated with the cytoskeleton, cell junction, vasculogenesis, cell proliferation, ATP synthesis, oxidative stress, and immune responses involved in heat response. These miRNAs can be used as potential biomarkers for heat stress.
Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary transcription profiling data from the mouse hosts have also been deposited at ArrayExpress under accession number E-MTAB-3590 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3590/ ).
Project description:We used illumina-based next generation sequencing technology to to identify the regions bound by HSFA1b in the Arabidopsis genome. We sequenced HSFA1b chromatin immunoprecipitated genomic sequences under non-stress and heat stress conditions to understand the changes in the HSFA1b binding map when the growth conditions are switched from favorable to heat stress. We show that the binding map of HSFA1b in the Arabidopsis genome is subject to reconfiguration when the growth conditions are switched from non-stress to heat stress response. We also show that HSFA1b is targeting genes involved in developmental processes beside genes involved in stress response under both conditions indicating that HSFA1b possibly regulates the expression of both developmental and stress genes under non-stress and under heat stress, possibly for a limited duration prior heat acclimation.
Project description:Rainbow trout is a typical cold-water fish, with the intensification of global warming, high temperatures severely restrict the development of aquaculture in summer. Understanding the molecular regulation mechanisms of rainbow trout in response to heat stress will be salutary to alleviate heat stress-related damage. In the present study, we performed transcriptome analysis of liver tissues in rainbow trout under heat stress (24℃) and control (18℃) conditions to identify induced lncRNAs and pathways by heat stress. More than 658 million clean reads and 5,916 lncRNAs were identified from six liver libraries. A total of 927 novel lncRNAs were generated and 428 differentially expressed lncRNAs were screened through stringent thresholds. The RNA-seq results were verified by RT-qPCR. In addition, the regulatory network of important functional lncRNA-mRNA were constructed. GO and KEGG enrichment analysis of target gene of differentially expressed lncRNAs were performed. Many target genes involved in maintaining homeostasis or adapting to stress and stimuli were highly induced under heat stress. Several important regulatory pathways were involved in heat stress, including thyroid hormone signaling pathway, PI3K-Akt signaling pathway, estrogen signaling pathway, etc. This result broadens our understanding of lncRNA associated with heat stress and provides new insights into lncRNA-mediated regulation of rainbow trout heat stress.