Project description:<p><strong>BACKGROUND:</strong> Stool metabolites provide essential insights into the function of the gut microbiome. The current gold standard for storage of stool samples for metabolomics is flash-freezing at - 80 °C which can be inconvenient and expensive. Ambient temperature storage of stool is more practical, however no available methodologies adequately preserve the metabolomic profile of stool. A novel sampling kit (OMNImet.GUT; DNA Genotek, Inc.) was introduced for ambient temperature storage and stabilization of feces for metabolomics; we aimed to test the performance of this kit vs flash-freezing. To do this stool was collected from an infant's diaper was divided into 2 aliquots: 1) flash-frozen and 2) stored in an OMNImet.GUT tube at ambient temperature for 3-4 days. Samples from the same infant were collected at 2 different timepoints to assess metabolite changes over time. Subsequently, all samples underwent metabolomic analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS).</p><p><strong>RESULTS:</strong> Paired fecal samples (flash-frozen and ambient temperature) from 16 infants were collected at 2 timepoints (32 individual samples, 64 aliquots). Similar numbers of metabolites were detected in both the frozen and ambient temperature samples (1126 in frozen, 1107 in ambient temperature, 1064 shared between sample types). Metabolite abundances were strongly correlated between storage methods (median Spearman correlation Rs = 0.785 across metabolites). Hierarchical clustering analysis and principal component analysis showed that samples from the same individuals at a given timepoint clustered closely, regardless of the storage method. Repeat samples from the same individual were compared by paired t-test, separately for the frozen and OMNImet.GUT. The number of metabolites in each biochemical class that significantly changed (p < 0.05) at timepoint 2 relative to timepoint 1 was similar in flash-frozen vs ambient temperature storage. Changes in microbiota modified metabolites over time were also consistent across both methodologies.</p><p><strong>CONCLUSION:</strong> Ambient temperature storage and stabilization of stool in the OMNImet.GUT device yielded comparable metabolomic results to flash freezing in terms of 1) the identity and abundance of detected biochemicals 2) the distinct metabolomic profiles of subjects and 3) changes in metabolites over time that are plausibly microbiota-induced. This method potentially provides a more convenient, less expensive home collection and storage option for stool metabolomic analysis.</p>
Project description:Data was collected on a LC-MS/MS system (c-18 column) positive mode. Data analyzing storage conditions of different storage collection devices for human fecal samples.
Project description:We examine the RNA profile of LV and RV in donor heart with different period of storage (0, 4, and 8 hours) follwed by reperfusion. We find that both LV and RV has activated immune response after prolonged storage compared to 0h.
Project description:We conducted a comparison of scRNA-seq on four paired fresh and cryopreserved atheroma samples, two from coronary arteries and two from carotid arteries, to determine whether it is possible to obtain comparable data from frozen samples. After enzymatic digestion into single cell suspensions, we sorted CD45+ cells from half of each sample and immediately processed these using the 10X Genomics scRNA-seq workflow after collection, while the other half was frozen in liquid nitrogen. After cryopreservation for an average of 7 days, the other half of each sample was thawed and sorted identically to the fresh samples.
Project description:Dysbiotic configurations of the human gut microbiota have been linked with colorectal cancer (CRC). Human small non-coding RNAs are also implicated in CRC and recent findings suggest that their release in the gut lumen contributes to shape the gut microbiota. Bacterial small RNAs (bsRNAs) may also play a role in carcinogenesis but their role is less explored. Here, we performed small RNA and shotgun sequencing on 80 stool specimens of patients with CRC, or adenomas, and healthy subjects collected in a cross-sectional study to evaluate their combined use as a predictive tool for disease detection. We reported a considerable overlap and correlation between metagenomic and bsRNA quantitative taxonomic profiles obtained from the two approaches. Furthermore, we identified a combined predictive signature composed by 32 features from human and microbial small RNAs and DNA-based microbiome able to accurately classify CRC from healthy and adenoma samples (AUC= 0.87). In summary we reported evidence that host-microbiome dysbiosis in CRC can be observed also by altered small RNA stool profiles. Integrated analyses of the microbiome and small RNAs in the human stool may provide insights for designing more accurate tools for diagnostic purposes.
Project description:Human breast milk (HBM) is the ideal source of nutrients for infants and is rich in microRNA (miRNA). In recent years, expressed breast milk feeding rather than direct breastfeeding is becoming increasingly prevalent for various reasons. HBM requires storage and processing, which can cause various changes in the ingredients. We investigated how the miRNAs in HBM change due to processes often used in real life. HBM samples collected from 10 participants were each divided into 7 groups according to the storage temperature, thawing method, and storage period. And we analyzed the miRNA changes in each group. Significant changes in expression of several miRNAs were confirmed when HBM were heated by microwave immediately after collection, stored at room temperature for 1 week, or frozen for 1 week. Changes in expression were also dependent on the frozen period or thawing method. However, there was no change in the miRNA expression in all samples refrigerated for 1 week. The expression of miRNA can change depending on the diverse processing, storage, and thawing methods of breast milk, and refrigerated storage may be an ideal method to maintain a state of miRNA.
Project description:Data was collected on a LC-MS/MS system (c-18 column) positive mode. Data analyzing storage conditions of different storage collection devices for human fecal samples.