Project description:Study of Oxidative stress Markers (F2 Isoprostanes for lipid peroxidation, Carbonyl groups for protein peroxidation, 3 Nitrotyrosine for damage by nitrogens, and 8-Hydroxyguanosine for RNA peroxidation)in patients with colorectal cancer undergo surgical treatment (preoperatively during the intervention and postoperatively) and controls.
Project description:We described, for the first time, a robust protocol for direct differentiation of hPSCs into SGEP by mimicking the activity of retinoic acid and WNT signaling. These hPSC-derived SGEP expressed SOX9, KRT5 and KRT19, which were the important progenitor markers of developing salivary glands. The CD24 and α-SMA positive cells that are capable to restore the function of injured salivary glands were also present in SGEP cultures. Importantly, RNA-seq was performed to examine the similarity of SGEP to human fetal and mature salivary glands. The result revealed the SGEP resemble the transcript profile of human fetal submandibular glands. Therefore, we successfully induced hPSCs into SGEP and demonstrated that these SGEP potentially serves as models for studying mechanism underling salivary development, and as cell sources for clinical use.
Project description:ObjectivesSaliva is a biological fluid suitable for biomarker analysis, and differences in the salivary microbiota in oral health and disease have been reported. For such comparative analyses, time of sampling is critical since the bacterial composition may vary throughout the day, i.e., diurnal variation. The purpose of this study is to compare the salivary microbiome over time to determine the optimal time for sampling.DesignStimulated saliva samples were collected from 5 orally healthy individuals in 4 h intervals for 24 h, and collection was repeated 7 days later (number of samples per person, n = 12, total number of samples, n = 60). Salivary microbiota was analyzed using the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS), and statistical analysis was performed using the Kruskal-Wallis test with Benjamini-Hochberg's correction for multiple comparisons, cluster analysis, principal component analysis and correspondence analysis.ResultsFrom a total of 60 saliva samples, 477 probe targets were collectively identified with a mean number of probes per sample of 207 (range: 153-307). Little or no variation in microbial profiles within subjects was observed over time.ConclusionsAlthough there was considerable variation between subjects, microbial profiles within subjects were stable throughout a 24 hour period and after 1 week. Since there is little or no evidence of diurnal variation of the salivary microbiome, time of sampling of saliva is not critical for perturbation or other microbial studies.
Project description:Extracellular matrix remodeling is a natural response to injury but, excessive extracellular matrix accumulation or fibrosis, is a causative factor in hundreds of diseases that limit organ function and impede regenerative responses. Fibrosis is closely related to inflammation, both of which occur in the salivary glands of patients treated with radiation for head and neck cancers and in patients suffering from the autoimmune condition, Sjögren’s Disease. Despite the known involvement of fibrosis in disease and the inhibitory effects of fibrosis on tissue regeneration, the mechanisms through which fibrosis develops in the salivary gland are poorly understood. Stromal fibroblasts are the primary matrix-producing cells and are known to drive both fibrosis and inflammation. To define the signals produced by fibroblasts in response to injury, we induced a temporary obstructive injury though ligation of the primary submandibular and sublingual salivary gland ducts and then performed single-cell RNA sequencing and pathway analysis at timepoints immediately following the injury. Using bioinformatic approaches, we identified three unique fibroblast groups that dynamically respond to the injury. We characterized the changes in matrisomal and inflammatory gene expression over a 7-day time course and identified the group 2 fibroblasts to be the primary fibrogenic cells, although all groups produced ECM genes. Understanding how fibroblasts respond at early and late injury timepoints along with defining signaling pathways regulated by fibroblasts could lead to a better understanding of the contribution of fibroblast to acute injury responses to facilitate development of therapeutics that minimize fibrosis and promote regenerative gland responses in chronic disease states.
Project description:Oxidative stress is a common factor threating genomic stability in almost all aerobic organisms. Using a yeast screening system, we measured the frequency of mitotic recombination was greatly elevated after H2O2 treatment. H2O2 was able to break chromatid directly in G1 synchronized cells and homologous recombination was induced to repair DNA double stand breaks at S/G2 phase. By whole genome SNP microarray and sequencing, the patterns of H2O2 induced loss of heterozygosity (LOH; gene conversion and crossover), chromosomal rearrangement, and aneuploidy changes were revealed. LOH events were the most common genomic alterations induced by H2O2 and were randomly distributed throughout the genome.
Project description:Ovarian cancer is the leading cause of death in gynecological diseases, and has been considered as one of the most fatal cancers due to lack of reliable detection strategy in the early stage. Therefore the capability to detect the morbidity initiation with an sensitive and effective approach is one of the most desirable goals for curing ovarian cancer. In this study, we used microarray technology for salivary mRNA biomarkers discovery, and evaluated the performance and translational utilities of discovered markers from a clinical study using an independent sample cohort . We used microarrays to profile and compare the gene expressions between ovairan cancer patient and matched controls, and identified seven down-regulated genes after the validation study. To find salivary transcriptomic biomarkers for ovarian cancer, salivary transcriptomes in 11 ovarian cancer patients and 11 matched controls were profiled using Affymetrix HG-U133-Plus-2.0 array, and followed by t-test and fold-change analyses. The biomarker candidates selected from the microarray results were subjected to clinical validation using an independent sample cohort by RT-qPCR. The prediction power of biomarkers was analyzed by logistic regression approach