Project description:Age-related changes in microRNA levels in serum 20 nM biotinylated miRIDIAN miR-1248 mimic (Thermo Scientific) or a negative control, biotinylated miRIDIAN C. elegans miR-67 (here named Con-miR) using Lipofectamine 2000. Forty eight hours post transfection, total RNA was isolated using the mirVana kit (Invitrogen) according to manufacturer’s procedure. Three replicate experiments were performed and a technical repeat was included for each sample. Samples were analyzed using Illumina's Sentrix Human HT-12 ver4 Expression BeadChips (Illumina, San Diego, CA).
Project description:MicroRNAs are important negative regulators of protein coding gene expression, and have been studied intensively over the last few years. To this purpose, different measurement platforms to determine their RNA abundance levels in biological samples have been developed. In this study, we have systematically compared 12 commercially available microRNA expression platforms by measuring an identical set of 20 standardized positive and negative control samples, including human universal reference RNA, human brain RNA and titrations thereof, human serum samples, and synthetic spikes from homologous microRNA family members. We developed novel quality metrics in order to objectively assess platform performance of very different technologies such as small RNA sequencing, RT-qPCR and (microarray) hybridization. We assessed reproducibility, sensitivity, quantitative performance, and specificity. The results indicate that each method has its strengths and weaknesses, which helps guiding informed selection of a quantitative microRNA gene expression platform in function of particular study goals.
Project description:ChIP-Seq analyses of GR and PPARa occupancy in mouse E14.5 fetal liver BFU-E cells untreated or treated by DEX with or without GW7647 ChIP-Seq on GR and PPAR alpha in purified 10^7 mouse BFU-E cells purified from E14.5 fetal livers with or without treatment of Dexamethasone and/or GW7647
Project description:Altered DNA methylation patterns represent an attractive mechanism for the phenotypic changes associated with human aging. Several studies have described age-related methylation changes to various extents, but their functional significance has remained largely unclear. We have now used an integrated methylome and transcriptome sequencing approach to characterize age-related methylation changes in the human epidermis and to analyze their impact on gene expression. Our results show limited and localized methylation differences between young and old methylomes at single-base resolution. Similarly, the comparison of transcriptomes from young and old samples revealed a highly defined set of differentially expressed genes with functional annotations in skin homeostasis. Further data analysis showed a robust correlation between age-related promoter hypermethylation and gene silencing, particularly at promoters that were pre-marked with stem cell-specific chromatin features. In addition, we also observed age-related methylation changes at transcription factor binding sites, with a significant enrichment of stem cell regulatory networks. Our results provide a high-resolution analysis of age-related methylation changes and suggest that they result in highly defined alterations in the transcriptional programme of the human epidermis. Interestingly, several of our findings can be interpreted to reflect epigenetic changes in aging stem cells, thus supporting a critical role of stem cells in human aging. Whole transcriptome analysis of H. sapiens. Two samples were analyzed, one sample containing RNA from young, one sample containing RNA from old human skin.
Project description:Cancer-associated fibroblasts (CAFs) have been recognized as important contributors to cancer development and progression. However, opposing evidence has been published whether CAFs, in addition to epigenetic, also undergo somatic genetic alterations and whether these changes contribute to carcinogenesis and tumour progression. We combined multiparameter DNA flow cytometry, flow-sorting and 6K SNP-arrays to study DNA aneuploidy, % S-phase, loss of heterozygosity (LOH) and copy number alterations (CNAs) to study somatic genetic alterations in cervical cancer-associated stromal cell fractions (n = 58) from formalin-fixed, paraffin-embedded (FFPE) samples. Tissue sections were examined for the presence of CAFs. Microsatellite analysis was used to study LOH. By flow cytometry we found no proof for DNA aneuploidy in the vimentin-positive stromal cell fractions of any samples (CV G0G1 population 3.7% +/- 1.2; S-phase 1.4% +/- 1.8). The genotype concordance between the stromal cells and the paired normal endometrium samples was > 99.9%. No evidence for CNAs or LOH was found in the stromal cell fractions. In contrast, high frequencies of DNA content abnormalities (43/57), a significant higher S-phase (14.6% +/- 8.5)(p = 0.0001) and substantial numbers of CNAs and LOH were identified in the keratin-positive epithelial cell fractions (CV G0G1 population 4.1% +/- 1.0). Smooth muscle actin and vimentin immunohistochemistry verified the presence of CAFs in all cases tested. LOH hot-spots on chromosomes 3p, 4p and 6p were confirmed by microsatellite analysis but the stromal cell fractions showed retention of heterozygosity only. From our study we conclude that stromal cell fractions from cervical carcinomas are DNA diploid, have a genotype undistinguishable from patient-matched normal tissue and are genetically stable. Stromal genetic changes do not seem to play a role during cervical carcinogenesis and progression. In addition, the stromal cell fraction of cervical carcinomas can be used as reference allowing large retrospective studies of archival FFPE tissues for which no normal reference tissue is available. Paired experiment, Endometrial (non-tumor) cells vs stromal cells from cervical tumors. Biological replicates: 58 patients. From 5 tumors also the tumor fraction was profiled.
Project description:Recurrent non-medullary thyroid carcinoma (NMTC) is a rare disease. We initially characterized 27 recurrent NMTC: 13 papillary thyroid cancers (PTC), 10 oncocytic follicular carcinomas (FTC-OV), and 4 non-oncocytic follicular carcinomas (FTC). A validation cohort composed of benign and malignant (both recurrent and non-recurrent) thyroid tumours was subsequently analysed (n = 20). Methods Data from genome-wide SNP arrays and flow cytometry were combined to determine the chromosomal dosage (allelic state) in these tumours, including mutation analysis of components of PIK3CA/AKT and MAPK pathways. Results All FTC-OVs showed a very distinct pattern of genomic alterations. Ten out of 10 FTC-OV cases showed near-haploidisation with or without subsequent genome endoreduplication. Near-haploidisation was seen in 5/10 as extensive chromosome-wide monosomy (allelic state [A]) with near-haploid DNA indices and retention of especially chromosome 7 (seen as a heterozygous allelic state [AB]). In the remaining 5/10 chromosomal allelic states AA with near diploid DNA indices were seen with allelic state AABB of chromosome 7, suggesting endoreduplication after preceding haploidisation. The latter was supported by the presence of both near-haploid and endoreduplicated tumour fractions in some of the cases. Results were confirmed using FISH analysis. Relatively to FTC-OV limited numbers of genomic alterations were identified in other types of recurrent NMTC studied, except for chromosome 22q which showed alterations in 6 of 13 PTCs. Only two HRAS, but no mutations of EGFR or BRAF were found in FTC-OV. The validation cohort showed two additional tumours with the distinct pattern of genomic alterations (both with oncocytic features and recurrent). Conclusions We demonstrate that recurrent FTC-OV is frequently characterised by genome-wide DNA haploidisation, heterozygous retention of chromosome 7, and endoreduplication of a near-haploid genome. Whether normal gene dosage on especially chromosome 7 (containing EGFR, BRAF, cMET) is crucial for FTC-OV tumour survival is an important topic for future research. 28 thyroid tumors from 27 patients were profiled by SNP array. Comparisons between different types were made.
Project description:In recent years, thanks to the great development of mass spectrometry (MS)-based high-throughput proteomic techniques, a large-scale protein characterization is less challenging. Proteomic approaches have been successfully applied to SM in different experimental models [21–24]; however, to date, there is little information on ECM proteins and how they change during ageing. The identification and quantification of ECM components and their interactions are es-sential steps to understand the role of the matrisome in sarcopenia. In this context, we combined a proteomic approach (i.e., LC-MS/MS and bioinformatic analyses) with mor-phological and morphometrical evaluations at fluorescence and transmission electron microscopy of the gastrocnemius muscle in adult and old mice. This age range has been selected since it has been observed that most of changes in muscle protein expression take place after middle age. The gastrocnemius muscle was selected for analysis since it is prevalently composed of fast-twitch fibre, which are especially affected by atrophy during aging. Our findings highlighted several modifications of ECM protein composition and organization in old mice, which likely play a role in the alteration of muscle properties during aging.
Project description:Hui2014 - Age-related changes in articular
cartilage
This model is described in the article:
Oxidative changes and
signalling pathways are pivotal in initiating age-related
changes in articular cartilage
Wang Hui1, David A Young1, Andrew D
Rowan1, Xin Xu2, Tim E Cawston1, Carole J Proctor1,3
Annals of the Rheumatic Diseases
Abstract:
Objective: To use a computational approach to investigate
the cellular and extracellular matrix changes that occur with
age in the knee joints of mice. Methods: Knee joints from an
inbred C57/BL1/6 (ICRFa) mouse colony were harvested at
3–30?months of age. Sections were stained with H&E,
Safranin-O, Picro-sirius red and antibodies to matrix
metalloproteinase-13 (MMP-13), nitrotyrosine, LC-3B, Bcl-2, and
cleaved type II collagen used for immunohistochemistry. Based
on this and other data from the literature, a computer
simulation model was built using the Systems Biology Markup
Language using an iterative approach of data analysis and
modelling. Individual parameters were subsequently altered to
assess their effect on the model. Results: A progressive loss
of cartilage matrix occurred with age. Nitrotyrosine, MMP-13
and anaplastic lymphoma kinase (ALK1) staining in cartilage
increased with age with a concomitant decrease in LC-3B and
Bcl-2. Stochastic simulations from the computational model
showed a good agreement with these data, once transforming
growth factor-? signalling via ALK1/ALK5 receptors was
included. Oxidative stress and the interleukin 1 pathway were
identified as key factors in driving the cartilage breakdown
associated with ageing. Conclusions: A progressive loss of
cartilage matrix and cellularity occurs with age. This is
accompanied with increased levels of oxidative stress,
apoptosis and MMP-13 and a decrease in chondrocyte autophagy.
These changes explain the marked predisposition of joints to
develop osteoarthritis with age. Computational modelling
provides useful insights into the underlying mechanisms
involved in age-related changes in musculoskeletal tissues.
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