Identification of candidate regulatory elements controlling transcriptome during the formation of interphalangeal joints
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ABSTRACT: We report the ChIPseq derived Candidate Enhancer (CE) atlas generated for interphalangeal interzone and phalange, tissues collected during synovial joint formation. Three replicates for interzone and three replicated for phalange were immunoprecipitated (IP) with the H3K27ac antibodies. Also, two replicates for interzone and two replicates for phalange were immunoprecipitated with H3K4me1 antibodies. The IP samples for both histone marks were sequenced and used for annotation of CEs. Further, the CEs were functionally annotated. In parallel, the total RNA for three interzone and three phalange replicates was isolated and mRNA sequencing libraries were constructed. Next the identification of differentially expressed genes (DEGs) and integrative analysis of DEGs and CEs was performed.
Project description:We report the 3D chromatin organization of the 3.4Mb DACT2-SMOC2 locus generated for interphalangeal interzone and phalange, tissues collected during synovial joint formation. The interzone and phalange samples have been dissected from developing hindlimb digits of the chicken embryo at Hamilton Hamburger stage 32 (HH32). Collected material has been processed using the Targeted Chromatin Capture protocol optimized for the 1mln cell. Generation of the T2C-interaction maps has revealed the 3D chromatin architecture of the DACT2-SMOC2 locus in the interzone and phalange tissues as well as identified potential candidate enhancers located in spatial proximity of DACT2 and SMOC2 gene promoters. We report the ChIPseq derived Candidate Enhancer (CE) atlas generated for interphalangeal interzone and phalange, tissues collected during synovial joint formation. Three replicates for interzone and three replicated for phalange were immunoprecipitated (IP) with the H3K27ac antibodies. Also, two replicates for interzone and two replicates for phalange were immunoprecipitated with H3K4me1 antibodies. The IP samples for both histone marks were sequenced and used for annotation of CEs. Further, the CEs were functionally annotated. In parallel, the total RNA for three interzone and three phalange replicates was isolated and mRNA sequencing libraries were constructed. Next the identification of differentially expressed genes (DEGs) and integrative analysis of DEGs and CEs was performed.
Project description:Osteoarthritis (OA) of the hand is a common disease resulting in pain and impaired function. The pathogenesis of hand OA (HOA) is elusive and models to study it have not been described so far. Culture of chondrocytes is a model to study the development of cartilage degeneration, which is a hallmark of OA and well established in OA of the knee and hip. In the current study we investigated the feasibility human chondrocyte culture derived from proximal interphalangeal (PIP) finger joints of dissecting room cadavers. Index and middle fingers without signs of osteoarthritis were obtained from 30 cadavers using two different protocols. Hyaline cartilage from both articulating surfaces of the proximal interphalangeal (PIP) joint was harvested and digested in collagenase. Cultured chondrocytes were monitored for contamination, viability, and expression of chondrocyte specific genes. Chondrocytes derived from knee joints of the cadavers were cultured under identical conditions. Gene expression comparing chondrocytes from PIP and knee joints was carried out using Affymetrix GeneChip Human 2.0 ST arrays. The resulting differentially expressed genes were validated by real-time PCR and immunohistochemistry.Chondrocytes harvested up to 101 hours after death of the donors were viable. mRNA expression of collagen 2A1, aggrecan and Sox9 was significantly higher in chondrocytes as compared to cultured fibroblasts. Comparison of gene expression by chondrocytes from PIP and knee joints yielded 528 differentially expressed genes. Chondrocytes from the same joint region had a higher grade of similarity than chondrocytes of the same individual. These results were validated using real-time PCR and immunohistochemistry.We demonstrate for the first time a reliable method for culture of chondrocytes derived from PIP joints. PIP chondrocytes show a specific gene expression pattern and could be used as tool to study cartilage degeneration in HOA. Three samples of cultured chondrocytes from knee and proximal interphalangeal finger joints were compared. Gene expression of the four most differentially regulated genes was confirmed by real-time PCR in 10 independent samples.
Project description:In order to identify the protein co-factors of PUMILIO1 and PUMILIO2 in TCam-2 cell line, co-IP of these proteins performed followed mass spectrometry analysis for protein identification. Six biological replicates of co-IP with anti-PUM1, anti-PUM2 antibodies and anti-IgG were performed. Three biological replicates were performed without RNase A treatment, and another three biological replicates of co-IPs with 100 mg/ml RNase A.
Project description:Nascent embryonic joints, interzones, contain a distinct cohort of progenitor cells responsible for the formation of the majority of articular tissues. However, to date the interzone has largely been studied using in situ analysis for candidate genes in the context of the embryo rather than using an unbiased genome wide expression analysis on isolated interzone cells, leaving significant controversy regarding the exact role of the intermediate and outer interzone layers in joint formation. Therefore, in this study, using laser capture microdissection (three biological replicates), we selectively harvested the intermediate and outer interzones of mouse embryos at gestational age 15.5 days, just prior to cavitation, when the differences between the layers should be most profound. Microarray analysis (Agilent Whole Mouse Genome Oligo Microarrays) was performed and the differential gene expression between the intermediate interzone cells and outer interzone cells was examined by performing a 2-sided paired student t-test and pathway analysis. 197 genes were differentially expressed (≥ 2-fold) between the intermediate interzone and the outer interzone with a p-value ≤ 0.01. Of these, 91 genes showed higher expression levels in the intermediate interzone and 106 were expressed higher in the outer interzone. Pathway analysis of differentially expressed genes suggests an important role for inflammatory processes in the interzone layers, especially in the intermediate interzone, and hence in joint and articular cartilage development. The high representation of genes relevant to chondrocyte hypertrophy and endochondral ossification in the outer interzone suggests that it undergoes endochondral ossification.
Project description:Nascent embryonic joints, interzones, contain a distinct cohort of progenitor cells responsible for the formation of the majority of articular tissues. However, to date the interzone has largely been studied using in situ analysis for candidate genes in the context of the embryo rather than using an unbiased genome wide expression analysis on isolated interzone cells, leaving significant controversy regarding the exact role of the intermediate and outer interzone layers in joint formation. Therefore, in this study, using laser capture microdissection (three biological replicates), we selectively harvested the intermediate and outer interzones of mouse embryos at gestational age 15.5 days, just prior to cavitation, when the differences between the layers should be most profound. Microarray analysis (Agilent Whole Mouse Genome Oligo Microarrays) was performed and the differential gene expression between the intermediate interzone cells and outer interzone cells was examined by performing a 2-sided paired student t-test and pathway analysis. 197 genes were differentially expressed (M-bM-^IM-% 2-fold) between the intermediate interzone and the outer interzone with a p-value M-bM-^IM-$ 0.01. Of these, 91 genes showed higher expression levels in the intermediate interzone and 106 were expressed higher in the outer interzone. Pathway analysis of differentially expressed genes suggests an important role for inflammatory processes in the interzone layers, especially in the intermediate interzone, and hence in joint and articular cartilage development. The high representation of genes relevant to chondrocyte hypertrophy and endochondral ossification in the outer interzone suggests that it undergoes endochondral ossification. 2 study groups (intermediate and outer interzone) with three biological replicates (1 biological replicate = 1 embryo)
Project description:Transgenic Arabidopsis plants (AGO2::HA:AGO2) were treated with either mock (10 mM MgCl2) or Pseudomonas syringae pv. tomato (Pst) expressing avrRpt2 (R2) at a concentration of 2 x 107 cfu/ml for 14 hours. sRNAs associated with AGO1 and AGO2 were co-immunoprecipitated using antibodies against either AGO1 (AGO1-IP), or HA (hemagglutinin) (AGO2-IP). As controls, we also gel-purified the 18-28 nt fraction of the total RNAs from an AGO2 mutant (ago2-1). The co-immunoprecipitated or gel-purified RNAs were cloned and sequenced by Illumina deep sequencing.
Project description:RNA was isolated from material that had been immunoprecipitated (IP) from Hela cells using antibodies recognizing RNA-binding proteins HuR or AUF1, as well as using a control IgG1 antibody. RNA was reverse-transcribed in the presence of [alpha-33P]dCTP and the radiolabeled product used to hybridize human cDNA arrays. The experiment was repeated using three independent sample sets. The samples were numbered HuR-1, HuR-2, HuR-3, AUF1-1, AUF1-2, AUF1-3, IgG1-1, IgG1-2, IgG1-3. HuR represents RNA from IP reactions using an anti-HuR antibody, AUF1 represents RNA from IP reactions using an anti-AUF1 antibody and, IgG1 represents RNA from IP reactions using an anti-IgG1 antibody. The numbers 1, 2 and 3 correspond to the three independent experimental datasets. Keywords = RNa-binding protein Keywords = mRNA stability Keywords = exosome Keywords = polysome Keywords = RNA motif Keywords: ordered
Project description:Osteoarthritis (OA) of the hand is a common disease resulting in pain and impaired function. The pathogenesis of hand OA (HOA) is elusive and models to study it have not been described so far. Culture of chondrocytes is a model to study the development of cartilage degeneration, which is a hallmark of OA and well established in OA of the knee and hip. In the current study we investigated the feasibility human chondrocyte culture derived from proximal interphalangeal (PIP) finger joints of dissecting room cadavers. Index and middle fingers without signs of osteoarthritis were obtained from 30 cadavers using two different protocols. Hyaline cartilage from both articulating surfaces of the proximal interphalangeal (PIP) joint was harvested and digested in collagenase. Cultured chondrocytes were monitored for contamination, viability, and expression of chondrocyte specific genes. Chondrocytes derived from knee joints of the cadavers were cultured under identical conditions. Gene expression comparing chondrocytes from PIP and knee joints was carried out using Affymetrix GeneChip Human 2.0 ST arrays. The resulting differentially expressed genes were validated by real-time PCR and immunohistochemistry.Chondrocytes harvested up to 101 hours after death of the donors were viable. mRNA expression of collagen 2A1, aggrecan and Sox9 was significantly higher in chondrocytes as compared to cultured fibroblasts. Comparison of gene expression by chondrocytes from PIP and knee joints yielded 528 differentially expressed genes. Chondrocytes from the same joint region had a higher grade of similarity than chondrocytes of the same individual. These results were validated using real-time PCR and immunohistochemistry.We demonstrate for the first time a reliable method for culture of chondrocytes derived from PIP joints. PIP chondrocytes show a specific gene expression pattern and could be used as tool to study cartilage degeneration in HOA.
Project description:Characterization of AGO2 bound short RNAs from nuclear extracts of HeLaS3 cell line. Nuclei were isolated from HeLaS3 cells; a fraction of Nuclear lysates was harvsted and sequenced as the 'input' samples. The rest of nuclear lysates were Immunoprecipitated using AGO2 monoclonal antibodies or Isotype matched IgG. Following immunoprecipitation, RNA was extracted from AGO2 or control IgG IP for short RNA sequencing. Two independent biological replicates were carried out.
Project description:Characterization of AGO2 bound short RNAs from nuclear extracts of Jurkat cell line. Nuclei were isolated from cells; a fraction of Nuclear lysates was harvested and sequenced as the input samples. The rest of nuclear lysates were Immunoprecipitated using AGO2 monoclonal antibodies or Isotype matched IgG. Following immunoprecipitation, RNA was extracted from AGO2 or control IgG IP for short RNA sequencing. Two independent biological replicates were carried out.