Project description:A subset of long-noncoding RNAs (lncRNAs) are spatially correlated with transcription factors (TFs) across the genome, but how these lncRNA-TF gene duplexes regulate tissue development and homeostasis is unclear. We have identified a feedback loop within the NANCI-Nkx2.1 gene duplex that is essential for buffering Nkx2.1 expression, lung epithelial cell identity, and tissue homeostasis. Within this locus, Nkx2.1 directly inhibits NANCI, while NANCI acts in cis to promote Nkx2.1 transcription. Although loss of NANCI alone does not adversely affect lung development, concurrent heterozygous mutations in both NANCI and Nkx2.1 leads to persistent Nkx2.1 deficiency and reprogramming of lung epithelial cells to a posterior endoderm fate. This disruption in the NANCI-Nkx2.1 gene duplex results in a defective perinatal innate immune response, tissue damage, and progressive degeneration of the adult lung. These data point to a mechanism where lncRNAs act as rheostats within lncRNA-TF gene duplex loci that buffer TF expression, thereby maintaining tissue specific cellular identity during development and postnatal homeostasis.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:Nkx2.1 is a critical regulator of mammalian lung development. It is expressed in epithelial cells at the initiation of lung organogenesis, becoming progressively restricted during development to bronchiolar and alveolar type II epithelial cells. In humans, it is a common marker of carcinomas of lung and thyroid origin and is highly amplified in 10-15% of lung adenocarcinomas. Despite its key role in development and disease only a few genes directly regulated by Nkx2.1 are known. To identify direct Nkx2.1target genes and pathways controlled by this transcription factor in vivo we analyzed, by chromatin immuno-precipitation (chip)-on-chip method, Nkx2.1 binding to DNA cis-elements in developing mouse lung. We analyzed embryonic day E11.5 lungs, when Nkx2.1 expressing cells are undergoing predominantly proliferation, and day E19.5, when Nkx2.1 expressing cells are undergoing predominantly differentiation. Many highly bound targets are known and well described, such as surfactant proteins and secretoglobins. Unique or common target genes involved in a variety of developmental and tumorigenic pathways were identified at each developmental time point. Positive regulation of cell proliferation was the highest overrepresented biological process at E11.5 while ion transport was the highest overrepresented biological process at E19.5. New identified targets include proliferation related genes such as E2F3, Met, Ccnb1, and Ccnb2. Nkx2.1 downregulation in mouse epithelial and human carcinoma cell lines reduced cell proliferation by arresting cells in the G2/M phase. Reduced expression of Nkx2.1 target genes in both cell lines supports a direct role of Nkx2.1 in regulation of cell proliferation genes. The identification of these transcriptional regulatory pathways in vivo aid us to understand Nkx2.1 function in lung development and link it to disease, since many of the identified targets are aberrantly up regulated in cancer cells. Developing mouse lung, 2 developmental time points E11.5 and E19.5, genomic DNA fragments immunoprecipitated with a-Nkx2.1 (07-601, Upstate-Millipore) vs input, E11.5, 2 biological replicates and E19.5, 3 biological replicates
Project description:The importance of unanchored Ub in innate immunity has been shown only for a limited number of unanchored Ub-interactors. We investigated what additional cellular factors interact with unanchored Ub and whether unanchored Ub plays a broader role in innate immunity. To identify unanchored Ub-interacting factors from murine lungs, we used His-tagged recombinant poly-Ub chains as bait. These chains were mixed with lung tissue lysates and protein complexes were isolated with Ni-NTA beads. Sample elutions were subjected to mass spectrometry (LC-MSMS) analysis.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other