Project description:The goal of this study was to examine the effect of the major axis of biaxial mechanical stretch on cardiac myocyte gene expression and to identify the signaling pathways and transcription factors regulating these changes. Neonatal cardiac myocytes were cultured on a micropatterned substrate, and the primary stretch axis was applied either parallel or transverse to the myofibril direction. RNA sequencing was conducted to study whole genomic expression changes after acute cardiac myocyte stretch. The results showed a more robust gene response to longitudinal than to transverse stretch. After 30 minutes of stretch, 53 and 168 genes were considered differentially expressed (DE) from transverse and longitudinal stretch, respectively. After 4 hours, the number of DE genes increased to 795 in longitudinal stretch while it decreased to 35 in transverse stretch. Gene ontology term (GO) analysis indicated enrichment of TF activity and protein kinase activity by both stretch axes; whereas longitudinal but not transverse stretch caused expression of genes involved in sarcomere organization and cytoskeletal protein binding.
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
