Differential microRNA expressions during development of mouse cornea
ABSTRACT: Expression of microRNAs (miRNA) was examined in the wild type mouse cornea at postnatal day 9 (PN9) before stratification of the corneal epithelium and at 6 weeks of age when the epithelium is fully stratified. Using Sanger miRBase Version 10.0, we analysed 568 miRNAs across 4 biological replicates of the developing (PN9) and mature (6-week-old) mouse cornea.
Project description:While the mouse cornea has been well characterized morphologically, the transcriptional changes have not been described in detail. To characterize the genes, pathways, and transcriptional regulators involved in mouse cornea development and aging, we isolated whole cornea from wildtype CB6 mice at several developmental timepoints and every 6 months in the adult. Corneal epithelium and stroma were isolated at one timepoint to provide insights into the genes that are unique to each tissue. Total RNA was purified from whole mouse cornea at 12 time points over the life of the mouse and from corneal epithelium and stroma at a single timepoint.
Project description:Neutrophil infiltration occurres in two phases during sterile inflammation to cornea: small initial phase (Phase I) that began within 15 min, and larger second phase (Phase II) that peaked at 24-48 h. Microarrays were used to identify candidate stimuli that initiated the two phases.
Project description:Whole human conjunctivae and human corneas were obtained from the National Disease Research Interchange (NDRI, Philadelphia, PA) and processed between 48 - 72 hr of death. No donor details apart from age, sex and cause of death were released. Criteria for inclusion were donor ages between 25 - 65 years old and overt physical integrity of the epithelium over the central cornea as revealed by a quick stain with 0.1 % Trypan blue. For each replicate experiment (Conjunctiva 1 and Cornea 1; Conjunctiva 2 and Cornea 2;Conjunctiva 3 and Cornea 3), RNA from two different corneal or conjunctival specimens was pooled and converted into cDNA. Appropriately fragmented biotin-labeled cRNA was hybridized to the HG-U133A GeneChips® (Affymetrix) oligonucleotide microarray following the manufacture protocol. Three separate experiments each including one conjunctival and one corneal cRNA pool were performed (Conjunctiva 1 and Cornea 1; Conjunctiva 2 and Cornea 2;Conjunctiva 3 and Cornea 3).
Project description:To elucidate biological processes underlying the keratocyte, fibroblast, and myofibroblast phenotypes of corneal stromal cells, the gene expression patterns of these primary cultures from mouse cornea were compared with those of the adult and 10-day postnatal mouse cornea.
Project description:Corneal injuries remain a major cause of consultation in the ophthalmology clinics worldwide. Repair of corneal wounds is a complex mechanism that involves cell death, migration, proliferation, differentiation, and extracellular matrix (ECM) remodeling. In the present study, we used a tissue-engineered, two-layers (epithelium and stroma) human cornea as a biomaterial to study both the cellular and molecular mechanisms of wound healing. Gene profiling on microarrays revealed important alterations in the pattern of genes expressed by tissue-engineered corneas in response to wound healing. Expression of many MMPs-encoding genes was shown by microarray and qPCR analyses to increase in the migrating epithelium of wounded corneas. Many of these enzymes were converted into their enzymatically active form as wound closure proceeded. In addition, expression of MMPs by human corneal epithelial cells (HCECs) was affected both by the stromal fibroblasts and the collagen-enriched ECM they produce. Most of all, results from mass spectrometry analyses provided evidence that a fully stratified epithelium is required for proper synthesis and organization of the ECM on which the epithelial cells adhere. In conclusion, and because of the many characteristics it shares with the native cornea, this human two layers corneal substitute may prove particularly useful to decipher the mechanistic details of corneal wound healing. Primary cultures of human corneal epithelial cells cultivated on BSA (number of replicates: 7), Collagen type I (number of replicates: 2), Collagen type IV (number of replicates: 2), Fibronectin (number of replicates: 2), Tenascin C (number of replicates: 2) and Laminin (number of replicates: 2) matrix. Central, internal and external ring of wounded Tissue-engineered human cornea.
Project description:In the current study, we expanded our previous work to identify miRNAs implicated in the myogenesis regulation through the comparison of miRNAs transcriptome in skeletal muscle tissues between broilers and layers. miRNA expression studies of two different intra-species breeds
Project description:TGFBIp is a constituent of the extracellular matrix in many human tissues including the cornea, where it is one of the most abundant proteins expressed. TGFBIp interacts with type I, II, IV, VI and XII collagens as well as several members of the integrin family, suggesting that it plays an important role in maintaining structural integrity and possibly corneal transparency as well. More than 60 point mutations in the TGFBI gene have been described in four types of corneal dystrophies (granular, lattice, Thiel-Behnke and Reis-Bückler). These defects are characterized by aberrant protein folding, leading to TGFBIp aggregation in the cornea and resulting in severe visual impairment and blindness. Several studies have focused on targeting TGFBIp expression in the cornea as a therapeutic approach to treat TGFBI-linked corneal dystrophies, but the effect of this approach on corneal homeostasis and integrity remained unknown. In the current study, we evaluated the histological and proteomic profiles of corneas from TGFBI-deficient mice as well as potential redundant functions of the paralogous protein periostin. The absence of TGFBIp in mouse corneas did not grossly affect the collagen scaffold, and periostin was unable to compensate for TGFBIp. However, a proteomic comparison of wild-type and TGFBI-/- mice revealed that 11 other proteins were differentially regulated, including type VI and XII collagens. Hence, the complete elimination of TGFBIp in the cornea as a treatment for TGFBI-linked corneal dystrophies may cause unintended consequences at the molecular level that are not evident at the macroscopic or functional levels.
Project description:Considerable interest has been generated for the development through cell-tissue engineering of suitable corneal endothelial graft alternatives, which can potentially alleviate the shortage of corneal transplant material. The advent of less invasive suture-less key-hole surgery options such as Descemet’s Stripping Endothelial Keratoplasty (DSEK) and Descemet’s Membrane Endothelial Keratoplasty (DMEK), which involve transplantation of solely the endothelial layer instead of full thickness cornea, provide further impetus for the development of alternative endothelial grafts for clinical applications. A major challenge for this endeavor is the lack of specific markers for this cell type. To identify genes that reliably mark corneal endothelial cells (CECs) in vivo and in vitro, we performed RNA-sequencing on freshly isolated human CECs (from both young and old donors), CEC cultures, and corneal stroma. Gene expression of these corneal cell types were also compared to that of other human tissue types. Based on high throughput comparative gene expression analysis, we identified a panel of markers that are: i) highly expressed in CECs from both young donors and old donors; ii) expressed in CECs in vivo and in vitro; and iii) not expressed in corneal stroma keratocytes and the activated corneal stroma fibroblasts. These were SLC4A11, COL8A2 and CYYR1. The use of this panel of genes in combination reliably ascertains the identity of the CEC cell type. A total of 20 donor corneas consisting of 10 single donor corneas and 5 paired donor corneas were used in this study. Donor age ranged from 19 - 76. This RNA-seq study included 15 pooled corneas (5 each) used form CEC old, CEC young and stroma samples.
Project description:The gene expression profile of the adult zebrafish cornea was assessed in comparison to those from closely associated surface tissues: the dermis and epidermis. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series