Limbal Niche
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Jeppe Emmersen
PROVIDER: E-MTAB-1498 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Transplantation of amniotic membrane-expanded limbal epithelium (AMLE) in place of donor tissue grafts results in significantly improved outcomes for patients suffering from severe limbal stem cell deficiency; however the reasons for such superior results are unclear. The purpose of this study was to identify transcriptional gene profiles specific to AMLE and donor central corneal epithelium (CE), which may contribute to the divergent clinical outcomes observed following transplant. Limbal fibroblasts which underlie the epithelium and secrete extracellular matrix proteins following injury/surgery were also profiled. Using cell culture, immunofluorescence, microarray gene expression profiling and qRT-PCR validation; this study aims to identify enriched biological processes and pathways which characterise AMLE and CE tissues. We hope the study outcomes will shed light onto the factors which contribute to provide the improved clinical outcomes associated with AMLE transplantation. Gene expression profiling of three central corneal buttons, three amniotic membrane-expanded limbal epithelial cultures and three limbal fibroblast cultures
2014-10-02 | E-GEOD-56421 | biostudies-arrayexpress
Project description:To gain new insights into molecular changes in skeletal muscle aging and disease with a special focus on differential alternative splicing and senescence, we performed RNA-seq on tibialis muscles from 15 months old (adult, a) and 27 months old (old, o) rats. Whole (w) muscle samples were prepared for both age groups (w/a and w/o). Additionally, for both age groups, muscle fibers were isolated. For adult rats, this resulted in one group (f/a). For old rats, fibers were subjected to Laser capture microdissection guided by expression of aging markers Tmem158 and Cdkn1a, giving rise to two groups, aging marker-positive fibers (f/o+) and aging marker-negative fibers (f/o-). The entire experiment comprises 5 groups (w/a, w/o, f/a, f/o+, f/o-), with 5 animals per group, ie. 25 samples total.
2021-06-26 | E-MTAB-10582 | biostudies-arrayexpress
Project description:The Krüppel-like factors, KLF1 and KLF2, positively regulate embryonic β-globin expression, and have additional overlapping roles in embryonic (primitive) erythropoiesis. KLF1-/-KLF2-/- double knockout mice are anemic at embryonic day 10.5 (E10.5) and die by E11.5, in contrast to single knockouts. To investigate the combined roles of KLF1 and KLF2 in primitive erythropoiesis, expression profiling of E9.5 erythroid cells was performed. A limited number of genes had a significantly decreasing trend of expression in wild-type, KLF1-/- and KLF1-/-KLF2-/-. Among these, c-myc emerged as a central node in the most significant gene network. c-myc expression is synergistically regulated by KLF1 and KLF2, and both factors bind the c-myc promoters. To characterize the role of c-myc in primitive erythropoiesis, ablation was performed specifically in mouse embryonic proerythroblast cells. After E9.5, these embryos exhibit an arrest in the normal expansion of circulating red cells and develop anemia analogous to KLF1-/-KLF2-/-. In the absence of c-myc, circulating erythroid cells do not show the normal increase in α- and β-like globin expression, but interestingly, have accelerated erythroid maturation, between E9.5 and E11.5. This study reveals a novel regulatory network by which KLF1 and KLF2 regulate c-myc, to control the primitive erythropoietic program. Timed-pregnant KLF1+/-, KLF1+/- KLF2+/- females were anesthetized and sacrificed. E9.5 yolk sacs were dissected from the embryo, cryoprotected in 20% sucrose in PBS and frozen in OCT media. A small portion of the embryo tail was used for PCR genotyping. Eight micron frozen yolk sac sections were obtained and laser capture microdissection (LCM) was used to isolate primitive erythroid precursors. For each biological replicate, 2 to 4 yolk sacs from 2 different litters were used. Total RNA was isolated from 8 different wild-type, 3 KLF1-/-, 3 KLF1-/- KLF2-/- erythroid samples and hybridized to Affymetrix 430 A 2.0 microarrays.
2012-03-12 | E-GEOD-36427 | biostudies-arrayexpress
Project description:Our overall objective is to identify key differences in gene expression signaling pathways in the epithelial and intralobular stromal compartments during prepartum mammary remodeling and development in the dry cow. 2 cell types (epithelia or stroma) from each of 6 animals were collected by Laser Capture Microdissection
2011-06-30 | E-GEOD-18768 | biostudies-arrayexpress
Project description:Systemic hypertension has a profound impact on the renal vascular physiology. In order to elucidate the biological pathways and macromolecules deregulated by hypertension renal vessels were obtained by Laser Capture Microdissection (LCM) from Spontaneously Hypertensive Rats (SHR) and age-matched controls (20 weeks). Proteomic analysis was performed aiming to detect early molecular alterations associated with hypertension at the renal vessels before the onset of vascular damage. Proteomic analysis identified 688 proteins, of which 58 were differentially expressed (15 up-regulated and 43 down-regulated in SHR). Many of these proteins are involved in vascular tone regulation by modulating the activity of endothelial Nitric Oxide Synthase (eNOS) (e.g. Xaa-Pro aminopeptidase 1 (XPP1), N(G) N(G)-dimethylarginine dimethylaminohydrolase 1 (DDAH1), Dehydropteridine reductase (DHPR)) or in blood pressure control by regulating the renin-angiotensin system (e.g. Glutamyl aminopeptidase/Aminopeptidase A (AMPE), Aminopeptidase N (AMPN)). Moreover, pathway enrichment analysis revealed that the eNOS activation pathway is deregulated only in SHR. Our study demonstrates that hypertension causes early proteomic changes in the renal vessels of SHR. These changes are relevant to vascular tone regulation and consequently may be involved in the development of vascular damage and hypertensive nephrosclerosis. Therefore, the identified proteins could be considered as therapeutic targets.
2022-03-03 | PXD008792 | Pride
Project description:Proliferative zone chondrocytes were microdissected from control and Ift88-deleted growth plates to determine gene expression profiles regulated by primary cilia. Four total samples were analyzed. Two biological replicates of proliferative zone chondrocytes microdissected from control mice and two biological replicates from Ift88 deleted (Col2aCre;Ift88fl/fl) mice. Control and experimental mice were in the Bl/6 background.
2013-01-02 | E-GEOD-35003 | biostudies-arrayexpress
Project description:Recently we had discovered a solid cord like structure at the limbus of human eyes, termed as the Limbal Epithelial Crypt (LEC). It arises from the undersurface of the interpalisade rete ridges and extends towards the conjunctiva over the conjunctival stroma. Anatomical and immunohistochemical studies have shown it to be potentially a Stem Cell Niche. To confirm this hypothesis we conducted comparative gene expression profile of LEC with pathway and Geneontology studies in comparison with other ocular surface epithelial regions such as cornea, limbus, LEC stroma and conjunctiva. Frozen tissue blocks of corneoscleral buttons dissected from cadaver eyes were cryosectioned. These tissue sections from different ocular surface regions were laser microdissected. Extracted RNA was amplified & hybridized to 30,000k Human spotted cDNA microarray chips. Raw data obtained with Genepix Pro6 software was filtered, normalized & analysed on BASE & Jexpresspro software. Unpaired T-Test, Significance Analysis of Microarrays were performed on the data. Database for Annotation, Visualisation, and Integrated Discovery (DAVID) (http://www.DAVID.niaid.nih.gov) and Ingenuity Pathway Analysis (IPA) was used to determine the enriched GO terms and pathways in the differentially expressed genes. Quantitative gene expression analysis (qPCR) and immunohistochemistry was performed on the genes of interest. Statistical analysis for real time PCR was performed on SPSS16 to determine the normalised expression of gene of interest on ocular surface regions. Samples were prepared from five human ocular surface epithelial regions such as Cornea, Limbus, LEC, LEC Stroma, Conjunctiva. There were four replicates in each groups except Cornea and Conjunctiva with 3 each. The Standard Probe (SP) was prepared from mixing equal amount of Corneal and conjunctival epithelial RNA followed by ethanol precipitation. Samples were labelled with Cy5 dye and Standard Probe with Cy3 Dye. These were mixed in equal amount to prepare hybrid probes which were then hybridised to microarray slide.
2010-03-23 | E-GEOD-19035 | biostudies-arrayexpress
Project description:Background The dramatic increase in incidence of ductal carcinoma in situ (DCIS) associated with mammographic screening for breast cancer has given emphasis to the challenges of managing this important clinical entity. Unlike invasive breast cancer, there is no established histopathologic grading system for DCIS, nor are there biological markers of prognosis to guide clinical management. The aim of this study is to use molecular profiling to identify robust and clinically applicable indicators of DCIS malignant potential. Methods Areas of intraduct carcinoma, atypical ductal hyperplasia and benign epithelium were isolated from 46 well-characterised invasive breast cancers by laser capture microdissection. Microarray based gene expression profiling was used to identify genes differentially expressed between DCIS associated with grade 1 and grade 3 invasive carcinoma (‘grade associated genes’). The expression profile of these genes was then determined in all samples and used to define ‘molecular grade’ categories. The genomic basis of gene expression derived categories was examined by array-based comparative genomic hybridisation (CGH). Results DCIS samples could be divided into two subgroups, designated low and high molecular grade (MG) on the basis of expression at 173 grade associated oligonucleotide probes. The low MG subgroup included 21 DCIS samples of low (n=10) and intermediate (n=11) nuclear grade as well as all samples of ADH (n=4) and benign epithelium (n=7). The high MG subgroup included 27 DCIS samples of intermediate (n=7) and high (n=19) nuclear grade. Array CGH revealed distinct differences in the character and degree of genomic aberration associated with MG and the clinical significance of MG was verified by a strong correlation with survival in two independent invasive breast cancer gene expression datasets (n=295 and n=186). MG categories were strongly associated with histopathologic and biomarker features of DCIS. Using a classification tree model, DCIS MG could be accurately predicted in 44/46 (95.7%) of samples using a combination of nuclear grade and Ki67 score. Conclusions Molecular profiling indicates a binary grading scheme for DCIS that is both biologically relevant and clinically informative. The low and high MG DCIS classification could be recapitulated by a novel combination of routinely accessible features. This practical approach has potential to immediately improve clinical evaluation and management of DCIS. Keywords: Paired gene expression and CGH Paired CGH and Gene Expression on DCIS of the breast
2008-11-24 | E-GEOD-7882 | biostudies-arrayexpress
Project description:85 radical prostatectomy specimens (where 16 samples are in Placebo group (PL), 15 are in Selenium group (SE), 25 are in Vitamin E group (VE) and 27 are in Vitamin E & Selenium group (VS.Treatment groups: l-selenomethionine, 400 ug + placebo (vitamin E); vitamin E, 400 IU + placebo (l-selenomethionine); l-selenomethionine, 400 ug + vitamin E, 400 IU; placebos) were subjected to laser capture microdissection to isolate prostate cancer cells, normal epithelial prostatic cells, or stroma cells. RNA extraction and amplification were performed. Transcription profiling was conducted using the HG-U133A Affymetrix arrays.
2008-07-01 | E-MEXP-1327 | biostudies-arrayexpress
Project description:The long term objective is to create an encyclopedia of the expression levels of all genes in multiple components of the developing kidney. The central thesis is straightforward. The combination of laser capture microdissection (LCM) plus microarray analysis offers a powerful, efficient and effective method for the creation of a global gene expression atlas of the developing kidney. Microarrays with essentially complete genome coverage can be used to quantitate expression levels of every gene in laser capture microdissected components of the developing kidney. The ensuing rapid read-out provides an expression atlas that is more sensitive, more economical and more complete than would be possible by in situ hybridizations alone. Keywords: Comparison of kidney components. At different developmental time points we isolate discrete elements of the kidney by using laser capture microdissection and then define their gene expression profiles with microarrays.
2006-11-18 | E-GEOD-6290 | biostudies-arrayexpress