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Biomedical subjects

R F O'Shaughnessy

Publications and source records attributed to R F O'Shaughnessy.

3 recordsLinked to original sources

Analysis of gene expression using high-density and IFN-gamma-specific low-density cDNA arrays.

The combination of high and low density cDNA filter array technology potentially permits both the identification of subsets of induced genes and convenient and rapid multisample expression profiling of such subsets under a variety of conditions. The JAK/STAT1 pathway for IFN-gamma signaling in human cells has been well characterized, but the extent and importance of additional pathways remain to be established. Here, using high-density filter arrays of the RZPD UniGene set, we identified 18 novel IFN-gamma-inducible genes. Expression profiling was carried out using low-density arrays representing both novel and known IFN-gamma-inducible genes. Initial experiments failed to detect evidence for any novel non-JAK-dependent pathways in cells expressing a kinase-dead JAK2. The data, however, validated the potential of the combined methods in establishing rapid and convenient expression profiling of several hundred genes in response to any ligand of choice.

Gene Expression Profiling↗

PA-FABP, a novel marker of human epidermal transit amplifying cells revealed by 2D protein gel electrophoresis and cDNA array hybridisation.

Human epidermal stem cells express higher levels of beta1 integrins than their more differentiated daughters, transit amplifying cells. In a search for additional stem and transit cell markers we used proteomics and differential cDNA hybridisation to compare keratinocytes fractionated on the basis of beta1 integrin expression. There were remarkably few differences between the two populations and none of the RNAs differed in abundance by more than 2-fold. Nevertheless, proteomics revealed upregulated expression of epidermal fatty acid binding protein (PA-FABP, also known as E-FABP), Annexin II and two keratin related proteins in the transit population. An unknown high molecular mass protein was upregulated in the stem cell population. The upregulation of PA-FABP was confirmed by Northern blotting and conventional and whole mount labelling of human epidermis. We conclude that PA-FABP is a novel marker of epidermal transit amplifying cells.

3T3 Cells↗

Stem cells in the epidermis.

The epidermis consists of three actively proliferating units, the interfollicular epidermis, the hair follicle, and the sebaceous gland. Stem cells in the epidermis have the capacity to produce all three of these units. The fate of the epidermal stem cells and some of their progeny can be altered, dependent on the environment in which they reside and the genes they express. In this review, we describe the major experiments that have contributed to the understanding of the epidermal stem cells and the control of their fate.

Animals↗