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Cell Diversity (cell + diversity)
Selected AbstractsCell diversity in the retina: more than meets the eyeBIOESSAYS, Issue 10 2003Tiffany Cook Over 10 years ago, Pax-6 was shown to play an evolutionarily conserved role in controlling eye formation from Drosophila to humans.1 Since then, the identification of an entire cascade of conserved eye determination genes has brought a new understanding to the developmental relationship between the insect compound eye and the vertebrate camera eye.2 Additional studies are now beginning to suggest that even late aspects of eye development, including cell type specification, also share common molecular machinery. In this commentary, I will discuss some of these findings, with a particular focus on the recent study by Dyer et al.3 describing a novel role for the Prox1 transcription factor in specifying horizontal cells in the mouse retina. As Prospero, the Drosophila homolog of Prox1, also participates in retinal cell specification, these data provide a forum for asking new questions concerning pathways that may regulate retinogenesis across evolution. BioEssays 25:921,925, 2003. © 2003 Wiley Periodicals, Inc. [source] Natural killer cells: integrating diversity with functionIMMUNOLOGY, Issue 4 2009Kuldeep Cheent Summary The key role of natural killer cells in many aspects of the immune response is now being recognized. The last decade has seen an exponential increase in our understanding of the workings of these cells. Receptor diversity is crucial in allowing natural killer cells to respond effectively to a variety of different pathogens. This article reviews aspects of natural killer cell diversity that combine to generate populations of functional natural killer cells that exist within both the individual and throughout the population at large. [source] Thiazolidinedione treatment and constitutive-PPAR, activation induces ectopic adipogenesis and promotes age-related thymic involutionAGING CELL, Issue 4 2010Yun-Hee Youm Summary Age-related thymic involution is characterized by reduction in T cell production together with ectopic adipocyte development within the hematopoietic and thymic niches. Peroxisome proliferator-activated receptor gamma (PPAR,) is required for adipocyte development, glucose homeostasis and is a target for several insulin-sensitizing drugs. Our prior studies showed that age-related elevation of PPAR, expression in thymic stromal cells is associated with thymic involution. Here, using clinically relevant pharmacological and genetic manipulations in mouse models, we provide evidence that activation of PPAR, leads to reduction in thymopoiesis. Treatment of aged mice with antihyperglycemic PPAR,-ligand class of thiazolidinedione drug, rosiglitazone caused robust thymic expression of classical pro-adipogenic transcripts. Rosiglitazone reduced thymic cellularity, lowered the naïve T cell number and T cell receptor excision circles (TRECs) indicative of compromised thymopoiesis. To directly investigate whether PPAR, activation induces thymic involution, we created transgenic mice with constitutive-active PPAR, (CA-PPARg) fusion protein in cells of adipogenic lineage. Importantly, CA-PPAR, transgene was expressed in thymus and in fibroblast-specific protein-1/S100A4 (FSP1+) cells, a marker of secondary mesenchymal cells. The CAPPAR, fusion protein mimicked the liganded PPAR, receptor and the transgenic mice displayed increased ectopic thymic adipogenesis and reduced thymopoiesis. Furthermore, the reduction in thymopoiesis in CA-PPAR, mice was associated with higher bone marrow adiposity and lower hematopoietic stem cell progenitor pool. Consistent with lower thymic output, CAPPAR, transgenic mice had restricted T cell receptor repertoire diversity. Collectively, our data suggest that activation of PPAR, accelerates thymic aging and thymus-specific PPAR, antagonist may forestall age-related decline in T cell diversity. [source] Generating cell diversity in the nervous systemBIOESSAYS, Issue 4 2002Noel Buckley No abstract is available for this article. [source] | ||||||||||