Differential expression of receptor protein tyrosine phosphatases accompanies the reorganisation of the retina upon laser lesion.
The regulation of protein phosphorylation plays an essential role in virtually all aspects of eukaryotic development. Beginning with the regulation of the cell cycle to cellular proliferation and differentiation, the delicate balance between the phosphorylating activity of kinases and the dephosphorylation by phosphatases controls the outcome of many signal transduction cascades. The generation of cellular diversity occurs in an environment that is structured by the extracellular matrix (ECM) which forms a surrounding niche for stem and progenitor cells. Cell-cell and cell-matrix interactions elicit specific signaling pathways that control cellular behavior. In pathological situations such as neural degenerating diseases, gene expression patterns and finally the composition of the ECM change dramatically. This leads to changes of cell behavior and finally results in the failure of regeneration and functional restoration in the adult central nervous system. In order to study the roles of tyrosine phosphatases and ECM in this context, we analyzed the effects of laser-induced retinal injury on the regulation of the receptor protein tyrosine phosphatases (RPTP) RPTPBr7, Phogrin and RPTPbeta/zeta. The latter occurs in several isoforms, including the soluble released chondroitin sulfate proteoglycan phosphacan that is expressed in the developing retina. The receptor variants RPTPbeta/zeta(long) and RPTPbeta/zeta(short) may serve as receptors of tenascin-proteins and serve as modulators of cell intrinsic signaling in response to the ECM. Using quantitative real-time RT-PCR analysis, we show here a time-dependent pattern of gene expression of these molecules following laser lesions of the retina.
Besser
Manuela
M
Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany.
Horvat-Bröcker
Andrea
A
Eysel
Ulf T
UT
Faissner
Andreas
A
D000818:Animals; D002450:Cell Communication / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D007834:Lasers; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D009416:Nerve Regeneration / Q000235:genetics*; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D054557:Receptor-Like Protein Tyrosine Phosphatases / Q000235:genetics*; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5 / Q000235:genetics; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8 / Q000235:genetics; D020127:Recovery of Function / Q000235:genetics; D012160:Retina / Q000293:injuries / Q000378:metabolism* / Q000503:physiopathology; D013234:Stem Cells / Q000378:metabolism*; D019063:Tenascin / Q000235:genetics
D016326:Extracellular Matrix Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D019063:Tenascin; D054557:Receptor-Like Protein Tyrosine Phosphatases; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; C533193:phogrin protein, mouse