The first two authors contributed equally to this work.
Transforming growth factor-β and bone morphogenetic proteins: Cooperative players in chick and murine programmed retinal cell death
Article first published online: 26 JAN 2006
Copyright © 2006 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 495, Issue 3, pages 263–278, 20 March 2006
How to Cite
Franke, A. G., Gubbe, C., Beier, M. and Duenker, N. (2006), Transforming growth factor-β and bone morphogenetic proteins: Cooperative players in chick and murine programmed retinal cell death. J. Comp. Neurol., 495: 263–278. doi: 10.1002/cne.20869
- Issue published online: 26 JAN 2006
- Article first published online: 26 JAN 2006
- Manuscript Accepted: 6 OCT 2005
- Manuscript Revised: 11 AUG 2005
- Manuscript Received: 15 APR 2005
- Deutsche Forschungsgemeinschaft through the DFG-Research Center for Molecular Physiology of the Brain
- cell culture;
Transforming growth factor-β (TGF-β) and bone morphogenetic protein (BMP) are extracellular molecules known to mediate programmed cell death (PCD) in the developing retina. In the present study, we investigated the expression profiles and activity levels of ligands and receptors of the TGF-β and BMP4 family during the physiological PCD periods of the developing chick and mouse retina and possible interactions of both proapoptotic molecules in mediating apoptosis in chick and murine retinal whole-mount cultures. Immunocytochemical double-labeling studies with the established ganglion cell marker Islet revealed overlapping expression patterns for TGF-β and BMP4 ligands and receptors on the surface of retinal ganglion cells. The biphasic peak of activity and expression levels of TGF-β and BMP4 ligands and receptors, revealed by Western blots and mink lung epithelial cell (MLEC) assays, coincided with the two main periods of retinal chick and murine PCD. In organotypic retinal cultures, we were able to increase apoptosis over basal levels by application of recombinant TGF-β or BMP4. Double-factor treatment induced an additional increase of apoptosis, suggesting a cooperation of both proapoptotic pathways. A significant increase in the number of apoptotic cells in the ganglion cell layer was observed in a TUNEL staining of retinal whole mounts treated with recombinant TGF-β or BMP4, suggesting a concerted action of both factors in triggering ganglion cell death. Blockage experiments revealed that both pathways do not interact at the ligand, receptor, or Smad protein level but converge at the transcriptional level of the TGF-β immediate-early response gene TIEG and the transcriptional coactivator Gcn5. J. Comp. Neurol. 495:263–278, 2006. © 2006 Wiley-Liss, Inc.