XB-ART-53175Dev Neurobiol. October 14, 2017;
Upregulation of matrix metalloproteinase triggers transdifferentiation of retinal pigmented epithelial cells in Xenopus laevis: A Link between inflammatory response and regeneration.
PubMed ID: 28371543
Article link: Dev Neurobiol.
Genes referenced: cacna1b mmp19 mmp7 mmp9 pax6 rax rpe tnf
Article Images: [+] show captions
|Figure 2 Phase contrast image of tissue cultured Xenopus RPE1choroid on Day 14 and (A to H) detection of Xmmp9 and Xmmp18 expression on Day 5. Normally, 4 different zones can be discriminated around Day 14 of culture, depending on the cell–cell interactions. In the epithelial zone, both N-cadherin and Connexin-43 are detected, while in the transitional zone only N-cadherin can be detected (Nabeshima et al., 2013). (A–D) In situ hybridization of Xmmp9 and Xmmp18 at the early stage of culture. RPE cells migrating from the periphery of the explant (asterisks) and in the epithelial zone are positively stained for both Xmmp9 and Xmmp18. (E–H) No positive staining was detected when sense probes were applied. Cultures were treated for de-pigmentation before they were processed for in situ hybridization. [Color figure can be viewed at wileyonlinelibrary.com]|
|Figure 4 Effects of 1, 10-PNTL on the RPE cell-cell adhesion and Pax6 expression. Cell adhesion profiles were examined using anti-connexin-43 and N-cadherin antibodies. (A, B and E, F) In the control cultures, connexin-43 immunoreaction was detected in the epithelial zone, while N-cadherin was found both in the epithelial and transitional zones. (C, D and G, H) In the presence of the inhibitor, no positive staining for both antibodies was detected. (I–K) In the control culture, intense Pax6 immunoreactivity was detected in the transitional zone, while no positive cells were detected in the presence of the inhibitor (L–N). Asterisks indicate tissue explants and the dotted lines indicate the boundaries between the explant and the epithelial zone. Four separate experiments were performed and the representative data are shown in the figures. [Color figure can be viewed at wileyonlinelibrary.com]|
|Figure 8 Summary of the hypothetical sequence of retinal regeneration in X. laevis. Surgical removal of the retina causes an inflammatory reaction in the capillary-rich tissue, the choroid, and some cytokines will be released in the tissue. These substances will induce RPE cells to upregulate Mmp genes. Accordingly, RPE cells detach from their basement membrane and migrate to the other basement membrane (the retinal vascular membrane), where they re-form an epithelial structure and finally upregulate the regeneration genes, Rax and Pax6. [Color figure can be viewed at wileyonlinelibrary.com]|