Abstracts
the ependymal canal in the adult zebrafish spinal cord express Foxj1a. We demonstrate that ependymal cells express Foxj1a since their birth in the embryonic neural tube and that Foxj1a activity is required for the final positioning of the ependymal canal. We also show that in response to spinal cord injury, Foxj1a ependymal cells actively proliferate and contribute for the restoration of the spinal cord structure. Finally, this study reveals that Foxj1a expression in the injured spinal cord is regulated by regeneration-specific regulatory elements. These data establish Foxj1a as a pan-ependymal marker in development, homeostasis and regeneration and may help identify the signals that enable this progenitor population to replace lost cells after spinal cord injury. doi:10.1016/j.mod.2017.04.095
PS1.89 col10a1+ osteoblast progenitors contribute to bone formation during lineage-restricted fin regeneration in Medaka Wen Hui Tana, Manish Dasyania, Lazaro Centaninb, Joachim Wittbrodtb, Christoph Winklera a
National University of Singapore, Singapore University of Heidelberg, Germany
b
While mammals can only repair bone defects below a critical size, teleost fishes can almost perfectly and repeatedly regenerate their bony fin rays upon fin amputations. Fin regeneration, a form of epimorphic regeneration, is mediated by the formation of a blastema, a mass of undifferentiated proliferative cells. Currently, the cellular sources and potency of cells contributing to the blastema have not been clearly defined. Previous studies on zebrafish fin regeneration suggested that regeneration of bone in the fin is lineage-restricted and that a cellular source for regenerating bone comes from dedifferentiation of pre-existing osterix+ mature osteoblasts.1 However, subsequent studies showed that amputated fins completely depleted of such osteoblasts could still regenerate bone at normal rates.2 This suggests that osterix+ mature osteoblasts are dispensable for bone regeneration and that an alternative cellular source(s) exist. Using medaka as a model and gaudi mediated Cre/lox technology for lineage tracing, our results suggest that similar to zebrafish, medaka fin regeneration is lineage-restricted. In addition, upon fin amputation, pre-existing col10a1+ osteoblast progenitors migrate beyond the amputation plane towards the blastema, proliferate and contribute to the regenerating bone. Based on our findings, we propose a model of bone regeneration in the teleost fin in which col10a1+ osteoblast progenitors serve as an alternative cellular source for lineage-restricted bone regeneration. References 1 Knopf, F., Hammond, C., Chekuru, A., Kurth, T., Hans, S., Weber, C.W., Mahatma, G., Fisher, S., Brand, M., Schulte-Merker, S., et al. (2011). Bone regenerates via dedifferentiation of osteoblasts in the zebrafish fin. Developmental Cell 20, 713-724. 2 Singh, S.P., Holdway, J.E., and Poss, K.D. (2012). Regeneration of amputated zebrafish fin rays from de novo osteoblasts. Developmental Cell 22, 879-886. doi:10.1016/j.mod.2017.04.096
PS1.90 Unique determinant among ‘PLETHORA’ of factors in conferring regenerative potential to organ beyond the competence zone Kavya Durgaprasada, Merin V. Roya, Anjali Venugopala, Abdul Kareema, Mähönen Ari Pekkab, Kalika Prasada
S51
a Indian Institute of Science Education and Research-Thiruvananthapuram, Thiruvananthapuram, India b University of Helsinki, Finland
Multicellular organisms display striking ability to repair the damages they incur during the period of growth. Compared to animals, plants possess better regenerative capabilities owing to their remarkable cellular plasticity. Despite evolving independently, plants and animals share some of the fundamental processes to regenerate the wounded organs. Interestingly, some organisms show differential regenerative potential along the organ axis e.g., Zebra fish fins, Arabidopsis root. The entire plant root is not competent to regenerate upon resection and the regenerative potential resides only in a portion of meristematic cells at the root tip. The molecular basis of such positional specificity in organ regeneration remains largely unknown. Here, we unravel the novel role of a transcription factor belonging to PLETHORA (PLT) gene family in conferring the competence during organ regeneration. PLT is distributed at the root tip in the shape of a gradient and the high expression domain of PLT overlaps with the competence zone for regeneration. Rapid ramp up of PLT upon resection is noticed prior to any visible cellular response, signifying its role as an early determinant during organ regeneration. In the absence of such PLT upregulation, even the elevated levels of key plant hormone, auxin fails to trigger organ regeneration. Intriguingly, we could force the non-competent cells of the differentiation zone acquire the regenerative potential upon mere delivery of high levels of PLT. Transient loss of PLT in multiple plethora mutant background renders the highly competent cells of root meristem incapable of regeneration. Taken together, our studies elucidate the pivotal role of PLT in determining the competence during organ regeneration and its uniqueness in being able to force cells of differentiation zone acquire regeneration competence. We further probe mechanistic aspects of organ regeneration and show the possible involvement of an auto-regulatory loop of PLT in the expansion of competence zone.
doi:10.1016/j.mod.2017.04.097
PS1.91 A passe-PAR2 for tissue regeneration and inflammation Ron Piran Bar Ilan University, Safed, Israel The different processes by which cells and tissues perceive and react to injury are not sufficiently understood. Elucidating them will allow for the development of efficient tissue regeneration treatments. We have been interested in pancreatic beta-cell regeneration and our work, which described cell transdifferentiation process in the setting of severe beta-cell ablation, was recently published. Here, we will show that the signaling pathway responsible for inducing islet cell transdifferentiation in that model is the activation of the Protease-Activated Receptor 2 (PAR2) GPCR. It was both necessary and sufficient to induce islet cell transdifferentiation. In addition to that role, we almost accidentally found a much broader role for PAR2 in fundamental other pathways of inflammation, necrosis, apoptosis and regeneration. Specifically, we found that PAR2 played a central role in: • Protecting beta-cells from apoptosis. Thus, PAR2 is the first molecule characterized to mediate selective beta-cell death and we showed that it is highly regulated in type I diabetes, where specific beta-cell destruction is a cardinal feature.
S52
Abstracts
• The liver regeneration process in the carbon tetrachloride model. • The ConA model of autoimmune hepatitis. • The digit regeneration process following amputation, which was done to test the generality of the role of PAR2 in tissue regeneration.
doi:10.1016/j.mod.2017.04.098
PS1.92 Polymorphism of protein a gene in Staphylococcus aureus isolates from milk and cheese Javid Eghbala, Arian Eghbalb, Ghazaleh Manafvandb, Asma Khanzadea a
Islamic Azad University, Urmia, Iran Urmia University of Medical Sciences, Urmia, Iran
b
The purpose of this study was to analysis protein A producing gene in staphylococcus aureus which has been isolated from bovine milk and cheese by using PCR-RFLP method. 40 number of isolated staphylococcus including14 samples from traditional cheese, 19 samples from bovine milk and 7 samples from buffalo milk have been tested by using PCR-RFLP method. After proliferation of spa gen the enzymatic section with specific primers was produced by using Hhal gen. The spa gene was proliferated by using the primers of
polymerase chain reaction. The proliferated products with the approximate size of 1270,1350,1380,and 1410 nucleotides pairs were made. From 40 samples of under studied staphylococcus aureus 25 samples contained the spa gene with the proliferated section of 1270 nucleotides pairs, 10 samples contained proliferated section of 1350 nucleotides pairs, 1 sample contained 1380 nucleotides pairs and 5 samples which all of them were belonged to cheese, contained proliferated section of 1410nucleotides pairs. The results of cutting the spa gene by using the Hhal cutting enzyme showed 4 different cutting patterns of the target gene but each one them were related to one size of the band of proliferated products and there was no significant diversity in one proliferated product. In dairy industry the production of healthy cheese and milk considered as an important issue, special milk and its products which contain diverse microorganism such as staphylococcus aureus. Staphylococcus aureus is one of the most important food pathogens which seems that the significant population of this bacteria were only belonged to cheese samples that can probably transmitted from humans to milk and from milk to cheese and other dairy products during milk production from bovine mastitis or transportation time. The existing staphylococcus in diary can cause food poisoning by enterotoxin.
doi:10.1016/j.mod.2017.04.099