scholarly journals Bacteria are required for regeneration of the Xenopus tadpole tail

2018 ◽  
Author(s):  
Thomas F. Bishop ◽  
Caroline W. Beck
Keyword(s):  
Reactive Oxygen Species ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Oxygen Species ◽  
Transcription Factor Activity ◽  
Factor Activity ◽  
Regenerative Processes ◽  
Tail Regeneration ◽  
Positive Feedback Loop ◽  
Tadpole Tail

AbstractThe impressive regenerative capabilities of amphibians have been studied for over a century. Although we have learnt a great deal about regenerative processes, the factors responsible for the initiation of regeneration have remained elusive. A previous study implicated reactive oxygen species (ROS) and the ROS-generator, NADPH oxidase (Nox), in Xenopus tadpole tail regeneration. In this study we suggest that Nox is expressed as a consequence of NF-κB transcription factor activity and that ROS produced by Nox, in turn, help to maintain the activity of NF-κB, forming a positive-feedback loop. Microorganisms were found to be required for regeneration through binding to toll-like receptors (TLR). NF-κB is a downstream component of TLR pathways and its activation through TLR stimulation could jump-start the positive-feedback loop. These findings provide potential targets for the activation of regeneration in non-regenerative animals.

scholarly journals A Positive Feedback Loop Ensures Propagation of ROS Production and JNK Signaling Throughout Drosophila Tissue Regeneration

2017 ◽  
Author(s):  
Sumbul Jawed Khan ◽  
Syeda Nayab Fatima Abidi ◽  
Andrea Skinner ◽  
Yuan Tian ◽  
Rachel K. Smith-Bolton
Keyword(s):  
Reactive Oxygen Species ◽  
Differentially Expressed Genes ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Transcriptional Profiling ◽  
High Expression ◽  
Oxygen Species ◽  
Positive Feedback Loop ◽  
Jnk Signaling ◽  
Regenerative Growth

AbstractRegenerating tissue must initiate the signaling that drives regenerative growth, and sustain that signaling long enough for regeneration to complete. How these key signals are sustained is unclear. To gain a comprehensive view of the changes in gene expression that occur during regeneration, we performed wholegenome mRNAseq of actively regenerating tissue from damaged Drosophila wing imaginal discs. We used genetic tools to ablate the wing primordium to induce regeneration, and carried out transcriptional profiling of the regeneration blastema by fluorescent labeling and sorting the blastema cells, thus identifying differentially expressed genes. Importantly, by using genetic mutants of several of these differentially expressed genes we have confirmed that they have roles in regeneration. Using this approach, we show that high expression of the gene moladietz (mol), which encodes the Duox-maturation factor NIP, is required during regeneration to produce reactive oxygen species (ROS), which in turn sustain JNK signaling during regeneration. We also show that JNK signaling upregulates mol expression, thereby activating a positive feedback signal that ensures the prolonged JNK activation required for regenerative growth. Thus, by wholegenome transcriptional profiling of regenerating tissue we have identified a positive feedback loop that regulates the extent of regenerative growth.Author summaryRegenerating tissue must initiate the signaling that drives regenerative growth, and then sustain that signaling long enough for regeneration to complete. Drosophila imaginal discs, the epithelial structures in the larva that will form the adult animal during metamorphosis, have been an important model system for tissue repair and regeneration for over 60 years. Here we show that damage-induced JNK signaling leads to the upregulation of a gene called moladietz, which encodes a co-factor for an enzyme, NADPH dual oxidase (DUOX), that generates reactive oxygen species (ROS), a key tissue-damage signal. High expression of moladietz induces continuous production of ROS in the regenerating tissue. The sustained production of ROS then continues to activate JNK signaling throughout the course of regeneration, ensuring maximal tissue regrowth.

scholarly journals An early Shh-H2O2 feedback loop controls the progression of the regenerative program during adult zebrafish fin regeneration

2021 ◽  
Author(s):  
Marion Thauvin ◽  
Rodolphe Matias de Sousa ◽  
Marine Alves ◽  
Michel Volovitch ◽  
Sophie Vriz ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Sonic Hedgehog ◽  
Feedback Loop ◽  
Ros Production ◽  
Oxygen Species ◽  
Adult Zebrafish ◽  
Regenerative Processes ◽  
Fin Regeneration ◽  
Spatiotemporal Regulation ◽  
New Findings

AbstractReactive oxygen species (ROS), originally classified as toxic molecules, have attracted increasing interest given their actions in cell signaling. Among these molecules, Hydrogen peroxide (H2O2) is the major ROS produced by cells and acts as a second messenger to modify redox-sensitive proteins or lipids. After amputation, tight spatiotemporal regulation of ROS is required first for wound healing and later to initiate the regenerative program. However, the mechanisms carrying out this sustained ROS production and their integration with signaling pathways are still poorly understood. We focused on the early dialog between H2O2 and Sonic Hedgehog (Shh) during fin regeneration. We demonstrate that H2O2 controls Shh expression and that Shh in turn regulates the H2O2 level via a canonical pathway. Moreover, this tightly controlled feedback loop changes during the successive phases of the regenerative program. Dysregulation of the Hedgehog pathway has been implicated in several developmental syndromes, diabetes and cancer. These data support the existence of a very early feedback loop between Shh and H2O2 that might be more generally involved in various physiological or pathological processes. These new findings pave the way to improve regenerative processes, particularly in vertebrates.

scholarly journals Amputation-induced reactive oxygen species are required for successful Xenopus tadpole tail regeneration

2013 ◽  
Vol 15 (2) ◽  
pp. 222-228 ◽  
Author(s):  
Nick R. Love ◽  
Yaoyao Chen ◽  
Shoko Ishibashi ◽  
Paraskevi Kritsiligkou ◽  
Robert Lea ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Tail Regeneration ◽  
Xenopus Tadpole ◽  
Tadpole Tail
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