In recent years, interest in the possible molecular regulators of cell proliferation and differentiation in a wide range of regeneration models has grown significantly, but the cell kinetics of this process remain largely a mystery. (mdpi.com)
In biology, regeneration is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. (wikipedia.org)
Cells in the primordia of zebrafish fins, for example, express four genes from the homeobox msx family during development and regeneration. (wikipedia.org)
Dedifferentiation of cells means that they lose their tissue-specific characteristics as tissues remodel during the regeneration process. (wikipedia.org)
This should not be confused with the transdifferentiation of cells which is when they lose their tissue-specific characteristics during the regeneration process, and then re-differentiate to a different kind of cell. (wikipedia.org)
Upon limb amputation in salamanders, anterior and posterior connective tissue cells form distinct signalling centres that together fuel successful regeneration. (sciety.org)
These anterior and posterior identities, crucial for regeneration, were thought to be established during development and to persist through successive regeneration cycles as positional memory. (sciety.org)
During regeneration, Shh feeds back and reinforces Hand2 expression in nearby cells. (sciety.org)
In this way, regeneration is an opportunity and entry point to re-write positional memory. (sciety.org)
Given that the axolotl limb seems to have somewhat different contribution of cell types to the limb compared to other well-studied vertebrates (for example, the proportion of cells descended from the Shh population), it would also be interesting to know whether this particularity of axolotl limb development plays any role in their capacity for limb regeneration. (sciety.org)
It is still controversial whether positional memory in the blastema cells regulates reconstruction of fin morphology as in amphibian limb regeneration, in which limb blastema cells located at the same proximal-distal level have the same positional identity. (elsevierpure.com)
The contributors discuss the dramatic molecular and cellular changes that occur when a regeneration program is initiated, the progenitor cells and morphogenic signals involved, the formation of a blastema, the roles of reprogramming and polyploidy, the diversity of cell fates, the integration of new structures with existing body parts, and our current understanding of why some structures are more resistant to regeneration than others. (cshlpress.com)
The importance of technologies (e.g., single-cell RNA-seq) that have been instrumental in deciphering various aspects of regeneration in recent years is emphasized throughout. (cshlpress.com)
This volume is therefore essential reading for molecular, cell, and developmental biologists studying regeneration in animals, as well as for all interested in the development of regenerative therapies for clinical application. (cshlpress.com)
During limb epimorphic regeneration: committed mesenchymal cells at the stump site dedifferentiate, forming a cluster of heterogeneous population of stem cells, known as the blastema. (eurekaselect.com)
Epimorphic regeneration and retrodifferentiation both have the capacity to recreate and reconstruct tissue with precise positional integration of cells in such a way that will enable us to heal without scars and to understand how to maintain tissue integrity and architecture in the face of a hostile environment. (eurekaselect.com)
Published in Development , this reports yields new insights into the coordination that occurs between stem and differentiated cells in an important model of animal regeneration. (riken.jp)
Analysis of the expression of these genes, Djislet and Djwnt1/P-1 , showed co-localization at the midline of the blastema, the locus of regeneration in planarians, at day 3 of regeneration. (riken.jp)
and Class III, which are mainly expressed in γ-ray-sensitive cells and strongly downregulated by Djislet(RNAi) at day 3 of regeneration. (riken.jp)
Unidirectional regeneration in the basal chordate Ciona intestinalis involves the proliferation of adult stem cells residing in the branchial sac vasculature and the migration of progenitor cells to the site of distal injury. (biomedcentral.com)
However, after the Ciona body is bisected, regeneration occurs in the proximal but not in the distal fragments, even if the latter include a part of the branchial sac with stem cells. (biomedcentral.com)
siRNA-mediated gene knockdown showed that hsp70 and dnaJb4, but not bag3, are required for progenitor cell targeting and distal regeneration. (biomedcentral.com)
Heat shock treatment of distal body fragments activated hsp70 and dnaJb4 expression indicative of a stress response, induced cell proliferation in branchial sac vasculature cells, and promoted distal regeneration. (biomedcentral.com)
The stress response is absent from distal fragments, but can be induced by a heat shock, which activates cell division in the branchial sac vasculature and promotes distal regeneration. (biomedcentral.com)
This study demonstrates the importance of a stress response for stem cell activation and regeneration in a basal chordate, which may have implications for understanding the limited regenerative activities in other animals, including vertebrates. (biomedcentral.com)
Regeneration involves the activity of adult stem cells in the branchial sac, which proliferate and produce migratory progenitor cells for tissue and organ replacement. (biologists.com)
After bisection across the mid-body, apoptosis occurred only in the regenerating basal fragments, although both fragments contained a part of the branchial sac, suggesting that apoptosis is unilateral at the wound site and the presence of branchial sac stem cells is insufficient for regeneration. (biologists.com)
Progenitor cells3
In vertebrates, the Islet family of LIM-homeobox transcription factors is known to be involved in the proliferation, maintenance and migration of stem and progenitor cells in a range of tissues. (riken.jp)
The upregulation of HSP70 chaperone genes was verified and their expression confirmed in BS vasculature cells previously identified as stem and progenitor cells. (biomedcentral.com)
Inhibition of apoptosis did not affect branchial sac stem cell proliferation but prevented the survival of progenitor cells. (biologists.com)
Regenerative5
Here, we identify a positive feedback mechanism encoding posterior identity in the axolotl limb, which can be used to newly encode positional memory in regenerative cells. (sciety.org)
Because modifying positional memory changes signalling outputs from regenerative cells, our findings have wider implications for tissue engineering. (sciety.org)
The results of these experiments - indicating that axolotl limbs use Hand2 as a memory marker for positional identity - would be interesting to explore in other regenerative, partially-regenerative, and non-regenerative organisms. (sciety.org)
Blastema cells are not derived from stem cells but behave as such, because they are slow-cycling and are thought to provide rapidly proliferating daughter cells that drive regenerative outgrowth. (elsevierpure.com)
Atta-ur-Rahman, Shazia Anjum , " Frontiers in Stem Cell and Regenerative Medicine Research ", Bentham Science Publishers (2017). (eurekaselect.com)
Posterior9
The molecular properties that distinguish anterior and posterior cells prior to injury, which enable them to initiate different signalling centres after amputation, are not known. (sciety.org)
Posterior cells express residual levels of the bHLH transcription factor Hand2 from development and this is a priming molecule necessary and sufficient to establish a Shh signalling centre after limb amputation. (sciety.org)
Posterior cells are stabilised against anteriorisation as their expression of Hand2 poises them to trigger the Hand2-Shh loop. (sciety.org)
Our results implicate positive feedback in the stability of positional memory and explain why positional memory is more easily altered in one direction (anterior to posterior) than the other. (sciety.org)
In this manuscript, the authors use RNA-sequencing, lineage tracing, and pharmacological treatments to identify the molecular basis of anterior-posterior positional memory in salamanders. (sciety.org)
Taken together, these results indicate that anterior blastema cells readily acquire a posterior memory, while posterior blastema cells retained their posterior memory in this transplantation assay. (sciety.org)
A new study by Tetsutaro Hayashi and others in the Genome Resource and Analysis Unit (Fumio Matsuzaki, Unit Leader) now reveals an additional factor, encoded by a planarian LIM- homeobox gene known as Djislet , is required for the posterior differentiation of Wnt-expressing cells. (riken.jp)
Moreover, in Djislet(RNAi) worms, the expression of Djwnt1/P-1 disappeared from the posterior blastema, suggesting that this gene functions downstream of the Islet function. (riken.jp)
These findings collectively point to a role for Islet via Wnt signaling in the maintenance and activation of posterior genes in differentiating blastema cells for tail formation. (riken.jp)
Tissue5
Mesenchymal cells derived from the dermomyotome condense within connective tissue (mesenchymal) scaffolds to form 2 common muscle masses. (medscape.com)
Strategies include the rearrangement of pre-existing tissue, the use of adult somatic stem cells and the dedifferentiation and/or transdifferentiation of cells, and more than one mode can operate in different tissues of the same animal. (wikipedia.org)
During this process, leukocytes lose lineage-associated markers home and undergo homocytic aggregation, upregulate expression of stem cell antigens, and subsequently redifferentiate to give rise original tissue or, transdifferentiate into a different tissue altogether. (eurekaselect.com)
The robustness and efficacy of the retrodifferentiation process in generating unprecedented quantities of stem cells belonging to the three germ layers will enable organ and tissue reconstruction ex vivo, using bio-printing and various scaffold materials. (eurekaselect.com)
In both processes, rapid proliferation gives rise to new tissue, cell fate has to be specified within that tissue, and distinct positional identities have to be established to generate a properly patterned structure. (frontiersin.org)
Proliferation1
Amputation-induced proliferation occurred predominantly within the epidermal and intestinal epithelium, as well as wound-adjacent muscle fibers, where clusters of cells at the same stage of the cell cycle were found. (mdpi.com)
Regenerate2
After the limb or tail has been autotomized, cells move into action and the tissues will regenerate. (wikipedia.org)
Neural cells, for example, express growth-associated proteins, such as GAP-43, tubulin, actin, an array of novel neuropeptides, and cytokines that induce a cellular physiological response to regenerate from the damage. (wikipedia.org)
Molecular basis1
The molecular basis of blastema formation is not understood. (elsevierpure.com)
Genes2
873 During the developmental process, genes are activated that serve to modify the properties of cell as they differentiate into different tissues. (wikipedia.org)
This positional information is thought to be conferred by gradients in the expression of various genes that activate, modulate or inhibit cell differentiation. (riken.jp)
Stress2
In addition, mtDNA stress in TFAM-deficient mouse melanoma cells produces tumours that are more resistant to doxorubicin in vivo. (regenerativemedicine.net)
Therefore, we propose that damage to and subsequent release of mtDNA elicits a protective signalling response that enhances nDNA repair in cells and tissues, suggesting that mtDNA is a genotoxic stress sentinel. (regenerativemedicine.net)
Apoptosis1
hsp60 expression is increased during formation of blastema cells, and dysfunction leads to mitochondrial defects and apoptosis in these cells. (elsevierpure.com)
Branchial sac1
Branchial sac-derived stem cells also replenish recycling cells lining the pharyngeal fissures during homeostatic growth. (biologists.com)
Tissues1
The formation of new cells, tissues, and organs enables animals to recover from day-to-day wear and tear, injury, and disease. (cshlpress.com)
Stem cell3
In response to ligation of monomorphic regions of MHC class II antigens with monoclonal antibody CR3/43, human leukocytes retrodifferentiate into a variety of heterogeneous stem cell types belonging to the mesoderm, ectoderm or endoderm lineage, depending on culture media and conditions. (eurekaselect.com)
The ease by which various stem cell types can be generated from human peripheral blood has allowed the design of various kits to guarantee the specificity, sterility and efficacy of stem cells production for various clinical and research applications. (eurekaselect.com)
Importantly, this second phase is senstitive to γ-ray irradiation, suggesting that it involves stem cell-derived cells. (riken.jp)
Mesenchymal2
[ 2 ] It is 2-5 cells thick and covers a layer of undifferentiated, proliferating mesenchymal cells 5-15 cells thick. (medscape.com)
During the fifth week, differentiating mesenchymal cells condense in a proximal-to-distal fashion to form blastemas, which eventually develop into cartilaginous models of, ultimately, the bones of the upper extremity. (medscape.com)
Pattern formation in the morphogenesis of an animal is regulated by genetic induction factors that put cells to work after damage has occurred. (wikipedia.org)
Here, we show that heat-shock protein 60 (hsp60) is required for blastema formation and maintenance. (elsevierpure.com)
Clinical1
The hematopoietic retrodifferentiated stem cells have been shown to engraft an animal host in two proofs of principle clinical studies, demonstrating long-term engraftment and safety in acquired aplastic anaemia, while transient amelioration of beta thalassemia major was also observed. (eurekaselect.com)
Experiments1
However, experiments demonstrate that even at this early stage, cells are already polarized in some sense and carry positional information. (medscape.com)
Identity1
I found Fig. 5, in which the authors visually demonstrate reprogramming of cell identity by recruitment to the blastema, to be particularly beautiful in terms of the simplicity and clarity of the results. (sciety.org)
Organs1
Once wounded, their cells become activated and restore the organs back to their pre-existing state. (wikipedia.org)
Integration1
Upon blastema integration, positioning and expansion, constituent cells embark on redifferentiation and remorphogenesis to restore the lost appendage. (eurekaselect.com)
Results1
Positional cloning and mutational analyses revealed that nbl results from a V324E missense mutation in hsp60. (elsevierpure.com)
Structures1
Thousands of copies of the circular mtDNA are present in most cell types that are packaged by TFAM into higher-order structures called nucleoids1. (regenerativemedicine.net)
Activation1
In cultured primary fibroblasts and cancer cells, the chemotherapeutic drug doxorubicin causes mtDNA damage and release, which leads to cGAS STING dependent ISG activation. (regenerativemedicine.net)