AmputationAppendage regenerationXenopusAmong vertebratesTadpoleTadpolesHindlimbTissue regenerationTailAmphibiansTissuesDigitEarlyRequiresFormAbility to regrowDedifferentiationAxolotlVertebratesInnervateOrgansTissueSpeciesCordMammalsStructuresFormationProcessesHumansProteinsCellsProcessCellResultsImportanceFullyStudies
Amputation5
- Just as plant cells respond to injury by undergoing callus formation via dedifferentiation, some animal models dedifferentiate their cells to form blastema, which are analogous to plant calluses, after limb amputation. (wikipedia.org)
- The wound epithelium of N1 transgenic hindlimb buds, which forms over the cut surface of the limb bud after amputation, does not transition normally into the distal thickened apical epithelial cap. (biomedcentral.com)
- N1 transgenic hindlimbs, which do not regenerate, do not form an apical epithelial cap or cone shaped blastema following amputation. (biomedcentral.com)
- In mammals, a limb amputation or spinal cord transection is followed by inflammation and fibrotic scarring that leaves the animal with a permanent disability. (frontiersin.org)
- We examined the bioelectric properties (resting potential gradients in the epidermis) of Xenopus laevis froglets undergoing hindlimb amputation and observed that the contralateral (undamaged) limb exhibits apparent depolarization signals immediately after the opposite hindlimb is amputated. (biologists.com)
Appendage regeneration2
- We have used this line to show that BMP function is not only required for appendage regeneration but that it is specifically needed to generate a proliferating blastema while being dispensable for wound healing [ 12 ]. (biomedcentral.com)
- Appendage regeneration, particularly of the tadpole tail, has been widely studied before, during and after this period. (frontiersin.org)
Xenopus8
- This type of regeneration is rare among vertebrates but does occur in the African clawed frog Xenopus laevis , traditionally a model organism for the study of early development. (biomedcentral.com)
- Xenopus tadpoles can regenerate their tails, limb buds and the lens of the eye, although the ability of the latter two organs to regenerate diminishes with advancing developmental stage. (biomedcentral.com)
- Activation of this transgene blocks regeneration of the tail and limb of Xenopus tadpoles. (biomedcentral.com)
- Gene Ontology analysis showed that genes involved in embryonic development and growth are significantly over-represented in regenerating early hindlimb buds and that successful regeneration in the Xenopus hindlimb correlates with the induction of stress response pathways. (biomedcentral.com)
- Gene over-expression analyses in Xenopus limb and tail regeneration have indicated that successful regeneration requires the re-activation of developmental FGF or BMP signalling pathways [ 8 - 12 ]. (biomedcentral.com)
- We have developed a heat shock inducible transgenic line ( N1 ) of Xenopus in which the BMP antagonist Noggin can be induced at a specific time during either development or regeneration, repressing BMP signalling [ 10 , 12 ]. (biomedcentral.com)
- The frogs Xenopus laevis and Xenopus tropicalis undergo temporally restricted regenerative healing of appendage amputations and spinal cord truncations, injuries that are both devastating and relatively common in human patients. (frontiersin.org)
- Here we review recent insights into the biophysical, biochemical, and epigenetic processes that underlie regenerative healing in amphibians, focusing particularly on tail and limb regeneration in Xenopus . (frontiersin.org)
Among vertebrates1
- Injuries that sever tissues such as the limb or spinal cord are met with radically different outcomes among vertebrates. (frontiersin.org)
Tadpole3
- Downregulation of the BMP pathway led to a downregulation of MSx1, resulting in no regeneration in the tadpole. (wikipedia.org)
- The Notch1 [8] pathway has demonstrated importance in regeneration of frog tadpole tails. (wikipedia.org)
- Lowered Notch1 expression resulted in no tadpole tail regeneration, and induced Notch1 expression was able to partially rescue tail regeneration in the form of notochord and spinal cord (but very little musculature. (wikipedia.org)
Tadpoles1
- The BMP pathway has been shown to be necessary for dedifferentiation and regeneration in tadpoles. (wikipedia.org)
Hindlimb1
- Comparison of gene expression in stage matched N1 vs. wild type hindlimb buds has revealed several new targets for regeneration research. (biomedcentral.com)
Tissue regeneration1
- While all vertebrates are capable of some types of tissue regeneration, most, including humans, have lost the ability to regenerate whole structures such as limbs ( epimorphic regeneration ), [ 1 ]. (biomedcentral.com)
Tail1
- Elegant experiments using heat-shock inducible expression of inhibitory proteins have further refined these observations to establish epistatic relationships, in which BMP acts upstream of Wnt, which in turn acts upstream of FGF during regeneration of the limb bud and tail ( Lin and Slack, 2008 ). (frontiersin.org)
Amphibians1
- In urodele amphibians such as axolotls and newts, the same injury is followed by scarless regenerative healing that can fully restore both the lost tissue and its function (reviewed in Tanaka, 2016 ). (frontiersin.org)
Tissues2
- Once the wound is healed, the cells of the stump must mobilise under the wound epidermis and begin the process of replacing lost tissues, by forming a proliferating blastema. (biomedcentral.com)
- The pattern of depolarization matches that of the amputated limb and is correlated to the position and type of injury, revealing that information about damage is available to remote body tissues and is detectable non-invasively in vivo by monitoring the bioelectric state. (biologists.com)
Digit1
- Once BMP expression was restored, Msx1 expression was also restored, and regeneration proceeded.19 Similar studies have shown similar results in mouse digit tip regeneration. (wikipedia.org)
Early2
- For example, MMP, the matrix metalloproteinase, has shown up-regulated activity during early stages of limb regeneration. (wikipedia.org)
- It is well-established that early embryonic signaling pathways are critical for growth and patterning of new tissue during regeneration. (frontiersin.org)
Requires1
- Regeneration of damaged body parts requires coordination of size, shape, location and orientation of tissue with the rest of the body. (biologists.com)
Form1
- Furthermore, the underlying mesenchyme remains rounded and does not expand to form a cone shaped blastema, a normal feature of successful regeneration. (biomedcentral.com)
Ability to regrow2
- Aside from being used to generally describe any number of specific healing processes, regeneration also is a specific method of healing that is noted for its ability to regrow lost limbs, severed nerve connections, and other wounds that mammals cannot heal. (academickids.com)
- Some lower order vertebrates such as salamanders and newts have the ability to regrow severed limbs through a process called epimorphic regeneration. (nih.gov)
Dedifferentiation5
- In another, injection of a solution of tissue taken from a newt's blastema into a rat's wound duplicated many of the elements of dedifferentiation. (academickids.com)
- The pathways discussed below are found to be closely related to dedifferentiation and regeneration in some species. (wikipedia.org)
- Because not one pathway has been elucidated as necessary for all dedifferentiation and regeneration, it is possible that the mechanism functions differently in different species. (wikipedia.org)
- The BMP pathway has been shown to be necessary for dedifferentiation and regeneration in tadpoles. (wikipedia.org)
- The epimorphic regeneration process occurs through the formation of a blastema, a process that includes dedifferentiation, trans-differentiation, migration of adult stem cells to the site of injury and other morphogenetic events permissive of proper tissue growth and patterning. (nih.gov)
Axolotl3
- Limb regeneration in the axolotl has been extensively studied. (academickids.com)
- The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. (nih.gov)
- Upon injury the axolotl generates a population of regeneration-competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. (nih.gov)
Vertebrates4
- It is a common feature in invertebrates , such as worms , but the only vertebrates known to have a significant ability for regeneration is the urodeles . (academickids.com)
- In contrast, regeneration appears to be severely limited in higher level vertebrates. (nih.gov)
- The current state of the science suggests that focused investment in research on key aspects of epimorphic regeneration is necessary for developing strategies to regenerate limbs in higher vertebrates and mammals including humans. (nih.gov)
- In summary, to directly address an aspirational goal of the NICHD Strategic Plan, the proposed initiative is primarily focused on gaining insight on the body's own growth pathways and processes that can be manipulated to promote limb regeneration in higher vertebrates (including mammals) that might otherwise lack the capacity for regeneration. (nih.gov)
Innervate2
- Motor neurons grow with the regenerated limb, and innervate the same target muscles they originally controlled. (academickids.com)
- We found that, after spinal cord transection, which silences the electromotor neurons that innervate the electrocytes, or destruction of the spinal cord, which denervates the electrocytes, mature electrocytes re-express sarcomeric myosin and tropomyosin, although keratin expression persists. (biologists.com)
Organs4
- Regeneration is the ability to restore lost or damaged tissues, organs or limbs. (academickids.com)
- They were also aware that electric organs are embryologically derived from striated muscle. (biologists.com)
- He noted that electric organs pose a potential problem for the theory of evolution by natural selection since it is difficult to account for the adaptive value of a muscle in a transitional state no longer serving a contractile function, but perhaps not yet being a fully functional electric organ. (biologists.com)
- Thus, we may paraphrase Darwin and ask: how do electric organs develop from muscle and how have they developed in each lineage? (biologists.com)
Tissue3
- During aging, numerous tissues exhibit a progressive decline in homeostasis and regeneration that results in tissue degeneration, malfunction and pathology. (mdpi.com)
- Understanding how these mechanisms impact on regenerative processes is essential to devise therapeutic approaches to improve tissue regeneration and extend healthspan. (mdpi.com)
- In mammals, for example, wound healing in response to injury typically leads to scarring/fibrotic tissue formation, rather than regeneration. (nih.gov)
Species2
- In this review we focus on the crucial early events that occur during wound healing, the neural-epithelial interactions that drive the formation of the early blastema, and how these mechanisms differ from those of other species that have restricted regenerative potential, such as humans. (nih.gov)
- Next, we used clodronate liposomes to deplete macrophages, which inhibited lens regeneration in both newt species. (bvsalud.org)
Cord1
- Lowered Notch1 expression resulted in no tadpole tail regeneration, and induced Notch1 expression was able to partially rescue tail regeneration in the form of notochord and spinal cord (but very little musculature. (wikipedia.org)
Mammals1
- This is not possible in mammals because there are specific factors, still being explored, that inhibit the expression of regeneration. (academickids.com)
Structures1
- Distal structures such as toes form first from the blastema. (academickids.com)
Formation2
- This results in the formation of a blastema - or a layer of dedifferentiated cells. (academickids.com)
- At the same time, pattern formation genes - such as Hox A and HoxD - are activated as they were when the limb was formed in the embryo. (academickids.com)
Processes3
- If the processes behind regeneration are fully understood, it is believed this would lead to better treatment for individuals with nerve injuries, broken backs, paralysis, and missing limbs. (academickids.com)
- In addition, it raised the question as to whether the electric organ evolved from muscle by similar or different processes in each lineage. (biologists.com)
- This initiative addresses the Aspirational Goal in the NICHD Strategic Plan titled advancing the ability to regenerate human limbs by using emerging technology to activate the body's own growth pathways and processes. (nih.gov)
Humans1
- Nevertheless, even humans possess some degree of regeneration ability. (academickids.com)
Proteins1
- Electrocytes briefly co-express sarcomeric proteins, such as myosin and tropomyosin, and keratin, a protein not found in mature muscle. (biologists.com)
Cells2
- We also discuss how the presence of cells from the different axes of the limb is required for the continued growth and establishment of pattern in the blastema as described in the polar coordinate model, and how this positional information is reprogrammed in blastema cells during regeneration. (nih.gov)
- Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration, and we discuss the contribution of these types to the regenerate with reference to whether they are "pattern-forming" or "pattern-following" cells. (nih.gov)
Process3
- The entire process takes around 3 month in the adult - and the limb becomes fully functional. (academickids.com)
- Although the process has been investigated in many labs using a variety of models and approaches, the identity of key regulators of wound repair and regeneration remain unknown. (nih.gov)
- Re-injury alleviated the effects of macrophage depletion and re-started the regeneration process. (bvsalud.org)
Cell2
- In one test involving rats, blocking two of these factors led to greatly increased nerve cell healing in severed spinal chords. (academickids.com)
- How does a differentiated muscle cell change its fate to become an electrocyte? (biologists.com)
Results1
- Once BMP expression was restored, Msx1 expression was also restored, and regeneration proceeded.19 Similar studies have shown similar results in mouse digit tip regeneration. (wikipedia.org)
Importance1
- The Notch1 [8] pathway has demonstrated importance in regeneration of frog tadpole tails. (wikipedia.org)
Fully1
- Electrocytes arise from the fusion of fully differentiated muscle fibers, mainly those expressing fast isoforms of myosin. (biologists.com)
Studies1
- Previous studies indicated that macrophages play a role during lens regeneration in newts, but their function has not been tested experimentally. (bvsalud.org)