Mechanisms and Translational Applications of Regeneration in Limbs: From Renewable Animals to Humans

Annals of Anatomy - Anatomischer Anzeiger, Journal Year: 2024, Volume and Issue: 255, P. 152288 - 152288

Published: May 31, 2024

Language: Английский

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Lmx1b activation in axolotl limb regeneration

Developmental Dynamics, Journal Year: 2022, Volume and Issue: 251(9), P. 1509 - 1523

Published: April 11, 2022

Axolotls can regenerate their limbs. In limb regeneration process, developmental genes are re-expressed and reorganize the axes, in which position-specific properly re-expressed. However, how such position specificity is reorganized processes has not been clarified. To address this issue, we focused on reactivation process of Lmx1b, determines dorsal identity many animals.Here, show that Lmx1b expression maintained skin before amputation activated after amputation. Furthermore, demonstrate only cells located side prior to could reactivate We also found activation was achieved by nerve presence. The factors, BMP2+FGF2+FGF8 (B2FF), consistently when applied skin.These results imply retained intact plays a role positional memory, instruct about spatial positioning This memory reactivated nerves or factors trigger entire process. Our findings highlight amphibian regeneration, including both initiation gene expression.

Language: Английский

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In preprints: cellular memory – the tension between old and new identities in the blastema

Development, Journal Year: 2024, Volume and Issue: 151(1)

Published: Jan. 1, 2024

During salamander limb regeneration, a blastema – mass of progenitor cells forms at the site amputation. The proliferates, differentiates and is patterned to form regenerated tissues (McCusker et al., 2015) in process that has often been compared initial development limb. Indeed, there are many important molecular parallels between developmental bud; however, regeneration presents with unique challenges not present during development. development, bud follows consistent progression steps, emerging from predefined position specific time animal's Regeneration, by contrast, must restore missing structures, composition size which varies greatly injury as animal increases through growth 2015). Crucially, correctly establish its along proximodistal axis for precise replacement components. Further, orientation coordinates, such dorsoventral anterior-posterior axes, be properly specified regenerate appropriate structures correctly, largely achieved redeployment fibroblast factor (FGF), sonic hedgehog (SHH) bone morphogenetic protein (BMP) signaling gradients, but increasing evidence supports hypothesis population mature retains positional memory their migration into instructs patterning 2015; Otsuki Tanaka, 2021). Until recently, identity mechanisms cell remained mysterious.In preprint, colleagues make compelling case group Hand2-expressing dermal fibroblasts posterior may represent seat this axolotl (Ambystoma mexicanum) (Otsuki 2023 preprint). Hand2 transcription activates Shh expression zone posteriorizing activity (ZPA) then initiates regulatory cascade directs polarity developing (Charité 2000). Through transcriptomics several sophisticated reporter animals, demonstrate that, whereas gene fades shortly after maintains study uses inducible Cre reporters trace lineage expressed real-time express regeneration. authors find descended Shh-expressing ZPA do not, whole, major contribution regenerating In they see those later enriched regenerative ZPA.Having found give rise within ZPA, sought examine whether functionally required role, using CRISPR mutagenesis. 45% F0Hand2 CRISPants displayed defects were seen controls. These amplified 75% showing defects. mosaic knockout reduces degree disruption correlates severity both phenotypes. also tested ability CRISPant tissue accessory model (ALM). ALM, skin grafted an innervated wound anterior part limb; wild-type induces ectopic graft (Carlson, 1974; Endo 2004). does induce limb, suggesting activity. overexpressed Prrx1-promoter driven Hand2; Prrx1 throughout mesenchyme. F0 saw range phenotypes polydactyly formation limbs, indicating overexpression sufficient expression. Anterior animals strong induced limbs when transplanted weak did not. Together, these results suggest necessary regeneration.With likely carries memory, could reprogram They created Alx4-mCherry label Hand2-GFP tissue. Alx4-expressing When anterior, stopped expressing Alx4 began Shh, can reprogrammed Conversely, continued locations, once programmed, becomes fixed. performed similar experiments presence inhibition, agonists, finding expression, potentially enforcing fixed regeneration.Considering results, speculate specifies bud, initiating long-lasting small subpopulation cells. model, retain axolotl's life, allowing it recall events. Recent transcriptional lineage-tracing studies transition arguably some previous identities: although most origin, other contribute blastema. populations distinct identities entire process, giving same derived (Kragl 2009; Currie 2016; Choi 2017; Flowers Gerber 2018; Leigh 2018). combined recent findings colleagues, picture emerges have discrete aspects identities, despite undergoing drastic changes behavior, morphology Inevitably, reprogrammed, because no way fingers stubbornly elbow memories, and, arguably, profound preprint pertain reprogramming. cellular identity, more 'stubborn' than others, Alx4, identity. beautifully illustrate (in figure 5d), competence limited state. An obvious future direction circuitry perhaps interesting massively upregulates response injury, allows reprogramming Another our shows amputation triggers body-wide proliferation axolotls, priming creation (Payzin-Dogru 2023). As already primed would respond systemic signals provoked Ultimately, field will benefit we elucidate different origins descendent heed common call enter

Language: Английский

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David L. Stocum (1939-2023): Authority in regenerative biology, passionate educator, visionary administrative leader, and cherished colleague and friend

Developmental Biology, Journal Year: 2024, Volume and Issue: 512, P. 89 - 92

Published: May 15, 2024

Language: Английский

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Unbiased profiling of multipotency landscapes reveals spatial modulators of clonal fate biases

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 17, 2024

Abstract Embryogenesis is commonly viewed through a tree model of cell differentiation, which does not adequately represent the spatiotemporal modulation multipotency underlying morphogenesis. Here we develop an integrated approach, combining in vivo single-cell high-throughput clonal lineage tracing with machine learning, to systematically decompose continuous spectra fate biases mouse embryos traced from neurulation until mid-gestation. The reconstructed patterns variation uncovered gene programs driving dynamic positional biasing composition during axial skeletogenesis and peripheral neurogenesis. Mosaic combinatorial perturbations targeting multiple receptors, including Hedgehog pathway, led novel clone types, has implications for engineering custom type assemblages well-defined progenitors . Altogether, our work demonstrates effective practical approach interrogating guiding specification.

Language: Английский

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An overview of recent progress in the molecular mechanisms and key biological macromolecules involved in limb regeneration of decapods

International Journal of Biological Macromolecules, Journal Year: 2024, Volume and Issue: 292, P. 139354 - 139354

Published: Dec. 30, 2024

Language: Английский

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In vivoassessment of mechanical properties during axolotl development and regeneration using confocal Brillouin microscopy

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: March 4, 2022

ABSTRACT In processes such as development and regeneration, where large cellular tissue rearrangements occur, cell fate behavior are strongly influenced by mechanics. While most well-established tools probing mechanical properties require an invasive sample preparation, confocal Brillouin microscopy captures parameters optically with high resolution in a contact-free label-free fashion. this work, we took advantage of tool the transparency highly regenerative axolotl to probe its vivo for first time. We mapped frequency shift developing limbs regenerating digits, studied structures axolotl. detected gradual increase cartilage shift, suggesting decreasing compressibility during both regeneration. Moreover, were able correlate regeneration stage, which was undetected fluorescence imaging. The present work evidences potential unravel changes occurring axolotls, setting basis apply technique growing field epimorphic

Language: Английский

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The shh limb enhancer is activated in patterned limb regeneration but not in hypomorphic limb regeneration in Xenopus laevis

Developmental Biology, Journal Year: 2023, Volume and Issue: 500, P. 22 - 30

Published: May 27, 2023

Language: Английский

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Theshhlimb enhancer is activated in patterned limb regeneration but not in hypomorphic limb regeneration inXenopus laevis

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Dec. 29, 2022

ABSTRACT Xenopus young tadpoles regenerate a limb with the anteroposterior (AP) pattern, but metamorphosed froglets hypomorphic after amputation. The key gene for AP patterning, shh , is expressed in regenerating of tadpole not that froglet. Genomic DNA limb-specific enhancer, MFCS1 (ZRS), hypermethylated hypomethylated tadpoles: expression may be controlled by epigenetic regulation MFCS1. Is specifically activated AP-patterned limb? We generated transgenic laevis lines visualize enhancer activity GFP reporter. showed hoxd13- and shh- expressing domains developing limbs, whereas no limbs despite having hoxd13 expression. Genome sequence analysis co-transfection assays using cultured cells revealed Hoxd13 can activate These results suggest activation correlates regeneration re-activation epigenetically inactivated would crucial to confer ability non-regenerative animals properly patterned limb.

Language: Английский

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Investigating cell cycle regulation and morphogenesis during axolotl limb development and regeneration

Published: Jan. 1, 2021

Mammals, including humans, are severely limited in their capability for limb regeneration, only being able to regenerate amputated digit tips. Axolotl salamanders (Ambystoma mexicanum), however, whole, functional limbs following amputation. For this reason, regeneration the axolotl is a strong model understanding how elicit more robust regenerative response mammals. The process by which axolotls broadly occurs three steps: wound healing, blastema formation/proliferation, and patterning. In dissertation, I focus on latter two steps. my first chapter, provide brief overview of with cell cycling patterning during while relating embryonic development. second present published work from collaboration between Monaghan Shefelbine Labs outlining method dimensional volumetric imaging macromolecule synthesis whole mount tissues. Using method, we quantify rate DNA innervated denervated blastemas show that transection nerve supply slows synthesis. chapter three, revision where generated ubiquitous FUCCI (fluorescent ubiquitination-based cycle indicator) transgenic reports state in-vivo. This animal line enables discrimination cells G1 phase S/G2/M phases. By using line, were live image formation, demonstrate local contribution blastema, arrest denervation. My next chapters four, retinoic acid (RA) breakdown required positional identity distally limbs, but not proximally limbs. If RA perturbed distal observe duplications proximal segments We proximalization due molecular reprogramming it requires de-novo signaling proximalize. Limb often described as recapitulation Thus, explore development five. utilize hybridization chain reaction fluorescence in-situ (HCR FISH) evidence an evolutionarily novel mechanisms whereby produced bud, unlike amniotes. speculate difference may contribute axolotl's lifelong capabilities absent final outline future directions presented through all, dissertation should foundation many studies will hopefully improving humans.--Author's abstract

Language: Английский

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