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Alibardi L. Progressive modifications during evolution involving epigenetic changes have determined loss of regeneration mainly in terrestrial animals: A hypothesis. Dev Biol 2024; 515:169-177. [PMID: 39029569 DOI: 10.1016/j.ydbio.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/10/2024] [Accepted: 07/17/2024] [Indexed: 07/21/2024]
Abstract
In order to address a biological explanation for the different regenerative abilities present among animals, a new evolutionary speculation is presented. It is hypothesized that epigenetic mechanisms have lowered or erased regeneration during the evolution of terrestrial invertebrates and vertebrates. The hypothesis indicates that a broad regeneration can only occur in marine or freshwater conditions, and that life on land does not allow for high regeneration. This is due to the physical, chemical and microbial conditions present in the terrestrial environment with respect to those of the aquatic environment. The present speculation provides examples of hypothetic evolutionary animal lineages that colonized the land, such as parasitic annelids, terrestrial mollusks, arthropods and amniotes. These are the animals where regeneration is limited or absent and their injuries are only repaired through limited healing or scarring. It is submitted that this loss derived from changes in the developmental gene pathways sustaining regeneration in the aquatic environment but that cannot be expressed on land. Once regeneration was erased in terrestrial species, re-adaptation to freshwater niches could not reactivate the previously altered gene pathways that determined regeneration. Therefore a broad regeneration was no longer possible or became limited and heteromorphic in the derived, extant animals. Only in few cases extensive healing abilities or regengrow, a healing process where regeneration overlaps with somatic growth, have evolved among arthropods and amniotes. The present paper is an extension of previous speculations trying to explain in biological terms the different regenerative abilities present among metazoans.
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2
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Jonz MG. Cell proliferation and regeneration in the gill. J Comp Physiol B 2024; 194:583-593. [PMID: 38554225 DOI: 10.1007/s00360-024-01548-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/02/2024] [Accepted: 02/29/2024] [Indexed: 04/01/2024]
Abstract
Seminal studies from the early 20th century defined the structural changes associated with development and regeneration of the gills in goldfish at the gross morphological and cellular levels using standard techniques of light and electron microscopy. More recently, investigations using cell lineage tracing, molecular biology, immunohistochemistry and single-cell RNA-sequencing have pushed the field forward and have begun to reveal the cellular and molecular processes that orchestrate cell proliferation and regeneration in the gills. The gill is a multifunctional organ that mediates an array of important physiological functions, including respiration, ion regulation and excretion of waste products. It is comprised of unique cell types, such as pavement cells, ionocytes, chemoreceptors and undifferentiated stem or progenitor cells that regulate growth and replenish cell populations. The gills develop from the embryonic endoderm and are rich in cell types derived from the neural crest. The gills have the capacity to remodel themselves in response to environmental change, such as in the case of ionocytes, chemoreceptors and the interlamellar cell mass, and can completely regenerate gill filaments and lamellae. Both processes of remodeling and regeneration invariably involve cell proliferation. Although gill regeneration has been reported in only a limited number of fish species, the process appears to have many similarities to regeneration of other organs in fish and amphibians. The present article reviews the studies that have described gill development and growth, and that demonstrate a suite of genes, transcription factors and other proteins involved in cell proliferation and regeneration in the gills.
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Affiliation(s)
- Michael G Jonz
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt, Ottawa, ON, K1N 6N5, Canada.
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3
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Alibardi L. Regeneration Abilities among Extant Animals Depend on Their Evolutionary History and Life Cycles. J Dev Biol 2024; 12:8. [PMID: 38390959 PMCID: PMC10885101 DOI: 10.3390/jdb12010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
The present brief manuscript summarizes the main points supporting recently proposed hypotheses explaining the different distributions of regenerative capacity among invertebrates and vertebrates. The new hypotheses are based on the evolution of regeneration from marine animals to the terrestrial animals derived from them. These speculations suggest that animals that were initially capable of broad regeneration in the sea underwent epigenetic modifications during terrestrial adaptation that determined the loss of their regenerative abilities in sub-aerial conditions. These changes derived from the requirements of life on land that include variable dry and UV-exposed conditions. Terrestrial conditions do not allow for organ regeneration, especially in arthropods and amniotes. Nematodes, the other main metazoan group unable of regeneration, instead evolved eutely (a fixed number of body cells), a process which is incompatible with regeneration. All these changes involved gene loss, modification and new gene interactions within the genomes of terrestrial adapting animals that gave rise to sophisticated invertebrates and vertebrates adapted to living on land but with low cellular plasticity.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova, 35100 Padova, Italy
- Department of Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
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Markitantova YV, Grigoryan EN. Cellular and Molecular Triggers of Retinal Regeneration in Amphibians. Life (Basel) 2023; 13:1981. [PMID: 37895363 PMCID: PMC10608152 DOI: 10.3390/life13101981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023] Open
Abstract
Understanding the mechanisms triggering the initiation of retinal regeneration in amphibians may advance the quest for prevention and treatment options for degenerating human retina diseases. Natural retinal regeneration in amphibians requires two cell sources, namely retinal pigment epithelium (RPE) and ciliary marginal zone. The disruption of RPE interaction with photoreceptors through surgery or injury triggers local and systemic responses for retinal protection. In mammals, disease-induced damage to the retina results in the shutdown of the function, cellular or oxidative stress, pronounced immune response, cell death and retinal degeneration. In contrast to retinal pathology in mammals, regenerative responses in amphibians have taxon-specific features ensuring efficient regeneration. These include rapid hemostasis, the recruitment of cells and factors of endogenous defense systems, activities of the immature immune system, high cell viability, and the efficiency of the extracellular matrix, cytoskeleton, and cell surface remodeling. These reactions are controlled by specific signaling pathways, transcription factors, and the epigenome, which are insufficiently studied. This review provides a summary of the mechanisms initiating retinal regeneration in amphibians and reveals its features collectively directed at recruiting universal responses to trauma to activate the cell sources of retinal regeneration. This study of the integrated molecular network of these processes is a prospect for future research in demand biomedicine.
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Affiliation(s)
| | - Eleonora N. Grigoryan
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
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Tajer B, Savage AM, Whited JL. The salamander blastema within the broader context of metazoan regeneration. Front Cell Dev Biol 2023; 11:1206157. [PMID: 37635872 PMCID: PMC10450636 DOI: 10.3389/fcell.2023.1206157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/26/2023] [Indexed: 08/29/2023] Open
Abstract
Throughout the animal kingdom regenerative ability varies greatly from species to species, and even tissue to tissue within the same organism. The sheer diversity of structures and mechanisms renders a thorough comparison of molecular processes truly daunting. Are "blastemas" found in organisms as distantly related as planarians and axolotls derived from the same ancestral process, or did they arise convergently and independently? Is a mouse digit tip blastema orthologous to a salamander limb blastema? In other fields, the thorough characterization of a reference model has greatly facilitated these comparisons. For example, the amphibian Spemann-Mangold organizer has served as an amazingly useful comparative template within the field of developmental biology, allowing researchers to draw analogies between distantly related species, and developmental processes which are superficially quite different. The salamander limb blastema may serve as the best starting point for a comparative analysis of regeneration, as it has been characterized by over 200 years of research and is supported by a growing arsenal of molecular tools. The anatomical and evolutionary closeness of the salamander and human limb also add value from a translational and therapeutic standpoint. Tracing the evolutionary origins of the salamander blastema, and its relatedness to other regenerative processes throughout the animal kingdom, will both enhance our basic biological understanding of regeneration and inform our selection of regenerative model systems.
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Affiliation(s)
| | | | - Jessica L. Whited
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, United States
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Kawasaki T, Fujimori KE, Imada J, Yuba S. Analysis of medaka GAP43 gene promoter activity in transgenic lines. Gene 2023:147590. [PMID: 37364694 DOI: 10.1016/j.gene.2023.147590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/03/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
We produced transgenic medaka fish lines that mimicked the expression of the GAP43 gene. Fish lines with the proximal 2-kilobase (kb) 5'-untranslated region (UTR) as the expression promoter specifically expressed enhanced green fluorescent protein (EGFP) in neural tissues, such as the brain, spinal cord, and peripheral nerves, and its expression decreased with growth, but persisted until adulthood. A functional analysis of the promoter using partially deleted UTRs revealed that functions related to neural tissue-specific promoter activity were widely distributed in the region upstream of the proximal 400-b. Furthermore, the distal half of the 2-kb UTR contributed to expression throughout the brain, while the region 400-b upstream of the proximal 600-b was strongly associated with expression in specific areas, such as the telencephalon. In addition, a region from 957 to 557 b upstream of the translation initiation site was important for the long-term maintenance of promoter activity into adulthood. Among the transcription factors with recognition sequences in this region, Sp1 and CREB1 have been suggested to play important roles in the GAP43 promoter expression characteristics, such as strong expression in the telencephalon and long-term maintenance of expression.
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Affiliation(s)
- Takashi Kawasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan
| | - Kazuhiro E Fujimori
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi, Tsukuba, Ibaraki 305-0046, Japan.
| | - Junko Imada
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan
| | - Shunsuke Yuba
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan.
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Alibardi L. Regeneration among animals: An evolutionary hypothesis related to aquatic versus terrestrial environment. Dev Biol 2023:S0012-1606(23)00112-4. [PMID: 37353104 DOI: 10.1016/j.ydbio.2023.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/31/2023] [Accepted: 06/21/2023] [Indexed: 06/25/2023]
Abstract
The present hypothesis tries to explain animal regeneration in relation to the life cycles and environment of different animals. Regeneration is a basic phenomenon present since the origin of life in the sea, as testimonial in lower or more complex extant marine animals. Aquatic animals that evolved an indirect development, forming larvae and transiting into the adult stage through metamorphosis, use gene networks present in their genome for these transformations. In case of injury or organ loss as adults, they can re-utilize most or part of the gene networks previously activated during larval growth and metamorphosis. In contrast, terrestrial animals that evolved life cycles with the elimination of larvae and metamorphosis for the adaptation to land conditions lost some of the genes implicated in these post-developmental processes and consequently also the ability to regenerate. Few arthropods and lizards are capable to form hydrated regenerative blastemas with a similar consistence of embryonic tissues. The present hypothesis submits that regeneration cannot be activated in the dry land environment and consequently was largely or completely abolished in terrestrial animals. After injury or organ loss, nematodes, most arthropods and terrestrial vertebrates can only form scars or a limited healing or regengrow in juveniles. This is a process where somatic growth is superimposed to wound healing so that the apparent regeneration derives from the combination from both processes. When full growth is terminated these terrestrial animals can only heal by scarring.
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Alibardi L. Regeneration or Scarring Derive from Specific Evolutionary Environmental Adaptations of the Life Cycles in Different Animals. BIOLOGY 2023; 12:biology12050733. [PMID: 37237545 DOI: 10.3390/biology12050733] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/13/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023]
Abstract
The ability to heal or even regenerate large injuries in different animals derives from the evolution of their specific life cycles during geological times. The present, new hypothesis tries to explain the distribution of organ regeneration among animals. Only invertebrates and vertebrates that include larval and intense metamorphic transformations can broadly regenerate as adults. Basically, regeneration competent animals are aquatic while terrestrial species have largely or completely lost most of the regeneration ability. Although genomes of terrestrial species still contain numerous genes that in aquatic species allow a broad regeneration ("regenerative genes"), the evolution of terrestrial species has variably modified the genetic networks linking these genes to the others that evolved during land adaptation, resulting in the inhibition of regeneration. Loss of regeneration took place by the elimination of intermediate larval phases and metamorphic transformations in the life cycles of land invertebrates and vertebrates. Once the evolution along a specific lineage generated species that could no longer regenerate, this outcome could not change anymore. It is therefore likely that what we learn from regenerative species will explain their mechanisms of regeneration but cannot or only partly be applied to non-regenerative species. Attempts to introduce "regenerative genes" in non-regenerative species most likely would disorder the entire genetic networks of the latter, determining death, teratomas and cancer. This awareness indicates the difficulty to introduce regenerative genes and their activation pathways in species that evolved genetic networks suppressing organ regeneration. Organ regeneration in non-regenerating animals such as humans should move to bio-engineering interventions in addition to "localized regenerative gene therapies" in order to replace lost tissues or organs.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, 40126 Bologna, Italy
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Paiola M, Dimitrakopoulou D, Pavelka MS, Robert J. Amphibians as a model to study the role of immune cell heterogeneity in host and mycobacterial interactions. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 139:104594. [PMID: 36403788 DOI: 10.1016/j.dci.2022.104594] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Mycobacterial infections represent major concerns for aquatic and terrestrial vertebrates including humans. Although our current knowledge is mostly restricted to Mycobacterium tuberculosis and mammalian host interactions, increasing evidence suggests common features in endo- and ectothermic animals infected with non-tuberculous mycobacteria (NTMs) like those described for M. tuberculosis. Importantly, most of the pathogenic and non-pathogenic NTMs detected in amphibians from wild, farmed, and research facilities represent, in addition to the potential economic loss, a rising concern for human health. Upon mycobacterial infection in mammals, the protective immune responses involving the innate and adaptive immune systems are highly complex and therefore not fully understood. This complexity results from the versatility and resilience of mycobacteria to hostile conditions as well as from the immune cell heterogeneity arising from the distinct developmental origins according with the concept of layered immunity. Similar to the differing responses of neonates versus adults during tuberculosis development, the pathogenesis and inflammatory responses are stage-specific in Xenopus laevis during infection by the NTM M. marinum. That is, both in human fetal and neonatal development and in tadpole development, responses are characterized by hypo-responsiveness and a lower capacity to contain mycobacterial infections. Similar to a mammalian fetus and neonates, T cells and myeloid cells in Xenopus tadpoles and axolotls are different from the adult immune cells. Fetal and amphibian larval T cells, which are characterized by a lower T cell receptor (TCR) repertoire diversity, are biased toward regulatory function, and they have distinct progenitor origins from those of the adult immune cells. Some early developing T cells and likely macrophage subpopulations are conserved in adult anurans and mammals, and therefore, they likely play an important role in the host-pathogen interactions from early stages of development to adulthood. Thus, we propose the use of developing amphibians, which have the advantage of being free-living early in their development, as an alternative and complementary model to study the role of immune cell heterogeneity in host-mycobacteria interactions.
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Affiliation(s)
- Matthieu Paiola
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Dionysia Dimitrakopoulou
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Martin S Pavelka
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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Alibardi L. Activation of cell adhesion molecules and Snail during epithelial to mesenchymal transition prior to formation of the regenerative tail blastema in lizards. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:56-67. [PMID: 35451552 DOI: 10.1002/jez.b.23139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/24/2022] [Accepted: 04/03/2022] [Indexed: 12/16/2022]
Abstract
After few days from tail amputation in lizards the stump is covered with mesenchymal cells accumulated underneath a wound epidermis and forms a regenerative blastema. During migration, some keratinocytes transit from a compact epidermis into relatively free keratinocytes in a process of "epithelial to mesenchymal transition" (EMT). EMT is also induced after damaging the regenerating epidermis by cauterization, whereas keratinocytes detach and migrate as mesenchymal-like cells among the superficial blastema cells and reconstruct a wound epidermis after about a week from the damage. In normal amputation or after cauterization, no malignant transformation is observed during the transition and migration of keratinocytes. Immunolabeling for markers of EMT confirms the histological description and shows a unique pattern of expression for l-CAM (E-cadherin), N-CAM, and SNAIL-1 and -2 (SLUG). These proteins are present in the cytoplasm and nuclei of migrating keratinocytes. It is hypothesized that the nuclear labeling for E-cadherin coupled to cytoplasmic SNAIL-labeling is somehow related to an initially regulated EMT. After the migrating keratinocytes have reached confluence over the stump, they reverse into a "mesenchymal to epithelial transition" (MET) forming the wound epidermis. The basal layers of the apical wound epidermis of the blastema show some nuclear E-cadherin labeling, while the tail regenerates. It is hypothesized that, together with other tumor suppressors proteins, the apical epidermis and mesenchyme are kept under a tight proliferative control, while in proximal regions the prevalent effect of tumor suppressors determine the differentiation of the new tail tissues.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Bologna, Italy
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Alibardi L. Immunolocalization of tumor suppressors arhgap28 and retinoblastoma in the lizard Podarcis muralis suggests that they contribute to the regulated regeneration of the tail. J Morphol 2022; 283:973-986. [PMID: 35708299 DOI: 10.1002/jmor.21484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/13/2022] [Accepted: 05/22/2022] [Indexed: 11/09/2022]
Abstract
Tail regeneration in lizards is an outstanding and unique postembryonic morphogenetic process. This developmental process is regulated by poorly known factors, but recent studies have suggested that it derives from a balanced activity between oncoproteins and tumor suppressors. Transcriptome and expression data have indicated that arhgap28 and retinoblastoma proteins are among the main tumor suppressors activated during tail regeneration. However, their cellular localization is not known. Therefore, in the present immunohistochemical study, two proteins have been detected in various tissues at the beginning of their differentiation. Both proteins are present especially in the new scales, axial cartilage, and muscle bundles of the regenerating tail, the main tissues forming the new tail. Sparse or occasionally labeled cells are observed in the blastema, but intense labeling is seen in the basal layers of the wound (regenerating) epidermis and in external differentiating epidermal layers. Numerous keratinocytes also show a nuclear localization for both proteins, suggesting that the latter may activate a gene program for tissue differentiation after the inhibition of cell multiplication. Based on microscopic, molecular, experimental, and in vitro studies, a hypothesis on the "inhibition of contact" among the apical cells of the blastema and those of proximal differentiating tissues is proposed to explain the permanence of an active blastema only at the apex of the regenerating tail without tail growth can degenerate into a tumorigenic outgrowth.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab, Padova, Italy.,Department of Biology, University of Bologna, Bologna, Italy
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12
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Alibardi L. Invited Letter. Organ regeneration occurs in vertebrates with aquatic-related life cycles including metamorphosis and was lost during land transition. Integr Comp Biol 2022; 62:121-123. [PMID: 35030244 DOI: 10.1093/icb/icac004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Italy
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Alibardi L. Review. Limb regeneration in lizards under natural and experimental conditions with considerations on the induction of appendages regeneration in amniotes. Ann Anat 2021; 239:151844. [PMID: 34662737 DOI: 10.1016/j.aanat.2021.151844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Study on the failure of limb regeneration in lizards evidences the difficult problems met from amniotes to regenerate organs. Contrary to the tail, limb loss in terrestrial environment is generally fatal and no selection for its regeneration occurred during lizard evolution. METHODS Experimentally amputated limbs were fixed and embedded for microscopy. RESULTS After limb loss an intense inflammatory reaction occurs and immune cells are recruited underneath a wound epidermis, forming a vascularized granulation tissue. The regenerating epidermis takes 2-3 weeks to cover the limb stump since degenerating long bones must be excised first while a dense connective tissue is formed and no limb growth occurs. Cell proliferation occurs in granulation tissues and wound epidermis during the initial 2-3 weeks of wound healing but disappears later determining the arrest of growth. Transcriptome data indicates that the limb, contrary to the tail, activates numerous genes involved in inflammation, immunity and fibroplasia while down-regulates some proliferative and most myogenic genes. Attempts to stimulate limb regeneration, by implants of nervous tissues or growth factors such as FGFs only maintain proliferation for few weeks but eventually the scarring program prevails and only short outgrowths missing of autopodial elements are regenerated. CONCLUSIONS While lizard limbs show the typical scarring outcome of mammals, the comparison of genes activated in the regenerating tail has allowed identifying key genes implicated in organ regeneration in amniotes.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Italy.
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Alibardi L. Review: Regeneration of the tail in lizards appears regulated by a balanced expression of oncogenes and tumor suppressors. Ann Anat 2021; 239:151824. [PMID: 34478856 DOI: 10.1016/j.aanat.2021.151824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Tail regeneration in lizards is the only case of large multi-tissue organ regeneration in amniotes. METHODS The present Review summarizes numerous immunolocalization and gene-expression studies indicating that after tail amputation in lizards the stump is covered in 7-10 days by the migration of keratinocytes. This allows the accumulation of mesenchymal-fibroblasts underneath the wound epidermis and forms a regenerative blastema and a new tail. RESULTS During migration keratinocytes transit from a compact epidermis into relatively free keratinocytes in a process of "Epithelial Mesenchymal Transition" (EMT). While EMT has been implicated in carcinogenesis no malignant transformation is observed during these cell movements in the regenerative blastema. Immunolabeling for E-cadherin and snail shows that these proteins are present in the cytoplasm and nuclei of migrating keratinocytes. The basal layer of the wound epithelium of the apical blastema express onco-proteins (wnt2b, egfr, c-myc, fgfs, fgfr, rhov, etc.) and tumor suppressors (p53/63, fat2, ephr, apc, retinoblastoma, arhgap28 etc.). This suggests that their balanced action regulates proliferation of the blastema. CONCLUSIONS While apical epidermis and mesenchyme are kept under a tight proliferative control, in more proximal regions of the regenerating tail the expression of tumor-suppressors triggers the differentiation of numerous tissues, forming the large myomeres, axial cartilage, simple spinal cord and nerves, new scales, arteries and veins, fat deposits, dermis and other connective tissues. Understanding gene expression patterns of developmental pathways activated during tail regeneration in lizards is useful for cancer research and for future attempts to induce organ regeneration in other amniotes including humans.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Dipartmento di Biologia, Universita' di Bologna, Italy.
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Evolution and medicine - The central role of anatomy. Ann Anat 2021; 239:151809. [PMID: 34324995 DOI: 10.1016/j.aanat.2021.151809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 06/10/2021] [Accepted: 07/13/2021] [Indexed: 11/24/2022]
Abstract
In medicine, there is an increasing number of publications that deal with or at least consider an evolutionary background. In zoology or comparative anatomy, work on evolutionary developments is taking on an ever-greater role in parallel. The pre-clinical (or pre-medical) phase in medical studies would be able to form a bridge between these related and yet so distant subjects but is currently completely evolution-free. This means that there is no consideration of the evolution of the healthy human being as a prerequisite for a systematic study of the evolutionary background in medicine. In this work the view is expressed that anatomy should be given a central, framework-giving and integrating role, which should urgently be actively pursued.
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Alibardi L. Regeneration in anamniotes was replaced by regengrow and scarring in amniotes after land colonization and the evolution of terrestrial biological cycles. Dev Dyn 2021; 251:1404-1413. [PMID: 33793005 DOI: 10.1002/dvdy.341] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/01/2021] [Accepted: 03/24/2021] [Indexed: 12/11/2022] Open
Abstract
An evolutionary hypothesis explaining failure of regeneration among vertebrates is presented. Regeneration derives from postembryonic processes present during the life cycles of fish and amphibians that include larval and metamorphic phases with broad organ reorganizations. Developmental programs imprinted in their genomes are re-utilized with variations also in adults for regeneration. When vertebrates colonized land adopting the amniotic egg, some genes driving larval changes, and metamorphosis were lost and new genes evolved, further limiting regeneration. These included neural inhibitors for maintaining complex nervous systems, behavior and various levels of intelligence, and adaptive immune cells. The latter, that in anamniotes are executioners of metamorphic reorganization, became intolerant to embryonic-oncofetal-antigens impeding organ regeneration, a process that requires de-differentiation of adult cells and/or expansion of stem cells where these early antigens are formed. The evolution of terrestrial lifecycles produced vertebrates with complex bodies but no longer capable to regenerate their organs, mainly repaired by regengrow. Efforts of regenerative medicine to improve healing in humans should determine the diverse developmental pathways evolved between anamniotes and amniotes before attempting genetic manipulations such as the introduction of "anamniote regenerative genes" in amniotes. This operation may determine alteration in amniote developmental programs leading to teratomes, cancer, or death.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Bologna, Italy
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Delgado-Coello B. Liver regeneration observed across the different classes of vertebrates from an evolutionary perspective. Heliyon 2021; 7:e06449. [PMID: 33748499 PMCID: PMC7970152 DOI: 10.1016/j.heliyon.2021.e06449] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/17/2021] [Accepted: 03/04/2021] [Indexed: 12/24/2022] Open
Abstract
The liver is a key organ that performs diverse functions such as metabolic processing of nutrients or disposal of dangerous substances (xenobiotics). Accordingly, it seems to be protected by several mechanisms throughout the life of organisms, one of which is compensatory hyperplasia, also known as liver regeneration. This review is a recapitulation of the scientific reports describing the different ways in which the various classes of vertebrates deal with liver injuries, where since mammals have an improved molecular toolkit, exhibit optimized regeneration of the liver compared to lower vertebrates. The main molecules involved in the compensatory process, such as proinflammatory and inhibitory cytokines, are analyzed across vertebrates with an evolutionary perspective. In addition, the possible significance of this mechanism is discussed in the context of the long life span of vertebrates, especially in the case of mammals.
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Affiliation(s)
- Blanca Delgado-Coello
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apdo. Postal 70-243, C.P. 04510, Mexico City, Mexico
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18
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Daponte V, Tylzanowski P, Forlino A. Appendage Regeneration in Vertebrates: What Makes This Possible? Cells 2021; 10:cells10020242. [PMID: 33513779 PMCID: PMC7911911 DOI: 10.3390/cells10020242] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/18/2021] [Accepted: 01/22/2021] [Indexed: 12/26/2022] Open
Abstract
The ability to regenerate amputated or injured tissues and organs is a fascinating property shared by several invertebrates and, interestingly, some vertebrates. The mechanism of evolutionary loss of regeneration in mammals is not understood, yet from the biomedical and clinical point of view, it would be very beneficial to be able, at least partially, to restore that capability. The current availability of new experimental tools, facilitating the comparative study of models with high regenerative ability, provides a powerful instrument to unveil what is needed for a successful regeneration. The present review provides an updated overview of multiple aspects of appendage regeneration in three vertebrates: lizard, salamander, and zebrafish. The deep investigation of this process points to common mechanisms, including the relevance of Wnt/β-catenin and FGF signaling for the restoration of a functional appendage. We discuss the formation and cellular origin of the blastema and the identification of epigenetic and cellular changes and molecular pathways shared by vertebrates capable of regeneration. Understanding the similarities, being aware of the differences of the processes, during lizard, salamander, and zebrafish regeneration can provide a useful guide for supporting effective regenerative strategies in mammals.
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Affiliation(s)
- Valentina Daponte
- Biochemistry Unit, Department of Molecular Medicine, University of Pavia, via Taramelli 3/B, 27100 Pavia, Italy;
| | - Przemko Tylzanowski
- Skeletal Biology and Engineering Research Center, Department of Development and Regeneration, University of Leuven, 3000 Leuven, Belgium;
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-059 Lublin, Poland
| | - Antonella Forlino
- Biochemistry Unit, Department of Molecular Medicine, University of Pavia, via Taramelli 3/B, 27100 Pavia, Italy;
- Correspondence: ; Tel.: +39-0382-987235
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19
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Grigoryan EN. Study of Natural Longlife Juvenility and Tissue Regeneration in Caudate Amphibians and Potential Application of Resulting Data in Biomedicine. J Dev Biol 2021; 9:2. [PMID: 33477527 PMCID: PMC7838874 DOI: 10.3390/jdb9010002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
The review considers the molecular, cellular, organismal, and ontogenetic properties of Urodela that exhibit the highest regenerative abilities among tetrapods. The genome specifics and the expression of genes associated with cell plasticity are analyzed. The simplification of tissue structure is shown using the examples of the sensory retina and brain in mature Urodela. Cells of these and some other tissues are ready to initiate proliferation and manifest the plasticity of their phenotype as well as the correct integration into the pre-existing or de novo forming tissue structure. Without excluding other factors that determine regeneration, the pedomorphosis and juvenile properties, identified on different levels of Urodele amphibians, are assumed to be the main explanation for their high regenerative abilities. These properties, being fundamental for tissue regeneration, have been lost by amniotes. Experiments aimed at mammalian cell rejuvenation currently use various approaches. They include, in particular, methods that use secretomes from regenerating tissues of caudate amphibians and fish for inducing regenerative responses of cells. Such an approach, along with those developed on the basis of knowledge about the molecular and genetic nature and age dependence of regeneration, may become one more step in the development of regenerative medicine.
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Affiliation(s)
- Eleonora N Grigoryan
- Kol'tsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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20
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Cadiz L, Jonz MG. A comparative perspective on lung and gill regeneration. ACTA ACUST UNITED AC 2020; 223:223/19/jeb226076. [PMID: 33037099 DOI: 10.1242/jeb.226076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The ability to continuously grow and regenerate the gills throughout life is a remarkable property of fish and amphibians. Considering that gill regeneration was first described over one century ago, it is surprising that the underlying mechanisms of cell and tissue replacement in the gills remain poorly understood. By contrast, the mammalian lung is a largely quiescent organ in adults but is capable of facultative regeneration following injury. In the course of the past decade, it has been recognized that lungs contain a population of stem or progenitor cells with an extensive ability to restore tissue; however, despite recent advances in regenerative biology of the lung, the signaling pathways that underlie regeneration are poorly understood. In this Review, we discuss the common evolutionary and embryological origins shared by gills and mammalian lungs. These are evident in homologies in tissue structure, cell populations, cellular function and genetic pathways. An integration of the literature on gill and lung regeneration in vertebrates is presented using a comparative approach in order to outline the challenges that remain in these areas, and to highlight the importance of using aquatic vertebrates as model organisms. The study of gill regeneration in fish and amphibians, which have a high regenerative potential and for which genetic tools are widely available, represents a unique opportunity to uncover common signaling mechanisms that may be important for regeneration of respiratory organs in all vertebrates. This may lead to new advances in tissue repair following lung disease.
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Affiliation(s)
- Laura Cadiz
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, Canada, K1N 6N5
| | - Michael G Jonz
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, Canada, K1N 6N5
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21
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Alibardi L. Appendage regeneration in anamniotes utilizes genes active during larval-metamorphic stages that have been lost or altered in amniotes: The case for studying lizard tail regeneration. J Morphol 2020; 281:1358-1381. [PMID: 32865265 DOI: 10.1002/jmor.21251] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/20/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022]
Abstract
This review elaborates the idea that organ regeneration derives from specific evolutionary histories of vertebrates. Regenerative ability depends on genomic regulation of genes specific to the life-cycles that have differentially evolved in anamniotes and amniotes. In aquatic environments, where fish and amphibians live, one or multiple metamorphic transitions occur before the adult stage is reached. Each transition involves the destruction and remodeling of larval organs that are replaced with adult organs. After organ injury or loss in adult anamniotes, regeneration uses similar genes and developmental process than those operating during larval growth and metamorphosis. Therefore, the broad presence of regenerative capability across anamniotes is possible because generating new organs is included in their life history at metamorphic stages. Soft hyaluronate-rich regenerative blastemas grow in submersed or in hydrated environments, that is, essential conditions for regeneration, like during development. In adult anamniotes, the ability to regenerate different organs decreases in comparison to larval stages and becomes limited during aging. Comparisons of genes activated during metamorphosis and regeneration in anamniotes identify key genes unique to these processes, and include thyroid, wnt and non-coding RNAs developmental pathways. In the terrestrial environment, some genes or developmental pathways for metamorphic transitions were lost during amniote evolution, determining loss of regeneration. Among amniotes, the formation of soft and hydrated blastemas only occurs in lizards, a morphogenetic process that evolved favoring their survival through tail autotomy, leading to a massive although imperfect regeneration of the tail. Deciphering genes activity during lizard tail regeneration would address future attempts to recreate in other amniotes regenerative blastemas that grow into variably completed organs.
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22
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He JQ, Barron C. Signaling pathways in modulation of tissue and organ regeneration in vertebrates. Semin Cell Dev Biol 2020; 100:1-2. [PMID: 31831358 PMCID: PMC9793442 DOI: 10.1016/j.semcdb.2019.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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23
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Alibardi L. Presence of immune cells in the regenerating caudal spinal cord of frog tadpoles indicates active immune-surveillance before metamorphosis. ZOOLOGY 2020; 139:125745. [PMID: 32106043 DOI: 10.1016/j.zool.2020.125745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 01/03/2023]
Abstract
During spinal cord (SC) regeneration in the tail of Rana dalmatina tadpoles few neurons are regenerated from the ependymal epithelium. Using microscopic methods, immunofluorescence, tract tracing and electron microscopy, the present study has analyzed the cells generated in the caudal SC during the first 20 days of regeneration under normal and stress conditions. Since early larval stages, the regenerating SC contains few nerve cells (2-3%) and more numerous immune cells (5-7%), namely heterophil granulocytes, macrophages and lymphocytes. Few regenerated nerve cells are connected to the normal SC by axons detected after application of the retrograde fluorescent tracer Dil. Cell degeneration in the regenerating SC is commonly observed, including also loss of nerve cells, a process that occurs well in advance from metamorphosis. Furthermore, under lightly stress conditions, when tadpoles are kept in agitated water during tail regeneration, nerve degeneration and the number of immune cells significantly increases in the regenerating SC, a mean of 13.5% versus 5.6% in normal conditions. The study shows that normal and regenerating SC are under immune surveillance since early tadpole stages, well in advance of metamorphosis when immune cells determine the degeneration of the SC and the complete reabsorption of the tail.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology at University of Bologna, via Selmi 3, 40126, Bologna, Italy.
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24
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Alibardi L. Immunogold labelling reveals intense distribution of hyaluronate in the regenerating fin blastema of the goldfish. ACTA ZOOL-STOCKHOLM 2020. [DOI: 10.1111/azo.12321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology University of Bologna Bologna Italy
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25
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Alibardi L. Microscopic observations on amputated and scarring lizard digits show an intense inflammatory reaction. ZOOLOGY 2019; 139:125737. [PMID: 32062299 DOI: 10.1016/j.zool.2019.125737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/28/2019] [Accepted: 12/09/2019] [Indexed: 01/27/2023]
Abstract
The microscopic details of the failure of digit regeneration in lizards are not known. The present study reports some histological, ultrastructural and 5BrdU-immunohistochemical observations on healing digits after amputation in the lizard Podarcis muralis. At 7-12 days post-amputation, the stump of digits forms a multilayered wound epidermis covering a loose connective tissue that is invaded by granulocytes, macrophages and lymphocytes. In addition to macrophages also electron-pale multinuclear giant cells are seen underneath or penetrating the wound epidermis while osteoclasts are present in the degrading bone of the severed phalanges. Granulocytes and macrophages invading the wound epidermis indicate the formation of an intra-epidermal immune barrier beneath the scab where numerous bacteria remain entrapped. Immunofluorescence for 5BrdU reveals that few proliferating cells are present in the wound epidermis and the underlying connective tissue at 12 and 32 days post-amputation. Outgrowths of less than 1mm stop growing and at 32 days they appear scaling. Most of connective cells give rise to fibrocytes and large irregular collagen bundles, as is typical for scar tissue. In conclusion, like for the amputated limb, the intense inflammatory reaction and scarring here described after digit loss appears associated with immune cells invasion.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Dipartimento di Biologia, University of Bologna, via Semi 3, 40126 Bologna, Italy.
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26
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Alibardi L. Observations on the recovering lumbar spinal cord of lizards show multiple origins of the cells forming the bridge region including immune cells. J Morphol 2019; 281:95-109. [DOI: 10.1002/jmor.21082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/21/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and University of Bologna Bologna Italy
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27
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Alibardi L. Tail regeneration in Lepidosauria as an exception to the generalized lack of organ regeneration in amniotes. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 336:145-164. [PMID: 31532061 DOI: 10.1002/jez.b.22901] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/14/2019] [Accepted: 08/08/2019] [Indexed: 02/06/2023]
Abstract
The present review hypothesizes that during the transition from water to land, amniotes lost part of the genetic program for metamorphosis utilized in larvae of their amphibian ancestors, a program that in extant fish and amphibians allows organ regeneration. The direct development of amniotes, with their growth from embryos to adults, occurred with the elimination of larval stages, increases the efficiency of immune responses and the complexity of nervous circuits. In amniotes, T-cells and macrophages likely eliminate embryonic-larval antigens that are replaced with the definitive antigens of adult organs. Among lepidosaurians numerous lizard families during the Permian and Triassic evolved the process of tail autotomy to escape predation, followed by tail regeneration. Autotomy limits inflammation allowing the formation of a regenerative blastema rich in the immunosuppressant and hygroscopic hyaluronic acid. Expression loss of developmental genes for metamorphosis and segmentation in addition to an effective immune system, determined an imperfect regeneration of the tail. Genes involved in somitogenesis were likely lost or are inactivated and the axial skeleton and muscles of the original tail are replaced with a nonsegmented cartilaginous tube and segmental myotomes. Lack of neural genes, negative influence of immune system, and isolation of the regenerating spinal cord within the cartilaginous tube impede the production of nerve and glial cells, and a stratified spinal cord with ganglia. Tissue and organ regeneration in other body regions of lizards and other reptiles is relatively limited, like in the other amniotes, although the cartilage shows a higher regenerative capability than in mammals.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Bologna, Italy
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