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1.
PLoS One ; 15(10): e0239755, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052951

RESUMO

Knowledge of the recruitment of dominant forest species is a key aspect for forest conservation and the ecosystem services they provide. In this paper, we address how the simultaneous action of climate change and the intensity of land use in the past influence the recruitment of a forest species that depends on the provision of nurse plants to recruit. We compared the number of saplings (up to 15 years old) and juveniles (16 to 50 years old) of Quercus ilex in 17, 5.3 ha plots in the Iberian System (eastern Spain). We used a gradient of past deforestation intensity crossed with two levels of average annual precipitation, one of them at the lower limit of the species' precipitation niche (semi-arid) and the other at the optimum (sub-humid). We also examined the association between recruits and nurse plants and the effect on this association of plot-scale factors, such as seed abundance (reproductive Q. ilex), microsites (nurse species and soil availability), and large herbivores. The increase in aridity in the last decades has drastically reduced the recruitment of new individuals in the forests of Q. ilex located in the lower limit of their precipitation niche, regardless of the intensity of past deforestation that they suffered. Recruitment in these climatic conditions depends almost exclusively on large trees and shrubs whose abundance may also be limited by aridity. The lack of regeneration questions the future of these populations, as the number of individuals will decrease over time despite the strong resistance of adult trees to disturbance and drought.


Assuntos
Secas , Ecossistema , Quercus/fisiologia , Regeneração/fisiologia , Mudança Climática , Conservação dos Recursos Naturais/métodos , Florestas , Herbivoria/fisiologia , Estações do Ano , Solo , Espanha , Árvores/fisiologia , Água
2.
PLoS One ; 15(9): e0239152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956427

RESUMO

Volumetric muscle loss (VML) is the loss of skeletal muscle that results in significant and persistent impairment of function. The unique characteristics of craniofacial muscle compared trunk and limb skeletal muscle, including differences in gene expression, satellite cell phenotype, and regenerative capacity, suggest that VML injuries may affect craniofacial muscle more severely. However, despite these notable differences, there are currently no animal models of craniofacial VML. In a previous sheep hindlimb VML study, we showed that our lab's tissue engineered skeletal muscle units (SMUs) were able to restore muscle force production to a level that was statistically indistinguishable from the uninjured contralateral muscle. Thus, the goals of this study were to: 1) develop a model of craniofacial VML in a large animal model and 2) to evaluate the efficacy of our SMUs in repairing a 30% VML in the ovine zygomaticus major muscle. Overall, there was no significant difference in functional recovery between the SMU-treated group and the unrepaired control. Despite the use of the same injury and repair model used in our previous study, results showed differences in pathophysiology between craniofacial and hindlimb VML. Specifically, the craniofacial model was affected by concomitant denervation and ischemia injuries that were not exhibited in the hindlimb model. While clinically realistic, the additional ischemia and denervation likely created an injury that was too severe for our SMUs to repair. This study highlights the importance of balancing the use of a clinically realistic model while also maintaining control over variables related to the severity of the injury. These variables include the volume of muscle removed, the location of the VML injury, and the geometry of the injury, as these affect both the muscle's ability to self-regenerate as well as the probability of success of the treatment.


Assuntos
Traumatismos Faciais/cirurgia , Músculos Faciais/cirurgia , Regeneração Tecidual Guiada/métodos , Doenças Musculares/cirurgia , Engenharia Tecidual/métodos , Animais , Modelos Animais de Doenças , Face/cirurgia , Traumatismos Faciais/complicações , Músculos Faciais/fisiopatologia , Feminino , Humanos , Masculino , Doenças Musculares/etiologia , Recuperação de Função Fisiológica , Regeneração/fisiologia , Ovinos , Tecidos Suporte
3.
Nat Commun ; 11(1): 4549, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917889

RESUMO

Arterial macrophages have different developmental origins, but the association of macrophage ontogeny with their phenotypes and functions in adulthood is still unclear. Here, we combine macrophage fate-mapping analysis with single-cell RNA sequencing to establish their cellular identity during homeostasis, and in response to angiotensin-II (AngII)-induced arterial inflammation. Yolk sac erythro-myeloid progenitors (EMP) contribute substantially to adventitial macrophages and give rise to a defined cluster of resident immune cells with homeostatic functions that is stable in adult mice, but declines in numbers during ageing and is not replenished by bone marrow (BM)-derived macrophages. In response to AngII inflammation, increase in adventitial macrophages is driven by recruitment of BM monocytes, while EMP-derived macrophages proliferate locally and provide a distinct transcriptional response that is linked to tissue regeneration. Our findings thus contribute to the understanding of macrophage heterogeneity, and associate macrophage ontogeny with distinct functions in health and disease.


Assuntos
Artérias/citologia , Arterite/imunologia , Diferenciação Celular/fisiologia , Homeostase/fisiologia , Macrófagos/fisiologia , Envelhecimento/fisiologia , Angiotensina II/administração & dosagem , Angiotensina II/imunologia , Animais , Artérias/fisiologia , Medula Óssea/fisiologia , Transplante de Medula Óssea , Linhagem da Célula , Modelos Animais de Doenças , Feminino , Células-Tronco Hematopoéticas/fisiologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , RNA-Seq , Regeneração/fisiologia , Análise de Célula Única , Quimeras de Transplante
4.
Proc Biol Sci ; 287(1935): 20192939, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32933441

RESUMO

Salamanders, frog tadpoles and diverse lizards have the remarkable ability to regenerate tails. Palaeontological data suggest that this capacity is plesiomorphic, yet when the developmental and genetic architecture of tail regeneration arose is poorly understood. Here, we show morphological and molecular hallmarks of tetrapod tail regeneration in the West African lungfish Protopterus annectens, a living representative of the sister group of tetrapods. As in salamanders, lungfish tail regeneration occurs via the formation of a proliferative blastema and restores original structures, including muscle, skeleton and spinal cord. In contrast with lizards and similar to salamanders and frogs, lungfish regenerate spinal cord neurons and reconstitute dorsoventral patterning of the tail. Similar to salamander and frog tadpoles, Shh is required for lungfish tail regeneration. Through RNA-seq analysis of uninjured and regenerating tail blastema, we show that the genetic programme deployed during lungfish tail regeneration maintains extensive overlap with that of tetrapods, with the upregulation of genes and signalling pathways previously implicated in amphibian and lizard tail regeneration. Furthermore, the lungfish tail blastema showed marked upregulation of genes encoding post-transcriptional RNA processing components and transposon-derived genes. Our results show that the developmental processes and genetic programme of tetrapod tail regeneration were present at least near the base of the sarcopterygian clade and establish the lungfish as a valuable research system for regenerative biology.


Assuntos
Peixes/fisiologia , Cauda/fisiologia , Animais , Extremidades/fisiologia , Filogenia , Regeneração/fisiologia
5.
Nat Commun ; 11(1): 4435, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895385

RESUMO

Colonial ascidians are the only chordates able to undergo whole body regeneration (WBR), during which entire new bodies can be regenerated from small fragments of blood vessels. Here, we show that during the early stages of WBR in Botrylloides diegensis, proliferation occurs only in small, blood-borne cells that express integrin-alpha-6 (IA6), pou3 and vasa. WBR cannot proceed when proliferating IA6+ cells are ablated with Mitomycin C, and injection of a single IA6+ Candidate stem cell can rescue WBR after ablation. Lineage tracing using EdU-labeling demonstrates that donor-derived IA6+ Candidate stem cells directly give rise to regenerating tissues. Inhibitors of either Notch or canonical Wnt signaling block WBR and reduce proliferation of IA6+ Candidate stem cells, indicating that these two pathways regulate their activation. In conclusion, we show that IA6+ Candidate stem cells are responsible for whole body regeneration and give rise to regenerating tissues.


Assuntos
Integrina alfa6/metabolismo , Regeneração/fisiologia , Urocordados , Animais , Cordados não Vertebrados/embriologia , Expressão Gênica , Integrina alfa6/genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Urocordados/citologia , Urocordados/embriologia , Urocordados/crescimento & desenvolvimento
6.
Nat Genet ; 52(9): 908-918, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32807988

RESUMO

The identification of prostate stem/progenitor cells and characterization of the prostate epithelial cell lineage hierarchy are critical for understanding prostate cancer initiation. Here, we characterized 35,129 cells from mouse prostates, and identified a unique luminal cell type (termed type C luminal cell (Luminal-C)) marked by Tacstd2, Ck4 and Psca expression. Luminal-C cells located at the distal prostate invagination tips (termed Dist-Luminal-C) exhibited greater capacity for organoid formation in vitro and prostate epithelial duct regeneration in vivo. Lineage tracing of Luminal-C cells indicated that Dist-Luminal-C cells reconstituted distal prostate luminal lineages through self-renewal and differentiation. Deletion of Pten in Dist-Luminal-C cells resulted in prostatic intraepithelial neoplasia. We further characterized 11,374 human prostate cells and confirmed the existence of h-Luminal-C cells. Our study provides insights into the prostate lineage hierarchy, identifies Dist-Luminal-C cells as the luminal progenitor cell population in invagination tips and suggests one of the potential cellular origins of prostate cancer.


Assuntos
Próstata/citologia , Células-Tronco/citologia , Transcriptoma/genética , Animais , Diferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Organoides/citologia , Organoides/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Regeneração/fisiologia , Células-Tronco/metabolismo
7.
PLoS One ; 15(8): e0238076, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857768

RESUMO

Epidermal lineages and injury induced regeneration are controlled by transcriptional programs coordinating cellular signaling and epigenetic regulators, but the mechanism remains unclear. Previous studies showed that conditional deletion of the transcriptional coactivator Mediator 1 (Med1) changes epidermal lineages and accelerates wound re-epithelialization. Here, we studied a molecular mechanism by which Med1 facilitates these processes, in particular, by focusing on TGFß signaling through genome wide transcriptome analysis. The expression of the TGF ligands (Tgfß1/ß2) and their downstream target genes is decreased in both normal and wounded Med1 null skin. Med1 silencing in cultured keratinocytes likewise reduces the expression of the ligands (TGFß1/ß2) and diminishes activity of TGFß signaling as shown by decreased p-Smad2/3. Silencing Med1 increases keratinocyte proliferation and migration in vitro. Epigenetic studies using chromatin immuno-precipitation and next generation DNA sequencing reveals that Med1 regulates transcription of TGFß components by forming large clusters of enhancers called super-enhancers at the regulatory regions of the TGFß ligand and SMAD3 genes. These results demonstrate that Med1 is required for the maintenance of the TGFß signaling pathway. Finally, we show that pharmacological inhibition of TGFß signaling enhances epidermal lineages and accelerates wound re-epithelialization in skin similar to that seen in the Med1 null mice, providing new insights into epidermal regeneration.


Assuntos
Subunidade 1 do Complexo Mediador/genética , Regeneração/fisiologia , Transdução de Sinais , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta2/metabolismo , Animais , Linhagem da Célula , Movimento Celular , Proliferação de Células , Regulação para Baixo , Epiderme/fisiologia , Queratinócitos/citologia , Queratinócitos/metabolismo , Subunidade 1 do Complexo Mediador/antagonistas & inibidores , Subunidade 1 do Complexo Mediador/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Pele/metabolismo , Pele/patologia , Proteína Smad3/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta2/genética , Regulação para Cima
8.
Nat Commun ; 11(1): 4167, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820177

RESUMO

Muscle regeneration depends on a robust albeit transient inflammatory response. Persistent inflammation is a feature of age-related regenerative deficits, yet the underlying mechanisms are poorly understood. Here, we find inflammatory-related CC-chemokine-receptor 2 (Ccr2) expression in non-hematopoietic myogenic progenitors (MPs) during regeneration. After injury, the expression of Ccr2 in MPs corresponds to the levels of its ligands, the chemokines Ccl2, 7, and 8. We find stimulation of Ccr2-activity inhibits MP fusion and contribution to myofibers. This occurs in association with increases in MAPKp38δ/γ signaling, MyoD phosphorylation, and repression of the terminal myogenic commitment factor Myogenin. High levels of Ccr2-chemokines are a feature of regenerating aged muscle. Correspondingly, deletion of Ccr2 in MPs is necessary for proper fusion into regenerating aged muscle. Finally, opportune Ccr2 inhibition after injury enhances aged regeneration and functional recovery. These results demonstrate that inflammatory-induced activation of Ccr2 signaling in myogenic cells contributes to aged muscle regenerative decline.


Assuntos
Mediadores da Inflamação/metabolismo , Músculo Esquelético/fisiopatologia , Receptores CCR2/metabolismo , Regeneração/fisiologia , Transdução de Sinais/fisiologia , Fatores Etários , Animais , Transplante de Células/métodos , Quimiocina CCL2/metabolismo , Quimiocina CCL7/metabolismo , Quimiocina CCL8/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Desenvolvimento Muscular/genética , Músculo Esquelético/lesões , Músculo Esquelético/metabolismo , Miogenina/genética , Miogenina/metabolismo , Receptores CCR2/genética , Regeneração/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/transplante , Transdução de Sinais/genética , Ferimentos e Lesões/genética , Ferimentos e Lesões/fisiopatologia , Ferimentos e Lesões/terapia
11.
Am J Respir Crit Care Med ; 202(8): 1088-1104, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32628504

RESUMO

Rationale: Promoting endogenous pulmonary regeneration is crucial after damage to restore normal lungs and prevent the onset of chronic adult lung diseases.Objectives: To investigate whether the cell-cycle inhibitor p16INK4a limits lung regeneration after newborn bronchopulmonary dysplasia (BPD), a condition characterized by the arrest of alveolar development, leading to adult sequelae.Methods: We exposed p16INK4a-/- and p16INK4a ATTAC (apoptosis through targeted activation of caspase 8) transgenic mice to postnatal hyperoxia, followed by pneumonectomy of the p16INK4a-/- mice. We measured p16INK4a in blood mononuclear cells of preterm newborns, 7- to 15-year-old survivors of BPD, and the lungs of patients with BPD.Measurements and Main Results: p16INK4a concentrations increased in lung fibroblasts after hyperoxia-induced BPD in mice and persisted into adulthood. p16INK4a deficiency did not protect against hyperoxic lesions in newborn pups but promoted restoration of the lung architecture by adulthood. Curative clearance of p16INK4a-positive cells once hyperoxic lung lesions were established restored normal lungs by adulthood. p16INK4a deficiency increased neutral lipid synthesis and promoted lipofibroblast and alveolar type 2 (AT2) cell development within the stem-cell niche. Besides, lipofibroblasts support self-renewal of AT2 cells into alveolospheres. Induction with a PPARγ (peroxisome proliferator-activated receptor γ) agonist after hyperoxia also increased lipofibroblast and AT2 cell numbers and restored alveolar architecture in hyperoxia-exposed mice. After pneumonectomy, p16INK4a deficiency again led to an increase in lipofibroblast and AT2 cell numbers in the contralateral lung. Finally, we observed p16INK4a mRNA overexpression in the blood and lungs of preterm newborns, which persisted in the blood of older survivors of BPD.Conclusions: These data demonstrate the potential of targeting p16INK4a and promoting lipofibroblast development to stimulate alveolar regeneration from childhood to adulthood.


Assuntos
Displasia Broncopulmonar/patologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Fibroblastos/metabolismo , Pulmão/fisiologia , Regeneração/fisiologia , Adolescente , Adulto , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Animais , Animais Recém-Nascidos , Apoptose , Displasia Broncopulmonar/metabolismo , Células Cultivadas , Criança , Modelos Animais de Doenças , Fibroblastos/patologia , Humanos , Hiperóxia/complicações , Hiperóxia/metabolismo , Hiperóxia/patologia , Recém-Nascido , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Alvéolos Pulmonares/patologia , Distribuição Aleatória , Amostragem , Adulto Jovem
12.
Proc Natl Acad Sci U S A ; 117(26): 15322-15331, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32541049

RESUMO

Wound healing in plant tissues, consisting of rigid cell wall-encapsulated cells, represents a considerable challenge and occurs through largely unknown mechanisms distinct from those in animals. Owing to their inability to migrate, plant cells rely on targeted cell division and expansion to regenerate wounds. Strict coordination of these wound-induced responses is essential to ensure efficient, spatially restricted wound healing. Single-cell tracking by live imaging allowed us to gain mechanistic insight into the wound perception and coordination of wound responses after laser-based wounding in Arabidopsis root. We revealed a crucial contribution of the collapse of damaged cells in wound perception and detected an auxin increase specific to cells immediately adjacent to the wound. This localized auxin increase balances wound-induced cell expansion and restorative division rates in a dose-dependent manner, leading to tumorous overproliferation when the canonical TIR1 auxin signaling is disrupted. Auxin and wound-induced turgor pressure changes together also spatially define the activation of key components of regeneration, such as the transcription regulator ERF115. Our observations suggest that the wound signaling involves the sensing of collapse of damaged cells and a local auxin signaling activation to coordinate the downstream transcriptional responses in the immediate wound vicinity.


Assuntos
Arabidopsis/fisiologia , Ácidos Indolacéticos/metabolismo , Células Vegetais/fisiologia , Raízes de Plantas/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Divisão Celular , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/antagonistas & inibidores , Cinurenina/farmacologia , Lasers , Ftalimidas/farmacologia , Células Vegetais/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Regeneração/fisiologia , Transdução de Sinais/fisiologia , Triazóis/farmacologia
13.
Life Sci ; 256: 117989, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32565250

RESUMO

AIMS: The beneficial effects of cannabinoid type 2 receptor (CB2R) activation have been verified in various tissue repair processes. Our recent study revealed CB2R activation promotes myogenesis partly through Nrf2 signaling in a mouse skeletal muscle ischemia-reperfusion (IR) injury model. Other relevant mechanisms need to be further elucidated. Macrophages orchestrate tissue regeneration mainly by changing their phenotype and function. The aim of this study was to investigate the role of CB2R in IR-induced skeletal muscle regeneration, focusing on its impact on macrophage polarization and the consequences on myogenesis. MAIN METHODS: The effects of CB2R on skeletal muscle regeneration, and the macrophage infiltration and M1/M2 polarization were tested with the IR injury model in wild type (WT) and CB2R knockout (CB2R-KO) mice. The effect of CB2R on peritoneal macrophage polarization, and its impact on the myoblasts differentiation was evaluated by co-culture experiments in vitro. KEY FINDINGS: The present study revealed the myofiber regeneration was hindered in the CB2R-KO mice. The infiltration of M1 macrophages and relevant markers' protein expression were enhanced in the CB2R-KO mice, while that of M2 macrophages was decreased compared with the WT mice. The in vitro studies further demonstrated that the absence of CB2R promoted M1 polarization while inhibited M2 polarization. The promoted M1 polarization and retarded M2 polarization in CB2R-KO macrophages hindered myoblasts differentiation. SIGNIFICANCE: Overall, these results suggested CB2R plays a beneficial effect on skeletal muscle regeneration partly by regulating macrophage M1/M2 polarization after IR injury in mice.


Assuntos
Polaridade Celular/fisiologia , Macrófagos/fisiologia , Músculo Esquelético/fisiologia , Receptor CB2 de Canabinoide/deficiência , Regeneração/fisiologia , Traumatismo por Reperfusão/metabolismo , Animais , Células Cultivadas , Técnicas de Cocultura , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/irrigação sanguínea
14.
J Vis Exp ; (159)2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32510477

RESUMO

Hair cells are mechanosensory cells that mediate the sense of hearing. These cells do not regenerate after damage in humans, but they are naturally replenished in non-mammalian vertebrates such as zebrafish. The zebrafish lateral line system is a useful model for characterizing sensory hair cell regeneration. The lateral line is comprised of hair cell-containing organs called neuromasts, which are linked together by a string of interneuromast cells (INMCs). INMCs act as progenitor cells that give rise to new neuromasts during development. INMCs can repair gaps in the lateral line system created by cell death. A method is described here for selective INMC ablation using a conventional laser-scanning confocal microscope and transgenic fish that express green fluorescent protein in INMCs. Time-lapse microscopy is then used to monitor INMC regeneration and determine the rate of gap closure. This represents an accessible protocol for cell ablation that does not require specialized equipment, such as a high-powered pulsed ultraviolet laser. The ablation protocol may serve broader interests, as it could be useful for the ablation of additional cell types, employing a tool set that is already available to many users. This technique will further enable the characterization of INMC regeneration under different conditions and from different genetic backgrounds, which will advance the understanding of sensory progenitor cell regeneration.


Assuntos
Bioensaio/métodos , Interneurônios/citologia , Terapia a Laser , Microscopia Confocal , Regeneração/fisiologia , Peixe-Zebra/fisiologia , Anestesia , Animais , Animais Geneticamente Modificados , Corpo Celular/metabolismo , Morte Celular , Fluorescência , Proteínas de Fluorescência Verde/metabolismo , Processamento de Imagem Assistida por Computador , Larva/citologia , Modelos Logísticos , Peixe-Zebra/genética
15.
PLoS One ; 15(6): e0232308, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32530962

RESUMO

Zebrafish have the ability to regenerate damaged cells and tissues by activating quiescent stem and progenitor cells or reprogramming differentiated cells into regeneration-competent precursors. Proliferation among the cells that will functionally restore injured tissues is a fundamental biological process underlying regeneration. Midkine-a is a cytokine growth factor, whose expression is strongly induced by injury in a variety of tissues across a range of vertebrate classes. Using a zebrafish Midkine-a loss of function mutant, we evaluated regeneration of caudal fin, extraocular muscle and retinal neurons to investigate the function of Midkine-a during epimorphic regeneration. In wildtype zebrafish, injury among these tissues induces robust proliferation and rapid regeneration. In Midkine-a mutants, the initial proliferation in each of these tissues is significantly diminished or absent. Regeneration of the caudal fin and extraocular muscle is delayed; regeneration of the retina is nearly completely absent. These data demonstrate that Midkine-a is universally required in the signaling pathways that convert tissue injury into the initial burst of cell proliferation. Further, these data highlight differences in the molecular mechanisms that regulate epimorphic regeneration in zebrafish.


Assuntos
Midkina/metabolismo , Regeneração/fisiologia , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Nadadeiras de Animais/fisiologia , Animais , Animais Geneticamente Modificados/metabolismo , Diferenciação Celular , Proliferação de Células , Midkina/genética , Mutagênese , Neuroglia/citologia , Neuroglia/metabolismo , Músculos Oculomotores/fisiologia , Neurônios Retinianos/fisiologia , Proteínas de Peixe-Zebra/genética
16.
PLoS One ; 15(5): e0233261, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413092

RESUMO

The transcription factor Hypoxia-inducible factor 1 (HIF-1) plays a pivotal role in tissue regeneration. HIF-1 is negatively controlled by O2-dependent prolyl hydroxylases with a predominant role of prolyl hydroxylase 2 isoform (Phd2). Transgenic mice, hypomorphic for this isoform, accumulate more HIF-1 under normoxic conditions. Using these mice, we investigated the influence of Phd2 and HIF-1 on the regenerative capability of skeletal muscle tissue after myotrauma. Phd2-hypomorphic and wild type mice (on C57Bl/6 background) were grouped with regeneration times from 6 to 168 hours after closed mechanic muscle trauma to the hind limb. Tissue samples were analysed by immuno-staining and real-time PCR. Bone marrow derived macrophages of wild type and Phd2-hypomorphic mice were isolated and analysed via flow cytometry and quantitative real-time PCR. Phd2 reduction led to a higher regenerative capability due to enhanced activation of myogenic factors accompanied by induction of genes responsible for glucose and lactate metabolism in Phd2-hypomorphic mice. Macrophage infiltration into the trauma areas in hypomorphic mice started earlier and was more pronounced compared to wild type mice. Phd2-hypomorphic mice also showed higher numbers of macrophages in areas with sustained trauma 72 hours after myotrauma application. In conclusion, we postulate that the HIF-1 pathway is activated secondary to a Phd2 reduction which may lead to i) higher activation of myogenic factors, ii) increased number of positive stem cell proliferation markers, and iii) accelerated macrophage recruitment to areas of trauma, resulting in faster muscle tissue regeneration after myotrauma. With the current development of prolyl hydroxylase domain inhibitors, our findings point towards a potential clinical benefit after myotrauma.


Assuntos
Prolina Dioxigenases do Fator Induzível por Hipóxia/deficiência , Músculo Esquelético/fisiologia , Regeneração/fisiologia , Lesões dos Tecidos Moles/fisiopatologia , Animais , Proliferação de Células/fisiologia , Modelos Animais de Doenças , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Distribuição Aleatória , Fator A de Crescimento do Endotélio Vascular/metabolismo
17.
Nat Commun ; 11(1): 2461, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424153

RESUMO

It is well established that pluripotent stem cells in fetal and postnatal liver (LPCs) can differentiate into both hepatocytes and cholangiocytes. However, the signaling pathways implicated in the differentiation of LPCs are still incompletely understood. Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy, is known to be involved in osteoblast and myeloid differentiation, but its role in lineage commitment in the liver has not been investigated. Here we show that during development and upon regeneration TFEB drives the differentiation status of murine LPCs into the progenitor/cholangiocyte lineage while inhibiting hepatocyte differentiation. Genetic interaction studies show that Sox9, a marker of precursor and biliary cells, is a direct transcriptional target of TFEB and a primary mediator of its effects on liver cell fate. In summary, our findings identify an unexplored pathway that controls liver cell lineage commitment and whose dysregulation may play a role in biliary cancer.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Linhagem da Célula , Fígado/citologia , Fígado/fisiologia , Regeneração/fisiologia , Animais , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/metabolismo , Diferenciação Celular , Proliferação de Células , Colangiocarcinoma/patologia , Regulação para Baixo/genética , Hepatócitos/citologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Fenótipo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Esferoides Celulares/citologia , Células-Tronco/citologia , Células-Tronco/metabolismo , Regulação para Cima/genética
18.
PLoS One ; 15(5): e0232981, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396580

RESUMO

Cell signaling pathways play key roles in coordinating cellular events in development. The Notch signaling pathway is highly conserved across all multicellular animals and is known to coordinate a multitude of diverse cellular events, including proliferation, differentiation, fate specification, and cell death. Specific functions of the pathway are, however, highly context-dependent and are not well characterized in post-traumatic regeneration. Here, we use a small-molecule inhibitor of the pathway (DAPT) to demonstrate that Notch signaling is required for proper arm regeneration in the brittle star Ophioderma brevispina, a highly regenerative member of the phylum Echinodermata. We also employ a transcriptome-wide gene expression analysis (RNA-seq) to characterize the downstream genes controlled by the Notch pathway in the brittle star regeneration. We demonstrate that arm regeneration involves an extensive cross-talk between the Notch pathway and other cell signaling pathways. In the regrowing arm, Notch regulates the composition of the extracellular matrix, cell migration, proliferation, and apoptosis, as well as components of the innate immune response. We also show for the first time that Notch signaling regulates the activity of several transposable elements. Our data also suggests that one of the possible mechanisms through which Notch sustains its activity in the regenerating tissues is via suppression of Neuralized1.


Assuntos
Equinodermos/fisiologia , Receptores Notch/fisiologia , Regeneração/fisiologia , Estruturas Animais/efeitos dos fármacos , Estruturas Animais/fisiologia , Animais , Elementos de DNA Transponíveis , Dipeptídeos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Equinodermos/efeitos dos fármacos , Equinodermos/genética , Receptores Notch/antagonistas & inibidores , Receptores Notch/genética , Regeneração/efeitos dos fármacos , Regeneração/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Transcriptoma/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
19.
Nat Commun ; 11(1): 2656, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32461609

RESUMO

The earthworm is particularly fascinating to biologists because of its strong regenerative capacity. However, many aspects of its regeneration in nature remain elusive. Here we report chromosome-level genome, large-scale transcriptome and single-cell RNA-sequencing data during earthworm (Eisenia andrei) regeneration. We observe expansion of LINE2 transposable elements and gene families functionally related to regeneration (for example, EGFR, epidermal growth factor receptor) particularly for genes exhibiting differential expression during earthworm regeneration. Temporal gene expression trajectories identify transcriptional regulatory factors that are potentially crucial for initiating cell proliferation and differentiation during regeneration. Furthermore, early growth response genes related to regeneration are transcriptionally activated in both the earthworm and planarian. Meanwhile, single-cell RNA-sequencing provides insight into the regenerative process at a cellular level and finds that the largest proportion of cells present during regeneration are stem cells.


Assuntos
Perfilação da Expressão Gênica/métodos , Oligoquetos/genética , Regeneração/genética , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Oligoquetos/citologia , Oligoquetos/metabolismo , RNA-Seq/métodos , Regeneração/fisiologia , Elementos Reguladores de Transcrição/genética , Sequenciamento Completo do Exoma , Sequenciamento Completo do Genoma
20.
Nat Commun ; 11(1): 2591, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444641

RESUMO

The intestine is a highly dynamic environment that requires tight control of the various inputs to maintain homeostasis and allow for proper responses to injury. It was recently found that the stem cell niche and epithelium is regenerated after injury by de-differentiated adult cells, through a process that gives rise to Sca1+ fetal-like cells and is driven by a transient population of Clu+ revival stem cells (revSCs). However, the molecular mechanisms that regulate this dynamic process have not been fully defined. Here we show that TNFAIP8 (also known as TIPE0) is a regulator of intestinal homeostasis that is vital for proper regeneration. TIPE0 functions through inhibiting basal Akt activation by the commensal microbiota via modulating membrane phospholipid abundance. Loss of TIPE0 in mice results in injury-resistant enterocytes, that are hyperproliferative, yet have regenerative deficits and are shifted towards a de-differentiated state. Tipe0-/- enterocytes show basal induction of the Clu+ regenerative program and a fetal gene expression signature marked by Sca1, but upon injury are unable to generate Sca-1+/Clu+ revSCs and could not regenerate the epithelium. This work demonstrates the role of TIPE0 in regulating the dynamic signaling that determines the injury response and enables intestinal epithelial cell regenerative plasticity.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Microbioma Gastrointestinal/fisiologia , Intestinos/citologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Ataxina-1/metabolismo , Diferenciação Celular , Colite/induzido quimicamente , Colite/patologia , Enterócitos/patologia , Feminino , Técnicas de Silenciamento de Genes , Homeostase , Intestinos/irrigação sanguínea , Intestinos/patologia , Intestinos/efeitos da radiação , Isquemia/genética , Isquemia/patologia , Antígenos Comuns de Leucócito/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/patologia , Regeneração/fisiologia , Transdução de Sinais , Nicho de Células-Tronco , Células-Tronco/metabolismo
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