Midkine-a regulates the formation of a fibrotic scar during zebrafish heart regeneration
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ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE166732 | GEO | 2021/05/26
REPOSITORIES: GEO
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Project description:In the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Müller glia. Recently, Müller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine-b (mdkb). Midkine is a highly conserved heparin-binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here, we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are co-expressed in horizontal cells and proliferating Müller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration. Experiment Overall Design: As a means to identify genes necessary for photoreceptor regeneration, we evaluated transcriptional in the retina of the zebrafish as photoreceptors are regenerated. Albino zebrafish were dark adapted, then half were exposed to bright constant light and half were returned to normal lighting. After 72hrs of light exposure, retinal RNA was isolated and analysis of gene expression was performed using Affymetriz zebrafish gene arrays.
2009-01-13 | E-GEOD-13999 | biostudies-arrayexpress
Project description:In the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Müller glia. Recently, Müller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine-b (mdkb). Midkine is a highly conserved heparin-binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here, we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are co-expressed in horizontal cells and proliferating Müller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration.
2008-12-17 | GSE13999 | GEO
Project description:Midkine-a regulates the formation of a fibrotic scar during zebrafish heart regeneration
| PRJNA701763 | ENA
Project description:Canonical roles for macrophages in mediating the fibrotic response after a heart attack (myocardial infarction) include turnover of the extracellular matrix and activation of cardiac fibroblasts to initiate collagen deposition. Here we reveal through studying the functional kinetics of fibrosis during zebrafish heart regeneration and mouse heart repair that macrophages can directly contribute collagen to the forming scar. Unbiased transcriptomics revealed an up-regulation of collagen isoforms in both zebrafish and mouse macrophages following injury. Adoptive transfer of macrophages from collagen-tagged transgenic zebrafish and splenic monocyte-derived macrophages from adult mouse GFPtpz-collagen donors, enhanced scar formation and induced fibrosis, respectively, via cell autonomous production of collagen. In zebrafish, macrophage-specific targeting of collagen 4a binding protein and cognate collagen 4a1 followed by transfer led to significantly reduced scarring in cryo-injured hosts. These findings contrast with the current model of scarring whereby collagen deposition is exclusively attributed to myofibroblasts, and implicate macrophages as direct contributors to fibrosis during heart repair.
2019-12-18 | GSE100029 | GEO
Project description:The adult mammalian heart heals after myocardial infarction (MI) by deposition of scar tissue, leading to downstream arrhythmia, remodelling and heart failure1. In contrast, adult zebrafish and neonatal mouse hearts are capable of regenerating after injury. Macrophages are key mediators of tissue repair and appear to be required for both regeneration and healing by scar formation, but the mechanisms underlying these distinct roles are poorly understood2-4. Here we investigated how macrophages differentially influence the mode of repair by determining their responses in scar-free versus scar-induced healing, comparing ventricular resection with cryo-injured adult zebrafish hearts and neonatal versus adult mouse hearts after MI. Unbiased transcriptomics revealed molecular programmes implicating macrophages in the initiation and resolution of inflammation to dictate the kinetics of scarring during zebrafish regeneration and the activation of direct and indirect pathways to drive fibrosis in the adult mouse heart. Most notably we observed up-regulation of collagen isoforms in both zebrafish and mouse macrophages following injury. Adoptive transfer of macrophages, from resected zebrafish hearts into cryo-injured hosts and splenic monocyte-derived macrophages from adult mouse donors into neonatal hearts, enhanced scar formation and induced fibrosis, respectively, via cell autonomous production of collagen. In zebrafish, macrophage-specific targeting of collagen 4a binding protein and cognate collagen 4a1 followed by transfer led to significantly reduced scarring in cryo-injured hosts, as further evidence of a direct macrophage contribution to collagen deposition and scar formation. These findings contrast with the current model of scarring, whereby collagen is laid down exclusively by myofibroblasts, and implicate macrophages as critical regulators of heart repair.
2019-12-18 | GSE126772 | GEO
Project description:The mammalian heart possesses a poor ability to regenerate after acute ischemic cardiac injury and lost cardiac muscle is replaced by scar tissue. Multiple clinical studies demonstrate that the size of scar tissue following myocardial infarction is an independent predictor of cardiovascular outcomes, yet little is known about factors that regulate the size of scar after ischemic cardiac injury. In this report, we demonstrate that collagen V, a fibrillar collagen and a minor constituent of heart scars regulates the size of heart scars after ischemic cardiac injury. Depletion of collagen V in heart scars in two independent animal models led to a significant and paradoxical increase in post infarction scar tissue size with worsening of heart function. A systems genetics approach analyzing genes versus traits across 100 in-bred strains of mice independently demonstrated that collagen V is a critical driver of post injury heart function. We show that collagen V deficiency alters the ultra-structure and mechanical properties of scar tissue that make it more vulnerable to expansion. There is altered reciprocal feedback between matrix and cells that induce expression of specific mechanosensitive integrins which drive fibroblast activation and increased ECM gene expression. Scar size increases. Administration of cilengitide, an inhibitor of specific integrins, completely rescues the phenotype of increased post injury scarring, myofibroblast formation and cardiac dysfunction in collagen V deficient mice. These observations demonstrate that collagen V, a structural constituent of heart scar tissue regulates scar size in an integrin dependent manner.
2020-06-05 | GSE151834 | GEO
Project description:The mammalian heart possesses a poor ability to regenerate after acute ischemic cardiac injury and lost cardiac muscle is replaced by scar tissue. Multiple clinical studies demonstrate that the size of scar tissue following myocardial infarction is an independent predictor of cardiovascular outcomes, yet little is known about factors that regulate the size of scar after ischemic cardiac injury. In this report, we demonstrate that collagen V, a fibrillar collagen and a minor constituent of heart scars regulates the size of heart scars after ischemic cardiac injury. Depletion of collagen V in heart scars in two independent animal models led to a significant and paradoxical increase in post infarction scar tissue size with worsening of heart function. A systems genetics approach analyzing genes versus traits across 100 in-bred strains of mice independently demonstrated that collagen V is a critical driver of post injury heart function. We show that collagen V deficiency alters the ultra-structure and mechanical properties of scar tissue that make it more vulnerable to expansion. There is altered reciprocal feedback between matrix and cells that induce expression of specific mechanosensitive integrins which drive fibroblast activation and increased ECM gene expression. Scar size increases. Administration of cilengitide, an inhibitor of specific integrins, completely rescues the phenotype of increased post injury scarring, myofibroblast formation and cardiac dysfunction in collagen V deficient mice. These observations demonstrate that collagen V, a structural constituent of heart scar tissue regulates scar size in an integrin dependent manner.
2020-06-04 | GSE151695 | GEO
Project description:Fibroblasts are activated to repair the heart following injury. Fibroblast activation in the mammalian heart leads to a permanent fibrotic scar that impairs cardiac function. In other organisms, such as zebrafish, cardiac injury is followed by transient fibrosis and scar-free regeneration. The mechanisms that drive scarring versus scar-free regeneration are not well understood. Here, we show that the homeobox-containing transcription factor Prrx1b is required for scar-free regeneration of the zebrafish heart as the loss of Prrx1b results in excessive fibrosis and impaired cardiomyocyte proliferation. Through lineage tracing and single-cell RNA sequencing we find that Prrx1b is activated in epicardial-derived cells where it restricts TGFβ ligand expression and collagen production. Furthermore, through combined in vitro experiments in human fetal epicardial-derived cells and in vivo rescue experiments in zebrafish, we conclude that Prrx1 stimulates Nrg1 expression and promotes cardiomyocyte proliferation. Collectively, these results indicate that Prrx1 is a key transcription factor that balances fibrosis and regeneration in the injured zebrafish heart.
2021-09-16 | GSE153170 | GEO
Project description:Runx1 is a transcription factor that plays a key role in determining the proliferative and differential state of multiple cell types, during both development and adulthood. Here, we report how runx1 is specifically upregulated at the injury site during zebrafish heart regeneration, but unexpectedly, absence of runx1 results in enhanced regeneration. Using single cell sequencing, we found that the wild-type injury site consists of Runx1-positive endocardial cells and thrombocytes that express smooth muscle and collagen genes without differentiating into myofibroblasts. Both these populations are absent in runx1 mutants, resulting in a less collagenous and fibrinous scar. The reduction in fibrin in the mutant is further explained by reduced myofibroblast formation and by upregulation of components of the fibrin degradation pathway, including plasminogen receptor Annexin 2A as well as downregulation of plasminogen activator inhibitor serpine1 in myocardium and endocardium, resulting in increased levels of Plasminogen. In addition, this we also find enhanced myocardial proliferation as well as increased myocardial survival in the mutant. Our findings suggest that Runx1 controls the regenerative response of multiple cardiac cell-types and that targeting Runx1 is a novel therapeutic strategy to induce endogenous heart repair.
2020-04-16 | GSE138181 | GEO
Project description:Macrophages directly contribute collagen to scar formation during zebrafish heart regeneration and mouse heart repair
| PRJNA523576 | ENA