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Sanz-Morejon, A.

Publications and source records attributed to Sanz-Morejon, A..

4 recordsLinked to original sources

Paternal cardiac injury elicits an inflammatory signal relay to the gonads with intergenerational cardiac effects in vertebrates

The blood-gonadal barrier protects the germline from parental exposures. A phenomenon known as intergenerational inheritance suggests that, exceptionally, this barrier can be surpassed with consequences for the subsequent generation. Specific diet regimes and early traumatic experiences have been among the chronic stressors shown to be able to lead to intergenerational inheritance in mammals. Less is known about how acute stress can affect the germline. Cardiac damage leads to several alterations in peripheral organs and, overall, affects blood flow, metabolism, and the immune response. Whether cardiac damage can also affect the reproductive system is not known and might offer new insights into the potential inheritance of cardiovascular disease. Here, we used zebrafish and mouse models to explore the intergenerational role of cardiac damage and repair. In the first week after a cardiac cryolesion, male zebrafish gonads and gametes activated responses associated with inflammation. In sperm, chromatin accessibility was found altered in response to cardiac cryolesion. Offspring of cryoinjured zebrafish males revealed changes in cardiac function and cardiac gene expression. Induction of systemic sterile inflammation in the paternal generation mimicked cardiac injury effects in the following generation, while anti-inflammatory treatments in the injured paternal generation partially recovered F1 cardiac features. Similar features were found in mouse testis after a neonatal injury, and in the hearts of their offspring, suggesting a conserved role of sterile inflammation as a vector for intergenerational transmission of cardiac injury.

developmental biology↗

A paternal cardiac lesion induces cardiac adaptation in offspring

BackgroundFollowing cardiac injury, whether the heart is permanently damaged or regenerating, distal organs are subjected to changes in physiological function. It remains largely unknown whether a cardiac lesion can affect gametes and transmit heritable changes to subsequent generations. Here, we report the influence of paternal cardiac injury on the following generation. MethodsWe studied the intergenerational influence of neonatal cardiac injury in the mouse, an animal model capable of regenerating the heart after early life injury. Neonatal male mice were subjected to ventricular cryoinjury, crossed at adulthood, and their sires were compared with litters derived from uninjured male mice. We used echocardiography, histology, and single nuclei RNA-sequencing to thoroughly characterize cardiac morphology, composition, function, and response to cardiac insult. ResultsWe show that paternal cardiac injury affects the heart morphology of offspring under physiological conditions. Furthermore, in response to the same injury, the F1 generation derived from injured fathers shows better systemic and cardiac recovery, with non-pathological left ventricular enlargement and improved cardiac function during the regenerative process. This is accompanied by the activation of the immune system healing program at 3 weeks post-injury, together with enhanced transcription of genes associated with physiological hypertrophy. ConclusionsThe memory of a paternal neonatal lesion can be transmitted to offspring and improve their recovery from a cardiac insult.

developmental biology↗

Downregulation of WT1 transcription factor gene expression is required to promote myocardial fate

During cardiac development, cells from the precardiac mesoderm fuse to form the primordial heart tube, which then grows by addition of further progenitors to the venous and arterial poles. In the zebrafish, wilms tumor 1 transcription factor a (wt1a) and b (wt1b) are expressed in the pericardial mesoderm at the venous pole of the forming heart tube. The pericardial mesoderm forms a single layered mesothelial sheet that contributes to further the growth of the myocardium, and forms the proepicardium. Proepicardial cells are subsequently transferred to the myocardial surface and give rise to the epicardium, the outer layer covering the myocardium in the adult heart. wt1a/b expression is downregulated during the transition from pericardium to myocardium, but remains high in proepicardial cells. Here we show that sustained wt1 expression impaired cardiomyocyte maturation including sarcomere assembly, ultimately affecting heart morphology and cardiac function. ATAC-seq data analysis of cardiomyocytes overexpressing wt1 revealed that chromatin regions associated with myocardial differentiation genes remain closed upon wt1b overexpression in cardiomyocytes, suggesting that wt1 represses a myocardial differentiation program. Indeed, a subset of wt1a/b-expressing cardiomyocytes changed their cell adhesion properties, delaminated from the myocardial epithelium, and upregulated the expression of epicardial genes, as confirmed by in vivo imaging. Thus, we conclude that wt1 acts as a break for cardiomyocyte differentiation by repressing chromatin opening at specific genomic loci and that sustained ectopic expression of wt1 in cardiomyocytes can lead to their transformation into epicardial cells.

developmental biology↗

Transient fibrosis resolves via fibroblast inactivation in the regenerating zebrafish heart

In the zebrafish (Danio rerio), regeneration and fibrosis after cardiac injury are not mutually exclusive responses. Upon cardiac cryoinjury, collagen and other extracellular matrix (ECM) proteins accumulate at the injury site. However, in contrast to the situation in mammals, fibrosis is transient in zebrafish and its regression is concomitant with regrowth of the myocardial wall. Little is known about the cells producing this fibrotic tissue or how it resolves. Using novel genetic tools to mark periostin b- and collagen 1alpha2 (col1a2)-expressing cells in combination with transcriptome analysis, we explored the sources of activated fibroblasts and traced their fate. We describe that during fibrosis regression, fibroblasts are not fully eliminated, but become inactivated. Unexpectedly, limiting the fibrotic response by genetic ablation of col1a2-expressing cells impaired cardiomyocyte proliferation. We conclude that ECM-producing cells are key players in the regenerative process and suggest that anti-fibrotic therapies might be less efficient than strategies targeting fibroblast inactivation.\n\nSCIENTIFIC STATEMENTAfter myocardial infarction in the mammalian heart, millions of cardiomyocytes are lost and replaced by fibrotic scar tissue. While fibrosis is persistent in adult mammals, there are some vertebrates, including zebrafish, with the capacity for regeneration. This process does not occur in the absence of fibrosis. Here we studied subpopulations of collagen producing cells and analyzed their fate after complete regeneration of the zebrafish myocardium. Our data show that fibroblasts persisted in the regenerated heart, but shut down the profibrotic program. While fibrosis could be considered as detrimental to the regeneration process, our study reveals a positive effect on cardiomyocyte proliferation. Accordingly, a fibrotic response can be beneficial for heart regeneration.

developmental biology↗