scholarly journals hrT is required for cardiovascular development in zebrafish

Development ◽  
2002 ◽  
Vol 129 (21) ◽  
pp. 5093-5101 ◽  
Author(s):  
Daniel P. Szeto ◽  
Kevin J. P. Griffin ◽  
David Kimelman

The recently identified zebrafish T-box gene hrT is expressed in the developing heart and in the endothelial cells forming the dorsal aorta. Orthologs of hrT are expressed in cardiovascular cells fromDrosophila to mouse, suggesting that the function of hrT is evolutionarily conserved. The role of hrT in cardiovascular development, however, has not thus far been determined in any animal model. Using morpholino antisense oligonucleotides, we show that zebrafish embryos lacking hrT function have dysmorphic hearts and an absence of blood circulation. Although the early events in heart formation were normal inhrT morphant embryos, subsequently the hearts failed to undergo looping, and late onset defects in chamber morphology and gene expression were observed. In particular, we found that the loss of hrT function led to a dramatic upregulation of tbx5, a gene required for normal heart morphogenesis. Conversely, we show that overexpression of hrT causes a significant downregulation of tbx5, indicating that one key role ofhrT is to regulate the levels of tbx5. Secondly, we found that HrT is required to inhibit the expression of the blood lineage markersgata1 and gata2 in the most posterior lateral plate mesoderm. Finally, we show that HrT is required for vasculogenesis in the trunk, leading to similar vascular defects to those observed in midline mutants such as floating head. hrT expression in the vascular progenitors depends upon midline mesoderm, indicating that this expression is one important component of the response to a midline-derived signal during vascular morphogenesis.

2021 ◽  
Author(s):  
Scott A rankin ◽  
Jeffery D Steimle ◽  
Xinan Yang ◽  
Ariel B Rydeen ◽  
Kunal Agarwal ◽  
...  

The gene regulatory networks that coordinate the development of the cardiac and pulmonary systems are essential for terrestrial life but poorly understood. The T-box transcription factor Tbx5 is critical for both pulmonary specification and heart development, but how these activities are mechanistically integrated remains unclear. We show that Tbx5 regulates an evolutionarily conserved retinoic acid (RA)-Hedgehog-Wnt signaling cascade coordinating cardiopulmonary development. We demonstrate that Tbx5 directly maintains expression of the RA-synthesizing enzyme Aldh1a2 in the foregut lateral plate mesoderm via an intronic enhancer that is evolutionarily conserved among terrestrial vertebrates. Tbx5 promotes posterior second heart field identity in a positive feedback loop with RA, antagonizing a Fgf8-Cyp regulatory module and restricting FGF activity to the anterior. Tbx5/Aldh1a2-dependent RA signaling also directly activates Shh transcription in the adjacent foregut endoderm through the conserved MACS1 enhancer. Epithelial Hedgehog then signals back to the mesoderm, where together with Tbx5 it activates expression of Wnt2/2b that ultimately induce pulmonary fate in the foregut endoderm. These results provide mechanistic insight into the interrelationship between heart and lung development informing cardiopulmonary evolution and birth defects.


2021 ◽  
Author(s):  
Yuqi You ◽  
Lucas R. Novak ◽  
Kevin Clancy ◽  
Wen Li

ABSTRACTAnimal research has recognized the role of the sensory cortex in fear memory and two key underlying mechanisms—pattern separation and tuning shift. We interrogated these mechanisms in the human sensory cortex in an olfactory differential conditioning study with a delayed (9-day) retention test. Combining affective appraisal and olfactory psychophysics with functional magnetic resonance imaging (fMRI) multivoxel pattern analysis and voxel-based tuning analysis over a linear odor-morphing continuum, we confirmed affective and perceptual learning and memory and demonstrated associative plasticity in the human olfactory (piriform) cortex. Specifically, the piriform cortex exhibited immediate and lasting enhancement in pattern separation (between the conditioned stimuli/CS and neighboring non-CS) and late-onset yet lasting tuning shift towards the CS, especially in anxious individuals. These findings highlight an evolutionarily conserved sensory cortical system of fear memory, which can underpin sensory encoding of fear/threat and confer a sensory mechanism to the neuropathophysiology of anxiety.


2020 ◽  
Author(s):  
Sascha Werner ◽  
Sihem Zitouni ◽  
Pilar Okenve-Ramos ◽  
Susana Mendonca ◽  
Anje Sporbert ◽  
...  

Cilia are involved in a plethora of motility and sensory-related functions. Ciliary defects cause several ciliopathies, some of which with late-onset, suggesting cilia are actively maintained. While much is known about cilia assembly, little is understood about the mechanisms of their maintenance. Given that intraflagellar transport (IFT) is essential for cilium assembly, we investigated the role of one of its main players, IFT88, in ciliary maintenance. We show that DmIFT88, the Drosophila melanogaster orthologue of IFT88, continues to move along fully formed sensory cilia, and that its acute knockdown in the ciliated neurons of the adult affects sensory behaviour. We further identify DmGucy2d, the Drosophila guanylyl cyclase 2d, as a DmIFT88 cargo, whose loss also leads to defects in sensory behaviour maintenance. DmIFT88 binds to the intracellular part of DmGucy2d, a highly, evolutionarily conserved and mutated in several degenerative retina diseases, taking the cyclase into the cilia. Our results offer a novel mechanism for the maintenance of sensory cilia function and its potential role in human diseases.


Development ◽  
1997 ◽  
Vol 124 (7) ◽  
pp. 1355-1366 ◽  
Author(s):  
H.G. Simon ◽  
R. Kittappa ◽  
P.A. Khan ◽  
C. Tsilfidis ◽  
R.A. Liversage ◽  
...  

In certain urodeles, a lost appendage, including hand and foot, can be completely replaced through epimorphic regeneration. The regeneration process involves cellular activities similar to those described for embryogenesis. Working on the assumption that the morphological pattern specific for a forelimb or a hindlimb is controlled by different gene activities in the two limbs, we employed a mRNA differential display screen for the detection of candidate limb identity genes. Using this approach, we have isolated a newt gene which in regenerating and developing limbs reveals properties expected of a gene having a role in controlling limb morphology: (1) it is exclusively expressed in the forelimbs, but not hindlimbs, (2) during embryonic development its expression is co-incident with forelimb bud formation, (3) it has an elevated message level throughout the undifferentiated limb bud and the blastema, respectively, and (4) it is expressed only in mesenchymal, but not in epidermal tissues. This novel newt gene shares a conserved DNA-binding domain, the T-box, with putative transcription factors including the Brachyury (T) gene product. In a following PCR-based screen, we used the evolutionarily conserved T-box motif and amplified a family of related genes in the newt; their different expression patterns in normal and regenerating forelimbs, hindlimbs and tail suggest, in general, an important role of T-domain proteins in vertebrate pattern formation.


Author(s):  
Yuwen Chen ◽  
Deyong Xiao ◽  
Lu Zhang ◽  
Chen-Leng Cai ◽  
Bai-Yan Li ◽  
...  

Tbx20 is a member of the Tbx1 subfamily of T-box-containing genes and is known to play a variety of fundamental roles in cardiovascular development and homeostasis as well as cardiac remodeling in response to pathophysiological stresses. Mutations in TBX20 are widely associated with the complex spectrum of congenital heart defects (CHDs) in humans, which includes defects in chamber septation, chamber growth, and valvulogenesis. In addition, genetic variants of TBX20 have been found to be associated with dilated cardiomyopathy and heart arrhythmia. This broad spectrum of cardiac morphogenetic and functional defects is likely due to its broad expression pattern in multiple cardiogenic cell lineages and its critical regulation of transcriptional networks during cardiac development. In this review, we summarize recent findings in our general understanding of the role of Tbx20 in regulating several important aspects of cardiac development and homeostasis and heart function.


2021 ◽  
Vol 8 (10) ◽  
pp. 125
Author(s):  
Angello Huerta Gomez ◽  
Sanika Joshi ◽  
Yong Yang ◽  
Johnathan D. Tune ◽  
Ming-Tao Zhao ◽  
...  

The Notch intercellular signaling pathways play significant roles in cardiovascular development, disease, and regeneration through modulating cardiovascular cell specification, proliferation, differentiation, and morphogenesis. The dysregulation of Notch signaling leads to malfunction and maldevelopment of the cardiovascular system. Currently, most findings on Notch signaling rely on animal models and a few clinical studies, which significantly bottleneck the understanding of Notch signaling-associated human cardiovascular development and disease. Recent advances in the bioengineering systems and human pluripotent stem cell-derived cardiovascular cells pave the way to decipher the role of Notch signaling in cardiovascular-related cells (endothelial cells, cardiomyocytes, smooth muscle cells, fibroblasts, and immune cells), and intercellular crosstalk in the physiological, pathological, and regenerative context of the complex human cardiovascular system. In this review, we first summarize the significant roles of Notch signaling in individual cardiac cell types. We then cover the bioengineering systems of microfluidics, hydrogel, spheroid, and 3D bioprinting, which are currently being used for modeling and studying Notch signaling in the cardiovascular system. At last, we provide insights into ancillary supports of bioengineering systems, varied types of cardiovascular cells, and advanced characterization approaches in further refining Notch signaling in cardiovascular development, disease, and regeneration.


2020 ◽  
Vol 21 (12) ◽  
pp. 1164-1173
Author(s):  
Siju Ellickal Narayanan ◽  
Nikhila Sekhar ◽  
Rajalakshmi Ganesan Rajamma ◽  
Akash Marathakam ◽  
Abdullah Al Mamun ◽  
...  

: Alzheimer’s disease (AD) is a progressive brain disorder and one of the most common causes of dementia and death. AD can be of two types; early-onset and late-onset, where late-onset AD occurs sporadically while early-onset AD results from a mutation in any of the three genes that include amyloid precursor protein (APP), presenilin 1 (PSEN 1) and presenilin 2 (PSEN 2). Biologically, AD is defined by the presence of the distinct neuropathological profile that consists of the extracellular β-amyloid (Aβ) deposition in the form of diffuse neuritic plaques, intraneuronal neurofibrillary tangles (NFTs) and neuropil threads; in dystrophic neuritis, consisting of aggregated hyperphosphorylated tau protein. Elevated levels of (Aβ), total tau (t-tau) and phosphorylated tau (ptau) in cerebrospinal fluid (CSF) have become an important biomarker for the identification of this neurodegenerative disease. The aggregation of Aβ peptide derived from amyloid precursor protein initiates a series of events that involve inflammation, tau hyperphosphorylation and its deposition, in addition to synaptic dysfunction and neurodegeneration, ultimately resulting in dementia. The current review focuses on the role of proteomes in the pathogenesis of AD.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Aileen Patricia Szczepanski ◽  
Lu Wang

AbstractHistone H2AK119 mono-ubiquitination (H2AK119Ub) is a relatively abundant histone modification, mainly catalyzed by the Polycomb Repressive Complex 1 (PRC1) to regulate Polycomb-mediated transcriptional repression of downstream target genes. Consequently, H2AK119Ub can also be dynamically reversed by the BAP1 complex, an evolutionarily conserved multiprotein complex that functions as a general transcriptional activator. In previous studies, it has been reported that the BAP1 complex consists of important biological roles in development, metabolism, and cancer. However, identifying the BAP1 complex’s regulatory mechanisms remains to be elucidated due to its various complex forms and its ability to target non-histone substrates. In this review, we will summarize recent findings that have contributed to the diverse functional role of the BAP1 complex and further discuss the potential in targeting BAP1 for therapeutic use.


2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Ahmed Ayuna ◽  
Nik Abidin

Abstract Background Anthracycline-induced cardiotoxicity has been classified based on its onset into acute, early, and late. It may have a significant burden on the quality and quantity of life of those exposed to this class of medication. Currently, there are several ongoing debates on the role of different measures in the primary prevention of cardiotoxicity in cancer survivors. Our article aims to focus on the role of neurohormonal blockers in the primary prevention of anthracycline-induced cardiotoxicity, whether it is acute, early, or late onset. Main body of the abstract PubMed and Google Scholar database were searched for the relevant articles; we reviewed and appraised 15 RCTs, and we found that angiotensin-converting enzyme inhibitors (ACEI) and B-blockers were the most commonly used agents. Angiotensin II receptor blockers (ARBs) and mineralocorticoid receptor antagonists (MRAs) were used in a few other trials. The follow-up period was on the range of 1–156 weeks (mode 26 weeks). Left ventricular ejection fraction (LVEF), left ventricular diameters, and diastolic function were assessed by either echocardiogram or occasionally by cardiac magnetic resonance imaging (MRI). The occurrence of myocardial injury was assessed by troponin I. It was obvious that neurohormonal blockers reduced the occurrence of LVEF and myocardial injury in 14/15 RCTs. Short conclusion Beta-blockers, especially carvedilol and ACEI, especially enalapril, should be considered for the primary prevention of acute- and early-onset cardiotoxicity. ARB and MRA are suitable alternatives when patients are intolerant to ACE-I and B-blockers. We recommend further studies to explore and establish the role of neurohormonal blockers in the primary prevention of the acute-, early-, and late-onset cardiotoxicity.


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