Abstract P316: Role Of Scleraxis In Cardiac Valve Development And Disease

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Madhav Karthik Kodigepalli ◽  
Joy Lincoln
Keyword(s):  
Heart Development ◽  
Heart Valves ◽  
High Throughput Sequencing ◽  
Temporal Analysis ◽  
Cardiac Valve ◽  
Common Disease ◽  
Bhlh Transcription Factor ◽  
Loss Of Function ◽  
Valve Development

Valvular heart disease is one of the major causes of cardiac-related deaths in the US and effective treatment is currently limited to surgical repair or replacement. Mature heart valves are composed of highly organized and stratified layers of extracellular matrix (ECM) regulated by valve interstitial cells (VICs). This stratification that is initiated during embryogenesis and completed during valve maturation after birth, needs to be maintained throughout life for normal valve function. Myxomatous degeneration is a common disease histologically characterized by imbalance in ECM composition and organization resulting in valve biomechanical failure. Yet, key regulators of ECM homeostasis are not well characterized. Scleraxis (Scx) is a bHLH transcription factor that we previously showed to be critical for heart valve development and its loss of function leads to defective VIC maturation and aberrant ECM organization. However, due to lack of efficient tools, the mechanistic function of Scx in valve development and disease in vivo remains to be understood. Herein, we performed temporal analysis of Scx transcript levels during development of murine homeostatic valves and identified that Scx is predominantly expressed in the VICs between E13.5 and P14. We also assessed Scx levels and ECM abnormalities in valve tissues derived from patients with cardiac valve diseases and identified several distinct populations of VICs with high Scx levels that partially colocalized with elevated collagen fragmentation and proteoglycan (PG) deposition in the neighboring ECM. Scx levels were also elevated in valves of Fbn1 C1039G/+ and osteogenesis imperfecta murine ( OIM ) mice that develop myxomatous valve abnormalities signifying a potential role in pathogenesis. To further study the function of Scx in valve development and disease in vivo , we have generated a conditional Scx-transgenic model (Scx-TG) that will allow for overexpression in targeted cell lineages upon Cre recombination. Additionally, we will employ Scx-Cre mouse model expressing Scx-promoter driven Cre -recombinase to perform Scx-expressing cell lineage analyses and high-throughput sequencing analyses to identify direct gene targets and protein-interaction partners of Scx to better understand its mechanistic role in regulating valve ECM homeostasis. Together these in vivo approaches will provide novel insights into the function of Scx in heart development and disease.

scholarly journals EJE Prize 2013: Regulation of aldosterone secretion: from physiology to disease

2013 ◽  
Vol 168 (6) ◽  
pp. R85-R93 ◽  
Author(s):  
Felix Beuschlein
Keyword(s):  
High Throughput Sequencing ◽  
Secondary Hypertension ◽  
Small Sample ◽  
Cellular Systems ◽  
Common Disease ◽  
Aldosterone Secretion ◽  
Technical Developments ◽  
Starting Point

Arterial hypertension is a major cardiovascular risk factor that affects between 10 and 40% of the population in industrialized countries. Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of around 10% in referral centers and 4% in a primary care setting. Despite its high prevalence until recently, the underlying genetic and molecular basis of this common disease had remained largely obscure. Over the past decade, a number of insights have been achieved that have relied onin vitrocellular systems, wild-type and genetically modifiedin vivomodels, as well as clinical studies in well-characterized patient populations. This progress has been made possible by a number of independent technical developments including that of specific hormone assays that allow measurement in small sample volumes as well as genetic techniques that enable high-throughput sequencing of a large number of samples. Furthermore, animal models have provided important insights into the physiology of aldosterone regulation that have served as a starting point for investigation of mechanisms involved in autonomous aldosterone secretion. Finally, national and international networks that have built up registries and biobanks have been instrumental in fostering translational research endeavors in PA. Therefore, it is to be expected that in the near future, further pathophysiological mechanisms that result in autonomous aldosterone secretion will be unraveled.

Abstract MP235: PROX1 Contributes To Cardiac Valve Disease

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
YenChun Ho ◽  
Xin Geng ◽  
Rohan Varshney ◽  
Jang Kim ◽  
Sandeep Surbrahmanian ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Heart Valves ◽  
Cardiac Valve ◽  
Valve Disease ◽  
Matrix Composition ◽  
Cardiac Valves ◽  
Aortic Valves ◽  
Mitral Valves ◽  
Valve Development ◽  
Cardiac Valve Disease

Background: Heart valves regulate the unidirectional forward flow and prevent retrograde backflow of blood during the cardiac cycle. Cardiac valve disease (CVD) is observed in approximately 2.5% of the general population and the incidence increases to ~10% in elderly people. Patients with severe CVD require surgery and effective pharmacological treatments are currently not available. PROX1 is a transcription factor that regulates the development of lymphatic, venous, and lymphovenous valves (vascular valves). We identified that PROX1 is also expressed in a subset of valvular endothelial cells (VECs) that are located on the downstream (fibrosa) side of cardiac valves. Whether PROX1 regulates cardiac valve development and disease is not known. Method and Results: We have discovered that mice lacking Prox1 in their VECs ( Prox1 ΔVEC ) develop enlarged aortic and mitral valves in which the expression of proteoglycans is increased (control, N=10; Prox1 ΔVEC , N=9, p <0.05). Echocardiography revealed moderate to severe stenosis of aortic valves of Prox1 ΔVEC mice (control, N=5; Prox1 ΔVEC , N=9, p <0.05). PROX1 regulates the expression of the transcription factor FOXC2 in the vascular valves. Similarly, we have found that the expression of FOXC2 is downregulated in the VECs of Prox1 ΔVEC mice. Specific knockdown of FOXC2 in VECs results in the thickening of aortic valves (control, N=10; shFoxc2 ΔVEC , N=8, p <0.05). Furthermore, restoration of FOXC2 expression in VECs ( Foxc2 OE-VEC ) ameliorates the thickening of the aortic valves of Prox1 ΔVEC mice ( Prox1 ΔVEC , N=9; Foxc2 OE-VEC ; Prox1 ΔVEC , N=8, p <0.05). We have also determined that the expression of platelet-derived growth factor-B ( Pdgfb ) is increased in the valve tissue of Prox1 ΔVEC mice and in PROX1 deficient sheep mitral valve VECs (MVECs) (siCtrl , N=4; siProx1 , N=4, p <0.05). Additionally, hyperactivation of PDGF-B signaling in mice results in a phenotype that is similar to Prox1 ΔVEC mice (control , N=4; Pdgfb GOF , N=3, p <0.05). Conclusion: Together these data suggest that PROX1 maintains the extracellular matrix composition of cardiac valves by regulating the expressions of FOXC2 and PDGF-B in VECs.

scholarly journals Exposure to Mites Sensitizes Intestinal Stem Cell Maintenance, Splenic Marginal Zone B Cell Homeostasis, And Heart Development to Notch Dosage and Cooperativity

2020 ◽  
Author(s):  
Francis M. Kobia ◽  
Kristina Preusse ◽  
Quanhui Dai ◽  
Nicholas Weaver ◽  
Praneet Chaturvedi ◽  
...  
Keyword(s):  
B Cell ◽  
Heart Development ◽  
Marginal Zone ◽  
B Cell Lymphoma ◽  
Mite Infestation ◽  
List Type ◽  
Loss Of Function ◽  
B Cell Homeostasis

AbstractCooperative DNA binding is a key feature of transcriptional regulation. Here we examined the role of cooperativity in Notch signaling by CRISPR-mediated engineering of mice in which neither Notch1 nor Notch2 can homo- or heterodimerize, essential for cooperative binding to sequence paired sites (SPS) located near many Notch-regulated genes. While most known Notch-dependent phenotypes were unaffected in Notch1/2 dimer-deficient mice, a subset of tissues proved highly sensitive to loss of cooperativity. These phenotypes include heart development, compromising viability in combination with low gene dose, and the gut, developing ulcerative colitis in response to 1% DSS. The most striking phenotypes – gender imbalance and splenic marginal zone B cell lymphoma – emerged in combination with dose reduction or when challenged by chronic fur mite infestation. This study highlights the role of the environment in malignancy and colitis, and is consistent with Notch-dependent anti-parasite immune responses being compromised in the dimer deficient animals.HighlightsNotch dimerization has an in vivo role in contributing to intestinal homeostasisLoss of cooperativity can manifest as Notch gain or loss of function phenotypesMite infestation exacerbates all phenotypes, triggers MZB hyperproliferation in mutant animalsMite-infested mutant mice develop SMZL with age

scholarly journals ChEC-seq kinetics discriminates transcription factor binding sites by DNA sequence and shape in vivo

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Gabriel E. Zentner ◽  
Sivakanthan Kasinathan ◽  
Beibei Xin ◽  
Remo Rohs ◽  
Steven Henikoff
Keyword(s):  
Transcription Factor ◽  
High Throughput Sequencing ◽  
Temporal Analysis ◽  
Micrococcal Nuclease ◽  
Time Resolved ◽  
Calcium Dependent ◽  
Consensus Motifs ◽  
Dna Shape ◽  
Kinetics Of

Abstract Chromatin endogenous cleavage (ChEC) uses fusion of a protein of interest to micrococcal nuclease (MNase) to target calcium-dependent cleavage to specific genomic loci in vivo. Here we report the combination of ChEC with high-throughput sequencing (ChEC-seq) to map budding yeast transcription factor (TF) binding. Temporal analysis of ChEC-seq data reveals two classes of sites for TFs, one displaying rapid cleavage at sites with robust consensus motifs and the second showing slow cleavage at largely unique sites with low-scoring motifs. Sites with high-scoring motifs also display asymmetric cleavage, indicating that ChEC-seq provides information on the directionality of TF-DNA interactions. Strikingly, similar DNA shape patterns are observed regardless of motif strength, indicating that the kinetics of ChEC-seq discriminates DNA recognition through sequence and/or shape. We propose that time-resolved ChEC-seq detects both high-affinity interactions of TFs with consensus motifs and sites preferentially sampled by TFs during diffusion and sliding.

scholarly journals Systems Pharmacology-Based Precision Therapy and Drug Combination Discovery for Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3586
Author(s):  
Ze-Jia Cui ◽  
Min Gao ◽  
Yuan Quan ◽  
Bo-Min Lv ◽  
Xin-Yu Tong ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Discovery ◽  
High Throughput Sequencing ◽  
High Reliability ◽  
Animal Experiments ◽  
Common Disease ◽  
Biomedical Data ◽  
Systems Pharmacology

Breast cancer (BC) is a common disease and one of the main causes of death in females worldwide. In the omics era, researchers have used various high-throughput sequencing technologies to accumulate massive amounts of biomedical data and reveal an increasing number of disease-related mutations/genes. It is a major challenge to use these data effectively to find drugs that may protect human health. In this study, we combined the GeneRank algorithm and gene dependency network to propose a precision drug discovery strategy that can recommend drugs for individuals and screen existing drugs that could be used to treat different BC subtypes. We used this strategy to screen four BC subtype-specific drug combinations and verified the potential activity of combining gefitinib and irinotecan in triple-negative breast cancer (TNBC) through in vivo and in vitro experiments. The results of cell and animal experiments demonstrated that the combination of gefitinib and irinotecan can significantly inhibit the growth of TNBC tumour cells. The results also demonstrated that this systems pharmacology-based precision drug discovery strategy effectively identified important disease-related genes in individuals and special groups, which supports its efficiency, high reliability, and practical application value in drug discovery.

scholarly journals Different combinations of ErbB receptor dimers generate opposing signals that regulate cell proliferation in cardiac valve development

2016 ◽  
Author(s):  
Ryo Iwamoto ◽  
Naoki Mine ◽  
Hiroto Mizushima ◽  
Eisuke Mekada
Keyword(s):  
Cell Proliferation ◽  
Egf Receptor ◽  
Ex Vivo ◽  
Mesenchymal Cell ◽  
Cardiac Valve ◽  
Erbb Receptors ◽  
Ex Vivo Model ◽  
Intracellular Domain ◽  
Valve Development

AbstractHB-EGF plays an indispensable role in suppression of cell proliferation in mouse valvulogenesis. However, ligands of the EGF receptor (EGFR/ErbB1), including HB-EGF, are generally considered as growth-promoting factors, as shown in cancers. HB-EGF binds to and activates ErbB1 and ErbB4. We investigated the role of ErbB receptors in valvulogenesis in vivo using ErbB1- and ErbB4-deficient mice, and an ex vivo model of endocardial cushion explants. We show that HB-EGF suppresses valve mesenchymal cell proliferation through a heterodimer of ErbB1 and ErbB4, and an ErbB1 ligand(s) promotes cell proliferation through a homodimer of ErbB1. Moreover, a rescue experiment with cleavable or uncleavable isoforms of ErbB4 in ERBB4 null cells suggests that the cytoplasmic intracellular domain of ErbB4, rather than the membrane-anchored tyrosine kinase, achieves this suppression. Our study demonstrates that opposing signals generated by different ErbB dimer combinations function in the same cardiac cushion mesenchymal cells for proper cardiac valve formation.Summary statementIn valvulogenesis, opposing signals generated by different combinations of ErbB-dimers elaborately regulate cell proliferation, in which proteolytically released intracellular domain of ErbB4 activated by HB-EGF is required to suppress proliferation.

NeuroD regulates multiple functions in the developing neural retina in rodent

Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 23-36 ◽  
Author(s):  
E.M. Morrow ◽  
T. Furukawa ◽  
J.E. Lee ◽  
C.L. Cepko
Keyword(s):  
Cell Fate ◽  
Neural Retina ◽  
Bhlh Transcription Factor ◽  
Loss Of Function ◽  
Fourfold Increase ◽  
Helix Loop Helix ◽  
Retinal Explants ◽  
Fate Decision ◽  
And Function

The expression and function of the basic helix-loop-helix (bHLH) transcription factor NeuroD were studied in the developing neural retina in rodent. neuroD was expressed in areas of undetermined retinal cells as well as developing photoreceptors and amacrine interneurons. Expression was maintained in a subset of mature photoreceptors in the adult retina. Using both loss-of-function and gain-of-function approaches, NeuroD was found to play multiple roles in retinal development. (1) NeuroD was found to be a critical regulator of the neuron versus glial cell fate decision. Retinal explants derived from NeuroD-null mice demonstrated a three- to fourfold increase in Muller glia. Forced expression of neuroD in progenitors in rat using retroviruses hastened cell cycle withdrawal and blocked gliogenesis in vivo. (2) NeuroD appeared to regulate interneuron development, favouring amacrine over bipolar differentiation. Forced NeuroD expression resulted in an increase in amacrine interneurons and a decrease in bipolar interneurons. In the complementary experiment, retinae derived from NeuroD-null mice demonstrated a twofold increase in bipolar interneurons and a delay in amacrine differentiation. (3) NeuroD appeared to be essential for the survival of a subset of rod photoreceptors. In conclusion, these results implicate NeuroD in a variety of developmental functions including cell fate determination, differentiation and neuron survival.

scholarly journals Focal adhesions are essential to drive zebrafish heart valve morphogenesis

2019 ◽  
Vol 218 (3) ◽  
pp. 1039-1054 ◽  
Author(s):  
Felix Gunawan ◽  
Alessandra Gentile ◽  
Ryuichi Fukuda ◽  
Ayele Taddese Tsedeke ◽  
Vanesa Jiménez-Amilburu ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Heart Valves ◽  
Focal Adhesions ◽  
Complex Structures ◽  
Loss Of Function ◽  
Integrin Α5β1 ◽  
Vertebrate Model ◽  
Retrograde Blood Flow ◽  
Zebrafish Heart

Elucidating the morphogenetic events that shape vertebrate heart valves, complex structures that prevent retrograde blood flow, is critical to understanding valvular development and aberrations. Here, we used the zebrafish atrioventricular (AV) valve to investigate these events in real time and at single-cell resolution. We report the initial events of collective migration of AV endocardial cells (ECs) into the extracellular matrix (ECM), and their subsequent rearrangements to form the leaflets. We functionally characterize integrin-based focal adhesions (FAs), critical mediators of cell–ECM interactions, during valve morphogenesis. Using transgenes to block FA signaling specifically in AV ECs as well as loss-of-function approaches, we show that FA signaling mediated by Integrin α5β1 and Talin1 promotes AV EC migration and overall shaping of the valve leaflets. Altogether, our investigation reveals the critical processes driving cardiac valve morphogenesis in vivo and establishes the zebrafish AV valve as a vertebrate model to study FA-regulated tissue morphogenesis.

scholarly journals AGO HITS-CLIP in Adipose Tissue Reveals miR-29 as a Post-Transcriptional Regulator of Leptin

2020 ◽  
Author(s):  
Sean O’Connor ◽  
Elisabeth Murphy ◽  
Sarah K. Szwed ◽  
Matt Kanke ◽  
François Marchildon ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Binding Sites ◽  
High Throughput Sequencing ◽  
Transcriptional Regulator ◽  
Binding Activity ◽  
Loss Of Function ◽  
Individual Mirnas ◽  
Brown Adipose ◽  
Therapeutic Opportunity

MicroRNAs (miRNAs) are short, non-coding RNAs that associate with Argonaute (AGO) to regulate mRNA stability and translation. While individual miRNAs have been shown to play important roles in white and brown adipose tissue in normal physiology and disease1,2,3, a comprehensive analysis of miRNA activity in these tissues has not been performed. We used high-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP) to comprehensively characterize the network of high-confidence, in vivo mRNA:miRNA interactions across white and brown fat, revealing over 100,000 unique miRNA binding sites. Targets for each miRNA were ranked to generate a catalog of miRNA binding activity, and the miR-29 family emerged as a top regulator of adipose tissue gene expression. Among the top targets of miR-29 was leptin, an adipocyte-derived hormone that acts on the brain to regulate food intake and energy expenditure4. Two independent miR-29 binding sites in the leptin 3’-UTR were validated using luciferase assays, and miR-29 gain and loss-of-function modulated leptin mRNA and protein secretion in primary adipocytes. In mice, miR-29 abundance inversely correlated with leptin levels in two independent models of obesity. This work represents the only experimentally generated miRNA targetome in adipose tissue and identifies the first known post-transcriptional regulator of leptin. Future work aimed at manipulating miR-29:leptin binding may provide a therapeutic opportunity to treat obesity and its sequelae.

scholarly journals circITGA7 Acts as a miR-370-3p Sponge to Suppress the Proliferation of Prostate Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Gang Luo ◽  
Guohao Li ◽  
Zhihua Wan ◽  
Yuanjie Zhang ◽  
Dong Liu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
High Throughput Sequencing ◽  
Target Genes ◽  
Expression Profiles ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Loss Of Function

Prostate cancer (PCa) refers to one of the most common tumors in male’s genitourinary system. Emerging research has confirmed that circRNAs play an important role in the occurrence and development of tumors. However, the correlation between circular RNA circITGA7 and PCa still remains unclear. Here, the role of circITGA7 in PCa was explored and the underlying mechanism was investigated as well. The circRNA expression profiles in PCa and the paracancerous tissues were established by high-throughput sequencing. The expression levels of circITGA7 in PCa tissues and cells were detected by qRT-PCR. Cell Counting Kit-8, colony formation, EdU, and flow cytometry assays were used to detect the effects of circITGA7 on PCa cell proliferation. To further explore the underlying mechanisms, bioinformatics analysis on downstream target genes was carried out. RNA immunoprecipitation and dual-luciferase reporter assays were used to verify the direct relationship between miR-370-3p and circITGA7 or P21CIP1. The present results demonstrated that circITGA7 was downregulated in PCa tissues and cells. Gain- or loss-of-function assays showed that circITGA7 inhibited the proliferation of PCa cells in vivo and in vitro. Mechanically, circITGA7 served as a sponge for miR-370-3p, and miR-370-3p could target P21CIP1 in PCa cells. The inhibition of cell proliferation induced by circITGA7 could be reversed by transfecting miR-370-3p mimic. Collectively, our data indicated that circITGA7 played an important role in inhibiting tumor proliferation in PCa and might be a potential therapeutic target.

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