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Lymphedema is a debilitating disease with no effective cure and affects an estimated 250 million individuals worldwide. Prior studies have identified mutations in piezo-type mechanosensitive ion channel component 1 (PIEZO1), angiopoietin 2 (ANGPT2), and tyrosine kinase with Ig-like and EGF-like domains 1 (TIE1) in patients with primary lymphedema. Here, we identified crosstalk between these molecules and showed that activation of the mechanosensory channel PIEZO1 in lymphatic endothelial cells (LECs) caused rapid exocytosis of the TIE ligand ANGPT2, ectodomain shedding of TIE1 by disintegrin and metalloproteinase domain-containing protein 17 (ADAM17), and increased TIE/PI3K/AKT signaling, followed by nuclear export of the transcription factor FOXO1. These data establish a functional network between lymphedema-associated genes and provide what we believe to be the first molecular mechanism bridging channel function with vascular signaling and intracellular events culminating in transcriptional regulation of genes expressed in LECs. Our study provides insights into the regulation of lymphatic function and molecular pathways involved in human disease., Introduction Lymphedema is a common disease worldwide, with no cure and variable response to interventions. It may occur as the result of mutations in genes involved in lymphatic development or [...]

Molecular characterization of vascular anomalies has revealed that affected endothelial cells (ECs) harbor gain-of-function (GOF) mutations in the gene encoding the catalytic a subunit of PI3K[alpha] (PIK3CA). These PIK3CA mutations are known to cause solid cancers when occurring in other tissues. PIK3CA-related vascular anomalies, or 'PIKopathies,' range from simple, i.e., restricted to a particular form of malformation, to complex, i.e., presenting with a range of hyperplasia phenotypes, including the PIK3CA-related overgrowth spectrum. Interestingly, development of PIKopathies is affected by fluid shear stress (FSS), a physiological stimulus caused by blood or lymph flow. These findings implicate PI3K in mediating physiological EC responses to FSS conditions characteristic of lymphatic and capillary vessel beds. Consistent with this hypothesis, increased PI3K signaling also contributes to cerebral cavernous malformations, a vascular disorder that affects low- perfused brain venous capillaries. Because the GOF activity of PI3K and its signaling partners are excellent drug targets, understanding PIK3CA's role in the development of vascular anomalies may inform therapeutic strategies to normalize EC responses in the diseased state. This Review focuses on PIK3CA's role in mediating EC responses to FSS and discusses current understanding of PIK3CA dysregulation in a range of vascular anomalies that particularly affect low-perfused regions of the vasculature. We also discuss recent surprising findings linking increased PI3K signaling to fast-flow arteriovenous malformations in hereditary hemorrhagic telangiectasias., Introduction Vascular malformations are caused by genetic defects in endothelial cells (ECs) that line the interior of blood and lymphatic vessels. Most vascular anomalies arise during early vascular development and [...]

BACKGROUND. Preclinical studies suggest that cholesterol accumulation leads to insulin resistance. We previously reported that alterations in a monocyte cholesterol metabolism transcriptional network (CMTN)--suggestive of cellular cholesterol accumulation--were cross-sectionally associated with obesity and type 2 diabetes (T2D). Here, we sought to determine whether the CMTN alterations independently predict incident prediabetes/T2D risk, and correlate with cellular cholesterol accumulation. METHODS. Monocyte mRNA expression of 11 CMTN genes was quantified among 934 Multi-Ethnic Study of Atherosclerosis (MESA) participants free of prediabetes/T2D; cellular cholesterol was measured in a subset of 24 monocyte samples. RESULTS. During a median 6-year follow-up, lower expression of 3 highly correlated LXR target genes--ABCG1 and ABCA1 (cholesterol efflux) and MYLIP (cholesterol uptake suppression)--and not other CMTN genes, was significantly associated with higher risk of incident prediabetes/T2D. Lower expression of the LXR target genes correlated with higher cellular cholesterol levels (e.g., 47% of variance in cellular total cholesterol explained by ABCG1 expression). Further, adding the LXR target genes to overweight/obesity and other known predictors significantly improved prediction of incident prediabetes/T2D. CONCLUSION. These data suggest that the aberrant LXR/ABCG1-ABCA1-MYLIP pathway (LAAMP) is a major T2D risk factor and support a potential role for aberrant LAAMP and cellular cholesterol accumulation in diabetogenesis. FUNDING. The MESA Epigenomics and Transcriptomics Studies were funded by NIH grants 1R01HL101250, 1RF1AG054474, R01HL126477, R01DK101921, and R01HL135009. This work was supported by funding from NIDDK R01DK103531 and NHLBI R01HL119962., Introduction While hypercholesterolemia is a common feature of patients with type 2 diabetes (T2D), its role in the pathogenesis of this disease is not well established. The negative impact of [...]

Lesion mimic mutants (LMMs) often display hypersensitive response-like (HR-like) cell death and enhanced resistance to pathogens. LMMs have heen viewed as useful for the study of the mechanism of cell death and plant immunity. To date, few LMMs have heen found in woody plants. We previously identified an LMM termed Imd, which showed spontaneous cell death in hirch. In the current study, we investigated Imd, oe21 (transgenic control), and NT (nontransgenic control), focusing on cell death and gene expression profile of Imd. We found that cell death in the Imd occurred gradually during leaf development. The number of necrotic spots increased as the leaf developed, with no significant change in spot size. Subcellular observations showed degradation of both mitochondria and chloroplasts in Imd cells but not in NT and oe21 cells. Autophagosomes were visible in dying cells of Imd. We then performed RNA-seq of the four most apical leaves of Imd and oe21 to explore the gene expression profile during cell death. Genes that were functional in signal perception, respiratory burst, signal transduction, and defense were enriched. TGA1, WRKY33, WRKY40, Chitinase, FLS2, RbohA/D, and SBT were identified as key genes involved in cell death in Imd. Key words: birch, cell death, defense, lesion mimic mutant, transcriptome Les mutants mimetiques d'une lesion (LMM) presentent souvent une mort cellulaire de type reponse hypersensible (HR) et une resistance accrue aux agents pathogenes. Les LMM ont ete considered comme utiles pour 1'etude des mecanismes de mort cellulaire et d'immunite chez les plantes. Jusqu'a present, peu de LMM ont ete decouverts chez les plantes ligneuses. Les auteurs ont precedemment identifie un LMM appele Imd, qui presentait une mort cellulaire spontanee chez le bouleau. Dans la presente etude, ils ont etudie Imd, oe21 (controle transgenique) et NT (controle non transgenique), en se concentrant sur la mort cellulaire et le profil d'expression genetique de Imd. Ils ont constate que la mort cellulaire de Imd se produisait progressivement au cours du developpement foliaire. Le nombre de taches necrotiques augmentait au cours du developpement foliaire, sans changement significatif de la taille des taches. Les observations subcellulaires montraient une degradation des mitochondries et des chloroplastes dans les cellules Imd contrairement aux cellules NT et oe21. Des autophagosomes etaient visibles dans les cellules Imd moribondes. Ils ont par la suite realise un sequencage de 1ARN des quatre feuilles les plus apicales de Imd et oe21 arm d'explorer le profil d'expression des genes pendant la mort cellulaire. Les genes qui etaient fonctionnels dans la perception des signaux, l'explosion respiratoire, la transduction des signaux et la defense etaient enrichis. TGA1, WKKY33, WRKY40, Chitinase, FLS2, EbohA/D et SBT ont ete identifies comme des genes cles impliques dans la mort cellulaire chez Imd. [Traduit par la Redaction] Mots-cles : bouleau, mort cellulaire, defense, mutant mimetique d'une lesion, transcriptome, Introduction Programmed cell death (PCD) occurs during all growth and developmental stages in plants including anther development, cell division, leaf morphogenesis, and senescence; this process is also known as developmentally [...]

The highly regulated proliferation of adipocytes plays a momentous role in fat development and obesity. Hoxa5 is an important member of the Hox family, its encoded protein is an important transcription factor related to development, and its differential expression in different adipose tissues seems to indicate that Hoxa5 may be involved in the regulation of adipocyte proliferation. To evaluate the regulatory mechanism of Hoxa5 on adipocyte proliferation, we constructed a variety of Hoxa5 expression vectors in vivo and in vitro to explore its mechanism on adipocyte proliferation and its potential impact on obesity. We observed that the overexpression of Hoxa5 strongly reduces cell counts and Hoxa5 can inhibit cell proliferation and block cell cycle progression by regulating the expression of genes such as Cyclin E, Cyclin Dl, and p53. Most importantly, we demonstrated that Hoxa5 exerts its effect by regulating the signaling pathway of Janus kinase 2 (JAK2) signal transduction and transcription 3 (STAT3) activator, as well as binding to the promoter region of Ccnel and inhibiting the transcription of Ccnel. This study provides an in-depth understanding of the potential molecular mechanism of Hoxa5 inhibiting adipocyte proliferation. Our results suggest the importance of Hoxa5 in the treatment of obesity. Key words: Hoxa5, adipose, cell cycle, Ccnel, JAK2/STAT3 pathway La proliferation hautement regulee des adipocytes joue un role cle dans le developpement du tissu graisseux et l'obesite. Hoxa5 est un membre important de la famille Hox, la proteine qu'il code etant un facteur de transcription important lie au developpement. Son expression differentielle dans differents types de tissus adipeux semble indiquer que Hoxa5 pourrait etre implique dans la regulation de la proliferation des adipocytes. Afin d'evaluer le mecanisme de regulation de Hoxa5 sur la proliferation des adipocytes, les auteurs ont construit une variete de vecteurs d'expression de Hoxa5 in vivo et in vitro pour explorer son mecanisme sur la proliferation des adipocytes et son impact potentiel sur l'obesite. Ils observe que la surexpression de Hoxa5 reduit fortement le nombre de cellules, et que Hoxa5 peut inhiber la proliferation cellulaire et bloquer la progression du cycle cellulaire en regulant l'expression de genes tels cycline E, cycline Dl etp53. Qui plus est, ils ont demontre que Hoxa5 exerce son effet en regulant la voie de signalisation de la Janus kinase 2 (JAK2) et de l'activateur de la transduction du signal et de la transcription 3 (STAT3), ainsi qu'en se liant a la region promotrice de Ccnel et en inhibant la transcription de Ccnel. Cette etude permet de comprendre de maniere approfondie le mecanisme moleculaire potentiel de Hoxa5 dans l'inhibition la proliferation des adipocytes. Ces resultats suggerent l'importance de Hoxa5 dans le traitement de l'obesite. [Traduit par la Redaction] Mots-cles : Hoxa5, adipeux, cycle cellulaire, Ccnel, voie JAK2/STAT3, Introduction Obesity has gradually become the focus of attention, which is characterized by energy imbalance and excessive accumulation of adipose tissue (Haslam and James 2005; Basham and Luik 2008). Its [...]

Introduction Atherosclerosis is a chronic progressive disease involving the buildup of plaque in the arterial wall and leads to coronary artery disease, the principal cause of global mortality (Benjamin et [...], Human arterial endothelial cells (HAECs) regulate their phenotype by integrating signals encoded in the frictional forces exerted by flowing blood, fluid shear stress (FSS). High laminar FSS promotes establishment of adaptive HAEC phenotype protective against atherosclerosis, whereas low or disturbed FSS cause HAECs to adopt atheroprone phenotypes. A vascular endothelial cadherin (VE cadherin)-based mechanosensory complex allows HAECs to regulate barrier function, cell morphology,/ and gene expression in response to FSS. Previously, we reported that this mechanosensor integrated exchange protein activated by cAMP (EPAC1) and a PDE4D gene derived cyclic nucleotide phosphodiesterase (PDE), but had not identified the PDE4D variant involved. Our hypothesis here was that only one of the two ~100 kDa PDE4D variants expressed in HAECs coordinated these responses. Now, we show one unique PDE4D splice variant, PDE4D7, controls transcriptional responses of HAECs to FSS while another, PDE4D5, does not. Adaptive transcriptional responses of HAECs subjected to laminar FSS in vitro were blunted in cells in which PDE4D7 was silenced, but unaffected in cells with silenced PDE4D5. This work identifies a specific therapeutic target for the treatment or prevention of atherosclerosis and improves our understanding of the role of cAMP signaling in modulating mechanosensory signal transduction in the vascular endothelium. Key words: endothelium, fluid shear stress, nitric oxide synthase, phosphodiesterase, cAMP, atherosclerosis, mechanosensory. Les cellules endotheliales arterielles humaines (CEAH) parviennent a reguler leur phenotype en integrant des signaux codes issus de forces de friction exercees par le flux sanguin et des forces de cisaillement engendrees par les liquides (FCL). Des FCL laminaires elevees favorisent l&apos;etablissement d&apos;un phenotype adaptatif protecteur des CEAH contre l&apos;atherosclerose, tandis que des FCL faibles ou desordonnees font en sorte que les CEAH adoptent des phenotypes enclins a l&apos;atherosclerose. Un complexe de capteur mecanique fonde sur les cadherines de l&apos;endothelium vasculaire (cadherine EV) permet aux CEAH de reguler leur fonction de barriere, la morphologie des cellules et l&apos;expression genique en reaction aux FCL. Precedemment, nous avons rapporte que ce capteur mecanique integrait l&apos;EPAC1 (pour << exchange protein activated by cAMP >>) et une phosphodiesterase (PDE) de nucleotides cycliques issue du gene PDE4D, mais nous n&apos;avions pas etabli quelle variante de PDE4D jouait un role. Ici, notre hypothese voulait qu&apos;uniquement l&apos;une des deux variantes de PDE4D d&apos;environ 100 kDa exprimees dans les CEAH coordonnait ces reactions. Nous montrons maintenant que les reactions transcriptionnelles des CEAH aux FCL sont sous le controle d&apos;un variant d&apos;epissage PDE4D unique, le PDE4D7, mais pas d&apos;un autre, le PDE4D5. Les reactions transcriptionnelles adaptatives des CEAH subissant des FCL laminaires in vitro s&apos;attenuaient dans les cellules ou PDE4D7 etait reprime, mais n&apos;etaient pas affectees dans les cellules ou PDE4D5 etait reprime. Ces travaux designent une cible therapeutique specifique pour le traitement ou la prevention de l&apos;atherosclerose, et permettent d&apos;ameliorer notre comprehension du role de la signalisation par l&apos;AMPc dans la modulation de la transduction des signaux mecanosensoriels dans l&apos;endothelium vasculaire. [Traduit par la Redaction] Mots-cles : endothelium, forces de cisaillement engendrees par les liquides, oxyde nitrique synthase, phosphodiesterase, AMPc, atherosclerose, mecanosensoriel.

Author(s): Tyler A. Square [sup.1] [sup.4] , David Jandzik [sup.1] [sup.2] [sup.3] , James L. Massey [sup.1] , Marek Romásek [sup.1] [sup.5] , Haley P. Stein [sup.1] , Andrew W. [...], Neural crest cells (NCCs) are migratory, multipotent embryonic cells that are unique to vertebrates and form an array of clade-defining adult features. The evolution of NCCs has been linked to various genomic events, including the evolution of new gene-regulatory networks.sup.1,2, the de novo evolution of genes.sup.3 and the proliferation of paralogous genes during genome-wide duplication events.sup.4. However, conclusive functional evidence linking new and/or duplicated genes to NCC evolution is lacking. Endothelin ligands (Edns) and endothelin receptors (Ednrs) are unique to vertebrates.sup.3,5,6, and regulate multiple aspects of NCC development in jawed vertebrates.sup.7-10. Here, to test whether the evolution of Edn signalling was a driver of NCC evolution, we used CRISPR-Cas9 mutagenesis.sup.11 to disrupt edn, ednr and dlx genes in the sea lamprey, Petromyzon marinus. Lampreys are jawless fishes that last shared a common ancestor with modern jawed vertebrates around 500 million years ago.sup.12. Thus, comparisons between lampreys and gnathostomes can identify deeply conserved and evolutionarily flexible features of vertebrate development. Using the frog Xenopus laevis to expand gnathostome phylogenetic representation and facilitate side-by-side analyses, we identify ancient and lineage-specific roles for Edn signalling. These findings suggest that Edn signalling was activated in NCCs before duplication of the vertebrate genome. Then, after one or more genome-wide duplications in the vertebrate stem, paralogous Edn pathways functionally diverged, resulting in NCC subpopulations with different Edn signalling requirements. We posit that this new developmental modularity facilitated the independent evolution of NCC derivatives in stem vertebrates. Consistent with this, differences in Edn pathway targets are associated with differences in the oropharyngeal skeleton and autonomic nervous system of lampreys and modern gnathostomes. In summary, our work provides functional genetic evidence linking the origin and duplication of new vertebrate genes with the stepwise evolution of a defining vertebrate novelty. CRISPR-Cas9-mediated disruption of the endothelin-signalling pathway in the sea lamprey Petromyzon marinus and the frog Xenopus laevis were used to delineate ancient and lineage-specific roles of endothelin signalling and provide insights into vertebrate evolution.

Allelopathy is a hot topic of research; however, little is known regarding microRNA (miRNA) expression profiles in plants in response to allelochemicals. In this study, we combined the analyses of the transcriptome, small RNAs (sRNAs), and the degradome to identify key regulatory miRNA-targeted circuits under para-hydroxybenzoic acid (pHBA) stress. A total of 739 and 673 miRNAs were identified in leaves and roots, respectively. Of those, 214 and 148 miRNAs were significantly differentially expressed and identified as pHBA-responsive miRNAs in leaves and roots, respectively. The target genes for the pHBA-responsive miRNAs are involved in signal transduction, response to stress, and secondary metabolite pathways. Furthermore, an integrated analysis of the miRNA-target expression profiles was used to screen the 60 differentially expressed target genes from the 46 differentially expressed miRNAs in the leaves and the 51 differentially expressed target genes from the 36 differentially expressed miRNAs in roots. This integrated analysis revealed 17 and 30 pairs of miRNA targets in the leaves and roots, respectively, which had negatively correlated expression profiles. According to a real-time quantitative polymerase chain reaction (PCR) analysis, 14 miRNA-target pairs also exhibited negative correlations. Moreover, four coexpression regulatory networks were constructed based on the profiles of the differentially expressed miRNA-target pairs. These results suggest that comprehensive analyses of transcriptomes, sRNAs, and the degradome provide a useful platform for investigating the molecular mechanism underlying the pHBA-induced stress response in plants. Key words: Populus x euramericana 'Neva', para-hydroxybenzoic acid stress, allelopathic interference, integration analysis, miRNA-target interaction network. Resume : L'allelopathie est un sujet de recherche tres en vogue, cependant on connait peu les profils d'expression de l'ARNmi chez les plantes en reponse a des substances allelochimiques. Dans cette etude, nous avons combine des analyses du transcriptome, des petits ARNs et des composes relies a la degradation des molecules afin d'identifier les circuits regulateurs cles cibles par les ARNmi induits par un stress du a l'acide para-hydroxybenzoique (pHBA). Un total de 739 ARNmi et de 673 ARNmi ont ete respectivement identifies dans les feuilles et les racines. Parmi ceux-ci, 214 et 148 ARNmi ont ete respectivement exprimes dans les feuilles et les racines de maniere significativement differente et ont ete identifies en tant qu'ARNmi sensibles au pHBA. Les genes cibles pour les ARNmi sensibles au pHBA sont impliques dans la transduction des signaux, la reponse au stress et les sentiers metaboliques secondaires. De plus, un systeme integre d'analyse des profils d'expression des cibles d'ARNmi a ete utilise pour cribler les 60 genes cibles differemment exprimes relies aux 46 ARNmi exprimes differemment dans les feuilles, et les 51 genes cibles differemment exprimes relies aux 36 ARNmi exprimes differemment dans les racines. Cette analyse integree a revele la presence respective de 17 et 30 paires de cibles d'ARNmi dans les feuilles et les racines, qui montraient des profils d'expression correles negativement. Selon une analyse de PCR quantitatif en temps reel, 14 paires de cibles d'ARNmi montraient egalement des correlations negatives. De plus, quatre reseaux de regulation en coexpression ont ete inferes a partir des profils des paires de cibles d'ARNmi exprimees differemment. Ces resultats indiquent que des analyses completes de transcriptomes, des petits ARNs et des composes relies a la degradation des molecules constituent une approche utile pour etudier les mecanismes moleculaires sous-jacents a la reponse au stress induit par le pHBA chez les plantes. [Traduit par la Redaction] Mots-cles : Populus x euramericana 'Neva', stress cause par l'acide para-hydroxybenzoique, interference allelopathique, analyse d'integration, reseau d'interactions entre ARNmi-cibles., Introduction Plant allelopathy is one of the main reasons for continuous cropping obstacles worldwide. In recent years, an increasing number of intensive studies has been conducted to address this problem [...]