scholarly journals The formation of the thumb requires direct modulation of Gli3 transcription by Hoxa13

2020 ◽  
Vol 117 (2) ◽  
pp. 1090-1096 ◽  
Author(s):  
Maria Félix Bastida ◽  
Rocío Pérez-Gómez ◽  
Anna Trofka ◽  
Jianjian Zhu ◽  
Alvaro Rada-Iglesias ◽  
...  
Keyword(s):  
Negative Regulator ◽  
Human Hand ◽  
Regulatory Sequences ◽  
Functional Importance ◽  
Mutual Antagonism ◽  
Special Morphology ◽  
Repressor Activity ◽  
Development And Evolution ◽  
Anterior Posterior

In the tetrapod limb, the digits (fingers or toes) are the elements most subject to morphological diversification in response to functional adaptations. However, despite their functional importance, the mechanisms controlling digit morphology remain poorly understood. Here we have focused on understanding the special morphology of the thumb (digit 1), the acquisition of which was an important adaptation of the human hand. To this end, we have studied the limbs of the Hoxa13 mouse mutant that specifically fail to form digit 1. We show that, consistent with the role of Hoxa13 in Hoxd transcriptional regulation, the expression of Hoxd13 in Hoxa13 mutant limbs does not extend into the presumptive digit 1 territory, which is therefore devoid of distal Hox transcripts, a circumstance that can explain its agenesis. The loss of Hoxd13 expression, exclusively in digit 1 territory, correlates with increased Gli3 repressor activity, a Hoxd negative regulator, resulting from increased Gli3 transcription that, in turn, is due to the release from the negative modulation exerted by Hox13 paralogs on Gli3 regulatory sequences. Our results indicate that Hoxa13 acts hierarchically to initiate the formation of digit 1 by reducing Gli3 transcription and by enabling expansion of the 5′Hoxd second expression phase, thereby establishing anterior−posterior asymmetry in the handplate. Our work uncovers a mutual antagonism between Gli3 and Hox13 paralogs that has important implications for Hox and Gli3 gene regulation in the context of development and evolution.

scholarly journals The lin-3/let-23 pathway mediates inductive signalling during male spicule development in Caenorhabditis elegans

Development ◽  
1994 ◽  
Vol 120 (10) ◽  
pp. 2713-2721 ◽  
Author(s):  
H.M. Chamberlin ◽  
P.W. Sternberg
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Positional Information ◽  
Precursor Cells ◽  
Negative Regulator ◽  
Genetic Pathway ◽  
Cell Position ◽  
Function Defect ◽  
Anterior Posterior

During Caenorhabditis elegans male spicule development, four pairs of precursor cells respond to multiple positional cues and establish a pattern of fates that correlates with relative anterior-posterior cell position. One of the extracellular cues is provided by the F and U cells, which promote anterior fates. We show that the genes in the lin-3/let-23 signalling pathway required for hermaphrodite vulval induction also mediate this F/U signal. Reduction-of-function mutations in lin-3, let-23, sem-5, let-60 or lin-45 disrupt the fate of anterior cells. Likewise, activation of the pathway with ubiquitously produced signal results in posterior cells inappropriately adopting the anterior fates even in the absence of F and U. We have further used this genetic pathway to begin to understand how multiple positional cues are integrated to specify cell fate. We demonstrate that lin-15 acts in spicule development as it does in vulval induction, as a negative regulator of let-23 receptor activity. A second extracellular cue, from Y.p, also acts antagonistically to the lin-3/let-23 pathway. However, this signal is apparently integrated into the lin-3/let-23 pathway at some step after lin-45 raf and is thus functionally distinct from lin-15. We have also investigated the role of lin-12 in forming the anterior/posterior pattern of fates. A lin-12 gain-of-function defect is masked by redundant positional information from F and U.

scholarly journals GSK-3α Inhibition in Drug-Resistant CML Cells Promotes Susceptibility to NK Cell-Mediated Lysis in an NKG2D- and NKp30-Dependent Manner

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1802
Author(s):  
Nayoung Kim ◽  
Mi Yeon Kim ◽  
Woo Seon Choi ◽  
Eunbi Yi ◽  
Hyo Jung Lee ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Negative Regulator ◽  
Target Cells ◽  
Dependent Manner ◽  
Cell Functions ◽  
Cell Based Therapy ◽  
Activating Receptors ◽  
Gsk 3Β

Natural killer (NK) cells are innate cytotoxic lymphocytes that provide early protection against cancer. NK cell cytotoxicity against cancer cells is triggered by multiple activating receptors that recognize specific ligands expressed on target cells. We previously demonstrated that glycogen synthase kinase (GSK)-3β, but not GSK-3α, is a negative regulator of NK cell functions via diverse activating receptors, including NKG2D and NKp30. However, the role of GSK-3 isoforms in the regulation of specific ligands on target cells is poorly understood, which remains a challenge limiting GSK-3 targeting for NK cell-based therapy. Here, we demonstrate that GSK-3α rather than GSK-3β is the primary isoform restraining the expression of NKG2D ligands, particularly ULBP2/5/6, on tumor cells, thereby regulating their susceptibility to NK cells. GSK-3α also regulated the expression of the NKp30 ligand B7-H6, but not the DNAM-1 ligands PVR or nectin-2. This regulation occurred independently of BCR-ABL1 mutation that confers tyrosine kinase inhibitor (TKI) resistance. Mechanistically, an increase in PI3K/Akt signaling in concert with c-Myc was required for ligand upregulation in response to GSK-3α inhibition. Importantly, GSK-3α inhibition improved cancer surveillance by human NK cells in vivo. Collectively, our results highlight the distinct role of GSK-3 isoforms in the regulation of NK cell reactivity against target cells and suggest that GSK-3α modulation could be used to enhance tumor cell susceptibility to NK cells in an NKG2D- and NKp30-dependent manner.

scholarly journals Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo

2021 ◽  
Author(s):  
Dorothy Benton ◽  
Eva C Jaeger ◽  
Arielle Kilner ◽  
Ashley Kimble ◽  
Josh Lowry ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Oocyte Maturation ◽  
Protective Role ◽  
C Elegans ◽  
Direct Target ◽  
The One ◽  
Actomyosin Cytoskeleton ◽  
Embryonic Viability ◽  
Anterior Posterior

Abstract Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior-posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. While the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome-cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. While depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.

Autopoiesis and evolution: the role of organisms in natural drift

2021 ◽  
pp. 105971232110306
Author(s):  
Vincenzo Raimondi
Keyword(s):  
Living Systems ◽  
Explanatory Framework ◽  
Alternative Framework ◽  
Natural Drift ◽  
Genetic Reductionism ◽  
Development And Evolution

Genetic reductionism is increasingly seen as a severely limited approach to understanding living systems. The Neo-Darwinian explanatory framework tends to overlook the role of the organism for an understanding of development and evolution. In the current fast-changing theoretical landscape, the autopoietic approach provides conceptual distinctions and tools that may contribute to building an alternative framework. In this article, I examine the implications of the theories of autopoiesis and natural drift for an organism-centered view of evolution. By shifting the attention from genes to ontogenetic organism-niche configurations and their transformations over generations, this approach presents a compelling perspective on the role of organismal behavior in guiding phylogenetic drift.

scholarly journals Controlled Transcription of Regulator Gene carS by Tet-on or by a Strong Promoter Confirms Its Role as a Repressor of Carotenoid Biosynthesis in Fusarium fujikuroi

2020 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Julia Marente ◽  
Javier Avalos ◽  
M. Carmen Limón
Keyword(s):  
Wild Strain ◽  
Ring Finger ◽  
Carotenoid Biosynthesis ◽  
Negative Regulator ◽  
Fusarium Fujikuroi ◽  
Structural Genes ◽  
Gene Encoding ◽  
In The Wild ◽  
Set Up

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.

scholarly journals The Role of White Matter Disconnection in the Symptoms Relating to the Anarchic Hand Syndrome: A Single Case Study

2021 ◽  
Vol 11 (5) ◽  
pp. 632
Author(s):  
Valentina Pacella ◽  
Giuseppe Kenneth Ricciardi ◽  
Silvia Bonadiman ◽  
Elisabetta Verzini ◽  
Federica Faraoni ◽  
...  
Keyword(s):  
White Matter ◽  
Single Case ◽  
Brain Lesion ◽  
Structural Connectivity ◽  
Disconnection Syndrome ◽  
Neuroimaging Data ◽  
Neuropsychological Investigation ◽  
Anterior Posterior

The anarchic hand syndrome refers to an inability to control the movements of one’s own hand, which acts as if it has a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on this topic.

scholarly journals Promoter-Proximal Regulatory Elements Involved in oriP-EBNA1-Independent and -Dependent Activation of the Epstein-Barr Virus C Promoter in B-Lymphoid Cell Lines

2001 ◽  
Vol 75 (13) ◽  
pp. 5796-5811 ◽  
Author(s):  
Tina Nilsson ◽  
Henrik Zetterberg ◽  
Yuyan Camilla Wang ◽  
Lars Rymo
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Regulatory Elements ◽  
Negative Regulator ◽  
Regulatory Sequences ◽  
Barr Virus ◽  
Group I ◽  
Epstein Barr ◽  
B Lymphoid ◽  
Virus C

ABSTRACT The identification of the cellular factors that control the transcription regulatory activity of the Epstein-Barr virus C promoter (Cp) is fundamental to the understanding of the molecular mechanisms that control virus latent gene expression. Using transient transfection of reporter plasmids in group I phenotype B-lymphoid cells, we have previously shown that the −248 to −55 region (−248/−55 region) of Cp contains elements that are essential fororiPI-EBNA1-dependent as well asoriPI-EBNA1-independent activation of the promoter. We now establish the importance of this region by a detailed mutational analysis of reporter plasmids carrying Cp regulatory sequences together with or without oriPI. The reporter plasmids were transfected into group I phenotype Rael cells and group III phenotype cbc-Rael cells, and the Cp activity measured was correlated with the binding of candidate transcription factors in electrophoretic mobility shift assays and further assessed in cotransfection experiments. We show that the NF-Y transcription factor interacts with the previously identified CCAAT box in the −71/−63 Cp region (M. T. Puglielli, M. Woisetschlaeger, and S. H. Speck, J. Virol. 70:5758–5768, 1996). We also show that members of the C/EBP transcription factor family interact with a C/EBP consensus sequence in the −119/−112 region of Cp and that this interaction is important for promoter activity. A central finding is the identification of a GC-rich sequence in the −99/−91 Cp region that is essential fororiPI-EBNA1-independent as well asoriPI-EBNA1-dependent activity of the promoter. This region contains overlapping binding sites for Sp1 and Egr-1, and our results suggest that Sp1 is a positive and Egr-1 is a negative regulator of Cp activity. Furthermore, we demonstrate that a reporter plasmid that in addition to oriPI contains only the −111/+76 region of Cp still retains the ability to be activated by EBNA1.

scholarly journals Genomic imprinting in germ cells: imprints are under control

Reproduction ◽  
2010 ◽  
Vol 140 (3) ◽  
pp. 411-423 ◽  
Author(s):  
Philippe Arnaud
Keyword(s):  
Dna Methylation ◽  
Genomic Imprinting ◽  
Germ Cells ◽  
Imprinted Genes ◽  
Regulatory Sequences ◽  
Sequence Specificity ◽  
Maternal Allele ◽  
Primary Sequence ◽  
Chromatin Configuration

The cis-acting regulatory sequences of imprinted gene loci, called imprinting control regions (ICRs), acquire specific imprint marks in germ cells, including DNA methylation. These epigenetic imprints ensure that imprinted genes are expressed exclusively from either the paternal or the maternal allele in offspring. The last few years have witnessed a rapid increase in studies on how and when ICRs become marked by and subsequently maintain such epigenetic modifications. These novel findings are summarised in this review, which focuses on the germline acquisition of DNA methylation imprints and particularly on the combined role of primary sequence specificity, chromatin configuration, non-histone proteins and transcriptional events.

Abstract P317: Cardiac Fibroblast GSK3α Promotes Myocardial Fibrotic Remodeling Through GSK3α-ERK-IL11 Signaling Circuit

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Prachi Umbarkar ◽  
Sultan Tousif ◽  
Anand P Singh ◽  
Joshua C Anderson ◽  
qinkun zhang ◽  
...  
Keyword(s):  
Myocardial Fibrosis ◽  
Cardiac Fibrosis ◽  
Critical Role ◽  
Flow Cytometric Analysis ◽  
Collagen Gel ◽  
Pressure Overload ◽  
Negative Regulator ◽  
Post Injury

Background: Myocardial fibrosis contributes significantly to heart failure (HF). Fibroblasts are among the predominant cell type in the heart and are primary drivers of fibrosis. To identify the kinases involved in fibrosis, we analyzed the kinome of mouse cardiac fibroblasts (CF) isolated from normal and failing hearts. This unbiased screening revealed the critical role of the GSK-3 family-centric pathways in fibrosis. Previously we have shown that among two isoforms of GSK3, CF-GSK3β acts as a negative regulator of fibrosis in the injured heart. However, the role of CF-GSK3α in the pathogenesis of cardiac diseases is completely unknown. Methods and Results: To define the role of CF-GSK3α in HF, we employed two novel fibroblast-specific KO mouse models. Specifically, GSK3α was deleted from fibroblasts or myofibroblasts with tamoxifen-inducible Tcf21- or periostin- promoter-driven Cre recombinase. In both models, GSK3α deletion restricted pressure overload-induced cardiac fibrosis and preserved cardiac function. We examined the effect of GSK3α deletion on myofibroblast transformation and pro-fibrotic TGFβ1-SMAD3 signaling in vitro . A significant reduction in cell migration, collagen gel contraction, and α-SMA expression in TGFβ1-treated KO CFs confirmed that GSK3α is required for myofibroblast transformation. Surprisingly, GSK3α deletion did not affect SMAD3 activation, indicating the pro-fibrotic role of GSK3α is SMAD3 independent. To further delineate the underlying mechanisms, proteins were isolated from CFs of WT and KO mice at 4 weeks post-injury, and kinome profiling was performed. The kinome analysis identified the downregulation of RAF family kinase activity in KO CFs. Moreover, mapping of significantly altered kinases against literature annotated interactions generated ERK-centric networks. Consistently, flow cytometric analysis of CFs confirmed significantly low levels of pERK in KO mice. Additionally, our in vitro studies demonstrated that GSK3α deletion prevents TGFβ1-induced ERK activation. Interestingly, IL-11, a pro-fibrotic downstream effector of TGFβ1, was remarkably reduced in KO CFs and ERK inhibition further decreased IL-11 expression. Taken together, herein, we discovered the GSK3α-ERK-IL-11 signaling as a critical pro-fibrotic pathway in the heart. Strategies to inhibit this pro-fibrotic network could prevent adverse fibrosis and HF. Conclusion: CF-GSK3α plays a causal role in myocardial fibrosis that could be therapeutically targeted for future clinical applications.

Anterior mesendoderm induces mouse Engrailed genes in explant cultures

Development ◽  
1993 ◽  
Vol 118 (1) ◽  
pp. 139-149 ◽  
Author(s):  
S.L. Ang ◽  
J. Rossant
Keyword(s):  
Direct Evidence ◽  
Neural Tissue ◽  
Explant Culture ◽  
Neural Plate ◽  
Explant Cultures ◽  
Neural Marker ◽  
Engrailed Genes ◽  
Anterior Posterior

We have developed germ layer explant culture assays to study the role of mesoderm in anterior-posterior (A-P) patterning of the mouse neural plate. Using isolated explants of ectodermal tissue alone, we have demonstrated that the expression of Engrailed-1 (En-1) and En-2 genes in ectoderm is independent of mesoderm by the mid- to late streak stage, at least 12 hours before their onset of expression in the neural tube in vivo at the early somite stage. In recombination explants, anterior mesendoderm from headfold stage embryos induces the expression of En-1 and En-2 in pre- to early streak ectoderm and in posterior ectoderm from headfold stage embryos. In contrast, posterior mesendoderm from embryos of the same stage does not induce En genes in pre- to early streak ectoderm but is able to induce expression of a general neural marker, neurofilament 160 × 10(3) M(r). These results provide the first direct evidence for a role of mesendoderm in induction and regionalization of neural tissue in mouse.

Sign in / Sign up

Export Citation Format

Share Document