scholarly journals Wnt1 Lineage Specific Deletion of Gpr161 Results in Embryonic Midbrain Malformation and Failure of Craniofacial Skeletal Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Sung-Eun Kim ◽  
Karla Robles-Lopez ◽  
Xuanye Cao ◽  
Kristyn Liu ◽  
Pooja J. Chothani ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Neural Progenitor Cells ◽  
Skeletal Development ◽  
Specific Role ◽  
Negative Regulator ◽  
Structural Defects ◽  
Shh Signaling ◽  
Embryonic Neurogenesis ◽  
Signaling Activity

Sonic hedgehog (Shh) signaling regulates multiple morphogenetic processes during embryonic neurogenesis and craniofacial skeletal development. Gpr161 is a known negative regulator of Shh signaling. Nullizygous Gpr161 mice are embryonic lethal, presenting with structural defects involving the neural tube and the craniofacies. However, the lineage specific role of Gpr161 in later embryonic development has not been thoroughly investigated. We studied the Wnt1-Cre lineage specific role of Gpr161 during mouse embryonic development. We observed three major gross morphological phenotypes in Gpr161 cKO (Gpr161 f/f; Wnt1-Cre) fetuses; protrusive tectum defect, encephalocele, and craniofacial skeletal defect. The overall midbrain tissues were expanded and cell proliferation in ventricular zones of midbrain was increased in Gpr161 cKO fetuses, suggesting that protrusive tectal defects in Gpr161 cKO are secondary to the increased proliferation of midbrain neural progenitor cells. Shh signaling activity as well as upstream Wnt signaling activity were increased in midbrain tissues of Gpr161 cKO fetuses. RNA sequencing further suggested that genes in the Shh, Wnt, Fgf and Notch signaling pathways were differentially regulated in the midbrain of Gpr161 cKO fetuses. Finally, we determined that cranial neural crest derived craniofacial bone formation was significantly inhibited in Gpr161 cKO fetuses, which partly explains the development of encephalocele. Our results suggest that Gpr161 plays a distinct role in midbrain development and in the formation of the craniofacial skeleton during mouse embryogenesis.

scholarly journals Elongator Subunit 3 (Elp3) Is Required for Zebrafish Trunk Development

2020 ◽  
Vol 21 (3) ◽  
pp. 925 ◽  
Author(s):  
Diego Rojas-Benítez ◽  
Miguel L. Allende
Keyword(s):  
Molecular Mechanism ◽  
Sonic Hedgehog ◽  
Functional Relationship ◽  
Shh Signaling ◽  
Transfer Rnas ◽  
Zebrafish Development ◽  
Knock Down ◽  
Elongator Complex ◽  
Signaling Activity

Transfer RNAs (tRNAs) are the most post-transcriptionally modified RNA species. Some of these modifications, especially the ones located in the anti-codon loop, are required for decoding capabilities of tRNAs. Such is the case for 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U), synthetized by the Elongator complex. Mutants for its sub-units display pleiotropic phenotypes. In this paper, we analyze the role of elp3 (Elongator catalytic sub-unit) in zebrafish development. We found that it is required for trunk development; elp3 knock-down animals presented diminished levels of mcm5s2U and sonic hedgehog (Shh) signaling activity. Activation of this pathway was sufficient to revert the phenotype caused by elp3 knockdown, indicating a functional relationship between Elongator and Shh through a yet unknown molecular mechanism.

Interpassivity and Misdemeanours: The Art of Thinking in Examples and the Žižekian Toolbox

2018 ◽  
Author(s):  
Robert Pfaller
Keyword(s):  
Specific Role ◽  
Slavoj Zizek ◽  
Slavoj Žižek ◽  
The Sublime

Starting from a passage from Slavoj Žižek`s brilliant book The Sublime Object of Ideology, the very passage on canned laughter that gave such precious support for the development of the theory of interpassivity, this chapter examines a question that has proved indispensable for the study of interpassivity: namely, what does it mean for a theory to proceed by examples? What is the specific role of the example in certain example-friendly theories, for example in Žižek’s philosophy?

scholarly journals A Sex-Specific Role of Endothelial Sirtuin 3 on Blood Pressure and Diastolic Dysfunction in Female Mice

2020 ◽  
Vol 21 (24) ◽  
pp. 9744
Author(s):  
Heng Zeng ◽  
Xiaochen He ◽  
Jian-Xiong Chen
Keyword(s):  
Blood Pressure ◽  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Normal Diet ◽  
Specific Role ◽  
Sirtuin 3 ◽  
Control Female ◽  
Female Mice ◽  
Flow Reserve

Background: Heart failure with preserved ejection fraction (HFpEF) is characterized by a diastolic dysfunction and is highly prevalent in aged women. Our study showed that ablation of endothelial Sirtuin 3 (SIRT3) led to diastolic dysfunction in male mice. However, the sex-specific role of endothelial SIRT3 deficiency on blood pressure and diastolic function in female mice remains to be investigated. Methods and Results: In this study, we demonstrate that the ablation of endothelial SIRT3 in females elevated blood pressure as compared with control female mice. Diastolic function measurement also showed that the isovolumic relaxation time (IVRT) and myocardial performance index (MPI) were significantly increased, whereas the E’ velocity/A’ velocity (E’/A’) ratio was reduced in the endothelial-specific SIRT3 knockout (SIRT3 ECKO) female mice. To further investigate the regulatory role of endothelial SIRT3 on blood pressure and diastolic dysfunction in metabolic stress, SIRT3 ECKO female mice were fed a normal diet and high-fat diet (HFD) for 20 weeks. The knockout of endothelial SIRT3 resulted in an increased blood pressure in female mice fed with an HFD. Intriguingly, SIRT3 ECKO female mice + HFD exhibited impaired coronary flow reserve (CFR) and more severe diastolic dysfunction as evidenced by an elevated IVRT as compared with control female mice + HFD. In addition, female SIRT3 ECKO mice had higher blood pressure and diastolic dysfunction as compared to male SIRT3 ECKO mice. Moreover, female SIRT3 ECKO mice + HFD had an impaired CFR and diastolic dysfunction as compared to male SIRT3 ECKO mice + HFD. Conclusions: These results implicate a sex-specific role of endothelial SIRT3 in regulating blood pressure and diastolic function in mice. Deficiency of endothelial SIRT3 may be responsible for a diastolic dysfunction in aged female.

scholarly journals Inhibition of Aurora Kinase B activity disrupts development and differentiation of salivary glands

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Abeer K. Shaalan ◽  
Tathyane H. N. Teshima ◽  
Abigail S. Tucker ◽  
Gordon B. Proctor
Keyword(s):  
Cell Cycle ◽  
Embryonic Development ◽  
Salivary Glands ◽  
Aurora Kinase ◽  
Serine Threonine Kinase ◽  
Aurora Kinase B ◽  
Development And Differentiation ◽  
Differentiation Marker ◽  
Key Events

AbstractLittle is known about the key molecules that regulate cell division during organogenesis. Here we determine the role of the cell cycle promoter aurora kinase B (AURKB) during development, using embryonic salivary glands (E-SGs) as a model. AURKB is a serine/threonine kinase that regulates key events in mitosis, which makes it an attractive target for tailored anticancer therapy. Many reports have elaborated on the role of AURKB in neoplasia and cancer; however, no previous study has shown its role during organ development. Our previous experiments have highlighted the essential requirement for AURKB during adult exocrine regeneration. To investigate if AURKB is similarly required for progression during embryonic development, we pharmacologically inhibited AURKB in developing submandibular glands (SMGs) at embryonic day (E)13.5 and E16.5, using the highly potent and selective drug Barasertib. Inhibition of AURKB interfered with the expansion of the embryonic buds. Interestingly, this effect on SMG development was also seen when the mature explants (E16.5) were incubated for 24 h with another cell cycle inhibitor Aphidicolin. Barasertib prompted apoptosis, DNA damage and senescence, the markers of which (cleaved caspase 3, γH2AX, SA-βgal and p21, respectively), were predominantly seen in the developing buds. In addition to a reduction in cell cycling and proliferation of the epithelial cells in response to AURKB inhibition, Barasertib treatment led to an excessive generation of reactive oxygen species (ROS) that resulted in downregulation of the acinar differentiation marker Mist1. Importantly, inhibition of ROS was able to rescue this loss of identity, with Mist1 expression maintained despite loss of AURKB. Together, these data identify AURKB as a key molecule in supporting embryonic development and differentiation, while inhibiting senescence-inducing signals during organogenesis.

scholarly journals Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

2016 ◽  
Vol 37 (2) ◽  
pp. 135-187 ◽  
Author(s):  
J. H. Duncan Bassett ◽  
Graham R. Williams
Keyword(s):  
Thyroid Hormones ◽  
Skeletal Development ◽  
Bone Maintenance

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.

Sign in / Sign up

Export Citation Format

Share Document