scholarly journals Hormone-Responsive BMP Signaling Expands Myoepithelial Cell Lineages and Prevents Alveolar Precocity in Mammary Gland

2021 ◽  
Vol 9 ◽  
Author(s):  
Chunlei Shao ◽  
Pengbo Lou ◽  
Ruiqi Liu ◽  
Xueyun Bi ◽  
Guilin Li ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Myoepithelial Cells ◽  
Bmp Signaling ◽  
Conditional Knockout ◽  
Signaling Mechanism ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse ◽  
Morphogenetic Protein ◽  
Organ Systems ◽  
Mammary Stem

Myoepithelial and luminal cells synergistically expand in the mammary gland during pregnancy, and this process is precisely governed by hormone-related signaling pathways. The bone morphogenetic protein (BMP) signaling pathway is now known to play crucial roles in all organ systems. However, the functions of BMP signaling in the mammary gland remain unclear. Here, we found that BMPR1a is upregulated by hormone-induced Sp1 at pregnancy. Using a doxycycline (Dox)-inducible BMPR1a conditional knockout mouse model, we demonstrated that loss of BMPR1a in myoepithelium results in compromised myoepithelial integrity, reduced mammary stem cells and precocious alveolar differentiation during pregnancy. Mechanistically, BMPR1a regulates the expression of p63 and Slug, two key regulators of myoepithelial maintenance, through pSmad1/5-Smad4 complexes, and consequently activate P-cadherin during pregnancy. Furthermore, we observed that loss of BMPR1a in myoepithelium results in the upregulation of a secreted protein Spp1 that could account for the precocious alveolar differentiation in luminal layer, suggesting a defective basal-to-luminal paracrine signaling mechanism. Collectively, these findings identify a novel role of BMP signaling in maintaining the identity of myoepithelial cells and suppressing precocious alveolar formation.

scholarly journals Specificity and Redundancy of Profilin 1 and 2 Function in Brain Development and Neuronal Structure

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2310
Author(s):  
Marina Di Domenico ◽  
Melanie Jokwitz ◽  
Walter Witke ◽  
Pietro Pilo Boyl
Keyword(s):  
Actin Polymerization ◽  
Conditional Knockout ◽  
Brain Morphology ◽  
Actin Dynamics ◽  
Neuronal Structure ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse ◽  
Neuronal Stem Cell ◽  
Neuronal Precursors ◽  
Redundant Functions

Profilin functions have been discussed in numerous cellular processes, including actin polymerization. One puzzling aspect is the concomitant expression of more than one profilin isoform in most tissues. In neuronal precursors and in neurons, profilin 1 and profilin 2 are co-expressed, but their specific and redundant functions in brain morphogenesis are still unclear. Using a conditional knockout mouse model to inactivate both profilins in the developing CNS, we found that threshold levels of profilin are necessary for the maintenance of the neuronal stem-cell compartment and the generation of the differentiated neurons, irrespective of the specific isoform. During embryonic development, profilin 1 is more abundant than profilin 2; consequently, modulation of profilin 1 levels resulted in a more severe phenotype than depletion of profilin 2. Interestingly, the relevance of the isoforms was reversed in the postnatal brain. Morphology of mature neurons showed a stronger dependence on profilin 2, since this is the predominant isoform in neurons. Our data highlight redundant functions of profilins in neuronal precursor expansion and differentiation, as well as in the maintenance of pyramidal neuron dendritic arborization. The specific profilin isoform is less relevant; however, a threshold profilin level is essential. We propose that the common activity of profilin 1 and profilin 2 in actin dynamics is responsible for the observed compensatory effects.

scholarly journals A PINCH-1–Smurf1 signaling axis mediates mechano-regulation of BMPR2 and stem cell differentiation

2019 ◽  
Vol 218 (11) ◽  
pp. 3773-3794
Author(s):  
Ling Guo ◽  
Rong Wang ◽  
Kuo Zhang ◽  
Jifan Yuan ◽  
Jiaxin Wang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Differentiation ◽  
Bmp Signaling ◽  
Signaling Mechanism ◽  
Ubiquitin Protein Ligase ◽  
Signaling Mechanisms ◽  
Morphogenetic Protein ◽  
Signaling Axis ◽  
Fate Decision

Mechano-environment plays multiple critical roles in the control of mesenchymal stem cell (MSC) fate decision, but the underlying signaling mechanisms remain undefined. We report here a signaling axis consisting of PINCH-1, SMAD specific E3 ubiquitin protein ligase 1 (Smurf1), and bone morphogenetic protein type 2 receptor (BMPR2) that links mechano-environment to MSC fate decision. PINCH-1 interacts with Smurf1, which inhibits the latter from interacting with BMPR2 and consequently suppresses BMPR2 degradation, resulting in augmented BMP signaling and MSC osteogenic differentiation (OD). Extracellular matrix (ECM) stiffening increases PINCH-1 level and consequently activates this signaling axis. Depletion of PINCH-1 blocks stiff ECM-induced BMP signaling and OD, whereas overexpression of PINCH-1 overrides signals from soft ECM and promotes OD. Finally, perturbation of either Smurf1 or BMPR2 expression is sufficient to block the effects of PINCH-1 on BMP signaling and MSC fate decision. Our findings delineate a key signaling mechanism through which mechano-environment controls BMPR2 level and MSC fate decision.

scholarly journals A Conditional Knockout Mouse Model Reveals That Calponin-3 Is Dispensable for Early B Cell Development

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0128385 ◽  
Author(s):  
Alexandra Flemming ◽  
Qi-Quan Huang ◽  
Jian-Ping Jin ◽  
Hassan Jumaa ◽  
Sebastian Herzog
Keyword(s):  
Mouse Model ◽  
B Cell ◽  
Knockout Mouse ◽  
Cell Development ◽  
B Cell Development ◽  
Conditional Knockout ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse

scholarly journals A Survey of Strategies to Modulate the Bone Morphogenetic Protein Signaling Pathway: Current and Future Perspectives

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Jonathan W. Lowery ◽  
Brice Brookshire ◽  
Vicki Rosen
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Bmp Signaling ◽  
Protein Signaling ◽  
Bone Morphogenetic Protein Signaling ◽  
Human Organ ◽  
Morphogenetic Protein ◽  
Organ Systems ◽  
Bmp Pathway ◽  
Wide Perspective ◽  
The Relationship

Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the TGF-βfamily of ligands and are unequivocally involved in regulating stem cell behavior. Appropriate regulation of canonical BMP signaling is critical for the development and homeostasis of numerous human organ systems, as aberrations in the BMP pathway or its regulation are increasingly associated with diverse human pathologies. In this review, we provide a wide-perspective on strategies that increase or decrease BMP signaling. We briefly outline the current FDA-approved approaches, highlight emerging next-generation technologies, and postulate prospective avenues for future investigation. We also detail how activating other pathways may indirectly modulate BMP signaling, with a particular emphasis on the relationship between the BMP and Activin/TGF-βpathways.

scholarly journals A dual role for integrin-linked kinase in platelets: regulating integrin function and α-granule secretion

Blood ◽  
2008 ◽  
Vol 112 (12) ◽  
pp. 4523-4531 ◽  
Author(s):  
Katherine L. Tucker ◽  
Tanya Sage ◽  
Joanne M. Stevens ◽  
Peter A. Jordan ◽  
Sarah Jones ◽  
...  
Keyword(s):  
Thrombus Formation ◽  
Dense Granule ◽  
Conditional Knockout ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse ◽  
Fibrinogen Binding ◽  
Integrin Linked Kinase ◽  
Dense Granule Secretion ◽  
Granule Secretion

Abstract Integrin-linked kinase (ILK) has been implicated in the regulation of a range of fundamental biological processes such as cell survival, growth, differentiation, and adhesion. In platelets ILK associates with β1- and β3-containing integrins, which are of paramount importance for the function of platelets. Upon stimulation of platelets this association with the integrins is increased and ILK kinase activity is up-regulated, suggesting that ILK may be important for the coordination of platelet responses. In this study a conditional knockout mouse model was developed to examine the role of ILK in platelets. The ILK-deficient mice showed an increased bleeding time and volume, and despite normal ultrastructure the function of ILK-deficient platelets was decreased significantly. This included reduced aggregation, fibrinogen binding, and thrombus formation under arterial flow conditions. Furthermore, although early collagen stimulated signaling such as PLCγ2 phosphorylation and calcium mobilization were unaffected in ILK-deficient platelets, a selective defect in α-granule, but not dense-granule, secretion was observed. These results indicate that as well as involvement in the control of integrin affinity, ILK is required for α-granule secretion and therefore may play a central role in the regulation of platelet function.

scholarly journals Follistatin is critical for mouse uterine receptivity and decidualization

2017 ◽  
Vol 114 (24) ◽  
pp. E4772-E4781 ◽  
Author(s):  
Paul T. Fullerton ◽  
Diana Monsivais ◽  
Ramakrishna Kommagani ◽  
Martin M. Matzuk
Keyword(s):  
Molecular Mechanisms ◽  
Recurrent Miscarriage ◽  
Embryo Implantation ◽  
Bmp Signaling ◽  
Conditional Knockout ◽  
Uterine Receptivity ◽  
Vitro Fertilization ◽  
Morphogenetic Protein ◽  
Proliferation And Differentiation

Embryo implantation remains a significant challenge for assisted reproductive technology, with implantation failure occurring in ∼50% of in vitro fertilization attempts. Understanding the molecular mechanisms underlying uterine receptivity will enable the development of new interventions and biomarkers. TGFβ family signaling in the uterus is critical for establishing and maintaining pregnancy. Follistatin (FST) regulates TGFβ family signaling by selectively binding TGFβ family ligands and sequestering them. In humans, FST is up-regulated in the decidua during early pregnancy, and women with recurrent miscarriage have lower endometrial expression of FST during the luteal phase. Because global knockout of Fst is perinatal lethal in mice, we generated a conditional knockout (cKO) of Fst in the uterus using progesterone receptor-cre to study the roles of uterine Fst during pregnancy. Uterine Fst-cKO mice demonstrate severe fertility defects and deliver only 2% of the number of pups delivered by control females. In Fst-cKO mice, the uterine luminal epithelium does not respond properly to estrogen and progesterone signals and remains unreceptive to embryo attachment by continuing to proliferate and failing to differentiate. The uterine stroma of Fst-cKO mice also responds poorly to artificial decidualization, with lower levels of proliferation and differentiation. In the absence of uterine FST, activin B expression and signaling are up-regulated, and bone morphogenetic protein (BMP) signals are impaired. Our findings support a model in which repression of activin signaling by FST enables uterine receptivity by preserving critical BMP signaling.

scholarly journals A Homeostatic Shift Facilitates Endoplasmic Reticulum Proteostasis through Transcriptional Integration of Proteostatic Stress Response Pathways

2016 ◽  
Vol 37 (4) ◽  
Author(s):  
Liam Baird ◽  
Tadayuki Tsujita ◽  
Eri H. Kobayashi ◽  
Ryo Funayama ◽  
Takeshi Nagashima ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcriptional Regulation ◽  
Ubiquitin Proteasome System ◽  
Conditional Knockout ◽  
Protein Homeostasis ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse ◽  
Wide Range ◽  
Ubiquitin Proteasome ◽  
Inducible Systems

ABSTRACT Eukaryotic cells maintain protein homeostasis through the activity of multiple basal and inducible systems, which function in concert to allow cells to adapt to a wide range of environmental conditions. Although the transcriptional programs regulating individual pathways have been studied in detail, it is not known how the different pathways are transcriptionally integrated such that a deficiency in one pathway can be compensated by a change in an auxiliary response. One such pathway that plays an essential role in many proteostasis responses is the ubiquitin-proteasome system, which functions to degrade damaged, unfolded, or short half-life proteins. Transcriptional regulation of the proteasome is mediated by the transcription factor Nrf1. Using a conditional knockout mouse model, we found that Nrf1 regulates protein homeostasis in the endoplasmic reticulum (ER) through transcriptional regulation of the ER stress sensor ATF6. In Nrf1 conditional-knockout mice, a reduction in proteasome activity is accompanied by an ATF6-dependent downregulation of the endoplasmic reticulum-associated degradation machinery, which reduces the substrate burden on the proteasome. This indicates that Nrf1 regulates a homeostatic shift through which proteostasis in the endoplasmic reticulum and cytoplasm are coregulated based on a cell's ability to degrade proteins.

Bone Morphogenetic Protein 2 Coordinates Early Tooth Mineralization

2018 ◽  
Vol 97 (7) ◽  
pp. 835-843 ◽  
Author(s):  
Z. Malik ◽  
M. Alexiou ◽  
B. Hallgrimsson ◽  
A.N. Economides ◽  
H.U. Luder ◽  
...  
Keyword(s):  
Tooth Development ◽  
Bmp Signaling ◽  
Conditional Knockout ◽  
Bone Morphogenetic Protein 2 ◽  
Micro Computed Tomography ◽  
Tooth Mineralization ◽  
Morphogenetic Protein ◽  
Dental Hard Tissues ◽  
Dentin Sialoprotein ◽  
Tooth Germs

Formation of highly organized dental hard tissues is a complex process involving sequential and ordered deposition of an extracellular scaffold, followed by its mineralization. Odontoblast and ameloblast differentiation involves reciprocal and sequential epithelial-mesenchymal interactions. Similar to early tooth development, various Bmps are expressed during this process, although their functions have not been explored in detail. Here, we investigated the role of odontoblast-derived Bmp2 for tooth mineralization using Bmp2 conditional knockout mice. In developing molars, Bmp2LacZ reporter mice revealed restricted expression of Bmp2 in early polarized and functional odontoblasts while it was not expressed in mature odontoblasts. Loss of Bmp2 in neural crest cells, which includes all dental mesenchyme, caused a delay in dentin and enamel deposition. Immunohistochemistry for nestin and dentin sialoprotein (Dsp) revealed polarization defects in odontoblasts, indicative of a role for Bmp2 in odontoblast organization. Surprisingly, pSmad1/5/8, an indicator of Bmp signaling, was predominantly reduced in ameloblasts, with reduced expression of amelogenin ( Amlx), ameloblastin ( Ambn), and matrix metalloproteinase ( Mmp20). Quantitative real-time polymerase chain reaction (RT-qPCR) analysis and immunohistochemistry showed that loss of Bmp2 resulted in increased expression of the Wnt antagonists dickkopf 1 ( Dkk1) in the epithelium and sclerostin ( Sost) in mesenchyme and epithelium. Odontoblasts showed reduced Wnt signaling, which is important for odontoblast differentiation, and a strong reduction in dentin sialophosphoprotein ( Dspp) but not collagen 1 a1 ( Col1a1) expression. Mature Bmp2-deficient teeth, which were obtained by transplanting tooth germs from Bmp2-deficient embryos under a kidney capsule, showed a dentinogenesis imperfecta type II–like appearance. Micro–computed tomography and scanning electron microscopy revealed reduced dentin and enamel thickness, indistinguishable primary and secondary dentin, and deposition of ectopic osteodentin. This establishes that Bmp2 provides an early temporal, nonredundant signal for directed and organized tooth mineralization.

BMPR-IA signaling is required for the formation of the apical ectodermal ridge and dorsal-ventral patterning of the limb

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4449-4461 ◽  
Author(s):  
Kyung Ahn ◽  
Yuji Mishina ◽  
Mark C. Hanks ◽  
Richard R. Behringer ◽  
E. Bryan Crenshaw
Keyword(s):  
Limb Development ◽  
Apical Ectodermal Ridge ◽  
Bmp Signaling ◽  
Conditional Knockout ◽  
Limb Bud ◽  
Gene Encoding ◽  
Bone Morphogenetic Protein Receptor ◽  
Protein Receptor ◽  
Morphogenetic Protein ◽  
Embryonic Limb

We demonstrate that signaling via the bone morphogenetic protein receptor IA (BMPR-IA) is required to establish two of the three cardinal axes of the limb: the proximal-distal axis and the dorsal-ventral axis. We generated a conditional knockout of the gene encoding BMPR-IA (Bmpr) that disrupted BMP signaling in the limb ectoderm. In the most severely affected embryos, this conditional mutation resulted in gross malformations of the limbs with complete agenesis of the hindlimbs. The proximal-distal axis is specified by the apical ectodermal ridge (AER), which forms from limb ectoderm at the distal tip of the embryonic limb bud. Analyses of the expression of molecular markers, such as Fgf8, demonstrate that formation of the AER was disrupted in the Bmpr mutants. Along the dorsal/ventral axis, loss of engrailed 1 (En1) expression in the non-ridge ectoderm of the mutants resulted in a dorsal transformation of the ventral limb structures. The expression pattern of Bmp4 and Bmp7 suggest that these growth factors play an instructive role in specifying dorsoventral pattern in the limb. This study demonstrates that BMPR-IA signaling plays a crucial role in AER formation and in the establishment of the dorsal/ventral patterning during limb development.

Anti-obesity effects of GIPR antagonists alone and in combination with GLP-1R agonists in preclinical models

2018 ◽  
Vol 10 (472) ◽  
pp. eaat3392 ◽  
Author(s):  
Elizabeth A. Killion ◽  
Jinghong Wang ◽  
Junming Yie ◽  
Stone D.-H. Shi ◽  
Darren Bates ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Body Weight Gain ◽  
Association Studies ◽  
Conditional Knockout ◽  
Genome Wide Association Studies ◽  
Knockout Mouse Model ◽  
Conditional Knockout Mouse ◽  
Glucagon Like Peptide 1 ◽  
Treatment Of Obesity

Glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) has been identified in multiple genome-wide association studies (GWAS) as a contributor to obesity, and GIPR knockout mice are protected against diet-induced obesity (DIO). On the basis of this genetic evidence, we developed anti-GIPR antagonistic antibodies as a potential therapeutic strategy for the treatment of obesity and observed that a mouse anti-murine GIPR antibody (muGIPR-Ab) protected against body weight gain, improved multiple metabolic parameters, and was associated with reduced food intake and resting respiratory exchange ratio (RER) in DIO mice. We replicated these results in obese nonhuman primates (NHPs) using an anti-human GIPR antibody (hGIPR-Ab) and found that weight loss was more pronounced than in mice. In addition, we observed enhanced weight loss in DIO mice and NHPs when anti-GIPR antibodies were codosed with glucagon-like peptide-1 receptor (GLP-1R) agonists. Mechanistic and crystallographic studies demonstrated that hGIPR-Ab displaced GIP and bound to GIPR using the same conserved hydrophobic residues as GIP. Further, using a conditional knockout mouse model, we excluded the role of GIPR in pancreatic β-cells in the regulation of body weight and response to GIPR antagonism. In conclusion, these data provide preclinical validation of a therapeutic approach to treat obesity with anti-GIPR antibodies.

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