scholarly journals Comprehensive series of Irx cluster mutants reveals diverse roles in facial cartilage development

Development ◽  
2021 ◽  
Author(s):  
D'Juan T. Farmer ◽  
Punam Patel ◽  
Rachelle Choi ◽  
Chih-Yu Liu ◽  
J. Gage Crump
Keyword(s):  
Function Analysis ◽  
Skeletal Development ◽  
Proper Function ◽  
Loss Of Function ◽  
Facial Skeleton ◽  
Cartilage Development ◽  
The Face ◽  
Vertebrate Skeleton ◽  
And Cartilage

Proper function of the vertebrate skeleton requires the development of distinct articulating embryonic cartilages. Irx transcription factors are arranged in co-regulated clusters that are expressed in the developing skeletons of the face and appendages. IrxB cluster genes are required for the separation of toes in mice and formation of the hyoid joint in zebrafish, yet whether Irx genes had broader roles in skeletal development remained unclear. Here we perform a comprehensive loss-of-function analysis of all 11 Irx genes in zebrafish. We uncover conserved requirements for IrxB genes in formation of the fish and mouse scapula. In the face, we find a requirement for IrxAb genes and irx7 in formation of anterior neural crest precursors of the jaw, and for IrxBa genes in formation of endodermal pouches and gill cartilages. We also observe extensive joint loss and cartilage fusions in animals with combinatorial losses of Irx clusters, with in vivo imaging revealing that at least some of these fusions arise through inappropriate chondrogenesis. Our analysis reveals diverse roles for Irx genes in the formation and later segmentation of the facial skeleton.

scholarly journals Notch Signaling in Skeletal Development, Homeostasis and Pathogenesis

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 332 ◽  
Author(s):  
Jennifer T. Zieba ◽  
Yi-Ting Chen ◽  
Brendan H. Lee ◽  
Yangjin Bae
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Human Genetics ◽  
Skeletal Development ◽  
Gene Activation ◽  
Fracture Repair ◽  
Loss Of Function ◽  
Age Related ◽  
Complex Process ◽  
And Cartilage

Skeletal development is a complex process which requires the tight regulation of gene activation and suppression in response to local signaling pathways. Among these pathways, Notch signaling is implicated in governing cell fate determination, proliferation, differentiation and apoptosis of skeletal cells-osteoblasts, osteoclasts, osteocytes and chondrocytes. Moreover, human genetic mutations in Notch components emphasize the critical roles of Notch signaling in skeletal development and homeostasis. In this review, we focus on the physiological roles of Notch signaling in skeletogenesis, postnatal bone and cartilage homeostasis and fracture repair. We also discuss the pathological gain- and loss-of-function of Notch signaling in bone and cartilage, resulting in osteosarcoma and age-related degenerative diseases, such as osteoporosis and osteoarthritis. Understanding the physiological and pathological function of Notch signaling in skeletal tissues using animal models and human genetics will provide new insights into disease pathogenesis and offer novel approaches for the treatment of bone/cartilage diseases.

scholarly journals Loss-of-Function Analysis Suggests That Omi/HtrA2 Is Not an Essential Component of the pink1/parkin Pathway In Vivo

2008 ◽  
Vol 28 (53) ◽  
pp. 14500-14510 ◽  
Author(s):  
J. Yun ◽  
J. H. Cao ◽  
M. W. Dodson ◽  
I. E. Clark ◽  
P. Kapahi ◽  
...  
Keyword(s):  
Function Analysis ◽  
Loss Of Function ◽  
Essential Component

scholarly journals Loss offlflTriggers JNK-Dependent Cell Death inDrosophila

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiuhong Huang ◽  
Lei Xue
Keyword(s):  
Cell Death ◽  
Function Analysis ◽  
Ectopic Expression ◽  
Negative Regulator ◽  
Loss Of Function ◽  
Jnk Pathway ◽  
Dependent Cell ◽  
Jnk Activation ◽  
First Time

falafel(flfl) encodes aDrosophilahomolog of human SMEK whosein vivofunctions remain elusive. In this study, we performed gain-of-function and loss-of-function analysis inDrosophilaand identified flfl as a negative regulator of JNK pathway-mediated cell death. While ectopic expression offlflsuppresses TNF-triggered JNK-dependent cell death, loss offlflpromotes JNK activation and cell death in the developing eye and wing. These data report for the first time an essential physiological function offlflin maintaining tissue homeostasis and organ development. As the JNK signaling pathway has been evolutionary conserved from fly to human, a similar role of PP4R3 in JNK-mediated physiological process is speculated.

scholarly journals TCN1 Deficiency Inhibits The Malignancy of Colorectal Cancer Cells By Regulating The ITGB4 Pathway

2021 ◽  
Author(s):  
Xinqiang Zhu ◽  
Xuetong Jiang ◽  
Qinglin Zhang ◽  
Hailong Huang ◽  
Xiaohong Shi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Molecular Mechanisms ◽  
Function Analysis ◽  
Hct116 Cell ◽  
Tumor Xenograft ◽  
Integrin Subunit ◽  
Filamin A ◽  
Loss Of Function ◽  
Colorectal Cancer Cells

Abstract Background: This study aimed to investigate the biological function and regulatory mechanism of TCN1 in colorectal cancer (CRC). Methods: We studied the biological functions of TCN1 using gain-of-function and loss-of-function analysis in HCT116 cell lines, and examined the effects of TCN1 on the proliferation, apoptosis, and invasion of CRC cells and determined its potential molecular mechanisms using CRC lines and mouse xenotransplantation models. Tumor xenograft and tumor metastasis studies were performed to detect the tumorigenicity and metastasis of cells in vivo. Results: TCN1-knockdown attenuated CRC cell proliferation, invasion and promoted cell apoptosis. Overexpression of TCN1 yielded the opposite effects. In addition, TCN1-knockdown HCT116 cells failed to form metastatic foci in the peritoneum after intravenous injection. Molecular mechanism studies showed that TCN1 interacts with integrin subunit β4 (ITGB4) to positively regulate the expression of ITGB4. TCN1-knockdown promoted the degradation of ITGB4 and increased the instability of ITGB4 and filamin A (FLNA). Downregulation of ITGB4 at the protein level resulted in the disassociation of the ITGB4/PLEC complex, leading to cytoskeletal damage. Conclusion: TCN1 might exert oncogenic role in CRC via regulating the ITGB4 signaling pathway.

scholarly journals Long noncoding RNA GAS5 inhibits progression of colorectal cancer by interacting with and triggering YAP phosphorylation and degradation and is negatively regulated by the m6A reader YTHDF3

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Wen Ni ◽  
Su Yao ◽  
Yunxia Zhou ◽  
Yuanyuan Liu ◽  
Piao Huang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Progression ◽  
Noncoding Rna ◽  
Function Analysis ◽  
Loss Of Function ◽  
Functional Link ◽  
Protein Levels ◽  
Lncrna Gas5

Abstract Background YAP activation is crucial for cancer development including colorectal cancer (CRC). Nevertheless, it remains unclear whether N6-Methyladenosine (m6A) modified transcripts of long noncoding RNAs (lncRNAs) can regulate YAP activation in cancer progression. We investigated the functional link between lncRNAs and the m6A modification in YAP signaling and CRC progression. Methods YAP interacting lncRNAs were screened by RIP-sequencing, RNA FISH and immunofluorescence co-staining assays. Interaction between YAP and lncRNA GAS5 was studied by biochemical methods. MeRIP-sequencing combined with lncRNA-sequencing were used to identify the m6A modified targets of YTHDF3 in CRC. Gain-of-function and Loss-of-function analysis were performed to measure the function of GAS5-YAP-YTHDF3 axis in CRC progression in vitro and in vivo. Results GAS5 directly interacts with WW domain of YAP to facilitate translocation of endogenous YAP from the nucleus to the cytoplasm and promotes phosphorylation and subsequently ubiquitin-mediated degradation of YAP to inhibit CRC progression in vitro and in vivo. Notably, we demonstrate the m6A reader YTHDF3 not only a novel target of YAP but also a key player in YAP signaling by facilitating m6A-modified lncRNA GAS5 degradation, which profile a new insight into CRC progression. Clinically, lncRNA GAS5 expressions is negatively correlated with YAP and YTHDF3 protein levels in tumors from CRC patients. Conclusions Our study uncovers a negative functional loop of lncRNA GAS5-YAP-YTHDF3 axis, and identifies a new mechanism for m6A-induced decay of GAS5 on YAP signaling in progression of CRC which may offer a promising approach for CRC treatment.

Determinating the role of the E3 Ubiquitin Ligase Ariadne 2 in mammalian systemss

2007 ◽  
Vol 30 (4) ◽  
pp. 87
Author(s):  
A. E. Lin ◽  
A. Wakeham ◽  
A. You-Ten ◽  
G. Wood ◽  
T. W. Mak
Keyword(s):  
Function Analysis ◽  
Critical Role ◽  
Ring Finger ◽  
E3 Ligase ◽  
Signalling Pathways ◽  
Loss Of Function ◽  
In Vivo Models

Ubiquitination is a eukaryotic process of selective proteolysis, where a highly conserved ubiquitin protein is selectively added as a chain to the targeted to a protein for degradation. In recent years, the process of ubiquitination has been shown to be a critical mechanism that can affect essential signalling pathways, including apoptosis, cell cycle arrest and induction of the inflammatory response. Thus, alterations in the ubiquitination process can alter signalling pathways pivotal to numerous disease pathologies. This is clearly demonstrated in perturbations of ubiquitination in the NFκB giving rise to cancer and other immunological disease processes. To gain insight into pathways that require regulation by ubiquitination, our lab has directed focus on the highly conserved E3 ligase, Ariadne 2. Ariadne 2 is characterized as a putative RING finger E3 ligase and is part of the family of highly conserved RBR (RING-B-Box-RING) superfamily. The role of Ariadne 2 has been well studied in Drosophila melanogaster, however, little is known of the function of Ariadne 2 in mammalian systems. Therefore, the main objectives of the project are as follows: To determine the biological role of Ariadne 2, the role of Ariadne 2 in development and differentiation, and the consequences of in vivo loss of Ariadne 2 expression. We are currently investigating the role of Ariadne 2 as an E3 ligase and its involvement in the immune response. To date, we have shown that Ariadne 2 is ubiquitously expressed, especially in the brain, heart, spleen and thymus. For in vivo loss of function analysis, mice were generated by homologous recombination to be deficient for Ariadne 2. These deficient mice die prematurely soon after birth, suggesting a critical role for Ariadne 2 in development and survival. We are currently focusing on the role of Ariadne 2 in development and it’s role in immune pathologies, in particular, spontaneous autoimmunity, using both in vitro studies and in vivo models.

scholarly journals Proteins and Molecular Pathways Relevant for the Malignant Properties of Tumor-Initiating Pancreatic Cancer Cells

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1397
Author(s):  
Lisa Samonig ◽  
Andrea Loipetzberger ◽  
Constantin Blöchl ◽  
Marc Rurik ◽  
Oliver Kohlbacher ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Function Analysis ◽  
Critical Role ◽  
Three Dimensional ◽  
Small Subset ◽  
Loss Of Function ◽  
Tumor Initiating Cells ◽  
Differential Proteomics ◽  
Pancreatic Cancer Cells

Cancer stem cells (CSCs), a small subset of the tumor bulk with highly malignant properties, are deemed responsible for tumor initiation, growth, metastasis, and relapse. In order to reveal molecular markers and determinants of their tumor-initiating properties, we enriched rare stem-like pancreatic tumor-initiating cells (TICs) by harnessing their clonogenic growth capacity in three-dimensional multicellular spheroid cultures. We compared pancreatic TICs isolated from three-dimensional tumor spheroid cultures with nontumor-initiating cells (non-TICs) enriched in planar cultures. Employing differential proteomics (PTX), we identified more than 400 proteins with significantly different expression in pancreatic TICs and the non-TIC population. By combining the unbiased PTX with mRNA expression analysis and literature-based predictions of pro-malignant functions, we nominated the two calcium-binding proteins S100A8 (MRP8) and S100A9 (MRP14) as well as galactin-3-binding protein LGALS3BP (MAC-2-BP) as putative determinants of pancreatic TICs. In silico pathway analysis followed by candidate-based RNA interference mediated loss-of-function analysis revealed a critical role of S100A8, S100A9, and LGALS3BP as molecular determinants of TIC proliferation, migration, and in vivo tumor growth. Our study highlights the power of combining unbiased proteomics with focused gene expression and functional analyses for the identification of novel key regulators of TICs, an approach that warrants further application to identify proteins and pathways amenable to drug targeting.

scholarly journals Smpd3Expression in both Chondrocytes and Osteoblasts Is Required for Normal Endochondral Bone Development

2016 ◽  
Vol 36 (17) ◽  
pp. 2282-2299 ◽  
Author(s):  
Jingjing Li ◽  
Garthiga Manickam ◽  
Seemun Ray ◽  
Chun-do Oh ◽  
Hideyo Yasuda ◽  
...  
Keyword(s):  
Bone Development ◽  
Skeletal Development ◽  
Loss Of Function ◽  
Endochondral Bone ◽  
Transgenic Expression ◽  
Phosphodiesterase 3 ◽  
Skeletal Phenotype ◽  
Metabolizing Enzyme ◽  
Bone Abnormalities ◽  
And Cartilage

Sphingomyelin phosphodiesterase 3 (SMPD3), a lipid-metabolizing enzyme present in bone and cartilage, has been identified to be a key regulator of skeletal development. A homozygous loss-of-function mutation called fragilitas ossium (fro) in theSmpd3gene causes poor bone and cartilage mineralization resulting in severe congenital skeletal deformities. Here we show thatSmpd3expression in ATDC5 chondrogenic cells is downregulated by parathyroid hormone-related peptide through transcription factor SOX9. Furthermore, we show that transgenic expression ofSmpd3in the chondrocytes offro/fromice corrects the cartilage but not the bone abnormalities. Additionally, we report the generation ofSmpd3flox/floxmice for the tissue-specific inactivation ofSmpd3using the Cre-loxPsystem. We found that the skeletal phenotype inSmpd3flox/flox; Osx-Cremice, in which theSmpd3gene is ablated in both late-stage chondrocytes and osteoblasts, closely mimics the skeletal phenotype infro/fromice. On the other hand,Smpd3flox/flox;Col2a1-Cremice, in which theSmpd3gene is knocked out in chondrocytes only, recapitulate thefro/fromouse cartilage phenotype. This work demonstrates thatSmpd3expression in both chondrocytes and osteoblasts is required for normal endochondral bone development.

scholarly journals Targeting NUFIP1 Suppresses Growth and Induces Senescence of Colorectal Cancer Cells

2020 ◽  
Author(s):  
Aling Shen ◽  
Meizhu Wu ◽  
Liya Liu ◽  
Youqin Chen ◽  
Xiaoping Chen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fruits And Vegetables ◽  
Rna Binding ◽  
Function Analysis ◽  
Fragile X ◽  
Disease Free Survival ◽  
Loss Of Function ◽  
Patient Prognosis

Abstract Background: NUFIP1 is an RNA-binding protein that interacts with fragile X mental retardation protein (FMRP) in the messenger ribonucleoprotein particle (mRNP). We previously showed that NUFIP1 was upregulated in colorectal cancer (CRC), but how the protein may contribute to the disease and patient prognosis is unknown. Methods: Here we combine database analysis, microarray, quantitative PCR, and immunohistochemistry of patients' samples to confirm our previous findings on NUFIP1 overexpression in CRC, and to reveal that increased expression of NUFIP1 in CRC tissues correlated with worse overall, recurrence-free, event-free and disease-free survival in patients, as well as with more advanced CRC clinicopathological stage. Results: Loss of function analysis demonstrated that NUFIP1 knockdown suppressed cell growth in vitro and in vivo, inhibited cell viability and survival, and induced cell cycle arrest and apoptosis in vitro. In addition, as a natural anticancer triterpene from various fruits and vegetables, ursolic acid (UA) treatment suppressed cell proliferation, down-regulated NUFIP1 protein expression, and further enhanced the effects of NUFIP1 knockdown in CRC cells in vitro. NUFIP1 knockdown up-regulated the expression of 136 proteins, down-regulated the expression of 41 proteins, and enriched multiple signaling pathways including the senescence-associated heterochromatin foci (SAHF) pathway. Furthermore, NUFIP1 knockdown enhanced the expression of senescence-associated-β-galactosidase (SA-β-gal), the SAHF markers HP1γ and trimethylation (H3k9me3), and the senescence-related protein HMGA2. Conclusion: Our findings suggest that NUFIP1 is overexpressed in CRC and correlates with disease progression and poor patient survival. NUFIP1 may exert oncogenic effects partly by altering senescence. UA may show potential to treat CRC by down-regulating NUFIP1.

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