scholarly journals Cleaved Delta like 1 intracellular domain regulates neural development via Notch signal dependent and independent pathways

Development ◽  
2021 ◽  
Author(s):  
Yusuke Okubo ◽  
Fumiaki Ohtake ◽  
Katsuhide Igarashi ◽  
Yukuto Yasuhiko ◽  
Yoko Hirabayashi ◽  
...  

Notch-Delta signaling regulates many developmental processes, including tissue homeostasis, and maintenance of stem cells. Upon interaction of juxtaposed cells via Notch and Delta proteins, intracellular domains of both transmembrane proteins are cleaved and translocate to the nucleus. Notch intracellular domain activates target gene expression; however, the role of the Delta intracellular domain remains elusive. Here, we show the biological function of Delta like 1 intracellular domain (D1ICD) by modulating its production. We find the sustained production of D1ICD abrogates cell proliferation but enhances neurogenesis in the developing dorsal root ganglia (DRG), whereas inhibition of D1ICD production promotes cell proliferation and gliogenesis. D1ICD acts as an integral component of lateral inhibition mechanism by inhibiting Notch activity. In addition, D1ICD promotes neurogenesis through a Notch signaling independent manner. We show that D1ICD binds to Erk1/2 in neural crest stem cells, and inhibits the phosphorylation of Erk1/2. In summary, our results indicate that D1ICD regulates DRG development via modulating not only Notch signaling but also the MAP kinase pathway.

2014 ◽  
Vol 396 (1-2) ◽  
pp. 281-293 ◽  
Author(s):  
Natarajan Gopalakrishnan ◽  
Marimuthu Saravanakumar ◽  
Perumal Madankumar ◽  
Mani Thiyagu ◽  
Halagowder Devaraj

2002 ◽  
Vol 250 (1) ◽  
pp. 168-180 ◽  
Author(s):  
Christian Paratore ◽  
Guya Brugnoli ◽  
Hye-Youn Lee ◽  
Ueli Suter ◽  
Lukas Sommer

Oncogene ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 1185-1197 ◽  
Author(s):  
Mónica López-Guerra ◽  
Sílvia Xargay-Torrent ◽  
Patricia Fuentes ◽  
Jocabed Roldán ◽  
Blanca González-Farré ◽  
...  

Abstract Targeting Notch signaling has emerged as a promising therapeutic strategy for chronic lymphocytic leukemia (CLL), particularly in NOTCH1-mutated patients. We provide first evidence that the Notch ligand DLL4 is a potent stimulator of Notch signaling in NOTCH1-mutated CLL cells while increases cell proliferation. Importantly, DLL4 is expressed in histiocytes from the lymph node, both in NOTCH1-mutated and -unmutated cases. We also show that the DLL4-induced activation of the Notch signaling pathway can be efficiently blocked with the specific anti-Notch1 antibody OMP-52M51. Accordingly, OMP-52M51 also reverses Notch-induced MYC, CCND1, and NPM1 gene expression as well as cell proliferation in NOTCH1-mutated CLL cells. In addition, DLL4 stimulation triggers the expression of protumor target genes, such as CXCR4, NRARP, and VEGFA, together with an increase in cell migration and angiogenesis. All these events can be antagonized by OMP-52M51. Collectively, our results emphasize the role of DLL4 stimulation in NOTCH1-mutated CLL and confirm the specific therapeutic targeting of Notch1 as a promising approach for this group of poor prognosis CLL patients.


Author(s):  
Luciana Petti ◽  
Giulia Rizzo ◽  
Federica Rubbino ◽  
Sudharshan Elangovan ◽  
Piergiuseppe Colombo ◽  
...  

Abstract Background Sphingosine-1-phosphate receptor 2 (S1PR2) mediates pleiotropic functions encompassing cell proliferation, survival, and migration, which become collectively de-regulated in cancer. Information on whether S1PR2 participates in colorectal carcinogenesis/cancer is scanty, and we set out to fill the gap. Methods We screened expression changes of S1PR2 in human CRC and matched normal mucosa specimens [N = 76]. We compared CRC arising in inflammation-driven and genetically engineered models in wild-type (S1PR2+/+) and S1PR2 deficient (S1PR2−/−) mice. We reconstituted S1PR2 expression in RKO cells and assessed their growth in xenografts. Functionally, we mimicked the ablation of S1PR2 in normal mucosa by treating S1PR2+/+ organoids with JTE013 and characterized intestinal epithelial stem cells isolated from S1PR2−/−Lgr5-EGFP- mice. Results S1PR2 expression was lost in 33% of CRC; in 55%, it was significantly decreased, only 12% retaining expression comparable to normal mucosa. Both colitis-induced and genetic Apc+/min mouse models of CRC showed a higher incidence in size and number of carcinomas and/or high-grade adenomas, with increased cell proliferation in S1PR2−/− mice compared to S1PR2+/+ controls. Loss of S1PR2 impaired mucosal regeneration, ultimately promoting the expansion of intestinal stem cells. Whereas its overexpression attenuated cell cycle progression, it reduced the phosphorylation of AKT and augmented the levels of PTEN. Conclusions In normal colonic crypts, S1PR2 gains expression along with intestinal epithelial cells differentiation, but not in intestinal stem cells, and contrasts intestinal tumorigenesis by promoting epithelial differentiation, preventing the expansion of stem cells and braking their malignant transformation. Targeting of S1PR2 may be of therapeutic benefit for CRC expressing high Lgr5. Graphical Abstract. Schematic drawing of the role of S1PR2 in normal mucosa and colorectal cancer. In the normal mucosa, S1PR2 is highly expressed by differentiated cells at the upper region of both colon and intestinal crypts (S1PR2 ON), but not by the undifferentiated stem cell at the base of the crypts (S1PR2 OFF), in which acts as a negative proliferative regulator promoting epithelial differentiation. Its loss leads to the expansion of stem cells and reduced levels of PTEN and Axin-2, two negative regulators respectively of PI3K/AKT and Wnt signaling that control β-catenin signaling. The translocation of β-catenin into the nucleus promotes the transcription of target genes involved in the proliferation and malignant transformation. Thereby, S1PR2 works in the intestine as a tumor suppressor


2019 ◽  
Vol 12 (606) ◽  
pp. eaay2369 ◽  
Author(s):  
Sanchez M. Jarrett ◽  
Tom C. M. Seegar ◽  
Mark Andrews ◽  
Guillaume Adelmant ◽  
Jarrod A. Marto ◽  
...  

Canonical Notch signaling relies on regulated proteolysis of the receptor Notch to generate a nuclear effector that induces the transcription of Notch-responsive genes. In higher organisms, one Notch-responsive gene that is activated in many different cell types encodes the Notch-regulated ankyrin repeat protein (NRARP), which acts as a negative feedback regulator of Notch responses. Here, we showed that NRARP inhibited the growth of Notch-dependent T cell acute lymphoblastic leukemia (T-ALL) cell lines and bound directly to the core Notch transcriptional activation complex (NTC), requiring both the transcription factor RBPJ and the Notch intracellular domain (NICD), but not Mastermind-like proteins or DNA. The crystal structure of an NRARP-NICD1-RBPJ-DNA complex, determined to 3.75 Å resolution, revealed that the assembly of NRARP-NICD1-RBPJ complexes relied on simultaneous engagement of RBPJ and NICD1, with the three ankyrin repeats of NRARP extending the Notch1 ankyrin repeat stack. Mutations at the NRARP-NICD1 interface disrupted entry of the proteins into NTCs and abrogated feedback inhibition in Notch signaling assays in cultured cells. Forced expression of NRARP reduced the abundance of NICD in cells, suggesting that NRARP may promote the degradation of NICD. These studies establish the structural basis for NTC engagement by NRARP and provide insights into a critical negative feedback mechanism that regulates Notch signaling.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4987-4987
Author(s):  
Hiroshi Ikeda ◽  
Yuka Aoki ◽  
Nasanori Nojima ◽  
Hiroshi Yasui ◽  
Toshiaki Hayashi ◽  
...  

Abstract Abstract 4987 The Bone marrow (BM) microenvironment plays crucial role in pathogenesis of Multiple myeloma(MM). Myeloma cells contacts with bone marrow stromal cells (BMSCs), which secrete factors/cytokines, promoting tumor cell growth and survival. Paracrine secretion of cytokines(i. e., interleukin-6 (IL-6) insulin-like growth factor-1, inflammatory protein-1a) in BM stromal cells promotes multiple myeloma cell proliferation and protects against drug-induced cytotoxicity. These cytokines provide stimulatory signals for multiple myeloma growth and survival. Bone involvement is a common feature in MM patient, solid and hematologic cancers. MM localizes to the bone in nearly all patients ranges between 40% and 75%. Disease-related skeletal complications result in significant morbidity due to pain, pathologic fractures and spinal cord compression. The bone microenvironment creates a supportive niche for tumor growth. Osteoclasts and bone marrow stromal cells, along with extracellular matrix and cytokines stimulate tumor cell proliferation and confer chemoresistance. Therefore, the reciprocal interactions between tumor cells, osteoclasts, osteoblasts, and bone marrow stromal cells present an important. In current study, monocyte can directly promote mesenchymal stem cells osteogenic differentiation through cell contact interactions, thus resulting in the production of osteogenic factors by the monocytes. This mechanism is mediated by the activation of STAT3 signaling pathway in the mesechymal stem cells that leads to the upregulation of Osteoblasts-associated genes such as Runx2 and alkaline phosphatase (ALP), and the down-regulation of inhibitors such as DKK1 to drive the differentiation of mesechymal stem cells into osteoblasts. In this study, we examined the role of monocyte, component of BM cells, as a potential niche component that supports myeloma cells. We investigated the proliferation of MM cell lines cultured alone or co-cultured with BM stromal cells, monocytes, or a combination of BM stromal cells and monocytes. Consistently, we observed increased proliferation of MM cell lines in the presence of either BM stromal cells or monocytes compared to cell line-only control. Furthermore, the co-culture of BM stromal cells plus monocytes induced the greatest degree of proliferation of myeloma cells. In addition to increased proliferation, BMSCs and monocytes decreased the rate of apoptosis of myeloma cells. Our results therefore suggest that highlights the role of monocyte as an important component of the BM microenvironment. Disclosures: No relevant conflicts of interest to declare.


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