Hedgehog signals regulate multiple aspects of gastrointestinal development

Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2763-2772 ◽  
Author(s):  
M. Ramalho-Santos ◽  
D.A. Melton ◽  
A.P. McMahon

The gastrointestinal tract develops from the embryonic gut, which is composed of an endodermally derived epithelium surrounded by cells of mesodermal origin. Cell signaling between these two tissue layers appears to play a critical role in coordinating patterning and organogenesis of the gut and its derivatives. We have assessed the function of Sonic hedgehog and Indian hedgehog genes, which encode members of the Hedgehog family of cell signals. Both are expressed in gut endoderm, whereas target genes are expressed in discrete layers in the mesenchyme. It was unclear whether functional redundancy between the two genes would preclude a genetic analysis of the roles of Hedgehog signaling in the mouse gut. We show here that the mouse gut has both common and separate requirements for Sonic hedgehog and Indian hedgehog. Both Sonic hedgehog and Indian hedgehog mutant mice show reduced smooth muscle, gut malrotation and annular pancreas. Sonic hedgehog mutants display intestinal transformation of the stomach, duodenal stenosis (obstruction), abnormal innervation of the gut and imperforate anus. Indian hedgehog mutants show reduced epithelial stem cell proliferation and differentiation, together with features typical of Hirschsprung's disease (aganglionic colon). These results show that Hedgehog signals are essential for organogenesis of the mammalian gastrointestinal tract and suggest that mutations in members of this signaling pathway may be involved in human gastrointestinal malformations.

2019 ◽  
Vol 20 (7) ◽  
pp. 666-673 ◽  
Author(s):  
Sujuan Ding ◽  
Gang Liu ◽  
Hongmei Jiang ◽  
Jun Fang

The rapid self-renewal of intestinal epithelial cells enhances intestinal function, promotes the nutritional needs of animals and strengthens intestinal barrier function to resist the invasion of foreign pathogens. MicroRNAs (miRNAs) are a class of short-chain, non-coding RNAs that regulate stem cell proliferation and differentiation by down-regulating hundreds of conserved target genes after transcription via seed pairing to the 3' untranslated regions. Numerous studies have shown that miRNAs can improve intestinal function by participating in the proliferation and differentiation of different cell populations in the intestine. In addition, miRNAs also contribute to disease regulation and therefore not only play a vital role in the gastrointestinal disease management but also act as blood or tissue biomarkers of disease. As changes to the levels of miRNAs can change cell fates, miRNA-mediated gene regulation can be used to update therapeutic strategies and approaches to disease treatment.


Blood ◽  
2014 ◽  
Vol 124 (13) ◽  
pp. 2061-2071 ◽  
Author(s):  
Zhiqiang Liu ◽  
Jingda Xu ◽  
Jin He ◽  
Yuhuan Zheng ◽  
Haiyan Li ◽  
...  

Key Points CD138+ MM cells are a major source of SHH. Autocrine SHH enhances MM drug resistance.


2018 ◽  
Vol 115 (26) ◽  
pp. 6786-6791 ◽  
Author(s):  
Jiaxi Wu ◽  
Huaizhu Wu ◽  
Jinping An ◽  
Christie M. Ballantyne ◽  
Jason G. Cyster

CD11c, also known as integrin alpha X, is the most widely used defining marker for dendritic cells (DCs). CD11c can bind complement iC3b and mediate phagocytosis in vitro, for which it is also referred to as complement receptor 4. However, the functions of this prominent marker protein in DCs, especially in vivo, remain poorly defined. Here, in the process of studying DC activation and immune responses induced by cells lacking self-CD47, we found that DC capture of CD47-deficient cells and DC activation was dependent on the integrin-signaling adaptor Talin1. Specifically, CD11c and its partner Itgb2 were required for DC capture of CD47-deficient cells. CD11b was not necessary for this process but could partially compensate in the absence of CD11c. Mice with DCs lacking Talin1, Itgb2, or CD11c were defective in supporting T-cell proliferation and differentiation induced by CD47-deficient cell associated antigen. These findings establish a critical role for CD11c in DC antigen uptake and activation in vivo. They may also contribute to understanding the functional mechanism of CD47-blockade therapies.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 4111-4111
Author(s):  
Rita Elie El-Khoueiry ◽  
Takeru Wakatsuki ◽  
Yan Ning ◽  
Wu Zhang ◽  
Dongyun Yang ◽  
...  

4111 Background: The Wnt/β-catenin signaling pathwaycontrols cell proliferation and differentiation. Disruption of this pathway has been shown in the majority of colorectal (CRC) and gastric cancer (GC). The TCF7L2 complex plays a critical role in this pathway. Interaction of TCF7L2 and β-catenin results in translocation to the nucleus and leads to up-regulation of target genes, including c-myc and cyclin D1. Previous reports have shown that TCF7L2 polymorphism rs7903146 C/T is associated with CRC risk and outcome; however, the prognostic role of this polymorphism in GC is unknown. Therefore, we tested the hypothesis of whether this polymorphism could predict outcome in GC in three independent cohorts. Methods: A total of 369 patients (pts) with histopathologically-confirmed localized GC were enrolled from Japan (n=169), the US (n=137), and Austria (n=63) between 2002 and 2010. Results: In the US cohort, pts with at least one-T allele ((T/T or C/T; n=46) showed a median TTR of 1.7 yrs vs. 4.4 yrs compared to pts homozygous C/C (n=76) (HR: 2.09 95%CI: 1.21- 3.59, p=0.0053). A similar trend was shown in the Austrian cohort, where pts harboring at least one-T allele (n=25) showed a median DFS of 2.08 yrs vs. 5.42 yrs for pts homozygous C/C (n=38) (HR: 1.79 [95%CI: 0.90-3.55], p=0.092). Moreover, in the Japanese cohort, pts homozygous for T/T demonstrated (n=2) a median DFS of 0.15 yrs vs. 4.82 yrs for pts harboring at least one-C allele (n=165) (HR: 10.5 [95%CI: 2.46-45.5], p=0.001). These results were confirmed in the OS in the US and Japanese cohorts. Pts at least one-T allele (n=46) showed a median OS of 3.3 yrs vs. 5.5 yrs for pts homozygous C/C (n=76) (HR: 2.41 95%CI: 1.28-4.53, p=0.0043) in the US cohort, while pts homozygous T/T showed (n=2) a median OS of 0.22 yrs vs 5.76 yrs for pts harboring at least one-C allele (n=165) (HR: 15.2 [95%CI: 3.50-66.7], p<0.001). Conclusions: TCF7L2 polymorphism was associated with worse prognosis in recurrence in pts with GC in three independently global cohorts. This polymorphism may be negative prognostic factor in GC regardless of ethnicity and etiology, suggesting the importance role of Wnt/β-Catenin signaling in GC.


2002 ◽  
Vol 22 (18) ◽  
pp. 6471-6479 ◽  
Author(s):  
Hong Liu ◽  
Hyeog Kang ◽  
Rui Liu ◽  
Xin Chen ◽  
Keji Zhao

ABSTRACT The mammalian SWI/SNF-like chromatin-remodeling BAF complex plays several important roles in controlling cell proliferation and differentiation. Interferons (IFNs) are key mediators of cellular antiviral and antiproliferative activities. In this report, we demonstrate that the BAF complex is required for the maximal induction of a subset of IFN target genes by alpha IFN (IFN-α). The BAF complex is constitutively associated with the IFITM3 promoter in vivo and facilitates the chromatin remodeling of the promoter upon IFN-α induction. Furthermore, we show that the ubiquitous transcription activator Sp1 interacts with the BAF complex in vivo and augments the BAF-mediated activation of the IFITM3 promoter. Sp1 binds constitutively to the IFITM3 promoter in the absence of the BAF complex, suggesting that it may recruit and/or stabilize the BAF complex binding to the IFITM3 promoter. Our results bring new mechanistic insights into the antiproliferative effects of the chromatin-remodeling BAF complex.


2017 ◽  
Vol 313 (2) ◽  
pp. L328-L338 ◽  
Author(s):  
Carol S. Trempus ◽  
Weifeng Song ◽  
Ahmed Lazrak ◽  
Zhihong Yu ◽  
Judy R. Creighton ◽  
...  

Primary cilia (PC) are solitary cellular organelles that play critical roles in development, homeostasis, and disease pathogenesis by modulating key signaling pathways such as Sonic Hedgehog and calcium flux. The antenna-like shape of PC enables them also to facilitate sensing of extracellular and mechanical stimuli into the cell, and a critical role for PC has been described for mesenchymal cells such as chondrocytes. However, nothing is known about the role of PC in airway smooth muscle cells (ASMCs) in the context of airway remodeling. We hypothesized that PC on ASMCs mediate cell contraction and are thus integral in the remodeling process. We found that PC are expressed on ASMCs in asthmatic lungs. Using pharmacological and genetic methods, we demonstrated that PC are necessary for ASMC contraction in a collagen gel three-dimensional model both in the absence of external stimulus and in response to the extracellular component hyaluronan. Mechanistically, we demonstrate that the effect of PC on ASMC contraction is, to a small extent, due to their effect on Sonic Hedgehog signaling and, to a larger extent, due to their effect on calcium influx and membrane depolarization. In conclusion, PC are necessary for the development of airway remodeling by mediating calcium flux and Sonic Hedgehog signaling.


2007 ◽  
Vol 179 (4) ◽  
pp. 717-731 ◽  
Author(s):  
Tania Habib ◽  
Heon Park ◽  
Mark Tsang ◽  
Ignacio Moreno de Alborán ◽  
Andrea Nicks ◽  
...  

Deregulated expression of the Myc family of transcription factors (c-, N-, and L-myc) contributes to the development of many cancers by a mechanism believed to involve the stimulation of cell proliferation and inhibition of differentiation. However, using B cell–specific c-/N-myc double-knockout mice and Eμ-myc transgenic mice bred onto genetic backgrounds (recombinase-activating gene 2−/− and Btk−/− Tec−/−) whereby B cell development is arrested, we show that Myc is necessary to stimulate both proliferation and differentiation in primary B cells. Moreover, Myc expression results in sustained increases in intracellular Ca2+ ([Ca2+]i), which is required for Myc to stimulate B cell proliferation and differentiation. The increase in [Ca2+]i correlates with constitutive nuclear factor of activated T cells (NFAT) nuclear translocation, reduced Ca2+ efflux, and decreased expression of the plasma membrane Ca2+–adenosine triphosphatase (PMCA) efflux pump. Our findings demonstrate a revised model whereby Myc promotes both proliferation and differentiation, in part by a remarkable mechanism whereby Myc amplifies Ca2+ signals, thereby enabling the concurrent expression of Myc- and Ca2+-regulated target genes.


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