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Malgorzata Pierzchalska, Malgorzata Panek, Malgorzata Czyrnek, Maja Grabacka
The intestinal epithelium isolated from chicken embryos in last 3 days of development can be used to establish the 3D culture of intestinal organoids. When fragments of epithelial tissue released by incubation with EGTA (2.5 mM, 2 h) are embedded in Matrigel matrix on cell culture inserts the formation of empty spheres covered by epithelial cells is observed in first 24 h of culture. The growth and survival of organoids are supported by the addition of R-spondin 1, Noggin, and prostaglandin E2 to the culture medium...
October 28, 2016: Methods in Molecular Biology
Thierry Jardé, Bethan Lloyd-Lewis, Mairian Thomas, Howard Kendrick, Lorenzo Melchor, Lauriane Bougaret, Peter D Watson, Kenneth Ewan, Matthew J Smalley, Trevor C Dale
The development of in vitro culture systems quantitatively and qualitatively recapitulating normal breast biology is key to the understanding of mammary gland biology. Current three-dimensional mammary culture systems have not demonstrated concurrent proliferation and functional differentiation ex vivo in any system for longer than 2 weeks. Here, we identify conditions including Neuregulin1 and R-spondin 1, allowing maintenance and expansion of mammary organoids for 2.5 months in culture. The organoids comprise distinct basal and luminal compartments complete with functional steroid receptors and stem/progenitor cells able to reconstitute a complete mammary gland in vivo...
October 26, 2016: Nature Communications
Hanseol Kim, Jihye Ryu, Chaeyoung Lee
A genome-wide association study was conducted to identify expression quantitative trait loci (eQTL) for human telomerase.We tested the genetic associations of nucleotide variants with expression of the genes encoding human telomerase reverse transcriptase (hTERT) and telomerase RNA components (TERC) in lymphoblastoid cell lines derived from 373 Europeans.Our results revealed 6 eQTLs associated with hTERT (P < 5 × 10). One eQTL (rs17755753) was located in the intron 1 of the gene encoding R-spondin-3 (RSPO3), a well-known Wnt signaling regulator...
October 2016: Medicine (Baltimore)
Peng Xu, Yongyan Dang, Luyang Wang, Xia Liu, Xiaolin Ren, Jun Gu, Mingyao Liu, Xing Dai, Xiyun Ye
Lgr4 is a member of the leucine-rich, G protein-coupled receptor family of proteins, and has recently been shown to augment Wnt/β-catenin signaling via binding to Wnt agonists R-spondins. It plays an important role in skin development, but its involvement in skin tumorigenesis is unclear. Here, we report that mice deficient for Lgr4 are resistant to 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced keratinocyte proliferation and papilloma formation. We show that TPA treatment activates MEK1, ERK1/2 and downstream effector AP-1 in wild-type (WT) epidermal cells and mice, but not in cells or mice where Lgr4 is depleted...
September 30, 2016: Cancer Letters
Tobias Hofmann, Ulf Elbelt, Verena Haas, Anne Ahnis, Burghard F Klapp, Matthias Rose, Andreas Stengel
While physical hyperactivity represents a frequent symptom of anorexia nervosa and may have a deleterious impact on the course of the disease, the underlying mechanisms are poorly understood. Since several food intake-regulatory hormones affect physical activity, the aim of the study was to investigate the association of physical activity with novel candidate hormones (kisspeptin, ghrelin, oxyntomodulin, orexin-A, FGF-21, R-spondin-1) possibly involved in patients with anorexia nervosa. Associations with psychometric parameters and body composition were also assessed...
September 28, 2016: Appetite
Amanda T Mah, Kelley S Yan, Calvin J Kuo
Wnt signalling is involved in multiple aspects of embryonic development and adult tissue homeostasis, notably via controlling cellular proliferation and differentiation. Wnt signalling is subject to stringent positive and negative regulation to promote proper development and homeostasis yet avoid aberrant growth. Such multi-layer regulation includes post-translational modification and processing of Wnt proteins themselves, R-spondin (Rspo) amplification of Wnt signalling, diverse receptor families, and intracellular and extracellular antagonists and destruction and transcription complexes...
September 1, 2016: Journal of Physiology
Hui Yan, Shuai Wang, Zhenwei Li, Zewei Sun, Jie Zan, Wenting Zhao, Yanyun Pan, Zhen Wang, Mingjie Wu, Jianhua Zhu
Oxidized low density lipoprotein (oxLDL)-induced apoptosis of macrophages contributes to the formation of atherosclerotic plaques. R‑spondin 2 (Rspo2), a member of the cysteine‑rich secreted proteins, has been shown to be involved in the oncogenesis of several types of cancer. It has also been found to be abundantly expressed among the four R‑spondin members in macrophages. The present study was performed to determine whether Rspo2 is involved in the ox‑LDL‑induced apoptosis of macrophages. It was identified that Rspo2 inhibited oxLDL‑induced apoptosis in the presence of endoplasmic reticulum (ER) stress activator using flow cytometry...
October 2016: Molecular Medicine Reports
Magdalena Żak, Thijs van Oort, Ferry G Hendriksen, Marie-Isabelle Garcia, Gilbert Vassart, Wilko Grolman
In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the activity of Wnt/β-catenin signaling is modulated by an interaction between LGR receptors and their ligands from the R-spondin family. The deficiency in Lgr4 and Lgr5 genes leads to developmental malformations and lethality...
2016: Frontiers in Cellular Neuroscience
Yang-Yi Fan, Laurie A Davidson, Robert S Chapkin
Colonic organoids, three-dimensional colonic crypts grown in vitro that show realistic microanatomy, have many potential applications for studying physiology, developmental biology, and pathophysiology of intestinal diseases including inflammatory bowel disease and colorectal cancer. Here, we describe detailed protocols for mouse colonic crypt isolation, organoid culture, and downstream applications. Specific culture strategies including growth factor enriched Matrigel and Wnt and R-spondin conditioned media serve as key factors for enhancing the growth and cost efficiency of colonic organoid cultures...
August 19, 2016: Methods in Molecular Biology
Lixing Zhang, Mohammad Adileh, Maria Laura Martin, Stefan Klingler, Julie White, Xiaojing Ma, Louise R Howe, Anthony M C Brown, Richard Kolesnick
Recent evidence suggests that mammary cells expressing R-spondin receptor and Wnt pathway regulator Lgr5, regarded as a stem cell marker in multiple tissues, might represent mammary stem cells (MaSCs). Whether L gr5 marks a multipotent subpopulation of Lin-CD24(low/med)CD49f(high) MaSCs remains controversial. To some extent the differing results reflect different assays used to assess properties of stemness, including lineage tracing in vivo, mammosphere culture, and mammary fat pad transplantation assays. To address this issue directly, we isolated Lgr5(+) cells from mammary glands of Lgr5-lacZ mice and established organoids based on principles adapted from studies of Wnt-driven Lgr5(+) cell populations in other organs...
August 7, 2016: Cellular Signalling
John Hilkens, Nikki C Timmer, Mandy Boer, Gerjon J Ikink, Matthias Schewe, Andrea Sacchetti, Martijn A J Koppens, Ji-Ying Song, Elvira R M Bakker
OBJECTIVE: The gross majority of colorectal cancer cases results from aberrant Wnt/β-catenin signalling through adenomatous polyposis coli (APC) or CTNNB1 mutations. However, a subset of human colon tumours harbour, mutually exclusive with APC and CTNNB1 mutations, gene fusions in RSPO2 or RSPO3, leading to enhanced expression of these R-spondin genes. This suggested that RSPO activation can substitute for the most common mutations as an alternative driver for intestinal cancer. Involvement of RSPO3 in tumour growth was recently shown in RSPO3-fusion-positive xenograft models...
August 10, 2016: Gut
Heather Jackson, David Granger, Gavin Jones, Louisa Anderson, Sarah Friel, Daniel Rycroft, William Fieles, James Tunstead, Michael Steward, Trevor Wattam, Adam Walker, Jeremy Griggs, Muhammad Al-Hajj, Christopher Shelton
UNLABELLED: Aberrant WNT signaling is associated with the formation and growth of numerous human cancer types. The low-density lipoprotein receptor-related protein 6 (LRP6) is the least redundant component of the WNT receptor complex with two independent WNT ligand-binding sites. Using domain antibody (dAb) technology, a bispecific antibody (GSK3178022) to LRP6 was identified that is capable of blocking stimulation in the presence of a range of WNT and R-spondin (RSPO) ligands in vitro GSK3178022 was also efficacious in reducing WNT target gene expression in vivo, in both cancer cell line and patient-derived xenograft models, and delays tumor growth in a patient-derived RSPO fusion model of colorectal cancer...
September 2016: Molecular Cancer Research: MCR
Masahiro Nakajima, Ikuyo Kou, Hirofumi Ohashi, Shiro Ikegawa
Ossification of the posterior longitudinal ligament of the spine (OPLL) is a common spinal disorder that results from ectopic ossification of the posterior longitudinal ligament and causes intractable myelopathy and radiculopathy. In a previous genome-wide association study (GWAS), we found six loci associated with OPLL; however, susceptibility genes in these loci have not been identified yet. Here, we examined one of the GWAS loci and identified RSPO2 (encoding R-spondin 2) as a susceptibility gene for OPLL...
July 7, 2016: American Journal of Human Genetics
Huai-Xiang Hao, Xiaomo Jiang, Feng Cong
Aberrant activation of the Wnt/β-catenin pathway is frequently found in various cancers, often through mutations of downstream components. Inhibiting β-catenin signaling in tumors with downstream pathway mutations remains challenging, due to a lack of favorable targets. On the other hand, targeting upstream components of the Wnt pathway is rather straightforward. However, it is difficult to identify tumors addicted to autocrine or paracrine Wnt signaling. Discovery of the R-spondin-ZNRF3/RNF43 signaling module and its genetic alterations in cancers represents a breakthrough in this area...
2016: Cancers
Hiroaki Nakashima, Bisei Ohkawara, Shinsuke Ishigaki, Takayasu Fukudome, Kenyu Ito, Mikito Tsushima, Hiroyuki Konishi, Tatsuya Okuno, Toshiro Yoshimura, Mikako Ito, Akio Masuda, Gen Sobue, Hiroshi Kiyama, Naoki Ishiguro, Kinji Ohno
At the neuromuscular junction (NMJ), acetylcholine receptor (AChR) clustering is mediated by spinal motor neuron (SMN)-derived agrin and its receptors on the muscle, the low-density lipoprotein receptor-related protein 4 (LRP4) and muscle-specific receptor tyrosine kinase (MuSK). Additionally, AChR clustering is mediated by the components of the Wnt pathway. Laser capture microdissection of SMNs revealed that a secreted activator of Wnt signaling, R-spondin 2 (Rspo2), is highly expressed in SMNs. We found that Rspo2 is enriched at the NMJ, and that Rspo2 induces MuSK phosphorylation and AChR clustering...
2016: Scientific Reports
Chiung-Fang Chang, Li-Sung Hsu, Chieh-Yu Weng, Chih-Kai Chen, Shu-Ying Wang, Yi-Hwa Chou, Yan-Yu Liu, Zi-Xiu Yuan, Wen-Ying Huang, Ho Lin, Yau-Hung Chen, Jen-Ning Tsai
R-spondin 1 (Rspo1) plays an essential role in stem cell biology by potentiating Wnt signaling activity. Despite the fact that Rspo1 holds therapeutic potential for a number of diseases, its biogenesis is not fully elucidated. All Rspo proteins feature two amino-terminal furin-like repeats, which are responsible for Wnt signal potentiation, and a thrombospondin type 1 (TSR1) domain that can provide affinity towards heparan sulfate proteoglycans. Using chemical inhibitors, deglycosylase and site-directed mutagenesis, we found that human Rspo1 and Rspo3 are both N-glycosylated at N137, a site near the C-terminus of the furin repeat 2 domain, and Rspo2 is N-glycosylated at N160, a position near the N-terminus of TSR1 domain...
2016: International Journal of Molecular Sciences
Gui-Xun Shi, Wei-Wei Mao, Xin-Feng Zheng, Lei-Sheng Jiang
R-spondins are a family of four secreted proteins and act as agonists of the canonical Wnt/β-catenin signaling pathway. They are broadly expressed in different phases of skeleton tissues. Recently, three closely related leucine-rich repeat containing G-protein-coupled receptors (Lgr4/5/6) have been identified as the new and exact receptors of R-spondins. On the cell surface, R-spondins binding with Lgr4/5/6 and Znrf3/Rnf43 lead to reduced turnover of Wnts-receptors and potentiate Wnt/β-catenin signaling pathway which is critical for the control of bone development and remodeling...
May 26, 2016: Progress in Biophysics and Molecular Biology
Chao Zhu, Xin-Feng Zheng, Yue-Hua Yang, Bo Li, Yu-Ren Wang, Sheng-Dan Jiang, Lei-Sheng Jiang
R-spondin proteins are identified as secreted agonists of the canonical Wnt/β-catenin signaling pathway, and leucine-rich repeat-containing G-protein-coupled receptors (LGR) are recognized as R-spondin receptors. The potential role of R-spondin 2 (Rspo2) and LGR4 in mediating osteogenesis remains poorly understood. In our in vitro experiments, we found that Rspo2 could promote osteogenesis through activating the Wnt signaling pathway in MC3T3-E1 cells. However, this effect of Rsop2 disappeared in the cells with functional disruption of LGR4...
August 2016: Cellular Signalling
Na Li, Shu Liu, Hui-Shan Zhang, Zhi-Li Deng, Hua-Shan Zhao, Qian Zhao, Xiao-Hua Lei, Li-Na Ning, Yu-Jing Cao, Hai-Bin Wang, Shuang Liu, En-Kui Duan
R-spondin proteins are novel Wnt/β-catenin agonists, which signal through their receptors leucine-rich repeat-containing G-protein coupled receptor (LGR) 4/5/6 and substantially enhance Wnt/β-catenin activity. R-spondins are reported to function in embryonic development. They also play important roles in stem cell functions in adult tissues, such as the intestine and mammary glands, which largely rely on Wnt/β-catenin signaling. However, in the skin epithelium and hair follicles, the information about R-spondins is deficient, although the expressions and functions of their receptors, LGR4/5/6, have already been studied in detail...
2016: International Journal of Molecular Sciences
Eugene Kang, Mitra Yousefi, Samantha Gruenheid
The R-spondin family of proteins has recently been described as secreted enhancers of β-catenin activation through the canonical Wnt signaling pathway. We previously reported that Rspo2 is a major determinant of susceptibility to Citrobacter rodentium-mediated colitis in mice and recent genome-wide association studies have revealed RSPO3 as a candidate Crohn's disease-specific inflammatory bowel disease susceptibility gene in humans. However, there is little information on the endogenous expression and cellular source of R-spondins in the colon at steady state and during intestinal inflammation...
2016: PloS One
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