Project description:In order to characterize the differences between the co-receptors LRP5 and LRP6, we have analyzed the transcriptome of HCC38 cells - a triple negative breast cancer cell line - 24, 48 and 72 hours following the depletion of LRP5 or LRP6 using siRNAs.
Project description:Wnt signaling is a major regulator of osteoblast differentiation and function. To investigate how Wnt3a signaling regulates osteoblastic gene expression and to identify the role of Lrp5 and Lrp6 in mediating Wnt3a signaling in osteoblasts, neonatal calvarial osteoblasts isolated from C57Bl6 (WT) and osteoblasts lacking Lrp5 (Lrp5KO), Lrp6 (Lrp6KO) and, both Lrp5 and 6 (Lrp5/6KO) were treated with Wnt3a for 24 hours and gene expression changes were quantified by RNA-seq.
Project description:The canonical Wnt signaling pathway has been demonstrated as a critical role in the self-renewal, proliferation and differentiation of Hematopoietic Stem Cells (HSCs), but the functions are indeterminacy in adult HSCs since the different experimental systems using gain- or loss- functions mice models. Low-density lipoprotein receptor-related proteins 5 and 6 (LRP5 and LRP6) are important co-receptors in the canonical Wnt/β-catenin pathway. In this study, the knockout mice models were established for adult HSC investagation via conditional ablation of LRP5 and LRP6 in adult hematopoiesis by Vav-Cre Loxp system. We found the HSC numbers were diminished due to the decreased proliferation and cell cycle. To investigate the molecular mechanisms, RNA-seq was performed using HSC cells isolated from WT and dKO mice.
Project description:Cancer cachexia with profound weight loss and frailty impairs quality of life, limits cancer therapy and decreases survival, against which no effective therapy is available. Dkk1 is a secreted antagonist of Wnt/β-catenin pathway via interacting with Wnt co-receptors LRP5 and 6 (LRP5/6) and inducing their endocytosis1-4. Although Dkk1 is critical for animal development3,5, its mRNA is undetectable in most adult organs6. Of note, elevated circulating Dkk1 leads to poor prognosis in patients with a variety of types of cancer by a completely unknown mechanism. Here, we show that administration of a recombinant Dkk1 protein accelerated cancer cachexia-related death through inducing LRP6 endocytosis but not β-catenin inhibition, whereas pharmacological blockade of Dkk1-induced membrane LRP6 downregulation completely prevented cancer cachexia and robustly prolonged survival in tumor-bearing mice. Pharmacological blockade of Dkk1-induced membrane LRP6 downregulation prevented alterations of a number of GPCR pathways and all main cancer cachexia-related pathways in skeletal muscle of mice bearing tumor as shown by a genome-wide transcriptional analysis. Furthermore, Dkk1 injection into hindlimb directly triggered activations of GPCR pathways and cachexia-related pathways. These findings establish a key role of the Dkk1-LRP6 axis in cancer cachexia development through affecting GPCR pathways and suggest a highly promising therapeutic approach for preventing cancer cachexia.
Project description:Investigation of whole-genome gene expression level changes in C57Bl6 Lrp5-/- mammary epithelial cells, compared to the wild-type strain. The mammary epithelial cells were isolated from numbers 4 and 5 mammary glands. The Lrp5-/- mouse strain described in this study has been further described in Lindvall C, Evans NC, Zylstra CR, Li Y, Alexander CM, Williams BO. 2006. The Wnt signaling receptor Lrp5 is required for mammary ductal stem cell activity and Wnt1-induced tumorigenesis. J Biol Chem. 2006 Nov 17;281(46):35081-7. Epub 2006 Sep 13. PMID: 16973609. Mammary epithelial cells were isolated from 6 groups of Lrp5+/+ and 3 groups of Lrp5-/- mice. The isolated RNA was submitted to the Gene Expression Center, University of Wisconsin-Madison where it was labelled with Cy3. Labelled samples were submitted to Roche Nimblegen and were hybridized to Mus musculus 1-Plex arrays that represent 42,586 mouse genes.
Project description:Purpose: The goals of this study are to determine the LRP6-mediated splicing regulation, and cellular transcriptomes from rat and human are analysised by deep sequencing. Methods: The mRNA profiles of WT and LRP6 KD were generated by deep sequencing, using Illumina HiSeq 4000. And the transcript isoform difference betwwen the two group were analysied by bioinformation, Semiquantitative PCR was performed to identify the analysis result. Results and conclusions: We detected a substantial number of Lrp6 loss-induced AS events, and up to nearly 50 of them were exon-skipped. A gene ontology analysis of the conserved LRP6-driven network showed enrichment for ninety-four genes encoding proteins mainly involved in cellular and metabolic processes . Among them, a decade of genes with LRP6-dependent isoform expression showed identical splicing patterns on the exon level across species. The RNA sequencing results were further verified by Semiquantitative PCR. We conclude that LRP6 could regulate mRNA splicing.
Project description:Investigation of whole-genome gene expression level changes in C57Bl6 Lrp5-/- mammary epithelial cells, compared to the wild-type strain. The mammary epithelial cells were isolated from numbers 4 and 5 mammary glands. The Lrp5-/- mouse strain described in this study has been further described in Lindvall C, Evans NC, Zylstra CR, Li Y, Alexander CM, Williams BO. 2006. The Wnt signaling receptor Lrp5 is required for mammary ductal stem cell activity and Wnt1-induced tumorigenesis. J Biol Chem. 2006 Nov 17;281(46):35081-7. Epub 2006 Sep 13. PMID: 16973609.
Project description:Vision is essential for vertebrates including humans. Sustained vision is accomplished by retinoid metabolism, the ‘visual cycle’, where all-trans retinol (atROL) is incorporated into the retinal pigment epithelium (RPE) from photoreceptors presumably through decade-long missing receptor(s). Here, we show that the LDL-related receptor-5 (Lrp5) protein is linked to the retinol binding protein 1a (Rbp1a), the transporter of atROL in the visual cycle, by generating and analyzing the digenic eyes shut homolog+/-; lrp5+/- zebrafish, the same form of gene defect detected in a human case of inherited retinal degeneration. Global gene expression analysis followed by genetic study clarified that rbp1a played a role downstream of lrp5. Rbp1a protein was colocalized with Lrp5 protein at microvilli of RPE cells. Furthermore, Rbp1a directly bound to the C-terminal intracellular region of Lrp5 in vitro. Collectively, these results strongly suggest that Lrp5 is a potent candidate of the receptor of atROL in the visual cycle.
Project description:Analysis of the gene expression profiles of primary neutrophils isolated from WT and LRP5-KO mouse bone marrow. Results provide insights into molecular mechanisms associated with the altered neutrophil functions resulting from LRP5-deficiency.