Topic
LRG1
About: LRG1 is a research topic. Over the lifetime, 6 publications have been published within this topic receiving 442 citations. The topic is also known as: HMFT1766 & LRG.
Papers
TL;DR: A new regulator of angiogenesis is revealed that mediates its effect by modulating TGF-β signalling, and is revealed to be leucine-rich alpha-2-glycoprotein 1 (Lrg1), of previously unknown function.
Abstract: Aberrant neovascularization contributes to diseases such as cancer, blindness and atherosclerosis, and is the consequence of inappropriate angiogenic signalling. Although many regulators of pathogenic angiogenesis have been identified, our understanding of this process is incomplete. Here we explore the transcriptome of retinal microvessels isolated from mouse models of retinal disease that exhibit vascular pathology, and uncover an upregulated gene, leucine-rich alpha-2-glycoprotein 1 (Lrg1), of previously unknown function. We show that in the presence of transforming growth factor-β1 (TGF-β1), LRG1 is mitogenic to endothelial cells and promotes angiogenesis. Mice lacking Lrg1 develop a mild retinal vascular phenotype but exhibit a significant reduction in pathological ocular angiogenesis. LRG1 binds directly to the TGF-β accessory receptor endoglin, which, in the presence of TGF-β1, results in promotion of the pro-angiogenic Smad1/5/8 signalling pathway. LRG1 antibody blockade inhibits this switch and attenuates angiogenesis. These studies reveal a new regulator of angiogenesis that mediates its effect by modulating TGF-β signalling. LRG1 is identified as a new regulator of TGF-β signalling that promotes angiogenesis via a TβRII–ALK1–ENG–Smad1/5/8 signalling pathway; antibody-mediated inhibition of LRG1 reduces pathogenic neovascularization in a mouse model of retinal injury. Defective angiogenesis is a common feature in many diseases including age-related macular degeneration, atherosclerosis, rheumatoid arthritis and cancer. Here John Greenwood and colleagues identify a novel angiogenic glycoprotein of previously unknown function — leucine-rich-alpha-2-glycoprotein 1 (LRG1) — that exerts its effect through modifying TGF-β signalling. LRG1, upregulated in vitreous samples from humans with proliferative diabetic retinopathy, activates an angiogenic switch by binding to the receptor endoglin and promoting pro-angiogenic TGF-β signalling. Antibody-mediated inhibition of LRG1 reduces pathogenic neovascularization in a mouse model of retinal injury, which suggests that LRG1 is a possible therapeutic target for controlling pathological angiogenesis in ocular disease.
476 citations
12 Nov 2021
TL;DR: In this paper, the effects of LRG1 antibody blockade as monotherapy, or in combination with co-therapies, on vascular function, tumor growth, and infiltrated lymphocytes were investigated.
Abstract: Summary Background A poorly functioning tumor vasculature is pro-oncogenic and may impede the delivery of therapeutics. Normalizing the vasculature, therefore, may be beneficial. We previously reported that the secreted glycoprotein leucine-rich α-2-glycoprotein 1 (LRG1) contributes to pathogenic neovascularization. Here, we investigate whether LRG1 in tumors is vasculopathic and whether its inhibition has therapeutic utility. Methods Tumor growth and vascular structure were analyzed in subcutaneous and genetically engineered mouse models in wild-type and Lrg1 knockout mice. The effects of LRG1 antibody blockade as monotherapy, or in combination with co-therapies, on vascular function, tumor growth, and infiltrated lymphocytes were investigated. Findings In mouse models of cancer, Lrg1 expression was induced in tumor endothelial cells, consistent with an increase in protein expression in human cancers. The expression of LRG1 affected tumor progression as Lrg1 gene deletion, or treatment with a LRG1 function-blocking antibody, inhibited tumor growth and improved survival. Inhibition of LRG1 increased endothelial cell pericyte coverage and improved vascular function, resulting in enhanced efficacy of cisplatin chemotherapy, adoptive T cell therapy, and immune checkpoint inhibition (anti-PD1) therapy. With immunotherapy, LRG1 inhibition led to a significant shift in the tumor microenvironment from being predominantly immune silent to immune active. Conclusions LRG1 drives vascular abnormalization, and its inhibition represents a novel and effective means of improving the efficacy of cancer therapeutics. Funding Wellcome Trust (206413/B/17/Z), UKRI/MRC (G1000466, MR/N006410/1, MC/PC/14118, and MR/L008742/1), BHF (PG/16/50/32182), Health and Care Research Wales (CA05), CRUK (C42412/A24416 and A17196), ERC (ColonCan 311301 and AngioMature 787181), and DFG (CRC1366).
38 citations
TL;DR: It is hypothesized that changes in the stool microbiome and urinary proteome of T1D patients implicate aberrant glycation of macromolecules that alter lysosomal function and metabolism in renal tubular epithelial cells, cells that line part of the upper urinary tract.
Abstract: While insulin replacement therapy restores the health and prevents the onset of diabetic complications (DC) for many decades, some T1D patients have elevated hemoglobin A1c values suggesting poor glycemic control, a risk factor of DC. We surveyed the stool microbiome and urinary proteome of a cohort of 220 adolescents and children, half of which had lived with T1D for an average of 7 years and half of which were healthy siblings. Phylogenetic analysis of the 16S rRNA gene did not reveal significant differences in gut microbial alpha-diversity comparing the two cohorts. The urinary proteome of T1D patients revealed increased abundances of several lysosomal proteins that correlated with elevated HbA1c values. In silico protein network analysis linked such proteins to extracellular matrix components and the glycoprotein LRG1. LRG1 is a prominent inflammation and neovascularization biomarker. We hypothesize that these changes implicate aberrant glycation of macromolecules that alter lysosomal function and metabolism in renal tubular epithelial cells, cells that line part of the upper urinary tract.
33 citations
TL;DR: The findings imply that downregulation of the expression of LRG1 is correlated with tumorigenesis but not with the development of HNSCC, indicating the potential clinical value ofLRG1 in the early diagnosis of H NSCC.
Abstract: Leucine-rich-α-2-glycoprotein 1 (LRG1) is considered as a potential biomarker as it is aberrantly expressed in various malignancies. However, there is limited information regarding its role in head and neck squamous cell carcinoma (HNSCC). In the present study, we aimed to explore the expression pattern of LRG1 in HNSCC and its clinicopathological significance. We first analyzed LRG1 gene expression in HNSCC by investigating data obtained from the Gene Expression Omnibus (GEO) database. The results showed that LRG1 was downregulated in HNSCC tissues and its expression level was negatively related to tumor T and N stages and degree of malignancy. Then, we further tested a tissue microassay and clinical samples, respectively, by immunohistochemical staining and western blotting. Consistently, the results revealed that LRG1 expression was decreased in tumor tissues regardless of the grade of the tumor. Moreover, the protein level of LRG1 showed slight differences among four T stages or three N stages. In addition, there were no significant associations between LRG1 protein expression and other clinicopathological parameters such as gender, age, tumor location and clinical staging. These findings imply that downregulation of the expression of LRG1 is correlated with tumorigenesis but not with the development of HNSCC, indicating the potential clinical value of LRG1 in the early diagnosis of HNSCC.
16 citations
TL;DR: Results suggest that LRG is a novel marker for early neutrophilic granulocyte differentiation.
Abstract: Using data obtained from cDNA representational difference analysis to identify genes induced during neutrophilic differentiation of the 32D clone 3G (32Dcl3G) cells, we isolated cDNA clones for murine and human leucine-rich alpha2-glycoprotein (hLRG), a protein with unknown function purified 25 years ago. Expression of LRG during differentiation of 32Dcl3G cells preceded the expression of lactoferrin and gelatinase but followed myeloperoxidase. LRG transcripts were also detected in human neutrophils and progenitor cells but not in peripheral blood mononuclear cells. Notably, LRG expression was up-regulated during neutrophilic differentiation of human MPD and HL-60 cells but down-regulated during monocytic differentiation of HL-60 cells. The hLRG gene was localized to chromosome 19p13.3, a region to which the genes for several neutrophil granule enzymes also map. The putative promoter region of LRG was found to contain consensus-binding sites for PU.1, C/EBP, STAT, and MZF1. These results suggest that LRG is a novel marker for early neutrophilic granulocyte differentiation.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2017 | 2 |
| 2013 | 1 |
| 2002 | 1 |