The Experts below are selected from a list of 42093 Experts worldwide ranked by ideXlab platform
Wolfgang Vogel - One of the best experts on this subject based on the ideXlab platform.
-
Expression of the tyrosine kinase discoidin domain receptor 1 (DDR1) in human central nervous system myelin.
Brain Research, 2010Co-Authors: Bàrbara Roig, Wolfgang Vogel, Neus Franco-pons, Lourdes Martorell, Jordi Tomàs, Elisabet VilellaAbstract:Abstract During development of the mouse brain, the protein kinase discoidin domain receptor 1 (DDR1) is present prenatally in neurons of the proliferative areas, and postnatally, DDR1 expression is no longer detected in neurons, but a spatial–temporal expression pattern in oligodendrocytes that overlaps with the dynamics of the myelination process is detected. Notably, oligodendrocytic DDR1 expression is upregulated in mice during experimentally induced remyelination. Recently, we demonstrated that DDR1 expression is high in human brain and that there is an association between the gene and schizophrenia in a case–control study. However, data regarding expression of DDR1 in the human brain are scarce. Here, we describe the expression pattern of DDR1 in the human adult cerebral cortex. Using several immunohistological techniques and in situ hybridization, we identified DDR1 in the following: a) myelin, b) capillary endothelial cells in the gray as well as white matter, and c) in the soma of some oligodendrocytes and astrocytes in the white matter. The most important overall finding in this study was that DDR1 is present in myelin and is expressed by oligodendrocyte cells. We detected the presence of DDR1 mRNA and protein in myelin and observed that DDR1 co-localized with the classical myelin basic protein (MBP). Moreover, we found a strong positive correlation between expression levels of DDR1 and two myelin-associated genes, myelin-associated glycoprotein (MAG) and oligodendrocyte transcription factor 2 (OLIG2). These observations suggest that DDR1 could be an important constituent of myelin. Because defects in myelination are linked to several mental disorders such as schizophrenia, the function of DDR1 in the process of myelination warrants further investigation.
-
discoidin domain receptor 1 DDR1 deletion decreases atherosclerosis by accelerating matrix accumulation and reducing inflammation in low density lipoprotein receptor deficient mice
Circulation Research, 2008Co-Authors: Christopher Franco, Wolfgang Vogel, Pamela J Ahmad, Edwin Y K Fu, Michelle P BendeckAbstract:Collagens are abundant within the atherosclerotic plaque, where they contribute to lesion volume and mechanical stability and influence cell signaling. The discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that binds to collagen, is expressed in blood vessels, but evidence for a functional role during atherogenesis is incomplete. In the present study, we generated DDR1 +/+ ; Ldlr −/− and DDR1 −/− ; Ldlr −/− mice and fed them an atherogenic diet for 12 or 24 weeks. Targeted deletion of DDR1 resulted in a 50% to 60% reduction in atherosclerotic lesion area in the descending aorta at both 12 and 24 weeks. DDR1 −/− ; Ldlr −/− plaques exhibited accelerated deposition of fibrillar collagen and elastin at 12 weeks compared with DDR1 +/+ ; Ldlr −/− plaques. Expression analysis of laser microdissected lesions in vivo, and of DDR1 −/− smooth muscle cells in vitro, revealed increased mRNA levels for procollagen α1(I) and α1(III) and tropoelastin, suggesting an enhancement of matrix synthesis in the absence of DDR1. Furthermore, whereas plaque smooth muscle cell content was unchanged, DDR1 −/− ; Ldlr −/− plaques had a 49% decrease in macrophage content at 12 weeks, with a concomitant reduction of in situ gelatinolytic activity. Moreover, mRNA expression of both monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 was reduced in vivo, and DDR1 −/− ; Ldlr −/− macrophages demonstrated impaired matrix metalloproteinase expression in vitro. These data suggest novel roles for DDR1 in macrophage recruitment and invasion during atherogenesis. In conclusion, our data support a role for DDR1 in the regulation of both inflammation and fibrosis early in plaque development. Deletion of DDR1 attenuated atherogenesis and resulted in the formation of matrix-rich plaques.
-
expression and mutation analysis of the discoidin domain receptors 1 and 2 in non small cell lung carcinoma
British Journal of Cancer, 2007Co-Authors: Caroline E Ford, Tommy Andersson, Mingsound Tsao, Wolfgang VogelAbstract:The discoidin domain receptors, (DDR)1 and DDR2, have been linked to numerous human cancers. We sought to determine expression levels of DDRs in human lung cancer, investigate prognostic determinates, and determine the prevalence of recently reported mutations in these receptor tyrosine kinases. Tumour samples from 146 non-small cell lung carcinoma (NSCLC) patients were analysed for relative expression of DDR1 and DDR2 using quantitative real-time PCR (qRT-PCR). An additional 23 matched tumour and normal tissues were tested for differential expression of DDR1 and DDR2, and previously reported somatic mutations. Discoidin domain receptor 1 was found to be significantly upregulated by 2.15-fold (P=0.0005) and DDR2 significantly downregulated to an equivalent extent (P=0.0001) in tumour vs normal lung tissue. Discoidin domain receptor 2 expression was not predictive for patient survival; however, DDR1 expression was significantly associated with overall (hazard ratio (HR) 0.43, 95% CI=0.22–0.83, P=0.014) and disease-free survival (HR=0.56, 95% CI=0.33–0.94, P=0.029). Multivariate analysis revealed DDR1 is an independent favourable predictor for prognosis independent of tumour differentiation, stage, histology, and patient age. However, contrary to previous work, we did not observe DDR mutations. We conclude that whereas altered expression of DDRs may contribute to malignant progression of NSCLC, it is unlikely that this results from mutations in the DDR1 and DDR2 genes that we investigated.
-
tyrosine kinase activity of discoidin domain receptor 1 is necessary for smooth muscle cell migration and matrix metalloproteinase expression
Circulation Research, 2002Co-Authors: Wolfgang Vogel, Michelle P BendeckAbstract:Smooth muscle cell (SMC) interactions with collagen mediate cell migration during the pathogenesis of atherosclerosis and restenosis. Discoidin domain receptors (DDRs) have been identified as novel collagen receptors. We used aortic SMCs from wild-type and DDR1−/− mice to evaluate the function of the DDR1 in regulating migration. DDR1−/− SMCs exhibited impaired attachment to and migration toward a type I collagen substrate. Matrix metalloproteinase-2 (MMP-2) and MMP-9 activities were concomitantly reduced in these cells. Transfection of a full-length cDNA for DDR1b rescued these deficits, whereas kinase-dead mutants of DDR1 restored attachment but not migration and MMP production. These results suggest that active DDR1 kinase is a central mediator of SMC migration.
-
discoidin domain receptor 1 tyrosine kinase has an essential role in mammary gland development
Molecular and Cellular Biology, 2001Co-Authors: Wolfgang Vogel, Tony Pawson, F. Alves, Attila AszodiAbstract:Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor tyrosine kinases, DDR1 and DDR2. Here, we used a recombinant fusion protein between the extracellular domain of DDR1 and alkaline phosphatase to detect specific receptor binding sites during mouse development. Major sites of DDR1-binding activity, indicative of ligand expression, were found in skeletal bones, the skin, and the urogenital tract. Ligand expression in the uterus during implantation and in the mammary gland during pregnancy colocalized with the expression of the DDR1 receptor. The generation of DDR1-null mice by gene targeting yielded homozygous mutant animals that were viable but smaller in size than control littermates. The majority of mutant females were unable to bear offspring due to a lack of proper blastocyst implantation into the uterine wall. When implantation did occur, the mutant females were unable to lactate. Histological analysis showed that the alveolar epithelium failed to secrete milk proteins into the lumen of the mammary gland. The lactational defect appears to be caused by hyperproliferation and abnormal branching of mammary ducts. These results suggest that DDR1 is a key mediator of the stromal-epithelial interaction during ductal morphogenesis in the mammary gland.
Tony Pawson - One of the best experts on this subject based on the ideXlab platform.
-
discoidin domain receptor 1 tyrosine kinase has an essential role in mammary gland development
Molecular and Cellular Biology, 2001Co-Authors: Wolfgang Vogel, Tony Pawson, F. Alves, Attila AszodiAbstract:Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor tyrosine kinases, DDR1 and DDR2. Here, we used a recombinant fusion protein between the extracellular domain of DDR1 and alkaline phosphatase to detect specific receptor binding sites during mouse development. Major sites of DDR1-binding activity, indicative of ligand expression, were found in skeletal bones, the skin, and the urogenital tract. Ligand expression in the uterus during implantation and in the mammary gland during pregnancy colocalized with the expression of the DDR1 receptor. The generation of DDR1-null mice by gene targeting yielded homozygous mutant animals that were viable but smaller in size than control littermates. The majority of mutant females were unable to bear offspring due to a lack of proper blastocyst implantation into the uterine wall. When implantation did occur, the mutant females were unable to lactate. Histological analysis showed that the alveolar epithelium failed to secrete milk proteins into the lumen of the mammary gland. The lactational defect appears to be caused by hyperproliferation and abnormal branching of mammary ducts. These results suggest that DDR1 is a key mediator of the stromal-epithelial interaction during ductal morphogenesis in the mammary gland.
-
discoidin domain receptor 1 is activated independently of beta 1 integrin
Journal of Biological Chemistry, 2000Co-Authors: Wolfgang Vogel, F. Alves, C. Brakebusch, R. Fassler, Florence Ruggiero, Tony PawsonAbstract:Abstract Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is presently unclear whether collagen-induced DDR receptor activation, which occurs with very slow kinetics, involves additional proteins with kinase activity or membrane-anchored proteins serving as coreceptors. In particular, the role of the collagen-binding integrins α1β1 or α2β1 in the DDR activation process is undefined. Here, we provide three lines of evidence suggesting that DDR1 signaling is distinct from integrin activation. First we demonstrate that the enzymatic activity of DDR1 is essential for receptor tyrosine phosphorylation. Collagen-induced DDR receptor autophosphorylation can be blocked either by a dominant negative mutant or by a preparation of recombinant extracellular domain. Second, we show DDR1 signals independent of the epidermal growth factor (EGF) receptor. In cells that endogenously express both DDR1 and the EGF receptor, stimulation with EGF does not induce DDR activation. Third, we detected full DDR1 activation after collagen stimulation in cells that have been treated with blocking antibodies for α2β1 integrin or in cells with a targeted deletion of the β1 integrin gene. Finally, we show that overexpression of dominant negative DDR1 in the myoblast cell line C2C12 blocks cellular differentiation and the formation of myofibers.
-
discoidin domain receptor 1 is activated independently of beta 1 integrin
Journal of Biological Chemistry, 2000Co-Authors: Wolfgang F Vogel, Tony Pawson, F. Alves, C. Brakebusch, R. Fassler, Florence RuggieroAbstract:Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is presently unclear whether collagen-induced DDR receptor activation, which occurs with very slow kinetics, involves additional proteins with kinase activity or membrane-anchored proteins serving as coreceptors. In particular, the role of the collagen-binding integrins alpha(1)beta(1) or alpha(2)beta(1) in the DDR activation process is undefined. Here, we provide three lines of evidence suggesting that DDR1 signaling is distinct from integrin activation. First we demonstrate that the enzymatic activity of DDR1 is essential for receptor tyrosine phosphorylation. Collagen-induced DDR receptor autophosphorylation can be blocked either by a dominant negative mutant or by a preparation of recombinant extracellular domain. Second, we show DDR1 signals independent of the epidermal growth factor (EGF) receptor. In cells that endogenously express both DDR1 and the EGF receptor, stimulation with EGF does not induce DDR activation. Third, we detected full DDR1 activation after collagen stimulation in cells that have been treated with blocking antibodies for alpha(2)beta(1) integrin or in cells with a targeted deletion of the beta(1) integrin gene. Finally, we show that overexpression of dominant negative DDR1 in the myoblast cell line C2C12 blocks cellular differentiation and the formation of myofibers.
-
the discoidin domain receptor tyrosine kinases are activated by collagen
Molecular Cell, 1997Co-Authors: Wolfgang Vogel, Gerrald D Gish, Tony PawsonAbstract:Abstract Two mammalian receptor tyrosine kinases (DDR1 and DDR2) have extracellular domains closely related to a D. discoideum lectin, discoidin, required for cell aggregation. Here, we show that the mammalian DDR receptors bind and are activated by specific types of collagen. Stimulation of DDR receptor tyrosine kinase activity requires the native triple-helical structure of collagen and occurs over an extended period of time. Collagen activation of DDR1 induces phosphorylation of a docking site for the Shc phosphotyrosine binding domain, whose presence is controlled by alternative splicing. Activation of DDR2 by collagen results in the up-regulation of matrix metalloproteinase-1 expression. These results suggest that the discoidin-related DDR tyrosine kinases are novel collagen receptors with the potential to control cellular responses to the extracellular matrix.
M Morino - One of the best experts on this subject based on the ideXlab platform.
-
1 8 v 800 mb s pin ddr2 and 2 5 v 400 mb s pin DDR1 compatibly designed 1gb sdram with dual clock input latch scheme and hybrid multi oxide output buffer
IEEE Journal of Solid-state Circuits, 2005Co-Authors: H Fujisawa, Masayuki Nakamura, Yoshimi Takai, Yasuji Koshikawa, T Matano, S Narui, N Usuki, Chiaki Dono, Shinichi Miyatake, M MorinoAbstract:This paper describes three circuit techniques for a DDR1/DDR2-compatible chip architecture designed for both high-speed and high-density DRAMs: 1) a dual-clock input-latch scheme, which reduces the excessive timing margin for random input commands by using a pair of latch circuits controlled by dual-phase one-shot clock signals, achieves a 0.9-ns reduction in cycle time from 3.05 to 2.15 ns; 2) a hybrid multi-oxide output buffer reduces the area penalty of the output buffer caused by compatible chip design from 1.35% to 0.3%; and 3) a quasi-shielded distributed data transfer scheme enables a 2.6-ns reduction in access time to 10.25 ns in both 2-b and 4-b prefetch operations. By using these techniques, we developed a 175.3-mm/sup 2/ 1-Gb SDRAM that operates as an 800-Mb/s/pin DDR2 or 400-Mb/s/pin DDR1.
-
1 8 v 800 mb s pin ddr2 and 2 5 v 400 mb s pin DDR1 compatibly designed 1gb sdram with dual clock input latch scheme and hybrid multi oxide output buffer
Symposium on VLSI Circuits, 2004Co-Authors: H Fujisawa, Masayuki Nakamura, Yoshimi Takai, Yasuji Koshikawa, T Matano, S Narui, N Usuki, Chiaki Dono, Shinichi Miyatake, M MorinoAbstract:Two circuit techniques of DDR1/DDR2 compatible chip architecture designed for both high-speed and high-density DRAMs are presented. The dual clock input latch scheme, which reduces the excessive timing margin for random input commands by using a pair of latch circuits controlled by dual-phase 1-shot clock signals, achieves a 0.9-ns reduction in cycle time from 3.05 ns to 2.15 ns. By using these techniques in combination with a hybrid multi-oxide output buffer, we developed a 175.3 mm/sup 2/ 1Gb SDRAM which operates as a 800-Mb/s/pin DDR2 or 400Mb/s/pin DDR1.
Ke Ding - One of the best experts on this subject based on the ideXlab platform.
-
design and optimization of 3 imidazo 1 2 a pyrazin 3 yl 1 1 biphenyl 3 carboxamides as selective DDR1 inhibitors
ACS Medicinal Chemistry Letters, 2020Co-Authors: Zhang Zhang, Jinfeng Luo, Minhao Huang, Jian Zou, Xiaomei Ren, Ke DingAbstract:DDR1 is considered as a promising target for cancer therapy, and selective inhibitors against DDR1 over other kinases may be considered as promising therapeutic agents. Herein, we have identified a series of 3'-(imidazo[1,2-a]pyrazin-3-yl)-[1,1'-biphenyl]-3-carboxamides as novel selective DDR1 inhibitors. Among these, compound 8v potently inhibited DDR1 with an IC50 of 23.8 nM, while it showed less inhibitory activity against DDR2 (IC50 = 1740 nM) and negligible activities against Bcr-Abl (IC50 > 10 μM) and c-Kit (IC50 > 10 μM). 8v also exhibited excellent selectivity in a KINOMEscan screening platform with 468 kinases. This compound dose-dependently suppressed NSCLC cell tumorigenicity, migration, and invasion. Collectively, these studies support its potential application for treatment of NSCLC.
-
discoidin domain receptor 1 activity drives an aggressive phenotype in gastric carcinoma
BMC Cancer, 2017Co-Authors: Hoon Hur, In-hye Ham, Hyejin Jin, Sang-uk Han, Ji Eun Kwon, Young Bae Kim, Dakeun Lee, Kristina Y Aguilera, Ke DingAbstract:Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that utilizes collagen as a ligand, is a key molecule in the progression of solid tumors as it regulates the interaction of cancer cells with the tumor stroma. However, the clinical relevance of DDR1 expression in gastric carcinoma is yet to be investigated. Here, we assessed the role of DDR1 in mediating the aggressive phenotype of gastric carcinoma and its potential as a therapeutic target. We conducted DDR1 immunohistochemistry using a tissue microarray of 202 gastric carcinoma specimens. We examined the effect of collagen-induced activation of DDR1 on cell signaling, tumorigenesis, and cell migration in gastric cancer cell lines, and tumor growth in a xenograft animal model of gastric cancer. Our results showed that 50.5% of gastric cancer tissues are positive for DDR1 expression, and positive DDR1 expression was significantly correlated with a poor prognosis (P = 0.015). In a subgroup analysis, DDR1 expression was prognostically meaningful only in patients receiving adjuvant treatment (P = 0.013). We also demonstrated that collagen was able to activate DDR1 and increase the clonogenicity and migration of gastric cancer cells. We observed that a DDR1 inhibitor, 7rh benzamide, suppressed tumor growth in gastric cancer xenografts. Our findings suggest a key role for DDR1 signaling in mediating the aggressive phenotype of gastric carcinoma. Importantly, inhibition of DDR1 is an attractive strategy for gastric carcinoma therapy.
-
Discoidin domain receptor 1 activity drives an aggressive phenotype in gastric carcinoma
BioMed Central Ltd., 2017Co-Authors: Hur Hoon, Ham In-hye, Lee Dakeun, Jin Hyejin, Aguilera Kristina, Oh Hye, Han Sang-uk, Kwon, Ji Eun, Kim Young-bae, Ke DingAbstract:Abstract Background Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that utilizes collagen as a ligand, is a key molecule in the progression of solid tumors as it regulates the interaction of cancer cells with the tumor stroma. However, the clinical relevance of DDR1 expression in gastric carcinoma is yet to be investigated. Here, we assessed the role of DDR1 in mediating the aggressive phenotype of gastric carcinoma and its potential as a therapeutic target. Methods We conducted DDR1 immunohistochemistry using a tissue microarray of 202 gastric carcinoma specimens. We examined the effect of collagen-induced activation of DDR1 on cell signaling, tumorigenesis, and cell migration in gastric cancer cell lines, and tumor growth in a xenograft animal model of gastric cancer. Results Our results showed that 50.5% of gastric cancer tissues are positive for DDR1 expression, and positive DDR1 expression was significantly correlated with a poor prognosis ( P \u2009=\u20090.015). In a subgroup analysis, DDR1 expression was prognostically meaningful only in patients receiving adjuvant treatment ( P \u2009=\u20090.013). We also demonstrated that collagen was able to activate DDR1 and increase the clonogenicity and migration of gastric cancer cells. We observed that a DDR1 inhibitor, 7rh benzamide, suppressed tumor growth in gastric cancer xenografts. Conclusions Our findings suggest a key role for DDR1 signaling in mediating the aggressive phenotype of gastric carcinoma. Importantly, inhibition of DDR1 is an attractive strategy for gastric carcinoma therapy
-
up regulation of n cadherin by collagen i activated discoidin domain receptor 1 in pancreatic cancer requires the adaptor molecule shc1
Journal of Biological Chemistry, 2016Co-Authors: Huocong Huang, Ke Ding, Robert A Svoboda, Audrey J Lazenby, Jintana Saowapa, Nina V Chaika, Margaret J Wheelock, Keith R JohnsonAbstract:Abstract Pancreatic ductal adenocarcinomas (PDAC) are highly malignant cancers characterized by extensive invasion into surrounding tissues, metastasis to distant organs, and a limited response to therapy. A main feature of PDAC is desmoplasia, which leads to extensive deposition of collagen I. We have demonstrated that collagen I can induce epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. A hallmark of EMT is an increase in the expression of the mesenchymal cadherin N-cadherin. Previously we showed up-regulation of N-cadherin promotes tumor cell invasion and collagen I-induced EMT is mediated by two collagen receptors, alpha2beta1-integrin and discoidin domain receptor 1 (DDR1). DDR1 is a receptor tyrosine kinase widely expressed during embryonic development and in many adult tissues and is also highly expressed in many different cancers. In the signaling pathway initiated by collagen, we have shown Proline-rich tyrosine kinase 2 (Pyk2) is downstream of DDR1. In this study, we found isoform b of DDR1 is responsible for collagen I-induced up-regulation of N-cadherin and Tyrosine513 of DDR1b is necessary. Knocking down Shc1, which binds to Tyrosine513 of DDR1b via its PTB domain, eliminates the up-regulation of N-cadherin. The signaling does not require a functional SH2 domain or the Tyrosine residues commonly phosphorylated in Shc1 but is mediated by the interaction between a short segment of the central domain of Shc1 and the proline-rich region of Pyk2. Taken together, these data illustrate DDR1b, but not DDR1a, mediates collagen I-induced N-cadherin up-regulation and Shc1 is involved in this process by coupling to both DDR1 and Pyk2.
-
up regulation of n cadherin by collagen i activated discoidin domain receptor 1 in pancreatic cancer requires the adaptor molecule shc1
Journal of Biological Chemistry, 2016Co-Authors: Huocong Huang, Ke Ding, Robert A Svoboda, Audrey J Lazenby, Jintana Saowapa, Nina V Chaika, Margaret J Wheelock, Keith R JohnsonAbstract:Pancreatic ductal adenocarcinomas are highly malignant cancers characterized by extensive invasion into surrounding tissues, metastasis to distant organs, and a limited response to therapy. A main feature of pancreatic ductal adenocarcinomas is desmoplasia, which leads to extensive deposition of collagen I. We have demonstrated that collagen I can induce epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. A hallmark of EMT is an increase in the expression of the mesenchymal cadherin N-cadherin. Previously we showed up-regulation of N-cadherin promotes tumor cell invasion and that collagen I-induced EMT is mediated by two collagen receptors, α2β1-integrin and discoidin domain receptor 1 (DDR1). DDR1 is a receptor-tyrosine kinase widely expressed during embryonic development and in many adult tissues and is also highly expressed in many different cancers. In the signaling pathway initiated by collagen, we have shown proline-rich tyrosine kinase 2 (Pyk2) is downstream of DDR1. In this study we found isoform b of DDR1 is responsible for collagen I-induced up-regulation of N-cadherin and tyrosine 513 of DDR1b is necessary. Knocking down Shc1, which binds to tyrosine 513 of DDR1b via its PTB (phosphotyrosine binding) domain, eliminates the up-regulation of N-cadherin. The signaling does not require a functional SH2 domain or the tyrosine residues commonly phosphorylated in Shc1 but is mediated by the interaction between a short segment of the central domain of Shc1 and the proline-rich region of Pyk2. Taken together, these data illustrate DDR1b, but not DDR1a, mediates collagen I-induced N-cadherin up-regulation, and Shc1 is involved in this process by coupling to both DDR1 and Pyk2.
Michelle P Bendeck - One of the best experts on this subject based on the ideXlab platform.
-
discoidin domain receptor 1 deficiency in vascular smooth muscle cells leads to mislocalisation of n cadherin contacts
Biology Open, 2019Co-Authors: Sudarshan Bala, Michelle P BendeckAbstract:N-cadherin mediates cell-cell contacts in vascular smooth muscle cells (VSMCs), and regulates VSMC behaviours including migration and proliferation. Discoidin domain receptor 1 (DDR1) is a collagen binding receptor also implicated in these processes. Previous studies have shown that both N-cadherin and DDR1 are upregulated after vascular injury, but it is not known whether there is a relationship between the two molecules. In the current study we found that N-cadherin was mislocalised from cell-cell junctions in the absence of DDR1. This occurred in spite of the fact that there was no significant difference in total cell lysate levels of N-cadherin between DDR1+/+ and DDR1-/- VSMCs. Analysis of lipid raft fractions revealed decreased N-cadherin and associated junctional complex catenins in DDR1-/- compared to DDR1+/+ VSMCs. Treatment with cholesterol oxidase or methyl-β-cyclodextrin to disrupt lipid rafts removed N-cadherin and DDR1 from the raft fractions. Reciprocal co-immunoprecipitations suggested the association of DDR1 and N-cadherin. Importantly, transfection of DDR1-/- cells with full-length DDR1b rescued the formation of N-cadherin junctions. Together, these data reveal that N-cadherin cell-cell contacts in VSMCs are regulated through interactions with DDR1 and both molecules are located in lipid rafts.
-
tumor extrinsic discoidin domain receptor 1 promotes mammary tumor growth by regulating adipose stromal interleukin 6 production in mice
Journal of Biological Chemistry, 2018Co-Authors: Kshama Gupta, Michelle P Bendeck, Bogang Wu, Deyi Zhang, Bin Yuan, Xiaowen Zhang, Huaichin Chiang, Chi Zhang, Tyler J Curiel, Stephen D HurstingAbstract:Discoidin domain receptor 1 (DDR1) is a collagen receptor that mediates cell communication with the extracellular matrix (ECM). Aberrant expression and activity of DDR1 in tumor cells are known to promote tumor growth. Although elevated DDR1 levels in the stroma of breast tumors are associated with poor patient outcome, a causal role for tumor-extrinsic DDR1 in cancer promotion remains unclear. Here we report that murine mammary tumor cells transplanted to syngeneic recipient mice in which DDR1 has been knocked out (KO) grow less robustly than in WT mice. We also found that the tumor-associated stroma in DDR1-KO mice exhibits reduced collagen deposition compared with the WT controls, supporting a role for stromal DDR1 in ECM remodeling of the tumor microenvironment. Furthermore, the stromal-vascular fraction (SVF) of DDR1 knockout adipose tissue, which contains committed adipose stem/progenitor cells and preadipocytes, was impaired in its ability to stimulate tumor cell migration and invasion. Cytokine array-based screening identified interleukin 6 (IL-6) as a cytokine secreted by the SVF in a DDR1-dependent manner. SVF-produced IL-6 is important for SVF-stimulated tumor cell invasion in vitro, and, using antibody-based neutralization, we show that tumor promotion by IL-6 in vivo requires DDR1. In conclusion, our work demonstrates a previously unrecognized function of DDR1 in promoting tumor growth.
-
deletion of discoidin domain receptor 2 does not affect smooth muscle cell adhesion migration or proliferation in response to type i collagen
Cardiovascular Pathology, 2012Co-Authors: Guangpei Hou, David Wang, Michelle P BendeckAbstract:Abstract Collagen receptors expressed on vascular smooth muscle cells include the discoidin domain receptors (DDR1 and DDR2). DDR1 is known to play important roles in mediating smooth muscle cell responses to vascular injury, including neointimal hyperplasia, but much less is known about the function of DDR2. In this study, we harvested smooth muscle cells from DDR2 wild-type and knockout mice and studied the cells using in vitro models of migration and growth. There were no significant differences in the ability of Ddr2+/+ or Ddr2−/− smooth muscle cells to attach to, migrate, or proliferate on type I collagen. Furthermore, neither matrix metalloproteinase (MMP) 2 nor MMP-9 activity nor type I collagen expression was different between the cell types. We conclude that in vitro, endogenous DDR2 is not required for smooth muscle cell hyperplastic responses to collagen.
-
collagen stimulates discoidin domain receptor 1 mediated migration of smooth muscle cells through src
Cardiovascular Pathology, 2011Co-Authors: Katherine Kun Lu, Dan Trcka, Michelle P BendeckAbstract:Abstract Background Discoidin domain receptor 1 (DDR1) is a collagen-binding receptor tyrosine kinase which mediates the migration and proliferation of several cell types. DDR1 is expressed in vascular smooth muscle cells (SMCs) during atherosclerosis and following vascular injury, mediating cell migration and contributing to disease pathogenesis. However, very little is known about the signaling pathways activated by the DDR1 in SMCs. Therefore we have studied the involvement of Src and mitogen-activated protein kinase (MAPK) signaling pathways downstream of DDR1 in vascular SMCs. Methods Cells harvested from DDR1 −/− , DDR1 +/+ mice, and DDR1 +/+ cells overexpressing human DDR1b (O/hDDR1b) were used for these studies. Results Stimulation of O/hDDR1b cells with type I collagen resulted in increased tyrosine phosphorylation of DDR1. The non-receptor kinase Src co-immunoprecipitated with DDR1, and the Src inhibitor PP2 inhibited type I collagen-induced tyrosine phosphorylation of DDR1. Stimulation of DDR1-expressing cells with collagen resulted in the activation of extracellular signal-regulated kinase 1/2 (ERK1/2); however, ERK1/2 was not activated in DDR1-deficient cells. By contrast, p38 MAPK (p38) was activated by collagen stimulation in both DDR1-expressing and DDR1-deficient cells. Treatment with PP2 attenuated DDR1-dependent ERK1/2 activation, but not p38 activation. Finally, treatment of SMCs with PP2, or the MEK inhibitor PD98059, inhibited migration toward type I collagen in a chemotaxis chamber. However, PP2 but not PD98059 had a greater effect in reducing the migration of DDR1 +/+ cells compared to DDR1 −/− cells, suggesting that Src but not ERK1/2 was important in regulating DDR1-dependent SMC migration. Conclusions Type I collagen induces SMC migration through DDR1 and this is mediated via Src signaling.
-
increased cell and matrix accumulation during atherogenesis in mice with vessel wall specific deletion of discoidin domain receptor 1
Circulation Research, 2010Co-Authors: Christopher Franco, Eric Wong, Pamela J Ahmad, Michelle P BendeckAbstract:Rationale: Discoidin domain receptor (DDR)1 is a collagen receptor expressed on both smooth muscle cells (SMCs) and macrophages, where it plays important roles regulating cell and matrix accumulation during atherogenesis. Systemic deletion of DDR1 resulted in attenuated plaque growth but accelerated matrix accumulation in LDLR-deficient mice. Deletion of DDR1 solely on bone marrow–derived cells resulted in decreased macrophage accumulation and plaque growth but no change in matrix accumulation. Objective: These findings led us to hypothesize that accelerated matrix accumulation was attributable to the increased synthetic ability of DDR1 −/− resident vascular wall SMCs. Methods and Results: We used bone marrow transplantation to generate chimeric mice and investigate the role of SMC DDR1 during atherogenesis. Mice with deficiency of DDR1 in vessel wall–derived cells ( DDR1 +/+→−/− ) or control mice ( DDR1 +/+→+/+ ) were fed an atherogenic diet for 12 weeks. We observed a 3.8-fold increase in the size of aortic sinus plaques in DDR1 +/+→−/− compared to DDR1 +/+→+/+ mice. This was attributed to pronounced accumulation of collagen, elastin, proteoglycans, and fibronectin and resulted in a thickened fibrous cap. The enhanced matrix accumulation decreased the proportion of plaque area occupied by cells but was associated with a shift in the cellular composition of the lesions toward increased numbers of vessel wall–derived SMCs compared to bone marrow–derived macrophages. In vitro studies confirmed that DDR1 −/− SMCs expressed more matrix, proliferated more, and migrated farther than DDR1 +/+ SMCs. Conclusions: DDR1 expression on resident vessel wall SMCs limits proliferation, migration and matrix accumulation during atherogenesis.