The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Lester F Lau - One of the best experts on this subject based on the ideXlab platform.
-
xenopus CYR61 regulates gastrulation movements and modulates wnt signalling
Development, 2003Co-Authors: Branko V Latinkic, Lester F Lau, S Mercurio, B Bennett, Elizabeth M A Hirst, Timothy J Mohun, James C SmithAbstract:CYR61 is a secreted, heparin-binding, extracellular matrix-associated protein whose activities include the promotion of adhesion and chemotaxis, and the stimulation of fibroblast and endothelial cell growth. Many, if not all, of these activities of CYR61 are mediated through interactions with integrins. We explore the role of CYR61 in the early development of Xenopus laevis. Gain- and loss-of-function experiments show that XCYR61 is required for normal gastrulation movements. This role is mediated in part through the adhesive properties of XCYR61 and its related ability to modulate assembly of the extracellular matrix. In addition, XCYR61 can, in a context-dependent manner, stimulate or inhibit signalling through the Wnt pathway. These properties of XCYR61 provide a mechanism for integrating cell signalling, cell adhesion and cell migration during gastrulation.
-
CYR61 ccn1 is essential for placental development and vascular integrity
Molecular and Cellular Biology, 2002Co-Authors: Andrew G Muntean, Chih Chiun Chen, Donna B Stolz, Simon C Watkins, Lester F LauAbstract:CYR61 (CCN1) is a member of the CCN family of secreted matricellular proteins that includes connective tissue growth factor (CCN2), NOV (CCN3), WISP-1 (CCN4), WISP-2 (CCN5), and WISP-3 (CCN6). First identified as the product of a growth factor-inducible immediate-early gene, CYR61 is an extracellular matrixassociated angiogenic inducer that functions as a ligand of integrin receptors to promote cell adhesion, migration, and proliferation. Aberrant expression of CYR61 is associated with breast cancer, wound healing, and vascular diseases such as atherosclerosis and restenosis. To understand the functions of CYR61 during development, we have disrupted the CYR61 gene in mice. We show here that CYR61-null mice suffer embryonic death: 30% succumbed to a failure in chorioallantoic fusion, and the reminder perished due to placental vascular insufficiency and compromised vessel integrity. These findings establish CYR61 as a novel and essential regulator of vascular development. CYR61 deficiency results in a specific defect in vessel bifurcation (nonsprouting angiogenesis) at the chorioallantoic junction, leading to an undervascularization of the placenta without affecting differentiation of the labyrinthine syncytiotrophoblasts. This unique phenotype is correlated with impaired Vegf-C expression in the allantoic mesoderm, suggesting that CYR61-regulated expression of Vegf-C plays a role in vessel bifurcation. The genetic and molecular basis of vessel bifurcation is presently unknown, and these findings provide new insight into this aspect of angiogenesis.
-
pro angiogenic activities of CYR61 ccn1 mediated through integrins αvβ3 and α6β1 in human umbilical vein endothelial cells
Journal of Biological Chemistry, 2002Co-Authors: Shrjeng Leu, Stephen C T Lam, Lester F LauAbstract:CYR61 (CCN1) is an extracellular matrix-associated protein of the CCN family, which also includes CTGF (CCN2), NOV (CCN3), WISP-1 (CCN4), WISP-2 (CCN5), and WISP-3 (CCN6). Purified CYR61 induces neovascularization in corneal implants, and CYR61-null mice suffer embryonic death due to vascular defects, thus establishing that CYR61 is an important regulator of angiogenesis. Aberrant expression ofCYR61 is associated with breast cancer, wound healing, and vascular diseases such as atherosclerosis and restenosis. In culture, CYR61 functions through integrin-mediated pathways to promote cell adhesion, migration, and proliferation. Here we show that CYR61 can also promote cell survival and tubule formation in human umbilical vein endothelial cells. Furthermore, we have dissected the integrin receptor requirements of CYR61 with respect to its pro-angiogenic activities. Thus, CYR61-induced cell adhesion and tubule formation occur through interaction with integrin α6β1 in early passage endothelial cells in which integrins have not been activated. By contrast, in endothelial cells in which integrins are activated by phorbol ester or vascular endothelial growth factor, CYR61-promoted cell adhesion, migration, survival, growth factor-induced mitogenesis, and endothelial tubule formation are all mediated through integrin αvβ3. These findings indicate that CYR61 is an activation-dependent ligand of integrin αvβ3 and an activation-independent ligand of integrin α6β1 and that these integrins differentially mediate the pro-angiogenic activities of CYR61. These findings help to define the mechanisms by which CYR61 acts as an angiogenic regulator, provide a molecular interpretation for the loss of vascular integrity and increased apoptosis of vascular cells inCYR61-null mice, and underscore the importance of CYR61 in the development and homeostasis of the vascular system.
-
the angiogenic factor cysteine rich 61 CYR61 ccn1 supports vascular smooth muscle cell adhesion and stimulates chemotaxis through integrin α6β1 and cell surface heparan sulfate proteoglycans
Endocrinology, 2002Co-Authors: Tatiana M Grzeszkiewicz, Volkhard Lindner, Ningyu Chen, Stephen C T Lam, Lester F LauAbstract:Cysteine-rich 61 (CYR61, CCN1) is a heparin-binding, extracellular, matrix-associated protein of the cysteine-rich 61/nephroblastoma family, which also includes connective tissue growth factor, nephroblastoma overexpressed, Wnt-induced secreted protein-1 (WISP-1), WISP-2, and WISP-3. CYR61 induces angiogenesis in vivo and supports cell adhesion, promotes cell migration, and enhances growth factor-stimulated mitogenesis in fibroblasts and endothelial cells. Although the expression of CYR61 has been observed in arterial walls, its function in vascular smooth muscle cells (VSMCs) has not been examined to date. Here we show that purified CYR61 supports VSMC adhesion in a dose-dependent, saturable manner through integrin α6β1 with an absolute requirement of cell surface heparan sulfate proteoglycans. In addition, CYR61 induces VSMC chemotaxis, but not chemokinesis, through integrin α6β1 and heparan sulfate proteoglycans. Heparin-binding defective CYR61 mutants are unable to support VSMC adhesion but can still ...
-
the angiogenic factor CYR61 activates a genetic program for wound healing in human skin fibroblasts
Journal of Biological Chemistry, 2001Co-Authors: Chih Chiun Chen, Lester F LauAbstract:CYR61 is a heparin-binding, extracellular matrix-associated protein of the CCN family, which also includes connective tissue growth factor, Nov, WISP-1, WISP-2, and WISP-3. CYR61 is capable of multiple functions, including induction of angiogenesis in vivo. Purified CYR61 mediates cell adhesion and induces adhesive signaling, stimulates cell migration, enhances cell proliferation, and promotes cell survival in both fibroblasts and endothelial cells. In this study, we have used cDNA array hybridization to identify genes regulated by CYR61 in primary human skin fibroblasts. The CYR61-regulated genes fall into several groups known to participate in processes important for cutaneous wound healing, including: 1) angiogenesis and lymphogenesis (VEGF-A and VEGF-C); 2) inflammation (interleukin-1beta); 3) extracellular matrix remodeling (MMP1, MMP3, TIMP1, uPA, and PAI-1); and 4) cell-matrix interactions (Col1alpha1, Col1alpha2, and integrins alpha(3) and alpha(5)). CYR61-mediated gene expression requires heparin binding activity of CYR61, cellular de novo transcription, and protein synthesis and is largely dependent on the activation of p42/p44 MAPKs. CYR61 regulates gene expression not only in serum-free medium but also in fibroblasts cultured on various matrix proteins or in the presence of 10% serum. These effects of CYR61 can be sustained for at least 5 days, consistent with the time course of wound healing in vivo. Interestingly, CYR61 can interact with transforming growth factor-beta1 to regulate expression of specific genes in an antagonistic, additive, or synergistic manner. Furthermore, we show that the CYR61 gene is highly induced in dermal fibroblasts of granulation tissue during cutaneous wound repair. Together, these results show that CYR61 is inducibly expressed in granulation tissues after wounding and that CYR61 activates a genetic program for wound repair in skin fibroblasts. We propose a model in which CYR61 integrates its activities on endothelial cells, fibroblasts, and macrophages to regulate the processes of angiogenesis, inflammation, and matrix remodeling in the context of cutaneous wound healing.
Ningyu Chen - One of the best experts on this subject based on the ideXlab platform.
-
identification of integrin αmβ2 as an adhesion receptor on peripheral blood monocytes for CYR61 ccn1 and connective tissue growth factor ccn2 immediate early gene products expressed in atherosclerotic lesions
Blood, 2002Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Joseph M Schober, Igor Jovanovic, Eugene E EmesonAbstract:Cysteine-rich 61 (CYR61, CCN1) and connective tissue growth factor (CTGF, CCN2) are growth factor–inducible immediate-early gene products found in blood vessel walls and healing cutaneous wounds. We previously reported that the adhesion of endothelial cells, platelets, and fibroblasts to these extracellular matrix–associated proteins is mediated through integrin receptors. In this study, we demonstrated that both CYR61 and CTGF are expressed in advanced atherosclerotic lesions of apolipoprotein E–deficient mice. Because monocyte adhesion and transmigration are important for atherosclerosis, wound healing, and inflammation, we examined the interaction of THP-1 monocytic cells and isolated peripheral blood monocytes with CYR61 and CTGF. THP-1 cells and monocytes adhered to CYR61- or CTGF-coated wells in an activation-dependent manner and this process was mediated primarily through integrin α M β 2 . Additionally, expression of α M β 2 on human embryonic kidney 293 cells resulted in enhanced cell adhesion to CYR61. Consistent with these data, a GST-fusion protein containing the I domain of the integrin α M subunit bound specifically to immobilized CYR61 or CTGF. We have also investigated the requirement of cell surface heparan sulfate proteoglycans (HSPGs) as coreceptors for monocyte adhesion to CYR61. Pretreatment of monocytes with heparin or heparinase I resulted in partial inhibition of cell adhesion to CYR61. However, monocytes, but not fibroblasts, were capable of adhering to a CYR61 mutant deficient in heparin binding activity. Collectively, these results show that activated monocytes adhere to CYR61 and CTGF through integrin α M β 2 and cell surface HSPGs. However, unlike fibroblast adhesion to CYR61, cell surface HSPGs are not absolutely required for this adhesion process.
-
the angiogenic factor cysteine rich 61 CYR61 ccn1 supports vascular smooth muscle cell adhesion and stimulates chemotaxis through integrin α6β1 and cell surface heparan sulfate proteoglycans
Endocrinology, 2002Co-Authors: Tatiana M Grzeszkiewicz, Volkhard Lindner, Ningyu Chen, Stephen C T Lam, Lester F LauAbstract:Cysteine-rich 61 (CYR61, CCN1) is a heparin-binding, extracellular, matrix-associated protein of the cysteine-rich 61/nephroblastoma family, which also includes connective tissue growth factor, nephroblastoma overexpressed, Wnt-induced secreted protein-1 (WISP-1), WISP-2, and WISP-3. CYR61 induces angiogenesis in vivo and supports cell adhesion, promotes cell migration, and enhances growth factor-stimulated mitogenesis in fibroblasts and endothelial cells. Although the expression of CYR61 has been observed in arterial walls, its function in vascular smooth muscle cells (VSMCs) has not been examined to date. Here we show that purified CYR61 supports VSMC adhesion in a dose-dependent, saturable manner through integrin α6β1 with an absolute requirement of cell surface heparan sulfate proteoglycans. In addition, CYR61 induces VSMC chemotaxis, but not chemokinesis, through integrin α6β1 and heparan sulfate proteoglycans. Heparin-binding defective CYR61 mutants are unable to support VSMC adhesion but can still ...
-
CYR61 stimulates human skin fibroblast migration through integrin alpha vbeta 5 and enhances mitogenesis through integrin alpha vbeta 3 independent of its carboxyl terminal domain
Journal of Biological Chemistry, 2001Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Deborah J Kirschling, Lester F LauAbstract:Abstract CYR61, an angiogenic factor and a member of the CCN protein family, is an extracellular matrix-associated, heparin-binding protein that mediates cell adhesion, promotes cell migration, and enhances growth factor-stimulated cell proliferation. CYR61 induces angiogenesis and promotes tumor growth in vivo and is expressed in dermal fibroblasts during cutaneous wound healing. It has been demonstrated recently that adhesion of primary skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans, resulting in adhesive signaling and up-regulation of matrix metalloproteinases 1 and 3. CYR61 is composed of four discrete structural domains that bear sequence similarities to the insulin-like growth factor-binding proteins, von Willebrand factor type C repeat, thrombospondin type 1 repeat, and a carboxyl-terminal (CT) domain that resembles cysteine knots found in some growth factors. In this study, we show that a CYR61 mutant (CYR61ΔCT) that has the CT domain deleted is unable to support adhesion of primary human skin fibroblasts but is still able to stimulate chemotaxis and enhance basic fibroblast growth factor-induced mitogenesis similar to wild type. In addition, fibroblast migration to CYR61 is mediated through integrin αvβ5 but not integrins α6β1 or αvβ3. Furthermore, we show that CYR61 binds directly to purified integrin αvβ5 in vitro. By contrast, CYR61 enhancement of basic fibroblast growth factor-induced DNA synthesis is mediated through integrin αvβ3, a known receptor for CYR61 that mediates CYR61-dependent cell adhesion and chemotaxis in vascular endothelial cells. Thus, CYR61 promotes primary human fibroblast adhesion, migration, and mitogenesis through integrins α6β1, αvβ5, and αvβ3, respectively. Together, these findings establish CYR61 as a novel ligand for integrin αvβ5 and show that CYR61 interacts with distinct integrins to mediate disparate activities in a cell type-specific manner.
-
CYR61 stimulates human skin fibroblast migration through integrin αvβ5 and enhances mitogenesis through integrin αvβ3 independent of its carboxyl terminal domain
Journal of Biological Chemistry, 2001Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Deborah J Kirschling, Lester F LauAbstract:CYR61, an angiogenic factor and a member of the CCN protein family, is an extracellular matrix-associated, heparin-binding protein that mediates cell adhesion, promotes cell migration, and enhances growth factor-stimulated cell proliferation. CYR61 induces angiogenesis and promotes tumor growth in vivo and is expressed in dermal fibroblasts during cutaneous wound healing. It has been demonstrated recently that adhesion of primary skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans, resulting in adhesive signaling and up-regulation of matrix metalloproteinases 1 and 3. CYR61 is composed of four discrete structural domains that bear sequence similarities to the insulin-like growth factor-binding proteins, von Willebrand factor type C repeat, thrombospondin type 1 repeat, and a carboxyl-terminal (CT) domain that resembles cysteine knots found in some growth factors. In this study, we show that a CYR61 mutant (CYR61ΔCT) that has the CT domain deleted is unable to support adhesion of primary human skin fibroblasts but is still able to stimulate chemotaxis and enhance basic fibroblast growth factor-induced mitogenesis similar to wild type. In addition, fibroblast migration to CYR61 is mediated through integrin αvβ5 but not integrins α6β1 or αvβ3. Furthermore, we show that CYR61 binds directly to purified integrin αvβ5 in vitro. By contrast, CYR61 enhancement of basic fibroblast growth factor-induced DNA synthesis is mediated through integrin αvβ3, a known receptor for CYR61 that mediates CYR61-dependent cell adhesion and chemotaxis in vascular endothelial cells. Thus, CYR61 promotes primary human fibroblast adhesion, migration, and mitogenesis through integrins α6β1, αvβ5, and αvβ3, respectively. Together, these findings establish CYR61 as a novel ligand for integrin αvβ5 and show that CYR61 interacts with distinct integrins to mediate disparate activities in a cell type-specific manner.
-
adhesion of human skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans
Journal of Biological Chemistry, 2000Co-Authors: Ningyu Chen, Chih Chiun Chen, Lester F LauAbstract:The angiogenic inducer CYR61 is an extracellular matrix-associated heparin-binding protein that can mediate cell adhesion, stimulate cell migration, and enhance growth factor-stimulated DNA synthesis in both fibroblasts and endothelial cells in culture. In vivo, CYR61 induces neovascularization and promotes tumor growth. CYR61 is a prototypic member of a highly conserved family of secreted proteins that includes connective tissue growth factor, nephroblastoma overexpressed, Elm-1/WISP-1, Cop-1/WISP-2, and WISP-3. Encoded by an immediate early gene, CYR61 synthesis is induced by serum growth factors in cultured fibroblasts and in dermal fibroblasts during cutaneous wound healing. We previously demonstrated that CYR61 mediates adhesion of vascular endothelial cells and activation-dependent adhesion of blood platelets through direct interaction with integrins alpha(V)beta(3) and alpha(IIb)beta(3), respectively. In this study, we show that the adhesion of primary human skin fibroblasts to CYR61 is mediated through integrin alpha(6)beta(1) and cell surface heparan sulfate proteoglycans (HSPGs), which most likely serve as co-receptors. Either destruction of cell surface HSPGs or prior occupancy of the CYR61 heparin-binding site completely blocked cell adhesion to CYR61. A heparin-binding defective mutant of CYR61 was unable to mediate fibroblast adhesion through integrin alpha(6)beta(1) but still mediated endothelial cell adhesion through integrin alpha(V)beta(3), indicating that endothelial cell adhesion through integrin alpha(V)beta(3) is independent of the heparin-binding activity of CYR61. These results identify CYR61 as a novel adhesive substrate for integrin alpha(6)beta(1) and provide the first demonstration of the requirement for HSPGs in integrin-mediated cell attachment. In addition, these findings suggest that CYR61 might elicit disparate biological effects in different cell types through interaction with distinct integrin receptors.
Chih Chiun Chen - One of the best experts on this subject based on the ideXlab platform.
-
CYR61 ccn1 is essential for placental development and vascular integrity
Molecular and Cellular Biology, 2002Co-Authors: Andrew G Muntean, Chih Chiun Chen, Donna B Stolz, Simon C Watkins, Lester F LauAbstract:CYR61 (CCN1) is a member of the CCN family of secreted matricellular proteins that includes connective tissue growth factor (CCN2), NOV (CCN3), WISP-1 (CCN4), WISP-2 (CCN5), and WISP-3 (CCN6). First identified as the product of a growth factor-inducible immediate-early gene, CYR61 is an extracellular matrixassociated angiogenic inducer that functions as a ligand of integrin receptors to promote cell adhesion, migration, and proliferation. Aberrant expression of CYR61 is associated with breast cancer, wound healing, and vascular diseases such as atherosclerosis and restenosis. To understand the functions of CYR61 during development, we have disrupted the CYR61 gene in mice. We show here that CYR61-null mice suffer embryonic death: 30% succumbed to a failure in chorioallantoic fusion, and the reminder perished due to placental vascular insufficiency and compromised vessel integrity. These findings establish CYR61 as a novel and essential regulator of vascular development. CYR61 deficiency results in a specific defect in vessel bifurcation (nonsprouting angiogenesis) at the chorioallantoic junction, leading to an undervascularization of the placenta without affecting differentiation of the labyrinthine syncytiotrophoblasts. This unique phenotype is correlated with impaired Vegf-C expression in the allantoic mesoderm, suggesting that CYR61-regulated expression of Vegf-C plays a role in vessel bifurcation. The genetic and molecular basis of vessel bifurcation is presently unknown, and these findings provide new insight into this aspect of angiogenesis.
-
the angiogenic factor CYR61 activates a genetic program for wound healing in human skin fibroblasts
Journal of Biological Chemistry, 2001Co-Authors: Chih Chiun Chen, Lester F LauAbstract:CYR61 is a heparin-binding, extracellular matrix-associated protein of the CCN family, which also includes connective tissue growth factor, Nov, WISP-1, WISP-2, and WISP-3. CYR61 is capable of multiple functions, including induction of angiogenesis in vivo. Purified CYR61 mediates cell adhesion and induces adhesive signaling, stimulates cell migration, enhances cell proliferation, and promotes cell survival in both fibroblasts and endothelial cells. In this study, we have used cDNA array hybridization to identify genes regulated by CYR61 in primary human skin fibroblasts. The CYR61-regulated genes fall into several groups known to participate in processes important for cutaneous wound healing, including: 1) angiogenesis and lymphogenesis (VEGF-A and VEGF-C); 2) inflammation (interleukin-1beta); 3) extracellular matrix remodeling (MMP1, MMP3, TIMP1, uPA, and PAI-1); and 4) cell-matrix interactions (Col1alpha1, Col1alpha2, and integrins alpha(3) and alpha(5)). CYR61-mediated gene expression requires heparin binding activity of CYR61, cellular de novo transcription, and protein synthesis and is largely dependent on the activation of p42/p44 MAPKs. CYR61 regulates gene expression not only in serum-free medium but also in fibroblasts cultured on various matrix proteins or in the presence of 10% serum. These effects of CYR61 can be sustained for at least 5 days, consistent with the time course of wound healing in vivo. Interestingly, CYR61 can interact with transforming growth factor-beta1 to regulate expression of specific genes in an antagonistic, additive, or synergistic manner. Furthermore, we show that the CYR61 gene is highly induced in dermal fibroblasts of granulation tissue during cutaneous wound repair. Together, these results show that CYR61 is inducibly expressed in granulation tissues after wounding and that CYR61 activates a genetic program for wound repair in skin fibroblasts. We propose a model in which CYR61 integrates its activities on endothelial cells, fibroblasts, and macrophages to regulate the processes of angiogenesis, inflammation, and matrix remodeling in the context of cutaneous wound healing.
-
the angiogenic factor CYR61 activates a genetic program for wound healing in human skin fibroblasts
Journal of Biological Chemistry, 2001Co-Authors: Chih Chiun Chen, Lester F LauAbstract:CYR61 is a heparin-binding, extracellular matrix-associated protein of the CCN family, which also includes connective tissue growth factor, Nov, WISP-1, WISP-2, and WISP-3. CYR61 is capable of multiple functions, including induction of angiogenesis in vivo. Purified CYR61 mediates cell adhesion and induces adhesive signaling, stimulates cell migration, enhances cell proliferation, and promotes cell survival in both fibroblasts and endothelial cells. In this study, we have used cDNA array hybridization to identify genes regulated by CYR61 in primary human skin fibroblasts. The CYR61-regulated genes fall into several groups known to participate in processes important for cutaneous wound healing, including: 1) angiogenesis and lymphogenesis (VEGF-A and VEGF-C); 2) inflammation (interleukin-1β); 3) extracellular matrix remodeling (MMP1, MMP3, TIMP1, uPA, and PAI-1); and 4) cell-matrix interactions (Col1α1, Col1α2, and integrins α3 and α5). CYR61-mediated gene expression requires heparin binding activity of CYR61, cellular de novo transcription, and protein synthesis and is largely dependent on the activation of p42/p44 MAPKs. CYR61 regulates gene expression not only in serum-free medium but also in fibroblasts cultured on various matrix proteins or in the presence of 10% serum. These effects of CYR61 can be sustained for at least 5 days, consistent with the time course of wound healingin vivo. Interestingly, CYR61 can interact with transforming growth factor-β1 to regulate expression of specific genes in an antagonistic, additive, or synergistic manner. Furthermore, we show that the CYR61 gene is highly induced in dermal fibroblasts of granulation tissue during cutaneous wound repair. Together, these results show that CYR61 is inducibly expressed in granulation tissues after wounding and that CYR61 activates a genetic program for wound repair in skin fibroblasts. We propose a model in which CYR61 integrates its activities on endothelial cells, fibroblasts, and macrophages to regulate the processes of angiogenesis, inflammation, and matrix remodeling in the context of cutaneous wound healing.
-
adhesion of human skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans
Journal of Biological Chemistry, 2000Co-Authors: Ningyu Chen, Chih Chiun Chen, Lester F LauAbstract:The angiogenic inducer CYR61 is an extracellular matrix-associated heparin-binding protein that can mediate cell adhesion, stimulate cell migration, and enhance growth factor-stimulated DNA synthesis in both fibroblasts and endothelial cells in culture. In vivo, CYR61 induces neovascularization and promotes tumor growth. CYR61 is a prototypic member of a highly conserved family of secreted proteins that includes connective tissue growth factor, nephroblastoma overexpressed, Elm-1/WISP-1, Cop-1/WISP-2, and WISP-3. Encoded by an immediate early gene, CYR61 synthesis is induced by serum growth factors in cultured fibroblasts and in dermal fibroblasts during cutaneous wound healing. We previously demonstrated that CYR61 mediates adhesion of vascular endothelial cells and activation-dependent adhesion of blood platelets through direct interaction with integrins alpha(V)beta(3) and alpha(IIb)beta(3), respectively. In this study, we show that the adhesion of primary human skin fibroblasts to CYR61 is mediated through integrin alpha(6)beta(1) and cell surface heparan sulfate proteoglycans (HSPGs), which most likely serve as co-receptors. Either destruction of cell surface HSPGs or prior occupancy of the CYR61 heparin-binding site completely blocked cell adhesion to CYR61. A heparin-binding defective mutant of CYR61 was unable to mediate fibroblast adhesion through integrin alpha(6)beta(1) but still mediated endothelial cell adhesion through integrin alpha(V)beta(3), indicating that endothelial cell adhesion through integrin alpha(V)beta(3) is independent of the heparin-binding activity of CYR61. These results identify CYR61 as a novel adhesive substrate for integrin alpha(6)beta(1) and provide the first demonstration of the requirement for HSPGs in integrin-mediated cell attachment. In addition, these findings suggest that CYR61 might elicit disparate biological effects in different cell types through interaction with distinct integrin receptors.
-
adhesion of human skin fibroblasts to CYR61 is mediated through integrin alpha 6beta 1 and cell surface heparan sulfate proteoglycans
Journal of Biological Chemistry, 2000Co-Authors: Ningyu Chen, Chih Chiun Chen, Lester F LauAbstract:The angiogenic inducer CYR61 is an extracellular matrix-associated heparin-binding protein that can mediate cell adhesion, stimulate cell migration, and enhance growth factor-stimulated DNA synthesis in both fibroblasts and endothelial cells in culture. In vivo, CYR61 induces neovascularization and promotes tumor growth. CYR61 is a prototypic member of a highly conserved family of secreted proteins that includes connective tissue growth factor, nephroblastoma overexpressed, Elm-1/WISP-1, Cop-1/WISP-2, and WISP-3. Encoded by an immediate early gene, CYR61 synthesis is induced by serum growth factors in cultured fibroblasts and in dermal fibroblasts during cutaneous wound healing. We previously demonstrated that CYR61 mediates adhesion of vascular endothelial cells and activation-dependent adhesion of blood platelets through direct interaction with integrins alpha(V)beta(3) and alpha(IIb)beta(3), respectively. In this study, we show that the adhesion of primary human skin fibroblasts to CYR61 is mediated through integrin alpha(6)beta(1) and cell surface heparan sulfate proteoglycans (HSPGs), which most likely serve as co-receptors. Either destruction of cell surface HSPGs or prior occupancy of the CYR61 heparin-binding site completely blocked cell adhesion to CYR61. A heparin-binding defective mutant of CYR61 was unable to mediate fibroblast adhesion through integrin alpha(6)beta(1) but still mediated endothelial cell adhesion through integrin alpha(V)beta(3), indicating that endothelial cell adhesion through integrin alpha(V)beta(3) is independent of the heparin-binding activity of CYR61. These results identify CYR61 as a novel adhesive substrate for integrin alpha(6)beta(1) and provide the first demonstration of the requirement for HSPGs in integrin-mediated cell attachment. In addition, these findings suggest that CYR61 might elicit disparate biological effects in different cell types through interaction with distinct integrin receptors.
Stephen C T Lam - One of the best experts on this subject based on the ideXlab platform.
-
pro angiogenic activities of CYR61 ccn1 mediated through integrins αvβ3 and α6β1 in human umbilical vein endothelial cells
Journal of Biological Chemistry, 2002Co-Authors: Shrjeng Leu, Stephen C T Lam, Lester F LauAbstract:CYR61 (CCN1) is an extracellular matrix-associated protein of the CCN family, which also includes CTGF (CCN2), NOV (CCN3), WISP-1 (CCN4), WISP-2 (CCN5), and WISP-3 (CCN6). Purified CYR61 induces neovascularization in corneal implants, and CYR61-null mice suffer embryonic death due to vascular defects, thus establishing that CYR61 is an important regulator of angiogenesis. Aberrant expression ofCYR61 is associated with breast cancer, wound healing, and vascular diseases such as atherosclerosis and restenosis. In culture, CYR61 functions through integrin-mediated pathways to promote cell adhesion, migration, and proliferation. Here we show that CYR61 can also promote cell survival and tubule formation in human umbilical vein endothelial cells. Furthermore, we have dissected the integrin receptor requirements of CYR61 with respect to its pro-angiogenic activities. Thus, CYR61-induced cell adhesion and tubule formation occur through interaction with integrin α6β1 in early passage endothelial cells in which integrins have not been activated. By contrast, in endothelial cells in which integrins are activated by phorbol ester or vascular endothelial growth factor, CYR61-promoted cell adhesion, migration, survival, growth factor-induced mitogenesis, and endothelial tubule formation are all mediated through integrin αvβ3. These findings indicate that CYR61 is an activation-dependent ligand of integrin αvβ3 and an activation-independent ligand of integrin α6β1 and that these integrins differentially mediate the pro-angiogenic activities of CYR61. These findings help to define the mechanisms by which CYR61 acts as an angiogenic regulator, provide a molecular interpretation for the loss of vascular integrity and increased apoptosis of vascular cells inCYR61-null mice, and underscore the importance of CYR61 in the development and homeostasis of the vascular system.
-
the angiogenic factor cysteine rich 61 CYR61 ccn1 supports vascular smooth muscle cell adhesion and stimulates chemotaxis through integrin α6β1 and cell surface heparan sulfate proteoglycans
Endocrinology, 2002Co-Authors: Tatiana M Grzeszkiewicz, Volkhard Lindner, Ningyu Chen, Stephen C T Lam, Lester F LauAbstract:Cysteine-rich 61 (CYR61, CCN1) is a heparin-binding, extracellular, matrix-associated protein of the cysteine-rich 61/nephroblastoma family, which also includes connective tissue growth factor, nephroblastoma overexpressed, Wnt-induced secreted protein-1 (WISP-1), WISP-2, and WISP-3. CYR61 induces angiogenesis in vivo and supports cell adhesion, promotes cell migration, and enhances growth factor-stimulated mitogenesis in fibroblasts and endothelial cells. Although the expression of CYR61 has been observed in arterial walls, its function in vascular smooth muscle cells (VSMCs) has not been examined to date. Here we show that purified CYR61 supports VSMC adhesion in a dose-dependent, saturable manner through integrin α6β1 with an absolute requirement of cell surface heparan sulfate proteoglycans. In addition, CYR61 induces VSMC chemotaxis, but not chemokinesis, through integrin α6β1 and heparan sulfate proteoglycans. Heparin-binding defective CYR61 mutants are unable to support VSMC adhesion but can still ...
-
activation dependent adhesion of human platelets to CYR61 and fisp12 mouse connective tissue growth factor is mediated through integrin αiibβ3
Journal of Biological Chemistry, 1999Co-Authors: Arom Jedsadayanmata, Chih Chiun Chen, Lester F Lau, Maria L Kireeva, Stephen C T LamAbstract:CYR61 and connective tissue growth factor (CTGF), members of a newly identified family of extracellular matrix-associated signaling molecules, are found to mediate cell adhesion, promote cell migration and enhance growth factor-induced cell proliferation in vitro, and induce angiogenesis in vivo. We previously showed that vascular endothelial cell adhesion and migration to CYR61 and Fisp12 (mouse CTGF) are mediated through integrin alpha(v)beta(3). Both CYR61 and Fisp12/mCTGF are present in normal blood vessel walls, and it has been demonstrated that CTGF is overexpressed in advanced atherosclerotic lesions. In the present study, we examined whether CYR61 and Fisp12/mCTGF could serve as substrates for platelet adhesion. Agonist (ADP, thrombin, or U46619)-stimulated but not resting platelets adhered to both CYR61 and Fisp12/mCTGF, and this process was completely inhibited by prostaglandin I(2), which prevents platelet activation. The specificity of CYR61- and Fisp12/mCTGF-mediated platelet adhesion was demonstrated by specific inhibition of this process with polyclonal anti-CYR61 and anti-Fisp12/mCTGF antibodies, respectively. The adhesion of ADP-activated platelets to both proteins was divalent cation-dependent and was blocked by RGDS, HHLGGAKQAGDV, or echistatin, but not by RGES. Furthermore, this process was specifically inhibited by the monoclonal antibody AP-2 (anti-alpha(IIb)beta(3)), but not by LM609 (anti-alpha(v)beta(3)), indicating that the interaction is mediated through integrin alpha(IIb)beta(3). In a solid phase binding assay, activated alpha(IIb)beta(3), purified by RGD affinity chromatography, bound to immobilized CYR61 and Fisp12/mCTGF in a dose-dependent and RGD-inhibitable manner. In contrast, unactivated alpha(IIb)beta(3) failed to bind to either protein. Collectively, these findings identify CYR61 and Fisp12/mCTGF as two novel activation-dependent adhesive ligands for the integrin alpha(IIb)beta(3) on human platelets, and implicate a functional role for these proteins in hemostasis and thrombosis.
-
adhesion of human umbilical vein endothelial cells to the immediate early gene product CYR61 is mediated through integrin αvβ3
Journal of Biological Chemistry, 1998Co-Authors: Maria L Kireeva, Stephen C T Lam, Lester F LauAbstract:Abstract CYR61 is a member of a family of growth factor-inducible immediate-early gene products thought to act cooperatively with the activities of growth factors. Upon synthesis, CYR61 is secreted and is predominantly incorporated into the extracellular matrix. Recently, we demonstrated that CYR61 promotes cell adhesion and migration and augments growth factor-induced DNA synthesis (Kireeva, M. L., Mo, F.-E., Yang, G. P., and Lau, L. F. (1996) Mol. Cell. Biol. 16, 1326–1334). In the present study, we investigated possible candidate receptor(s) on human umbilical vein endothelial cells (HUVECs) mediating adhesion to CYR61. Under both serum-containing and serum-free conditions, adhesion of HUVECs to CYR61 was dose-dependent, saturable, and abolished by affinity-purified anti-CYR61 antibodies. Cell adhesion to CYR61 was divalent cation-dependent and specifically inhibited by the peptide RGDS and LM609, a monoclonal antibody against integrin αvβ3. Furthermore, purified αvβ3 bound directly to an affinity matrix of CYR61-coupled Sepharose 4B, and this interaction was specifically blocked by anti-CYR61 antibodies. Additionally, in a solid phase binding assay, soluble CYR61 bound to immobilized αvβ3 in a dose-dependent manner, and half-saturation binding occurred at approximately 5 nm CYR61. As expected, the interaction of CYR61 with immobilized αvβ3 was blocked by RGDS and LM609. In sum, these results identified CYR61 as a novel ligand for αvβ3 and indicate that the adhesion of HUVECs to CYR61 is mediated through interaction with this integrin. The possibility that integrin αvβ3 functions as a signaling receptor for CYR61 accounts for most if not all activities that can be ascribed to CYR61 to date and suggests a mechanism of action discussed herein.
Tatiana M Grzeszkiewicz - One of the best experts on this subject based on the ideXlab platform.
-
identification of integrin αmβ2 as an adhesion receptor on peripheral blood monocytes for CYR61 ccn1 and connective tissue growth factor ccn2 immediate early gene products expressed in atherosclerotic lesions
Blood, 2002Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Joseph M Schober, Igor Jovanovic, Eugene E EmesonAbstract:Cysteine-rich 61 (CYR61, CCN1) and connective tissue growth factor (CTGF, CCN2) are growth factor–inducible immediate-early gene products found in blood vessel walls and healing cutaneous wounds. We previously reported that the adhesion of endothelial cells, platelets, and fibroblasts to these extracellular matrix–associated proteins is mediated through integrin receptors. In this study, we demonstrated that both CYR61 and CTGF are expressed in advanced atherosclerotic lesions of apolipoprotein E–deficient mice. Because monocyte adhesion and transmigration are important for atherosclerosis, wound healing, and inflammation, we examined the interaction of THP-1 monocytic cells and isolated peripheral blood monocytes with CYR61 and CTGF. THP-1 cells and monocytes adhered to CYR61- or CTGF-coated wells in an activation-dependent manner and this process was mediated primarily through integrin α M β 2 . Additionally, expression of α M β 2 on human embryonic kidney 293 cells resulted in enhanced cell adhesion to CYR61. Consistent with these data, a GST-fusion protein containing the I domain of the integrin α M subunit bound specifically to immobilized CYR61 or CTGF. We have also investigated the requirement of cell surface heparan sulfate proteoglycans (HSPGs) as coreceptors for monocyte adhesion to CYR61. Pretreatment of monocytes with heparin or heparinase I resulted in partial inhibition of cell adhesion to CYR61. However, monocytes, but not fibroblasts, were capable of adhering to a CYR61 mutant deficient in heparin binding activity. Collectively, these results show that activated monocytes adhere to CYR61 and CTGF through integrin α M β 2 and cell surface HSPGs. However, unlike fibroblast adhesion to CYR61, cell surface HSPGs are not absolutely required for this adhesion process.
-
the angiogenic factor cysteine rich 61 CYR61 ccn1 supports vascular smooth muscle cell adhesion and stimulates chemotaxis through integrin α6β1 and cell surface heparan sulfate proteoglycans
Endocrinology, 2002Co-Authors: Tatiana M Grzeszkiewicz, Volkhard Lindner, Ningyu Chen, Stephen C T Lam, Lester F LauAbstract:Cysteine-rich 61 (CYR61, CCN1) is a heparin-binding, extracellular, matrix-associated protein of the cysteine-rich 61/nephroblastoma family, which also includes connective tissue growth factor, nephroblastoma overexpressed, Wnt-induced secreted protein-1 (WISP-1), WISP-2, and WISP-3. CYR61 induces angiogenesis in vivo and supports cell adhesion, promotes cell migration, and enhances growth factor-stimulated mitogenesis in fibroblasts and endothelial cells. Although the expression of CYR61 has been observed in arterial walls, its function in vascular smooth muscle cells (VSMCs) has not been examined to date. Here we show that purified CYR61 supports VSMC adhesion in a dose-dependent, saturable manner through integrin α6β1 with an absolute requirement of cell surface heparan sulfate proteoglycans. In addition, CYR61 induces VSMC chemotaxis, but not chemokinesis, through integrin α6β1 and heparan sulfate proteoglycans. Heparin-binding defective CYR61 mutants are unable to support VSMC adhesion but can still ...
-
CYR61 stimulates human skin fibroblast migration through integrin alpha vbeta 5 and enhances mitogenesis through integrin alpha vbeta 3 independent of its carboxyl terminal domain
Journal of Biological Chemistry, 2001Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Deborah J Kirschling, Lester F LauAbstract:Abstract CYR61, an angiogenic factor and a member of the CCN protein family, is an extracellular matrix-associated, heparin-binding protein that mediates cell adhesion, promotes cell migration, and enhances growth factor-stimulated cell proliferation. CYR61 induces angiogenesis and promotes tumor growth in vivo and is expressed in dermal fibroblasts during cutaneous wound healing. It has been demonstrated recently that adhesion of primary skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans, resulting in adhesive signaling and up-regulation of matrix metalloproteinases 1 and 3. CYR61 is composed of four discrete structural domains that bear sequence similarities to the insulin-like growth factor-binding proteins, von Willebrand factor type C repeat, thrombospondin type 1 repeat, and a carboxyl-terminal (CT) domain that resembles cysteine knots found in some growth factors. In this study, we show that a CYR61 mutant (CYR61ΔCT) that has the CT domain deleted is unable to support adhesion of primary human skin fibroblasts but is still able to stimulate chemotaxis and enhance basic fibroblast growth factor-induced mitogenesis similar to wild type. In addition, fibroblast migration to CYR61 is mediated through integrin αvβ5 but not integrins α6β1 or αvβ3. Furthermore, we show that CYR61 binds directly to purified integrin αvβ5 in vitro. By contrast, CYR61 enhancement of basic fibroblast growth factor-induced DNA synthesis is mediated through integrin αvβ3, a known receptor for CYR61 that mediates CYR61-dependent cell adhesion and chemotaxis in vascular endothelial cells. Thus, CYR61 promotes primary human fibroblast adhesion, migration, and mitogenesis through integrins α6β1, αvβ5, and αvβ3, respectively. Together, these findings establish CYR61 as a novel ligand for integrin αvβ5 and show that CYR61 interacts with distinct integrins to mediate disparate activities in a cell type-specific manner.
-
CYR61 stimulates human skin fibroblast migration through integrin αvβ5 and enhances mitogenesis through integrin αvβ3 independent of its carboxyl terminal domain
Journal of Biological Chemistry, 2001Co-Authors: Tatiana M Grzeszkiewicz, Ningyu Chen, Deborah J Kirschling, Lester F LauAbstract:CYR61, an angiogenic factor and a member of the CCN protein family, is an extracellular matrix-associated, heparin-binding protein that mediates cell adhesion, promotes cell migration, and enhances growth factor-stimulated cell proliferation. CYR61 induces angiogenesis and promotes tumor growth in vivo and is expressed in dermal fibroblasts during cutaneous wound healing. It has been demonstrated recently that adhesion of primary skin fibroblasts to CYR61 is mediated through integrin α6β1 and cell surface heparan sulfate proteoglycans, resulting in adhesive signaling and up-regulation of matrix metalloproteinases 1 and 3. CYR61 is composed of four discrete structural domains that bear sequence similarities to the insulin-like growth factor-binding proteins, von Willebrand factor type C repeat, thrombospondin type 1 repeat, and a carboxyl-terminal (CT) domain that resembles cysteine knots found in some growth factors. In this study, we show that a CYR61 mutant (CYR61ΔCT) that has the CT domain deleted is unable to support adhesion of primary human skin fibroblasts but is still able to stimulate chemotaxis and enhance basic fibroblast growth factor-induced mitogenesis similar to wild type. In addition, fibroblast migration to CYR61 is mediated through integrin αvβ5 but not integrins α6β1 or αvβ3. Furthermore, we show that CYR61 binds directly to purified integrin αvβ5 in vitro. By contrast, CYR61 enhancement of basic fibroblast growth factor-induced DNA synthesis is mediated through integrin αvβ3, a known receptor for CYR61 that mediates CYR61-dependent cell adhesion and chemotaxis in vascular endothelial cells. Thus, CYR61 promotes primary human fibroblast adhesion, migration, and mitogenesis through integrins α6β1, αvβ5, and αvβ3, respectively. Together, these findings establish CYR61 as a novel ligand for integrin αvβ5 and show that CYR61 interacts with distinct integrins to mediate disparate activities in a cell type-specific manner.
