Serglycin belongs to a family of small proteoglycans with Ser-Gly dipeptide repeats,and it is modified with different types of glycosaminoglycan side chains.Intracellular serglycin affects the retention and secretion ...Serglycin belongs to a family of small proteoglycans with Ser-Gly dipeptide repeats,and it is modified with different types of glycosaminoglycan side chains.Intracellular serglycin affects the retention and secretion of proteases,chemokines,or other cytokines by physically binding to these factors in secretory granules.Extracellular serglycin has been found to be released by several types of human cancer cells,and it is able to promote the metastasis of nasopharyngeal carcinoma cells.Serglycin can bind to CD44,which is another glycoprotein located in cellular membrane.Serglycin's function of promoting cancer cell metastasis depends on glycosylation of its core protein,which can be achieved by autocrine as well as paracrine secretion mechanisms.Further investigations are warranted to elucidate serglycin signaling mechanisms with the goal of targeting them to prevent cancer cell metastasis.展开更多
Aggrecan is the major proteoglycan in the articular cartilage. This molecule is important in the proper functioning of articular cartilage because it provides a hydrated gel structure (via its interaction with hyaluro...Aggrecan is the major proteoglycan in the articular cartilage. This molecule is important in the proper functioning of articular cartilage because it provides a hydrated gel structure (via its interaction with hyaluronan and link protein) that endows the cartilage with load-bearing properties. It is also crucial in chondroskeletal morphogenesis during development. Aggrecan is a multimodular molecule expressed by chondrocytes. Its core protein is composed of three globular domains (G1, G2, and G3) and a large extended region (CS) between G2 and G3 for glycosaminoglycan chain attachment. G1 comprises the amino terminus of the core protein. This domain has the same structural motif as link protein. Functionally, the G1 domain interacts with hyaluronan acid and link protein, forming stable ternary complexes in the extracellular matrix. G2 is homologous to the tandem repeats of G1 and of link protein and is involved in product processing. G3 makes up the carboxyl terminus of the core protein. It enhances glycosaminoglycan modification and product secretion. Aggrecan plays an important role in mediating chondrocyte-chondrocyte and chondrocyte-matrix interactions through its ability to bind hyaluronan.展开更多
Background Low back pain has emerged as a widespread disease often caused by intervertebral disc degeneration.This study aimed to establish an in vitro cell culture model of rhesus monkey lumbar intervertebral discs a...Background Low back pain has emerged as a widespread disease often caused by intervertebral disc degeneration.This study aimed to establish an in vitro cell culture model of rhesus monkey lumbar intervertebral discs and to investigate the effect of combined connective tissue growth factor （CTGF） and tissue inhibitor of metalloprotease-1（TIMP-1） expression mediated by adeno-associated virus （AAV） on collagen type Ⅱ and proteoglycan levels.The purpose of these investigations was to explore potential methods for relieving the degeneration of lumbar intervertebral disc cells.Methods Rhesus monkey lumbar intervertebral disc nucleus pulposus cells （NPCs） were isolated by enzyme digestion,cultured, and transduced with rAAV2-CTGF-IRES-TIMP-1, rAAV2-CTGF, or rAAV2-TIMP-1 at a multiplicity of infection （MOl） of 106.The expression of collagen type Ⅱ and proteoglycan was measured using RT-PCR and Western blotting.The synthetic rate of proteoglycan was measured using 35S incorporation.Results Rhesus monkey lumbar intervertebral disc NPCs were transduced with rAAV2-CTGF-IRES-TIMP-1,rAAV2-CTGF, and rAAV2-TIMP-1 and the transduced genes were expressed and detected.Compared to the control,CTGF promoted the synthesis of collagen type Ⅱ and proteoglycan.TIMP-1 showed an enhancing effect on the expression of proteoglycan but no effect on collagen type Ⅱ.Expression of both genes in rhesus monkey lumbar intervertebral disc NPCs significantly enhances the synthesis of proteoglycan and collagen type Ⅱ.Conclusions Single gene transduction of CTGF or TIMP-1 can enhanced synthesis of proteoglycan.CTGF expression can also enhance collagen type Ⅱ protein synthesis.Combined transduction of both CTGF and TIMP1 can significantly promote the expression of proteoglycan and collagen type Ⅱ to levels greater than transduction of a single gene alone.Our study provides a good basis for multi-gene therapy to treat lumbar intervertebral disc degeneration.展开更多
Versican belongs to the family of the large aggregating chondroitin sulfate proteoglycans located primarily within the extracellular matrix （ECM）. Versican, like other members of its family, has unique N- and C-term...Versican belongs to the family of the large aggregating chondroitin sulfate proteoglycans located primarily within the extracellular matrix （ECM）. Versican, like other members of its family, has unique N- and C-terminal globular regions, each with multiple motifs. A large glycosaminoglycan-binding region lies between them. This review will begin by outlining these structures, in the context of ECM proteoglycans. The diverse binding partners afforded to versican by virtue of its modular design will then be examined. These include ECM components, such as hyaluronan, type Ⅰ collagen, tenascin-R, fibulin-1, and -2, fibrillin-1, fibronectin, P- and L-selectins, and chemokines. Versican also binds to the cell surface proteins CD44, integrin β1, epidermal growth factor receptor, and P-selectin glycoprotein ligand-1. These multiple interactors play important roles in cell behaviour, and the roles of versican in modulating such processes are discussed.展开更多
基金supported by a grant from the State Key Program of National Natural Science Foundation of China (No. 81030043)
文摘Serglycin belongs to a family of small proteoglycans with Ser-Gly dipeptide repeats,and it is modified with different types of glycosaminoglycan side chains.Intracellular serglycin affects the retention and secretion of proteases,chemokines,or other cytokines by physically binding to these factors in secretory granules.Extracellular serglycin has been found to be released by several types of human cancer cells,and it is able to promote the metastasis of nasopharyngeal carcinoma cells.Serglycin can bind to CD44,which is another glycoprotein located in cellular membrane.Serglycin's function of promoting cancer cell metastasis depends on glycosylation of its core protein,which can be achieved by autocrine as well as paracrine secretion mechanisms.Further investigations are warranted to elucidate serglycin signaling mechanisms with the goal of targeting them to prevent cancer cell metastasis.
文摘Aggrecan is the major proteoglycan in the articular cartilage. This molecule is important in the proper functioning of articular cartilage because it provides a hydrated gel structure (via its interaction with hyaluronan and link protein) that endows the cartilage with load-bearing properties. It is also crucial in chondroskeletal morphogenesis during development. Aggrecan is a multimodular molecule expressed by chondrocytes. Its core protein is composed of three globular domains (G1, G2, and G3) and a large extended region (CS) between G2 and G3 for glycosaminoglycan chain attachment. G1 comprises the amino terminus of the core protein. This domain has the same structural motif as link protein. Functionally, the G1 domain interacts with hyaluronan acid and link protein, forming stable ternary complexes in the extracellular matrix. G2 is homologous to the tandem repeats of G1 and of link protein and is involved in product processing. G3 makes up the carboxyl terminus of the core protein. It enhances glycosaminoglycan modification and product secretion. Aggrecan plays an important role in mediating chondrocyte-chondrocyte and chondrocyte-matrix interactions through its ability to bind hyaluronan.
基金This study was supported by a grant from the National Natural Science Foundation of China （No. 30471750）.
文摘Background Low back pain has emerged as a widespread disease often caused by intervertebral disc degeneration.This study aimed to establish an in vitro cell culture model of rhesus monkey lumbar intervertebral discs and to investigate the effect of combined connective tissue growth factor （CTGF） and tissue inhibitor of metalloprotease-1（TIMP-1） expression mediated by adeno-associated virus （AAV） on collagen type Ⅱ and proteoglycan levels.The purpose of these investigations was to explore potential methods for relieving the degeneration of lumbar intervertebral disc cells.Methods Rhesus monkey lumbar intervertebral disc nucleus pulposus cells （NPCs） were isolated by enzyme digestion,cultured, and transduced with rAAV2-CTGF-IRES-TIMP-1, rAAV2-CTGF, or rAAV2-TIMP-1 at a multiplicity of infection （MOl） of 106.The expression of collagen type Ⅱ and proteoglycan was measured using RT-PCR and Western blotting.The synthetic rate of proteoglycan was measured using 35S incorporation.Results Rhesus monkey lumbar intervertebral disc NPCs were transduced with rAAV2-CTGF-IRES-TIMP-1,rAAV2-CTGF, and rAAV2-TIMP-1 and the transduced genes were expressed and detected.Compared to the control,CTGF promoted the synthesis of collagen type Ⅱ and proteoglycan.TIMP-1 showed an enhancing effect on the expression of proteoglycan but no effect on collagen type Ⅱ.Expression of both genes in rhesus monkey lumbar intervertebral disc NPCs significantly enhances the synthesis of proteoglycan and collagen type Ⅱ.Conclusions Single gene transduction of CTGF or TIMP-1 can enhanced synthesis of proteoglycan.CTGF expression can also enhance collagen type Ⅱ protein synthesis.Combined transduction of both CTGF and TIMP1 can significantly promote the expression of proteoglycan and collagen type Ⅱ to levels greater than transduction of a single gene alone.Our study provides a good basis for multi-gene therapy to treat lumbar intervertebral disc degeneration.
文摘Versican belongs to the family of the large aggregating chondroitin sulfate proteoglycans located primarily within the extracellular matrix （ECM）. Versican, like other members of its family, has unique N- and C-terminal globular regions, each with multiple motifs. A large glycosaminoglycan-binding region lies between them. This review will begin by outlining these structures, in the context of ECM proteoglycans. The diverse binding partners afforded to versican by virtue of its modular design will then be examined. These include ECM components, such as hyaluronan, type Ⅰ collagen, tenascin-R, fibulin-1, and -2, fibrillin-1, fibronectin, P- and L-selectins, and chemokines. Versican also binds to the cell surface proteins CD44, integrin β1, epidermal growth factor receptor, and P-selectin glycoprotein ligand-1. These multiple interactors play important roles in cell behaviour, and the roles of versican in modulating such processes are discussed.
