title: Lysophosphatidic acid enhanced the angiogenic capability of human chondrocytes by regulating Gi/NF-kB-dependent angiogenic factor expression.
abstract: Lysophosphatidic acid (LPA) has been found to mediate myeloid differentiation, stimulate osteogenesis, alter cell proliferation and migration, and inhibit apoptosis in chondrocytes. The effect of LPA on the angiogenic capability of chondrocytes is not clear. This study aimed to investigate its effect on the angiogenic capability of human chondrocytes and the underlying mechanism of these effects. Human chondrocyte cell line, CHON-001, commercialized human chondrocytes (HC) derived from normal human articular cartilage, and human vascular endothelial cells (HUVECs) were used as cell models in this study. The angiogenic capability of chondrocytes was determined by capillary tube formation, monolayer permeability, cell migration, and cell proliferation. An angiogenesis protein array kit was used to evaluate the secretion of angiogenic factors in conditioned medium. Angiogenin, insulin-like growth factor-binding protein 1 (IGFBP-1), interleukin (IL)-8, monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase (MMP)-9, and vascular endothelial growth factor (VEGF) mRNA and protein expressions were evaluated by Q-RT-PCR and EIA, respectively. LPA receptor (LPAR) expression was determined by RT-PCR. Signaling pathways were clarified using inhibitors, Western blot analysis, and reporter assays. The LPA treatment promoted the angiogenic capability of CHON-001 cells and HC, resulting in enhanced HUVEC capillary tube formation, monolayer permeability, migration, and cell growth. Angiogenin, IGFBP-1, IL-8, MCP-1, MMP-9, and VEGF mRNA and protein expressions were significantly enhanced in LPA-treated chondrocytes. LPA2, 3, 4 and 6 were expressed in CHON-001 and HC cells. Pretreatment with the Gi/o type G protein inhibitor, pertussis toxin (PTX), and the NF-kB inhibitor, PDTC, significantly inhibited LPA-induced angiogenin, IGFBP-1, IL-8, MCP-1, MMP-9, and VEGF expressions in chondrocytes. The PTX pretreatment also inhibited LPA-mediated NF-kB activation, suggesting the presence of active Gi/NF-kB signaling in CHON-001 and HC cells. The effect of LPA on the angiogenesis-inducing capacity of chondrocytes may be due to the increased angiogenesis factor expression via the Gi/NF-kB signaling pathway.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Chia-Yi Chang Gung Memorial Hospital, Chia-Yi, Taiwan; Department of Nursing, Chang-Gung University of Science and Technology, Chia-Yi, Taiwan.
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Chuang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Chia-Yi Chang Gung Memorial Hospital, Chia-Yi, Taiwan; Department of Nursing, Chang-Gung University of Science and Technology, Chia-Yi, Taiwan.
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Chang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Chia-Yi Chang Gung Memorial Hospital, Chia-Yi, Taiwan; Department of Nursing, Chang-Gung University of Science and Technology, Chia-Yi, Taiwan.
authors.forename: Kai-Hua
authors.initials: KH
authors.lastname: Chen
authors.affiliation: Department of Physical therapy, HungKuang University, Taichung, Taiwan.
authors.forename: Chang-Zern
authors.initials: CZ
authors.lastname: Hong
authors.affiliation: Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Pey-Jium
authors.initials: PJ
authors.lastname: Chang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Chia-Yi Chang Gung Memorial Hospital, Chia-Yi, Taiwan; Department of Nursing, Chang-Gung University of Science and Technology, Chia-Yi, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Hung-Chih
authors.initials: HC
authors.lastname: Hsu
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000166:cytology; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D008246:Lysophospholipids / Q000494:pharmacology*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D043925:Angiogenesis Inducing Agents; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D018970:Insulin-Like Growth Factor Binding Protein 1; D016209:Interleukin-8; D008246:Lysophospholipids; D016328:NF-kappa B; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C046366:angiogenin; D012259:Ribonuclease, Pancreatic; D020780:Matrix Metalloproteinase 9; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C032881:lysophosphatidic acid