Role Of CTGF Research Articles

A Novel Role of Connective Tissue Growth Factor in the Regulation of the Epithelial Phenotype.

Epithelial-mesenchymal transition (EMT) is a biological process where epithelial cells lose their adhesive properties and gain invasive, metastatic, and mesenchymal properties. Maintaining the balance between the epithelial and mesenchymal stage is essential for tissue homeostasis. Many of the genes promoting mesenchymal transformation have been identified; however, our understanding of the genes responsible for maintaining the epithelial phenotype is limited. Our objective was to identify the genes responsible for maintaining the epithelial phenotype and inhibiting EMT. RNA seq was performed using an vitro model of EMT. CTGF expression was determined via qPCR and Western blot analysis. The knockout of CTGF was completed using the CTGF sgRNA CRISPR/CAS9. The tumorigenic potential was determined using NCG mice. The knockout of CTGF in epithelial ovarian cancer cells leads to the acquisition of functional characteristics associated with the mesenchymal phenotype such as anoikis resistance, cytoskeleton remodeling, increased cell stiffness, and the acquisition of invasion and tumorigenic capacity. We identified CTGF is an important regulator of the epithelial phenotype, and its loss is associated with the early cellular modifications required for EMT. We describe a novel role for CTGF, regulating cytoskeleton and the extracellular matrix interactions necessary for the conservation of epithelial structure and function. These findings provide a new window into understanding the early stages of mesenchymal transformation.

Analysis of longitudinal semicontinuous data using marginalized two-part model

BackgroundConnective tissue growth factor (CTGF), is a secreted matricellular factor that has been linked to increased risk of cardiovascular disease in diabetic subjects. Despite the biological role of CTGF in diabetes, it still remains unclear how CTGF expression is regulated. In this study, we aim to identify the clinical parameters that modulate plasma CTGF levels measured longitudinally in type 1 diabetic patients over a period of 10 years. A number of patients had negligible measured values of plasma CTGF that formed a point mass at zero, whereas others had high positive values of CTGF that were measured on a continuous scale. The observed combination of excessive zero and continuous positively distributed non-zero values in the CTGF outcome is referred to as semicontinuous data.MethodsWe propose a novel application of a marginalized two-part model (mTP) extended to accommodate longitudinal semicontinuous data in which the marginal mean is expressed in terms of the covariates and estimates of their effect on the mean responses are generated. The continuous component is assumed to follow distributions that stem from the generalized gamma family whereas the binary measure is analyzed using logistic model and both have correlated random effects. Other approaches including the one- and two-part with uncorrelated and correlated random effects models were also applied and their estimates were all compared.ResultsOur results using the mTP model identified intensive glucose control treatment and smoking as clinical factors that were associated with decreased and increased odds of observing non-zero CTGF values respectively. In addition, hemoglobin A1c, systolic blood pressure, and high density lipoprotein were all shown to be significant risk factors that contribute to increasing CTGF levels. These findings were consistently observed under the mTP model but varied with the distributions for the other models. Accuracy and precision of the mTP model was further validated using simulation studies.ConclusionThe mTP model identified new clinical determinants that modulate the levels of CTGF in diabetic subjects. Applicability of this approach can be extended to other biomarkers measured in patient populations that display a combination of negligible zero and non-zero values.

Nitric oxide mediates anomalous tubuloglomerular feedback in rats fed high-NaCl diet after subtotal nephrectomy.

Tubuloglomerular feedback (TGF) responses become anomalous in rats fed high-NaCl diet after subtotal nephrectomy (STN), such that stimulating TGF causes single nephron GFR (SNGFR) to increase rather than decrease. Micropuncture experiments were performed to determine whether this anomaly results from heightened nitric oxide response to distal delivery, which is a known mechanism for resetting TGF, or from connecting tubule TGF (cTGF), which is a novel amiloride-inhibitable system for offsetting TGF responses. Micropuncture was done in Wistar Froemter rats fed high-NaCl diet (HS) for 8-10 days after STN or sham nephrectomy. TGF was manipulated by orthograde microperfusion of Henle's loop with artificial tubular fluid with or without NOS inhibitor, LNMMA, or the cell-impermeant amiloride analog, benzamil. SNGFR was measured by inulin clearance in tubular fluid collections from the late proximal tubule. TGF responses were quantified as the increase in SNGFR that occurred when the perfusion rate was reduced from 50 to 8 nl/min in STN or 40 to 8 nl/min in sham animals. The baseline TGF response was anomalous in STN HS (-4 ± 3 vs 14 ± 3 nl/min, P < 0.001). TGF response was normalized by perfusing STN nephron with LNMMA (14 ± 3 nl/min, P < 0.005 for ANOVA cross term) but not with benzamil (-3 ± 4 nl/min, P = 0.4 for ANOVA cross term). Anomalous TGF occurs in STN HS due to heightened effect of tubular flow on nitric oxide signaling, which increases to the point of overriding the normal TGF response. There is no role for cTGF in this phenomenon.

Differential protective effects of connective tissue growth factor against Aβ neurotoxicity on neurons and glia.

Impaired clearance of amyloid-β peptide (Aβ) leads to abnormal extracellular accumulation of this neurotoxic protein that drives neurodegeneration in sporadic Alzheimer's disease (AD). Connective tissue growth factor (CTGF/CCN2) expression is elevated in plaque-surrounding astrocytes in AD patients. However, the role of CTGF in AD pathogenesis remains unclear. Here we characterized the neuroprotective activity of CTGF. We found that CTGF facilitated Aβ uptake and subsequent degradation within primary glia and neuroblastoma cells. CTGF enhanced extracellular Aβ degradation via membrane-bound matrix metalloproteinase-14 (MMP14) in glia and extracellular MMP13 in neurons. In the brain of a Drosophila AD model, glial-expression of CTGF reduced Aβ deposits, improved locomotor function, and rescued memory deficits. Neuroprotective potential of CTGF against Aβ42-induced photoreceptor degeneration was disrupted through silencing MMPs. Therefore, CTGF may represent a node for potential AD therapeutics as it intervenes in glia-neuron communication via specific MMPs to alleviate Aβ neurotoxicity in the central nervous system.

Abstract 4144: Role of CTGF in hyperthermia resistance in ovarian and uterine cancers

Abstract Objective. Even though hyperthermia is a promising treatment for cancer, multiple obstacles remain to be cleared. Among these, the tumor temperatures that must be reached for obtaining clinical efficacy are undefined. The purpose of our study was to identify the molecular predictors of response to hyperthermia in ovarian and uterine cancers. Methods. The temperature transition in tumors during hyperthermic intraperitoneal chemotherapy (HIPEC) in ovarian cancer patients was examined. To evaluate sensitivity to hyperthermia, 10 ovarian and uterine cancer cells were treated with hyperthermia and determined median lethal temperature 50 (LT50). An integrative analysis was performed to identify molecules associated with hyperthermia resistance by comparison with gene and protein expression between hyperthermia-resistant (HTR) and -sensitive (HTS) cells. The effect of identified gene silencing on sensitization to hyperthermia and tumor growth in orthotopic models of ovarian cancers by using liposomal siRNA and local hyperthermia by NIR and CuS nanoparticles. Results. The temperature during HIPEC in human tumors was &amp;lt; 40°C even though the perfusion temperature at the entrance was maintained at 42.5°C. Based on LT50, we identified 5 cell lines as HTR (SKOV3, HeyA8, KLE, PEO4, and ES2; LT50 47.5 ± 0.3°C) and 5 as HTS (A2780, A2780CP20, Hec-1A, SKKUT-2, and ISHIKAWA; LT50 45.5 ± 0.2°C). Gene expression studies identified 15 genes that were highly upregulated in HTR compared with HTS cells. Proteomic analyses showed that glucose metabolism-related proteins were down-regulated in SKOV3 cells after hyperthermia. Pathway analysis indicated that FN1, SGK1, and CTGF among the 15 genes were potentially connected with glucose metabolism-related proteins. CTGF siRNA sensitized HTR cells to hyperthermia. The combination of CTGF silencing and local hyperthermia significantly inhibited tumor growth and metastasis in HeyA8 and SKOV3 orthotopic models. Conclusion. Collectively, we identified CTGF as a key target for enhancing response to hyperthermia in ovarian and uterine cancers. Citation Format: Hiroto Hatakeyama, Sherry Y. Wu, Yasmin A. Lyons, Sunila Pradeep, Wanqin Wang, Qian Huang, Karem A. Court, Tao Liu, Song Nie, Cristian Rodriguez-Aguayo, Fangrong Shen, Yan Huang, Takeshi Hisamatsu, Takashi Mitamura, Piotr L. Dorniak, Lingegowda S. Mangala, Marco Petrillo, Madeline Torres-Lugo, Karin D. Rodland, Anna Fagotti, Gabriel Lopez-Berestein, Chun Li, Anil K. Sood. Role of CTGF in hyperthermia resistance in ovarian and uterine cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4144. doi:10.1158/1538-7445.AM2017-4144

Connective tissue growth factor decreases mitochondrial metabolism through ubiquitin-mediated degradation of mitochondrial transcription factor A in oral squamous cell carcinoma.

Deregulation of metabolic pathways is one of the hallmarks of cancer progression. Connective tissue growth factor (CTGF/CCN2) acts as a tumor suppressor in oral squamous cell carcinoma (OSCC). However, the role of CTGF in modulating cancer metabolism is still unclear. OSCC cells stably overexpressing CTGF (SAS/CTGF) and shRNA against CTGF (TW2.6/shCTGF) were established. Oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were examined by the Seahorse XF24 analyzer. The expression of CTGF and mitochondrial biogenesis related genes was measured by real-time polymerase chain reaction or Western blot analysis. CTGF decreased OCR, ECAR, adenosine triphosphate (ATP) generation, mitochondrial DNA (mtDNA), and mitochondrial transcription factor A (mtTFA) protein expression in OSCC cells. Overexpression of mtTFA restored CTGF-decreased OCR, ECAR, mtDNA copy number, migration and invasion of SAS/CTGF cells. Immunoprecipitation assay showed a higher level of ubiquitinated mtTFA protein after CTGF treatment. MG132, an inhibitor of proteasomal degradation, reversed the effect of CTGF on mtTFA protein expression in SAS cells. CTGF can decrease glycolysis, mitochondrial oxidative phosphorylation, ATP generation, and mtDNA copy number by increasing mtTFA protein degradation through ubiquitin proteasome pathway and in turn reduces migration and invasion of OSCC cells. Therefore, CTGF may be developed as a potential additive therapeutic drug for oral cancer in the near future.

Role of CTGF in Sensitivity to Hyperthermia in Ovarian and Uterine Cancers

Even though hyperthermia is a promising treatment for cancer, the relationship between specific temperatures and clinical benefits and predictors of sensitivity of cancer to hyperthermia is poorly understood. Ovarian and uterine tumors have diverse hyperthermia sensitivities. Integrative analyses of the specific gene signatures and the differences in response tohyperthermia between hyperthermia-sensitive and -resistant cancer cells identified CTGF as a key regulator of sensitivity. CTGF silencing sensitized resistant cells to hyperthermia. CTGF small interfering RNA (siRNA) treatment also sensitized resistant cancers to localized hyperthermia induced by copper sulfide nanoparticles and near-infrared laser in orthotopic ovarian cancer models. CTGF silencing aggravated energy stress induced by hyperthermia and enhanced apoptosis of hyperthermia-resistant cancers.

Abstract B46: Connective Tissue Growth Factor (CTGF/CCN2) is increased in pre-B acute lymphoblastic leukemia and confers a growth advantage within the bone marrow niche

Abstract Introduction: Acute lymphoblastic leukaemia (ALL) is the most common form of cancer in children. Despite major improvements in cure rates, a significant number of patients still relapse. ALL originates in the bone marrow and cell-cell interactions in this microenvironment can alter disease progression and treatment efficacy. Connective tissue growth factor (CTGF/CCN2) is expressed at significantly higher levels in approximately 75% of pre-B ALL specimens compared to normal cells. CTGF is a secreted protein associated with the extracellular matrix. Because the role of CTGF in ALL is currently unknown, we developed in vivo model systems to assess the function of CTGF. Method: Pre-B ALL cell lines were derived from patient specimens. They were then modified using lentiviral and short hairpin (sh)RNA technology to express CTGF at elevated or at reduced levels. They were characterised by various in vitro technologies and were examined in a NOD/SCID xenograft model. Outcomes: Expression and secretion of high levels of CTGF in cell line PER-371 did not alter their proliferation rate in vitro. However, when xenografted in NOD/SCID mice, high CTGF-expressing PER-371 cells showed accelerated leukaemic development. The median survival was 70 days, compared to 89 days (p=0.03) for mice injected with PER-371 control cells that express basal levels of CTGF. Leukaemic cell infiltration was measured in the haemopoietic organs of mouse cohorts at various times during disease development. There were no significant differences in leukaemic cell infiltration early in disease, however, high CTGF-expressing PER-371 cells were significantly increased in the bone marrow approximately two weeks before full development of disease, compared to control PER-371 xenografts (44% vs 8%; p=0.01). This suggests that high levels of CTGF in these cells does not influence homing, but confers a growth advantage within the bone marrow niche. Reduced CTGF expression using shRNA significantly reduced proliferation in vitro in PER-371 (0.9%; p&amp;lt;0.005) and PER-377 (4.8%; p&amp;lt;0.005) cell lines compared to their respective controls. Conclusions: CTGF is elevated in approximately 75% of pre-B ALL specimens. We demonstrate that high CTGF confers a growth advantage of pre-B ALL cells within the bone marrow niche. Planned immunohistochemical studies aim to highlight possible differences in vasculature, location of disease or changes to the extracellular matrix. Citation Format: Julia E. Wells, Meegan Howlett, Heloise M. Halse, Jette Ford, Jasmin Heng, Amy L. Samuels, Catherine H. Cole, Ursula R. Kees. Connective Tissue Growth Factor (CTGF/CCN2) is increased in pre-B acute lymphoblastic leukemia and confers a growth advantage within the bone marrow niche. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr B46. doi:10.1158/1538-7445.CHTME14-B46

Spheroid formation of human thyroid cancer cells under simulated microgravity: a possible role of CTGF and CAV1.

BackgroundMulticellular tumor spheroids (MCTS) formed scaffold-free under microgravity are of high interest for research and medicine. Their formation mechanism can be studied in space in real microgravity or on Earth using ground-based facilities (GBF), which simulate microgravity. On Earth, these experiments are more cost-efficient and easily performable. However, each GBF might exert device-specific and altered superimposingly gravity-dependent effects on the cells.ResultsFTC-133 human thyroid cancer cells were cultivated on a 2D clinostat (CN) and a random positioning machine (RPM) and compared with corresponding 1 g control cells. Harvested cell samples were investigated by microscopy, quantitative realtime-PCR and Multi-Analyte Profiling. Spheroid formation and growth occurred during 72 h of cultivation on both devices. Cytokine secretion and gene activation patterns frequently altered in different ways, when the cells were cultured either on the RPM or the CN. A decreased expression of CAV1 and CTGF in MCTS compared to adherent cells was observed after cultivation on both machines.ConclusionThe development of MCTS proceeds similarly on the RPM and the CN resembling the situation observed under real microgravity conditions, while no MCTS formation was observed at 1 g under identical experimental conditions. Simultaneously, changes in the regulation of CTGF and CAV1 appeared in a comparable manner on both machines. A relationship between these molecules and MCTS formation is discussed.

The Role of CTGF in Osteosarcoma Progression

The Role of CTGF in Osteosarcoma Progression

Reducing CTGF/CCN2 slows down mdx muscle dystrophy and improves cell therapy

In Duchenne muscular dystrophy (DMD) and the mdx mouse model, the absence of the cytoskeletal protein dystrophin causes defective anchoring of myofibres to the basal lamina. The resultant myofibre degeneration and necrosis lead to a progressive loss of muscle mass, increased fibrosis and ultimately fatal weakness. Connective tissue growth factor (CTGF/CCN-2) is critically involved in several chronic fibro-degenerative diseases. In DMD, the role of CTGF might extend well beyond replacement fibrosis secondary to loss of muscle fibres, since its overexpression in skeletal muscle could by itself induce a dystrophic phenotype. Using two independent approaches, we here show that mdx mice with reduced CTGF availability do indeed have less severe muscular dystrophy. Mdx mice with hemizygous CTGF deletion (mdx-Ctgf+/-), and mdx mice treated with a neutralizing anti-CTGF monoclonal antibody (FG-3019), performed better in an exercise endurance test, had better muscle strength in isolated muscles and reduced skeletal muscle impairment, apoptotic damage and fibrosis. Transforming growth factor type-β (TGF-β), pERK1/2 and p38 signalling remained unaffected during CTGF suppression. Moreover, both mdx-Ctgf+/- and FG-3019 treated mdx mice had improved grafting upon intramuscular injection of dystrophin-positive satellite cells. These findings reveal the potential of targeting CTGF to reduce disease progression and to improve cell therapy in DMD.

Tu1496 Pancreatitis and Pancreatic Adenocarcinoma: Clinical Features and Effect on Stage and Survival

results show that CTGF is expressed in mouse acinar cells during ACP at a time that corresponds to increased infiltration of inflammatory cells as well as of acinar IL-1β expression. In Vitro, acinar-derived CTGF stimlulates IL-1 β-dependent chemokines or chemokine receptor expression, and CTGF-expressing acinar cells liberate soluble stimulators of T cell migration. Taken together, these data support a role for acinar cell-derived CTGF as a modulator of the immune response via its effects on Il-1β and identify a hitherto unrecognized role for CTGF that is distinct from its regulation of fibrogenic pathways in PSC.

The role of CTGF in mediating hepatocytes epithelial-to-mesenchymal transition and hepatic fibrogenesis

纤维化是器官(肝、肾、肺等)慢性功能衰竭的一个共同机制,目前尚无有效防治方法.对上皮-间充质转分化(epithelial-to-mesenchymal transition,EMT)的研究使人们对器官纤维化的传统认识受到挑战,逆转分化已被认为是未来抗肝纤维化治疗的重要策略之一[l].肝细胞EMT被认为是肝纤维化时肝内肌成纤维细胞(myofibroblast)即活化肝星状细胞(HSC)的一种新的重要来源,对肝纤维化形成具有决定性影响[2-3].日益增加的证据表明,结缔组织生长因子(connective tissure growth factor,CTGF)可能介导了肝细胞EMT及肝纤维化形成[4-5].现就近年来CTGF在肝细胞EMT及肝纤维化形成中的作用研究进展作一综述. 关键词：肝硬化;结缔组织生长因子;上皮-间质转分化

Downregulation of connective tissue growth factor inhibits the growth and invasion of gastric cancer cells and attenuates peritoneal dissemination

BackgroundConnective tissue growth factor (CTGF) has been shown to be implicated in tumor development and progression. However, the role of CTGF in gastric cancer remains largely unknown.ResultsIn this study, we showed that CTGF was highly expressed in gastric cancer tissues compared with matched normal gastric tissues. The CTGF expression in tumor tissue was associated with histologic grade, lymph node metastasis and peritoneal dissemination (P < 0.05). Patients with positive CTGF expression had significantly lower cumulative postoperative 5 year survival rate than those with negative CTGF expression (22.9% versus 48.1%, P < 0.001). We demonstrated that knockdown of CTGF expression significantly inhibited cell growth of gastric cancer cells and decreased cyclin D1 expression. Moreover, knockdown of CTGF expression also markedly reduced the migration and invasion of gastric cancer cells and decreased the expression of matrix metalloproteinase (MMP)-2 and MMP-9. Animal studies revealed that nude mice injected with the CTGF knockdown stable cell lines featured a smaller number of peritoneal seeding nodules than the control cell lines.ConclusionsThese data suggest that CTGF plays an important role in cell growth and invasion in human gastric cancer and it appears to be a potential prognostic marker for patients with gastric cancer.

Study on the mechanism of themolecular biology of hepatocyte growth factor and connective tissue factor in proliferative vitreoretinopathy

Objective To determine the role of CTGF in PVR, we successfully down - regulated the expression of CTGF by RNA interference( RNAi) technology in ARPE-19 cell line. Methods Design and synthesis three CTGF siRNA, screen effective targeted points in Western blot, combine Oligo DNA of effective targeted point, anneal to form double chain DNA, connect with linearing pGC-LV-GFP carrier, sequence DNA in PCR screening positive clones. Results The shRNA-expression vector of CTGF was constructed successfully. And RT-PCR and Western Blot results showed that CTGF expression was significantly inhibited by siRNA transfectants in ARPE-19 cells at mRNA and protein levels. Conclusion We successfully construct shRNA-expression vector of CTGF which paves a way for CTGF-targeted gene therapy of proliferative vitreoretinopathy. Key words: Intercellular signaling peptides and proteins; RNA interference; Lentivirus infections; Pigment epithelium of eye; Far-Western blotting

Connective tissue growth factor associated with oncogenic activities and drug resistance in glioblastoma multiforme

Connective tissue growth factor (CTGF or CCN2) is a secreted protein that belongs to the CCN [cysteine-rich CYR61/CTGF/nephroblastoma-overexpressed gene] family. These proteins have been implicated in various biological processes, including stimulation of cell proliferation, migration, angiogenesis and tumorigenesis. In a previous study, we found that CTGF mRNA was elevated in primary gliomas, and a significant correlation existed between CTGF mRNA levels versus tumor grade, histology and patient survival. In this study, the role of CTGF in glioma tumorigenesis was explored. Forced expression of CTGF in glioblastoma multiforme (GBM) cells accelerated their growth in liquid culture and soft agar, stimulated cells migration in Boyden chamber assays and significantly increased their ability to form large, vascularized tumors in nude mice. CTGF induced the expression of the antiapoptotic proteins, Bcl-xl, Survivin and Flip. Overexpression of CTGF caused the U343 GBM cells to survive for longer than 40 days in serum-free medium and resist antitumor drugs including tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand, VELCADE (bortezomib, proteasome inhibitor) and temozolomide. Our data suggest that CTGF plays an important role in glioma progression, by supporting tumor cells survival and drug resistance.

Role of CTGF in beta cell differentiation, proliferation and function

Role of CTGF in beta cell differentiation, proliferation and function

Induction of Antiproliferative Connective Tissue Growth Factor Expression in Wilms' Tumor Cells by Sphingosine-1-Phosphate Receptor 2

Connective tissue growth factor (CTGF), a member of the CCN family of secreted matricellular proteins, regulates fibrosis, angiogenesis, cell proliferation, apoptosis, tumor growth, and metastasis. However, the role of CTGF and its regulation mechanism in Wilms' tumor remains largely unknown. We found that the bioactive lipid sphingosine-1-phosphate (S1P) induced CTGF expression in a concentration- and time-dependent manner in a Wilms' tumor cell line (WiT49), whereas FTY720-phosphate, an S1P analogue that binds all S1P receptors except S1P2, did not. Further, the specific S1P2 antagonist JTE-013 completely inhibited S1P-induced CTGF expression, whereas the S1P1 antagonist VPC44116 did not, indicating that this effect was mediated by S1P2. This was confirmed by adenoviral transduction of S1P2 in WiT49 cells, which showed that overexpression of S1P2 increased the expression of CTGF. Induction of CTGF by S1P was sensitive to ROCK inhibitor Y-27632 and c-Jun NH2-terminal kinase inhibitor SP600125, suggesting the requirement of RhoA/ROCK and c-Jun NH2-terminal kinase pathways for S1P-induced CTGF expression. Interestingly, the expression levels of CTGF were decreased in 8 of 10 Wilms' tumor tissues compared with matched normal tissues by quantitative real-time PCR and Western blot analysis. In vitro, human recombinant CTGF significantly inhibited the proliferation of WiT49 cells. In addition, overexpression of CTGF resulted in significant inhibition of WiT49 cell growth. Taken together, these data suggest that CTGF protein induced by S1P2 might act as a growth inhibitor in Wilms' tumor.

Nucleus pulposus notochord cells secrete connective tissue growth factor and Up‐regulate proteoglycan expression by intervertebral disc chondrocytes

To identify the components of conditioned medium obtained from intervertebral disc nucleus pulposus-derived canine notochord cells, and to evaluate the capacity of such factors to affect disc-derived chondrocyte gene expression of aggrecan, versican, and hyaluronic acid synthase 2 (HAS-2) as a function of culture conditions. Canine notochord cells obtained from nonchondrodystrophic dogs were cultured within alginate beads under conditions of serum deficiency (Dulbecco's modified Eagle's medium [DMEM]) to produce notochord cell-conditioned medium (NCCM). NCCM was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and liquid chromatography-tandem mass spectroscopy. Bovine disc-derived chondrocytes were cultured with serum-deficient medium (DMEM) and NCCM and assayed for the effect of tissue culture conditions on aggrecan, versican, and HAS-2 gene expression. Next, chondrocyte gene expression for aggrecan was evaluated using DMEM containing recombinant connective tissue growth factor (rCTGF), and the results compared with those obtained using NCCM and DMEM. NCCM contained aggrecan, Cu/Zn superoxide dismutase, fibronectin, and CTGF precursor. Culture with NCCM caused an up-regulation of aggrecan, versican, and HAS-2 gene expression. NCCM induced aggrecan gene expression in chondrocytes at a level similar to that induced by 100-200 ng/ml rCTGF. Nonchondrodystrophic and chondrodystrophic canine notochord cells exhibited similar levels of CTGF gene expression. Nucleus pulposus-derived notochord cells secrete CTGF (CCN2), a recently discovered multifunctional growth factor. There is no difference between CTGF gene expression in nonchondrodystrophic and chondrodystrophic canine notochord cells, suggesting a possible role of CTGF as an anabolic factor within the disc nucleus that is, to at least some degree, dependent on the population of notochord cells within the disc nucleus.

The role of CTGF in mediating the pathogenesis of diabetic nephropathy

The role of CTGF in mediating the pathogenesis of diabetic nephropathy