Human Connective Tissue Growth Factor Research Articles

Identification and Characterization of a Novel Nanobody Against Human CTGF to Reveal Its Antifibrotic Effect in an in vitro Model of Liver Fibrosis.

No agents are currently available for the treatment or reversal of liver fibrosis. Novel antifibrotic therapies for chronic liver diseases are thus urgently needed. Connective tissue growth factor (CTGF) has been shown to contributes profoundly to liver fibrogenesis, which makes CTGF as a promising target for developing antifibrotic agents. In this study, we identified a novel nanobody (Nb) against human CTGF (anti-CTGF Nb) by phage display using an immunized camel, which showed high affinity and specificity in vitro. LX-2 cells, the immortalized human hepatic stellate cells, were induced by transforming growth factor beta1 (TGFβ1) as an in vitro model of liver fibrosis to verify the antifibrotic activity of the anti-CTGF Nb. Our data demonstrated that anti-CTGF Nb effectively alleviated TGFβ1-induced LX-2 cell proliferation, activation, and migration, and promoted the apoptosis of activated LX-2 cells in response to TGFβ1. Moreover, the anti-CTGF Nb remarkably reduced the levels of TGFβ1, Smad2, and Smad3 expression in LX-2 stellate cells stimulated by TGFβ1. Taken together, we successfully identified a novel Nb against human CTGF, which exhibited antifibrotic effects in vitro by regulating the biological functions of human stellate cells LX-2.

Pamrevlumab, a Fully Human Monoclonal Antibody Targeting Connective Tissue Growth Factor, for Non-Ambulatory Patients with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is a neuromuscular disease stemming from dystrophin gene mutations. Lack of dystrophin leads to progressive muscle damage and replacement of muscle with fibrotic and adipose tissue. Pamrevlumab (FG-3019), a fully human monoclonal antibody that binds to connective tissue growth factor (CTGF), is in Phase III development for treatment of DMD and other diseases. MISSION (Study 079; NCT02606136) was an open-label, Phase II, single-arm trial of pamrevlumab in 21 non-ambulatory patients with DMD (aged≥12 years, receiving corticosteroids) who received 35-mg/kg intravenous infusions every 2 weeks for 2 years. The primary endpoint was change from baseline in percent predicted forced vital capacity (ppFVC). Secondary endpoints included other pulmonary function tests, upper limb function and strength assessments, and changes in upper arm fat and fibrosis scores on magnetic resonance imaging. Fifteen patients completed the trial. Annual change from baseline (SE) in ppFVC was -4.2 (0.7) (95% CI -5.5, -2.8). Rate of decline in ppFVC in pamrevlumab-treated patients was slower than observed in historical published trials of non-ambulatory patients. MISSION participants experienced slower-than-anticipated muscle function declines compared with natural history and historical published trials of non-ambulatory patients with DMD. Pamrevlumab was well-tolerated. Treatment-emergent adverse events were mild to moderate, and none led to study discontinuation. nti-CTGF therapy with pamrevlumab represents a potential treatment for DMD. The lack of internal control group limits the results.

Efficiency of Promoters of Human Genes FAP and CTGF at Organism Level in a Danio rerio Model.

The identification of tissue-specific promoters for gene therapeutic constructs is one of the aims of complex tumor therapy. The genes encoding the fibroblast activation protein (FAP) and the connective tissue growth factor (CTGF) can function in tumor-associated stromal cells but are practically inactive in normal adult cells. Accordingly, the promoters of these genes can be used to develop vectors targeted to the tumor microenvironment. However, the efficiency of these promoters within genetic constructs remains underexplored, particularly, at the organism level. Here, we used the model of Danio rerio embryos to study the efficiency of transient expression of marker genes under the control of promoters of the FAP, CTGF, and immediate early genes of Human cytomegalovirus (CMV). Within 96 h after the injection of vectors, the CTGF and CMV promoters provided similar equal efficiency of reporter protein accumulation. In the case of the FAP promoter, a high level of reporter protein accumulation was observed only in certain zebrafish individuals that were considered developmentally abnormal. Disturbed embryogenesis was the factor of changes in the exogenous FAP promoter function. The data obtained make a significant contribution to understanding the function of the human CTGF and FAP promoters within vectors to assess their potential in gene therapy.

A fully human connective tissue growth factor blocking monoclonal antibody ameliorates experimental rheumatoid arthritis through inhibiting angiogenesis

BackgroundConnective tissue growth factor (CTGF) plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA) by facilitating angiogenesis and is a promising therapeutic target for RA treatment. Herein, we generated a fully human CTGF blocking monoclonal antibody (mAb) through phage display technology.ResultsA single-chain fragment variable (scFv) with a high affinity to human CTGF was isolated through screening a fully human phage display library. We carried out affinity maturation to elevate its affinity for CTGF and reconstructed it into a full-length IgG1 format for further optimization. Surface plasmon resonance (SPR) data showed that full-length antibody IgG mut-B2 bound to CTGF with a dissociation constant (KD) as low as 0.782 nM. In the collagen-induced arthritis (CIA) mice, IgG mut-B2 alleviated arthritis and decreased the level of pro-inflammatory cytokines in a dose-dependent manner. Furthermore, we confirmed that the TSP-1 domain of CTGF is essential for the interaction. Additionally, the results of Transwell assays, tube formation experiments, and chorioallantoic membrane (CAM) assays showed that IgG mut-B2 could effectively inhibit angiogenesis.ConclusionThe fully human mAb that antagonizes CTGF could effectively alleviate arthritis in CIA mice, and its mechanism is tightly associated with the TSP-1 domain of CTGF.

PS-B04-12: DEVELOPMENT OF VACCINE AGAINST CONNECTIVE TISSUE GROWTH FACTOR TO PREVENT THE PROGRESSION OF RENAL FIBROSIS

Objective: Hypertension is closely related with chronic kidney disease (CKD); Hypertension and CKD can cause and exacerbate each other, forming a vicious cycle. There is a critical need for efficient treatment of CKD. Renal fibrosis is a final common pathway to end-stage renal disease, and connective tissue growth factor (CTGF) is a well-recognized central profibrotic factor in fibrosis of various organ systems. Here, we developed a novel peptide vaccine against CTGF to prevent the progression of renal fibrosis. Design and method: Among sequences of CTGF, the sequence common to mice and humans in the interaction region with transforming growth factor-β; (TGF-β;) and bone morphogenic proteins was selected as the epitope for the vaccine. The efficacy of this vaccine was verified in two renal fibrosis models using male C57BL/6J mice: adenine-induced CKD and unilateral ureteral obstruction (UUO) models. Moreover, the functions of CTGF vaccine-elicited IgG antibodies were evaluated in an in vitro study. Results: Three immunizations with this CTGF vaccine at 2-week intervals elicited serum IgG antibodies specifically binding to human full-length CTGF, and the antigen-specific antibody titers were maintained at high level for > 30 weeks. In adenine-induced CKD model, histological analyses showed that immunization with the CTGF vaccine significantly attenuated renal interstitial fibrosis compared to the vehicle treatment (8.5 ± 0.8% vs 12.3 ± 0.8%; P < 0.01). The CTGF vaccination also suppressed the increased mRNA expressions of collagen 1α and α-smooth muscle actin (α-SMA) in kidney tissue samples. Moreover, vaccinated mice showed lower levels of serum urea nitrogen (UN) and creatinine and lower urine albumin-creatinine ratio compared with vehicle-treated mice (UN: 77.7 ± 5.0 vs 104.0 ± 6.8 mg/dL; P < 0.01. creatinine: 0.42 ± 0.02 vs 0.51 ± 0.04 mg/dL; P = 0.06. albumin-creatinine ratio: 74.7 ± 13.8 vs 132.0 ± 15.3 μg/mg; P < 0.05). In UUO model, the CTGF vaccination also ameliorated the expansion of the interstitial fibrotic areas (7.7 ± 0.4 vs 9.8 ± 0.7%; P < 0.05). In an in vitro study, CTGF vaccine-elicited IgG antibodies efficiently suppressed CTGF-induced- and TGF-β;-induced α-SMA expression in cultured kidney fibroblasts. Conclusions: The CTGF vaccine has the potential to prevent the progression of renal fibrosis and delay the deterioration of renal function with a low frequency of administration. Thus, this CTGF vaccine could be a promising preventive strategy for CKD patients.

EGF promotes human trophoblast cell invasion by downregulating CTGF expression via PI3K/AKT signaling.

Although the pro-invasive role of epidermal growth factor (EGF) has been reported in human trophoblast cells, the underlying mechanism remains largely unexplored. This work reveals that EGF-induced downregulation of connective tissue growth factor (CTGF) mediates the EGF-stimulated human trophoblast cell invasion. During the development of the placenta, trophoblast cell invasion must be carefully regulated. Although EGF has been shown to promote trophoblast cell invasion, the underlying mechanism remains largely undetermined. Our previous study using RNA-sequencing (RNA-seq) has identified that kisspeptin-1 is a downstream target of EGF in a human trophoblast cell line, HTR-8/SVneo, and mediates EGF-stimulated cell invasion. In the present study, after re-analysis of our previous RNA-seq data, we found that the CTGF was also downregulated in response to the EGF treatment. The inhibitory effects of EGF on CTGF mRNA and protein levels were confirmed in HTR-8/SVneo cells by reverse transcription quantitative real-time PCR and western blot, respectively. Treatment with EGF activated both PI3K/AKT and ERK1/2 signaling pathways. Using pharmacological inhibitors, our results showed that EGFR-mediated activation of PI3K/AKT signaling was required for the EGF-downregulated CTGF mRNA and protein levels. Matrigel-coated transwell invasion assays demonstrated that EGF treatment stimulated cell invasion. In addition, the invasiveness of HTR-8/SVneo cells was suppressed by treatment with recombinant human CTGF. By contrast, siRNA-mediated knockdown of CTGF increased cell invasion. Notably, the EGF-promoted HTR-8/SVneo cell invasion was attenuated by co-treatment with CTGF. This study provides important insights into the molecular mechanisms mediating EGF-stimulated human trophoblast cell invasion and increases the understanding of the biological functions of CTGF in the human placenta.

Long non-coding RNA PVT1 promotes the proliferation, migration and EMT process of ovarian cancer cells by regulating CTGF.

Ovarian cancer remains one of the most common gynecological malignancies with a poor prognosis. The present study investigated the roles of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) in the regulation of the malignant phenotype of ovarian cancer cells, including cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT). SKOV3 and CAOV3 cells were transfected with small interfering RNA (siRNA) targeting lncRNA PVT1 (si-PVT1) or control siRNA and the si-PVT1 transfected cells were co-cultured with recombinant human connective tissue growth factor (rhCTGF). The proliferation, migration and invasion abilities of the cells were examined via Cell Counting Kit-8, colony formation, wound-healing and Transwell assays. The relative expression levels of lncRNA PVT1, CTGF, E-cadherin and vimentin were analyzed using reverse transfection-quantitative polymerase chain reaction, and western blotting was employed to detect the protein levels of CTGF, E-cadherin and vimentin. The expression of lncRNA PVT1 was significantly reduced in SKOV3 and CAOV3 cells following transfection with si-PVT1. In addition, the proliferation, migration and invasion abilities of SKOV3 and CAOV3 cells were repressed following lncRNA PVT1 knockdown. The knockdown of lncRNA PVT1 also reduced the expression of CTGF and vimentin, and increased the expression of E-cadherin. The changes in the proliferation, migration and invasion of the cells induced by transfection with si-PVT1 were partially attenuated in the presence of rhCTGF. Furthermore, co-culture with rhCTGF reversed the si-PVT1-induced changes in the expression of EMT-associated proteins. In conclusion, lncRNA PVT1 promotes the proliferation, migration, invasiveness and EMT process of ovarian cancer cells, and CTGF contributes to the effect of lncRNA PVT1.

Vaccination against connective tissue growth factor attenuates the development of renal fibrosis

There is a critical need for efficient treatment of chronic kidney disease (CKD). Renal fibrosis is a final common pathway to end-stage renal disease independent of the underlying etiology, and connective tissue growth factor (CTGF) is a well-recognized profibrotic factor in fibrosis of various organ systems. Here, we developed a novel peptide vaccine against CTGF to attenuate the development of renal fibrosis. Three inoculations with this CTGF vaccine at 2-week intervals elicited antibodies specifically binding to human full-length CTGF, and the antigen-specific serum IgG antibody titers were maintained for > 30 weeks. The efficacy of the CTGF vaccine on renal fibrosis was evaluated in adenine-induced CKD and unilateral ureteral obstruction (UUO) murine models. In adenine-induced CKD model, immunization with the CTGF vaccine attenuated renal interstitial fibrosis. Vaccinated mice showed low levels of serum creatinine and urea nitrogen and low urine albumin–creatinine ratio compared with vehicle-treated mice. In UUO model, the CTGF vaccination also suppressed the onset of renal fibrosis. In an in vitro study, CTGF vaccine-elicited IgG antibodies efficiently suppressed CTGF-induced- and transforming growth factor-β-induced α-smooth muscle actin expression in kidney fibroblasts. These results demonstrate that the CTGF vaccine is a promising strategy to attenuate the development of renal fibrosis.

Connective tissue growth factor expression maintains the epithelial phenotype of ovarian cancer in early epithelial to mesenchymal transition.

e17544 Background: Epithelial to Mesenchymal Transition (EMT) is essential to the process of metastasis in ovarian cancer (OC). Early expressions of proteins and pathways during EMT essential for understanding mechanism and potential therapeutic targets in OC. The aim of our study is to evaluate the role and mechanism of Connective Tissue Growth Factor (CTGF) in OC. Methods: R182 and R2615 are well-characterized epithelial OC cell lines. CTGF expression +/- Transforming Growth Factor -b (TGF-b) was determined via Western blot. R182 and R2615 CTGF knock out (KO) were derived utilizing a Cas9/CRISPR-Cas9 lentivirus plasmid vector and confirmed via PCR. Anoikis resistance and invasion assays were performed to characterize phenotypes of R182 and R2615 wild type (WT) and KO cells. For anoikis resistance, cells were plated in triplicate in an ultra-low adhesive (ULA) cell plate Promega CellTiter assay which measured cell viability quantified by absorbance at 450 nm at 0, 24, 48, and 72 hrs. For invasion assay, 3000 cells were suspended in 50% reduced growth factor Basement Membrane Extract. Human recombinant CTGF was added at 50 and 100 ng/mL concentrations. Cells were plated in tissue culture plate and placed in Cytation 5/Biospa and imaged at 4-hour interval for up to 6 days. Western blot evaluated expression of mesenchymal markers. Chemo-sensitivity was measured by half maximal inhibitory concentration (IC50) for Cisplatin between the WT and KO cells. RNA sequence analysis was performed for both R182 WT and KO cells and analyzed utilizing iPathway Guide. Results: CTGF is constitutively expressed in R182 and R2615 OC cells line as early as 6 hrs of culture and after 30 min of TGF-b treatment. Loss of CTGF promoted anoikis resistance. At 72 hr, R182 CTGF WT cells displayed 75% viability while R182 KO only have 10% viability. Further, we demonstrated that loss of CTGF increases invasion. Administration of exogeneous CTGF in KO cells suppresses invasion in a dose dependent manner demonstrated. Along with epithelial markers CK-18 and beta-catenin, the KO cells expressed the mesenchymal marker SNAIL. No difference in chemo-sensitivity to Cisplatin was seen between WT and KO in either cell line. RNA sequence analysis identified 1106 out of 14054 differentially expressed genes between the WT and KO cells. PI3KAkt, cell adhesion molecules and ECM receptor interaction were pathway that were most significantly regulated. Conclusions: CTGF expression maintains the epithelial phenotype of OC cells during EMT. Loss of CTGF allows anoikis resistance and invasion which are vital characteristics in the metastatic nature of OC. We suggest that loss of CTGF expression in OC cells could be a biomarker for more aggressive OC.

Connective tissue growth factor promotes retinal pigment epithelium mesenchymal transition via the PI3K/AKT signaling pathway.

Proliferative vitreoretinopathy (PVR) is a disease leading to the formation of contractile preretinal membranes (PRMs) and is one of the leading causes of blindness. Connective tissue growth factor (CTGF) has been identified as a possible key determinant of progressive tissue fibrosis and excessive scarring. Therefore, the present study investigated the role and mechanism of action of CTGF in PVR. Immunohistochemical staining was performed to detect the expression of CTGF, fibronectin and collagen type III in PRMs from patients with PVR. The effects and mechanisms of recombinant human CTGF and its upstream regulator, TGF-β1, on epithelial-mesenchymal transition (EMT) and the synthesis of extracellular matrix (ECM) by retinal pigment epithelium (RPE) cells were investigated using reverse transcription-quantitative PCR, western blotting and a [3H]proline incorporation assay. The data indicated that CTGF, fibronectin and collagen type III were highly expressed in PRMs. In vitro, CTGF significantly decreased the expression of the epithelial markers ZO-1 and E-cadherin and increased that of the mesenchymal markers fibronectin, N-cadherin and α-smooth muscle actin in a concentration-dependent manner. Furthermore, the expression of the ECM protein collagen type III was upregulated by CTGF. However, the trends in expression for the above-mentioned markers were reversed after knocking down CTGF. The incorporation of [3H]proline into RPE cells was also increased by CTGF. In addition, 8-Bromoadenosine cAMP inhibited CTGF-stimulated collagen synthesis and transient transfection of RPE cells with a CTGF antisense oligonucleotide inhibited TGF-β1-induced collagen synthesis. The phosphorylation of PI3K and AKT in RPE cells was promoted by CTGF and TGF-β1 and the latter promoted the expression of CTGF. The results of the present study indicated that CTGF may promote EMT and ECM synthesis in PVR via the PI3K/AKT signaling pathway and suggested that targeting CTGF signaling may have a therapeutic or preventative effect on PVR.

Transdermal peptide conjugated to human connective tissue growth factor with enhanced cell proliferation and hyaluronic acid synthesis activities produced by a silkworm silk gland bioreactor.

Human connective tissue growth factor (CTGF) is a secreted cysteine-rich peptide that stimulates cell proliferation, migration, and extracellular matrix production during tissue development, differentiation, angiogenesis, implantation, wound healing, and fibrosis processes, with broad application in the medical and cosmetic medical fields. However, the production of CTGF is currently limited by its low yield and purity in current bioreactors. In this study, two genetically modified silkworm strains were generated harboring artificially designed CTGF-8ht and pepCTGF-8ht genes, respectively, that contain an enhanced His-tag with eight histidine residues with or without a transdermal peptide (pep). Both recombinant CTGF-8ht and pepCTGF-8ht proteins were successfully expressed in the silkworm silk gland and cocoon, and could be easily extracted and purified from the cocoon by single-affinity immunoprecipitation column chromatography, achieving a purity of more than 95%. Moreover, compared with CTGF-8ht protein, pepCTGF-8ht protein exhibited better cell proliferation activity by activating the extracellular signal-regulated kinase (ERK) pathway and enhanced hyaluronic acid synthesis activity by upregulating hyaluronan synthase 3 expression; moreover, the addition of pep significantly improved the transmembrane ability of CTGF-8ht protein. These results should help to promote the application prospects of CTGF and further guide the design and development of protein drugs from silkworm and other bioreactor systems. KEY POINTS : A silkworm bioreactor was optimized to produce connective tissue growth factor (CTGF) The transgene contained an enhanced 8-His-tag and transmembrane peptide (pep) Recombinant CTGF was easily purified with maintained or higher biological activity.

Thalidomide inhibits the gene promoter of connective tissue growth factor in human embryonic lung fibroblasts.

The etiology and pathogenesis of idiopathic pulmonary fibrosis (IPF) remain unclear, and the early detection and treatment are vital to the prognosis of IPF patients. It's necessary to investigate the effect of thalidomide on the gene promoter activation of connective tissue growth factor (CTGF) induced by transforming growth factor-β1 (TGF-β1) in human embryonic lung fibroblast (HELF). The gene vector of pGL3-CTGFP containing human CTGF gene promoter was constructed and transfected into HELF cells. We used different TGF-β1 (0, 2.5, 5, 10 and 20 µg/L respectively) to stimulate HELF to identify the optimal concentration for gene promoter of CTGF. The activity of luciferase was measured to observe the effect of TGF-β1 and THALIDOMIDE on the activity of CTGF gene promoter. The relative luciferase activity increased significantly with the stimulation of TGF-β1, and the relative luciferase activity peaked in the 5 µg/L TGF-β1 group (all P<0.01). The thalidomide inhibited the TGF-β1-induced activation of CTGF gene promoter in HELF, and the effect peaked in the 25 µg/L group (all P<0.001). Thalidomide produces a significant inhibitory effect on the gene promoter activation of CTGF induced by TGF-β1 in HELF, it may be a potentially effective drug for the treatment of pulmonary fibrosis.

Investigation of the Effect of Secreted Factors from Mesenchymal Stem Cells on Disc Cells from Degenerated Discs

Low back pain is experienced by a large number of people in western countries and may be caused and influenced by many different pathologies and psychosocial factors including disc degeneration. Disc degeneration involves the increased expression of proinflammatory cytokines and matrix metalloproteinases (MMPs) in the disc environment, which leads to the loss of extracellular matrix (ECM) and the viability of the native disc cells (DCs). Treatment approaches using growth factors and cell therapy have been proposed due to the compelling results that growth factors and mesenchymal stem cells (MSCs) can influence the degenerated discs. The aim of this study was to investigate the effects of conditioned media (CM) from human MSCs (hMSCs) and connective tissue growth factor (CTGF) and TGF-β on disc cells, and hMSCs isolated from patients with degenerative discs and severe low back pain. The aim was also to examine the constituents of CM in order to study the peptides that could bring about intervertebral disc (IVD) regeneration. DCs and hMSC pellets (approx.. 200,000 cells) were cultured and stimulated with hMSC-derived CM or CTGF and TGF-β over 28 days. The effects of CM and CTGF on DCs and hMSCs were assessed via cell viability, proteoglycan production, the expression of ECM proteins, and chondrogenesis in 3D pellet culture. To identify the constituents of CM, CM was analyzed with tandem mass spectrometry. The findings indicate that CM enhanced the cellular viability and ECM production of DCs while CTGF and the control exhibited nonsignificant differences. The same was observed in the hMSC group. Mass spectrometry analysis of CM identified >700 peptides, 129 of which showed a relative abundance of ≥2 (CTGF among them). The results suggest that CM holds potential to counter the progression of disc degeneration, likely resulting from the combination of all the substances released by the hMSCs. The soluble factors released belong to different peptide families. The precise mechanism underlying the regenerative effect needs to be investigated further, prior to incorporating peptides in the development of new treatment strategies for low back pain that is potentially caused by IVD degeneration.

Anti-inflammatory effect of adipose-derived stem cells in the treatment of pelvic organ prolapse.

ObjectiveThis study investigated the effect of recombinant human connective tissue growth factor (hCTGF) on rat adipose-derived stem cells (ADSCs) and explored the feasibility of using ADSCs to treat pelvic organ prolapse.MethodsADSCs were isolated from rat inguinal adipose tissue and characterized by flow cytometry and for osteogenic and adipogenic differentiation. ADSCs were treated with recombinant hCTGF and qRT-PCR was performed to detect collagen I and III expression on post-treatment days 7, 14, and 28. Osteogenic and adipogenic differentiation of ADSCs was performed to evaluate the effect of hCTGF. ADSCs were seeded in biological grafting materials, acellular porcine pericardium (APP) and acellular bovine pericardium (ABP), then implanted in the rat vagina. Histology was performed to observe inflammation among different groups.ResultsCollagen I and III expression in ADSCs was significantly increased, and the ability to differentiate into osteogenic and adipogenic lineages was diminished after hCTGF treatment. APP and ABP seeded with ADSCs significantly decreased inflammation and protected from degradation in vivo compared with APP and ABP only; ABP seeded with ADSCs had the lowest inflammation.ConclusionhCTGF regulates collagen I and III expression and induces ADSC differentiation in vitro. ADSCs decrease inflammation associated with APP and ABP in vivo.

Identification of novel fibroblast-like cells from stem cells from human exfoliated deciduous teeth.

This study aimed to differentiate and characterize fibroblast-like cells from stem cells from human exfoliated deciduous teeth (SHED). The differentiation of fibroblast-like cells from SHED was carried out by using specific human recombinant connective tissue growth factor (CTGF). To characterize fibroblastic differentiation, the induced cells were subjected to morphological changes, proliferation rate, gene expression analysis using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), flow cytometry, and immunofluorescence staining. The commercial primary human gingival fibroblasts served as positive control in this study. The results from characterization analysis were compared with that of commercial cells to ensure that the cells differentiated from SHED were fibroblast-like cells. The results showed the inductive effect of CTGF for fibroblastic differentiation in SHED. SHED-derived fibroblasts were successfully characterized despite having similar morphological appearance, i.e., (i) significant proliferation rate between fibroblast-like cells and SHED, (ii) high expression of fibroblast-associated markers in qRT-PCR analysis, and (iii) positive staining against collagen type 1, fibroblast-specific protein 1, and human thymic fibroblasts in flow cytometry analysis and immunofluorescence staining. The same expression patterns were found in primary human gingival fibroblasts, respectively. SHED as negative control showed lower expression or no signal, thus confirming the cells differentiated from SHED were fibroblast-like cells. Taken together, the protocol adopted in this study suggests CTGF to be an appropriate inducer in the differentiation of SHED into fibroblast-like cells. The fibroblast-like cells differentiated from SHED could be used in future in vitro and in vivo dental tissue regeneration studies as well as in clinical applications where these cells are needed.

22P - Therapeutic potential of connective tissue growth factor (CTGF) in triple-negative breast cancer

Background: Matricellular proteins are a subset of extracellular matrix (ECM) proteins which are dynamically expressed and serve many regulatory roles. Among matricellular proteins, the CCN family, a group of secreted proteins are known to regulate cell adhesion, migration, proliferation, differentiation, apoptosis, survival, senescence, and gene expression. Connective tissue growth factor (CTGF), also known as CCN2, is a member of the CCN family. CTGF is known to have many roles in biological processes such as cell proliferation, migration, adhesion, and angiogenesis. Methods: To investigate the function of CTGF in triple-negative breast cancer cells (TNBC), we silenced CTGF in TNBC cell lines using short hairpin RNA. Knockdown of CTGF was verified by western blot, qPCR, and immunostaining. The effect of CTGF knockdown on TNBCs was examined by cell proliferation assay, adhesion assay, migration assays, metabolism assays, and cell cycle analysis. Results: Knockdown of CTGF decreased cell proliferation, adhesion, migration, glucose uptake, ATP production and lactate production. Since CTGF is a secreted protein, we gave recombinant human CTGF (rhCTGF) to the cells and found that rhCTGF induced activation of the Src/FAK/MAPK pathway and led to expression of proteins related to cell cycle progression. Also, when CTGF-specific antibodies were given to the cells, they expressed cytotoxicity by neutralizing the extracellular CTGF and decreasing CTGF-mediated signalling. Conclusions: We suggest that the secreted CTGF mediates tumor cell progression via modulation of cell proliferation, adhesion, migration and metabolism and could possess a potential for being a therapeutic target. Legal entity responsible for the study: Hanyang University. Funding: National Research Foundation of Korea. Disclosure: All authors have declared no conflicts of interest.

A Placebo-controlled Study of PF-06473871 (Anti-Connective Tissue Growth Factor Antisense Oligonucleotide) in Reducing Hypertrophic Skin Scarring.

Connective tissue growth factor (CTGF) is a matricellular protein that plays a key role in wound healing and scar formation. Inhibition of CTGF by a specific antisense oligonucleotide significantly reduced scarring and fibrosis in animal models. This study examined whether an antisense oligonucleotide that inhibits human CTGF expression could reduce the severity of hypertrophic scar formation in patients following surgical revision of preexisting breast scars. This study was a 24-week multicenter, randomized, double-blind, within-subject, placebo-controlled phase 2b study evaluating the efficacy and safety of PF-06473871 in 2 regimens of either 3 or 4 intradermal injections (postsurgery weeks 2, 5, 8, and 11) of 5 mg/cm adjacent to the new surgical incision. One hundred subjects with bilateral hypertrophic scars resulting from prior breast surgery were randomized. Efficacy was determined by the Patient and Observer Scar Assessment Scale (POSAS). The Physician/Observer POSAS overall opinion score at (week 24) for the 4-injection regimen demonstrated a statistically significant (P = 0.022) treatment difference from placebo of 0.68, and the treatment difference for the 3-injection regimen was nonsignificant (P = 0.4). Physician evaluation of scar severity at (week 24) with the photo-guide in the 4-injection regimen had a significant reduction (point estimate of treatment difference of 0.43 favoring PF-06473871). The surgical effect was approximately 2.0 at week 24 and was nearly 3 times greater than the treatment effect. Patient evaluations using the POSAS and photo-guide were not significantly improved with either dose regimen. PF-06473871 was generally well tolerated systemically and locally. The 4-dose regimen of PF-06473871 provided statistically significant improvement, inhibiting severity of hypertrophic scar formation based on physician assessment. However, the effect of revision surgery alone is significant and may dominate the treatment effect of PF-06473871.

Essential role of connective tissue growth factor (CTGF) in transforming growth factor-\u03b21 (TGF-\u03b21)-induced myofibroblast transdifferentiation from Graves\u2019 orbital fibroblasts

Connective tissue growth factor (CTGF) associated with transforming growth factor-β (TGF-β) play a pivotal role in the pathophysiology of many fibrotic disorders. However, it is not clear whether this interaction also takes place in GO. In this study, we investigated the role of CTGF in TGF-β-induced extracellular matrix production and myofibroblast transdifferentiation in Graves’ orbital fibroblasts. By Western blot analysis, we demonstrated that TGF-β1 induced the expression of CTGF, fibronectin, and alpha-smooth muscle actin (α-SMA) in Graves’ orbital fibroblasts. In addition, the protein levels of fibronectin and α-SMA in Graves’ orbital fibroblasts were also increased after treatment with a recombinant human protein CTGF (rhCTGF). Moreover, we transfected the orbital fibroblasts with a small hairpin RNA of CTGF gene (shCTGF) to knockdown the expression levels of CTGF, which showed that knockdown of CTGF significantly diminished TGF-β1-induced expression of CTGF, fibronectin and α-SMA proteins in Graves’ orbital fibroblasts. Furthermore, the addition of rhCTGF to the shCTGF-transfected orbital fibroblasts could restore TGF-β1-induced expression of fibronectin and α-SMA proteins. Our findings demonstrate that CTGF is an essential downstream mediator for TGF-β1-induced extracellular matrix production and myofibroblast transdifferentiation in Graves’ orbital fibroblasts and thus may provide with a potential therapeutic target for treatment of GO.

Sustained Administration of β-cell Mitogens to Intact Mouse Islets Ex Vivo Using Biodegradable Poly(lactic-co-glycolic acid) Microspheres.

The development of biomaterials has significantly increased the potential for targeted drug delivery to a variety of cell and tissue types, including the pancreatic β-cells. In addition, biomaterial particles, hydrogels, and scaffolds also provide a unique opportunity to administer sustained, controllable drug delivery to β-cells in culture and in transplanted tissue models. These technologies allow the study of candidate β-cell proliferation factors using intact islets and a translationally relevant system. Moreover, determining the effectiveness and feasibility of candidate factors for stimulating β-cell proliferation in a culture system is critical before moving forward to in vivo models. Herein, we describe a method to co-culture intact mouse islets with biodegradable compound of interest (COI)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres for the purpose of assessing the effects of sustained in situ release of mitogenic factors on β-cell proliferation. This technique describes in detail how to generate PLGA microspheres containing a desired cargo using commercially available reagents. While the described technique uses recombinant human Connective tissue growth factor (rhCTGF) as an example, a wide variety of COI could readily be used. Additionally, this method utilizes 96-well plates to minimize the amount of reagents necessary to assess β-cell proliferation. This protocol can be readily adapted to use alternative biomaterials and other endocrine cell characteristics such as cell survival and differentiation status.

Sustained Administration of &amp;#946;-cell Mitogens to Intact Mouse Islets &lt;em&gt;Ex Vivo&lt;/em&gt; Using Biodegradable Poly(lactic-co-glycolic acid) Microspheres

The development of biomaterials has significantly increased the potential for targeted drug delivery to a variety of cell and tissue types, including the pancreatic β-cells. In addition, biomaterial particles, hydrogels, and scaffolds also provide a unique opportunity to administer sustained, controllable drug delivery to β-cells in culture and in transplanted tissue models. These technologies allow the study of candidate β-cell proliferation factors using intact islets and a translationally relevant system. Moreover, determining the effectiveness and feasibility of candidate factors for stimulating β-cell proliferation in a culture system is critical before moving forward to in vivo models. Herein, we describe a method to co-culture intact mouse islets with biodegradable compound of interest (COI)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres for the purpose of assessing the effects of sustained in situ release of mitogenic factors on β-cell proliferation. This technique describes in detail how to generate PLGA microspheres containing a desired cargo using commercially available reagents. While the described technique uses recombinant human Connective tissue growth factor (rhCTGF) as an example, a wide variety of COI could readily be used. Additionally, this method utilizes 96-well plates to minimize the amount of reagents necessary to assess β-cell proliferation. This protocol can be readily adapted to use alternative biomaterials and other endocrine cell characteristics such as cell survival and differentiation status.