anti-CTGF Antibody Research Articles

Mechanical stress-induced connective tissue growth factor plays a critical role in intestinal fibrosis in Crohn's-like colitis.

Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well understood. Transmural inflammation is associated with inflammatory cell infiltration, stenosis, and distention, which present mechanical stress (MS) to the bowel wall. We hypothesize that MS induces gene expression of profibrotic mediators such as connective tissue growth factor (CTGF), which may contribute to fibrosis in CD. A rodent model of CD was induced by intracolonic instillation of TNBS to the distal colon. TNBS instillation induced a localized transmural inflammation (site I), with a distended colon segment (site P) proximal to site I. We detected significant fibrosis and collagen content not only in site I but also in site P in CD rats by day 7. CTGF expression increased significantly in sites P and I, but not in the segment distal to the inflammation site. Increased CTGF expression was detected mainly in the smooth muscle cells (SMCs). When rats were fed exclusively with clear liquid diet to prevent mechanical distention in colitis, expression of CTGF in sites P and I was blocked. Direct stretch led to robust expression of CTGF in colonic SMC. Treatment of CD rats with anti-CTGF antibody FG-3149 reduced fibrosis and collagen content in both sites P and I and exhibited consistent trends toward normalizing expression of collagen mRNAs. In conclusion, our studies suggest that mechanical stress, by upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.NEW & NOTEWORTHY We found that CTGF expression increased significantly not only in the inflammation site but in the distended segment proximal to inflammation in a rodent model of CD-like colitis. Release of mechanical distention prevented CTGF expression in CD rats, whereas direct stretch induced CTGF expression. Treatment with anti-CTGF antibody reduced fibrosis and collagen contents in CD rats. Thus, mechanical stress, via upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.

The pathogenic role of succinate-SUCNR1: a critical function that induces renal fibrosis via M2 macrophage

BackgroundRenal fibrosis significantly contributes to the progressive loss of kidney function in chronic kidney disease (CKD), with alternatively activated M2 macrophages playing a crucial role in this progression. The serum succinate level is consistently elevated in individuals with diabetes and obesity, both of which are critical factors contributing to CKD. However, it remains unclear whether elevated succinate levels can mediate M2 polarization of macrophages and contribute to renal interstitial fibrosis.MethodsMale C57/BL6 mice were administered water supplemented with 4% succinate for 12 weeks to assess its impact on renal interstitial fibrosis. Additionally, the significance of macrophages was confirmed in vivo by using clodronate liposomes to deplete them. Furthermore, we employed RAW 264.7 and NRK-49F cells to investigate the underlying molecular mechanisms.ResultsSuccinate caused renal interstitial macrophage infiltration, activation of profibrotic M2 phenotype, upregulation of profibrotic factors, and interstitial fibrosis. Treatment of clodronate liposomes markedly depleted macrophages and prevented the succinate-induced increase in profibrotic factors and fibrosis. Mechanically, succinate promoted CTGF transcription via triggering SUCNR1-p-Akt/p-GSK3β/β-catenin signaling, which was inhibited by SUCNR1 siRNA. The knockdown of succinate receptor (SUCNR1) or pretreatment of anti-CTGF(connective tissue growth factor) antibody suppressed the stimulating effects of succinate on RAW 264.7 and NRK-49F cells.ConclusionsThe causative effects of succinate on renal interstitial fibrosis were mediated by the activation of profibrotic M2 macrophages. Succinate-SUCNR1 played a role in activating p-Akt/p-GSK3β/β-catenin, CTGF expression, and facilitating crosstalk between macrophages and fibroblasts. Our findings suggest a promising strategy to prevent the progression of metabolic CKD by promoting the excretion of succinate in urine and/or using selective antagonists for SUCNR1.

The Inhibitory Effect of Connective Tissue Growth Factor Antibody on Postoperative Fibrosis in a Rabbit Model of Trabeculectomy.

To compare the efficacy of subconjunctival injection of an anti-connective tissue growth factor antibody (anti-CTGF) versus mitomycin-C (MMC) and placebo in reducing scar formation in a rabbit model of trabeculectomy. A total of 14 rabbits were included. Nine rabbits underwent trabeculectomy with subconjunctival injections of either anti-CTGF antibody, MMC, or balanced salt solution (BSS), each administered in three eyes, before peritomy. The anti-CTGF group received a repeated dose of the antibody five days after surgery. All nine rabbits were euthanized on day 14; the globes were stained with hematoxylin & eosin, Masson's Trichrome, and immunohistochemistry for detecting alpha-smooth muscle (α-SMA) actin. RNA extraction was performed on five eyes of the remaining rabbits which included one eye without any surgery, one eye 5 hr after trabeculectomy without any injection, one eye five days after trabeculectomy without any injection, and two eyes five days after trabeculectomy with administration of MMC and BSS, respectively. The mean bleb area in the anti-CTGF, MMC, and control groups was 3.8 1.45, 5.9 1.4, and 3.5 1.9 mm2, respectively. Collagenous tissue was found to occupy the bleb area by 13.7%, 13.5%, and 18.5%, respectively. This ratio was significantly higher in the BSS group (P = 0.04). The expression of CTGF mRNA after 5 hr and five days in eyes undergoing trabeculectomy were significantly more pronounced as compared to the unoperated eye. The mean H-SCORE of α-SMA-immune reactive cells calculated as the grade of staining multiplied by the percentage of immune stained cells was 14.6, 10.22, and 140.58 in the anti-CTGF, MMC, and control groups, respectively. While the control eyes had a significantly higher score (Ps 0.001), the anti-CTGF and MMC groups were comparable (P = 0.87). Based on the results of this animal study, the anti-CTGF antibody injection resulted in a significant reduction in collagenous tissue and myofibroblast cells after trabeculectomy.

Oxygen Desaturation Is Associated With Fibrocyte Activation via Epidermal Growth Factor Receptor/Hypoxia-Inducible Factor-1α Axis in Chronic Obstructive Pulmonary Disease.

Fibrocytes are bloodborne mesenchymal progenitors which accumulate and differentiate at the disease site. We investigated whether hypoxemia activates fibrocytes, accelerating airflow limitation and exercise intolerance in chronic obstructive pulmonary disease (COPD) patients. Flow cytometry was used to determine collagen I+/CD45+ fibrocytes and α-smooth muscle actin+ differentiating fibrocytes within peripheral blood and cultured cells, as well as the expression of CXC chemokine receptor 4 (CXCR4), epidermal growth factor receptor (EGFR), connective tissue growth factor (CTGF) and hypoxia-inducible factor (HIF)-1α. Fibrocytes in lung specimens were identified by confocal microscopy. Compared to non-desaturators, COPD desaturators (peripheral blood oxygen saturation ≤88% during exercise) had greater number of fibrocytes in peripheral blood and lung specimens, paralleled with faster yearly lung function decline and a 6-minute walk distance. Fibrocytes from desaturators expressed more EGFR, CXCR4, CTGF, and HIF-1α, with a higher capacity of proliferation and myofibroblastic differentiation. Hypoxia (5% oxygen) increased the expression of EGFR, CXCR4, CTGF, and HIF-1α, the number and differentiation in fibrocytes. These effects were attenuated by EGFR inhibitor gefitinib, HIF-1α gene silencing, and anti-CTGF antibody. These data elucidate that hypoxemia triggers fibrocyte activation through the EGFR/HIF-1α axis, aggravating airflow obstruction in COPD.

Oxygen Desaturation Is Associated With Fibrocyte Activation via Epidermal Growth Factor Receptor/ Hypoxia-Inducible Factor-1α Axis in Chronic Obstructive Pulmonary Disease

Background: Fibrocytes are bloodborne mesenchymal progenitors which accumulate and differentiate at disease site. We investigated whether hypoxemia activates fibrocytes, accelerating airflow limitation and exercise intolerance in chronic obstructive pulmonary disease (COPD) patients. Methods: Flow cytometry was used to determine collagen I+/CD45+ fibrocytes and α-smooth muscle actin+ differentiating fibrocytes within peripheral blood and cultured cells, as well as the expression of CXC chemokine receptor 4 (CXCR4), epidermal growth factor receptor (EGFR), connective tissue growth factor (CTGF) and hypoxia-inducible factor (HIF)-1α. Fibrocytes in lung specimens were identified by confocal microscopy. Findings: Compared to non-desaturators, COPD desaturators (peripheral blood oxygen saturation ≤88% during exercise) had greater number of fibrocytes in peripheral blood and lung specimens, paralleled with faster yearly lung function decline and 6-minute walk distance. Fibrocytes from desaturators expressed more EGFR, CXCR4, CTGF and HIF-1α, with a higher capacity to proliferation and myofibroblastic differentiation. Hypoxia (5% oxygen) increased the expression of EGFR, CXCR4, CTGF and HIF-1α, the number and differention in fibrocytes. These effects were attenuated by EGFR inhibitor gefitinib, HIF-1α gene silencing, and anti-CTGF antibody. Interpretation: These data elucidate that hypoxaemia triggers fibrocyte activation through the EGFR/HIF-1α axis, aggravating airflow obstruction in COPD. Funding Information: This work was supported by the National Medical Research Program (NMRP) grant 99-2314-B-182-043-MY3, 108-2314-B-182A-128-MY2 and the Chang Gung Medical Research Project (CMRP) grant CMRPG390041-2. Declaration of Interests: The authors have declared that no competing interest exists. Ethics Approval Statement: The study was approved by the Ethics Committee of Chang Gung Memorial Hospital (IRB: 98-3950B, 201801979A3). Written informed consents were obtained from all participants.

Late Intervention with Radiation-Induced Lung Fibrosis - Comparing Pamrevlumab Anti-CTGF Therapy vs. Pirfenidone vs. Nintedanib as Mono-, Dual- and Triple-therapy Combinations

Radiation-induced lung fibrosis (RILF) is a major late side effect of radiotherapy of thoracic malignancies. The severity of RILF depends on irradiated lung volume and prescribed dose/fractionation scheme. In contrast to acute and subacute pneumonitis that are responsive to steroids, RILF is a dose-limiting factor for curative treatment of tumors and is an unmet medical need for potential anti-fibrosis therapy. We investigated the impact of pamrevlumab (FG-3019), an anti-CTGF antibody, and compared it to approved IPF (idiopathic pulmonary fibrosis) drugs, pirfenidone and nintedanib, or to their combinations. Late intervention, after fibrosis begins (15-16-week post radiation in mice), is challenging for anti-fibrotic treatment. Therefore, we evaluated if dual or triple combinations of the antifibrotic drugs may elicit superior effects. C57Bl/6 mice received single dose 14.5 Gy whole thoracic irradiation (RT) and the antifibrotic treatments started 16 weeks after RT, when lung remodeling was evident by CT, for 8 weeks. Pamrevlumab or placebo IgG were administered IP 2/wk at 40 mg/kg. Pirfenidone or nintedanib were administered PO at a daily target dose of 300 or 100 mg/kg, either formulated into chow or by gavage. Lung density changes were assessed by CT, and lung function was assessed by blood gas analysis. Gene expression changes were assessed by RNAseq. Pamrevlumab was the only monotherapy to inhibit lung remodeling and to normalize a substantial number of RT-altered transcripts when the IPF drugs were administered in chow. Interestingly, pirfenidone appeared to antagonize some of the benefits of pamrevlumab, which was also supported by transcriptome analysis. Based on the known short plasma half-life of pirfenidone and nintedanib and their possible insufficient exposure in chow, both drugs were administered by gavage for the next experiments to ensure that mice received a full daily dose. Neither drug was tolerable at the full dose, so the daily doses were divided into two parts and administered 2/d. With gavage administration, both pirfenidone and nintedanib inhibited lung remodeling measured by CT (p< 0.05), but pamrevlumab remained the superior monotherapy (p< 0.001). Combining pirfenidone with pamrevlumab did not appear to alter the benefit of pamrevlumab, but the combination of nintedanib with pamrevlumab significantly decreased lung remodeling at 24 weeks after RT compared to pamrevlumab alone (p< 0.01). Pamrevlumab was the only monotherapy to significantly increase median survival (p< 0.01). Addition of pirfenidone or nintedanib to pamrevlumab resulted in non-significant changes of median survival. At late stage RILF development, pamrevlumab monotherapy exhibits potent antifibrotic activity that warrants further clinical evaluation.

Prognostic utility of inflammation biomarkers in a PDAC trial involving the human anti-CTGF antibody pamrevlumab.

752 Background: Pancreatic ductal adenocarcinomas (PDAC) often exhibit desmoplasia, elevated CTGF (connective tissue growth factor) expression and inflammation. The influence of inflammation on patient outcomes was examined in a dose-ranging trial of the anti-CTGF antibody pamrevlumab in combination with a fixed regimen of gemcitabine and erlotinib in locally advanced or metastatic PDAC patients (NCT01181245; Picozzi et al. J Cancer Clin Trials 2017 2:123; n = 75). Methods: The prognostic utility of pre-treatment plasma levels of C-reactive protein (CRP), transforming growth factor β1 (TGFβ1), albumin, CTGF and CA 19-9 were assessed by univariate and multivariate Cox analysis. Demographic parameters, treatment cohort, and pamrevlumab exposure determined on treatment day 15 were also evaluated, as were changes in biomarker levels over the first four weeks of treatment. Results: Elevated baseline CTGF and CRP were prognostic for shorter overall survival (OS) by univariate analysis (HR = 3.2 for CRP &gt; 10 mg/L, p= 0.00002 and HR = 1.6 for CTGF &gt; 10 ng/mL, p= 0.045). In a five-factor multivariate Cox model that included CRP and TGFβ1 as continuous Ln-transformed variables, performance status, age, and pamrevlumab treatment cohort, cohort assignments associated with increasing pamrevlumab exposure predicted improved OS (HR = 0.87, p= 0.03). Removing CRP from this model reduced the prognostic utility of pamrevlumab cohort assignment and exposure, indicating an important contribution of inflammation to interpretation of treatment outcome. Changes in inflammation biomarkers over the course of treatment were also evaluated, but were not prognostic in this study. Conclusions: In multivariate Cox models, assessment of pre-treatment CRP levels improved ability to detect significant differences in PDAC patient survival outcomes associated with pamrevlumab treatment. Our results emphasize the utility of accounting for pre-treatment CRP levels as an independent prognostic factor in PDAC treatment effect models.

Mycobacterium tuberculosis induces connective tissue growth factor expression through the TLR2‐JNK‐AP‐1 pathway in human lung fibroblasts

Mycobacterium tuberculosis (M.tb) infection in lung causes pulmonary fibrosis, which leads to the irreversible reduction of pulmonary function. Fibrotic protein connective tissue growth factor (CTGF) expression has been confirmed to play a crucial role in lung fibrosis. However, the underlying signal pathway and effect of M.tb on CTGF expression in human lung fibroblasts are unclear. Our results revaled that M.tb caused time- and concentration-dependent increases in CTGF expression in human lung fibroblasts. A mechanistic investigation revealed that M.tb induced CTGF expression through TLR2 but not TLR4. The promoter activity assay indicated that M.tb-induced CTGF activity was mainly controlled by the promoter region at -747 to -184 bp, which contained signal transducer and activator of transcription 3 and activator protein 1 (AP-1) binding sites. Moreover, curcumin (AP-1 inhibitor) restrained M.tb-induced CTGF expression. M.tb also induced increases in AP-1 luciferase activity and DNA binding activity of c-Jun and c-Fos on the CTGF promoter. Furthermore, the knockdown of c-Jun by small interfering RNA attenuated M.tb-induced CTGF expression and AP-1 luciferase activity. A JNK inhibitor (SP600125) and a JNK dominant-negative mutant suppressed M.tb-induced CTGF expression. We also discovered that M.tb could induce the phosphorylation of JNK and c-Jun. Furthermore, SP600125 inhibited M.tb-induced c-Jun phosphorylation and AP-1- luciferase activity. M.tb-induced fibronectin expression was inhibited by anti-CTGF antibody. These results demonstrate that M.tb is activated through TLR2 to induce JNK activation, further increasing the DNA binding activity of c-Jun and c-Fos and finally inducing CTGF expression and extracellular matrix production.-Lee, H.-S., Hua, H.-S., Wang, C.-H., Yu, M.-C., Chen, B.-C., Lin, C.-H. Mycobacterium tuberculosis induces connective tissue growth factor expression through the TLR2-JNK-AP-1 pathway in human lung fibroblasts.

Markers of renal fibrosis: How do they correlate with podocyte damage in glomerular diseases?

BackgroundRenal fibrosis is the result of the interaction of cellular and molecular pathways, which is induced by sustained glomerular injury and involves the podocytes and multiple profibrotic factors. In this study, we investigated the correlation of the mRNA expression of podocyte proteins and profibrotic factors with renal fibrosis measured in renal biopsies of patients with primary and secondary glomerulopathies.MethodsEighty-four adult patients with primary or secondary glomerular diseases and 12 controls were included. Demographic and clinical data were collected. Seventy-two percent of the renal biopsies were done less than one year from clinical disease manifestation. The quantification of the podocyte-associated mRNAs of alpha-actinin-4, podocin, and podocalyxin, as well as of the profibrotic factors TGF-β1, CTGF, and VEGF-A were quantified by real-time polymerase chain reaction. The percent positive area of renal fibrosis was measured by immunohistochemistry staining, using anti-CTGF and anti-HHF35 antibodies and unpolarized Sirius Red. Correlations between the expression of tissue mRNAs and the positive area of fibrosis for the measured markers were made by Spearman’s rank correlation coefficient.ResultsIn relation to control biopsies, podocyte-specific proteins were downregulated in podocytopathies, in proliferative nephritis, in diabetic kidney disease (DRD), and in IgA nephropathy (IgAN). Messenger RNA of TGF-β1, CTGF, and VEGF-A was upregulated in patients with podocytopathies and in DRD but not in proliferative nephritis and IgAN. Tissue mRNA expression of TGF-β1, CTGF, and VEGF-A were strongly correlated with renal fibrosis, as measured by HHF35; however, the correlation, albeit significant, was moderate for Sirius Red and weak for CTGF. The percent positive area of renal fibrosis measured by Sirius Red was similar between podocytopathies and DRD and significantly higher in podocytopathies compared to IgAN or proliferative nephritis.ConclusionsIn patients with glomerular diseases, the mRNA of TGF-β1, CTGF, and VEGF-A correlated positively with the extent of renal fibrosis, and the positive area of fibrosis was larger in the podocytopathies and in DRD as measured by Sirius Red. The pathways connecting podocyte damage and activation of profibrotic factors to kidney tissue fibrosis need to be better investigated.

CTGF Mediates Tumor-Stroma Interactions between Hepatoma Cells and Hepatic Stellate Cells to Accelerate HCC Progression.

Connective tissue growth factor (CTGF) is a matricellular protein related to hepatic fibrosis. This study aims to clarify the roles of CTGF in hepatocellular carcinoma (HCC), which usually develops from fibrotic liver. CTGF was overexpressed in 93 human HCC compared with nontumorous tissues, primarily in tumor cells. Increased CTGF expression was associated with clinicopathologic malignancy of HCC. CTGF was upregulated in hepatoma cells in hepatocyte-specific Kras-mutated mice (Alb-Cre KrasLSL-G12D/+). Hepatocyte-specific knockout of CTGF in these mice (Alb-Cre KrasLSL-G12D/+ CTGFfl/fl) decreased liver tumor number and size. Hepatic stellate cells (HSC) were present in both human and murine liver tumors, and α-SMA expression, a marker of HSC activation, positively correlated with CTGF expression. Forced expression of CTGF did not affect growth of PLC/PRF/5 cells, a hepatoma cell line with little CTGF expression, but facilitated their growth in the presence of LX-2 cells, an HSC line. The growth of HepG2 cells, which express high levels of CTGF, was promoted by coculture with LX-2 cells compared with monoculture. Growth promotion by LX-2 cells was negated by an anti-CTGF antibody in both culture and xenografts. Coculturing LX-2 cells with HepG2 cells drove LX-2-derived production of IL6, which led to STAT-3 activation and proliferation of HepG2 cells. An anti-CTGF antibody reduced IL6 production in LX-2 cells and suppressed STAT-3 activation in HepG2 cells. In conclusion, our data identify tumor cell-derived CTGF as a keystone in the HCC microenvironment, activating nearby HSC that transmit progrowth signals to HCC cells, and this interaction is susceptible to inhibition by an anti-CTGF antibody.Significance: Protumor cross-talk between cancer cells and hepatic stellate cells presents an opportunity for therapeutic intervention against HCC.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/17/4902/F1.large.jpg Cancer Res; 78(17); 4902-14. ©2018 AACR.

Effect of anti-CTGF human recombinant monoclonal antibody pamrevlumab on resectability and resection rate when combined with gemcitabine/nab-paclitaxel in phase 1/2 clinical study for the treatment of locally advanced pancreatic cancer patients.

4016Background: Pancreatic ductal adenocarcinomas exhibit high degree of desmoplasia with extensive connective tissue growth factor (CTGF) expression and extracellular matrix production. CTGF overexpression is associated with aberrant fibrous tissue in mouse model, in which progression of tissue adhesion was inhibited by pamrevlumab. We hypothesize that pamrevlumab, an anti-CTGF antibody, may influence resectability of locally advanced pancreatic cancer (LAPC) by inhibiting effects of CTGF. Methods: Pamrevlumab + gemcitabine/Nab-paclitaxel (G/N) (Arm A) vs G/N (Arm B) was given to treatment-naive LAPC patients to improve resection rate and overall survival (OS). Patients (N = 37) were randomized 2:1 in Arm A vs Arm B. Patients who completed 6 cycles of treatment underwent resectability assessment per protocol criteria (NCCN, CA 19-9, PET, RECIST) and, if found eligible, underwent resection. No adjuvant therapy was given; second line therapy was administered per investigator discretion. Results: In the ITT...

Connective Tissue Growth Factor Is a Novel Prodepressant

BackgroundWhile downregulation of several growth factors in major depressive disorder is well established, less attention has been paid to the upregulation of other growth factors. Yet, upregulated growth factors may offer better therapeutic targets. We show that connective tissue growth factor (CTGF) represents a target based on its upregulation in major depressive disorder and studies in animal models implicating it in negative affect. MethodsCTGF gene expression was first evaluated in the postmortem human amygdala. The findings were followed up in outbred rats and in two rat lines that were selectively bred for differences in novelty-seeking and anxiety behavior (bred low responders and bred high responders). We studied the impact of social defeat and early-life treatment with fibroblast growth factor 2 on CTGF expression. Finally, we assessed the ability of an anti-CTGF antibody (FG-3019) to alter CTGF expression and emotionality. ResultsIn the human amygdala, CTGF expression was significantly increased in major depressive disorder compared with control subjects. CTGF expression was also significantly increased in the dentate gyrus of adult bred low responders compared with bred high responders. Social defeat stress in bred low responders significantly increased CTGF expression in the dentate gyrus. Early-life fibroblast growth factor 2, a treatment that reduces anxiety-like behavior throughout life, decreased CTGF expression in the adult dentate gyrus. In outbred rats, CTGF administration increased depression-like behavior. Chronic treatment with FG-3019 decreased CTGF expression, and acute and chronic treatment was antidepressant. ConclusionsThis study is the first to implicate CTGF as a prodepressant molecule that could serve as a target for the development of novel therapeutics.

Optimizing NBE PK/PD assays using the Gyrolab Affinity Software; conveniently within the bioanalyst's existing workflow.

The fully automated microfluidics-based Gyrolab is a popular instrument for the bioanalysis of protein therapeutics; requiring minimal sample and reagent volumes. Gyros offers affinity software for determining binding affinity in solution using a high-throughput method and miniaturized reactions. Using this affinity software, multiple CTGF-targeting reagents were characterized on the Gyrolab after <100% target coverage was seen in a cynomolgus pharmacokinetic/PD study dosed with anti-CTGF antibodies. The results uncovered magnitude differences in binding affinities between the dosed antibody, target and assay reagents. The binding affinity values were used to investigate reduced target coverage and results highlight potential of the affinity software for incorporation into the bioanalyst's existing Gyrolab workflow for characterizing reagents and optimizing pharmacokinetic/PD bioanalytical assays.

Radiation-induced pulmonary gene expression changes are attenuated by the CTGF antibody Pamrevlumab

BackgroundFibrosis is a delayed side effect of radiation therapy (RT). Connective tissue growth factor (CTGF) promotes the development of fibrosis in multiple settings, including pulmonary radiation injury.MethodsTo better understand the cellular interactions involved in RT-induced lung injury and the role of CTGF in these responses, microarray expression profiling was performed on lungs of irradiated and non-irradiated mice, including mice treated with the anti-CTGF antibody pamrevlumab (FG-3019). Between group comparisons (Welch’s t-tests) and principal components analyses were performed in Genespring.ResultsAt the mRNA level, the ability of pamrevlumab to prolong survival and ameliorate RT-induced radiologic, histologic and functional lung deficits was correlated with the reversal of a clear enrichment in mast cell, macrophage, dendritic cell and mesenchymal gene signatures. Cytokine, growth factor and matrix remodeling genes that are likely to contribute to RT pneumonitis and fibrosis were elevated by RT and attenuated by pamrevlumab, and likely contribute to the cross-talk between enriched cell-types in injured lung.ConclusionsCTGF inhibition had a normalizing effect on select cell-types, including immune cells not typically regarded as being regulated by CTGF. These results suggest that interactions between RT-recruited cell-types are critical to maintaining the injured state; that CTGF plays a key role in this process; and that pamrevlumab can ameliorate RT-induced lung injury in mice and may provide therapeutic benefit in other immune and fibrotic disorders.

Connective Tissue Growth Factor Neutralization Aggravates the Psoriasis Skin Lesion: The Analysis of Psoriasis Model Mice and Patients.

BackgroundConnective tissue growth factor (CTGF) is a multifunctional cellular protein and playing a role as a central mediator in tissue remodeling and fibrosis. The physiological function of CTGF in psoriasis is unknown.ObjectiveThe purpose of this study was to investigate the function of CTGF in psoriasis using the established imiquimod (IMQ)-induced psoriasis murine model and psoriasis patients.MethodsAnti-CTGF monoclonal antibody was applied to IMQ induced psoriasis mice and those skin were clinically, pathologically and immunologically analyzed. Additionally, CTGF expression was analyzes using skin samples and plasma from psoriasis patients.ResultsCTGF expression was observed in the dermis from both IMQ-induced psoriatic mice and psoriasis patients. CTGF inhibition using an anti-CTGF antibody slightly worsened IMQ-induced dermatitis. In addition, the increase of CTGF showed tendency to suppress the psoriatic dermatitis through inhibition of suprabasal cells proliferation and macrophage infiltration in the skin. CTGF was also detected significantly higher in plasma from psoriasis patients comparing with healthy control.ConclusionOur findings suggest that CTGF could contribute to the healing rather than the worsening of psoriasis skin lesions.

1734PD - Anti-CTGF human recombinant monoclonal antibody pamrevlumab increases resectability and resection rate when combined with gemcitabine/Nab-paclitaxel in the treatment of locally advanced pancreatic cancer patients

1734PD - Anti-CTGF human recombinant monoclonal antibody pamrevlumab increases resectability and resection rate when combined with gemcitabine/Nab-paclitaxel in the treatment of locally advanced pancreatic cancer patients

Anti-connective tissue growth factor detects and reduces plaque inflammation in early-stage carotid atherosclerotic lesions

This study explored connective tissue growth factor (CTGF)-targeted ultrasmall superparamagnetic iron oxides (USPIOs) for noninvasive MRI of CTGF within carotid atherosclerotic lesions in apoE-deficient (apoE−/−) mice. Anti-CTGF polyclonal and nonspecific IgG antibodies were conjugated to polyethylene glycol-coated USPIOs, and apoE−/− carotid partial ligation-model mice were imaged via MRI before and after contrast administration. ApoE−/− mice were treated with CTGF-neutralizing antibodies for 3 weeks. Carotid artery diameter and plaque volume were measured via MRI in IgG and CTGF antibody-treated groups. Anti-CTGF-USPIO-treated macrophages showed the greatest iron uptake. MRI signal loss was observed in carotid atherosclerotic lesions 24 h after anti-CTGF-USPIO administration, consistent with the presence of nanoparticles, as indicated by pathological examinations. Atheromata in anti-CTGF-treated mice showed reduced macrophage deposition, CTGF expression, and plaque volume. Anti-CTGF-USPIOs can be used for the direct detection of CTGF and imaging of atherosclerotic lesions in vivo. CTGF is a potential therapeutic target for treating atherosclerosis.

Inhibition of CTGF ameliorates peritoneal fibrosis through suppression of fibroblast and myofibroblast accumulation and angiogenesis

Peritoneal fibrosis (PF) is a serious complication in various clinical settings, but the mechanisms driving it remain to be fully determined. Connective tissue growth factor (CTGF) is known to regulate fibroblast activities. We therefore examined if CTGF inhibition has anti-fibrotic effects in PF. PF was induced by repetitive intraperitoneal injections of chlorhexidine gluconate (CG) in mice with type I pro-collagen promoter-driven green fluorescent protein (GFP) expression to identify fibroblasts. FG-3019, an anti-CTGF monoclonal antibody, was used to inhibit CTGF. CG-induced PF was significantly attenuated in FG-3019-treated mice. CG challenges induced marked accumulations of proliferating fibroblasts and of myofibroblasts, which were both reduced by FG-3019. Levels of peritoneal CTGF expression were increased by CG challenges, and suppressed in FG-3019-treated mice. FG-3019 treatment also reduced the number of CD31+ vessels and VEGF-A-positive cells in fibrotic peritoneum. In vitro studies using NIH 3T3 fibroblasts and peritoneal mesothelial cells (PMCs) showed that CTGF blockade suppressed TGF-β1-induced fibroblast proliferation and myofibroblast differentiation, PMC mesothelial-to-mesenchymal transition, and VEGF-A production. These findings suggest that the inhibition of CTGF by FG-3019 might be a novel treatment for PF through the regulation of fibroblast and myofibroblast accumulation and angiogenesis.

Anti-connective tissue growth factor (CTGF/CCN2) monoclonal antibody attenuates skin fibrosis in mice models of systemic sclerosis

BackgroundSystemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. Although the involvement of connective tissue growth factor (CTGF/CCN2) has been well-documented in SSc fibrosis, the therapeutic potential of targeting CTGF in SSc has not been fully investigated. Our aim was to examine the therapeutic potential of CTGF blockade in a preclinical model of SSc using two approaches: smooth muscle cell fibroblast-specific deletion of CTGF (CTGF knockout (KO)) or a human anti-CTGF monoclonal antibody, FG-3019.MethodsAngiotensin II (Ang II) was administered for 14 days by subcutaneous osmotic pump to CTGF KO or C57BL/6 J mice. FG-3019 was administered intraperitoneally three times per week for 2 weeks. Skin fibrosis was evaluated by histology and hydroxyproline assay. Immunohistochemistry staining was used for alpha smooth muscle actin (αSMA), platelet-derived growth factor receptor β (PDGFRβ), pSmad2, CD45, von Willebrand factor (vWF), and immunofluorescence staining was utilized for procollagen and Fsp1.ResultsAng II-induced skin fibrosis was mitigated in both CTGF KO and FG-3019-treated mice. The blockade of CTGF reduced the number of cells expressing PDGFRβ, procollagen, αSMA, pSmad2, CD45, and Fsp1 in the dermis. In addition, inhibition of CTGF attenuated vascular injury as measured by the presence of vWF-positive cells.ConclusionsOur data indicate that inhibition of CTGF signaling presents an attractive therapeutic approach in SSc.

Ocular Safety of Intravitreal Connective Tissue Growth Factor Neutralizing Antibody

ABSTRACTPurpose: To detect the safety of intravitreal injection of anti-connective tissue growth factor (CTGF) (IVAC) in rat eyes in order to apply this neutralizing antibody for experimental animal studies.Methods: Forty-five Lister Hooded male pigmented rats were divided into five groups that received IVAC (2 μl) corresponding to the doses of 10 (B), 20 (C), 50 (D), and 100 μg/ml (E), equal to 1.25, 2.5, 6.25, and 12.5 µg/ml of antibody concentration in rat vitreous, respectively. The sham group (A) received 2 μl of normal saline. Full field electroretinography (ERG) was performed at baseline and on days 7 and 28 after IVAC. The animals were euthanized and the corresponding eyes were subjected to routine histopathology, immunohistochemistry for glial fibrillary acidic protein (GFAP), and terminal transferase dUTP nick end-labeling (TUNEL) assay.Results: Scotopic rod b-wave amplitude and maximal combined b-wave amplitude were 111.89 ± 71.2 and 178.57 ± 55.58 μV, respectively, at baseline which significantly reduced to 79.31 ± 52.59 and 128.73 ± 41.61 μV, respectively, after 28 days in group E (p < 0.05). There was no significant reduction of amplitudes in other groups with lower doses of anti-CTGF antibody. Retinal ganglion cells were significantly decreased in group E as compared to other groups. GFAP immune reactivity was not significant in any of the groups. TUNEL test showed inner retinal neural cell apoptosis only in group E.Conclusions: ERG, histopathologic, and apoptotic assays revealed no toxic effects of 10–50 μg/ml of IVAC in rat eyes. Using 100 μg/ml IVAC led to a significant toxic effect in terms of functional, histopathologic, and TUNEL findings.