Regulation of pancreatic inflammation by connective tissue growth factor (CTGF/CCN2)

Pancreatic stellate cells: Key players in pancreatic health and diseases (Review)

As a pluripotent cell, activated pancreatic stellate cells (PSCs) can differentiate into various pancreatic parenchymal cells and participate in the secretion of extracellular matrix and the repair of pancreatic damage. Additionally, PSCs characteristics allow them to contribute to pancreatic inflammation and carcinogenesis. Moreover, a detailed study of the pathogenesis of activated PSCs in pancreatic disease can offer promise for the development of innovative therapeutic strategies and improved patient prognoses. Therefore, the present study review aimed to examine the involvement of activated PSCs in pancreatic diseases and elucidate the underlying mechanisms to provide a viable therapeutic strategy for the management of pancreas‑related diseases.

Pancreatic Ubap2 deletion regulates glucose tolerance, inflammation, and protection from cerulein-induced pancreatitis

Ubiquitin-binding associated protein 2 (UBAP2) is reported to promote macropinocytosis and pancreatic adenocarcinoma (PDAC) growth, however, its role in normal pancreatic function remains unknown. We addressed this knowledge gap by generating UBAP2 knockout (U2KO) mice under a pancreas-specific Cre recombinase (Pdx1-Cre). Pancreatic architecture remained intact in U2KO animals, but they demonstrated slight glucose intolerance compared to controls. Upon cerulein challenge to induce pancreatitis, U2KO animals had reduced levels of several pancreatitis-relevant cytokines, amylase and lipase in the serum, reduced tissue damage, and lessened neutrophil infiltration into the pancreatic tissue. Mechanistically, cerulein-challenged U2KO animals revealed reduced NF-κB activation compared to controls. In vitro promoter binding studies confirmed the reduction of NF-κB binding to its target molecules supporting UBAP2 as a new regulator of inflammation in pancreatitis and may be exploited as a therapeutic target in future to inhibit pancreatitis.

Production, Exacerbating Effect, and EV-Mediated Transcription of Hepatic CCN2 in NASH: Implications for Diagnosis and Therapy of NASH Fibrosis

Non-alcoholic steatohepatitis (NASH) is characterized by steatosis, hepatocyte ballooning, and inflammation and may progress to include increasingly severe fibrosis, which portends more serious disease and is predictive of patient mortality. Diagnostic and therapeutic options for NASH fibrosis are limited, and the underlying fibrogenic pathways are under-explored. Cell communication network factor 2 (CCN2) is a well-characterized pro-fibrotic molecule, but its production in and contribution to NASH fibrosis requires further study. Hepatic CCN2 expression was significantly induced in NASH patients with F3-F4 fibrosis and was positively correlated with hepatic Col1A1, Col1A2, Col3A1, or αSMA expression. When wild-type (WT) or transgenic (TG) Swiss mice expressing enhanced green fluorescent protein (EGFP) under the control of the CCN2 promoter were fed up to 7 weeks with control or choline-deficient, amino-acid-defined diet with high (60%) fat (CDAA-HF), the resulting NASH-like hepatic pathology included a profound increase in CCN2 or EGFP immunoreactivity in activated hepatic stellate cells (HSC) and in fibroblasts and smooth muscle cells of the vasculature, with little or no induction of CCN2 in other liver cell types. In the context of CDAA-HF diet-induced NASH, Balb/c TG mice expressing human CCN2 under the control of the albumin promoter exhibited exacerbated deposition of interstitial hepatic collagen and activated HSC compared to WT mice. In vitro, palmitic acid-treated hepatocytes produced extracellular vesicles (EVs) that induced CCN2, Col1A1, and αSMA in HSC. Hepatic CCN2 may aid the assessment of NASH fibrosis severity and, together with pro-fibrogenic EVs, is a therapeutic target for reducing NASH fibrosis.

CCN2 Increases TGF-β Receptor Type II Expression in Vascular Smooth Muscle Cells: Essential Role of CCN2 in the TGF-β Pathway Regulation

The cellular communication network factor 2 (CCN2/CTGF) has been traditionally described as a mediator of the fibrotic responses induced by other factors including the transforming growth factor β (TGF-β). However, several studies have defined a direct role of CCN2 acting as a growth factor inducing oxidative and proinflammatory responses. The presence of CCN2 and TGF-β together in the cellular context has been described as a requisite to induce a persistent fibrotic response, but the precise mechanisms implicated in this relation are not described yet. Considering the main role of TGF-β receptors (TβR) in the TGF-β pathway activation, our aim was to investigate the effects of CCN2 in the regulation of TβRI and TβRII levels in vascular smooth muscle cells (VSMCs). While no differences were observed in TβRI levels, an increase in TβRII expression at both gene and protein level were found 48 h after stimulation with the C-terminal fragment of CCN2 (CCN2(IV)). Cell pretreatment with a TβRI inhibitor did not modify TβRII increment induced by CCN2(VI), demonstrating a TGF-β-independent response. Secondly, CCN2(IV) rapidly activated the SMAD pathway in VSMCs, this being crucial in the upregulation of TβRII since the preincubation with an SMAD3 inhibitor prevented it. Similarly, pretreatment with the epidermal growth factor receptor (EGFR) inhibitor erlotinib abolished TβRII upregulation, indicating the participation of this receptor in the observed responses. Our findings suggest a direct role of CCN2 maintaining the TGF-β pathway activation by increasing TβRII expression in an EGFR-SMAD dependent manner activation.

Tissue distribution and transcriptional regulation of CCN5 in the heart after myocardial infarction

CCN5 is a divergent member of the cellular communication network factor (CCN) family in that it lacks the carboxyl terminal cystine knot domain common to the other CCN family members. CCN5 has been reported to antagonize the profibrotic actions of CCN2 and to inhibit myocardial collagen deposition and fibrosis in chronic pressure overload of the heart. However, what mechanisms that regulate CCN5 activity in the heart remain unknown. Recombinant, replication defective adenovirus encoding firefly luciferase under control of the human CCN5 promoter was prepared and used to investigate what mechanisms regulate CCN5 transcription in relevant cells. Tissue distribution of CCN5 in hearts from healthy mice and from mice subjected to myocardial infarction was investigated. Contrary to the profibrotic immediate early gene CCN2, we find that CCN5 is induced in the late proliferation and maturation phases of scar healing. CCN5 was identified principally in endothelial cells, fibroblasts, smooth muscle cells, and macrophages. Our data show that CCN5 gene transcription and protein levels are induced by catecholamines via β₂-adrenergic receptors. Myocardial induction of CCN5 was further confirmed in isoproterenol-infused mice. We also find that CCN5 transcription is repressed by TNF-α, an inflammatory mediator highly elevated in early phases of wound healing following myocardial infarction. In conclusion, CCN5 predominates in endothelial cells, fibroblasts, and macrophages of the differentiating scar tissue and its transcription is conversely regulated by β₂-adrenergic agonists and TNF-α.

BMP6 increases CD68 expression by up-regulating CTGF expression in human granulosa-lutein cells

Bone morphogenetic protein 6 (BMP6) and connective tissue growth factor (CTGF) are critical growth factors required for normal follicular development and luteal function. Cluster of Differentiation 68 (CD68) is an intraovarian marker of macrophages that plays an important role in modulating the physiological regression of the corpus luteum. The aim of this study was to investigate the effect of BMP6 on the expression of CTGF and the subsequent increase in CD68 expression as well as its underlying mechanisms. Primary and immortalized (SVOG) human granulosa cells obtained from infertile women undergoing in vitro fertilization treatment were used as cell models to conduct the in vitro experiments. Our results showed that BMP6 treatment significantly increased the expression levels of CTGF and CD68. Using BMP type I receptor inhibitors (dorsomorphin, DMH-1 and SB431542), we demonstrated that both activin receptor-like kinase (ALK)2 and ALK3 are involved in BMP6-induced stimulatory effects on the expression of CTGF and CD68. Additionally, SMAD4-knock down reversed the BMP6-induced up-regulation of CTGF and CD68, indicating that the canonical SMAD signaling pathway is required for these effects. Moreover, CTGF-knock down abolished the BMP6-induced up-regulation of CD68 expression. These findings indicate that intrafollicular CTGF mediates BMP6-induced increases in CD68 expression through the ALK2/ALK3-mediated SMAD-dependent signaling pathway.

Dysregulation of PI3K and Hippo signaling pathways synergistically induces chronic pancreatitis via CTGF upregulation

The role of PI3K and Hippo signaling in chronic pancreatitis (CP) pathogenesis is unclear. Therefore, we assessed the involvement of these pathways in CP by examining the PI3K and Hippo signaling components PTEN and SAV1, respectively. We observed significant decreases in pancreatic PTEN and SAV1 levels in 2 murine CP models: repeated cerulein injection and pancreatic ductal ligation. Additionally, pancreas-specific deletion of Pten and Sav1 (DKO) induced CP in mice. Pancreatic connective tissue growth factor (CTGF) was markedly upregulated in both CP models and DKO mice, and pancreatic CCAAT/enhancer-binding protein-α (CEBPA) expression was downregulated in the CP models. Interestingly, in pancreatic acinar cells (PACs), CEBPA knockdown reduced PTEN and SAV1 and increased CTGF levels in vitro. Furthermore, CEBPA knockdown in PACs induced acinar-to-ductal metaplasia and activation of cocultured macrophages and pancreatic stellate cells. These results were mitigated by CTGF inhibition. CP in DKO mice was also ameliorated by Ctgf gene deletion, and cerulein-induced CP was alleviated by antibody-mediated CTGF neutralization. Finally, we observed significantly decreased PTEN, SAV1, and CEBPA and increased CTGF levels in human CP tissues compared with nonpancreatitis tissues. Taken together, our results indicate that dysregulation of PI3K and Hippo signaling induces CP via CTGF upregulation.

FOXD1 promotes dedifferentiation and targeted therapy resistance in melanoma by regulating the expression of connective tissue growth factor

Metastatic melanoma is an aggressive skin cancer and associated with a poor prognosis. In clinical terms, targeted therapy is one of the most important treatments for patients with BRAF^V600E -mutated advanced melanoma. However, the development of resistance to this treatment compromises its therapeutic success. We previously demonstrated that forkhead box D1 (FOXD1) regulates melanoma migration and invasion. Here, we found that FOXD1 was highly expressed in melanoma cells and was associated with a poor survival of patients with metastatic melanoma. Upregulation of FOXD1 expression enhanced melanoma cells' resistance to vemurafenib (BRAF inhibitor [BRAFi]) or vemurafenib and cobimetinib (MEK inhibitor) combination treatment whereas loss of FOXD1 increased the sensitivity to treatment. By comparing gene expression levels between FOXD1 knockdown (KD) and overexpressing (OE) cells, we identified the connective tissue growth factor (CTGF) as a downstream factor of FOXD1. Chromatin immunoprecipitation and luciferase assay demonstrated the direct binding of FOXD1 to the CTGF promoter. Similar to FOXD1, knockdown of CTGF increased the sensitivity of BRAFi-resistant cells to vemurafenib. FOXD1 KD cells treated with recombinant CTGF protein were less sensitive towards vemurafenib compared to untreated FOXD1 KD cells. Based on these findings, we conclude that FOXD1 might be a promising new diagnostic marker and a therapeutic target for the treatment of targeted therapy resistant melanoma.

CCN2 (Cellular Communication Network factor 2) in the bone marrow microenvironment, normal and malignant hematopoiesis

CCN2, formerly termed Connective Tissue Growth Factor, is a protein belonging to the Cellular Communication Network (CCN)-family of secreted extracellular matrix-associated proteins. As a matricellular protein it is mainly considered to be active as a modifier of signaling activity of several different signaling pathways and as an orchestrator of their cross-talk. Furthermore, CCN2 and its fragments have been implicated in the regulation of a multitude of biological processes, including cell proliferation, differentiation, adhesion, migration, cell survival, apoptosis and the production of extracellular matrix products, as well as in more complex processes such as embryonic development, angiogenesis, chondrogenesis, osteogenesis, fibrosis, mechanotransduction and inflammation. Its function is complex and context dependent, depending on cell type, state of differentiation and microenvironmental context. CCN2 plays a role in many diseases, especially those associated with fibrosis, but has also been implicated in many different forms of cancer. In the bone marrow (BM), CCN2 is highly expressed in mesenchymal stem/stromal cells (MSCs). CCN2 is important for MSC function, supporting its proliferation, migration and differentiation. In addition, stromal CCN2 supports the maintenance and longtime survival of hematopoietic stem cells, and in the presence of interleukin 7, stimulates the differentiation of pro-B lymphocytes into pre-B lymphocytes. Overexpression of CCN2 is seen in the majority of B-acute lymphoblastic leukemias, especially in certain cytogenetic subgroups associated with poor outcome. In acute myeloid leukemia, CCN2 expression is increased in MSCs, which has been associated with leukemic engraftment in vivo. In this review, the complex function of CCN2 in the BM microenvironment and in normal as well as malignant hematopoiesis is discussed. In addition, an overview is given of data on the remaining CCN family members regarding normal and malignant hematopoiesis, having many similarities and some differences in their function.

Extracellular Vesicles From Hepatocytes Are Therapeutic for Toxin-Mediated Fibrosis and Gene Expression in the Liver

Extracellular vesicles (EVs) are nano-sized membrane-limited organelles that are liberated from their producer cells, traverse the intercellular space, and may interact with other cells resulting in the uptake of the EV molecular payload by the recipient cells which may become functionally reprogramed as a result. Previous in vitro studies showed that EVs purified from normal mouse AML12 hepatocytes ("EVNorm") attenuate the pro-fibrogenic activities of activated hepatic stellate cells (HSCs), a principal fibrosis-producing cell type in the liver. In a 10-day CCl4 injury model, liver fibrogenesis, expression of hepatic cellular communication network factor 2 [CCN2, also known as connective tissue growth factor (CTGF)] or alpha smooth muscle actin (αSMA) was dose-dependently blocked during concurrent administration of EVNorm. Hepatic inflammation and expression of inflammatory cytokines were also reduced by EVNorm. In a 5-week CCl4 fibrosis model in mice, interstitial collagen deposition and mRNA and/or protein for collagen 1a1, αSMA or CCN2 were suppressed following administration of EVNorm over the last 2 weeks. RNA sequencing (RNA-seq) revealed that EVNorm therapy of mice receiving CCl4 for 5 weeks resulted in significant differences [false discovery rate (FDR) <0.05] in expression of 233 CCl4-regulated hepatic genes and these were principally associated with fibrosis, cell cycle, cell division, signal transduction, extracellular matrix (ECM), heat shock, cytochromes, drug detoxification, adaptive immunity, and membrane trafficking. Selected gene candidates from these groups were verified by qRT-PCR as targets of EVNorm in CCl4-injured livers. Additionally, EVNorm administration resulted in reduced activation of p53, a predicted upstream regulator of 40% of the genes for which expression was altered by EVNorm following CCl4 liver injury. In vitro, EVs from human HepG2 hepatocytes suppressed fibrogenic gene expression in activated mouse HSC and reversed the reduced viability or proliferation of HepG2 cells or AML12 cells exposed to CCl4. Similarly, EVs produced by primary human hepatocytes (PHH) protected PHH or human LX2 HSC from CCl4-mediated changes in cell number or gene expression in vitro. These findings show that EVs from human or mouse hepatocytes regulate toxin-associated gene expression leading to therapeutic outcomes including suppression of fibrogenesis, hepatocyte damage, and/or inflammation.

Systemic inflammation contributes to impairment of quality of life in chronic pancreatitis

Chronic pancreatitis (CP) is a fibrotic disorder of the pancreas leading to clinical sequelae like pain and an excess of comorbidity including cardiovascular disease and cancers. The aim of this study was to determine the relationship between systemic inflammation and quality of life in patients with CP. Patients were prospectively recruited and underwent a quality of life assessment (EORTC QLQ-C30 and PAN 28). The serum inflammatory profile was assessed using an MSD 30-plex array. The relationship between clinical variables, inflammatory cytokines and quality of life was determined by a GLM-MANOVA and the individual impact of significant variables evaluated by a second ANOVA. In total, 211 patients with a median age of 53 years were recruited across 5 European centres. Gender, age, nicotine and alcohol abuse were clinical variables associated with altered quality of life. Systemic inflammation with high levels of pro-inflammatory cytokines (Eotaxin, IL-1β, IL-7, IL-8, IL-12/IL-23p40, IL-12p70, IL-13, IL-16, IP-10, MCP-1, MCP-4, MDC, MIP-1a, TARC, TNFß) was associated with diminished quality of life in general and specific domains including pain, physical and cognitive functioning. As conclusion, CP is associated with a systemic inflammatory response that has a negative impact on quality of life and accelerates aging.

Heterogeneous macrophages: Supersensors of exogenous inducing factors

As heterogeneous immune cells, macrophages mount effective responses to various internal and external changes during disease progression. Macrophage polarization, rather than macrophage heterogenization, is often used to describe the functional differences between macrophages. While macrophage polarization partially contributes to heterogeneity, it does not completely explain the concept of macrophage heterogeneity. At the same time, there are abundant and sophisticated endogenous and exogenous substances that can affect macrophage heterogeneity. While the research on endogenous factors has been systematically reviewed, the findings on exogenous factors have not been well summarized. Hence, we reviewed the characteristics and inducing factors of heterogeneous macrophages to reveal their functional plasticity as well as their targeting manoeuvreability. In the process of constructing and analysing a network organized by disease-related cells and molecules, paying more attention to heterogeneous macrophages as mediators of this network may help to explore a novel entry point for early prevention of and intervention in disease.

Role of Epidermal Growth Factor Receptor (EGFR) and Its Ligands in Kidney Inflammation and Damage

Chronic kidney disease (CKD) is characterized by persistent inflammation and progressive fibrosis, ultimately leading to end-stage renal disease. Although many studies have investigated the factors involved in the progressive deterioration of renal function, current therapeutic strategies only delay disease progression, leaving an unmet need for effective therapeutic interventions that target the cause behind the inflammatory process and could slow down or reverse the development and progression of CKD. Epidermal growth factor receptor (EGFR) (ERBB1), a membrane tyrosine kinase receptor expressed in the kidney, is activated after renal damage, and preclinical studies have evidenced its potential as a therapeutic target in CKD therapy. To date, seven official EGFR ligands have been described, including epidermal growth factor (EGF) (canonical ligand), transforming growth factor-α, heparin-binding epidermal growth factor, amphiregulin, betacellulin, epiregulin, and epigen. Recently, the connective tissue growth factor (CTGF/CCN2) has been described as a novel EGFR ligand. The direct activation of EGFR by its ligands can exert different cellular responses, depending on the specific ligand, tissue, and pathological condition. Among all EGFR ligands, CTGF/CCN2 is of special relevance in CKD. This growth factor, by binding to EGFR and downstream signaling pathway activation, regulates renal inflammation, cell growth, and fibrosis. EGFR can also be “transactivated” by extracellular stimuli, including several key factors involved in renal disease, such as angiotensin II, transforming growth factor beta (TGFB), and other cytokines, including members of the tumor necrosis factor superfamily, showing another important mechanism involved in renal pathology. The aim of this review is to summarize the contribution of EGFR pathway activation in experimental kidney damage, with special attention to the regulation of the inflammatory response and the role of some EGFR ligands in this process. Better insights in EGFR signaling in renal disease could improve our current knowledge of renal pathology contributing to therapeutic strategies for CKD development and progression.

Therapeutic effects of serum extracellular vesicles in liver fibrosis

The lack of approved therapies for hepatic fibrosis seriously limits medical management of patients with chronic liver disease. Since extracellular vesicles (EVs) function as conduits for intercellular molecular transfer, we investigated if EVs from healthy individuals have anti-fibrotic properties. Hepatic fibrogenesis or fibrosis in carbon tetrachloride (CCl₄)- or thioacetic acid-induced liver injury models in male or female mice were suppressed by serum EVs from normal mice (EVN) but not from fibrotic mice (EVF). CCl₄-treated mice undergoing EVN therapy also exhibited reduced levels of hepatocyte death, inflammatory infiltration, circulating AST/ALT levels and hepatic or circulating pro-inflammatory cytokines. Hepatic histology, liver function tests or circulating proinflammatory cytokine levels were unaltered in control mice receiving EVN. As determined using PKH26-labelled EVN, principal target cells included hepatic stellate cells (HSC; a normally quiescent fibroblastic cell that undergoes injury-induced activation and produces fibrosis during chronic injury) or hepatocytes which showed increased EVN binding after, respectively, activation or exposure to CCl₄. In vitro, EVN decreased proliferation and fibrosis-associated molecule expression in activated HSC, while reversing the inhibitory effects of CCl₄ or ethanol on hepatocyte proliferation. In mice, microRNA-34c, -151-3p, -483-5p, -532-5p and -687 were more highly expressed in EVN than EVF and mimics of these microRNAs (miRs) individually suppressed fibrogenic gene expression in activated HSC. A role for these miRs in contributing to EVN actions was shown by the ability of their corresponding antagomirs to individually and/or collectively block the therapeutic effects of EVN on activated HSC or injured hepatocytes. Similarly, the activated phenotype of human LX-2 HSC was attenuated by serum EVs from healthy human subjects and contained higher miR-34c, -151-3p, -483-5p or -532-5p than EVs from hepatic fibrosis patients. In conclusion, serum EVs from normal healthy individuals are inherently anti-fibrogenic and anti-fibrotic, and contain microRNAs that have therapeutic actions in activated HSC or injured hepatocytes.

Abbreviations: ALT: alanine aminotransferase; AST: aspartate aminotransferase; CCl₄: carbon tetrachloride; CCN2: connective tissue growth factor; E: eosin; EGFP: enhanced green fluorescent protein; EVs: extracellular vesicles; EVF: serum EVs from mice with experimental hepatic fibrosis; EVN: serum EVs from normal mice; H: hematoxylin; HSC: hepatic stellate cell; IHC: immunohistochemistry; IL: interleukin; MCP-1: monocyte chemotactic protein-1; miR: microRNA; mRNA: messenger RNA; NTA: nanoparticle tracking analysis; PCNA: proliferating cell nuclear antigen; qRT-PCR: quantitative real-time polymerase chain reaction; SDS-PAGE: sodium dodecyl sulphate – polyacrylamide gel electrophoresis; αSMA: alpha smooth muscle actin; TAA: thioacetic acid; TG: transgenic; TGF-β: transforming growth factor beta; TEM: transmission electron microscopy; TNFα: tumour necrosis factor alpha.

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

Background

Systemic 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.

Methods

Angiotensin 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.

Results

Ang 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.

Conclusions

Our data indicate that inhibition of CTGF signaling presents an attractive therapeutic approach in SSc.

Expression of connective tissue growth factor in the livers of non-viral hepatocellular carcinoma patients with metabolic risk factors

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) associated with metabolic risk factors, such as diabetes and obesity, has been increasing. However, the underlying mechanism that links these diseases remains unclear.

METHODS

We performed genome-wide expression analysis of human liver tissues of non-viral HCC patients with or without metabolic risk factors. The upregulated genes that associated with diabetes and obesity were investigated by in vitro and in vivo experiments, and immunohistochemistry of human liver tissues was performed.

RESULTS

Among the upregulated genes, connective tissue growth factor (CTGF) expression was induced to a greater extent by combined glucose and insulin administration to human hepatoma cells. Genome-wide expression analysis revealed upregulation of a chemokine network in CTGF-overexpressing hepatoma cells, which displayed an increased ability to induce in vitro activation of macrophages, and in vivo infiltration of liver macrophages. Immunohistochemistry of human liver tissues validated the correlations between CTGF expression and diabetes or obesity as well as activation of liver macrophages in patients with non-viral HCC. Recurrence-free survival was significantly poorer in the CTGF-positive patients compared with the CTGF-negative patients (p = 0.002). Multivariate analysis determined that CTGF expression (HR 2.361; 95 % CI 1.195-4.665; p = 0.013) and vascular invasion (HR 2.367; 95 % CI 1.270-4.410; p = 0.007) were independent prognostic factors for recurrence of non-viral HCC.

CONCLUSIONS

Our data suggest that CTGF could be involved in oncogenic pathways promoting non-viral HCC associated with metabolic risk factors via induction of liver inflammation and is expected to be a novel HCC risk biomarker and potential therapeutic target.

Endoscopic Pancreas Fluid Collection: Methods and Relevance for Clinical Care and Translational Science

Pancreatic secretions have an important role in the regulation of a normal nutritional state but can be altered owing to a variety of pathophysiological mechanisms in the context of exocrine pancreatic disease. The development of an endoscopic technique for collection of pancreatic fluid, termed endoscopic pancreatic function testing, has led to improved understanding of these alterations and is particularly helpful to characterize chronic pancreatitis. In addition, investigators have found endoscopically collected pancreatic fluid to be a valuable biofluid for the purposes of translational science. Techniques such as proteomic, cytokine, genetic mutation, DNA methylation, and microRNA analyses, among others, can be utilized to gain a better understanding of the molecular characteristics of chronic pancreatitis and other pancreatic diseases. Endoscopic collection of pancreatic fluid is safe and relatively straightforward, permitting opportunities for longitudinal analysis of these translational markers throughout the course of disease. This manuscript summarizes our current knowledge of pancreatic fluid, with an emphasis on proper techniques for sample collection and handling, its clinical utility, and preliminary observations in translational science.

NF-κB Enhances Androgen Receptor Expression through 5′-UTR Binding in Gingival Cells

Dihydropyridine-induced gingival overgrowth (DIGO) is a side effect observed in patients treated for hypertension. The disease is aggravated by inflammation. Nifedipine (Nif), a dihydropyridine, causes gingival overgrowth by increasing the expression of the androgen receptor (AR). Furthermore, the proinflammatory cytokine interleukin 1β (IL-1β) induces collagen α1(I) expression through the AR in DIGO fibroblasts. These observations prompted us to investigate whether and how nuclear factor kappa B (NF-κB) affects AR expression in DIGO. Therefore, gingival fibroblasts obtained from the tissues of patients with DIGO and healthy subjects were stimulated with IL-1β, Nif, or both. mRNA and protein expression was detected with real-time polymerase chain reaction and Western blotting. High correlation coefficients were observed for the mRNA expression of the AR, connective tissue growth factor, and collagen α1(I) induced by both drugs. Western blot analysis showed that IL-1β and Nif increased and activated NF-κB more in DIGO cells than in healthy cells. An electrophoretic mobility shift assay demonstrated that the promoter and 5′-untranslated regions (5′-UTRs) of the AR gene contains 3 binding sites for the NF-κB p65 subunit. A chromatin immunoprecipitation assay revealed that the NF-κB p65 subunit was associated with AR 5′-UTRs in gingival fibroblasts. A site-directed mutagenesis study indicated that a mutation of NF-κB binding sites reduced Nif- and IL-1β-induced AR promoter activities. Collectively, these data indicate that NF-κB is an essential transcriptional regulator of AR gene expression and thus plays a crucial role in collagen overproduction in DIGO fibroblasts.

Macrophages are essential for CTGF-mediated adult β-cell proliferation after injury

Objective

Promotion of endogenous β-cell mass expansion could facilitate regeneration in patients with diabetes. We discovered that the secreted protein CTGF (aka CCN2) promotes adult β-cell replication and mass regeneration after injury via increasing β-cell immaturity and shortening the replicative refractory period. However, the mechanism of CTGF-mediated β-cell proliferation is unknown. Here we focused on whether CTGF alters cells of the immune system to enhance β-cell replication.

Methods

Using mouse models for 50% β-cell ablation and conditional, β-cell-specific CTGF induction, we assessed changes in immune cell populations by performing immunolabeling and gene expression analyses. We tested the requirement for macrophages in CTGF-mediated β-cell proliferation via clodronate-based macrophage depletion.

Results

CTGF induction after 50% β-cell ablation increased both macrophages and T-cells in islets. An upregulation in the expression of several macrophage and T-cell chemoattractant genes was also observed in islets. Gene expression analyses suggest an increase in M1 and a decrease in M2 macrophage markers. Depletion of macrophages (without changes in T cell number) blocked CTGF-mediated β-cell proliferation and prevented the increase in β-cell immaturity.

Conclusions

Our data show that macrophages are critical for CTGF-mediated adult β-cell proliferation in the setting of partial β-cell ablation. This is the first study to link a specific β-cell proliferative factor with immune-mediated β-cell proliferation in a β-cell injury model.

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Following partial beta cell ablation, induction of CTGF in beta cells increases the number of pancreatic macrophages and T cells.

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Increased macrophages are found preferentially within islets.

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Expression of genes involved in macrophage and T cell chemoattraction is increased in islets following CTGF induction.

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Depletion of macrophages completely abrogates CTGF-mediated increases in beta cell proliferation after injury.