CCN3 (NOV) is a novel angiogenic regulator of the CCN protein family

An overview of CCN4 (WISP1) role in human diseases

CCN4 (cellular communication network factor 4), a highly conserved, secreted cysteine-rich matricellular protein is emerging as a key player in the development and progression of numerous disease pathologies, including cancer, fibrosis, metabolic and inflammatory disorders. Over the past two decades, extensive research on CCN4 and its family members uncovered their diverse cellular mechanisms and biological functions, including but not limited to cell proliferation, migration, invasion, angiogenesis, wound healing, repair, and apoptosis. Recent studies have demonstrated that aberrant CCN4 expression and/or associated downstream signaling is key to a vast array of pathophysiological etiology, suggesting that CCN4 could be utilized not only as a non-invasive diagnostic or prognostic marker, but also as a promising therapeutic target. The cognate receptor of CCN4 remains elusive till date, which limits understanding of the mechanistic insights on CCN4 driven disease pathologies. However, as therapeutic agents directed against CCN4 begin to make their way into the clinic, that may start to change. Also, the pathophysiological significance of CCN4 remains underexplored, hence further research is needed to shed more light on its disease and/or tissue specific functions to better understand its clinical translational benefit. This review highlights the compelling evidence of overlapping and/or diverse functional and mechanisms regulated by CCN4, in addition to addressing the challenges, study limitations and knowledge gaps on CCN4 biology and its therapeutic potential.

Single-cell transcriptome analysis of cavernous tissues reveals the key roles of pericytes in diabetic erectile dysfunction

Erectile dysfunction (ED) affects a significant proportion of men aged 40-70 and is caused by cavernous tissue dysfunction. Presently, the most common treatment for ED is phosphodiesterase 5 inhibitors; however, this is less effective in patients with severe vascular disease such as diabetic ED. Therefore, there is a need for development of new treatment, which requires a better understanding of the cavernous microenvironment and cell-cell communications under diabetic condition. Pericytes are vital in penile erection; however, their dysfunction due to diabetes remains unclear. In this study, we performed single-cell RNA sequencing to understand the cellular landscape of cavernous tissues and cell type-specific transcriptional changes in diabetic ED. We found a decreased expression of genes associated with collagen or extracellular matrix organization and angiogenesis in diabetic fibroblasts, chondrocytes, myofibroblasts, valve-related lymphatic endothelial cells, and pericytes. Moreover, the newly identified pericyte-specific marker, Limb Bud-Heart (Lbh), in mouse and human cavernous tissues, clearly distinguishing pericytes from smooth muscle cells. Cell-cell interaction analysis revealed that pericytes are involved in angiogenesis, adhesion, and migration by communicating with other cell types in the corpus cavernosum; however, these interactions were highly reduced under diabetic conditions. Lbh expression is low in diabetic pericytes, and overexpression of LBH prevents erectile function by regulating neurovascular regeneration. Furthermore, the LBH-interacting proteins (Crystallin Alpha B and Vimentin) were identified in mouse cavernous pericytes through LC-MS/MS analysis, indicating that their interactions were critical for maintaining pericyte function. Thus, our study reveals novel targets and insights into the pathogenesis of ED in patients with diabetes.

CD4+CD25+ regulatory T cells ex vivo generated from autologous naïve CD4+ T cells suppress EAE progression

CD4+CD25+ regulatory T cells (Tregs) play an important role in maintaining immune homeostasis in multiple sclerosis (MS). Hence, we aimed to explore the therapeutic efficacy and safety of adoptive cell therapy (ACT) utilizing induced antigen-specific Tregs in an animal model of MS, that is, in an experimental autoimmune encephalomyelitis (EAE) model. B cells from EAE model that were activated with soluble CD40L were used as antigen-presenting cells (APCs) to induce the differentiation of antigen-specific Tregs from naïve CD4 precursors, and then, a stepwise isolation of CD4+CD25highCD127low Tregs was performed using a flow sorter. All EAE mice were divided into Treg-treated group (2 × 104 cells in 0.2 mL per mouse, n = 14) and sham-treated group (0.2 mL normal saline (NS), n = 20), which were observed daily for clinical assessment, and for abnormal appearance for 6 weeks. Afterward, histological analysis, immunofluorescence and real-time PCR were performed. Compared to sham-treated mice, Treg-treated mice exhibited a significant decrease in disease severity scores and reduced inflammatory infiltration and demyelination in the spinal cord. Additionally, Tregs-treated mice demonstrated higher CCN3 protein and mRNA levels than sham-treated mice. The results of this preclinical study further support the therapeutic potential of this ACT approach in the treatment of MS.

Novel mediators regulating angiogenesis in diabetic foot ulcer healing

A non-healing diabetic foot ulcer (DFU) is a debilitating clinical problem amounting to socioeconomic and psychosocial burdens. DFUs increase morbidity due to prolonged treatment and mortality in the case of non-treatable ulcers resulting in gangrene and septicemia. The overall amputation rate of the lower extremity with DFU ranges from 3.34% to 42.83%. Wound debridement, antibiotics, applying growth factors, negative pressure wound therapy, hyperbaric oxygen therapy, topical oxygen, and skin grafts are common therapies for DFU. However, recurrence and nonhealing ulcers are still major issues. Chronicity of inflammation, hypoxic environment, poor angiogenesis, and decreased formation of the extracellular matrix (ECM) are common impediments leading to nonhealing patterns of DFUs. Angiogenesis is crucial for wound healing since proper vessel formation facilitates nutrients, oxygen, and immune cells to the ulcer tissue to help in clearing out debris and facilitate healing. However, poor angiogenesis due to decreased expression of angiogenic mediators and matrix formation results in nonhealing and ultimately amputation. Multiple proangiogenic mediators and vascular endothelial growth factor (VEGF) therapy exist to enhance angiogenesis, but the results are not satisfactory. Thus, there is a need to investigate novel pro-angiogenic mediators that can either alone or in combination enhance the angiogenesis and healing of DFUs. In this article, we critically reviewed the existing pro-angiogenic mediators followed by potentially novel factors that might play a regulatory role in promoting angiogenesis and wound healing in DFUs.

Association between endothelin-1 and systemic lupus erythematosus: insights from a case-control study

Systemic lupus erythematosus (SLE) is a chronic rheumatic disorder. Endothelin-1, a vasoconstrictor, belongs to the endothelin family and is associated with vascular-related damages. To date, association between ET-1 and pathogenesis of SLE remains unclear. This case-control study was carried out by 314 SLE, 252 non-SLE diseases patients and 500 healthy controls. Serum ET-1, CCN3, IL-28B levels were detected by ELISA, and ET-1 gene polymorphisms (rs5369, rs5370, rs1476046, rs2070699, rs2071942, rs2071943, rs3087459, rs4145451, rs6458155, rs9369217) were genotyped with Kompetitive Allele-Specific PCR. SLE patients had high levels of ET-1, which were correlated with some clinical, laboratory features. Serum CCN3, IL-28B levels were higher in SLE patients, and ET-1 levels were positively correlated with the two cytokines. Rs5370, rs1476046, rs2070699, rs2071942, rs2071943, rs3087459, rs6458155 and rs2070699 were associated with SLE risk. Rs2070699 (T, TT) was related to SLE patients with alopecia. Rs5370 (T, TT, TG), rs1476046 (G,GA), rs2071942 (G,GA) and rs2071943 (G,GA) were associated with SLE patients with pericarditis, pyuria and fever manifestation, respectively. Rs3087459 (CC) and rs9369217 (TC) were related to SLE patients with positive anti-SSB antibody. Rs5369 (AA) was associated with IgG and CRP levels in SLE patients. In conclusion, elevated serum ET-1 in SLE patients may be a potential disease marker, and its gene polymorphisms were related to SLE susceptibility.

The advance of CCN3 in fibrosis

The extracellular matrix (ECM) is comprised of various extracellular macromolecules, including collagen, enzymes, and glycoproteins, which offer structural and biochemical support to neighboring cells. After tissue injury, extracellular matrix proteins deposit in the damaged tissue to promote tissue healing. However, an imbalance between ECM production and degradation can result in excessive deposition, leading to fibrosis and subsequent organ dysfunction. Acting as a regulatory protein within the extracellular matrix, CCN3 plays a crucial role in numerous biological processes, such as cell proliferation, angiogenesis, tumorigenesis, and wound healing. Many studies have demonstrated that CCN3 can reduce the production of ECM in tissues through diverse mechanisms thereby exerting an inhibitory effect on fibrosis. Consequently, CCN3 emerges as a promising therapeutic target for ameliorating fibrosis.

WISP2 downregulation inhibits the osteogenic differentiation of BMSCs in congenital scoliosis by regulating Wnt/β-catenin pathway

OBJECTIVES

Bone marrow mesenchymal stem cells (BMSCs) are instrumental in bone development, metabolism, and marrow microenvironment homeostasis. Despite this, the relevant effects and mechanisms of BMSCs on congenital scoliosis (CS) remain undefined. Herein, it becomes our focus to reveal the corresponding effects and mechanisms implicated.

METHODS

BMSCs from CS patients (hereafter referred as CS-BMSCs) and healthy donors (NC-BMSCs) were observed and identified. Differentially expressed genes in BMSCs were analyzed utilizing scRNA-seq and RNA-seq profiles. The multi-differentiation potential of BMSCs following the transfection or infection was evaluated. The expression levels of factors related to osteogenic differentiation and Wnt/β-catenin pathway were further determined as appropriate.

RESULTS

A decreased osteogenic differentiation ability was shown in CS-BMSCs. Both the proportion of LEPR⁺ BMSCs and the expression level of WNT1-inducible-signaling pathway protein 2 (WISP2) were decreased in CS-BMSCs. WISP2 knockdown suppressed the osteogenic differentiation of NC-BMSCs, while WISP2 overexpression facilitated the osteogenesis of CS-BMSCs via acting on the Wnt/β-catenin pathway.

CONCLUSIONS

Our study collectively indicates WISP2 knockdown blocks the osteogenic differentiation of BMSCs in CS by regulating Wnt/β-catenin signaling, thus providing new insights into the aetiology of CS.

Do not overwork: cellular communication network factor 3 for life in cartilage

Cellular communication network factor (CCN) 3, which is one of the founding members of the CCN family, displays diverse functions. However, this protein generally represses the proliferation of a variety of cells. Along with skeletal development, CCN3 is produced in cartilaginous anlagen, growth plate cartilage and epiphysial cartilage. Interestingly, CCN3 is drastically induced in the growth plates of mice lacking CCN2, which promotes endochondral ossification. Notably, chondrocytes in these mutant mice with elevated CCN3 production also suffer from impaired glycolysis and energy metabolism, suggesting a critical role of CCN3 in cartilage metabolism. Recently, CCN3 was found to be strongly induced by impaired glycolysis, and in our study, we located an enhancer that mediated CCN3 regulation via starvation. Subsequent investigations specified regulatory factor binding to the X-box 1 (RFX1) as a transcription factor mediating this CCN3 regulation. Impaired glycolysis is a serious problem, resulting in an energy shortage in cartilage without vasculature. CCN3 produced under such starved conditions restricts energy consumption by repressing cell proliferation, leading chondrocytes to quiescence and survival. This CCN3 regulatory system is indicated to play an important role in articular cartilage maintenance, as well as in skeletal development. Furthermore, CCN3 continues to regulate cartilage metabolism even during the aging process, probably utilizing this regulatory system. Altogether, CCN3 seems to prevent "overwork" by chondrocytes to ensure their sustainable life in cartilage by sensing energy metabolism. Similar roles are suspected to exist in relation to systemic metabolism, since CCN3 is found in the bloodstream.

The matricellular protein CCN3 supports lung endothelial homeostasis and function

Aberrant vascular remodeling contributes to the progression of many aging-associated diseases, including idiopathic pulmonary fibrosis (IPF), where heterogeneous capillary density, endothelial transcriptional alterations, and increased vascular permeability correlate with poor disease outcomes. Thus, identifying disease-driving mechanisms in the pulmonary vasculature may be a promising strategy to limit IPF progression. Here, we identified Ccn3 as an endothelial-derived factor that is upregulated in resolving but not in persistent lung fibrosis in mice, and whose function is critical for vascular homeostasis and repair. Loss and gain of function experiments were carried out to test the role of CCN3 in lung microvascular endothelial function in vitro through RNAi and the addition of recombinant human CCN3 protein, respectively. Endothelial migration, permeability, proliferation, and in vitro angiogenesis were tested in cultured human lung microvascular endothelial cells (ECs). Loss of CCN3 in lung ECs resulted in transcriptional alterations along with impaired wound-healing responses, in vitro angiogenesis, barrier integrity as well as an increased profibrotic activity through paracrine signals, whereas the addition of recombinant CCN3 augmented endothelial function. Altogether, our results demonstrate that the matricellular protein CCN3 plays an important role in lung endothelial function and could serve as a promising therapeutic target to facilitate vascular repair and promote lung fibrosis resolution.

Matricellular proteins in cutaneous wound healing

Cutaneous wound healing is a complex process that encompasses alterations in all aspects of the skin including the extracellular matrix (ECM). ECM consist of large structural proteins such as collagens and elastin as well as smaller proteins with mainly regulative properties called matricellular proteins. Matricellular proteins bind to structural proteins and their functions include but are not limited to interaction with cell surface receptors, cytokines, or protease and evoking a cellular response. The signaling initiated by matricellular proteins modulates differentiation and proliferation of cells having an impact on the tissue regeneration. In this review we give an overview of the matricellular proteins that have been found to be involved in cutaneous wound healing and summarize the information known to date about their functions in this process.

The novel transcriptomic signature of angiogenesis predicts clinical outcome, tumor microenvironment and treatment response for prostate adenocarcinoma

Angiogenesis plays the critical roles in promoting tumor progression, aggressiveness, and metastasis. Although few studies have revealed some angiogenesis-related genes (ARGs) could serve as prognosis-related biomarkers for the prostate cancer (PCa), the integrated role of ARGs has not been systematically studied. The RNA-sequencing data and clinical information of prostate adenocarcinoma (PRAD) were downloaded from The Cancer Genome Atlas (TCGA) as discovery dataset. Twenty-three ARGs in total were identified to be correlated with prognosis of PRAD by the univariate Cox regression analysis, and a 19-ARG signature was further developed with significant correlation with the disease-free survival (DFS) of PRAD by the least absolute shrinkage and selection operator (LASSO) Cox regression with tenfold cross-validation. The signature stratified PRAD patients into high- and low-ARGs signature score groups, and those with high ARGs signature score were associated with significantly poorer outcomes (median DFS: 62.71 months vs unreached, p < 0.0001). The predicting ability of ARGs signature was subsequently validated in two independent cohorts of GSE40272 & PRAD_MSKCC. Notably, the 19-ARG signature outperformed the typical clinical features or each involved ARG in predicting the DFS of PRAD. Furthermore, a prognostic nomogram was constructed with three independent prognostic factors, including the ARGs signature, T stage and Gleason score. The predicted results from the nomogram (C-index = 0.799, 95%CI = 0.744-0.854) matched well with the observed outcomes, which was verified by the calibration curves. The values of area under receiver operating characteristic curve (AUC) for DFS at 1-, 3-, 5-year for the nomogram were 0.82, 0.83, and 0.83, respectively, indicating the performance of nomogram model is of reasonably high accuracy and robustness. Moreover, functional enrichment analysis demonstrated the potential targets of E2F targets, G2M checkpoint pathways, and cell cycle pathways to suppress the PRAD progression. Of note, the high-risk PRAD patients were more sensitive to immune therapies, but Treg might hinder benefits from immunotherapies. Additionally, this established tool also could predict response to neoadjuvant androgen deprivation therapy (ADT) and some chemotherapy drugs, such as cisplatin, paclitaxel, and docetaxel, etc. The novel ARGs signature, with prognostic significance, can further promote the application of targeted therapies in different stratifications of PCa patients.

Hypoxia-induced inhibin promotes tumor growth and vascular permeability in ovarian cancers

Hypoxia, a driver of tumor growth and metastasis, regulates angiogenic pathways that are targets for vessel normalization and ovarian cancer management. However, toxicities and resistance to anti-angiogenics can limit their use making identification of new targets vital. Inhibin, a heteromeric TGFβ ligand, is a contextual regulator of tumor progression acting as an early tumor suppressor, yet also an established biomarker for ovarian cancers. Here, we find that hypoxia increases inhibin levels in ovarian cancer cell lines, xenograft tumors, and patients. Inhibin is regulated primarily through HIF-1, shifting the balance under hypoxia from activins to inhibins. Hypoxia regulated inhibin promotes tumor growth, endothelial cell invasion and permeability. Targeting inhibin in vivo through knockdown and anti-inhibin strategies robustly reduces permeability in vivo and alters the balance of pro and anti-angiogenic mechanisms resulting in vascular normalization. Mechanistically, inhibin regulates permeability by increasing VE-cadherin internalization via ACVRL1 and CD105, a receptor complex that we find to be stabilized directly by inhibin. Our findings demonstrate direct roles for inhibins in vascular normalization via TGF-β receptors providing new insights into the therapeutic significance of inhibins as a strategy to normalize the tumor vasculature in ovarian cancer.

Hypoxia increases levels of the heteromeric TGFβ ligand inhibin in ovarian cancer and inhibin promotes tumor growth, endothelial cell invasion and permeability.

Multi-Omics Analysis After Vaginal Administration of Bacteroides fragilis in Chickens

The reproductive tract of chickens is an important organ for egg formation. The vagina is in close contact with the external environment, which may lead to the invasion of a variety of pathogenic bacteria, affect the internal and external quality of eggs, and even increase mortality and cause economic loss. In recent years, probiotics as a substitute for antibiotics have brought economic benefits in livestock and poultry production. In the present study, we investigated the effects of vaginal administration of Bacteroides fragilis on the cloacal microbiota, vaginal transcriptome and metabolomics of chickens and evaluated the beneficial potential of B. fragilis. The results showed that B. fragilis treatment could affect the microbial composition of the cloaca. Transcriptome analysis found that the immune-related genes CCN3, HAS2, and RICTOR were upregulated, that the inflammatory genes EDNRB, TOX, and NKX2-3 were downregulated, and that DEGs were also enriched in the regulation of the inflammatory response, cellular metabolism, and synaptic response pathways. In addition, the differential metabolites were mainly related to steroid hormone biosynthesis, unsaturated fatty acid biosynthesis, and arachidonic acid metabolism, and we identified associations between specific differential metabolites and genes. Overall, this study provides a theoretical basis for the application of B. fragilis as a potential probiotic in livestock and poultry production.

3D-printed dermis-specific extracellular matrix mitigates scar contraction via inducing early angiogenesis and macrophage M2 polarization

Scar contraction frequently happens in patients with deep burn injuries. Hitherto, porcine dermal extracellular matrix (dECM) has supplied microenvironments that assist in wound healing but fail to inhibit scar contraction. To overcome this drawback, we integrate dECM into three-dimensional (3D)-printed dermal analogues (PDA) to prevent scar contraction. We have developed thermally gelled, non-rheologically modified dECM powder (dECMp) inks and successfully transformed them into PDA that was endowed with a micron-scale spatial structure. The optimal crosslinked PDA exhibited desired structure, good mechanical properties as well as excellent biocompatibility. Moreover, in vivo experiments demonstrated that PDA could significantly reduced scar contraction and improved cosmetic upshots of split thickness skin grafts (STSG) than the commercially available dermal templates and STSG along. The PDA has also induced an early, intense neovascularization, and evoked a type-2-like immune response. PDA's superior beneficial effects may attribute to their desired porous structure, the well-balanced physicochemical properties, and the preserved dermis-specific ECM cues, which collectively modulated the expression of genes such as Wnt11, ATF3, and IL1β, and influenced the crucial endogenous signalling pathways. The findings of this study suggest that PDA is a clinical translatable material that possess high potential in reducing scar contraction.

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Current dermal analogues have supplied microenvironments that assist in wound healing but cannot inhibit scar contraction.

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dECMp ink was formulated and transformed into PDA endowed with a micron-scale designed spatial structure.

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The PDAs were neatly superior to split thickness skin grafts and commercial dermal templates in hindering scar contraction.

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The transcriptome data may reveal how at the molecular level the IS and skin wounds respond to biomaterial stimuli.

Cellular communication network factor 3 in cartilage development and maintenance

Cellular communication network factor (CCN) 3 is one of the classical members of the CCN family, which are characterized by common molecular structures and multiple functionalities. Although this protein was discovered as a gene product overexpressed in a truncated form in nephroblastoma, recent studies have revealed its physiological roles in the development and homeostasis of mammalian species, in addition to its pathological association with a number of diseases. Cartilage is a tissue that creates most of the bony parts and cartilaginous tissues that constitute the human skeleton, in which CCN3 is also differentially produced to exert its molecular missions therein. In this review article, after the summary of the molecular structure and function of CCN3, recent findings on the regulation of ccn3 expression and the roles of CCN3 in endochondral ossification, cartilage development, maintenance and disorders are introduced with an emphasis on the metabolic regulation and function of this matricellular multifunctional molecule.

The Emerging Roles of CCN3 Protein in Immune-Related Diseases

The CCN proteins are a family of extracellular matrix- (ECM-) associated proteins which currently consist of six secreted proteins (CCN1-6). CCN3 protein, also known as nephroblastoma overexpressed protein (NOV), is a member of the CCN family with multiple biological functions, implicated in major cellular processes such as cell growth, migration, and differentiation. Recently, CCN3 has emerged as a critical regulator in a variety of diseases, including immune-related diseases, including rheumatology arthritis, osteoarthritis, and systemic sclerosis. In this review, we will briefly introduce the structure and function of the CCN3 protein and summarize the roles of CCN3 in immune-related diseases, which is essential to understand the functions of the CCN3 in immune-related diseases.

Role of Matricellular CCN Proteins in Skeletal Muscle: Focus on CCN2/CTGF and Its Regulation by Vasoactive Peptides

The Cellular Communication Network (CCN) family of matricellular proteins comprises six proteins that share conserved structural features and play numerous biological roles. These proteins can interact with several receptors or soluble proteins, regulating cell signaling pathways in various tissues under physiological and pathological conditions. In the skeletal muscle of mammals, most of the six CCN family members are expressed during embryonic development or in adulthood. Their roles during the adult stage are related to the regulation of muscle mass and regeneration, maintaining vascularization, and the modulation of skeletal muscle fibrosis. This work reviews the CCNs proteins' role in skeletal muscle physiology and disease, focusing on skeletal muscle fibrosis and its regulation by Connective Tissue Growth factor (CCN2/CTGF). Furthermore, we review evidence on the modulation of fibrosis and CCN2/CTGF by the renin-angiotensin system and the kallikrein-kinin system of vasoactive peptides.

High NOV/CCN3 expression during high-fat diet pregnancy in mice affects GLUT3 expression and the mTOR pathway

We investigated the expression levels of nephroblastoma overexpressed [NOV or CCN3 (cellular communication network factor 3)] in the serum and placenta of pregnant women and of pregnant mice fed a high-fat diet (HFD), and its effect on placental glucose transporter 3 (GLUT3) expression, to examine its role in gestational diabetes mellitus (GDM). NOV/CCN3 expression was increased in the mouse serum during pregnancy. At gestational day 18, NOV/CCN3 protein expression was increased in the serum and placenta of the HFD mice compared with that of mice fed a normal diet. Compared with non-GDM patients, the patients with GDM had significantly increased serum NOV/CCN3 protein expression and placental NOV/CCN3 mRNA expression. Therefore, we hypothesized that NOV/CCN3 signaling may be involved in the pathogenesis of GDM. We administered NOV/CCN3 recombinant protein via intraperitoneal injections to pregnant mice fed HFD or normal diet. NOV/CCN3 overexpression led to glucose intolerance. Combined with the HFD, NOV/CCN3 exacerbated glucose intolerance and caused insulin resistance. NOV/CCN3 upregulates GLUT3 expression and affects the mammalian target of rapamycin (mTOR) pathway in the GDM environment in vivo and in vitro. In summary, our results demonstrate, for the first time, the molecular mechanism of NOV/CCN3 signaling in maternal metabolism to regulate glucose balance during pregnancy. NOV/CCN3 may be a potential target for detecting and treating GDM.NEW & NOTEWORTHY NOV/CCN3 regulates glucose homeostasis in mice during pregnancy. NOV/CCN3 upregulates GLUT3 expression and affects the mTOR pathway in the GDM environment in vivo and in vitro.

[Regulatory effect of CCN3 on proliferation of mouse embryonic fibroblasts and its mechanism]

OBJECTIVE

To investigate the role of NOV/CCN3 in regulating the proliferation of mesenchymal stem cells (MSCs) and its regulatory mechanism and assess the value of CCN3 as a proliferative factor in bone tissue engineering.

METHODS

Mouse embryonic fibroblasts (MEFs) were used as the MSC model, in which CCN3 expression was up-regulated and downregulated by transfection with the recombinant adenovirus vectors Ad-CCN3 and Ad-siCCN3, respectively. Flow cytometry was used to analyze the changes in cell cycle and apoptosis of the transfected cells. Western blotting was used to detect the expression levels of the proliferation indicators (PCNA, cyclin E, and cyclin B1) and the apoptosis indicators (Bax and Bcl-2) to assess the effect of modulation of CCN3 expression on MEF proliferation and apoptosis. CCN3 protein secretion by the cells was detected using ELISA. RT-qPCR and Western blotting were employed to analyze the changes in the expressions of Notch1, ligand DLL1, the downstream key proteins or genes (Hey1, P300, H3K9) and MAPK pathway-related proteins ERK1+2 and p-ERK1+2.

RESULTS

Flow cytometry showed that compared with the control cells, MEFs transfected with Ad-CCN3 exhibited significantly increased cell proliferation index (P < 0.01) and lowered cell apoptosis rate (P < 0.05) with obviously enhanced expressions of PCNA, cyclin E and Bcl-2 proteins (P < 0.05). The results of RT-qPCR and Western blotting demonstrated that CCN3 overexpression significantly promoted the expression of Notch1 in the Notch signaling pathway (P < 0.001), inhibited the expressions of DLL1, Hey1, P300, and H3K9 (P < 0.05), and increased the protein expressions of ERK1+2 and P-ERk1+2 in the MAPK pathway (P < 0.01).

CONCLUSIONS

CCN3 over-expression promotes the proliferation and inhibits apoptosis of MEFs possibly by inhibiting the classical Notch signaling pathway and activating the MAPK pathway via binding to Notch1, suggesting the potential value of CCN3 as a proliferative factor of MSCs in bone tissue engineering.

PVT1 signals an androgen-dependent transcriptional repression program in prostate cancer cells and a set of the repressed genes predicts high-risk tumors

BACKGROUND

Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored.

METHODS

LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specific GapmeRs (or a control with scrambled GapmeR) was followed by differentially expressed genes (DEGs) determination with Agilent microarrays and with Significance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifier with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG.

RESULTS

We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically significant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a significantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classification of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC = 0.89 ± 0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed significant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing.

CONCLUSIONS

Overall, we provide first evidence that PVT1 was involved in signaling a genome-wide androgen-dependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identification of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investigation of mechanisms that lie behind the oncogenic role of PVT1 in cancer. Video Abstract.

CCN3 is dynamically regulated by treatment and disease state in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease that damages myelin in the central nervous system (CNS). We investigated the profile of CCN3, a known regulator of immune function and a potential mediator of myelin regeneration, in multiple sclerosis in the context of disease state and disease-modifying treatment.

METHODS

CCN3 expression was analysed in plasma, immune cells, CSF and brain tissue of MS patient groups and control subjects by ELISA, western blot, qPCR, histology and in situ hybridization.

RESULTS

Plasma CCN3 levels were comparable between collective MS cohorts and controls but were significantly higher in progressive versus relapsing-remitting MS and between patients on interferon-β versus natalizumab. Higher body mass index was associated with higher CCN3 levels in controls as reported previously, but this correlation was absent in MS patients. A significant positive correlation was found between CCN3 levels in matched plasma and CSF of MS patients which was absent in a comparator group of idiopathic intracranial hypertension patients. PBMCs and CD4+ T cells significantly upregulated CCN3 mRNA in MS patients versus controls. In the CNS, CCN3 was detected in neurons, astrocytes and blood vessels. Although overall levels of area immunoreactivity were comparable between non-affected, demyelinated and remyelinated tissue, the profile of expression varied dramatically.

CONCLUSIONS

This investigation provides the first comprehensive profile of CCN3 expression in MS and provides rationale to determine if CCN3 contributes to neuroimmunological functions in the CNS.

Analysis of putative cis-regulatory elements regulating blood pressure variation

Hundreds of loci have been associated with blood pressure (BP) traits from many genome-wide association studies. We identified an enrichment of these loci in aorta and tibial artery expression quantitative trait loci in our previous work in ~100 000 Genetic Epidemiology Research on Aging study participants. In the present study, we sought to fine-map known loci and identify novel genes by determining putative regulatory regions for these and other tissues relevant to BP. We constructed maps of putative cis-regulatory elements (CREs) using publicly available open chromatin data for the heart, aorta and tibial arteries, and multiple kidney cell types. Variants within these regions may be evaluated quantitatively for their tissue- or cell-type-specific regulatory impact using deltaSVM functional scores, as described in our previous work. We aggregate variants within these putative CREs within 50 Kb of the start or end of 'expressed' genes in these tissues or cell types using public expression data and use deltaSVM scores as weights in the group-wise sequence kernel association test to identify candidates. We test for association with both BP traits and expression within these tissues or cell types of interest and identify the candidates MTHFR, C10orf32, CSK, NOV, ULK4, SDCCAG8, SCAMP5, RPP25, HDGFRP3, VPS37B and PPCDC. Additionally, we examined two known QT interval genes, SCN5A and NOS1AP, in the Atherosclerosis Risk in Communities Study, as a positive control, and observed the expected heart-specific effect. Thus, our method identifies variants and genes for further functional testing using tissue- or cell-type-specific putative regulatory information.

Higher Serum CCN3 Is Associated with Disease Activity and Inflammatory Markers in Rheumatoid Arthritis

Nephroblastoma overexpressed protein (NOV/CCN3), the early discovered member of the CCN family, has recently been suggested to be involved in a number of inflammatory processes, including wound healing, alveolar epithelial cell inflammation, cancer metastasis, and macrophage foam cell formation. However, the role of CCN3 in rheumatoid arthritis (RA), a classic autoimmune and inflammatory disease, remains elusive. RA is a chronic systemic autoimmune disease that eventually leads to cartilage and bone destruction and joint dysfunction. In this study, we investigated the potential of serum CCN3 as a biomarker for RA. The serum levels of CCN3 were measured by ELISA. The clinical and laboratory parameters were collected from a clinical record system, and disease activity was determined by joint disease activity score 28 (DAS28). Our results showed that the serum levels of CCN3 were significantly increased in RA patients compared to healthy controls. Furthermore, the CCN3 level was positively correlated with DAS28 (CRP), DAS28 (ESR), and the level of anti-CCP Ab, an autoantibody highly specific for RA. Furthermore, CCN3 showed a positive correlation with inflammatory cytokine IL-6, while no significant correlation with TNF-α was observed. These data suggest that CCN3 plays an important role in the development of RA and might be a potential disease activity biomarker for RA.

Decreased CCN3 in Systemic Sclerosis Endothelial Cells Contributes to Impaired Angiogenesis

Systemic sclerosis (SSc) is a rare and severe connective tissue disease combining autoimmune and vasculopathy features, ultimately leading to organ fibrosis. Impaired angiogenesis is an often silent and life-threatening complication of the disease. We hypothesize that CCN3, a member of the CCN family of extracellular matrix proteins, which is an antagonist of the profibrotic protein CCN2 as well as a proangiogenic factor, is implicated in SSc pathophysiology. We performed skin biopsies on 26 patients with SSc, both in fibrotic and nonfibrotic areas for 17 patients, and collected 18 healthy control skin specimens for immunohistochemistry and cell culture. Histological analysis of nonfibrotic and fibrotic SSc skin shows a systemic decrease of papillary dermis surface as well as disappearance of capillaries. CCN3 expression is systematically decreased in the dermis of patients with SSc compared with healthy controls, particularly in dermal blood vessels. Moreover, CCN3 is decreased in vitro in endothelial cells from patients with SSc. We show that CCN3 is essential for endothelial cell migration and angiogenesis in vitro. In conclusion, CCN3 may represent a promising therapeutic target for patients with SSc presenting with vascular involvement.

Cell type-specific endometrial transcriptome changes during initial recognition of pregnancy in the mare

Previous endometrial gene expression studies during the time of conceptus migration did not provide final conclusions on the mechanisms of maternal recognition of pregnancy (MRP) in the mare. This called for a cell type-specific endometrial gene expression analysis in response to embryo signals to improve the understanding of gene expression regulation in the context of MRP. Laser capture microdissection was used to collect luminal epithelium (LE), glandular epithelium and stroma from endometrial biopsies from Day 12 of pregnancy and Day 12 of the oestrous cycle. RNA sequencing (RNA-Seq) showed greater expression differences between cell types than between pregnant and cyclic states; differences between the pregnant and cyclic states were mainly found in LE. Comparison with a previous RNA-Seq dataset for whole biopsy samples revealed the specific origin of gene expression differences. Furthermore, genes specifically differentially expressed (DE) in one cell type were found that were not detectable as DE in biopsies. Overall, this study revealed spatial information about endometrial gene expression during the phase of initial MRP. The conceptus induced changes in the expression of genes involved in blood vessel development, specific spatial regulation of the immune system, growth factors, regulation of prostaglandin synthesis, transport prostaglandin receptors, specifically prostaglandin F receptor (PTGFR) in the context of prevention of luteolysis.

Systems-wide analysis unravels the new roles of CCM signal complex (CSC)

Cerebral cavernous malformations (CCMs) are characterized by abnormally dilated intracranial capillaries that result in increased susceptibility to stroke. Three genes have been identified as causes of CCMs; KRIT1 (CCM1), MGC4607 (CCM2) and PDCD10 (CCM3); one of them is disrupted in most CCM cases. It was demonstrated that both CCM1 and CCM3 bind to CCM2 to form a CCM signaling complex (CSC) to modulate angiogenesis. In this report, we deployed both RNA-seq and proteomic analysis of perturbed CSC after depletion of one of three CCM genes to generate interactomes for system-wide studies. Our results demonstrated a unique portrait detailing alterations in angiogenesis and vascular integrity. Interestingly, only in-direct overlapped alterations between RNA and protein levels were detected, supporting the existence of multiple layers of regulation in CSC cascades. Notably, this is the first report identifying that both β4 integrin and CAV1 signaling are downstream of CSC, conveying the angiogenic signaling. Our results provide a global view of signal transduction modulated by the CSC, identifies novel regulatory signaling networks and key cellular factors associated with CSC.

Repurposing an anti-cancer agent for the treatment of hypertrophic heart disease

Coronary microvascular dysfunction combined with maladaptive cardiomyocyte morphology and energetics is a major contributor to heart failure advancement. Thus, dually enhancing cardiac angiogenesis and targeting cardiomyocyte function to slow, or reverse, the development of heart failure is a logical step towards improved therapy. We present evidence for the potential to repurpose a former anti-cancer Arg-Gly-Asp (RGD)-mimetic pentapeptide, cilengitide, here used at low doses. Cilengitide targets αvβ3 integrin and this protein is upregulated in human dilated and ischaemic cardiomyopathies. Treatment of mice after abdominal aortic constriction (AAC) surgery with low-dose cilengitide (ldCil) enhances coronary angiogenesis and directly affects cardiomyocyte hypertrophy with an associated reduction in disease severity. At a molecular level, ldCil treatment has a direct effect on cardiac endothelial cell transcriptomic profiles, with a significant enhancement of pro-angiogenic signalling pathways, corroborating the enhanced angiogenic phenotype after ldCil treatment. Moreover, ldCil treatment of Angiotensin II-stimulated AngII-stimulated cardiomyocytes significantly restores transcriptomic profiles similar to those found in normal human heart. The significance of this finding is enhanced by transcriptional similarities between AngII-treated cardiomyocytes and failing human hearts. Taken together, our data provide evidence supporting a possible new strategy for improved heart failure treatment using low-dose RGD-mimetics with relevance to human disease. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The Predictive Role of Tenascin-C and Cellular Communication Network Factor 3 (CCN3) in Post Hepatectomy Liver Failure in a Rat Model and 50 Patients Following Partial Hepatectomy

Background

Matricellular proteins of the extracellular matrix (ECM) include tenascin-C (TNC) and cellular communication network factor 3 (CCN3). This study aimed to investigate the role of TNC and CCN3 as prognostic factors for post hepatectomy liver failure (PHLF) in a rat model of partial hepatectomy and 50 patients following partial hepatectomy.

Material/Methods

Sprague-Dawley rats underwent 85% (n=53) or 90% hepatectomy (n=53) in the partial hepatectomy (PHx) model. TNC and CCN3 mRNA expression in residual liver tissue was evaluated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and enzyme-linked immunoassay (ELISA) determined the serum levels of TNC and CCN3. In 50 patients who underwent partial hepatectomy, TNC and CCN3 serum levels were measured on postoperative day 1 and day 3.

Results

In the rat partial hepatectomy model, mRNA and serum levels of TNC and CCN3 were significantly increased within the first 24 h, and were higher in the 90% PHx group compared with the 85% PHx group. Fifty patients who underwent partial hepatectomy, included patients with PHLF (n=12) and patients without PHLF (n=38). Multivariate analysis confirmed that serum levels on postoperative day 3 TNC^high+CCN3^high was a significant predictor of PHLF, which was associated with more than twice the risk of severe morbidity when compared with the low-risk patients (80% vs. 30%) and a significantly longer hospital stay (17 days vs. 8 days).

Conclusions

Further studies are needed to evaluate the potential role of the matricellular proteins, TNC and CCN3 as early clinical predictors for PHLF.

Functional Vascular Tissue Engineering Inspired by Matricellular Proteins

Modern regenerative medicine, and tissue engineering specifically, has benefited from a greater appreciation of the native extracellular matrix (ECM). Fibronectin, collagen, and elastin have entered the tissue engineer's toolkit; however, as fully decellularized biomaterials have come to the forefront in vascular engineering it has become apparent that the ECM is comprised of more than just fibronectin, collagen, and elastin, and that cell-instructive molecules known as matricellular proteins are critical for desired outcomes. In brief, matricellular proteins are ECM constituents that contrast with the canonical structural proteins of the ECM in that their primary role is to interact with the cell. Of late, matricellular genes have been linked to diseases including connective tissue disorders, cardiovascular disease, and cancer. Despite the range of biological activities, this class of biomolecules has not been actively used in the field of regenerative medicine. The intent of this review is to bring matricellular proteins into wider use in the context of vascular tissue engineering. Matricellular proteins orchestrate the formation of new collagen and elastin fibers that have proper mechanical properties-these will be essential components for a fully biological small diameter tissue engineered vascular graft (TEVG). Matricellular proteins also regulate the initiation of thrombosis via fibrin deposition and platelet activation, and the clearance of thrombus when it is no longer needed-proper regulation of thrombosis will be critical for maintaining patency of a TEVG after implantation. Matricellular proteins regulate the adhesion, migration, and proliferation of endothelial cells-all are biological functions that will be critical for formation of a thrombus-resistant endothelium within a TEVG. Lastly, matricellular proteins regulate the adhesion, migration, proliferation, and activation of smooth muscle cells-proper control of these biological activities will be critical for a TEVG that recellularizes and resists neointimal formation/stenosis. We review all of these functions for matricellular proteins here, in addition to reviewing the few studies that have been performed at the intersection of matricellular protein biology and vascular tissue engineering.

Imatinib independent aberrant methylation of NOV/CCN3 in chronic myelogenous leukemia patients: a mechanism upstream of BCR-ABL1 function?

Background

The NOV gene product, CCN3, has been reported in a diverse range of tumors to serve as a negative growth regulator, while acting as a tumor suppressor in Chronic Myelogenous Leukemia (CML). However, the precise mechanism of its silencing in CML is poorly understood. In the current study, we aimed to query if the gene regulation of CCN3 is mediated by the promoter methylation in the patients with CML. In addition, to clarify whether the epigenetic silencing is affected by BCR-ABL1 inhibition, we assessed the methylation status in the patients at different time intervals following the tyrosine kinase inhibition using imatinib therapy, as the first-line treatment for this type of leukemia.

Methods

To address this issue, we applied bisulfite-sequencing technique as a high-resolution method to study the regulatory segment of the CCN3 gene. The results were analyzed in newly diagnosed CML patients as well as following imatinib therapy. We also evaluated the correlation of CCN3 promoter methylation with BCR-ABL1 levels.

Results

Our findings revealed that the methylation occurs frequently in the promoter region of CML patients showing a significant increase of the methylated percentage at the CpG sites compared to normal individuals. Interestingly, this hypermethylation was indicated to be independent of BCR-ABL1 titers in both groups, which might suggest a mechanism beyond the BCR-ABL1 function.

Conclusion

Despite suggesting that the CCN3 hypermethylation acts as a molecular mechanism independent of BCR-ABL1 function in CML patients, this scenario requires further validation by complementary experiments. In the case of acting upstream of BCR-ABL1 signaling, the methylation marker can provide early detection and a novel platform for targeted epigenetic modifiers for efficient treatment in imatinib resistant patients.

Osteoblasts are "educated" by crosstalk with metastatic breast cancer cells in the bone tumor microenvironment

INTRODUCTION

In a cancer-free environment in the adult, the skeleton continuously undergoes remodeling. Bone-resorbing osteoclasts excavate erosion cavities, and bone-depositing osteoblasts synthesize osteoid matrix that forms new bone, with no net bone gain or loss. When metastatic breast cancer cells invade the bone, this balance is disrupted. Patients with bone metastatic breast cancer frequently suffer from osteolytic bone lesions that elicit severe bone pain and fractures. Bisphosphonate treatments are not curative. Under ideal circumstances, osteoblasts would synthesize new matrix to fill in erosion cavities caused by osteoclasts, but this is not what occurs. Our prior evidence demonstrated that osteoblasts are diverted from laying down bone matrix to producing cytokines that facilitate breast cancer cell maintenance in late-stage disease. Here, we have new evidence to suggest that there are subpopulations of osteoblasts in the tumor niche as evidenced by their protein marker expression that have distinct roles in tumor progression in the bone.

METHODS

Tumor-bearing tibia of mice was interrogated by immunofluorescent staining for the presence of osteoblasts and alterations in niche protein expression. De-identified tissue from patients with bone metastatic breast cancer was analyzed for osteoblast subpopulations via multi-plex immunofluorescent staining. Effects of breast cancer cells on osteoblasts were recapitulated in vitro by osteoblast exposure to breast cancer-conditioned medium. Triple-negative and estrogen receptor-positive breast cancer proliferation, cell cycle, and p21 expression were assessed upon contact with "educated" osteoblasts.

RESULTS

A subpopulation of osteoblasts was identified in the bone tumor microenvironment in vivo of both humans and mice with bone metastatic breast cancer that express RUNX2/OCN/OPN but is negative for IL-6 and alpha-smooth muscle actin. These tumor "educated" osteoblasts (EOs) have altered properties compared to "uneducated" osteoblasts and suppress both triple-negative and estrogen receptor-positive breast cancer cell proliferation and increase cancer cell p21 expression. EO effects on breast cancer proliferation were mediated by NOV and decorin. Importantly, the presence of EO cells in the tibia of mice bearing tumors led to increased amounts of alkaline phosphatase and suppressed the expression of inflammatory cytokines in vivo.

CONCLUSIONS

Our work reveals that there is a subpopulation of osteoblasts in the bone tumor microenvironment that demonstrate a functional role in retarding breast cancer cell growth.

Role of the CCN protein family in cancer

The CCN protein family is composed of six matricellular proteins, which serve regulatory roles rather than structural roles in the extracellular matrix. First identified as secreted proteins which are induced by oncogenes, the acronym CCN came from the names of the first three members: CYR61, CTGF, and NOV. All six members of the CCN family consist of four cysteine-rich modular domains. CCN proteins are known to regulate cell adhesion, proliferation, differentiation, and apoptosis. In addition, CCN proteins are associated with cardiovascular and skeletal development, injury repair, inflammation, and cancer. They function either through binding to integrin receptors or by regulating the expression and activity of growth factors and cytokines. Given their diverse roles related to the pathology of certain diseases such as fibrosis, arthritis, atherosclerosis, diabetic nephropathy, retinopathy, and cancer, there are many emerging studies targeting CCN protein signaling pathways in attempts to elucidate their potentials as therapeutic targets. [BMB Reports 2018; 51(10): 486-493].

CCN proteins as potential actionable targets in scleroderma

Systemic sclerosis (SSc) is a complex autoimmune connective tissue disease combining inflammatory, vasculopathic and fibrotic manifestations. Skin features, which give their name to the disease and are considered as diagnostic as well as prognostic markers, have not been thoroughly investigated in terms of therapeutic targets. CCN proteins (CYR61/CCN1, CTGF/CCN2, NOV/CCN3 and WISP1-2-3 as CCN4-5-6) are a family of secreted matricellular proteins implicated in major cellular processes such as cell growth, migration, differentiation. They have already been implicated in key pathophysiological processes of SSc, namely fibrosis, vasculopathy and inflammation. In this review, we discuss the possible implication of CCN proteins in SSc pathogenesis, with a special focus on skin features, and identify the potential actionable CCN targets.

Regenerating CNS myelin: Emerging roles of regulatory T cells and CCN proteins

Efficient myelin regeneration in the central nervous system (CNS) requires the migration, proliferation and differentiation of oligodendrocyte progenitor cells (OPC) into myelinating oligodendrocytes. In demyelinating diseases such as multiple sclerosis (MS), this regenerative process can fail, and therapies targeting myelin repair are currently completely lacking in the clinic. The immune system is emerging as a key regenerative player in many tissues, such as muscle and heart. We recently reported that regulatory T cells (Treg) are required for efficient CNS remyelination. Furthermore, Treg secrete CCN3, a matricellular protein from the CCN family, implicated in regeneration of other tissues. Treg-derived CCN3 promoted oligodendrocyte differentiation and myelination. In contrast, previous studies showed that CCN2 inhibited myelination. These studies highlight the need for further scrutiny of the roles that CCN proteins play in myelin development and regeneration. Collectively, these findings open up exciting avenues of research to uncover the regenerative potential of the adaptive immune system.

CCN3 Expression Marks a Sulfomucin-nonproducing Unique Subset of Colonic Goblet Cells in Mice

Intestinal goblet cells are characterized by their unique morphology and specialized function to secrete mucins. Although it is known that they are a heterogeneous population of cells, there have been few studies that relate the expression of a particular gene with functionally distinct subpopulations of intestinal goblet cells. Here we show that CCN3, a gene encoding a member of the CCN family proteins, is induced by inhibition of Notch signaling in colonic epithelial cells and expressed in goblet cells in mice. We demonstrate that CCN3 expression is confined to a subpopulation of goblet cells in the lower crypt of the proximal and middle colon. In addition, CCN3+ cells in the colon correlate well with the cells that are positive for alcian blue (AB) staining but negative for high-iron diamine (HID) staining in histology. We also show that CCN3+ cells, which are absent in the normal distal colon, transiently and ectopically emerge in regenerating crypts during the repair phase of DSS-induced colitis model. Our study thus suggests that CCN3 labels a unique subpopulation of sulfomucin-nonproducing colonic goblet cells that function in both normal and diseased colonic epithelia.

CCN3 promotes epithelial-mesenchymal transition in prostate cancer via FAK/Akt/HIF-1α-induced twist expression

Epithelial-mesenchymal transition (EMT) has received considerable attention as a conceptual paradigm for explaining metastatic behavior during cancer progression. NOV/CCN3 is a matrix-associated protein involved in many cellular functions. Previous studies have shown that CCN3 expression is upregulated in prostate cancer (PCa) cells and in PCa patients. In this study, we have provided evidence of tumor promoting effects of CCN3, which includes induction of epithelial-to-mesenchymal transition (EMT) and tumor metastasis. We used an orthotopic in vivo model to demonstrate the prometastatic effects of CCN3. Overexpression or knockdown of CCN3 changed the EMT phenotype in PCa cells. Moreover, treatment with recombinant CCN3 promoted EMT in PCa cells. We also found that CCN3 may promote EMT by activating the FAK/Akt/HIF-1α pathway and this activation is responsible for Twist expression. IHC staining confirmed a positive correlation between the expression of CCN3, Twist, and tumor stage in PCa tissue. Our findings provide insight into the involvement of CCN3 in the EMT regulation of prostate cancer. CCN3 is a promising molecular target that may contribute to a novel therapeutic strategy against metastatic PCa.

The Role of Angiogenesis in Cancer Treatment

A number of anti-angiogenesis drugs have been FDA-approved and are being used in cancer treatment, and a number of other agents are in different stages of clinical development or in preclinical evaluation. However, pharmacologic anti-angiogenesis strategies that arrest tumor progression might not be enough to eradicate tumors. Decreased anti-angiogenesis activity in single mechanism-based anti-angiogenic strategies is due to the redundancy, multiplicity, and development of compensatory mechanism by which blood vessels are remodeled. Improving anti-angiogenesis drug efficacy will require identification of broad-spectrum anti-angiogenesis targets. These strategies may have novel features, such as increased porosity, and are the result of complex interactions among endothelial cells, extracellular matrix proteins, growth factors, pericyte, and smooth muscle cells. Thus, combinations of anti-angiogenic drugs and other anticancer strategies such as chemotherapy appear essential for optimal outcome in cancer patients. This review will focus on the role of anti-angiogenesis strategies in cancer treatment.

The Role of Angiogenesis in Cancer Treatment

A number of anti-angiogenesis drugs have been FDA-approved and are being used in cancer treatment, and a number of other agents are in different stages of clinical development or in preclinical evaluation. However, pharmacologic anti-angiogenesis strategies that arrest tumor progression might not be enough to eradicate tumors. Decreased anti-angiogenesis activity in single mechanism-based anti-angiogenic strategies is due to the redundancy, multiplicity, and development of compensatory mechanism by which blood vessels are remodeled. Improving anti-angiogenesis drug efficacy will require identification of broad-spectrum anti-angiogenesis targets. These strategies may have novel features, such as increased porosity, and are the result of complex interactions among endothelial cells, extracellular matrix proteins, growth factors, pericyte, and smooth muscle cells. Thus, combinations of anti-angiogenic drugs and other anticancer strategies such as chemotherapy appear essential for optimal outcome in cancer patients. This review will focus on the role of anti-angiogenesis strategies in cancer treatment.

The Role of Angiogenesis in Cancer Treatment

A number of anti-angiogenesis drugs have been FDA-approved and are being used in cancer treatment, and a number of other agents are in different stages of clinical development or in preclinical evaluation. However, pharmacologic anti-angiogenesis strategies that arrest tumor progression might not be enough to eradicate tumors. Decreased anti-angiogenesis activity in single mechanism-based anti-angiogenic strategies is due to the redundancy, multiplicity, and development of compensatory mechanism by which blood vessels are remodeled. Improving anti-angiogenesis drug efficacy will require identification of broad-spectrum anti-angiogenesis targets. These strategies may have novel features, such as increased porosity, and are the result of complex interactions among endothelial cells, extracellular matrix proteins, growth factors, pericyte, and smooth muscle cells. Thus, combinations of anti-angiogenic drugs and other anticancer strategies such as chemotherapy appear essential for optimal outcome in cancer patients. This review will focus on the role of anti-angiogenesis strategies in cancer treatment.

Structural analyses of von Willebrand factor C domains of collagen 2A and CCN3 reveal an alternative mode of binding to bone morphogenetic protein-2

Bone morphogenetic proteins (BMPs) are secreted growth factors that promote differentiation processes in embryogenesis and tissue development. Regulation of BMP signaling involves binding to a variety of extracellular proteins, among which are many von Willebrand factor C (vWC) domain-containing proteins. Although the crystal structure of the complex of crossveinless-2 (CV-2) vWC1 and BMP-2 previously revealed one mode of the vWC/BMP-binding mechanism, other vWC domains may bind to BMP differently. Here, using X-ray crystallography, we present for the first time structures of the vWC domains of two proteins thought to interact with BMP-2: collagen IIA and matricellular protein CCN3. We found that these two vWC domains share a similar N-terminal fold that differs greatly from that in CV-2 vWC, which comprises its BMP-2-binding site. We analyzed the ability of these vWC domains to directly bind to BMP-2 and detected an interaction only between the collagen IIa vWC and BMP-2. Guided by the collagen IIa vWC domain crystal structure and conservation of surface residues among orthologous domains, we mapped the BMP-binding epitope on the subdomain 1 of the vWC domain. This binding site is different from that previously observed in the complex between CV-2 vWC and BMP-2, revealing an alternative mode of interaction between vWC domains and BMPs.

Regulatory T cells promote myelin regeneration in the central nervous system

Regeneration of CNS myelin involves differentiation of oligodendrocytes from oligodendrocyte progenitor cells. In multiple sclerosis, remyelination can fail despite abundant oligodendrocyte progenitor cells, suggesting impairment of oligodendrocyte differentiation. T cells infiltrate the CNS in multiple sclerosis, yet little is known about T cell functions in remyelination. We report that regulatory T cells (T_reg) promote oligodendrocyte differentiation and (re)myelination. T_reg-deficient mice exhibited substantially impaired remyelination and oligodendrocyte differentiation, which was rescued by adoptive transfer of T_reg. In brain slice cultures, T_reg accelerated developmental myelination and remyelination, even in the absence of overt inflammation. T_reg directly promoted oligodendrocyte progenitor cell differentiation and myelination in vitro. We identified CCN3 as a T_reg-derived mediator of oligodendrocyte differentiation and myelination in vitro. These findings reveal a new regenerative function of T_reg in the CNS, distinct from immunomodulation. Although the cells were originally named 'T_reg' to reflect immunoregulatory roles, this also captures emerging, regenerative T_reg functions.

Extracellular Matrix, a Hard Player in Angiogenesis

The extracellular matrix (ECM) is a complex network of proteins, glycoproteins, proteoglycans, and polysaccharides. Through multiple interactions with each other and the cell surface receptors, not only the ECM determines the physical and mechanical properties of the tissues, but also profoundly influences cell behavior and many physiological and pathological processes. One of the functions that have been extensively explored is its impingement on angiogenesis. The strong impact of the ECM in this context is both direct and indirect by virtue of its ability to interact and/or store several growth factors and cytokines. The aim of this review is to provide some examples of the complex molecular mechanisms that are elicited by these molecules in promoting or weakening the angiogenic processes. The scenario is intricate, since matrix remodeling often generates fragments displaying opposite effects compared to those exerted by the whole molecules. Thus, the balance will tilt towards angiogenesis or angiostasis depending on the relative expression of pro- or anti-angiogenetic molecules/fragments composing the matrix of a given tissue. One of the vital aspects of this field of research is that, for its endogenous nature, the ECM can be viewed as a reservoir to draw from for the development of new more efficacious therapies to treat angiogenesis-dependent pathologies.

Notch: A multi-functional integrating system of microenvironmental signals

The Notch signaling cascade is an evolutionarily ancient system that allows cells to interact with their microenvironmental neighbors through direct cell-cell interactions, thereby directing a variety of developmental processes. Recent research is discovering that Notch signaling is also responsive to a broad variety of stimuli beyond cell-cell interactions, including: ECM composition, crosstalk with other signaling systems, shear stress, hypoxia, and hyperglycemia. Given this emerging understanding of Notch responsiveness to microenvironmental conditions, it appears that the classical view of Notch as a mechanism enabling cell-cell interactions, is only a part of a broader function to integrate microenvironmental cues. In this review, we summarize and discuss published data supporting the idea that the full function of Notch signaling is to serve as an integrator of microenvironmental signals thus allowing cells to sense and respond to a multitude of conditions around them.

Protein Imaging of CCN2 and CCN3 in Living Cells

Recent progress in molecular imaging technology has had a strong impact on improving our understanding of molecular translocation, receptor internalization, and interactions in living cells. The protocol in this chapter introduces an optimized technique for intracellular localization of CCN2 and CCN3 in live cells, one using GFP-tagged CCN2 and Halo-tagged CCN3.

Human pancreatic cancer progression: an anarchy among CCN-siblings

Decades of basic and translational studies have identified the mechanisms by which pancreatic cancer cells use molecular pathways to hijack the normal homeostasis of the pancreas, promoting pancreatic cancer initiation, progression, and metastasis, as well as drug resistance. These molecular pathways were explored to develop targeted therapies to prevent or cure this fatal disease. Regrettably, the studies found that majority of the molecular events that dictate carcinogenic growth in the pancreas are non-actionable (potential non-responder groups of targeted therapy). In this review we discuss exciting discoveries on CCN-siblings that reveal how CCN-family members contribute to the different aspects of the development of pancreatic cancer with special emphasis on therapy.

Cell surface receptors for CCN proteins

The CCN family (CYR61; CTGF; NOV; CCN1-6; WISP1-3) of matricellular proteins in mammals is comprised of six homologous members that play important roles in development, inflammation, tissue repair, and a broad range of pathological processes including fibrosis and cancer. Despite considerable effort to search for a high affinity CCN-specific receptor akin to growth factor receptors, no such receptor has been found. Rather, CCNs bind several groups of multi-ligand receptors as characteristic of other matricellular proteins. The most extensively documented among CCN-binding receptors are integrins, including αvβ3, αvβ5, α5β1, α6β1, αIIbβ3, αMβ2, and αDβ2, which mediate diverse CCN functions in various cell types. CCNs also bind cell surface heparan sulfate proteoglycans (HSPGs), low density liproprotein receptor-related proteins (LRPs), and the cation-independent mannose-6-phosphate (M6P) receptor, which are endocytic receptors that may also serve as co-receptors in cooperation with other cell surface receptors. CCNs have also been reported to bind FGFR-2, Notch, RANK, and TrkA, potentially altering the affinities of these receptors for their ligands. The ability of CCNs to bind a multitude of receptors in various cell types may account for the remarkable versatility of their functions, and underscore the diverse signaling pathways that mediate their activities.

Matricellular protein CCN3 mitigates abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a major cause of morbidity and mortality; however, the mechanisms that are involved in disease initiation and progression are incompletely understood. Extracellular matrix proteins play an integral role in modulating vascular homeostasis in health and disease. Here, we determined that the expression of the matricellular protein CCN3 is strongly reduced in rodent AAA models, including angiotensin II-induced AAA and elastase perfusion-stimulated AAA. CCN3 levels were also reduced in human AAA biopsies compared with those in controls. In murine models of induced AAA, germline deletion of Ccn3 resulted in severe phenotypes characterized by elastin fragmentation, vessel dilation, vascular inflammation, dissection, heightened ROS generation, and smooth muscle cell loss. Conversely, overexpression of CCN3 mitigated both elastase- and angiotensin II-induced AAA formation in mice. BM transplantation experiments suggested that the AAA phenotype of CCN3-deficient mice is intrinsic to the vasculature, as AAA was not exacerbated in WT animals that received CCN3-deficient BM and WT BM did not reduce AAA severity in CCN3-deficient mice. Genetic and pharmacological approaches implicated the ERK1/2 pathway as a critical regulator of CCN3-dependent AAA development. Together, these results demonstrate that CCN3 is a nodal regulator in AAA biology and identify CCN3 as a potential therapeutic target for vascular disease.

WISP-1 a novel angiogenic regulator of the CCN family promotes oral squamous cell carcinoma angiogenesis through VEGF-A expression

Oral squamous cell carcinoma (OSCC), which accounts for nearly 90% of head and neck cancers, is characterized by poor prognosis and a low survival rate. VEGF-A is the most established angiogenic factor involved in the angiogenic-regulated tumor progression. WISP-1/CCN4 is an extracellular matrix-related protein that belongs to the Cyr61, CTGF, Nov (CCN) family and regulates many biological functions, such as angiogenesis. Previous studies indicated the role of WISP-1 in tumor progression. However, the angiogenic property of WISP-1 in the cancer microenvironment has never been discussed. Here, we provide novel insights regarding the role of WISP-1 in the angiogenesis through promoting VEGF-A expression. In this study, the correlation of WISP-1 and VEGF-A was confirmed by IHC staining of specimens from patients with OSCC. In vitro results indicated that WISP-1 induced VEGF-A expression via the integrin αvβ3/FAK/c-Src pathway, which transactivates the EGFR/ERK/HIF1-α signaling pathway in OSCC. This pathway in turn induces the recruitment of endothelial progenitor cells and triggers the neovascularization in the tumor microenvironment. Our in vivo data revealed that tumor-secreted WISP-1 promoted the angiogenesis through VRGF expression and increased angiogenesis-related tumor growth. Our study offers new information that highlights WISP-1 as a potential novel therapeutic target for OSCC.