Dynamic CCN3 expression in the murine CNS does not confer essential roles in myelination or remyelination.

CCN3 is a matricellular protein that promotes oligodendrocyte progenitor cell differentiation and myelination in vitro and ex vivo. CCN3 is therefore a candidate of interest in central nervous system (CNS) myelination and remyelination, and we sought to investigate the expression and role of CCN3 during these processes. We found CCN3 to be expressed predominantly by neurons in distinct areas of the CNS, primarily the cerebral cortex, hippocampus, amygdala, suprachiasmatic nuclei, anterior olfactory nuclei, and spinal cord gray matter. CCN3 was transiently up-regulated following demyelination in the brain of cuprizone-fed mice and spinal cord lesions of mice injected with lysolecithin. However, CCN3-/- mice did not exhibit significantly different numbers of oligodendroglia or differentiated oligodendrocytes in the healthy or remyelinating CNS, compared to WT controls. These results suggest that despite robust and dynamic expression in the CNS, CCN3 is not required for efficient myelination or remyelination in the murine CNS in vivo.

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-ß 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.

CCN3 Regulates Macrophage Foam Cell Formation and Atherosclerosis.

Recent studies implicate the Cyr61, CTGF, Nov (CCN) matricellular signaling protein family as emerging players in vascular biology, with NOV (alias CCN3) as an important regulator of vascular homeostasis. Herein, we examined the role of CCN3 in the pathogenesis of atherosclerosis. In response to a 15-week high-fat diet feeding, CCN3-deficient mice on the atherosclerosis-prone Apoe-/- background developed increased aortic lipid-rich plaques compared to control Apoe-/- mice, a result that was observed in the absence of alterations in plasma lipid content. To address the cellular contributor(s) responsible for the atherosclerotic phenotype, we performed bone marrow transplantation experiments. Transplantation of Apoe; Ccn3 double-knockout bone marrow into Apoe-/- mice resulted in an increase of atherosclerotic plaque burden, whereas transplantation of Apoe-/- marrow to Apoe; Ccn3 double-knockout mice caused a reduction of atherosclerosis. These results indicate that CCN3 deficiency, specifically in the bone marrow, plays a major role in the development of atherosclerosis. Mechanistically, cell-based studies in isolated peritoneal macrophages demonstrated that CCN3 deficiency leads to an increase of lipid uptake and foam cell formation, an effect potentially attributed to the increased expression of scavenger receptors CD36 and SRA1, key factors involved in lipoprotein uptake. These results suggest that bone marrow-derived CCN3 is an essential regulator of atherosclerosis and point to a novel role of CCN3 in modulating lipid accumulation within macrophages.

A novel, dual role of CCN3 in experimental glomerulonephritis: pro-angiogenic and antimesangioproliferative effects.

In contrast to factors that promote mesangial cell proliferation, little is known about their endogenous inhibitors. During experimental mesangioproliferative nephritis, expression of the glomerular CCN3 (nephroblastoma overexpressed gene [NOV]) gene is reduced before the proliferative phase and increased in glomeruli and serum when mesangial cell proliferation subsides. To further elucidate its role in mesangioproliferative glomerulonephritis, CCN3 systemically was overexpressed by muscle electroporation in healthy or nephritic rats. This increased CCN3 serum concentrations more than threefold for up to 56 days. At day 5 after disease induction, CCN3-transfected rats showed an increase in glomerular endothelial area and in mRNA levels of the pro-angiogenic factors vascular endothelial growth factor and PDGF-C. At day 7, CCN3 overexpression decreased mesangial cell proliferation, including expression of α-smooth muscle actin and matrix accumulation of fibronectin and type IV collagen. In progressive nephritis (day 56), overexpression of CCN3 resulted in decreased albuminuria, glomerulosclerosis, and reduced cortical collagen type I accumulation. In healthy rat kidneys, overexpression of CCN3 induced no morphologic changes but regulated glomerular gene transcripts (reduced transcription of PDGF-B, PDGF-D, PDGF-receptor-ß, and fibronectin, and increased PDGF-receptor-α and PDGF-C mRNA). These data identify a dual role for CCN3 in experimental glomerulonephritis with pro-angiogenic and antimesangioproliferative effects. Manipulation of CCN3 may represent a novel approach to help repair glomerular endothelial damage and mesangioproliferative changes.

The CCN family of proteins: structure-function relationships.

The CCN proteins are key signalling and regulatory molecules involved in many vital biological functions, including cell proliferation, angiogenesis, tumourigenesis and wound healing. How these proteins influence such a range of functions remains incompletely understood but is probably related to their discrete modular nature and a complex array of intra- and inter-molecular interactions with a variety of regulatory proteins and ligands. Although certain aspects of their biology can be attributed to the four individual modules that constitute the CCN proteins, recent results suggest that some of their biological functions require cooperation between modules. Indeed, the modular structure of CCN proteins provides important insight into their structure-function relationships.

Time has come to address the spatiotemporal combinatorial model for CCN proteins biological activitites by spatial transcriptomics and genome wide association studies.

It is a renewed pleasure to wish our authors, editorial board members, and readership an excellent new year, full of professional and personal satisfactions. According to the Chinese Horoscope, 2023, the Year of Water Rabbit, is predicted to be quiet; a year to step back, assess the situation and make plans. It will be the time to carefully appraise, with the patience of the Water Rabbit, the future and scientific wealth of our Journal. Based on a few aspects of the CCN3 biology status that remain open questions, I am presenting below a short summary of a few CCN research directions that in my eyes, become necessary to undertake through wide-angle collaborative approaches.

Farewell Springer Hello Wiley : The tale of an academic scientific periodical -"20 years later" the Journal of Cell Communication and Signaling.

Academic publishing is the support for dissemination of research findings that constitute the grounds upon which new orientations and improvements are based on sharing breaking ideas, critical analyses of data, and argumentations that sustain the development of collaborative research projects. The wide diffusion of new scientific findings is pivotal to the progress of medical sciences, a salient feature of human societal fullness and intellectual welfare. In a practical way, the value of academic publishing can be ascertained by its capacity to reach a wide number of readers from different fields that may provide the soil for interactive projects. The challenges are numerous (Zul in Challenges in Academic Publishing; Navigating the Obstacles, 2023). An examination of the means developed to survey the individual performances of scientists, based on their publications, has led me to comment in this editorial on pitfalls that muddle the way to upstanding evaluations mainly based on irrelevant metrics.

Cooperation is the key: the CCN biological system as a gate to high complex protein superfamilies' signaling.

Cellular signaling is generally understood as the support of communication between contiguous cells belonging to the same tissue or cells being far apart of each other, at a molecular scale, when the message emitted by the transmitters is traveling in liquid or solid matter to reach recipient targets. Subcellular signaling is also important to ensure the proper cell constitution and functioning. However cell signaling is mostly used in the first understanding, to describe how the message sent from one point to another one, will reach a target where it will be interpreted. The Cellular Communication Network (CCN) factors (Perbal et al. 2018) constitute a family of biological regulators thought to be responsible for signaling pathways coordination (Perbal 2018). Indeed, these proteins interact with a diverse group of cell receptors, such as integrins, low density lipoprotein receptors, heparan sulfate proteoglycan receptors (HSPG), and the immunoglobulin superfamily expressed exclusively in the nervous system, or with soluble factors such as bone morphogenetic proteins (BMPS) and other growth factors such as vascular endothelial growth factor, fibroblastic growth factor, and transforming growth factor (TGFbeta). Starting from the recapitulation of basic concepts in enzymology and protein-ligands interactions, we consider, in this manuscript, interpretations of the mechanistic interactions that have been put forward to explain the diversity of CCN proteins biological activities. We suggest that the cross-talks between superfamilies of proteins under the control of CCNs might play a central role in the coordination of developmental signaling pathways.

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.

Report on the 11th international workshop on the CCN family of genes, Nice, October 20-24, 2022.

In celebration of the twentieth anniversary of the inception of the CCN society, and of the first post-Covid-19 live meeting, the executive board of the ICCNS had chosen Nice as the venue for the 11th International workshop on the CCN family of genes. On this occasion participation in the meeting was extended to colleagues from other cell signaling fields who were invited to present both an overview of their work and the future directions of their laboratory. Also, for the first time, the members of the JCCS Editorial Board were invited to participate in a JCCS special session during which all aspects of the journal « life ¼ were addressed and opened to free critical discussion. The scientific presentations and the discussions that followed showed once more that an expansion of the session topics was beneficial to the quality of the meeting and confirmed that the ARBIOCOM project discussed last April in Nice was now on track to be launched in 2023. The participants unanimously welcomed Professor Attramadal's proposition to organize the 2024, 12th International CCN workshop in Oslo, Norway.

CCN3 impairs osteoblast and stimulates osteoclast differentiation to favor breast cancer metastasis to bone.

Bone is a preferred site for breast cancer metastasis, causing pain, fractures, spinal cord compressions, and hypercalcemia, all of which can significantly diminish the patient's quality of life. We identified CCN3 as a novel factor that is highly expressed in bone metastatic breast cancer cells from a xenograft mouse model and in bone metastatic lesions from patients with breast cancer. We demonstrate that CCN3 overexpression enhances the ability of weakly bone metastatic breast cancer cells to colonize and grow in the bone without altering their growth in the mammary fat pad. We further demonstrated that human recombinant CCN3 inhibits osteoblast differentiation from primary bone marrow cultures, leading to a higher receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) ratio. In conjunction with its ability to impair osteoblast differentiation, we uncovered a novel role for CCN3 in promoting osteoclast differentiation from RANKL-primed monocyte precursors. CCN3 exerts its pro-osteoclastogenic effects by promoting calcium oscillations and nuclear factor of activated T cells c1 (NFATc1) nuclear translocation. Together, these results demonstrate that CCN3 regulates the differentiation of bone resident cells to create a resorptive environment that promotes the formation of osteolytic breast cancer metastases.

Transforming growth factor ß controls CCN3 expression in nucleus pulposus cells of the intervertebral disc.

OBJECTIVE: To investigate transforming growth factor ß (TGFß) regulation of CCN3 expression in cells of the nucleus pulposus. METHODS: Real-time reverse transcription-polymerase chain reaction and Western blot analyses were used to measure CCN3 expression in the nucleus pulposus. Transfections were used to measure the effect of Smad3, MAPKs, and activator protein 1 (AP-1) on TGFß-mediated CCN3 promoter activity. Lentiviral knockdown of Smad3 was performed to assess the role of Smad3 in CCN3 expression. RESULTS: CCN3 was expressed in embryonic and adult intervertebral discs. TGFß decreased the expression of CCN3 and suppressed its promoter activity in nucleus pulposus cells. DN-Smad3, Smad3 small interfering RNA, or DN-AP-1 had little effect on TGFß suppression of CCN3 promoter activity. However, p38 and ERK inhibitors blocked suppression of CCN3 by TGFß, suggesting involvement of these signaling pathways in the regulation of CCN3. Interestingly, overexpression of Smad3 in the absence of TGFß increased CCN3 promoter activity. We validated the role of Smad3 in controlling CCN3 expression in Smad3-null mice and in nucleus pulposus cells transduced with lentiviral short hairpin Smad3. In terms of function, treatment with recombinant CCN3 showed a dose-dependent decrease in the proliferation of nucleus pulposus cells. Moreover, CCN3-treated cells showed a decrease in aggrecan, versican, CCN2, and type I collagen expression. CONCLUSION: The opposing effect of TGFß on CCN2 and CCN3 expression and the suppression of CCN2 by CCN3 in nucleus pulposus cells further the paradigm that these CCN proteins form an interacting triad, which is possibly important in maintaining extracellular matrix homeostasis and cell numbers.

2022, a year of the water tiger.

According to Chinese astrology, the Tiger is considered as the king of all animals. The Year of the Tiger 2022 was meant to symbolize determinism, vitality, strength, spontaneity and novelty, with the water element making it wiser and thoughtful. Often associated with the defeat of evil, a Water Tiger year occurs only every 60 years. The 2022 version was indeed a year of resilience, even in the time of conflict and the struggles that we have faced both in personal and professional realms. It was a good time to reflect in order to overcome all challenges and difficulties. The revamping of both the International CCN society (ICCNS) and the Journal of Cell Communication and Signaling (JCCS) that I had previously initiated and officially announced in 2019, are on track to becoming a successful reality and will be pursued over the coming years, thanks to the strong support of our colleagues, members of the JCCS Editorial board and representatives of other scientific societies who support our efforts to broaden the scope of the ICCNS and its communication organ. I will schematically draw below the guidelines that we intend to follow in the near future.

Another Step Forward to the understanding of Biological Signaling Networks.

In this editorial I briefly review the new JCCS scientific directions that have emerged from the complicated situations created by the pandemics of COVID- 19, and by the internal audit of both Journal of Cell Communication and Signaling and International CCN Society, that were initiated since my proposal at the 2019 International Workshop on the CCN family of genes.I also welcome the distinguished members of our renewed JCCS Editorial and congratulate all those who have in many different ways participated to the consolidation of the 2021 JCCS Impact Factor attaining 5.908.

Inception and establishment of the International CCN Society (ICCNS) and of the Journal of Cell Communication and Signaling (JCCS): A response to A. Leask's Editorial entitled "Modeling the microenvironment special issue".

A little over a year ago, on January 25, 2021, the new Editor-in-Chief (EiC) of JCCS stated in his Editorial: "ICCNS and JCCS were the brainchildren of Bernard Perbal, and without his energy and drive, neither would exist, to the detriment of us who are driven to solve difficult problems in science, and not picking low-hanging fruit. All one has to do is examine all the editorials written in JCCS (and CCS!) to see evidence of this. It will be tough to fill those shoes."I disagree with the assertion in the Editorial published on March 29, 2022 that G. Martin contributed "to the initial growth of the International CCN Society, and, ultimately, to the establishment of this journal." My opinion is based on the evidence that the International CCN Society (ICCNS) and its official organ journal, the Journal of Cell Communication and Signaling (JCCS), were created by myself. Over a span of 21 years until the present, and in spite of his contribution to the early history of CTGF, we never heard from G. Martin being involved or interested in any aspect of the ICCNS and its biannual meetings, nor in any aspect in the growth of JCCS.In order to further clarify the confusion stemming from the Editorial in question and to give credit where it is due, I provide below detailed evidence that undoubtedly ascribes the true inception of both ICCNS and JCCS, and merit to the efforts of all those who trusted and supported us during the initial difficult creative moments.I am of the opinion that the Editorial, and the implications that it carries do not justice to the efforts of those who were really involved in the creation of both the ICCNS and JCCS.In the name of respectful scientific integrity, I will provide the evidence that correctly attributes the inception of ICCNS and JCCS.

CCN3 controls 3D spatial localization of melanocytes in the human skin through DDR1.

Melanocytes reside within the basal layer of the human epidermis, where they attach to the basement membrane and replicate at a rate proportionate to that of keratinocytes, maintaining a lifelong stable ratio. In this study, we report that coculturing melanocytes with keratinocytes up-regulated CCN3, a matricellular protein that we subsequently found to be critical for the spatial localization of melanocytes to the basement membrane. CCN3 knockdown cells were dissociated either upward to the suprabasal layers of the epidermis or downward into the dermis. The overexpression of CCN3 increased adhesion to collagen type IV, the major component of the basement membrane. As the receptor responsible for CCN3-mediated melanocyte localization, we identified discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that acts as a collagen IV adhesion receptor. DDR1 knockdown decreased melanocyte adhesion to collagen IV and shifted melanocyte localization in a manner similar to CCN3 knockdown. These results demonstrate an intricate and necessary communication between keratinocytes and melanocytes in maintaining normal epidermal homeostasis.

CCN3 inhibits neointimal hyperplasia through modulation of smooth muscle cell growth and migration.

OBJECTIVE: CCN3 belongs to the CCN family, which constitutes multifunctional secreted proteins that act as matrix cellular regulators. We investigated the pathophysiological roles of CCN3 in the vessels. METHODS AND RESULTS: We examined the effects of CCN3 on the proliferation and migration of rat vascular smooth muscle cells (VSMC). CCN3 knockout mice were created, and vascular phenotypes and neointimal hyperplasia induced by photochemically induced thrombosis were investigated. CCN3 suppressed the VSMC proliferation induced by fetal bovine serum. The neutralizing antibody for transforming growth factor-beta did not affect the growth inhibitory effect of CCN3. Moreover, CCN3 enhanced the mRNA expression of cyclin-dependent kinase inhibitors, p21 and p15. Gamma secretase inhibitor, an inhibitor of Notch signaling, partially inhibited the enhanced expression of p21 induced by CCN3. CCN3 also inhibited the VSMC migration. Finally, the histopathologic evaluation of the arteries 21 days after the endothelial injury revealed a 6-fold enhancement of neointimal thickening in the null mice compared with the wild-type mice. CONCLUSIONS: CCN3 suppresses neointimal thickening through the inhibition of VSMC migration and proliferation. Our findings indicate the involvement of CCN3 in vascular homeostasis, especially on injury, and the potential usefulness of this molecule in the modulation of atherosclerotic vascular disease.

The driving forces behind the impressive progression of the journal of cell communication and signaling (JCCS).

The recent increase of the Journal of Cell Signaling and Communication' 2020 Impact Factor to 5.782, and its growing audience in the scientific community, provides an opportunity to step back and look at different aspects of this indicator's value. The take home message is that the top-ten major contributions to the 2020 ranking originated from North America and Europe followed by India with a high percentage of CCN-related publications and an excellent proportion of Editorial Board members' contributions to the Top10 best citations for the 2018-2019 period.

Mastering health: liberating beauty : Will the cosmetics of tomorrow be genetic?

Systems that have yet to stand the test of time carry imperfections that need to be skillfully addressed with the least amount of authoritarianism as possible. The communication and transmission of knowledge that we hold dear are essential pillars to social progress. As such, it is necessary to analyze with the greatest scientific objectivity the applications arising from the deep revolution rooted in the total sequencing of the human genome which affects all aspects of our societies. This extraordinary advance in human knowledge and the resulting technological achievements should not lend themselves to the fears or fantasies often fueled by those who criticize all scientific progress calling into question the most established dogmas. Certain supposedly scholarly analyses of the health situation with which we are currently confronted worldwide are a perfect illustration of this unfortunate trend. It is undeniable that the progress of molecular genetics has opened up a wide range of applications in many fields, affecting the well-being of humans, their mental and physical health. The apparent universal and individual interest for the most advanced genetic profile analyzing technologies is a testimony to this strong common desire to better understand one's genetic heritage and to control their usage. Despite this movement, little attention is given to the recent advances in genetics applied to essential aspects of the social life of individuals through their inter-personal interactions. It is particularly distressing that the contributions of molecular biology and genetics to the daily well-being of individuals have not yet allowed open-access non-medical genetic testing to gain the recognition it deserves and are still viewed as recreational applications. Through an analysis of the cross influences that genetic biotechnologies have had since the beginning of the century in the fields of nutrition and cosmetics, we have tried to project ourselves into the near future which should witness major behavioral and social upheavals.

The CCN axis in cancer development and progression.

Since the authors first reviewed this subject in 2016 significant progress has been documented in the CCN field with advances made in the understanding of how members of the CCN family of proteins, CCN1-6, contribute to the pathogenesis and progression, positive and negative, of a larger variety of cancers. As termed matricellular proteins, and more recently the connective communication network, it has become clearer that members of the CCN family interact complexly with other proteins in the extracellular microenvironment, membrane signaling proteins, and can also operate intracellularly at the transcriptional level. In this review we expand on this earlier information providing new detailed information and insights that appropriate a much greater involvement and importance of their role in multiple aspects of cancer. Despite all the new information many more questions have been raised and intriguing results generated that warrant greater investigation. In order to permit the reader to smoothly integrate the new information we discuss all relevant CCN members in the context of cancer subtypes. We have harmonized the nomenclature with CCN numbering for easier comparisons. Finally, we summarize what new has been learned and provide a perspective on how our knowledge about CCN1-6 is being used to drive new initiatives on cancer therapeutics.