WISP-1/CCN4 regulates osteogenesis by enhancing BMP-2 activity

Unlocking the therapeutic potential of WISP-1: A comprehensive exploration of its role in age-related musculoskeletal disorders

As the global population ages, the incidence of age-related musculoskeletal diseases continues to increase, driven by numerous complex and poorly understood factors. WNT-1 inducible secreted protein 1 (WISP-1), a secreted matrix protein, plays a critical role in the growth and development of the musculoskeletal system, including chondrogenesis, osteogenesis, and myogenesis. Numerous in vivo and in vitro studies have demonstrated that WISP-1 is significantly upregulated in age-related musculoskeletal conditions, such as osteoarthritis, osteoporosis, and sarcopenia, suggesting its involvement in the pathogenesis of these diseases. Regulating WISP-1 expression holds promise as a therapeutic strategy for improving musculoskeletal function, potentially offering new avenues for treating age-related musculoskeletal diseases in clinical practice. This review highlights the signaling pathways associated with WISP-1, its physiological roles within the musculoskeletal system, and its therapeutic potential in treating age-related musculoskeletal disorders.

A glucocorticoid spike derails muscle repair to heterotopic ossification after spinal cord injury

Why severe injury to the central nervous system (CNS) triggers the development of large neurogenic heterotopic ossifications (NHOs) within periarticular muscles remains unknown. We report that spinal cord injury (SCI) triggers a rapid corticosterone spike in mice, which is causal for NHO development because treatments with corticosterone or the synthetic glucocorticoid (GC) receptor (GR) agonist dexamethasone are sufficient to trigger heterotopic ossification and upregulate the expression of osteoinductive and osteogenic differentiation genes in injured muscles even without SCI. The central role for GR signaling in causing NHO is further demonstrated in mice deleted for the GR gene (Nr3c1), which no longer develop NHO after SCI. Furthermore, administration of clinical GR antagonists inhibits NHO development in mice with SCI. This study identifies endogenous GC as causing pathological NHO after CNS injury and suggests that GR antagonists may be of prophylactic use to prevent NHO development in victims of severe CNS injuries.

CCN4 (WISP-1) reduces apoptosis and atherosclerotic plaque burden in an ApoE mouse model

BACKGROUND AND AIMS

CCN4/WISP-1 regulates various cell behaviours that contribute to atherosclerosis progression, including cell adhesion, migration, proliferation and survival. We therefore hypothesised that CCN4 regulates the development and progression of atherosclerotic plaques.

METHODS

We used a high fat fed ApoE-/- mouse model to study atherosclerotic plaque progression in the brachiocephalic artery and aortic root. In protocol 1, male ApoE-/- mice with established plaques were given a CCN4 helper-dependent adenovirus to see the effect of treatment with CCN4, while in protocol 2 male CCN4-/-ApoE-/- were compared to CCN4+/+ApoE-/- mice to assess the effect of CCN4 deletion on plaque progression.

RESULTS

CCN4 overexpression resulted in reduced occlusion of the brachiocephalic artery with less apoptosis, fewer macrophages, and attenuated lipid core size. The amount of plaque found on the aortic root was also reduced. CCN4 deficiency resulted in increased apoptosis and occlusion of the brachiocephalic artery as well as increased plaque in the aortic root. Additionally, in vitro cells from CCN4-/-ApoE-/- mice had higher apoptotic levels. CCN4 deficiency did not significantly affect blood cholesterol levels or circulating myeloid cell populations.

CONCLUSIONS

We conclude that in an atherosclerosis model the most important action of CCN4 is the effect on cell apoptosis. CCN4 provides pro-survival signals and leads to reduced cell death, lower macrophage number, smaller lipid core size and reduced atherosclerotic plaque burden. As such, the pro-survival effect of CCN4 is worthy of further investigation, in a bid to find a therapeutic for atherosclerosis.

WISP1 and Macrophage Migration Inhibitory Factor in Respiratory Inflammation: Novel Insights and Therapeutic Potentials for Asthma and COPD

Recent advancements highlight the intricate interplay between the extracellular matrix (ECM) and immune responses, notably in respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD). The ECM, a dynamic structural framework within tissues, orches-trates a plethora of cellular processes, including immune cell behavior and tissue repair mecha-nisms. WNT1-inducible-signaling pathway protein 1 (WISP1), a key ECM regulator, controls immune cell behavior, cytokine production, and tissue repair by modulating integrins, PI3K, Akt, β-catenin, and mTOR signaling pathways. WISP1 also induces macrophage migration inhibitory factor (MIF) expression via Src kinases and epidermal growth factor receptor (EGFR) activation. MIF, through its wide range of activities, enhances inflammation and tissue restructuring. Rec-ognized for its versatile roles in regulating the immune system, MIF interacts with multiple immune components, such as the NLRP3 inflammasome, thereby sustaining inflammatory pro-cesses. The WISP1-MIF axis potentially unveils complex molecular mechanisms governing im-mune responses and inflammation. Understanding the intricate roles of WISP1 and MIF in the pathogenesis of chronic respiratory diseases such as asthma and COPD could lead to the identi-fication of novel targets for therapeutic intervention to alleviate disease severity and enhance patient outcomes.

Extensive study of CCN4, VCAM-1, MMP-3, and GM-CSF as reliable markers for disease activity in rheumatoid arthritis

Background

The involvement of Wnt-1-induced secreted protein-1 (WISP1/CCN4) in several inflammatory reaction has recently been proposed. Nevertheless, this protein's involvement in rheumatoid arthritis (RA) remains debated. Associations between poorly diagnosed RA and several classical markers derived from demography and biochemistry have been reported.

Aim

We sought to investigate the reliability and effectiveness of serum concentrations of CCN4, vascular cell adhesion molecule-1 (VCAM-1), matrix melloprotenase-3 (MMP-3), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in monitoring and predicting RA and bone damage, and their correlation with RA disease course.

Methods

The study analyzed 128 patients with RA, comprising 68 newly diagnosed and 60 previously diagnosed patients, as well as 60 controls. Biomarker levels were measured with enzyme linked immuno-sorbent assays. Routine laboratory parameters such as serological, clinical, biochemical, and hematological parameters were additionally measured. Demography, anthropometry, and clinical symptom data were collected through interviews and a questionnaire. The joint disease activity score 28 (DAS28) was used to determine disease activity.

Results

Concentrations of four biomarkers were significantly higher in the RA group than the healthy controls. Elevated biomarker concentrations were also observed in patients with high, rather than moderate or low, DAS28-ESR activity status, except for monocyte count, hematocrit (%), and urea level. Furthermore, CCN4 level positively correlated with VCAM-1, MMP-3, and GM-CSF levels, DA-S28-CRP and DAS28-ESR. The levels of three predictive markers, CCN4, VCAM-1, and MMP-3, were elevated in non-treated patients, whereas GM-CSF level showed no difference. The highest area under the curve was 73.3% for CCN4, with 93.3% sensitivity and 64.7% specificity.

Conclusion

Our data suggest that CCN4 can be reliably used to indicate activity and therapeutic response associated with RA, thus facilitating earlier RA diagnosis.

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.

Latest Advances in Chondrocyte-Based Cartilage Repair

Chondrocyte-based cell therapy has been used for more than 30 years and is still considered to be a promising method of cartilage repair despite some limitations. This review introduces the latest developments of four generations of autologous chondrocyte implantation and current autologous chondrocyte products. The regeneration of cartilage from adult chondrocytes is limited by culture-induced dedifferentiation and patient age. Cartibeads is an innovative three-step method to produce high-quality hyaline cartilage microtissues, and it is developed from adult dedifferentiated chondrocytes with a high number of cell passages. In addition, allogeneic chondrocyte therapies using the Quantum hollow-fiber bioreactor and several signaling pathways involved in chondrocyte-based cartilage repair are mentioned, such as WNT signaling, the BMP-2/WISP1 pathway, and the FGF19 pathway.

Unraveling the mechanism in l-Caldesmon regulating the osteogenic differentiation of PDLSCs: An innovative perspective

Maxillofacial bone defect is one of the common symptoms in maxillofacial, which affects the function and aesthetics of maxillofacial region. Periodontal ligament stem cells (PDLSCs) are extensively used in bone tissue engineering. The mechanism that regulates the osteogenic differentiation of PDLSCs remains not fully elucidated. Previous studies demonstrated that l-Caldesmon (l-CALD, or CALD1) might be involved in the osteogenic differentiation of PDLSCs. Here, the mechanism by which CALD1 regulates the osteogenic differentiation of PDLSCs is investigated. The osteogenic differentiation of PDLSCs is enhanced with Cald1 knockdown. Whole transcriptome sequencing (RNA-seq) analysis shows that bone morphogenetic proteins (BMP) signaling pathway and Wingless type (Wnt) pathway have significant change with Cald1 knockdown, and the expressions of Wnt-induced secreted protein 1 (WISP1), BMP2, Smad1/5/9, and p-Smad1/5/9 are significantly upregulated, while Glycogen synthase kinase 3β (GSK3β) and p-GSK3β are downregulated. In addition, subcutaneous implantation in nude mice shows that knockdown of Cald1 enhances the osteogenic differentiation of PDLSCs in vivo. Taken together, this study demonstrates that knockdown of Cald1 enhances the osteogenic differentiation of PDLSCs by BMP and Wnt signaling pathways, and provides a novel approach for subsequent clinical treatment.

Antimicrobial peptides in bone regeneration: mechanism and potential

INTRODUCTION

Antimicrobial peptides (AMPs) are small-molecule peptides with a unique antimicrobial mechanism. Other notable biological activities of AMPs, including anti-inflammatory, angiogenesis, and bone formation effects, have recently received widespread attention. These remarkable bioactivities, combined with the unique antimicrobial mechanism of action of AMPs, have led to their increasingly important role in bone regeneration.

AREAS COVERED

In this review, on the one hand, we aimed to summarize information about the AMPs that are currently used for bone regeneration by reviewing published literature in the PubMed database. On the other hand, we also highlight some AMPs with potential roles in bone regeneration and their possible mechanisms of action.

EXPERT OPINION

The translation of AMPs to the clinic still faces many problems, but their unique antimicrobial mechanisms and other conspicuous biological activities suggest great potential. An in-depth understanding of the structure and mechanism of action of AMPs will help us to subsequently combine AMPs with different carrier systems and perform structural modifications to reduce toxicity and achieve stable release, which may be a key strategy for facilitating the translation of AMPs to the clinic.

WISP1 induces the expression of macrophage migration inhibitory factor in human lung fibroblasts through Src kinases and EGFR-activated signaling pathways

Wnt1-inducible signaling protein 1 (WISP1/CCN4) is a secreted matricellular protein that is implicated in lung and airway remodeling. The macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that has been associated with chronic lung diseases. In this study, we aimed to investigate the WISP1 signaling pathway and its ability to induce the expression of MIF in primary cultures of fibroblasts from normal human lungs (HLFs). Our results showed that WISP1 significantly stimulated the expression of MIF in a concentration- and time-dependent fashion. In WISP1-induced expression of MIF, αvβ5-integrin and chondroitin sulfate proteoglycans as well as Src tyrosine kinases, MAP kinases, phosphatidylinositol 3-kinase/Akt, PKC, and NF-κB were involved. WISP1-induced expression of MIF was attenuated in the presence of the Src kinase inhibitor PP2 or the MIF tautomerase activity inhibitor ISO-1. Moreover, WISP1 significantly increased the phosphorylation and activation of EGF receptor (EGFR) through transactivation by Src kinases. WISP1 also induced the expression of MIF receptor CD74 and coreceptor CD44, through which MIF exerts its effects on HLFs. In addition, it was found that MIF induced its own expression, as well as its receptors CD74/CD44, acting in an autocrine manner. Finally, WISP1-induced MIF promoted the expression of cyclooxygenase 2, prostaglandin E2, IL-6, and matrix metalloproteinase-2 demonstrating the regulatory role of WISP1-MIF axis in lung inflammation and remodeling involving mainly integrin αvβ5, Src kinases, PKC, NF-κB, and EGFR. The specific signaling pathways involved in WISP1-induced expression of MIF may prove to be excellent candidates for novel targets to control inflammation in chronic lung diseases.NEW & NOTEWORTHY The present study demonstrates for the first time that Wnt1-inducible signaling protein 1 (WISP1) regulates migration inhibitory factor (MIF) expression and activity and identifies the main signaling pathways involved. The newly discovered WISP1-MIF axis may drive lung inflammation and could result in the design of novel targeted therapies in inflammatory lung diseases.

Differential molecular profiles and associated functionalities characterize connective tissue grafts obtained at different locations and depths in the human palate

The present study aimed to assess the molecular profiles of subepithelial connective tissue grafts (CTGs) obtained at different locations and depths in the human palate. Sixty-four CTGs belonging to anterior deep (AD), anterior superficial (AS), posterior deep (PD), and posterior superficial (PS) groups were subjected to RNA-Sequencing and their transcriptomes were analyzed computationally. Functional correlations characterizing the CTG groups were validated by cell biological experiments using primary human palatal fibroblasts (HPFs) extracted from the CTGs. A clearly more pronounced location-dependent than depth-dependent difference between the grafts, with a minimal number of genes (4) showing no dependence on the location, was revealed. Epithelial, endothelial, and monocytic cell migration was strongly (P < 0.001) potentiated by AD- and PS-HPFs. Moreover, significantly increased expression of genes encoding C-C and C-X-C motif chemokine ligands as well as significantly (P < 0.01) activated p38 signaling suggested immunomodulatory phenotype for AD- and PS-HPFs. Increased growth factor gene expression and significantly activated (P < 0.001) Erk and Akt signaling in HPFs originating from A-CTGs implied their involvement in cell survival, proliferation, and motility. Prominent collagen-rich expression profile contributing to high mechanical stability, increased osteogenesis-related gene expression, and strongly activated (P < 0.001) Smad1/5/8 signaling characterized HPFs originating from P-CTGs. The present data indicate that in humans, differences between palatal CTGs harvested from different locations and depths appear to be location- rather than depth-dependent. Our findings provide the basis for future personalization of the therapeutic strategy by selecting an optimal graft type depending on the clinical indications.

Development of artificial bone graft via in vitro endochondral ossification (ECO) strategy for bone repair

Endochondral ossification (ECO) is a form of bone formation whereby the newly deposited bone replaces the cartilage template. A decellularized artificial cartilage graft (dLhCG), which is composed of hyaline cartilage matrixes, has been developed in our previous study. Herein, the osteogenesis of bone marrow-derived MSCs in the dLhCG through chondrogenic differentiation, chondrocyte hypertrophy, and subsequent transdifferentiation induction has been investigated by simulating the physiological processes of ECO for repairing critical-sized bone defects. The MSCs were recellularized into dLhCGs and subsequently allowed to undergo a 14-day proliferation period (mrLhCG). Following this, the mrLhCG constructs were subjected to two distinct differentiation induction protocols to achieve osteogenic differentiation: chondrogenic medium followed by chondrocytes culture medium with a high concentration of fetal bovine serum (CGCC group) and canonical osteogenesis inducing medium (OI group). The formation of a newly developed artificial bone graft, ossified dLhCG (OsLhCG), as well as its capability of aiding bone defect reconstruction were characterized by in vitro and in vivo trials, such as mRNA sequencing, quantitative real-time PCR (qPCR), immunohistochemistry, the greater omentum implantation in nude mice, and repair for the critical-sized femoral defects in rats. The results reveal that the differentiation induction of MSCs in the CGCC group can realize in vitro ECO through chondrogenic differentiation, hypertrophy, and transdifferentiation, while the MSCs in the OI group, as expected, realize ossification through direct osteogenic differentiation. The angiogenesis and osteogenesis of OsLhCG were proved by being implanted into the greater omentum of nude mice. Besides, the OsLhCG exhibits the capability to achieve the repair of critical-size femoral defects.

The Molecular Regulatory Mechanism in Multipotency and Differentiation of Wharton's Jelly Stem Cells

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are isolated from Wharton's jelly tissue of umbilical cords. They possess the ability to differentiate into lineage cells of three germ layers. WJ-MSCs have robust proliferative ability and strong immune modulation capacity. They can be easily collected and there are no ethical problems associated with their use. Therefore, WJ-MSCs have great tissue engineering value and clinical application prospects. The identity and functions of WJ-MSCs are regulated by multiple interrelated regulatory mechanisms, including transcriptional regulation and epigenetic modifications. In this article, we summarize the latest research progress on the genetic/epigenetic regulation mechanisms and essential signaling pathways that play crucial roles in pluripotency and differentiation of WJ-MSCs.

Connective tissue growth factor: Role in trabecular meshwork remodeling and intraocular pressure lowering

Connective tissue growth factor (CTGF) is a distinct signaling molecule modulating many physiological and pathophysiological processes. This protein is upregulated in numerous fibrotic diseases that involve extracellular matrix (ECM) remodeling. It mediates the downstream effects of transforming growth factor beta (TGF-β) and is regulated via TGF-β SMAD-dependent and SMAD-independent signaling routes. Targeting CTGF instead of its upstream regulator TGF-β avoids the consequences of interfering with the pleotropic effects of TGF-β. Both CTGF and its upstream mediator, TGF-β, have been linked with the pathophysiology of glaucomatous optic neuropathy due to their involvement in the regulation of ECM homeostasis. The excessive expression of these growth factors is associated with glaucoma pathogenesis via elevation of the intraocular pressure (IOP), the most important risk factor for glaucoma. The raised in the IOP is due to dysregulation of ECM turnover resulting in excessive ECM deposition at the site of aqueous humor outflow. It is therefore believed that CTGF could be a potential therapeutic target in glaucoma therapy. This review highlights the CTGF biology and structure, its regulation and signaling, its association with the pathophysiology of glaucoma, and its potential role as a therapeutic target in glaucoma management.

Simulation of Microgravity and Coculturing with Hematopoietic Cells Oppositely Modulate Wnt Signaling in Mesenchymal Stromal Cells

The osteogenic potential of mesenchymal stromal cells (MSCs) can determine bone homeostasis and the physical characteristics of bones. Microgravity reduces the ability of these cells to differentiate in osteogenic direction. It has been shown that the addition of hematopoietic stem and progenitor cells (HSPCs) to MSC culture in vitro can have the opposite effect. The aim of this study was to identify transcriptional changes in 84 genes associated with Wnt signaling in MSCs during microgravity simulation and interaction with HSPCs. The results indicate an increase in the non-canonical Wnt signaling activity during coculturing of MSCs and HSPCs, while simulated microgravity enhances the canonical component of this signaling pathway. These changes may underlie the modulation of osteogenic potential of MSCs in hematopoietic niche under microgravity.

The role of integrin family in bone metabolism and tumor bone metastasis

Integrins have been the research focus of cell-extracellular matrix adhesion (ECM) and cytokine receptor signal transduction. They are involved in the regulation of bone metabolism of bone precursor cells, mesenchymal stem cells (MSCs), osteoblasts (OBs), osteoclasts (OCs), and osteocytes. Recent studies expanded and updated the role of integrin in bone metabolism, and a large number of novel cytokines were found to activate bone metabolism pathways through interaction with integrin receptors. Integrins act as transducers that mediate the regulation of bone-related cells by mechanical stress, fluid shear stress (FSS), microgravity, hypergravity, extracellular pressure, and a variety of physical factors. Integrins mediate bone metastasis of breast, prostate, and lung cancer by promoting cancer cell adhesion, migration, and survival. Integrin-mediated targeted therapy showed promising prospects in bone metabolic diseases. This review emphasizes the latest research results of integrins in bone metabolism and bone metastasis and provides a vision for treatment strategies.

Roles of focal adhesion proteins in skeleton and diseases

The skeletal system, which contains bones, joints, tendons, ligaments and other elements, plays a wide variety of roles in body shaping, support and movement, protection of internal organs, production of blood cells and regulation of calcium and phosphate metabolism. The prevalence of skeletal diseases and disorders, such as osteoporosis and bone fracture, osteoarthritis, rheumatoid arthritis, and intervertebral disc degeneration, increases with age, causing pain and loss of mobility and creating a huge social and economic burden globally. Focal adhesions (FAs) are macromolecular assemblies that are composed of the extracellular matrix (ECM), integrins, intracellular cytoskeleton and other proteins, including kindlin, talin, vinculin, paxillin, pinch, Src, focal adhesion kinase (FAK) and integrin-linked protein kinase (ILK) and other proteins. FA acts as a mechanical linkage connecting the ECM and cytoskeleton and plays a key role in mediating cell-environment communications and modulates important processes, such as cell attachment, spreading, migration, differentiation and mechanotransduction, in different cells in skeletal system by impacting distinct outside-in and inside-out signaling pathways. This review aims to integrate the up-to-date knowledge of the roles of FA proteins in the health and disease of skeletal system and focuses on the specific molecular mechanisms and underlying therapeutic targets for skeletal diseases.

Myeloid CCN3 protects against aortic valve calcification

BACKGROUND

Cellular communication network factor 3 (CCN3) has been implicated in the regulation of osteoblast differentiation. However, it is not known if CCN3 can regulate valvular calcification. While macrophages have been shown to regulate valvular calcification, the molecular and cellular mechanisms of this process remain poorly understood. In the present study, we investigated the role of macrophage-derived CCN3 in the progression of calcific aortic valve disease.

METHODS

Myeloid-specific knockout of CCN3 (Mye-CCN3-KO) and control mice were subjected to a single tail intravenous injection of AAV encoding mutant mPCSK9 (rAAV8/D377Y-mPCSK9) to induce hyperlipidemia. AAV-injected mice were then fed a high fat diet for 40 weeks. At the conclusion of high fat diet feeding, tissues were harvested and subjected to histologic and pathologic analyses. In vitro, bone marrow-derived macrophages (BMDM) were obtained from Mye-CCN3-KO and control mice and the expression of bone morphogenic protein signaling related gene were verified via quantitative real-time PCR and Western blotting. The BMDM conditioned medium was cocultured with human valvular intersititial cells which was artificially induced calcification to test the effect of the conditioned medium via Western blotting and Alizarin red staining.

RESULTS

Echocardiography revealed that both male and female Mye-CCN3-KO mice displayed compromised aortic valvular function accompanied by exacerbated valve thickness and cardiac dysfunction. Histologically, Alizarin-Red staining revealed a marked increase in aortic valve calcification in Mye-CCN3-KO mice when compared to the controls. In vitro, CCN3 deficiency augmented BMP2 production and secretion from bone marrow-derived macrophages. In addition, human valvular interstitial cells cultured with conditioned media from CCN3-deficient BMDMs resulted in exaggerated pro-calcifying gene expression and the consequent calcification.

CONCLUSION

Our data uncovered a novel role of myeloid CCN3 in the regulation of aortic valve calcification. Modulation of BMP2 production and secretion in macrophages might serve as a key mechanism for macrophage-derived CCN3's anti-calcification function in the development of CAVD. Video Abstract.

Repairing a critical cranial defect using WISP1-pretreated chondrocyte scaffolds

In cranial flat bone fractures, spontaneous bone repair will occur only when the fracture ends are in close contact. However, in cases wherein bone discontinuity is extensive, surgical interventions are often required. To this end, autologous bone is harvested and surgically integrated into the site of fracture. Here we propose to use cartilage, as an alternative autologous source, to promote cranial fracture repair. The advantage of this approach is the potential reduction in donor site morbidity, likely due to the avascular and aneural nature of cartilage. As a first step we attempted to induce cartilage mineralization in vitro, using micromass primary chondrocyte cultures, incubated with BMP2 and/or WISP1, which were examined histologically following a 3-week culture period. Next, chondrocyte seeded collagen scaffolds were evaluated in vitro for expression profiles and ALP activity. Finally, chondrocyte-seeded collagen scaffolds were implanted in a Lewis rats 8 mm critical calvaria defect model, which was imaged via live CT for 12 weeks until sacrifice. End points were analyzed for microCT, histology, and serum levels of bone related markers. Micromass cultures exhibited an osseous inducing trend following WISP1 administration, which was maintained in chondrocyte seeded scaffolds. Accordingly, in vivo analysis was carried out to assess the impact of WISP1-pretreated chondrocytes (WCS) versus untreated chondrocytes (UCS) in calvaria defect model and compared to untreated control comprised of a defect-associated blood clot (BC) or empty collagen scaffold (CS) implant. Live CT and microCT exhibited higher mineralization volumes in critical defect implanted with UCS, with some structural improvements in WCS. Histological analysis exhibited higher anabolic bone formation in WCS and trabecular bone was detected in WCS and UCS groups. Chondrocytes implanted into critical cranial defect expedite the formation of native-like osseous tissue, especially after WISP1 priming in culture. Ultimately, these data support the use of autologous chondrocytes to repair critical maxillofacial defects.

The ADAM9/WISP-1 axis cooperates with osteoblasts to stimulate primary prostate tumor growth and metastasis

Background: Metastatic prostate cancer (PCa) predicts a poor prognosis and lower likelihood of survival. Osteoblasts (OBs) are known to be responsible for the synthesis and mineralization of bone, although it is unclear as to whether PCa in the prostate gland cooperates with OBs in bone to promote PCa malignant transformation. We aimed to elucidate how primary PCa cells cooperate with distal OBs and contribute to the vicious cycle that leads to metastatic PCa. Methods: N-cadherin, E-cadherin, and Twist protein expression were measured by Western blot. Twist translocation into the nucleus was detected by the immunofluorescence (IF) assay. Enzyme-linked immunosorbent assay (ELISA) detected protein levels in human serum samples. Levels of candidate protein expression were examined by the human cytokine array. Prostate tumor growth and metastasis were analyzed by orthotopic and metastatic prostate cancer models, respectively. Immunohistochemistry (IHC) staining was used to observe ADAM metallopeptidase domain 9 (ADAM9) and WNT1 inducible signaling pathway protein 1 (WISP-1) expression in tissue. Results: Our in vitro and in vivo analyses have now discovered that primary PCa expressing ADAM9 protein enables the transformation of OBs into PCa-associated osteoblasts (PCa-OBs), inducing WISP-1 secretion from PCa-OBs in the bone microenvironment. The upregulation of WISP-1 in bone provided feedback to primary PCa and promoted PCa cell aggressiveness via epithelial-mesenchymal transition (EMT) activity. Elevated levels of WISP-1 expression were detected in the serum of patients with PCa. ADAM9 levels were overexpressed in tumor tissue from PCa patients; ADAM9 blockade interrupted OB-induced release of WISP-1 and also suppressed primary tumor growth and distal metastasis in orthotopic PCa mouse models. Conclusion: Our study suggests that the ADAM9/WISP-1 axis assists with metastatic PCa progression. Thus, targeting the ADAM9/WISP-1 axis may help to prevent the malignant phenotypes of PCa cells.

Novel Peptides Derived from Sea Cucumber Intestine Promotes Osteogenesis by Upregulating Integrin-Mediated Transdifferentiation of Growth Plate Chondrocytes to Osteoblasts

The sea cucumber intestine is a major by-product of sea cucumber processing and contains high levels of protein. In this study, we isolated and identified 28 novel osteogenic peptides from sea cucumber intestinal hydrolysis by the activity-tracking method for the first time. In vitro experimental results showed that compared with high molecular weight, the peptides from sea cucumber intestine (SCIP) with molecular weight <3 kDa more significantly promoted the proliferation and mineralized nodules of MC3T3-E1 cell and exhibited potential integrin binding capacity. In vivo experimental results showed that the SCIP supplement significantly increased the longitudinal bone length and elevated the height of the growth plate (especially the hypertrophic zone, 37.2%, p < 0.01) in adolescent mice. Further, immunofluorescence labeling results indicated that the SCIP supplement increased chondrocyte transdifferentiate to osteoblast in the growth plate close to the diaphysis. Mechanistically, transcriptome analysis revealed that the SCIP supplement induced the dedifferentiation of chondrocyte to osteoprogenitor cell via integrin-mediated histone acetylation and then redifferentiated to osteoblast via integrin-mediated Wnt/β-catenin signaling. These results reported for the first time that sea cucumber intestine had the potential to develop into a dietary supplement for promoting osteogenic, and provide new evidence for the mechanism of dietary promotes chondrocyte to osteoblast transdifferentiation.

A WISP1 antibody inhibits MRTF signaling to prevent the progression of established liver fibrosis

Fibrosis is the major risk factor associated with morbidity and mortality in patients with non-alcoholic steatohepatitis (NASH)-driven chronic liver disease. Although numerous efforts have been made to identify the mediators of the initiation of liver fibrosis, the molecular underpinnings of fibrosis progression remain poorly understood, and therapies to arrest liver fibrosis progression are elusive. Here, we identify a pathway involving WNT1-inducible signaling pathway protein 1 (WISP1) and myocardin-related transcription factor (MRTF) as a central mechanism driving liver fibrosis progression through the integrin-dependent transcriptional reprogramming of myofibroblast cytoskeleton and motility. In mice, WISP1 deficiency protects against fibrosis progression, but not fibrosis onset. Moreover, the therapeutic administration of a novel antibody blocking WISP1 halted the progression of existing liver fibrosis in NASH models. These findings implicate the WISP1-MRTF axis as a crucial determinant of liver fibrosis progression and support targeting this pathway by antibody-based therapy for the treatment of NASH fibrosis.

WNT1-inducible signalling pathway protein 1 stabilizes atherosclerotic plaques in apolipoprotein-E-deficient mice via the focal adhesion kinase/mitogen-activated extracellular signal-regulated kinase/extracellular signal-regulated kinase pathway

BACKGROUND

The migration, proliferation and apoptosis of vascular smooth muscle cells (VSMCs) are critical for plaque stability. WNT-inducible signalling pathway protein-1 (WISP1), a member of the CCN family of extracellular matrix proteins, can expedite the migration and proliferation of VSMCs. However, its underlying mechanism and relationship with atherosclerosis remain elusive. The relationship between WISP1 and apoptosis of VSMCs has not been determined previously.

METHOD

In the study, we aimed to investigate the relationship between WISP1 and plaque stability and its related mechanism.ApoE-/- mice were divided following groups: the null lentivirus (NC), lentivirus WISP1 (IvWISP1) and WISP1-shRNA (shWISP1) groups. Immunofluorescence, Oil Red O and Masson's staining of the carotid arteries were performed. Transwell wound healing assay, CCK8 assay, and TdT-mediated dUTP nick-end labeling (TUNEL) staining were performed using VSMCs. The levels of WISP1, P38, C-Jun N-terminal kinase, extracellular signal-regulated kinase (ERK), mitogen-activated extracellular signal-regulated kinase (MEK), focal adhesion kinase (FAK), phosphatidylinositol 3-kinase (PI3K), Akt (also known as PKB, protein kinase B), mammalian target of rapamycin (mTOR), cleaved caspase3, Bcl2 and Bax were detected by western blotting.

RESULTS

The relative area of lipids and monocytes/macrophages in the shWISP1 group increased compared with that of the NC group. However, the relative area of smooth muscle cell and collagen in the IvWISP1 group increased compared with that in the NC group. Therefore, WISP1 could stabilize atherosclerotic plaques. Besides, WISP1 accelerate the migration and proliferation of VSMCs via integrin α5β1 and FAK/MEK/ERK signalling pathways. In addition, WISP1 can inhibit the apoptosis of VSMCs via the PI3K/Akt/mTOR pathway.

CONCLUSION

WISP1 not only inhibits the apoptosis of VSMCs via the PI3K/Akt/mTOR pathway but also enhances the migration and proliferation of VSMCs via the integrin α5β1 and FAK/MEK/ERK pathways. Therefore, WISP1 could enhance the stability of atherosclerotic plaques.

Contribution to the 3R Principle: Description of a Specimen-Specific Finite Element Model Simulating 3-Point-Bending Tests in Mouse Tibiae

Bone mechanical properties are classically determined by biomechanical tests, which normally destroy the bones and disable further histological or molecular analyses. Thus, obtaining biomechanical data from bone usually requires an additional group of animals within the experimental setup. Finite element models (FEMs) may non-invasively and non-destructively simulate mechanical characteristics based on material properties. The present study aimed to establish and validate an FEM to predict the mechanical properties of mice tibiae. The FEM was established based on µCT (micro-Computed Tomography) data of 16 mouse tibiae. For validating the FEM, simulated parameters were compared to biomechanical data obtained from 3-point bending tests of the identical bones. The simulated and the measured parameters correlated well for bending stiffness (R2 = 0.9104, p < 0.0001) and yield displacement (R2 = 0.9003, p < 0.0001). The FEM has the advantage that it preserves the bones’ integrity, which can then be used for other analytical methods. By eliminating the need for an additional group of animals for biomechanical tests, the established FEM can contribute to reducing the number of research animals in studies focusing on bone biomechanics. This is especially true when in vivo µCT data can be utilized where multiple bone scans can be performed with the same animal at different time points. Thus, by partially replacing biomechanical experiments, FEM simulations may reduce the overall number of animals required for an experimental setup investigating bone biomechanics, which supports the 3R (replace, reduce, and refine) principle.

Systematic Analysis of mRNAs and ncRNAs in BMSCs of Senile Osteoporosis Patients

Senile osteoporosis (SOP) is a worldwide age-related disease characterized by the loss of bone mass and decrease in bone strength. Bone mesenchymal stem cells (BMSCs) play an important role in the pathology of senile osteoporosis. Abnormal expression and regulation of non-coding RNA (ncRNA) are involved in a variety of human diseases. In the present study, we aimed to identify differentially expressed mRNAs and ncRNAs in senile osteoporosis patient-derived BMSCs via high-throughput transcriptome sequencing in combination with bioinformatics analysis. As a result, 415 mRNAs, 30 lncRNAs, 6 circRNAs and 27 miRNAs were found to be significantly changed in the senile osteoporosis group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were applied to analyze the function of differentially expressed mRNAs and ncRNAs. The circRNA–miRNA–mRNA regulatory network was constructed using the cytoHubba plugin based on the Cytoscape software. Interestingly, circRNA008876-miR-150-5p-mRNA was the sole predicted circRNA-miRNA-mRNA network. The differential expression profile of this ceRNA network was further verified by qRT-PCR. The biological function of this network was validated by overexpression and knockdown experiments. In conclusion, circRNA008876-miR-150-5p-mRNA could be an important ceRNA network involved in senile osteoporosis, which provides potential biomarkers and therapeutic targets for senile osteoporosis.

Aneurysm severity is suppressed by deletion of CCN4

Patients with abdominal aortic aneurysms are frequently treated with high-risk surgery. A pharmaceutical treatment to reverse aneurysm progression could prevent the need for surgery and save both lives and healthcare resources. Since CCN4 regulates cell migration, proliferation and apoptosis, processes involved in aneurysm progression, it is a potential regulator of aneurysm progression. We investigated the role of CCN4 in a mouse aneurysm model, using apolipoprotein-E knockout (ApoE^-/-) mice fed high fat diet and infused with Angiotensin II (AngII). Blood pressure was similarly elevated in CCN4^-/-ApoE^-/- mice and CCN4^+/+ApoE^-/- mice (controls) in response to AngII infusion. Deletion of CCN4 significantly reduced the number of ruptured aortae, both thoracic and abdominal aortic area, and aneurysm grade score, compared to controls. Additionally, the frequency of vessel wall remodelling and the number of elastic lamina breaks was significantly suppressed in CCN4^-/-ApoE^-/- mice compared to controls. Immunohistochemistry revealed a significantly lower proportion of macrophages, while the proportion of smooth muscle cells was not affected by the deletion of CCN4. There was also a reduction in both proliferation and apoptosis in CCN4^-/-ApoE^-/- mice compared to controls. In vitro studies showed that CCN4 significantly increased monocyte adhesion beyond that seen with TNFα and stimulated macrophage migration by more than threefold. In summary, absence of CCN4 reduced aneurysm severity and improved aortic integrity, which may be the result of reduced macrophage infiltration and cell apoptosis. Inhibition of CCN4 could offer a potential therapeutic approach for the treatment of aneurysms.

Aneurysm severity is suppressed by deletion of CCN4

Patients with abdominal aortic aneurysms are frequently treated with high-risk surgery. A pharmaceutical treatment to reverse aneurysm progression could prevent the need for surgery and save both lives and healthcare resources. Since CCN4 regulates cell migration, proliferation and apoptosis, processes involved in aneurysm progression, it is a potential regulator of aneurysm progression. We investigated the role of CCN4 in a mouse aneurysm model, using apolipoprotein-E knockout (ApoE^-/-) mice fed high fat diet and infused with Angiotensin II (AngII). Blood pressure was similarly elevated in CCN4^-/-ApoE^-/- mice and CCN4^+/+ApoE^-/- mice (controls) in response to AngII infusion. Deletion of CCN4 significantly reduced the number of ruptured aortae, both thoracic and abdominal aortic area, and aneurysm grade score, compared to controls. Additionally, the frequency of vessel wall remodelling and the number of elastic lamina breaks was significantly suppressed in CCN4^-/-ApoE^-/- mice compared to controls. Immunohistochemistry revealed a significantly lower proportion of macrophages, while the proportion of smooth muscle cells was not affected by the deletion of CCN4. There was also a reduction in both proliferation and apoptosis in CCN4^-/-ApoE^-/- mice compared to controls. In vitro studies showed that CCN4 significantly increased monocyte adhesion beyond that seen with TNFα and stimulated macrophage migration by more than threefold. In summary, absence of CCN4 reduced aneurysm severity and improved aortic integrity, which may be the result of reduced macrophage infiltration and cell apoptosis. Inhibition of CCN4 could offer a potential therapeutic approach for the treatment of aneurysms.

Adipose-PAS interactions in the context of its localised bio-engineering potential (Review)

Adipocytes are a known source of stem cells. They are easy to harvest, and are a suitable candidate for autogenous grafts. Adipose derived stem cells (ADSCs) have multiple target tissues which they can differentiate into, including bone and cartilage. In adipose tissue, ADSCs are able to differentiate, as well as providing energy and a supply of cytokines/hormones to manage the hypoxic and lipid/hormone saturated adipose environment. The plasminogen activation system (PAS) controls the majority of proteolytic activities in both adipose and wound healing environments, allowing for rapid cellular migration and tissue remodelling. While the primary activation pathway for PAS occurs through the urokinase plasminogen activator (uPA), which is highly expressed by endothelial cells, its function is not limited to enabling revascularisation. Proteolytic activity is dependent on protease activation, localisation, recycling mechanisms and substrate availability. uPA and uPA activated plasminogen allows pluripotent cells to arrive to new local environments and fulfil the niche demands. However, overstimulation, the acquisition of a migratory phenotype and constant protein turnover can be unconducive to the formation of structured hard and soft tissues. To maintain a suitable healing pattern, the proteolytic activity stimulated by uPA is modulated by plasminogen activator inhibitor 1. Depending on the physiological settings, different parts of the remodelling mechanism are activated with varying results. Utilising the differences within each microenvironment to recreate a desired niche is a valid therapeutic bio-engineering approach. By controlling the rate of protein turnover combined with a receptive stem cell lineage, such as ADSC, a novel avenue on the therapeutic opportunities may be identified, which can overcome limitations, such as scarcity of stem cells, low angiogenic potential or poor host tissue adaptation.

The genomic architecture of metastasis in breast cancer: focus on mechanistic aspects, signalling pathways and therapeutic strategies

Breast cancer is a multifactorial, heterogeneous disease and the second most frequent cancer amongst women worldwide. Metastasis is one of the most leading causes of death in these patients. Early-stage or locally advanced breast cancer is limited to the breast or nearby lymph nodes. When breast cancer spreads to farther tissues/organs from its original site, it is referred to as metastatic or stage IV breast cancer. Normal breast development is regulated by specific genes and signalling pathways controlling cell proliferation, cell death, cell differentiation and cell motility. Dysregulation of genes involved in various signalling pathways not only leads to the formation of primary tumour but also to the metastasis as well. The metastatic cascade is represented by a multi-step process including invasion of the local tumour cell followed by its entry into the vasculature, exit of malignant cells from the circulation and ultimately their colonization at the distant sites. These stages are referred to as formation of primary tumour, angiogenesis, invasion, intravasation and extravasation, respectively. The major sites of metastasis of breast cancer are the lymph nodes, bone, brain and lung. Only about 28% five-year survival rate has been reported for stage IV breast cancer. Metastasis is a serious concern for breast cancer and therefore, various therapeutic strategies such as tyrosine kinase inhibitors have been developed to target specific dysregulated genes and various signalling pathways involved in different steps of metastasis. In addition, other therapies like hyperbaric oxygen therapy, RNA interference and CRISPR/Cas9 are also being explored as novel strategies to cure the stage IV/metastatic breast cancer. Therefore, the current review has been compiled with an aim to evaluate the genetic basis of stage IV breast cancer with a focus on the molecular mechanisms. In addition, the therapeutic strategies targeting these dysregulated genes involved in various signalling pathways have also been discussed. Genome editing technologies that can target specific genes in the affected areas by making knock-in and knock-out alternations and thereby bring significant treatment outcomes in breast cancer have also been summarized.

Early satellite cell communication creates a permissive environment for long-term muscle growth

Using in vivo muscle stem cell (satellite cell)-specific extracellular vesicle (EV) tracking, satellite cell depletion, in vitro cell culture, and single-cell RNA sequencing, we show satellite cells communicate with other cells in skeletal muscle during mechanical overload. Early satellite cell EV communication primes the muscle milieu for proper long-term extracellular matrix (ECM) deposition and is sufficient to support sustained hypertrophy in adult mice, even in the absence of fusion to muscle fibers. Satellite cells modulate chemokine gene expression across cell types within the first few days of loading, and EV delivery of miR-206 to fibrogenic cells represses Wisp1 expression required for appropriate ECM remodeling. Late-stage communication from myogenic cells during loading is widespread but may be targeted toward endothelial cells. Satellite cells coordinate adaptation by influencing the phenotype of recipient cells, which extends our understanding of their role in muscle adaptation beyond regeneration and myonuclear donation.

The Potential Roles of Exosomal miR-214 in Bone Metastasis of Lung Adenocarcinoma

Bone metastasis is closely related to the alterations of bone microenvironment. In this article, we hypothesize that exosomes may be involved in the "vicious circle" by transferring miR-214. miR-214 is highly expressed in lung adenocarcinoma, and is closely related to the degree of lung cancer progression. As a key regulator of bone homeostasis, miR-214 promotes osteoclast differentiation and mediates intercellular communication between osteoclasts and osteoblasts via the way of exosomal miRNA. Therefore, it is highly probable that exosomal miR-214 derived from lung adenocarcinoma may disrupt bone homeostasis by enhancing bone resorption. Exosomal miR-214 can be released by lung adenocarcinoma cells, enters peripheral circulation, and is taken up by osteoclasts, consequently stimulating osteoclast differentiation. The enhanced bone resorption alters the bone microenvironment by releasing multiple cytokines and growth factors favoring cancer cells. The circulating cancer cells migrate to bone, proliferate, and colonize, resulting in the formation of metastasis. Furthermore, osteoclasts derived exosomal miR-214 may in turn contribute to cancer progression. In this way, the exosomal miR-214 from osteoclasts and lung adenocarcinoma cells mediates the positive interaction between bone resorption and bone metastasis. The levels of exosomal miR-214 in the peripheral circulation may help predict the risk of bone metastasis. The exosomal miR-214 may be a potential therapeutic target for both prevention and treatment of bone metastasis in patients with lung adenocarcinoma.

Tryptophan and Kynurenine Enhances the Stemness and Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells In Vitro and In Vivo

Aging tissues present a progressive decline in homeostasis and regenerative capacities, which has been associated with degenerative changes in tissue-specific stem cells and stem cell niches. We hypothesized that amino acids could regulate the stem cell phenotype and differentiation ability of human bone marrow-derived mesenchymal stromal cells (hBMSCs). Thus, we performed a screening of 22 standard amino acids and found that D-tryptophan (10 μM) increased the number of cells positive for the early stem cell marker SSEA-4, and the gene expression levels of OCT-4, NANOG, and SOX-2 in hBMSCs. Comparison between D- and L-tryptophan isomers showed that the latter presents a stronger effect in inducing the mRNA levels of Oct-4 and Nanog, and in increasing the osteogenic differentiation of hBMSCs. On the other hand, L-tryptophan suppressed adipogenesis. The migration and colony-forming ability of hBMSCs were also enhanced by L-tryptophan treatment. In vivo experiments delivering L-tryptophan (50 mg/kg/day) by intraperitoneal injections for three weeks confirmed that L-tryptophan significantly increased the percentage of cells positive for SSEA-4, mRNA levels of Nanog and Oct-4, and the migration and colony-forming ability of mouse BMSCs. L-kynurenine, a major metabolite of L-tryptophan, also induced similar effects of L-tryptophan in enhancing stemness and osteogenic differentiation of BMSCs in vitro and in vivo, possibly indicating the involvement of the kynurenine pathway as the downstream signaling of L-tryptophan. Finally, since BMSCs migrate to the wound healing site to promote bone healing, surgical defects of 1 mm in diameter were created in mouse femur to evaluate bone formation after two weeks of L-tryptophan or L-kynurenine injection. Both L-tryptophan and L-kynurenine accelerated bone healing compared to the PBS-injected control group. In summary, L-tryptophan enhanced the stemness and osteoblastic differentiation of BMSCs and may be used as an essential factor to maintain the stem cell properties and accelerate bone healing and/or prevent bone loss.

Investigation for GSK3β expression in diabetic osteoporosis and negative osteogenic effects of GSK3β on bone marrow mesenchymal stem cells under a high glucose microenvironment

Osteoporosis is a common skeletal complication of diabetes mellitus (DM). The mechanisms underlying the pathophysiology of diabetic osteoporosis are complex. Glycogen synthase kinase-3β (GSK-3β) is a widely expressed serine/threonine kinase and associated with both DM and bone metabolism, which arouse our concern. In this study, we established the diabetic mouse model by high-fat diet combined with streptozotocin injection. Decreased bone mass and reduced osteogenesis were observed in femurs of the mice. Besides, we identified that there is an activated expression of GSK3β in the bone marrow mesenchymal stem cells (BMSCs) of diabetic mice. To explore the link between GSK3β and diabetic osteoporosis, we exposed BMSCs to a high glucose microenvironment in vitro and discovered that the glucose-induced GSK3β activation has negative osteogenic effects on BMSCs by suppressing β-catenin/Tcf7/Ccn4 signaling axis. Inhibition of GSK3β by specific concentrations of LiCl could reverse the impaired osteogenesis of BMSCs and increase expression of β-catenin, Tcf7 and Ccn4. Our research indicated that abnormal activation of GSK3β plays a role in diabetic osteoporosis and might be a potential target to treat diabetic osteoporosis.

Wisp1 is a circulating factor that stimulates proliferation of adult mouse and human beta cells

Expanding the mass of pancreatic insulin-producing beta cells through re-activation of beta cell replication has been proposed as a therapy to prevent or delay the appearance of diabetes. Pancreatic beta cells exhibit an age-dependent decrease in their proliferative activity, partly related to changes in the systemic environment. Here we report the identification of CCN4/Wisp1 as a circulating factor more abundant in pre-weaning than in adult mice. We show that Wisp1 promotes endogenous and transplanted adult beta cell proliferation in vivo. We validate these findings using isolated mouse and human islets and find that the beta cell trophic effect of Wisp1 is dependent on Akt signaling. In summary, our study reveals the role of Wisp1 as an inducer of beta cell replication, supporting the idea that the use of young blood factors may be a useful strategy to expand adult beta cell mass.

The proliferation of pancreatic beta cells decreases with age, partly due to systemic changes. Here the authors identify Wisp1 as a circulating factor enriched in young serum that induces adult beta cell proliferation, supporting the idea that young blood factors may be useful to expand beta cell mass.

Ablation of Fat Cells in Adult Mice Induces Massive Bone Gain

Adipocytes control bone mass, but the mechanism is unclear. To explore the effect of postnatal adipocyte elimination on bone cells, we mated mice expressing an inducible primate diphtheria toxin receptor (DTR) to those bearing adiponectin (ADQ)-Cre. DTR activation eliminates peripheral and marrow adipocytes in these DTR^ADQ mice. Within 4 days of DTR activation, the systemic bone mass of DTR^ADQ mice began to increase due to stimulated osteogenesis, with a 1,000% expansion by 10-14 days post-DTR treatment. This adipocyte ablation-mediated enhancement of skeletal mass reflected bone morphogenetic protein (BMP) receptor activation following the elimination of its inhibitors, associated with simultaneous epidermal growth factor (EGF) receptor signaling. DTR^ADQ-induced osteosclerosis is not due to ablation of peripheral adipocytes but likely reflects the elimination of marrow ADQ-expressing cells. Thus, anabolic drugs targeting BMP receptor inhibitors with short-term EGF receptor activation may be a means of profoundly increasing skeletal mass to prevent or reverse pathological bone loss.

Adipokines: New Potential Therapeutic Target for Obesity and Metabolic, Rheumatic, and Cardiovascular Diseases

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like 1 (FSTL1), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C1q/TNF-related proteins (CTRPs), family with sequence similarity to 19 member A5 (FAM19A5), wingless-type inducible signaling pathway protein-1 (WISP1), progranulin (PGRN), nesfatin-1 (nesfatin), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-1 (PAI-1) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

WISP-2 expression induced by Teriparatide treatment affects in vitro osteoblast differentiation and improves in vivo osteogenesis

The Osteocyte, recognized as a major orchestrator of osteoblast and osteoclast activity, is the most important key player during bone remodeling processes. Imbalances occurring during bone remodeling, caused by hormone perturbations or by mechanical loading alterations, can induce bone pathologies such as osteoporosis. Recently, the active fraction of parathormone, PTH (1-34) or Teriparatide (TPTD), was chosen as election treatment for osteoporosis. The effect of such therapy is dependent on the temporal manner of administration. The molecular reasons why the type of administration regimen is so critical for the fate of bone remodeling are numerous and not yet well known. Our study attempts to analyze diverse signaling pathways directly activated in osteocytes upon TPTD treatment. By means of gene array analysis, we found many molecules upregulated or downregulated in osteocytes. Later, we paid attention to Wisp-2, a protein involved in the Wnt pathway, that is secreted by MLO-Y4 cells and increases upon TPTD treatment and that is able to positively influence the early phases of osteogenic differentiation. We also confirmed the pro osteogenic property of Wisp-2 during mesenchymal stem cell differentiation into the preliminary osteoblast phenotype. The same results were confirmed with an in vivo approach confirming a remarkable Wisp-2 expression in metaphyseal trabecular bone. These results highlighted the anabolic roles unrolled by osteocytes in controlling the action of neighboring cells, suggesting that the perturbation of certain signaling cascades, such as the Wnt pathway, is crucial for the positive regulation of bone formation.

Endogenous CCN family member WISP1 inhibits trauma-induced heterotopic ossification

Heterotopic ossification (HO) is defined as abnormal differentiation of local stromal cells of mesenchymal origin, resulting in pathologic cartilage and bone matrix deposition. Cyr61, CTGF, Nov (CCN) family members are matricellular proteins that have diverse regulatory functions on cell proliferation and differentiation, including the regulation of chondrogenesis. However, little is known regarding CCN family member expression or function in HO. Here, a combination of bulk and single-cell RNA sequencing defined the dynamic temporospatial pattern of CCN family member induction within a mouse model of trauma-induced HO. Among CCN family proteins, Wisp1 (also known as Ccn4) was most upregulated during the evolution of HO, and Wisp1 expression corresponded with chondrogenic gene profile. Immunohistochemistry confirmed WISP1 expression across traumatic and genetic HO mouse models as well as in human HO samples. Transgenic Wisp1LacZ/LacZ knockin animals showed an increase in endochondral ossification in HO after trauma. Finally, the transcriptome of Wisp1-null tenocytes revealed enrichment in signaling pathways, such as the STAT3 and PCP signaling pathways, that may explain increased HO in the context of Wisp1 deficiency. In sum, CCN family members, and in particular Wisp1, are spatiotemporally associated with and negatively regulate trauma-induced HO formation.

WISP1 promotes bovine MDSC differentiation via recruitment of ANXA1 for the regulation of the TGF-β signalling pathway

Skeletal muscle is one of the most important tissues of the human body necessary for sporting activities. The differentiation of muscle-derived satellite cells (MDSCs) plays an important role in the development and regeneration of skeletal muscles. Similarly, the Wnt/β-catenin signalling pathway plays an important role in the process of muscle differentiation. Wnt1-inducible signalling pathway protein-1 (WISP1), a downstream protein of the Wnt/β-catenin signalling pathway and a member of the CCN family that also plays an important role in the differentiation process, and its expression increase during the differentiation of bovine MDSCs. However, its role in MDSC differentiation is poorly understood. Therefore, we investigated the mechanisms regulating this process via Western blot and immunofluorescence staining. Immunoprecipitation and mass spectrometry detected annexin A1 (ANXA1), a protein that interacts with WISP1. To determine whether WISP1 influences TGF-β signalling and differentiation independently of ANXA1, the latter was knocked down, while WISP1 was activated. WISP1 expression increased significantly during bovine MDSC differentiation. However, WISP1 did not affect the TGF-β signalling pathway protein marker when ANXA1 was inhibited. Taken together, WISP1 regulates the TGF-β signalling pathway through ANXA1 recruitment, thereby promoting bovine MDSC differentiation, suggesting the Wnt/β-catenin signalling pathway as another target to promote cell differentiation.

The Effects of microRNA-515-5p on the Toll-Like Receptor 4 (TLR4)/JNK Signaling Pathway and WNT1-Inducible-Signaling Pathway Protein 1 (WISP-1) Expression in Rheumatoid Arthritis Fibroblast-Like Synovial (RAFLS) Cells Following Treatment with Receptor Activator of Nuclear Factor-kappa-B Ligand (RANKL)

BACKGROUND This study aimed to investigate the effects of microRNA-515-5p (miR-515-5p) on the expression of the WNT1-inducible-signaling pathway protein 1 (WISP-1) gene in rheumatoid arthritis fibroblast-like synovial (RAFLS) cells following treatment with the receptor activator of nuclear factor-kappa-B ligand (RANKL). MATERIAL AND METHODS RAFLS cells were cultured in vitro and were divided into six study groups: a normal control group; a miR-515-5p mimic group; a miR-515-5p inhibitor group; a RANKL (50 ng/ml) treatment group; a miR-515-5p mimic+RANKL treatment group; and a miR-515-5p inhibitor+RANKL treatment group. The luciferase assay was used to determine the effects of miR-515-5p on the WISP1 expression. Cell proliferation, cell apoptosis, the cell cycle, and protein expression were determined using the Cell Counting Kit-8 (CCK-8) assay, flow cytometry, Western blot, and real-time polymerase chain reaction (RT-PCR). RESULTS The luciferase assay showed that the effects of miR-515-on the 3'-UTR of WISP1 inhibited the gene expression. The miR-515-5p mimics promoted cell proliferation, reduced apoptosis, and promoted the cell cycle. The miR-515-5p mimics reduced, the expression of TLR4, WISP1, and JNK at the mRNA level, while the miR-515-5p inhibitor promoted the expression of TLR4, WISP1, and JNK. Both the miR-515-5p inhibitor and mimic promoted the phosphorylation of AKT in RAFLS cells treated with or without RANKL compared with the control, and the miR-515-5p inhibitor promoted the phosphorylation of JNK in the RAFLS cells. CONCLUSIONS In RAFLS cells, miR-515-5p inhibited the expression of the WISP1 gene, and treatment with RANKL inhibited the TLR4/JNK signaling pathway.

Bone morphogenetic proteins mediate crosstalk between cancer cells and the tumour microenvironment at primary tumours and metastases (Review)

Bone morphogenetic proteins (BMP) are pluripotent molecules, co‑ordinating cellular functions from early embryonic and postnatal development to tissue repair, regeneration and homeostasis. They are also involved in tumourigenesis, disease progression and the metastasis of various solid tumours. Emerging evidence has indicated that BMPs are able to promote disease progression and metastasis by orchestrating communication between cancer cells and the surrounding microenvironment. The interactions occur between BMPs and epidermal growth factor receptor, hepatocyte growth factor, fibroblast growth factor, vascular endothelial growth factor and extracellular matrix components. Overall, these interactions co‑ordinate the cellular functions of tumour cells and other types of cell in the tumour to promote the growth of the primary tumour, local invasion, angiogenesis and metastasis, and the establishment and survival of cancer cells in the metastatic niche. Therefore, the present study aimed to provide an informative summary of the involvement of BMPs in the tumour microenvironment.

Multifactor dimensionality reduction reveals a strong gene-gene interaction between STC1 and COL11A1 genes as a possible risk factor of knee osteoarthritis

Articular cartilage is an avascular tissue with a structure that allows it to support and cushion the overload of the surfaces in contact. It maintains its metabolic functions due to the contribution of different signaling pathways. However, several factors play a role in its deterioration, allowing to the development of osteoarthritis (OA), and one of the major factors is genetic. Our goal was to identify gene-gene interactions (epistasis) between five signaling pathways involved in the articular cartilage metabolism as possible indicators of OA risk. We applied the Multifactor-Dimensionality Reduction (MDR) method to identify and characterize the epistasis between 115 SNPs located in 73 genes related to HIF-1α, Wnt/β-catenin, cartilage extracellular matrix metabolism, oxidative stress, and uric acid transporters. Ninety three patients diagnosed with primary knee OA and 150 healthy controls were included in the study. Genotyping was performed with the OpenArray system, the statistical analysis was carried out with the STATA software v14, and epistasis was analyzed with the MDR software v3.0.2. The MDR analysis revealed that the best interaction model was between polymorphisms rs17786744 of the STC1 gene and rs2615977 of the COL11A1 gene, with an entropy value of 4.44%, CVC 8/10, OR 5.60, 95% CI 3.27-9.59, p < 0.0001. Under this interaction model, we identified high and low risk genotypes involved in OA development. Our results suggest complex interactions between STC1 and COL11A1 genes that might have an impact on genetic susceptibility to develop OA. Further studies are required to confirm it.

Cell Communication Network Factor 4 (CCN4/WISP1) Shifts Melanoma Cells from a Fragile Proliferative State to a Resilient Metastatic State

Introduction

Cellular communication network factor 4 (CCN4/WISP1) is a secreted matricellular protein that stimulates metastasis in multiple malignancies but has an unclear impact on phenotypic changes in melanoma. Recent data using cells edited via a double-nickase CRISPR/Cas9 approach suggest that CCN4/WISP1 stimulates invasion and metastasis of melanoma cells. While these data also suggest that loss of CCN4/WISP1 increases cell proliferative, the CRISPR approach used may be an alternative explanation rather than the loss of gene function.

Methods

To test whether CCN4/WISP1 also influences the proliferative phenotype of melanoma cells, we used mouse melanoma models and knocked out Ccn4 using a homology-directed repair CRISPR/Cas9 system to generate pools of Ccn4-knockout cells. The resulting edited cell pools were compared to parental cell lines using an ensemble of in vitro and in vivo assays.

Results

In vitro assays using knockout pools supported previous findings that CCN4/WISP1 promoted an epithelial-mesenchymal-like transition in melanoma cells and stimulated invasion and metastasis. While Ccn4 knockout also enhanced cell growth in optimal 2D culture conditions, the knockout suppressed certain cell survival signaling pathways and rendered cells less resistant to stress conditions. Tumor cell growth assays at sub-optimal conditions in vitro, quantitative analysis of tumor growth assays in vivo, and transcriptomics analysis of human melanoma cell lines were also used to quantify changes in phenotype and generalize the findings.

Conclusions

In addition to stimulating invasion and metastasis of melanoma cells, the results suggested that CCN4/WISP1 repressed cell growth and simultaneously enhanced cell survival.

Regulatory Effects and Interactions of the Wnt and OPG-RANKL-RANK Signaling at the Bone-Cartilage Interface in Osteoarthritis

Cartilage and the bordering subchondral bone form a functionally active regulatory interface with a prominent role in osteoarthritis pathways. The Wnt and the OPG-RANKL-RANK signaling systems, as key mediators, interact in subchondral bone remodeling. Osteoarthritic osteoblasts polarize into two distinct phenotypes: a low secretory and an activated, pro-inflammatory and anti-resorptive subclass producing high quantities of IL-6, PGE2, and osteoprotegerin, but low levels of RANKL, thus acting as putative effectors of subchondral bone sclerosis. Wnt agonists, Wnt5a, Wisp-1 initiate excessive bone remodeling, while Wnt3a and 5a simultaneously cause loss of proteoglycans and phenotype shift in chondrocytes, with decreased expression of COL2A, aggrecan, and Sox-9. Sclerostin, a Wnt antagonist possesses a protective effect for the cartilage, while DKK-1 inhibits VEGF, suspending neoangiogenesis in the subchondral bone. Experimental conditions mimicking abnormal mechanical load, the pro-inflammatory milieu, but also a decreased OPG/RANKL ratio in the cartilage, trigger chondrocyte apoptosis and loss of the matrix via degradative matrix metalloproteinases, like MMP-13 or MMP-9. Hypoxia, an important cofactor exerts a dual role, promoting matrix synthesis via HIF-1α, a Wnt silencer, but turning on HIF-2α that enhances VEGF and MMP-13, along with aberrant collagen expression and extracellular matrix deterioration in the presence of pro-inflammatory cytokines.

Fibro-Adipogenic Progenitors Cross-Talk in Skeletal Muscle: The Social Network

Skeletal muscle is composed of a large and heterogeneous assortment of cell populations that interact with each other to maintain muscle homeostasis and orchestrate regeneration. Although satellite cells (SCs) – which are muscle stem cells – are the protagonists of functional muscle repair following damage, several other cells such as inflammatory, vascular, and mesenchymal cells coordinate muscle regeneration in a finely tuned process. Fibro–adipogenic progenitors (FAPs) are a muscle interstitial mesenchymal cell population, which supports SCs differentiation during tissue regeneration. During the first days following muscle injury FAPs undergo massive expansion, which is followed by their macrophage-mediated clearance and the re-establishment of their steady-state pool. It is during this critical time window that FAPs, together with the other cellular components of the muscle stem cell niche, establish a dynamic network of interactions that culminate in muscle repair. A number of different molecules have been recently identified as important mediators of this cross-talk, and its alteration has been associated with different muscle pathologies. In this review, we will focus on the soluble factors that regulate FAPs activity, highlighting their roles in orchestrating the inter-cellular interactions between FAPs and the other cell populations that participate in muscle regeneration.

WNT1-inducible signaling pathway protein 1 (WISP1/CCN4) stimulates melanoma invasion and metastasis by promoting the epithelial-mesenchymal transition

Besides intrinsic changes, malignant cells also release soluble signals that reshape their microenvironment. Among these signals is WNT1-inducible signaling pathway protein 1 (WISP1), a secreted matricellular protein whose expression is elevated in several cancers, including melanoma, and is associated with reduced survival of patients diagnosed with primary melanoma. Here, we found that WISP1 knockout increases cell proliferation and represses wound healing, migration, and invasion of mouse and human melanoma cells in multiple in vitro assays. Metastasis assays revealed that WISP1 knockout represses tumor metastasis of B16F10 and YUMM1.7 melanoma cells in both C57BL/6Ncrl and NOD-scid IL2Rγ^null (NSG) mice. WT B16F10 cells having an invasion phenotype in a transwell assay possessed a gene expression signature similar to that observed in the epithelial-mesenchymal transition (EMT), including E-cadherin repression and fibronectin and N-cadherin induction. Upon WISP1 knockout, expression of these EMT signature genes went in the opposite direction in both mouse and human cell lines, and EMT-associated gene expression was restored upon exposure to media containing WISP1 or to recombinant WISP1 protein. In vivo, Wisp1 knockout-associated metastasis repression was reversed by the reintroduction of either WISP1 or snail family transcriptional repressor 1 (SNAI1). Experiments testing EMT gene activation and inhibition with recombinant WISP1 or kinase inhibitors in B16F10 and YUMM1.7 cells suggested that WISP1 activates AKT Ser/Thr kinase and that MEK/ERK signaling pathways shift melanoma cells from proliferation to invasion. Our results indicate that WISP1 present within the tumor microenvironment stimulates melanoma invasion and metastasis by promoting an EMT-like process.

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].

Aberrant mRNA splicing generates oncogenic RNA isoforms and contributes to the development and progression of cholangiocarcinoma

Cholangiocarcinoma is a lethal biliary cancer, with an unclear molecular pathogenesis. Alternative splicing is a post-transcriptional modification that generates mature mRNAs, which are subsequently translated into proteins. Aberrant alternative splicing has been reported to serve a role in tumor initiation, maintenance and metastasis in several types of human cancer, including cholangiocarcinoma. In this review, the aberrant splicing of genes and the functional contributions of the spliced genes, in the carcinogenesis, progression and aggressiveness of cholangiocarcinoma are summarized. In addition, factors that influence this aberrant splicing that may be relevant as therapeutic targets or prognosis markers for cholangiocarcinoma are discussed.

The emerging role of WISP proteins in tumorigenesis and cancer therapy

Accumulated evidence has demonstrated that WNT1 inducible signaling pathway protein (WISP) genes, which belong to members of the CCN growth factor family, play a pivotal role in tumorigenesis and progression of a broad spectrum of human cancers. Mounting studies have identified that WISP proteins (WISP1-3) exert different biological functions in various human malignancies. Emerging evidence indicates that WISP proteins are critically involved in cell proliferation, apoptosis, invasion and metastasis in cancers. Because the understanding of a direct function of WISP proteins in cancer development and progression has begun to emerge, in this review article, we describe the physiological function of WISP proteins in a variety of human cancers. Moreover, we highlight the current understanding of how the WISP protein is involved in tumorigenesis and cancer progression. Furthermore, we discuss that targeting WISP proteins could be a promising strategy for the treatment of human cancers. Hence, the regulation of WISP proteins could improve treatments for cancer patients.

WISP-1 drives bone formation at the expense of fat formation in human perivascular stem cells

The vascular wall within adipose tissue is a source of mesenchymal progenitors, referred to as perivascular stem/stromal cells (PSC). PSC are isolated via fluorescence activated cell sorting (FACS), and defined as a bipartite population of pericytes and adventitial progenitor cells (APCs). Those factors that promote the differentiation of PSC into bone or fat cell types are not well understood. Here, we observed high expression of WISP-1 among human PSC in vivo, after purification, and upon transplantation in a bone defect. Next, modulation of WISP-1 expression was performed, using WISP-1 overexpression, WISP-1 protein, or WISP-1 siRNA. Results demonstrated that WISP-1 is expressed in the perivascular niche, and high expression is maintained after purification of PSC, and upon transplantation in a bone microenvironment. In vitro studies demonstrate that WISP-1 has pro-osteogenic/anti-adipocytic effects in human PSC, and that regulation of BMP signaling activity may underlie these effects. In summary, our results demonstrate the importance of the matricellular protein WISP-1 in regulation of the differentiation of human stem cell types within the perivascular niche. WISP-1 signaling upregulation may be of future benefit in cell therapy mediated bone tissue engineering, for the healing of bone defects or other orthopaedic applications.