Speeding up Glioblastoma Cancer Research: Highlighting the Zebrafish Xenograft Model.

Glioblastoma multiforme (GBM) is a very aggressive and lethal primary brain cancer in adults. The multifaceted nature of GBM pathogenesis, rising from complex interactions between cells and the tumor microenvironment (TME), has posed great treatment challenges. Despite significant scientific efforts, the prognosis for GBM remains very poor, even after intensive treatment with surgery, radiation, and chemotherapy. Efficient GBM management still requires the invention of innovative treatment strategies. There is a strong necessity to complete cancer in vitro studies and in vivo studies to properly evaluate the mechanisms of tumor progression within the complex TME. In recent years, the animal models used to study GBM tumors have evolved, achieving highly invasive GBM models able to provide key information on the molecular mechanisms of GBM onset. At present, the most commonly used animal models in GBM research are represented by mammalian models, such as mouse and canine ones. However, the latter present several limitations, such as high cost and time-consuming management, making them inappropriate for large-scale anticancer drug evaluation. In recent years, the zebrafish (Danio rerio) model has emerged as a valuable tool for studying GBM. It has shown great promise in preclinical studies due to numerous advantages, such as its small size, its ability to generate a large cohort of genetically identical offspring, and its rapid development, permitting more time- and cost-effective management and high-throughput drug screening when compared to mammalian models. Moreover, due to its transparent nature in early developmental stages and genetic and anatomical similarities with humans, it allows for translatable brain cancer research and related genetic screening and drug discovery. For this reason, the aim of the present review is to highlight the potential of relevant transgenic and xenograft zebrafish models and to compare them to the traditionally used animal models in GBM research.

Multipotential Role of Growth Factor Mimetic Peptides for Osteochondral Tissue Engineering.

Articular cartilage is characterized by a poor self-healing capacity due to its aneural and avascular nature. Once injured, it undergoes a series of catabolic processes which lead to its progressive degeneration and the onset of a severe chronic disease called osteoarthritis (OA). In OA, important alterations of the morpho-functional organization occur in the cartilage extracellular matrix, involving all the nearby tissues, including the subchondral bone. Osteochondral engineering, based on a perfect combination of cells, biomaterials and biomolecules, is becoming increasingly successful for the regeneration of injured cartilage and underlying subchondral bone tissue. To this end, recently, several peptides have been explored as active molecules and enrichment motifs for the functionalization of biomaterials due to their ability to be easily chemically synthesized, as well as their tunable physico-chemical features, low immunogenicity issues and functional group modeling properties. In addition, they have shown a good aptitude to penetrate into the tissue due to their small size and stability at room temperature. In particular, growth-factor-derived peptides can play multiple functions in bone and cartilage repair, exhibiting chondrogenic/osteogenic differentiation properties. Among the most studied peptides, great attention has been paid to transforming growth factor-ß and bone morphogenetic protein mimetic peptides, cell-penetrating peptides, cell-binding peptides, self-assembling peptides and extracellular matrix-derived peptides. Moreover, recently, phage display technology is emerging as a powerful selection technique for obtaining functional peptides on a large scale and at a low cost. In particular, these peptides have demonstrated advantages such as high biocompatibility; the ability to be immobilized directly on chondro- and osteoinductive nanomaterials; and improving the cell attachment, differentiation, development and regeneration of osteochondral tissue. In this context, the aim of the present review was to go through the recent literature underlining the importance of studying novel functional motifs related to growth factor mimetic peptides that could be a useful tool in osteochondral repair strategies. Moreover, the review summarizes the current knowledge of the use of phage display peptides in osteochondral tissue regeneration.

Current knowledge of pituitary adenylate cyclase activating polypeptide (PACAP) in articular cartilage.

Pituitary adenylate cyclase activating polypeptide (PACAP) is an evolutionally well conserved neuropeptide, mainly expressed by neuronal and peripheral cells. It proves to be an interesting object of study both for its trophic functions during the development of several tissues and for its protective effects against oxidative stress, hypoxia, inflammation and apoptosis in different degenerative diseases. This brief review summarises the recent findings concerning the role of PACAP in the articular cartilage. PACAP and its receptors are expressed during chondrogenesis and are shown to activate the pathways involved in regulating cartilage development. Moreover, this neuropeptide proves to be chondroprotective against those stressors that determine cartilage degeneration and contribute to the onset of osteoarthritis (OA), the most common form of degenerative joint disease. Indeed, the degenerated cartilage exhibits low levels of PACAP, suggesting that its endogenous levels in adult cartilage may play an essential role in maintaining physiological properties. Thanks to its peculiar characteristics, exogenous administration of PACAP could be suggested as a potential tool to slow down the progression of OA and for cartilage regeneration approaches.

Evaluation of a Cell-Free Collagen Type I-Based Scaffold for Articular Cartilage Regeneration in an Orthotopic Rat Model.

The management of chondral defects represents a big challenge because of the limited self-healing capacity of cartilage. Many approaches in this field obtained partial satisfactory results. Cartilage tissue engineering, combining innovative scaffolds and stem cells from different sources, emerges as a promising strategy for cartilage regeneration. The aim of this study was to evaluate the capability of a cell-free collagen I-based scaffold to promote cartilaginous repair after orthotopic implantation in vivo. Articular cartilage lesions (ACL) were created at the femoropatellar groove in rat knees and cell free collagen I-based scaffolds (S) were then implanted into right knee defect for the ACL-S group. No scaffold was implanted for the ACL group. At 4-, 8- and 16-weeks post-transplantation, degrees of cartilage repair were evaluated by morphological, histochemical and gene expression analyses. Histological analysis shows the formation of fibrous tissue, at 4-weeks replaced by a tissue resembling the calcified one at 16-weeks in the ACL group. In the ACL-S group, progressive replacement of the scaffold with the newly formed cartilage-like tissue is shown, as confirmed by Alcian Blue staining. Immunohistochemical and quantitative real-time PCR (qRT-PCR) analyses display the expression of typical cartilage markers, such as collagen type I and II (ColI and ColII), Aggrecan and Sox9. The results of this study display that the collagen I-based scaffold is highly biocompatible and able to recruit host cells from the surrounding joint tissues to promote cartilaginous repair of articular defects, suggesting its use as a potential approach for cartilage tissue regeneration.

Cycloastragenol as an Exogenous Enhancer of Chondrogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells. A Morphological Study.

Stem cell therapy and tissue engineering represent a promising approach for cartilage regeneration. However, they present limits in terms of mechanical properties and premature de-differentiation of engineered cartilage. Cycloastragenol (CAG), a triterpenoid saponin compound and a hydrolysis product of the main ingredient in Astragalus membranaceous, has been explored for cartilage regeneration. The aim of this study was to investigate CAG's ability to promote cell proliferation, maintain cells in their stable active phenotype, and support the production of cartilaginous extracellular matrix (ECM) in human adipose-derived mesenchymal stem cells (hAMSCs) in up to 28 days of three-dimensional (3D) chondrogenic culture. The hAMSC pellets were cultured in chondrogenic medium (CM) and in CM supplemented with CAG (CAG-CM) for 7, 14, 21, and 28 days. At each time-point, the pellets were harvested for histological (hematoxylin and eosin (H&E)), histochemical (Alcian-Blue) and immunohistochemical analysis (Type I, II, and X collagen, aggrecan, SOX9, lubricin). After excluding CAG's cytotoxicity (MTT Assay), improved cell condensation, higher glycosaminoglycans (sGAG) content, and increased cell proliferation have been detected in CAG-CM pellets until 28 days of culture. Overall, CAG improved the chondrogenic differentiation of hAMSCs, maintaining stable the active chondrocyte phenotype in up to 28 days of 3D in vitro chondrogenic culture. It is proposed that CAG might have a beneficial impact on cartilage regeneration approaches.

Moderate Physical Activity as a Prevention Method for Knee Osteoarthritis and the Role of Synoviocytes as Biological Key.

The purpose of this study was to investigate the influence of moderate physical activity (MPA) on the expression of osteoarthritis (OA)-related (IL-1ß, IL-6, TNF-α, MMP-13) and anti-inflammatory and chondroprotective (IL-4, IL-10, lubricin) biomarkers in the synovium of an OA-induced rat model. A total of 32 rats were divided into four groups: Control rats (Group 1); rats performing MPA (Group 2); anterior cruciate ligament transection (ACLT)-rats with OA (Group 3); and, ACLT-rats performing MPA (Group 4). Analyses were performed using Hematoxylin & Eosin (H & E) staining, histomorphometry and immunohistochemistry. In Group 3, OA biomarkers were significantly increased, whereas, IL-4, IL-10, and lubricin were significantly lower than in the other experimental groups. We hypothesize that MPA might partake in rescuing type B synoviocyte dysfunction at the early stages of OA, delaying the progression of the disease.

Physical activity and Mediterranean diet based on olive tree phenolic compounds from two different geographical areas have protective effects on early osteoarthritis, muscle atrophy and hepatic steatosis.

PURPOSE: Osteoarthitis (OA) leads to progressive loss of articular cartilage, pain and joint disability. An acute injury constitutes an important risk factor for early OA, determining an inflammatory process responsible of cartilage degeneration and muscle atrophy, due to the joint pain and immobility. The study aims to assess the effects of conjugation of physical activity and diet enriched by olive tree compounds [extra virgin olive oil (EVOO) and olive leaf extract (OLE)], on the musculoskeletal system in OA rat model. METHODS: OA was induced by anterior cruciate ligament transection and confirmed by Mankin and OARSI scores. Rats were subjected to physical activity on treadmill 5 days a week for 10 min daily and fed with experimental diets (standard diet enriched with Sicilian EVOO, Tunisian EVOO and Tunisian EVOO-OLE) for 12 weeks. Immunohistochemistry was used to evaluate IL-6 and lubricin expression in cartilage tissue and ELISA was used to quantify these proteins in serum at different time points. Histology and histomorphometry analysis were done to valuate liver steatosis, muscle atrophy and cartilage pathological changes. RESULTS: Compared to the OA group, the experimental groups showed general increased lubricin and decreased IL-6 expression, significant muscle hypertrophy and no signs of liver steatosis, suggesting the beneficial effects of physical activity coupled with EVOO-enriched diets on rat articular cartilage. Interestingly, the best result was shown for Sicilian EVOO-enriched diet. CONCLUSION: In conclusion, the conjugation of physical activity and EVOO-enriched diet determines a significant articular cartilage recovery process in early OA.

Early effects of high-fat diet, extra-virgin olive oil and vitamin D in a sedentary rat model of non-alcoholic fatty liver disease.

BACKGROUND AND AIM: Western high-fat diet is related to metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Decreased levels of Vitamin D (VitD) and IGF-1 and their mutual relationship were also reported. We aimed to evaluate whether different dietary profiles, containing or not VitD, may exert different effects on liver tissue. METHODS: Twenty-eight male rats were fed for 10 weeks by different dietary regimens: R, regular diet; R-DS and R-DR, regular diet with respectively VitD supplementation (DS) and restriction (DR); HFB-DS and HFB-DR (41% energy from fat), high fat (butter) diet; HFEVO-DS and HFEVO-DR (41% energy from fat), high fat (Extra-virgin olive oil-EVO) diet. Severity of NAFLD was assessed by NAFLD Activity Score. Collagen type I, IL-1beta, VitD-receptor, DKK-1 and IGF1 expressions were evaluated by immunohistochemistry. RESULTS: All samples showed a NAS between 0 and 2 considered not diagnostic of steatohepatitis. Collagen I, although weakly expressed, was statistically greater in HFB-DS and HFB-DR groups. IL-1 was mostly expressed in rats fed with HFBs and HFEVOs and R-DR, and almost absent in R and R-DS diets. IGF-1 and DKK-1 were reduced in HFBs and HFEVOs diets and in particular in DR groups. CONCLUSIONS: A short-term high-fat diet could damage liver tissue in terms of inflammation and collagen I deposition, setting the basis for the subsequent steatohepatitis, still not identifiable anatomopathologically. Vitamin D restriction increases inflammation and reduces the expression of IGF-1 in the liver, worsening the fat-induced changing. EVOO seems be protective against the collagen I production.

Runx2 mediated Induction of Novel Targets ST2 and Runx3 Leads to Cooperative Regulation of Hypertrophic Differentiation in ATDC5 Chondrocytes.

Knowledge concerning expression and function of Suppression of Tumorigenicity 2 (ST2) in chondrocytes is at present, limited. Analysis of murine growth plates and ATDC5 chondrocytes indicated peak expression of the ST2 transmembrane receptor (ST2L) and soluble (sST2) isoforms during the hypertrophic differentiation concomitant with the expression of the hypertrophic markers Collagen X (Col X), Runx2 and MMP-13. Gain- and loss-of-function experiments in ATDC5 and primary human growth plate chondrocytes (PHCs), confirmed regulation of ST2 by the key transcription factor Runx2, indicating ST2 to be a novel Runx2 target. ST2 knock-out mice (ST2-/-) exhibited noticeable hypertrophic zone (HZ) reduction in murine growth plates, accompanied by lower expression of Col X and Osteocalcin (OSC) compared to wild-type (WT) mice. Likewise, ST2 knockdown resulted in decreased Col X expression and downregulation of OSC and Vascular Endothelial Growth Factor (VEGF) in ATDC5 cells. The ST2 suppression was also associated with upregulation of the proliferative stage markers Sox9 and Collagen II (Col II), indicating ST2 to be a new regulator of ATDC5 chondrocyte differentiation. Runx3 was, furthermore, identified as a novel Runx2 target in chondrocytes. This study suggests that Runx2 mediates ST2 and Runx3 induction to cooperatively regulate hypertrophic differentiation of ATDC5 chondrocytes.

RETRACTED: Polar and apolar extra virgin olive oil and leaf extracts as a promising anti-inflammatory natural treatment for osteoarthritis.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors. An anonymous reader made the authors aware of potential errors in the presentation and the experimental design for the Western blot data in Figure 3. Upon thorough investigation the authors concluded that in fact, in addition to an honest error (wrong image selected for inclusion into the article), the experimental design was not state-of-the-art in that the loading controls were run on parallel gels rather than on the gels to be probed for iNOS and collagen II. Therefore, in order to avoid any potentially wrong conclusions, the authors decided to retract the article, to confirm the data in a separate series of experiments and to submit the manuscript again after proper confirmation of the results and conclusions. The authors thank the anonymous reader, who spotted this error, and apologize for any inconvenience caused.

Engineered cartilage regeneration from adipose tissue derived-mesenchymal stem cells: A morphomolecular study on osteoblast, chondrocyte and apoptosis evaluation.

The poor self-repair capacity of cartilage tissue in degenerative conditions, such as osteoarthritis (OA), has prompted the development of a variety of therapeutic approaches, such as cellular therapies and tissue engineering based on the use of mesenchymal stem cells (MSCs). The aim of this study is to demonstrate, for the first time, that the chondrocytes differentiated from rat adipose tissue derived-MSCs (AMSCs), are able to constitute a morphologically and biochemically healthy hyaline cartilage after 6 weeks of culture on a Collagen Cell Carrier (CCC) scaffold. In this study we evaluated the expression of some osteoblasts (Runt-related transcription factor 2 (RUNX2) and osteocalcin), chondrocytes (collagen I, II and lubricin) and apoptosis (caspase-3) biomarkers in undifferentiated AMSCs, differentiated AMSCs in chondrocytes cultured in monolayer and AMSCs-derived chondrocytes seeded on CCC scaffolds, by different techniques such as immunohistochemistry, ELISA, Western blot and gene expression analyses. Our results showed the increased expression of collagen II and lubricin in AMSCs-derived chondrocytes cultured on CCC scaffolds, whereas the expression of collagen I, RUNX2, osteocalcin and caspase-3 resulted decreased, when compared to the controls. In conclusion, this innovative basic study could be a possible key for future therapeutic strategies for articular cartilage restoration through the use of CCC scaffolds, to reduce the morbidity from acute cartilage injuries and degenerative joint diseases.

Clinical evidence of traditional vs fast track recovery methodologies after total arthroplasty for osteoarthritic knee treatment. A retrospective observational study.

BACKGROUND: During the last years, programs to enhance postoperative recovery and decrease morbidity after total knee arthroplasty, have been developed across a variety of surgical procedures and referred to as "Fast-Track Surgery". In this study we aimed to find some answers in the management of osteoarthritic patients subjected to total knee arthroplasty, by using the Fast-Track methodology. To this purpose we evaluated parameters such as early mobilization of patients, better pain management, bleeding, possible complications, reduced hospitalization time, an overall improved recovery and patient satisfaction. METHODS: 132 patients were selected, of which, 95 treated with "Fast Track" method and 37 treated with traditional method (control group). All the patients were hospitalized and underwent the same rehabilitation program for the first three days after surgery. RESULTS: In both groups, the parameters of pain and deformity demonstrated the most rapid improvement, while those of function and movement were normalized as gradual and progressive improvement over the next 2 months. The different functional test used (Barthel, MRC, VAS) showed that the mean values were significantly greater in Fast Track group when compared to the control. CONCLUSION: The results of the study confirm that the application of the Fast Track protocol in orthopaedics after total knee replacement results in rapid post-surgery recovery. LEVEL OF EVIDENCE: IV. Case series, low-quality cohort or case-control studies.

Protective effects of high Tryptophan diet on aging-induced passive avoidance impairment and hippocampal apoptosis.

In our previous work we have shown that L-Tryptophan (TrP) enriched diet prevents the age-induced decline of hippocampal Serotonin (5-HT) production. Considering that loss or reduction in 5-HT neurotransmission may contribute to age-related cognitive decline, here we have investigated the effect of such diet on passive avoidance (PA) behavior, cell death, pro- and anti- apoptotic molecules (BAX, Bcl-2 and Caspase-3) and an important transcription factor involved in synaptic plasticity and memory (CREB). The increase in 5-HT neurotransmission in the Hippocampus (Hp) of aged rats was induced by 1 month of high TrP administration. In the first phase of our study we found that high TrP diet improves PA behaviour of aged rats and this correlated with a decrease of TUNEL positive cells in all hippocampal regions tested (CA1, CA2, CA3, DG). Interestingly, the Hp of aged animals fed with high TrP diet showed a significant downregulation of proapoptotic proteins, caspase-3 and BAX, and an increase of antiapoptotic molecules Bcl-2 as indicated by Western Blot and immunohistochemical analyses. Also, high TrP diet partially rescued the age-induced inhibition of hippocampal CREB phosphorylation. Altogether, our data suggest that enhanced TrP intake, and in consequence a potential increase in 5-HT neurotransmission, might be beneficial in preventing age-related detrimental features by inhibition of hippocampal apoptosis.

Angiogenesis correlates with macrophage and mast cell infiltration in lung tissue of animals exposed to fluoro-edenite fibers.

Angiogenesis plays a crucial role in progression of pleural malignant mesothelioma. A significantly increased incidence of pleural mesothelioma has been attributed to exposure to fluoro-edenite, a fibrous amphibole extracted from a local stone quarry. In this study, we have investigated the expression of CD68-positive macrophages, tryptase-positive mast cells and CD31 positive areas, as expression of microvascular density, in lung tissue of sheeps exposed to fluoro-edenite fibers vs controls, by immunohistochemical, morphometric and Western blot analysis. The result have evidenced a significant increase in the expression of CD68-positive macrophages, tryptase-positive mast cells as well as a significant increase in microvascular density evaluated as CD31 positive areas in lung tissue of of sheeps exposed to fluoro-edenite fibers vs controls. These data confirmed the important role played by tumor microenvironment components, including macrophages and mast cells, in favour of angiogenesis in pleural mesothelioma induced by fluoro-edenite exposure.

Mammary gland: From embryogenesis to adult life.

The aim of this review is to focus on the molecular factors that ensure the optimal development and maintenance of the mammary gland thanks to their integration and coordination. The development of the mammary gland is supported, not only by endocrine signals, but also by regulatory molecules, which are able to integrate signals from the surrounding microenvironment. A major role is certainly played by homeotic genes, but their incorrect expression during the spatiotemporal regulation of proliferative, functional and differentiation cycles of the mammary gland, may result in the onset of neoplastic processes. Attention is directed also to the endocrine aspects and sexual dimorphism of mammary gland development, as well as the role played by ovarian steroids and their receptors in adult life.

Ameliorative effects of PACAP against cartilage degeneration. Morphological, immunohistochemical and biochemical evidence from in vivo and in vitro models of rat osteoarthritis.

Osteoarthritis (OA); the most common form of degenerative joint disease, is associated with variations in pro-inflammatory growth factor levels, inflammation and hypocellularity resulting from chondrocyte apoptosis. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide endowed with a range of trophic effects in several cell types; including chondrocytes. However; its role in OA has not been studied. To address this issue, we investigated whether PACAP expression is affected in OA cartilage obtained from experimentally-induced OA rat models, and then studied the effects of PACAP in isolated chondrocytes exposed to IL-1ß in vitro to mimic the inflammatory milieu of OA cartilage. OA induction was established by histomorphometric and histochemical analyses. Changes in PACAP distribution in cartilage, or its concentration in synovial fluid (SF), were assessed by immunohistochemistry and ELISA. Results showed that PACAP abundance in cartilage tissue and SF was high in healthy controls. OA induction decreased PACAP levels both in affected cartilage and SF. In vitro, PACAP prevented IL-1ß-induced chondrocyte apoptosis, as determined by MTT assay; Hoechst staining and western blots of apoptotic-related proteins. These changes were also accompanied by decreased i-NOS and COX-2 levels, suggesting an anti-inflammatory effect. Altogether, these findings support a potential role for PACAP as a chondroprotective agent for the treatment of OA.

N-Cadherin, ADAM-10 and Aquaporin 1 expression in lung tissue exposed to fluoro-edenite fibers: an immunohistochemical study.

Fluoro-edenite (FE) fibers are similar to other amphibole asbestos fibers. The scientific relevance of FE is due to its ability to lead to chronic inflammation and carcinogenesis in lung tissue shown after its inhalation. These fibers stimulate aberrant host cell proliferation and induce the release of cytokines, growth factors, reactive oxygen and nitrite species, which results in DNA damage. In previous studies, we showed that FE induces functional modifications in sheep and human lung fibroblasts and alveolar epithelial cells, where the overexpression of several molecules probably involved in pathological cellular mechanisms induced by FE exposition have been detected. However, the mechanisms of cellular and molecular toxicity and the cellular response to FE fibers are still not well known. N-cadherin, ADAM-10 and AQP1 are molecules involved in carcinogenesis and in inflammatory process. In this study we analyzed, through immunohistochemistry, their expression in the lung tissue of sheep exposed to FE. Our results showed different patterns of immunolabeling for N-cadherin, ADAM-10 and AQP1. N-cadherin and ADAM-10 were more expressed in FE exposed lung tissue, when compared with the control. On the contrary, AQP1 was more expressed in non exposed lung tissue. These results suggest that N-Cadherin, ADAM-10 and AQP1 are probably involved in different pathological processes induced by FE fiber exposition. The aim of the study was to better understand the mechanisms of cellular and molecular toxicity and of cellular response to FE fibers in order to identify, in the future, a possible therapeutic intervention in cases of FE-associated pathogenesis.

Biosynthesis of collagen I, II, RUNX2 and lubricin at different time points of chondrogenic differentiation in a 3D in vitro model of human mesenchymal stem cells derived from adipose tissue.

The first aim of the study was to identify the most appropriate time for differentiation of adipose tissue derived mesenchymal stem cells (MSCs) to chondrocytes, through the self-assembly process. For this purpose, the expression of some chondrocyte markers, such as collagen type I, collagen type II, RUNX2 and lubricin was investigated at different times (7, 14, 21 and 28 days) of chondrogenic differentiation of MSCs, by using immunohistochemistry and Western blot analysis. The second aim of the study was to demonstrate that the expression of lubricin, such as the expression of collagen type II, could be a possible biomarker for the detection of chondrocytes well-being and viability in the natural self-assembling constructs, called 'cell pellets'. Histology (hematoxylin and eosin) and histochemistry (alcian blue staining) methods were used to assess the chondrogenic differentiation of MSCs. The results showed that after 21 days the differentiated chondrocytes, when compared with MSCs cultured without chondrogenic medium (CD44, CD90 and CD105 positive; CD45, CD14 and CD34 negative), were able to produce significant quantities of collagen type I, collagen type II, and lubricin, suggesting hyaline cartilage formation. During the differentiation phase, the cells showed a reduced expression of RUNX2, a protein expressed by osteoblasts. Our studies demonstrated that 21 days is the optimum time for the implantation of chondrocytes differentiated from adipose tissue-derived MSCs. This information could be useful for the future development of cell-based repair therapies for degenerative diseases of articular cartilage.

ADAM-10 could mediate cleavage of N-cadherin promoting apoptosis in human atherosclerotic lesions leading to vulnerable plaque: a morphological and immunohistochemical study.

Atherosclerosis remains a major cause of mortality. Whereas the histopathological progression of atherosclerotic lesions is well documented, much less is known about the development of unstable or vulnerable plaque, which can rupture leading to thrombus, luminal occlusion and infarct. Apoptosis in the fibrous cap, which is rich in vascular smooth muscle cells (VSMCs) and macrophages, and its subsequent weakening or erosion seems to be an important regulator of plaque stability. The aim of our study was to improve our knowledge on the biological mechanisms that cause plaque instability in order to develop new therapies to maintain atherosclerotic plaque stability and avoid its rupture. In our study, we collected surgical specimens from atherosclerotic plaques in the right or left internal carotid artery of 62 patients with evident clinical symptoms. Histopathology and histochemistry were performed on wax-embedded sections. Immunohistochemical localization of caspase-3, N-cadherin and ADAM-10 was undertaken in order to highlight links between apoptosis, as expressed by caspase-3 immunostaining, and possible roles of N-cadherin, a cell-cell junction protein in VSMCs and macrophages that provides a pro-survival signal reducing apoptosis, and ADAM-10, a "disintegrin and metalloproteases" that is able to cleave N-cadherin in glioblastomas. Our results showed that when apoptosis, expressed by caspase-3 immunostaining, increased in the fibrous cap, rich in VSMCs and macrophages, the expression of N-cadherin decreased. The decreased N-cadherin expression, in turn, was linked to increased ADAM-10 expression. This study shows that apoptotic events are probably involved in the vulnerability of atherosclerotic plaque.