Search

Levels of the enzyme autotaxin (ATX) are elevated in synovial fluid and plasma of osteoarthritic patients, correlating positively with radiographic and symptomatic severity of the disease. Therefore, ATX is studied as potential marker for the progression of osteoarthritis (OA), whereas the chondrocyte-secreted glycoprotein Lubricin has chondroprotective properties. The aim of this study was to evaluate the expression of ATX and Lubricin in healthy and mild OA rat articular cartilage of femur, tibia and patella, and to analyse the effect of a protocol of moderate physical activity on their expressions. Mild OA resulted from anterior cruciate ligament transection and rats exercised on a treadmill for 12 weeks. Computerized staining intensity of immunostaining was used to evaluate ATX and Lubricin expressions. Higher expressions of ATX were found in femur and tibia of OA rats, suggesting that this molecule could participate in the progression of the disease, although not involved in the patella. In the femur, physical activity performed by OA rats was able to lower ATX expression, encouraging the evidence that joint movement is beneficial for the cartilage, although no significant differences in Lubricin expression were detected in femur, tibia and patella. This evidence might shade some light about the role of ATX, Lubricin and physical exercise in OA progression., (Copyright © 2022 Elsevier GmbH. All rights reserved.)

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors.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., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

The purpose of this study was to determine the presence of ADAM10 in temporomandibular joint disk with internal derangement. Twenty-five paraffin blocks of displaced temporomandibular joint (TMJ) disk specimens from earlier investigations were retrieved from the archives of the University of Catania. Of these 16 had been removed from females and 9 from males; 11 with anterior disk displacement with reduction (ADDwR) and 14 with anterior disk displacement without reduction (ADDwoR). The sections were dehydrated, embedded in paraffin and cut. Then they were incubated in 0.3% H2O2/methanol and half of sections from each sample were incubated in diluted rabbit polyclonal anti-ADAM10 antibody. Then biotinylated anti-mouse/anti-rabbit IgG was applied to the sections, followed by avidin-biotin-perioxidase complex. The results were analyzed and the results were that ADAM10 was overexpressed in the posterior band of sections from patients with ADDwR compared to the other bands of both ADDwR and ADDwoR sections. Overexpression correlated with severe histopathological degeneration. We believe these results have the potential to provide insights into the pathogenesis of TMJ disk degeneration and to help design new therapeutic approaches targeting the proteolytic events that lead to tissue degeneration. Early therapeutic block of ADAM10 activity could succeed in limiting aggrecan-rich matrix breakdown without affecting normal physiology., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The pituitary gland and the hypothalamus are morphologically and functionally associated in the endocrine and neuroendocrine control of other endocrine glands. They therefore play a key role in a number of regulatory feedback processes that co-ordinate the whole endocrine system. Here we review the neuroendocrine system, from the discoveries that led to its identification to some recently clarified embryological, functional, and morphological aspects. In particular we review the pituitary gland and the main notions related to its development, organization, cell differentiation, and vascularization. Given the crucial importance of the factors controlling neuroendocrine system development to understand parvocellular neuron function and the aetiology of the congenital disorders related to hypothalamic-pituitary axis dysfunction, we also provide an overview of the molecular and genetic studies that have advanced our knowledge in the field. Through the action of the hypothalamus, the pituitary gland is involved in the control of a broad range of key aspects of our lives: the review focuses on the hypothalamic-pituitary-gonadal axis, particularly GnRH, whose abnormal secretion is associated with clinical conditions involving delayed or absent puberty and reproductive dysfunction., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

The purpose of this study was to investigate the expression of lubricin, the product of the human PRG4 (proteoglycan 4) gene, in menisci and synovial fluid from normal donors and patients with osteoarthritis (OA), using a combination of histology, immunohistochemistry, ELISA and Western blotting analysis, to provide further insight on the role of this protein in the progression of OA and pathological processes in the meniscus. Lubricin expression was studied in samples from 40 patients and in 9 normal donors after arthroscopic partial meniscectomy. Histological analysis confirmed normal microanatomy and the absence of structural changes in control samples. Menisci derived from OA patients showed evidence of structural alterations, fibrillations and clefts. Immunohistochemical analysis revealed very strong lubricin immunostaining in normal menisci in contrast to weak/moderate staining seen in osteoarthritic menisci. Quantitative ELISA and Western blot analysis confirmed the above results. The findings of this study support the notion that changes in lubricin expression and boundary-lubricating ability of cartilage is followed by the development of OA. This study could provide the biological foundation for the development of novel therapeutic treatments, to be applied before the surgery, for the prevention of post-traumatic cartilage damage., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

The phenotypes of the temporomandibular joint (TMJ) disc cells range from fibroblasts to chondrocytes. There are relatively few reported studies using transmission electron microscopy (TEM) to determine the ultrastructural features of these cells. It was hypothesized that at least a subpopulation of TMJ stromal cells could be represented by the telocytes, cells with telopodes. In this regard a TEM study was performed on rat TMJ samples. Collagen-embedded networks were found built-up by cells with telopodes with subplasmalemmal caveolae, moderate content in matrix secretory organelles and well-represented intermediate filaments. Appositions of cell bodies were found. Prolongations of such cells were closely related to nerves and microvessels. Our study indicates that the TMJ disc attachment seems equipped with telocytes capable of stromal signaling. However, further studies are needed to assess whether the telocytes belong to a renewed cell population derived from circulating precursors., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Serotonin (5HT) is a neurotransmitter synthesized in serotonergic neurons of the central nervous system and in the enterochromaffin cells of the gastrointestinal tract. 5HT regulates growth and maturation of some cerebral regions in the developing brain as well as the secretion of pituitary growth hormone. This hormone is necessary for development and growth through the stimulation of insulin-like growth factor synthesis. The precursor of 5HT, tryptophan (Trp), is an essential amino acid, since the human organism is unable to synthesize it and it is assumed only through diet. The aim of our study was to analyze how a high-tryptophan diet in pregnant rats affects growth and survival of pups until weaning. We monitored the number and weight of pups until weaning. Then, we detected serotonin and growth hormone levels in whole blood by ELISA of surviving pups at the end of the lactation period. We also analyzed by means of immunohistochemistry and Western blot the expression of serotonin in rat gastric tissue and the morphological structure of skeletal muscle tissue of both control and experimental pups. Hyperserotonemia and very low levels of growth hormone were detected in experimental pups compared to controls. Immunohistochemistry demonstrated a strong serotonin expression in stomach samples confirming that a high intake of tryptophan increases the production of serotonin in enterochromaffin cells, thereby resulting in hyperserotonemia in pups. These data were also strengthened by Western blot analysis. Histological alterations of skeletal muscle fibers in experimental pups were found and showed that in experimental samples the muscle tissue demonstrated deleterious alterations, being less developed and defined. Our data suggest that a high-tryptophan diet in pregnant rats induces hyperserotonemia in the fetus. Hyperserotonemia results in an excess of serotonin in the brain where it has a negative influence on development of serotonergic neurons and consequently on growth hormone production., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Melanoma, a cancer notorious for its high potential to metastasize, arises from melanocytes, cells dedicated to melanin production and located in the basal layer of the epidermis. Raf-1 kinase inhibitor protein (RKIP) is an inhibitory molecule that down-regulates the effects of the Ras/Raf/MEK/ERK signaling pathway. The aim of this study was to examine the expression of RKIP and pRKIP in melanomas at different stages. We evaluated the RKIP and pRKIP protein by immunohistochemistry in control skin, pigmented nevi and melanomas, and through Western blotting in human normal melanocytes and in four different melanoma-derived cell lines (WM35, A375, M14, and A2058). Our results demonstrated a correlation between the expression of RKIP and pRKIP, and metastatic ability in melanoma cells. This raises the possibility to analyze both RKIP and pRKIP in all melanomas. Down-regulation of both RKIP and pRKIP expression could represent a useful marker of metastatic melanoma. On the contrary for non-metastatic melanoma, especially in Clark I and II, low RKIP and high pRKIP expression could be indicative. In conclusion, the observed negative correlation of the RKIP and pRKIP expression in metastatic melanomas indicates that expression of these proteins may become a prognostic marker for the progression of human cutaneous melanoma. We propose that the investigation of both RKIP and pRKIP may provide a useful tool indicative for metastatic or non-metastatic melanoma in different Clark's level melanomas. Further studies are required to verify the molecular background of the observed RKIP and pRKIP variations., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Astrocytes are considered as neuromodulators of the CNS. Whereas experimental studies on astrocitary functions are gaining importance, the anatomy of the astrocitary niches in the human CNS has been overlooked. The study was performed on the brainstem of 10 adult cadavers. We aimed to determine astrocitary niches in the human medulla oblongata using immunohistochemical labeling with vimentin and also CD34 immunostaining to accurately diagnose associated microvessels. Niches rich in astrocytes were identified as follows: (a) the superficial layer of astrocytes, ventral and ventrolateral, in the rostral medulla oblongata; (b) the median raphe; (c) medullary nuclei: arcuate nucleus, area postrema, nucleus of the solitary tract; (d) the subependymal zone (SEZ, caudal medulla) and subventricular zone (SVZ, rostral medulla). Astrocytes were scarce in the ventrolateral medulla, and mostly present within the pyramidal tract and the olivary nucleus. Apart from the SEZ and SVZ, the brainstem niches of astrocytes mostly overlap those regions known to perform roles as central respiratory chemoreceptors. The astrocytes of the SEZ and SVZ, which are known as stem cell niches, are related to an increased microvascular density., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Nestin labels neuroepithelial stem cells and endothelial cells in newly formed blood vessels. The aim of the study was to investigate the immunolocalization of nestin in human adult trigeminal ganglia. Autopsy samples from eight human adult cadavers were paraffin embedded, and immunostained with anti-nestin antibody. Satellite glial cells (SGCs) and intraganglionic microvessels were positively labeled with nestin, which is usually expressed in endothelial cells of newly formed blood vessels. Nestin-positive SGCs have been previously reported in rat trigeminal ganglia. Our study is the first to identify them in human trigeminal ganglia. Further studies are needed to evaluate if the nestin phenotype of SGCs relates to the functional plasticity of these cells or to glial and/or neuronal remodeling in adults. Intrinsic angiogenesis in the adult trigeminal ganglion should be further checked as to whether it relates to a normal vascular remodeling or if it represents an overlooked determinant of trigeminal neuralgia., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Defensins are antibiotic peptides involved in host defense mechanisms, wound healing and tissue repair. Furthermore, they seem to play an important role in protection mechanisms in articular joints. The aim of this study was to investigate β-defensin-4 expression in chondrocytes taken from articular cartilage of knees of patients with osteoarthritis (OA) compared to normal cartilage, in vivo in explanted tissue, and in vitro in chondrocytes encapsulated in construct PEGDA hydrogels. The present investigation was conducted to try and elucidate the possible use of β-defensin-4 as a relevant marker for the eventual use of successive scaffold allografts, and to provide new insights for hydrogel PEGDA scaffold efficacy in re-differentiation or repair of OA chondrocytes in vitro. Articular cartilage specimens from OA cartilage and normal cartilage were assessed by histology, histochemistry, immunohistochemistry and Western blot analysis. The results showed strong β-defensin-4 immunoexpression in explanted tissue from OA cartilage and weak β-defensin-4 expression in control cartilage. The chondrocytes from OA cartilage after 4 weeks of culture in PEGDA hydrogels showed the formation of new hyaline cartilage and a decreased expression of β-defensin-4 immunostaining comparable to that of control cartilage. Our results suggest the possibility of applying autologous cell transplantation in conjunction with scaffold materials for repair of cartilage lesions in patients with OA using β-defensin-4 as a relevant marker., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Lubricin is a protein which contributes to the boundary lubrication, facilitating low friction levels at the interfacing surfaces of joints. In tendons and ligaments it facilitates the relative movement of collagen bundles. Its expression is affected by mechanical signals and cytokines. During application of orthodontic forces to teeth, there is a transduction of mechanical forces to the cells of the periodontal ligament (PDL), which triggers several biological reactions causing the synthesis of prostaglandins, cytokines and growth factors. The aim of the present study was to examine the immunolocalization of lubricin and to evaluate if it is time-dependently and differentially detected within the PDL following the application of orthodontic forces to create areas of compression and tension. This was achieved by placing elastic bands between the maxillary first and second molars of 16 male Sprague-Dawley rats (each weighing 120-200g) for 12 and 24h. The molar-bearing segments were dissected and processed for histological and immunohistochemical examination. Binding of a monoclonal antibody was used to evaluate lubricin localization using an indirect streptavidin/biotin immunperoxidase technique. Lubricin, was constitutively expressed in the PDL of rat molars. After the experimental force was applied to the tooth, lubricin was down-regulated, on both sides (compression and tension) of the PDL, in a time-dependent fashion, although to a different extent, being at any time more expressed on the tension side. Furthermore, in every sample, almost all PDL cells in the adjacent tooth cementum and alveolar bone, were more heavily immunolabeled by lubricin antibody, contrary to those located in the central portion of the PDL. Lubricin expression therefore seems related to PDL remodeling and tooth displacement following the application of an orthodontic force, and it appears that lubricin may play an important role during tooth movement., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Aquaporins (AQPs) are a family of hydrophobic membrane channel proteins. The expression of several AQP isoforms has been investigated in different human tissues, including the orofacial region. However, information on the role and localization of AQP1 in joints is limited, and no data are available on aquaporins in the normal temporomandibular joint (TMJ) disc. Sixteen human TMJ discs without degenerative changes were taken from fresh cadavers to investigate the presence and distribution of AQP1 by immunohistochemistry. The aim of the study was to gain additional insights into the biomolecular composition of aquaporins and their role in homeostasis of the TMJ. Porcine TMJ discs were also studied by Western blotting for comparison. Scattered AQP1 immunoexpression was detected in human disc cells, documenting its constitutive expression, but differences amongst the three disc regions were not significant. AQP1 expression was demonstrated in porcine TMJ disc by Western blotting. Our findings suggest that AQP1 is normally expressed in the TMJ disc and confirm a role for it in the maintenance of TMJ homeostasis. Further studies are needed to elucidate expression patterns of aquaporins in diseased TMJ discs., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Lubricin, which is a boundary joint lubricant, was investigated immunohistochemically in the bilaminar zone (BZ) of the human temporomandibular joint (TMJ), without any degenerative changes. Immunohistochemistry for lubricin detection was carried out on 33 TMJ discs obtained from 17 cadavers. Sections were incubated with diluted rabbit polyclonal anti-lubricin antibody and scored according to the percentage of lubricin immunopositive cells. Three different TMJ disc tissue compartments were analyzed, namely: the upper lamina, the inferior lamina and the loose connective tissue in the space between the laminae. The Mann-Whitney U test was used to compare protein expression (lubricin) among disc specimens' regions. Staining was noted within the TMJ disc cell populations in every disc tissue sample, with almost every cell immunolabeled by the lubricin antibody. The number of disc cells immunolabeled was almost the same in the 3 bilaminar zone regions. Positive extracellular matrix staining was also seen. The results of the present study suggest that lubricin is expressed in the TMJ disc bilaminar zone. Lubricin may have a role in normal disc posterior attachment physiology through the prevention of cellular adhesion as well as providing lubrication during normal bilaminar zone function., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Osteopenia is a significant problem associated with Diabetes mellitus. Osteopenia may result in an increased delay in healing of bone fractures and subsequently affect the quality of life. We evaluated the immunohistochemical localization of TRAIL and its receptor DR5 in the femoral bone of 10-week-old Sprague-Dawley male rats treated with sesame oil (control, group 1), streptozotocin (STZ), a diabetes inducer (group 2), L-NAME, a general inhibitor of NOS activity (group 3), L-arginine (group 4), (arginine acts as a NO substrate) and iNOS immunostaining in group 1 and group 4. Histological and histochemical findings showed decreased growth of metaphyseal cartilage (which was thinner), decreased osteoid surface, and reduced mineral apposition rate in STZ- and L-NAME-treated rats. These findings confirm that bone formation is impaired in diabetic osteopenia. L-arginine supplementation seems to prevent diabetes-induced bone alterations and preserve the calcification process, allowing synthesis of new bone matrix. The immunohistochemical study revealed increased immunostaining of TRAIL and DR5 in osteoblastic cells of the diaphysis (pre-metaphysis) and epiphysis treated with STZ and L-NAME, related to activation of osteoblastic apoptotic death, while the group receiving L-arginine was comparable to the control group and the higher indications of iNOS activity that may reflect its induction by L-arginine administration. The action of L-arginine suggests that increased NO synthesis and availability is potentially useful for effective prevention and treatment of diabetic osteopenia., (Copyright © 2010 Elsevier GmbH. All rights reserved.)

The c-Met system is involved in skeletogenesis and is expressed in the cartilage of growth plates. However, the localization and role of c-Met during endochondral ossification of developing mandibular condyles or during intramembranous ossification has not yet been elucidated. In this study, c-Met was examined immunohistochemically in the mandibles of human fetuses during weeks 9 and 16 of pregnancy. c-Met was immunolocalised in the whole area of the developing mandible, although to different extents. In the intramembranous bone, mesenchymal cells showed a weak immunopositivity. Osteoprogenitor cells demonstrated a moderate immunopositivity for c-Met, while osteoblasts and osteocytes showed a very strong immunolabelling of c-Met. In the developing mandibular condyles, c-Met immunopositivity increased gradually throughout the proliferative layer towards the pre-hypertrophic cell layer, whereas the cells of the hypertrophic layer were weakly immunopositive. These findings have demonstrated, for the first time, the prominent immunolocalization of c-Met in osteogenic and chondrogenic tissues of developing human mandibles, which indicates possible functions for this receptor during mandibular development., (2009 Elsevier GmbH. All rights reserved.)

We evaluated if immunolocalization of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in odontoblast dentinal tubuli changes in response to caries attack in human carious teeth. Ten permanent premolar teeth with moderate to advanced caries and two sound teeth were collected. The premolars were decalcified in ethylene-diamininetetracetic acid (EDTA) and processed for embedding in paraffin wax. Sections of 3-4mum thick were cut and processed for immunohistochemistry. A mouse monoclonal anti-TIMP-1 antibody was used for the localization of TIMP-1 using an immunperoxidase technique. TIMP-1 immunoreactivity was observed in dentine of both sound and carious teeth. In both cases, the density of immunolabelled dentinal tubuli was typically higher toward the pulp chamber. In all the carious teeth, most, but never all, dilated dentinal tubuli were strongly positively immunolabelled. In sound teeth, a weak immunoreaction, only slightly above the background, was observed in dentinal tubuli. These results provide evidence for increased TIMP-1 immunolabelling in dentinal tubuli of carious teeth, in contrast to sound teeth. Overall, these in vivo findings indicate a possible role for TIMP-1 in the pathology of adult human dental tissues following an injury such as a caries lesion., (2008 Elsevier GmbH. All rights reserved.)

The normal articular disc of the human temporomandibular joint (TMJ) consists of regularly arranged collagen fibers and fibroblast-like cells. Disc tissue is subjected to various types of loading. Adaptive remodelling entails microscopic changes in which different types of collagen and non-collagen proteins, as well as matrix metalloproteinases (MMPs), are involved. Collagenase-3 (MMP-13) seems to play a key role. The aim of the study was to evaluate its involvement in TMJ disc histopathology. We studied 10 discs from patients with arthropathy of the TMJ. Paraffin wax-embedded sections were processed for histological and immunohistochemical analysis. A well-characterized mouse monoclonal anti-MMP-13 antibody (anti-collagenase 3) was used. The results showed increased MMP-13 immunoreactivity in TMJ diseased disc tissue was correlated with the severity of the histopathological changes. The more severe the pathological changes, the greater the number of immunolabelled cells detected. Nearly all chondrocyte-like cells were immunopositive, whereas fibroblast-like cells and fibrochondrocytes were more rarely labelled. MMP-13 upregulation in disc tissue from patients with TMJ internal derangement suggests that MMP-13 is involved in disc histopathology, and that disc cells actively participate in the synthesis of extracellular matrix-degrading proteinases.

Matrix metalloproteinases (MMPs) are enzymes that play a central role in periodontal ligament (PDL) space remodelling during orthodontic tooth movement. It has previously been shown that messenger RNA levels of MMP-13 increase significantly following the application of orthodontic forces. The aim of the present study was to examine immunolocalisation of MMP-13 and to evaluate if this collagenase is time-dependently and differentially detected within the PDL following the application of orthodontic forces to create areas of compression and tension. This was achieved by placing elastic bands between the maxillary first and second molars of 16 male Sprague-Dawley rats (each weighing 120-200g) for 12 and 24h. The molar-bearing segments were dissected and processed for histological and immunohistochemical examination. Binding of a monoclonal antibody was used to evaluate MMP-13 localization using an indirect streptavidin/biotin immunperoxidase technique. MMP-13 was found to be inducible at the protein level by the application of forces. The PDL and osteoblast-lineage cells showed a time-dependent increase in immunolabelling of MMP-13. Immunolabelling of MMP-13 was detected initially on the compression side, and then on both the compression and the tension sides. Since this increase in MMP-13 immunolabelling occurred very early following the application of an orthodontic force in both PDL and alveolar bone, this would indicate that MMP-13 might play an important role during tooth movement.

CD44s (standard form) is an integral membrane glycoprotein, which plays an important role in both cell-cell and cell-substrate adhesion. Few studies have demonstrated that CD44s and its isoforms are involved in mediating cell-cell and cell-substrate interactions in the periodontium and surrounding tissues. The present study was undertaken as so little data are available on its presence in human adult hard dental structures. Six extracted premolars from children, aged 10-12 years, were used in the present study. They were fixed in 10% neutral buffered formalin and decalcified in 7.5% EDTA for 2 weeks. Immunohistochemistry to reveal binding of a monoclonal mouse anti-CD44s was used for the localization of CD44s. The antibody was applied directly onto the tissue section and the slides incubated overnight (4 degrees C) in a humidified chamber. In serial sagittal sections of teeth, binding of anti-CD44s was seen in odontoblasts, periodontal ligament fibroblasts and cementoblasts. Our findings present evidence that CD44s is localized in periodontal ligament fibroblasts, cementocytes and odontoblasts of mature human teeth. CD44s may be involved in tooth cell differentiation and later in cell-matrix interaction and in the accumulation of inflammatory cells in the extravascular connective tissue in these sites.