Collagen and non-collagenous proteins molecular crosstalk in the pathophysiology of osteoporosis.

Abstract Collagenous and non-collagenous proteins (NCPs) in the extracellular matrix, as well as the coupling mechanisms between osteoclasts and osteoblasts, work together to ensure normal bone metabolism. Each protein plays one or more critical roles in bone metabolism, sometimes even contradictory, thus affecting the final mechanical, physical and chemical properties of bone tissue. Anomalies in the amount and structure of one or more of these proteins can cause abnormalities in bone formation and resorption, which consequently leads to malformations and defects, such as osteoporosis (OP). The connections between key proteins involved in matrix formation and resorption are far from being elucidated. In this review, we resume knowledge on the crosstalk between collagen type I and selected NCPs (Transforming Growth Factor-β, Insulin-like Growth Factor-1, Decorin, Osteonectin, Osteopontin, Bone Sialoprotein and Osteocalcin) of bone matrix, focusing on their possible involvement and role in OP. The different elements of this network can be pharmacologically targeted or used for the design/development of innovative regenerative strategies to modulate a feedback loop in bone remodelling

Analysis of multiple protein detection methods in human osteoporotic bone extracellular matrix: From literature to practice

The punctual analysis of bone Extracellular Matrix (ECM) proteins represents a pivotal point for medical research in bone diseases like osteoporosis. Studies in this field, historically done to appreciate bone biology, were mainly conducted on animal samples and, up to today, only a few studies on protein detection in human bone are present. The challenges in bone ECM protein extraction and quantitation protocols are related to both the separation of proteins from the mineral content (i.e. hydroxyapatite) and the difficulty of avoiding protein denaturation during the extraction processes. The aim of the present work was to define appropriate protocol(s) for bone ECM protein extraction that could be applied to investigate both normal and pathological conditions. We compared and optimised some of the most used protocols present in the literature, modifying the protein precipitation method, the buffer used for resuspension and/or the volume of reagent used. Bradford and BCA assays and Western Blotting were used to evaluate the variations in the total protein recovery and the amount of selected proteins (Type I Collagen, TGF-β, IGF-1, Decorin, Osteopontin, Bone Sialoprotein-2 and Osteocalcin). Collectively, we were capable to draw-up two single-extract protocols with optimal recovery and ideal protein content, that can be used for a detailed analysis of ECM proteins in pathological bone samples. Time-consuming multi-extract procedures, optimised in their precipitation methods, are however crucial for a precise detection of specific proteins, like osteocalcin. As the matter of fact, also the demineralization processes, commonly suggested and performed in several protocols, could hinder an accurate protein detection, thus inherently affecting the study of a pathological bone ECM. This study represents a starting point for the definition of appropriate strategies in the study of bone extracellular matrix proteins involved in the onset and maintenance of bone diseases, as well as a tool for the development of customized scaffolds capable to modulate a proper feedback loop in bone remodelling, altered in case of diseases like osteoporosis

Analysis of multiple protein detection methods in human osteoporotic bone extracellular matrix: From literature to practice

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miR125b1 and TROP2 in preeclampsia complicated by foetal growth restriction: a morphological and biomolecular study

Trophoblast cell surface antigen 2 (TROP2) is a transmembrane glycoprotein originally identified in human trophoblast cell lines and is highly expressed in a variety of epithelial cancers. The TROP2 gene was validated as a direct target of miR-125b1. The purpose of our study was: - to investigate the expression of TROP2 protein in normal placental tissues, in placentas affected by preeclampsia as well as in placentas with preeclampsia complicated by foetal growth restriction (IUGR); - to verify how miR-125b1 was involved in the regulation of TROP2 gene expression. TROP2 protein expression was assessed by immunohistochemistry and quantitative western blotting analyses while miR-125b1 expression was detected by quantitative real-time PCR. The studies were made in normal and pathologic placental tissues. Increasing expression of TROP2 was detected in physiological placental tissue, in according with the increasing gestational age. Probably, it means that TROP2 is related with the differentiation of the cytotrophoblast in syncytiotrophoblast, that occurs during the development of placenta. Moreover, miR-125b1 showed an unchanged expression during normal pregnancy. Higher expression of TROP2 protein was detected in placental tissues collected from patients with preeclampsia complicated by foetal growth restriction, compared with those from preeclampsia and gestational age-matched control samples. The miR-125b1 expression in samples from placentas affected by preeclampsia complicated by IUGR was detected higher than in normal placentas and in placentas affected by preeclampsia. These results suggest that miR-125b1 is not involved I the overproduction of the TROP2 mRNA although the high expression of the miRNA. Our study suggests a possible involvement of TROP2 in the differentiation of the syncytiotrophoblast from villous cytotrophoblast and a possible role of this protein in preeclampsia complicated by foetal growth restriction

Human trophoblast differentiation: possible role for trophoblast cell surface antigen 2

Human trophoblast cell surface antigen 2 (Trop2) is a 40-kDa transmembrane glycoprotein, encoded by TACSTD2 gene and identified for the first time in human trophoblast and choriocarcinoma cell lines. Trop2 has a short intracytoplasmic tail essential for the control of several pathways that regulate cellular functions such as cell- cell adhesion, cell proliferation and mobility [1]. We analysed the expression of Trop2 in human normal placentas during gestation and in placentas complicated by preeclampsia (PE). Trop2 protein expression and miR125b1 were analysed by morphological and bio-molecular techniques. Trop2 increased during gestation, i.e. from first to third trimester of gestation while it was low expressed in placental tissues collected from patients with PE. Since PE is a pathology associated with placental hypoxia, we demonstrated that Trop2 is downregulated in hypoxic conditions by in vitro model. Our study suggests a possible involvement of Trop2 in maintaining trophoblast morphology and function during placental development in normal and PE conditions

Expression of the ciliary neurotrophic factor and its receptor α in human placenta of first and third trimester of gestation

The ciliary neurotrophic factor (CNTF) is a member of the IL-6 family of cytokines along with cardiotrophin-1, IL-11, leukemia inhibitory factor, oncostatin-M and IL-6 itself. These cytokines play an important role in the regulation of cellular processes such as gene activation and cell proliferation and differentiation. CNTF is a pleiotropic cytokine which effects are mediated via CNTF receptor α (CNTFRα). CNTF increases differentiation and/or survival in neuronal cells but it also has different effects on other cell types such as muscle cells, bone cells, adipocytes, retinal cells and pancreatic β-cells (1, 2). In addition, recent studies demonstrate that CNTF plays an important role in weight control since exogenously administration of CNTF has an anorectic effect in mice (3,4). Although many studies proved that CNTF plays different roles in many cell types, its role in the development of human placenta has never been investigated. In this study we investigated the expression of CNTF and CNTFRα in human trophoblast by, immunohistochemistry, immunocytochemistry and Western Blot analysis using normal first and third trimester human placentas and HTR-8/SVneo cell lines. Interestingly, using immunohistochemistry CNTF and CNTFRα were expressed in the cytotrophoblast and syncytiotrophoblast in the first and third trimester of gestation respectively. Moreover, the immunofluorescence analyses by confocal microscopy showed that CNTF is expressed in the cytoplasm and nuclei whereas CNTFRα is mainly expressed in the cell membrane and cytoplasm of HTR-8/SVneo cell line. In this study we demonstrated that CNTF and CNTFRα are normally expressed in human placenta and they may play an important role during placental development

An osteochondral bio-engineered model to in vitro mimicking osteoarthritis

To date, treatments of Osteoarthritis are not able to provide the pathology regression. In vitro models are therefore necessary to: i) investigate the mechanisms involved in the disease evolution, ii) identify pharmacological targets, and iii) perform predictive tests for new drug delivery strategies

Expression of Trop2 in bladder cancer is modulated by miR125b: in vivo and in vitro analyses

Human trophoblastic cell surface antigen 2 (Trop-2) is a 40-kDa transmembrane glycoprotein, first identified as a cell surface marker for human trophoblast cells (1). Elevated expression of Trop-2 has been shown in several types of epithelial cancers and correlated with tumour aggressive and poor prognosis (2-3). The first aim of this study was to evaluate the variation of the Trop-2 expression in normal urothelium and urothelial bladder cancer. The immunohistochemical results showed an increase of Trop-2 levels in bladder cancer tissues with the increase of the severity of the pathology. Recent data identified Trop-2 as a target for miR-125b suggesting a pos sible role of miR-125b in the modulation of Trop-2 protein expression (4). The second aim was to verify if Trop-2 could be a target for miR-125b in bladder cells and to evaluate the possible role of miR-125b in the modulation of Trop-2 protein expression in normal bladder as well as in urothelial bladder cancer. In vitro we showed a contribution of miR-125b in deregulation of Trop-2 protein expression in a bladder cell line and we found that the expression of miR-125b was inversely correlated with the expression of Trop-2 protein on a cohort of bladder cancer tissues. We concluded to investigate in a larger population the use of Trop-2 and/or miR-125b as potential diagnostic markers in urothelial bladder cancer

Autoimmune polyglandular syndrome type 4: experience from a single reference center

Purpose: To characterize patients with APS type 4 among those affected by APS diagnosed and monitored at our local Reference Center for Autoimmune Polyglandular Syndromes. Methods: Monocentric observational retrospective study enrolling patients affected by APS diagnosed and monitored in a Reference Center. Clinical records were retrieved and analyzed. Results: 111 subjects (51 males) were affected by APS type 4, mean age at the onset was 23.1 ± 15.1 years. In 15 patients the diagnosis of APS was performed during the first clinical evaluation, in the other 96 after a latency of 11 years (range 1-46). The most frequent diseases were type I diabetes mellitus and celiac disease, equally distributed among sexes. Conclusions: The prevalence of APS type 4 is 9:100,000 people. Type I diabetes mellitus was the leading indicator of APS type 4 in 78% subjects and in 9% permitted the diagnosis occurring as second manifestation of the syndrome. Our data, showing that 50% of patients developed APS type 4 within the first ten years, don't suggest any particular follow-up time and, more importantly, don't specify any particular disease. It is important to emphasize that 5% of women developed premature ovarian failure