1,721,046 research outputs found
EZR-PLC and RhoGTPases interactions in osteosarcoma pathogenesis and metastatic process
Full text linkEzrin-related phosphoinositide pathway modifies RhoA and Rac1 in human osteosarcoma cell lines
Full text linkSelected Phosphoinositide-specific Phospholipase C (PI-PLC) enzymes occupy the convergence point of the broad range of pathways that promote Rho and Ras GTPase mediated signalling, which also regulate the activation of ezrin, a member of the ezrin-radixin-moesin (ERM) proteins family involved in the metastatic osteosarcoma spread. Previous studies described that in distinct human osteosarcoma cell lines ezrin networks the PI-PLC with complex interplay controlling the expression of the PLC genes, which codify for PI-PLC enzymes. In the present study, we analyzed the expression and the sub-cellular distribution of RhoA and Rac1 respectively after ezrin silencing and after PI-PLC ε silencing, in order to investigate whether ezrin-RhoGTPAses signalling might involve one or more specific PI-PLC isoforms in cultured 143B and Hs888 human osteosarcoma cell lines. In the present experiments, both ezrin and PLCE gene silencing had different effects upon RhoA and Rac1 expression and sub-cellular localization. Displacements of Ezrin and of RhoA localization were observed, probably playing functional roles
Use of a new generation of capillary electrophoresis to quantify circulating free DNA in non-small cell lung cancer.
No full textCirculating free DNA (cfDNA) is present in higher concentration in non-small-cell lung cancer (NSCLC) patients than in controls. This study was designed to assess the sensitivity and specificity of Agilent 2100 Bioanalyzer to identify patients with NSCLC and to compare it with quantitative RealTime-PCR (RT-qPCR) assay. 30 NSCLC patients and 26 controls were analyzed. The amount of cfDNA was determined both through quantitative RT-PCR targeting the human β-actin gene and by Agilent 2100 Bioanalyzer. Performances of the assays were calculated by the receiver operating characteristic (ROC) curves. The mean cfDNA concentration, obtained through the use of Agilent 2100 Bioanalyzer, in NSCLC patients (94.5. ng/mL) was almost twice the concentration detected in controls (42.8. ng/mL) as well as found by RT-qPCR (22.5. ng/mL vs 7.1. ng/mL, p. <. 0.001). The area under curve of Agilent 2100 Bioanalyzer and RT-PCR showed that there are no statistically significant differences between these tests (p. <. 0.92).This study shows that Agilent 2100 Bioanalyzer is an effective diagnostic tool to discriminate NSCLC patients from healthy individuals and suggests a new approach for early detection of NSCLC. © 2013 Elsevier B.V
Supernatants from human osteosarcoma cultured cell lines induce modifications in growth and differentiation in THP-1 cells and in Phosphoinositide specific Phospholipase C enzymes
No full textIntroduction: molecular components in the microenvironment could affect cell growth, survival/apoptosis and proliferation. Immune system cells respond to molecules, such as cytokines, chemokines and growth factors, produced by the tumor and released in the surrounding microenvironment.
Methods: we evaluated the morphological and functional changes in THP-1 cells cultured in culture medium mixed with the culture supernatant of one of three different osteosarcoma (OS) cell lines, namely 143B, HS888 and MG-63 cells. We analyzed the effect of supernatant from OS cultures upon morphology and growth of THP-1 cells, and expression of Phosphoinositide-specific PLC enzymes (PLCs).
Results: in supernatants from each OS cell line we identified the presence of selected ILs, of TNF and GM-CSF. Each OS derived supernatant differently modified the growth rate of THP-1 cells, depending on the OS cell line. OS supernatants in the in vitro microenvironment of cells’ culture greatly modified the panel of expression of PLC enzymes expressed by THP-1 cells. THP-1 cells differently express PLC enzymes, depending on the origin of the supernatant. The differences in PLCs’ expression induced by adding OS supernatants to the cultures of THP-1 cells resulted statistically significant for PLCB1 and PLCG2 genes.
Conclusions: OS supernatants induce the differentiation of THP-1 cells into macrophages. THP-1 cells cultured in OS supernatants express different panels of expression of PLC enzymes. The panel of expression of PLC enzymes differs during the differentiation of monocyte/macrophage lineage THP-1 cells
OPG and RANKL mRNA and protein expressions in the primary and secondary metaphyseal trabecular bone of PTH-treated rats are independent of that of SOST
No full textSclerostin, encoded by the SOST gene, is a recently identified protein which seems to affect bone remodeling by inhibiting bone formation via Wnt pathways. A previous study on OPG and RANKL, two cytokines involved in the control of osteoclastogenesis, showed that the anabolic effect produced by intermittent treatment with parathyroid hormone was characterized by an increase in OPG/RANKL mRNA ratio in the primary spongiosa of metaphyseal bone of rat femur, and by its falling in the secondary spongiosa, in comparison to controls (Silvestrini et al. (2007a)). Considering that Wnt pathway components seem to regulate osteoclast formation and bone resorption by repression of RANKL transcription and by positive regulation of OPG gene in osteoblastic cells, we have evaluated, in the same rats, whether and how SOST mRNA and protein in the primary and secondary metaphyseal bone are affected by PTH. SOST mRNA and protein significantly fell in both primary and secondary spongiosa where only a few osteocytes were positive to sclerostin. These data show that in the two metaphyseal areas no relationship does exist between the trends of OPG and RANKL mRNA and that of SOST, suggesting that there are no direct links between the effects induced by PTH on these molecules, at least in terms of gene expression
Comparison of phosphoinositide-specific phospholipase c panel of expression of human osteoblasts versus mg-63 and saos osteoblast-like cells
Full text linkBackground: A large number of phospholipase C (PLC) enzymes, both mRNA transcripts and proteins, have been detected in osteoblasts,
corroborating the importance of calcium regulation in bone tissue. MG-63 and SaOS-2 human osteosarcoma cell lines are
actually considered osteoblast-like cells, and are therefore widely used as experimental models for osteoblasts.
Objectives: Our aim was to verify whether MG-63 or SaOS-2 cells might also represent appropriate experimental osteoblast models
for signal transduction studies, with special regard to the phosphoinositide (PI) pathway. We analyzed the expression and the
subcellular distribution of enzymes related to calcium signal transduction (the PI-specific PLC family), which are known to possess
high cell/tissue specificity. Materials and Methods: The expression of PLC genes was analyzed by performing RT-PCR experiments. The presence of PLC enzymes
and their subcellular distribution within the cells was analyzed with immunofluorescence experiments.
Results: Osteoblasts, MG-63 cells, and SaOS-2 cells have expression panels similar to those of PLC enzymes. However, slight differences
were found in the expression of enzymes belonging to the PLC subfamily.
Conclusions: MG-63 and SaOS-2 osteosarcoma cell lines might not represent appropriate experimental models for studies that aim
to analyze signal transduction in osteoblasts
IS RAGE THE SO FAR UNIDENTIFIED TRAIT D'UNION BETWEEN VASCULAR RISK FACTORS AND ALZHEIMER'S DISEASE?
No full text889
IS RAGE THE SO FAR UNIDENTIFIED TRAIT D'UNION BETWEEN VASCULAR RISK FACTORS AND
ALZHEIMER'S DISEASE?
Rita Businaro1, L. Capriotti1, M. Corsi1, M. Leopizzi1, V. Nicolia2, A. Fuso2
1Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, 2Surgery 'P.
Valdoni', Sapienza University of Rome, Rome, Italy
Aim: The receptor for advanced glycation end products (RAGE), is considered to be a key mediator of
atherogenesis. Recent findings indicate the important role played by RAGE in the progression of
Alzheimer's disease (AD). It has been shown that RAGE signaling contributes to the production of
proinflammatory cytokines, leading to the impairment of neuronal functions and to the amyloid
accumulation. Moreover, atherosclerosis, stroke and cardiac disease in the aging individual, could result
in cerebrovascular dysfunction and trigger AD pathology. It is known that diet depleted in folate and
vitamins B6 and B12 promotes an enhanced expression of RAGE and leads to hyperhomocysteinemia, a
well-known risk factor for the development of cardiovascular disease as well as for late onset AD. This
work aims at evaluating the effects of hyperhomocysteinemia, induced by B vitamin deficiency, on RAGE
expression.
Methods: TgCNRD8 mice carrying a Indiana/Swedish mutated APP transgene, an animal model of AD,
were grown either with control or B vitamin deficient diet. We measured RAGE by immunohistochemistry,
western blots, real-time PCR.
Results: B vitamin deficiency enhances RAGE expression in particular at the level of frontal and parietal
microvasculature. Both neurons and endothelium in the hippocampus were stained, showing an increase
in the number of positive cells as well as in the amount of reaction, compared to the animals fed with a
standard diet.
Conclusions: B vitamin deficiency and hyperomocysteinemia are able to modulate RAGE expression,
promoting in this way atherosclerosis progression and the transport of beta Amyloid across the BBB
The attempt of spontaneous repair of rotator cuff tear: the role of periostin
No full textThe development of a periostin-rich microenvironment in areas associated with insult, orchestrating pathways of repair and rebuilding, is documented. Literature lacks information regarding the presence of periostin in the context of rotator cuff tear (RCT). 55 consecutive patients with RCT were enrolled. Immunohistochemical periostin detection was performed on tissue samples excised from tear margins. Our study documented the presence of periostin in the margins of RCT. It is plausible that, when a tear occurs, multiple stimuli, both mechanical and inflammatory, lead to the development of a periostin-rich microenvironment as an attempt to tendon healing
Effects of intermittent parathyroid hormone (PTH) administration on SOST mRNA and protein in rat bone
No full textSclerostin, the secreted protein product of the SOST gene, which is mainly expressed by osteocytes, has recently been proposed as a negative regulator of bone osteoblastogenesis. Chronic elevation of PTH reduces SOST expression by osteocytes, while controversial results have been obtained by intermittent PTH administration. We have investigated the effects of intermittently administered PTH on SOST expression and sclerostin localization, comparing them with those of controls, as they appeared in three different bone segments of rat tibia: secondary trabecular metaphyseal and epiphyseal bone, and cortical diaphyseal bone. The histomorphometric results demonstrate that PTH enhances bone turnover through anabolic effects, as shown by the association of increased bone resorption variables with a significant rise in BV/TV, Tb.Th and Tb.N and a fall in Tb.Sp. PTH induces a SOST mRNA and protein fall in secondary metaphyseal trabeculae, diaphyseal bone and in epiphyseal trabeculae. Numbers of sclerostin immunopositive osteocytes/mm2 show no change, compared with controls; there are fewer sclerostin-positive osteocytes in secondary metaphyseal trabeculae than in the other two bone areas, both in the control and PTH groups. The low numbers of sclerostin-positive osteocytes in the metaphyseal trabecular bone seem to be directly related to the fact that this area displays a high remodeling rate. The anabolic effects of PTH are in line with the fall of SOST mRNA and protein in all the three bone segments examined; the rise of bone turnover supports a negative role of SOST in bone formation. © 2007 Springer Science+Business Media B.V
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