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Néphrologie & Thérapeutique 06/2012; 8(3):177-8. · 0.47 Impact Factor
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ABSTRACT: IQGAP1 is a scaffold protein that interacts with proteins of the cytoskeleton and the intercellular adhesion complex. In podocytes, IQGAP1 is associated with nephrin in the glomerular slit diaphragm (SD) complex, but its role remains ill-defined. In this work, we investigated the interaction of IQGAP1 with the cytoskeleton and SD proteins in podocytes in culture, and its role in podocyte migration and permeability. Expression, localization, and interactions between IQGAP1 and SD or cytoskeletal proteins were determined in cultured human podocytes by Western blot (WB), immunocytolocalization (IC), immunoprecipitation (IP), and In situ Proximity Ligation assay (IsPL). Involvement of IQGAP1 in migration and permeability was also assessed. IQGAP1 expression in normal kidney biopsies was studied by immunohistochemistry. IQGAP1 expression by podocytes increased during their in vitro differentiation. IC, IP, and IsPL experiments showed colocalizations and/or interactions between IQGAP1 and SD proteins (nephrin, MAGI-1, CD2AP, NCK 1/2, podocin), podocalyxin, and cytoskeletal proteins (α-actinin-4). IQGAP1 silencing decreased podocyte migration and increased the permeability of a podocyte layer. Immunohistochemistry on normal human kidney confirmed IQGAP1 expression in podocytes and distal tubular epithelial cells and also showed an expression in glomerular parietal epithelial cells. In summary, our results suggest that IQGAP1, through its interaction with components of SD and cytoskeletal proteins, is involved in podocyte barrier properties.
PLoS ONE 01/2012; 7(5):e37695. · 4.09 Impact Factor
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ABSTRACT: The Fas pathway is described as an activator of the glioblastoma proliferation by increasing the pathogenicity of this tumour. The lipopolysaccharide (LPS) pathway depending on Toll-like receptor 4 (TLR4) could limit the glioblastoma spreading. Here, Fas and TLR4 pathways were activated in glioblastoma cell lines by an agonist antibody and/or LPS treatment. Activation of the Fas pathway or of the TLR4 pathway induced cell proliferation. However, simultaneous treatment with agonist antibody and LPS decreased proliferation. This anti-proliferative effect was caspase dependent, and a decreased cell migration and matrix metalloproteinase (MMP)-9 expression were also observed. Both TLR4 and MMP-9 were highly expressed in human glioblastoma tissues. These data suggest that TLR4 signal transduction pathways neutralize proliferation and migration induced by Fas pathway activation in glioblastoma cell lines.
Cancer letters 07/2011; 311(2):195-202. · 4.86 Impact Factor
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ABSTRACT: The anterior gradient protein-2 (AGR2) is overexpressed in numerous tumours such as breast, prostate or pancreas carcinomas and recently reported in fibrolamellar hepatocellular carcinoma (HCC).
In the present study, we further describe AGR2 expression patterns all along the adult and fetal biliary tree and in cholangiocarcinomas.
Immunohistochemistry using anti-AGR2 antibodies was performed in adult and fetal livers, gallbladders as well as cholangiocarcinomas and HCCs.
In adult and fetal liver, the tall epithelial cells covering the large bile ducts as well as gallbladder epithelial cells showed strong AGR2 staining. Hilar and extrahepatic cholangiocarcinomas, and a subset of intrahepatic cholangiocarcinomas, which displayed a morphological mucus-excreting feature, also displayed AGR2 expression. In contrast, AGR2 expression was not detected in typical HCCs.
Our study shows that the differential expression of AGR2 is a phenotypic feature of the cholangiocytes covering different segments of the biliary tree. This pattern of expression is conserved during fetal and adult life, as well as during biliary carcinogenesis.
Liver international: official journal of the International Association for the Study of the Liver 03/2011; 31(3):322-8. · 3.82 Impact Factor
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ABSTRACT: The case presented here points towards the fact that skin lesion observed with a cowpox virus is a rare event but should be considered more as the number of cases has increased in the last years. Cowpox virus (CPXV) belongs to the Poxviridae family. The transmission of CPXV to humans is caused by wild rodents or mostly by domestic animals and pet rats. In humans, CPXV is responsible for localized skin lesions regularly accompanied by lymphadenopathy. The lesions remain localized but self-inoculation from the primary lesions could occur. Then physicians have to be vigilant concerning bandages. In this case report, a necrotic and ulcerated lesion of a CPXV infection in a young boy is reported. The CPXV was possibly transmitted by wild rodents. The importance of performing the diagnosis is also pointed out. Virus information was obtained from phylogenetic analyses showing that the CPXV isolate was distinct from outbreaks of human cowpox which occurred in 2009 in France and Germany but was close to the CPXV Brighton Red strain. For several years, cases of viral zoonosis caused by CPXV have increased and physicians should be made aware that people could be infected without history of direct contact with animals.
Case Reports in Dermatology 01/2011; 3(3):186-94.
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ABSTRACT: The debate concerning the potential remodelling and/or reversibility of cirrhotic lesions and biliary fibrosis is still open.
In this work, we have used the precision-cut liver slice (PCLS) model, which maintains cell-cell and cell-matrix interactions to study, by immunohistochemistry, the behaviour of the different fibrogenic cells, i.e. hepatic stellate cells (HSC) and portal fibroblasts, in cultured (for 1 week) PCLS derived from normal and fibrotic human livers.
In normal liver, before and after culture, α-smooth muscle (SM) actin was present only in the vessel walls. Platelet-derived growth factor (PDGF) receptor-β was expressed before and after culture by portal fibroblasts, and appeared after culture in HSC. Before culture, CD 34 was not expressed in parenchyma, but appeared after culture in sinusoidal endothelial cells. In cirrhotic lesions, before culture, α-SM actin, PDGF receptor-β and Thy-1 were expressed in septa; after culture, α-SM actin expression disappeared but the expression of the PDGF receptor-β and Thy-1 was maintained. In cholestatic liver specimens, α-SM actin, PDGF receptor-β and Thy-1 expression, which was present before culture in enlarged portal areas, disappeared after culture, and apoptosis was detected. In the parenchyma of both cirrhotic and cholestatic livers, the expression of the PDGF receptor-β and of CD 34, which was not observed before culture, was present in HSC and sinusoidal endothelial cells, respectively, after culture.
These results indicate that during remodelling of pathological tissues in cultured liver slices, the myofibroblastic cells derived from HSC or from portal fibroblasts show different behaviours, suggesting different mechanisms of activation/deactivation.
Liver international: official journal of the International Association for the Study of the Liver 11/2010; 30(10):1529-40. · 3.82 Impact Factor
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ABSTRACT: Myopericytoma is an uncommon perivascular (pericytic) tumour, which develops in the skin or in soft tissues from the extremities. Usually, the lesion is small and shows a myopericytic differentiation. The cells are short, fusiform and arranged concentrically around small vascular lumen. We reported here the second case of arterial mural myopericytoma.
Annales de Pathologie 08/2010; 30(4):325-7. · 0.25 Impact Factor
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Julien Villeneuve, Sébastien Lepreux,
Audrey Mulot,
Annie M Bérard,
Arisa Higa-Nishiyama,
Pierre Costet,
Victor De Ledinghen,
Paulette Bioulac-Sage,
Charles Balabaud,
Alan T Nurden,
Jean Rosenbaum,
Eric Chevet,
Jean Ripoche
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ABSTRACT: Inflammation and lipid metabolism pathways are linked, and deregulation of this interface may be critical in hepatic steatosis. The importance of the dialog between inflammatory signaling pathways and the unfolded protein response (UPR) in metabolism has been underlined. Herein, we studied the role of CD154, a key mediator of inflammation, in hepatic steatosis. To this end, Balb/c mice, wild-type or deficient in CD154 (CD154KO), were fed a diet rich in olive oil. In vitro, the effect of CD154 was studied on primary hepatocyte cultures and hepatocyte-derived cell lines. Results showed that CD154KO mice fed a diet rich in olive oil developed hepatic steatosis associated with reduced apolipoprotein B100 (apoB100) expression and decreased secretion of very low-density lipoproteins. This phenotype correlated with an altered UPR as assessed by reduced X-Box binding protein-1 (XBP1) messenger RNA (mRNA) splicing and reduced phosphorylation of eukaryotic initiation factor 2α. Altered UPR signaling in livers of CD154KO mice was confirmed in tunicamycin (TM) challenge experiments. Treatment of primary hepatocyte cultures and hepatocyte-derived cell lines with soluble CD154 increased XBP1 mRNA splicing in cells subjected to either oleic acid (OA) or TM treatment. Moreover, CD154 reduced the inhibition of apoB100 secretion by HepG2 cells grown in the presence of high concentrations of OA, an effect suppressed by XBP1 mRNA silencing and in HepG2 cells expressing a dominant negative form of inositol requiring ER-to-nucleus signaling protein-1. The control of the UPR by CD154 may represent one of the mechanisms involved in the pathophysiology of hepatic steatosis. Conclusion: Our study identifies CD154 as a new mediator of hepatic steatosis.
Hepatology 08/2010; 52(6):1968-79. · 11.66 Impact Factor
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British Journal of Haematology 04/2010; 149(2):302-6. · 4.94 Impact Factor
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ABSTRACT: Local drug delivery by ultrasound (US)-induced cavitation is a promising strategy for increasing the drug concentration at the target location and for decreasing the systemic toxicity effects. The presence of microbubbles during sonication at the targeted location improves the likelihood for cavitation that can be exploited to increase the capillary permeability. The objective of this work was to evaluate the magnetic resonance imaging (MRI) contrast changes in hepatic tissue in vivo, induced by US-triggered cavitation and destruction of microbubbles (Sonovue), in the presence of a coinjected blood pool MRI contrast agent (Vistarem) used as a reporter macromolecule. The potential tissue damage induced by microbubbles destruction was also evaluated by histology.
The change in the hepatic distribution of the macromolecular MRI contrast agent associated with cavitation was monitored at 1.5 T with a look-locker fast inversion recovery sequence to map the longitudinal relaxation rates, before and during 1 hour after intravenous administration of Vistarem and Sonovue. In 1 group of rats (n = 5), these microbubbles were immediately destroyed with a clinical echograph, using a high mechanical index (MI = 1.5) at low frequency (2 MHz). The control group (n = 7) received identical injections without application of US. The parametric relaxation rate images were computed, and the changes in time were analyzed to account for the potential effect of microbubble destruction by US on the permeability of the hepatic vessels. The animals were killed 1 day after the experiment for routine histology of the liver.
For both groups of animals, after an initial increase, a transient decay of the longitudinal relaxation rate was observed, followed by a constant plateau after 20 minutes. The analysis of the mean relaxation rates in the liver showed significant (P < 0.01) higher values for the group with destruction of microbubbles as compared with the control group. The US-triggered cavitation and destruction of microbubble with the proposed protocol suggests an increased concentration of Vistarem of a factor 2 in the hepatic tissue. No tissue damage was observed at the microscopic analysis.
The absence of tissue alterations indicates that the destruction of this US contrast agent could be safe in vivo under an appropriate choice of the sonication parameters. This approach opens new perspectives for translation toward clinical applications of local drug delivery. Ultrasound-mediated microbubble destruction may help in increasing the local concentration of a drug currently limited by the endothelial barrier. In addition, it may help in reducing the systemic toxicity to normal cells in standard chemotherapies, because the enhanced capillary permeability effect can be spatially adjusted by selecting the sonicated region.
Investigative radiology 04/2010; 45(5):282-7. · 4.85 Impact Factor
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ABSTRACT: Spinal epidural angiolipoma is a rare tumor revealed by a slowly progressive paraplegia. We reported a case of a 44-year-old female and point out the peculiar pattern of this lesion characterized by the prominence of the vascular component over the lipomatous component. Recognition of this entity is important because this is a benign and curable cause of paraplegia.
Annales de Pathologie 02/2010; 30(1):30-2. · 0.25 Impact Factor
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British Journal of Haematology 01/2010; 149(2):302 - 306. · 4.94 Impact Factor
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ABSTRACT: Cholangiocarcinoma is an adenocarcinoma of the liver which has increased in incidence over the last thirty years to reach similar levels to other liver cancers. Diagnosis of this disease is usually late and prognosis is poor, therefore it is of great importance to identify novel candidate markers and potential early indicators of this disease as well as molecules that may be potential therapeutic targets. We have used a proteomic approach to identify differentially expressed proteins in peripheral cholangiocarcinoma cases and compared expression with paired non-tumoral liver tissue from the same patients. Two-dimensional fluorescence difference gel electrophoresis after labeling of the proteins with cyanines 3 and 5 was used to identify differentially expressed proteins. Overall, of the approximately 2,400 protein spots visualised in each gel, 172 protein spots showed significant differences in expression level between tumoral and non-tumoral tissue with p < 0.01. Of these, 100 spots corresponding to 138 different proteins were identified by mass spectrometry: 70 proteins were over-expressed whereas 68 proteins were under-expressed in tumoral samples compared to non-tumoral samples. Among the over-expressed proteins, immunohistochemistry studies confirmed an increased expression of 14-3-3 protein in tumoral cells while α-smooth muscle actin and periostin were shown to be overexpressed in the stromal myofibroblasts surrounding tumoral cells. α-Smooth muscle actin is a marker of myofibroblast differentiation and has been found to be a prognostic indicator in colon cancer while periostin may also have a role in cell adhesion, proliferation and migration and has been identified in other cancers. This underlines the role of stromal components in cancer progression and their interest for developing new diagnostic or therapeutic tools.
Cancer Microenvironment 01/2010; 4(1):73-91.
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ABSTRACT: A 72-year-old man presented with a Merkel cell carcinoma (MCC) of the left cheek with concomitant nodal spread. A 61-year-old man presented with an MCC of the right thigh with rapid nodal recurrence.
Skin biopsy samples proved the MCC nature of the neoplasm in both patients. Staging procedure included clinical and radiological investigations.
Advanced stage II MCC.
Neoadjuvant cisplatin, etoposide and cyclophosphamide (EPC) regimen led to local control in the first patient and allowed curative surgery associated with adjuvant radiation therapy. Complete remission was maintained for 32 months. The second patient was treated by surgery plus radiation therapy. Nodal and cutaneous recurrences were treated with a neoadjuvant EPC regimen leading to a 5-year complete remission.
Nature Reviews Clinical Oncology 10/2009; 6(9):544-8. · 11.96 Impact Factor
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Anne Solanilla,
Julien Villeneuve,
Patrick Auguste,
Michel Hugues,
Ahmadou Alioum, Sébastien Lepreux,
Jean-Pierre Ducroix,
Pierre Duhaut,
Claude Conri,
Jean-François Viallard,
Alan T Nurden,
Joël Constans,
Jean Ripoche
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ABSTRACT: Altered angiogenesis is a characteristic feature in SSc and remains ill-understood. VEGF is believed to play a central role. Serum VEGF is elevated in SSc patients but questions remain concerning the source of circulating VEGF. Here we investigated platelet activation and the role of platelets as a source of VEGF and other angiogenic mediators in this disease.
A cohort of 40 patients with SSc was included. Age- and sex-matched healthy subjects and subjects presenting a primary RP were included as controls. Platelets were isolated, activated with thrombin and the secretion of VEGF, platelet derived growth factor, homodimeric form BB (PDGF-BB), TGF-beta1 and angiopoietins-1 and -2 measured. Plasma concentrations of these mediators and the functionality of platelet-derived VEGF were also studied. Platelet activation was assayed by measuring plasma beta-thromboglobulin and expression of P-selectin on platelets. The effect of iloprost on VEGF secretion by platelets was studied.
Platelets from SSc patients, in contrast to controls, secreted large amounts of VEGF when activated, but not PDGF-BB, TGF-beta1 or angiopoietins. Increased expression of membrane P-selectin confirmed platelet activation in the patients. Iloprost inhibited VEGF secretion by platelets both in vivo and in vitro, through inhibition of platelet activation.
Platelets transport high levels of VEGF in SSc. They may contribute to circulating VEGF because of ongoing activation in the course of the disease. If activated at the contact of injured endothelium, platelets may be important in the altered angiogenesis associated with the disease through the secretion of high levels of VEGF.
Rheumatology (Oxford, England) 07/2009; 48(9):1036-44. · 4.24 Impact Factor
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ABSTRACT: Expression of tissue inhibitors of matrix metalloproteinases (TIMPs) is one way that activated platelets intervene in tissue remodeling and angiogenesis. Our study was designed to investigate their synthesis in megakaryocytes (MKs) and their storage in platelets.
TIMP expression in MKs derived from blood CD34(+) progenitor cells of normal donors and a megakaryocytic cell line (CHRF-288-11) grown in serum-free conditions and platelets from normal donors or two patients with gray platelet syndrome was studied by immunofluorescence labeling, reverse transcription-polymerase chain reaction, and western blotting.
Biosynthesis of TIMPs 1-4 in MKs was indicated by presence of their messenger RNAs as shown by polymerase chain reaction and of their proteins. Immunofluorescence labeling suggested a primarily granular localization of TIMPs in MKs and platelets. But when colocalization with von Willebrand factor, fibrinogen, P-selectin, and other alpha-granule proteins was assessed in platelets by confocal microscopy, TIMP-1, -2, and -4 were localized as distinct fluorescent patches apart from the established alpha-granule markers and largely independent of platelet metalloproteinases. TIMP-3 differed for it also had an alpha-granule location. Western blotting confirmed the presence of TIMPs 1-4 in platelets and thrombin activation resulted in their extensive release to the medium. Platelets from two patients with gray platelet syndrome, congenitally deficient in alpha-granules, showed sparse labeling of von Willebrand factor and fibrinogen confined to vestigial alpha-granules; however, localization of the TIMPs was unchanged.
TIMPs are synthesized and organized in MKs and platelets independently of other secreted proteins present in alpha-granule pools.
Experimental hematology 05/2009; 37(7):849-56. · 3.11 Impact Factor
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ABSTRACT: In adult liver, the mesenchymal cells, portal fibroblasts and vascular smooth muscle cells can transdifferentiate into myofibroblasts, and are involved in portal fibrosis. Differential expression of markers, such as alpha-smooth muscle actin (ASMA), h-caldesmon and cellular retinol-binding protein-1 allows their phenotypic discrimination. The aim of our study was to explore the phenotypic evolution of the mesenchymal cells during fetal development in normal liver and in liver with portal fibrosis secondary to ductal plate malformation in a series of Meckel-Gruber syndrome, autosomal recessive polycystic kidney disease and Ivemark's syndrome.
At the early steps of the portal tract maturation, portal mesenchymal cells expressed only ASMA. During the maturation process, these cells were found condensed around the biliary and vascular structures. At the end of maturation process, only cells around vessels expressed ASMA and cells of the artery tunica media also expressed h-caldesmon. In contrast, ASMA positive cells persisted around the abnormal biliary ducts in fibrous livers.
As in adult liver, there is a phenotypic heterogeneity of the mesenchymal cells during fetal liver development. During portal tract maturation, myofibroblastic cells disappear in normal development but persist in fibrosis following ductal plate malformation.
Comparative Hepatology 02/2009; 8:5. · 1.88 Impact Factor
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ABSTRACT: Since 1987 we have run a Dermatologic Surgical Paediatric Outpatient Clinic (DSPOC) within the Children's Hospital in Bordeaux.
We analyse the consequences of an audit survey concerning the management of patients with congenital nevi (CN) seen at this clinic.
We reviewed the cases of 192 children examined and photographed at the DSPOC during the period January 1990-December 1997. Patients were contacted for a reassessment of their status. The management options chosen at the DSPOC were reviewed as well as the satisfaction of the patients or parents of young children.
Of 192 children pre-recruited, 56 girls and 52 boys could be included in the survey. They were mostly European whites and 67% were <6 months of age at the first DSPOC visit. 65/108 (61%) had been operated following the first DSPOC visit. The mean follow-up based on the 1997-1998 survey was 33 months (8 months to 10 years). The size of the nevus, independently of location, influenced decision for early surgery. Another important factor was the estimated disfigurement risk (15% of decisions) mostly related to CN of the face. There was a significant risk of pigmentary recurrence around the scar in children operated before the age of 2, but long-term follow-up indicated a spontaneously regressive course.
Nevus recurrence in cases operated early suggests a time-dependent phenomenon in nevogenesis. Early counselling is important. Early surgery seems associated with a better scar quality. Explanations concerning risks and outcome are best given with the cooperation of a surgeon and a dermatologist.
Dermatology 01/2009; 218(2):126-33. · 2.05 Impact Factor
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ABSTRACT: Adventitial cyst is a rare vascular disease frequently localized in the popliteal artery rarely in a vein. We report a case discovering in a 47-year-old man. As described, this lesion is characterized by an extrinsic compression of the vessel lumen by an adventitial myxoid nodule on histology. Recognition of this entity is important to ensure proper treatment.
Annales de Pathologie 01/2009; 28(6):498-500. · 0.25 Impact Factor
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Nadège Lapeyrere,
Marie Parrens,
Jean-Michel Coindre,
Isabelle Soubeyran,
Antoine de Mascarel,
Jean-Philippe Merlio,
Brigitte Lebail, Sébastien Lepreux,
Anne Jaffre,
Véronique Gilleron,
Simone Mathoulin-Pélissier,
Béatrice Vergier
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ABSTRACT: The goal of this work was to evaluate the impact of expert pathological second opinion on the diagnosis and management of patients with cancer, in a French region (Aquitaine) and with an economic point of view.
The study was first quantitative, performed retrospectively on all cases of cancer, voluntary sent for a second opinion to an expert pathologist of two centers. Secondly, we restricted the study to lymphoid, melanocytic and soft tissue tumors sent for second opinion. We considered that the expert review had an important diagnostic impact either when the initial pathologist sent the specimen to identify or classify malignant tumor or hesitated between benign and malignant tumor or had no hypothesis, or if there were discordant diagnoses (malignant/benign) between the two pathologists. We considered that the expert review had a high therapeutic impact if the disagreement between initial and expert diagnoses induced a complete modification in therapy. We evaluated the cost of second opinion for the expert centers and the cost of care management.
Over the year 2006, the expert centers received 5077 lesions for consultation: 3769 specimens were sent by a pathologist for a second review, 1324 by pathologists of Aquitania and of these, 751 samples were submitted for lymphoid (55%), soft tissues (30%) or melanocytic tumors (15%). There was an important diagnostic impact for 75% of the samples; the impact of the expert review on patient management was considered high for 46% of specimens and the expert pathological diagnosis modified the clinical prognosis for 40% of the specimens. We estimated that for 53 discordant diagnoses (malignant/benign), second opinion allowed an economy of 500,000 euro.
Expert second opinion is very important not only for diagnosis and management for patient with cancer but also for economic reasons.
Annales de Pathologie 01/2009; 28(6):478-85. · 0.25 Impact Factor
