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Das humane Cytomegalovirus (HCMV) kann sich zwischen Zellen zellfrei oder zellassoziiert ausbreiten. Beim Eintritt zellfreier Virionen in Fibroblasten benötigt HCMV den Glykoprotein-Trimer aus den Glykoproteinen H, L und O (gH/gL/gO), um an den zellulären Rezeptor platelet-derived-growth-factor-receptor-alpha (PDGFRα) zu binden und das virale Fusionsprotein Glykoprotein B zu aktivieren. Über die molekularen Grundlagen der zellassoziierten Ausbreitung ist weniger bekannt. In dieser Arbeit sollte der Beitrag des viralen Proteins gO bzw. seines zellulären Rezeptors PDGFRα zum zellassoziierten Wachstum untersucht und die Wirkweise von PDGFRα-Peptiden bei der Hemmung dieser Ausbreitung analysiert werden. In Fibroblastenkulturen, die mit klinischen HCMV-Isolaten infiziert waren, wurde die Expression der Proteine durch Knockdown mittels siRNA vermindert und mit quantitativen Immunoblotting-Analysen gemessen. Der Effekt auf die Virusausbreitung wurde durch Immunfluoreszenz-Nachweis infizierter Zellen in den Isolat-Kulturen erfasst. Um den Wirkmechanismus der inhibitorischen PDGFRα-Peptide GT40 und IK40 zu analysieren, wurden Dosis-Wirkungs-Kurven erstellt und der Transfer einzelner Viruspartikel in den Infektionsherden durch Immunfluoreszenz visualisiert. Die Verwendung eines doppelt-fluoreszierenden Modellvirus erlaubte dabei, Effekte auf Adsorption und Penetration zu differenzieren. Mit einer gO-Deletionsmutante wurde schließlich geprüft, ob die Hemmwirkung der Peptide von gO abhängt. Sowohl der Knockdown von gO als auch von PDGFRα reduzierte die zellassoziierte Virusausbreitung der klinischen HCMV-Isolate, was die Bedeutung der beiden Proteine für die zellassoziierte Ausbreitung von HCMV belegt. Die Immunfluoreszenz-Färbung der Viruspartikel zeigte, dass die PDGFRα-Peptide GT40 und IK40 den Partikeltransfer von infizierten Zellen auf neue Zielzellen hemmen, indem sie die Zahl der adsorbierten und den Anteil der penetrierten Viruspartikel vermindern, und zwar mit einer halbmaximalen Hemmkonzentration von 6-7,5 bzw. 13-15 µmol/l. Auch die gO-Deletionsmutante wurde in gleichem Maße gehemmt, was bedeutet, dass eine Bindung an gO für die Hemmwirkung nicht nötig ist. Insgesamt zeigt diese Arbeit, dass gO und sein zellulärer Rezeptor auch für das zellassoziierte Wachstum von HCMV wichtig sind und damit potenzielle Ziele für eine antivirale Strategie zur Hemmung dieser Ausbreitungsform darstellen. Die PDGFRα-Peptide GT40 und IK40 wirken zwar offensichtlich nicht über eine Störung dieser Interaktion, ihr Wirkmechanismus macht sie aber zu wertvollen Werkzeugen, um die Partikelübertragung bei der zellassoziierten Ausbreitung im Detail zu analysieren.

Type 2 diabetes mellitus (T2DM) is associated with impaired skeletal muscle function and degeneration of the skeletal muscles. However, the mechanisms underlying the degeneration are not well described in human skeletal muscle. Here we show that skeletal muscle of T2DM patients exhibit degenerative remodeling of the extracellular matrix that is associated with a selective increase of a subpopulation of fibro-adipogenic progenitors (FAPs) marked by expression of THY1 (CD90)—the FAPCD90+. We identify platelet-derived growth factor (PDGF) as a key FAP regulator, as it promotes proliferation and collagen production at the expense of adipogenesis. FAPsCD90+ display a PDGF-mimetic phenotype, with high proliferative activity, clonogenicity, and production of extracellular matrix. FAPCD90+ proliferation was reduced by in vitro treatment with metformin. Furthermore, metformin treatment reduced FAP content in T2DM patients. These data identify a PDGF-driven conversion of a subpopulation of FAPs as a key event in the fibrosis development in T2DM muscle. Sin financiación 31.373 JCR (2021) Q1, 8/195 Cell Biology 9.297 SJR (2021) Q1, 9/293 Cell Biology No data IDR 2021 UEM

Merkel cell carcinoma (MCC) is a highly malignant skin cancer characterized by early metastases and poor survival. Although MCC is a rare malignancy, its incidence is rapidly increasing in the U.S. and Europe. The discovery of the Merkel cell polyomavirus (MCPyV) has enormously impacted our understanding of its etiopathogenesis and biology. MCCs are characterized by trilinear differentiation, comprising the expression of neuroendocrine, epithelial and B-lymphoid lineage markers. To date, it is generally accepted that the initial assumption of MCC originating from Merkel cells (MCs) is unlikely. This is owed to their post-mitotic character, absence of MCPyV in MCs and discrepant protein expression pattern in comparison to MCC. Evidence from mouse models suggests that epidermal/dermal stem cells might be of cellular origin in MCC. The recently formulated hypothesis of MCC originating from early B-cells is based on morphology, the consistent expression of early B-cell lineage markers and the finding of clonal immunoglobulin chain rearrangement in MCC cells. In this review we elaborate on the cellular ancestry of MCC, the identification of which could pave the way for novel and more effective therapeutic regimens. (C) 2017 The Authors. Published by Elsevier Ireland Ltd.

WOS: 000493372200002 PubMed ID: 31709947 Introduction: Mesothelioma is an aggressive tumour that originates in serous surfaces. The primary end point of this study was to invastigate the relationship of progression free survival (PFS) and overall survival (OS) with the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels in the tumour tissue of pleural and peritoneal mesothelioma cases. Materials and Methods: The study included 53 patients diagnosed with mesothelioma between 2005 and 2016. The cases were separated into 2 groups as pleural and peritoneal. The effects on OS and PFS were examined of the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels and also clinicopathological parameters and the treatments given. In the statistical analysis of the data obtained, IBM SPSS vn 20.0 software was used. Results: Of the 53 patients included in the study, 39 (73.6%) were diagnosed with pleural mesothelioma and 14 (26.4%) with peritoneal mesothelioma. According to the c-Met and mTOR expression, OS and PFS of the peritoneal cases with high expression (2+, 3+) was seen to be significantly better than that of the peritoneal cases with low expression (0, 1+) (p < 0.05). According to the PDGFR expression, OS and PFS of the pleural cases with low expression (0, 1+) was seen to be significantly better than that of the pleural cases with high expression (2+, 3+) (p < 0.05). Conclusion: The examination of c-MET, PDGFR-alpha and m-TOR expression in the in the tumor tissue of mesothelioma cases may be important in determining prognosis.

PubMedID: 31709947 Introduction: Mesothelioma is an aggressive tumour that originates in serous surfaces. The primary end point of this study was to invastigate the relationship of progression free survival (PFS) and overall survival (OS) with the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels in the tumour tissue of pleural and peritoneal mesothelioma cases. Materials and Methods: The study included 53 patients diagnosed with mesothelioma between 2005 and 2016. The cases were separated into 2 groups as pleural and peritoneal. The effects on OS and PFS were examined of the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels and also clinicopathological parameters and the treatments given. In the statistical analysis of the data obtained, IBM SPSS vn 20.0 software was used. Results: Of the 53 patients included in the study, 39 (73.6%) were diagnosed with pleural mesothelioma and 14 (26.4%) with peritoneal mesothelioma. According to the c-Met and mTOR expression, OS and PFS of the peritoneal cases with high expression (2+, 3+) was seen to be significantly better than that of the peritoneal cases with low expression (0, 1+) (p< 0.05). According to the PDGFR expression, OS and PFS of the pleural cases with low expression (0, 1+) was seen to be significantly better than that of the pleural cases with high expression (2+, 3+) (p< 0.05). Conclusion: The examination of c-MET, PDGFR-alpha and m-TOR expression in the in the tumor tissue of mesothelioma cases may be important in determining prognosis. © 2019 by Tuberculosis and Thorax.

Key points: Exogenous Na + /H + exchanger 1 (NHE1) expression stimulated the collective migration of epithelial cell sheets Stimulation with epidermal growth factor, a key morphogen, primarily increased migration of the front row of cells, whereas NHE1 increased that of submarginal cell rows, and the two stimuli were additive Accordingly, NHE1 localized not only to the leading edges of leader cells, but also in cryptic lamellipodia in submarginal cell rows NHE1 expression disrupted the morphology of epithelial cell sheets and three-dimensional cysts. Abstract: Collective cell migration plays essential roles in embryonic development, in normal epithelial repair processes, and in many diseases including cancer. The Na + /H + exchanger 1 (NHE1, SLC9A1) is an important regulator of motility in many cells and has been widely studied for its roles in cancer, although its possible role in collective migration of normal epithelial cells has remained unresolved. In the present study, we show that NHE1 expression in MDCK-II kidney epithelial cells accelerated collective cell migration. NHE1 localized to the leading edges of leader cells, as well as to cryptic lamellipodia in submarginal cell rows. Epidermal growth factor, a kidney morphogen, increased displacement of the front row of collectively migrating cells and reduced the number of migration fingers. NHE1 expression increased the number of migration fingers and increased displacement of submarginal cell rows, resulting in additive effects of NHE1 and epidermal growth factor. Finally, NHE1 expression resulted in disorganized development of MDCK-II cell cysts. Thus, NHE1 contributes to collective migration and epithelial morphogenesis, suggesting roles for the transporter in embryonic and early postnatal development.

Objective: Chordoma is a rare malignant bone tumor with a poor outcome. Although radiotherapy and gamma knife surgery have been used for treatment, providing a cure for the tumor is not easy, because of the frequent recurrences. Molecular targeted therapy against tyrosine kinases has been effective in the treatment of malignancies such as breast and lung cancers and brain tumors. We aimed to analyse the histopathological features of chordomas and the immunoexpression profiles of the three receptor tyrosine kinases of EGFR, c-Met and c-Erb-B2 in chordomas. We have correlated these results with recurrence and overall survival status of the patients. Material and Method: We studied 49 chordoma patients in order to evaluate the histopathological features and immunohistochemical stainings by EGFR, c-Met and c-ErbB2 antibodies. Of the 49 patients, follow up data was available for 40 patients. Clinical data of the patients were correlated with histopathological features and survival analysis was performed. Results: The immunostaining rate by EGFR and c-Met was 73.5% and 12.2% respectively. None of the cases showed immunoreactivity by c-ErbB2 (0%). Of the 40 cases, 17 cases showed recurrences. EGFR expression was detected in 14 recurrent (14/17) and 17 non-recurrent cases (17/23). Four of the 17 recurrent cases (4/17) were positive by c-Met, while none of the non-recurrent cases (0/23) were positive by this antibody. Significantly, all cases with positive c-Met expression showed recurrences (p

Gliosarcomas are rare and poorly characterized malignant brain tumors that exhibit a biphasic tissue pattern with areas of gliomatous and sarcomatous differentiation. These tumors are histological variants of glioblastoma, displaying a similar genetic profile and dismal prognosis. Up-regulation of PDGFR subfamily of tyrosine kinase members, PDGFR-α and c-Kit, and their intracellular effectors RAS/RAF/MAPK has a crucial role in the cancer development. In addition, signal transduction mediated by activating mutations of c-Kit and PDGFR can be effectively blocked by specific tyrosine kinase inhibitors, such as Imatinib mesylate. The aim of this study was to characterize the molecular alterations of PDGFR signaling in gliosarcomas. Six cases were analyzed by immunohistochemistry for the expression of PDGFR-α, c-Kit and their ligands PDGF-A and SCF, respectively. The cases were further evaluated for the presence of activating mutations of PDGFR-α (exons 12 and 18) and c-kit (exons 9, 11, 13, and 17), as well as B-RAF (exons 11 and 15). Expression of PDGF-A was found in all cases and co-expression of PDGFR-α was observed in three cases. Four cases showed expression of SCF, and c-Kit was observed only in one case that also expressed SCF. Generally, immunoreaction predominates in the glial component. The mutational analysis of PDGFR-α showed the presence of an IVS17-50insT intronic insertion in two cases, one of them also with a 2472C > T silent mutation; this silent mutation was also found in another case. Glioma cell line analysis of IVS17-50insT insertion showed no influence on PDGFR-α gene splicing. No mutations were detected in c-kit and B-RAF oncogenes. Our results indicate that activating mutations of PDGFR-α, c-kit and B-RAF are absent in gliosarcomas. Nevertheless, the presence of a PDGFR-a/PDGFA and c-Kit/SCF autocrine/paracrine stimulation loop in a proportion of cases, supports the potential role of specific tyrosine kinase inhibitors in the treatment of gliosarcomas., Novartis Portugal.

The purpose of this study was to examine the effect of capsaicin administration immunohistochemically on platelet-derived growth factor (PDGF)-C and platelet-derived growth factor receptor (PDGFR)-alpha release in the small intestine tissues of rats. Rats were divided into three groups: group 1 (subcutaneous drug administration), group 2 (oral drug administration), and group 3 (subcutaneous sham administration). Histometric measurements and counts were performed in order to determine whether there was a difference between groups in terms of height of villi, depth of crypts, and goblet cell count in small intestine. The small intestine was examined by Crossman's triple staining method and streptavidin-biotin peroxidase complex method. As a result of statistical analysis, it was found that body weight increased in group 3, while it decreased in groups 1 and 2. Capsaicin administration increased height of villi, depth of crypts, and count of goblet cells located on villi and crypts. Immunohistochemical examinations revealed that capsaicin administration increased PDGF-C and PDGFR-alpha release. It was concluded that capsaicin has a stimulatory effect on growth and is an enhancer for PDGF-C and PDGFR-alpha release.