Functional Heterogeneity of Embryonic Stem Cells Revealed through Translational Amplification of an Early Endodermal Transcript

Detection of low-level, lineage-specific transcription aids in the identification of lineage-primed populations of ES cells provides a new framework for pluripotency

Increased Cycling Cell Numbers and Stem Cell Associated Proteins as Potential Biomarkers for High Grade Human Papillomavirus+ve Pre-Neoplastic Cervical Disease

High risk (oncogenic) human papillomavirus (HPV) infection causes cervical cancer. Infections are common but most clear naturally. Persistent infection can progress to cancer. Pre-neoplastic disease (cervical intraepithelial neoplasia/CIN) is classified by histology (CIN1-3) according to severity. Cervical abnormalities are screened for by cytology and/or detection of high risk HPV but both methods are imperfect for prediction of which women need treatment. There is a need to understand the host virus interactions that lead to different disease outcomes and to develop biomarker tests for accurate triage of infected women. As cancer is increasingly presumed to develop from proliferative, tumour initiating, cancer stem cells (CSCs), and as other oncogenic viruses induce stem cell associated gene expression, we evaluated whether presence of mRNA (detected by qRT-PCR) or proteins (detected by flow cytometry and antibody based proteomic microarray) from stem cell associated genes and/or increased cell proliferation (detected by flow cytometry) could be detected in well-characterised, routinely collected cervical samples from high risk HPV+ve women. Both cytology and histology results were available for most samples with moderate to high grade abnormality. We found that stem cell associated proteins including human chorionic gonadotropin, the oncogene TP63 and the transcription factor SOX2 were upregulated in samples from women with CIN3 and that the stem cell related, cell surface, protein podocalyxin was detectable on cells in samples from a subset of women with CIN3. SOX2, TP63 and human gonadotrophin mRNAs were upregulated in high grade disease. Immunohistochemistry showed that SOX2 and TP63 proteins clearly delineated tumour cells in invasive squamous cervical cancer. Samples from women with CIN3 showed increased proliferating cells. We believe that these markers may be of use to develop triage tests for women with high grade cervical abnormality to distinguish those who may progress to cancer from those who may be treated more conservatively

Characterization of ATG8 Family Protein Binding to TRIM23 and TRIM31

Macroautophagy (hereafter called autophagy) is a process where proteins, organelles and intracellular micro-organisms are degraded by the lysosome. The autophagosome engulfs a part of the cytoplasm where the cargo is, and transports it to the endosomal-lysosomal system for degradation. Autophagy can also be selective, where cargos are recognized directly by the autophagy receptors or by other proteins in which target a specific cargo for degradation and can bind to for example ATG8s via a LIR domain. There are many proteins involved in autophagy, and TRIM proteins represent some of them. TRIM proteins are classified in a family of E3 ligases because of their RING domain, even though not all TRIM proteins contain this RING domain. Some TRIM proteins have been shown to be of great importance in the process of autophagy and the selectivity of autophagy by binding to autophagy-related proteins. Recent studies show that TRIM23 and TRIM31 are important in autophagy. ATG8 family proteins have hydrophobic pockets which bind LIR motifs in other proteins. Here, the interaction of TRIM23 and TRIM31 with the ATG8 family proteins is studied, and moreover their interaction with human ATG8 family proteins and if the binding is LIR dependent. GST pulldown, and co-localization assays with confocal fluorescence microscope were methods used for this purpose. Furthermore, the mCherry-EYFP double-tag was used to monitor if TRIM23 and TRIM31 are degraded in the lysosome. The lysosomal inhibitor Bafilomycin A1 (Baf) and the proteosomal inhibitor MG132 were included in the assays performed in HeLa cells to determine the degradation pathway. The results showed that both TRIM23 and TRIM31 bind ATG8s in a LIR-dependent manner. Neither TRIM23 nor TRIM31 were found to be degraded by autophagy using the double-tag assay, even though both were degraded upon starvation. Confocal imaging showed that TRIM31 co-localizes with LC3A, LC3B and GABARAP in HeLa cells

Effects of Irradiation on Porous Silicon

Besides the well-known effect of photoluminescence, the impinging of photons and other kinds of particles such as electrons, ions, and muons on porous silicon produces important effects. Some of these effects can modify the structure and properties of the material, distorting the interpretation of data based on the use of irradiation. Some of the irradiation effects are useful in different applications such as photodynamic therapy or display applications. This work is a review of the effects of irradiation on porous silicon.Fil: Koropecki, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Arce, Roberto Delio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentin