0000000000070738
AUTHOR
Di Liegro C. M.
H1° mRNA-containing complexes in rat brain cells. In: Proceedings of the Abstracts
Post-transcriptional regulation of gene expression depends on RNA-binding proteins (RBPs), which are able to regulate translation, stability and subcellular localization of mRNAs [1]. RNA-protein complexes start to be built up since transcription; some proteins remain then bound to the transcript, while others behave as only transient components. In the developing nervous system of mammals, the postnatal production of the histone variants H1° and H3.3 is mainly regulated at the post-transcriptional level. Synthesis and incorporation into chromatin of the two histone proteins has been suggested to be involved in the epigenetic regulation of gene expression, both in normal brain development a…
G26/24 extracellular microvesicles contain both H1° protein and RNA
Extracellular vesicles (EVs) are released into the extracellular space from both tumor and normal brain cells. By releasing EVs which contain FGF2 and VEGF1-2, astrocytes and neurons, co-cultured with brain capillary endothelial cells, are for example able to induce them to form a blood-brain barrier-like monolayer. On the other hand, membrane microvesicles (MVs) shed from G26/24 oligodendroglioma cells, when added to primary cultures of rat cortical neurons, induce neuronal damage; the damaging effects include a strong reduction of neurite outgrowth, and apoptosis in about 75% of the cells3. The same amount of shed MVs induce apoptosis in about 40% of astrocytes4. These effects are probab…
Melanoma cells release extracellular vesicles which contain RNA-binding proteins able to bind the mRNA encoding histone H1°
Extracellular vesicles (EVs) are produced by most prokaryotic and eukaryotic cells; tumour cells, however, release much higher amounts of EVs, which contain cancer-specific proteins and RNAs. Molecules carried by EVs are captured by surrounding cells, which then undergo profound phenotypic modifications. G26/24 oligodendroglioma cells release, for example, EVs containing FasL and TRAIL, which induce apoptosis in rat cortical neurons and astrocytes in culture. By metabolic labelling of cells, EV-mediated horizontal transfer of radioactive proteins was clearly demonstrated. Among the proteins present in EVs produced by oligodendroglioma cells, extracellular matrix remodelling proteases, and t…
Extracellular vesicles released from melanoma cells contain H1° mRNA-binding proteins, one of which is (probably) MYEF2.
Release of extracellular vesicles (EVs) is a process conserved from prokaryotes to eucaryotes. Although EVs are produced from both normal and cancer cells, malignant cells release a much higher amount of EVs, which contain tumour-specific proteins and RNAs. We previously found that G26/24 oligodendroglioma cells shed EVs that contain the pro-apoptotic factors FasL and TRAIL and are able to inhibit neurite outgrowth, and induce apoptosis in about 75% of rat cortical neurons [1] and 40% of astrocytes [2] in culture. By labelling proteins synthesized in one cell type, we also demonstrated EV-mediated horizontal transfer of proteins among brain cells. Interestingly, G2624 release, via EVs, extr…
Melanoma cells release extracellular vesicles which contain H1° RNA and RNA-binding proteins
G26/24 oligodendroglioma cells produce EVs that contain pro-apoptotic proteins, such as FasL and TRAIL, able to induce neuronal- [1] and astrocytic- [2] death. Cancer cells release EVs [3] through which transferring proteins, such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. By releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used A375 melanoma cells. EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assays were performed on total cell lysates and EVs, as described elsewhere [6]. RNA-binding proteins…
Developing rat brain as well as cultured astrocytes contain H1° mRNA-protein complexes
RNA-binding proteins (RBPs) regulate intracellular transport, pre-localization, stability, and translation of mRNAs [1]. We previously identified a set of proteins which interact with mRNAs encoding H1° and H3.3 histones [2-5]. All these proteins are probably part of a ribonucleoprotein particle [6]. Here we report the results of a more detailed study on the expression and intracellular localization of some of these RBPs, such as hnRNP K and A1, and Hsc70, during rat brain development and in cultured rat astrocytes. We also investigated the presence in the complexes of PIPPin/CSD-C2 protein. Affinity chromatography was performed as already described [6]. Preparation of total lysates and cel…
Melanoma cells release extracellular vesicle which contain H1° linker histone as well as RNA-binding proteins which bind to the H1° mRNA
We previously demonstrated that G26/24 oligodendroglioma cells release EVs that contain proteins, such as FasL and TRAIL, which induce apoptosis in rat cortical neurons [1] and astrocytes [2]. We also reported that cancer cells use EVs for transferring, into the environment [3], proteins such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. In particular, by releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used as a model A375 melanoma cells. METHODS EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assa…
Expression and intracellular localization of H1° mRNA-containing complexes in developing rat brain and astrocytes
INTRODUCTION: Post-transcriptional regulation of gene expression relies on RNA-binding proteins (RBPs), which regulate intracellular transport, stability, and translation of mRNAs [1]. We previously identified a set of proteins which interact with mRNAs encoding H1° and H3.3 histones [2-5]. All these proteins are probably part of a ribonucleoprotein particle [6]. Here we report more details on the expression and intracellular localization of some of these RBPs, during rat brain development and in isolated rat astrocytes. METHODS: Affinity chromatography was performed as already described [6]. Preparation of total lysates and cellular sub-fractions was done as reported in [3]. Possible co-lo…