We have previously shown that rheumatoid factors (RF) produced by Fas-deficient autoimmune-prone mice typically bind autologous IgG2a with remarkably low affinity. Nevertheless, B cells representative of this RF population proliferate vigorously in response IgG2a/chromatin immune complexes through a mechanism dependent on the sequential engagement of the BCR and Toll-like receptor 9 (TLR9). To more precisely address the role of both receptors in this response, we analyzed the signaling pathways activated in AM14 B cells stimulated with these complexes. We found that the BCR not only serves to direct the chromatin complex to an internal compartment where it can engage TLR9 but also transmits a suboptimal signal that in combination with the signals emanating from TLR9 leads to NF?B activation and proliferation. Importantly, engagement of both receptors leads to the upregulation of a group of gene products, not induced by the BCR or TLR9 alone, that include IL-2. These data indicate that autoreactive B cells, stimulated by a combination of BCR and TLR9 ligands, acquire functional properties that may contribute to the activation of additional cells involved in the autoimmune disease process.
Functional outcome of B cell activation by chromatin immune complex engagement of the B cell receptor and TLR9.
No sample metadata fields
View SamplesThis study aims at a comprehensive understanding of the genomic program activated during early-phase of collateral vessel growth in a rat model for cerebral adaptive arteriogenesis (3-VO). While arteriogenesis constitutes a promising therapeutic concept for cerebrovascular ischemia, genomic profiles essential for therapeutic target identification were analysed solely for collateral arteries of the heart and periphery. Despite challenging anatomical conditions of the brain the 3-VO model allows identification of differentially expressed genes during adaptive cerebral arteriogenesis by selective removal of the posterior cerebral artery (PCA).
Induction of cerebral arteriogenesis leads to early-phase expression of protease inhibitors in growing collaterals of the brain.
Age
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A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesCCAR2 is a nuclear protein recently emerged as a pivotal player of the DNA damage response since it has been found involved in both apoptosis induction and DNA repair. Differently, its role in tumorigenesis and cancer progression is still elusive. In our studies we found that CCAR2 depletion impairs the proliferation of human cancer cell lines, but leaves unaffected the growth of normal immortalized cells. To better investigate this point we performed a genome wide gene expression analyses in U2OS and BJ-hTERT depleted of CCAR2 and we found that loss of this protein causes the deregulation of genes implicated in the AKT pathway specifically in U2OS cells, but not in BJ-hTERT. In accordance with these results we found a reduction in AKT activation in all the tested cancer cell lines depleted of CCAR2, but not in the normal ones. The defective activation of AKT is caused by the upregulation of TRB3 gene in cancer cells depleted of CCAR2 and finally results in the reduction of GSK3 phosphorylation, prevention of G1/S transition and inhibition of cancer cell growth.
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesCCAR2 is a nuclear protein recently emerged as a pivotal player of the DNA damage response since it has been found involved in both apoptosis induction and DNA repair. Differently, its role in tumorigenesis and cancer progression is still elusive. In our studies we found that CCAR2 depletion impairs the proliferation of human cancer cell lines, but leaves unaffected the growth of normal immortalized cells. To better investigate this point we performed a genome wide gene expression analyses in U2OS and BJ-hTERT depleted of CCAR2 and we found that loss of this protein causes the deregulation of genes implicated in the AKT pathway specifically in U2OS cells, but not in BJ-hTERT. In accordance with these results we found a reduction in AKT activation in all the tested cancer cell lines depleted of CCAR2, but not in the normal ones. The defective activation of AKT is caused by the upregulation of TRB3 gene in cancer cells depleted of CCAR2 and finally results in the reduction of GSK3 phosphorylation, prevention of G1/S transition and inhibition of cancer cell growth.
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesAdministration of exogenous mesenchymal stem cells (MSCs) has been shown to improve the recovery from acute kidney injury (AKI). It has been suggested that the beneficial effect of MSCs is related to the paracrine release of factors favouring proliferation of intrinsic epithelial cells survived to injury rather than to their trans-differentiation. However the factors involved remain to be determined. In the present study we demonstrated that microvesicles (MVs) derived from human bone marrow MSCs are able to stimulate in vitro proliferation and apoptosis resistance of tubular epithelial cells (TEC). In addition, MVs were found to accelerate in vivo the morphological and functional recovery of glycerol induced AKI in SCID mice by inducing TEC proliferation. The effect of MVs on the recovery of AKI was comparable to that of human MSC treatment. In vitro we found that the CD44 and beta1-integrin-dependent incorporation of MVs in TEC was required for their biological action. However, despite their internalization, RNase-treated MVs failed to induce in vitro apoptosis resistance and TEC proliferation, and in vivo recovery from AKI, suggesting an RNA-dependent biological effect. Microarray analysis and quantitative RT-PCR of MV-RNA extract indicated that MVs were shuttling a specific subset of cellular mRNA, such as mRNA associated with the mesenchymal differentiative phenotype and with several cell functions involved in the control of transcription, proliferation, apoptosis and cell immune regulation. These results suggest that MVs derived from MSCs may activate a proliferative program in TEC survived to injury in AKI by an horizontal transfer of mRNA.
Mesenchymal stem cell-derived microvesicles protect against acute tubular injury.
No sample metadata fields
View SamplesWe isolated the meristematic and elongation zones of Col-0, upb1-1 mutant and 35S::UPB1-3YFP/upb1-1 plants by micro-dissection and extracted RNA from each section independently.
Transcriptional regulation of ROS controls transition from proliferation to differentiation in the root.
Age, Specimen part
View SamplesTCP transcription factors from the CYC2-class are involved in the development of monosymmetric flowers in all core eudicot species analysed so far. In Antirrhinum majus, the CYC2/TCP transcription factor CYCLOIDEA (CYC) is the molecular key regulator driving the development of flower monosymmetry (Luo D, Carpenter R, Vincent C, Copsey L, Coen E: Origin of floral asymmetry in Antirrhinum. Nature 1996, 383:794-799). In the Brassicaceae Iberis amara, a stronger expression of the CYC2 gene IaTCP1 in the small adaxial petals likely leads to the reduced petal size in comparison to large abaxial petals, with hardly any IaTCP1 expression. This results in the formation of the monosymmetric Iberis flower (Busch A, Zachgo S: Control of corolla monosymmetry in the Brassicaceae Iberis amara. PNAS 2007, 104:16714-16719). In contrast, the orthologous TCP/CYC2 transcription factor TCP1 from Arabidopsis thaliana, which forms equally sized and shaped petal pairs, only shows an early and transient expression in the adaxial area of floral primordia. This implies that monosymmetry in the Brassicaceae evolved through a heterochronic expression shift of the TCP/CYC2 key regulator gene IaTCP1.
Differential transcriptome analysis reveals insight into monosymmetric corolla development of the crucifer Iberis amara.
Specimen part
View SamplesUsing cell-restricted transcriptome analysis, here we show that Drosophila ommatidial cone (or Semper) cells are enriched for conserved glial regulators and effectors, including many characteristic of vertebrate retinal glia: Müller glia and astrocytes. Overall design: RNA-seq based analysis of Drosophila retinal cone cells (3 developmental stages) and photoreceptors. 1 sample per cell type - 4 total libraries sequenced.
Multifunctional glial support by Semper cells in the Drosophila retina.
Specimen part, Subject
View SamplesStandard chemotherapy is the only systemic treatment for triple-negative breast cancer (TNBC). Despite the good initial responses, resistance remains a major therapeutic obstacle. Here, we employed a High-Throughput Screen to identify targeted therapies that overcome chemoresistance in TNBC. We applied short-term paclitaxel treatment and screened 320 small-molecule inhibitors of known targets to identify drugs that preferentially and efficiently target paclitaxel-treated TNBC cells. Among these compounds the SMAC mimetics (BV6, Birinapant) and BH3-mimetics (ABT-737/263) were recognized as potent targeted therapy for multiple paclitaxel-residual TNBC cell lines. However, acquired paclitaxel resistance through repeated paclitaxel pulses result in desensitization to BV6, but not to ABT-263, suggesting that short- and long-term paclitaxel resistance are mediated by distinct mechanisms. Gene expression profiling of paclitaxel-residual, -resistant and nave MDA-MB-231 cells demonstrated that paclitaxel-residual, as opposed to -resistant cells, were characterized by an apoptotic signature, with downregulation of anti-apoptotic genes (BCL2, BIRC5), activation of apoptosis inducers (IL24, PDCD4), and enrichment of TNF/NF-B pathway, including upregulation of TNFSF15, coupled with cell-cycle arrest. BIRC5 and FOXM1 downregulation and IL24 induction was also evident in breast cancer patient datasets following taxane treatment. Exposure of nave and paclitaxel-resistant cells to supernatants of paclitaxel-residual cells sensitized them to BV6, and treatment with TNF enhanced the potency of BV6, suggesting that sensitization to BV6 is mediated, at least partially, by secreted factor(s). Our results suggest that administration of SMAC or BH3 mimetics following short-term paclitaxel treatment could be an effective therapeutic strategy for TNBC, while only BH3-mimetics could effectively overcome long-term paclitaxel resistance
Targeting of apoptotic pathways by SMAC or BH3 mimetics distinctly sensitizes paclitaxel-resistant triple negative breast cancer cells.
Sex, Age, Specimen part, Cell line, Treatment
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