Bone morphogenic proteins (BMPs) function in virtually all tissues with cell-type specific outcomes. Since there are a relatively small number of BMP receptors this exquisite signaling specificity requires additional molecules to regulate the output of this pathway. We demonstrated that the receptor tyrosine kinase MuSK that is selectively expressed in muscle and plays a critical role in synapse formation and maintenance binds to BMP4 and related BMPs. Since BMPs regulate the transcription of a set of genes, we performed microarrays for wild-type and MuSK null muscle cells to test if MuSK regulates BMP responses in muscle cells.
MuSK is a BMP co-receptor that shapes BMP responses and calcium signaling in muscle cells.
No sample metadata fields
View SamplesWe expressed a constitutively active mutant of MEK5 (MEK5D) in human primary endothelial cells (EC) to study the transcriptional and functional responses to Erk5 activation under static conditions.
Erk5 activation elicits a vasoprotective endothelial phenotype via induction of Kruppel-like factor 4 (KLF4).
Cell line
View SamplesInflammation has a causal role in many cancers. In prostate cancers, epidemiological data suggest a link between prostatitis and subsequent cancer development, but a proof for this concept in a tumor model has been lacking. A constitutively active version of the IkappaB kinase 2 (IKK2), the molecule activated by a plethora of inflammatory stimuli, was expressed specifically in the prostate epithelium. Signaling of the IKK2/NF-kappaB axis was insufficient for transformation of prostate tissue. However, while PTEN+/- epithelia exhibited intraepithelial neoplasias only recognizable by nuclear alterations, additional IKK2 activation led to an increase in tumor size and formation of cribriform structures and to a fiber increase in the fibroblastic stroma. This phenotype was coupled with inflammation in the prostate gland characterized by infiltration of granulocytes and macrophages. Molecular characterization of the tissues showed a specific loss of smooth muscle markers as well as expression of chemokines attracting immune cells. Isolation of epithelial and stromal cells showed differential chemokine expression by these cells. Correlation studies showed the inflammatory phenotype coupled to loss of smooth muscle in infiltrated glands, but maintenance of the phenotype in glands where inflammation had decreased. Despite the loss of the smooth muscle barrier, tumors were not invasive in a stable genetic background. Data mining revealed that smooth muscle markers are downregulated in human prostate cancers and literature data show that loss of these markers in primary tumors is associated with subsequent metastasis. Our data show that loss of smooth muscle and invasiveness of the tumor are not coupled. Thus, inflammation during early steps of tumorigenesis can lead to increased tumor size and a potential change in the subsequent metastatic potential, but the tumor requires an additional transformation to become a carcinoma.
Persistent inflammation leads to proliferative neoplasia and loss of smooth muscle cells in a prostate tumor model.
Age, Specimen part
View SamplesThe objective of this study was to compare the transcriptional repertoire of mature human neutrophils before and after GM-CSF treatment by using oligonucleotide microarrays.
RhoH/TTF negatively regulates leukotriene production in neutrophils.
Specimen part
View SamplesAlveolar epithelial type II (ATII)-like cells can be generated from murine embryonic stem cells (ESCs), although to date, no robust protocols applying specific differentiation factors are established. We hypothesized that the keratinocyte growth factor (KGF), an important mediator of lung organogenesis and primary ATII cell maturation and proliferation, together with dexamethasone, 8-bromoadenosine-cAMP, and isobutylmethylxanthine (DCI), which induce maturation of primary fetal ATII cells, also support the alveolar differentiation of murine ESCs. Here we demonstrate that the above stimuli synergistically potentiate the alveolar differentiation of ESCs as indicated by increased expression of the surfactant proteins (SP-) C and SP-B. This effect is most profound if KGF is supplied not only in the late stage, but at least also during the intermediate stage of differentiation. Our results indicate that KGF most likely does not enhance the generation of (mes)endodermal or NK2 homeobox 1 (Nkx2.1) expressing progenitor cells but rather, supported by DCI, accelerates further differentiation/maturation of respiratory progeny in the intermediate phase and maturation/proliferation of emerging ATII cells in the late stage of differentiation. Ultrastructural analyses confirmed the presence of ATII-like cells with intracellular composite and lamellar bodies. Finally, induced pluripotent stem cells (iPSCs) were generated from transgenic mice with ATII cell-specific lacZ reporter expression. Again, KGF and DCI synergistically increased SP-C and SP-B expression in iPSC cultures, and lacZ expressing ATII-like cells developed. In conclusion, ATII cell-specific reporter expression enabled the first reliable proof for the generation of murine iPSC-derived ATII cells. In addition, we have shown KGF and DCI to synergistically support the generation of ATII-like cells from ESCs and iPSCs. Combined application of these factors will facilitate more efficient generation of stem cell-derived ATII cells for future basic research and potential therapeutic application.
Keratinocyte growth factor and dexamethasone plus elevated cAMP levels synergistically support pluripotent stem cell differentiation into alveolar epithelial type II cells.
Specimen part, Treatment
View SamplesAnalysis of bone marrow derived macrophages (BMDM) incubated with dexamethasone&IL4 (Dexa+IL4), B16F1 tumor conditioned medium (cmB16), and B16F1 tumor conditioned medium supplemented with dexamethasone&IL4 (cmB16+dexa+IL4). Results allow detection of genes that require synergistic stimulation of tumor factors and Th2 cytokines.
Synergistic activation by p38MAPK and glucocorticoid signaling mediates induction of M2-like tumor-associated macrophages expressing the novel CD20 homolog MS4A8A.
Specimen part
View SamplesTumor-associated macrophages (TAMs) represent alternatively activated (M2) macrophages that support tumor growth. Previously, we have described a special LYVE-1(+) M2 TAM subset in vitro and in vivo; gene profiling of this TAM subset identified MS4A8A as a novel TAM molecule expressed in vivo by TAM in mammary carcinoma and malignant melanoma. In vitro, Ms4a8a mRNA and MS4A8A protein expression was strongly induced in bone marrow-derived macrophages (BMDMs) by combining M2 mediators (IL-4, glucocorticoids) and tumor-conditioned media (TCM). Admixture of MS4A8A(+) TCM/IL-4/GC-treated BMDM significantly enhanced the tumor growth rate of subcutaneously transplanted TS/A mammary carcinomas. Upon forced overexpression of MS4A8A, Raw 264.7 macrophage-like cells displayed a special gene signature. Admixture of these MS4A8A(+) Raw 264.7 cells also significantly enhanced the tumor growth rate of subcutaneously transplanted mammary carcinomas. To identify the signaling pathways involved in synergistic induction of MS4A8A, the major signaling cascades with known functions in TAM were analyzed. Although inhibitors of NF-B activation and of the MAPK JNK and ERK did not show relevant effects, the p38/ MAPK inhibitor SB203580 strongly and highly significantly (p > 0.001) inhibited MS4A8A expression on mRNA and protein level. In addition, MS4A8A expression was restricted in M2 BMDM from mice with defective GC receptor (GR) dimerization indicating that classical GR gene regulation is mandatory for MS4A8A induction. In conclusion, expression of MS4A8A within the complex signal integration during macrophage immune responses may act to fine tune gene regulation. Furthermore, MS4A8A(+) TAM may serve as a novel cellular target for selective cancer therapy.
Synergistic activation by p38MAPK and glucocorticoid signaling mediates induction of M2-like tumor-associated macrophages expressing the novel CD20 homolog MS4A8A.
Specimen part
View SamplesBackground: Neuroblastoma is the most common extracranial solid tumor in childhood. The vast majority of stage M patients present with disseminated tumor cells (DTCs) in the bone marrow (BM). Although these cells represent a major obstacle in the treatment of neuroblastoma patients, their transcriptomic profile was not intensively analyzed so far. Results: RNA-Seq of stage M primary tumors, enriched BM-derived DTCs and the corresponding non-tumor mononuclear cells (MNCs) revealed that DTCs largely retained the gene expression signature of tumors. However, we identified 322 genes that were differentially expressed (q < 0.001, |log2FC|>2). Particularly genes encoded by mitochondrial DNA were highly up-regulated in DTCs, whereas e.g. genes involved in angiogenesis were down-regulated. Furthermore, 224 genes were highly expressed in DTCs and only slightly, if at all, in MNCs (q < 8x10-75 log2FC > 6). Interestingly, we found that the gene expression profiles of diagnostic DTCs largely resembled those of relapse DTCs with only 113 differentially expressed genes under relaxed cut-offs (q < 0.01, |log2FC| > 0.5). Notably, relapse DTCs showed a positional enrichment of 31 down-regulated genes encoded by chromosome 19, including five tumor suppressor genes (SIRT6, PUMA, STK11, CADM4 and GLTSCR2). Conclusion: This first RNA-Seq analysis of DTCs from neuroblastoma patients revealed their unique expression profile in comparison to the corresponding MNCs and tumor samples, and, interestingly, also expression differences between diagnostic and relapse DTCs preferentially affecting chromosome 19. As these alterations might be associated with treatment failure and disease relapse, they should be considered for further functional studies. Overall design: Tumor (n=16), bone marrow-derived disseminated tumor cells (n=42) and corresponding bone marrow-derived non-tumor cells (n=28) of stage M neuroblastoma patients were used for RNA-Seq
Neuroblastoma cells undergo transcriptomic alterations upon dissemination into the bone marrow and subsequent tumor progression.
Specimen part, Subject
View SamplesThe animal piRNA pathway is a small RNA silencing system that acts in gonads and protects the genome against the deleterious influence of transposons. A major bottleneck in the field is the lack of comprehensive knowledge of the factors and molecular processes that constitute this pathway. We conducted an RNAi screen in Drosophila and identified ~50 genes that strongly impact the ovarian somatic piRNA pathway. Many identified genes fall into functional categories that indicate essential roles for mitochondrial metabolism, RNA export, the nuclear pore, transcription elongation and chromatin regulation in the pathway. Follow-up studies on two factors demonstrate the identification of components acting at distinct hierarchical levels of the pathway. Finally, we define CG2183/Gasz as a novel primary piRNA biogenesis factor in somatic and germline cells. Based on the similarities between insect and vertebrate piRNA pathways our results have far-reaching implications for the understanding of this conserved genome defense system. Overall design: Steady-state RNA levels in wild-type ovarian somatic cells (OSC) and RNAi knock-downs of the piRNA pathway components.
The genetic makeup of the Drosophila piRNA pathway.
Specimen part, Subject
View SamplesThe fungal pathogen Ustilago maydis establishes a biotrophic relationship with its host plant maize. Hallmarks of the disease are large plant tumors in which fungal proliferation occurs. Plants have developed various defense pathways to cope with pathogens. We used microarrays to detail the global programme of gene expression during the infection process of Ustilago maydis in its host plant to get insights into the defense programs and the metabolic reprogramming needed to supply the fungus with nutrients.
Ustilago maydis infection strongly alters organic nitrogen allocation in maize and stimulates productivity of systemic source leaves.
Specimen part
View Samples