Spatial Segregation of BMP/Smad Signaling Affects Osteoblast Differentiation in C2C12 Cells

BACKGROUND: Bone morphogenetic proteins (BMPs) are involved in a plethora of cellular processes in embryonic development and adult tissue homeostasis. Signaling specificity is achieved by dynamic processes involving BMP receptor oligomerization and endocytosis. This allows for spatiotemporal control of Smad dependent and non-Smad pathways. In this study, we investigate the spatiotemporal regulation within the BMP-induced Smad transcriptional pathway. METHODOLOGY/PRINCIPAL FINDINGS: Here we discriminate between Smad signaling events that are dynamin-dependent (i.e., require an intact endocytic pathway) and dynamin-independent. Inhibition of dynamin-dependent endocytosis in fluorescence microscopy and fractionation studies revealed a delay in Smad1/5/8 phosphorylation and nuclear translocation after BMP-2 stimulation of C2C12 cells. Using whole genome microarray and qPCR analysis, we identified two classes of BMP-2 induced genes that are differentially affected by inhibition of endocytosis. Thus, BMP-2 induced gene expression of Id1, Id3, Dlx2 and Hey1 is endocytosis-dependent, whereas BMP-2 induced expression of Id2, Dlx3, Zbtb2 and Krt16 is endocytosis-independent. Furthermore, we demonstrate that short term inhibition of endocytosis interferes with osteoblast differentiation as measured by alkaline phosphatase (ALP) production and qPCR analysis of osteoblast marker gene expression. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that dynamin-dependent endocytosis is crucial for the concise spatial activation of the BMP-2 induced signaling cascade. Inhibition of endocytic processes during BMP-2 stimulation leads to altered Smad1/5/8 signaling kinetics and results in differential target gene expression. We show that interfering with the BMP-2 induced transcriptional network by endocytosis inhibition results in an attenuation of osteoblast differentiation. This implies that selective sensitivity of gene expression to endocytosis provides an additional mechanism for the cell to respond to BMP in a context specific manner. Moreover, we suggest a novel Smad dependent signal cascade induced by BMP-2, which does not require endocytosis

Sarcoma classification by DNA methylation profiling

Sarcomas are malignant soft tissue and bone tumours affecting adults, adolescents and children. They represent a morphologically heterogeneous class of tumours and some entities lack defining histopathological features. Therefore, the diagnosis of sarcomas is burdened with a high inter-observer variability and misclassification rate. Here, we demonstrate classification of soft tissue and bone tumours using a machine learning classifier algorithm based on array-generated DNA methylation data. This sarcoma classifier is trained using a dataset of 1077 methylation profiles from comprehensively pre-characterized cases comprising 62 tumour methylation classes constituting a broad range of soft tissue and bone sarcoma subtypes across the entire age spectrum. The performance is validated in a cohort of 428 sarcomatous tumours, of which 322 cases were classified by the sarcoma classifier. Our results demonstrate the potential of the DNA methylation-based sarcoma classification for research and future diagnostic applications

The initial trauma associated hemorrhagic shock in the multiply injured patient has pro-inflammatory effects. A retrospective single center cohort study

Background :The development of a Systemic Inflammatory Response Syndrome (SIRS) has been discussed to be related to the trauma load. Trauma, especially the multiple injured patient suffers blood loss in a various extent. The outcome of such patients is also linked with the need for transfusions and SIRS. Therefore, the association between the initial blood loss and the incidence of IL 6 release following multiple injuries was examined. Methods : Totally 545 patients ≥16 years and with an ISS >16 were included into this retrospective cohort study. The sample was divided according to the ATLS shock classes I-IV on admission in the trauma bay and the shock-index ( 1.5) at trauma site. The systemic levels of IL6 were measured 24 and 48 hours after admission. Data were analyzed using Kruskal-Wallis H test. The predictive quality was tested using receiver-operating curves (AUC), the independent predictive power was analyzed using binary logistic regression. The analysis was conducted using IBM SPSS® 23.0. Level of evidence III. Results :IL6 significantly increased within the first 24h according to shock (252ng – 872ng, p < 0.001). There were highly predictive values between IL6 and SIRS (24h) (AUC: 0.345 – 0.951 for ATLS shock I-IV, p < 0.001; AUC: 0.443 – 0.963 for shock-index 0.5 - 1.5, p < 0.001). ATLS shock revealed as an independent predictor for IL6 increase after 48h (p < 0.001). Conclusion :Initial shock-index at trauma site and the ATLS shock degree in the trauma bay are high predictors for IL6 release what may serve as a primer for the induction of SIRS. Very early control of blood loss seems to be the key point. However, these results might also point on the change of transfusion protocols in the multiple injured patient

Incentivos para que los/las agricultores/as utilicen semillas ecológicas (resumen)

Four industry driven pilots to incentivise use of organic seed in Italy, the Netherlands, Hungary and Romania are presented. The summary identifies four main areas in which incentives can be offered: pre-financing of organic seed through the value chain, offering access to varieties requested by the market, expanding the range of locally adapted cultivars and improving seed quality. The summary of the case studies provides some details of how the initiatives originated, what incentives were involved and their outcomes. It is meant to give insights to anyone interested in financing innovation in the organic seed supply chain that is not comfortable reading the longer version in English

Novel crosstalk to BMP signalling: cGMP-dependent kinase I modulates BMP receptor and Smad activity

Integration of multiple signals into the canonical BMP/Smad pathway poses a big challenge during the course of embryogenesis and tissue homeostasis. Here, we show that cyclic guanosine 3′,5′-monophosphate (cGMP)-dependent kinase I (cGKI) modulates BMP receptors and Smads, providing a novel mechanism enhancing BMP signalling. cGKI, a key mediator of vasodilation and hypertension diseases, interacts with and phosphorylates the BMP type II receptor (BMPRII). In response to BMP-2, cGKI then dissociates from the receptors, associates with activated Smads, and undergoes nuclear translocation. In the nucleus, cGKI binds with Smad1 and the general transcription factor TFII-I to promoters of BMP target genes such as Id1 to enhance transcriptional activation. Accordingly, cGKI has a dual function in BMP signalling: (1) it modulates BMP receptor/Smad activity at the plasma membrane and (2) after redistribution to the nucleus, it further regulates transcription as a nuclear co-factor for Smads. Consequently, cellular defects caused by mutations in BMPRII, found in pulmonary arterial hypertension patients, were compensated through cGKI, supporting the positive action of cGKI on BMP-induced Smad signalling downstream of the receptors

Defective homologous recombination DNA repair as therapeutic target in advanced chordoma

Chordomas are rare bone tumors with limited therapeutic options. Here, the authors identify molecular alterations associated with defective homologous recombination DNA repair in advanced chordomas and report prolonged response in a patient treated with a PARP inhibitor, which later acquired resistance due to a newly gained PARP1 mutation