Project description:Induced pluripotent stem cells generated from patients with geographic atrophy as well as healthy individuals were differentiated to retinal pigment epithelium (RPE) cells. By integrating transcriptional profiles of 127,659 RPE cells generated from 43 individuals with geographic atrophy and 36 controls with genotype data, we identified 439 expression Quantitative Trait (eQTL) loci in cis that were associated with disease status and specific to subpopulations of RPE cells. We identified loci linked to two genes with known associations with geographic atrophy - PILRB and PRPH2, in addition to 43 genes with significant genotype x disease interactions that are candidates for novel genetic associations for geographic atrophy. On a transcriptome-only level, we identified molecular pathways significantly upregulated in geographic atrophy-RPE including in mitochondrial functions, metabolic pathways, and extracellular cellular matrix reorganisation. We subsequently implemented a large-scale proteomics analysis, confirming modification in proteins associated with these pathways. We also identified six significant protein (p) QTL that regulate protein expression in the RPE cells and in geographic atrophy - two of which share variants with cis-eQTL, including proteins involve in mitochondrial biology and neuodegeneration. Investigation of mitochondrial functions in the two cohorts confirmed a modification of respiration etc…. This study provides strong proof of concept of the validity of using iPSC for the modeling of complex diseases. It is the first to use a large scale patient -derived iPSC cohort to uncover important differences in RPE homeostasis associated with geographic atrophy. It clearly identifies mitochondrial activity as a core constitutive difference of the RPE from patients with geographic atrophy, and could be a target of potential therapies for this condition (STACEY/MATT).
Project description:Investigating muscle wasting in a murine model of cancer cachexia, we identified Oncostatin M (OSM) as a potential mediator of inflammatory responses in skeletal muscle. OSM is a member of the IL-6 family of cytokines and has crucial functions in cell growth, differentiation, and inflammation. Our results demonstrate that OSM induces muscle atrophy. To understand if its effect is specific or it is a general effect of IL6 family cytokines, primary myotubes were treated with OSM, IL6 and LIF for 48hrs. Our findings showed that OSM potently induces muscle wasting in differentiated myotubes.
Project description:Cachexia is an exacerbating event in many types of cancer that is strongly associated with a poor prognosis. We have identified cytokine, signaling and transcription factors that are required for cachexia in the mouse C26 colon carcinoma model of cancer. C2C12 myotubes treated with conditioned medium from C26 cancer cells induced atrophy and activated a STAT-dependent reporter gene but not reporter genes dependent on SMAD, FOXO, C/EBP, NF-ĸB, or AP-1. Of the gp130 family members IL-11, IL-6, oncostatin M (OSM), and leukemia inhibitory factor (LIF), only OSM and LIF were sufficient to activate the STAT reporter in myotubes. A LIF blocking antibody abolished C26 CM-induced STAT reporter activation STAT3 phosphorylation and myotube atrophy, but blocking antibodies to IL-6 or OSM did not. JAK2 inhibitors also blocked the C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and atrophy in myotubes. LIF at levels found in the C26 CM was sufficient for STAT reporter activation and atrophy in myotubes. In vivo, an increase in serum LIF preceded the increase in IL-6 in mice with C26 tumors. Overexpression of a dominant negative Stat3Cβ-EGFP gene in myotubes and in mouse muscle blocked the atrophy caused by C26 CM or C26 tumors, respectively. Taken together these data support an important role of LIF- JAK2-STAT3 in C26 cachexia and point to a therapeutic approach for at least some types of cancer cachexia. from three replicate wells of cells at each treatment, pools of total RNA were used to create cDNA which were evaluated on Affymetrix mouse gene 1.0 ST v.1 arrays.
Project description:Cachexia is an exacerbating event in many types of cancer that is strongly associated with a poor prognosis. We have identified cytokine, signaling and transcription factors that are required for cachexia in the mouse C26 colon carcinoma model of cancer. C2C12 myotubes treated with conditioned medium from C26 cancer cells induced atrophy and activated a STAT-dependent reporter gene but not reporter genes dependent on SMAD, FOXO, C/EBP, NF-ĸB, or AP-1. Of the gp130 family members IL-11, IL-6, oncostatin M (OSM), and leukemia inhibitory factor (LIF), only OSM and LIF were sufficient to activate the STAT reporter in myotubes. A LIF blocking antibody abolished C26 CM-induced STAT reporter activation STAT3 phosphorylation and myotube atrophy, but blocking antibodies to IL-6 or OSM did not. JAK2 inhibitors also blocked the C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and atrophy in myotubes. LIF at levels found in the C26 CM was sufficient for STAT reporter activation and atrophy in myotubes. In vivo, an increase in serum LIF preceded the increase in IL-6 in mice with C26 tumors. Overexpression of a dominant negative Stat3Cβ-EGFP gene in myotubes and in mouse muscle blocked the atrophy caused by C26 CM or C26 tumors, respectively. Taken together these data support an important role of LIF- JAK2-STAT3 in C26 cachexia and point to a therapeutic approach for at least some types of cancer cachexia.
Project description:Musculoskeletal diseases such as muscular dystrophy, cachexia, osteoarthritis, and rheumatoid arthritis impair overall physical health. Patients suffer from increased pain and death rate, decreased productivity and function. Inflammation and fibrosis are commonly observed in musculoskeletal disorders either at the bone, muscle, or joint. The Interleukin-6 Family of Cytokines primarily Interleukin-6 (IL-6) are implicated in the context of musculoskeletal disorders. In this study, we utilized adeno-associated virus expressing murine Oncostatin M or an empty vector at 10^11 viral particles to observe effects in muscle and bone of mice in the presence and absence of Interleukin-6. We performed echocardiography, microCT, quantitative polymerase chain reaction, histology, and RNA-sequencing to characterize the functional effects on muscle and bone. The echocardiography results demonstrated cardiac dysfunction as shown by reduced ejection fraction (%) and fractional shortening (%) with AAV-Osm compared to AAV-Null. RNA-sequencing results on cardiac muscle showed increased cardiac inflammation and fibrosis genes with AAV-Osm. Skeletal muscle weights and histology revealed muscle atrophy and fibrosis in the gastrocnemius, tibialis anterior, and quadriceps of the local limbs injected with AAV-Osm, but not observed in the non-injected side. MicroCT results revealed local and distant trabecular bone loss with AAV-Osm as shown by reduced bone volume, number, thickness, and increased trabeculae separation. Our findings show that Oncostatin M induces cardiac dysfunction, muscle, and bone atrophy independent of Interleukin-6.
Project description:To identify disease-specific transcriptional programs in retinal pigment epithelium (RPE) cells, fibroblasts from 43 patients with geographic atrophy (GA) were reprogrammed into induced pluripotent stem cells (iPSCs) before being differentiated into RPE and compared to those from 36 healthy individuals. 127,659 RPE cells were profiled via single cell RNA-sequencing (scRNA-seq) and cell classification identified 7 cellular states related to RPE maturation.
Project description:Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy characterised by a pathologicalfibroinflammatorymicroenvironment. Dichotomous tumour-promoting and -restrictive roles have been ascribed to the tumour microenvironment, however thedisparate effect of individual stromal subsets remains incompletely characterised. Here, we describe how heterocellular OSM-OSMR signalling instructsfibroblast reprogramming,tumourgrowth and metastasis.Macrophage-secreted OSM stimulatesinflammatory gene expression in cancer-associated fibroblasts (CAFs), which in turn induce a pro-tumorigenic environment and engage tumour cellsurvival and migratory signalling pathways. Tumour cells implanted in Osm-deficient (Osm-/-) mice display an epithelial-dominated morphology, reduced tumour growth and did notmetastasise. Moreover, the tumour microenvironment of Osm-/-animals exhibit increased abundance of αSMAposmyofibroblasts and a shift in myeloid and T cell phenotypes, consistent with a more immunogenic environment. Taken together, these data demonstrate how OSM-OSMR signalling coordinates heterocellular interactions to drive a pro-tumorigenic environment in PDA.
Project description:The JAK2 mutation V617F is detectable in a majority of patients with Ph-negative myeloproliferative neoplasms (MPN). Enforced expression of JAK2 V617F in mice induces myeloproliferation and bone marrow (BM) fibrosis suggesting a causal role for the JAK2 mutant in the pathogenesis of MPN. However, little is known about mechanisms and effector molecules contributing to JAK2 V617F-induced myeloproliferation and fibrosis. Here we show that JAK2 V617F promotes expression of oncostatin M (OSM) in neoplastic myeloid cells. Correspondingly, OSM was found to be overexpressed in the BM and elevated in the serum of patients with JAK2 V617F+ MPN. In addition, OSM secreted by JAK2 V617F+ cells stimulated growth of fibroblasts and microvascular endothelial cells and induced the production of angiogenic and profibrogenic cytokines (HGF, VEGF, and SDF-1) in BM fibroblasts. All effects of MPN cell-derived OSM were blocked by a neutralizing anti-OSM antibody, whereas the production of OSM in MPN cells was effectively suppressed by a pharmacologic JAK2 inhibitor or RNAi-mediated knockdown of JAK2. In summary, JAK2 V617F-mediated upregulation of OSM may contribute to fibrosis, neoangiogenesis, and the cytokine storm observed in JAK2 V617F+ MPN, suggesting that OSM could serve as a novel therapeutic target molecule in these neoplasms. IMR90 cells were treated with a single dose of rh Oncostatin M (10ng/ml).