Project description:The therapeutic benefits of L–3,4–dihydroxyphenylalanine (L-DOPA) in Parkinson’s disease (PD) patients severely diminishes with the onset of L-DOPA-induced dyskinesia (LID), a debilitating motor side effect. LID is mainly due to altered dopaminergic signaling in the striatum, a brain region that controls motor and cognitive functions. However, the molecular mechanisms that promote LID remain unclear. Here, we have reported that increased striatal RasGRP1 (also known as CalDAG-GEF-II) is instrumentally linked to the development of LID in a 6-hydroxydopamine (6-OHDA) lesioned mouse model of PD. L-DOPA treatment rapidly upregulated RasGRP1 in the dopamine-1 receptor positive neurons in the dorsal striatum. RasGRP1 deleted mice (RasGRP1–/–) had drastically diminished LID, and RasGRP1–/– mice did not interfere with the therapeutic benefits of L-DOPA. In terms of its mechanism, RasGRP1 mediated L-DOPA-induced extracellular regulated kinase (ERK), the mammalian target of rapamycin kinase (mTOR) and the cAMP/PKA pathway. RasGRP1 bind directly with and acts 2 as a guanine nucleotide exchange (GEF) for Ras-homolog-enriched in the brain (Rheb), a potent activator of mTOR, both in vitro and in the intact striatum. High-resolution tandem mass tag mass spectrometry analysis of striatal tissue revealed significant targets, such as phosphodiesterase 10a (Pde10a), Pde2a, catechol-o-methyltransferase (Comt), and glutamate decarboxylase 1 and 2 (Gad1 and Gad2), as downstream regulators of RasGRP1 that are linked to LID vulnerability. Moreover, we found that RASGRP1 protein is also upregulated predominantly in the striatum of MPTP-lesioned macaque treated with L-DOPA, emphasizing the translational potential of this protein. Collectively, the findings of this study demonstrated that RasGRP1 is a major regulator of LID in the dorsal striatum. Pharmacological or gene-depletion strategies targeting RasGRP1 may offer novel therapeutic opportunities for preventing LID in PD patients.
Project description:293T cells were infected with HIV-1 pseudovirions, and 0, 4 and 12 hours post-infection, the cell lysates were collected. Label-free proteomics was applied to examine the protein-level changes. Duplicate samples for six time points were collected (0, 4, and 12 hours post-transduction, virus- and mock transduced samples) and analyzed in duplicates, allowing for the measurement of two technical and two biological replicates for each time point. The results were used for the analysis of protein networks implementing both the qualitative and quantitative information.
Project description:Spider silk research has largely focused on spidroins, proteins that are the primary components of spider silk fibers. Although a number of spidroins have been characterized, other types of proteins associated with silk synthesis are virtually unknown. Previous comparison of tissue-specific RNAseq libraries identified 647 predicted genes that were differentially expressed in silk glands of the Western black widow, Latrodectus hesperus. Only ~5% of these transcripts encode spidroins and the remaining predicted genes presumably encode other proteins associated with silk production. Here, we used proteomic analysis of multiple silk glands and dragline silk fiber to investigate the translation of the differentially expressed genes. We find 48 proteins encoded by the differentially expressed transcripts in L. hesperus major ampullate, minor ampullate, and tubuliform silk glands, and detect 16 SST encoded proteins in major ampullate silk fibers. The observed proteins include known silk-related proteins, but most are uncharacterized, with no annotation. These unannotated proteins likely include novel silk associated proteins. Major ampullate and minor ampullate glands have the highest overlap of identified proteins, consistent with their shared, distinctive ampullate shape and the overlapping functions of major ampullate and minor ampullate silks. Our study substantiates and prioritizes predictions from differential expression analysis of spider silk gland transcriptomes.
Project description:Spider silk research has largely focused on spidroins, proteins that are the primary components of spider silk fibers. Although a number of spidroins have been characterized, other types of proteins associated with silk synthesis are virtually unknown. Previous comparison of tissue-specific RNAseq libraries identified 647 predicted genes that were differentially expressed in silk glands of the Western black widow, Latrodectus hesperus. Only ~5% of these transcripts encode spidroins and the remaining predicted genes presumably encode other proteins associated with silk production. Here, we used proteomic analysis of multiple silk glands and dragline silk fiber to investigate the translation of the differentially expressed genes. We find 48 proteins encoded by the differentially expressed transcripts in L. hesperus major ampullate, minor ampullate, and tubuliform silk glands, and detect 16 SST encoded proteins in major ampullate silk fibers. The observed proteins include known silk-related proteins, but most are uncharacterized, with no annotation. These unannotated proteins likely include novel silk associated proteins. Major ampullate and minor ampullate glands have the highest overlap of identified proteins, consistent with their shared, distinctive ampullate shape and the overlapping functions of major ampullate and minor ampullate silks. Our study substantiates and prioritizes predictions from differential expression analysis of spider silk gland transcriptomes.
Project description:Self-renewing tumor initiating cells that are capable of differentiation and responsible for tumor growth have been isolated from cancers and cell lines. If such minor populations are associated with tumor progression, understanding molecular pathways that are required for viability and maintenance of these populations will allow to target these pathways to eradicate tumors that are resistant to existing therapies. In this study we enriched for prostate cancer progenitors (Pr. CPM-CM-"M-BM-^@M-BM-^Ys) expressing cell surface markers CD44/CD133/alpha 2 beta 1 integrin in non-adherent serum-free growth conditions maintained as spheres. Cells grown in these conditions have increased in vivo clonogenic and in vivo tumorigenic potential. microarray analysis of cells grown in sphere conditions compared with long term monolayer culture conditions revealed preferential activation of PI3K/AKT pathway in prostate cancer progenitors. PI3K p110 alpha and beta protein levels were high in sphere condition cultured cells, and PTEN knockdown lead to an increase in Pr.CPM-CM-"M-BM-^@M-BM-^Ys, and to increased clonogenic and tumorigenic potential. Inhibition of Akt1 phosphorylation target FoxO3a lead to inhibition of tumorigenic capacity in vivo for prostate cancer cells. Inhibition of PI3K activity by PI3K inhibitor NVP-BEZ235 lead to a selective inhibition of Pr.CPM-CM-"M-BM-^@M-BM-^Ys, nuclear localization of FoxO3a and increase in GADD45a in prostate cancer cells. Taken together our data strongly suggest that PTEN and PI3K/Akt pathways are critical for prostate cancer stem-like cell maintenance and targeting the PI3K signaling by selective inhibitors may give an incredible advancement in prostate cancer treatment. Experiment Overall Design: sphere and monolayer cultures from two different prostate cancer cell lines
Project description:Bone marrow derived stromal cells (BMSCs) are a multipotent population that supports angiogenesis, wound healing, immunomodulation and plays an active role in the hematopoietic niche. On the other hand, they are also involved in the nurturing of bone marrow tumors and metastasis, showing a pro-tumorigenic behavior. BMSCs secrete a wide range of cytokines, growth factors and matrix proteins that are likely responsible for many of these effects. However, it is not clear whether this pro-tumorigenic behavior of BMSCs is induced by the tumor cells, neither in what extent the tumor cells affect the type and quantity of factors produced by BMSCs. To determine how tumor cells that arise from bone marrow affect the BMSCs, we selected three myeloid leukemia cell lines (TF-1, TF-1alpha and K562) and co-cultured them with BMSCs from healthy donors. We found that, under co-culture condition, the gene expression profiling of BMSCs revealed up-regulation of many pro-inflammatory signaling related genes, mainly IL-17 signaling-related genes. Moreover, IL-17 signaling-related cytokines CCL2 and IL8, were increased in co-culture supernatants. We conclude that BMSCs react to the presence of leukemia cells undergoing changes in the cytokine and chemokine secretion profile. Thus, BMSCs and leukemia cells both contribute to the creation of a competitive niche more favorable to leukemia stem cells. BMSCs from healthy donors were transwell co-cultured with three different myeloid leukemia cell lines: TF-1 (n=3), TF-1alpha (n=3) and K562 (n=3). A 1-um Transwell system (BDBiosciences, San Jose, CA USA) was used to maintain the cultured BMSC and leukemia cell populations separate from each other. As a control BMSCs were also transwell co-cultured under the same conditions with CD34+ cells (n=9) isolated from G-CSF-mobilized peripheral blood stem cells from healthy donors. An alternative co-culture method was used to analyze BMSCs and leukemia cells in direct contact: TF-1 (n=3), TF-alpha (n=3) and K562 (n=3). The two populations were cultured together in the same well without any membrane separation. BMSCs (n=18), TF-1 (n=3), TF-1alpha (n=3), K562 (n=3) and CD34+ (n=9) cells cultured alone (mono-cultures) were used as controls. Cells from both mono- and co-culture conditions were harvested at 4h, 10h, and 24h.
Project description:This project has the main aim to determine the protein composition of extracellular vesicles released by the African sleep sickness parasite, Trypanosoma brucei.
Project description:Mycoplasma hyopneumoniae pathogenic strains, like 7448, are the causative agents of porcine enzootic pneumonia. Non-pathogenic strains, like M. hyopneumoniae J, does not cause disease, although shares the entire repertoire of known virulence-related genes with M. hyopneumoniae 7448. In this context, the differential expression of ortholog genes is likely responsible, at least in part, for differences in pathogenicity or virulence level between these strains. Moreover, in the porcine lung, M. hyopneumoniae faces a hostile environment, with both oxidative and heat stresses. The performed comparative proteomics analyses provided evidence of differential stress responses between a pathogenic and a non-pathogenic M. hyopneumoniae strain, involving tens of proteins, including some known virulence factors. The results suggest that stress conditions trigger the expression of potential virulence factors in the pathogenic M. hyopneumoniae 7448, but not in the non-pathogenic M. hyopneumoniae J.