Project description:UMR106-01 osteoblastic cells are a model for studying bone mineralization. We have shown that mineralization is temporally synchronized within cultures grown under defined conditions . Cells are plated at time zero and differentiate into osteoblastic phenotype by 64 h later. If an exogenous phosphate source is added to the cultures, the cells form and deposit hydroxyapatite mineral within distinct extracellular supramolecular lipid protein complexes termed biomineralization foci (BMF) starting 12 h later. Mineralization is largely complete by 24 h later (88 h after plating). We have also shown that AEBSF, covalent serine protease inhibitor, blocks mineralization within BMF and inhibits the fragmentation of several proteins related to biomineralization. The present experiment was designed to test whether AEBSF treatment for 12 h has an effect on transcription by UMR106-01 osteoblastic cells. AEBSF is known to inactivate several serine proteases including SKI-1 (site 1, subtilisin kexin protease-1).SKI-1 functions intracellularly to activate transmembrane bound transcription factor precursors releasing the transcriptionally active N-terminal portions to imported into the nucleus. Thus, if AEBSF blocks transcription of mineralization related genes, it would support a role for SKI-1 in gene regulation in mineralizing UMR106-01 osteoblastic cells. Comparison of triplicate cultures treated with mineralizing conditions with triplicate cultures treated with AEBSF protease inhibitor for 12 h.
Project description:UMR106-01 osteoblastic cells are a model for studying bone mineralization. We have shown that mineralization is temporally synchronized within cultures grown under defined conditions . Cells are plated at time zero and differentiate into osteoblastic phenotype by 64 h later. If an exogenous phosphate source is added to the cultures, the cells form and deposit hydroxyapatite mineral within distinct extracellular supramolecular lipid protein complexes termed biomineralization foci (BMF) starting 12 h later. Mineralization is largely complete by 24 h later (88 h after plating). We have also shown that AEBSF, covalent serine protease inhibitor, blocks mineralization within BMF and inhibits the fragmentation of several proteins related to biomineralization. The present experiment was designed to test whether AEBSF treatment for 12 h has an effect on transcription by UMR106-01 osteoblastic cells. AEBSF is known to inactivate several serine proteases including SKI-1 (site 1, subtilisin kexin protease-1).SKI-1 functions intracellularly to activate transmembrane bound transcription factor precursors releasing the transcriptionally active N-terminal portions to imported into the nucleus. Thus, if AEBSF blocks transcription of mineralization related genes, it would support a role for SKI-1 in gene regulation in mineralizing UMR106-01 osteoblastic cells.
Project description:Beyond forming bone, osteoblasts play pivotal roles in various biological processes, including hematopoiesis and bone metastasis. Extracellular vesicles (EVs) have recently been implicated in intercellular communication via transfer of proteins and nucleic acids between cells. Here, we focused on the proteomic characterization of non-mineralizing (NMOBs) and mineralizing (MOBs) human osteoblast (SV-HFOs) EVs and investigated their effect on human prostate cancer (PC3) cells by microscopic, proteomic and gene expression analyses. Proteomic analysis showed that 97% of the proteins were shared among NMOB and MOB EVs, and 30% were novel osteoblast-specific EV proteins. Label-free quantification demonstrated mineralization stage-dependent five-fold enrichment of 59 and 451 EV proteins in NMOBs and MOBs, respectively. Interestingly, bioinformatic analyses of the osteoblast EV proteomes and EV-regulated prostate cancer gene expression profiles showed that they converged on pathways involved in cell survival and growth. This was verified by in vitro proliferation assays where osteoblast EV uptake led to two-fold increase in PC3 cell growth compared to cell-free culture medium-derived vesicle controls. Our findings elucidate the mineralization stage-specific protein content of osteoblast-secreted EVs, show a novel way by which osteoblasts communicate with prostate cancer, and open up innovative avenues for therapeutic intervention. PC3 cells were treated with extracellular vesicles from non-mineralizing and mineralizing SV-HFOs for three different incubation times (4hrs, 24hrs, 48hr)
Project description:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.
Project description:The Norway rat has important impacts on our life. They are amongst the most used research subjects, resulting in ground-breaking advances. At the same time, wild rats live in close association with us, leading to various adverse interactions. In face of this relevance, it is surprising how little is known about their natural behaviour. While recent laboratory studies revealed their complex social skills, little is known about their social behaviour in the wild. An integration of these different scientific approaches is crucial to understand their social life, which will enable us to design more valid research paradigms, develop more effective management strategies, and to provide better welfare standards. Hence, I first summarise the literature on their natural social behaviour. Second, I provide an overview of recent developments concerning their social cognition. Third, I illustrate why an integration of these areas would be beneficial to optimise our interactions with them.
Project description:BackgroundMurine kobuviruses (MuKV) are newly recognized picornaviruses first detected in murine rodents in the USA in 2011. Little information on MuKV epidemiology in murine rodents is available. Therefore, we conducted a survey of the prevalence and genomic characteristics of rat kobuvirus in Guangdong, China.ResultsFecal samples from 223 rats (Rattus norvegicus) were collected from Guangdong and kobuviruses were detected in 12.6% (28) of samples. Phylogenetic analysis based on partial 3D and complete VP1 sequence regions showed that rat kobuvirus obtained in this study were genetically closely related to those of rat/mouse kobuvirus reported in other geographical areas. Two near full-length rat kobuvirus genomes (MM33, GZ85) were acquired and phylogenetic analysis of these revealed that they shared very high nucleotide/amino acids identity with one another (95.4%/99.4%) and a sewage-derived sequence (86.9%/93.5% and 87.5%/93.7%, respectively). Comparison with original Aichivirus A strains, such human kobuvirus, revealed amino acid identity values of approximately 80%.ConclusionOur findings indicate that rat kobuvirus have distinctive genetic characteristics from other Aichivirus A viruses. Additionally, rat kobuvirus may spread via sewage.