Project description:Exosome-based cell-free therapeutics has received increasing attention in recent decades. Due to the potential demand for therapeutic exosomes, appropriate methods for preservation and storage of exosomes are essential. Current cryopreservation strategies mostly focus on addition of cryoprotectants. However, due to the high concentration of cryoprotectant required, this approach can lead to unfavorable effects. Thus, other storage methods are urgently needed. In this study, we found that Tetraspanin 4 (TSPAN4) and other Tetraspanin family proteins play an essential role in protecting exosomes from cryo-damage. Moreover, we engineered TSPAN4-loaded exosomes which are resistant to cryo-damage. These engineered exosomes show similar properties to wild-type exosomes in protein composition, uptake by recipient cells, and cargo delivery efficiency. We believe our strategy of exosome cryopreservation, without the need for additional agents, will promote the clinical translation of exosomes as therapeutic agents.
Project description:We found that cardiac fibroblasts produce and secrete exosomes. miRNA profiling and TaqMan qRT-PCR experiments identified miR-21 expression to be higher in cardiac fibroblasts compared to those of miR-21*, whereas in exosomes miR-21* expression was higher compared to miR-21. The purpose of the study was to validate these findings by miRNA sequencing in cardiac fibroblasts and fibroblasts-derived exosomes. Neonatal rat cardiac fibroblasts were cultured in DMEM + 1% exosome-depleted FBS for 48h. Conditioned medium was collected and exosomes were purified by several centrifugation and filtration steps, following ultracentrifugation. Afterwards total RNA from cardiac fibroblasts and exosomes was isolated for miRNA sequencing.
Project description:Chemotaxis allows bacteria to more efficiently colonize optimal microhabitats within their larger environment. Chemotaxis in Escherichia coli is the best-studied model system, and a large number of E. coli strains have been sequenced. The Escherichia/Shigella genus encompasses a great variety of commensal and pathogenic strains, but the role of chemotaxis in their association with the host remains poorly understood. Here we show that the core chemotaxis genes are lost in many, but not all, nonmotile strains but are well preserved in all motile strains. The genes encoding the Tar, Tsr, and Aer chemoreceptors, which mediate chemotaxis to a broad spectrum of chemical and physical cues, are also nearly uniformly conserved in motile strains. In contrast, the clade of extraintestinal pathogenic E. coli strains apparently underwent an ancestral loss of Trg and Tap chemoreceptors, which sense sugars, dipeptides, and pyrimidines. The broad range of time estimated for the loss of these genes (1 to 3 million years ago) corresponds to the appearance of the genus Homo.
Project description:The expression of interferon-related genes was more enhanced in irradiated ATM-deficient mouse embryonic fibroblasts (MEFs) than in irradiated ATM wild-type MEFs.
Project description:Gene duplication is a key first step in the process of expanding the functionality of a multigene family. In order to better understand the process of gene duplication and its role in the formation of new enzymes, we investigated recent duplication events in the M14 family of proteolytic enzymes. Within vertebrates, four of 23 M14 genes were frequently found in duplicate form. While AEBP1, CPXM1, and CPZ genes were duplicated once through a large-scale, likely whole-genome duplication event, the CPO gene underwent many duplication events within fish and Xenopus lineages. Bioinformatic analyses of enzyme specificity and conservation suggested a greater amount of neofunctionalization and purifying selection in CPO paralogs compared with other CPA/B enzymes. To examine the functional consequences of evolutionary changes on CPO paralogs, the four CPO paralogs from Xenopus tropicalis were expressed in Sf9 and HEK293T cells. Immunocytochemistry showed subcellular distribution of Xenopus CPO paralogs to be similar to that of human CPO. Upon activation with trypsin, the enzymes demonstrated differential activity against three substrates, suggesting an acquisition of new function following duplication and subsequent mutagenesis. Characteristics such as gene size and enzyme activation mechanisms are possible contributors to the evolutionary capacity of the CPO gene.
Project description:We found that cardiac fibroblasts produce and secrete exosomes. miRNA profiling and TaqMan qRT-PCR experiments identified miR-21 expression to be higher in cardiac fibroblasts compared to those of miR-21*, whereas in exosomes miR-21* expression was higher compared to miR-21. The purpose of the study was to validate these findings by miRNA sequencing in cardiac fibroblasts and fibroblasts-derived exosomes.
Project description:Lung cancer is a fatal complication of idiopathic pulmonary fibrosis (IPF) with a poor prognosis. Current treatments are insufficient in improving the prognosis of lung cancer patients with comorbid idiopathic pulmonary fibrosis (IPF-LC). Senescent fibroblasts play a pivotal role within the tumor microenvironment, influencing tumor progression by secreted exosomes. With evidence that fibroblast senescence is an important mechanism of IPF, we sought to investigate the impact of senescent IPF lung fibroblast-derived exosomes on non-small cell lung cancer (NSCLC). Our results show that IPF fibroblasts (diseased human lung fibroblasts, DHLF) express significant senescence markers, promoting NSCLC proliferation, invasion, and epithelial-mesenchymal transition. Specifically, we observed senescent DHLFs secret more exosomes (DHLF-exosomes), which could enhance proliferation and colony-forming ability of cancer cells. Proteomic analysis of DHLF-exosomes identified upregulation of SASP factors, notably MMP1, which activates the surface receptor PAR1. Knocking down MMP1 or using PAR1 inhibitors reduced the tumor-promoting effects of DHLF-exosomes in vivo and in vitro. Mechanistically, MMP1 acted via activating the PI3K-AKT-mTOR pathway. In conclusion, our results suggest that exosomal MMP1 derived from senescent IPF fibroblasts promotes NSCLC proliferation and colony formation by targeting PAR1 and activating the PI3K-AKT-mTOR pathway. These findings provide a novel therapeutic approach for patients with IPF-LC.
Project description:Exososmes, potent intercellular communicators, are supposed to contribute to metastasis formation, which we confirmed for exosomes of the metastatic rat pancreatic adenocarcinoma line BSp73ASML that promote metastatic settlement in lymph nodes and lung of poorly metastatic BSp73ASML cells with a selective CD44v4-v7 (BSp73ASML-CD44vkd) knockdown. To define the molecular pathway(s), whereby exosomes contribute to premetastatic niche preparation, we profiled mRNA miRNA of BSp73ASMLwt and BSp73ASML-CD44vkd- exosomes and evaluated the impact on potential target cells. BSp73ASML exosomes are recovered in the draining lymph node after subcutaneous injection. In vitro, they preferentially bind and are taken-up by lymph node stroma cells (LnStr) and lung fibroblasts (LuFb) that were chosen as exosome targets. BSp73ASMLwt and BSp73ASML-CD44kd exosomes contain a restricted repertoire of mRNA and miRNA, hwere the lattter differe significantly between the two lines and even more pronounced, exosomes derived thereof with a not yet explored dominance of tumor-suppressor miRNA in ASML-CD44kd cells and exosomes. Both, exosomal mRNA and miRNA are recovered in target cells and exosome-uptake is accompanied by significant changes in gene expression. We didn't observe a correlation between exosomal mRNA and changes in target cell mRNA or proteins. Instead transferred miRNA significantly affected target cell mRNA translation as demonstrated for selected, most abundant ASML exosomal miRNA besides others, miR-494 known target MAL (myelin and lymphocytes protein)/cadherin17, and miR-542-3p which targets TRAF/cadherin17. Furthermore, MMP transcription suggested to accompany cadherin17 dwon-regulation was upregulated in miR-494 or miR542-3p transfected or exosome co-cultured LnStr. Taken together, tumor exosomes target in vivo non-transformed cells in premetastatic organs. Exosome uptake induced altered target celll gene expression is strongly promoted by exosomal miRNA where we demonstrate for the first time that exosomes/exosomal miRNA from a metastasizing tumor line can modulate stroma cells from premetastatic organs. Endothelial cells lines were treated with pancreatic adenocarcinoma (AS) derived exosomes or pancreatic adenocarcinoma derived exosomes expressing tetraspanin 8. Total RNA was isolated and used to perform the Agilent gene expression microarrays. In this assay a replicate of endothelial cell lines treated with ASTspan8 were also included. Moreover, total RNA from both base line expression of endothelial cells and rat endothelial fibroblasts were also used to perfrom gene expression microarrays. RNA isolated from Rat endothelial fibroblasts treated with the exosomes derived from rat pancreatic adenocarcinoma and exosomes derived from rat pancreatic adenocarcinoma expressing tetraspanin8 were individually used to perfrom gene expression microarrays. RNA isolated from exosomes derived from rat pancreatic adenocarcinoma cell lines expressing tetraspanin were used to peform gene expresiion to see the base line expression. Another replicate were also used. RNA isolated from base line or control of rat pancreatic adenocarcinoma wild type cells and also base line RNA isolated from rat pancreatic adenocarcinoma cells lines where CD44 was knock-down.
Project description:We aimed to investigate whether EBV exosomes will affect gene expression in primary fibroblasts. By obtaining normalized read counts of genes generated from RNA-sequencing, we compared the transcriptomic alterations between fibroblasts treated with HK1EBV exosomes and untreated fibroblasts.
Project description:Exosomes from pancreatic cancer-associated fibroblasts and mesenchymal stem cells that have been transduced with the yeast cytosine deaminase::uracil phosphoribosyl transferase release suicide gene exosomes acting as "Trojan horse" drugs, effectively killing pancreatic cancer cells by converting the non-toxic prodrug 5-fluorocytosine intracellularly into the cytotoxic 5-fluorouracil. We have shown in experiments in vitro, involving a simulated desmoplastic pancreatic tumor, that the combined action of these targeted exosomes could be an approach for pancreatic ductal adenocarcinoma treatment.