ABSTRACT
BACKGROUND: Circulating RNA (circRNA) regulates various bioactivities in cells. A better understanding of the exosomal circRNA can provide novel insights into the pathogenesis and treatment of Graves' disease (GD). We aimed to profile the differentially expressed circRNAs (DEcRs) in plasma exosomes of patients with GD and speculate and probe the functions of the DEcR by comprehensive bioinformatics analyses. METHODS: Serum exosomes were isolated from five primary GD patients and five healthy controls via ultracentrifugation. After verification with transmission electron microscopy, exosome samples were subjected to microarray profiling using human circRNA microarrays. Two up-regulated and two down-regulated DEcRs were selected for validation in plasma exosomes from 20 GD and 20 healthy control participants using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The circRNA/microRNA/mRNA interaction network was then assembled and the analysis of the Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways was utilized to predict the potential functions of the DEcR associated genes. RESULTS: There were 15 DEcRs revealed in primary GD cases. The intronic circRNA hsa_circRNA_000102 was confirmed as an up-regulated component in plasma exosomes from patients with GD. The circRNA/microRNA/mRNA interaction network unveiled the most potential targeting microRNAs of hsa_circRNA_000102 and its associated genes. The functional analyses predicted involvement of hsa_circRNA_000102 associated genes in pathways of immune system activation, such as viral infection and interferon-beta signaling. CONCLUSIONS: hsa_circRNA_000102 is a differentially up-regulated plasma exosomal circRNA in patients with GD. Our study highlights multiple pathways, particularly virus infection and interferon-beta signaling, for mediating immune activation in Graves' disease.
Subject(s)
Humans , Male , Female , Graves Disease/genetics , Graves Disease/blood , Microarray Analysis , RNA, Circular/blood , RNA, Messenger , MicroRNAs , ExosomesABSTRACT
Background: Mutation breeding is one of the most important routes to achieving high docosahexaenoic acid (DHA) productivity using Schizochytrium. However, few selection strategies have been reported that aim to generate a high DHA content in Schizochytrium lipids. Results: First, culture temperature altered the butanol tolerance of Schizochytrium limacinum B4D1. Second, S. limacinum E8 was obtained by selecting mutants with high butanol tolerance. This mutant exhibited a 17.97% lower proportion of DHA than the parent strain S. limacinum B4D1. Third, a negative selection strategy was designed in which S. limacinum F6, a mutant with poor butanol tolerance, was obtained. The proportion of DHA in S. limacinum F6 was 11.22% higher than that of parent strain S. limacinum B4D1. Finally, the performances of S. limacinum B4D1, E8 and F6 were compared. These three strains had different fatty acid profiles, but there was no statistical difference in their biomasses and lipid yields. Conclusion: It was feasible to identified the relative DHA content of S. limacinum mutants based on their butanol tolerance.
Subject(s)
Docosahexaenoic Acids/biosynthesis , Butanols/metabolism , Stramenopiles/genetics , Stramenopiles/metabolism , Selection, Genetic , Temperature , Eicosapentaenoic Acid/metabolism , Biomass , Butanols/toxicity , Fatty Acids/metabolism , Fatty Acids/chemistry , Stramenopiles/drug effects , Fermentation , MutationABSTRACT
Background: Malate involves in the citrate/malate and transhydrogenase cycles to provide precursors for docosahexaenoic acid (DHA) synthesis. The optimal strategy was investigated for increasing DHA production in Schizochytrium species during fermentation. Results: DHA production increased by 47% and reached 5.51 g/L when 4 g malate/L was added during the rapid lipid accumulation stage in shake-flasks culture. Inducing effects of malate was further investigated through the analysis of three kinetic parameters, including specificcell growth rate(μ), specific glucose consumption rate (qGlu)and DHA formation rate (qDHA). DHA concentration was enhanced through a novel fed-batch strategy to a maximum value of 30.7 g/L, giving a yield of 0.103 g DHA/g glucose and a productivity of 284 mg L-1 h-1. Conclusion: A novel malate feeding strategy was developed that enhanced DHA yield and productivity of Schizochytrium species which may offer a desirable method for industrial applications.