Project description:High-temperature stress (HTS) is one of the main environmental stresses that limit plant growth and crop production in agricultural systems. Maca (Lepidium meyenii) is an important high-altitude herbaceous plant adapted to a wide range of environmental stimuli such as cold, strong wind and UV-B exposure. However, it is an extremely HTS-sensitive plant species. Thus far, there is limited information about gene/protein regulation and signaling pathways related to the heat stress responses in maca. In this study, proteome profiles of maca seedlings exposed to HTS for 12 h were investigated using a tandem mass tag (TMT)-based proteomic approach. In total, 6,966 proteins were identified, of which 300 showed significant alterations in expression following HTS. Bioinformatics analyses indicated that protein processing in endoplasmic reticulum was the most significantly up-regulated metabolic pathway following HTS. Quantitative RT-PCR (qRT-PCR) analysis showed that the expression levels of 19 genes encoding proteins mapped to this pathway were significantly up-regulated under HTS. These results show that protein processing in the endoplasmic reticulum may play a crucial role in the responses of maca to HTS. Our proteomic data can be a good resource for functional proteomics of maca and our results may provide useful insights into the molecular response mechanisms underlying herbal plants to HTS.
Project description:High-throughput sequencing (HTS) has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA) and other small RNAs (sRNA). Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps; specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material.
Project description:Human Cytomegalovirus (HCMV) causes severe morbidity and mortality in an immune-compromised or immune-naïve host. Among DNA viruses, the genetic diversity of HCMV is unexpectedly high and comparable to those of RNA viruses, which hinders the development of effective vaccines and causes the emergence of antiviral resistance. However, little is known about how HCMV acquires genetic variation. Here, we propose an evolution strategy of HCMV, that exploits host “jumping DNA” L1 retrotransposon as a mutagen. We found that HCMV infection switches on L1 expression by upregulating transcription factors YY1 and RUNX3. Furthermore, HCMV DNA processivity factor, UL44 recruits L1 ribonucleoproteins to viral replication compartments and induces DNA damage to its genome. Deep-sequencing analysis of cultured HCMV genome revealed that L1 retrotransposon facilitates mutation burden on the viral genome. Indeed, laboratory adaptation of HCMV to fibroblasts is only observed upon active L1 expression. These findings demonstrate the evolution mechanism and molecular insights of how HCMV acquires genetic fitness by the hijacking of host L1 retrotransposon.
Project description:We have established that human cytomegalovirus (HCMV) infection modulates the biology of target primary blood monocytes, allowing HCMV to use monocytes as 'vehicles' for its systemic spread. HCMV infection of monocytes results in rapid induction of PI(3)K and NF-kB activity. Integrins, which are upstream of the PI(3)K and NF-kB pathways, were shown to be involved in HCMV binding to and entry into fibroblasts, suggesting that receptor-ligand-mediated signaling following viral binding to integrins on monocytes could trigger the functional changes seen in infected monocytes. We now show that integrin engagement and the activation of the integrin/Src-signaling pathway is essential for the induction of HCMV-infected monocyte motility. To investigate how integrin engagement by HCMV triggers monocyte motility, we examined the infected monocyte transcriptome and found that the integrin/Src-signaling pathway regulates the expression of paxillin, which is an important signal transducer in the regulation of actin rearrangement during cell adhesion and movement. Functionally, we observed that paxillin is activated via the integrin/Src-signaling pathway and is required for monocyte motility. Because motility is intimately connected to cellular cytoskeletal organization, a process that is also important in viral entry, we investigated the role paxillin regulation plays in the process of viral entry of monocytes. New results confirmed that HCMV`s ability to enter target monocytes is significantly inhibited in cells deficient in paxillin expression or that had their integrin/Src/paxillin signaling pathway blocked. From our data, HCMV-cell interactions emerge as an essential trigger for the cellular changes that allow for HCMV entry and hematogenous dissemination. Monocytes were mock-infected, HCMV-infected, or pretreated with PP2 inhibitor prior to HCMV infection. There were three samples analyzed per individual replicate. Three replicates are included. comparative studies with a use of the specific Src kinase activity inhibitor
Project description:Congenital human cytomegalovirus (HCMV) infection is the leading infectious cause of birth defects, including neurodevelopmental disorders. HCMV infection mainly targets neural progenitor cells (NPCs) in fetal brains, inducing abnormal differentiation by altering key regulatory pathways. HCMV expresses a series of viral miRNAs during infection, but their roles, particularly in NPCs, are not fully understood. In this study, we characterized expression profiles of both cellular and viral miRNAs in HCMV-infected NPCs by microarray analysis during early infection time points and investigated the primary effects of these miRNAs on regulating NPC fate. While expression of most cellular miRNAs was unaffected by HCMV infection, one cellular miRNA was upregulated and six were downregulated from 2 to 24 h post infection. Moreover, of 17 HCMV miRNAs evaluated, six were differentially expressed in HCMV-infected NPCs during early infection time points.
Project description:To further elucidate the role of miRNAs, HTS was used to screen differential miRNAs. Mice hippocampus from the saline group, the LPS group, and the LPS+GAS group were removed to analyze using HTS.
Project description:High-throughput sequencing (HTS) has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA) and other small RNAs (sRNA). Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps; specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material. 28 samples were sequenced and the libraries were made using various synthetic oligo mixtures and adaptor combinations
Project description:We employed RNA-seq to map the transcriptome of human MRC5 fibroblasts during HCMV infection with AD169. These data will highlight the ways in which the HCMV infection alters RNA levels during infection.