Project description:Tree ring features are affected by environmental factors and therefore are the basis for dendrochronological studies to reconstruct past environmental conditions. Oak wood often provides the data for these studies because of the durability particularly of oak heartwood and, hence the availability of samples spanning long time periods of the distant past. Wood formation is regulated in part by epigenetic mechanisms such as DNA methylation. Studies in the methylation state of DNA preserved in oak heartwood thus could identify epigenetic tree ring features informing on past environmental conditions. We investigated the feasibility of such studies using heartwood samples core-drilled from the trunks of standing oak trees spanning the AD 1776-2014. Heartwood contains little DNA, and large amounts of phenolic compounds known to hinder the preparation of high-throughput sequencing libraries. We sequenced whole-genome and DNA methylome libraries for oak heartwood up to 100 and 50 years of age, respectively. However, only 56 genomic regions with sufficient coverage for quantitative methylation analysis were identified, suggesting that the high-throughput sequencing of DNA will be in principal feasible for wood formed <100 years ago is impeded by the reduction in library complexity caused by the bisulfite treatment used to generate the oak methylome.
Project description:siRNA-mediated inhibition compared to untreated cells and cells transfected with nonsense siRNA Together with far upstream element binding protein (FBP), the FBP-interacting repressor (FIR) represents a molecular tool for the transcriptional fine tune regulation of target genes. Previous evidence indicates that strong overexpression of FBP in human hepatocellular carcinoma (HCC) supports tumor growth and correlates with poor patient prognosis. However, the role of the transcriptional repressor FIR in hepatocarcinogenesis remains poorly delineated. We show that overexpression of FIR correlates with tumor dedifferentiation and tumor cell proliferation in about 60% of primary HCCs. Elevated FIR levels are associated with genomic gains of the fir gene locus at chromosome 8q24.3 in human HCC specimens. In vitro, nuclear enrichment of FIR supports HCC cell proliferation and migration. Expression profiling of HCC cells after siRNA-mediated silencing of FIR identified the transcription factor DP-1 (TFDP1) as a transcriptional target of FIR. Surprisingly, FIR stimulates the expression of FBP in a TFDP1/E2F-dependent manner. FIR splice variants lacking or containing exon 2 and/or exon 5 are expressed in the majority of HCCs. Specific inhibition of FIR isoforms with and without exon 2 revealed that all FIR splice variants facilitate tumor-supporting effects. This finding was confirmed in xenograft transplantation experiments with lentiviral-infected shRNA targeting all FIR variants as well as FIR with and without exon 2. In summary, high-level nuclear FIR does not facilitate repressor properties but supports tumor growth in HCC cells. Thus, the pharmacological inhibition of FIR might represent a promising therapeutic strategy for HCC patients.
Project description:Small non-coding RNAs (sRNAs) play key roles in plant development, growth and responses to biotic and abiotic stresses. At least four classes of sRNAs have been well characterized in plants, including repeat-associated siRNAs (rasiRNAs), microRNAs (miRNAs), trans-acting siRNAs (tasiRNAs) and natural antisense transcript-derived siRNAs. Chinese fir (Cunninghamia lanceolata) is one of the most important coniferous evergreen tree species in China. No sRNA from Chinese fir has been described to date. To obtain sRNAs in Chinese fir, we sequenced a sRNA library generated from seeds, seedlings, leaves, stems and calli, using Illumina high throughput sequencing technology. A comprehensive set of sRNAs were acquired, including conserved and novel miRNAs, rasiRNAs and tasiRNAs. With BLASTN and MIREAP we identified a total of 115 conserved miRNAs comprising 40 miRNA families and one novel miRNA with precursor sequence. The expressions of 16 conserved and one novel miRNAs and one tasiRNA were detected by RT-PCR. Utilizing real time RT-PCR, we revealed that four conserved and one novel miRNAs displayed developmental stage-specific expression patterns in Chinese fir. In addition, 209 unigenes were predicted to be targets of 30 Chinese fir miRNA families, of which five target genes were experimentally verified by 5' RACE, including a squamosa promoter-binding protein gene, a pentatricopeptide (PPR) repeat-containing protein gene, a BolA-like family protein gene, AGO1 and a gene of unknown function. We also demonstrated that the DCL3-dependent rasiRNA biogenesis pathway, which had been considered absent in conifers, existed in Chinese fir. Furthermore, the miR390-TAS3-ARF regulatory pathway was elucidated. We unveiled a complex population of sRNAs in Chinese fir through high throughput sequencing. This provides an insight into the composition and function of sRNAs in Chinese fir and sheds new light on land plant sRNA evolution.
Project description:siRNA-mediated inhibition compared to untreated cells and cells transfected with nonsense siRNA Together with far upstream element binding protein (FBP), the FBP-interacting repressor (FIR) represents a molecular tool for the transcriptional fine tune regulation of target genes. Previous evidence indicates that strong overexpression of FBP in human hepatocellular carcinoma (HCC) supports tumor growth and correlates with poor patient prognosis. However, the role of the transcriptional repressor FIR in hepatocarcinogenesis remains poorly delineated. We show that overexpression of FIR correlates with tumor dedifferentiation and tumor cell proliferation in about 60% of primary HCCs. Elevated FIR levels are associated with genomic gains of the fir gene locus at chromosome 8q24.3 in human HCC specimens. In vitro, nuclear enrichment of FIR supports HCC cell proliferation and migration. Expression profiling of HCC cells after siRNA-mediated silencing of FIR identified the transcription factor DP-1 (TFDP1) as a transcriptional target of FIR. Surprisingly, FIR stimulates the expression of FBP in a TFDP1/E2F-dependent manner. FIR splice variants lacking or containing exon 2 and/or exon 5 are expressed in the majority of HCCs. Specific inhibition of FIR isoforms with and without exon 2 revealed that all FIR splice variants facilitate tumor-supporting effects. This finding was confirmed in xenograft transplantation experiments with lentiviral-infected shRNA targeting all FIR variants as well as FIR with and without exon 2. In summary, high-level nuclear FIR does not facilitate repressor properties but supports tumor growth in HCC cells. Thus, the pharmacological inhibition of FIR might represent a promising therapeutic strategy for HCC patients. Expression profiling of cells transfected with scrambled/nonsense siRNA (control), and after siRNA-mediated FIR inhibition.
Project description:Far infrared radiation (FIR), a subdivision of the electromagnetic spectrum, has been proved to be beneficial for long-term effects of tissue healing, anti-inflammation, promoting growth, modulating sleep, acceleration of microcirculation, and pain relief. We attempt to study whether FIR would be beneficial for renal proximal tubule cell (RPTC) cultivation and renal tissue engineering. We observed the FIR effects on RPTCs, including cell viability, functional characteristics, immunofluorescence presentations, and subcellular findings. And the FIR protective effects would be further examined with HK-2 cell (Human proximal tubule cell line) against cisplatin, a nephrotoxic agent. Our study showed that daily exposure to FIR for 30 minutes could significantly increase rabbit RPTC viability in vitro assessed by MTT assay. FIR is not only beneficial in RPTC cell viability. RPTCs with FIR exposure presented higher expression of Na-K ATPase and GLUT1 (Glucose Transporter 1). The finding was documented with western blot analysis with statistical significance. With Q-PCR, CDK5R1, GNAS, NPPB, and TEK expressions were significantly enhanced. With HK-2 cell, the proximal tubule cell line, FIR had protective effects against cisplatin nephrotoxicity through reducing apoptosis. FIR is a potential photomodulation therapy to facilitate RPTC cultivation with higher cell viability and better functional chanacteristics and would possibly be applied in further nephrotoxicity protection and other cisplatin-sensitive cell protection.
Project description:High glucose impairs the angiogenic activities of late endothelial precursor cells (EPC). We found that far infrared (FIR) treatment restored partially the activity of late EPC. However, the mechanisms are unclear. We applied microRNA expression microarrays to assess the microRNA expression profiles of high glucose-treated late EPC with or without FIR treatment.
Project description:High glucose impairs the angiogenic activities of late endothelial precursor cells (EPC). We found that far infrared (FIR) treatment restored partially the activity of late EPC. However, the mechanisms are unclear. We performed gene expression microarray analysis to assess the expression profiles of high glucose-treated late EPC with or without FIR treatment.