Project description:Necrotizing enterocolitis (NEC) is an acute gut inflammatory disorder that mainly affects preterm neonates. A large proportion of NEC survivors develop neuronal deficits later in life, however the effect of early stages of NEC on the developing brain is unknown. Using preterm pigs as a NEC-sensitive animal model, we profiled the hippocampal gene expression in response to severe NEC lesions. The NEC-induced differentially expressed genes (DEGs) in the hippocampus segregated the piglets suffering from small intestinal NEC (Si-NEC) from those showing NEC lesions only in the colon (Co-NEC). Only when NEC lesions were observed in the small intestine, did piglets show reduced physical activity together with up-regulation of hippocampal genes related to inflammation and hypoxia, which was further verified by qPCR. Cluster analyses revealed key hippocampal NEC–related DEGs for Si-NEC (23 genes, including S100A8, PDK4, EDN1, IER3, Opalin, TXNIP) and Co-NEC (3 genes: GSTM3, TF, and S100A1). Both NEC phenotypes showed only two down-regulated DEGs (TMEM 167, HBB) and were devoid of any histological signs of microglia activation. Cerebrospinal fluid (CSF) from NEC-positive pigs contained elevated levels of several inflammatory proteins and in vitro exposure of immature hippocampal neurons to NEC-related CSF promoted neuritogenesis. Further in vitro experiments with neurite outgrowth indicated that VEGF, CINC-3, S100A9 and S100A8/S100A9 may play a role in NEC effects on hippocampal development. In conclusion, NEC lesions, especially when involving the small intestine, alter hippocampal gene expression with potential neuroinflammation and effects on neural circuit formation. Our results demonstrated that gut lesions affect the immature brain at early stages of disease progression. Thus, supportive care is important for preterm infants experienced with NEC to lessen possible later neurological dysfunctions.
Project description:To determine the physiological roles of NCOA4 and NCOA4-mediated ferritinophagy in hippocampal neurons, NCOA4 was depleted using siRNA and desferrioxamine (DFO; 100 µM, 24 h) was added to restrict iron availability. Cells were treated for NCOA4 depletion, iron restriction, or both, and then the transcriptome profiles acquired from RNA-seq were compared with those of control (scramble siRNA-treated) cells.
Project description:MicroRNAs (miRNAs) play important roles in intestinal diseases; however, the role of miRNAs during weaning stress is unknown. In our study, six jejunal small RNA libraries constructed from weaning piglets at 1, 4 and 7 d after weaning (libraries W1, W4 and W7, respectively) and from suckling piglets on the same days as the weaning piglets (libraries S1, S4 and S7, respectively) were sequenced using Solexa high-throughput sequencing technology. Overall, 260 known swine miRNAs and 317 novel candidate miRNA precursors were detected in the six libraries. The results revealed that 16 differentially expressed miRNAs were found between W1 and S1; 98 differentially expressed miRNAs were found between W4 and S4 (ssc-mir-146b had the largest difference and ssc-mir-215 had the highest expression level); and 22 differentially expressed miRNAs were found between W7 and S7. Sequencing miRNA results were validated using RT-qPCR. Approximately 12,819 miRNA-mRNA interactions corresponding to 4,250 target genes were predicted. The biological analyses revealed that the differentially expressed miRNAs regulated small intestinal metabolism, stressful responses, cellular and immune functions and miRNA biosynthesis in piglets. Therefore, the small intestine miRNA transcriptome was significantly different between weaning and suckling piglets; the difference varied with the number of days after weaning. six small RNA libraries from weaning piglets at 1, 4 and 7 d after weaning and from suckling piglets on the same days as the weaning piglets, respectively. For every small RNA library construction, 4 biological total RNA samples isolated from each treatment and control were separately pooled with equal contribution.
Project description:Sixty crossbred piglets (Duroc*Landrace*Yorkshire) weaned at the age of 21 days were maintained for one week and had free access to feed and water. During this week, all the piglets were scored for the severity of diarrhea. Diarrhea index was scored as follows: 1= hard feces; 2= no scours, feces of normal consistency; 3= mild scours, soft, partially formed feces; 4= moderate scours, loose, semi-liquid feces; 5= watery feces; as previously did Those piglets with a score of 4 or 5 for three continuous days were designated as diarrhea piglets, while those piglets with a score of 1 or 2 for three continuous days were designated as normal piglets..
Project description:We describe XmaI-RRBS method for rapid and affordable genome-wide DNA methylation analysis, with library preparation taking only four days and sequencing possible within four hours. Small sizes of the XmaI-RRBS libraries allow their multiplexing and sequencing on the benchtop high-throughput machines. Described here is the first RRBS protocol validated for the Ion Torrent Personal Genome Machine. DNA from MCF7 cell line and 6 normal breast samples (total 7 samples) were subjected to reduced representation bisulfite sequencing analysis (XmaI-RRBS) by using Ion Torrent platform.