Project description:Human monocytic THP-1 cells were exposed to HIV envelope protein gp120 or bacterial LPS in the presence and absence of a pharmacological inhibitor of the p38 mitogen-activated protein kinase (MAPK) for 4 and 24 hours. A microarray analysis was performed in order to assess differential gene expression at the RNA level.
Project description:Human monocytic THP-1 cells were exposed to HIV envelope protein gp120 or bacterial LPS in the presence and absence of a pharmacological inhibitor of the p38 mitogen-activated protein kinase (MAPK) for 4 and 24 hours. A microarray analysis was performed in order to assess differential gene expression at the RNA level. Human monocytic THP-1 cells were pre-treated for 15 min with 10 M-BM-5M SB203580 followed by exposure for 4 h or 24 h to 1 nM HIV gp120SF162 or 1 M-BM-5g/ml LPS. 0.1 % DMSO and 0.001 % BSA served as vehicle controls for SB203580 and gp120, respectively. The experimental samples were 1) control 4 h, 2) gp120 4 h, 3) LPS 4 h, 4) SB203580 (SB) 4 h, 5) SB+gp120 4 h, 6) SB+LPS 4 h, 7) control 24 h, 8) gp120 24 h, 9) LPS 24 h, 10) SB 24 h, 11) SB+gp120 24 h, 12) SB+LPS 24 h. RNA was isolated from three biological replicates for each experimental condition using an RNeasy kit commercially available from Qiagen (Valencia, CA). Roughly 2 X 106 cells were collected to obtain 500 ng M-bM-^@M-^S 2 M-BM-5g RNA. RNA quality (A260/A280 ratio ~1.8-2.0) was tested using the NanoDrop system from Thermo Scientific (Rockford, IL). High quality RNA was then provided to the Microarray/ QPCR Facility Core at Sanford-Burnham Medical Research Institute and DNA microarray was performed using the whole genome gene-expression analysis HumanHT-12 v4 Expression BeadChip kit from Illumina (San Diego, CA). Microarray results were further analyzed by Dr. Roy Williams (Bioinformatics Core, Sanford-Burnham Medical Research Institute) using the GeneSpring GX platform
Project description:Nitric oxide (NO) can stabilize mRNA by activating p38 mitogen-activated protein kinase (MAPK). Here, transcript stabilization by NO was investigated in human THP-1 cells using microarrays. After LPS pre-stimulation, cells were treated with actinomycin D and then exposed to NO without or with the p38 MAPK inhibitor SB202190. The decay of 220 mRNAs was affected; most were stabilized by NO. Unexpectedly, SB202190 often enhanced rather than antagonized transcript stability. NO activated p38 MAPK and Erk1/2; SB202190 blocked p38 MAPK, but further activated Erk1/2. PCR confirmed that NO and SB202190 could additively stabilize mRNA, an effect abolished by Erk1/2 inhibition. In affected genes, these responses were associated with CU-rich elements (CURE) in 3' un-translated regions. NO stabilized the mRNA of a CURE-containing reporter gene, while repressing translation. Dominant-negative Mek1, an Erk1/2 inhibitor, abolished this effect. NO similarly stabilized, but blocked translation of MAP3K7IP2, a natural CURE-containing gene. NO increased hnRNP translocation to the cytoplasm and binding to CURE. Over-expression of hnRNP K, like NO, repressed translation of CURE-containing mRNA. These findings define a sequence-specific mechanism of NO-triggered gene regulation that stabilizes mRNA, but represses translation. Keywords: time course and dose response
Project description:Nitric oxide (NO) can stabilize mRNA by activating p38 mitogen-activated protein kinase (MAPK). Here, transcript stabilization by NO was investigated in human THP-1 cells using microarrays. After LPS pre-stimulation, cells were treated with actinomycin D and then exposed to NO without or with the p38 MAPK inhibitor SB202190. The decay of 220 mRNAs was affected; most were stabilized by NO. Unexpectedly, SB202190 often enhanced rather than antagonized transcript stability. NO activated p38 MAPK and Erk1/2; SB202190 blocked p38 MAPK, but further activated Erk1/2. PCR confirmed that NO and SB202190 could additively stabilize mRNA, an effect abolished by Erk1/2 inhibition. In affected genes, these responses were associated with CU-rich elements (CURE) in 3ï¢ un-translated regions. NO stabilized the mRNA of a CURE-containing reporter gene, while repressing translation. Dominant-negative Mek1, an Erk1/2 inhibitor, abolished this effect. NO similarly stabilized, but blocked translation of MAP3K7IP2, a natural CURE-containing gene. NO increased hnRNP translocation to the cytoplasm and binding to CURE. Over-expression of hnRNP K, like NO, repressed translation of CURE-containing mRNA. These findings define a sequence-specific mechanism of NO-triggered gene regulation that stabilizes mRNA, but represses translation. Experiment Overall Design: THP-1 cells were first stimulated with LPS (1 µg/ml) for 4 h to boost transcript levels. After 30 min treatment with ActD (2.5 µg/ml), a transcription inhibitor, in the absence or presence of p38 MAPK inhibitor SB (0.1 µM), cells were then further incubated for 0-180 min with 400 µM of GSNO or GSH control (N = 4). Total RNA at different time points (0, 45, 90 and 180 min) was extracted, labeled and hybridized to human U133A microarrays, which were then scanned using Agilent GeneArray Scanner. Affymetrix MAS5 signal values were analyzed and first normalized to the 97th percentile, a value corresponding to the expression level of the 678th most intense probeset on the array. This normalization strategy assumed that the most intense probesets corresponded to mRNA species which were most stable and were generally unaffected by the treatments studied here. Then logarithmically transformed normalized data were subject to linear regression with respect to the 4 time points studied (0, 45, 90, 180 min following the start of incubation with GSH or GSNO), to estimate a slope corresponding to a first-order decay rate. The decay slope was calculated for each probeset, for each of the four conditions (GSH, GSNO, SB/GSH and SB/GSNO) using an Analysis of Covariance (ANCOVA), constraining the time 0 expression value to be identical for the pair of conditions without SB and the pair with SB, as necessitated by the design of the experiment. Further, since the experiment was replicated in 4 distinct batches, a blocked ANCOVA was utilized. The analysis results were then used to select genes which decayed, and whose decay rate changed following treatment. The p-value for a one-way, four level ANCOVA was calculated and used to compute a false discovery rate (FDR). The probesets with the lowest p-values, corresponding to a FDR of 10%, were selected and annotated based on information presented by Affymetrix at the NetAffx web-site as of April 12, 2004.
Project description:Controlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3´ untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice. We compared mRNA stability in LPS-treated BMDMs from WT and TTP-/- mice by microarray-based measurement of the remnant mRNA after transcriptional blockade with actinomycin D (act D). To increase the sensitivity of the mRNA decay profiling we inhibited the LPS-activated p38 MAPK with the specific inhibitor SB203580 since p38 MAPK negatively regulates the mRNA-destabilizing activity of TTP. LPS stimulation was for 3h before addition of act D. RNA was harvested at 0', 45' and 90' thereafter.
Project description:The objective of the study was to evaluate transcriptional response of endotoxin-stimulated human monocytic cells in presence or absence of host defense peptide LL-37 at low physiologically relevant concentrations. Human monocytic cells THP-1 were stimulated with LPS (10ng/ml) in presence or absence of LL-37 (5 ug/ml), as well as with the peptide alone, for 4 hours. The trends of LPS-induced altered gene expression in presence of the peptide were further validated by quantitative real-time PCR.
Project description:Transcriptional profiling of human umbilical vein endothelial cells, treated with MASP-1, thrombin, LPS, histamine, TNFalpha, MASP-1+SB203580 (p38-MAPK inhibitor) or MASP-1+Bay-117082 (NFKB inhibitor). Goal was to determine the effect of MASP-1 on HUVECs, to compare this with the effect of other endothelial cell activators and to determine the MASP-1 induced signalling pathways.
Project description:The objective of the study was to evaluate transcriptional response of endotoxin-stimulated human monocytic cells in presence and absence of host defense peptide LL-37. A functional genomics approach was used to establish a temporal transcriptional profile and identify differentially expressed genes in LPS (100ng/ml)-stimulated human monocytic THP-1 cells, in the presence or absence of LL-37 (20ug/ml) after 1, 2, 4 and 24 hrs of stimulation. The peptide significantly inhibited the expression of LPS-induced pro-inflammatory genes regulated by NF-kappa B, such as NF-kappa B1 (p105/p50) and TNF-alpha-induced protein 2 (TNFAIP2). In contrast, LL-37 did not significantly inhibit LPS-induced genes that antagonize inflammation, such as TNF-alpha-induced protein 3 (TNFAIP3) and the NF-kappa B inhibitor, NF-kappa BIA, or genes involved in cell movement and recruitment (chemokines). The trends of gene expression were further validated by quantitative real-time PCR. This study implicates that LL-37 plays a role in the delicate balancing act of inflammatory responses.
Project description:Monocytes are key players in inflammatory processes which are triggered by lipopolysaccharide (LPS), the major outer membrane component of gram-negative bacteria. The present study in human monocytic THP-1 cells was designed in order to identify LPS-inducible genes which are down-regulated by the reduced form of CoQ10 (ubiquinol, Q10H2). For this purpose, THP-1 cells were incubated with 10 µM Q10H2 for 24 h. Subsequently, cells were stimulated for 4 h with 1µg/ml LPS and the resulting gene expression levels were determined using microarrays. 14 LPS-inducible genes were identified to be significantly (p < 0.05) down-regulated by Q10H2 pre-treatment between a factor of 1.32 and 1.65. The strongest effect of Q10H2 incubation was found for the nuclear receptor coactivator 2 gene (NCOA2). Gene Ontology (GO) terms revealed for the Q10H2-sensitive genes an involvement in e.g. signal transduction processes (CENTD1, NCOA2, PSD3, PPP2R5C), transcriptional regulation (NCOA2, POU2F1, ETV3) and cell proliferation pathways (CCDC100, EPS15). In conclusion, we provide evidence in THP-1 cells that the reduced form of CoQ10 (Q10H2) modulates LPS-induced gene expression. Whole genome expression profiles were analysed from monocytes pre-incubated with the reduced form of CoQ10 (ubiquinol, Q10H2) before subsequent stimulation with LPS. Stimulated (+LPS) and unstimulated (-LPS) monocytes were used as positive and negative controls, respectively. For every experimental group (3 groups in total), three Affymetrix Human Genome U133 Plus 2.0 arrays were used, thus resulting in the analysis of 9 microarrays.
Project description:To better understand the interaction of TGFbeta and Toll-like-receptor 4 (TLR4) signaling in monocytes, we performed microarray analysis. We identified a unique set of genes whose expressions in monocytes were regulated by simultaneous stimulation of TLR4 and TGFβ signaling. THP-1 cells, a human monocytic cell line, were stimulated for 24 hours with PBS as control, LPS (100ng/ml), TGFbeta1 (1ng/ml) or LPS (100ng/ml) + TGFbeta1 (1ng/ml). After 24 hours of stimulation, total RNA was isolated and prepared for genome wide analyses using Illumina HumanRef8 V3.0 Beadchips. In total 32 arrays were analyzed including 8 samples of PBS-stimulated monocytes, 8 samples of LPS-stimulated monocytes, 8 samples of TGFbeta1 stimulated monocytes and 8 samples of monocytes stimulated with LPS + TGFbeta1.