Project description:A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the antimicrobial mechanism is unclear. Here, we demonstrate that vitamin A mediates host defense through regulation of cellular cholesterol content. Comparison of monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3, the biologically active forms of vitamin A and vitamin D respectively, indicates that ATRA and 1,25D3 induce mechanistically distinct antimicrobial activities. Gene expression profiling reveals that ATRA but not 1,25D3 triggers a lipid metabolism and efflux pathway, including expression of lysosomal lipid transport gene NPC2. ATRA-induced decrease in total cellular cholesterol content, subcellular lipid reorganization, lysosomal acidification and antimicrobial activity are all dependent upon expression of NPC2. Finally, the addition of HIV-protease inhibitors known to inhibit cholesterol efflux, Ritonavir and Nelfinavir, blocked both ATRA-induced cholesterol decrease as well as antimicrobial activity. Taken together, these results suggest that the vitamin A-mediated host defense mechanism against M. tuberculosis requires regulation of cellular cholesterol. Monocytes derived from four independent healthy blood donors that were stimulated with control (CTRL), ATRA or 1,25D3 at 10-8M for 18 hours.
Project description:A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the antimicrobial mechanism is unclear. Here, we demonstrate that vitamin A mediates host defense through regulation of cellular cholesterol content. Comparison of monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3, the biologically active forms of vitamin A and vitamin D respectively, indicates that ATRA and 1,25D3 induce mechanistically distinct antimicrobial activities. Gene expression profiling reveals that ATRA but not 1,25D3 triggers a lipid metabolism and efflux pathway, including expression of lysosomal lipid transport gene NPC2. ATRA-induced decrease in total cellular cholesterol content, subcellular lipid reorganization, lysosomal acidification and antimicrobial activity are all dependent upon expression of NPC2. Finally, the addition of HIV-protease inhibitors known to inhibit cholesterol efflux, Ritonavir and Nelfinavir, blocked both ATRA-induced cholesterol decrease as well as antimicrobial activity. Taken together, these results suggest that the vitamin A-mediated host defense mechanism against M. tuberculosis requires regulation of cellular cholesterol.
Project description:The leukemic cell line HL-60 is widely used to study normal and aberrant myelopoiesis. HL-60 cells can be treated with ATRA (all-trans retinoic acid) and Vit-D3 (1,25-Dihydroxyvitamin D3, calcitriol) to differentiate into granulocytes and monocytes respectively. Induced myeloid differentiation helps us to understand the molecular basis of myeloid differentiation. To understand the genome-wide gene expression changes associated with HL-60 cells upon myeloid differentiation, RNA-sequencing was carried out. We subjected the HL-60 cells with 10 µM ATRA and 50 nM Vit-D3 for 72 hours. Post induction, the uninduced and induced cells were sorted based on CD11b and CD14 markers. The uninduced cells were negative for both the markers while ATRA and Vit D3 inductions were highly positive for CD11b-FITC and CD14-APC-H7 markers respectively. Two biological replicates were used for this experiment. Sorted cells were collected for RNA extraction using RNAeasy Kit from Qiagen and RNA quality was assessed using Bioanalyzer. High quality RNA with RIN values greater than 8, were used to generate library using TrueSeq stranded library preparation kit from Illumina following manufacturer’s instructions. Finally, barcoded libraries were pooled, and a final concentration of 10 nM was loaded in HiSeq 2500 Illumina platform and paired-end sequencing for 2*126 cycles were carried out.
Project description:We have carried out global gene expression analysis to clarify the interrelationship between 1,25-dihydroxyvitamin D3 and differentiation-driven gene expression patterns in developing human monocyte-derived dendritic cells. Monocytes were treated with 10 nM 1,25-dihydroxyvitamin D3 or vehicle 14 hours after plating for 12 hours or 5 days. Monocytes, differentiating dendritic cells (+/-1,25-dihydroxyvitamin D3 for 12 hours) and immature dendritic cells (+/-1,25-dihydroxyvitamin D3 for 5 days) were harvested. This design allows one to identify genes regulated by differentiation and/or 1,25-dihydroxyvitamin D3 in human monocyte-derived dendritic cells.
Project description:In SKBR3 cells, simultaneous targeting of RARM-kM-1 with all-trans retinoic acid (ATRA) and HER2 with lapatinib results in synergistic anti-tumor responses. SKBR3 cells were treated with vehicle (DMSO), lapatinib (100 nM), ATRA (100 nM) or lapatinib+ATRA for 36 hours and miRNA expression profile was determined by one-color Agilent microarray experiments.
Project description:Mammalian lung development during the saccular and alveolar stages is dependent upon antagonistic molecular signalling by endogenous retinoic acid (RA) and glucocorticoids (GCs) which regulate gene expression via the retinoic acid receptor (RAR) family and the glucocorticoid receptor (GR), respectively. The genomic mechanism of this antagonism was investigated with in vitro distal lung explant cultures from E18.5 GR-null (GR-/-) mice treated with all-trans-RA (atRA) for 2h . Whole mouse genome microarray analysis from lung explant tissue identified a small number of gene targets which were not only significantly induced by atRA in the wildtype lung, but also significantly stimulated to levels greater than atRA-treated wildtype lungs in GR-/- lungs.
Project description:We have carried out global gene expression analysis to clarify the interrelationship between 1,25-dihydroxyvitamin D3 and differentiation-driven gene expression patterns in developing human monocyte-derived dendritic cells. Monocytes were treated with 10 nM 1,25-dihydroxyvitamin D3 or vehicle 14 hours after plating for 12 hours or 5 days. Monocytes, differentiating dendritic cells (+/-1,25-dihydroxyvitamin D3 for 12 hours) and immature dendritic cells (+/-1,25-dihydroxyvitamin D3 for 5 days) were harvested. This design allows one to identify genes regulated by differentiation and/or 1,25-dihydroxyvitamin D3 in human monocyte-derived dendritic cells. Experiment Overall Design: Human monocytes were obtained from buffy coats from healthy donors by Ficoll gradient centrifugation followed by immunomagnetic cell separation with anti-CD14-conjugated microbeads. Monocytes were cultured in RPMI-1640 supplemented with 10% FBS, 800 U/ml GM-CSF and 500 U/ml IL-4. Monocytes were treated with 10 nM 1,25-dihydroxyvitamin D3 or vehicle 14 hours after plating for 12 hours or 5 days. Monocytes, differentiating dendritic cells (+/-1,25-dihydroxyvitamin D3 for 12 hours) and immature dendritic cells (+/-1,25-dihydroxyvitamin D3 for 5 days) were harvested. Experiments were performed in biological triplicates representing samples from different donors. 15 samples were processed and hybridized to Human Genome U133 Plus 2.0 Arrays.
Project description:All-trans retinoic acid (ATRA) has been shown to have anti-proliferative effects, particularly in the context of cancer. However, the effects of ATRA on gene and microRNA expression in solid tumors have not been investigated. In this study, we performed gene expression and microRNA analysis of the squamous cell carcinoma cell line, ME180, following treatment with 10 micromolar all-trans retinoic acid (ATRA) for 1, 3, and 6 hours. Results provide insight into the temporal regulation of genes and microRNAs by retinoids.
Project description:Combination of new therapeutics with trans-retinoic acid (ATRA) could improve efficiency of acute myeloid leukemia (AML) treatment. Modeling the process of ATRA-induced differentiation based on transcriptomic profile of leukemic cells allows us to identify key molecules that could be affected to enhance the therapeutic effect of ATRA. Moreover, transcriptome analysis reveals the earliest steps of molecular response to inducer treatment. Thus, the transcriptomic profile of leukemic cells under the ATRA treatment at the different time points is considered as input data for further upstream regulator search.