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Gillespie ZE, MacKay K, Sander M, Trost B, Dawicki W, Wickramarathna A, Gordon J, Eramian M, Kill IR, Bridger JM, Kusalik A, Mitchell JA, Eskiw CH. Rapamycin reduces fibroblast proliferation without causing quiescence and induces STAT5A/B-mediated cytokine production. Nucleus 2016; 6:490-506. [PMID: 26652669 DOI: 10.1080/19491034.2015.1128610] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rapamycin is a well-known inhibitor of the Target of Rapamycin (TOR) signaling cascade; however, the impact of this drug on global genome function and organization in normal primary cells is poorly understood. To explore this impact, we treated primary human foreskin fibroblasts with rapamycin and observed a decrease in cell proliferation without causing cell death. Upon rapamycin treatment chromosomes 18 and 10 were repositioned to a location similar to that of fibroblasts induced into quiescence by serum reduction. Although similar changes in positioning occurred, comparative transcriptome analyses demonstrated significant divergence in gene expression patterns between rapamycin-treated and quiescence-induced fibroblasts. Rapamycin treatment induced the upregulation of cytokine genes, including those from the Interleukin (IL)-6 signaling network, such as IL-8 and the Leukemia Inhibitory Factor (LIF), while quiescent fibroblasts demonstrated up-regulation of genes involved in the complement and coagulation cascade. In addition, genes significantly up-regulated by rapamycin treatment demonstrated increased promoter occupancy of the transcription factor Signal Transducer and Activator of Transcription 5A/B (STAT5A/B). In summary, we demonstrated that the treatment of fibroblasts with rapamycin decreased proliferation, caused chromosome territory repositioning and induced STAT5A/B-mediated changes in gene expression enriched for cytokines.
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Affiliation(s)
- Zoe E Gillespie
- a Department of Food and Bioproduct Sciences ; University of Saskatchewan ; Saskatoon , Canada.,b Institute of Environment, Health and Societies; Brunel University; London , Uxbridge , United Kingdom
| | - Kimberly MacKay
- c Department of Computer Science ; University of Saskatchewan ; Saskatoon , Canada
| | - Michelle Sander
- a Department of Food and Bioproduct Sciences ; University of Saskatchewan ; Saskatoon , Canada
| | - Brett Trost
- c Department of Computer Science ; University of Saskatchewan ; Saskatoon , Canada
| | - Wojciech Dawicki
- d Department of Medicine ; Division of Respirology, Critical Care and Sleep Medicine; Royal University Hospital ; Saskatoon , Canada
| | - Aruna Wickramarathna
- a Department of Food and Bioproduct Sciences ; University of Saskatchewan ; Saskatoon , Canada
| | - John Gordon
- d Department of Medicine ; Division of Respirology, Critical Care and Sleep Medicine; Royal University Hospital ; Saskatoon , Canada
| | - Mark Eramian
- c Department of Computer Science ; University of Saskatchewan ; Saskatoon , Canada
| | - Ian R Kill
- b Institute of Environment, Health and Societies; Brunel University; London , Uxbridge , United Kingdom
| | - Joanna M Bridger
- b Institute of Environment, Health and Societies; Brunel University; London , Uxbridge , United Kingdom
| | - Anthony Kusalik
- c Department of Computer Science ; University of Saskatchewan ; Saskatoon , Canada
| | - Jennifer A Mitchell
- e Department of Cell and Systems Biology ; University of Toronto ; Toronto , Canada.,f Centre for the Analysis of Genome Evolution and Function; University of Toronto , Toronto , ON , Canada
| | - Christopher H Eskiw
- a Department of Food and Bioproduct Sciences ; University of Saskatchewan ; Saskatoon , Canada.,b Institute of Environment, Health and Societies; Brunel University; London , Uxbridge , United Kingdom
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Mietkiewska E, Miles R, Wickramarathna A, Sahibollah AF, Greer MS, Chen G, Weselake RJ. Combined transgenic expression of Punica granatum conjugase (FADX) and FAD2 desaturase in high linoleic acid Arabidopsis thaliana mutant leads to increased accumulation of punicic acid. Planta 2014; 240:575-583. [PMID: 25000918 DOI: 10.1007/s00425-014-2109-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 06/17/2014] [Indexed: 06/03/2023]
Abstract
Arabidopsis was engineered to produce 21.2 % punicic acid in the seed oil. Possible molecular factors limiting further accumulation of the conjugated fatty acid were investigated. Punicic acid (18:3Δ(9cis,11trans,13cis) ) is a conjugated linolenic acid isomer and is a main component of Punica granatum (pomegranate) seed oil. Medical studies have shown that punicic acid is a nutraceutical with anti-cancer and anti-obesity properties. It has been previously demonstrated that the conjugated double bonds in punicic acid are produced via the catalytic action of fatty acid conjugase (FADX), which is a homolog of the oleate desaturase. This enzyme catalyzes the conversion of the Δ(12)-double bond of linoleic acid (18:2Δ(9cis,12cis) ) into conjugated Δ(11trans) and Δ(13cis) -double bonds. Previous attempts to produce punicic acid in transgenic Arabidopsis thaliana seeds overexpressing P. granatum FADX resulted in a limited accumulation of punicic acid of up to 4.4 %, accompanied by increased accumulation of oleic acid (18:1∆(9cis) ), suggesting that production of punicic acid in some way inhibits the activity of oleate desaturase (Iwabuchi et al. 2003). In the current study, we applied a new strategy to enhance the production of punicic acid in a high linoleic acid A. thaliana fad3/fae1 mutant background using the combined expression of P. granatum FADX and FAD2. This approach led to the accumulation of punicic acid at the level of 21 % of total fatty acids and restored the natural proportion of oleic acid observed in the A. thaliana fad3/fae1 mutant. In addition, we provide new insights into the high oleate phenotype and describe factors limiting the production of punicic acid in genetically engineered plants.
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Affiliation(s)
- Elzbieta Mietkiewska
- Alberta Innovates Phytola Centre, Department of Agricultural, Food and Nutritional Science, University of Alberta, 4-10 Agriculture/Forestry Centre, Edmonton, AB, T6G 2P5, Canada
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