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Landis GN, Bell HS, Peng O, Bognar B, Tong A, Manea TD, Bao H, Han X, Tower J. Dhr96[1] mutation and maternal tudor[1] mutation increase life span and reduce the beneficial effects of mifepristone in mated female Drosophila. PLoS One 2023; 18:e0292820. [PMID: 38127988 PMCID: PMC10735022 DOI: 10.1371/journal.pone.0292820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/28/2023] [Indexed: 12/23/2023] Open
Abstract
Mating and receipt of male Sex Peptide hormone cause increased egg laying, increased midgut size and decreased life span in female Drosophila. Feeding mated females with the synthetic steroid mifepristone decreases egg production, reduces midgut size, and increases life span. Here, several gene mutations were assayed to investigate possible mechanisms for mifepristone action. Drosophila Dhr96 is a hormone receptor, and a key positive regulator of midgut lipid uptake and metabolism. Dhr96[1] null mutation increased female life span, and reduced the effects of mifepristone on life span, suggesting that Dhr96[1] mutation and mifepristone may act in part through the same mechanism. Consistent with this idea, lipidomics analysis revealed that mating increases whole-body levels of triglycerides and fatty-acids in triglycerides, and these changes are reversed by mifepristone. Maternal tudor[1] mutation results in females that lack the germ-line and produce no eggs. Maternal tudor[1] mutation increased mated female life span, and reduced but did not eliminate the effects of mating and mifepristone on life span. This indicates that decreased egg production may be related to the life span benefits of mifepristone, but is not essential. Mifepristone increases life span in w[1118] mutant mated females, but did not increase life span in w[1118] mutant virgin females. Mifepristone decreased egg production in w[1118] mutant virgin females, indicating that decreased egg production is not sufficient for mifepristone to increase life span. Mifepristone increases life span in virgin females of some, but not all, white[+] and mini-white[+] strains. Backcrossing of mini-white[+] transgenes into the w[1118] background was not sufficient to confer a life span response to mifepristone in virgin females. Taken together, the data support the hypothesis that mechanisms for mifepristone life span increase involve reduced lipid uptake and/or metabolism, and suggest that mifepristone may increase life span in mated females and virgin females through partly different mechanisms.
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Affiliation(s)
- Gary N. Landis
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Hans S. Bell
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Oscar Peng
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Brett Bognar
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Andy Tong
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Tomás D. Manea
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Hanmei Bao
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - John Tower
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
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N. Landis G, Ko S, Peng O, Bognar B, Khmelkov M, S. Bell H, Tower J. A screen of small molecule and genetic modulators of life span in female Drosophila identifies etomoxir, RH5849 and unanticipated temperature effects. Fly (Austin) 2022; 16:397-413. [PMID: 36412257 PMCID: PMC9683069 DOI: 10.1080/19336934.2022.2149209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/02/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022] Open
Abstract
Mifepristone increases life span in female Drosophila melanogaster, and its molecular target(s) remain unclear. Here small molecule and genetic interventions were tested for ability to mimic mifepristone, or to decrease life span in a way that can be rescued by mifepristone. Etomoxir inhibits lipid metabolism, and significantly increased life span in virgin and mated females, but not males, at 50 µM concentration. Pioglitazone is reported to activate both mammalian PPARγ and its Drosophila homolog Eip75B. Pioglitazone produced minor and inconsistent benefits for female Drosophila life span, and only at the lowest concentrations tested. Ecdysone is a Drosophila steroid hormone reported to regulate responses to mating, and RH5849 is a potent mimic of ecdysone. RH5849 reduced virgin female life span, and this was partly rescued by mifepristone. Mifepristone did not compete with RH5849 for activation of an ecdysone receptor (EcR)-responsive transgenic reporter, indicating that the relevant target for mifepristone is not EcR. The conditional GAL4/GAL80ts system was used in attempt to test the effect of an Eip75B RNAi construct on female life span. However, the 29°C temperature used for induction reduced or eliminated mating-induced midgut hypertrophy, the negative life span effects of mating, and the positive life span effects of mifepristone. Even when applied after mating was complete, a shift to 29°C temperature reduced mating-induced midgut hypertrophy by half, and the life span effects of mating by 4.8-fold. Taken together, these results identify promising small molecules for further analysis, and inform the design of experiments involving the GAL4/GAL80ts system.
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Affiliation(s)
- Gary N. Landis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sebastian Ko
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Oscar Peng
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Brett Bognar
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Michael Khmelkov
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Hans S. Bell
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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