Research Paper Volume 10, Issue 4 pp 622—631
Stress resistance and lifespan enhanced by downregulation of antimicrobial peptide genes in the Imd pathway
- 1 Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark, NJ 07103, USA
- 2 Present address: Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan
- 3 Present address: Institute of Ophthalmology and Visual Science, Rutgers, State University of New Jersey, Newark, NJ 07103, USA
received: March 7, 2018 ; accepted: April 10, 2018 ; published: April 19, 2018 ;https://doi.org/10.18632/aging.101417
How to Cite
Copyright: Lin et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Biological behaviors and longevity of ectothermic animals are remarkably influenced by ambient temperature. Development at 18°C significantly enhances the stress resistance of adult flies with more accumulation of nutrients (especially fat) in the body than development at 25°C. Gene expression analysis between the flies developed at 18°C and 25°C revealed that the Immune deficiency (Imd) pathway, including the downstream antimicrobial peptides (AMPs), is downregulated in the flies developed at 18°C. When hypomorphic imd mutant flies with reduced AMP expressions were developed at 25°C, they showed induced stress resistance with higher fat content in the body similar to the wild-type flies developed at 18°C. However, severe hypomorphic imd mutants could not enhance stress resistance due to the downregulation of another downstream JNK pathway that expresses stress tolerance genes. Interestingly, the downregulation of AMP genes, itself, extended lifespan with increased stress resistance. Especially, fat body-specific downregulation of Imd AMP genes exhibited a longer lifespan with higher heat resistance. The fat body is known to function in metabolic homeostasis, stress tolerance, growth, and longevity in Drosophila. Here, we provide the first evidence that mild downregulation of the Imd pathway with AMP genes increases fat content, stress resistance, and lifespan in adult flies.