Assessing Basal and Acute Autophagic Responses in the Adult Drosophila Nervous System: The Impact of Gender, Genetics and Diet on Endogenous Pathway Profiles

Abstract

The autophagy pathway is critical for the long-term homeostasis of cells and adult organisms and is often activated during periods of stress. Reduced pathway efficacy plays a central role in several progressive neurological disorders that are associated with the accumulation of cytotoxic peptides and protein aggregates. Previous studies have shown that genetic and transgenic alterations to the autophagy pathway impacts longevity and neural aggregate profiles of adult Drosophila. In this study, we have identified methods to measure the acute in vivo induction of the autophagy pathway in the adult fly CNS. Our findings indicate that the genotype, age, and gender of adult flies can influence pathway responses. Further, we demonstrate that middle-aged male flies exposed to intermittent fasting (IF) had improved neuronal autophagic profiles. IF-treated flies also had lower neural aggregate profiles, maintained more youthful behaviors and longer lifespans, when compared to ad libitum controls. In summary, we present methodology to detect dynamic in vivo changes that occur to the autophagic profiles in the adult Drosophila CNS and that a novel IF-treatment protocol improves pathway response in the aging nervous system.

TGFB-INHB/activin signaling regulates age-dependent autophagy and cardiac health through inhibition of MTORC2

“…The epitope used to generate GABARAP antibody has identical amino acid sequences to Drosophila Atg8a protein (personal communication with Cell Signaling Technology and see sequence alignment in Figure S2A). This antibody has been previously used in several Drosophila autophagy studies [25][26][27], and verified by Kim et al [28]. We further verified the specificity of the GABARAP antibody using an Atg8a loss-offunction mutant Atg8a Δ4 (Figure S2B-D).…”

Aging and Intermittent Fasting Impact on Transcriptional Regulation and Physiological Responses of Adult Drosophila Neuronal and Muscle Tissues

“…Both human and model organism studies have shown even modest dietary modifications can have a significant positive influence on longevity and the health of aging individuals [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Existing research into the molecular mechanisms that underpin such improved health and longevity metrics indicates that the long-term function of multiple cellular systems is essential [ 3 , 5 , 8 , 9 , 10 ].…”

“…We have recently characterized a mild intermittent fasting (IF) protocol that promotes longevity and neural function of middle-aged adult Drosophila strains from divergent genetic backgrounds [ 1 , 16 , 17 ]. The beneficial effects of this fasting protocol included a delay in the progressive decline of locomotor behaviors and a reduction in neural aggregate levels [ 1 , 16 , 17 ]. This was associated with improvements in the acute and long-term functions of the autophagy pathway within middle-aged fly neurons [ 1 , 16 , 17 ].…”

“…The beneficial effects of this fasting protocol included a delay in the progressive decline of locomotor behaviors and a reduction in neural aggregate levels [ 1 , 16 , 17 ]. This was associated with improvements in the acute and long-term functions of the autophagy pathway within middle-aged fly neurons [ 1 , 16 , 17 ]. Multiple studies have established that this pathway plays a central role in stress responses and in promoting healthy aging, partly through facilitating the clearance of protein aggregates and damaged cellular components [ 13 , 18 , 19 ].…”

“…Multiple studies have established that this pathway plays a central role in stress responses and in promoting healthy aging, partly through facilitating the clearance of protein aggregates and damaged cellular components [ 13 , 18 , 19 ]. At the mechanistic level, autophagy represents a downstream effector pathway, the activity of which is tightly regulated by multiple upstream factors that control and coordinate complex cellular responses [ 1 , 16 , 17 , 19 , 20 ]. The impact of IF-treatment on the aging CNS could reflect the alteration to multiple signaling and metabolic pathways that in turn influence pathway function, and as a result, the long-term maintenance of the aging nervous system [ 1 , 16 , 17 , 19 , 20 ].…”