Autophagy-Associated Shrinkage of the Hepatopancreas in Fasting Male Macrobrachium rosenbergii Is Rescued by Neuropeptide F

Abstract

Invertebrate neuropeptide F-I (NPF-I), much alike its mammalian homolog neuropeptide Y, influences several physiological processes, including circadian rhythms, cortical excitability, stress response, and food intake behavior. Given the role of autophagy in the metabolic stress response, we investigated the effect of NPF-1 on autophagy during fasting and feeding conditions in the hepatopancreas and muscle tissues of the male giant freshwater prawn Macrobrachium rosenbergii. Starvation up-regulated the expression of the autophagy marker LC3 in both tissues. Yet, based on the relative levels of the autophagosome-associated LC3-II isoform and of its precursor LC3-I, the hepatopancreas was more responsive than the muscle to starvation-induced autophagy. Injection of NPF-I inhibited the autophagosome formation in the hepatopancreas of fasting prawns. Relative to the body weight, the muscle weight was not affected, while that of the hepatopancreas decreased upon starvation and NPF-1 treatment could largely prevent such weight loss. Thus, the hepatopancreas is the reserve organ for the nutrient homeostasis during starvation and NPF-I plays a crucial role in the balancing of energy expenditure and energy intake during starvation by modulating autophagy.

Cell proliferation controls body size growth, tentacle morphogenesis, and regeneration in hydrozoan jellyfishCladonema pacificum

“…Similarly, upon starvation, Hydra polyps cease asexual budding and decrease their size (Buzgariu, Chera & Galliot, 2008; Chera et al, 2009a), suggesting that cnidarian animals are sensitive to nutrition availability and adapt to metabolic changes. At the organ and tissue level, such size reduction can occur via autophagy or cell death during starvation in diverse phyla (Jeschke et al, 2000; O’Brien et al, 2011; Thongrod et al, 2018; Tracy & Baehrecke, 2013). Cnidarians thus may utilize similar mechanisms to reduce cell size and/or cell number to adjust their body size in response to environmental changes.…”

Differential expression of neuropeptide F in the digestive organs of female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle

“…Additionally, the HP is a major source of immune reactive molecules, including lectins, nitric oxide (NO), stress proteins, antibacterial and antiviral proteins, enzymes, and apoptotic genes. In male prawn M. rosenbergii , MrNPF in the HP could modulate autophagy to help balance energy expenditure and energy intake during starvation (Thongrod et al 2018 ). Our finding that MrNPF-ir was found in F- and B-cells suggests the role of this neuropeptide in modulating intracellular digestion, releasing digestive enzymes, and regulating immune responses in female M. rosenbergii .…”

Peer Review #2 of "Cell proliferation controls body size growth, tentacle morphogenesis, and regeneration in hydrozoan jellyfish Cladonema pacificum (v0.1)"

“…Similarly, upon starvation, Hydra polyps cease asexual budding and decrease their size (Buzgariu et al 2008;Chera et al 2009a), suggesting that cnidarian animals are sensitive to nutrition availability and adapt to metabolic changes. At the organ and tissue level, such size reduction can occur via autophagy or cell death during starvation in diverse phyla (Jeschke et al 2000;O'Brien et al 2011;Thongrod et al 2018;Tracy & Baehrecke 2013). Cnidarians thus may utilize similar mechanisms to reduce cell size and/or cell number to adjust their body size in response to environmental changes.…”