Antioxidant response is a protective mechanism against nutrient deprivation in C. elegans

Abstract

Animals often experience periods of nutrient deprivation; however, the molecular mechanisms by which animals survive starvation remain largely unknown. In the nematode Caenorhabditis elegans, the nuclear receptor DAF-12 acts as a dietary and environmental sensor to orchestrate diverse aspects of development, metabolism, and reproduction. Recently, we have reported that DAF-12 together with co-repressor DIN-1S is required for starvation tolerance by promoting fat mobilization. In this report, we found that genetic inactivation of the DAF-12 signaling promoted the production of reactive oxygen species (ROS) during starvation. ROS mediated systemic necrosis, thereby inducing organismal death. The DAF-12/DIN-1S complex up-regulated the expression of antioxidant genes during starvation. The antioxidant enzyme GST-4 in turn suppressed ROS formation, thereby conferring worm survival. Our findings highlight the importance of antioxidant response in starvation tolerance and provide a novel insight into multiple organisms survive and adapt to periods of nutrient deprivation.

Oxytocin‐like signaling in ants influences metabolic gene expression and locomotor activity

“…These genes account for 26% of all annotated down-regulated transcripts in our differential expression analyses. In Blaberus discoidalis CYP450-4C1 is involved in fatty acid oxidation during starvation to synthesize trehalose, the main circulating carbohydrate of insects, but is not needed for vitellogenin synthesis, which is up-regulated under high-feeding conditions (57–59). In summary, ~100 differentially expressed genes were identified in IP-KD ants, many of which can be linked to various metabolic processes, such as fat, protein, and DNA metabolism.…”

Glial loss of the metallo β-lactamase domain containing protein, SWIP-10, induces age- and glutamate-signaling dependent, dopamine neuron degeneration

“…The gst-4 gene encodes a glutathione-s-transferase, and is a target for the ROS responsive transcriptional regulator SKN-1( C . elegans Nrf2 ortholog) [ 86 , 87 ]. As shown in Fig 7B and 7C , tm5915 animals demonstrate a significant elevation in P gst-4 ::GFP expression.…”

“…To determine levels of stress we used the transcriptional reporter strains, dvIs19 [ p gst-4 :GFP] and zcIs4 [ p hsp-4 :GFP] to measure oxidative stress and ER stress respectively. We adapted previously described methods [ 87 , 88 ]. Briefly, the overall p gst-4 :GFP fluorescence intensity/μm per 15–20 3 day adult swip-10 animals and 15–20 3 day adult N2 animals (with subtracted background fluorescence per animal) was determined, and the fold change GFP intensity compared to N2 signal was calculated for all animals assayed from one population and subsequently averaged over 4 independent days (n = 60–75 animals assayed).…”

Oxidative Stress and Antioxidant Defense Mechanisms in Response to Starvation and Refeeding in the Intestine of Stellate Sturgeon (Acipenser stellatus) Juveniles from Aquaculture

“…GST activity was severely reduced by starvation, while subsequent refeeding induced an even greater decrease in the intestine of Acipenser stellatus juveniles. It was reported that starvation usually enhances the innate enzymatic capacity of detoxification by up-regulating the expression of genes that are related to antioxidant mechanisms, especially GST [ 50 ]. In starved individuals, GPx activity was highly increased compared to constantly fed ones and GSH reserves might have been used with priority as cofactor for GPx than for GST enzyme during starvation.…”