Starvation Decreases Immunity and Immune Regulatory Factor NF-κB in the Starlet Sea Anemone Nematostella vectensis

Abstract

Lack of proper nutrition (malnutrition) or the complete absence of all food (starvation) have important consequences on the physiology of all organisms. In many cases, nutritional status affects immunity, but, for the most part, the relationship between nutrition and immunity has been limited to studies in vertebrates and terrestrial invertebrates. Herein, we describe a positive correlation between nutrition and immunity in the sea anemone Nematostella vectensis. Gene expression profiling of adult fed and starved anemones showed downregulation of many genes involved in nutrient metabolism and cellular respiration, as well as immune-related genes, in starved animals. Starved adult anemones also had reduced protein levels and DNA-binding activity of immunity-related transcription factor NF-κB. Starved juvenile anemones had increased sensitivity to bacterial infection and also had lower NF-κB protein levels, as compared to fed controls. Weighted Gene Correlation Network Analysis (WGCNA) revealed significantly correlated gene networks that were inversely associated with starvation. Based on the WGCNA and a reporter gene assay, we identified TRAF3 as a likely NF-κB target gene in N. vectensis. Overall, these experiments demonstrate a correlation between nutrition and immunity in a basal marine metazoan, and the results have implications for the survival of marine organisms as they encounter changing environments.

AutoMorFi: Automated Whole-image Morphometry in Fiji/ImageJ for Diverse Image Analysis Needs

“…They are differentially regulated in many diseases such as cancer, arthritis, chronic inflammation, asthma, neurodegenerative disease, and heart disease. Starvation of sea anemones reduces NF-kB and leaves them vulnerable to infection 28 . By reanalyzing the images used in the study using AutoMorFi and taking intensity measurements of NF-kB, we validated the earlier findings and discovered in addition that starvation does not alter the gross morphology or NF-kB distribution in these animals (Fig.…”