Inter-Kingdom Signaling of Stress Hormones: Sensing, Transport and Modulation of Bacterial Physiology

Abstract

Prokaryotes and eukaryotes have coexisted for millions of years. The hormonal communication between microorganisms and their hosts, dubbed inter-kingdom signaling, is a recent field of research. Eukaryotic signals such as hormones, neurotransmitters or immune system molecules have been shown to modulate bacterial physiology. Among them, catecholamines hormones epinephrine/norepinephrine, released during stress and physical effort, or used therapeutically as inotropes have been described to affect bacterial behaviors (i.e., motility, biofilm formation, virulence) of various Gram-negative bacteria (e.g., Escherichia coli, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Vibrio sp.). More recently, these molecules were also shown to influence the physiology of some Gram-positive bacteria like Enterococcus faecalis. In E. coli and S. enterica, the stress-associated mammalian hormones epinephrine and norepinephrine trigger a signaling cascade by interacting with the QseC histidine sensor kinase protein. No catecholamine sensors have been well described yet in other bacteria. This review aims to provide an up to date report on catecholamine sensors in eukaryotes and prokaryotes, their transport, and known effects on bacteria.

Microbe–Immune–Stress Interactions Impact Behaviour during Postnatal Development

“…In this regard, stress is well known to impact the microbiome and vice versa. For one, environmental stress has been shown to reduce richness and functional diversity of the microbiota [ 52 ], while stress-related catecholamines and other neuroendocrine hormones secreted by cells in the gastrointestinal (GI) tract can directly modulate microbial growth [ 53 ]. Further, signalling via the vagus nerve and enteric nervous system alter GI motility and reduce digestive activity, impacting the gut microbiota through changes in their physical environment and biochemical milieu [ 54 ].…”

Effect of cycle ergometer training using different intensities in increasing catecholamine hormone of overweight females

“…Furthermore, the increase in the rate of lipolysis is also one of the causes of catecholamine hormones, especially epinephrine, which has a higher binding to adrenoreceptors which results in increased fat breakdown. Increased levels of catecholamines stimulated by exercise and decreased insulin concentrations result in increased lipolysis and FFA release (Boukerb et al 2021).…”

Neuromodulators as Interdomain Signaling Molecules Capable of Occupying Effector Binding Sites in Bacterial Transcription Factors

“…Microbial endocrinology, which comprehensively studies such inter-kingdom signaling systems, is based on the idea that symbiont interactions can be mediated by hormones and neurotransmitters, natural components of the humoral and neural regulatory systems of eukaryotes [1][2][3][4]. By recognizing signaling molecules in their environment, microbes can adapt their gene expression profile for successful colonization [5,6]. Both neurotransmitters [2,[6][7][8] and hormones [9,10] were found in varying amounts in the intestinal lumen of vertebrates, the hormonal background of which is collectively created by the cells of the intestinal mucosa [11] and a microbial consortium that synthesizes and secretes a variety of bioactive molecules [12][13][14].…”