IL-10-induced STAT3/NF-κB crosstalk modulates pineal and extra-pineal melatonin synthesis.

Immune-pineal axis activation is part of the assembly of immune responses. Proinflammatory cytokines inhibit the pineal synthesis of melatonin while inducing it in macrophages by mechanisms dependent on nuclear factor-κB (NF-κB) activation. Cytokines activating the Janus kinase/signal transducer and activator of transcription (STAT) pathways, such as interferon-gamma (IFN-γ) and interleukin-10 (IL-10), modulate melatonin synthesis in the pineal, bone marrow (BM), and spleen.

MEL-Index: Estimation of Tissue Melatonin Levels Using Gene Expression Data.

Melatonin synthesis by extrapineal sources adjusts physiological and pathophysiological processes in several types of cells and tissues. As measuring locally produced melatonin in fresh tissues might be a challenge due to limited material availability, we created a simple predictive model, the MEL-Index, which infers the content of tissue melatonin using gene expression data. The MEL-Index can be a powerful tool to study the role of melatonin in different contexts.

Behavioral fever decreases metabolic response to lipopolysaccharide in yellow Cururu toads (Rhinella icterica).

Ectothermic vertebrates develop behavioral fever in response to bacterial products, with potential corresponding metabolic costs associated with immune stimulation. Although behavioral fever has been described in several taxa under laboratory conditions, some important questions regarding metabolic response to bacterial products at different temperatures and effectiveness of behavioral fever remain open. Many ectotherms, such as nocturnal anurans, may be active in the field at environmental conditions that restrict thermoregulation during the immune response.