A signalling molecule that regulates red blood cell production also has an important role in maintaining normal fat mass and energy expenditure. This finding is reported in a mouse study in Nature Communications this week. Identification of factors that regulate energy homeostasis and the generation of fat cells could assist the development of effective approaches for the treatment or prevention of human obesity.
Erythropoietin is essential for erythropoiesis — the formation of red blood cells (erythrocytes) — but its role in metabolic homeostasis is uncertain. Receptors for this signalling molecule are not constrained to blood-forming tissues; they are also highly expressed in white fat tissue and in the hypothalamus, Constance Noguchi and colleagues find. They demonstrate that disruption of erythropoietin signalling in the hypothalamus decreases energy expenditure in mice, leading to the development of obesity and insulin resistance. An absence of erythropoietin signalling in the white fat tissue results in an increase in fat cell numbers, which may also contribute to obesity.
Together, these findings provide evidence for a role of erythropoietin in maintaining normal fat mass in mice. The authors suggest than further investigations are needed to fully understand the importance of erythropoietin in energy homeostasis.