Metal transporter Slc39a10 regulates susceptibility to inflammatory stimuli by controlling macrophage survival.

Abstract

Zn plays a key role in controlling macrophage function during an inflammatory event. Cellular Zn homeostasis is regulated by two families of metal transporters, the SLC39A family of importers and the SLC30A family of exporters; however, the precise role of these transporters in maintaining macrophage function is poorly understood. Using macrophage-specific <i>Slc39a10</i>-knockout (<i>Slc39a10</i>^<i>fl/fl</i><i>;LysM-Cre</i>^<i>+</i> ) mice, we found that Slc39a10 plays an essential role in macrophage survival by mediating Zn homeostasis in response to LPS stimulation. Compared with <i>Slc39a10</i>^<i>fl/fl</i> mice, <i>Slc39a10</i>^<i>fl/fl</i><i>;LysM-Cre</i>^<i>+</i> mice had significantly lower mortality following LPS stimulation as well as reduced liver damage and lower levels of circulating inflammatory cytokines. Moreover, reduced intracellular Zn concentration in <i>Slc39a10</i>^<i>fl/fl</i><i>;LysM-Cre</i>^<i>+</i> macrophages led to the stabilization of p53, which increased apoptosis upon LPS stimulation. Concomitant knockout of <i>p53</i> largely rescued the phenotype of <i>Slc39a10</i>^<i>fl/fl</i><i>;LysM-Cre</i>^<i>+</i> mice. Finally, the phenotype in <i>Slc39a10</i>^<i>fl/fl</i><i>;LysM-Cre</i>^<i>+</i> mice was mimicked in wild-type mice using the Zn chelator TPEN and was reversed with Zn supplementation. Taken together, these results suggest that Slc39a10 plays a role in promoting the survival of macrophages through a Zn/p53-dependent axis in response to inflammatory stimuli.