Aging does not affect calcium response to CCL2 and LPS in human monocytes

Monocytes play important roles in anti-microbial and anti-viral responses and chronic inflammatory diseases. Monocytes' functions are altered by aging. We investigated age-changes in calcium (Ca²⁺) response to CCL2 and LPS in human monocytes. CCL2 and LPS induced a slow increase of the cytosolic Ca²⁺ level, with a maximum response at ∼360 s and ∼300 s, respectively, in monocytes of young and older adults. No difference was observed in the magnitude and in the Ca²⁺ kinetic with both stimuli. Furthermore, store-operated Ca²⁺ entry and plasma membrane expression of ORAI1 showed no difference between both groups. In summary, monocytes from older adults maintained the capacity to mobilize calcium as their counterparts in young adults suggesting that the mechanisms underlying the dysfunctions in monocytes in aging might not involve alterations in Ca²⁺ flow through the plasma membrane.