Figure 2.

Potential mechanisms of altered hematopoiesis and immunity for life following nicotine exposure: (a) Nicotine directly influences the hematopoietic compartment. Nicotine binds to nicotinic-acetyl choline receptors (nAChRs) expressed by hematopoietic stem cells or other mature hematopoietic cell types. These cells then undergo molecular changes which lead to proliferation, apoptosis, differentiation, and/or activation; (b) Nicotine indirectly influences the hematopoietic compartment. Nicotine binds to nicotinic-acetyl choline receptors (nAChRs) expressed by non-hematopoietic cells. These cells undergo molecular changes that then lead to release of inflammatory-mediating cytokines. Cytokines released by the non-hematopoietic cells bind to receptors on hematopoietic cell types. Hematopoietic cells then undergo molecular changes in response to the cytokines (directly) and nicotine (indirectly) which leads to proliferation, apoptosis, differentiation, and/or activation.