Figure 2.

Mechanosensory cilia and nitric oxide production. The presence of cilia in vasculature plays an important role in the biochemical production of a potent vasodilator, nitric oxide (NO). The figure depicts the production of NO in an artery. Increases in blood pressure, which are translated to higher vascular shear stress, will be sensed by mechanosensory cilia. Bending or activation of the cilia involves mechanosensory polycystin-1 and polycystin-2 complex and a cascade of biochemical synthesis of NO. The cascade will further involve extracellular calcium influx (Ca²⁺), followed by activation of various calcium-dependent proteins, including calmodulin (CaM) and protein kinase C (PKC). Akt/PKB, CaM, and PKC are important downstream molecular components to activate endothelial nitric oxide synthase (eNOS). This figure is reproduced with permission [23].