The α1- and β1-Subunits of Nitric Oxide-Sensitive Guanylyl Cyclase in Pericytes of Healthy Human Dental Pulp

Nitric oxide-sensitive guanylyl cyclase (NO-GC) is a heterodimeric enzyme with an α- and a β-subunit. In its active form as an α₁β₁-heterodimer, NO-GC produces cyclic guanosine-3',5'-monophophate (cGMP) to regulate vasodilation and proliferation of vascular smooth muscle cells (VSMCs). In contrast to VSMCs, only a few studies reported on the expression of the NO-GC α₁β₁-heterodimer in human pericytes. Since NO-GC is a marker for platelet-derived growth factor-β (PDGFRβ)-positive pericytes, we investigated whether NO-GC is expressed in its active α₁β₁-heterodimer in pericytes of healthy human dental pulp. In our previous studies, we developed and validated an antibody against the α₁-subunit of human NO-GC. Here, we developed a new antibody against the β₁-subunit of human NO-GC and validated it by immunoblot, mass spectrometry, and immunohistochemistry on tissue samples from humans and NO-GC knockout (GCKO) mice. Using both antibodies, we detected α₁- and β₁-subunits of NO-GC in pericytes of pre-capillary arterioles, capillaries, and post-capillary venules in dental pulp of decalcified and non-decalcified human molars. We concluded that NO-GC as an active α₁β₁-heterodimer may be involved in the regulation of vascular permeability, vascular stability, organ homeostasis, and organ regeneration in healthy human dental pulp.