Title : First data on putative baroreceptors in human aorta and aortic arch
Abstract:
The baroreflex is a key mechanism for regulating blood pressure and heartbeat, mediated by mechanosensitive baroreceptors. The entire knowledge on baroreceptors, however, has been derived predominantly from animal studies. No data focusing on the molecular nature of the human aortic baroreceptors has been reported thus far. Therefore, we conducted extensive histological, proteomic, and transcriptomic analyses of human aortic arch and aorta to identify putative baroreceptors in humans.
For analysis, three healthy human aortic arches, six abdominal aortic aneurysms, and four control abdominal aortic tissue samples from our vascular biobank were selected. For immunohistochemistry, antibodies targeting various neuronal markers were used. Proteomics and transcriptomics were performed with the macrodissected adventitial layer containing the nerves in collaboration with the Functional Genomics Center Zurich.
Histological analyses showed a heterogeneous distribution of nerves in the adventitia throughout the aortic arch, with the highest density in the ascending aorta up to the left subclavian artery. Proteomic analysis identified three putative baroreceptor candidates (PIEZO1, TRPV2, TRPM4) in human aortic arches, abdominal aortic aneurysms, and control abdominal aortas. None of the three baroreceptor candidates were found using transcriptomics analysis.
For the first time, our study identified possible baroreceptors in the human aortic arch and aorta without significant differences in their expression. No baroreceptor candidate RNA was present in the adventitia, probably because these genes get translated into proteins in the neuronal cell bodies in the brain stem. Further research is required to confirm these findings and explore the functional role of these potential baroreceptors in regulating blood pressure and heartbeat in the human aortic arch.
