Overview

According to the data from WHO, cardiovascular diseases are the main leading cause of death globally. Cyclic guanosine monophosphate (cGMP) is a critical second messenger molecule.It can transduce nitric-oxide (NO) and natriuretic-peptide-coupled signaling and remit the myocardial hypertrophy by relaxing the blood vessels. This summer, we tried to use synthetic biology to modify the cGMP metabolic pathway in a human cell line.We hope that our work would provide the proof of principle for future gene therapy.

Soluble guanylate cyclase (sGC) is an enzyme that synthesize cGMP from GTP. We up-regulate sGC by overexpressing its α and β subunits in a mammalian cell line. However, elevated levels of cGMP leads to the feed-back expression of PDE5a, a cGMP-specific phosphodiesteras that degrades cGMP. Thus, we further modified the pathway by silencing the PDE5a. To achieve controllable up-regulation of cGMP level in the cell, we designed a hypoxia-inducible operon, HRE, as a switch to up regulate cGMP only in hypoxia situation.