Zheng, Ye

Despite optimal current therapies, cardiovascular disease remains the leading cause for death worldwide. Importantly, advances in peptide engineering have accelerated the development of innovative therapeutics for diverse human disease states. Additionally, the advancement of bispecific therapeutics targeting >1 signaling pathway represents a highly innovative strategy for the treatment of cardiovascular disease. We, therefore, engineered a novel, designer peptide, which simultaneously targets the pGC-A (particulate guanylyl cyclase A) receptor and the MasR (Mas receptor), potentially representing an attractive cardiorenoprotective therapeutic for cardiovascular disease. We engineered a novel, bispecific receptor activator, NPA7, that represents the fusion of a 22-amino acid sequence of BNP (B-type natriuretic peptide; an endogenous ligand of pGC-A) with Ang 1–7 (angiotensin 1–7)—the 7-amino acid endogenous activator of MasR. We assessed NPA7’s dual receptor activating actions in vitro (second messenger production and receptor interaction). Further, we performed an intravenous peptide infusion comparison study in normal canines to study its biological actions in vivo, including in the presence of an MasR antagonist. Our in vivo and in vitro studies demonstrate the successful synthesis of NPA7 as a bispecific receptor activator targeting pGC-A and MasR. In normal canines, NPA7 possesses enhanced natriuretic, diuretic, systemic, and renal vasorelaxing and cardiac unloading properties. Importantly, NPA7’s actions are superior to that of the individual native pGC-A or MasR ligands. These studies advance NPA7 as a novel, bispecific designer peptide with potential cardiorenal therapeutic benefit for the treatment of cardiovascular disease, such as hypertension and heart failure.

AbstractEndocrine regulation of uterine biology is critical for embryo receptivity and human reproduction. Uterine endometrium depends on extrinsic sex steroid input and hence likely has mechanisms that enable adaptation to hormonal variation. Emerging evidence suggests that sex steroid bioavailability in the endometrium is determined by adjusting their metabolic rate and fate via regulation of cytochrome (CYP) p450 enzymes. The CYP enzymes are targeted by ubiquitously expressed Sp/Krüppel-like (Sp/KLF) transcription factors. Specifically, KLF11 is highly expressed in reproductive tissues, regulates an array of endocrine/metabolic pathways via epigenetic histone-based mechanisms and, when aberrantly expressed, is associated with diabetes and reproductive tract diseases, such as leiomyoma and endometriosis. Using KLF11 as a model to investigate epigenetic regulation of endometrial first-pass metabolism, we evaluated the expression of a comprehensive array of metabolic enzymes in Ishikawa cells. KLF11 repressed most endometrial CYP enzymes. To characterize KLF11-recruited epigenetic regulatory mechanisms, we focused on the estrogen-metabolizing enzyme CYP3A4. KLF11 expression declined in secretory phase endometrial epithelium associated with increased CYP3A4 expression. Additionally, KLF11 bound to CYP3A4 promoter GC elements and thereby repressed promoter, message, protein as well as enzymatic function. This repression was epigenetically mediated, because KLF11 colocalized with and recruited the corepressor SIN3A/histone deacetylase resulting in selective deacetylation of the CYP3A4 promoter. Repression was reversed by a mutation in KLF11 that abrogated cofactor recruitment and binding. This repression was also pharmacologically reversible with an histone deacetylase inhibitor. Pharmacological alteration of endometrial metabolism could have long-term translational implications on human reproduction and uterine disease.