cGMP-inhibited 3',5'-cyclic phosphodiesterase 3B (PDE3B)

cGMP-inhibited 3',5'-cyclic phosphodiesterase 3B (PDE3B) is a key enzyme that regulates intracellular signaling by hydrolyzing the second messengers cAMP and cGMP [1, 3]. It is predominantly expressed in tissues central to energy metabolism, such as adipocytes, hepatocytes, and pancreatic beta cells, where it serves as a crucial mediator of insulin signaling [1, 5, 8]. Insulin-stimulated activation of PDE3B reduces cAMP levels, thereby inhibiting lipolysis in fat cells and glycogenolysis in the liver [6, 17]. Furthermore, PDE3B is involved in non-metabolic processes, including the regulation of cardiac contractility, angiogenesis, and platelet aggregation [1, 10, 15]. PDE3B is a significant therapeutic target for metabolic and cardiovascular conditions. Inhibition of the enzyme leads to elevated cAMP concentrations, which promotes the breakdown of fats and improves insulin sensitivity, making it a focus for obesity and type 2 diabetes research [3, 14]. While established PDE3 inhibitors like cilostazol and milrinone are used for cardiovascular indications, they often lack selectivity between PDE3B and PDE3A, leading to side effects like tachycardia and arrhythmias [5, 14]. Recent human genetic studies have highlighted that loss-of-function variants in PDE3B may be protective against cardiometabolic diseases, encouraging the development of isoform-selective inhibitors [8, 14].

Other names

cGMP-inhibited 3',5'-cyclic phosphodiesterase BPhosphodiesterase 3BCGIPDE1CGIP1Cyclic GMP-inhibited phosphodiesterase BCGI-PDE BHcGIP1

PDE3B inhibitors block the catalytic hydrolysis of cAMP and cGMP, resulting in the accumulation of these second messengers within the cell [3, 9, 12]. Elevated cAMP levels subsequently activate Protein Kinase A (PKA) and Epac signaling pathways [1, 4, 9]. In adipocytes, this leads to increased lipolysis, while in the heart and blood vessels, it enhances myocardial contractility and promotes smooth muscle relaxation [3, 15, 17].