bay-58-2667 and 3-(5--hydroxymethyl-2--furyl)-1-benzylindazole

Lower urinary tract symptoms (LUTS), comprising storage (such as urinary incontinence and urinary frequency), voiding, and postmicturition symptoms, are highly prevalent conditions that affect millions of people worldwide. LUTS have a profound effect on quality of life and are a considerable cost to health care systems. In men specifically, BPH commonly leads to LUTS. Clinical studies also show an association of LUTS with erectile dysfunction (ED). Nitric oxide (NO) has long been recognized as an important nonadrenergic, noncholinergic (NANC) transmitter in bladder, urethra, prostate, and corpus cavernosum smooth muscle. Data from clinical and basic research show that oxidation and degradation of soluble guanylate cyclase (sGC; also known as GCS) and reduced cyclic GMP (cGMP) levels are involved in the physiopathology of genitourinary diseases. The NO-sGC-cGMP signalling pathway has a role in disease pathophysiology of the bladder, urethra, prostate, and corpus cavernosum in animal models and humans. Advances in targeting sGC directly to enhance cGMP production independently of endogenous NO have been made using NO-independent stimulators and activators of sGC. These molecules are potential therapeutics in the treatment of LUTS and ED.

Topics: Aging; Animals; Benzoates; Diabetes Complications; Enzyme Activators; Humans; Hypertension; Indazoles; Lower Urinary Tract Symptoms; Nitric Oxide; Obesity; Phosphodiesterase 5 Inhibitors; Pyrazoles; Pyridines; Reactive Oxygen Species; Risk Factors; Soluble Guanylyl Cyclase; Urinary Tract

Soluble guanylate cyclase (sGC) is the receptor for nitric oxide (NO) in human. It is an important validated drug target for cardiovascular diseases. sGC can be pharmacologically activated by stimulators and activators. However, the detailed structural mechanisms, through which sGC is recognized and positively modulated by these drugs at high spacial resolution, are poorly understood. Here, we present cryo-electron microscopy structures of human sGC in complex with NO and sGC stimulators, YC-1 and riociguat, and also in complex with the activator cinaciguat. These structures uncover the molecular details of how stimulators interact with residues from both β H-NOX and CC domains, to stabilize sGC in the extended active conformation. In contrast, cinaciguat occupies the haem pocket in the β H-NOX domain and sGC shows both inactive and active conformations. These structures suggest a converged mechanism of sGC activation by pharmacological compounds.

Topics: Animals; Benzoates; Binding Sites; Cell Line; Cryoelectron Microscopy; Enzyme Activation; Enzyme Activators; Humans; Indazoles; Models, Molecular; Nitric Oxide; Protein Multimerization; Pyrazoles; Pyrimidines; Soluble Guanylyl Cyclase

There is a correlation between cell volume changes and changes in the rate of aqueous humor outflow; agents that decrease trabecular meshwork (TM) cell volume increase the rate of aqueous humor outflow. This study investigated the effects of the nitric oxide (NO)-independent activators of soluble guanylate cyclase (sGC), YC-1, and BAY-58-2667 on TM cell volume and the signal transduction pathways and ion channel involved.. Cell volume was measured with the use of calcein AM fluorescent dye, detected by confocal microscopy. Inhibitors and activators of sGC, 3',5'-cyclic guanosine monophosphate (cGMP), protein kinase G (PKG), and the BK(Ca) channel were used to characterize their involvement in the YC-1- and BAY-58-2667-induced regulation of TM cell volume. cGMP was assayed by an enzyme immunoassay.. YC-1 (10 nM-200 microM) and BAY-58-2667 (10 nM-100 microM) each elicited a biphasic effect on TM cell volume. YC-1 (1 microM) increased TM cell volume, but higher concentrations decreased TM cell volume. Similarly, BAY-58-2667 (100 nM) increased TM cell volume, but higher concentrations decreased cell volume. The YC-1-induced cell volume decrease was mimicked by 8-Br-cGMP and abolished by the sGC inhibitor ODQ, the PKG inhibitor (RP)-8-Br-PET-cGMP-S, and the BK(Ca) channel inhibitor IBTX. The BAY-58-2667-induced cell volume decrease was mimicked by 8-Br-cGMP and was abolished by the PKG inhibitor and the BK(Ca) channel inhibitor. Unlike the YC-1 response, ODQ potentiated the BAY-58-2667-induced decreases in cell volume.. These data suggest that the NO-independent decrease in TM cell volume is mediated by the sGC/cGMP/PKG pathway and involves K(+) efflux.

Topics: Adult; Aged; Aged, 80 and over; Benzoates; Cell Size; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Enzyme Activators; Enzyme Inhibitors; Fluoresceins; Fluorescent Dyes; Guanylate Cyclase; Humans; Indazoles; Large-Conductance Calcium-Activated Potassium Channels; Microscopy, Confocal; Nitric Oxide; Oxadiazoles; Quinoxalines; Trabecular Meshwork

Soluble guanylate cyclase (sGC), a heterodimer consisting of alpha- and beta-subunit, is the key enzyme of the NO/cGMP signaling pathway. The heme moiety ligated to the beta-subunit via His(105) is crucial for the activation of the enzyme by NO. In addition to this NO binding capability, the heme status of the enzyme influences the activity of non-NO sGC activators and sGC inhibitors. Different sGC activity profiles were observed in the presence, absence, or the oxidized form of heme. Modulating the heme status is therefore crucial for the investigation of the mechanism of sGC activation. Here, we present a simple and reliable procedure for the removal of the heme moiety of sGC that is capable of eliminating any traces of unbound heme and detergent from the sample mixture in one single step. Samples containing 15 microg sGC and the non-ionic detergent Tween 20 (2%) were incubated at 37 degrees C for 10 min and loaded onto centrifugal ion exchange columns. After centrifugation, heme was bound entirely to the ion exchanger and could not be eluted, even after incubation with 1M NaCl. Tween 20 was found completely within the flowthrough. Heme-free sGC was eluted from the ion exchanger after application of 300 mM NaCl. The absence of the heme moiety was confirmed by UV/Vis spectra and determination of the enzymatic activity. In summary, the described procedure is suitable for the preparation of very small amounts of highly purified heme-free sGC for the investigation of the mechanism of action of different types of sGC activators.

Topics: Benzoates; Chromatography, Ion Exchange; Cyclic GMP; Enzyme Activation; Enzyme Activators; Guanosine Triphosphate; Guanylate Cyclase; Heme; Hemeproteins; Histidine; Indazoles; Nitroprusside; Polysorbates; Proteins; Protoporphyrins; Spectrophotometry; Zinc