A series of cardiac troponin I-interacting kinase (TNNI3K) inhibitors arising from 3-((9H-purin-6-yl)amino)-N-methyl-benzenesulfonamide (1) is disclosed along with fundamental structure-function relationships that delineate the role of each element of 1 for TNNI3K recognition. An X-ray structure of 1 bound to TNNI3K confirmed its Type I binding mode and is used to rationalize the structure-activity relationship and employed to design potent, selective, and orally bioavailable TNNI3K inhibitors. Identification of the 7-deazapurine heterocycle as a superior template (vs purine) and its elaboration by introduction of C4-benzenesulfonamide and C7- and C8-7-deazapurine substituents produced compounds with substantial improvements in potency (>1000-fold), general kinase selectivity (10-fold improvement), and pharmacokinetic properties (>10-fold increase in poDNAUC). Optimal members of the series have properties suitable for use in in vitro and in vivo experiments aimed at elucidating the role of TNNI3K in cardiac biology and serve as leads for developing novel heart failure medicines.
Rho kinase (ROCK1) mediates vascular smooth muscle contraction and is a potential target for the treatment of hypertension and related disorders. Indazole amide 3 was identified as a potent and selective ROCK1 inhibitor but possessed poor oral bioavailability. Optimization of this lead resulted in the discovery of a series of dihydropyridones, exemplified by 13, with improved pharmacokinetic parameters relative to the initial lead. Indazole substitution played a critical role in decreasing clearance and improving oral bioavailability.
Background and purpose: The recent development of the UT ligand palosuran (1-[2-(4-benzyl-4-hydroxy-piperidin-1-yl)-ethyl]-3-(2-methyl-quinolin-4-yl)-urea sulphate salt) has led to the proposition that urotensin-II (U-II) plays a significant pathological role in acute and chronic renal injury in the rat. Experimental approach: In the present study, the pharmacological properties of palosuran were investigated further using a series of radioligand binding and functional bioassays. Key results: Palosuran functioned as a 'primate-selective' UT ligand in recombinant cell membranes (monkey and human UT K i values of 4±1 and 5±1 nM), lacking appreciable affinity at other mammalian UT isoforms (rodent and feline K i values 41 mM). Paradoxically, however, palosuran lost significant (10-to 54-fold) affinity for native and recombinant human UT when radioligand binding was performed in intact cells (K i values of 50±3 and 276±67 nM). In accordance, palosuran also exhibited diminished activity in hUT (human urotensin-II receptor)-CHO (Chinese hamster ovary) cells (IC 50 323 ± 67 nM) and isolated arteries (K b 410 mM in rat aorta; K b 48.5 mM in cat arteries; K b 41.6 mM in monkey arteries; K b 2.2±0.6 mM in hUT transgenic mouse aorta). Relative to recombinant binding K i values, palosuran was subjected to a 392-to 690-fold reduction in functional activity in monkey isolated arteries. Such phenomena were peculiar to palosuran and were not apparent with an alternative chemotype, SB-657510 (2-bromo-N-[4-chloro-3-((R)-1-methyl-pyrrolidin-3-yloxy)-phenyl]-4,5-dimethoxybenzenesulphonamide HCl). Conclusions and implications: Collectively, such findings suggest that caution should be taken when interpreting data generated using palosuran. The loss of UT affinity/activity observed in intact cells and tissues cf. membranes offers a potential explanation for the disappointing clinical efficacy reported with palosuran in diabetic nephropathy patients. As such, the (patho)physiological significance of U-II in diabetic renal dysfunction remains uncertain.
The excitatory roles of EP3 receptors at the peripheral afferent nerve innervating the rat urinary bladder have been evaluated by using the selective EP3 antagonist (2E)-3-{1-[(2,4-dichlorophenyl)methyl]-5-fluoro-3-methyl-1H-indol-7-yl}-N-[(4,5-dichloro-2-thienyl)sulfonyl]-2-propenamide (DG-041). The bladder rhythmic contraction model and a bladder pain model measuring the visceromotor reflex (VMR) to urinary bladder distension (UBD) have been used to evaluate DG-041 in female rats. In addition, male rats [spontaneously hypertensive rat (SHR), WistarKyoto (WKY), and Sprague-Dawley (SD)] were anesthetized with pentobarbital sodium, and primary afferent fibers in the L 6 dorsal root were isolated for recording the inhibitory response to UBD following intravenous injection of DG-041. Intravenous injection of DG-041 (10 mg/kg), a peripherally restricted EP 3 receptor antagonist, significantly reduced the frequency of bladder rhythmic contraction and inhibited the VMR response to bladder distension. The magnitude of reduction of the VMR response was not different in the different strains of rats (SD, SHR, and WKY). Furthermore, quantitative characterization of the mechanosensitive properties of bladder afferent nerves in SHR, WKY, and SD rats did not show the SHR to be supersensitive to bladder distension. DG-041 selectively attenuated responses of mechanosensitive afferent nerves to UBD, with strong suppression on the slow-conducting, high-threshold afferent fibers, with equivalent activity in the three strains. We conclude that sensitization of afferent nerve activity was not one of the mechanisms of bladder hypersensitivity in SHR. EP 3 receptors are involved in the regulation of bladder micturition and bladder nociception at the peripheral level.EP3; viscermotor reflex; bladder rhythmic contraction; bladder distension; afferent nerve SENSATION ASSOCIATED WITH the urinary bladder is conveyed primarily by pelvic and hypogastric nerves, by which the signal is relayed to the central nervous system (CNS). Most afferent fibers innervating the musculature of the bladder body pass through the pelvic nerve, whereas the majority of afferent endings in the bladder submucosa are derived from the hypogastric nerve (41), suggesting that the afferent fibers in the pelvic and hypogastric nerves have different roles, signaling mechanical stimulation (e.g., bladder distension) and chemical stimulation (e.g., inflammation), respectively (20,22,30,34). Bladder distension is a natural mechanical stimulus to evoke sensations such as fullness, urgency, and pain while the literature suggests a complex regulatory role of prostaglandins (PGs) in multiple aspects of urinary bladder physiology/pathophysiology. PGE 2 , one of the principal PGs, is synthesized in urothelium and detrusor smooth muscle (19,24,25,27) as well as in neurons and glial cells (18,23) and is released in response to various physiological (e.g., bladder distension) and pathological (e.g., mediators of inflammation) stimulation. PGE 2 interacts with four EP receptor subt...
Sirtuin 1 is a nicotinamide adenine dinucleotide-dependent protein deacetylase which regulates longevity and improves metabolism. Activation of Sirtuin 1 confers beneficial effects in models of neurodegenerative diseases. We and others have provided convincing evidence that overexpression of Sirtuin 1 plays a neuroprotective role in mouse models of Huntington's disease. In this study, we report that SRT2104, a small molecule Sirtuin 1 activator, penetrated the blood–brain barrier, attenuated brain atrophy, improved motor function, and extended survival in a mouse model of Huntington's disease. These findings imply a novel therapeutic strategy for Huntington's disease by targeting Sirtuin 1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.