Pharmacological Characterization of SAR407899, a Novel Rho-Kinase Inhibitor

Abstract

Abstract-Recent advances in basic and clinical research have identified Rho kinase as an important target potentially implicated in a variety of cardiovascular diseases. Rho kinase is a downstream mediator of RhoA that leads to stress fiber formation, membrane ruffling, smooth muscle contraction, and cell motility. Increased Rho-kinase activity is associated with vasoconstriction and elevated blood pressure. We identified a novel inhibitor of Rho kinase (SAR407899) and characterized its effects in biochemical, cellular, tissue-based, and in vivo assays. SAR407899 is an ATP-competitive Rho-kinase inhibitor, equipotent against human and rat-derived Rho-kinase 2 with inhibition constant values of 36 nM and 41 nM, respectively. It is highly selective in panel of 117 receptor and enzyme targets. SAR407899 is Ϸ8-fold more active than fasudil. In vitro, SAR407899 demonstrated concentration-dependent inhibition of Rho-kinase-mediated phosphorylation of myosin phosphatase, thrombin-induced stress fiber formation, platelet-derived growth factor-induced proliferation, and monocyte chemotactic protein-1-stimulated chemotaxis. SAR407899 potently (mean IC 50 values: 122 to 280 nM) and species-independently relaxed precontracted isolated arteries of different species and different vascular beds. In vivo, over the dose range 3 to 30 mg/kg PO, SAR407899 lowered blood pressure in a variety of rodent models of arterial hypertension. The antihypertensive effect of SAR407899 was superior to that of fasudil and Y-27632. In conclusion, SAR407899 is a novel and potent selective Rho-kinase inhibitor with promising antihypertensive activity. Key Words: arterial hypertension Ⅲ Rho kinase Ⅲ vascular smooth muscle Ⅲ antihypertensive therapy Ⅲ blood pressure Ⅲ cardiovascular diseases R ho kinase (ROCK) has been identified as an important target for several cardiovascular diseases. [1][2][3][4][5] This serine/ threonine kinase is the effector of the small G protein, RhoA, and is activated by a broad variety of vasoactive molecules through their specific receptors. RhoA-ROCK activation regulates many critical cellular functions like stress fiber formation in different cell types, 6 smooth muscle contraction, 7 cell adhesion, membrane ruffling, cell motility, and apoptosis. 8,9 In vascular smooth muscle cells (SMC) and endothelial cells, both ROCK1 and ROCK2 are very abundant although the precise role of each is still not entirely clear. 6,10 In SMC, ROCK regulates contractility and expression of cytoskeletal genes, eg, SMC actin and SM22␣, through serum response factor and myocardin-related transcription factors. 11,12 Proliferation of SMCs induced either by growth factors, eg, platelet-derived growth factor, or vasoactive mediators, eg, thrombin or urotensin II, can be blocked by the inhibition of ROCK. Although the molecular mechanism is not clear, it may also depend on ROCK-mediated gene expression regulation. 8,13 Involvement of ROCK in thrombin-induced stress fiber formation and contraction of vascular endothelial cells has been described...

Involvement of Rho GTPases and their regulators in the pathogenesis of hypertension

“…In vivo inhibition of Rock by treatment with Y27632 decreases blood pressure in the DOCA-salt rat model of hypertension. 2 This finding has then been confirmed by the use of other Rock inhibitors such as fasudil and SAR407899 in other animal models including spontaneously hypertensive rats (SHR), 23,24 Ang II-induced hypertension, 25 and L-NAME-induced hypertension (Fig. 3).…”

Rho Kinases in Health and Disease: From Basic Science to Translational Research

“…They both relax arterial contraction in vitro and decrease blood pressure in rats in vivo (Doe et al, 2007). The Sanofi compound SAR407899 [6-(piperidin-4-yloxy)isoquinolin-1(2H)-one], with IC 50 values of 276 nM and 102 nM for ROCK1 and ROCK-2, respectively, was 4-fold more active than Y-27632 and 8-fold more active than fasudil (Löhn et al, 2009). Despite its ability to potently relax precontracted arteries, its efficient antihypertensive properties after oral administration in rodents, and testing in clinical trials, the development of this compound has been discontinued.…”

Discovery and pharmacological characterization of a novel potent inhibitor of diacylglycerol‐sensitive TRPC cation channels

“…After 24 h, rats received either vehicle alone or were treated with 10 mg·kg -1 SAR7334. Telemetric measurement of BP was performed as described (Lohn et al, 2009). In brief, a telemetric device (TL11M2-C50-PXT PMP, Data Sciences International, St. Paul, MN, USA) was placed between the aorta and the vena cava and the catheter tip of the transmitter was inserted into the aorta.…”