Design, Synthesis, and Structure–Activity Relationships of Pyridine-Based Rho Kinase (ROCK) Inhibitors

The novel ROCK2 selective inhibitor NRL-1049 preserves the blood-brain barrier after acute injury

Endothelial blood-brain barrier (BBB) dysfunction is critical in the pathophysiology of brain injury. Rho-associated protein kinase (ROCK) activation disrupts BBB integrity in the injured brain. We aimed to test the efficacy of a novel ROCK2 inhibitor in preserving the BBB after acute brain injury. We characterized the molecular structure and pharmacodynamic and pharmacokinetic properties of a novel selective ROCK2 inhibitor, NRL-1049, and its first metabolite, 1-hydroxy-NRL-1049 (referred to as NRL-2017 hereon) and tested the efficacy of NRL-1049 on the BBB integrity in rodent models of acute brain injury. Our data show that NRL-1049 and NRL-2017 both inhibit ROCK activity and are 44-fold and 17-fold more selective towards ROCK2 than ROCK1, respectively. When tested in a mouse model of cortical cryoinjury, NRL-1049 significantly attenuated the increase in water content. Interestingly, 60% of the mice in the vehicle arm developed seizures within 2 hours after cryoinjury versus none in the NRL-1049 arm. In spontaneously hypertensive rats, NRL-1049 attenuated the dramatic surge in Evans Blue extravasation compared with the vehicle arm after transient middle cerebral artery occlusion. Hemorrhagic transformation was also reduced. We show that NRL-1049, a selective ROCK2 inhibitor, is a promising drug candidate to preserve the BBB after brain injury.

Discovery of dual rho-associated protein kinase 1 (ROCK1)/apoptosis signal-regulating kinase 1 (ASK1) inhibitors as a novel approach for non-alcoholic steatohepatitis (NASH) treatment

In the current study we suggest a novel approach to curb non-alcoholic steatohepatitis (NASH) progression, and we suggest privileged scaffolds for the design of novel compounds for this aim. NASH is an advanced form of non-alcoholic fatty liver disease that can further progress into fibrosis, cirrhosis, and hepatocellular carcinoma. It is a widely emerging disease affecting 25% of the global population and has no current approved treatments. Protein kinases are key regulators of cellular pathways, of which, Rho-associated protein kinase 1 (ROCK1) and apoptosis signal-regulating kinase 1 (ASK1) play an important role in the progression of NASH and they stand out as promising targets for NASH therapy. Interestingly, their kinase domains are found to be similar in sequence and topology; therefore, dual inhibition of ROCK1 and ASK1 is expected to be amenable and could achieve a more favourable outcome. To reach this goal, a training set of ROCK1 and ASK1 protein structures co-crystalized with type 1 (ATP-competitive) inhibitors was constructed to manually generate receptor-based pharmacophore models representing ROCK1 and ASK1 inhibitors' common pharmacophoric features. The models produced were assessed using a test set of both ROCK1 and ASK1 actives and decoys, and their performance was evaluated using different assessment metrics. The best pharmacophore model obtained, showing a Mathew's correlation coefficient (MCC) of 0.71, was then used to screen the ZINC purchasable database retrieving 6178 hits that were filtered accordingly using several medicinal chemistry and pharmacokinetics filters returning 407 promising compounds. To confirm that these compounds are capable of binding to the target kinases, they were subjected to molecular docking simulations at both protein structures. The results were then assessed individually and filtered, setting the spotlight on various privileged scaffolds that could be exploited as the nucleus for designing novel ROCK1/ASK1 dual inhibitors.

Recent advances in the development of Rho kinase inhibitors (2015-2021)

Rho-associated coiled-coil kinases (ROCKs) are key downstream effectors of small GTPases. ROCK plays a central role in diverse cellular events with accumulating evidence supporting the concept that ROCK is important in tumor development and progression. Numerous ROCK inhibitors have been investigated for their therapeutic potential in the treatment of cancers. In this article, we review recent research progress on ROCK inhibitors, especially those with potential for the treatment of cancers, reported in the literature from 2015 to 2021. Most ROCK inhibitors show potent in vitro and in vivo antitumor activities and have potential in the treatment of cancers.

Metal- and Solvent-Free Synthesis of Substituted Pyrimidines via an NH4I-Promoted Three-Component Tandem Reaction

A facile and practical approach for the preparation of substituted pyrimidines from ketones, NH4OAc, and N,N-dimethylformamide dimethyl acetal has been described. This NH4I-promoted three-component tandem reaction affords a broad range of substituted pyrimidines in acceptable yields under metal- and solvent-free conditions. The present methodology features the advantages of simple and easily available starting materials, metal- and solvent-free conditions, a broad substrate scope with good functional group tolerance, and gram-scale synthesis.

Discovery of indoline-based derivatives as effective ROCK2 inhibitors for the potential new treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and devastating lung disease with a median survival of only 3-5 years. Due to the lack of effective therapy, IPF threatens human health. Recently, increasing reports have indicated that Rho-associated coiled-coil protein kinases (ROCKs) play important roles in the development of IPF and might represent a novel target for the treatment of IPF. Herein, a new series of selective ROCK2 inhibitors based on indoline were designed and synthesized. Structural modification resulted in optimized compound 9b with an IC₅₀ value of 6 nM against ROCK2 and the inhibition of collagen gel contraction. Cellular assays demonstrated that 9b could significantly suppress the expression of collagen I and α-SMA, and inhibited ROCK signaling pathway. Oral administration of compound 9b (10 mg/kg) exerted more significant anti-pulmonary fibrosis effects than nintedanib (100 mg/kg) and KD025 (100 mg/kg) in a bleomycin-induced IPF rat model, suggesting that 9b could serve as a potential lead compound for the treatment of IPF.

Application and Study of ROCK Inhibitors in Pulmonary Fibrosis: Recent Developments and Future Perspectives

Rho-associated coiled-coil-containing kinases (ROCKs), serine/threonine protein kinases, were initially identified as downstream targets of the small GTP-binding protein Rho. Pulmonary fibrosis (PF) is a lethal disease with limited therapeutic options and a particularly poor prognosis. Interestingly, ROCK activation has been demonstrated in PF patients and in animal PF models, making it a promising target for PF treatment. Many ROCK inhibitors have been discovered, and four of these have been approved for clinical use; however, no ROCK inhibitors are approved for the treatment of PF patients. In this article, we describe ROCK signaling pathways and the structure-activity relationship, potency, selectivity, binding modes, pharmacokinetics (PKs), biological functions, and recently reported inhibitors of ROCKs in the context of PF. We will also focus our attention on the challenges to be addressed when targeting ROCKs and discuss the strategy of ROCK inhibitor use in the treatment of PF.

Discovery of Quaternized Pyridine-Thiazole-Pleuromutilin Derivatives with Broad-Spectrum Antibacterial and Potent Anti-MRSA Activity

The quaternization of compounds has emerged as a promising molecular design strategy for the development of antibiotics. Herein, we report the design, synthesis, antibacterial activities, and structure-activity relationships of a series of novel pleuromutilin derivatives containing a quaternary amine C-14 side chain. Most of these derivatives exhibited broad-spectrum antibacterial activity against the tested bacteria. 10b was the most effective antibacterial agent that displayed excellent antibacterial activity against five clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates, remarkable antimycoplasma activity, rapid bactericidal effects, and a strong ability to damage bacterial biofilms. Further mechanistic studies indicated that 10b destroyed bacterial cell membranes to exert its antibacterial effects. Moreover, 10b exhibited high survival protection and potent in vivo antibacterial efficacy (ED₅₀ = 4.94 mg/kg) in a mouse model of systemic MRSA infection. These findings suggest that 10b is a promising candidate for the treatment of multi-drug-resistant infectious diseases, especially MRSA infections.

Identification of a Potent, Selective, and Brain-Penetrant Rho Kinase Inhibitor and its Activity in a Mouse Model of Huntington's Disease

The Rho kinase (ROCK) pathway is implicated in the pathogenesis of several conditions, including neurological diseases. In Huntington's disease (HD), ROCK is implicated in mutant huntingtin (HTT) aggregation and neurotoxicity, and members of the ROCK pathway are increased in HD mouse models and patients. To validate this mode of action as a potential treatment for HD, we sought a potent, selective, central nervous system (CNS)-penetrant ROCK inhibitor. Identifying a compound that could be dosed orally in mice with selectivity against other AGC kinases, including protein kinase G (PKG), whose inhibition could potentially activate the ROCK pathway, was paramount for the program. We describe the optimization of published ligands to identify a novel series of ROCK inhibitors based on a piperazine core. Morphing of the early series developed in-house by scaffold hopping enabled the identification of a compound exhibiting high potency and desired selectivity and demonstrating a robust pharmacodynamic (PD) effect by the inhibition of ROCK-mediated substrate (MYPT1) phosphorylation after oral dosing.

IDL-PPBopt: A Strategy for Prediction and Optimization of Human Plasma Protein Binding of Compounds via an Interpretable Deep Learning Method

The prediction and optimization of pharmacokinetic properties are essential in lead optimization. Traditional strategies mainly depend on the empirical chemical rules from medicinal chemists. However, with the rising amount of data, it is getting more difficult to manually extract useful medicinal chemistry knowledge. To this end, we introduced IDL-PPBopt, a computational strategy for predicting and optimizing the plasma protein binding (PPB) property based on an interpretable deep learning method. At first, a curated PPB data set was used to construct an interpretable deep learning model, which showed excellent predictive performance with a root mean squared error of 0.112 for the entire test set. Then, we designed a detection protocol based on the model and Wilcoxon test to identify the PPB-related substructures (named privileged substructures, PSubs) for each molecule. In total, 22 general privileged substructures (GPSubs) were identified, which shared some common features such as nitrogen-containing groups, diamines with two carbon units, and azetidine. Furthermore, a series of second-level chemical rules for each GPSub were derived through a statistical test and then summarized into substructure pairs. We demonstrated that these substructure pairs were equally applicable outside the training set and accordingly customized the structural modification schemes for each GPSub, which provided alternatives for the optimization of the PPB property. Therefore, IDL-PPBopt provides a promising scheme for the prediction and optimization of the PPB property and would be helpful for lead optimization of other pharmacokinetic properties.

Photoresponsive Small Molecule Inhibitors for the Remote Control of Enzyme Activity

The development of new and effective therapeutics is reliant on the ability to study the underlying mechanisms of potential drug targets in live cells and multicellular systems. A persistent challenge in many drug development programmes is poor selectivity, which can obscure the mechanisms involved and lead to poorly understood modes of action. In efforts to improve our understanding of these complex processes, small molecule inhibitors have been developed in which their OFF/ON therapeutic activity can be toggled using light. Photopharmacology is devoted to using light to modulate drugs. Herein, we highlight the recent progress made towards the development of light‐responsive small molecule inhibitors of selected enzymatic targets. Given the size of this field, literature from 2015 onwards has been reviewed.

The Design, Synthesis and Evaluation of Rho-kinase Inhibitory Activity of 4-aryl-thiazole-2-amines

Rho-associated kinases (ROCK) are a class of serine/threonine kinases that play important roles in various biological processes. ROCK are becoming attractive targets for drug designing. A novel scaffold was designed according to molecular hybridization strategy, then a series of 4-aryl-5-aminomethyl-thiazole-2-amines were synthesized, and their inhibitory activities on ROCK were screened by enzyme-linked immunosorbent assay (ELISA). The results showed that 4-aryl-5-aminomethyl-thiazole-2-amines derivatives displayed certain ROCK II inhibitory activities. The IC₅₀ value of the most potent compound 4v was found to be 20 nM. The preliminary structure-activity-relationship investigation showed that compounds with 4-pyridine substitution were generally found to be more potent than compounds with 3-pyridine substitution. The molecular docking studies indicated that more optimization work needs to conduct to obtain more potent ROCK inhibitors.

A visible light-controllable Rho kinase inhibitor based on a photochromic phenylazothiazole

Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine-threonine kinase whose inhibitors are useful for the regulation of the actomyosin system. Here, we developed a photoswitchable ROCK inhibitor based on a phenylazothiazole scaffold. The reversible trans-cis isomerization by visible light stimuli enabled us to manipulate ROCK activities in vitro and in cells.

Design, synthesis, and biological evaluation of urea-based ROCK2 inhibitors

A series of urea-based ROCK2 inhibitors were design and synthesized. The inhibitory activity on ROCK2 was screened by enzyme-linked immunosorbent assay (ELISA). The study results showed that the urea derivatives exhibited certain ROCK2 inhibitory activity. The most potent compound 10p showed ROCK2 inhibitory activity with the IC₅₀  value of 0.03 μM. A preliminary structure-activity relationship was then summarized. The molecular docking studies showed that further optimization needs to conduct to obtain more potent ROCK inhibitors.

Discovery of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of ROCK inhibitors for the treatment of glaucoma

The Rho-associated protein kinases (ROCKs) are associated with the pathology of glaucoma and discovery of ROCK inhibitors has attracted much attention in recent years. Herein, we report a series of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of ROCK inhibitors. Structure-activity relationship studies led to the discovery of compound 12b, which showed potent activities against ROCK I and ROCK Ⅱ with IC₅₀ values of 93 nM and 3 nM, respectively. 12b also displayed considerable selectivity for ROCKs. The mean IOP-lowering effect of 12b in an ocular normotensive model was 34.3%, and no obvious hyperemia was observed. Overall, this study provides a good starting point for ROCK-targeting drug discovery against glaucoma.

Pyrazoles and fused pyrimidines: Synthesis, structure elucidation, antitubercular activity and molecular docking study

BACKGROUND

Synthesis of new heterocyclic drugs in short reaction time with sufficient quantity is considered as a target for several pharmaceutical scientists. Thus, organic reactions proceeded on the surface of nano-sized catalysts to speed up the stimulation process.

OBJECTIVE

we aimed in this research to synthesize a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst to investigate their anti-tubercular activity.

METHODS

ZnO(NPs) was used in synthesis of novel series of thienylpyrazolopyrimidines bearing arylazo group by reaction of thiophene-enaminone and the amino-arylazopyrazoles in excellent yield. On the other hand, another series of theinyl-pyrazoles was synthesized through the reaction of the same enaminone with hydrazonoyl chlorides but the usage of ZnO(NPs) failed in such reactions.

RESULTS

The proposed structures of the products and the mechanistic pathways of the reactions were assured based on the spectral data and chemical evidences. Thienylpyrazole derivatives were assessed for their activity as Mycobacterium tuberculosis inhibitor and their results revealed that two thienylpyrazole derivatives 24d & 24f showed the most significant anti-mycobacterial activity with MIC values 0.70 & 1.29 µM/mL, respectively comparing with the MIC value = 0.60 µM/mL of the standard drug Rifampicin. Furthermore, the most active thienylpyrazole derivatives were investigated for their cytotoxic impact versus normal cells WI-38 (Normal human Lung fibroblast cells) using MTT assay. These thienylpyrazole derivatives exhibited good selective index profile. Moreover, 1,3,4-trisubstituted pyrazole analogues showed good interaction with the active site of enoyl-acyl carrier protein reductase (Mt InhA) through the molecular docking studies.

CONCLUSION

We succeeded to synthesis a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst as anti-tubercular agents.

Design, synthesis and biological evaluation of 4-aryl-5-aminoalkyl-thiazole-2-amines derivatives as ROCK II inhibitors

A series of 4-aryl-5-aminoalkyl-thiazole-2-amines were designed and synthesized, and their inhibitory activity on ROCK II was screened by enzyme-linked immunosorbent assay (ELISA). The results showed that 4-aryl-5-aminomethyl-thiazole-2-amines derivatives had certain ROCK II inhibitory activities. Compound 10l showed ROCK II inhibitory activity with IC₅₀ value of 20 nM.

Identification of Novel Rho-Kinase-II Inhibitors with Vasodilatory Activity

Small GTPase protein Rho-kinase (ROCK) plays an important role in the pathogenesis of hypertension. Inhibition of ROCK II brings about the biochemical changes leading to vascular smooth muscles relaxation, finally resulting into potent antihypertensive activity. In the quest for potent ROCK-II inhibitors, a ligand-based pharmacophore containing four essential chemical features, namely two hydrogen bond acceptor (HBA), one hydrogen bond donor (HBD), and one hydrophobe (HY), was developed and rigorously validated. The pharmacophore was used for virtual screening, and hits retrieved from the National Cancer Institute (NCI) database were sorted on the basis of fit value, estimate value, and Lipinski's violation. Potential feature interaction of hits was also observed during docking studies with the amino acids present in the active site of Rho-kinase. Based on the above screening, three hits (NSC 2488, NSC 2888, and NSC 4231) were chosen and subjected to in vitro Rho-kinase enzyme-based assay, followed by ex vivo rat aortic vasodilatory assay. All three compounds showed good biological activity as predicted by the model and confirmed by the docking studies.

Rho-kinase (ROCK) Inhibitors - A Neuroprotective Therapeutic Paradigm with a Focus on Ocular Utility

BACKGROUND

Glaucoma is a progressive optic neuropathy causing visual impairment and Retinal Ganglionic Cells (RGCs) death gradually posing a need for neuroprotective strategies to minimize the loss of RGCs and visual field. It is recognized as a multifactorial disease, Intraocular Pressure (IOP) being the foremost risk factor. ROCK inhibitors have been probed for various possible indications, such as myocardial ischemia, hypertension, kidney diseases. Their role in neuroprotection and neuronal regeneration has been suggested to be of value in the treatment of neurological diseases, like spinal-cord injury, Alzheimer's disease and multiple sclerosis but recently Rho-associated Kinase inhibitors have been recognized as potential antiglaucoma agents.

EVIDENCE SYNTHESIS

Rho-Kinase is a serine/threonine kinase with a kinase domain which is constitutively active and is involved in the regulation of smooth muscle contraction and stress fibre formation. Two isoforms of Rho-Kinase, ROCK-I (ROCK β) and ROCK-II (ROCK α) have been identified. ROCK II plays a pathophysiological role in glaucoma and hence the inhibitors of ROCK may be beneficial to ameliorate the vision loss. These inhibitors decrease the intraocular pressure in the glaucomatous eye by increasing the aqueous humour outflow through the trabecular meshwork pathway. They also act as anti-scarring agents and hence prevent post-operative scarring after the glaucoma filtration surgery. Their major role involves axon regeneration by increasing the optic nerve blood flow which may be useful in treating the damaged optic neurons. These drugs act directly on the neurons in the central visual pathway, interrupting the RGC apoptosis and therefore serve as a novel pharmacological approach for glaucoma neuroprotection.

CONCLUSION

Based on the results of high-throughput screening, several Rho kinase inhibitors have been designed and developed comprising of diverse scaffolds exhibiting Rho kinase inhibitory activity from micromolar to subnanomolar ranges. This diversity in the scaffolds with inhibitory potential against the kinase and their SAR development will be intricated in the present review. Ripasudil is the only Rho kinase inhibitor marketed to date for the treatment of glaucoma. Another ROCK inhibitor AR-13324 has recently passed the clinical trials whereas AMA0076, K115, PG324, Y39983 and RKI-983 are still under trials. In view of this, a detailed and updated account of ROCK II inhibitors as the next generation therapeutic agents for glaucoma will be discussed in this review.

Auto In Silico Ligand Directing Evolution to Facilitate the Rapid and Efficient Discovery of Drug Lead

Motivated by the growing demand for reducing the chemical optimization burden of H2L, we developed auto in silico ligand directing evolution (AILDE, http://chemyang.ccnu.edu.cn/ccb/server/AILDE), an efficient and general approach for the rapid identification of drug leads in accessible chemical space. This computational strategy relies on minor chemical modifications on the scaffold of a hit compound, and it is primarily intended for identifying new lead compounds with minimal losses or, in some cases, even increases in ligand efficiency. We also described how AILDE greatly reduces the chemical optimization burden in the design of mesenchymal-epithelial transition factor (c-Met) kinase inhibitors. We only synthesized eight compounds and found highly efficient compound 5g, which showed an ∼1,000-fold improvement in in vitro activity compared with the hit compound. 5g also displayed excellent in vivo antitumor efficacy as a drug lead. We believe that AILDE may be applied to a large number of studies for rapid design and identification of drug leads.

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AILDE was developed for the rapid identification of drug leads

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A potent drug lead targeted to c-Met was found by synthesizing only eight compounds

Metabolic and Pharmaceutical Aspects of Fluorinated Compounds

The applications of fluorine in drug design continue to expand, facilitated by an improved understanding of its effects on physicochemical properties and the development of synthetic methodologies that are providing access to new fluorinated motifs. In turn, studies of fluorinated molecules are providing deeper insights into the effects of fluorine on metabolic pathways, distribution, and disposition. Despite the high strength of the C-F bond, the departure of fluoride from metabolic intermediates can be facile. This reactivity has been leveraged in the design of mechanism-based enzyme inhibitors and has influenced the metabolic fate of fluorinated compounds. In this Perspective, we summarize the literature associated with the metabolism of fluorinated molecules, focusing on examples where the presence of fluorine influences the metabolic profile. These studies have revealed potentially problematic outcomes with some fluorinated motifs and are enhancing our understanding of how fluorine should be deployed.

IODVA1, a guanidinobenzimidazole derivative, targets Rac activity and Ras-driven cancer models

We report the synthesis and preliminary characterization of IODVA1, a potent small molecule that is active in xenograft mouse models of Ras-driven lung and breast cancers. In an effort to inhibit oncogenic Ras signaling, we combined in silico screening with inhibition of proliferation and colony formation of Ras-driven cells. NSC124205 fulfilled all criteria. HPLC analysis revealed that NSC124205 was a mixture of at least three compounds, from which IODVA1 was determined to be the active component. IODVA1 decreased 2D and 3D cell proliferation, cell spreading and ruffle and lamellipodia formation through downregulation of Rac activity. IODVA1 significantly impaired xenograft tumor growth of Ras-driven cancer cells with no observable toxicity. Immuno-histochemistry analysis of tumor sections suggests that cell death occurs by increased apoptosis. Our data suggest that IODVA1 targets Rac signaling to induce death of Ras-transformed cells. Therefore, IODVA1 holds promise as an anti-tumor therapeutic agent.

In-Silico QSAR Modelling of Predicted Rho Kinase Inhibitors Against Cardio Vascular Diseases

BACKGROUND

Rho-kinase is an essential downstream target of GTP-binding protein RhoA, and plays a crucial role in the calcium-sensitization pathway. Rho-kinase pathway is critically involved in phosphorylation state of myosin light chain, leading to increased contraction of smooth muscles. Inhibition of this pathway has turned out to be a promising target for several indications such as cardiovascular diseases, glaucoma and inflammatory diseases.

METHODS

The present work focuses on a division-based 2D quantitative structure-activity relationship (QSAR) analysis along with a docking study to predict structural features that may be essential for the enhancement of selectivity and potency of the target compounds. Furthermore, a set of indoles and azaindoles were also projected based on the regression equation as novel developments. Molecular docking was applied for exploring the binding sites of the newly predicted set of compounds with the receptor.

RESULTS

Results of the docked conformations suggested that introduction of non-bulky and substituted groups in the hinge region of ROCK-II ATP binding pocket would improve the activity by decreasing the bulkiness or length of the compounds.

CONCLUSION

ADME studies were performed to ascertain the novelty and drug-like properties of the designed molecules, respectively.

Chemo- and regioselective synthesis of polysubstituted 2-aminothiophenes by the cyclization of gem-dibromo or gem-dichloroalkenes with β-keto tertiary thioamides

A facile and practical method for the synthesis of 2,3,4-trisubstituted 2-aminothiophenes by the cyclization of gem-dibromoalkenes or gem-dichloroalkenes with β-keto tertiary thioamides has been developed. The cyclization reaction proceeded chemoselectively and regioselectively under metal-catalyst-free conditions, providing various structurally diverse 2,3,4-trisubstituted N,N'-dialkyl 2-aminothiophenes in good to excellent yields.

Rho-associated coiled-coil kinase 1 activation mediates amyloid precursor protein site-specific Ser655 phosphorylation and triggers amyloid pathology

Rho‐associated coiled‐coil kinase 1 (ROCK1) is proposed to be implicated in Aβ suppression; however, the role for ROCK1 in amyloidogenic metabolism of amyloid precursor protein (APP) to produce Aβ was unknown. In the present study, we showed that ROCK1 kinase activity and its APP binding were enhanced in AD brain, resulting in increased β‐secretase cleavage of APP. Furthermore, we firstly confirmed that APP served as a substrate for ROCK1 and its major phosphorylation site was located at Ser655. The increased level of APP Ser655 phosphorylation was observed in the brain of APP/PS1 mice and AD patients compared to controls. Moreover, blockade of APP Ser655 phosphorylation, or inhibition of ROCK1 activity with either shRNA knockdown or Y‐27632, ameliorated amyloid pathology and improved learning and memory in APP/PS1 mice. These findings suggest that activated ROCK1 targets APP Ser655 phosphorylation, which promotes amyloid processing and pathology. Inhibition of ROCK1 could be a potential therapeutic approach for AD.

A Brain-Targeted Orally Available ROCK2 Inhibitor Benefits Mild and Aggressive Cavernous Angioma Disease

Cavernous angioma (CA) is a vascular pathology caused by loss of function in one of the 3 CA genes (CCM1, CCM2, and CCM3) that result in rho kinase (ROCK) activation. We investigated a novel ROCK2 selective inhibitor for the ability to reduce brain lesion formation, growth, and maturation. We used genetic methods to explore the use of a ROCK2-selective kinase inhibitor to reduce growth and hemorrhage of CAs. The role of ROCK2 in CA was investigated by crossing Rock1 or Rock2 hemizygous mice with Ccm1 or Ccm3 hemizygous mice, and we found reduced lesions in the Rock2 hemizygous mice. A ROCK2-selective inhibitor, BA-1049 was used to investigate efficacy in reducing CA lesions after oral administration to Ccm1^+/- and Ccm3^+/- mice that were bred into a mutator background. After assessing the dose range effective to target brain endothelial cells in an ischemic brain model, Ccm1^+/- and Ccm3^+/- transgenic mice were treated for 3 (Ccm3^+/-) or 4 months (Ccm1^+/-), concurrently, randomized to receive one of three doses of BA-1049 in drinking water, or placebo. Lesion volumes were assessed by micro-computed tomography. BA-1049 reduced activation of ROCK2 in Ccm3^+/-Trp53^-/- lesions. Ccm1^+/-Msh2^-/- (n=68) and Ccm3^+/-Trp53^-/- (n=71) mice treated with BA-1049 or placebo showed a significant dose-dependent reduction in lesion volume after treatment with BA-1049, and a reduction in hemorrhage (iron deposition) near lesions at all doses. These translational studies show that BA-1049 is a promising therapeutic agent for the treatment of CA, a disease with no current treatment except surgical removal of the brain lesions.

Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease

The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.

ROCK inhibitors 2. Improving potency, selectivity and solubility through the application of rationally designed solubilizing groups

Solubilizing groups have been frequently appended to kinase inhibitor drug molecules when solubility is insufficient for pharmaceutical development. Such groups are usually located at substitution sites that have minimal impact on target activity. In this report we describe the incorporation of solubilizing groups in a class of Rho kinase (ROCK) inhibitors that not only confer improved solubility, but also enhance target potency and selectivity against a closely related kinase, PKA.

ROCK inhibitors 3: Design, synthesis and structure-activity relationships of 7-azaindole-based Rho kinase (ROCK) inhibitors

Rho kinase (ROCK) inhibitors are potential therapeutic agents for the treatment of a variety of disorders including hypertension, glaucoma and erectile dysfunction. Here we disclose a series of potent and selective ROCK inhibitors based on a substituted 7-azaindole scaffold. Substitution of the 3-position of 7-azaindole led to compounds such as 37, which possess excellent ROCK inhibitory potency and high selectivity against the closely related kinase PKA.

Discovery and Characterization of CD12681, a Potent RORγ Inverse Agonist, Preclinical Candidate for the Topical Treatment of Psoriasis

With possible implications in multiple autoimmune diseases, the retinoic acid receptor-related orphan receptor RORγ has become a sought-after target in the pharmaceutical industry. Herein are described the efforts to identify a potent RORγ inverse agonist compatible with topical application for the treatment of skin diseases. These efforts culminated in the discovery of N-(2,4-dimethylphenyl)-N-isobutyl-2-oxo-1-[(tetrahydro-2H-pyran-4-yl)methyl]-2,3-dihydro-1H-benzo[d]imidazole-5-sulfonamide (CD12681), a potent inverse agonist with in vivo activity in an IL-23-induced mouse skin inflammation model.

Rho Kinase (ROCK) Inhibitors and Their Therapeutic Potential

Rho kinases (ROCKs) belong to the serine-threonine family, the inhibition of which affects the function of many downstream substrates. As such, ROCK inhibitors have potential therapeutic applicability in a wide variety of pathological conditions including asthma, cancer, erectile dysfunction, glaucoma, insulin resistance, kidney failure, neuronal degeneration, and osteoporosis. To date, two ROCK inhibitors have been approved for clinical use in Japan (fasudil and ripasudil) and one in China (fasudil). In 1995 fasudil was approved for the treatment of cerebral vasospasm, and more recently, ripasudil was approved for the treatment of glaucoma in 2014. In this Perspective, we present a comprehensive review of the physiological and biological functions for ROCK, the properties and development of over 170 ROCK inhibitors as well as their therapeutic potential, the current status, and future considerations.

Rho-associated kinase signalling and the cancer microenvironment: novel biological implications and therapeutic opportunities

The Rho/ROCK pathway is involved in numerous pivotal cellular processes that have made it an area of intense study in cancer medicine, however, Rho-associated coiled-coil containing protein kinase (ROCK) inhibitors are yet to make an appearance in the clinical cancer setting. Their performance as an anti-cancer therapy has been varied in pre-clinical studies, however, they have been shown to be effective vasodilators in the treatment of hypertension and post-ischaemic stroke vasospasm. This review addresses the various roles the Rho/ROCK pathway plays in angiogenesis, tumour vascular tone and reciprocal feedback from the tumour microenvironment and explores the potential utility of ROCK inhibitors as effective vascular normalising agents. ROCK inhibitors may potentially enhance the delivery and efficacy of chemotherapy agents and improve the effectiveness of radiotherapy. As such, repurposing of these agents as adjuncts to standard treatments may significantly improve outcomes for patients with cancer. A deeper understanding of the controlled and dynamic regulation of the key components of the Rho pathway may lead to effective use of the Rho/ROCK inhibitors in the clinical management of cancer.

Copper–cobalt synergy in Cu1−xCoxFe2O4spinel ferrite as a highly efficient and regioselective nanocatalyst for the synthesis of 2,4-dinitrotoluene

Highly regioselective dinitration of toluene with nitric acid as nitrating agent in the presence of Cu_1−xCo_xFe₂O₄(0 ≤x≤ 1) as nanocatalysts is described.