Knockdown siRNA Targeting GPR55 Reveals Significant Differences Between the Anti-inflammatory Actions of KLS-13019 and Cannabidiol.

KLS-13019 was reported previously to reverse paclitaxel-induced mechanical allodynia in a mouse model of chemotherapy-induced peripheral neuropathy (CIPN). Recent studies demonstrated that paclitaxel-induced increases in inflammatory markers (GPR55, NLRP3, and IL-1ß) of dorsal root ganglion (DRG) cultures were shown to be reversed by KLS-13019 treatment. The mechanism of action for KLS-13019-mediated reversal of paclitaxel-induced neuroinflammation now has been explored using GPR55 siRNA. Pre-treatment of DRG cultures with GPR55 siRNA produced a 21% decrease of immunoreactive (IR) area for GPR55 in cell bodies and a 59% decrease in neuritic IR area, as determined by high-content imaging. Using a 24-h reversal treatment paradigm, paclitaxel-induced increases in the inflammatory markers were reversed back to control levels after KLS-3019 treatment. Decreases in these inflammatory markers produced by KLS-13019 were significantly attenuated by GPR55 siRNA co-treatment, with mean IR area responses being attenuated by 56% in neurites and 53% in cell bodies. These data indicate that the percentage decreases in siRNA-mediated attenuation of KLS-13019-related efficacy on the inflammatory markers were similar to the percentage knockdown observed for neuritic GPR55 IR area. Similar studies conducted with cannabidiol (CBD), the parent compound of KLS-13019, produced low efficacy (25%) reversal of all inflammatory markers that were poorly attenuated (29%) by GPR55 siRNA. CBD was shown previously to be ineffective in reversing paclitaxel-induced mechanical allodynia. The present studies indicated significant differences between the anti-inflammatory properties of KLS-13019 and CBD which may play a role in their observed differences in the reversibility of mechanical allodynia in a mouse model of CIPN.

Knockdown siRNA targeting GPR55 reveals significant differences between the anti-inflammatory actions of KLS-13019 and cannabidiol.

KLS-13019 was reported previously to reverse paclitaxel-induced mechanical allodynia in a mouse model of chemotherapy-induced peripheral neuropathy (CIPN). Recent studies demonstrated that paclitaxel-induced increases in inflammatory markers (GPR55, NLRP3 and IL-1b) of dorsal root ganglion (DRG) cultures were shown to be reversed by KLS-13019 treatment. The mechanism of action for KLS-13019-mediated reversal of paclitaxel-induced neuroinflammation now has been explored using GPR55 siRNA. Pretreatment of DRG cultures with GPR55 siRNA produced a 21% decrease of immunoreactive (IR) area for GPR55 in cell bodies and a 59% decrease in neuritic IR area, as determined by high content imaging. Using a 24-hour reversal treatment paradigm, paclitaxel-induced increases in the inflammatory markers were reversed back to control levels after KLS-3019 treatment. Decreases in these inflammatory markers produced by KLS-13019 were significantly attenuated by GPR55 siRNA co-treatment, with mean IR area responses being attenuated by 56% in neurites and 53% in cell bodies. These data indicate that the percentage decreases in siRNA-mediated attenuation of KLS-13019-related efficacy on the inflammatory markers were similar to the percentage knockdown observed for neuritic GPR55 IR area. Similar studies conducted with cannabidiol (CBD), the parent compound of KLS-13019, produced low efficacy (25%) reversal of all inflammatory markers that were poorly attenuated (29%) by GPR55 siRNA. CBD was shown previously to be ineffective in reversing paclitaxel-induced mechanical allodynia. The present studies indicated significant differences between the anti-inflammatory properties of KLS-13019 and CBD which may play a role in their observed differences in the reversibility of mechanical allodynia in a mouse model of CIPN.

Quantitative Attribution of the Protective Effects of Aminosterols against Protein Aggregates to Their Chemical Structures and Ability to Modulate Biological Membranes.

Natural aminosterols are promising drug candidates against neurodegenerative diseases, like Alzheimer and Parkinson, and one relevant protective mechanism occurs via their binding to biological membranes and displacement or binding inhibition of amyloidogenic proteins and their cytotoxic oligomers. We compared three chemically different aminosterols, finding that they exhibited different (i) binding affinities, (ii) charge neutralizations, (iii) mechanical reinforcements, and (iv) key lipid redistributions within membranes of reconstituted liposomes. They also had different potencies (EC50) in protecting cultured cell membranes against amyloid-ß oligomers. A global fitting analysis led to an analytical equation describing quantitatively the protective effects of aminosterols as a function of their concentration and relevant membrane effects. The analysis correlates aminosterol-mediated protection with well-defined chemical moieties, including the polyamine group inducing a partial membrane-neutralizing effect (79 ± 7%) and the cholestane-like tail causing lipid redistribution and bilayer mechanical resistance (21 ± 7%), linking quantitatively their chemistry to their protective effects on biological membranes.

Efficient Syntheses of KLS-13019 Using Palladium Mediated Cross Couplings.

KLS-13019 is a structural analogue of cannabidiol, that shows improved bioavailability and potency in both preventing and reversing paclitaxel-induced neurotoxicity in vitro and in vivo. KLS-13019 was selected as a development candidate and attention was turned to development of a scalable synthesis. The original synthesis of KLS-13019 was not efficient, regioselective, or high yielding. Two new syntheses are reported that make use of the palladium catalyzed cross couplings to a chemically advanced intermediate 5, dramatically shortening (3-4 steps) and improving the overall yield. In addition, a convenient one pot Boc-cleavage and acetylation procedure is described to avoid impurities generated from a step-wise process.

Anti-Inflammatory Properties of KLS-13019: a Novel GPR55 Antagonist for Dorsal Root Ganglion and Hippocampal Cultures.

KLS-13019, a novel devised cannabinoid-like compound, was explored for anti-inflammatory actions in dorsal root ganglion cultures relevant to chemotherapy-induced peripheral neuropathy (CIPN). Time course studies with 3 µM paclitaxel indicated > 1.9-fold increases in immunoreactive (IR) area for cell body GPR55 after 30 min as determined by high content imaging. To test for reversibility of paclitaxel-induced increases in GPR55, cultures were treated for 8 h with paclitaxel alone and then a dose response to KLS-13019 added for another 16 h. This "reversal" paradigm indicated established increases in cell body GPR55 IR areas were decreased back to control levels. Because GPR55 had previously reported inflammatory actions, IL-1ß and NLRP3 (inflammasome-3 marker) were also measured in the "reversal" paradigm. Significant increases in all inflammatory markers were produced after 8 h of paclitaxel treatment alone that were reversed to control levels with KLS-13019 treatment. Accompanying studies using alamar blue indicated that decreased cellular viability produced by paclitaxel treatment was reverted back to control levels by KLS-13019. Similar studies conducted with lysophosphatidylinositol (GPR55 agonist) in DRG or hippocampal cultures demonstrated significant increases in neuritic GPR55, NLRP3 and IL-1ß areas that were reversed to control levels with KLS-13019 treatment. Studies with a human GPR55-ß-arrestin assay in Discover X cells indicated that KLS-13019 was an antagonist without agonist activity. These studies indicated that KLS-13019 has anti-inflammatory properties mediated through GPR55 antagonist actions. Together with previous studies, KLS-13019 is a potent neuroprotective, anti-inflammatory cannabinoid with therapeutic potential for high efficacy treatment of neuropathic pain.

Behavioural and pharmacological effects of cannabidiol (CBD) and the cannabidiol analogue KLS-13019 in mouse models of pain and reinforcement.

BACKGROUND AND PURPOSE: Cannabidiol (CBD) is a non-euphorigenic component of Cannabis sativa that prevents the development of paclitaxel-induced mechanical sensitivity in a mouse model of chemotherapy-induced peripheral neuropathy (CIPN). We recently reported that the CBD structural analogue KLS-13019 shows efficacy in an in vitro model of CIPN. The present study was to characterize the behavioural effects of KLS-13019 compared to CBD and morphine in mouse models of CIPN, nociceptive pain and reinforcement. EXPERIMENTAL APPROACH: Prevention or reversal of paclitaxel-induced mechanical sensitivity were assessed following intraperitoneal or oral administration of CBD, KLS-13019 or morphine. Antinociceptive activity using acetic acid-induced stretching and hot plate assay, anti-reinforcing effects on palatable food or morphine self-administration and binding to human opioid receptors were also determined. KEY RESULTS: Like CBD, KLS-13019 prevented the development of mechanical sensitivity associated with paclitaxel administration. In contrast to CBD, KLS-13019 was also effective at reversing established mechanical sensitivity. KLS-13019 significantly attenuated acetic acid-induced stretching and produced modest effects in the hot plate assay. KLS-13019 was devoid of activity at µ-, δ- or κ-opioid receptors. Lastly, KLS-13019, but not CBD, attenuated the reinforcing effects of palatable food or morphine. CONCLUSIONS AND IMPLICATIONS: KLS-13019 like CBD, prevented the development of CIPN, while KLS-13019 uniquely attenuated established CIPN. Because KLS-13019 binds to fewer biological targets, this will help to identifying molecular mechanisms shared by these two compounds and those unique to KLS-13019. Lastly, KLS-13019 may possess the ability to attenuate reinforced behaviour, an effect not observed in the present study with CBD.

4F-MDMB-BINACA: A New Synthetic Cannabinoid Widely Implicated in Forensic Casework.

This is the first report regarding the characterization of the new synthetic cannabinoid 4F-MDMB-BINACA. 4F-MDMB-BINACA was first analytically confirmed in seized drug material using gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF), and nuclear magnetic resonance (NMR) spectroscopy. Subsequent to this characterization, 4F-MDMB-BINACA was detected in biological specimens collected as part of forensically relevant casework, including medicolegal death investigations and drug impaired driving investigations, from a variety of regions in the United States. Further analysis of biological specimens resulted in the identification of the metabolites 4F-MDMB-BINACA 3,3-dimethylbutanoic acid and 4-OH-MDMB-BINACA. 4F-MDMB-BINACA is appearing with increasing frequency as a contributory factor in deaths, creating morbidity and mortality risks for drug users. Laboratories must be aware of its presence and impact, incorporating 4F-MDMB-BINACA into workflows for detection and confirmation.

Knockdown siRNA Targeting the Mitochondrial Sodium-Calcium Exchanger-1 Inhibits the Protective Effects of Two Cannabinoids Against Acute Paclitaxel Toxicity.

Treatment with cannabidiol (CBD) or KLS-13019 (novel CBD analog), has previously been shown to prevent paclitaxel-induced mechanical allodynia in a mouse model of chemotherapy-induced peripheral neuropathy (CIPN). The mechanism of action for CBD- and KLS-13019-mediated protection now has been explored with dissociated dorsal root ganglion (DRG) cultures using small interfering RNA (siRNA) to the mitochondrial Na+ Ca2+ exchanger-1 (mNCX-1). Treatment with this siRNA produced a 50-55% decrease in the immunoreactive (IR) area for mNCX-1 in neuronal cell bodies and a 72-80% decrease in neuritic IR area as determined with high-content image analysis. After treatment with 100 nM KLS-13019 and siRNA, DRG cultures exhibited a 75 ± 5% decrease in protection from paclitaxel-induced toxicity; whereas siRNA studies with 10 µM CBD produced a 74 ± 3% decrease in protection. Treatment with mNCX-1 siRNA alone did not produce toxicity. The protective action of cannabidiol and KLS-13019 against paclitaxel-induced toxicity during a 5-h test period was significantly attenuated after a 4-day knockdown of mNCX-1 that was not attributable to toxicity. These data indicate that decreases in neuritic mNCX-1 corresponded closely with decreased protection after siRNA treatment. Pharmacological blockade of mNCX-1 with CGP-37157 produced complete inhibition of cannabinoid-mediated protection from paclitaxel in DRG cultures, supporting the observed siRNA effects on mechanism.

Pharmacological Comparisons Between Cannabidiol and KLS-13019.

Cannabidiol (CBD) exhibits neuroprotective properties in many experimental systems. However, development of CBD as a drug has been confounded by the following: (1) low potency; (2) a large number of molecular targets; (3) marginal pharmacokinetic properties; and (4) designation as a schedule 1 controlled substance. The present work compared the properties of CBD with a novel molecule (KLS-13019) that has structural similarities to CBD. The design strategy for KLS-13019 was to increase hydrophilicity while optimizing neuroprotective potency against oxidative stress toxicity relevant to hepatic encephalopathy. The protective responses of CBD and KLS-13019 were compared in dissociated rat hippocampal cultures co-treated with toxic levels of ethanol and ammonium acetate. This comparison revealed that KLS-13019 was 31-fold more potent than CBD in preventing neuronal toxicity from the combined toxin treatment, while both compounds exhibited complete protective efficacy back to control values. In addition, treatment with KLS-13019 alone was 5-fold less toxic (TC50) than CBD. Previous studies suggested that CBD targeted the Na+-Ca2+ exchanger in mitochondria (mNCX) to regulate intracellular calcium levels, an important determinant of neuronal survival. After treatment with an inhibitor of mNCX (CGP-37157), no detectable neuroprotection from ethanol toxicity was observed for either CBD or KLS-13019. Furthermore, AM630 (CB2 antagonist) significantly attenuated CBD-mediated neuroprotection, while having no detectable effect on neuroprotection from KLS-13019. Our studies indicated KLS-13019 was more potent and less toxic than CBD. Both compounds can act through mNCX. KLS-13019 may provide an alternative to CBD as a therapeutic candidate to treat diseases associated with oxidative stress.

Nature's combinatorial biosynthesis and recently engineered production of nucleoside antibiotics in Streptomyces.

Modified nucleosides produced by Streptomyces and related actinomycetes are widely used in agriculture and medicine as antibacterial, antifungal, anticancer and antiviral agents. These specialized small-molecule metabolites are biosynthesized by complex enzymatic machineries encoded within gene clusters in the genome. The past decade has witnessed a burst of reports defining the key metabolic processes involved in the biosynthesis of several distinct families of nucleoside antibiotics. Furthermore, genome sequencing of various Streptomyces species has dramatically increased over recent years. Potential biosynthetic gene clusters for novel nucleoside antibiotics are now apparent by analysis of these genomes. Here we revisit strategies for production improvement of nucleoside antibiotics that have defined mechanisms of action, and are in clinical or agricultural use. We summarize the progress for genetically manipulating biosynthetic pathways for structural diversification of nucleoside antibiotics. Microorganism-based biosynthetic examples are provided and organized under genetic principles and metabolic engineering guidelines. We show perspectives on the future of combinatorial biosynthesis, and present a working model for discovery of novel nucleoside natural products in Streptomyces.

Discovery of KLS-13019, a Cannabidiol-Derived Neuroprotective Agent, with Improved Potency, Safety, and Permeability.

Cannabidiol is the nonpsychoactive natural component of C. sativa that has been shown to be neuroprotective in multiple animal models. Our interest is to advance a therapeutic candidate for the orphan indication hepatic encephalopathy (HE). HE is a serious neurological disorder that occurs in patients with cirrhosis or liver failure. Although cannabidiol is effective in models of HE, it has limitations in terms of safety and oral bioavailability. Herein, we describe a series of side chain modified resorcinols that were designed for greater hydrophilicity and "drug likeness", while varying hydrogen bond donors, acceptors, architecture, basicity, neutrality, acidity, and polar surface area within the pendent group. Our primary screen evaluated the ability of the test agents to prevent damage to hippocampal neurons induced by ammonium acetate and ethanol at clinically relevant concentrations. Notably, KLS-13019 was 50-fold more potent and >400-fold safer than cannabidiol and exhibited an in vitro profile consistent with improved oral bioavailability.

Strategies for strengthening patent protection of pharmaceutical inventions in light of federal court decisions.

In this article, a brief history of patent law is presented, along with recent changes in its interpretation that are relevant in securing patents in the current landscape. Specific patent examples are presented to illustrate key issues. For example, the case of KSR International Co. v. Teleflex, Inc. is an important recent decision by the United States Supreme Court, which developed a more flexible definition of the teaching-suggestion-motivation (TSM) test in determining obviousness, which negates patentability. Although KSR case involved a mechanical invention, the ruling in this case has had implications in other areas of patent law, particularly as it applied to pharmaceutical and chemical inventions. It has had a significant impact on the outcome of patent prosecution at the United States Patent and Trademark Office (USPTO), as well as in defending patents in federal courts. If an invention is obvious to try and there are a finite number of predictable solutions in the prior art, then the invention will be considered obvious by current standards. Bayer Schering Pharma AG v. Barr Laboratories, Inc is presented as a case in which the court of appeals has applied the KSR standard of obviousness in invalidating a formulation patent claim, in which a finite number of options were available to the formulator. Unlike the formulation patent example, patents covering new molecules have survived challenges more successfully. In The Procter & Gamble Co. v. Teva Pharmaceuticals USA, Inc., the court of appeals for the Federal Circuit determined that the invention of risedronate was unobvious, although it was a mere positional isomer of a prior bisphosphonate. However in Altana Pharma AG v. Teva Pharmaceuticals USA, Inc., the court of appeals judged against the innovator company when there was a clearer case of predictable prior art. Finally, Ortho-McNeil Pharmaceutical, Inc. v. Mylan Laboratories, Inc. presents an example of a case at the Federal Circuit where topiramate was more easily defended, because the scientist had at his disposal a great number of unpredictable options and the results were clearly surprising. In light of these and other court decisions the USPTO has established new guidelines for patent examinations going forward that this article describes.

Nonpeptide urotensin-II receptor antagonists: a new ligand class based on piperazino-phthalimide and piperazino-isoindolinone subunits.

We have discovered two related chemical series of nonpeptide urotensin-II (U-II) receptor antagonists based on piperazino-phthalimide (5 and 6) and piperazino-isoindolinone (7) scaffolds. These structure types are distinctive from those of U-II receptor antagonist series reported in the literature. Antagonist 7a exhibited single-digit nanomolar potency in rat and human cell-based functional assays, as well as strong binding to the human U-II receptor. In advanced pharmacological testing, 7a blocked the effects of U-II in vitro in a rat aortic ring assay and in vivo in a rat ear-flush model. A discussion of U-II receptor antagonist pharmacophores is presented, and a specifically defined model is suggested from tricycle 13, which has a high degree of conformational constraint.

Thrombogenic collagen-mimetic peptides: Self-assembly of triple helix-based fibrils driven by hydrophobic interactions.

Collagens are integral structural proteins in animal tissues and play key functional roles in cellular modulation. We sought to discover collagen model peptides (CMPs) that would form triple helices and self-assemble into supramolecular fibrils exhibiting collagen-like biological activity without preorganizing the peptide chains by covalent linkages. This challenging objective was accomplished by placing aromatic groups on the ends of a representative 30-mer CMP, (GPO)(10), as with l-phenylalanine and l-pentafluorophenylalanine in 32-mer 1a. Computational studies on homologous 29-mers 1a'-d' (one less GPO), as pairs of triple helices interacting head-to-tail, yielded stabilization energies in the order 1a' > 1b' > 1c' > 1d', supporting the hypothesis that hydrophobic aromatic groups can drive CMP self-assembly. Peptides 1a-d were studied comparatively relative to structural properties and ability to stimulate human platelets. Although each 32-mer formed stable triple helices (CD) spectroscopy, only 1a and 1b self-assembled into micrometer-scale fibrils. Light microscopy images for 1a depicted long collagen-like fibrils, whereas images for 1d did not. Atomic force microscopy topographical images indicated that 1a and 1b self-organize into microfibrillar species, whereas 1c and 1d do not. Peptides 1a and 1b induced the aggregation of human blood platelets with a potency similar to type I collagen, whereas 1c was much less effective, and 1d was inactive (EC(50) potency: 1a/1b >> 1c > 1d). Thus, 1a and 1b spontaneously self-assemble into thrombogenic collagen-mimetic materials because of hydrophobic aromatic interactions provided by the special end-groups. These findings have important implications for the design of biofunctional CMPs.

Suzuki-Miyaura approach to JNJ-26076713, an orally active tetrahydroquinoline-containing alphaVbeta3/alphaVbeta5 integrin antagonist. enantioselective synthesis and stereochemical studies.

An improved scale-up synthesis was required for the alpha(V)beta(3)/alpha(V)beta(5) integrin antagonist 1, which had demonstrated oral efficacy in eye disease models of angiogenesis and vascular permeability. A stereodefined, quinoline-substituted, unsaturated ester was conveniently prepared by a Suzuki-Miyaura coupling to facilitate exploration of multiple methods of asymmetric reduction. The catalytic chiral hydrogenation of the corresponding unsaturated acid (Z-5b) with a ruthenium-based metal precursor and the (R)-XylPhanePhos ligand proved particularly efficient and economical. The resulting (3S)-quinoline-containing intermediate was reduced to an equal mixture of tetrahydroquinoline diastereomers. The undesired diastereomer could be recycled to the desired one by an oxidation/reduction protocol. The absolute stereochemistry of 1 was established as 3S,3'S by a combination of X-ray diffraction and chemical means.

Studies with an orally bioavailable alpha V integrin antagonist in animal models of ocular vasculopathy: retinal neovascularization in mice and retinal vascular permeability in diabetic rats.

The alpha(V) integrins are key receptors involved in mediating cell migration and angiogenesis. In age-related macular degeneration (AMD) and diabetic retinopathy, angiogenesis plays a critical role in the loss of vision. These ocular vasculopathies might be treatable with a suitable alpha(V) antagonist, and an oral drug would offer a distinct advantage over current therapies. (3,S,beta,S)-1,2,3,4-Tetrahydro-beta-[[1-[1-oxo-3-(1,5,6,7-tetrahydro-1,8-naphthyridin-2-yl)propyl]-4-piperidinyl]methyl]-3-quinolinepropanoic acid (JNJ-26076713) is a potent, orally bioavailable, nonpeptide alpha(V) antagonist derived from the arginine-glycine-asparagine binding motif in the matrix protein ligands (e.g., vitronectin). This compound inhibits alpha(V)beta(3) and alpha(V)beta(5) binding to vitronectin in the low nanomolar range, it has excellent selectivity over integrins alpha(IIb)beta(3) and alpha(5)beta(1), and it prevents adhesion to human, rat, and mouse endothelial cells. JNJ-26076713 blocks cell migration induced by vascular endothelial growth factor, fibroblast growth factor (FGF), and serum, and angiogenesis induced by FGF in the chick chorioallantoic membrane model. JNJ-26076713 is the first alpha(V) antagonist reported to inhibit retinal neovascularization in an oxygen-induced model of retinopathy of prematurity after oral administration. In diabetic rats, orally administered JNJ-26076713 markedly inhibits retinal vascular permeability, a key early event in diabetic macular edema and AMD. Given this profile, JNJ-26076713 represents a potential therapeutic candidate for the treatment of age-related macular degeneration, macular edema, and proliferative diabetic retinopathy.

Phenylpiperidine-benzoxazinones as urotensin-II receptor antagonists: synthesis, SAR, and in vivo assessment.

Various 4-phenylpiperidine-benzoxazin-3-ones were synthesized and biologically evaluated as urotensin-II (U-II) receptor antagonists. Compound 12i was identified from in vitro evaluation as a low nanomolar antagonist against both rat and human U-II receptors. This compound showed in vivo efficacy in reversing the ear-flush response induced by U-II in rats.

Nanoparticles that display short collagen-related peptides. Potent stimulation of human platelet aggregation by triple helical motifs.

Collagen plays a key role in the activation and adhesion of blood platelets via their cell-surface receptors. Normally, collagen-related peptides (CRPs), even one as long as a 30-mer (10 Gly-Pro-Hyp (GPO) repeats), are unable to effectively express collagen's platelet-activating behavior. We attached two short CRPs, AcHN-(Gly-Pro-Hyp)nGly-OH with n = 5 (1) and n = 10 (2), via the C-terminus to amino-functionalized latex nanoparticles to create a multimeric display of triple helical motifs. These nanomaterials were characterized by dynamic light scattering and environmental scanning electron microscopy. The nanoparticles bearing the 31-mer CRP sequence, 2, but not the 16-mer sequence, 1, effectively induced the aggregation of human platelets, with a potency level approaching that of native type I collagen. Our results highlight the importance of presenting triple helical CRP motifs of sufficient length on a suitable scaffold in order to stimulate platelets.