Lysophosphatidic acid receptor 1 antagonist (EPGN2154) causes regression of NASH in preclinical NASH models.

BACKGROUND: NASH causes a tremendous health care burden in the United States. A glucagon-like peptide-1 agonist, semaglutide (Sema), treatment resulted in hepatic steatosis reduction in clinical trials of NASH. Lysophosphatidic acid receptor 1 antagonists are known to have antifibrotic effects in several organs. We tested Sema and a novel lysophosphatidic acid receptor 1 antagonist, EPGN2154, individually and in combination to evaluate their efficacy for NASH remission in preclinical models. METHODS: In the present study, we used (1) C57Bl6/J wild-type mice fed on a high-fat, high-carbohydrate (HFHC) diet for 16 weeks and (2) leptin-deficient mice (ob/ob) fed on an Amylin liver NASH diet for 16 weeks. After 16 weeks, the mice were randomly distributed in equal numbers in (1) no-drug, (2) EPGN2154, (3) Sema, and (4) EPGN2154+Sema treatment groups for 8 additional weeks at a dosage of 10 mg/kg body weight for EPGN2154 (oral gavage, 5 days a week) and 6.17 µg/kg body weight of Sema (subcutaneous injection every alternate day, 3 days a week). RESULTS: In the wild-type-high-fat, high-carbohydrate model, we observed the most body weight loss in the EPGN2154+Sema combination group compared to the other treatment groups. All groups led to a significant reduction in alanine transaminase levels when compared to high-fat, high-carbohydrate-fed wild type. However, no significant difference in alanine transaminase levels was observed among the treatment groups. In the ob/ob mice study, Sema did not cause body weight loss. Moreover, the EPGN2154 and the combination groups had a lower NAFLD Activity Score and incidence of advanced-stage hepatic fibrosis than the Sema group. CONCLUSIONS: EPGN2154 demonstrated a hepato-protective effect independent of body weight loss in preclinical NASH models.

Drug-Eluting Embolic Loaded with Tyrosine Kinase Inhibitor Targeted Therapies for Transarterial Chemoembolization in a VX2 Model.

Drug-eluting embolic transarterial chemoembolization (DEE-TACE) improves the overall survival of hepatocellular carcinoma (HCC), but the agents used are not tailored to HCC. Our patented liposomal formulation enables the loading and elution of targeted therapies onto DEEs. This study aimed to establish the safety, feasibility, and pharmacokinetics of sorafenib or regorafenib DEE-TACE in a VX2 model. DEE-TACE was performed in VX2 hepatic tumors in a selective manner until stasis using liposomal sorafenib- or regorafenib-loaded DEEs. The animals were euthanized at 1, 24, and 72 h timepoints post embolization. Blood samples were taken for pharmacokinetics at 5 and 20 min and at 1, 24, and 72 h. Measurements of sorafenib or regorafenib were performed in all tissue samples on explanted hepatic tissue using the same mass spectrometry method. Histopathological examinations were carried out on tumor tissues and non-embolized hepatic specimens. DEE-TACE was performed on 23 rabbits. The plasma concentrations of sorafenib and regorafenib were statistically significantly several folds lower than the embolized liver at all examined timepoints. This study demonstrates the feasibility of loading sorafenib or regorafenib onto commercially available DEEs for use in TACE. The drugs eluted locally without release into systemic circulation.

Hybrid plasmonic metasurface as enhanced Raman hot-spots for pesticide detection at ultralow concentrations.

A surface-enhanced Raman scattering (SERS) active metasurface composed of metallic nanohole arrays and metallic nanoparticles is developed. The metasurface can operate in aqueous environments, achieves an enhancement factor of 1.83 × 109 for Rhodamine 6G, and enables the detection of malachite green at a concentation of 0.46 ppb.

Tuning the Functionalization of Graphite for Hydrovoltaic Power Generation.

The recent discovery of hydrovoltaic devices for power generation has led to a rapid growth into new materials for harvesting energy specifically for this research field. Of the materials investigated, carbon materials have dominated, and graphene oxide (GO) has emerged as the leader. While graphite is conductive, it does not have functional groups to strongly interact with water, and highly functionalized GO forms strong interaction with water to generate necessary surface charges but does not typically have high conductivity. Herein, we report the fabrication and functionalization of a graphite-based structure, controlling the extent of oxidation to balance the effects of conductivity and functionalization to achieve high power outputs in hydrovoltaics. Devices prepared using the functionalized graphite achieve a power output of 53.3 µW/g. High power output and good film stability are key advances toward the practical application of hydrovoltaic devices for renewable energy.

Normalization of cholesterol metabolism in spinal microglia alleviates neuropathic pain.

Neuroinflammation is a major component in the transition to and perpetuation of neuropathic pain states. Spinal neuroinflammation involves activation of TLR4, localized to enlarged, cholesterol-enriched lipid rafts, designated here as inflammarafts. Conditional deletion of cholesterol transporters ABCA1 and ABCG1 in microglia, leading to inflammaraft formation, induced tactile allodynia in naive mice. The apoA-I binding protein (AIBP) facilitated cholesterol depletion from inflammarafts and reversed neuropathic pain in a model of chemotherapy-induced peripheral neuropathy (CIPN) in wild-type mice, but AIBP failed to reverse allodynia in mice with ABCA1/ABCG1-deficient microglia, suggesting a cholesterol-dependent mechanism. An AIBP mutant lacking the TLR4-binding domain did not bind microglia or reverse CIPN allodynia. The long-lasting therapeutic effect of a single AIBP dose in CIPN was associated with anti-inflammatory and cholesterol metabolism reprogramming and reduced accumulation of lipid droplets in microglia. These results suggest a cholesterol-driven mechanism of regulation of neuropathic pain by controlling the TLR4 inflammarafts and gene expression program in microglia and blocking the perpetuation of neuroinflammation.

Therapeutic efficacy of α7 ligands after acute ischaemic stroke is linked to conductive states of α7 nicotinic ACh receptors.

BACKGROUND AND PURPOSE: Targeting α7 nicotinic ACh receptors (nAChRs) in neuroinflammatory disorders including acute ischaemic stroke holds significant therapeutic promise. However, therapeutically relevant signalling mechanisms remain unidentified. Activation of neuronal α7 nAChRs triggers ionotropic signalling, but there is limited evidence for it in immunoglial tissues. The α7 ligands which are effective in reducing acute ischaemic stroke damage promote α7 ionotropic activity, suggesting a link between their therapeutic effects for treating acute ischaemic stroke and activation of α7 conductive states. EXPERIMENTAL APPROACH: This hypothesis was tested using a transient middle cerebral artery occlusion (MCAO) model of acute ischaemic stroke, NS6740, a known selective non-ionotropic agonist of α7 nAChRs and 4OH-GTS-21, a partial α7 agonist. NS6740-like ligands exhibiting low efficacy/potency for ionotropic activity will be referred to as non-ionotropic agonists or "metagonists". KEY RESULTS: 4OH-GTS-21, used as a positive control, significantly reduced neurological deficits and brain injury after MCAO as compared to vehicle and NS6740. By contrast, NS6740 was ineffective in identical assays and reversed the effects of 4OH-GTS-21 when these compounds were co-applied. Electrophysiological recordings from acute hippocampal slices obtained from NS6740-injected animals demonstrated its remarkable brain availability and protracted effects on α7 nAChRs as evidenced by sustained (>8 h) alterations in α7 ionotropic responsiveness. CONCLUSION AND IMPLICATIONS: These results suggest that α7 ionotropic activity may be obligatory for therapeutic efficacy of α7 ligands after acute ischaemic stroke yet, highlight the potential for selective application of α7 ligands to disease states based on their mode of receptor activation.

Targeting toll-like receptor-4 (TLR4)-an emerging therapeutic target for persistent pain states.

Toll-like receptors (TLRs) are a family of pattern recognition receptors that initiate signaling in innate and adaptive immune pathways. The highly conserved family of transmembrane proteins comprises an extracellular domain that recognizes exogenous and endogenous danger molecules and an ectodomain that activates downstream pathways in response. Recent studies suggest that continuous activation or dysregulation of TLR signaling may contribute to chronic disease states. The receptor is located not only on inflammatory cells (meningeal and peripheral macrophages) but on neuraxial glia (microglia and astrocytes), Schwann cells, fibroblasts, dorsal root ganglia, and dorsal horn neurons. Procedures blocking TLR functionality have shown pronounced effects on pain behavior otherwise observed in models of chronic inflammation and nerve injury. This review addresses the role of TLR4 as an emerging therapeutic target for the evolution of persistent pain and its role in noncanonical signaling, mediating anomalous pro-algesic actions of opiates. Accordingly, molecules targeting inhibition of this receptor have promise as disease-modifying and opioid-sparing alternatives for persistent pain states.

Systemic TAK-242 prevents intrathecal LPS evoked hyperalgesia in male, but not female mice and prevents delayed allodynia following intraplantar formalin in both male and female mice: The role of TLR4 in the evolution of a persistent pain state.

OBJECTIVE: Pain resulting from local tissue injury or inflammation typically resolves with time. Frequently, however, this pain may unexpectedly persist, becoming a pathological chronic state. Increasingly, the innate and adaptive immune systems are being implicated in the initiation and maintenance of these persistent conditions. In particular, Toll-like receptor 4 (TLR4) signaling has been shown to mediate the transition to a persistent pain state in a sex-dependent manner. In the present work, we explored this contribution using the TLR4 antagonist, TAK-242. METHODS: Male and female C57Bl/6 mice were given intravenous (IV), intrathecal (IT), or intraperitoneal (IP) TAK-242 prior to IT delivery of lipopolysaccharide (LPS), and tactile reactivity was assessed at regular intervals over 72-h. Additional groups of mice were treated with IP TAK-242 prior to intraplantar formalin, and flinching was monitored for 1-h. Tactile reactivity was assessed at 7-days after formalin delivery. RESULTS: LPS evoked TNF release from male and female macrophages and RAW267.4 cells, which was blocked in a concentration dependent fashion by TAK-242. In vivo, IT LPS evoked tactile allodynia to a greater degree in male than female mice. TAK-242, given by all routes, prevented development of IT LPS-induced tactile allodynia in male animals, but did not reverse their established allodynia. TLR4 deficiency and TAK-242 treatment attenuated IT LPS-induced allodynia in male, but not female mice. In the formalin model, pre-treatment with TAK-242 did not affect Phase 1 or Phase 2 flinching, but prevented the delayed tactile allodynia in both male and unexpectedly in female mice (Phase 3). CONCLUSIONS: Together, these results suggest that TAK-242 is a TLR4 antagonist that has efficacy after systemic and intrathecal delivery and confirms the role of endogenous TLR4 signaling in triggering the development of a delayed allodynia in both male and female mice.

Lead optimization of 2-(piperidin-3-yl)-1H-benzimidazoles: identification of 2-morpholin- and 2-thiomorpholin-2-yl-1H-benzimidazoles as selective and CNS penetrating H1-antihistamines for insomnia.

The structure-activity relationships of 2-(piperidin-3-yl)-1H-benzimidazoles, 2-morpholine and 2-thiomorpholin-2-yl-1H-benzimidazoles are described. In the lead optimization process, the pK(a) and/or logP of benzimidazole analogs were reduced either by attachment of polar substituents to the piperidine nitrogen or incorporation of heteroatoms into the piperidine heterocycle. Compounds 9a and 9b in the morpholine series and 10g in the thiomorpholine series demonstrated improved selectivity and CNS profiles compared to lead compound 2 and these are potential candidates for evaluation as sedative hypnotics.

Influence of pKa on the biotransformation of indene H1-antihistamines by CYP2D6.

Structure-activity relationship studies were conducted to reduce CYP2D6-mediated metabolism in a series of indene H(1)-antihistamines. Reductions in pK(a) via incorporation of a ß-fluoro substituent or a heteroaryl moiety were shown to reduce contributions to metabolism through this pathway. Several compounds, including 8l, 8o, and 12f were identified with promising primary in vitro profiles and reduced biotransformation via CYP2D6.

Identification of a novel selective H1-antihistamine with optimized pharmacokinetic properties for clinical evaluation in the treatment of insomnia.

Analogs of the known H(1)-antihistamine R-dimethindene with suitable selectivity for key GPCRs, P450 enzymes and hERG channel were assessed for metabolism profile and in vivo properties. Several analogs were determined to exhibit diverse metabolism. One of these compounds, 10a, showed equivalent efficacy in a rat EEG/EMG model to a previously identified clinical candidate and a potentially superior pharmacokinetic profile as determined from a human microdose study.

The expanding role of H1 antihistamines: a patent survey of selective and dual activity compounds 2005-2010.

IMPORTANCE OF THE FIELD: Histamine plays a key role in physiological processes through its interaction with H(1-4) histamine receptors. The H(1) receptor is a key element in the pathophysiology of allergic responses. H(1) antihistamine use is a key strategy for therapy in allergy. AREAS COVERED IN THIS REVIEW: Several new chemical entities with improved efficacy in allergic disease have been pursued. Addition of multiple antagonist activities in single compounds has been the focus of current research. Involvement of the H(1) receptor in sleep has led to the evaluation of new compounds as sedative hypnotics. WHAT THE READER WILL GAIN: In all, 57 patents detail the evolution of new chemical entities. Dual H(1)-CC-chemokine receptor-3 and H(1)-H(3) antagonists have entered the clinic for allergic indications. Efforts to develop H(1) antihistamines as sedative hypnotics have increased, with several compounds entering the clinic. The dual H(1)-5-HT(2A) antagonist doxepin has been approved for sleep disorders while another compound is currently in clinical trials. TAKE HOME MESSAGE: The development of multiple activity H(1) antihistamines in allergy has met with limited success due in part to a competitive commercial environment. New sedative hypnotics may show potential but will need to demonstrate significant benefits in an increasingly competitive landscape.

The discovery and structure-activity relationships of 2-(piperidin-3-yl)-1H-benzimidazoles as selective, CNS penetrating H1-antihistamines for insomnia.

A series of 2-(3-aminopiperidine)-benzimidazoles were identified as selective H(1)-antihistamines for evaluation as potential sedative hypnotics. Representative compounds showed improved hERG selectivity over a previously identified 2-aminobenzimidazole series. While hERG activity could be modulated via manipulation of the benzimidazole N1 substituent, this approach led to a reduction in CNS exposure for the more selective compounds. One example, 9q, retained a suitable selectivity profile with CNS exposure equivalent to known centrally active H(1)-antihistamines.

Selectivity profiling of novel indene H(1)-antihistamines for the treatment of insomnia.

A series of indene analogs of the H(1)-antihistamine (-)-R-dimethindene was evaluated for selectivity in the search for potentially improved sedative-hypnotics. Variation of the 6-substitutent in the indene core in combination with a pendant electron rich heterocycle led to the identification of several potent H(1)-antihistamines with desirable selectivity over CYP enzymes, the M(1) muscarinic receptor and the hERG channel. These compounds were candidates for further ADME profiling and in vivo evaluation.

Novel benzothiophene H1-antihistamines for the treatment of insomnia.

SAR of lead benzothiophene H(1)-antihistamine 2 was explored to identify backup candidates with suitable pharmacokinetic profiles for an insomnia program. Several potent and selective H(1)-antihistamines with a range of projected half-lives in humans were identified. Compound 16d had a suitable human half-life as demonstrated in a human microdose study, but variability in pharmacokinetic profile, attributed to metabolic clearance, prevented further development of this compound. Compound 28b demonstrated lower predicted clearance in preclinical studies, and may represent a more suitable backup compound.

Characterization of novel selective H1-antihistamines for clinical evaluation in the treatment of insomnia.

Analogues of the known H(1)-antihistamine R-dimethindene were profiled as potential agents for the treatment of insomnia. Several highly selective compounds were efficacious in rodent sleep models. On the basis of overall profile, indene 1d and benzothiophene 2a had pharmacokinetic properties suitable for evaluation in night time dosing. Compound 2a did not show an in vivo cardiovascular effect from weak hERG channel inhibition.

A pharmacokinetic evaluation of five H(1) antagonists after an oral and intravenous microdose to human subjects.

AIMS: To evaluate the pharmacokinetics (PK) of five H(1) receptor antagonists in human volunteers after a single oral and intravenous (i.v.) microdose (0.1 mg). METHODS: Five H(1) receptor antagonists, namely NBI-1, NBI-2, NBI-3, NBI-4 and diphenhydramine, were administered to human volunteers as a single 0.1-mg oral and i.v. dose. Blood samples were collected up to 48 h, and the parent compound in the plasma extract was quantified by high-performance liquid chromatography and accelerator mass spectroscopy. RESULTS: The median clearance (CL), apparent volume of distribution (V(d)) and apparent terminal elimination half-life (t(1/2)) of diphenhydramine after an i.v. microdose were 24.7 l h(-1), 302 l and 9.3 h, and the oral C(max) and AUC(0-infinity) were 0.195 ng ml(-1) and 1.52 ng h ml(-1), respectively. These data were consistent with previously published diphenhydramine data at 500 times the microdose. The rank order of oral bioavailability of the five compounds was as follows: NBI-2 > NBI-1 > NBI-3 > diphenhydramine > NBI-4, whereas the rank order for CL was NBI-4 > diphenhydramine > NBI-1 > NBI-3 > NBI-2. CONCLUSIONS: Human microdosing provided estimates of clinical PK of four structurally related compounds, which were deemed useful for compound selection.

Brain-penetrating 2-aminobenzimidazole H(1)-antihistamines for the treatment of insomnia.

The benzimidazole core of the selective non-brain-penetrating H(1)-antihistamine mizolastine was used to identify a series of brain-penetrating H(1)-antihistamines for the potential treatment of insomnia. Using cassette PK studies, brain-penetrating H(1)-antihistamines were identified and in vivo efficacy was demonstrated in a rat EEG/EMG model. Further optimization focused on strategies to attenuate an identified hERG liability, leading to the discovery of 4i with a promising in vitro profile.

Identification of ring-fused pyrazolo pyridin-2-ones as novel poly(ADP-ribose)polymerase-1 inhibitors.

A novel class of PARP-1 inhibitors was identified containing a non-aromatic heterocycle or carbocycle fused to a pyrazolo pyridin-2-one. Compounds displayed low nanomolar binding activity in the PARP-1 binding assay and submicromolar activity in a cell based chemosensitization assay.