This Letter describes the continued optimization of an MLPCN probe molecule (ML012) through an iterative parallel synthesis approach. After exploring extensive modifications throughout the parent structure, we arrived at a more highly M1-selective antagonist, compound 13l (VU0415248). Muscarinic subtype selectivity across all five human and rat receptors for 13l, along with rat selectivity for the lead compound (ML012), is presented.

T-type Ca2+ channel inhibitors hold tremendous therapeutic potential for the treatment of pain, epilepsy, sleep disorders, essential tremor and other neurological disorders; however, a lack of truly selective tools has hindered basic research, and selective tools from the pharmaceutical industry are potentially burdened with intellectual property (IP) constraints. Thus, an MLPCN high-throughput screen (HTS) was conducted to identify novel T-type Ca2+ channel inhibitors free from IP constraints, and freely available through the MLPCN, for use by the biomedical community to study T-type Ca2+ channels. While the HTS provided numerous hits, these compounds could not be optimized to the required level of potency to be appropriate tool compounds. Therefore, a scaffold hopping approach, guided by SurflexSim, ultimately afforded ML218 (CID 45115620) a selective T-Type Ca2+ (Cav3.1, Cav3.2, Cav3.3) inhibitor (Cav3.2, IC50 = 150 nM in Ca2+ flux; Cav3.2 IC50 = 310 nM and Cav3.3 IC50 = 270 nM, respectively in patch clamp electrophysiology) with good DMPK properties, acceptable in vivo rat PK and excellent brain levels. Electrophysiology studies in subthalamic nucleus (STN) neurons demonstrated robust effects of ML218 on the inhibition of T-Type calcium current, inhibition of low threshold spike and rebound burst activity. Based on the basal ganglia circuitry in Parkinson’s disease (PD), the effects of ML218 in STN neurons suggest a therapeutic role for T-type Ca2+ channel inhibitors, and ML218 was found to be orally efficacious in haloperidol-induced catalepsy, a preclinical PD model, with comparable efficacy to an A2A antagonist, a clinically validated PD target. ML218 proves to be a powerful new probe to study T-Type Ca2+ function in vitro and in vivo, and freely available.

T-Type Ca2+ channel inhibitors hold tremendous therapeutic potential for the treatment of pain, epilepsy, sleep disorders, essential tremor, and other neurological disorders; however, a lack of truly selective tools has hindered basic research, and selective tools from the pharmaceutical industry are potentially burdened with intellectual property (IP) constraints. Thus, an MLPCN high-throughput screen (HTS) was conducted to identify novel T-type Ca2+ channel inhibitors free from IP constraints, and freely available through the MLPCN, for use by the biomedical community to study T-type Ca2+ channels. While the HTS provided numerous hits, these compounds could not be optimized to the required level of potency to be appropriate tool compounds. Therefore, a scaffold hopping approach, guided by SurflexSim, ultimately afforded ML218 (CID 45115620), a selective T-type Ca2+ (Cav3.1, Cav3.2, Cav3.3) inhibitor (Cav3.2, IC50 = 150 nM in Ca2+ flux; Cav3.2 IC50 = 310 nM; and Cav3.3 IC50 = 270 nM, respectively in patch clamp electrophysiology) with good DMPK properties, acceptable in vivo rat PK, and excellent brain levels. Electrophysiology studies in subthalamic nucleus (STN) neurons demonstrated robust effects of ML218 on the inhibition of T-type calcium current, inhibition of low threshold spike, and rebound burst activity. Based on the basal ganglia circuitry in Parkinson’s disease (PD), the effects of ML218 in STN neurons suggest a therapeutic role for T-type Ca2+ channel inhibitors, and ML218 was found to be orally efficacious in haloperidol-induced catalepsy, a preclinical PD model, with comparable efficacy to an A2A antagonist, a clinically validated PD target. ML218 proves to be a powerful new probe to study T-type Ca2+ function in vitro and in vivo, and freely available.

There is an increasing amount of literature data showing the positive effects on preclinical anti-Parkinsonian rodent models with selective positive allosteric modulators of metabotropic glutamate receptor 4 (mGlu4).1 However, most of the data generated utilize compounds that have not been optimized for drug-like properties and, as a consequence, they exhibit poor pharmacokinetic properties and thus do not cross the blood-brain barrier. Herein, we report on a series of N-4-(2,5-dioxopyrrolidin-1-yl)-phenylpicolinamides with improved PK properties with excellent potency and selectivity as well as improved brain exposure in rodents. Finally, ML182 was shown to be orally active in the haloperidol induced catalepsy model, a well-established anti-Parkinsonian model.

Herein we report the discovery and SAR of a novel series of M1 agonists based on the MLPCN probe, ML071. From this, VU0364572 emerged as a potent, orally bioavailable and CNS penetrant M1 agonist with high selectivity, clean ancillary pharmacology and enantiospecific activity.

Background

Objectively measured physical activity is low in British children, and declines as childhood progresses. Observational studies suggest that dog-walking might be a useful approach to physical activity promotion in children and adults, but there are no published public health interventions based on dog-walking with children. The Children, Parents, and Pets Exercising Together Study aims to develop and evaluate a theory driven, generalisable, family-based, dog walking intervention for 9-11 year olds.

Methods/design

The Children, Parents, and Pets Exercising Together Study is an exploratory, assessor-blinded, randomised controlled trial as defined in the UK MRC Framework on the development and evaluation of complex interventions in public health. The trial will follow CONSORT guidance. Approximately 40 dog-owning families will be allocated randomly in a ratio of 1.5:1 to receive a simple behavioural intervention lasting for 10 weeks or to a 'waiting list' control group. The primary outcome is change in objectively measured child physical activity using Actigraph accelerometry. Secondary outcomes in the child, included in part to shape a future more definitive randomised controlled trial, are: total time spent sedentary and patterning of sedentary behaviour (Actigraph accelerometry); body composition and bone health from dual energy x-ray absorptiometry; body weight, height and BMI; and finally, health-related quality of life using the PedsQL. Secondary outcomes in parents and dogs are: changes in body weight; changes in Actigraph accelerometry measured physical activity and sedentary behaviour. Process evaluation will consist of assessment of simultaneous child, parent, and dog accelerometry data and brief interviews with participating families.

Discussion

The Children, Parents, and Pets Exercising Together trial should be the first randomised controlled study to establish and evaluate an intervention aimed at dog-based physical activity promotion in families. It should advance our understanding of whether and how to use pet dogs to promote physical activity and/or to reduce sedentary behaviour in children and adults. The trial is intended to lead to a subsequent more definitive randomised controlled trial, and the work should inform future dog-based public health interventions such as secondary prevention interventions in children or adults.

Trial registration number

ISRCTN85939423

Phospholipase D (PLD) catalyzes the conversion of phosphatidylcholine to the lipid second messenger phosphatidic acid. Two mammalian isoforms of PLD have been identified, PLD1 and PLD2, which share 53% sequence identity and are subject to different regulatory mechanisms. Inhibition of PLD enzymatic activity leads to increased cancer cell apoptosis, decreased cancer cell invasion and decreased metastasis of cancer cells; therefore, the development of isoform-specific, PLD inhibitors is a novel approach for the treatment of cancer. Previously, we developed potent dual PLD1/PLD2, PLD1-specific (>1,700-fold selective) and moderately PLD2 preferring (>10-fold preferring) inhibitors. Here, we describe a matrix library strategy that afforded the most potent (PLD2 IC50 = 20 nM) and selective (75-fold selective versus PLD1) PLD2 inhibitor to date, N-(2(1-(3-fluorophenyl)-4-oxo-1,3,8-triazaspiro[4.5]decan-8-yl)ethyl)-2-naphthamide (22a), with an acceptable DMPK profile. Thus, these new isoform-selective PLD inhibitors will enable researchers to dissect the signaling roles and therapeutic potential of individual PLD isoforms to an unprecedented degree.

Abstract

Polyamines spermine and spermidine are highly regulated, ubiquitous aliphatic cations that maintain DNA structure and function as immunomodulators and as antioxidants. Polyamine homeostasis is disrupted after brain injuries, with concomitant generation of toxic metabolites that may contribute to secondary injuries. To test the hypothesis of increased brain polyamine catabolism after traumatic brain injury (TBI), we determined changes in catabolic enzymes and polyamine levels in the rat brain after lateral controlled cortical impact TBI. Spermine oxidase (SMO) catalyzes the degradation of spermine to spermidine, generating H2O2 and aminoaldehydes. Spermidine/spermine-N1-acetyltransferase (SSAT) catalyzes acetylation of these polyamines, and both are further oxidized in a reaction that generates putrescine, H2O2, and aminoaldehydes. In a rat cortical impact model of TBI, SSAT mRNA increased subacutely (6–24 h) after TBI in ipsilateral cortex and hippocampus. SMO mRNA levels were elevated late, from 3 to 7 days post-injury. Polyamine catabolism increased as well. Spermine levels were normal at 6 h and decreased slightly at 24 h, but were normal again by 72 h post-injury. Spermidine levels also decreased slightly (6–24 h), then increased by ∼50% at 72 h post-injury. By contrast, normally low putrescine levels increased up to sixfold (6–72 h) after TBI. Moreover, N-acetylspermidine (but not N-acetylspermine) was detectable (24–72 h) near the site of injury, consistent with increased SSAT activity. None of these changes were seen in the contralateral hemisphere. Immunohistochemical confirmation indicated that SSAT and SMO were expressed throughout the brain. SSAT-immunoreactivity (SSAT-ir) increased in both neuronal and nonneuronal (likely glial) populations ipsilateral to injury. Interestingly, bilateral increases in cortical SSAT-ir neurons occurred at 72 h post-injury, whereas hippocampal changes occurred only ipsilaterally. Prolonged increases in brain polyamine catabolism are the likely cause of loss of homeostasis in this pathway. The potential for simple therapeutic interventions (e.g., polyamine supplementation or inhibition of polyamine oxidation) is an exciting implication of these studies.

Despite advances in treatment, cancer remains the 2nd most common cause of death in the United States. Poor cure rates may result from the ability of cancer to recur and spread after initial therapies have seemingly eliminated detectable signs of disease. A growing body of evidence supports a role for cancer stem cells (CSCs) in tumor regrowth and spread after initial treatment. Thus, targeting CSCs in combination with traditional induction therapies may improve treatment outcomes and survival rates. Unfortunately, CSCs tend to be resistant to chemo- and radiation therapy, and a better understanding of the mechanisms underlying CSC resistance to treatment is necessary. This paper provides an update on evidence that supports a fundamental role for CSCs in cancer progression, summarizes potential mechanisms of CSC resistance to treatment, and discusses classes of drugs currently in preclinical or clinical testing that show promise at targeting CSCs.