mS-11, a mimetic of the mSin3-binding helix in NRSF, ameliorates social interaction deficits in a prenatal valproic acid-induced autism mouse model.

Growing evidence suggests pivotal roles for epigenetic mechanisms in both animal models of and individuals with autism spectrum disorders (ASD). Neuron-restrictive silencer factor (NRSF) binds to neuron-restrictive silencing elements in neuronal genes and recruits co-repressors, such as mSin3, to epigenetically inhibit neuronal gene expression. Because dysregulation of NRSF is related to ASD, here we examined the effects of mS-11, a chemically optimized mimetic of the mSin3-binding helix in NRSF, on the behavioral and morphological abnormalities found in a mouse model of valproic acid (VPA)-induced ASD. Chronic treatment with mS-11 improved prenatal VPA-induced deficits in social interaction. Additionally, we found that NRSF mRNA expression was greater in the somatosensory cortex of VPA-exposed mice than of controls. Agreeing with these behavioral findings, mice that were prenatally exposed to VPA showed lower dendritic spine density in the somatosensory cortex, which was reversed by chronic treatment with mS-11. These findings suggest that mS-11 has the potential for improving ASD-related symptoms through inhibition of mSin3-NRSF binding.

A mimetic of the mSin3-binding helix of NRSF/REST ameliorates abnormal pain behavior in chronic pain models.

The neuron-restrictive silencing factor NRSF/REST binds to neuron-restrictive silencing elements in neuronal genes and recruits corepressors such as mSin3 to inhibit epigenetically neuronal gene expression. Because dysregulation of NRSF/REST is related to neuropathic pain, here, we have designed compounds to target neuropathic pain based on the mSin3-binding helix structure of NRSF/REST and examined their ability to bind to mSin3 by NMR. One compound, mS-11, binds strongly to mSin3 with a binding mode similar to that of NRSF/REST. In a mouse model of neuropathic pain, mS-11 was found to ameliorate abnormal pain behavior and to reverse lost peripheral morphine analgesia. Furthermore, even in the less well epigenetically defined case of fibromyalgia, mS-11 ameliorated symptoms in a mouse model, suggesting that fibromyalgia is related to the dysfunction of NRSF/REST. Taken together, these findings show that the chemically optimized mimetic mS-11 can inhibit mSin3-NRSF/REST binding and successfully reverse lost peripheral and central morphine analgesia in mouse models of pain.

3-Cyano-6-(5-methyl-3-pyrazoloamino)pyridines: selective Aurora A kinase inhibitors.

A new class of Aurora A kinase inhibitor was created by transforming 4-(5-methyl-3-pyrazoloamino)pyrimidine moiety of VX-680 to 3-cyano-6-(5-methyl-3pyrazoloamino)pyridine. Compound 6 exhibited a potent Aurora A kinase inhibitory activity, excellent selectivity to Aurora B kinase and other 60 kinases, good cell permeability and good PK profile. Therefore compound 6 was effective in antitumor mice model at a dose of 30 mg/kg po qd without decrease of body weight.

Modulation of Valpha19 NKT cell immune responses by alpha-mannosyl ceramide derivatives consisting of a series of modified sphingosines.

We have demonstrated that analogues of alpha-mannosyl ceramide (alpha-ManCer) consisting of a series of immunosuppressive 2-aminoalcohol derivatives in place of sphingosine promote a greater immune response from mouse invariant Valpha19-Jalpha26 (AV19-AJ33) TCR-bearing NKT (Valpha19 NKT) cells than alpha-ManCer itself. To further characterize the immune responses of Valpha19 NKT cells to the alpha-ManCer analogues, cytokine production by the cells was examined in detail. We found that certain alpha-ManCer derivatives individually induced either Th1- or Th2-dominant cytokine production in culture. The Th1- or Th2-biased immune responses of Valpha19 NKT cells were dependent on MHC class I-like MR1, since they were induced by coculture with the MR1 transfectants previously loaded with the glycolipids and were inhibited in the presence of anti-MR1 antiserum. Presumably, the recognition of the alpha-mannosyl residue of the alpha-ManCer analogues by the invariant TCR is individually modulated, depending on the altered interaction with the groove of the antigen-presenting MR1. Priming of the Valpha19 invariant TCR-transgenic mice in vivo with these glycolipid derivatives resulted in the induction of the Th1- or Th2-biased immune responses. Thus, these alpha-ManCer derivatives are likely to be useful in immunotherapy for either Th1 or Th2 excess autoimmune diseases, modulating the function of Valpha19 NKT cells.

Induction of promotive rather than suppressive immune responses from a novel NKT cell repertoire Valpha19 NKT cell with alpha-mannosyl ceramide analogues consisting of the immunosuppressant ISP-I as the sphingosine unit.

A 2-substituted 2-aminopropane-1,3-diol or 2-aminoethanol is the minimum structure required for the immunosuppressive activity of ISP-I, an antibiotic isolated from the culture broth of Isaria sinclairil. A series of alpha-mannosyl ceramide (alpha-ManCer) analogues was derived from 2-substituted 2-aminopropane-1,3-diols or 2-aminoethanols in place of sphingosine. The newly synthesized glycosides were evaluated for their effects on immune responses. In contrast to the immunosuppressive activity of the precursors, the alpha-ManCer analogues induced immunopromotive responses from invariant Valpha19-Jalpha26 transgenic mouse lymphocytes more effectively than the original alpha-ManCer. Collectively, it is strongly suggested that the 2-substituted 2-aminopropane-1,3-diols and 2-aminoethanols mimic sphingosine in the alpha-ManCer analogues so that they potentially acquire specific antigenicity toward Valpha19 NKT cell, a novel NKT cell subset.

Identification of a potent and orally active non-peptide C5a receptor antagonist.

The anaphylatoxin C5a is a potent chemotactic factor for neutrophils and other leukocytes, and functions as an important inflammatory mediator. Through a high capacity screening followed by chemical optimization, we identified a novel non-peptide C5a receptor antagonist, N-[(4-dimethylaminophenyl)methyl]-N-(4-isopropylphenyl)-7-methoxy-1,2,3,4-tetrahydronaphthalen-1- carboxamide hydrochloride (W-54011). W-54011 inhibited the binding of (125)I-labeled C5a to human neutrophils with a K(i) value of 2.2 nm. W-54011 also inhibited C5a-induced intracellular Ca(2+) mobilization, chemotaxis, and generation of reactive super oxide species in human neutrophils with IC(50) values of 3.1, 2.7, and 1.6 nm, respectively. In C5a-induced intracellular Ca(2+) mobilization assay with human neutrophils, W-54011 did not show agonistic activity at up to 10 microm and shifted rightward the concentration-response curves to C5a without depressing the maximal responses. Examination on the species specificity of W-54011 revealed that it was able to inhibit C5a-induced intracellular Ca(2+) mobilization in neutrophils of cynomolgus monkeys and gerbils but not mice, rats, guinea pigs, rabbits, and dogs. In gerbils, oral administration of W-54011 (3-30 mg/kg) inhibited C5a-induced neutropenia in a dose-dependent manner. The present report is the first description of an orally active non-peptide C5a receptor antagonist that could contribute to the treatment of inflammatory diseases mediated by C5a.