Pharmacological characterization of JWX-A0108 as a novel type I positive allosteric modulator of α7 nAChR that can reverse acoustic gating deficits in a mouse prepulse inhibition model.

The α7 nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca2+-permeable homopentameric ion channel implicated in cognition and neuropsychiatric disorders. Pharmacological enhancement of α7 nAChR function has been suggested for improvement of cognitive deficits. In the present study, we characterized a thiazolyl heterocyclic derivative, 6-(2-chloro-6-methylphenyl)-2-((3-fluoro-4-methylphenyl)amino)thiazolo[4,5-d]pyrimidin-7(6H)-one (JWX-A0108), as a novel type I α7 nAChR positive allosteric modulator (PAM), and evaluated its ability to reverse auditory gating and spatial working memory deficits in mice. In Xenopus oocytes expressing human nAChR channels, application of JWX-A0108 selectively enhanced α7 nAChR-mediated inward current in the presence of the agonist ACh (EC50 value = 4.35 ± 0.12 µM). In hippocampal slices, co-application of ACh and JWX-A0108 (10 µM for each) markedly increased both the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) recorded in pyramidal neurons, but JWX-A0108 did not affect GABA-induced current in oocytes expressing human GABAA receptor α1ß3γ2 and α5ß3γ2 subtypes. In mice with MK-801-induced deficits in auditory gating, administration of JWX-A0108 (1, 3, and 10 mg/kg, i.p.) dose-dependently attenuates MK-801-induced auditory gating deficits in five prepulse intensities (72, 76, 80, 84, and 88 dB). Furthermore, administration of JWX-A0108 (0.03, 0.1, or 0.3 mg/kg, i.p.) significantly reversed MK-801-induced impaired spatial working memory in mice. Our results demonstrate that JWX-A0108 is a novel type I PAM of α7 nAChR, which may be beneficial for improvement of cognitive deficits commonly found in neuropsychiatric disorders such as schizophrenia and Alzheimer's disease.

[Relationship between vitamin D deficiency and early-onset neonatal sepsis].

OBJECTIVE: To evaluate the effect of vitamin D level on early-onset sepsis (EOS) in neonates. METHODS: Seventy-eight full-term neonates with EOS were used as the research group (EOS group). sixty healthy full-term neonates without clinical and/or laboratory features related to infections were used as the control group. Blood samples of the neonates and their mothers in both groups were collected within 72 hours of delivery to determine 25-hydroxyvitamin D(25-OHD) levels. The rate of vitamin D deficiency in the neonates and the level of 25-OHD supplemented to their mothers during pregnancy were compared between the two groups. RESULTS: There was a significant positive correlation between the serum level of 25-OHD of the mothers and that of the neonates in both groups (EOS group: r=0.797, P<0.01; control group: r=0.929, P<0.01). The neonates and their mothers in the EOS group had significantly lower 25-OHD levels than those in the control group (P<0.01). The rate of vitamin D deficiency among the neonates in the EOS group was significantly higher than that of the control group (P<0.01). The level of vitamin D supplemented to the mothers during the last 3 months of pregnancy in the EOS group was significantly lower than that in the control group (P<0.01). CONCLUSIONS: Low serum level of 25-OHD is associated with the development of early-onset sepsis in full-term neonates.

[The structure-activity relationships of novel α7 nicotinic acetylcholine receptor agonists based on indolizine scaffold].

Alpha7 nicotinic acetylcholine receptor（α7 nAChR） is a ligand-gated ion channel critical for cognition, learning and memory. Deficiency of neuronal α7 nAChR has been implicated in the cognitive deficits and neuropsychiatric disorders. Chemical activation of α7 nAChR improves neurological functions in animal models. In this study, we designed and synthesized a series of indolizine derivatives with various substitutions at different positions on the scaffold, and investigated their structure-activity relationships（SAR）. All compounds were screened and evaluated for their agonist activity using the two-electrode voltage clamp recording system in Xenopus oocytes expressing human α7 nAChR. Compound 16 c carrying 6-methylindolizine moiety activates α7 nAChR with EC50 at 1.60 ± 0.19 µmol·L-1 and maximum effect (Emax) of 69.0% ± 2.8% compared with 3 mmol·L-1 ACh. Compound 17 b with 8-cyclopropyl substitution shows an increased Emax of 81.1% ± 9.3% with EC50 at 2.74 ± 0.74 µmol·L-1. The SAR of the series shows that introducing the small hydrophobic groups at 6- or 8- position can improve both potency and maximum effect.