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Overactivation of N-methyl-D-aspartate receptor (NMDAR) in the spinal cord dorsal horn (SDH) in the setting of injury represents a key mechanism of neuropathic pain. However, directly blocking NMDAR or its downstream signaling, interaction between postsynaptic density-95 (PSD-95) and neuronal nitric oxide synthase (nNOS), causes analgesic tolerance, mainly due to GABAergic disinhibition. The aim of this study is to explore the possibility of preventing analgesic tolerance through co-targeting NMDAR downstream signaling and γ-aminobutyric acid type A receptors (GABAARs). Methods: Mechanical/thermal hyperalgesia were quantified to assess analgesic effects. Miniature postsynaptic currents were tested by patch-clamp recording to evaluate synaptic transmission in the SDH. GABA-evoked currents were tested on HEK293 cells expressing different subtypes of recombinant GABAARs to assess the selectivity of (+)-borneol and ZL006-05. The expression of α2 and α3 subunits of GABAARs and BDNF, and nNOS-PSD-95 complex levels were analyzed by western blotting and coimmunoprecipitation respectively. Open field test, rotarod test and Morris water maze task were conducted to evaluate the side-effect of ZL006-05. Results: (+)-Borneol selectively potentiated α2- and α3-containing GABAARs and prevented the disinhibition of laminae I excitatory neurons in the SDH and analgesic tolerance caused by chronic use of ZL006, a nNOS-PSD-95 blocker. A dual-target compound ZL006-05 produced by linking ZL006 and (+)-borneol through an ester bond blocked nNOS-PSD-95 interaction and potentiated α2-containing GABAAR selectively. Chronic use of ZL006-05 did not produce analgesic tolerance and unwanted side effects. Conclusion: By targeting nNOS-PSD-95 interaction and α2-containing GABAAR simultaneously, chronic use of ZL006-05 can avoid analgesic tolerance and unwanted side effects. Therefore, we offer a novel candidate drug without analgesic tolerance for treating neuropathic pain.

The discovery of mammalian target of rapamycin (mTOR) kinase inhibitors has always been a research hotspot of antitumor drugs. Consensus scoring used in the docking study of mTOR kinase inhibitors usually improves hit rate of virtual screening. Herein, we attempt to build a series of consensus scoring models based on a set of the common scoring functions. In this paper, twenty-five kinds of mTOR inhibitors (16 clinical candidate compounds and 9 promising preclinical compounds) are carefully collected, and selected for the molecular docking study used by the Glide docking programs within the standard precise (SP) mode. The predicted poses of these ligands are saved, and revaluated by twenty-six available scoring functions, respectively. Subsequently, consensus scoring models are trained based on the obtained rescoring results by the partial least squares (PLS) method, and validated by Leave-one-out (LOO) method. In addition, three kinds of ligand efficiency indices (BEI, SEI, and LLE) instead of pIC50 as the activity could greatly improve the statistical quality of build models. Two best calculated models 10 and 22 using the same BEI indice have following statistical parameters, respectively: for model 10, training set R2 = 0.767, Q2 = 0.647, RMSE = 0.024, and for test set R2 = 0.932, RMSE = 0.026; for model 22, raining set R2 = 0.790, Q2 = 0.627, RMSE = 0.023, and for test set R2 = 0.955, RMSE = 0.020. These two consensus scoring model would be used for the docking virtual screening of novel mTOR inhibitors.

Summary Notch signaling is critically involved in neural development, but the downstream effectors remain incompletely understood. In this study, we cultured neurospheres from Nestin-Cre-mediated conditional Rbp-j knockout (Rbp-j cKO) and control embryos and compared their miRNA expression profiles using microarray. Among differentially expressed miRNAs, miR-342-5p showed upregulated expression as Notch signaling was genetically or pharmaceutically interrupted. Consistently, the promoter of the miR-342-5p host gene, the Ena-vasodilator stimulated phosphoprotein-like (Evl), was negatively regulated by Notch signaling, probably through HES5. Transfection of miR-342-5p promoted the differentiation of neural stem cells (NSCs) into intermediate neural progenitors (INPs) in vitro and reduced the stemness of NSCs in vivo. Furthermore, miR-342-5p inhibited the differentiation of neural stem/intermediate progenitor cells into astrocytes, likely mediated by targeting GFAP directly. Our results indicated that miR-342-5p could function as a downstream effector of Notch signaling to regulate the differentiation of NSCs into INPs and astrocytes commitment., Graphical Abstract, Highlights • miR-342-5p acts as a downstream effector of canonical Notch signaling • Notch signal inhibits miR-342-5p expression by regulating its host gene Evl • miR-342-5p promotes the transition of NSCs into INPs • Astrocyte commitment was suppressed by miR-342-5p targeting GFAP, In this article, Han and colleagues show that miR-342-5p acts as a downstream effector of Notch signaling in the mouse CNS. Notch signal inhibits miR-342-5p expression by regulating its host gene Evl. And with attenuated Notch signal in NSCs, miR-342-5p is upregulated to promote NSCs transition into INPs, and to inhibit astrocyte commitment by targeting GFAP.

(+)-Borneol, a bicyclic monoterpene, has been shown to possess valuable biological properties and potential as a pharmaceutical agent due to anti-inflammatory, anti-oxidant and GABA receptor-enhancing functions; it also enhances the permeability of the blood brain barrier to improve the efficacy of CNS drugs. In this study, we have developed a simple, selective, and rapid liquid chromatography-tandem mass spectrometry method for the assay of (+)-borneol in rat plasma. Verapamil was used as an internal standard. Plasma samples were deproteinized using methanol. The analyte was detected by a mass spectrometer with positive atmospheric pressure chemical ionization by multiple reaction monitoring mode for transitions at m/z [M + H]+ 137.2 → 81.0 for (+)-borneol and 455.2 → 165.1 for verapamil. The method has been fully validated to ensure good selectivity, a satisfactory lower limit of quantification at 10.0 ng/mL, acceptable intra- and inter-day accuracy, and high precision. The method was used for the pharmacokinetic evaluation of (+)-borneol in Sprague-Dawley rats after intravenous, oral, and sublingual administration. The results indicate that oral bioavailability of (+)-borneol was extremely low but sublingual administration yielded rapid absorption and favorable bioavailability of (+)-borneol.