Neuroprotective Effects of Leptin on the APP/PS1 Alzheimer's Disease Mouse Model: Role of Microglial and Neuroinflammation.

Background: Microglia are closely linked to Alzheimer's disease (AD) many years ago; however, the pathological mechanisms of AD remain unclear. The purpose of this study was to determine whether leptin affected microglia in the hippocampus of young and aged male APP/PS1 mice. Objective: In a transgenic model of AD, we investigated the association between intraperitoneal injection of leptin and microglia. Methods: We intraperitoneal injection of leptin (1mg/kg) every day for one week and analyzed inflammatory markers in microglia in the hippocampus of adult (6 months) and aged (12 months) APP/PS1 mice. Results: In all leptin treatment group, the brain Aß levels were decrease. We found increased levels of IL-1ß, IL-6 and microglial activation in the hippocampus of adult mice. Using aged mice as an experimental model for chronic neuroinflammation and leptin resistance, the number of Iba-1+ microglia and the levels of IL-1ß/IL-6 in the hippocampus were greatly increased as compared to the adult. But between the leptin treatment and un-treatment, there were no difference. Conclusion: Leptin signaling would regulate the activation of microglia and the release of inflammatory factors, but it is not the only underlying mechanism in the neuroprotective effects of AD pathogenesis.

miR-140 ameliorates neuropathic pain in CCI rats by targeting S1PR1.

OBJECTIVES: Neuropathic pain, with lots of clinical conditions in various diseases, whose physiopathology is implicated in inflammation. MicroRNAs (miRNAs) have largely been shown to exert anti-inflammatory effects against chronic diseases. We then evaluated the effects and regulatory mechanism of miR-140 on neuropathic pain. METHODS: Rats model with neuropathic pain were established via chronic constriction injury (CCI) and verified by determination of mechanical withdrawal threshold (MWT) and paw withdrawal latency (PWL). The expression level of miR-140 was determined via qRT-PCR (quantitative real-time polymerase chain reaction). Intrathecal injection of miR-140 agomiR was conducted to evaluate the influence of miR-140 on CCI rats via evaluation of MWT, PWL and inflammatory factors secretion. The binding target of miR-140 was predicted and characterized via dual luciferase activity assay. RESULTS: Decreased MWT and PWL, as well as increased inflammatory factor secretion, including IL (interleukin)-1ß, IL-6 and interferon-γ (IFN-γ), were found in rats under CCI compared with sham rats. MiR-140 was decreased in rats under CCI. Intrathecal injection of miR-140 agomiR increased MWT and PWL, thus attenuating mechanical and thermal hyperalgesia in CCI rats. Moreover, decreased inflammatory factor secretion in rats under CCI injected with miR-140 agomiR, suggesting a negatively regulatory role of miR-140 on neuroinflammation. MiR-140 could bind with Sphingosine-1-phosphate receptor 1 (S1PR1). S1PR1 agonist, SEW2871, could reverse the suppression of miR-140 on neuropathic pain. CONCLUSIONS: MiR-140 could mollify CCI-stimulated neuropathic pain via targeting S1PR1, suggesting a potential therapeutic target in the treatment of neuropathic pain.

Comparative study of intravenous thrombolysis with rt-PA and urokinase for patients with acute cerebral infarction.

OBJECTIVE: Cerebral infarction has a poor prognosis and causes a serious burden on families and society. Recombinant tissue plasminogen activator (rt-PA) and urokinase (UK) are commonly used thrombolytic agents in the clinic. However, direct and powerful clinical trial evidence to determine the therapeutic effect of rt-PA and UK on intravenous thrombolysis is lacking. METHODS: In this study, 180 patients with acute cerebral infarction were treated with rt-PA or UK. The National Institutes of Health Stroke Scale (NIHSS) scores, Barthel index, bleeding complications, and biomarkers were evaluated. RESULTS: No significant differences in NIHSS or Barthel scores were found between the groups. However, UK increased the risk of intracranial haemorrhage compared with rt-PA. rt-PA had increased activity in reducing serum levels of MMP-9 than UK. CONCLUSION: Intravenous thrombolysis with rt-PA and UK in the time window of acute cerebral infarction can achieve similar therapeutic effects, but rt-PA can further reduce the risk of cerebral haemorrhage and is relatively safer than UK.

Palladium-Catalyzed Dearomative syn-1,4-Carboamination with Grignard Reagents.

A protocol for palladium-catalyzed dearomative functionalization of simple, nonactivated arenes with Grignard reagents has been established. This one-pot method features a visible-light-mediated [4+2] cycloaddition between an arene and an arenophile, and subsequent palladium-catalyzed allylic substitution of the resulting cycloadduct with a Grignard reagent. A variety of arenes and Grignard reagents can participate in this process, forming carboaminated products with exclusive syn-1,4-selectivity. Moreover, the dearomatized products are amenable to further elaborations, providing functionalized alicyclic motifs and pharmacophores. For example, naphthalene was converted into sertraline, one of the most prescribed antidepressants, in only four operations. Finally, this process could also be conducted in an enantioselective fashion, as demonstrated with the desymmetrization of naphthalene.

Chiral Primary Amine Catalyzed Asymmetric α-Benzylation with In Situ Generated ortho-Quinone Methides.

A dual activation strategy integrating primary amine catalysis and Lewis base activation has been developed for an asymmetric α-benzylation reaction. Enamines derived from ß-ketocarbonyls could react effectively with in situ generated ortho-quinone methides under Lewis base activation in asymmetric α-benzylation of ß-ketocarbonyls and α-branched aldehydes. The approach enables the creation of acyclic all-carbon quaternary stereocenters with excellent enantioselectivities and good activity.

Asymmetric Retro-Claisen Reaction by Chiral Primary Amine Catalysis.

The communication describes an enamine-based asymmetric retro-Claisen reaction of ß-diketones by primary amine catalysis. The reaction proceeds via a sequence of stereoselective C-C formation, C-C cleavage, and a highly stereospecific enamine protonation to afford chiral α-alkylated ketones or macrolides with high yields and enantioselectivities. A detailed mechanism was explored on the basis of experimental evidence and computational studies to account for the observed stereocontrol.

Asymmetric α-photoalkylation of ß-ketocarbonyls by primary amine catalysis: facile access to acyclic all-carbon quaternary stereocenters.

We describe the direct construction of all-carbon quaternary stereocenters via α-photoalkylation of ß-ketocarbonyls with high efficacy and enantioselectivities by merging photoredox catalysis and primary amine catalysis. The open-shell photoradical approach enables asymmetric α-alkylations that are difficult under thermal conditions.