Generation of Dynamical Environmental Conditions using a High-Throughput Microfluidic Device

Mimicking in vivo environmental conditions is crucial for in vitro studies on complex life machinery. However, current techniques targeting live cells and ...

Northwest University

Levo-tetrahydropalmatine (L-THP) is the main active ingredient of traditional Chinese herbal medicine Corydalis and Stephania, which have been used for sedative, neuroleptic, and analgesic purposes. Previous studies have demonstrated that L-THP has antagonistic activation on dopamine receptors. Despite its effectiveness on treating drug addiction, L-THP's underlying molecular mechanisms in modulating methamphetamine (METH) reward behavior remain unclear. In order to clarify the mechanisms behind, we designed an experiment of conditioned place preference (CPP) to investigate the effects of L-THP on METH-induced CPP in mice. We then dissected the underlying molecular mechanisms of L-THP in modulating METH-induced CPP by evaluating accompanying changes in expression of phosphorylated extracellular signal-regulated kinase (p-ERK) in reward-relevant brain regions, including nucleus accumbens (NAc), prefrontal cortex (PFc), caudate putamen (CPu), and hippocampus (Hip), which may mediate the effects of L-THP on METH-induced CPP. The results showed that 1.0 mg/kg METH could induce obvious CPP in mice; 10.0 mg/kg L-THP could significantly attenuate METH-induced CPP in mice, though it could not induce CPP or conditioned place aversion by itself. Moreover, the levels of p-ERK in NAc and PFc of the METH group were significantly higher than that of the saline group. Although there was no evident difference between the levels of p-ERK of the L-THP group with that of the saline group, the levels of p-ERK in NAc and PFc of the M + T group were significantly lower than that of the METH group. There was no striking difference among the levels of p-ERK in CPu and Hip of all experimental groups. Our research suggested that NAc and PFc function as circuits contributing to METH addiction, and the activation of the ERK phosphorylation plays an important role in the mechanisms of METH addiction. Besides, L-THP significantly decreased ERK phosphorylation's high expression induced by METH, which suggested that the inhibitory effect of L-THP on modulating METH reward behavior may be related to the suppression of ERK phosphorylation in NAc and PFc of mice. In conclusion, L-THP could suppress the reward properties of METH, therefore, it may be a promising candidate for the treatment of METH addiction.

Levo-tetrahydropalmatine attenuates methamphetamine reward behavior and the accompanying activation of ERK phosphorylation in mice.

Emerging evidence indicates that the redistribution of phosphatidylethanolamine (PE) across the bilayer of the plasma membrane is an important molecular marker for apoptosis. However, the effect of PE on apoptosis and the underlying mechanism of PE remain unclear. In the current study, MTT and flow cytometric assays were used to examine the effects of PE on apoptosis in SMMC‑7721 cells. The level of mitochondrial membrane potential (ΔΨm) and the expression of Bax, Bcl‑2, caspase‑3, phospho‑Erk and phospho‑Stat1/2 in SMMC‑7721 cells that were exposed to PE were also investigated. The results showed that PE inhibited proliferation, caused G0/G1 phase cell cycle arrest and induced apoptosis in SMMC‑7721 cells in a dose‑dependent manner. Rhodamine 123 staining showed that the treatment of SMMC‑7721 cells with different concentrations of PE for 24 h significantly decreased the level of ΔΨm and exerted dose‑dependent effects. Using immunofluorescence and western blotting, we found that the expression of Bax was upregulated, whereas that of Bcl‑2 was downregulated in PE‑induced apoptotic cells. In addition, these events were accompanied by an increase in caspase‑3 expression in a dose‑dependent manner following PE treatment. PE‑induced apoptosis was accompanied by a decrease in Erk phospho-rylation and by the activation of Stat1/2 phosphorylation in SMMC‑7721 cells. In conclusion, the results suggested that PE‑induced apoptosis is involved in upregulating the Bax/Bcl‑2 protein ratio and decreasing the ΔΨm. Moreover, the results showed that the Erk and Stat1/2 signalling pathways may be involved in the process of PE‑induced apoptosis.

PE‑induced apoptosis in SMMC‑7721 cells: involvement of Erk and Stat signalling pathways.

Previous studies demonstrated that histone acetylation modulated the transcription of associated gene expression and thus contributed to the persistence of addictive behaviors and neuroplasticity. Nonetheless, the roles of histone acetylation in distinct phases of methamphetamine (METH)-induced conditioned place preference (CPP) remain unclear. The current study examines the effects of the histone deacetylases (HDACs) inhibitor sodium butyrate (NaB) on the acquisition, extinction, and reinstatement of METH-induced CPP in mice. Our results showed that 1 mg/kg METH induced CPP in mice after four conditioning sessions. METH-induced CPP was extinguished after three extinction training sessions and could be triggered by the same dose (1 mg/kg) of METH on the reinstatement test day. Meanwhile, NaB (400 mg/kg) per se had no effect on the natural preference of mice, but injections of NaB during the conditioning and extinction phases facilitated the acquisition and extinction of METH-induced CPP, respectively. Additionally, although the effect of a single NaB injection prior to the trigger of CPP reinstatement was not observed, repeated NaB injections during the extinction phase totally blocked the reinstatement of METH-induced CPP. Taken together, our results suggested a specific effect of histone acetylation on modulating distinct phases of METH-induced CPP and that treatment of NaB during the extinction phase not only produced beneficial effects on eliminating already established CPP but also blocked the reinstatement of METH-induced CPP. © 2016 Wiley Periodicals, Inc.

Sodium butyrate modulates a methamphetamine-induced conditioned place preference.

Previous studies demonstrated that dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis played an important role in morphine dependence. Nonetheless, the molecular mechanism underlying morphine-induced HPA axis dysfunction and morphine dependence remains unclear. In the current study, 5'-aza-2'-deoxycytidine (5-aza), an inhibitor of DNA methyltransferases (DNMTs), was used to examine the effects of glucocorticoid receptor (GR) promoter 1 methylation on chronic morphine-induced HPA axis dysfunction and behavioral changes in rats and the underlying mechanism. Our results showed that chronic but not acute morphine downregulated the expression of nuclear GR protein and GR exon 1 variant mRNA, and upregulated the methylation of GR 1 exon promoter in the hippocampus of rats. Meanwhile, 5-aza per se had no effect on observed molecular and behavior change. In contrast, pretreatment of 5-aza into rat hippocampus reversed chronic morphine-induced hypermethylation of GR 1 promoter and decrease in GR expression. Moreover, pretreatment of 5-aza attenuated chronic morphine-enhanced HPA axis reactivity and the naloxone-precipitated somatic signs in morphine-dependent rats. Our results suggest that chronic morphine induced hypermethylation of GR 1 promoter, which then downregulated the expression of hippocampal GR, and was thus involved in chronic morphine-induced dysfunction of the HPA axis and the modulation of morphine dependence. Moreover, chronic morphine-induced hypermethylation of GR 1 promoter may be at least partially due to the increase in hippocampal DNMT 1 expression and its binding at GR 1 promoter in the rat hippocampus. © 2016 Wiley Periodicals, Inc.

Methylation of glucocorticoid receptor gene promoter modulates morphine dependence and accompanied hypothalamus-pituitary-adrenal axis dysfunction.

Oil spill accident and oily water have potential risks to environment and human health, thus need to be imperatively treated. Herein, a magnetic fibrous sorbent was designed via electrospinning of suspension containing polymer and magnetic nanoparticles in one step for remote and efficient oil adsorption. The morphology of the magnetic fibrous sorbent was characterized by scanning electron microscopy. The magnetic property and the wetting behavior were measured by vibrating sample magnetometer and contact angle system, respectively. The results showed that the morphology of the fibers was homogeneous and the magnetic nanoparticles were well dispersed within the fibers. It was also found that this composite sorbent had good magnetic response, special wettability, and remote oil adsorption capacity. We believed this novel polymer/FeO fibrous sorbent could be used as a promising material for the remote oil/water separation.

Magnetic fibrous sorbent for remote and efficient oil adsorption.

Thyroid dyshormonogenesis (DH) is a genetically heterogeneous inherited disorder caused by thyroid hormone synthesis abnormalities. This study aims at comprehensively characterizing the mutation spectrum in Chinese patients with DH.

Jie Zhu

Northwest University

Generation of Dynamical Environmental Conditions using a High-Throughput Microfluidic Device