GPR17 mediates ischemia-like neuronal injury via microglial activation.

GPR17 is a G (i)-coupled dual receptor, linked to P2Y and CysLT receptors stimulated by uracil nucleotides and cysteinyl leukotrienes, respectively. Recent evidence has demonstrated that GPR17 inhibition ameliorates the progression of cerebral ischemic injury by regulating neuronal death and microglial activation. The present study aimed to assess the detailed regulatory roles of this receptor in oxygen‑glucose deprivation/recovery (OGD/R)‑induced ischemia‑like injury in vitro and explore the underlying mechanism.

NAMPT inhibitor protects ischemic neuronal injury in rat brain via anti-neuroinflammation.

Nicotinamide phosphoribosyltransferase (NAMPT) is an important neuroprotective factor in cerebral ischemia, and it has been reported that NAMPT inhibitors can aggravate neuronal injury in the acute phase. However, because it is a cytokine, NAMPT participates in many inflammatory diseases in the peripheral system, and its inhibitors have therapeutic effects. Following cerebral ischemia, the peripheral and resident inflammatory and immune cells produce many pro-inflammatory mediators in the ischemic area, which induce neuroinflammation and impair the brain.

Specific cell surface labeling of GPCRs using split GFP.

Specific cell surface labeling is essential for visualizing the internalization processes of G-protein coupled receptors (GPCRs) and for gaining mechanistic insight of GPCR functions. Here we present a rapid, specific, and versatile labeling scheme for GPCRs at living-cell membrane with the use of a split green fluorescent protein (GFP). Demonstrated with two GPCRs, GPR17 and CysLT2R, we show that two β-stands (β-stands 10 and 11) derived from a superfolder GFP (sfGFP) can be engineered to one of the three extracellular loop of a GPCR.

Nicotinamide phosphoribosyltransferase inhibitor APO866 induces C6 glioblastoma cell death via autophagy.

APO866 is a potent inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), and inhibits nicotinamide adenine dinucleotide (NAD) synthesis. Our previous study showed that APO866 inhibits the proliferation of C6 glioblastoma cells, but failed to induce apoptosis. Since APO866 inhibits cellular metabolism and such metabolic stress is closely related with autophagy, thus we determined whether APO866 can induce autophagy in C6 glioblastoma cells and whether the autophagy induced by APO866 is pro-death or pro-survival.

CysLT2 receptor mediates lipopolysaccharide-induced microglial inflammation and consequent neurotoxicity in vitro.

Neuroinflammation induced by microglial activation plays a critical role in many neurodegenerative diseases, including Parkinson's disease (PD). Recent studies have indicated that cysteinyl leukotriene receptor 2 (CysLT2R) is involved in inflammation and brain injury after cerebral ischemia. However, the role of CysLT2R in microglial responses associated with PD remains unclear.

Autophagy in synaptic development, function, and pathology.

In the nervous system, neurons contact each other to form neuronal circuits and drive behavior, relying heavily on synaptic connections. The proper development and growth of synapses allows functional transmission of electrical information between neurons or between neurons and muscle fibers. Defects in synapse-formation or development lead to many diseases.

[Research progress on epithelial-mesenchymal transition in cancer recurrence and metastasis].

Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells lose their morphology and function and gradually transformed into mesenchymal-like cells. It is considered that EMT is the main cause for tumor recurrence and metastasis. Many factors are involved in the regulation of EMT, such as E-cadherin, transforming growth factor-β, Wnt signaling pathway, microRNA and EMT-related transcription factors.

[Protective effect of grape seed proanthocyanidin on cultured RGC-5 cells against CoCl2-induced hypoxic injury].

Objective: To investigate the protective effects of grape seed proanthocyanidin extracts (GSPE) against CoCl2-induced hypoxic injury in cultured RGC-5 cells.

Methods: CoCl2(400 μmol/L) was used to induce hypoxic injury in cultured RGC-5 cells; the cells were pretreated with 0,100,200,400 and 800μmol/L GSPE for 24h. The cell viability was assayed by MTT; the apoptosis was detected by Hoechst 33342 staining; the intracellular reactive oxygen species (ROS) was measured by H2DCFDA oxidative reaction.

[Influence of object material and inter-trial interval on novel object recognition test in mice].

Objective: To investigate the efficacy of novel object recognition (NOR) test in assessment of learning and memory ability in ICR mice in different experimental conditions.

Methods: One hundred and thirty male ICR mice were randomly divided into 10 groups: 4 groups for different inter-trial intervals (ITI: 10 min, 90 min, 4 h, 24 h), 4 groups for different object materials (wood-wood, plastic-plastic, plastic-wood, wood-plastic) and 2 groups for repeated test (measured once a day or every 3 days, totally three times in each group). The locomotor tracks in the open field were recorded.

[Application of locomotor activity test to evaluate functional injury after global cerebral ischemia in C57BL/6 mice].

Objective: To evaluate the application of locomotor activity test in functional injury after global cerebral ischemia (GCI) in C57BL/6 mice.

Methods: GCI was induced by bilateral carotid arteries occlusion for 30 min in C57BL/6 mice. Mice were divided into sham group, GCI group and minocycline group.

[Effects of leukotriene D4 on proliferation and migration of lung epithelial A549 cells in vitro].

Objective: To investigate the effects of cysteinyl leukotriene (CysLT) receptor agonist leukotriene D4 (LTD4) on proliferation and migration in lung epithelial A549 cells.

Methods: The expression of CysLT1 receptor and CysLT2 receptor was determined by immunofluoresence staining in A549 cells. A549 cells were treated with LTD4 (0.

[Effects of the water channel aquaporin 4 deficiency on bleomycin-induced lung fibrosis in mice].

Objective: To evaluate the effect of water channel aquaporin 4 (AQP4) on bleomycin-induced lung fibrosis in mice.

Methods: In wild type and AQP4 gene knockout (AQP4-/-) mice, lung fibrosis was induced by injection of bleomycin (3 mg/kg) into the trachea and saline injection was used as a control. At d3, 7, 14, 28 after bleomycin-treatment, mice were randomly sacrificed in batch and the lung coefficient was determined.

[Zileuton, a 5-lipoxygenase inhibitor, attenuates mouse microglial cell-mediated rotenone toxicity in PC12 cells].

Objective: To examine the effect of a selective inhibitor of 5-lipoxygenase (5-LOX) zileuton on microglia-mediated rotenone neurotoxicity.

Methods: The supernatant from different concentrations of rotenone-stimulated mouse microglia BV2 cells was used as the conditioned media (CM) for PC12 cells. The viability of PC12 cells was determined by MTT assay and lactate dehydrogenase (LDH) release.

[Effect of histone deacetylase inhibitor NL101 on rat neurons].

Objective: To investigate the protective effect of histone deacetylase inhibitor NL101 on L-homocysteine (HCA)-induced toxicity in rat neurons, and the toxic effect on normal rat neurons.

Methods: In the presence of NL101 at various concentrations, HCA (5 mmol/L)-induced changes in cell density, necrosis, and viability were determined in the mixed cultures of rat cortical cells and the primary cultures of rat neurons. The direct effect of NL101 on primary neurons was also observed in the absence of HCA.

[Antioxidative effects of cysteinyl leukotriene receptor antagonists montelukast and HAMI 3379 on ischemic injury in rat cortical neurons in vitro].

Objective: To investigate the antioxidative effects of two cysteinyl leukotriene receptors antagonists (CysLT1R and CysLT2R) montelukast and HAMI 3379 on ischemic injury of rat cortical neurons in vitro.

Methods: Cultured rat cortical neurons were pretreated with CysLT1R antagonist montelukast and CysLT2R antagonist HAMI 3379, and then exposed to oxygen-glucose deprivation/recovery (OGD/R）or H2O2. Reactive oxygen species (ROS) mitochondrial membrane potential (MMP) depolarization, neuronal viability and lactate dehydrogenase (LDH) release were determined.

Regulation of rotenone-induced microglial activation by 5-lipoxygenase and cysteinyl leukotriene receptor 1.

The 5-lipoxygenase (5-LOX) products cysteinyl leukotrienes (CysLTs) are potent pro-inflammatory mediators. CysLTs mediate their biological actions through activating CysLT receptors (CysLT(1)R and CysLT(2)R). We have recently reported that 5-LOX and CysLT(1)R mediated PC12 cell injury induced by high concentrations of rotenone (0.

Cerebral ischemia is exacerbated by extracellular nicotinamide phosphoribosyltransferase via a non-enzymatic mechanism.

Intracellular nicotinamide phosphoribosyltransferase (iNAMPT) in neuron has been known as a protective factor against cerebral ischemia through its enzymatic activity, but the role of central extracellular NAMPT (eNAMPT) is not clear. Here we show that eNAMPT protein level was elevated in the ischemic rat brain after middle-cerebral-artery occlusion (MCAO) and reperfusion, which can be traced to at least in part from blood circulation. Administration of recombinant NAMPT protein exacerbated MCAO-induced neuronal injury in rat brain, while exacerbated oxygen-glucose-deprivation (OGD) induced neuronal injury only in neuron-glial mixed culture, but not in neuron culture.

Cysteinyl leukotriene receptor 1 mediates LTD4-induced activation of mouse microglial cells in vitro.

Aim: To investigate the roles of cysteinyl leukotriene receptors CysLT1R and CysLT2R in leukotriene D4 (LTD4)-induced activation of microglial cells in vitro.

Methods: Mouse microglial cell line BV2 was transfected with pcDNA3.1(+)-hCysLT1R or pcDNA3.

HAMI 3379, a CysLT2 receptor antagonist, attenuates ischemia-like neuronal injury by inhibiting microglial activation.

The cysteinyl leukotrienes (CysLTs) are inflammatory mediators closely associated with neuronal injury after brain ischemia through the activation of their receptors, CysLT1R and CysLT2R. Here we investigated the involvement of both receptors in oxygen-glucose deprivation/recovery (OGD/R)-induced ischemic neuronal injury and the effect of the novel CysLT2R antagonist HAMI 3379 [3-({[(1S,3S)-3- carboxycyclohexyl]amino}carbonyl)-4-(3-{4-[4-(cyclo-hexyloxy)butoxy]phenyl}propoxy)benzoic acid] in comparison with the CysLT1R antagonist montelukast. In primary neurons, neither the nonselective agonist leukotriene D4 (LTD4) nor the CysLT2R agonist N-methyl-leukotriene C4 (NMLTC4) induced neuronal injury, and HAMI 3379 did not affect OGD/R-induced neuronal injury.

Biomechanical properties of retinal glial cells: comparative and developmental data.

The biomechanical properties of Müller glial cells may have importance in understanding the retinal tissue alterations after retinal surgery with removal of the inner limiting membrane and during the ontogenetic development, respectively. Here, we compared the viscoelastic properties of Müller cells from man and monkey as well as from different postnatal developmental stages of the rat. We determined the complex Young's modulus E = E' + iE″ in a defined range of deforming frequencies (30, 100, and 200 Hz) using a scanning force microscope, where the real part E' reflects the elastic property (energy storage or elastic stiffness) and the imaginary part E″ reflects the viscous property (energy dissipation) of the cells.

[Research advances on the roles of nicotinamide phosphoribosyltransferase in inflammation].

Nicotinamide phosphoribosyltransferase (Nampt) is also called visfatin or pre-B-cell colony-enhancing factor. The functions of Nampt have been reported as a cytokine, an adipokine and the rate-limiting enzyme in nicotinamide adenine dinucleotide biosynthesis. As a pleiotropic multifunctional protein, Nampt is involved in a variety of physiological and pathological conditions including innate immunity, metabolic disorders, and stress; and Nampt also participates in inflammatory disorders such as acute lung injury, atherosclerosis, myocardial infarct, obesity, type 2 diabetes, and rheumatoid arthritis.

Aggravated inflammation and increased expression of cysteinyl leukotriene receptors in the brain after focal cerebral ischemia in AQP4-deficient mice.

Objective: Aquaporin-4 (AQP4), the main water channel protein in the brain, plays a critical role in water homeostasis and brain edema. Here, we investigated its role in the inflammatory responses after focal cerebral ischemia.

Methods: In AQP4-knockout (KO) and wild-type mice, focal cerebral ischemia was induced by 30 min of middle cerebral arterial occlusion (MCAO).

Nuclear translocation of cysteinyl leukotriene receptor 1 is involved in oxygen-glucose deprivation-induced damage to endothelial cells.

Aim: Cysteinyl leukotriene receptor 1 (CysLT(1) receptor) is located in epithelial cells, and translocates from the plasma membrane to the nucleus in a ligand-dependent manner. Here, we investigated whether CysLT(1) receptors translocated to the nucleus in endothelial cells after ischemic insult in vitro and whether it was involved in ischemic injury to endothelial cells.

Methods: EA.

Nicotinamide phosphoribosyltransferase may be involved in age-related brain diseases.

Nicotinamide phosphoribosyltransferase (NAMPT) is a key enzyme for nicotinamide adenine dinucleotide (NAD) biosynthesis, and can be found either intracellularly (iNAMPT) or extracellularly (eNAMPT). Studies have shown that both iNAMPT and eNAMPT are implicated in aging and age-related diseases/disorders in the peripheral system. However, their functional roles in aged brain remain to be established.

Intracerebroventricular injection of HAMI 3379, a selective cysteinyl leukotriene receptor 2 antagonist, protects against acute brain injury after focal cerebral ischemia in rats.

Cysteinyl leukotrienes (CysLTs) induce inflammatory responses by activating their receptors, CysLT(1)R and CysLT(2)R. We recently reported that CysLT(2)R is involved in neuronal injury, astrocytosis and microgliosis after focal cerebral ischemia in rats. Here, we determined whether HAMI 3379, a selective CysLT(2)R antagonist, protects against acute brain injury after focal cerebral ischemia in rats.