ABSTRACT
Objective To observe the effect of morphine on the proliferation of glioblastoma T98G and U118MG cells and to explore the possible mechanism. Methods Glioblastoma T98G and U118MG cells were cultured in plates for 24 h and randomly divided into five groups: control (con), morphine 0.1 μmol/L(M1),1.0 μmol/L (M2),10.0 μmol/L (M3) and 100.0 μmol/L (M4). MTS and BrdU methods were used to detect the prolifera-tion of glioblastoma T98G and U118MG cells-treated with morphine for 24 h and 48 h. Western blot analysis was applied for determing the level of p-ERK1/2 and cyclin D1 protein expression.Results Compared with the control group,morphine in M3 and M4 groups significantly promoted the proliferation of T98G and U118MG cells (P<0.05) in a concentration-and time-dependent manner. In addition,the level of ERK1/2 phosphorylation and cyclin D1 protein expression significantly increased in both M3 and M4 groups as compared with those of control group (P<0.05). Conclusions Morphine may promote the proliferation of glioblastoma T98G and U118MG cells through activating the ERK1/2 signaling pathway.
ABSTRACT
<p><b>BACKGROUND</b>Collapsin response mediator protein-2 (CRMP2), a multifunctional cytosolic protein highly expressed in the brain, is degraded by calpain following traumatic brain injury (TBI), possibly inhibiting posttraumatic neurite regeneration. Lipid peroxidation (LP) is involved in triggering postinjury CRMP2 proteolysis. We examined the hypothesis that propofol could attenuate LP, calpain-induced CRMP2 degradation, and brain injury after TBI.</p><p><b>METHODS</b>A unilateral moderate controlled cortical impact injury was induced in adult male Sprague-Dawley rats. The animals were randomly divided into seven groups: Sham control group, TBI group, TBI + propofol groups (including propofol 1 h, 2 h, and 4 h groups), TBI + U83836E group and TBI + fat emulsion group. The LP inhibitor U83836E was used as a control to identify that antioxidation partially accounts for the potential neuroprotective effects of propofol. The solvent of propofol, fat emulsion, was used as the vehicle control. Ipsilateral cortex tissues were harvested at 24 h post-TBI. Immunofluorescent staining, Western blot analysis, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling were used to evaluate LP, calpain activity, CRMP2 proteolysis and programmed cell death. The data were statistically analyzed using one-way analysis of variance and a paired t-test.</p><p><b>RESULTS</b>Propofol and U83836E significantly ameliorated the CRMP2 proteolysis. In addition, both propofol and U83836E significantly decreased the ratio of 145-kDa αII-spectrin breakdown products to intact 270-kDa spectrin, the 4-hydroxynonenal expression and programmed cell death in the pericontusional cortex at 24 h after TBI. There was no difference between the TBI group and the fat emulsion group.</p><p><b>CONCLUSIONS</b>These results demonstrate that propofol postconditioning alleviates calpain-mediated CRMP2 proteolysis and provides neuroprotective effects following moderate TBI potentially by counteracting LP and reducing calpain activation.</p>
Subject(s)
Animals , Male , Rats , Blotting, Western , Brain Injuries , Drug Therapy , Metabolism , Calpain , Metabolism , Intercellular Signaling Peptides and Proteins , Metabolism , Lipid Peroxidation , Nerve Tissue Proteins , Metabolism , Propofol , Therapeutic Uses , Proteolysis , Rats, Sprague-DawleyABSTRACT
<p><b>BACKGROUND</b>Sevoflurane and propofol are widely used anesthetics for surgery. Studies on the mechanisms of general anesthesia have focused on changes in protein expression properties and membrane lipid. MicroRNAs (miRNAs) regulate neural function by altering protein expression. We hypothesize that sevoflurane and propofol affect miRNA expression profiles in the brain, expect to understand the mechanism of anesthetic agents.</p><p><b>METHODS</b>Rats were randomly assigned to a 2% sevoflurane group, 600 μg·kg - 1·min - 1 propofol group, and a control group without anesthesia (n = 4, respectively). Treatment group was under anesthesia for 6 h, and all rats breathed spontaneously with continuous monitoring of respiration and blood gases. Changes in rat cortex miRNA expression profiles were analyzed by miRNA microarrays and validated by quantitative real-time polymerase chain reaction (qRT-PCR). Differential expression of miRNA using qRT-PCR among the control, sevoflurane, and propofol groups were compared using one-way analysis of variance (ANOVA).</p><p><b>RESULTS</b>Of 677 preloaded rat miRNAs, the microarray detected the expression of 277 miRNAs in rat cortex (40.9%), of which 9 were regulated by propofol and (or) sevoflurane. Expression levels of three miRNAs (rno-miR-339-3p, rno-miR-448, rno-miR-466b-1FNx01) were significantly increased following sevoflurane and six (rno-miR-339-3p, rno-miR-347, rno-miR-378FNx01, rno-miR-412FNx01, rno-miR-702-3p, and rno-miR-7a-2FNx01) following propofol. Three miRNAs (rno-miR-466b-1FNx01, rno-miR-3584-5p and rno-miR-702-3p) were differentially expressed by the two anesthetic treatment groups.</p><p><b>CONCLUSIONS</b>Sevoflurane and propofol anesthesia induced distinct changes in brain miRNA expression patterns, suggesting differential regulation of protein expression. Determining the targets of these differentially expressed miRNAs may help reveal both the common and agent-specific actions of anesthetics on neurological and physiological function.</p>