MiR-126 suppresses proliferation and migration of vascular smooth muscle cell treated with oxLDL through MAPK signal pathway / 中国免疫学杂志

Objective:To explore the role of miR-216 and the underlying mechanism in vascular smooth muscle cell treated with oxLDL.Methods: The model was conducted by treating human aortic vascular smooth muscle cell with oxidized low density lipoprotein(oxLDL).The expression of miR-216 was detected by quantitative real-time reverse transcription PCR(qRT-PCR).Cell pro-liferation was tested by CCK-8 assay.Cell migration was measured through Transwell assay.The expression of proliferation marker proteins antigen identified by monoclonal antibody(Ki-67)and proliferating cell nuclear antigen(PCNA),migration marker proteins matrix metalloprotein 9(MMP-9)and vascular endothelial growth factor(VEGF),mitogen-activated protein kinase(MAPK)signal pathway related proteins ERK1/2,p-ERK1/2,p38,p-p38,JNK and p-JNK was detected by Western blot.Results: The expression of miR-216 in model group was lower than the control group(P<0.01).Compared with the model group,the expression of miR-216 in miR-126 mimic group was remarkably enhanced(P<0.001).Cell proliferation and migration in the model group and mimic control group were higher than the control group(P<0.05).Compared with the model group,cell proliferation and migration in miR-126 mimic group were decreased(P<0.05).At the same time,the expression of Ki-67,PCNA,MMP-9 and VEGF in model group and mimic control group was obviously higher than the control group(P<0.01).Compared with the model group,the expression of Ki-67,PCNA, MMP-9 and VEGF in miR-126 mimic group was attenuated(P<0.05).Compared with control group,relative expression rate of p-ERK1/2/ERK1/2,p-p38/p38 and p-JNK/JNK in model group and mimic control group was largely increased(P<0.01).Relative expression rate of p-ERK1/2/ERK1/2,p-p38/p38 and p-JNK/JNK in miR-126 mimic group was lower than the model group(P<0.05).Compared with control group,relative expression level of Ki-67,PCNA,MMP-9 and VEGF in model group was enhanced (P<0.05).Compared with the model group,relative expression level of Ki-67,PCNA,MMP-9 and VEGF in miR-126 mimic group were de-creased(P<0.05)while relative expression level of Ki-67,PCNA,MMP-9 and VEGF in Anisomycin group was elevated(P<0.05).The difference about relative expression level of Ki-67,PCNA,MMP-9 and VEGF was not found between miR-mimic+Anisomycin group and model group.Conclusion: MiR-126 inhibits proliferation and migration of vascular smooth muscle cell treated with oxLDL through MAPK signal pathway

Effect of 5-HT7 receptor agonist on pyramidal neurons in the medial frontal cortex in a rat model of Parkinson's disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the activity of pyramidal neurons in the medial prefrontal cortex (mPFC) of normal and 6-OHDA-lesioned rats and the responses of the neurons to 5-hydroxytryptamine-7 (5-HT(7)) receptor stimulation.</p><p><b>METHODS</b>The changes in spontaneous firing of the pyramidal neurons in the mPFC in response to 5-HT(7) receptor stimulation were observed by extracellular recording in normal and 6-OHDA-lesioned rats.</p><p><b>RESULTS</b>Both systemic and local administration of 5-HT(7) receptor agonist AS 19 resulted in 3 response patterns (excitation, inhibition and no change) of the pyramidal neurons in the mPFC of normal and 6-OHDA-lesioned rats. In normal rats, the predominant response of the pyramidal neurons to AS 19 stimulation was excitatory, and the inhibitory effect of systemically administered AS 19 was reversed by GABAA receptor antagonist picrotoxinin. In the lesioned rats, systemic administration of AS 19 also increased the mean firing rate of the pyramidal neurons, but the cumulative dose for producing excitation was higher than that in normal rats. Systemic administration of AS 19 produced an inhibitory effect in the lesioned rats, which was partially reversed by picrotoxinin. Local administration of AS 19 at the same dose did not change the ?ring rate of the neurons in the lesioned rats.</p><p><b>CONCLUSION</b>The activity of mPFC pyramidal neurons is directly or indirectly regulated by 5-HT7 receptor, and degeneration of the nigrostriatal pathway leads to decreased response of these neurons to AS 19.</p>

Changes of synaptic structure after long-lasting LTP induced by high and low frequency tetanus in slices of the rat visual cortex / 生理学报

Synaptic ultrastructural changes after long-lasting long-term potentiation (L-LTP) induced by 2 and 100 Hz tetanus were investigated by electron microscopic and stereological approach in slices of the developing rat visual cortex (postnatal days 15~21). Both 2 and 100 Hz tetanus-induced L-LTP groups showed significant increases in synaptic interface curvature, synaptic numeric density and postsynaptic density thickness, as well as significant decreases in the cleft width, as compared with the control groups. In addition, the volume density of the active zone (AZ) was increased significantly in the 100 Hz tetanus-induced L-LTP group, but not in the 2 Hz group. The mean lateral area of individual AZ in the 100 Hz group was relatively higher than that in the 2 Hz group. These data suggest that newly formed synapses in the 100 Hz tetanus-induced L-LTP group are larger than those in the 2 Hz group and that 100 Hz tetanus might trigger reorganization or synthesis of postsynaptic cytoskeleton.

Different effects of 2 and 100 Hz tetanus on the expression of long-lasting long-term potentiation in rat visual cortical slices / 生理学报

Long-term potentiation (LTP) can be induced by various tetanic parameters in the mammalian visual cortex. However, little researches have been done on the relationship between the expression of the long-lasting LTP (late phase LTP or L-LTP) lasting more than 3 h and the tetanic parameters. In the present study, the effects of 2 Hz and 100 Hz tetanic parameters on L-LTP of the field potentials were recorded from the layer II/III of the rat visual cortical slices in response to stimulation of the layer IV. As a result, tetanic parameters that had more than 300 pulses reliably induced L-LTP in the postnatal day 15-21 rats. Obviously different L-LTP expressions were induced by 2 Hz and 100 Hz tetani. There was no difference in L-LTP expression induced by the parameters with the same frequency and different total pulses. These data suggest that L-LTPs induced by different frequency parameters may have different induction and maintenance mechanisms; L-LTPs induced by the parameters with the same frequency may have the same mechanisms.

Morphological alteration of the hippocampal synapses in rats prenatally exposed to magnetic resonance imaging magnetic fields / 生理学报

The present study investigated the effects of prenatal exposure to the magnetic resonance imaging (MRI) magnetic fields on the synaptic ultrastructure of hippocampal formation of rats at different postnatal development stages. Pregnant rats with gestation of 12-18 days were exposed to the magnetic fields used for MRI clinical applications. When the offspring were 1, 2, or 5-month-old, the synaptic morphologic parameters were measured in female offspring. In the 2-month-old MRI group, the curvature of synaptic interface, the length of active zone and the surface density per unit volume (S(v)) of active zone in the dentate gyrus (DG) decreased significantly, and the width of synaptic cleft increased in the CA1 area. In the 5-month-old MRI group, the width of synaptic cleft increased, the thickness of postsynaptic density and the curvature of synaptic interface decreased significantly in the CA1 region, and the width of synaptic cleft increased in the DG. No significant change was observed in the 1-month-old group. These results suggest that prenatal exposure to the medical magnetic fields causes synaptic ultrastructural changes. The relationship of these changes with behavioral impairments was discussed.