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Objective:To evaluate the relationship between hippocampal miR-3065-5p and insulin-like growth factor-1/phosphatidylinositol 3-kinase/protein kinase B(IGF-1/PI3K/Akt)signaling pathway in a mouse model of perioperative neurocognitive disorder (PND).Methods:Eighty clean-grade healthy male C75BL/6 mice, aged 12-14 weeks, weighing 20-30 g, were divided them into 4 groups ( n=20 each) using the random number table method: control group (C group), PND group, miR-3065-5p agonist group (Ag group) and miR-3065-5p agonist negative control group (Ag-NC group). PND model was prepared by internal fixation of tibial fracture under anesthesia with 1.5% isoflurane. Two days before developing the model, miR-3065-5p agomir 2 μl was injected into the lateral ventricle in Ag group, miR-3065-5p agomir negative control 2 μl was injected into the lateral ventricle in Ag-NC group. Morris water maze test and open field test were performed at 7 days after surgery. The mice were sacrificed after the end of test, and hippocampal tissues were obtained for determination of the expression of miR-3065-5p, IGF-1 mRNA and Bcl-2 mRNA (by quantitative real-time polymerase chain reaction) and expression of IGF-1, phosphorylated Akt (p-Akt), phosphorylated glycogen synthase kinase-3β (p-GSK3β) and Bcl-2 (by Western blot). Results:There was no significant difference in each parameter in the open field test among the four groups ( P>0.05). Compared with group C, the postoperative escape latency was significantly prolonged, the percentage of time of stay at the target quadrant was decreased, the number of crossing the original platform was reduced, the expression of miR-3065-5p was up-regulated, and the expression of IGF-1 mRNA, Bcl-2 mRNA, IGF-1, p-Akt, p-GSK3β and Bcl-2 was down-regulated in the other three groups ( P<0.05). Compared with PND group and Ag-NC group, the postoperative escape latency was significantly prolonged, the percentage of time of stay at the target quadrant was decreased, the number of crossing the original platform was reduced, the expression of miR-3065-5p was up-regulated, and the expression of IGF-1 mRNA, Bcl-2 mRNA, IGF-1, p-Akt, p-GSK3β and Bcl-2 was down-regulated in Ag group ( P<0.05). Conclusions:Up-regulation of miR-3065-5p can inhibit the activation of IGF-1/PI3K/Akt signaling pathway, which might be one of the mechanisms of PND developed in mice.
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Microglia are widely present in the central nervous system and participate in various pathophysiological processes.They play an important role in degenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease.In recent years, the study of exosomes produced by microglia activation involved in the pathophysiological processes of various diseases has attracted extensive attention, but the role of exosomes has not been fully clarified.This article reviewed the characteristics and functions of microglia, the characteristics and functions of microglia-derived exosomes and their roles in central neurodegenerative diseases.
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Objective:To evaluate the relationship between microRNA-93-5p and mitochondrial fusion protein-2 (Mfn2) in mouse nerve cells subjected to oxygen-glucose deprivation and reoxygenation (OGD/R).Methods:Mouse neuroblastoma cells were cultured in vitro to logarithmic growth phase.Experiment Ⅰ Cells were divided into 5 groups ( n=20 each) by the random number table method: control group (group C), group OGD/R, miR-93-5p inhibitor group (group I), siRNA-mfn2 plus miR-93-5p group (group siMfn2+ I) and miR-93-5p negative control group (group NC). Oxygen-glucose deprivation: the cells were cultured for 3 h in a low-glucose balanced salt solution at 37 ℃ in an environment of 5% CO 2-95% N 2.Restoration of oxygen and glucose: the cells were cultured in normal medium at 37℃ in 5% CO 2-95% air for 24 h. Group I, group siMfn2+ I and group NC were transfected with miR-93-5p inhibitor, miR-93-5p inhibitor plus siRNA-mfn2 and negative control miRNA, respectively, at 48 h before the OGD/R model was developed.Cell viability was measured by CCK-8 assay.Cell apoptosis rate was measured by flow cytometry.Quantitative real-time polymerase chain reaction was used to detect the expression of miR-93-5p and Mfn2 mRNA.Western blot was used to detect Mfn2 protein expression.Experiment Ⅱ The wild-type (WT)-Mfn2 and mutant (MUT)-Mfn2 were constructed and transfected into neuroblastoma cells with miR-93-5p mimic and miR-93-5p blank control (miR-93-5pNC), respectively.The cells were divided into 4 groups ( n=5 each) after 48 h of transfection by the random number table method: miR-93-5p NC-WT-Mfn2 co-transfection group, miR-93-5p mimic-WT-Mfn2 co-transfection group, miR-93-5p NC-MUT-Mfn2 co-transfection group, and miR-93-5p mimic-MUT-Mfn2 co-transfection group.The activity of luciferases was measured by double luciferase assay. Results:Experiment Ⅰ Compared with group C, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of miR-93-5p was up-regulated, and the expression of Mfn2 protein and mRNA was down-regulated in the other gorups ( P<0.05). Compared with group OGD/R or group NC, the cell viability was significantly increased, the apoptosis rate of cells was decreased, miR-93-5p expression was down-regulated, and the expression of Mfn2 protein and mRNA was up-regulated in group I ( P<0.05). Compared with group I, the cell viability was significantly decreased, the apoptosis rate of cells was increased, and the expression of Mfn2 protein and mRNA was down-regulated in group siMfn2+ I ( P<0.05). Experiment Ⅱ Compared with miR-93-5p NC-WT-Mfn2 co-transfection group, the luciferase activity was significantly decreased in miR-93-5p mimic-WT-Mfn2 co-transfection group ( P<0.05). There was no significant difference in luciferase activity between miR-93-5p NC-MUT-Mfn2 co-transfection group and miR-93-5p mimic-MUT-Mfn2 co-transfection group ( P>0.05). Conclusions:The miR-93-5p expression is up-regulated, which further targetedly down-regulates the expression of Mfn2, and this may be a mechanism of OGD/R in mouse nerve cells.
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Objective:To evaluate the role of hsa_circ_0025853 in hypothermia-induced reduction of oxygen-glucose deprivation and restoration (OGD/R) injury to neuroblastoma cells (SK-N-SH cells). Methods:SK-N-SH cells were cultured in vitro to the logarithmic phase and divided into 4 groups ( n=20 each) using a random number table method: control group (group C), group OGD/R, hypothermia group (group H) and hsa_circ_0025853 small interfering RNA (siRNA) plus hypothermia group (group S+ H). The cells were cultured in normal culture atmosphere in group C. The cells were subjected to OGD for 3 h followed by restoration of oxygen-glucose supply for 24 h in group OGD/R.The cells were subjected to OGD for 3 h followed by restoration of oxygen-glucose supply for 24 h at 32 ℃ in group H. The cells were transfected with siRNA at 48 h before establishing OGD/R model, and the other treatments were similar to those previously described in group H. At 24 h of restoration of oxygen-glucose, cell viability was measured by Cell Counting Kit-8, apoptosis rate were measured by flow cytometry.the expression of dynamin-related protein 1 (Drp1) mRNA and hsa_circ_0025853 was detected by quantitative real-time-polymerase chain reaction, and the expression of Drp1 protein was detected by Western blot. Results:Compared with group C, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of hsa_circ_0025853 was down-regulated, and the expression of Drp1 protein and mRNA was up-regulated in the other 3 groups ( P<0.05). Compared with group OGD/R, the cell viability was significantly increased, the apoptosis rate of cells was decreased, the expression of hsa_circ_0025853 was up-regulated, and the expression of Drp1 protein and mRNA was down-regulated in H and S+ H groups ( P<0.05). Compared with group H, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of hsa_circ_0025853 was down-regulated, and the expression of Drp1 protein and mRNA was up-regulated in group S+ H ( P<0.05). Conclusion:The mechanism by which hypothermia alleviates the OGD/R injury to SK-N-SH cells is related to the up-regulation of hsa_circ_0025853 expression, thus reducing the expression level of Drp1.
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Objective To investigate the clinical efficacy of fixation of distal radius fracture with dorsal instability with locking compression plate (LCP) via radial approach.Methods From September 2009 to October 2012, 21 cases underwent LCP fixation of the distal radius fracture with dorsal instability via radial approach.The study included 14 males and 7 females (mean age, 54.5 years;range, 38-81 years).Twelve cases were injured in traffic accidents, 7 in falls and 2 in high falls.Fracture AO classification was type A3 in 10 cases, type C1 in 8 cases and type C2 in 3 cases.Two cases (one type A3 and one type C1) had malunion.When the lateral column, intermediate column, radial edge and dorsal plane were exposed by radial incision, LCP fixation with bone grafting was performed to restore the height of radial styloid process, ulnar deviation and palmar tilt.According to the GartlandWerley score, wrist joint function was evaluated.Results Mean duration of follow-up was 13.5 months (range, 12 to 24 months).Stage Ⅰ bone union was shown on X-rays, with the healing time of 7.5 weeks.Based on the X-rays at postoperative 6 months, 1 year and 2 years, the shortening of radial styloid process was ≤ 2 mm, mean volar tilt was 12.5°(range, 8°-17°) , mean ulnar tilt was 20.5° (range, 15°-26°), and step-off or gap of the articular surface was ≤ 2 mm.In postoperative wrist motion assay, mean volar flexion was 60°(range, 30°-70°), mean dorsal flexion was 55° (range, 30°-65°), mean radial deviation was 17°(range, 10°-20°), mean ulnar deviation was 25.5° (range, 20°-30°),pronation was 65.5° (range, 60°-70°) , and mean supination was 75.5° (range, 60°-80°).Mean grip strength was 75％ (60％-95％)of the contralateral side.Two cases suffered from pain (one complained of moderate pain and one minor pain occasionally).According to the Gartland-Werley score, 16 cases were rated excellent, 2 good, 2 fair and 1 poor, with the excellent rate of 86％.No complication was found as injury of the superficial branch of radial nerve, infection, nonunion, nail loosening, medium neuritis and tendon injury.Conclusions Lateral column, intermediate column, radial edge and dorsal plane can be shown via the radial approach.LCP fixation combined with bone grafting contributes to fracture anatomical reduction.