ABSTRACT
OBJECTIVE@#To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells.@*METHODS@#The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting.@*RESULTS@#The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein.@*CONCLUSION@#The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.
Subject(s)
Humans , Apoptosis/genetics , bcl-2-Associated X Protein , Caspase 3 , Cell Line, Tumor , Cell Proliferation/genetics , MicroRNAs/metabolism , Mitochondria/metabolism , Mitochondrial Permeability Transition Pore , Reactive Oxygen Species , Stomach Neoplasms/pathologyABSTRACT
Objective To investigate the neuroprotective effect and its mechanism of p38 mitogenactivated protein kinase inhibitor after subarachnoid hemorrhage (SAH).Methods Twenty-seven SPF-grade adult male SD rats were selected to induce a SAH model using the prechiasmal pool blood injection.Three dead rats were excluded.Twenty-four rats were randomly divided into four groups:sham operation group,SAH group,dimethyl sulfoxide (DMSO) group,and DMSO +p38 inhibitor group (n =6 in each group).Western blot was used to detect the expression levels of p38,phosphorylation p38,Parkinson's disease protein 7 (DJ-1),autophagy associated gene 5 (Atg5),autophagy adaptor protein p62,microtubule-associated protein Ⅰ Light Chain 3 (LC3-Ⅰ),microtubule-associated protein Ⅱ light chain 3 Ⅱ (LC3-Ⅱ),and the Garcia neurological function score was used to judge the nerve injury.PC12 cell oxygenated hemoglobin was used to induce an in vitro SAH model.They were completely randomly divided into four groups:sham operative group,SAH group,DMSO group,and DMSO + p38 inhibitor group.Fluorescent probe JC-1 was used to observe the changes of mitochondrial membrane potential.Results (1) There were significant differences in the expression of p38,phosphorylation-p38 and DJ-1 in rat brain tissue among the 4 groups (F values were 94.959,150.293 and 698.476,respectively,all P ＜ 0.01).There were significant differences in mitochondrial membrane potential in PC12 cells among the 4 groups (F value was 24.989,P ＜ 0.01).There were significant differences in the expression levels of autophagy related protein LC3-Ⅱ/LC3-Ⅰ ratio,Atg5 and p62 in rat brain tissue among the 4 groups (F values were 235.319,110.490 and 36.311,respectively,all P ＜ 0.01).There was significant difference in nerve function score among the 4 groups (F value was 25.550,P ＜ 0.01).(2) Compared with the sham operative group,the expression levels of p38,phosphorylation-p38 and DJ-1 were upregulated significantly after SAH (from 0.43 ±0.06,0.41 ±0.02 and 0.07 ±0.01 to 0.61 ± 0.08,0.79 ± 0.07 and 0.17 ± 0.03,respectively,all P ＜ 0.01),mitochondria membrane potential depolarization (from 8.29 ±0.28 to 9.23 ±0.42,P ＜0.01);upregulation of Atg5 expression and increase of LC3-Ⅱ/LC3-Ⅰratio (from 0.23 ± 0.04 and 0.25 ± 0.04 to 0.47 ± 0.04 and 0.46 ± 0.04,respectively,all P ＜ 0.01),down regulation of p62 expression (from 1.09 ± 0.14 to 0.54 ± 0.10,P ＜ 0.01);neurological score was decreased (from 17.5 ± 0.6 to 11.3 ± 2.7,P ＜ 0.01);p38 inhibitor was significantly down regulated the expression of phosphorylation-p38 after SAH (from 0.79 ± 0.07 to 0.47 ± 0.04,P ＜ 0.01),the expression of DJ-1 was up-regulated (from 0.17 ± 0.03 to 1.02 ± 0.06,P ＜ 0.01),mitochondrial membrane potential recovery (from 9.23 ±0.42 to 8.47 ±0.36,P ＜0.01),cell autophagy related protein LC3-Ⅱ/LC3-Ⅰ ratio and Atg5 were upregulated(from 0.46 ±0.04 and 0.47 ±0.04 to 0.77 ± 0.06 and 0.95 ± 0.12,all P ＜ 0.01),p62 expression returned to the levels of SAH group (from 0.57 ± 0.09,to 0.54 ± 0.10,P =0.650),and the neurological score was significantly improved (from 11.3 ± 2.7 to 15.5 ± 1.0,P ＜0.01).Conclusions After SAH,the p38 inhibitor downregulates the activity of2 phosphorylation p38.It may inhibit abnormal autophagy and maintain mitochondrial function by up-regulating the expression of DJ-1 protein,and then play a neuroprotective function.
ABSTRACT
Objective To research the expressions of Sirtuin 1 (SIRT1) in colorectal cancer and normal tissue and the relationship with clinicopathologic features.Methods The expression levels of SIRT1 mRNA and protein were detected respectively by quantitative real-time reverse transcriptase PCR (RT-QPCR) and immunohistochemistry (IHC) in 45 cases of colorectal carcinoma and 30 cases of normal mucous membrane tissue,and the relationships between the expression status and clinicopathologic features were analyzed.Results In colorectal carcinoma,the expression of SIRT1 mRNA were higher than that in control group [M(QR):2.488(3.447) vs.1.563(2.867),Z =-2.304,P ＜0.05],so was the protein level (71.1％ vs.43.3％,x2 =5.787,P =0.029).The expression of SIRTI was associated with lymph node metastasis (RT-QPCR:Z =-2.160,P =0.031;IHC:P =0.043),neoplasm stages (RT-QPCR:Z =-2.411,P =0.016;IHC:P =0.008),and might associated with the tissue differentiation (RT-QPCR:x2 =10.864,P =0.004;IHC:P =0.322).On the other hand,no significant differences were observed regarding age,sex,tumor size,gross type,depth of invasion,tumor site and distant metastasis.Conclusion The expression of SIRT1 in colorectal cancer is higher than that in control group,the high level of SIRT1 is related to the tumorigenesis and progression of colorectal cancer as well as correlated with prognosis in colorectal cancer.
ABSTRACT
Proteomics is an emerging branch of bioscience which studies proteome. The main techniques in proteomics include sample preparation in proteomic, two-dimensional gel electrophoresis, two-dimensional difference gel electrophoresis, multidimensional protein identification technology, surface enhanced laser desorption/ionization time-of-flight mass spectrometry. Colorectal cancer is one of the most common cancers worldwide. During the last several years, many advances have been achieved in terms of applications of proteomics in biomarker research for colorectal cancer.
ABSTRACT
Objective To study the feasibility of semi-laminectomy procedures for the management of intradural extramedullary tumors of the spinal cord.Method Retrospective analysis of 19 cases of in-tradural extramedullary tumors of the spinal cord were treated by the approach of semi-laminectomy.including 11 cases of neurilemmoma and 8 cases of meningioma.Results Seventeen cases of extraspinal tumors were totally resection,2 of dumbbell neurilemmomas underwent subtotal resection.No new neurologi-cal disfunetions as well as recurrence or comphcations were found in all cases after the operation.Conclu-sion Semi-laminectomy procedures for the management of intradural extramedullary tumors of the spinal cord is a mini-invasive procedure,and is beneficial to the stability of spine,with the advantages of short hos-pitalization time,slight postoperative reactions and less complications.
ABSTRACT
Objective On the basis of developing a new animal model for oxyhemoglobin (OxyHb) injection into subarachnoid space in mice, this research was to explore the temporal dependence and spatial distribution of OxyHb- induced apoptosis in the mouse brain cells in vivo and the mechanism of neurocyte injury induced by OxyHb. Methods The animal model for OxyHb injection into subarachnoid space in mice was developed. Mice were divided randomly into the experimental group (n=40) and the control group (n= 35). The control group received saline injection (50 μL ) and the experimental group received OxyHb injection (50 μL ), both into the subarachnoid space. The mice of the two groups were subdivided according to different postoperative time (3 h, 6 h, 12 h, 24 h and 48 h). The apoptosis or necrosis of cells was distinguished with microscopy (HE staining), transmission electron microscopy and TUNEL method. Results The distribution of apoptosis was mainly in the ipsilateral neocortex and bilateral hippocampal gyrus. The apoptotic mouse brain cells showed morphological changes in the experimental group by HE staining and transmission electron microscopy. The count of TUNEL-positive cells showed substantial increase in the experimental group, and there was a significant difference between the control and experimental groups, and the number of OxyHb- induced apoptotic cells decreased with time. Conclusion OxyHb in subarachnoid space in mice can induce apoptasis, but not necrosis of mouse brain cells in viro. The apoptotic brain cells show the pattern of temporal dependence and spatial distribution. It is suggested that the early treatment should be the method of first choice for treating the hemorrhagic brain injury.