ObjectiveTo investigate the effect and significance of early coronary artery bypass graft (CABG) on the expression level of ionophorous protein at infracted border zone (IBZ) in dog with acute myocardial infarction. MethodsThe anterior descending coronary artery of all thirty healthy mongrel dogs were ligated into myocardial infarction model, whose successful criteria was that the regional myocardium supplied by ligated coronary artery became darker. Coronary artery bypass surgery performed at different time points after myocardial infarction (in the 1st week, the 2nd week, the 4th week, the 6th week respectively) was as an experimental group. While myocardial infarction without coronary artery bypass surgery was set up as a control group. Myocardial tissue without ligation of coronary artery was as a normal group. After 8 weeks, myocardial specimens were cut out in the experimental group and the control group. The local expression levels of ionophorous proteins such as Cav1.2, Kv4.3 and KchIP2 mRNA were detected by means of reverse transcription- polymerase chain reaction (RT-PCR) at normal myocardium and IBZ of the experimental group and the control group. ResultsFour dogs in every experimental group and all dogs in the control group survived to the end of the study. Three myocardial ion channel proteins expression in the control group were lower than those of the normal group or the experimental group significantly (P<0.01). Cav1.2 mRNA expression in the experimental group in the 4th week or the 6th week was lower than that in the normal group significantly (P<0.05). Kv4.3 and KchIP2 mRNA expression in the experimental group in the 4th week or the 6th week were lower than those in the normal group and the experimental group significantly in the 1st week or the 2nd week (P<0.05). ConclusionEarly CABG surgery for acute myocardial infarction could lessen the changes of expression level of ionophorous protein at infracted border zone (IBZ) of dog with acute myocardial infarction. Especially, CABG surgery among two weeks could improve expression level of ionophorous protein, and reduce the effect of ischemia for ionophorous protein and myocardial electrophysiology at IBZ.
Objective To investigate the feasibility of recombinant lentivirus (LVs) mediated hyperpolarization- activated cyclic nucleotide-gated cation channel 4 (HCN4) gene transfecting rat bone mesenchymal stem cells (BMSCs) so as to construct the biological pacemaker cells. Methods Sprague Dawley rats at the age of 3-5 weeks were selected to isolate and culture BMSCs using modified whole bone marrow adherent culture method. LVs was used as carrier, and enhanced green fluorescent protein (EGFP) as marker to build LVs-HCN4-EGFP virus liquid. The BMSCs at passage 3 were transfected with LVs-HCN4-EGFP virus liquid (experimental group) and LVs-EGFP null virus liquid (control group). Fluorescence microscope was used to observe the green fluorescent protein expression after 24, 48, and 72 hours of transfection; Western blot method was used to detect the HCN4 protein expression. The electrophysiology was used to detect the pacemaker current in the experimental group. Results After transfection, BMSCs in the experimental group showed normal morphology and good growth; scattered green fluorescence could be seen at 48 hours under fluorescence microscope, with a transfection efficiency of about 10%; the fluorescence expression increased slightly, with the transfection efficiency of 20% to 25% at 72 hours. While no expression of green fluorescence was seen in the control group. Western blot results showed that the same band expression as a relative molecular mass of HCN4 protein were found at 72 hours after transfection in the experimental group, only weak expression of protein band was seen in the control group; the gray value of the experimental group (33.75 ± 0.41) was significantly higher than that of the control group (23.39 ± 0.33) (t=17.524, P=0.013). In the experimental group, the pacemaker current was recorded, and it could be blocked by CsCl, in accordance with the characteristics of pacemaker current. Conclusion The recombinant LVs mediated HCN4 gene is successfully transfected into rat BMSCs, and the expression of HCN4 protein and the pacemaker current can be detected.
Ion channels are involved in the mechanism of anesthetic action and side effect. The transcription and expression of ion channel genes can be modulated by general anesthetics. The adverse effect of continuous infusion of etomidate has been concerned. However, the effects of etomidate on mRNA expressions of ion channel genes remain unclear. In this study, we exposed Daphnia pulex in 250 μmol/L of etomidate for 240 min and observed the change of heart rate, phototactic behavior and blood glucose during the period of exposure, as well as the mRNA expressions of 120 ion channel genes at the end of the experiment. Compared to the controls, heart rate, phototactic behavior and blood glucose were not influenced by 250 μmol/L of etomidate. According to the quantitative PCR results, 18 of 120 Daphnia pulex ion channel genes transcripts were affected by persistent 240 min exposure to 250 μmol/L of etomidate: 2 genes were upregulated and 16 genes were down-regulated, suggesting that etomidate showed effects on many different ion channels in transcription level. Systematical exploration of transcriptional changes of ion channels could contribute to understanding of the pharmacological mechanism of etomidate.
Chloride voltage-gated channel 7 (CLCN7) gene mutations can cause the disorder of acidification in lacunas and osteolysis, leading to osteopetrosis characterized by increased bone density throughout the body and lysosomal storage diseases. Deafness can be caused by nerve injury for bone compression, negative pressure in the middle ear and otosclerosis. This article will introduce structure and function of CLCN7 gene and CLCN7 protein, osteolysis process, including the introduction of osteoclasts and the mechanism of osteolysis, osteopetrosis, mechanism and treatment of osteopetrosis caused by CLCN7 gene mutations, as well as osteopetrosis and syndromic deafness, in order to provide a basis for clinical diagnosis and treatment.
ObjectiveTo explore the expression of chloride intracellular channel protein 1 (CLIC1) protein in the matched colorectal normal mucosa tissue, colorectal adenoma tissue， and colorectal cancer tissue, and its relationship with tumorigenesis, tumor progression， and prognosis of patients with colorectal cancer . MethodsThe expression of CLIC1 protein was detected in 150 cases of colorectal normal mucosa tissues, 62 cases of colorectal adenoma tissues, and 187 cases of colorectal cancer tissues by using immunohistochemistry tissue microarray, and the relationships between the expression of CLIC1 protein and clinicopathologic features, and the survival rate of patients with colorectal cancer were analyzed. ResultsThe positive rate of CLIC1 protein expression in normal mucosa tissues (26.00%, 39/150), colorectal adenoma tissues (66.13%, 41/62), and colorectal cancer tissues (82.89%, 187/155) increased in turn and the difference was statistically significant (Plt;0.001). The expression of CLIC1 protein was related to TNM staging (P=0.007), but it was not related to gender (P=0.553), age (P=0.206), tumor diameter (P=0.185), tumor differentiation (P=0.062), and tumor location (P=0.598). The median survival time after surgery in patients with CLIC1 protein positive expression was 80 months, and it was 111 months in patients with CLIC1 protein negative expression. The survival rate of patients with CLIC1 protein positive expression was lower than that with CLIC1 protein negative expression by log-rank test (66.40% vs. 80.00%, P=0.031). ConclusionsThe expression of CLIC1 protein is related to the tumorigenesis and progression of colorectal cancer as well as the survival of patients with colorectal cancer. CLIC1 is a potential tumor biomarker.
【摘要】 目的 探讨慢性缺氧对大鼠岩神经节神经元酸敏感离子通道（acid-sensing ion channels，ASICs）亚型3（ASIC3）和亚型2a（ASIC2a）表达的影响。 方法 将12只健康成年SD大鼠随机分为正常组和缺氧组。用免疫组织化学法（PV）观察正常和慢性缺氧大鼠岩神经节神经元ASIC3和ASIC2a的表达。 结果 给予慢性缺氧刺激后，岩神经节ASIC3阳性表达神经元数目增多（Plt;0.05），灰度值降低（Plt;0.05）；而ASIC2a阳性表达神经元数目和灰度值无明显变化（Pgt;0.05）。 结论 慢性缺氧可上调大鼠岩神经节神经元ASIC3的表达，而对ASIC2a的表达无明显影响，提示ASIC3和ASIC2a可能在岩神经节对缺氧的反应中起着不同的作用。【Abstract】 Objective To investigate the effects of chronic hypoxia on expression of acid-sensing ion channels (ASIC) 3 and ASIC2a in neurons of petrosal ganglions of rats. Methods A total of 12 SD rats were randomly assigned to control group and hypoxia group. The expressions of ASIC3 and ASIC2a of the neurons in the petrosal ganglions in the two groups were investigated with the immunohistochemical technique. Results The level of positive ASIC3 expression in the petrosal ganglions was higher in the hypoxia group than that in the control group (Plt;0.05); the difference of positive ASIC2a expression levels between the control group and the hypoxia group was not statistically significant (Pgt;0.05). Conclusion Chronic hypoxia can significantly increase the expression of ASIC3, but not that of ASIC2a, of the neurons in the petrosal ganglions, suggesting their different roles in mediating a cellular response to chronic hypoxia.
Objective To obtain the full-length gene and functional domains of FXYD6 gene which is a cholangiocarcinoma related gene. Methods A new strategy with the integration of bioinformatics and molecular biology was used. Bioinformatical methods were used to analyze the full-length sequence, and to predict the functional domains of its protein. And the full-length sequence of FXYD6 was isolated by polymerase chain reaction from fetal hepatic, brain and spleen cDNA libraries, and then cloned in pGEM-T vector for sequence analyzing. Goldkey Sequence Analyzing Software was used to analyze the sequence of candidate domain without signal peptide.Results The full-length sequence of FXYD6 was isolated by Touch-down PCR from fetal hepatic and brain cDNA library, but was not from spleen cDNA library. The open reading frame Finder software was used in the National Center for Biotechnology Information website to find the most probable encoding regions of FXYD6 gene. And the +1 phase was selected as the template sequence, from 67 bp to 354 bp, to predict the functional domains by Goldkey Sequence Analyzing Software. The signal peptide was located from 1 amino acid (aa) to 17 aa， and the main domain was composed from 18 aa to 34 aa. The region between 35 aa and 57 aa was the transmembrane region. The FHYD peptide chain was highly conserved amino acids. Conclusion The study of full-length cDNA cloning of FXYD6 gene and its functional domains provides the basis for understanding the relationship between the structure and function of FXYD6. More work shall be performed on FXYD6 protein and its influence on the mechanism of cholangiocarcinoma.
Mechanical stress modulates almost all functions of cells. The key to exploring its biological effects lies in studying the perception of mechanical stress and its mechanism of mechanotransduction. This article details the perception and mechanotransduction mechanism of mechanical stress by extracellular matrix, cell membrane, cytoskeleton and nucleus. There are two main pathways for the perception and mechanotransduction of mechanical stress by cells, one is the direct transmission of force, and the other is the conversion of mechanical signal into chemical signal. The purpose of this study is to provide some reference for the exploration of precise treatment of mechanical stress-related diseases and the optimization of construction of tissue engineered organs by mechanical stress.
Objective To summarize the role of Piezo mechanosensitive ion channels in the osteoarticular system, in order to provide reference for subsequent research. Methods Extensive literature review was conducted to summarize the structural characteristics, gating mechanisms, activators and blockers of Piezo ion channels, as well as their roles in the osteoarticular systems. Results The osteoarticular system is the main load-bearing and motor tissue of the body, and its ability to perceive and respond to mechanical stimuli is one of the guarantees for maintaining normal physiological functions of bones and joints. The occurrence and development of many osteoarticular diseases are closely related to abnormal mechanical loads. At present, research shows that Piezo mechanosensitive ion channels differentiate towards osteogenesis by responding to stretching stimuli and regulating cellular Ca2+ influx signals; and it affects the proliferation and migration of osteoblasts, maintaining bone homeostasis through cellular communication between osteoblasts-osteoclasts. Meanwhile, Piezo1 protein can indirectly participate in regulating the formation and activity of osteoclasts through its host cells, thereby regulating the process of bone remodeling. During mechanical stimulation, the Piezo1 ion channel maintains bone homeostasis by regulating the expressions of Akt and Wnt1 signaling pathways. The sensitivity of Piezo1/2 ion channels to high strain mechanical signals, as well as the increased sensitivity of Piezo1 ion channels to mechanical transduction mediated by Ca2+ influx and inflammatory signals in chondrocytes, is expected to become a new entry point for targeted prevention and treatment of osteoarthritis. But the specific way mechanical stimuli regulate the physiological/pathological processes of bones and joints still needs to be clarified. Conclusion Piezo mechanosensitive ion channels give the osteoarticular system with important abilities to perceive and respond to mechanical stress, playing a crucial mechanical sensing role in its cellular fate, bone development, and maintenance of bone and cartilage homeostasis.