目的:探讨酸敏感离子通道(acid-sensing ion channels，ASICs)的四种亚型即ASIC1a、ASIC1b、ASIC2a和ASIC3是否表达于大鼠岩神经节(petrosal ganglion)神经元。方法:采用常规免疫组化法(PV法)，观察正常大鼠岩神经节神经元是否表达ASIC1a、ASIC1b、ASIC2a和ASIC3。结果:在正常大鼠岩神经节神经元，可见ASIC1a、ASIC1b、ASIC2a和ASIC3表达;ASIC1a与ASIC2a，ASIC3与ASIC1b，ASIC3与ASIC1a，ASIC3与ASIC2a在岩神经节神经元上共表达。结论:正常生理情况下，大鼠岩神经节神经元均表达ASIC1a、ASIC1b、ASIC2a和ASIC3;ASICs亚型之间的共表达提示,在岩神经节可能存在ASICs异聚体的方式。
【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.
【Abstract】 Objective To investigate the expression of connexin 40 (Cx40) and hyperpolarization-activated cycl icnucleotide-gated cation channel 4 (HCN4) in rat bone marrow mesenchymal stem cells (BMSCs) cocultured with the sinoatrialnode (SAN) tissues in vitro, so as to evaluate the possibil ity of BMSCs differentiation into SAN cells. Methods BMSCs wereisolated from Sprague Dawley rats (aged 4-6 weeks, male or female) by the adhesive method and cultured; BMSCs at the 3rdpassage were marked with carboxyfluorescein succinimidyl ester, and then were incubated on 6-well culture plate; cell climingsl ices were prepared at the same time. SAN tissue was taken and cut into 0.3 cm × 0.3 cm mass, and then placed into 4℃ PBSsolution. The SAN tissue mass was cocultured with marked BMSCs at the 3rd passage for 3 weeks as the experimental group, andBMSCs at 3rd passage were cultured alone for 1 week as the control group. At 1, 2, and 3 weeks after coculture, the mean integratedabsorbance (MIA) values of Cx40 and HCN4 were measured by Image pro plus 5.0 through the method of immunohistochemistry,and the mRNA expressions of Cx40 and HCN4 were identified by real-time fluorescent quantitative PCR. Results TheMIA values of Cx40 and HCN4 in the experimental group were higher than that in the control group, showing significantdifferences (P lt; 0.01). In the experimental group, the expressions of Cx40 and HCN4 increased gradually with time. The longerthe culture time was, the higher the expressions of Cx40 and HCN4 were, showing significant differences (P lt; 0.05). The mRNAexpressions of Cx40 and HCN4 in the experimental group were significantly higher than those in the control group (P lt; 0.01); inthe experimental group, the mRNA expressions of Cx40 and HCN4 increased gradually with time, showing significant differencesbetween different time points (P lt; 0.05). Conclusion The expressions of Cx40 and HCN4 increase obviously after coculturingBMSCs with SAN tissue, indicating that BMSCs could differentiate into SAN cells by coculturing with SAN tissue in vitro.
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.
Objective To summarize research progress of relationship between chloride intracellular channel protein 1 (CLIC1) and colonic cancer. Method The related literatures in recent years on the relationship between the CLIC1 and the colonic cancer were reviewed and analyzed. Results The CLIC1 could play its physiological function as a chloride ion channel, with a wide tissue distribution and high expression in many tumor tissues. The abnormal expression of CLIC1 could result in many diseases and participate in many processes such as the occurrence, development, metastasis, and treatment of the colonic cancer. Conclusions CLIC1 might be a biomarker for early diagnosis and a target for gene therapy of colonic cancer, key genes regulated its expression, signal transduction pathways involved in occurrence and progression of colonic cancer, and interaction with other related molecules are still unclear, and further study is needed.
Weightlessness in the space environment affects astronauts’ learning memory and cognitive function. Repetitive transcranial magnetic stimulation has been shown to be effective in improving cognitive dysfunction. In this study, we investigated the effects of repetitive transcranial magnetic stimulation on neural excitability and ion channels in simulated weightlessness mice from a neurophysiological perspective. Young C57 mice were divided into control, hindlimb unloading and magnetic stimulation groups. The mice in the hindlimb unloading and magnetic stimulation groups were treated with hindlimb unloading for 14 days to establish a simulated weightlessness model, while the mice in the magnetic stimulation group were subjected to 14 days of repetitive transcranial magnetic stimulation. Using isolated brain slice patch clamp experiments, the relevant indexes of action potential and the kinetic property changes of voltage-gated sodium and potassium channels were detected to analyze the excitability of neurons and their ion channel mechanisms. The results showed that the behavioral cognitive ability and neuronal excitability of the mice decreased significantly with hindlimb unloading. Repetitive transcranial magnetic stimulation could significantly improve the cognitive impairment and neuroelectrophysiological indexes of the hindlimb unloading mice. Repetitive transcranial magnetic stimulation may change the activation, inactivation and reactivation process of sodium and potassium ion channels by promoting sodium ion outflow and inhibiting potassium ion, and affect the dynamic characteristics of ion channels, so as to enhance the excitability of single neurons and improve the cognitive damage and spatial memory ability of hindlimb unloading mice.
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.
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.
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.