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.
【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.
Objective To explore the effect of hydrostatic pressure on intracellular free calcium concentration ([Ca2+]i) and the gene expression of transient receptor potential vanilloid (TRPV) in cultured human bladder smooth muscle cells (hb-SMCs), and to prel iminarily probe into the possible molecular mechanism of hb-SMCs prol iferation stimulated by hydrostatic pressure. Methods The passage 6-7 hb-SMCs were loaded with Ca2+ indicator Fluo-3/AM. When the hb-SMCs were under 0 cm H2O (1 cm H2O=0.098 kPa) (group A) or 200 cm H2O hydrostatic pressure for 30 minutes (group B) and then removing the 200 cm H2O hydrostatic pressure (group C), the [Ca2+]i was measured respectively by inverted laser anningconfocal microscope. When the hb-SMCs were given the 200 cm H2O hydrostatic pressure for 0 hour, 2 hours, 6 hours, 2 hours, and 24 hours, the mRNA expressions of TRPV1, TRPV2, and TRPV4 were detected by RT-PCR technique. Results The [Ca2+]i of group A, group B, and group C were (100.808 ± 1.724), (122.008 ± 1.575), and (99.918 ± 0.887) U, respectively; group B was significantly higher than groups A and C (P lt; 0.001). The [Ca2+]i of group C decreased to the base l ine level of group A after removing the pressure (t=0.919, P=0.394). The TRPV1, TRPV2, and TRPV4 genes expressed in hb-SMCs under 200 cm H2O hydrostatic pressure at 0 hour, 2 hours, 6 hours, 12 hours, and 24 hours, but the expressions had no obvious changes with time. There was no significant difference in the expressions of TRPV1, TRPV2, and TRPV4 among 3 groups (P gt; 0.05). Conclusion The [Ca2+]i of hb-SMCs increases significantly under high hydrostatic pressure. As possible genes in stretch-activated cation channel, the TRPV1, TRPV2, and TRPV4 express in hb-SMCs under 200 cm H2O hydrostatic pressure. It is possible that the mechanical pressure regulates the [Ca2+]i of hb-SMCs by opening the stretch-activated cation channel rather than up-regulating its expression.
Objective To study the influence of ischemia-reperfusion on the expression of the hyperpolarization activated cycl icnucleotide gated cation channel 4 (HCN4) and to discuss the mechanism of functional disturbance of sinoatrial node tissue (SANT) after ischemia reperfusion injury (IRI). Methods Eighty five healthy adult rabbits, weighing 2-3 kg, were randomly divided into 3 groups: control group [a suture passed under the root section of right coronary artery (RCA) without l igation, n=5], experimental group A (occluding the root section of RCA for 30 minutes, then loosening the root 2,4, 8 and 16 hours, n=10), experimental group B (occluding the root section of RCA for 1 hour, then loosening the root 2, 4,8 and 16 hours, n=10). At the end of the reperfusion, the SANT was cut off to do histopathological, transmission electronmicroscopical and immunohistochemical examinations and semi-quantitative analysis. Results The result of HE stainingshowed that patho-injure of sinoatrial node cell (SANC) happened in experimental groups A and B after 2 hours of reperfusion, the longer the reperfusion time was, the more serious patho-injure of SANC was after 4 and 8 hours of reperfusion, SANC reached peak of damage after 8 to 16 hours of reperfusion; patho-injure of SANC was more serious in experimental group B than in experimental group A at the same reperfusion time. Immunohistochemical staining showed that the expression of HCN4 located in cellular membrane and cytoplasm in the central area of SANC and gradually decreased from the center to borderl ine. The integral absorbance values of HCN4 expression in the control group (397.40 ± 34.11) was significantly higher than those in the experimental group A (306.20 ± 35.77, 216.60 ± 18.59, 155.40 ± 19.11 and 135.00 ± 12.30) and in the experimental group B (253.70 ± 35.66, 138.70 ± 13.28, 79.10 ± 9.60 and 69.20 ± 8.42) after 2, 4, 8 and 16 hours of reperfusion (P lt; 0.05). With reperfusion time, the expression of HCN4 of SANC decreased, which was lowest after 8 hours of reperfusion; showing significant difference among 2, 4 and 8 hours after reperfusion (P lt; 0.05) and no significant difference between 8 and 16 hours after reperfusion (P gt; 0.05). At the same reperfusion time, the expression of HCN4 was higher in the experimental group A than in the experimental group B. The result of transmission electron microscope showed that ultramicrostructure of SANC was damaged after reperfusion in experimental groups A and B. The longer the reperfusion time was, the more serious ultramicrostructure damage of SANC was, and reached the peak of damage after 8 hours of reperfusion. Ultramicrostructure of SANC was not different between 8 and 16 hours of reperfusion. At the same reperfusion time, the ultramicrostructure damage of SANC was moreserious in experimental group B than in experimental group A. Conclusion IRI is harmful to the morphous and structure ofSANC, and effects the expression of HCN4 of SANC, which is concerned with functional disturbance and arrhythmia.
【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.
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。
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.
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.