Site-directed mutagenesis and protein expression of SCN5A gene associated with congenital long QT syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To construct the sodium channel gene SCN5A-delQKP1507-1509 mutation associated with congenital long QT syndrome, and its eukaryotic expression vector, and to examine the expression of mutation protein in human embryonic kidney (HEK) 293 cells.</p><p><b>METHODS</b>Eukaryotic expression vector PEGFP-delQKP-hH1 for SCN5A-delQKP1507-1509 mutation was constructed by rapid site-directed mutagenesis. HEK293 cells were transfected with the wild or mutant vector using lipofectamine, and then subjected to confocal microscopy. The transfected cells were immunostained to visualize intracellular expression of the mutant molecules.</p><p><b>RESULTS</b>Direct sequence and electrophoresis analysis revealed 9 basic group absences at position 1507-1509. The delQKP1507-1509 mutation eukaryotic expression vector was expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both wild type and mutant molecules on the plasma membrane and there was no difference in the amount of protein, which suggested that the mutant delQKP1507-1509 did not impair normal protein expression in HEK293 cells.</p><p><b>CONCLUSIONS</b>Successful construction of mutant SCN5AdelQKP1507-1509 eukaryotic expression vector and expression of SCN5A protein in HEK293 cells provides a basis for further study on the functional effects of congenital long QT syndrome as a cause of SCN5A mutation.</p>

Association between paraoxonase concentration and risk of acute coronary syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between paraoxonase (PON) concentration and the risk of acute coronary syndrome (ACS).</p><p><b>METHODS</b>The levels of serum PON were detected by enzyme-linked immunosorbent assay in 229 patients with confirmed ACS and 129 control subjects without CHD. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were applied to analyze the association between PON and ACS.</p><p><b>RESULTS</b>PON was significantly lower in ACS group than in control group [lgPON: (5.72 ± 0.73) ng/L vs. (5.07 ± 0.57) ng/L, P < 0.05]. Logistic regression analysis showed that the level of PON was an independent risk factor of ACS (regression coefficient was -1.793 in univariate logistic regression, OR = 0.166, 95%CI: 0.088 - 0.316; -0.779 in multivariate logistic regression, OR = 0.459, 95%CI: 0.222 - 0.949). ROC analysis showed that the optimal diagnostic cut-off point of PON for ACS was 180 mg/L (sensitivity: 83.3%, specificity: 71.2%). Multiple stepwise regression analysis revealed that there was no significant correlation between lgPON and Gensini score in ACS patients.</p><p><b>CONCLUSION</b>Lower PON is linked with increased risk of ACS, but does not relate with the severity of coronary stenosis.</p>

Linkage analysis and gene mapping of one Chinese family with benign familial infantile convulsions / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The present study performed linkage analysis and gene mapping to find the possible chromosome locus harboring in one family with benign familial infantile convulsions (BFIC) and investigate the possible molecular pathogenesis of BFIC.</p><p><b>METHODS</b>A four-generation family with BFIC was investigated. The family was genotyped using eight hypervariable microsatellite markers covering four loci: D19S245 and D19S250 for the 19q12-13.1 region, D16S3131 and D16S3133 for the 16p12-q12 region, D2S156 and D2S286 for the 2q24 region, and D20S480 and D20S481 for the 20q13.3 region. Polymorphism fragments were amplified using polymerase chain reaction (PCR) method. PCR products for the markers were subjected to electrophoresis on 8% denatured polyacrylamide gel and silver staining for length judgment of amplification fragment. Linkage analysis was performed by use of MLINK in the LINKAGE computer package. Two-point LOD scores were calculated to estimate the linkage relationship.</p><p><b>RESULTS</b>The two-point LOD scores were less than -2.0 for the genetic markers at chromosomes 19q12-13.1, 16p12-q12 and 2q24 at the recombination rate between 0.000 and 0.01. The two-point LOD scores for D20S481 at the 20q13.3 region were 0.3 and 0.25 at the recombination rate of 0.000 and 0.01, respectively.</p><p><b>CONCLUSIONS</b>There is no evidence that this family with BFIC is linked to one of the following loci: 19q12-13.1, 16p12-q12 and 2q24, but a possible linkage with 20q13.3 region cannot be excluded.</p>

Bone marrow stem cell mobilization to the peripheral blood and tumor necrosis factor-alpha expression in ischemic myocardium in rabbit models of hibernating myocardium / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in peripheral blood bone marrow stem cells and tumor necrosis factor-alpha gene expression in the ischemic myocardium in rabbit models of hibernating myocardium.</p><p><b>METHODS</b>Twenty-four male Japanese white rabbits were randomized into 4 groups, including a sham-operated group and 3 model groups with hibernating myocardium induced by partial ligation of the left anterior descending coronary artery. The percentage of CD34-positive cells in the peripheral blood was evaluated by flow cytometry, and TNF-alpha mRNA expression in the ischemic myocardium was determined by real-time RT-PCR in the 3 model groups (at 3, 7, or 28 days after the operation) and in the sham-operated group.</p><p><b>RESULTS</b>In rabbits with partial ligation of the left anterior descending coronary artery, the percentage of CD34-positive cells in the peripheral blood and myocardial TNF-alpha mRNA expression were significantly increased at 3 and 7 days after the operation in comparison with those in the sham-operated group and those at 28 days postoperatively (P<0.01). No significant differences were found in the percentage of CD34 positive cells or myocardial TNF-alpha mRNA expression between the sham-operated group and the rabbits 28 days after the coronary artery ligation (P>0.05).</p><p><b>CONCLUSION</b>Bone marrow stem cell can be mobilized into the peripheral blood in rabbit hibernating myocardium model possibly by increasing TNF-alpha gene expression in the ischemic myocardium.</p>

Sinoatrial node cells phenotype expression is induced by direct bone marrow stem cells contact with sinoatrial node cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the differentiation of bone mesenchymal stem cells (BMSCs) co-cultured with purified sinoatrial node cells (SNC) of neonate rats.</p><p><b>METHODS</b>SNC from neonatal SD rat were cultured and purified with differential attachment method and labeled with BrdU. Rat BMSCs were isolated by a Percoll's gradient solution and cultured in DMEM. After 2 passages, these BMSCs were transfected with pEGFP-N1 by Lipofectamine and labeled with GFP. EGFP-BMSC were co-cultured with SNC in a rate of 1:5 for 1 week. EGFP-BMSC cultured in SNC culture medium served as controls. SNC marker hyperpolarization activated cyclic nucleotide gated cation channel 4 (HCN4) and connexin 45 (Cx45) expressions were determined by immunofluorescence staining.</p><p><b>RESULT</b>Positive immunofluorescence staining against HCN4 and Cx45 were detected in EGFP-BMSC co-cultured with SNC but not in EGFP-BMSC cultured in SNC culture medium.</p><p><b>CONCLUSION</b>Direct cell-to-cell contact between BMSCs and SNC cells may induce BMSCs differentiation into sinus node-like cells.</p>

Gene mutation analysis of a Chinese family of congenital long Q-T syndrome type three / 中华儿科杂志

<p><b>OBJECTIVE</b>The congenital long QT syndrome (LQTs) is a hereditary disorder in which most affected family members have delayed ventricular repolarization manifested on the electrocardiogram (ECG) as QT interval prolongation. The disorder is associated with an increased propensity to arrhythmogenic syncope, polymorphous ventricular tachycardia (torsade de pointes), and sudden arrhythmic death. LQTs is due to mutations involving principally the myocyte ion-channels, and this monogenetic disorder has an autosomal inheritance pattern. This study investigated the gene mutation of a Chinese family of LQTs with multiple phenotypes including dilated cardiomyopathy (DCM) and cardiac conduction defects, thus to understand the molecular pathogenesis of the diseases.</p><p><b>METHODS</b>A three-generation Chinese LQTs family with multiple phenotypes was investigated. Blood sample was collected from the 8 family members and 100 unassociated normal individuals. Polymerase chain reaction (PCR)-DNA direct sequencing was performed to screen all exons and their flanking introns of SCN5A gene for mutation analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to exclude polymorphism.</p><p><b>RESULTS</b>PCR amplification and subsequent direct sequencing of SCN5A from proband revealed a heterozygous deletion of nine base pairs (CAGAAGCCC) in exon 26, corresponding to the three amino acid residues Gln1507-Lys1508-Pro1509 (QKP). This mutation is localized in the linker region between DIII-DIV of SCN5A. The same mutation was found in another patient (her grandmother) and excluded in the remaining living subjects in this family. This mutation was confirmed using SSCP in 100 unassociated healthy individuals. Similar analysis excluded possible mutations that would lead to amino acid changes in KCNQ1, KCNH2 and LAMIN A/C commonly associated with LQTs and DCM with conduction disorders, no new mutations that would lead to amino acid changes was found.</p><p><b>CONCLUSION</b>The result of the present study suggests that SCN5A mutation delQKP1507-1509 exists in patients with LQTs. The delQKP1507-1509 of SCN5A is a novel mutation in Chinese people. The same mutation was previously reported in a French family with only a single LQTs phenotype. Further studies on functional expression of SCN5A mutation delQKP1507-1509 will be helpful to understand the mechanism of the multiple phenotypes.</p>

Effect of short-term intensive treatment with insulin pump on beta cell function and the mechanism of oxidative stress in newly diagnosed type 2 diabetic patients / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of short-term intensive treatment with insulin pump on beta cell function and the mechanism of oxidative stress in newly diagnosed type 2 diabetic patients.</p><p><b>METHODS</b>Totally 120 newly diagnosed type 2 diabetic patients were treated with insulin pump for 2 weeks. The levels of fasting plasma glucose (FPG), 2-hour postprandial blood glucose (2hPG), homeostatic model assessment of the insulin secretion index and insulin resistance index (HOMA-beta and HOMAIR, respectively), blood malondialdehyde (MDA) and superoxide dismutase (SOD) were measured before and after insulin pump treatment.</p><p><b>RESULTS</b>After insulin pump treatment, FPG, 2hPG, HOMAIR and blood MDA were significantly decreased (P<0.01), while HOMA-beta and blood SOD were significantly increased (P<0.01).</p><p><b>CONCLUSION</b>Short-term intensive treatment with insulin pump can effectively improve beta cell function probably by decreasing oxidative stress in newly diagnosed type 2 diabetic patients.</p>

Expression and function of voltage-gated Na+ channel isoforms in rat sinoatrial node / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the expression of voltage-gated Na(+) channel (NaCh) isoforms in rat sinoatrial node and explore their functions.</p><p><b>METHODS</b>Expressions of NaCh isoforms Nav1.1, Nav1.2, Nav1.3, Nav1.5, Nav1.6 and Nav1.7 in the rat sinoatrial node were detected by immunohistochemistry. The functional roles of the NaChs were tested by observing the effect of tetrodotoxin, a specific blocker of NaChs, on the intrinsic heart rate of isolated rat working heart.</p><p><b>RESULTS</b>The tetrodotoxin- sensitive neuronal isoforms Nav1.1, Nav1.6 and Nav1.7 as well as the tetrodotoxin-resistant cardiac isoform Nav1.5 were present in the rat sinoatrial node, and the neuronal isoforms were more abundant than Nav1.5 (P<0.05). The selective blockade of tetrodotoxin-sensitive isoforms (presumably Nav1.1, Nav1.6 and Nav1.7) by 100 nmol/L tetrodotoxin scarcely affected the intrinsic heart rate (0.5-/+2.9%, P>0.05) while blockade of tetrodotoxin-resistant isoform (presumably Nav1.5) by 2 micromol/L tetrodotoxin resulted in an obvious decline in the intrinsic heart rate (22.1-/+2.1%, P<0.001).</p><p><b>CONCLUSIONS</b>Nav1.1, Nav1.5, Nav1.6 and Nav1.7 are all present in rat sinoatrial node. Although neuronal isoforms are more abundant, Nav1.5 seems to contribute more to activity of the sinoatrial node.</p>

Implications of serum matrix metalloproteinase-8 elevation in patients with acute coronary syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the clinical significance of serum matrix metalloproteinase-8 (MMP-8) concentration variation in patients with acute coronary syndrome (ACS).</p><p><b>METHODS</b>Enzyme-linked immunosorbent assay (ELISA) was employed to detect serum MMP-8 content in 80 ACS patients, including 43 with acute myocardial infarction (AMI), and 37 with unstable angina pectoris (UAP), as well as in 43 with stable angina pectoris (SAP) cases and 37 control subjects. The risk factors for atherosclerosis pertaining to age, sex, hypertension, body mass index, smoking, family history, diabetes, hyperlipidemia, etc. were evaluated statistically in each case.</p><p><b>RESULTS</b>Serum MMP-8 concentration was significantly higher in ACS group than in SAP and control groups (Plt;0.01). In ASC group, serum MMP-8 was much higher in AMI patients than in those with UAP (Plt;0.01), but similar between UAP and SAP groups (P>0.05). Logistic regression analysis identified serum MMP-8 concentration as the possible indicator of ACS (B=4.493, P=0.000), and particularly AMI (B=9.961, P=0.000). Linear correlation and linear regression analysis revealed that only neutrophils were associated with serum MMP-8 concentration variation (r=0.274, P=0.001).</p><p><b>CONCLUSIONS</b>Serum MMP-8 concentration is closely associated with ACS, particularly AMI, and may serve as an indicator for predicting ACS and AMI. Neutrophils may be connected with the variation of serum MMP-8 concentration, but not as the major factor.</p>

Measurement peripheral blood index related to inflammation and ox-LDL, ox-LDLAb in patients with coronary heart disease and its clinical significance / 中南大学学报(医学版)

OBJECTIVE@#To detect the levels of index related to inflammation such as soluble CD40 ligand (sCD40L), neutrophil collagenase-8 (MMP-8), and pregnancy associated plasma protein-A (PAPP-A) , lipid peroxidation and autoimmune indexes such as oxidized low density lipoprotein (ox-LDL) and its antibody (ox-LDL Ab) in patients with coronary heart disease, and to investigate its relationship with acute coronary syndrome (ACS).@*METHODS@#Contents of sCD40L, MMP-8, PAPP-A, ox-LDL and ox-LDL Ab in the peripheral blood were measured by enzyme-linked immunosorbent assay from 109 patients with coronary heart disease including 36 acute myocardial infarction (AMI), 38 unstable angina pectoris (UAP), and 35 stable angina pectoris (SAP) and 36 controls without coronary heart disease.@*RESULTS@#The levels of each index in the peripheral blood of ACS patients (including AMI and UAP) were higher than those of SAP patients and controls (P 0.05). The levels of each index of SAP patients, except PAPP-A, were all higher than those of controls (P <0.05). All the indexes were helpful in diagnosis of ACS. The area under the ROC curve of each index is between 0.7 and 0.9.@*CONCLUSION@#The increase of sCD40L, MMP-8, PAPP-A, ox-LDL and ox-LDL Ab levels in peripheral blood may be related to the pathogenesis of ACS, and can be used as potential markers of unstable atherosclerosis plaque.

Inhibition of human macrophage-derived foam cell differentiation by blocking Kv1.3 and Kir2.1 channels / 中南大学学报(医学版)

OBJECTIVE@#To investigate the expression of Kv1.3 and Kir2.1 during human monocyte-derived macrophages differentiation into foam cells and their function in foam cells formation.@*METHODS@#The human macrophage-derived foam cells were obtained by incubating macrophages with ox-LDL (30 mg/L) for 60 h. The expression of Kv1.3 and Kir2.1 channels were examined by immunocytochemistry, RT-PCR and Western blot. Effects of channel blockers (rMargatoxin and BaCl2) on the cellular cholesterol metabolism were studied by measuring the cellular contents of total cholesterol (TC), free cholesterol (FC), and cholesterol ester (CE) in the presence or absence of the channel blockers.@*RESULTS@#After incubating macrophages with 30 mg/L ox-LDL for 60 h, the cellular contents of TC, FC and CE were markedly increased and the ratio of CE/TC was raised from (14.4+/-6.8)% to (57.9+/-3.5)% (P0.05); After being blocked specifically (rMargatoxin: 0.1, 10 nmol/L; BaC(12): 75, 125 micromol/L), the cellular contents of TC and CE were markedly reduced without exception and the ratios of CE/TC were all less than 50% (P<0.05).@*CONCLUSION@#Both Kv1.3 and Kir2.1 channels play a critical role in differentiation of macrophages into foam cells and blockage of corresponding potassium channels would prevent the formation of the foam cells.

Correlation of changes in circulating bone marrow stem cells in pregnant rabbits after acute myocardial infarction with serum estradiol / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in circulating bone marrow stem cells in pregnant rabbits after AMI (AMI) and their relationship with estradiol.</p><p><b>METHODS</b>Three groups of rabbits were used, namely pregnancy and AMI group, AMI group without pregnancy, and sham operation group with pregnancy. The ratio of CD90(+) cells in the peripheral blood was determined with flow cytometry in all the rabbits, and serum estradiol level measured. Four weeks after AMI, hemodynamic measurements were carried out. The morphological changes of the myocardial tissues were examined with ImageJ 1.31.</p><p><b>RESULTS AND CONCLUSION</b>Four weeks after AMI, the two pregnancy groups showed a higher Left ventricular end systolic pressure(LVESP) and+dp/dtmax, lower left ventricular end-diastolic pressure (LVEDP) and -dp/dtmax and high levels of CD90(+) cells in peripheral blood than AMI group without pregnancy (P<0.01). The ratio of circulating CD90(+) cells increased gradually with gestational age and peaked at the end stage of pregnancy. After delivery the circulating CD90+ cell ratio decreased sharply, showing a significant correlation with serum estradiol level (r=0.725, P<0.01). Four weeks after AMI, the pregnancy group had smaller myocardial infarction (MI) volume than the non-pregnant group (22.17+/-6.34% vs 38.86+/-5.97%, P<0.05). Circulating bone marrow stem cells increased during pregnancy with gestational age and peaked at the end stage of pregnancy. Ten days after delivery, the stem cells resumed basically the normal level. The proportion of circulating bone marrow stem cells was significantly correlated with the level of serum estradiol during pregnancy, and mobilization of the bone marrow stem cells induced by acute ischemic event in pregnant rabbits was advanced. 4 weeks after AMI, the pregnant rabbits showed better heart contraction and diastolic function than the non-pregnant ones.</p>

Dynamic changes of plasma VEGF, SDF-1 and peripheral CD34+ cells in patients with acute myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in plasma levels of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) and in peripheral CD34(+) cells in patients with acute myocardial infarction (AMI), and explore their role in AMI.</p><p><b>METHODS</b>Enzyme-linked immunoassay (ELISA) was employed for measuring the levels of VEGF and SDF-1 in AMI patients on days 1, 3, 7, 10, and 14 of onset and in normal control subjects. The absolute counts of CD34(+) in the peripheral blood were measured on days 1, 7, and 14 by flow cytometry in AMI patients, with their myocardial enzyme and troponin I detected and electrocardiography (ECG) and echocardiography (UCG) recorded.</p><p><b>RESULTS</b>Peripheral CD34(+) cells obviously increased on day 7 after AMI onset (2.35-/+0.72/microl vs 1.48-/+0.49/micro, P<0.05). VEGF levels were significantly higher in AMI patients than in the control subjects, reaching the peak level and on day 14 (197.56-/+39.87 vs 53.79-/+18.12 pg/ml, P<0.01). SDF-1 level obviously decreased on day 1 after AMI onset (1683.12-/+224.79 vs 2178.67-/+265.34 pg/ml, P<0.01), followed by gradually increased to the control level. Obvious correlation was noted between the level of VEGF on day 7 and the peak level of peripheral CD34(+) cells, and the peak plasma VEGF level was obviously associated with the peak serum CK-MB and troponin I levels.</p><p><b>CONCLUSION</b>The stem cells are mobilized into the peripheral blood in the event of AMI. Obviously increased VEGF level following AMI may persist for at least 2 weeks, whereas SDF-1 level undergoes temporary decrement after AMI. The dynamic changes of VEGF and SDF-1 can be related to the mobilization and homing of the stem cells to the injured myocardium.</p>

ERK1/2 pathway involved in the expression of ETB receptors of the culturing smooth muscle cells of rat mesenteric artery / 药学学报

<p><b>AIM</b>To determine the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in the expression of endothelin receptor type B (ETB) during culture.</p><p><b>METHODS</b>SB386023, a specific inhibitor for ERK1/2 pathway, was used to define the intracellular signaling pathway for the upregulation of ETB receptors and sarafotoxin 6c (S6c), a selective agonist for ETB receptors, induced contraction in isolated rat superior mesenteric arteries. The contraction was recorded by a sensitive in vitro myograph and the receptor mRNA was quantified by a real-time PCR. The phosphorylated ERK1/2 proteins were analyzed by phosphoELISA assay.</p><p><b>RESULTS</b>S6c induced strong contractile responses of the artery after culture for 24 h, while there was no response to S6c in fresh vessel segments. The enhanced contractile response to S6c paralleled with an increase of mRNA for ETB receptors. The phosphorylated ERK1/2 proteins significantly increased after culture for 3 h. After co-culture with SB386023 for 24 h, S6c-induced contractions significantly decreased with reduction of Emax from (217 +/- 14) % to (127 +/- 23) % (P <0.01). This response paralleled with a decreased level of ETB receptor mRNA.</p><p><b>CONCLUSION</b>ERK1/2 pathway was involved in the up-regulation of ETB receptors on smooth muscle cells isolated from rat mesenteric arteries during culture.</p>

A novel mutation in KCNQ2 gene causes benign familial infantile convulsions (BFIC) in a Chinese family / 中华儿科杂志

<p><b>OBJECTIVE</b>Benign familial infantile convulsions (BFIC) is a form of idiopathic epileptic syndrome characterized by onset of afebrile seizures between 3 and 12 months of life, Spontaneous remission after several weeks or months, and autosomal dominant mode of inheritance. Previous linkage analysis in western countries defined three susceptible loci on chromosomes 19q12.0-13.1, 16p12-q12, and 2q23-31, but studies performed in several Chinese families with BFIC got negative results of these previously reported loci. The authors investigated the relation of voltage-gated potassium channel gene KCNQ2 to BFIC in a Chinese family and thus to understand the molecular pathogenesis of BFIC.</p><p><b>METHODS</b>A four-generation Chinese BFIC family was investigated. All the affected 17 members had similar pattern of seizures starting from 2 to 6 months of age. In 15 of them, the seizures disappeared spontaneously within the first year of life. The phenotype extended beyond infancy only in two patients. Blood sample was collected from the 41 family members and 75 unassociated normal individuals. Polymerase chain reaction (PCR)-DNA direct sequencing was performed to screen all exons and their flanking introns of KCNQ2 gene for mutation analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to ascertain the co-segregation of genotype and phenotype and to exclude polymorphism.</p><p><b>RESULTS</b>PCR amplification and subsequent direct sequencing of KCNQ2 from the DNA of proband revealed a heterozygous guanine to thymine nucleotide exchange (G812T) in exon 5, leading to the substitution of glycine by valine at amino acid position 271 (G271V) of the predicted protein. The same mutation with a comparable localization has been previously described for KCNQ3 in benign familial neonatal convulsions (BFNC). The glycine at this position (G271) is located in pore region of KCNQ2 protein and is evolutionarily highly conserved. The same SSCP variant as that of the proband was shown in the rest of the affected members of this family but not in the unaffected members enrolled in the study of this family and all the 75 unrelated normal individuals.</p><p><b>CONCLUSION</b>Previously reported mutations of KCNQ2 were mainly identified in BFNC family in which at least one individual had an onset of seizures during the first week of life, a hallmark of the BFNC disorder. The results of the present study suggest the possibility that KCNQ2 mutation exist in patients with BFIC diagnosis. G812T of KCNQ2 gene is a novel mutation found in BFIC and functional expression of KCNQ2 G812T is required for understanding the mechanism of BFIC and other idiopathic epilepsy.</p>

Altered expression of renal bumetanide-sensitive sodium-potassium-2 chloride cotransporter and Cl- channel -K2 gene in angiotensin II-infused hypertensive rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Little information is available regarding the effect of angiotensin II (Ang II) on the bumetanide-sensitive sodium-potassium-2 chloride cotransporter (NKCC2), the thiazide-sensitive sodium-chloride cotransporter (NCC), and the Cl- channel (CLC)-K2 at both mRNA and protein expression level in Ang II-induced hypertensive rats. This study was conducted to investigate the influence of Ang II with chronic subpressor infusion on nephron-specific gene expression of NKCC2, NCC and CLC-K2.</p><p><b>METHODS</b>Sprague Dawleys rats were treated subcutaneously with either Ang II (100 ng.kg-1.min-1) or vehicle for 14 days. Expression of NKCC2, NCC and CLC-K2 mRNA in kidneys was determined by real time polymerase chain reaction (PCR). Western blotting analysis was used to measure NKCC2 and NCC protein expression.</p><p><b>RESULTS</b>Ang II significantly increased blood pressure and up-regulated NKCC2 mRNA and protein expression in the kidney. Expression of CLC-K2 mRNA in the kidney increased 1.6 fold (P < 0.05). There were no changes in NCC mRNA or protein expression in AngII-treated rats versus control.</p><p><b>CONCLUSIONS</b>Chronic subpressor Ang II infusion can significantly alter NKCC2 and CLC-K2 mRNA expression in the kidney, and protein abundance of NKCC2 in kidney is positively regulated by Ang II. These effects may contribute to enhanced renal Na+ and Cl- reabsorption in response to Ang II.</p>

Effect of ginsenoside on the cellular proliferation, apoptosis and cell cycles in LC A549 and HUVEC 304 cell lines / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of ginsenoside on the cellular proliferation, apoptosis and cell cycles in LC A549 and HUVEC 304 cell lines.@*METHODS@#A549 and HUVEC 304 cell lines were cultured with different concentrations of ginsenoside. Cellular proliferation was detected with MTT, apoptosis and cell cycles were checked with Flow Cytometer, and change of microstructure was observed by transmission electron microscope.@*RESULTS@#The apoptosis rate was 29.8% in A549 cell lines after being interfered with ginsenoside at 3 x 10(-6) mol/L, significantly higher than that in the control group ( P < 0.05). No change was observed in the cell cycles after being interfered with ginsenoside. The inhibitive rate of ginsenoside was 12.53% for HUVEC 304 cell line at 1 x 10(-4) mol/L (P < 0.05 ). The cells induced by conditioned medium could be inhibited by ginsenoside, and apoptotic body could be found in cells induced by conditioned medium at 10(-6) mol/L.@*CONCLUSION@#The proliferation of vascular endothelial cell could be inhibited by ginsenoside, and apoptosis could also be found in both tumor cells and cells induced by conditioned medium after being interfered with ginsenoside.

Differentiation of mesenchymal stem cells into cardiomyocytes induced by cardiomyocytes / 中南大学学报(医学版)

OBJECTIVE@#To investigate the role of adult cardiomyocytes in the differentiation of mesenchymal stem cells (MSCs) into cardiomyocytes.@*METHODS@#Rat MSCs were isolated by a Percoll's gradient solution and cultured in low-glucose Dulbecco' s modified Eagle' s medium (DMEM). After 2 passages, cell-surface antigen CD34, CD71 and CD90 for rat MSCs were determined by flow cytometry, and these MSCs were transfected with pEGFP-N3 by Lipofectamine2000. Then those MSCs labeled with GFP, were cultured in contacted, nocontacted and conditioned with adult rat myocardiocytes. Immunofluorescence staining against alpha-actin, desmin, and troponin-T were performed after 1 week.@*RESULTS@#Immunofluorescence staining was positive against alpha-actin, desmin, and troponin-T on MSCs in contacted culture group. In contrast, no alpha-actin, desmin, and troponin-T expression on MSCs were observed in the noncontacted culture group and the conditioned culture group.@*CONCLUSION@#Direct cell-to-cell contact between MSCs and adult cardiomyocytes may induce differentiation of MSCs into cardiomyocytes.

Migration of intravenously grafted mesenchymal stem cells to injured heart in rats / 生理学报

The present study aimed to determine the role of tissue injury in migration of mesenchymal stem cells (MSCs) intravenously transplanted into heart and to establish experimental basis for improving stem cell therapy in its targeting and effectiveness. MSCs were isolated from bone marrow of male Sprague-Dawley rats and purified by density centrifuge and adhered to the culture plate in vitro. Female rats were divided randomly into four groups. Myocardial ischemia (MI) transplanted group received MSCs infusion through tail vein 3 h after MI and compared with sham-operated group or normal group with MSCs infusion, or control group received culture medium infusion. MI was created in female rats by ligating the left anterior descending coronary artery. The heart was harvested 1 week and 8 weeks after transplantation. The characteristics of migration of MSCs to heart were detected with expression of sry gene of Y chromosome by using fluorescence in situ hybridization (FISH). Ultrastructural changes of the ischemic myocardium of the recipient rats were observed by transmission electron microscope (TEM). One week or 8 weeks after transplantation, sry positive cells were observed in the cardiac tissue in both of MI transplanted group and sham-operated group, the number of sry positive cells being significantly higher in MI transplanted group (P<0.01). No significant difference was found in the number of sry positive cells between 1 week and 8 weeks after transplantation. No sry positive cells were observed in the hearts of control and normal group. In addition, the ultrastructure of some cells located in the peri-infarct area of MI rats with MSCs transplantation was similar to that of MSCs cultured in vitro. These results indicate that MSCs are capable of migrating towards ischemic myocardium in vivo and the fastigium of migration might appear around 1 week after MI. The tissue injury and its degree play an important role in the migration of MSCs.

Clinical significance of serum cytokines IL-1beta, sIL-2R, IL-6, TNF-alpha, and IFN-v in acute coronary syndrome / 中国医学科学杂志(英文版)

<p><b>OBJECTIVES</b>To explore serum cytokines levels (including IL-1beta, sIL-2R, IL-6, TNF-alpha, and IFN-upsilon) and their significance in patients with acute coronary syndrome (ACS) and the subsequent follow-ups, with attempt to estimate the role of various serum inflammatory markers in the diagnosis and assessment of ACS.</p><p><b>METHODS</b>The study population include 40 patients with acute myocardial infarction (AMI), 40 patients with unstable angina pectoris (UAP), and 40 controls. Among the 80 patients, 60 patients attended a follow up 4 months later. Serum inflammatory markers including IL-1beta, slL-2R, IL-6, TNF-alpha, and IFN-upsilon were measured by enzyme linked immunosorbent assay.</p><p><b>RESULTS</b>Serum IL-1beta, sIL-2R, IL-6, TNF-alpha were significantly higher in AMI group or UAP group compared to the control group and became significantly lower 4 months later in the follow-up patients. Serum levels of IFN-upsilon shows no significant difference between AMI group or UAP group and controls, also showing no significant change when measured in follow up patients. There was no correlation between serum creatine kinase-MB isoenzyme levels and serum inflammatory markers either in UAP or AMI group. Furthermore, when divided into two subgroups using Wagner's QRS scoring system in the AMI group, there is no difference of each serum inflammatory marker between < or = 6 scores group and > 6 scores group.</p><p><b>CONCLUSION</b>Serum levels of certain inflammatory markers may have some diagnostic value for ACS, and can be a useful marker reflecting disease stability.</p>