Role of apoptosis signal-regulating kinase 1 in left ventricular remodeling in mice / 中国当代儿科杂志

OBJECTIVE@#To study the changes and significance of apoptosis signal-regulating kinase 1 (ASK1) in left ventricular remodeling in FVB/N mice.@*METHODS@#A total of 54 FVB/N mice were randomly divided into 4 groups: 0 d group with 8 mice, 7 d group with 10 mice, 14 d group with 16 mice, and 21 d group with 20 mice. A model of cardiac remodeling was established by intraperitoneal injection of isoproterenol (ISO) at a daily dose of 30 mg/kg, and the 7 d, 14 d, and 21 d groups were injected for 7, 14, and 21 consecutive days respectively. The 0 d group was given intraperitoneal injection of an equal volume of normal saline. Echocardiography was used to measure left ventricular posterior wall thickness at end diastole (dLVPW) and the ratio of heart weight to tibia length (HW/TL) was measured. Hematoxylin-eosin staining was used to measure left ventricular myocardial fiber diameter. Picric-Sirius red staining was used to measure myocardial collagen deposition area in the left ventricle. Quantitative real-time PCR was used to measure the mRNA expression of ASK1, type I collagen (collagen I), and B-type natriuretic peptide (BNP). The mortality rate was observed for each group.@*RESULTS@#There were gradual increases in HW/TL, myocardial fiber diameter, and dLVPW after 0, 7, and 14 days of ISO injection (P0.05), while there was a significant reduction in myocardial fiber diameter (P0.05). There were significant increases in myocardial collagen deposition area and the mRNA expression of collagen I, ASK1, and BNP after 0, 7, 14, and 21 days of ISO injection, which reached the peaks on day 21 (P<0.01). The mRNA expression of ASK1 was positively correlated with myocardial collagen deposition area and the mRNA expression of collagen I and BNP and had a weak correlation with HW/TL, myocardial fiber diameter, and dLVPW. There was a significant increase in the mortality rate of the mice over the time of ISO injection.@*CONCLUSIONS@#The expression of ASK1 in the myocardium is closely associated with left ventricular remodeling. The increase of ASK1 expression may lead to the aggravation of left ventricular remodeling, and the mechanism of which needs further study.

Expression of Nod-like receptor protein 3 inflammasome in peripheral blood mononuclear cells of children with Kawasaki disease in the acute stage / 中国当代儿科杂志

OBJECTIVE@#To study the association of Nod-like receptor protein 3 (NLRP3) inflammasome with inflammatory response in the acute stage and coronary artery lesion (CAL) in children with Kawasaki disease (KD).@*METHODS@#A total of 42 children with KD who were hospitalized from January to October 2017 were enrolled as the KD group, among whom 9 had CAL (CAL group) and 33 had no CAL (NCAL group). Fifteen age- and gender-matched children with pneumonia and pyrexia were enrolled as the pneumonia-pyrexia group. Fifteen healthy children were enrolled as the healthy control group. Real-time PCR was used to measure the mRNA expression of NLRP3 inflammasome (NLRP3, ASC and caspase-1) in peripheral blood mononuclear cells. The Spearman rank correlation test was used to investigate the correlation of NLRP3 mRNA expression with serum levels of C-reactive protein, erythrocyte sedimentation rate, interleukin-6, interleukin-1β, procalcitonin, albumin and prealbumin.@*RESULTS@#The KD group had significantly higher mRNA expression of NLRP3, ASC and caspase-1 in the acute stage than the pneumonia-pyrexia and healthy control groups (P<0.05). The CAL group had significantly higher mRNA expression of NLRP3 than the NCAL group (P<0.05). NLRP3 mRNA expression was correlated with C-reactive protein, interleukin-6, interleukin-1β, and prealbumin levels in children with KD in the acute stage (r=0.449, 0.376, 0.427, and -0.416 respectively; P<0.05).@*CONCLUSIONS@#NLRP3 inflammasome may participate in inflammatory response in the acute stage and the development of CAL in children with KD.

Establishment of cardiac remodeling model in FVB/N mice by intraperitoneal injection of isoproterenol / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of intraperitoneal injection of isoproterenol (ISO) to induce cardiac remodeling in FVB/N mice.</p><p><b>METHODS</b>Forty-eight FVB/N mice were divided into back subcutaneous saline group (subcutaneous saline group), intraperitoneal saline group, back subcutaneous ISO group (subcutaneous ISO group), and intraperitoneal ISO group according to the route of administration of saline or ISO. ISO (30 μg/g body weight/day) was given to the subcutaneous ISO group and the intraperitoneal ISO group, twice daily with an interval of 12 hours, for 14 consecutive days. The subcutaneous saline group and the intraperitoneal saline group were injected with an equal volume of saline. The left ventricular end-diastolic posterior wall thickness was measured by echocardiography, and the ratio of heart weight to tibia length was determined. Hematoxylin-eosin staining was used to determine the myocardial fiber diameter. Picric-sirius red staining was used to determine the myocardial collagen deposition area. Quantitative real-time PCR was used to measure the mRNA expression of collagen I.</p><p><b>RESULTS</b>Compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups, the intraperitoneal ISO group had increased sizes of the cardiac cavity and the heart. Compared with the subcutaneous saline and intraperitoneal saline groups, the subcutaneous ISO group showed no significant changes in the gross morphology of the cardiac cavity and the heart. The intraperitoneal ISO group showed significant increases in the ratio of heart weight to tibia length, myocardial fiber diameter, left ventricular end-diastolic posterior wall thickness, myocardial collagen area percentage, and the mRNA expression of collagen I compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups (P<0.01). There were no significant differences in the above five indices between the subcutaneous ISO group and the subcutaneous saline and intraperitoneal saline groups (P>0.05). No significant difference in the mortality rate was found between the subcutaneous ISO and intraperitoneal ISO groups (P>0.05).</p><p><b>CONCLUSIONS</b>Intraperitoneal injection of ISO can induce cardiac hypertrophy and fibrosis in FVB/N mice.</p>

Studies on association of HSL repeat polymorphism and aerobic endurance / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between hormone sensitive lipase (HSL) gene polymorphism and aerobic endurance.</p><p><b>METHODS</b>The (CA)n repeats polymorphism genotypes in HSL intro 6 of 123 outstanding long distance runners and 127 controls of Han nationality in northern China were analyzed by PCR and Fluorescence labeled STR-genescan. Repeat polymorphisms were grouped according to segmentation point and alleles were divided into long or short chains. Chi-square test was used to analyze the frequency difference of allelic and genotypic between athlete and control groups.</p><p><b>RESULTS</b>(CA) n repeats polymorphism in HSL gene was total of 9 different repeat number of alleles, which composed of 25 different genotypes. The chi-square test result showed that when compared short and long chain alleles split by 4, there was a significant difference (P <0.05) of genotype distribution in 5/10 km group compared with control. Compared the rest groups with control, there was no significant difference.</p><p><b>CONCLUSION</b>Compared short and long chain alleles split by 4, the LL genotype of (CA)n of HSL was associated with aerobic endurance and it might be a molecular marker of elite 5/10 km long distance runners.</p>

Effects of E23K polymorphism in KCNJ11 gene on membrane current / 中国应用生理学杂志

<p><b>OBJECTIVE</b>E23K polymorphism in KCNJ11 gene is associated with cardiovascular disease and diabetes. In order to explore the mechanism of E23K correlation to related diseases, the effect of E23K polymorphism in KCNJ11 gene on membrane current was investigated.</p><p><b>METHODS</b>The exon of KCNJ11 was obtained by PCR amplification and the G-->A mutation was completed by overlap extension PCR. The sequences of KCNJ11 exon contained 23E or 23K was inserted into pcDNA3.1/CT-GFP vector respectively. The recombinant plasmid, pcDNA3.1-KCNJ11(E) and pcDNA3.1-KCNJ11(K), were transfected into HEK293T cells by lipofectamine and the membrane current density was determined by whole-cell patch clamp technique.</p><p><b>RESULTS</b>1,173 bp sequences of KCNJ11 gene's exon were amplified by PCR and the recombinant expression plasmid, pcDNA3.1-KCNJ11(E) and pcDNA3.1-KCNJ11(K), were constructed successful. Positive and negative currents were detected in HEK293T cells transfected with difference plasmid by whole-cell patch clamp technique. Results showed that the reversed voltage was 50mV. The current in HEK293T cells with pcDNA3.1-KCNJ11(E) was significantly greater than that with pcDNA3.1-KCNJ11(K) (P < 0.05, n = 10).</p><p><b>CONCLUSION</b>The polymorphism of E23K in exon of KCNJ11 gene changed the membrane currents in HEK293T cells. It could be an experiment support for the possible mechanism between the locus and related diseases.</p>