Effect of neuregulin-1 on cardiac glucose metabolism in rats with experimental myocardial infarction / 中华心血管病杂志

Objective: To investigate the effect of neuregulin-1(NRG-1) on cardiac glucose metabolism in Sprague Dawley (SD) rats with experimental myocardial infarction (MI). Methods: Adult male SD rats were randomly divided into three groups: the sham-operated group, MI group, and MI+NRG1 group. The rat MI model was established via ligation of the left anterior descending coronary artery. Two weeks after operation, echocardiography was performed, MI rats with left ventricular ejection fraction (LVEF) between 0.3-0.5 were selected and randomly assigned to MI group and MI+NRG-1 group. Rats in MI+NRG-1 group were treated with recombinant human NRG-1β (100 μg/kg) via tail vein at 2 weeks after operation (twice per week for 6 weeks); while rats in sham-operated group and MI group received equal volume of physiological saline. By the end of administration, echocardiography and small animal positron emission tomography (PET) were performed to detect cardiac function and myocardial glucose uptake. Myocardial morphology and collagen volume fraction, cardiomyocyte apoptosis and reactive oxygen species (ROS) production were evaluated by histopathologic analysis. Myocardial pyruvate dehydrogenase (PDH) and citrate synthase (CS) activity, as well as ATP production were detected by commercial kits. The mRNA and protein expression levels of NRG-1, p-ErbB4, and key factors involved in glucose metabolism (including Glut-4, HK2, PDK4, PDH, CS) were detected by quantitative real-time PCR (qRT-PCR) and Western blot assay, respectively. Results: With the MI model successfully established, the left ventricular ejection fraction(LVEF) and left ventricular shortening fraction(LVFS) were significantly lower in MI group and MI+NRG-1 group than that in sham group (both P<0.01), while there was no significant difference between MI group and MI+NRG-1 group(all P>0.05). After 6 weeks of NRG-1β intervention, the LVEF and LVFS were significantly higher in MI+NRG-1 group than in MI group (both P<0.01). By the end of experiment, PET imaging showed that the mean standardized uptake value (SUVmean) were lower in MI+NRG-1 group than in the sham group (4.06±0.28 vs. 5.18±0.37, P<0.01), while significantly higher than that in MI group (4.06±0.28 vs.2.86±0.49, P<0.01). Histopathological analysis showed that compared with MI group, rats in MI+NRG-1 group exhibited significantly decreased left ventricle collagen volume fraction ((7.83±1.24) % vs. (18.31±3.58) %, P<0.01), cardiomyocyte apoptosis((37.98±4.26)% vs. (67.04±5.38)%, P<0.01), and DHE fluorescence intensity(0.057 28±0.007 06 vs. 0.076 94±0.008 46, P<0.01), indicating that NRG-1β could reduce ROS production. PDH activity, CS activity, and ATP production were significantly higher in MI+NRG-1 group than in MI group (all P<0.05). qRT-PCR demonstrated an upregulated Glut-4, HK2 and CS, but downregulated PDK4 mRNA expression in MI+NRG-1 group compared with MI group (all P<0.01). Western blot assay showed significantly higher protein expression of NRG-1, p-ErbB4, Glut-4, HK2, PDH, CS in MI+NRG-1 group than in MI group (all P<0.01). Conclusion: NRG-1 could improve glucose uptake and utilization in myocardium by activating phosphorylation of myocardial ErbB4 receptor in MI rats, thus providing a therapeutic option for improving energy metabolism after MI.

Influence of rutin on the effects of neonatal cigarette smoke exposure-induced exacerbated MMP-9 expression, Th17 cytokines and NF-κB/iNOS-mediated inflammatory responses in asthmatic mice model

Allergic asthma is one of the most enduring diseases of the airway. The T-helper cells and regulatory T-cells are critically involved in inflammatory responses, mucus hypersecretion, airway remodelling and in airway hyper-responsiveness. Cigarette smoke (CS) has been found to aggravate inflammatory responses in asthma. Though currently employed drugs are effective, associated side effects demand identification and development of novel drugs with negligible or no adverse effects. Rutin, plant-derived flavonoid has been found to possess antioxidant and anti-inflammatory effects. We investigated the ability of rutin to modulate T-cells and inhibit inflammation in experimentally-induced asthma in cigarette smoke exposed mice. Separate groups of neonatal mice were exposed to CS for 10 days from post-natal days 2 to 11. After 2 weeks, the mice were sensitized and challenged with ovalbumin (OVA). Treatment group were given rutin (37.5 or 75 mg/kg body weight) during OVA sensitization and challenge. Rutin treatment was found to significantly inhibit cellular infiltration in the airways and Th2 and Th17 cytokine levels as well. Flow cytometry revealed effectively raised CD4⁺CD25⁺Fox3⁺ Treg cells and supressed Th17 cell population on rutin treatment. Airway hyper-responsiveness observed following CS and OVA challenge were inhibited by rutin. NF-κB and iNOS, chief regulators of inflammatory responses robustly activated by CS and OVA were down-regulated by rutin. Rutin also inhibited the expression of matrix metalloproteinase 9, thereby aiding in prevention of airway remodelling in asthma thereby revealing to be a potent candidate in asthma therapy.

Expression and activity of RhoA/Rho kinase in remodeling of high blood flow pulmonary vessels / 中华儿科杂志

<p><b>OBJECTIVE</b>High pulmonary blood flow induced pulmonary hypertension (PH) is often associated with increased vasoconstriction and deteriorating pulmonary artery remodeling, of which the exact mechanism has not been completely elucidated. The involvement of RhoA/Rho-kinase pathway has been demonstrated in the pathogenesis of hypoxia and monocrotaline induced PH. Thus the purpose of this study was to test whether RhoA/Rho-kinase pathway is involved in the process of high pulmonary flow induced pulmonary artery remodeling in rats.</p><p><b>METHODS</b>Wistar rats aged 4 weeks in the shunt group underwent left common carotid artery-external jugular vein shunt operation, those in control group received sham-operation. At weeks 1, 2, 4 and 8 of the study, rats underwent right ventricular systolic pressure (RVSP) measurement; blood gases were analyzed to calculate Qp/Qs. The morphologic alterations of the pulmonary arteries were observed under optical microscope. The mean percentage of media wall thickness (%MT) was also measured to assess the extent of medial wall thickness of moderate size pulmonary arteries. Proliferating smooth muscle cells (SMCs) were evaluated by proliferating cell nuclear antigen (PCNA) immunohistochemical staining. Apoptotic SMCs were detected by TUNEL method. RhoA activity in pulmonary arteries was detected using pull down assay. Rho kinase activity was quantified by the extent of MYPT1 phosphorylation with Western blotting. The expression of RhoA and Rho kinase (ROCK2) was also detected with Western blotting.</p><p><b>RESULTS</b>Carotid artery-jugular vein shunt resulted in high pulmonary blood flow, of all rats in shunted groups, the mean Qp/Qs was 2.26 +/- 0.35, which were all considered large shunts. Compared with the control group, RVSP in shunt group increased significantly at both week 1 and week 8 (t = 8.799, t = 5.332, respectively, P < 0.01). Compared with the control group, moderate pulmonary artery medial wall thickening characterized by SMCs hyper-proliferation and hypertrophy in shunted group was firstly appeared at week 4 and became more significant at week 8, as indicated by MT% (t = 9.192, t = 11.185, respectively, P < 0.01). Compared with the control group, the percentage of PCNA-positive SMCs in shunted group increased significantly at week 1 (t = 2.438, P < 0.05), and reached the maximal level at week 2 (t = 7.213, P < 0.01), then, it decreased to a level significantly lower than that of the control group at week 4 (t = 4.183, P < 0.01), and continued to decrease to so low a level that proliferative SMCs was scarcely observed at week 8 (t = 6.152, P < 0.01). The percentage of TUNEL-positive SMCs decreased significantly compared with the control group at week 2 (t = 2.418, P < 0.05), and continued to decrease to a level that apoptotic SMCs was scarcely observed at week 8 (t = 4.582, P < 0.01). Compared with the control group, the expression of RhoA and ROCK2 increased significantly at week 1 (t = 6.056, t = 8.411, respectively, P < 0.01), and reached the maximal level at week 2 (t = 9.342, t = 10.437, respectively, P < 0.01), then began to decrease at week 4, however, both of them were still significantly higher than those of the control group at week 8 (t = 4.743, t = 4.455, respectively, P < 0.01). In line with the expression of RhoA and ROCK2, both RhoA and Rho kinase activity of shunted group increased significantly compared with the control group at week 1 (t = 10.246, t = 19.110, respectively, P < 0.01), and reached the maximal level at week 4 (t = 24.984, t = 16.124, respectively, P < 0.01), then decreased, however, both of them were still higher than those of the control group at week 8 (t = 4.934, t = 10.426, respectively, P < 0.01).</p><p><b>CONCLUSION</b>Activated RhoA/Rho-kinase pathway is associated with both high pulmonary blood flow induced acute pulmonary vasoconstriction and chronic pulmonary artery remodeling in rats.</p>

Inhibition of rho kinase attenuates high flow induced pulmonary hypertension in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The RhoA/Rho kinase pathway may participate in the pathogenesis of hypoxia and monocrotaline induced pulmonary hypertension. This study tested whether RhoA/Rho kinase pathway is involved in the pathogenesis of high flow induced pulmonary hypertension in rats.</p><p><b>METHODS</b>Male Wistar rats (4 weeks) were randomly divided into 4 shunt groups, 4 treated groups and 4 control groups. Shunt and treated groups underwent left common carotid artery/external jugular vein shunt operation. Control groups underwent sham operation. Treated groups received fasudil treatment and the others received same dose of saline. At weeks 1, 2, 4 and 8 of the study, right ventricular systolic pressure was measured and blood gases were analysed to calculate Qp/Qs. The weight ratio of right ventricle to left ventricle plus septum and the mean percentage of medial wall thickness in moderate sized pulmonary arteries were obtained. RhoA activity in pulmonary arteries was detected using Rho activity assay reagent. Rho kinase activity was quantified by the extent of MYPT1 phosphorylation with Western blot. Proliferating cells were evaluated using proliferating cell nuclear antigen immunohistological staining.</p><p><b>RESULTS</b>Carotid artery/jugular vein shunt resulted in high pulmonary blood flow, both an acute and a chronic elevation of right ventricular systolic pressure, significant medial wall thickening characterized by smooth muscle cells proliferation, right ventricular hypertrophy and increased activation of RhoA and Rho kinase. Fasudil treatment lowered pulmonary artery systolic pressure, suppressed pulmonary artery smooth muscle cells proliferation, attenuated pulmonary artery medial wall thickening and inhibited right ventricular hypertrophy together with significant suppression of Rho kinase activity but not Rho activity.</p><p><b>CONCLUSIONS</b>Activated RhoA/Rho kinase pathway is associated with both the acute pulmonary vasoconstriction and the chronic pulmonary artery remodelling of high flow induced pulmonary hypertension. Fasudil treatment could improve pulmonary hypertension by inhibiting Rho kinase activity.</p>

A new modification of transanal Soave pull-through procedure for Hirschsprung's disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>One stage transanal Soave pull-through procedure (TSPP) is a recent popular operation in the treatment of Hirschsprung's disease (HD). With no visible scar and a short hospital stay, it is well accepted by surgeons and mothers. In the conventional Soave procedure, a long rectal muscular cuff left for anocolic anastomosis might increase the incidence of postoperative enterocolitis and constipation. This study presents a modified transanal Soave pull-through procedure (MTSPP) which includes an oblique mucosectomy and an oblique anastomosis with a short split muscular cuff.</p><p><b>METHODS</b>A review of two groups of HD patients was made: 112 underwent conventional transanal Soave procedure from 1999 to 2001 (group 1) and 140 underwent modified transanal Soave procedure from 2002 to 2004 (group 2). A comparison was made between the two groups on operative data and postoperative complications. The data included: age at the operation, operating time, blood loss, time to feeds and hospital stay, occurrence of postoperative enterocolitis or constipation, need for anal dilatation, postoperative bowel function and perianal skin problems.</p><p><b>RESULTS</b>There was no significant difference between two groups with respect to age, gender, length of colon resected, operating time, blood loss and hospital stay. However occurrence of postoperative enterocolitis, constipation, anastomotic stricture and time needed for anal dilatation were evidently less in group 2 (MTSPP). The mean operating time in group 1 was (106 +/- 39) minutes with a range of 60 to 170 minutes; in group 2 was (101 +/- 36) minutes with a range of 66 to 190 minutes. The average length of the bowel resected in group 1 was (24 +/- 7) cm, range 15 to 58 cm; in group 2 was (26 +/- 8) cm, range 15 to 70 cm. Two patients, one in each group, required laparoscopic assistance because of long aganglionic colon. Another patient in group 2 required laparotomy because of total colonic aganglionosis. Postoperative complications in group 1 included: temporary perianal excoriation in 34 patients (26 were < 3 months of age), enterocolitis in 21, anastomotic stricture in 11, recurrent constipation in 12, cuff abscess in 1, anastomosis leak in 1, soiling in 3 and rectal prolapse in 1. In group 2 post operative complications included: transient perianal excoriation in 37 patients (30 were < 3 months of age), enterocolitis in 13, anastomotic stricture in 5, recurrent constipation in 6, anastomotic leak in 1, adhesive bowel obstruction in 1 and soiling in 4. Complete bowel continence was found in 97 children (86.6%) in group 1 and in 129 children (92.1%) in group 2 at one year followup after operation.</p><p><b>CONCLUSIONS</b>Modified transanal Soave pull-through procedure for HD with oblique mucosectomy and anastomosis and a short split muscular cuff is a safe and feasible operation with low incidence of postoperative complication. It is an encouraging improvement of the conventional transanal Soave pull-through procedure. MTSPP is a preferable choice in the surgery of HD.</p>