RGFP966 inactivation of the YAP pathway attenuates cardiac dysfunction induced by prolonged hypothermic preservation / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Oxidative stress and apoptosis are the key factors that limit the hypothermic preservation time of donor hearts to within 4-6 h. The aim of this study was to investigate whether the histone deacetylase 3 (HDAC3) inhibitor RGFP966 could protect against cardiac injury induced by prolonged hypothermic preservation. Rat hearts were hypothermically preserved in Celsior solution with or without RGFP966 for 12 h followed by 60 min of reperfusion. Hemodynamic parameters during reperfusion were evaluated. The expression and phosphorylation levels of mammalian STE20-like kinase-1 (Mst1) and Yes-associated protein (YAP) were determined by western blotting. Cell apoptosis was measured by the terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method. Addition of RGFP966 in Celsior solution significantly inhibited cardiac dysfunction induced by hypothermic preservation. RGFP966 inhibited the hypothermic preservation-induced increase of the phosphorylated (p)-Mst1/Mst1 and p-YAP/YAP ratios, prevented a reduction in total YAP protein expression, and increased the nuclear YAP protein level. Verteporfin (VP), a small molecular inhibitor of YAP-transcriptional enhanced associate domain (TEAD) interaction, partially abolished the protective effect of RGFP966 on cardiac function, and reduced lactate dehydrogenase activity and malondialdehyde content. RGFP966 increased superoxide dismutase, catalase, and glutathione peroxidase gene and protein expression, which was abolished by VP. RGFP966 inhibited hypothermic preservation-induced overexpression of B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and cleaved caspase-3, increased Bcl-2 mRNA and protein expression, and reduced cardiomyocyte apoptosis. The antioxidant and anti-apoptotic effects of RGFP966 were cancelled by VP. The results suggest that supplementation of Celsior solution with RGFP966 attenuated prolonged hypothermic preservation-induced cardiac dysfunction. The mechanism may involve inhibition of oxidative stress and apoptosis via inactivation of the YAP pathway.

Protection of hypothermic preserved isolated rat hearts by resveratrol and its underlying mechanism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate whether resveratrol (RES) plays a protective role in hypothermic preserved isolated rat hearts and whether it is mediated by regulation of silent information regulator protein-1 (Sirt-1) expression.</p><p><b>METHODS</b>The Langendorff model of isolated rat heart was used. After stored in different Celsior solution at 4 degrees C for 9 h, SD rat hearts were randomly divided into 7 groups: blank control group;9 h group (soley hypothermic preservation for 9 h); RES group (3, 10, 30 micromol/L RES treatment plus hypothermic preservation for 9 h ), niacinamide (NAM) group (40 micromol/L NAM added in Celsior solution plus hypothermic preservation for 9 h), RES + NAM group (30 micromol/L RES and 40 micromol/L NAM were added in Celsior solution plus hypothermic preservation for 9 h). The morphological changes of cardiomyocytes were detected by the HE staining with the light microscope. The mRNA and protein expression levels of Sirt-1 were detected by Real-Time PCR and Western blot respectively.</p><p><b>RESULTS</b>(1) Compared with the blank control group, myocardiocytes were injured remarkably in the 9 h group and the Sirt-1 mRNA and protein expression levels were decreased significantly (P < 0.01); (2) Compared with the 9 h group, rat myocardial injury was alleviated gradually in 3, 10, 30 micromol/L RES group and the Sirt-1 mRNA and protein expression levels were increased in a dose-dependent manner (P < 0.05); (3) The above protective effects of RES were attenuated by Sirt-1 inhibitor NAM.</p><p><b>CONCLUSION</b>RES can protect myocardiocytes from injury caused by long range hypothermic preservation and this protective effect maybe mediated by upregulation of Sirt-1 expression.</p>

Effect of total flavonoids from Chrysanthemun morifolium on learning and memory in aging mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of total fiavonoids from Chrysanthemun morifolium (TFCM) on learning and memory, and cholinergic system function in aging mice.</p><p><b>METHODS</b>The aging mice model was established by subcutaneous injection of D-galactose. ICR mice were divided into five groups (n=10): contrA group, model group, and TFCM groups. Mice in TFCM groups were given TFCM (50,100 or 150 mg/kg) by gastric irrigation once a day. Learning and memory ability were evaluated by Morris water maze test. The MDA content, SOD and Ach E activity were also measured.</p><p><b>RESULTS</b>Compared with control group, learning and memory ability declined in the D-galactose-induced aging mice; meanwhile MDA content and AchE activity increased, SOD activity decreased. Treatment with TFCM (100, 150 mg/kg) ameliorated the decrease in learning and memory ability of aging mice. Compared with model group, TFCM (100, 150 mg/kg) could also decrease MDA content and Ach E activity, and increase SOD activity in aging mice.</p><p><b>CONCLUSION</b>TFCM may improve the learning and memory ability of aging mice. The mechanism is involved in its antioxidative characteristic and improvement of central cholinergic system function.</p>

Effects of diazoxide on the mitochondrial ultrastructure and permeability in donor rat myocardium / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of diazoxide (DE) on the myocardial ultrastructure and opening of maitochondrial permeability transition pore (MPTP) in donor rat heart suffered from long-term hypothermic preservation.</p><p><b>METHODS</b>The Langendorff model of isolated rat heart was used. The hearts were stored in 4 degrees C Celsior solution containing different concentration of DE (15, 30, or 45 micromol/L) for 9 h followed by 60 min of reperfusion. The recovery of rate-pressure product (RPP) was observed. The opening of MPTP and myocardial mitochondria ultrastructure were also evaluated.</p><p><b>RESULTS</b>(1) As compared with the celsior solution preserved group, DE (30 micromol/L) increased recovery of RPP during reperfusion and inhibited the opening of MPTP. DE also alleviated the myocardial mitochondrial ultrastucture damage induced by long-term hypothermic preservation. (2) The above effects of DE were attenuated by a mitoK(ATP) channel inhibitor 5-hydroxydecanoate and a MPTP opener atractyloside.</p><p><b>CONCLUSION</b>In the donor rat heart, DE protects myocardial mitochondria ultrastructure against long-term hypothermic preservation injury via inhibiting the opening of MPIP.</p>

Dynamic changes of Smac/DIABLO protein expression in rat donor myocardium suffered from hypothermic preservation / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of different duration of hypothermic preservation on the expression of Smac/DIABLO protein in rat hearts.</p><p><b>METHODS</b>The Langendorff model of isolated rat heart was used. After stored in 4 degrees C Celsior solution for different time (0, 3, 6, 9 or 12 h), the activity of SOD and the content of MDA in heart mitochondria were measured. Cell apoptosis was detected by TUNEL technique. The expression of Smac/DIABLO protein was also analyzed by Western blotting.</p><p><b>RESULTS</b>(1) After hypothermic preservation, the activity of SOD was decreased and the content of MDA was increased in rat hearts in a time-dependent manner. (2) Prolonged the hypothermic preservation, the percentage of apoptotic cell also enhanced. (3) After long-term of cold preservation, the expression of Smac/DIABLO protein increased at 3-6 h of preservation but decreased after 9 h.</p><p><b>CONCLUSION</b>Prolonged the hypothermic preservation might lead to the expression of Smac/DIABLO protein and induce cardiomyocytes apoptosis, which may in turn result in malfunction of cardiomyocytes.</p>

Effects of diazoxide on Fas/FasL protein expressions in rat myocardium suffered from long-term hypothermic preservation / 生理学报

The purpose of this study was to investigate the effect of a mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) opener, diazoxide (DE), on Fas/FasL protein expressions in rat heart suffered from long-term hypothermic preservation. The Langendorff isolated rat heart model was used. The hearts were stored in 4 °C Celsior solution with or without (control) DE for 8 h followed by 60 min of reperfusion. The recovery of rate-pressure product (RPP) was observed. Apoptotic cardiomyocytes were detected by TdT-mediated dUTP nick end labeling (TUNEL) technique. The expressions of Fas/FasL proteins were also analyzed by immunohistochemical method. The results showed that compared with the control group, DE (30 mmol/L) increased the recovery of RPP during reperfusion, reduced the percentage of apoptotic cells and the expressions of Fas and FasL proteins in rat hearts suffered from 8 h of hypothermic preservation. The above effects of DE were attenuated by a mitoK(ATP) channel inhibitor 5-hydroxydecanoate (5-HD). These results indicate that DE could alleviate rat myocardial injury induced by ischemia-reperfusion through reducing the expressions of Fas and FasL proteins via opening of mitoK(ATP)channel.

Effect of postconditioning on rat hearts suffered from long-term hypothermic preservation / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To assess the effect of postconditioning on cardiac protection of rat hearts suffered from long-term hypothermic preservation.</p><p><b>METHODS</b>The Langendorff model of isolated rat heart was used. After 30 min of stabilization, the hearts were stored in 4 degrees C Celsior solution for 3 or 5 h followed by 60 min of reperfusion. Postconditioning was initiated by 3 cycles of 30 s ischemia followed by 30 s reperfusion at the beginning of subsequent persistent reperfusion. The recovery of cardiac contractile function and arrhythmia score were observed.</p><p><b>RESULTS</b>(1) Compared with control group, postconditioning increased the recovery of heart rate (HR), left ventricular systolic pressure (LVDP), maximal rise/fall rate of ventricular pressure (dP/dt(max)) and coronary flow (CF) and rate-pressure product (RPP) during reperfusion after 3 h of hypothermic preservation. However, left ventricular end-diastolic pressure (LVEDP) and the cardiac arrhythmia score during the first 10 min of reperfusion was significantly lower in 3 h postconditioning group than that in 3 h control group. (2) The rat hearts treated by postconditioning with 5-HD(100 micromol/L) abolished the amelioration of contract function induced by postconditioning. And it could also increase the cardiac arrhythmia score. (3) Compared with 5 h control group, the HR, LVDP,dP/dt(max), CF, LVEDP, RPP and the cardiac arrhythmia score were not significantly different in postconditioning treated hearts during reperfusion after 5 h of hypothermic preservation.</p><p><b>CONCLUSION</b>Postconditioning could provide the cardiac protection on 3 h hypothermic preserved rat hearts,but not on 5 h hypothermic preserved rat hearts. The cardiac protection effect might be partly associated with activation of selective mitochondrial ATP-sensitive potassium channel.</p>

Light transmission measurement of focal ischemic cerebral infarction in mice / 浙江大学学报·医学版

OBJECTIVE: To evaluate the feasibility of light transmission to measure focal cerebral ischemia in mice. METHODS: Persistent focal cerebral ischemia was induced by middle cerebral artey occlusion (MCAO) in mice. The brain were removed 24 h after MCAO and coronally dissected into 1 mm sections. Using a stereomicroscope, the brain section was illuminated with a halogen lamp and computerized images were stored. Next the brain sections were stained for 30 minutes with 0.5% TTC (2, 3, 5-triphenylterzolim chloride) at 37 degrees C. Using an image analyzer (AnalyPower 1.0), the infarct volumes obtained by light transmittance and TTC staining were calculated. Integrated gray scales of sections of both hemispheres were calculated by Photoshop 5.0. RESULTS: A close correlation existed between cerebral infarct volume measured by light transmission and TTC staining (r=0.81). The mean gray scales measured by both techniques of the ischemic hemispheres as well as those of the cortex, subcortex and hippocampus were siginificantly higher than those of non-ischemic hemispheres and of control mouse hemispheres (P <0.001). Further there were no significant difference between the two hemispheres of control mice and between hemispheres of control mice and non-ischemic hemispheres of the MCAO mice. CONCLUSION: Light transmission can be used for qualitative analysis of focal cerebral ischemia.