Neuroprotection of aucubin in primary diabetic encephalopathy

Hippocampal neuronal apoptosis accompanied by impairment of cognitive function occurs in primary diabetic encephalopathy. In this study, we investigated the neuroprotective mechanism of the iridoid glycoside, aucubin, using rats (n=8). Diabetes mellitus was induced in the rats by intraperitoneal (i.p.) injection of streptozotocin (60 mg/kg body weight). After 65 d, half of the DM rats were administered aucubin (5 mg/kg; i.p.) for 15 d, yielding treatment DM A. A third group of rats received no strepto- zotocin or aucibin, and served as controls (CON). Encephalopathy was assessed using Y-maze be- havioral testing. Rats were euthanized on Day 87, and hippocampi were excised for visual (light and transmission electron microscopic) and immunochemical (Western blot; immunohistochemical) as- sessments of the CA1 subfield for apoptosis and expression of regulatory proteins Bcl-2 and Bax. Treatment responses to all the parameters examined (body weight, plasma glucose, Y-maze error rates, pyramidal cell ultrastructure, proportions of apoptotic cells, levels of expression of Bcl-2 and Bax, and survivability of neuronal cells) were identical: there were highly significant differences between DM and CON groups (P<0.001), but the effects were significantly moderated (P<0.01) in DM A compared with DM. These findings confirm the association of apoptosis with the encephalopathic effects of diabetes mellitus, and suggest a major role of the expression levels of Bcl-2 and Bax in the regulation of apop- totic cell death. All of the results suggest that aucubin could effectively inhibit apoptosis by modulating the expressions of Bcl-2 and Bax genes.     

The timing of re-institution of good blood glucose control affects apoptosis and expression of Bax and Bcl-2 in the retina of diabetic rats

Hyperglycemia initiates a sequence of events that leads to the development of diabetic retinopathy. We explored the effect of re-institution of good blood glucose control on apoptosis and apoptosis related genes (Bax and Bcl-2) in the retina of diabetic rats. Fifty male Wistar rats randomly divided into five groups : normal control group (CON), diabetic rats with high blood glucose levels for 8 months group (DM) ,diabetic rats with good blood glucose control for 8 months group (DM₁),diabetic rats with poor blood glucose control for 2 month followed by good blood glucose control for six additional months group (DM₂), rats with poor blood glucose control for 4 months followed by good blood glucose levels for four additional months group (DM₃). Expression of Bax and Bcl-2 in the retina was studied by immunohistochemistry and the apoptotic cells were stained using the TUNEL method. The apoptotic cell, expression of Bax and Bcl-2 and the ratio of Bax to Bcl-2 in the retina was increased in DM group compared with normal rats’ (P < 0.01). There was no significant difference in apoptotic cells and the ratio of Bax to Bcl-2 between DM₁ group and CON group. The number of TUNEL positive cells and Bax to Bcl-2 ratio was partially reversed in DM₂ group. But glucose control had no effect on the apoptotic cells and the expression of Bax and Bcl-2 in DM₃ group. There was a positive correlation between apoptotic cells and Bax/Bcl-2 ratio in the retina (r = 0.808, P < 0.01). Good blood glucose control at early stage can decrease the number of apoptotic cells in the retina; the decreased apoptosis is correlated with the down-regulation of Bax to Bcl-2 ratio.     

Neuroprotective properties of aucubin in diabetic rats and diabetic encephalopathy rats

In this study, we determined the neuroprotective effect of aucubin on diabetes and diabetic encephalopathy. With the exception of the control group, all rats received intraperitoneal injections of streptozotocin (STZ; 60?mg/kg) to induce type 1 diabetes mellitus (DM). Aucubin (1, 5, 10?mg/kg ip) was used after induction of DM (immediately) and diabetic encephalopathy (65?days after the induction of diabetes). The diabetic encephalopathy treatment groups were divided into short-term and long-term treatment groups. Treatment responses to all parameters were examined (body weight, plasma glucose, Y-maze error rates and proportion of apoptotic cells). In diabetic rats, aucubin controlled blood glucose levels effectively, prevented complications, and improved the quality of life of diabetic rats. In diabetic encephalopathy, aucubin significantly rescued neurons in the hippocampal CA1 subfield and reduced working errors during behavioral testing. The significant neuroprotective effect of aucubin could be seen not only in the short term (15?days) but also in the long term (45?days), which was a highly encouraging finding. These data suggest that aucubin may be a potential neuroprotective agent.     

IL-10 基因对糖尿病大鼠胰岛beta细胞凋亡的保护作用

目的：研究白细胞介素10（IL-10）基因对链脲佐菌素(STZ)诱导的糖尿病大鼠胰腺炎症浸润程度及胰腺组织中Bcl-2 及Bax 表达的影响。方法：建立链脲佐菌素性糖尿病模型,腺病毒介导的IL-10 基因(Ad-mIL-10)腹腔注射。检测大鼠空腹血糖值;免疫组 织化学法观察胰腺炎症浸润程度;TUNEL法检测胰岛细胞凋亡;免疫组化方法观察Ad-mIL-10 对实验性糖尿病大鼠胰岛凋亡调 控基因Bax 和Bcl-2 表达的影响。结果：Ad-mIL-10 腹腔注射糖尿病发病率低,平均血糖水平低,可以降低胰腺炎症浸润程度,减 少胰岛细胞凋亡。给予Ad-mIL-10 后大鼠Bax 基因的表达明显下降, Bcl-2 与Bax 的比值明显增加。结论：IL-10基因对实验性糖 尿病大鼠有降血糖作用,减少胰岛细胞凋亡,与调节Bcl-2 与Bax 基因的表达有关。     

The Effect of Continued Training with Crocin on Apoptosis Markers in Liver Tissue of High Fat Diet Induced Diabetic Rats

Diabetes mellitus (DM) disease can affect process of apoptosis by increasing oxidative stress, nevertheless exercise and crocin can improve apoptosis; therefore present study aimed to investigate the effect of continued training with crocin on apoptosis markers in liver tissue of diabetic rats. In this experimental study 32 diabetic rats based on fasting glucose divided into four groups of eight rats including: 1) sham, 2) training, 3) crocin, and 4) training with crocin also for investigate the effect of DM induction on apoptosis markers, eight healthy rats assigned in healthy control group. During eight weeks groups 2 and 4 ran 60 minutes on treadmill with intensity of 50–55% maximum speed for three sessions per week and groups 3 and 4 received 25 mg/kg/day crocin peritoneally. Shapiro–Wilk, one-way ANOVA with Tukey’s post-hot tests were used for statistical analysis of data (P ≤ 0.05). DM induction significantly increased Bcl-2 as well as decreased Bax and P52 (P ≤ 0.05) nevertheless training and training with crocin significantly decreased Bcl-2 and increased Bax and P53 (P ≤ 0.05); crocin significantly decreased Bcl-2 and increased P53 (P ≤ 0.05) and training with crocin had higher effect on increase of Bax and P53 compare to training (P ≤ 0.05) also increase of Bax compare to crocin. Although training and crocin alone can improve apoptotic markers in diabetic rats, nevertheless training simultaneously with crocin have better effects than training alone.     

IL-10基因对糖尿病大鼠胰岛β细胞凋亡的保护作用

目的：研究白细胞介素10（IL-10）基因对链脲佐菌素（STZ）诱导的糖尿病大鼠胰腺炎症浸润程度及胰腺组织中Bcl-2及Bax表达的影响。方法：建立链脲佐茵素性糖尿病模型,腺病毒介导的IL-10基因（Ad-mIL-10）腹腔注射。检测大鼠空腹血糖值;免疫组织化学法观察胰腺炎症浸润程度;TUNEL法检测胰岛细胞凋亡;免疫组化方法观察Ad-mIL-10对实验性糖尿病大鼠胰岛凋亡调控基因Bax和Bcl．2表达的影响。结果：Ad-mlL-10腹腔注射糖尿病发病率低,平均血糖水平低,可以降低胰腺炎症浸润程度,减少胰岛细胞凋亡。给予Ad-mlL-10后大鼠Bax基因的表达明显下降,Bcl-2与Bax的比值明显增加。结论：IL-10基因对实验性糖尿病大鼠有降血糖作用,减少胰岛细胞凋亡,与调节Bcl-2与Bax基因的表达有关。     

Kinetics of Apoptosis and Expression of Apoptosis-Related Proteins in Rat CA3 Hippocampus Cells After Experimental Diffuse Brain Injury

The present study examined kinetics of apoptosis and expression of apoptosis-related proteins Bcl-2, Bax, and caspase-3 in the CA3 hippocampus cells after diffuse brain injury (DBI) induced experimentally in rats. Percentage of apoptotic cells and expressions of above proteins were examined by flow cytometry and immunohistochemistry. Substantial neuronal apoptosis was documented in the CA3 hippocampus cells after DBI (22.26 ± 2.97 % at 72 h after DBI vs. 2.92 ± 0.88 % in sham-operated animals). Expression of Bc1-2 decreased, while expression of Bax and caspase-3 increased after DBI, with caspase-3 expression peaking after that of Bax (72 vs. 48 h, respectively). Further, the Bc1-2/Bax expression ratio decreased prior to increase of caspase-3 expression. In conclusion, cell apoptosis and altered expressions of Bcl-2, Bax, and caspase-3 are present in the CA3 region of hippocampus after experimental DBI. Changes in the Bc1-2/Bax expression ratio may facilitate activation of caspase-3 and aggravate neuronal apoptosis after brain injury.     

Aucubin modulates Bcl-2 family proteins expression and inhibits caspases cascade in H<Subscript>2</Subscript>O<Subscript>2</Subscript>-induced PC12 cells

In this study, the effect of aucubin on H₂O₂-induced apoptosis was studied by using a rat pheochromocytoma (PC12) cell line. We have analyzed the apoptosis of H₂O₂-induced PC12 cells, H₂O₂-induced apoptosis appeared to correlate with lower Bcl-2 expression, higher Bax expression and sequential activation of caspase-3 leading to cleavage of poly-ADP-ribose polymerase (PARP). Aucubin not only inhibited lower Bcl-2 expression, high Bax expression, but also modulated caspase-3 activation, PARP cleavage, and eventually protected against H₂O₂-induced apoptosis. These results indicated that aucubin can obstruct H₂O₂-induced apoptosis by regulating of the expression of Bcl-2 and Bax, as well as suppression of caspases cascade activation.     

厄贝沙坦对糖尿病大鼠心肌损伤中Notch1信号通路的影响

目的：观察厄贝沙坦对糖尿病大鼠心肌损伤的作用,分析Notch1信号通路在其中的变化。方法：实验分4组：正常对照组（CON）、高糖高脂组（HC）、糖尿病组（DM）和厄贝沙坦+糖尿病组（Ir+DM）。制作2型糖尿病（T2DM）大鼠模型成功后,第8周开始检测大鼠空腹血糖水平（FBG）、全心质量及左心室重量,计算心脏指数（H/B）及左室重量指数（LVWI）,检测大鼠血浆甘油三酯（TG）、胆固醇（TC）水平,检测心肌组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量变化,免疫组化检测Bcl-2、Bax表达变化,Western blot检测大鼠心肌组织Notch1、Hes-1及Jagged-1的蛋白表达。结果：与CON组相比,HC组H/B、LVWI、FBG无明显变化,血脂、MDA含量明显升高,SOD活性、Bcl-2/Bax及Notch1、Hes-1、Jagged-1蛋白表达降低;与HC组相比,DM组H/B、LVWI、FBG、MDA含量增加明显,血脂水平无明显变化,SOD活性、Bcl-2/Bax及Notch1信号通路蛋白表达进一步降低;与DM组相比,厄贝沙坦干预组H/B、LVWI明显降低,血脂、血糖水平无明显变化,但SOD活性、Bcl-2/Bax增加,MDA含量降低,同时Notch1信号通路相关蛋白表达增加。结论：糖尿病可导致大鼠发生心肌损伤,厄贝沙坦可能通过增强Notch1信号通路的表达发挥心肌保护作用。     

辛伐他汀对大鼠糖尿病所致心肌细胞凋亡的影响及其机制

目的：探讨辛伐他汀对糖尿病所致心肌损伤的保护作用及可能机制。方法：24只SD大鼠（180~220） g随机分为对照组（control组,n=8）和模型组（n=16）,模型组给予链脲佐菌素（STZ）腹腔注射建立糖尿病模型,然后随机将模型组分为糖尿病组（DM组,n=8）和糖尿病+辛伐他汀组（DM+S组,n=8）,DM+S组给予辛伐他汀40 mg/（kg·d）灌胃四周,其余两组给予的等量生理盐水。实验结束后,取心脏,分光光度测定法测定大鼠心肌组织脂质过氧化物丙二醛（MDA）含量、超氧化物歧化酶（SOD）的活性,HE染色观察大鼠心肌病理学改变,TUNEL法检测大鼠心肌细胞凋亡,免疫组织化学法测定大鼠p53的表达;Western blot检测心肌组织p53,p53-phospho-serine15,Bax,Bcl-2等蛋白的表达。结果：①与对照组比较,DM组大鼠心肌组织MDA含量显著升高（P<0.01）,SOD活性明显下降（P<0.01）,与DM组比较,DM+S组大鼠SOD活性显著增加（P<0.01）,MDA含量显著下降（P<0.01）。②HE染色结果表明,与对照组比较,DM组大鼠心肌细胞排列紊乱,结构不清晰,有大量炎性细胞浸润;与DM组比较,DM+S组的心肌细胞结构明显改善。③ TUNEL细胞凋亡检测结果表明,与control组相比,DM组心肌凋亡细胞阳性率显著增加（P<0.01）,给予辛伐他汀后细胞凋亡明显减少（P<0.01）;④免疫组织学检测结果显示,与对照组比较,DM组p53表达量显著增加,且p53在细胞质和细胞核中均有表达（P<0.01）;与DM组比较,DM+S组p53表达量明显下降,p53在细胞质和核中均有表达,但核内表达量减少（P<0.01）。⑤ Western blot检测结果表明,与对照组比较,DM组大鼠p53,p53-Phospho-Serine15,Bax表达量显著升高（P<0.01）,Bcl-2表达量减少（P<0.01）;与DM组比较,DM+S组p53（P<0.01）,p53-Phospho-Serine15（P<0.01）,Bax （P<0.05）表达量显著下降,Bcl-2（P< 0.05）表达量显著增加。结论：辛伐他汀通过改善心肌结构异常、抑制氧化应激和心肌细胞凋亡对糖尿病导致的心肌损伤起到保护作用,其机制与p53介导的细胞凋亡通路相关蛋白的调控有关。     

硫化氢对1型糖尿病大鼠肾脏的保护作用

目的：观察硫化氢（H₂S）对1型糖尿病大鼠肾脏的保护作用及其机制。方法：32只雄性SD大鼠随机分为4组：正常对照（NC）组、糖尿病（DM）组、糖尿病治疗（NaHS+DM）组和NaHS对照（NaHS）组（n=8）。DM组和NaHS+DM组大鼠采用链脲佐菌素（STZ）55 mg/kg腹腔注射诱导1型糖尿病模型。造模成功后,NaHS+DM组和NaHS组采用腹腔注射NaHS溶液56 μmol/kg干预治疗。8周后,测定大鼠24 h尿蛋白含量、肾重指数、空腹血糖、尿素氮、肌酐等指标;HE染色观察肾脏组织形态学变化;测定肾脏组织脂质过氧化物丙二醛（MDA）含量、超氧化物歧化酶（SOD）和Caspase-3的活性;Western blot检测肾脏组织Bcl-2和Bax蛋白表达。结果：与NC组相比,NaHS组各项指标均无显著差异,DM组,24 h尿蛋白含量、肾重指数、空腹血糖、尿素氮和肌酐水平均明显升高;HE染色结果显示肾小球基底膜增厚、系膜基质增多;MDA含量、Caspase-3活性和Bax蛋白表达明显增高;SOD活性和Bcl-2蛋白表达显著降低。与DM组相比,NaHS+DM组肾功能损伤明显减轻,肾脏组织形态学变化明显改善,MDA含量、Caspase-3活性和Bax蛋白表达明显下降,SOD活性和Bcl-2蛋白表达显著增高。结论：H₂S对1型糖尿病大鼠肾脏具有保护作用,其机制可能与抑制氧化应激和细胞凋亡有关。     

Effects of dual endothelin receptor antagonist on antiapoptotic marker Bcl-2 expression in streptozotocin-induced diabetic rats

Erectile dysfunction (ED) affects approximately 50% of male patients with diabetes mellitus (DM) and is possibly due to the vascular and neuropathic complications of DM. Recently, apoptosis has been regarded as a downstream event in ED. More recently, the importance of alterations in apoptosis-related molecules in the mechanism of DM-induced ED has begun to be appreciated. Endothelin-1 (ET-1) plays a role via ET(A) and ET(B) receptors in the regulation of cavernosal smooth-muscle tone in penile tissues. We found that the ET-1 level in the penis of rats with DM was higher than that in the penis of control animals. The present study investigated a rat model in which DM was induced by a 3-week regimen of streptozotocin (STZ) to assess the expression of several apoptosis-related molecules in penile tissue and, concomitantly, the effects of ET antagonism on these changes. Male Sprague-Dawley rats (weight [+/-SD], 450 +/- 26 g) received a citrate saline vehicle or STZ (65 mg/kg ip). DM was confirmed by the presence of hyperglycemia. Diabetic animals were further separated into two treatment groups 1 week after onset of disease: one group received ET(A/B) dual receptor antagonist (SB209670) by means of osmotic minipump at a dosage of 1 mg/day, and the other group received saline. Rats in both groups were treated for 2 weeks and then sacrificed. Plasma glucose levels (+/-SD) in rats with DM were significantly higher than those in rats without DM (506 +/- 70 vs. 111 +/- 11 mg/dl). In the penile tissue of rats with DM, a 35% decrease in the expression of Bcl-2 protein (an important antiapoptotic marker detectable by immunoblotting) was seen, and ET(A/B) dual antagonist was observed to significantly counteract this decrease. Real-time polymerase chain reaction revealed that the expression of Bcl-2 mRNA was consistent with Bcl-2 protein expression. Levels of Bax and caspase-3, two important proapoptotic markers, were not significantly altered in the present study. Thus, we conclude that, in the penis of rats with early stage DM, the protection against apoptosis has decreased but can be improved by ET antagonism.     

Evaluation of Insulin and Ascorbic Acid Effects on Expression of Bcl-2 Family Proteins and Caspase-3 Activity in Hippocampus of STZ-Induced Diabetic Rats

Aims Effects of insulin and ascorbic acid on expression of Bcl-2 family proteins and caspase-3 activity in hippocampus of diabetic rats were evaluated in this study. Methods Diabetes was induced in Wistar male rats by streptozotocin (STZ). Six weeks after verification of diabetes, the animals were treated for 2 weeks with insulin or/and ascorbic acid in separate groups. Hippocampi of rats were removed and evaluation of Bcl-2, Bcl-x_L, and Bax proteins expression in frozen hippocampi tissues were done by SDS-PAGE electrophoresis and blotting. The Bcl-2, Bcl-x_L, and Bax proteins bands were visualized after incubation with specific antibodies using enhanced chemiluminescences method. Caspase-3 activity was determined using the caspase-3/CPP32 Fluorometric Assay Kit. Results Diabetic rats showed increase in Bax protein expression and decrease in Bcl-2 and Bcl-x_L proteins expression. The Bax/Bcl-2 and Bax/Bcl-x_L ratios were found higher compared with non-diabetic control group. Treatments with insulin and/or ascorbic acid were resulted in decrease in Bax protein expression and increase in Bcl-2 and Bcl-x_L proteins expression. The Bcl-2/Bax and Bcl-x_L/Bax ratios were found higher in treated groups than untreated diabetic group. Caspase-3 activity level was found higher in diabetic group compared with non-diabetic group. Treatment with insulin and ascorbic acid did downregulated caspase-3 activity. Conclusions Our data provide supportive evidence to demonstrate the antiapoptotic effects of insulin and ascorbic acid on hippocampus of STZ-induced diabetic rats.     

二氮嗪预处理上调Bcl-2/Bax蛋白比值减少缺氧复氧所致体外培养的海马神经元凋亡

线粒体内膜ATP敏感钾通道（mitochondrial ATP-sensitive potassium channel,mitoKATP通道）的激活在药物预处理增强神经元对各种损伤的耐受力过程中发挥着重要作用。神经元内含有丰富的mito KATP,通道,二氮嗪（diazoxide,DZ）为选择性的mitoKATP通道开放剂,本实验探讨了DZ预处理能否减少缺氧复氧所致的海马神经元凋亡,以及DZ如何调控Bcl-2蛋白和Bax蛋白的表达。原代培养9～10d的Sprague-Dawley大鼠海马神经元随机分为5组：对照组、DZ0μmol／L、DZ30μmol／L、DZ100μmol／L和DZ100μmol／L＋5-羟癸酸（5-hydroxydecanoate,5-HD）100μmol／L。除对照组外,其他四组神经元白缺氧前3d开始,每天DZ预处理1h,连续3d。体外缺氧4h,于复氧后24h,四唑蓝比色法测定海马神经元存活率,annexin V-FITC流式细胞术测定凋亡率,Western blot法检测Bcl-2和Bax蛋白的表达量。结果显示：与对照组比较,缺氧复氧损伤显著降低海码神经元的存活率,升高凋亡率。与其他浓度比较,100μmol／LDZ预处理使神经元存活率升高约15％,而凋亡率降低约12％：Bcl-2蛋白表达增强约60％,Bax蛋白表达下降近30％。5-HD消除DZ对神经元的保护作用。因此,100μmol／LDZ可通过上调Bcl-2蛋白表达,降低Bax蛋白表达,减少缺氧复氧后海马神经元的凋亡。     

Role of microRNA-195 in cardiomyocyte apoptosis induced by myocardial ischaemia–reperfusion injury

This study aims to investigate microRNA-195 (miR-195) expression in myocardial ischaemia–reperfusion (I/R) injury and the roles of miR-195 in cardiomyocyte apoptosis though targeting Bcl-2. A mouse model of I/R injury was established. MiR-195 expression levels were detected by real-time quantitative PCR (qPCR), and the cardiomyocyte apoptosis was detected by TUNEL assay. After cardiomyocytes isolated from neonatal rats and transfected with miR-195 mimic or inhibitor, the hypoxia/reoxygenation (H/R) injury model was established. Cardiomyocyte apoptosis and mitochondrial membrane potential were evaluated using flow cytometry. Bcl-2 and Bax mRNA expressions were detected by RT-PCR. Bcl-2, Bax and cytochrome c (Cyt-c) protein levels were determined by Western blot. Caspase-3 and caspase-9 activities were assessed by luciferase assay. Compared with the sham group, miR-195 expression levels and rate of cardiomyocyte apoptosis increased significantly in I/R group (both P<0.05). Compared to H/R + negative control (NC) group, rate of cardiomyocyte apoptosis increased in H/R + miR-195 mimic group while decreased in H/R + miR-195 inhibitor group (both P<0.05). MiR-195 knockdown alleviated the loss of mitochondrial membrane potential (P<0.05). MiR-195 overexpression decreased Bcl-2 mRNA and protein expression, increased BaxmRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P<0.05). While, downregulated MiR-195 increased Bcl-2 mRNA and protein expression, decreased Bax mRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P<0.05). Our study identified that miR-195 expression was upregulated in myocardial I/R injury, and miR-195 overexpression may promote cardiomyocyte apoptosis by targeting Bcl-2 and inducing mitochondrial apoptotic pathway.     

Regulatory role of CD8+ T lymphocytes in bone marrow eosinophilopoiesis

Background

The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2).

Methods

Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression.

Results

TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days.

Conclusion

Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process.     

Astragaloside IV, a novel antioxidant, prevents glucose-induced podocyte apoptosis in vitro and in vivo

Glucose-induced reactive oxygen species (ROS) production initiates podocyte apoptosis, which represents a novel early mechanism leading to diabetic nephropathy (DN). Here, we tested the hypothesis that Astragaloside IV(AS-IV) exerts antioxidant and antiapoptotic effects on podocytes under diabetic conditions. Apoptosis, albuminuria, ROS generation, caspase-3 activity and cleavage, as well as Bax and Bcl-2 mRNA and protein expression were measured in vitro and in vivo. Cultured podocytes were exposed to high glucose (HG) with 50, 100 and 200 μg/ml of AS-IV for 24 h. AS-IV significantly attenuated HG-induced podocyte apoptosis and ROS production. This antiapoptotic effect was associated with restoration of Bax and Bcl-2 expression, as well as inhibition of caspase-3 activation and overexpression. In streptozotocin (STZ)-induced diabetic rats, severe hyperglycemia and albuminuria were developed. Increased apoptosis, Bax expression, caspase-3 activity and cleavage while decreased Bcl-2 expression were detected in diabetic rats. However, pretreatment with AS-IV (2.5, 5, 10 mg·kg(-1)·d(-1)) for 14 weeks ameliorated podocyte apoptosis, caspase-3 activation, renal histopathology, podocyte foot process effacement, albuminuria and oxidative stress. Expression of Bax and Bcl-2 mRNA and protein in kidney cortex was partially restored by AS-IV pretreatment. These findings suggested AS-IV, a novel antioxidant, to prevent Glucose-Induced podocyte apoptosis partly through restoring the balance of Bax and Bcl-2 expression and inhibiting caspase-3 activation.     

功能矫形前伸青春期大鼠下颌后浅层嚼肌细胞凋亡的研究

目的：研究功能矫形前伸大鼠下颌后浅层嚼肌细胞凋亡的变化规律,探讨功能矫形的肌肉改建机理。方法：选用50只5周龄Sprague-Dawley（SD）雄性大白鼠,随机分为实验组和对照组各25只。实验组大鼠戴自制上颌功能矫治嚣,引导下颌前伸,并打开咬合。利用RT-PCR方法检测两组大鼠浅层嚼肌Bcl-2和Bax基因表达情况,利用TUNEL方法检测浅层嚼肌细胞凋亡情况。结果：①Bcl-2和Bax基因表达随大鼠戴用矫治器时间的延长而升高,至第3周开始下降但仍高于对照组,但Bax的表达高于Bcl-2。Bax/Bcl-2比值随大鼠戴用矫治器时间的延长而升高,至第4周开始下降。②TUNEL实验结果显示浅层嚼肌细胞在戴用矫治器1天后,开始出现凋亡,随着时间延长而增加,至第3周达到顶峰,第4周开始下降。结论：①Bax/Bcl-2比值升高促进浅层嚼肌细胞凋亡。②功能矫形可引起浅层嚼肌细胞凋亡,导致肌肉的结构和功能发生适应性改建。     

Induction of lactadherin mediates the apoptosis of endothelial cells in response to advanced glycation end products and protective effects of grape seed procyanidin B2 and resveratrol

One of characteristics of diabetes mellitus (DM) is endothelial cell (EC) dysfunction and apoptosis which contributes to the development of vasculopathy. Advanced glycation end products (AGEs) continuously produced in the setting of DM play an important role in causing EC dysfunction and apoptosis. However, the underlying molecular mechanism remains largely elusive. Lactadherin, a secreted glycoprotein of milk-fat globule, is expressed by multiple cell types of arterial wall including ECs. Our previous proteomic studies showed that the expression of lactadherin was significantly increased in the aorta of diabetic rats as compared with control rats and treatment with grape seed procyanidin extracts significantly inhibited the lactadherin expression in diabetic rats. We hypothesized that lactadherin plays a critical role in AGEs-induced EC apoptosis; grape seed procyanidin B2 (GSPB2) and resveratrol protect against AGEs-induced EC apoptosis through lactadherin regulation. Our results showed that AGEs upregulated lactadherin expression and lactadherin RNA interference significantly attenuated AGEs-induced EC apoptosis. Overexpression of lactadherin increased EC apoptosis with up-regulation of Bax/Bcl-2 ratio, cytochrome c release, caspase-9 and caspase-3 activation suggesting the involvement of mitochondria apoptosis pathway. Mechanistically, overexpression of lactadherin reduced the phosphorylation of GSK3beta at baseline. Our study also revealed nine proteins interacting with lactadherin in HUVEC and study of these candidate proteins could unveil further underlying molecular mechanisms. In summary, our study identified lactadherin as a key player responsible for AGEs-induced EC apoptosis and antioxidants GSPB2 and resveratrol protect against AGEs-induced EC apoptosis by inhibiting lactadherin. Targeting lactadherin with antioxidant could be translated into clinical application in the fighting against DM complications.