Induction of heat shock protein 70 by sodium arsenite attenuates burn-induced intestinal injury in severe burned rats

The present study was designed to assess the effects of induced heat shock protein 70 (HSP70) on intestinal injury after severe burn. Wistar rats were randomly divided into four groups: control group, burn group (B group), sodium arsenite pretreatment group (SA group), and sodium arsenite+quercetin pretreatment group (SA+Qu group). Plasma endotoxin and d-lactic acid content were determined at 3, 6, 12, 24, and 48h after severe burn. Samples of small intestine were obtained for histologic assessment of intestinal mucosal injury and the expression of HSP70 was assayed by Western blot. Apoptosis of the intestinal epithelial cells was examined by the TUNEL method. Results showed that SA pretreatment significantly increased expression of HSP70 in the small intestine. SA pretreatment attenuated the burn-induced increase in plasma endotoxin and d-lactic acid content, intestinal injury scores and the percentage of apoptotic intestinal epithelial cells. Co-administration of quercetin with SA abolished the SA-induced HSP70 over-expression and the beneficial effects of SA. Our findings suggest increasing expression of HSP70 induced by SA pretreatment attenuates burn-induced intestinal injury apparently by preventing apoptosis.     

Quercetin protects human mesothelial cells against exposure to peritoneal dialysis fluid

During peritoneal dialysis, mesothelial cells have been shown to undergo severe damage due to continuous exposure to peritoneal dialysis fluid (PDF) with cytotoxic physicochemical properties. In this study, we investigated the cytoprotective role of the bioflavonoid Quercetin in the in vitro model of peritoneal dialysis. Immortalized human mesothelial cells (Met5A) were exposed either to regular growth medium or to standard acidic lactate-buffered PDF (Dianeal PD4) or to a more biocompatible lactate-bicarbonate-buffered PDF (Physioneal 40). Parallel cell cultures were supplemented with 200 μM Quercetin. Cytotoxicity was assessed qualitatively by morphologic assessment and quantitatively by the release of cytoplasmic lactate dehydrogenase and fluorescence-activated cell sorting (FACS). PDF exposure with bioincompatible Dianeal PD4 resulted in severe disruption of cell cultures and in significantly increased lactate dehydrogenase (LDH) release (p = 0.0007 vs. control). Addition of 200 μM Quercetin significantly decreased the LDH release (p = 0.04 vs. “pure” Dianeal PD4 exposure), comparable to control exposure and to more biocompatible Physioneal 40 exposure (p = 0.37) and resulted in marked preservation of cell culture monolayers and cellular viability as assessed by FACS. Introduction of cytoprotective agents such as Quercetin may represent an alternate approach to protect mesothelial cells from cytotoxicity of frequently used PDFs, comparably effective to the introduction of novel, more biocompatible, PDFs.     

Taurine, a conditionally essential amino acid, ameliorates arsenic-induced cytotoxicity in murine hepatocytes

Arsenic is a potent environmental toxin. Present study has been designed to evaluate the protective role of taurine (2-aminoethanesulfonic acid) against arsenic induced cytotoxicity in murine hepatocytes. Sodium arsenite (NaAsO₂) was chosen as the source of arsenic. Incubation of hepatocytes with the toxin (1 mM) for 2 h reduced the cell viability as well as intra-cellular antioxidant power. Increased activities of alanine transaminase (ALT) and alkaline phosphatase (ALP) due to toxin exposure confirmed membrane damage. Toxin treatment caused reduction in the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx). In addition, the same treatment reduced the level of glutathione (GSH), elevated the level of oxidized glutathione (GSSG) and increased the extent of lipid peroxidation. Incubation of hepatocytes with taurine, both prior to and in combination with NaAsO₂, attenuated the extent of lipid peroxidation and enhanced the activities of enzymatic as well as non enzymatic antioxidants. Besides, taurine administration normalized the arsenic-induced enhanced levels of the marker enzymes ALT and ALP in hepatocytes. The cytoprotective activity of taurine against arsenic poisoning was found to be comparable to that of a known antioxidant, vitamin C. Combining all, the results suggest that taurine protects mouse hepatocytes against arsenic induced cytotoxicity.     

紫芪方对缺氧复氧所致大鼠小肠上皮细胞损伤的保护作用

目的观察缺氧复氧对大鼠小肠上皮细胞（intestinal epithelial cell，IEC）-6培养液中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量及细胞内Ca^2＋浓度和线粒体膜电位的影响，探讨复方中药-紫芪方对IEC-6肠上皮细胞缺氧复氧损伤的保护作用及机制。方法复制IEC-6细胞缺氧复氧损伤模型，采用紫外分光法测定缺氧复氧后及紫芪方血清治疗后细胞培养液中SOD活性及MDA含量；采用激光共聚焦显微镜测定细胞Ca^2＋浓度和线粒体膜电位变化。结果细胞缺氧复氧损伤后，可导致细胞培养液中SOD活性显著降低、MDA含量显著升高、线粒体膜电位明显降低及细胞内Ca^2＋浓度明显升高（P〈0．01）。紫芪方药物血清治疗后，可提高细胞培养液中SOD活性并降低其MDA含量，同时稳定了线粒体膜电位并降低细胞内Ca^2＋浓度（P〈0．05）。结论缺氧复氧可导致IEC-6肠上皮细胞损伤；紫芪方血清对IEC-6小肠上皮细胞缺氧复氧损伤具有显著的保护作用。     

Nitric Oxide-Induced Autophagy in MC3T3-E1 Cells is Associated with Cytoprotection via AMPK Activation

Nitric oxide (NO) is important in the regulation of bone remodeling, whereas high concentration of NO promotes cell death of osteoblast. However, it is not clear yet whether NO-induced autophagy is implicated in cell death or survival of osteoblast. The present study is aimed to examine the role of NO-induced autophagy in the MC3T3-E1 cells and their underlying molecular mechanism. The effect of sodium nitroprusside (SNP), an NO donor, on the cytotoxicity of the MC3T3-E1 cells was determined by MTT assay and expression of apoptosis or autophagy associated molecules was evaluated by western blot analysis. The morphological observation of autophagy and apoptosis by acridine orange stain and TUNEL assay were performed, respectively. Treatment of SNP decreased the cell viability of the MC3T3-E1 cells in dose- and time-dependent manner. SNP increased expression levels of p62, ATG7, Beclin-1 and LC3-II, as typical autophagic markers and augmented acidic autophagolysosomal vacuoles, detected by acridine orange staining. However, pretreatment with 3-methyladenine (3MA), the specific inhibitor for autophagy, decreased cell viability, whereas increased the cleavage of PARP and caspase-3 in the SNP-treated MC3T3-E1 cells. AMP-activated protein kinase (AMPK), a major autophagy regulatory kinase, was activated in SNP-treated MC3T3-E1 cells. In addition, pretreatment with compound C, an inhibitor of AMPK, decreased cell viability, whereas increased the number of apoptotic cells, cleaved PARP and caspase-3 levels compared to those of SNP-treated MC3T3-E1 cells. Taken together, it is speculated that NO-induced autophagy functions as a survival mechanism via AMPK activation against apoptosis in the MC3T3-E1 cells.     

Cytoprotective gastric pentadecapeptide BPC 157 resolves major vessel occlusion disturbances,ischemia-reperfusion injury following Pringle maneuver,and Budd-Chiari syndrome

The stable gastric pentadecapeptide BPC 157 counteracts various venous occlusion-induced syndromes. Summarized are all these arguments, in the Robert’s cytoprotection concept, to substantiate the resolution of different major vessel occlusion disturbances, in particular ischemia-reperfusion injury following the Pringle maneuver and Budd-Chiari syndrome, which was obtained by BPC 157 therapy. Conceptually, there is a new point, namely, endothelium maintenance to epithelium maintenance (the recruitment of collateral blood vessels to compensate for vessel occlusion and reestablish blood flow or bypass the occluded or ruptured vessel). In this paper, we summarize the evidence of the native cytoprotective gastric pentadecapeptide BPC 157, which is stable in the human gastric juice, is a membrane stabilizer and counteracts gut-leaky syndrome. As a particular target, it is distinctive from the standard peptide growth factors, involving particular molecular pathways and controlling VEGF and NO pathways. In the early 1990s, BPC 157 appeared as a late outbreak of the Robert’s and Szabo’s cytoprotection-organoprotection concept, like the previous theoretical/practical breakthrough in the 1980s and the brain-gut axis and gut-brain axis. As the time went on, with its reported effects, it is likely most useful theory practical implementation and justification. Meantime, several reviews suggest that BPC 157, which does not have a lethal dose, has profound cytoprotective activity, used to be demonstrated in ulcerative colitis and multiple sclerosis trials. Likely, it may bring the theory to practical application, starting with the initial argument, no degradation in human gastric juice for more than 24 h, and thereby, the therapeutic effectiveness (including via a therapeutic per-oral regimen) and pleiotropic beneficial effects.     

低温氧合血微流量持续灌注保存大鼠心脏的效果

目的探讨低温氧合血微流量持续灌注保存大鼠心脏的效果。方法切取Wistar大鼠心脏，随机分为3组，实验组的心脏以4℃氧合血微流量（1ml／h）持续灌注低温保存10h；对照组的心脏以4℃St．Thomas液微流量持续灌注低温保存10h；单纯冷保存组的心脏以4℃St．Thomas液单纯浸泡保存10h。保存后的鼠心用Langendorff装置灌注，生物机能实验系统测定血流动力学指标；高效液相色谱仪测定心肌细胞的ATP含量；光镜和电镜观察心肌组织和线粒体的形态学改变。结果在再灌注30min时，实验组的左心室收缩压（LVSP）为（38．25±3．84）mm Hg，左心室发展压（LVDP）为（32．54±4．01）mm Hg，左心室压力微分（±dp／dt）为（1080±123）mm Hg／s；对照组的LVSP为（34．48±4．68）mm Hg，LVDP为（19．27±4．63）mmHg，±dp／dt为（935±196）mmHg／s；单纯冷保存组的LVSP为（32．14±4．95）mmHg，LVDP为（16．99±4．85）mmHg，±dp／dt为（825±302）mmHg／s，实验组的上述血流动力学指标优于对照组和单纯冷保存组（P〈0．05）。实验组心肌细胞的ATP含量为（1．759±0．502）μmol／L，对照组的ATP为（1．453±0．573）μmol／L，单纯保存组的ATP为（1．059±0．463）μmol／L，实验组的ATP含量明显高于对照组和单纯冷保存组（P〈0．05）。实验组的心肌组织和细胞超微结构的变化轻于对照组和单纯冷保存组。结论低温氧合血微流量持续灌注能改善大鼠心脏的保存效果。     

以环孢素A预处理供肾减轻肾脏损伤的实验研究

目的探讨以环孢素A(CsA)预处理供肾对肾脏损伤的防护作用。方法将30只日本大耳兔随机分为3组,每组10只,分别以生理盐水(对照组)、高渗枸橼酸盐嘌呤溶液(HCA液,灌注液对照组)及含CsA(30mg/L)的HCA液(实验组)原位灌洗左肾,然后采用自制的原位低温保存装置,将左肾置于0～4℃的低温水囊中,原位低温保存。2h后切除右肾,开放左肾血流,测定循环恢复后6h和24h后的血肌酐及尿素氮,24h时切取左肾标本,以免疫组织化学法测定左肾组织中热休克蛋白70(HSP70)和核因子κB(NFκB)的表达,原位末端标记法测定细胞凋亡率。结果实验组HSP70的表达水平明显高于两个对照组(P<0.01,P<0.01),NFκB的表达水平及细胞凋亡率明显低于两个对照组(P<0.01,P<0.01);实验组两个时间点的血肌酐及尿素氮水平明显低于两个对照组(P<0.01,P<0.01)。结论以CsA预处理肾脏,对肾脏的缺血再灌注损伤具有保护作用。     

总结69例心脏移植中供心的心肌保护技术

目的总结心脏移植中供心的心肌保护技术，分析供心的灌注、保存以及缺血时间对心脏移植效果的影响。方法回顾性分析2004年6月至2006年9月间的69例晚期心脏病患者行心脏移植术的临床资料。供心的心肌保护采用低温St．Thomas液和HTK液顺序灌注方法，术中供心保持持续低温状态。根据供心缺血时间长短将受者分为两组，A组36例，供心缺血时间小于240min；B组33例，供心缺血时间大于240min。术后对受者进行定期随访。结果在心脏移植术中，B组受者较A组的体外循环时间延长。术后两组受者的死亡率、移植心功能、排斥反应以及并发症等资料的比较，差异无统计学意义（P〈0．05）。所有受者在心脏移植后，无近期死亡，但随访期间死亡6例。结论采用St．Thomas液和HTK液顺序冷灌注的改良方法，能够有效的保护供心心肌组织；供心缺血时间的缩短会使心肌泵血功能恢复较快。这些对移植心功能的恢复和受者的预后具有良好的近期和中期效果。     

氨磷汀与峰龄多糖对人外周血粒-巨噬祖细胞的化疗保护作用

目的　观察氨磷汀 (amifostine ,化学代号 :WR 2 72 1)和峰龄多糖 (fenglingpolysaccharide ,FLPS)对人外周血粒 -巨噬祖细胞 (CFU GM )及HL60白血病细胞的化疗保护作用。方法　应用Ficoll分离单个核细胞 (MNC) ;甲基纤维素半固体培养法测定CFU GM集落 ;XTT法测定HL60细胞存活率 ;WR 2 72 1及FLPS处理的MNC ,与VP 16作用后 ,测定CFU GM集落产率 ,研究WR 2 72 1和FLPS对CFU GM的保护作用。结果　经WR 2 72 1和FLPS处理的MNC与VP 163 7℃作用 14h后 ,CFU GM集落产率均明显高于VP 16对照组 ,CFU GM集落数在VP 16对照组、空白对照组、WR 2 72 1 VP 16组、FLPS VP 16组和WR 2 72 1 FLPS VP 16组分别为每 1× 10 5个MNC 3 0 .9± 2 2 .5、83 .2± 43 .8、64 .6± 41.2、5 5 .3± 3 3 .5和 78.3± 48.2 ,与VP 16对照组相比 ,P值均 <0 .0 1;WR 2 72 1处理后的HL60细胞对VP 16的敏感性增强 ,IC50 由 5 2 .5 μg/ml下降为 40 .5 μg/ml ;VP 16对FLPS处理前后的HL60细胞的作用无明显改变。结论　WR 2 72 1和FLPS对人外周血CFU GM具有明显化疗保护作用。WR 2 72 1能增强HL60细胞对VP 16的敏感性。FLPS对HL60细胞的化疗损伤无保护作用