Protective effect of apelin on cultured rat bone marrow mesenchymal stem cells against apoptosis

Bone marrow-derived mesenchymal stem cells (BMSCs) have shown great promise for ischemic tissue repair. However, poor viability of transplanted BMSCs within ischemic tissues has limited their therapeutic potential. Apelin, an endogenous peptide, whose level is elevated following ischemia, has been shown to enhance survival of cardiomyocytes and neuronal cells during ischemia. We hypothesized that apelin-13 protects BMSCs from apoptotic death. In this paper we determined the potential mechanism of apelin-13 effects using cultured BMSCs from adult rats. Apoptosis was induced by the specific apoptotic insult serum deprivation (SD) for up to 36 h. Apoptotic cell death was measured using immunostaining and Western blotting in the presence and absence of apelin-13 (0.1 to 5.0 nM) co-applied during SD exposure. SD-induced apoptosis was significantly reduced by apelin-13 in a concentration-dependent manner. SD-induced mitochondrial depolarization, cytochrome c release, and caspase-3 activation were largely prevented by apelin-13. The apelin-13 anti-apoptotic effects were blocked by inhibiting the MAPK/ERK1/2 and PI3K/Akt signaling pathways. Taken together, our findings indicate that apelin-13 is a survival factor for BMSCs and its anti-apoptotic property may prove to be of therapeutic significance in terms of exploiting BMSC-based transplantation therapy.     

Protective effect of gap junction uncouplers given during hypoxia against reoxygenation injury in isolated rat hearts

It has been shown that cell-to-cell chemical coupling may persist during severe myocardial hypoxia or ischemia. We aimed to analyze the effects of different, chemically unrelated gap junction uncouplers on the progression of ischemic injury in hypoxic myocardium. First, we analyzed the effects of heptanol, 18alpha-glycyrrhetinic acid, and palmitoleic acid on intracellular Ca2+ concentration during simulated hypoxia (2 mM NaCN) in isolated cardiomyocytes. Next, we analyzed their effects on developed and diastolic tension and electrical impedance in 47 isolated rat hearts submitted to 40 min of hypoxia and reoxygenation. All treatments were applied only during the hypoxic period. Cell injury was determined by lactate dehydrogenase (LDH) release. Heptanol, but not 18alpha-glycyrrhetinic acid nor palmitoleic acid, attenuated the increase in cytosolic Ca2+ concentration induced by simulated ischemia in cardiomyocytes and delayed rigor development (rigor onset at 7.31 +/- 0.71 min in controls vs. 14.76 +/- 1.44 in heptanol-treated hearts, P < 0.001) and the onset of the marked changes in electrical impedance (tissue resistivity: 4.02 +/- 0.29 vs. 7.75 +/- 1.84 min, P = 0.016) in hypoxic rat hearts. LDH release from hypoxic hearts was minimal and was not significantly modified by drugs. However, all gap junction uncouplers, given during hypoxia, attenuated LDH release during subsequent reoxygenation. Dose-response analysis showed that increasing heptanol concentration beyond the level associated with maximal effects on cell coupling resulted in further protection against hypoxic injury. In conclusion, gap junction uncoupling during hypoxia has a protective effect on cell death occurring upon subsequent reoxygenation, and heptanol has, in addition, a marked protective effect independent of its uncoupling actions.     

脂联素对乳鼠心肌细胞缺氧/复氧损伤的保护作用

本研究通过在大鼠乳鼠心室肌细胞上建立缺氧/复氧(hypoxia/reoxygenation,H/R)模型,模拟在体心肌缺血/再灌注损伤,观察脂联素(adiponectin,APN)对心肌细胞H/R损伤的影响,并探讨其作用机制。采用胰蛋白酶消化法原代培养乳鼠心室肌细胞,α-肌动蛋白免疫荧光法进行鉴定。选用培养72h的单层心肌细胞进行实验,随机分为5组:对照组、单纯H/R组、H/R+APN组、H/R+APN+腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)特异性抑制剂阿糖胞苷(AraA)组、H/R+AraA组。观察各组心肌细胞形态及自发搏动频率,用琼脂糖凝胶电泳和流式细胞术检测各组心肌细胞凋亡情况,并测定细胞丙二醛(MDA)含量及培养液中超氧化物歧化酶(SOD)活性,激光共聚焦显微镜观察心肌细胞内钙荧光强度,Western blot检测各组心肌细胞AMPK磷酸化水平。结果显示,与对照组相比,单纯H/R组细胞生长状态较差,搏动频率减慢甚至消失,DNA电泳呈凋亡特征性的梯状条带,细胞凋亡率显著增加,胞浆MDA水平增高,上清液中SOD活性下降,胞内钙荧光强度明显增高,AMPK磷酸化水平升高(P0.05)。与H/R组细胞相比,APN预处理后再进行H/R的心肌细胞搏动频率较快,凋亡率明显减少,MDA水平明显下降,SOD活性明显升高,心肌细胞AMPK磷酸化水平明显增高(P0.05)。AraA可以阻断APN的上述保护作用。以上结果表明,APN可减轻H/R导致的心肌细胞凋亡,减轻脂质过氧化及细胞内钙超载,这一保护作用可能与AMPK途径激活有关。     

Protective effect of anti-anxiety drugs against hypoxia

The effect of psychotropic agents was studied on the survival of mice subjected to hypoxia. A significant prolongation of the survival time was observed in the animals pretreated with anti-anxiety drugs. However, anti-psychotic drugs or thymoleptics failed to exert such elongation effect under the same condition. The order of potency on anti-hypoxia activity was: Y-6047 = diazepam = nitrazepam > oxazapem > chlordiazepoxide > medazepam, namely in the ratio of 30 : 10 : 3 : 1, approximately. A relationship between anti-anxiety activity and anti-hypoxia activity is also discussed.     

GABA对大鼠海马脑片缺氧损伤的保护作用

目的：研究GABA对大鼠海马脑片急性缺氧损伤的保护机制。方法：采用成年大鼠离体海马脑片,用胞外记录的电生理技术,观察GABA对急性缺氧后海马脑片诱发电位的影响。结果：（1）GABA可明显延迟PV的消失,但对PS却无影响;（2）给予GABAA受体拮抗剂荷包牡丹碱（bicuculine)以及Cl^-通道阻抗剂NPPB可阻断GABA的保护作用。结论：GAB可提高海马脑片耐缺氧能力,其机制可能与GABA通过GABAA受体提高Cl^-内流有关。     

肌肽对低氧所致大鼠血管内皮细胞损伤的保护作用

目的：研究肌肽对低氧所致大鼠血管内皮细胞损伤的影响。方法：建立低氧条件下大鼠血管内皮细胞损伤模型,用MTT法观察肌肽对低氧损伤的血管内皮细胞活性的影响,测定细胞培养基中LDH活力,并对细胞骨架进行考马斯亮蓝R-250染色观测其细胞结构。结果：浓度为10mmol/L～20mmol/L肌肽孵育血管内皮细胞6h后,可以抑制缺氧12h和24h引起的血管内皮细胞活性下降,同时减少LDH的释放,保持细胞骨架完整。结论：肌肽对低氧所致的血管内皮细胞损伤具有保护作用。     

Recovery course in mouse spleen and bone marrow after continuous irradiation.

The paper deals with the recovery process of some parameters in the spleen and bone marrow till day 60 after continuous irradiation with a daily dose of 476.5 mGy (50 R), 957 mGy (100 R) and 4785 mGy (500 R) up to the total accumulated dose of 9570 mGy (1000 R). The recovery process in the spleen and bone marrow are relatively significant and completed till day 28 or 60 respectively after irradiation.     

白藜芦醇甙对大鼠心脏缺血/再灌注损伤的保护作用

本文利用冠脉结扎/放松方法和Langendorff灌注技术,建立在体和离体大鼠心脏缺血/再灌注(ischemia/reperfusion,I/R)损伤模型,探讨白藜芦醇甙(polydatin)对大鼠I/R心肌损伤的保护作用及其机制.观察白藜芦醇甙对缺血和再灌注心律失常、心肌梗死面积、心脏收缩功能、心肌超氧化物歧化酶(superoxide dismutase,SOD)活性、丙二醛(malondialdehyde,MDA)含量、NO含量以及一氧化氮合酶(nitric oxide synthase,NOS)活性的影响.结果显示:与对照组相比,白藜芦醇甙组大鼠缺血和再灌注心律失常明显降低(P<0.05,P<0.01);心肌梗死面积显著减少(P相似文献   

Protective effect of bone marrow and spleen suspensions on radiation-induced leukemogenesis in C57BL/6 mice

Summary The present experiments are an attempt to precise the type and localization of the cells involved in the protective effect of hemopoietic suspensions against the radiation-induced thymic lymphosarcoma (TLS) of C57BL/6 mice. Inocula containing variable numbers of BM or spleen CFUs from 60-day-old and 360-day-old donors were tested. According to their origin, the suspensions differed with respect to the CFU replication rate, the CFU ability to differentiate towards the T lineage and the content of the suspensions in thymic precursors. Two levels of inhibition were observed: BM suspensions from 60-day-old donors containing 1,500 CFUs had the best protective effect: 14.5% of TLS; 1,500 CFUs from 360-day-old donors were slightly but not significantly less efficient (28.5%). The second level of inhibition (36–46% of TLS) was obtained with all the following inocula:a) 1,200 and 300 spleen CFUs or 300 and 95 BM CFUs from 60-day-old donors,b) 1,500 spleen CFUs from aged donors. Seventy-six spleen CFUs from 60-day-old donors, 120 BM or 175 spleen CFUs from aged donors had no effect. These results suggest that in addition to the high replication rate of the BM CFUs as compared with spleen CFUs, cells endowed with an optimal protective effect are present in BM suspensions and are either absent or present in very small amount in spleen suspensions. These cells which induce an early repopulation of the thymus might correspond to thymic precursors.     

Protective effect of S-adenosylmethionine against galactosamine-induced injury of rat hepatocytes in primary culture

The protective effect of S-adenosylmethionine (SAMe) on D-galactosamine (GalN)-induced damage to rat hepatocytes was tested in primary cultures. SAMe at concentrations of 50 and 1000 mg/l significantly reduced lactate dehydrogenase release from cells injured by 40 mM GalN after 24 h of incubation. There were no significant changes in urea production after 24 h among tested groups, including control hepatocytes. Exposure of hepatocytes to GalN leads to 3.5-fold decrease in urea synthesis after 48 h in comparison with control cell cultures. Addition of the highest dose of SAMe (1000 mg/l) into the culture media attenuated this decrease by 180 %. None of the tested doses of SAMe (5, 25, 50 and 1000 mg/l) affected considerably the reduced activity of mitochondrial dehydrogenases. The content of reduced and oxidized glutathione in GalN-exposed cells was diminished to 1.5 % and 16 %, respectively, of the control values after 24 h. Using only the highest concentration SAMe increased significantly these contents. SAMe had no effect on dramatically decreased albumin synthesis. These findings indicate beneficial effect of SAMe, especially of the highest concentration, on GalN-induced toxicity to rat hepatocytes in primary culture. This action of SAMe seems to be associated with reduction of plasma membrane damage and increased synthesis of glutathione.     

Differential proliferation of erythroid and granuloid spleen colonies following sublethal irradiation of the bone marrow donor

Spleen colonies produced by sublethally irradiated mouse bone marrow cells were compared to those produced by unirradiated marrow cells in lethally irradiated mice. Sublethally irradiated marrow cells gave rise to many fewer spleen colonies. At seven days of colony age, the ratio of erythroid colonies to granuloid colonies was lower (< 1) than for colonies formed by unirradiated marrow (2 to 3 or more). Delay of harvest of colonies to day 10 or 12 resulted in 6 to 11 fold increase in the ratio of erythroid to granuloid colonies due largely to the belated appearance of erythroid colonies.     

大鼠肢体缺血预处理对肝缺血/再灌注损伤的保护作用

目的：研究肢体缺血预处理对大鼠肝缺血/再灌注损伤是否具有保护作用。方法：雄性SD大鼠32只,随机分为对照组（S组）;缺血/再灌注组（I/R组）;经典缺血预处理组（IPC组）;肢体缺血预处理组（远端缺血预处理组,RPC组）。S组仅行开腹,不作其他处理;IPC组以肝缺血5min作预处理;RPC组以双后肢缺血5min,反复3次作预处理,2个预处理组及I/R组均行肝缺血1h再灌注3h。取血用于血清谷丙转氨酶（ALT）与血清谷草转氨酶（AST）检测。切取肝组织用于测定湿干比（W/D）、中性粒细胞（PMN）计数及观察显微、超微结构的变化。结果：与I/R组比较,IPC组,RPC组ALT,AST,W/D值,及PMN计数均明显降低（P〈0.01）,肝脏的显微及超微结构损伤减轻。结论：肢体缺血预处理对大鼠肝脏I/R损伤有明显的保护作用,强度与经典缺血预处理相当,其机制可能与抑制肝脏炎症反应、减轻肝脏水肿、改善肝组织微循环有关。