In vitro and in vivo activities of a triterpenoid saponin extract (PX-6518) from the plant Maesa balansae against visceral leishmania species

The in vitro and in vivo activities of a mixture of six oleane triterpene saponins, recovered from the methanolic extract of the leaves of the Vietnamese plant Maesa balansae (PX-6518), were evaluated against drug-sensitive visceral Leishmania strains. The in vitro 50% inhibitory concentration (IC(50)) against intracellular Leishmania infantum amastigotes was 0.04 micro g/ml. The cytotoxic concentrations causing 50% cell death (CC(50)s) were about 1 micro g/ml in murine macrophage host cells and >32 micro g/ml in human fibroblasts (MRC-5 cell line). Evaluation in the Leishmania donovani BALB/c mouse model indicated that a single subcutaneous administration of 0.4 mg/kg at 1 day after infection reduced liver amastigote burdens by about 95% in all treated animals. If treatment was delayed until 14 days after infection, a dose of 1.6 mg/kg of body weight was required to maintain the same level of activity. Single 250-mg/kg doses of sodium stibogluconate (Pentostam) 1 and 14 days after infection produced comparable efficacies. A single dose of PX-6518 at 2.5 mg/kg administered 5 days before infection was still 100% effective in preventing liver infection, suggesting a particularly long residual action. Spleen and bone marrow could not be cleared by PX-6518 nor sodium stibogluconate. PX-6518 did not show activity after oral dosing at up to 200 mg/kg for 5 days. This study concludes that triterpenoid saponins from M. balansae show promising in vitro and in vivo antileishmanial potential and can be considered as new lead structures in the search for novel antileishmanial drugs.     

Prolonged survival of mice with multiple liver metastases of human colon cancer by intravenous administration of replicable E1B-55K-deleted adenovirus with E1A expressed by CEA promoter.

Liver is the most preferential site for metastasis of colon cancer. We, in the present study, constructed a self-replicable adenovirus in which E1A is driven by a CEA promoter and E1B-55K is deleted from the E1B region (AdCEAp/Rep) and examined its effects on multiple metastases of a human colon cancer cell in a mouse xenograft model. We first showed effective replication of the virus in various CEA-producing human colon cancer cells (M7609, HT-29) and subsequent lysis of the infected cells in vitro. We then demonstrated that a single intratumoral injection of the virus (1 x 10(8) PFU/100 microl) induced a complete regression of subcutaneous tumors (M7609) inoculated into nude mice. Further, we demonstrated that systemic administration of the virus (1 x 10(8) PFU/100 microl) through the tail vein to nude mice, which 1 week prior had been inoculated with tumor cells (colon carcinoma cell line HT-29) via the spleen and showed apparent multiple metastases in the liver, effectively suppressed the metastasis formation. The mean survival time of the treated mice was significantly longer than that of the controls. Thus, the systemic administration of AdCEAp/Rep was considered to be effective on multiple liver metastases of CEA-positive colon cancer in a xenograft model.     

In vitro cell cycle arrest, in vivo action on solid metastasizing tumors, and host toxicity of the antimetastatic drug NAMI-A and cisplatin

The effects of NAMI-A (imidazolium trans-imidazoledimethyl sulfoxide-tetrachlororuthenate) are compared with cisplatin on tumor cells cultured in vitro at doses of 1 to 100 microM and on tumor metastases in vivo at maximum tolerated doses. Using mouse tumors that metastasize to the lungs, NAMI-A given i.p. for 6 consecutive days at 35 mg/kg/day, was effective independently of the tumor line being treated and of the stage of metastasis growth. Conversely, cisplatin (2 mg/kg/day for 6 days) was as effective as NAMI-A on MCa mammary carcinoma and TS/A adenocarcinoma and less effective than NAMI-A on Lewis lung carcinoma. Cisplatin reduced body weight gain and spleen weight during treatment and was much more toxic than NAMI-A on liver sinusoids, kidney tubules, and lung epithelium. In vitro NAMI-A caused a transient cell cycle arrest of tumor cells in the premitotic G2/M phase, whereas cisplatin caused a progressive dose-dependent disruption of cell cycle phases. Correspondingly, NAMI-A did not modify cell growth, whereas cisplatin caused a dose-dependent reduction of cell proliferation, as determined by sulforhodamine B test. Thus, NAMI-A, unlike cisplatin, is a potent agent for the treatment of solid tumor metastases as well as when these tumor lesions are in an advanced stage of growth. NAMI-A is endowed with a mechanism of action unrelated to direct tumor cell cytotoxicity, and such mechanism of action is responsible for a reduced host toxicity.     

Intraportal and systemic allogeneic cell therapy in a murine model of hepatic metastatic breast cancer

Allogeneic immunocompetent splenocytes were tested for their ability to exert a GVT effect in a murine model of liver metastasis. Mammary carcinoma cells originating from an H-2(d) mouse were inoculated through the PV of F(1) (H-2(d/b)) mice, to mimic clinical hepatic involvement in malignant disease. Cell therapy was given either locally (PV) or systemically by IV inoculation to test differential efficacy of the GVT effect, and the differential expression of GVHD symptoms induced by diverse routes of administration. Livers of mice treated with H-2(b) derived splenocytes given PV or IV remained tumor-free for at least 4 weeks following tumor inoculation. Furthermore, all secondary recipients of adoptively transferred (AT) liver cells were tumor-free for >300 days. In contrast, all livers of untreated control mice or mice treated with syngeneic splenocytes displayed tumor metastases as early as 2 weeks following tumor inoculation, and large local tumors developed in AT secondary recipients. Our data demonstrate the efficacy of allogeneic cell therapy, given either locally or systemically, in the eradication of liver metastases. However, diverse routes of cell therapy administration did not show any difference in the expression and outcome of GVHD.     

脑源性神经营养因子单克隆抗体在NOD/SCID小鼠骨髓瘤模型体内的抗瘤活性

目的以多发性骨髓瘤（MM）细胞株RPMI8226异体移植小鼠为动物模型，评估抗脑源性神经营养因子（BDNF）单克隆抗体（单抗）在体内的抗肿瘤活性。方法选择糖尿病抵抗／重症联合免疫缺陷（NOD／SCID）小鼠，皮下注射RPMI8226细胞建立骨髓瘤细胞异体移植动物模型。以20μg／只的BDNF单抗剂量于接种肿瘤细胞后第1、2、3天腹腔内注射或者以100μg／只的剂量于检测到瘤体后每周1次腹腔内注射。采用组织学方法检测瘤细胞的形态特征，免疫化学染色法分析瘤组织的微血管密度（MVD）。用^3H—TdR掺入法和Matrigel网状结构形成实验分别检测BDNF单抗对RPMI8226细胞体外增殖和PRMI8226细胞诱导的内皮细胞血管新生的影响。结果在NOD／SCID小鼠体内建立的骨髓瘤细胞异体移植动物模型，其皮下种植的成瘤率高，具有多种与浆细胞瘤相似的病理学特征。未治疗组小鼠皮下注射RPMI8226细胞后（20±2）d可检测到皮下肿瘤；接种肿瘤细胞后连续3d注射20μgBDNF单抗的治疗组，小鼠平均无肿瘤生存期延长为（30±6）d，而相应对照抗体治疗组无肿瘤生存期为（22±3）d，与未治疗组相比差异无统计学意义；同时，其中位存活时间为（57±7）d，与相应的对照抗体治疗组[（48±4）d]相比明显延长（P〈0．05）；治疗组小鼠自然死亡时肿瘤体积为（157．94-21．6）mm^3，较对照抗体组[（405．5±35．2）mm^3]明显缩小（P〈0．05）。对于接种肿瘤细胞后第27天起每周注射1次BDNF单抗（100μg／次）的治疗组，肿瘤的生长亦受到部分抑制，相应对照抗体组与未治疗组相比肿瘤生长差异无统计学意义；同时在BDNF单抗治疗组瘤体的组织切片中，观察到部分瘤细胞出现凋亡的形态学表现，坏死区被纤维结缔组织浸润。未治疗组瘤块的MVD为38个／0．216mm^2，BDNF单抗治疗组（100μg／次）MVD为11个／0．216mm^2，与未治疗组相比对照抗体治疗组瘤块的MVD没有明显下降（35个／0．216mm^2）（P〉0．05）。在体外，BDNF单抗可显著抑制RPMI8226细胞的增殖和其诱导的内皮细胞网状结构形成（抑制率为68．2％），而相应的对照抗体却无此效应。结论BDNF单抗可抑制皮下浆细胞瘤的生长和血管新生，BDNF是治疗MM的潜在靶点。     

ZD6474, a vascular endothelial growth factor receptor tyrosine kinase inhibitor with additional activity against epidermal growth factor receptor tyrosine kinase, inhibits orthotopic growth and angiogenesis of gastric cancer

Vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) have been strongly implicated in the growth and metastasis of gastric cancer. The purpose of this study was to examine the effects of ZD6474, an inhibitor of inhibitor of VEGF receptor (VEGFR) tyrosine kinase with additional activity against EGF receptor (EGFR), on tumor growth and angiogenesis in an orthotopic model of gastric cancer. In vitro, ZD6474 inhibited human umbilical vascular endothelial cell and TMK-1 human gastric tumor cell proliferation in a dose-dependent fashion. EGF-mediated activation of EGFR and Erk-1/2 was decreased in tumor cells after ZD6474 treatment. In addition, VEGF-mediated activation of VEGFR2 and Erk-1/2 was decreased in human umbilical vascular endothelial cells. TMK-1 human gastric adenocarcinoma cells were injected into the gastric wall of nude mice. ZD6474 therapy was initiated on day 10. Mice (n = 14 per group) were treated p.o. with (a) 1% Tween 80 (control), (b) 50 mg/kg/d ZD6474, or (c) 100 mg/kg/d ZD6474. Mice were sacrificed on day 33. Tumors from each group were stained for markers of blood vessels, pericytes, proliferation, and apoptosis. ZD6474 at both 50 and 100 mg/kg/d led to marked inhibition of tumor growth (P < 0.05). ZD6474 reduced tumor cell proliferation by 48% in the 50 mg/kg/d group and 65% in the 100 mg/kg/d group (P < 0.03) and increased tumor cell apoptosis (P < 0.001) in vivo. ZD6474 led to a 69% decrease in microvessel density in the 50 mg/kg/d group (P < 0.001) and a 62% decrease in the 100 mg/kg/d group (P < 0.001). Although microvessel density was decreased by ZD6474, the remaining vessels showed a relatively higher percentage of pericyte coverage (3-fold increase; P < 0.001), perhaps reflecting selective loss of uncovered vessels in the ZD6474 group. In conclusion, therapies such as ZD6474 that target two distinct aspects of tumor growth, angiogenesis and tumor cell proliferation, warrant further investigation.     

Intensified regression of colon cancer liver metastases in mice treated with irinotecan and the immunomodulator JBT 3002

The authors recently reported that tumoricidal activation of macrophages by a new synthetic bacterial lipopeptide, JBT 3002, can augment chemotherapy-mediated tumor-cell killing. The aim of this study was to identify the mechanism responsible for the destruction of metastatic cells. Three daily oral doses of JBT 3002 before once-weekly intraperitoneal injections of 100 mg/kg irinotecan for 3 weeks significantly increased the eradication of established CT-26 murine colon cancer liver metastases compared with treatment with irinotecan alone. Immunohistochemical analyses revealed that the hepatic metastases in mice given combination therapy contained infiltrating CD8+ lymphocytes and a dense infiltrate of macrophages expressing both inducible nitric oxide synthase (iNOS) and interleukin-15. In vitro treatment of peritoneal macrophages with JBT 3002 plus interferon-gamma induced the expression of iNOS and the production of nitric oxide. In the presence of a low (subtoxic) dose of irinotecan, these activated macrophages produced significant lysis of CT-26 cells. The high level of cytotoxicity was inhibited by the specific inducible nitric oxide synthase inhibitor, NG-methyl-L-arginine. In contrast, irinotecan-mediated lysis of normal intestinal epithelial IEC-6 cells was not increased by activated macrophages. Scanning electron microscopy revealed that activated macrophages bound to CT-26 tumor cells but not to normal IEC-6 cells, confirming that nitric oxide-mediated cytotoxicity is specific for tumor cells. Collectively, the results suggest that augmentation of the therapeutic efficacy of irinotecan against colon cancer liver metastases by immunomodulation with JBT 3002 may be associated with elevated inducible nitric oxide synthase and endogenous interleukin-15 in tumor-infiltrating macrophages.     

Antitumor, hematostimulative and radioprotective action of water-soluble derivative of propolis (WSDP)

Several studies suggest that dietary supplementation with antioxidant can influence the response to chemotherapy as well as the development of adverse side effects caused by treatment with chemotherapeutic agents. Using CBA mouse model, we investigated a clinically potential use of a water-soluble derivative of propolis (WSDP) in the treatment of various cytopenias induced by radiation and/or chemotherapy. Also, the antimetastatic efficiency of WSDP given intraperitoneally alone or in combination with chemotherapeutic agents and their effects on the blood leukocytes count as well as on hematopoiesis were studied. Tumor was a transplantable mammary carcinoma (MCa) of CBA mouse. Metastases in the lung were generated by injecting viable tumor cells intravenously (iv). WSDP (50 or 150 mg/kg) exerted a significant antimetastatic effect (P < 0.001) when given either before or after tumor cell inoculation. In combined treatment WSDP and Epirubicin profoundly inhibited metastasis formation; this synergistic effect is maximal when Epirubicin and WSDP were administrated after tumor cell inoculation. Positive outcome of combined treatment with WSDP and Epirubicin was also found regarding the number of red and white blood cells in peripheral blood while in mice treated with Epirubicin alone the significant drop in all hematological parameters was noticed on day 13 after tumor cell inoculation. Furthermore, when WSDP (50 mg/kg) was given perorally (po) for 20 consecutive days an increased number of exogenous CFUs was found in treated mice. WSDP given either for 20 or 40 days increased cellularity of hematopoietic tissue and the number of leucocytes in peripheral blood; prolonged treatment with WSDP also elevated myeloid and megakaryocytic types of CFUs. To conclude, these findings indicate that the combination of WSDP with chemotherapeutics could increase the antimetastatic potential of chemotherapeutic agents; these findings suggest the benefits of potential clinical trials using WSDP combined with chemotherapeutic agents in order to maximize their antitumor activity and minimize postchemotherapeutic or radiotherapeutic deteriorated reactions.     

Anti-transforming growth factor (TGF)-beta antibodies inhibit breast cancer cell tumorigenicity and increase mouse spleen natural killer cell activity. Implications for a possible role of tumor cell/host TGF-beta interactions in human breast cancer progression.

TGF-beta effects on angiogenesis, stroma formation, and immune function suggest its possible involvement in tumor progression. This hypothesis was tested using the 2G7 IgG2b, which neutralizes TGF-beta 1, -beta 2, and -beta 3, and the MDA-231 human breast cancer cell line. Inoculation of these cells in athymic mice decreases mouse spleen natural killer (NK) cell activity. Intraperitoneal injections of 2G7 starting 1 d after intraperitoneal inoculation of tumor cells suppressed intraabdominal tumor and lung metastases, whereas the nonneutralizing anti-TGF-beta 12H5 IgG2a had no effect. 2G7 transiently inhibited growth of established MDA-231 subcutaneous tumors. Histologically, both 2G7-treated and control tumors were identical. Intraperitoneal administration of 2G7 resulted in a marked increase in mouse spleen NK cell activity. 2G7 did not inhibit MDA-231 primary tumor or metastases formation, nor did it stimulate NK cell-mediated cytotoxicity in beige NK-deficient nude mice. Finally, serum-free conditioned medium from MDA-231 cells inhibited the NK cell activity of human blood lymphocytes. This inhibition was blocked by the neutralizing anti-TGF-beta 2G7 antibody but not by a nonspecific IgG2. These data support a possible role for tumor cell TGF-beta in the progression of mammary carcinomas by suppressing host immune surveillance.     

蛇床子素对小鼠实验性肝损伤的干预效应

背景蛇床子素是一种广泛存在于伞形科植物中的香豆素,本课题组曾报道蛇床子素具有Ca2+拮抗作用和抗炎、抗氧化等作用,另据报道蛇床子素能抑制肝肿瘤等所致血清黄嘌呤氧化酶等升高.目的观察蛇床子素对四氯化碳诱发的小鼠肝损伤模型肝损伤的影响.设计完全随机对照动物实验.单位赣南医学院药理教研室,赣南师范学院体育系.材料选用昆明种小鼠40只,雌雄不拘,体质量为(20±2)g.实验药物蛇床子素为成都龙泉高科天然药业有限公司提供.方法实验于2005-03/07在赣南医学院药理教研室完成.实验小鼠以随机数字表法分成4组,即对照组,四氯化碳模型组,蛇床子素50,100 mg/kg剂量组,每组10只.对照组和模型组分别腹腔注射生理盐水10mL/kg;蛇床子素50mg/kg剂量组小鼠腹腔注射蛇床子素50mg/kg;蛇床子素100 mg/kg剂量组小鼠腹腔注射蛇床子素100 mg/kg.1次/d,连续15 d.末次给药后2 h,正常组腹腔注射容量花生油,其余各组均腹腔注射1 g/L四氯化碳花生油溶液10 mL/kg1次.禁食,自由饮水,16 h后各组小鼠麻醉下断头取血.测定血清谷丙转氨酶、谷草转氨酶活性、肝组织丙二醛含量,并观察肝组织病理变化.主要观察指标各组小鼠血清中谷丙转氨酶、谷草转氨酶活性、肝组织丙二醛含量,并观察肝组织病理变化.结果40只小鼠均进入最后结果分析.①给四氯化碳诱导16 h后,模型组小鼠血清中谷丙转氨酶和谷草转氨酶均高于对照组(P＜0.001).蛇床子素组呈剂量依赖性地抑制四氯化碳所致的谷丙转氨酶的升高,100 mg/kg剂量组显著性抑制四氯化碳所致的谷丙转氨酶的升高(P＜0.05),蛇床子素50,100 mg/kg剂量组均可显著性抑制四氯化碳所致的谷草转氨酶的升高(P＜0.01～0.001).②模型组丙二醛含量的增加(P＜0.05),蛇床子素100 mg/kg剂量组的丙二醛的含量接近对照组,可明显降低四氯化碳肝损伤小鼠肝脏丙二醛含量(P＜0.05),蛇床子素50 mg/kg组虽没有显著性抑制四氯化碳所致的丙二醛含量的升高,但有抑制四氯化碳所致肝损伤丙二醛含量的趋势.③四氯化碳肝损伤模型组肝组织明显损伤,肝细胞浊肿、气球样变性,病变以肝小叶中央静脉周围为重.肝小叶内可见轻度、中度肝细胞点状、碎片状坏死;坏死区内有中、重度淋巴细胞和浆细胞浸润,汇管区内有单核细胞浸润.蛇床子素50,100 mg/kg组也有不同程度的肝细胞破坏、炎性细胞浸润等肝损伤病变,但与模型组比较损伤程度明显减轻,尤其是100 mg/kg剂量组表现更为明显.结论蛇床子素能保护四氯化碳所致小鼠肝损伤,表现为降低血清谷丙转氨酶和谷草转氨酶活力和肝脏丙二醛含量.     

青蒿琥酯对小鼠宫颈癌U14细胞体内外抑制作用的研究

目的观察青蒿琥酯（Art）对小鼠宫颈癌U14细胞体外增殖的影响以及对U14荷瘤小鼠肿瘤生长的影响。方法四氮甲唑兰染色法（NTT法）检测不同浓度Art对体外培养的U14细胞增殖的影响;同时建立小鼠U14腹水瘤和实体瘤模型,分别用Art200mg／（k9·d）、100mg／（kg·d）、50mg／（kg·d）、顺铂2mg／（kg·d）、Art50mg／（kg·d）加顺铂1mg／（kg·d）治疗U14腹水瘤和实体瘤小鼠,生理盐水为对照组。观察实体瘤抑瘤率,腹水瘤的生命延长率。结果MTr法结果显示Art在体外对小鼠U14细胞增殖有明显抑制作用,其半抑制率（IC50）为62．77μg／ml;不同剂量Art组及阳性对照组和联合用药组对小鼠宫颈癌实体瘤抑瘤率分别为52．59％、44．44％、31．84％、61．45％和51．85％,Art大剂量组抑瘤率明显高于小剂量组（P〈0．05）,但大剂量与中剂量、中剂量与小剂量间抑瘤率差异无显著性（JP〉0．05）;腹水瘤组生命延长率分别为76．7％、45．0％、31．7％、100％和93．3％,Art大剂量组生命延长率明显高于中小剂量组（P〈0．05）。结论Art对小鼠宫颈癌U14细胞具有明显的抑制作用,其中大剂量抑瘤效果明显优于小剂量组。     

Effects of ER-37328 on primary tumor,liver metastasis,and life span in a murine colon 38 orthotopic transplantation model

12,13-Dihydro-5-[2-(dimethylamino)ethyl]-4H-benzo[c] pyrimido[5,6,1-jk] carbazole-4,6,10(5H,11H)-trione hydrochloride (ER-37328) is a novel topoisomerase II poison with potent tumoricidal activity against solid tumor cells both in vitro and in vivo. Here, we describe studies on the effects of ER-37328 on the primary tumor, liver metastasis, and survival in a murine Colon 38 orthotopic transplantation model. When ER-37328 (10 mg/kg) was administered i.v. at 11 days or 20 days after transplantation, strong regression of the primary tumor was observed on both administration schedules. On the later schedule, ER-37328 completely blocked liver metastasis, whereas the mean number of metastases in the control group was 23.9. To examine the antitumor activity against Colon 38 at the liver in more detail, ER-37328 was administered to mice that had received an inoculation of Colon 38 tumor into the liver. ER-37328 showed strong tumor-regression activity against Colon 38 growing in the liver. In addition, administration of ER-37328 on a schedule of every 7 days four times caused a significant increase of 79% in life span in the orthotopic transplantation model, calculated by using mean survival times. Pharmacokinetic study revealed that ER-37328 was highly distributed to the tumor and organs. The ratios of the area under the concentration-time curves of ER-37328 in the tumor, lung, liver, and kidney versus plasma were 81, 77, 47, and 40, respectively. This high distribution to the tumor and liver may explain the potent antitumor activity of ER-37328 against Colon 38 tumor in the liver. In conclusion, the topoisomerase II poison ER-37328 is a promising candidate for clinical application against colon cancer.     

新型人源细胞混合型生物人工肝的安全性

背景:目前原位肝移植是惟一有效治疗急性肝衰竭的方法,但其存在供体匮乏的问题。人工肝可作为肝移植过渡支持手段。目的:观察新型人源细胞混合型生物人工肝的安全性。方法:在全接触灌流型生物反应器接种微载体微重力中国人肝细胞系1细胞,结合血浆灌流对D-氨基半乳糖诱发急性肝功能衰竭模型食蟹猴进行治疗,治疗过程中观察循环管路的密闭性、不良反应及监测动物的生命体征变化,治疗结束后取灌流型生物反应器中的中国人肝细胞系1细胞,把细胞碎片与细胞分别接种至裸鼠的颈部、后背部皮下进行比较。结果与结论:对急性肝功能衰竭食蟹猴模型的治疗过程中未发现循环管路中有液体渗漏,未发生出血、过敏、高热及其他严重的不良反应,生命体征平稳。接种后4周时,细胞碎片接种裸鼠未见接种部位出现种植瘤,细胞接种裸鼠共有10个接种部位出现肿瘤,致瘤率为100%。说明新型人源细胞混合型生物人工肝是安全可靠的,可进一步探讨其有效性,有望用于各种动物实验研究及各期临床实验研究。     

Effect of chronic administration of aldosterone on bile secretion, on liver cytochrome P-450, and on red blood cell sodium content.

Male adult albino rabbits received, during a period of two weeks, a daily subcutaneous injection of aldosterone, 150 micrograms/kg body weight. Twenty-four hr after the last injection, bile was collected during two hr under anaestheia, then the liver was removed and submitted to cytochrome P-450 measurements and microscopic analyses. Red blood cell sodium content was measured before and after aldosterone treatment. In animals treated with aldosterone, compared with controls, we found: (1) a significant diminution (p less than 0.01) of bile flow rate, of sodium biliary excretion and of biliary bile acid output; (2) a significant increase (p less than 0.001) of liver cytochrome P-450; (3) hyaline modifications of hepatocytes without necrosis or steatosis; (4) a proliferation of liver smooth endoplasmic reticulum; (5) an increase (p less than 0.001) of red blood cell sodium content.     

Prevention of ethanol-induced liver injury in rats by an agonist of peroxisome proliferator-activated receptor-gamma,pioglitazone

Agonists of peroxisome proliferator-activated receptor (PPAR)-gamma have been shown to reduce tumor necrosis factor-alpha (TNF-alpha)-induced insulin resistance. On the other hand, sensitization of Kupffer cells to lipopolysaccharide (LPS) and their production of TNF-alpha are critical for progression of alcoholic liver injury. This study was intended to determine whether pioglitazone, a PPAR-gamma agonist, could prevent alcohol-induced liver injury. Rats were given ethanol (5 g/kg b.wt.) and pioglitazone (500 microg/kg) once every 24 h intragastrically. Ethanol for 8 weeks caused pronounced steatosis, necrosis, and inflammation in the liver. These pathological parameters were diminished greatly by pioglitazone. Kupffer cells were sensitized to LPS after ethanol for 4 weeks as evidenced by aggravation of liver pathology induced by LPS (5 mg/kg) and enhancement of LPS (100 ng/ml)-induced intracellular Ca2+ concentration elevation in Kupffer cells. The parameters were diminished by treatment with pioglitazone. LPS-induced TNF-alpha production by Kupffer cells from the 4-week ethanol group was 3 to 4 times higher than control. This increase was blunted by 70% with pioglitazone. Gut permeability was 10-fold higher in the 4-week ethanol group, and pioglitazone treatment did not change the value. Inclusion of TNF-alpha in culture media of Kupffer cells enhanced CD14 expression, LPS-induced intracellular Ca2+ concentration response, and production of TNF-alpha. These results indicate that pioglitazone prevents alcoholic liver injury through abrogation of Kupffer cell sensitization to LPS.     

Activation of the liver X receptor protects against hepatic injury in endotoxemia by suppressing Kupffer cell activation

Recent reports have demonstrated that liver X receptors (LXRs) of the nuclear receptor family have anti-inflammatory effects on macrophages. Here we examine whether activation of LXR by the synthetic agonist GW3965 can ameliorate the liver injury/dysfunction caused by endotoxins in the rat. Male Wistar rats received GW3965 (0.3 mg/kg) or vehicle (50% dimethyl sulfoxide) 30 min before coadministration of lipopolysaccharide (LPS, 5 mg/kg i.v.) and peptidoglycan (1 mg/kg i.v.). Treatment with GW3965 attenuated the increase in the plasma levels of alanine aminotransferase and bilirubin (markers of liver injury/dysfunction) as well as the focal hepatocyte necrosis (histology) caused by coadministration of LPS and peptidoglycan. This protective effect of GW3965 treatment was associated with reduced infiltration of mast cells in the liver (histopathology) and reduced gene expression of the chemokines eotaxins 1 and 2, whereas MIP-2 mRNA levels were not affected. Plasma levels of tumor necrosis factor alpha and prostaglandin E2 were significantly attenuated by GW3965, whereas plasma interleukins 6 and 10 were not altered. High expression of LXRalpha mRNA was observed in Kupffer cell cultures, suggesting that Kupffer cells are targets of GW3965. Subsequent in vitro studies in Kupffer cells demonstrated that exposure to GW3965 attenuated the LPS-induced release of tumor necrosis factor alpha and prostaglandin E2 in a dose-dependent manner. In conclusion, this study demonstrates that activation of LXR by GW3965 protects against liver injury and dysfunction in a rat model of endotoxemia, in part by exerting an anti-inflammatory effect on Kupffer cells.     

肝素酶RNAi对HepG2肝癌细胞生物学行为的影响

目的利用筛选出的肝素酶有效干扰细胞株HepG2/RNAi/1和HepG2/RNAi/3研究肝素酶RNAi对HepG2肝癌细胞生物学行为的影响。方法通过MTT实验、流式细胞技术、平皿克隆形成实验、Transwell侵袭实验、裸鼠成瘤实验分别检测HepG2肝癌细胞肝素酶RNAi后生长速度、单个细胞形成克隆能力、侵袭能力及成瘤能力的变化。结果MTT实验表明HepG2/RNAi/1与HepG2/RNAi/3组细胞增殖能力明显低于HepG2组和HepG2/RNAi/N组;流式细胞生长周期实验表明,与HepG2和HepG2/RNAi/N细胞相比,HepG2/RNAi/1与HepG2/RNAi/3 G0/G1期细胞比例增加,而增殖指数下降;平皿克隆形成实验表明HepG2/RNAi/1与HepG2/RNAi/3组单个细胞形成克隆的能力与HepG2组和HepG2/RNAi/N组相比显著降低[分别为(34±4)、(26±5)和(138±7)、(123±22),P<0.05)];Transwell体外侵袭实验表明,HepG2/RNAi/1与HepG2/RNAi/3细胞穿膜数较HepG2和HepG2/RNAi/N细胞穿膜数明显减少[分别为(85.1±9.1)、(78.1±10.4)和(182.2±9.7)(、183.5±9.3),P<0.05)];裸鼠成瘤实验显示,HepG2、HepG2/RNAi/N细胞成瘤率为100%,虽然HepG2/RNAi/1细胞成瘤亦为100%,但裸鼠皮下肿瘤体积较HepG2、HepG2/RNAi/N细胞明显缩小[分别为(0.099±0.030)和(0.585±0.135)(、0.690±0.099),P<0.01)],而HepG2/RNAi/3细胞裸鼠皮下未见肿瘤形成。结论肝素酶RNA干扰可以明显抑制HepG2肝癌细胞增殖速度、单个细胞克隆形成能力、体外侵袭能力以及裸鼠皮下成瘤能力。     

新型人源细胞混合型生物人工肝的安全性

背景：目前原位肝移植是惟一有效治疗急性肝衰竭的方法,但其存在供体匮乏的问题。人工肝可作为肝移植过渡支持手段。目的：观察新型人源细胞混合型生物人工肝的安全性。方法：在全接触灌流型生物反应器接种微载体微重力中国人肝细胞系1细胞,结合血浆灌流对D-氨基半乳糖诱发急性肝功能衰竭模型食蟹猴进行治疗,治疗过程中观察循环管路的密闭性、不良反应及监测动物的生命体征变化,治疗结束后取灌流型生物反应器中的中国人肝细胞系1细胞,把细胞碎片与细胞分别接种至裸鼠的颈部、后背部皮下进行比较。结果与结论：对急性肝功能衰竭食蟹猴模型的治疗过程中未发现循环管路中有液体渗漏,未发生出血、过敏、高热及其他严重的不良反应,生命体征平稳。接种后4周时,细胞碎片接种裸鼠未见接种部位出现种植瘤,细胞接种裸鼠共有10个接种部位出现肿瘤,致瘤率为100%。说明新型人源细胞混合型生物人工肝是安全可靠的,可进一步探讨其有效性,有望用于各种动物实验研究及各期临床实验研究。     

Liver, kidney and islet cell tumors in spontaneously hypertensive and normotensive rats treated neonatally with streptozotocin

We studied the oncogenic action of neonatal streptozotocin (STZ) treatment in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) for 12 months. Two-day-old male neonates were intraperitoneally injected with STZ of which doses were 37.5-75.0 mg/kg for SHR and 100.0-150.0 mg/kg for WKY. The 12-month survival rate was 16 of 22 (73%) in SHR and 10 of 14 (71%) in WKY, respectively. The incidence of tumors in STZ-treated SHR was 27% in liver, 14% in kidney and 5% in liver and kidney, being related to the dose of STZ given, namely, 25% in 37.5 mg/kg, 50% in 50.0 or 62.5 mg/kg and 75% in 75.0 mg/kg. In STZ-treated WKY which survived 12 months, all had tumors, namely, 70% in liver, 20% in kidney and 10% in liver and kidney. Histological features of liver and kidney tumors were characteristic of hepatoma and nephroblastoma, respectively. Islet cell tumor was evident in 4 of 10 (40%) in SHR treated with lower doses of STZ (less than or equal to 50 mg/kg) but not in SHR and WKY treated with higher doses (62.5-150.0 mg/kg). The present study indicates that neonatal STZ treatment has the oncogenic action on liver, kidney and pancreatic islet.