小鼠动物实验方法系列专题(二) 肝脏大部分切除实验在小鼠肝再生研究中的应用

小鼠肝大部分切除(partial hepatectomy,PH)实验是研究肝再生的一个重要的实验。本文以C57小鼠为例,对肝大部分切除实验做了较为详细的介绍。实验结果显示,在术后的1～8天,小鼠的肝脏体重比值逐渐增加,在术后的7～10天里可以达到原来肝重的90%以上,10天以后肝细胞停止分裂。正常情况下,实施肝大部分切除后,小鼠的存活率可以达到90%以上。该模型的建立为研究肝脏再生的细胞和分子生物学机制奠定了基础。     

简易高效的小鼠肝再生模型的建立

目的建立一种简易、高效的小鼠2/3肝切除方法。方法取3月龄健康昆明小鼠,进行肝顺次结扎切除手术,观察术后小鼠生存和肝组织再生状况。结果通过顺次结扎切除左小叶和中央小叶,可在15min内完成小鼠2/3肝脏切除手术,术后成活率为90%,术后42h时可见肝组织再生,术后7d肝脏可恢复75%以上的肝组织原质量。结论通过分叶顺次肝切除术,可准确量化肝脏切除的程度,简便易行、成功率高,为肝再生的机理研究提供了理想的动物模型。     

大鼠肝部分切除术后mTOR信号通路对肝再生的作用

目的:探讨mTOR信号通路对大鼠肝部分切除术后肝细胞蛋白质合成功能及肝细胞大小的影响。方法:采用Sprague-Dawley雄性大鼠70％肝切除模型和肝细胞分离与培养方法,在术后不同的时相点分离残肝的肝细胞,进行培养。实验分组:分离的残肝肝细胞分两组:对照组(Control组、C组)、雷帕霉素组(Rapamycin组、R组)。采用Western blot方法检测磷酸化mTOR蛋白在不同时相点的变化;采用3H-亮氨酸(3H-Leucine)掺入法测定肝细胞蛋白质合成;扫描电镜(AMRAY 1000B,US)获取肝细胞图像,病理图像分析系统(北航CM2000B)测定细胞面积。结果:1)C组中,磷酸化mTOR蛋白的含量由0h开始升高,6h达到高峰,以后即降低,而R组明显较C组含量降低;2)在术后的各时相点,C组的肝细胞的蛋白质合成率较R组显著升高(P<0．05),而且随时间点的延长,蛋白质合成率呈上升趋势;3)在2h和6h时相点C组肝细胞面积较R组显著增大(P<0．05)。但是,在C组肝细胞24h时相点面积较2h和6h减小(P<0．05)。结论:体外实验证实,肝部分切除术后mTOR信号通路即活化,促进肝细胞的蛋白质合成和细胞生长。因此,我们推测mTOR信号通路在肝再生过程中发挥重要作用。     

M1白血病细胞中PI—3激酶参与IL—6诱导的Stat3激活

Ｗｏｒｔｍａｎｎｉｎ是ＰＩ－３激酶的特异性抑制剂,它可拮抗ＩＬ－６对Ｍ１小鼠急性髓系白血病细胞生长的抑制作用,但Ｗｏｒｔｍａｎｎｉｎ本身对Ｍ１细胞的生长地胶阻滞电泳分析（ＥＭＳＡ）表明ｗｏｒｔｍａｎｎｉｎ选择性减低ＩＬ－６对Ｓｔａｔ３的激活作用而Ｓｔａｔ３有ＩＬ－６诱导的Ｍ１细胞生长停止与终末分化中占重要地位。这些结果说明ＰＩ－３激酶确实参与ＩＬ－６的信号转导并参与Ｓｔａｔ３的激活。     

白细胞介素-6在肝再生中的作用

白细胞介素-6(IL-6)是一种多功能的细胞因子。近年来发现,它是启动肝细胞增殖的早期信号中不可缺少的组成部分,在肝再生中有重要作用。现对IL-6在肝再生中的作用及可能机制进行综述,为肝脏疾病的治疗提供新的思路。     

大鼠短间隔连续部分肝切除上调表达基因的克隆与分析 *

以短间隔连续部分肝切除112h为试验方,以0h对照为驱动方,应用抑制性消减杂交技术构建了高效率的正向消减cDNA文库,从中随机挑取的50个克隆中有45个包含了100～350bp插入片段,对这些片段进行测序后经GenBank blast同源性检索,表明8个片段均为未知新序列。大鼠短间隔连续部分肝切除后肝再生cDNA正向消减文库的建立和未知的上调表达基因片段的克隆为研究肝再生的分子机理奠定了基础。     

IL-4 modulates the histamine content of mast cells in a mast cell/fibroblast co-culture through a Stat6 signaling pathway in fibroblasts

IL-4 plays a crucial role in the pathogenesis of allergic diseases, such as the induction of IgE synthesis and the development of mast cells. To further understand the effect of IL-4 on mast cells in skin, we utilized a mast cell/fibroblast co-culture system as an in vitro model of dermal mast cells. IL-4 induced mast cell growth in the culture with fibroblasts. Immunoblot analysis revealed that IL-4 activated Stat6 in both mast cells and fibroblasts. The over-expression of dominant-negative Stat6 in fibroblasts in the presence of IL-4 decreased the histamine content per mast cell, but not the number of mast cells. In contrast, the over-expression of constitutively-active Stat6 in fibroblasts increased the histamine content per mast cell, indicating that the activation of Stat6 in fibroblasts supports the maturation of mast cells co-cultured with fibroblasts.     

A Model of Differential Mammary Growth Initiation by Stat3 and Asymmetric Integrin-α6 Inheritance

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大鼠2/3肝切除72 h后再生肝脏质膜比较蛋白质组学研究

大鼠2/3肝切除模型为研究肝细胞增殖和生理性血管生成提供了一个很好的活体内模型.为了揭示肝再生过程中与肝细胞增殖终止相关及与血管生成启动相关的质膜蛋白质,本研究对大鼠肝2/3部分切除72 h后的肝脏质膜进行了研究：利用两步蔗糖密度梯度离心法对切除组和假手术组的肝脏质膜进行纯化;然后通过双向电泳和质谱技术对肝切除样品进行了比较分析并对几个关键蛋白程序性凋亡相关蛋白-6和丝蛋白-A进行了免疫印迹验证.相对于假手术对照组(Sham组),21种蛋白质在切除后72 h的肝脏中上调,15种蛋白质下调.所鉴定的差异表达蛋白参与了血管生成、细胞分裂增殖和凋亡、细胞分化调控、肝脏组织重新构建、代谢及应急反应.本研究为肝脏再生及其血管生成的研究提供了理论依据.     

IL-6/STAT3信号途径介导肉芽肿性乳腺炎的作用研究

目的:探讨IL-6/STAT3信号途径介导肉芽肿性乳腺炎的机制研究及临床意义。方法:收集我院2017年1月至2017年6月收治入住的30例肉芽肿性乳腺炎患者及30例普通患者的血清样本,对肉芽肿性乳腺炎患者同时采集炎性肿块组织样本及距离炎性肿块边缘大于等于3 cm且镜检为正常乳腺组织的样本。采用ELISA法检测血清样本中的IL-6的表达水平,同时采用Western blot检测组织样本中IL-6和pSTAT3蛋白的表达水平并分析二者的相关性。结果:与普通患者血清样本相比,肉芽肿性乳腺炎患者血清中IL-6的表达水平明显增高(P0.05),肉芽肿性乳腺炎组织样本中IL-6和pSTAT3蛋白的表达水平明显高于毗邻的正常乳腺组织(P0.01),IL-6表达与组织STAT3磷酸化水平具有明显的正相关性(r=0.353,P0.05)。结论:IL-6/STAT3信号途径可能介导肉芽肿性乳腺炎的发生发展。     

敲减突触结合蛋白1通过抑制 IL-6/STAT3信号通路改善结肠炎病变

突触结合蛋白1 (synaptotagmin 1,Syt1)属于突触结合蛋白家族一员,在神经递质囊泡转运和胞吐中发挥作用。Syt1在肠道上皮中有表达,但其在结肠炎中的生物学功能尚不明确。本工作以Syt1转基因小鼠结合葡聚糖硫酸钠(dextran sodium sulfate, DSS)诱导型溃疡性结肠炎模型,通过qRT-PCR、免疫染色及Western印迹检测Syt1在生理状态及肠炎状态下在结肠中表达的动态变化;采用H&E染色、免疫染色、Western印迹等方法,观察Syt1在结肠炎的炎症反应及肠道上皮再生修复中的作用。结果显示：正常野生小鼠的结肠上皮及结直肠癌患者癌旁组织的肠上皮细胞中均有较高水平的Syt1表达;DSS处理使Syt1在结肠中表达显著升高(P<0.01)。DSS诱导小鼠肠炎模型中,相较于对照组,Syt1敲减小鼠体重降低情况、结肠炎性红肿和长度缩短等均显著减轻(P<0.05),而再生隐窝数量则增多、Ki67增殖细胞也增多(P<0.01);结肠组织中的CD45免疫细胞、F4/80巨噬细胞浸润减少(P<0.001),炎症性肠病相关的促炎因子IL...     

Modeling Dynamics and Function of Bone Marrow Cells in Mouse Liver Regeneration

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大鼠部分肝切除前后热激处理对过氧化物酶基因表达的影响

用过氧化物酶原位复性电泳（SDS－POD－PAGE）技术分析了部分肝切除（partial hepatectomy,PH)、部分肝切除后再热激（partial hepatectomy following heat shock,PH-HS)和先热激再部分肝切除（heat shock following partial hepatectomy,HS-PH)后肝再生期间过氧化物酶（POD）基因表达差异,结果表明,PH中表达的POD基因种类（7个）＞PH－HS（5个）＞HS－PH（3个）;三个模型的POD总活性为：HS－PH＞PH－HS。根据实验结果推测,POD在肝再生和肝损伤恢复中起一定作用。     

The Role of MRE11 in the IL-6/STAT3 Pathway of Lung Cancer Cells

MRE11 is a pivotal protein for ATM activation during double-strand DNA break. ATM kinase activations may act as lung cancer biomarkers. The IL-6/STAT3 pathway plays an important role in tumor metastasis, including lung cancer. However, the mechanism between MRE11 and the IL-6/STAT3 pathway is still unclear. In this study, we discovered that MRE11 can interact with STAT3 under IL-6 treatment and regulate STAT3 Tyr705 phosphorylation. After the knockdown of MRE11 in lung cancer cells, we discovered that IL-6 or the conditional medium of THP-1 cells can induce the mRNA expression of STAT3 downstream genes, including CCL2, in the control cells, but not in MRE11-knockdown lung cancer cells. Moreover, CCL2 secretion was lower in MRE11-knockdown lung cancer cells than in control cells after treatment with the conditional medium of RAW264.7 cells. In addition, MRE11 deficiency in lung cancer cells decreases their ability to recruit RAW 264.7 cells. Furthermore, MRE11 is a potential target for lung cancer therapy.     

Accelerated regeneration of the skeletal muscle in RNF13-knockout mice is mediated by macrophage-secreted IL-4/IL-6

RING finger protein 13 (RNF13) is a newly identified E3 ligase reported to be functionally significant in the regulation of cancer development, muscle cell growth, and neuronal development. In this study, the function of RNF13 in cardiotoxin-induced skeletal muscle regeneration was investigated using RNF13-knockout mice. RNF13^-/- mice exhibited enhanced muscle regeneration —characterized by accelerated satellite cell proliferation —compared with wild-type mice. The expression of RNF13 was remarkably induced in macrophages rather than in the satellite cells of wild-type mice at the very early stage of muscle damage. This result indicated that inflammatory cells are important in RNF13-mediated satellite cell functions. The cytokine levels in skeletal muscles were further analyzed and showed that RNF13^-/- mice produced greater amounts of various cytokines than wild-type mice. Among these, IL-4 and IL-6 levels significantly increased in RNF13^-/- mice. The accelerated muscle regeneration phenotype was abrogated by inhibiting IL-4/IL-6 action in RNF13^-/- mice with blocking antibodies. These results indicate that RNF13 deficiency promotes skeletal muscle regeneration via the effects on satellite cell niche mediated by IL-4 and IL-6.     

沙眼衣原体持续感染对Hela细胞TLR4/IL-6/STAT3信号通路的影响

目的：分析沙眼衣原体（Chlamydia trachomatis,Ct）持续感染对靶细胞TLR4/IL-6/STAT3信号通路的影响.方法：利用Hela细胞分别建立Ct急性感染及持续性感染模型,通过qRT-PCR、ELISA等方法比较Ct感染过程中靶细胞TLR4、STAT3、IL-6转录水平及细胞因子IL-6分泌量的变化.结果：Ct感染后靶细胞TLR4、IL-6、STAT3转录水平及细胞因子IL-6分泌量均呈现时间相关性上调,且持续性感染状态下比急性感染状态下的上调更为显著;IL-6/STAT3的表达量与TLR4转录水平正相关.结论：Ct持续感染过程中TLR4 的持续活化可大幅上调IL-6/STAT3信号通路表达,可能参与了Ct持续感染后慢性炎性损伤过程.     

IL-6 modulates hepatocyte proliferation via induction of HGF/p21cip1: regulation by SOCS3

The precise role of IL-6 in liver regeneration and hepatocyte proliferation is controversial and the role of SOCS3 in liver regeneration remains unknown. Here we show that in vitro treatment with IL-6 inhibited primary mouse hepatocyte proliferation. IL-6 induced p21cip1 protein expression in primary mouse hepatocytes. Disruption of the p21cip1 gene abolished the inhibitory effect of IL-6 on cell proliferation. Co-culture with nonparenchymal liver cells diminished IL-6 inhibition of hepatocyte proliferation, which was likely due to IL-6 stimulation of nonparenchymal cells to produce HGF. Finally, IL-6 induced higher levels of p21cip1 protein expression and a slightly stronger inhibition of cell proliferation in SOCS3+/- mouse hepatocytes compared to wild-type hepatocytes, while liver regeneration was enhanced and prolonged in SOCS3+/- mice. Our findings suggest that IL-6 directly inhibits hepatocyte proliferation via a p21cip1-dependent mechanism and indirectly enhances hepatocyte proliferation via stimulating nonparenchymal cells to produce HGF. SOCS3 negatively regulates liver regeneration.     

紫草素调节IL-6/STAT3信号通路对牙髓炎大鼠牙髓组织损伤的影响

摘要 目的：探究紫草素（SHI）调节白细胞介素（IL）-6/信号转导子和转录激活子3（STAT3）信号通路对牙髓炎大鼠牙髓组织损伤的影响及机制。方法：建立牙髓炎大鼠模型。实验分为对照组（Control组）、模型组（Model组）、SHI低、中、高剂量组（SHI-L、SHI-M、SHI-H组,0.125 mg/kg/d、0.25 mg/kg/d、0.5 mg/kg/d SHI）、SHI高剂量+STAT3激动剂Colivelin组（SHI-H+Colivelin组,0.5 mg/kg/d SHI+1 mg/kg/d Colivelin）,每组18只。观察大鼠一般行为变化;酶联免疫吸附法（ELISA）检测血清IL-6、IL-1β、肿瘤坏死因子α（TNF-α）、CXC趋化因子配体10（CXCL10）、血管内皮生长因子（VEGF）水平。苏木精-伊红（HE）染色观察牙髓组织病理变化;免疫组化法检测牙髓组织IL-6表达;免疫印迹法检测IL-6/STAT3信号通路相关蛋白表达。结果：与Control组相比,Model组大鼠饮食减少,不敢咬食物,精神萎靡;牙髓组织出现坏死,牙本质细胞排列紊乱,炎性细胞浸润及纤维组织增加,根髓充血扩张;血清IL-6、IL-1β、TNF-α、CXCL10和VEGF水平,IL-6平均光密度及IL-6和JAK2蛋白水平、p-STAT3/STAT3水平显著增加（P<0.05）。与Model组相比,SHI-L、SHI-M和SHI-H组大鼠饮食较正常,精神状态较佳,牙髓组织病理变化减轻;血清IL-6、IL-1β、TNF-α、CXCL10和VEGF水平,IL-6平均光密度及IL-6和JAK2蛋白水平、p-STAT3/STAT3水平逐渐降低（P<0.05）。与SHI-H组相比,SHI-H+Colivelin组大鼠饮食较差,精神不佳,牙髓组织病变加重;血清IL-6、IL-1β、TNF-α、CXCL10和VEGF水平,IL-6平均光密度及IL-6和JAK2蛋白水平、p-STAT3/STAT3水平显著增加（P<0.05）。结论：SHI能抑制牙髓炎大鼠炎症水平,减轻牙髓组织损伤,其机制可能与抑制IL-6/STAT3信号通路有关。