Role of Kupffer cells in the outgrowth of colorectal cancer liver metastases

Colorectal cancer is one of the commonest malignancies in the "developed" world. The liver constitutes the main host organ for its distant metastases which, when present, augur a bad prognosis for the disease. Kupffer cells (KCs) are macrophages that constantly reside within the liver and form an effective first line defence against multiple harmful agents which reach the hepatic sinusoids via the portal circulation. KCs remove chemical compounds and dead or damaged cells, eliminate bacteria and protect against invading tumour cells. They may play a crucial tumouricidal role, exerting cytotoxic and cytostatic functions through the release of multiple cytokines and chemokines. Subsequently, colorectal metastasising cells are destroyed either by KC-performed phagocytosis or via the stimulation of other immune cells which migrate into the sinusoids and act accordingly. On the contrary, KC products, including cytokines, growth factors and matrix-degrading enzymes may promote liver metastasis, supporting tumour cell extravasation, motility and invasion. Current research aims to exploit the antineoplastic properties of KCs in new therapeutic approaches of colorectal cancer liver metastasis. Numerous agents, such as the granulocyte macrophage-colony stimulating factor, interferon gamma, muramyl peptide analogues and various antibody based treatments, have been tested in experimental models with promising results. Future trials may investigate their use in everyday clinical practice and compare their therapeutic value with current treatment of the disease.     

Relationship between cellular shape and receptor-mediated endocytosis: an ultrastructural and morphometric study in rat Kupffer cells

ABSTRACT— The relationship between cellular shape (i.e., size, volume, presence of microvilli, pseudopodia, flat or round shape) and receptor-mediated endocytotic activities (i.e., binding and internalization) was investigated using intact liver as well as freshly isolated Kupffer cells and Kupffer cells in culture. The morphological features of Kupffer cells were reconstructed by three-dimentional analysis from in situ experiments and by densitometric analysis of cells in suspension and in culture. By morphometry at the ultrastructural level, different cellular shapes were compared with the respective capacities for binding and internalization of glycoproteins with terminal galactosyl residues. The number of asialoglycoprotein-gold particles bound to the cell surface or internalized into endosomes was calculated. Our data show that differences in cellular shape, mainly related to the reduction of projection and microvilli and to the roundness of cell surface, accompany modulation of galactose-specific receptors in rat Kupffer cells, thus supporting the hypothesis that cell morphology is affected by endocytic activities. In fact, the progressive reduction in microvilli projections and cellular roundness is paralleled by the progressive decrement of both binding and uptake capacity from in situ, freshly isolated and cultured Kupffer cells.     

刚地弓形虫细胞培养上清对人结肠癌细胞sw480增殖与凋亡的影响

目的观察刚地弓形虫RH株速殖子与人结肠癌sw480细胞系共培养上清对人结肠癌sw480细胞增殖的影响和诱导其凋亡与坏死的情况。方法取对数生长期的人结肠癌sw480细胞(1×106),建立弓形虫RH株速殖子数目分别为2×106、4×106、8×106、16×106的共培养模型,观察弓形虫速殖子在sw480细胞中的寄生,提取共同孵育72h后的培养上清,以新鲜培养基稀释为半量,体外作用人结肠癌sw480细胞12h、24h、48h、72h,CKK-8法检测吸光度(A450值)并计算抑制率;Annexin-v-FITC/PI染色细胞后上流式细胞仪检测细胞凋亡与坏死率;琼脂糖凝胶电泳观察细胞凋亡DNA条带;透射电镜和荧光显微镜观察细胞形态学改变。结果弓形虫RH株速殖子可在人结肠癌sw480细胞内寄生和增殖。CKK-8法检测结果显示上述共培养上清对sw480细胞增殖抑制率随上清作用时间延长均明显增大,48h最大抑制率达44.55%。流式细胞仪检测显示实验组sw480细胞早期凋亡率和晚期凋亡与坏死率随上清作用时间延长均明显增加,48h早期凋亡率达最高值(11.54%),48h以后早期凋亡率下降,晚期凋亡和坏死率显著上升,72h总死亡率可达46.11%,细胞杀伤效果明显;琼脂糖凝胶电泳显示典型的DNA云梯状条带;荧光显微镜和透射电镜观察到细胞凋亡和坏死典型形态。结论弓形虫RH株速殖子与人结肠癌sw480细胞共培养上清对体外培养的sw480细胞增殖有明显的抑制作用,并可诱导sw480细胞凋亡与坏死。     

Suppression of autophagy sensitizes Kupffer cells to endotoxin

Aim: Recent evidence suggests that protein degradation system autophagy is implicated in a component of innate immunity. We report here that suppression of autophagy in Kupffer cells due to hepatic steatosis enhances an inflammatory response to endotoxin. Methods: Kupffer cells were isolated from C57BL/6J mice fed chow diet (control) or high‐fat diet (HFD) for 12 weeks, liver‐specific autophagy‐deficient mice (Atg7^F/F:Mx1‐Cre) and wild‐type mice (Atg7^F/F). Kupffer cells were incubated with 100 ng/mL lipopolysaccharide (LPS). The concentration of tumor necrosis factor (TNF)‐α in media was measured by enzyme‐linked immunoassay. Expression of Toll‐like receptor (TLR)4, IκB kinase (IKK)‐α/β, p38, p62 and LC3 in Kupffer cells was evaluated by western blot analysis. Results: Incubation with LPS increased LC3‐II expression of Kupffer cells from control mice; however, an increase in LC3‐II expression due to LPS was suppressed in Kupffer cells from HFD mice. Moreover, both p62 expression and TNF‐α production in Kupffer cells from HFD mice was higher than control mice. On the other hand, LPS exposure increased TNF‐α production from autophagy‐deficient Kupffer cells more than wild type. There was no significant difference in expression of TLR4 between wild and autophagy‐deficient Kupffer cells. Nevertheless, activation of p38 or IKK in Kupffer cells due to LPS was augmented by autophagy deficiency. The addition of the p38 inhibitor SB203580 attenuated TNF‐α production in both wild and autophagy‐deficient Kupffer cells. Conclusion: These results suggest that suppression of autophagy observed in Kupffer cells from steatotic liver sensitizes to endotoxin. In conclusion, suppression of autophagy may play a pivotal role on progression of NAFLD.     

Augmenter of liver regeneration promotes hepatocyte proliferation induced by Kupffer cells

AIM: To observe the effects of augmenter of liver regeneration (ALR) on Kupffer cells and to determine whether ALR promotes hepatocyte proliferation induced by Kupffer cells. METHODS: Kupffer cells and hepatocytes were cultured in vitro and various concentrations of recombinant rat ALR (rrALR) were added. 3H-thymidine, BrdU and 3H-leucine incorporation was determined in cultured Kupffer cells and hepatocytes, in hepatocytes conditioned by Kupffer cells, and in associated medium. rrALR was labeled by iodination and used to determine its binding activity by Scatchard analysis in Kupffer cells and primarily cultured rat hepatocytes. RESULTS: rrALR stimulated DMA replication in Kupffer cells and protein synthesis both in cells and in medium in a non-concentration-dependent manner. The effect was significant at the concentration of 1μg/L ALR. However, rrALR had no effect on primarily cultured hepatocytes, when hepatocytes were cultured with the Kupffer cell medium conditioned by ALR, DNA replication and protein synthesis in hepatocytes increased significantly at the concentration of 1μg/L ALR. When the ALR concentration was increased, its effect on hepatocyte proliferation decreased to the basal level. Scatchard analysis indicated the presence of a single class of high affinity receptors with a dissociation constant (Kd) of 0.883 nmol/L and a maximum binding capacity (Bmax) of 126.1 pmol/g protein in the rat Kupffer cells. CONCLUSION: ALR can promote hepatocyte proliferation induced by Kupffer cells, which is associated with the concentration of ALR, suggesting that Kupffer cells play a dual role in liver regeneration.     

库普弗细胞与肝纤维化的关系

活化的库普弗细胞发挥吞噬、抗原提呈、释放细胞因子、免疫调节等功能，成为机体防御的重要屏障，同时也参与了肝脏的炎症损伤、纤维化的形成和降解等病理过程。     

干细胞培养基成球培养法筛选结肠癌干细胞的生物学特性

目的探讨干细胞培养基成球培养法筛选结肠癌干细胞的相关蛋白表达及生物学特性。方法用干细胞培养基成球培养法筛选结肠癌干细胞,Western blot检测干细胞相关蛋白的表达,流式细胞仪检测细胞周期;同时检测干细胞增殖、黏附、耐药及侵袭能力,并摸索结肠癌干细胞最佳冻存条件。结果用干细胞培养基成球培养法成功培养出了结肠癌细胞球,检测发现干细胞相关蛋白表达增强,静止期细胞比例明显升高,细胞增殖速度慢,黏附性、耐药性、侵袭性均强于亲本细胞。结论干细胞培养基成球培养法筛选的细胞球中富集了肿瘤干细胞,为结肠癌干细胞的研究提供了良好的细胞模型。     

离心淘洗技术分离纯化大鼠肝库普弗细胞

目的通过制备肝非实质细胞悬液并离心淘洗的方法,分离纯化大鼠肝库普弗细胞.方法采用原位肝脏酶灌注、肝非实质细胞悬液的准备、离心淘洗和原代培养等方法进行分离.结果在经过胶原酶和链酶蛋白酶消化、Nycodenz分离和离心淘洗后,获得大鼠肝库普弗细胞产量约为(28±6)×106/鼠肝,细胞纯度为95%,细胞活力大于90%.结论应用离心淘洗技术能有效地分离纯化大鼠肝库普弗细胞,为体外进一步研究提供了高纯度和活力的库普弗细胞群.     

Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology

Background and Aim: Recently, the clinical and biological differences between right‐ and left‐sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large‐scale studies, have been scarcely reported. Methods: A total of 3552 consecutive Japanese colorectal cancer cases were examined and the clinical differences between right‐ and left‐sided colon cancer cases were investigated. Results: The proportion of right‐sided colon cancer was relatively high in patients aged less than 40 years (33%) and more than 80 years (43%). The proportion of right‐sided colon cancer in patients aged 40–59 years was relatively low (male 22% and female 29%). In male patients the proportion increased in the 70‐79 years age group (30%), while in female patients the proportion increased in the 60‐69 years age group (39%). Right‐sided colon cancer was more likely to be detected at an advanced stage (T1 stage; left 22%, right 15%) (P < 0.01) with severe symptoms. Polypoid‐type early cancer was dominant in the left colon (left 59%; right 40%) (P < 0.01), while the proportion of flat‐type early cancer in the right colon was significantly higher than that in the left colon (left 25%; right 44%) (P < 0.01). Conclusions: Specific age distribution of right‐sided colon cancer was observed and the difference between male and female patients was highlighted. Other clinical features also differed between right‐ and left‐sided colon cancer, suggesting that different mechanisms may be at work during right and left colon carcinogenesis.     

Influence of Kupffer cells and platelets on ischemia-reperfusion injury in mild steatotic liver

AIM: To investigate the effect of mild steatotic liver on ischemia-reperfusion injury by focusing on Kupffer cells (KCs) and platelets. METHODS: Wistar rats were divided into a normal liver group (N group) and a mild steatotic liver group (S group) induced by feeding a choline-deficient diet for 2 wk. Both groups were subjected to 20 min of warm ischemia followed by 120 min of reperfusion. The number of labeled KCs and platelets in sinusoids and the blood perfusion in sinusoids were observed by intravital microscopy (IVM), which was performed at 30, 60 and 120 min after reperfusion. To evaluate serum alanine aminotransferase as a marker of liver deterioration, blood samples were taken at the same time as IVM.RESULTS: In the S group, the number of platelets adhering to KCs decreased significantly compared with the N group (120 after reperfusion; 2.9±1.1 cells/acinus vs 4.8±1.2 cells/acinus, P<0.01). The number of KCs in sinusoids was significantly less in the S group than in the N group throughout the observation periods (before ischemia, 19.6±3.3 cells/acinus vs 28.2±4.1 cells/acinus, P<0.01 and 120 min after reperfusion, 29.0±4.3 cells/acinus vs 40.2±3.3 cells/acinus, P<0.01). The blood perfusion of sinusoids 120 min after reperfusion was maintained in the S group more than in the N group. Furthermore, elevation of serum alanine aminotransferase was lower in the S group than in the N group 120 min after reperfusion (99.7±19.8 IU/L vs 166.3±61.1 IU/L, P=0.041), and histological impairment of hepatocyte structure was prevented in the S group. CONCLUSION: Ischemia-reperfusion injury in mild steatotic liver was attenuated compared with normal liver due to the decreased number of KCs and the reduction of the KC-platelet interaction.     

Isolation and primary culture of rat Kupffer cells

The aim of this study was to describe a reproducible method for the isolation, purification and primary culture of rat Kupffer cells. Kupffer cells were isolated following sequential pronase/collagenase digestion of the liver and enrichment of a non-parenchymal cell fraction by a single-density gradient centrifugation step using 30% metrizamide. Kupffer cells were isolated and further purified from this cell fraction by centrifugal elutriation. Kupffer cells were isolated at 1017 g at 48–110 mL/min. All Kupffer cell fractions exhibited phagocytosis of 3 μm latex beads. Kupffer cell fractions isolated at 48 and 60 mL/min were predominantly ED2 negative while later fractions (80–110 mL/min) were ED2 positive. Kupffer cells were adherent in culture after 2 h. This method for Kupffer cell isolation resulted in a yield of 80–120 times 10⁶ Kupffer cells per liver.     

Alcoholic hepatitis: The pivotal role of Kupffer cells

Kupffer cells play a central role in the pathogenesis of alcoholic hepatitis (AH). It is believed that alcohol increases the gut permeability that results in raised levels of serum endotoxins containing lipopolysaccharides (LPS). LPS binds to LPS-binding proteins and presents it to a membrane glycoprotein called CD14, which then activates Kupffer cells via a receptor called toll-like receptor 4. This endotoxin mediated activation of Kupffer cells plays an important role in the inflammatory process resulting in alcoholic hepatitis. There is no effective treatment for AH, although notable progress has been made over the last decade in understanding the underlying mechanism of alcoholic hepatitis. We specifically review the current research on the role of Kupffer cells in the pathogenesis of AH and the treatment strategies. We suggest that the imbalance between the pro-inflammatory and the anti-inflammatory process as well as the increased production of reactive oxygen species eventually lead to hepatocyte injury, the final event of alcoholic hepatitis.     

Kupffer细胞与肝缺血再灌注损伤

Kupffer细胞作为肝脏固有巨噬细胞在炎症反应及肝脏缺血再灌注损伤中发挥重要作用.Kupffer细胞激活后将诱发TNF-α、前列腺素、一氧化氮及氧自由基等各种炎症细胞因子的大量形成,除导致自身功能形态发生改变外,还直接影响邻近的肝细胞、血管内皮细胞以及位于血窦腔内的中性粒细胞等多种细胞,进而启动热缺血或冷缺血后肝脏的缺血再灌注损害.现就Kupffer细胞在肝脏缺血再灌注损伤中的作用机制及对其治疗靶点研究进展作一综述.     

大鼠库普弗细胞分离培养方法的改良

目的建立一种稳定、高效的大鼠库普弗细胞(KCs)分离培养方法。方法采用大鼠肝脏离体链酶蛋白酶E消化和胶原酶循环灌注消化。低速离心去除肝细胞,Histodenz不连续密度梯度离心和选择性贴壁的方法分离KCs。采用ED2 CD163、兔抗大鼠溶酶体膜相关蛋白2(LAMP2)免疫细胞化学．latex-beads吞噬实验和电镜观察来鉴定 KCs。结果KCs得率为5×107个,活率为98％,经鉴定ED2阳性细胞大于98％,LAMP2阳性细胞大于99％,吞噬试验及电镜观察证明分离所得为KCs。结论改良的分离培养方法稳定、高效,为进一步的研究打下了基础。     

一种简便实用的大鼠Kupffer细胞的分离与鉴定方法

目的：研究一种简便实用的大鼠Kupffer细胞（KCs）的分离与鉴定方法.方法：原位两步灌流法对大鼠肝脏进行冲洗消化;利用Percoll液进行不连续密度梯度离心分离KCs;;选择性贴壁纯化KCs;台盼蓝染色法鉴定细胞存活率;吞噬实验鉴定细胞功能;ED1单克隆抗体免疫荧光细胞化学鉴定KCs;显微镜下观察KCs形态变化.结果：获取的KCs数量为（2.41±0.32）×107/只,其中活细胞数量占（92.3±2.12）％;吞噬实验显示（95.2±2.58）％的细胞内存在碳素颗粒;免疫荧光化学检测证明KCs纯度为（96.3±1.46）％;在显微镜下观察KCs形态,36h细胞形态变得不规则,3d后呈星形或多角形,体外培养可以存活7～10d.结论：此种KCs分离方法操作相对简便,获取的细胞数量、活性功能、纯度等方面均能达到进一步的实验要求,值得推广.     

Kupffer细胞在血吸虫病肝纤维化中的作用

肝纤维化是血吸虫病的严重后果之一,分子生物学和免疫学的发展为血吸虫病肝纤维化研究奠定了基础,并提供了科学依据。Kupffer细胞是肝脏内一种重要的非实质性细胞,其分泌的细胞因子(如转化生长因子、血小板源性生长因子等)作为重要的影响因素参与纤维化的发生与发展。本文就近几年来有关Kupffer细胞在血吸虫病肝纤维化中的作用作一综述。     

库普弗细胞在酒精性肝病发病机理中的作用

库普弗细胞(KC)是肝内定居的巨噬细胞,由于其细胞表面存在多种受体,可被多种配体和激活剂激活,通过产生反应氧、细胞因子和炎症介质等贯穿于酒精性肝病的发病过程,控制KC的活化将有助于减轻或阻止酒精性肝病的肝脏病变。     

Difference between periportal and pericentral Kupffer cells in uptaking lipopolysaccharides in rats

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An in vitro model for the study of phagocytosis of damaged hepatocytes by rat Kupffer cells

Abstract: Aims/Background: One function of Kupffer cells is the phagocytosis of nonviable hepatocytes. Our aims were to develop a model for phagocytosis of damaged hepatocytes by rat Kupffer cells in vitro, and to characterise prostaglandin E₂ (PGE₂), prostacyclin (PGI), and tumour necrosis factor-α (TNF) production in this model. Methods: Kupffer cells were incubated alone or with damaged hepatocytes for up to 18 h, then washed and cultured for up to 66 h. To compare mediator responses produced during inert particle phagocytosis, Kupffer cells were also incubated with latex beads. Results: Phagocytic uptake of hepatocyte debris was confirmed in at least 50% of Kupffer cells. A dissociation between TNF and PGI responses was found for both latex beads and damaged hepatocytes, such that a TNF secretory response was not triggered by either stimulus whereas PGI production was increased for both. Although phagocytosis of beads increased PGE₂ production, phagocytosis of hepatocytes did not. Conclusions: Phagocytosis of damaged hepatocytes by Kupffer cells results in the production of PGI but not PGE₂ or TNF.