Disordered development of macrophages in non-Hodgkin’s lymphoma

Macrophage development in 20 untreated patients with non-Hodgkin’s lymphoma (NHL) has been studied and compared with that in 20 normal subjects. Morphometric measurements were carried out on ultrastructural features of cell, nucleus and mitochondria during 6 days suspension culture of blood monocytes in the presence of autologous serum and lymphocytes. The results were subjected to multivariate and univariate analysis of variance. Statistically significant differences were found between the subject groups with respect to the volumes and surface areas of cell, nucleus and mitochondria, to the excess surface membrane of cell and nucleus (as compared with equivalent spheres) and to the number of mitochondrial profiles per section. It would appear that the patients’ cell grew less, showed less elaboration of surface features and had reduced nuclear and mitochondrial development, the latter affecting mitochondrial numbers rather than individual size. The findings provide further evidence that mononuclear phagocytes are deranged in NHL.     

Characterisation and validation of a new murine model of global ischaemia-reperfusion injury

A specially designed Langendorff apparatus was constructed to allow perfusion of the isolated mouse heart. Hearts were randomised into groups to receive differing periods of global (zero flow) ischaemia or continuous perfusion (controls). During reperfusion, recovery of baseline force was recorded and perfusate collected for LDH assay (U/L/g wet weight). After 30 min reperfusion, hearts were stained with tetrazolium and planimetry performed to measure infarct size. Dose-response relationships were demonstrated for all 3 end-points against duration of ischaemic insult. Functional recovery and enzyme leakage correlated well with infarct size (r = 0.77, p < 0.001 and r = 0.73, p < 0.001 respectively). Transgenic mice may now be used to study the effect of specific phenotypic changes on the pathogenesis of ischaemia-reperfusion injury using a reliable and reproducible technique.     

Preventive role of gallic acid on hepatic ischemia and reperfusion injury in rats

There is little information about the hepatoprotective effects of gallic acid against ischemia–reperfusion (I/R) damage. Animals were subjected to I/R. Gallic acid at doses of 50 and 100 mg/kg body weight (bw) were injected as a single dose prior to ischemia. Liver tissue homogenates were used for the measurement of malondialdehyde (MDA), catalase (CAT) and glutathione peroxidase (GPx) levels. At the same time alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were assayed in serum samples and compared statistically. While the ALT, AST, LDH activities and MDA levels were significantly increased, CAT and GPx activities significantly decreased in only I/R-induced control rats compared to normal control rats (P < 0.05). Treatment with gallic acid at a dose of 100 mg/kg bw significantly decreased the ALT, AST, LDH activities and MDA levels, and markedly increased activities of CAT and GPx in tissue homogenates compared to I/R-induced rats with no treatment group (P < 0.05). In oxidative stress generated by hepatic ischemia–reperfusion, gallic acid contributes partially an alteration in the delicate balance between the scavenging capacity of antioxidant defense systems and free radicals in favour of the antioxidant defense systems in the body.     

The role of macrophages in the uptake of endotoxin by the mouse liver

The purpose of this investigation was to analyse the macrophage subpopulations involved in the uptake of endotoxin in the liver. The results show that in normal B10.D2 mice the liver macrophages constitute a heterogeneous population of cells which, depending on their state of differentiation, are distinguished by their differential distribution in the liver acinus and by their ability to phagocytose latex.     

Post-transplant cholangiopathy: Classification,pathogenesis, and preventive strategies

Biliary complications are the most frequent cause of morbidity, re-transplantation, and even mortality after liver transplantation. In general, biliary leakage and anastomotic and non-anastomotic biliary strictures (NAS) can be recognized. There is no consensus on the exact definition of NAS and different names and criteria have been used in literature. We propose to use the term post-transplant cholangiopathy for the spectrum of abnormalities of large donor bile ducts, that includes NAS, but also intraductal casts and intrahepatic biloma formation, in the presence of a patent hepatic artery. Combinations of these manifestations of cholangiopathy are not infrequently found in the same liver and ischemia-reperfusion injury is generally considered the common underlying mechanism. Other factors that contribute to post-transplant cholangiopathy are biliary injury due to bile salt toxicity and immune-mediated injury. This review provides an overview of the various types of post-transplant cholangiopathy, the presumed pathogenesis, clinical implications, and preventive strategies.     

microRNA-222 modulates liver fibrosis in a murine model of biliary atresia

microRNA-222 (miR-222) has been shown to initiate the activation of hepatic stellate cells, which plays an important role in the pathogenesis of liver fibrosis. The aim of our study was to evaluate the role of miR-22 in a mouse model of biliary atresia (BA) induced by Rhesus Rotavirus (RRV) infection. New-born Balb/c mice were randomized into control and RRV infected groups. The extrahepatic bile ducts were evaluated. The experimental group was divided into BA group and negative group based on histology. The expression of miR-222, protein phosphatase 2 regulatory subunit B alpha (PPP2R2A), proliferating cell nuclear antigen (PCNA) and phospho-Akt were detected. We found that the experimental group showed signs of cholestasis, retardation and extrahepatic biliary atresia. No abnormalities were found in the control group. In the BA group, miR-222, PCNA and Akt were highly expressed, and PPP2R2A expression was significantly inhibited. Our findings suggest that miR-222 profoundly modulated the process of fibrosis in the murine BA model, which might represent a potential target for improving BA prognosis.     

Cholangiocytes in the pathogenesis of primary sclerosing cholangitis and development of cholangiocarcinoma

Primary sclerosing cholangitis (PSC) is an idiopathic cholangiopathy strongly associated with inflammatory bowel disease (IBD) and characterized by cholestasis, chronic immune infiltration and progressive fibrosis of the intrahepatic and extrahepatic bile ducts. PSC confers a high risk of cholangiocarcinoma (CCA) with PSC-CCA representing the leading cause of PSC-associated mortality. PSC-CCA is derived from cholangiocytes and associated progenitor cells – a heterogeneous group of dynamic epithelial cells lining the biliary tree that modulate the composition and volume of bile production by the liver. Infection, inflammation and cholestasis can trigger cholangiocyte activation leading to an increased expression of adhesion and antigen-presenting molecules as well as the release of various inflammatory and fibrogenic mediators. As a result, activated cholangiocytes engage in a myriad of cellular processes, including hepatocellular proliferation, apoptosis, angiogenesis and fibrosis. Cholangiocytes can also regulate the recruitment of immune cells, mesenchymal cells, and endothelial cells that participate in tissue repair and destruction in settings of persistent inflammation. In PSC, the role of cholangiocytes and the mechanisms governing their transformation to PSC-CCA are unclear however localization of disease suggests that cholangiocytes are a key target and potential regulator of hepatobiliary immunity, fibrogenesis and tumorigenesis. Herein, we summarize mechanisms of cholangiocyte activation in PSC and highlight new insights into disease pathways that may contribute to the development of PSC-CCA. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.     

Ameliorative role of Ziziphus spina-christi leaf extracts against hepatic injury induced by Plasmodium chabaudi infected erythrocytes

One of the most common deadliest parasitic diseases is Malaria. The biology and the pathogenesis of this fascinating parasite are not yet fully understood which make discovering effective alternative drugs a challenging task. Moreover, the emergence of resistant strains added an additional burden in the journey of malaria elimination. Traditional medicine used to be an alternative therapy choice owing to the presence of potent natural products. Ziziphus spina-christi (L.) considered being one of the common potent natural plant in gulf region and other nations. Therefore, this study designed to evaluate the ameliorative role of Z. spina-christi leaf extracts (ZSCLE) against Plasmodium chabaudi-induced hepatic injury. The study involved three groups were as follows; a vehicle control group, infected with 10⁶P. chabaudi-parasitized erythrocytes group and ZSCLE treated-infected mice with 10⁶P. chabaudi-parasitized erythrocytes group. The results showed a remarkable reduction of parasitemia level and notable reverse of the anemic picture among ZSCLE treated-infected mice. The effects of ZSCLE on the liver functions enzymes and on the histopathological pictures of liver were significant. It could be concluded that Z. spina-christi leaf extracts have a protective role against Plasmodium infection that also marked through significant restoration of hepatic oxidative markers.     

The effects of lycopene on hepatic ischemia/reperfusion injury in rats

There is a very little information about the protective effect of lycopene (LYC) against hepatic ischemia–reperfusion injury. The present study was designed to examine the possible protective effect of the strong antioxidant and anti-inflammatory agent, LYC, on hepatic ischemia/reperfusion injury. For this purpose, rats were subjected to 45 min of hepatic ischemia followed by 60 min of reperfusion period. LYC at the doses of 2.5 and 5 mg/kg body weight (bw) were injected intraperitoneally, 60 min prior to ischemia. Upon sacrification, hepatic tissue samples were used for the measurement of catalase (CAT) activity and malondialdehyde (MDA) levels. Also, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were assayed in serum samples. As a result of the use of LYC at the doses of 2.5 and 5 mg/kg bw; while improvements of the ALT, AST, LDH and MDA values were partial and dose-dependent, the improvement of CAT activity was total and dose-independent (p < 0.05). Our findings suggest that LYC has a protective effect against ischemia/reperfusion injury on the liver.     

Regulation of cholesterol homeostasis in macrophages and consequences for atherosclerotic lesion development

Foam cell formation due to excessive accumulation of cholesterol by macrophages is a pathological hallmark of atherosclerosis. Macrophages cannot limit the uptake of cholesterol and therefore depend on cholesterol efflux pathways for preventing their transformation into foam cells. Several ABC-transporters, including ABCA1 and ABCG1, facilitate the efflux of cholesterol from macrophages. These transporters, however, also affect membrane lipid asymmetry which may have important implications for cellular endocytotic pathways. We propose that in addition to the generally accepted role of these ABC-transporters in the prevention of foam cell formation by induction of cholesterol efflux from macrophages, they also influence the macrophage endocytotic uptake.     

Protective effect of berberine chloride on Plasmodium chabaudi-induced hepatic tissue injury in mice

The present study aimed to investigate the protective role of berberine (BER) against Plasmodium chabaudi-induced infection in mice. Animals were divided into three groups. Group I served as a vehicle control. Group II and group III were infected with 1000 P. chabaudi infected erythrocytes. Group III was gavaged with 100 μl of 10 mg/kg berberine chloride for 10 days. All mice were sacrificed at day 10 post-infection. The percentage of parasitemia was significantly reduced more than 30%, after treatment of mice with BER. Infection caused marked hepatic injuries as indicated by histopathological alterations as evidenced by the presence of hepatic lobular inflammatory cellular infiltrations, dilated sinusoids, vacuolated hepatocytes, increased number of Kupffer cells and the malaria pigment, hemozoin. These changes in livers led to the increased histological score. Also, infection induced a significant increase in liver alanine aminotransferase and aspartate aminotransferase and a significant increase in the total leucocytic count. Moreover, mice became anemic as proved by the significant decrease in erythrocyte number and haemoglobin content. BER showed a significant protective potential by improving the above mentioned parameters. Based on these results, it is concluded that berberine could offer protection against hepatic tissue damage.     

The protective role of myeloid-derived suppressor cells in concanavalin A-induced hepatic injury

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)- induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConAmediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)- depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.     

Destruction of Hassall's corpuscles by macrophages in the sheep thymus

Summary The dissolution of Hassall's corpuscles by macrophages has been demonstrated in the sheep thymus. The findings indicate that enlarged Hassall's corpuscles are rapidly broken down by macrophages at the end of gestation or immediately after birth and replaced by newly formed corpuscles, and that these cyclic changes in Hassall's corpuscles persist, under normal physiological conditions, throughout life.     

巨噬细胞亚型转变在大鼠肾脏缺血/再灌注损伤中的作用

目的：探讨巨噬细胞在大鼠肾脏缺血/再灌注损伤过程中的亚型转变及意义。方法：将30只雄性SD大鼠随机分成假手术组（Sham,n=6）和缺血/再灌组（IRI,夹闭肾动脉45 min,n=24）。IRI组分别于术后0、6、24和72 h取肾组织,每个时相组6只大鼠。用HE染色观察肾组织损伤程度;免疫组化染色检测细胞增殖核抗原（PCNA）的表达;实时定量RT-PCR检测巨噬细胞移动抑制因子（MIF） mRNA的表达;免疫组织荧光染色检测MIF、单核巨噬细胞趋化蛋白-1（MCP-1）以及活化巨噬细胞标志物CD68的表达,流式细胞分析检测巨噬细胞M1和M2亚型的分布特征。结果：病理结果显示大鼠肾局部损伤情况和炎症细胞浸润程度在24 h时最为严重,之后逐渐恢复。PCNA在再灌后表达明显增加,6 h达峰值,72 h表达下降。相比于正常组,再灌组大鼠肾组织中MIF的mRNA和蛋白表达明显升高;MCP-1表达则在6 h达峰值,随后下降;而CD68阳性的巨噬细胞数量明显增加,24 h达峰值,72 h表达下降。更进一步研究发现缺血/再灌注6 h时,M1亚型分布达最高值;之后随着缺血/再灌注时间延长,M1亚群相对含量开始下调,M2随之升高。结论：在肾脏缺血/再灌注早期,M1巨噬细胞介导的组织损伤发挥主要作用,随后M2型表达逐渐上调,并通过促进细胞增殖修复肾组织损伤。     

The role of macrophages in the tissues regeneration stimulated by the biomaterials

Allogenic grafted tissues are subjected to biodegradation and replaced by the regenerate. To minimize the immune response and improve the rebuilding of tissues there was developed a technology to treat tissues with a cells elimination and dosed out extraction of proteoglycanes (Alloplant^®). With aim to clarify the role of macrophages in the tissues regeneration resulting implantation the biomaterials 112 rats were injected the allogenic and xenogenic (rabbits) pulverized biomaterials in the form of suspension. Injections were performed subcutaneously into the animals back by the base of the tail. The control group (14 rats) were injected a physiologic saline. Animals were killed by ether inhalation on day 2, 4, 7, 14, 30, 90 and 180 and tissue sections were studied by light and electron microscopy. The study showed the key role of the macrophages in resorption of the allogenic biomaterial and formation of the newly-formed tissue. Implantation of the biomaterial induced activity a great number of the mature macrophages, which completely lysed and resorbed the biomaterial particles. Expression TNF was significantly higher whereas expression TGF-1 was significantly lower. With xenogenic biomaterial implantation there were less macrophages, their activity was restricted. Macrophages containing large vacuoles with an active endo- and exocytosis were revealed in the allogenic biomaterial implantation and were named matrix-forming macrophages. We may suppose that these macrophages synthesize (or re-synthesize) proteoglycan component of the newly-formed collagen fibers. There was put forward a hypothesis about the two component mechanism of the collagen fibers formation.     

The effects of lectins on the interaction between macrophages and bone in vitro

Summary Recent studies have demonstrated that the attachment of elicited rat macrophages to bone is mediated by specific saccharides located on the cell and/or bone surfaces. We have used a macrophage-bone culture system to study the effects of two lectins, concanavalin A (con A) and soybean agglutinin (SBA), on the morphology of macrophage attachment to a devitalized bone surface and subsequent functional activity. Macrophages were obtained from 3- to 4-week-old rats by peritoneal lavage and the adherent pool was used to prepare cell suspensions. Con A-treated, SBA-treated or control cell suspensions were aliquoted onto the endocranial surface of devitalized rat calvariae. The cells were allowed to attach for 1 h at 37° C, after which, the bone samples were removed from culture and prepared for scanning electron microscopy (SEM). The morphology of con A-treated macrophages attached to bone was markedly different from that of control or SBA-treated cells. Con A altered the attachment and subsequent spreading of macrophages on bone as visualized by SEM. Furthermore, the number of con A-treated cells that attached to bone and the average surface area of cell membrane apposed to the matrix was significantly different from that of control or SBA-treated cells. A ⁴⁵Ca bone-release assay was performed to evaluate the functional significance of the morphological findings. Lectin-treated or control cell suspensions were allowed to attach to the endocranial surface of ⁴⁵Ca pre-labeled calvariae for 1 h. Following attachment, the samples were cultured for 72 h. The con A-treated cultures demonstrated a significant decrease in the release of ⁴⁵Ca after 48 and 72 h in comparison to control cultures, while the ⁴⁵Ca released from SBA-treated cultures did not differ significantly from controls. These results suggest that certain sugar residues common to membrane-associated glycoconjugates and the organic component of the bone matrix regulate the attachment of macrophages to bone and their subsequent bone-resorbing activity.     

胆总管内注射无水乙醇致胆道闭锁动物模型的建立

目的应用胆总管内注射无水乙醇建立SD大鼠胆道闭锁模型。方法将SD雄性大鼠随机分为实验组和对照组,在实验组中经静脉留置针插入胆总管注入无水乙醇,对照组注入生理盐水。观察SD大鼠的生化及病理结果。结果在实验组中SD大鼠根据病理及生化检测分为肝功能持续恶化组和肝功能修复组,肝功能持续恶化组在8周以后生化明显高于对照组及肝功能修复组。常规HE染色及SMA、Masson染色也出现明显变化。结论胆总管无水乙醇注射诱导胆道闭锁模型是一种可靠的动物模型,此动物模型会帮助人们进一步研究胆道闭锁提供更多的研究手段。     

Protective effect of L-carnitine on renal ischaemia-reperfusion injury in the rat

This study was designed to investigate the effect of L-carnitine in ischaemia and reperfusion of the rat kidney. Rats were randomly allocated into three groups. Group I (control group; n = 6) received no treatment. Group II (isotonic saline group; n = 6), received 2 ml of isotonic saline 15 min before the renal ischaemia, and group III (carnitine group; n = 6) received L-carnitine hydrochloride (100 mg kg(-1)) intraperitoneally. At the end of the reperfusion period, rats were sacrificed. Tissue malondialdehyde level (MDA), myeloperoxidase (MPO) activity, and nitrite/nitrate (NO) level of renal tissue were measured to evaluate the lipid peroxidation, neutrophil function, and nitric oxide metabolism, respectively. The tissue levels of MDA, MPO and NO were lower in group III (71.8 +/- 8.4, 172.1 +/- 27.4 U g(-1) tissue, 76.3 +/- 29.7 micromol l(-1) respectively) than levels in groups I (103.4 +/- 13.4 nmol g(-1), 325.9 +/- 20.2 U g(-1) tissue, 144.5 +/- 39.2 micromol l(-1), respectively) and II (103.5 +/- 11.4 nmol g(-1), 317.1 +/- 41.5 U g(-1) tissue, 148.9 +/- 23.9 micromol l(-1), respectively). It is shown that carnitine protects kidney tissue against ischaemia-reperfusion injury.