乙型肝炎、肝硬变中一种小多角细胞的观察

我们曾在２６例肝硬变标本中发现一种小多角细胞－－肝小多角细胞（ＳＰＬＣ）,但其性质和来源仍不清。本研究在２６０例乙型肝炎、肝硬变组织中对ＳＰＬＣ的有无及其增生程度进行了观察,结果表明,急性肝炎中无ＳＰＬＣ,３７％的慢性迁延性肝炎、６４％的慢性活动性肝炎及６７％的肝硬变标本中均能见到ＳＰＬＣ,而且其数目随慢性肝脏病变的进展而逐渐增加。应用多种抗体进行的免疫组织化学染色表明,它们全为细胞角蛋白（ＣＫ）１８阳性,显示其上皮性质;界板附近的ＳＰＬＣ呈ＣＫ１９和Ｓ－１００蛋白阳性,提示它们具有增生胆小管上皮的某些表型;部分ＳＰＬＣＨＢｓＡＧ阳性,提示它们又有肝细胞的某些特点;多数ＳＰＬＣ表达胰岛素样生长因子（ＩＧＦⅡ）—一种癌胚性强致裂原,表明它们是一种幼稚细胞。我们认为,ＳＰＬＣ是一类兼有增生胆小管上皮和肝细胞性质的新型肝脏细胞,具有干细胞的性质,可能是上皮性于细胞向成熟肝细胞分化过程中的中间形态,其增生反映了非界板性肝细胞的大量损失。     

Portocaval shunt for hepatocyte package

In developing therapeutic alternatives to liver transplantation, we have used the strategy of applying a small intestinal segment as a scaffold for hepatocyte transplantation and also as a portocaval shunt (PCS) system to address both liver dysfunction and portal hypertension. The aim of this study was to investigate the feasibility of such an intestinal segment in animal models. Hepatocytes isolated from luciferase-transgenic Lewis rats were transplanted into jejunal segments of wild-type Lewis rats with mucosa removal without PCS application. Luciferase-derived luminescence from transplanted hepatocytes was stably detected for 30 days. Then, we performed autologous hepatocyte transplantation into the submucosal layer of an isolated and vascularized small intestinal segment in pigs. Transplanted hepatocytes were isolated from the resected left-lateral lobe of the liver. On day 7, hepatocyte clusters and bile duct-like structures were observed histologically. To create an intestinal PCS system in pigs, an auto-graft of the segmental ileum and interposing vessel graft were anastomosed to the portal vein trunk and inferior vena cava. However, thrombi were observed in vessels of the intestinal PCSs. We measured the correlation between infusion pressure and flow volume in whole intestines ex vivo in both species and found that the high pressure corresponding to portal hypertension was still insufficient to maintain the patency of the intestinal grafts. In conclusion, we demonstrated the feasibility of the small intestine as a scaffold for hepatocyte transplantation in rat and pig models, but PCS using an intestinal graft failed to maintain patency in a pig model.     

LC3-associated phagocytosis in myeloid cells,a fireman that restrains inflammation and liver fibrosis,via immunoreceptor inhibitory signaling

ABSTRACT

Control of systemic and hepatic inflammation, in particular originating from monocytes/macrophages, is crucial to prevent liver fibrosis and its progression to end-stage cirrhosis. LC3-associated phagocytosis (LAP) is a non-canonical form of autophagy that shifts the monocyte/macrophage phenotype to an anti-inflammatory phenotype. In a recent study, we uncovered LAP as a protective mechanism against inflammation-driven liver fibrosis and systemic inflammation in the context of cirrhosis. We observed that LAP is enhanced in blood and liver monocytes from patients with liver fibrosis or those who progress to cirrhosis. Combining studies in which LAP was pharmacologically or genetically inactivated, we found that LAP limits inflammation in monocytes from cirrhotic patients, and the hepatic inflammatory profile in mice with chronic liver injury, resulting in anti-fibrogenic effects. Mechanistically, LAP-induced anti-inflammatory and antifibrogenic signaling results from enhanced expression of the Fc immunoreceptor FCGR2A/FcγRIIA and activation of an FCGR2A-mediated PTPN6/SHP-1 anti-inflammatory pathway, leading to increased engulfment of IgG into LC3 ⁺ phagosomes. In patients with cirrhosis progressing to multi-organ failure (acute-on chronic liver failure), LAP is lost in monocytes, and can be restored by targeting FCGR2A-mediated PTPN6/SHP-1 signaling. These data suggest that sustaining LAP may open novel therapeutic perspectives for patients with end-stage liver disease.     

Insulin sensitivity in experimental cirrhosis

Summary To investigate insulin action in muscle and adipose tissue in hepatic cirrhosis, a recently described animal model was used. Dimethylnitrosamine administration induced histologically proven cirrhosis. Contrary to expectation, muscle strips from cirrhotic rats displayed increased insulin sensitivity both with respect to glycogen synthesis (ED₅₀ 0.11 ± 0.01 vs 0.23 ± 0.04 nmol/1; p < 0.03) and glucose oxidation (ED₅₀ 0.36 ±0.07 vs 0.97 ± 12 nmol/1; p < 0.02). As the cirrhotic rats had failed to gain weight normally, it is postulated that a state of relative starvation accounted for the enhanced insulin sensitivity. These data demonstrate that the severe insulin resistance characteristically associated with cirrhosis is reversible. Control of nutritional state in future studies upon DMNA induced cirrhosis should permit detailed examination of the cellular mechanisms controlling insulin sensitivity in hepatic cirrhosis.     

Isolation and characterization of parenchymal cells from normal and cirrhotic rat liver

A technique is described for isolation of adult rat hepatocytes from micronodular cirrhotic livers based on a collagenase digestion procedure. Hepatocytes from normal livers and those chronically injured by thioacetamide did not differ with respect to the viability measured by the trypan blue exclusion test or to the cellular concentrations of protein and glycogen, but the triglyceride content of cells from cirrhotic livers was significantly reduced. Hepatocytes isolated from cirrhotic livers are ultrastructurally in a good state of preservation but they appear to be poorer than controls in RER membranes, although the well-preserved mitochondria are somewhat richer in cristae. No differences were detected between the cell preparations in rates of gluconeogenesis and total de novo fatty acid synthesis, but the secretion of newly synthesized fatty acids was significantly reduced in cells from cirrhotic livers. Thus adult rat hepatocytes can be isolated from thioacetamide-induced micronodular cirrhotic livers with high yield and morphological integrity. Differentiated functions are maintained in suspension for at least 4 h.     

Predictors of Mortality in Hypercalcemia of Advanced Chronic Liver Disease

ObjectiveHypercalcemia is sometimes observed in patients with cirrhosis, but very little is known about the epidemiology in patients with hypercalcemia of chronic liver disease (HCLD) or how its presence may modulate the overall mortality risk. We assessed the associations between the clinical and laboratory characteristics of patients with HCLD with 90-day mortality.MethodsA systematic search of the medical records at our institution over a 10-year period was performed to retrospectively identify subjects with HCLD during inpatient admission. Univariate and multivariable regression analyses were performed to detect the risk factors for all-cause 90-day mortality.ResultsThirty-eight subjects with HCLD were identified using stringent inclusion and exclusion criteria to exclude individuals with other secondary causes of hypercalcemia. A total of 35 subjects had 90-day vital status available, which revealed 40% mortality. The model for end-stage liver disease sodium score and duration of inpatient hypercalcemia were positively associated with mortality with respective odds ratios of 1.23 (95% CI, 1.06-3.23) and 1.24 (95% CI, 1.04-1.49) in a univariate regression model and 1.30 (95% CI, 1.04-1.62) and 1.33 (95% CI, 1.04-1.71) in a multivariable regression model. The admission and peak serum calcium levels were not associated with mortality. Only 6 subjects received bisphosphonates or calcitonin during their admission, limiting our ability to assess the impact of treatment on outcomes.ConclusionIn patients admitted to the hospital with HCLD, the duration of hypercalcemia was positively associated with 90-day mortality, providing a potential interventional target to reduce mortality in this high-risk population. Studies to validate the utility of treating hypercalcemia are required.     

Defects in a liver-bone axis contribute to hepatic osteodystrophy disease progression

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Relationship between the level of serum L-tryptophan and its hepatic uptake and metabolism in rats with carbon tetrachloride-induced liver cirrhosis

Summary In the serum of rats with liver cirrhosis induced by 12-week intermittent carbon tetrachloride (CCl₄) injection, free L-tryptophan (Trp) levels increased with decreases in total Trp, albumin-bound Trp, and albumin levels. In the serum of the cirrhotic rats, there were no changes in the ratio of albumin-bound Trp to albumin and the level of free fatty acids which are known to weaken the binding of Trp to albumin. In the liver of the cirrhotic rats, there were increases in protein and free Trp (i.e., non-protein Trp) contents and a decrease in total tryptophan 2,3-dioxygenase (TDO) activity. The decreased TDO activity was mainly due to the reduction of apo-TDO activity. When [³H]Trp was injected into the portal vein of the cirrhotic and control rats, radioactivity derived from the injected [³H]Trp in the liver was higher in the cirrhotic rats than in the control rats at 10min after the injection, while the radioactivity in the serum was lower in the former rats than in the latter rats. These results indicate that the increased Trp is easily taken up into the cirrhotic liver, and suggest that the Trp taken up into the cirrhotic liver could be utilized for the maintenance of synthesis of proteins in the tissue through the reduction of Trp metabolism due to reduced TDO activity in the tissue.