Association between liver sinusoidal endothelial cells and liver fibrosis / 临床肝胆病杂志

Liver sinusoidal endothelial cells (LSECs) are crucial to the maintenance of hepatic homeostasis under physiologic conditions, while under the conditions of pathological liver damage, LSEC can respond to the damage by changing their structure through the process called capillarization, thereby aggravating liver damage. In addition, the interaction between LSEC and other cells in the liver plays a certain role in the development and progression of liver fibrosis, especially the interaction between LSEC and hepatic stellate cells, which are the primary effector cells of liver fibrosis. This article mainly elaborates on the role of LSEC in the development and progression of liver fibrosis during chronic liver injury.

Amygdalin Ameliorates Liver Fibrosis through Inhibiting Activation of TGF-β/Smad Signaling / 中国结合医学杂志

OBJECTIVE@#To observe the effect of amygdalin on liver fibrosis in a liver fibrosis mouse model, and the underlying mechanisms were partly dissected in vivo and in vitro.@*METHODS@#Thirty-two male mice were randomly divided into 4 groups, including control, model, low- and high-dose amygdalin-treated groups, 8 mice in each group. Except the control group, mice in the other groups were injected intraperitoneally with 10% carbon tetrachloride (CCl4)-olive oil solution 3 times a week for 6 weeks to induce liver fibrosis. At the first 3 weeks, amygdalin (1.35 and 2.7 mg/kg body weight) were administered by gavage once a day. Mice in the control group received equal quantities of subcutaneous olive oil and intragastric water from the fourth week. At the end of 6 weeks, liver tissue samples were harvested to detect the content of hydroxyproline (Hyp). Hematoxylin and eosin and Sirius red staining were used to observe the inflammation and fibrosis of liver tissue. The expressions of collagen I (Col-I), alpha-smooth muscle actin (α-SMA), CD31 and transforming growth factor β (TGF-β)/Smad signaling pathway were observed by immunohistochemistry, quantitative real-time polymerase chain reaction and Western blot, respectively. The activation models of hepatic stellate cells, JS-1 and LX-2 cells induced by TGF-β1 were used in vitro with or without different concentrations of amygdalin (0.1, 1, 10 µmol/L). LSECs. The effect of different concentrations of amygdalin on the expressions of liver sinusoidal endothelial cells (LSECs) dedifferentiation markers CD31 and CD44 were observed.@*RESULTS@#High-dose of amygdalin significantly reduced the Hyp content and percentage of collagen positive area, and decreased the mRNA and protein expressions of Col-I, α-SMA, CD31 and p-Smad2/3 in liver tissues of mice compared to the model group (P<0.01). Amygdalin down-regulated the expressions of Col-I and α-SMA in JS-1 and LX-2 cells, and TGFβ R1, TGFβ R2 and p-Smad2/3 in LX-2 cells compared to the model group (P<0.05 or P<0.01). Moreover, 1 and 10 µmol/L amygdalin inhibited the mRNA and protein expressions of CD31 in LSECs and increased CD44 expression compared to the model group (P<0.05 or P<0.01).@*CONCLUSIONS@#Amygdalin can dramatically alleviate liver fibrosis induced by CCl4 in mice and inhibit TGF-β/Smad signaling pathway, consequently suppressing HSCs activation and LSECs dedifferentiation to improve angiogenesis.

Overview and prospects of an in vitro cell model for studying liver fibrosis / 中华肝脏病杂志

Liver fibrosis incidence and adverse outcomes are high; however, there are no known chemical drugs or biological agents that are specific and effective for treatment. The paucity of a robust and realistic in vitro model for liver fibrosis is one of the major causes hindering anti-liver fibrosis drug development. This article summarizes the latest progress in the development of in vitro cell models for liver fibrosis, with a focus based on the analysis of induction and activation of hepatic stellate cells, cell co-culture, and 3D model co-construction, as well as concurrent potential methods based on hepatic sinusoidal endothelial cell establishment.

Molecular mechanism of the anti-liver fibrosis effect of curcumol: An analysis based on the TLR4/NF-κB signaling pathway / 临床肝胆病杂志

ObjectiveTo investigate the molecular mechanism of the anti-liver fibrosis effect of curcumol by observing the effect of curcumol on the TLR4/NF-κB signaling pathway in liver sinusoidal endothelial cells. MethodsA total of 50 mice were randomly divided into blank group, model group, and curcumol group, and cells were divided into blank control group, LPS positive control group, curcumol intervention group, and PDTC group. HE staining and Masson staining were used to observe the change in liver structure; Western blot and quantitative real-time PCR (RT-PCR) were used to measure the protein and mRNA expression of the key molecules TLR4 and NF-κB in the TLR4/NF-κB signaling pathway; immunofluorescence assay was used to observe the expression and nuclear import of NF-κB in cells. A one-way analysis of variance was used for comparison between multiple 　groups, and the least　significant difference t-test was used for further comparison between two groups.　ResultsRT-PCR showed that compared with the positive control group, the curcumol intervention group had significant reductions in the mRNA expression of TLR4 and NF-κB (both P＜0.05). Western blot showed that compared with the positive control group, the curcumol intervention group had significant reductions in the expression of TLR4 and NF-κB (both P＜005). Immunofluorescence assay showed that compared with the positive control group, the curcumol intervention group had significant improvement in NF-κB nuclear import. ConclusionCurcumol can exert an anti-liver fibrosis effect possibly by inhibiting the activity of the TLR4/NF-κB signaling pathway.

Gastrodin induced HO-1 and Nrf2 up-regulation to alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells through p38 MAPK phosphorylation

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H2O2, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H2O2-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H2O2-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H2O2 was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H2O2-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H2O2-induced oxidative injury, which may be regulated by p38 phosphorylation.

Liver sinusoidal endothelial cells regulate adaptive immune tolerance in the liver / 中华肝脏病杂志

Liver sinusoidal endothelial cells are a major group of nonparenchymal cells in the liver and are involved in immunological surveillance of the liver through the expression of various scavenger receptors and pattern recognition receptors. However, in case of several physiological states, viral infections, and tumor environment, liver sinusoidal endothelial cells maintain immune tolerance in the liver through various mechanisms and cause persistent viral infection and tumor metastasis. This article reviews the mechanisms of immune tolerance of CD4 + T cells and CD8 + T cells in the liver induced by liver sinusoidal endothelial cells.

Role of liver sinusoidal endothelial cells in the development and progression of liver fibrosis and related therapeutic strategy / 临床肝胆病杂志

Liver sinusoid endothelial cells are the first defense mechanism that protects the liver against various injuries,and they also play a significant role in the development of liver fibrosis and liver cirrhosis caused by chronic liver injury.They are involved in liver fibrosis by mediating liver inflammation,participating in sinusoid capillarization and revascularization,activating hepatic stellate cells,secreting many proinflammatory cytokines,participating in extracellular matrix formation,and mediating liver microcirculation disturbance.Clarification of these mechanisms helps to identify new targets and develop new regimens for the treatment of liver fibrosis.

Advances in Study on Liver Regeneration / 胃肠病学

One of the most important characteristics of adult liver is its regenerative ability to maintain its original mass and function after injury. With remarkable self-replication ability, hepatocytes play a critical role in liver regeneration. When there is a restriction in the proliferation capacity and/ or a massive loss of mature hepatocytes,other cells in liver can contribute to liver regeneration in different ways. Deep study on the effects and mechanisms of various hepatic cells’contribution to liver regeneration is helpful for increasing the understanding about liver regeneration and providing new insights for diagnosis and management of various advanced liver diseases.

Changes of liver sinusoidal endothelial cells and basement membrane in early stage of liver fibrosis induced by carbon tetrachloride in rats / 中国病理生理杂志

[ABSTRACT]AIM:Toexplorethedevelopmentofhepaticsinusoidalcapillarizationintheearlystageofliverfi-brosis induced by carbon tetrachloride (CCl4) in rats.METHODS:Clean SD rats were randomly divided into normal con-trol group (group N, n=6) and liver fibrotic model group (group M, n=32).The rats in group N were intraperitoneal in-jected with saline and the rats in group M were intraperitoneal injected with CCl 4(2 mL/kg, twice a week for 4 weeks).At the end of the 3rd day and the 1st, 2nd and 4th weeks, all rats were killed and then the samples were collected .The patho-logical changes in the livers were observed by HE staining and Masson straining .The development of hepatic sinusoidal capillarization was observed by transmission electron microscopy (TEM) and immunohistochemical staining .The cell sur-face expression of vascular endothelium-associated marker CD31, collagen type Ⅳ(Col IV) and laminin (LN) was deter-mined.RESULTS:HE and Masson staining showed the formation of liver fibrosis after treatment with CCl 4 for 4 weeks. TEM showed that the fenestrate diameter of liver sinusoidal endothelial cells (LSECs) grew down, the fenestrate numbers of LSECs were decreased along with the development of liver fibrosis , and the consecutive basement membrane was formed at the end of the experiment .The expression of CD31 was significantly increased along with the development of defenestration , and the expression of Col IV and LN was significantly increased after the treatment with CCl 4 for 2 weeks and 4 weeks , re-spectively .CONCLUSION:The typical hepatic sinusoidal capillarization was detected in the early stage of liver fibrosis , and the deposition of LN in the liver sinusoidal walls was the mainly factor of formation of the consecutive basement mem -brane .

Effects of cold preservation and reperfusion injury on the regeneration of donor liver and associated mechanisms / 中华消化外科杂志

Objective To investigate the effects of cold preservation and reperfusion injury on the regen-eration of donor liver and to study the mechanisms. Methods Male SD rats were divided in to sham group (6 rats), UW 1 h group (48 rats) and UW 12 h group (48 rats). Liver tissue specimens were collected at different time points after orthotopic liver transplantation or sham operation. The morphology of liver tissue was observed via light microscope and transmission electron microscope. Proliferation of hepatocytes and sinusoidal endothelial cells (SECs) were assessed by a double immunostaining technique using antibodies against rat endothelial cell antigen-1 and bromodeoxyuridine (BrdU). Expression of vascular endothelial growth factor (VEGF) and its receptors, fins-like tyrosine kinase-1 (flt-1) and fetal liver kinase-1 (flk-1) was evaluated by immunohistochemistry. The mRNA expression of flt-1 was detected by a RT-PCR method. Mean comparison in groups was conducted by one-way ANOVA or t test. Results BrdU labeling indexes of hepatocytes and SECs in UW 12 h group was significantly higher than those in UW 1 h group (F = 61.45,41.4, P < 0.05). The proliferation of hepatocytes peaked at 48 h after operation in both UW 1 h group and UW 12 h group. However, the proliferation of SECs was fallen behind compared to hepatocytes, with a peak appeared at 72 h in UW 1 h group and at 96 h in UW 12 h group, respec-tively. The expression of VEGF was up-regulated in both UW 1 h group and UW 12 h group compared to sham group. Furthermore, expression of flt-1 and flk-1 was found to be mainly limited in SECs, with a peak in expres-sion occurring between 72 h and 96 h, coinciding with the peak in SECs proliferation in UW 1 h group. Conversely, flt-1 was found to be reduced significantly on mRNA level at any time throughout the experiment in UW 12 h group compared to sham group (F = 141.67, P < 0.05). Conclusion Reduced expression of flt-1 results in a retarded regeneration of SECs, and then the recovery of rat donor liver function is delayed after cold-preserved transplantation.

Morphological changes of sinusoidal endothelial cells in the patients with chronic hepatitis B / 中华传染病杂志

Objective To observe the morphological changes of sinusoidal endothelial cells(SECs) in the patients with chronic hepatitis B, and to study the relationship between the SECs changes and the development of hepatic microcirculation disorders. Methods The liver biopsy tissues from fifty three cases with hepatitis B were observed with light microscope and transmitted electronic microscope. Results The morphologies of SECs in patients with chronic hepatitis B changed significantly. The main manifestations included decreased sizes and reduced numbers of penestrate on SECs, basal membrane formation, cellular connection development between SECs, occurrence of WP bodies in SECs and the disappearance of SECs. The intimate contact occurred between SEC and lymphocyte or Kupffer cell. Conclusions The morphologies of SECs in patients with chronic hepatitis B develop significant change, which might be the initial step in the development of hepatic microcirculation disturbances.

Study on the mechanisms of development of hepatic sinusoidal capillarization / 中华消化杂志

Objective To study the relationship between the liver sinusoidal pathological changes and portal hypertension during the dimethylnitrosamine (DMN) induced liver fibrosis in rats. Methods The rat liver fibrosis model was established by peritoneal injection of DMN (at a dose of 10 mg/kg, 3 times a week, for 4 weeks) in 40 male Wister mice. In the control group of 24 healthy mice, saline solution was injected peritoneally. The dynamic changes of liver fibrosis were observed at different time points (1, 2, 3 day, 1, 2, 4, 6 and 8 week). The pressure of portal vein (Ppv) was directly measured by the intubation of mesentery anterior vein in 5 mice of the model and 3 of the control. The expressions of type Ⅳ collagen (Col Ⅳ), laminin (LM) and type Ⅰ collagen (Col Ⅰ) were detected by immunohistochemistry. Hepatic ultrastructure was observed by electron microscopy. Results Positive expression of Col Ⅳ was observed in the normal liver sinusoidal walls. The various intensities of positive staining of Col Ⅳ were observed in the liver sinusoidal walls of the fibrosis model. Positive expressions of LM and Col Ⅰ increased, and the strongest positive staining displayed in the 4 week model rats. Meanwhile, the fenestrae in the sinusoidal endothelial cells (SECs) were lost and the basal membrane was formed. There was a remarkable positive correlation between the Ppv and the expressions of LM in the DMN induced rat fibrosis( P