Long live the liver: immunohistochemical and stereological study of hepatocytes, liver sinusoidal endothelial cells, Kupffer cells and hepatic stellate cells of male and female rats throughout ageing

2016 ◽  
Vol 366 (3) ◽  
pp. 639-649 ◽  
Author(s):  
Ricardo Marcos ◽  
Carla Correia-Gomes
2020 ◽  
Vol 245 (16) ◽  
pp. 1504-1512 ◽  
Author(s):  
Devaraj Ezhilarasan

Portal hypertension is one of the most important cirrhosis-associated complications of chronic liver disease, leading to significant morbidity and mortality. After chronic liver injury, hepatic stellate cells reside in the perisinusoidal space activted and acquire a myofibroblast-like phenotype. The activated hepatic stellate cells act as both sources as well as the target for a potent vasoconstrictor endothelin-1. Activation of hepatic stellate cells plays a vital role in the onset of cirrhosis by way of increased extracellular matrix production and the enhanced contractile response to vasoactive mediators such as endothelin-1. In fibrotic/cirrhotic liver, activated hepatic stellate cells produce endothelin-1 leading to an imbalance between pro and antifibrotic factors responsible for enormous extracellular matrix synthesis. Thus, extracellular matrix deposition in the perisinusoidal space further augments liver stiffness and elevates the vascular tone and portal hypertension. Portal hypertension is a complex process modulated by several cell types like hepatic stellate cells, liver sinusoidal endothelial cells, Kupffer cells, injured hepatocytes, immune cells, and biliary epithelial cells. Therefore, targeting a single cell type may not be useful for regression of cirrhosis and portal hypertension. Nevertheless, numerous findings indicate that functionally liver sinusoidal endothelial cells and hepatic stellate cells closely regulate the sinusoidal blood flow via synthesis of several vasoactive molecules including endothelin-1, and hence targeting these cells with novel pharmacological agents may offer promising results. Impact statement Portal hypertension is pathologically defined as increase of portal venous pressure, mainly due to chronic liver diseases such as fibrosis and cirrhosis. In fibrotic liver, activated hepatic stellate cells increase their contraction in response to endothelin-1 (ET-1) via autocrine and paracrine stimulation from liver sinusoidal endothelial cells and injured hepatocytes. Clinical studies are limited with ET receptor antagonists in cirrhotic patients with portal hypertension. Hence, studies are needed to find molecules that block ET-1 synthesis. Accumulation of extracellular matrix proteins in the perisinusoidal space, tissue contraction, and alteration in blood flow are prominent during portal hypertension. Therefore, novel matrix modulators should be tested experimentally as well as in clinical studies. Specifically, tumor necrosis factor-α, transforming growth factor-β1, Wnt, Notch, rho-associated protein kinase 1 signaling antagonists, and peroxisome proliferator-activated receptor α and γ, interferon-γ and sirtuin 1 agonists should be tested elaborately against cirrhosis patients with portal hypertension.


2000 ◽  
Vol 278 (2) ◽  
pp. G227-G233 ◽  
Author(s):  
Matthias Wettstein ◽  
Thorsten Peters-Regehr ◽  
Ralf Kubitz ◽  
Richard Fischer ◽  
Claudia Holneicher ◽  
...  

Betaine, taurine, and inositol participate as osmolytes in liver cell volume homeostasis and interfere with cell function. In this study we investigated whether osmolytes are also released from the intact liver independent of osmolarity changes. In the perfused rat liver, phagocytosis of carbon particles led to a four- to fivefold stimulation of taurine efflux into the effluent perfusate above basal release rates. This taurine release was inhibited by 70–80% by the anion exchange inhibitor DIDS or by pretreatment of the rats with gadolinium chloride. Administration of vasopressin, cAMP, extracellular ATP, and glucagon also increased release of betaine and/or taurine, whereas insulin, extracellular UTP, and adenosine were without effect. In isolated liver cells, it was shown that parenchymal cells and sinusoidal endothelial cells, but not Kupffer cells and hepatic stellate cells, release osmolytes upon hormone stimulation. This may be caused by a lack of hormone receptor expression in these cells, because single-cell fluorescence measurements revealed an increase of intracellular calcium concentration in response to vasopressin and glucagon in parenchymal cells and sinusoidal endothelial cells but not in Kupffer cells and hepatic stellate cells. The data show that Kupffer cells release osmolytes during phagocytosis via DIDS-sensitive anion channels. This mechanism may be used to compensate for the increase in cell volume induced by the ingestion of phagocytosable material. The physiological significance of hormone-induced osmolyte release remains to be evaluated.


2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhuo Yu ◽  
Jianfeng Guo ◽  
Yun Liu ◽  
Menglin Wang ◽  
Zhengsheng Liu ◽  
...  

Abstract Background Hepatocellular carcinoma (HCC) developed in fibrotic liver does not respond well to immunotherapy, mainly due to the stromal microenvironment and the fibrosis-related immunosuppressive factors. The characteristic of liver sinusoidal endothelial cells (LSECs) in contributing to fibrosis and orchestrating immune response is responsible for the refractory to targeted therapy or immunotherapy of HCC. We aim to seek a new strategy for HCC treatment based on an old drug simvastatin which shows protecting effect on LSEC. Method The features of LSECs in mouse fibrotic HCC model and human HCC patients were identified by immunofluorescence and scanning electron microscopy. The effect of simvastatin on LSECs and hepatic stellate cells (HSCs) was examined by immunoblotting, quantitative RT-PCR and RNA-seq. LSEC-targeted delivery of simvastatin was designed using nanotechnology. The anti-HCC effect and toxicity of the nano-drug was evaluated in both intra-hepatic and hemi-splenic inoculated mouse fibrotic HCC model. Results LSEC capillarization is associated with fibrotic HCC progression and poor survival in both murine HCC model and HCC patients. We further found simvastatin restores the quiescence of activated hepatic stellate cells (aHSCs) via stimulation of KLF2-NO signaling in LSECs, and up-regulates the expression of CXCL16 in LSECs. In intrahepatic inoculated fibrotic HCC mouse model, LSEC-targeted nano-delivery of simvastatin not only alleviates LSEC capillarization to regress the stromal microenvironment, but also recruits natural killer T (NKT) cells through CXCL16 to suppress tumor progression. Together with anti-programmed death-1-ligand-1 (anti-PD-L1) antibody, targeted-delivery of simvastatin achieves an improved therapeutic effect in hemi-splenic inoculated advanced-stage HCC model. Conclusions These findings reveal an immune-based therapeutic mechanism of simvastatin for remodeling immunosuppressive tumor microenvironment, therefore providing a novel strategy in treating HCC. Graphical Abstract


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sean C. Mulligan, MS1 ◽  
Wenjun Zhang, PhD ◽  
Lester J. Smith, PhD ◽  
Erika Gramelspacher, BS ◽  
Ping Li, PhD ◽  
...  

Background and Hypothesis: Recent progress with combination of chemicals in cell culture media prolongs hepatocyte (HC) function in vitro. However, without other cells of hepatic lineage that comprise natural liver, HC alone are not suitable for the study of complex liver diseases. Hepatic stellate cells (HSC) and liver sinusoidal endothelial cells (LSEC) play vital roles in physiological and pathological liver function in situ. We hypothesized that coculturing primary HC with HSC and LSEC as 3D liver organoids in the same chemical conditioned media would uphold HC function over time, creating a better physiological 3D liver microenvironment for liver disease research. Experimental Design: Freshly thawed primary human HCs were combined with immortalized human HSC alone, or together with immortalized human LSECs, to generate 3D liver spheroids. Spheroids were formed in HC maintenance media (HMM, Lonza) using low adhesion 96-well plates for 6 days before switching to the media with different combination of chemicals (SB31542, Forskolin, IWP2, DAPT, and LDN193189) for culturing another 14 days. Spheroids characterization, albumin secretion, mRNA transcription (CYP3A4), and histological analysis were performed for HC differentiation, maturation, and function. Results: Both co-cultures of HC:HSC (2.5:1 ratio), and HC:HSC:LSEC (2.5:1:1) formed spheroids in HMM within 4 to 6 days (Fig.1A). The introduction of the different chemical-based media affected the roundness and diameter of spheroids differently (Fig.1B). In the presence of all 5 chemicals (5C), HC function was better maintained up to 21 days in HC:HSC:LSEC spheroids, measured by albumin, CYP3A4, and CK-19 secretion (Fig.1C). Surprisingly, 5C-based media significantly upregulated the expression of CK-19, which is one of the markers for cholangiocytes and liver precursor cells. Conclusion and Potential Impact: 3D liver organoids composed of HC, HSC, and LSEC would create a niche environment mimicking the in vivo condition. Optimization of complex hepatic spheroids, as well as optimization of complex hepatic spheroid culturing media, would allow for the generation of a unique model for studying complex liver diseases.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1243 ◽  
Author(s):  
Jeremy Meyer ◽  
Alexandre Balaphas ◽  
Pierre Fontana ◽  
Philippe Morel ◽  
Simon C. Robson ◽  
...  

(1) Background: Platelets were postulated to constitute the trigger of liver regeneration. The aim of this study was to dissect the cellular interactions between the various liver cells involved in liver regeneration and to clarify the role of platelets. (2) Methods: Primary mouse liver sinusoidal endothelial cells (LSECs) were co-incubated with increasing numbers of resting platelets, activated platelets, or platelet releasates. Alterations in the secretion of growth factors were measured. The active fractions of platelet releasates were characterized and their effects on hepatocyte proliferation assessed. Finally, conditioned media of LSECs exposed to platelets were added to primary hepatic stellate cells (HSCs). Secretion of hepatocyte growth factor (HGF) and hepatocyte proliferation were measured. After partial hepatectomy in mice, platelet and liver sinusoidal endothelial cell (LSEC) interactions were analyzed in vivo by confocal microscopy, and interleukin-6 (IL-6) and HGF levels were determined. (3) Results: Co-incubation of increasing numbers of platelets with LSECs resulted in enhanced IL-6 secretion by LSECs. The effect was mediated by the platelet releasate, notably a thermolabile soluble factor with a molecular weight over 100 kDa. The conditioned medium of LSECs exposed to platelets did not increase proliferation of primary hepatocytes when compared to LSECs alone but stimulated hepatocyte growth factor (HGF) secretion by HSCs, which led to hepatocyte proliferation. Following partial hepatectomy, in vivo adhesion of platelets to LSECs was significantly increased when compared to sham-operated mice. Clopidogrel inhibited HGF secretion after partial hepatectomy. (4) Conclusion: Our findings indicate that platelets interact with LSECs after partial hepatectomy and activate them to release a large molecule of protein nature, which constitutes the initial trigger for liver regeneration.


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