Liver sinusoidal endothelial cells (LSECs) modifications in patients with chronic hepatitis C - PubMed (original) (raw)

Clinical Trial

Liver sinusoidal endothelial cells (LSECs) modifications in patients with chronic hepatitis C

Andrea Baiocchini et al. Sci Rep. 2019.

Erratum in

Abstract

The sinusoidal endothelial cells present in the liver (LSECs) are tipically characterized by the presence of pores (fenestrae). During some pathological conditions LSECs undergo "capillarization", a process characterized by loss of fenestrations and acquisition of a vascular phenotype. In chronic liver disease capillarization has been reported to precede the development of fibrosis. LSECs modification in the setting of HCV infection is currently poorly investigated. Considering that HCV accounts for important changes in hepatocytes and in view of the intimate connection between hepatocytes and LSECs, here we set out to study in great detail the LSECs modifications in individuals with HCV-dependent chronic hepatitis. Electron microscopy analysis, and evaluation of CD32, CD31 and caveolin-1 expression showed that in HCV infection LSECs display major morphological changes but maintain their phenotypical identity. Capillarization was observed only in cases at initial stages of fibrosis. Our findings showed that the severity of LSECs modifications appears to be correlated with hepatocytes damage and fibrosis stage providing novel insight in the pathogenesis of HCV-chronic hepatitis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1

Figure 1

Transmission electron micrographs of human liver of chronically HCV-infected patient. (a) Representative image of a preserved liver sinusoidal endothelium (E) and neighboring hepatocytes (H); a Kupffer cell (K) is visible into the sinusoidal lumen (asterisk). The inset shows intact cytoplasmic processes of sinusoidal endothelial cells with typical fenestrae (arrowheads). (b) The image show the sinusoidal lumen (asterisk) crowded by the presence of inflammatory cells and material originating from damaged cells. (c,d) Microvilli (arrowhead) extending from the surface of endothelial cells (E) and the presence of engulfed material (arrows) inside the cytoplasm are visible. Scale bars: a, b, c = 5 μm; d = 1.2 μm.

Figure 2

Figure 2

EM analysis of sinusoidal modifications in HCV-infected liver. (a,b) Representative electron micrographs of capillarized LSECs. The absence of fenestrae and the development of a continuous lining (a) with the appearance of abnormal basement membrane (arrowheads) on the basal side of LSECs is shown. (c) The micrograph shows the swelling of sinusoidal endothelium (E), and the presence of large gaps (arrows). (d,e) Images show variable degrees of discontinuous endothelial lining leading shedding of hepatocytes vesicles (white arrow) into the sinusoidal lumen (asterisk) and to a widening of the space of Disse (Di). (f) Box Plot representing the distribution of capillarized and discontinuous LSECs according with fibrosis stage (Ishak scoring system) in HCV-infected liver. (H) hepatocytes; (*) sinusoidal lumen. Scale bars: a,e = 1.2 μm; b–d = 5 μm.

Figure 3

Figure 3

EM analysis of hepatocytes damage in HCV-infected liver. (a–c) Low-power overview showing parenchyma modifications induced by HCV, including the presence of extensive vacuolation (arrows), lipid droplets (Li), and perisinusoidal collagen (asterisk). (d) Higher magnification of a portion of hepatocyte cytoplasm with clusters of contiguous vesicles (CV), multilamellar body (MB), and lisosomal residual bodies (L). (H) hepatocyte); (Di) Disse’s space; (m) mitochondria. Scale bars: a, b = 5μm; c = 1.2 μm; d = 0.6 μm.

Figure 4

Figure 4

Expression of CD32 and CD31 in liver from HCV-infected. (Upper panel) Immunohistochemical analysis showed positive immunoreactions of both CD32 and CD31. (Lower panel) Confocal microscope images reveals a diversity in the localization of the two markers (CD32 is expressed at the cell surface; CD31 is present inside the cytoplasm) as demonstrated by the separated colors in the merged of the fluorescence signals. Scale bars: Upper panel a,c = 100 μm; b,d = 70 μm; Lower panel 25 μm.

Figure 5

Figure 5

Confocal microscopy analysis of caveolin-1 (CAV-1) distribution. (Panel A) Normal liver (a) exhibits lack of CAV-1 expression in hepatocytes, while positive staining is restricted to the sinusoidal endothelial cells surface. In HCV-infected liver (b,c) the labeling is present both on hepatocytes and endothelial cells. (Panel B) Representative confocal images showing different staining pattern into parenchymal cells: the staining was found as absent in the nucleus and diffuse in the cytoplasm (I), or positive in the nucleus and present as puncta in the cytoplasm (II). Scale bar; A (a–c) = 25 μm; and B (I,II) = 12 μm.

Figure 6

Figure 6

Distribution of CAV-1 staining pattern into hepatocytes. (Panel A) Distribution of the staining pattern in hepatocytes of HCV-infected liver according to the different LSECs modifications. (Panel B) Distribution of CAV-1 expression pattern according to fibrosis stages. Protein expression was analyzed by Chi-square test. A statistically significant association was found between CAV-1 nuclear expression and S3–S6 (P < 0.005; CI 95%).

References

    1. Mohd Hanafiah K, Groeger J, Flaxman AD, Wiersma ST. Global epidemiology of hepatitis C virus infection: new estimates of age-specific antibody to HCV seroprevalence. Hepatology. 2013;57:1333–1342. - PubMed
    1. Kim A, Hepatitis C. Virus. Ann. Intern. Med. 2016;165:ITC33–ITC48. - PubMed
    1. Iwakiri Y, Shah V, Rockey DC. Vascular pathobiology in chronic liver disease and cirrhosis—current status and future directions. J. Hepatol. 2014;61:912–24. - PMC - PubMed
    1. Greuter T, Shah VH. Hepatic sinusoids in liver injury, inflammation, and fibrosis: new pathophysiological insights. J. Gastroenterol. 2016;51:511–9. - PubMed
    1. Wisse E, De Zanger RB, Charles K, Van Der Smissen P, McCuskey RS. The liver sieve: considerations concerning the structure and function of endothelial fenestrae, the sinusoidal wall and the space of Disse. Hepatology. 1985;5:683–692. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources