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Liver sinusoidal endothelial cells represents an important blood clearance system in pigs.

Nedredal GI, Elvevold KH, Ytrebø LM, Olsen R, Revhaug A, Smedsrød B - Comp Hepatol (2003)

Bottom Line: Use of specific anti-Kupffer cell- and anti-desmin antibodies, combined with endocytosis of fluorescently labeled macromolecular soluble ligands indicated that the LSEC fraction contained 62 x 107 (sd 12 x 107) purified LSEC.Cultured LSEC avidly endocytosed ligands for the mannose and scavenger receptors.CONCLUSIONS: We show here for the first time that pig LSEC, similar to what has been found earlier in rat LSEC, represent an effective scavenger system for removal of macromolecular waste products from the circulation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Digestive Surgery, University Hospital of Tromsø, 9038 Tromsø, Norway. Geir.Ivar.Nedredal@fagmed.uit.no

ABSTRACT
BACKGROUND: Numerous studies in rats and a few other mammalian species, including man, have shown that the sinusoidal cells constitute an important part of liver function. In the pig, however, which is frequently used in studies on liver transplantation and liver failure models, our knowledge about the function of hepatic sinusoidal cells is scarce. We have explored the scavenger function of pig liver sinusoidal endothelial cells (LSEC), a cell type that in other mammals performs vital elimination of an array of waste macromolecules from the circulation. RESULTS: 125I-macromolecules known to be cleared in the rat via the scavenger and mannose receptors were rapidly removed from the pig circulation, 50% of the injected dose being removed within the first 2-5 min following injection. Fluorescently labeled microbeads (2 &mgr;m in diameter) used to probe phagocytosis accumulated in Kupffer cells only, whereas fluorescently labeled soluble macromolecular ligands for the mannose and scavenger receptors were sequestered only by LSEC. Desmin-positive stellate cells accumulated no probes. Isolation of liver cells using collagenase perfusion through the portal vein, followed by various centrifugation protocols to separate the different liver cell populations yielded 280 x 107 (range 50-890 x 107) sinusoidal cells per liver (weight of liver 237.1 g (sd 43.6)). Use of specific anti-Kupffer cell- and anti-desmin antibodies, combined with endocytosis of fluorescently labeled macromolecular soluble ligands indicated that the LSEC fraction contained 62 x 107 (sd 12 x 107) purified LSEC. Cultured LSEC avidly endocytosed ligands for the mannose and scavenger receptors. CONCLUSIONS: We show here for the first time that pig LSEC, similar to what has been found earlier in rat LSEC, represent an effective scavenger system for removal of macromolecular waste products from the circulation.

No MeSH data available.


Related in: MedlinePlus

Specificity of endocytosis of 125I-formaldehyde-treated serum albumin (FSA) in cultured liver sinusoidal endothelial cells (LSEC) (grey and white bars), and 125I-asialo-orusomucoid protein (ASOR) in cultured hepatocytes (black and hatched bars). Monolayer cultures were incubated for 2 hrs, at 37°C, with trace amounts of labeled ligand alone (control) or together with excess amounts of unlabeled FSA (100 μg·mL-1) or galactose (50 mmol·L-1). The presence of unlabeled FSA inhibited effectively the endocytosis of 125I-FSA in LSEC, while galactose showed no such inhibitory effect. Galactose had an inhibitory effect on endocytosis of 125I-ASOR in hepatocytes, whereas unlabeled FSA showed no such inhibitory effect. Results, given as percent of control, are the means of triplicate experiments. Grey and white bars: 100% corresponds to 12.7% of added cpm, black and hatched bars: 100% corresponds to 14.6% of added cpm. White and hatched areas of bars represent % degraded ligand. Grey and black areas of bars represent % cell-associated ligand.
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Figure 8: Specificity of endocytosis of 125I-formaldehyde-treated serum albumin (FSA) in cultured liver sinusoidal endothelial cells (LSEC) (grey and white bars), and 125I-asialo-orusomucoid protein (ASOR) in cultured hepatocytes (black and hatched bars). Monolayer cultures were incubated for 2 hrs, at 37°C, with trace amounts of labeled ligand alone (control) or together with excess amounts of unlabeled FSA (100 μg·mL-1) or galactose (50 mmol·L-1). The presence of unlabeled FSA inhibited effectively the endocytosis of 125I-FSA in LSEC, while galactose showed no such inhibitory effect. Galactose had an inhibitory effect on endocytosis of 125I-ASOR in hepatocytes, whereas unlabeled FSA showed no such inhibitory effect. Results, given as percent of control, are the means of triplicate experiments. Grey and white bars: 100% corresponds to 12.7% of added cpm, black and hatched bars: 100% corresponds to 14.6% of added cpm. White and hatched areas of bars represent % degraded ligand. Grey and black areas of bars represent % cell-associated ligand.

Mentions: The specificity of endocytosis of 125I-FSA and 125I-asialo-orusomucoid protein (ASOR) in cultured LSEC and hepatocytes was studied by attempting to inhibit the uptake of trace amounts of radiolabeled ligands using excess amounts of unlabeled ligands. Incubation of LSEC cultures with 125I-FSA in the presence of excess amounts of unlabeled FSA (100 mg·mL-1) resulted in a 90% inhibition of uptake (Fig. 8). The presence of galactose (50 mmol·L-1) did not inhibit endocytosis of 125I-FSA by LSEC. Incubation of hepatocytes with 125I-ASOR in the presence of excess amounts of galactose (50 mmol·L-1) inhibited uptake by 85%. Unlabeled FSA did not inhibit endocytosis of 125I-ASOR by hepatocytes (Fig. 8).


Liver sinusoidal endothelial cells represents an important blood clearance system in pigs.

Nedredal GI, Elvevold KH, Ytrebø LM, Olsen R, Revhaug A, Smedsrød B - Comp Hepatol (2003)

Specificity of endocytosis of 125I-formaldehyde-treated serum albumin (FSA) in cultured liver sinusoidal endothelial cells (LSEC) (grey and white bars), and 125I-asialo-orusomucoid protein (ASOR) in cultured hepatocytes (black and hatched bars). Monolayer cultures were incubated for 2 hrs, at 37°C, with trace amounts of labeled ligand alone (control) or together with excess amounts of unlabeled FSA (100 μg·mL-1) or galactose (50 mmol·L-1). The presence of unlabeled FSA inhibited effectively the endocytosis of 125I-FSA in LSEC, while galactose showed no such inhibitory effect. Galactose had an inhibitory effect on endocytosis of 125I-ASOR in hepatocytes, whereas unlabeled FSA showed no such inhibitory effect. Results, given as percent of control, are the means of triplicate experiments. Grey and white bars: 100% corresponds to 12.7% of added cpm, black and hatched bars: 100% corresponds to 14.6% of added cpm. White and hatched areas of bars represent % degraded ligand. Grey and black areas of bars represent % cell-associated ligand.
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Related In: Results  -  Collection

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Figure 8: Specificity of endocytosis of 125I-formaldehyde-treated serum albumin (FSA) in cultured liver sinusoidal endothelial cells (LSEC) (grey and white bars), and 125I-asialo-orusomucoid protein (ASOR) in cultured hepatocytes (black and hatched bars). Monolayer cultures were incubated for 2 hrs, at 37°C, with trace amounts of labeled ligand alone (control) or together with excess amounts of unlabeled FSA (100 μg·mL-1) or galactose (50 mmol·L-1). The presence of unlabeled FSA inhibited effectively the endocytosis of 125I-FSA in LSEC, while galactose showed no such inhibitory effect. Galactose had an inhibitory effect on endocytosis of 125I-ASOR in hepatocytes, whereas unlabeled FSA showed no such inhibitory effect. Results, given as percent of control, are the means of triplicate experiments. Grey and white bars: 100% corresponds to 12.7% of added cpm, black and hatched bars: 100% corresponds to 14.6% of added cpm. White and hatched areas of bars represent % degraded ligand. Grey and black areas of bars represent % cell-associated ligand.
Mentions: The specificity of endocytosis of 125I-FSA and 125I-asialo-orusomucoid protein (ASOR) in cultured LSEC and hepatocytes was studied by attempting to inhibit the uptake of trace amounts of radiolabeled ligands using excess amounts of unlabeled ligands. Incubation of LSEC cultures with 125I-FSA in the presence of excess amounts of unlabeled FSA (100 mg·mL-1) resulted in a 90% inhibition of uptake (Fig. 8). The presence of galactose (50 mmol·L-1) did not inhibit endocytosis of 125I-FSA by LSEC. Incubation of hepatocytes with 125I-ASOR in the presence of excess amounts of galactose (50 mmol·L-1) inhibited uptake by 85%. Unlabeled FSA did not inhibit endocytosis of 125I-ASOR by hepatocytes (Fig. 8).

Bottom Line: Use of specific anti-Kupffer cell- and anti-desmin antibodies, combined with endocytosis of fluorescently labeled macromolecular soluble ligands indicated that the LSEC fraction contained 62 x 107 (sd 12 x 107) purified LSEC.Cultured LSEC avidly endocytosed ligands for the mannose and scavenger receptors.CONCLUSIONS: We show here for the first time that pig LSEC, similar to what has been found earlier in rat LSEC, represent an effective scavenger system for removal of macromolecular waste products from the circulation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Digestive Surgery, University Hospital of Tromsø, 9038 Tromsø, Norway. Geir.Ivar.Nedredal@fagmed.uit.no

ABSTRACT
BACKGROUND: Numerous studies in rats and a few other mammalian species, including man, have shown that the sinusoidal cells constitute an important part of liver function. In the pig, however, which is frequently used in studies on liver transplantation and liver failure models, our knowledge about the function of hepatic sinusoidal cells is scarce. We have explored the scavenger function of pig liver sinusoidal endothelial cells (LSEC), a cell type that in other mammals performs vital elimination of an array of waste macromolecules from the circulation. RESULTS: 125I-macromolecules known to be cleared in the rat via the scavenger and mannose receptors were rapidly removed from the pig circulation, 50% of the injected dose being removed within the first 2-5 min following injection. Fluorescently labeled microbeads (2 &mgr;m in diameter) used to probe phagocytosis accumulated in Kupffer cells only, whereas fluorescently labeled soluble macromolecular ligands for the mannose and scavenger receptors were sequestered only by LSEC. Desmin-positive stellate cells accumulated no probes. Isolation of liver cells using collagenase perfusion through the portal vein, followed by various centrifugation protocols to separate the different liver cell populations yielded 280 x 107 (range 50-890 x 107) sinusoidal cells per liver (weight of liver 237.1 g (sd 43.6)). Use of specific anti-Kupffer cell- and anti-desmin antibodies, combined with endocytosis of fluorescently labeled macromolecular soluble ligands indicated that the LSEC fraction contained 62 x 107 (sd 12 x 107) purified LSEC. Cultured LSEC avidly endocytosed ligands for the mannose and scavenger receptors. CONCLUSIONS: We show here for the first time that pig LSEC, similar to what has been found earlier in rat LSEC, represent an effective scavenger system for removal of macromolecular waste products from the circulation.

No MeSH data available.


Related in: MedlinePlus