TY - JOUR
T1 - Alterations in vesicle transport and cell polarity in rat hepatocytes subjected to mechanical or chemical cholestasis
AU - Török, Natalie J.
AU - Larusso, Elizabeth M.
AU - McNiven, Mark A.
PY - 2001/1/1
Y1 - 2001/1/1
N2 - Background & Aims: The molecular mechanisms that contribute to the cholestatic condition in hepatocytes are poorly defined. It has been postulated that a disruption of normal vesicle-based protein trafficking may lead to alterations in hepatocyte polarity. Methods: To determine if vesicle motility is reduced by cholestasis, hepatocytes cultured from livers of bile duct ligation (BDL)- or ethinyl estradiol (EE)-injected rats, were viewed and recorded by high-resolution video microscopy. Cholestatic hepatocytes were analyzed by phalloidin staining and electron microscopy. Functional analysis was done by the sodium fluorescein sequestration assay. Results: In cholestatic hepatocytes, there was a significant decrease in the number of motile cytoplasmic vesicles observed compared with control cells. Further examination of cells from BDL- or EE-treated livers revealed the presence of numerous large intracellular lumina. More than 24% of cells in BDL-treated livers and 19% of cells in EE-treated livers displayed these structures, compared with 1.1% found in control hepatocytes. Phalloidin staining of hepatocytes showed a prominent sheath of actin surrounding the lumina, reminiscent of those seen about bile canaliculi. Electron microscopy revealed that these structures were lined by actin-filled microvilli. Further, these pseudocanaliculi perform many of the functions exhibited by bona fide canaliculi, such as sequestering sodium fluorescein. Conclusions: Both mechanically and chemically induced cholestasis have substantial effects on vesicle-based transport, leading to marked disruption of hepatocellular polarity.
AB - Background & Aims: The molecular mechanisms that contribute to the cholestatic condition in hepatocytes are poorly defined. It has been postulated that a disruption of normal vesicle-based protein trafficking may lead to alterations in hepatocyte polarity. Methods: To determine if vesicle motility is reduced by cholestasis, hepatocytes cultured from livers of bile duct ligation (BDL)- or ethinyl estradiol (EE)-injected rats, were viewed and recorded by high-resolution video microscopy. Cholestatic hepatocytes were analyzed by phalloidin staining and electron microscopy. Functional analysis was done by the sodium fluorescein sequestration assay. Results: In cholestatic hepatocytes, there was a significant decrease in the number of motile cytoplasmic vesicles observed compared with control cells. Further examination of cells from BDL- or EE-treated livers revealed the presence of numerous large intracellular lumina. More than 24% of cells in BDL-treated livers and 19% of cells in EE-treated livers displayed these structures, compared with 1.1% found in control hepatocytes. Phalloidin staining of hepatocytes showed a prominent sheath of actin surrounding the lumina, reminiscent of those seen about bile canaliculi. Electron microscopy revealed that these structures were lined by actin-filled microvilli. Further, these pseudocanaliculi perform many of the functions exhibited by bona fide canaliculi, such as sequestering sodium fluorescein. Conclusions: Both mechanically and chemically induced cholestasis have substantial effects on vesicle-based transport, leading to marked disruption of hepatocellular polarity.
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U2 - 10.1053/gast.2001.28652
DO - 10.1053/gast.2001.28652
M3 - Article
C2 - 11677210
AN - SCOPUS:0034760440
VL - 121
SP - 1176
EP - 1184
JO - Gastroenterology
JF - Gastroenterology
SN - 0016-5085
IS - 5
ER -