TY - JOUR
T1 - Effects of keratin filament disruption on exocrine pancreas-stimulated secretion and susceptibility to injury
AU - Toivola, Diana
AU - NO, Ku
AU - Ghori, N
AU - Lowe, AW
AU - Michie, SA
AU - Omary, MB
PY - 2000
Y1 - 2000
N2 - Disruption or absence of hepatocyte keratins 8 and 18 is associated with chronic hepatitis, marked hepatocyte fragility, and a significant predisposition to stress-induced liver injury, In contrast, pancreatic keratin disruption in transgenic mice that express keratin 18 Arg89 --> Cys (K18C) is not associated with an obvious pancreatic pathology. We compared the effects of keratin filament disruption on pancreatic acini or acinar cell viability, and on cholecystokinin (CCK)-stimulated secretion, in transgenic mice that overexpress wild-type keratin 18 and harbor normal extended keratin filaments (TG2) and K18C mice, We also compared the response of these mice to pancreatitis induced by a choline-deficient ethionine-supplemented diet or by caerulein, Despite extensive cytoplasmic keratin filament disruption, the apicolateral keratin filament bundles appear intact in the acinar pancreas of K18C mice, as determined ultrastructurally and by light microscopy. No significant pancreatitis-associated histologic, serologic, or F-actin/keratin apicolateral redistribution differences were noted between TG2 and K18C mice. Acinar cell viability and yield after collagenase digestion were lower in K18C than in TG2 mice, but the yields of intact acini and their (125)I-CCK uptake and responses to CCK-stimulated secretion were similar, Our results indicate that keratin filament reorganization is a normal physiologic response to pancreatic cell injury, but an intact keratin cytoplasmic filament network is not as essential in protection from cell injury as in the liver, These findings raise the possibility that the abundant apicolateral acinar keratin filaments, which are not as evident in hepatocytes, may play the cytoprotective role that is seen in liver and other tissues, Alternatively, identical keratins may function differently in different tissues.
AB - Disruption or absence of hepatocyte keratins 8 and 18 is associated with chronic hepatitis, marked hepatocyte fragility, and a significant predisposition to stress-induced liver injury, In contrast, pancreatic keratin disruption in transgenic mice that express keratin 18 Arg89 --> Cys (K18C) is not associated with an obvious pancreatic pathology. We compared the effects of keratin filament disruption on pancreatic acini or acinar cell viability, and on cholecystokinin (CCK)-stimulated secretion, in transgenic mice that overexpress wild-type keratin 18 and harbor normal extended keratin filaments (TG2) and K18C mice, We also compared the response of these mice to pancreatitis induced by a choline-deficient ethionine-supplemented diet or by caerulein, Despite extensive cytoplasmic keratin filament disruption, the apicolateral keratin filament bundles appear intact in the acinar pancreas of K18C mice, as determined ultrastructurally and by light microscopy. No significant pancreatitis-associated histologic, serologic, or F-actin/keratin apicolateral redistribution differences were noted between TG2 and K18C mice. Acinar cell viability and yield after collagenase digestion were lower in K18C than in TG2 mice, but the yields of intact acini and their (125)I-CCK uptake and responses to CCK-stimulated secretion were similar, Our results indicate that keratin filament reorganization is a normal physiologic response to pancreatic cell injury, but an intact keratin cytoplasmic filament network is not as essential in protection from cell injury as in the liver, These findings raise the possibility that the abundant apicolateral acinar keratin filaments, which are not as evident in hepatocytes, may play the cytoprotective role that is seen in liver and other tissues, Alternatively, identical keratins may function differently in different tissues.
KW - keratins
KW - acute pancreatitis
KW - acinar cell
KW - caerulein
KW - choline-deficient diet
KW - keratins
KW - acute pancreatitis
KW - acinar cell
KW - caerulein
KW - choline-deficient diet
KW - keratins
KW - acute pancreatitis
KW - acinar cell
KW - caerulein
KW - choline-deficient diet
U2 - 10.1006/excr.1999.4787
DO - 10.1006/excr.1999.4787
M3 - Artikel
SN - 0014-4827
VL - 255
SP - 156
EP - 170
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -