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1.
Dynamic changes in protein components of the tight junction during liver regeneration 总被引:4,自引:0,他引:4
Takaki Y Hirai S Manabe N Izumi Y Hirose T Nakaya M Suzuki A Mizuno K Akimoto K Tsukita S Shuin T Ohno S 《Cell and tissue research》2001,305(3):399-409
The construction of the hepatocyte tight junction is one of the most important events during liver regeneration leading to the reorganization of the bile canaliculi and the repolarization of hepatocytes after cell division. To understand this event at the molecular level, we examined the expression of tight junction proteins by Western blot analysis and their cellular localization by immunofluorescence microscopy in regenerating rat liver after two-thirds hepatectomy. The levels of tight junction components such as claudin-3, ZO-1 and atypical protein kinase C (PKC)-specific interacting protein (ASIP) increased two- to three-fold over control levels in coordination with a peak 2-3 days after partial hepatectomy, whereas occludin levels remained unchanged. The bile canaliculi outlined by tight junction components and actin filaments reveal significant morphological changes from 2-3 days after partial hepatectomy. During this period, claudin-3/ZO-1 and ASIP/ZO-1 were nearly co-localized, whereas occludin was locally reduced or almost absent on the bile canaliculi outlined by ZO-1 staining. The uncoupled localization of F-actin and tight junction components was often observed. The function of hepatocytes, as revealed by the serum bile acids level, was distorted temporally at an early stage of regeneration but mostly restored 3 days after partial hepatectomy. These observations suggest that the de novo construction of tight junctions proceeds mainly 2-3 days after partial hepatectomy in parallel with the cell polarization required for hepatocyte function. However, the complete normalization of the composition of the tight junction components, such as occludin and the association with F-actin, requires additional time, which may support the regeneration of fully polarized normal hepatocytes. 相似文献
2.
Immunoreaction of alpha-fetoprotein (AFP) was detected not only in well-differentiated hepatocellular carcinoma but also in hepatocytes forming foci in livers with hyperplastic nodules during 3'-methyl-4-dimethylaminoazobenzene hepatocarcinogenesis. The subcellular location of AFP in hepatoma cells was in the rough endoplasmic reticulum, perinuclear space and well-developed Golgi apparatus around the nucleus. In livers with hyperplastic nodules it was also in some parts of the smooth endoplasmic reticulum and Golgi regions in hepatocytes in the vicinity of submembranous areas or bile canaliculi. These findings suggest that the Golgi apparatus in hepatoma cells acts mainly as an organelle for glycosylation of AFP and that the Golgi complexes in the hepatocytes in livers with hyperplastic nodules are organelles for secretion of AFP. Combined light microscopic immunoperoxidase study and autoradiography with 3H-thymidine revealed a higher cumulative labeling index in AFP-positive hepatoma cells than in non-tumorous areas. Combined electron microscopic immunoperoxidase study and autoradiography showed that hepatoma cells with AFP immunoreactivity only in the rough endoplasmic reticulum had a significantly higher labeling index than did cells with AFP immunoreactivity in both rough endoplasmic reticulum and Golgi apparatus. These findings suggest that AFP is synthesized in hepatoma cells before or during the stage of their DNA synthesis and is then transported to the Golgi apparatus. 相似文献
3.
A S Gle?berman 《Biulleten' eksperimental'no? biologii i meditsiny》1978,85(5):626-630
An acetone-formol fixation technique with subsequent paraffin-embedding suitable for immunofluorescent study of different antigens, including serum proteins, is described. This technique was used for detection of albumin, transferrin, and alpha-fetoprotein distribution in the normal and regenerating liver of mice. Albumin and transferrin were always found together in the same hepatocytes, both under normal conditions and in regeneration. In the regenerating liver alpha-fetoprotein was encountered independently of the two other proteins, although it was revealed in the same zones. Only in the perinecrotic zone did each alpha-fetoprotein-positive hepatocyte contain albumin and transferrin. 相似文献
4.
Hepatocytes of mammalian liver are known to contain intermediate-sized filaments of tonofilament morphology. Unlike many other epithelial cells, including cultured hepatocytes and hepatoma cells, hepatocytes present in normal liver tissue have been reported not to react, in significant intensity, with various preparations of antibodies to human and bovine epidermal prekeratin [2,6]. We have therefore examined, by biochemical and immunological methods, the cytoskeletal composition of hepatocytes grown in the body.Cytoskeletal preparations from hepatocytes of mouse and rat liver tissue resistant to high salt buffer and Triton X-100 are enriched in tangles of intermediate filaments and contain, besides some residual microfilamentous actin, a characteristic set of polypeptides. One- and two-dimensional gel electrophoresis reveals the presence of two major cytokeratin components, which appear as ‘pairs’ of isoelectric variants (component A, Mr 55 000, apparent pI values, 6.40 and 6.45; component D, Mr 49000, apparent pI values 5.43 and 5.38), and five minor components (Mr range from 41000 to 53 000), most of them also as ‘pairs’ of polypeptides slightly different in isoelectric pH value. These polypeptide patterns are very similar in mouse and rat liver although some minor but significant differences have been noted between the two species. The polypeptide patterns of liver cytoskeletons are also similar to—but clearly not identical with—the cytoskeletal protein patterns observed in other epithelial tissues and cells, including various lines of cultured rat hepatocytes and hepatoma cells.Guinea pig antibodies raised against individual cytokeratin proteins of mouse liver and against certain prekeratin polypeptides present in desmosome-attached tonofilaments of bovine muzzle are described which differ from previously described prekeratin antibodies. These prekeratin antibodies not only react with filament bundles of the prekeratin type present in many cultured epithelial cells (e.g. murine HEL, human HeLa, rat kangaroo PtK2) and various epithelial tissues, but also allow the detection of the cytokeratin components present in parenchymal cells of liver and pancreas of various species, man included. Immunofluorescence microscopy on frozen sections of liver using these antibodies reveals a novel structure, i.e. a three-dimensional filament meshwork extending throughout the whole cytoplasm of the hepatocyte, with higher intensity of staining in pericanalicular regions.The results show that parenchymal cells of normal liver and pancreas contain filaments of the cytokeratin type that are related to but not identical with epidermal prekeratin. The hepatocyte filaments appear to be different from prekeratin-type filaments present in epidermis and several other epithelial cells, both in some antigenic determinants exposed and in polypeptide composition. Our findings support the concept of the existence of a family of intermediate filament proteins, cytokeratins, containing many different polypeptides that are expressed in different epithelial cells in certain characteristic subsets in a cell type-specific mode. 相似文献
5.
N. I. Kuprina V. N. Baranov A. K. Yazova T. D. Rudinskaya M. Escribano J. Cordier A. S. Gleiberman A. I. Goussev 《Histochemistry and cell biology》1990,94(2):179-186
Summary The AgB10 antigen of bile canaliculi of the mouse hepatocyte was identified using monoclonal antibodies. The Mr value of 116000 for AgB10 was measured by immunoblotting. The tissue localization of AgB10 was studied by light and electron
microscopy using the immunoperoxidase technique. AgB10 was predominantly present on the microvillus membrane of bile canaliculi,
the brush border of intestinal mucosa and apical surfaces of the epithelial cells in some other organs. A small amount of
AgB10 was detected on the basolateral domain of the hepatocytes. AgB10 was specific for hepatocytes and was not found in the
other cell types of the liver. In primary hepatocyte culture, AgB10 was localized on the surface of cells during the first
24 h, predominantly at the sites of cell-cell and cell-substratum contacts. After 48 h of culture AgB10 gradually disappeared
from contracting cell surfaces and became concentrated only in the reconstituted bile canaliculi. 相似文献
6.
N I Kuprina V N Baranov A K Yazova T D Rudinskaya M Escribano J Cordier A S Gleiberman A I Goussev 《Histochemistry》1990,94(2):179-186
The AgB10 antigen of bile canaliculi of the mouse hepatocyte was identified using monoclonal antibodies. The Mr value of 116000 for AgB10 was measured by immunoblotting. The tissue localization of AgB10 was studied by light and electron microscopy using the immunoperoxidase technique. AgB10 was predominantly present on the microvillus membrane of bile canaliculi, the brush border of intestinal mucosa and apical surfaces of the epithelial cells in some other organs. A small amount of AgB10 was detected on the basolateral domain of the hepatocytes. AgB10 was specific for hepatocytes and was not found in the other cell types of the liver. In primary hepatocyte culture, AgB10 was localized on the surface of cells during the first 24 h, predominantly at the sites of cell-cell and cell-substratum contacts. After 48 h of culture AgB10 gradually disappeared from contacting cell surfaces and became concentrated only in the reconstituted bile canaliculi. 相似文献
7.
The immunocytochemical localization of alpha-fetoprotein (AFP)-producing cells was observed in pre- and postnatal and carbon tetrachloride (CCl4)-treated rat livers in comparison with that of albumin (ALB)-producing cells. According to immunoblotting data, considerable numbers of AFP-positive hepatocytes were observed in the differentiating liver between prenatal day 19 and postnatal day 0 (6 h after birth). Analyses by serial section profiles of these cells revealed that certain AFP-positive hepatocytes are also stained with ALB antiserum. Immunoelectron microscopy of the AFP-producing cells revealed that immunoreactive gold particles are preferentially localized in rough endoplasmic cisternae, Golgi apparatus and Golgi-derived vesicles near the cell surface. In addition, the release of the content of the Golgi-derived vesicles into the differentiating bile canaliculi as well as into the space of Disse by exocytosis is apparent. In CCl4-treated rat liver, immunoreactions to AFP are localized exclusively in newly formed hepatocytes of the regenerative tissue. These AFP-positive cells have not established the hepatic cell cords, and the adjacent ones are conjugated to each other mainly by simple attachment devices as in the case of those in pre- and postnatal rat liver. 相似文献
8.
N V Engel'gardt V S Poltoranina M N Lazareva S D Perova A S Gle?berman 《Biulleten' eksperimental'no? biologii i meditsiny》1976,82(10):1251-1254
Typical mature hepatocytes constituting not over several per cent of the total amount of preserved hepatocytes served as the principal site of the alpha-fetoprotein (AFP) localization in the liver of mice regenerating after the CCl4 poisoning or partial hepatectomy. Morphologically they failed to differ from the principal mass of hepatocytes and retained an antigen of the bile capillaries on the surface. A change id to the dynamics of the AFP level in the animal serum. Apparently in regeneration of the mouse liver the principal AFP production was realized by mature hepatocytes. 相似文献
9.
Yun JP Liew CT Chew EC Yin XY Lai PB Fai YH Li HK Jin ML Ding MX Li MT Lin HL Lau WY 《Journal of cellular biochemistry》2004,91(6):1269-1279
We explored the feasibility of studying nuclear matrix protein (NMP) expressions of the hepatocytes in normal and cirrhotic rat livers with liver regeneration after partial hepatectomy. Sixteen Wistar healthy rats were studied with experimental liver regeneration and/or liver cirrhosis. Two-dimensional (2-D) gel electrophoresis was used to generate these NMP compositions from these rat liver samples. Several antibodies against cytokeratin, vimentin, actin, B23, HNF4alpha, and heat shock protein 70 were used for identification by Western blot. Totally, 41 strongly stained protein spots were characterized on the 2-D gels. Thirty-four protein spots were detected in all of these rat livers, of which, cytokeratin, vimentin, actin, HNF4alpha, and heat shock protein 70 were identified. B23 was detected in the regenerated livers. Three protein spots (s33, s34, and s35) were detectable only in NMP preparation extracted from the regenerating rat livers after hepatectomy. Another three protein spots (s36, s37, and s38) were detectable only in NMP preparation extracted from thioacetamide-induced cirrhotic rat livers. Under these conditions including experimental liver regeneration and/or liver cirrhosis, Over thirty higher abundance NMPs of hepatocytes were consistently expressed and considered as common and basic NMPs. Some of the NMPs are specific for liver regeneration and may play a critical role in cell proliferation and cell cycle, and some are specific for liver cirrhosis. 相似文献
10.
Intermediate-sized filaments of the prekeratin type in myoepithelial cells 总被引:38,自引:14,他引:24
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W W Franke E Schmid C Freudenstein B Appelhans M Osborn K Weber T W Keenan 《The Journal of cell biology》1980,84(3):633-654
Myoepithelial cells from mammary glands, the modified sweat glands of bovine muzzle, and salivary glands have been studied by electron microscopy and by immunofluorescence microscopy in frozen sections in an attempt to further characterize the type of intermediate-sized filaments present in these cells. Electron microscopy has shown that all myoepithelial cells contain extensive meshworks of intermediate-sized (7--11-nm) filaments, many of which are anchored at typical desmosomes or hemidesmosomes. The intermediate-sized filaments are also intimately associated with masses of contractile elements, identified as bundles of typical 5--6-nm microfilaments and with characteristically spaced dense bodies. This organization resembles that described for various smooth muscle cells. In immunofluorescence microscopy, using antibodies specific for the various classes of intermediate-sized filaments, the myoepithelial cells are strongly decorated by antibodies to prekeratin. They are not specifically stained by antibodies to vimentin, which stain mesenchymal cells, nor by antibodies to chick gizzard desmin, which decorate fibrils in smooth muscle Z bands and intercalated disks in skeletal and cardiac muscle of mammals. Myoepithelial cells are also strongly stained by antibodies to actin. The observations show (a) that the epithelial character, as indicated by the presence of intermediate-sized filaments of the prekeratin type, is maintained in the differentiated contractile myoepithelial cell, and (b) that desmin and desmin-containing filaments are not generally associated with musclelike cell specialization for contraction but are specific to myogenic differentiation. The data also suggest that in myoepithelial cells prekeratin filaments are arranged--and might function--in a manner similar to the desmin filaments in smooth muscle cells. 相似文献
11.
Ehab O. A. Hafiz Beyza Bulutoglu Soheir S. Mansy Yibin Chen Hoda Abu‐Taleb Somia A. M. Soliman Ali A. F. El‐Hindawi Martin L. Yarmush Basak E. Uygun 《Biotechnology and bioengineering》2021,118(1):17-29
Liver tissue engineering aims to create transplantable liver grafts that can serve as substitutes for donor's livers. One major challenge in creating a fully functional liver tissue has been to recreate the biliary drainage in an engineered liver construct through integration of bile canaliculi (BC) with the biliary ductular network that would enable the clearance of bile from the hepatocytes to the host duodenum. In this study, we show the formation of such a hepatic microtissue by coculturing rat primary hepatocytes with cholangiocytes and stromal cells. Our results indicate that within the spheroids, hepatocytes maintained viability and function for up to 7 days. Viable hepatocytes became polarized by forming BC with the presence of tight junctions. Morphologically, hepatocytes formed the core of the spheroids, while cholangiocytes resided at the periphery forming a monolayer microcysts and tubular structures extending outward. The spheroids were subsequently cultured in clusters to create a higher order ductular network resembling hepatic lobule. The cholangiocytes formed functional biliary ductular channels in between hepatic spheroids that were able to collect, transport, and secrete bile. Our results constitute the first step to recreate hepatic building blocks with biliary drainage for repopulating the whole liver scaffolds to be used as transplantable liver grafts. 相似文献
12.
The ultrastructure of hepatocytes, bile canaliculi, and hepatic sinusoids of the larval lamprey, Petromyzon marinus, was examined using thin-sectioned and freeze-fractured tissues. The liver is a "tubular gland" with hepatocytes arranged in a tubular fashion around large bile canaliculi. Hepatocytes are roughly conical in shape, with their tapered apices facing a bile canalicular lumen. They possess extensive rough and smooth endoplasmic reticulum, a well-developed Golgi complex, abundant mitochondria, and varying numbers of large secondary lysosomes. Both secondary lysosomes and the Golgi complex are concentrated in the apical or peribiliary cytoplasm, indicating a possible role in bile secretion. The apical surfaces of the hepatocytes bear numerous elongate microvilli and occasional cilia, which project into the bile canaliculi. The hepatocytes are joined, apically, by junctional complexes composed of zonulae occludentes and adhaerentes. In freeze-fracture, the zonulae occludentes are of variable apicobasal depth and consist of honeycomb-like meshworks of fibrils. Spaces of variable width frequently appear in the P-face grooves, indicating that the zonulae occludentes are "leaky." Numerous communicating (gap) junctions join the hepatocytes laterally. Varying numbers of lateral microvilli project into the intercellular spaces and, basally, the plasma membrane is deeply infolded, resulting in the formation of apparently interdigitating basal processes resting upon a thin basal lamina. Sinusoids are composed of both a heavily-fenestrated, continuous endothelium, and phagocytic reticulo-endothelial (Kupffer) cells. Depsite the difference in arrangement of their hepatocytes, the mammalian and lamprey livers show similar ultrastructural features. 相似文献
13.
Reorganization of arrays of prekeratin filaments during mitosis : Immunofluorescence microscopy with multiclonal and monoclonal prekeratin antibodies 总被引:24,自引:0,他引:24
Benjamin Horwitz Hana Kupfer Zelig Eshhar Benjamin Geiger 《Experimental cell research》1981,134(2):281-290
Indirect immunofluorescent labelling of different epithelial cell lines for intermediate filaments of the prekeratin type revealed prominent changes in the organization of prekeratin during mitosis. In three out of four cell lines tested (Henle-407, A-431 and HeLa cells) the filamentous prekeratin networks disappeared at the initiation of mitosis and the immunofluorescent labelling was concentrated in small cytoplasmic bodies. This observation was obtained with both polyspecific rabbit anti-bovine prekeratin antibodies and with monospecific antibodies produced by mouse hybridomas. In a fourth cell line, PtK2, prekeratin filaments were retained throughout mitosis, mainly in the mitotic poles, whereas the central areas of the cells were apparently devoid of filaments. The addition of colchicine to the different cultured cells induced alterations in the organization of prekeratin filaments which were usually manifested by the formation of thicker filament bundles. It did not induce the formation of the prekeratin-cytoplasmic bodies in interphase cells. However, upon prolonged incubation in the presence of colchicine, there was an increase in the number of mitotically arrested cells and a parallel increase in the number of cells containing prekeratin cytoplasmic bodies. It is thus proposed that the state of organization of prekeratin in these cells is cell-cycle-dependent and may be modulated to permit radical shape changes as those occurring during mitosis. 相似文献
14.
Bertone V Tarantola E Ferrigno A Gringeri E Barni S Vairetti M Freitas I 《European journal of histochemistry : EJH》2011,55(1):e5
Biliary complications often lead to acute and chronic liver injury after orthotopic liver transplantation (OLT). Bile composition and secretion depend on the integrated action of all the components of the biliary tree, starting from hepatocytes. Fatty livers are often discarded as grafts for OLT, since they are extremely vulnerable to conventional cold storage (CS). However, the insufficiency of donors has stimulated research to improve the usage of such marginal organs as well as grafts. Our group has recently developed a machine perfusion system at subnormothermic temperature (20°C; MP20) that allows a marked improvement in preservation of fatty and even of normal rat livers as compared with CS. We sought to evaluate the response of the biliary tree of fatty liver to MP20, and a suitable marker was essential to this purpose. Alkaline phosphatase (AlkP, EC 3.1.3.1), frequently used as marker of membrane transport in hepatocytes and bile ducts, was our first choice. Since no histochemical data were available on AlkP distribution and activity in fatty liver, we have first settled to investigate AlkP activity in the steatotic liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. The AlkP reaction in Wistar rats was in accordance with the existing data and, in particular, was present in bile canaliculi of hepatocytes in the periportal region and midzone, in the canals of Hering and in small bile ducts but not in large bile ducts. In lean ZR liver the AlkP reaction in Hering canals and small bile ducts was similar to Wistar rat liver but hepatocytes had lower canalicular activity and besides presented moderate basolateral reaction. The difference between lean Zucker and Wistar rats, both phenotypically normal animals, could be related to the fact that lean Zucker rats are genotypically heterozygous for a recessive mutated allele. In fatty liver, the activity in ductules and small bile ducts was unchanged, but most hepatocytes were devoid of AlkP activity with the exception of clusters of macrosteatotic hepatocytes in the mid-zone, where the reaction was intense in basolateral domains and in distorted canaliculi, a typical pattern of cholestasis. The interpretation of these data was hindered by the fact that the physiological role of AlkP is still under debate. In the present study, the various functions proposed for the role of the enzyme in bile canaliculi and in cholangiocytes are reviewed. Independently of the AlkP role, our data suggest that AlkP does not seem to be a reliable marker to study the initial step of bile production during OLT of fatty livers, but may still be used to investigate the behaviour of bile ductules and small bile ducts. 相似文献
15.
L Benkoel J Brisse C Capo A M Benoliel P Bongrand T Garcia A Chamlian 《Cellular and molecular biology, including cyto-enzymology》1992,38(4):377-383
Two different methods, fluorescent phallotoxins and immunohistochemical amplification systems were used to visualize actin in normal human hepatocytes. With fluorescent phallotoxins (NBD-phallacidin or rhodamine phalloidin), F-actin was distributed along the plasma membranes and at the bile canaliculi. With immunohistochemical methods (biotin-avidin, biotin-streptavidin, silver enhancement), actin was found at the same level, however a cytoplasmic staining was observed and discussed as G-actin localization. 相似文献
16.
Both Atp7b (Wilson disease gene) and Atp7a (Menkes disease gene) have been reported to be trafficked by copper. Atp7b is trafficked
to the bile duct canaliculi and Atp7a to the plasma membrane. Whether or not liver ischemia or ischemia–reperfusion modulates
Atp7b expression and trafficking has not been reported. In this study, we report for the first time that the multi-specific
metal transporter Atp7b is significantly induced and trafficked by both liver ischemia alone and liver ischemia–reperfusion,
as judged by immunohistochemistry and Western blot analyses. Although hepatocytes also stained for Atp7b, localized intense
staining of Atp7b was found on bile duct canaliculi. Inductive coupled plasma-mass spectrometry analysis of bile copper, iron,
zinc, and manganese found a corresponding significant increase in biliary iron. In our attempt to determine if the increased
biliary iron transport observed may be a result of altered bile flow, lysosomal trafficking, or glutathione biliary transport,
we measured bile flow, bile acid phosphatase activity, and glutathione content. No significant difference was found in bile
flow, bile acid phosphatase activity, and glutathione, between control livers and livers subjected to ischemia–reperfusion.
Thus, we conclude that liver ischemia and ischemia–reperfusion induction and trafficking Atp7b to the bile duct canaliculi
may contribute to preferential iron transport into bile. 相似文献
17.
Bile canalicular barrier function and expression of tight-junctional molecules in rat hepatocytes during common bile duct ligation 总被引:3,自引:0,他引:3
Takakuwa Y Kokai Y Sasaki K Chiba H Tobioka H Mori M Sawada N 《Cell and tissue research》2002,307(2):181-189
Tight junctions of hepatocytes form the intercellular barrier between the blood circulation and bile flow. We focused on early stages of common bile duct ligation to observe changes in tight junctions without the irreversible changes seen after lengthy ligation. Common bile ducts of 12-week-old male rats were ligated for 6 h because, at this time point, no histological changes were observed. Serum bilirubin and bile acid levels began to increase 3 h after ligation and were restored to the control level immediately after surgical removal of the ligation. To examine the barrier of hapatocytes, horseradish peroxidase was injected via the femoral vein, and bile was collected for the first 10 min. A four-fold elevation of the secretion and concentration was observed in the bile of ligated rats compared with that of control animals. We next examined lanthanum permeability by perfusion fixation of the liver. At 6 h after ligation, both dilation of the bile canaliculi and partial loss of microvilli were commonly observed. There were dense deposits of lanthanum in almost all bile canaliculi of ligated rats. In control animals, neither dilation of the bile canaliculi nor loss of microvilli was detected, and only 44% of bile canaliculi exhibited deposits. An apparent increase of occludin mRNA expression was detected in livers after 6 h ligation, whereas the expression of claudin-1, -2, and -3 was not influenced by ligation. These results indicate that regulation of occludin gene expression is different from that of claudin-1, -2, and -3. The early phase of bile stasis employed in this study is thought to be an indispensable approach for understanding the precise regulation of tight junctions. 相似文献
18.
T Sawada H Itai Y Fujikura H Kuniki M Tamechika T Fukumoto 《Experimental cell research》1992,199(1):50-55
The distribution of rat bile-canalicular surface antigen (HAM-4 antigen) and cytoskeletal elements (microtubules, actin filaments, and cytokeratin filaments) was examined during the reformation of bile-canalicular structures (BC-structures) in primary cultures of dissociated hepatocytes obtained following collagenase perfusion. HAM-4 antigen, which initially dispersed after cell dissociation, became focused into regions of cell-to-cell contact even before formation of BC-structures. Typical bile-canalicular microvilli also appeared in these regions before the intercellular spaces were completely closed. Finally, after in vitro reformation of BC, HAM-4 antigen was localized specifically at the BC-surface. The process of BC-reformation and the intracellular organization of actin and cytokeratin filaments were not significantly affected by microtubule inhibitors (nocodazole, colcemid, and colchicine). However, the localization of HAM-4 antigen molecules at the surface of BC was disrupted by these inhibitors, suggesting that the distribution of HAM-4 antigen, which represents a marker for the reconstruction of surface polarity, is dependent on microtubule function. 相似文献
19.
Summary Antibodies against intermediate-sized filaments, of the prekeratin or vimentin type, were used to investigate the presence of these filaments by indirect immunofluorescence microscopy in cultured and non-cultured amniotic fluid cells, in frozen sections of the placenta and in isolated cells of the amniotic epithelium. Two major classes of cells can be cultured from amniotic fluids, namely cells of epithelial origin containing filaments of the prekeratin type and cells of different origin which contain filaments of the vimentin type but are negative when tested with antibodies to epidermal prekeratin. The presence of prekeratin type filaments correlates with the morphology of colonies of amniotic fluid cell cultures in vitro as classified by Hoehn et al. (1974). Cells of E-type colonies are shown to be of epithelial origin. In contrast our data indicate a different origin of almost all cells of F-type colonies and of the large majority of cells of AF-type colonies. Cells of epithelial origin and positively stained with antibodies to epidermal prekeratin are occasionally scattered in F-type colonies and in variable percentages (up to 30%) in AF-type colonies. Surprisingly, cryostat sections of the amniotic epithelium and isolated groups of amniotic cells showed positive reactions with both antibodies to vimentin and prekeratin. The possibility that amniotic cells may be different from other epithelial cells in that they contain both types of filaments simultaneously already in situ is presently under investigation.Part of this work is included in the doctoral thesis of Irmgard Treiss to be submitted to the Faculty of Medicine of the University of Heidelberg 相似文献
20.
Neil C. Talbot Vernon G. Pursel Caird E. Rexroad Jr. Thomas J. Caperna Anne M. Powell Roger T. Stone 《In vitro cellular & developmental biology. Animal》1994,30(12):851-858
Summary The secondary culture of non-transformed parenchymal hepatocytes has not been possible. STO feeder cell-dependent secondary
cultures of fetal pig hepatocytes were established by colony isolation from primary cultures of 26-d fetal livers. The liver
cells had the typical polygonal morphology of parenchymal hepatocytes. They also spontaneously differentiated to form small
biliary canaliculi between individual cells or progressed further to large multicellular duct-like structures or cells undergoing
gross lipid accumulation and secretion. The secondary hepatocyte cultures expressed alpha-fetoprotein (AFP), albumin, and
β-fibrinogen mRNA, and conditioned medium from the cells contained elevated levels of transferrin and albumin. STO feeder
cell co-culture may be useful for the sustainable culture of hepatocytes from other species. 相似文献