Functional properties of proximal tubule cell lines derived from transgenic mice harboring L-pyruvate kinase-SV40 (T) antigen hybrid gene.
This study describes the functional characterization of two cell lines derived from the proximal convoluted (PKSV-PCT cells) and proximal straight (PKSV-PR) tubules microdissected out from kidneys of transgenic mice harboring the simian virus 40 (SV40) large T and small t antigens placed under the control of the rat L-type pyruvate kinase (L-PK) 5' regulatory sequence. Both cell lines exhibited cellular cyclic AMP stimulated by parathormone (PTH) and calcitonin (CT) and a sodium-dependent glucose transporter. Uptake of the fluid-phase marker [3H]inulin showed that both cell lines grown on filters exhibited biphasic apical and basolateral endocytic rates. Results from Northern blot analysis indicate that the expression of the T antigen gene (Tag) is dependent on the concentration of D-glucose in the medium and show that the L-PK construct has maintained its capacity for up- or down-regulation by carbohydrates. Replacement of D-glucose by neoglucogenic substrates (lactate, oxaloacetate) blunted the expression of Tag transcripts and induced arrest of cell growth. Compared to cell grown in D-glucose-enriched medium, the hormonal sensitivities to PTH and CT and the sodium-dependent glucose uptake were unchanged whereas quiescent cells exhibited increased hydrolase content. Thus the proximal function has been preserved in these cultured cells derived from tissue-specific targeted oncogenesis in transgenic mice. As the expression of Tag transcripts is controlled by D-glucose, the structural and physiological characteristics of these cell lines can be studied in either quiescent or active growth conditions.
Laboratoire Hospitalo-Universitaire d'Histologie et de Biologie Tumorale, Hôpital Tenon, Paris, France.
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Lacave
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Bens
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Cartier
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Vallet
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Robine
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Pringault
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Kahn
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Vandewalle
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D002116:Calcitonin / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010281:Parathyroid Hormone / Q000494:pharmacology; D010641:Phenotype; D011770:Pyruvate Kinase / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid
D000952:Antigens, Polyomavirus Transforming; D003470:Culture Media; D009004:Monosaccharide Transport Proteins; D010281:Parathyroid Hormone; D012333:RNA, Messenger; D002116:Calcitonin; D000242:Cyclic AMP; D011770:Pyruvate Kinase; D005947:Glucose