The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Calvin U Cotton - One of the best experts on this subject based on the ideXlab platform.
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morphological and functional characterization of a conditionally immortalized Collecting Tubule Cell line
American Journal of Physiology-renal Physiology, 1998Co-Authors: Marcia Takacsjarrett, William E Sweeney, Ellis D Avner, Calvin U CottonAbstract:A conditionally immortalized Collecting Tubule Cell line, mCT1, was derived from the H-2Kb-ts A58 transgenic mouse (ImmortoMouse), which harbors a temperature-sensitive mutant of the SV40 large T antigen oncogene. Cells maintained under permissive conditions [33°C with interferon-γ (IFN-γ)] form epithelial monolayers, express large T antigen, and proliferate (>50 passages). The Cells retain properties characteristic of the renal Collecting Tubule (CT) including: vasopressin (VP)-stimulated cAMP accumulation, aquaporin-2 expression, high transepithelial electrical resistance, VP-stimulated ion transport, and amiloride-sensitive sodium absorption. When the Cells are transferred to nonpermissive conditions (39°C without IFN-γ), the steady-state level of large T antigen protein declines (>95% decrease) and Cell proliferation is arrested. This conditionally immortalized, murine renal Cell line should prove useful for studies of CT physiology and large T antigen biology.
R Cassingena - One of the best experts on this subject based on the ideXlab platform.
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activation of the simian virus 40 sv40 genome abrogates sensitivity to avp in a rabbit Collecting Tubule Cell line by repressing membrane expression of avp receptors
Journal of Cell Biology, 1991Co-Authors: Dominique Prie, P Ronco, B Baudouin, M Geniteaulegendre, M Antoine, Remi Piedagnel, S Estrade, B Lelongt, P Verroust, R CassingenaAbstract:To analyze the role of SV40 genome in the phenotypic alterations previously observed in SV40-transformed Cell lines, we infected rabbit renal cortical Cells with a temperature-sensitive SV40 mutant strain (tsA58) and compared the Cell phenotypes at temperatures permissive (33 degrees C) and restrictive (39.5 degrees C) for SV40 genome expression. At both temperatures, the resulting Cell line (RC.SVtsA58) expresses cytokeratin and uvomorulin, but epithelial differentiation is more elaborate at 39.5 degrees C as shown by the formation of a well-organized cuboidal monolayer with numerous tight junctions and desmosomes. Functional characteristics are also markedly influenced by the culture temperature: Cells grown at 33 degrees C respond only to isoproterenol (ISO, 10(-6) M) by a sevenfold increase in cAMP Cell content above basal values; in contrast, when transferred to 39.5 degrees C, they exhibit increased sensitivity to ISO (ISO/basal: 19.1) and a dramatic response to 10(-7) M dDarginine vasopressin (dDAVP/basal: 18.2, apparent Ka: 5 X 10(-9) M) which peaks 48 h after the temperature shift. The latter is associated with membrane expression of V2-type AVP receptors (approximately 50 fmol/10(6) Cells) which are undetectable when SV40 genome is activated (33 degrees C). Clonal analysis, additivity studies, and desensitization experiments argue for the presence of a single Cell type responsive to both AVP and ISO. The characteristics of the RC. SVtsA58 Cell line at 39.5 degrees C (effector-stimulated cAMP profile, lack of expression of brush-border hydrolases and Tamm-Horsfall protein) suggest that it originates from the cortical Collecting Tubule, and probably from principal Cells.
Marcia Takacsjarrett - One of the best experts on this subject based on the ideXlab platform.
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morphological and functional characterization of a conditionally immortalized Collecting Tubule Cell line
American Journal of Physiology-renal Physiology, 1998Co-Authors: Marcia Takacsjarrett, William E Sweeney, Ellis D Avner, Calvin U CottonAbstract:A conditionally immortalized Collecting Tubule Cell line, mCT1, was derived from the H-2Kb-ts A58 transgenic mouse (ImmortoMouse), which harbors a temperature-sensitive mutant of the SV40 large T antigen oncogene. Cells maintained under permissive conditions [33°C with interferon-γ (IFN-γ)] form epithelial monolayers, express large T antigen, and proliferate (>50 passages). The Cells retain properties characteristic of the renal Collecting Tubule (CT) including: vasopressin (VP)-stimulated cAMP accumulation, aquaporin-2 expression, high transepithelial electrical resistance, VP-stimulated ion transport, and amiloride-sensitive sodium absorption. When the Cells are transferred to nonpermissive conditions (39°C without IFN-γ), the steady-state level of large T antigen protein declines (>95% decrease) and Cell proliferation is arrested. This conditionally immortalized, murine renal Cell line should prove useful for studies of CT physiology and large T antigen biology.
William E Sweeney - One of the best experts on this subject based on the ideXlab platform.
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EGF-related growth factors in the pathogenesis of murine ARPKD
Kidney International, 2004Co-Authors: Katherine Macrae Dell, William E Sweeney, Raghad Nemo, Ellis D AvnerAbstract:EGF-related growth factors in the pathogenesis of murine ARPKD. Background Epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and their receptor, EGFR, play key roles in polycystic kidney disease (PKD) pathogenesis. Renal expression of two related growth factors, amphiregulin and heparin-binding EGF, has not been examined previously in PKD. The aims of this study of murine autosomal-recessive polycystic kidney disease (ARPKD) were ( 1 ) to characterize amphiregulin and heparin-binding EGF expression in cystic versus normal kidneys and Cells; and ( 2 ) to identify the functional effects of abnormal EGF-related growth factor expression. Methods Amphiregulin and heparin-binding-EGF expression were examined by immunohistology and Western blot of kidneys and conditionally-immortalized Collecting Tubule Cells obtained from cystic bpk mice (a murine model of ARPKD) and normal littermates. EGF, TGF-α, amphiregulin, and heparin-binding EGF in vitro effects on cystic and control Collecting Tubule Cells were assessed by Cell proliferation, cyst fluid mitogenicity, and EGFR activation. Results By immunohistology, amphiregulin and heparin-binding EGF localized to apical and basolateral surfaces of proximal Tubule cysts > normal proximal Tubules. In cystic Collecting Tubules, heparin-binding EGF (but not amphiregulin) localized to both apical and basolateral surfaces; whereas in normal Collecting Tubules, amphiregulin and heparin-binding EGF localized to the basolateral surface only. Increased amphiregulin and heparin-binding EGF expression by Western blot was seen in cystic vs. normal kidneys and increased heparin-binding EGF (but not amphiregulin) expression was present in cystic Collecting Tubule Cell lines vs. controls. EGF, TGF-α, amphiregulin, and heparin-binding EGF were all mitogenic to cystic > control Collecting Tubule Cells. Immunoprecipitation of EGF and TGF-α reduced cyst fluid mitogenicity by almost 80%, whereas heparin-binding EGF and amphiregulin immunoprecipitations had minimal effects. Differential receptor activation was also seen: Heparin-binding EGF markedly activated EGFR (>EGF = TGF-α > amphiregulin), with a greater effect seen in cystic vs. control Collecting Tubule Cells. Conclusion Multiple EGF-related growth factors are abnormally expressed in murine ARPKD and may have differential roles in disease pathogenesis. In particular, newly identified abnormalities in heparin-binding EGF expression in cystic kidneys and Cells may have important implications for disease pathogenesis.
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morphological and functional characterization of a conditionally immortalized Collecting Tubule Cell line
American Journal of Physiology-renal Physiology, 1998Co-Authors: Marcia Takacsjarrett, William E Sweeney, Ellis D Avner, Calvin U CottonAbstract:A conditionally immortalized Collecting Tubule Cell line, mCT1, was derived from the H-2Kb-ts A58 transgenic mouse (ImmortoMouse), which harbors a temperature-sensitive mutant of the SV40 large T antigen oncogene. Cells maintained under permissive conditions [33°C with interferon-γ (IFN-γ)] form epithelial monolayers, express large T antigen, and proliferate (>50 passages). The Cells retain properties characteristic of the renal Collecting Tubule (CT) including: vasopressin (VP)-stimulated cAMP accumulation, aquaporin-2 expression, high transepithelial electrical resistance, VP-stimulated ion transport, and amiloride-sensitive sodium absorption. When the Cells are transferred to nonpermissive conditions (39°C without IFN-γ), the steady-state level of large T antigen protein declines (>95% decrease) and Cell proliferation is arrested. This conditionally immortalized, murine renal Cell line should prove useful for studies of CT physiology and large T antigen biology.
Dominique Prie - One of the best experts on this subject based on the ideXlab platform.
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activation of the simian virus 40 sv40 genome abrogates sensitivity to avp in a rabbit Collecting Tubule Cell line by repressing membrane expression of avp receptors
Journal of Cell Biology, 1991Co-Authors: Dominique Prie, P Ronco, B Baudouin, M Geniteaulegendre, M Antoine, Remi Piedagnel, S Estrade, B Lelongt, P Verroust, R CassingenaAbstract:To analyze the role of SV40 genome in the phenotypic alterations previously observed in SV40-transformed Cell lines, we infected rabbit renal cortical Cells with a temperature-sensitive SV40 mutant strain (tsA58) and compared the Cell phenotypes at temperatures permissive (33 degrees C) and restrictive (39.5 degrees C) for SV40 genome expression. At both temperatures, the resulting Cell line (RC.SVtsA58) expresses cytokeratin and uvomorulin, but epithelial differentiation is more elaborate at 39.5 degrees C as shown by the formation of a well-organized cuboidal monolayer with numerous tight junctions and desmosomes. Functional characteristics are also markedly influenced by the culture temperature: Cells grown at 33 degrees C respond only to isoproterenol (ISO, 10(-6) M) by a sevenfold increase in cAMP Cell content above basal values; in contrast, when transferred to 39.5 degrees C, they exhibit increased sensitivity to ISO (ISO/basal: 19.1) and a dramatic response to 10(-7) M dDarginine vasopressin (dDAVP/basal: 18.2, apparent Ka: 5 X 10(-9) M) which peaks 48 h after the temperature shift. The latter is associated with membrane expression of V2-type AVP receptors (approximately 50 fmol/10(6) Cells) which are undetectable when SV40 genome is activated (33 degrees C). Clonal analysis, additivity studies, and desensitization experiments argue for the presence of a single Cell type responsive to both AVP and ISO. The characteristics of the RC. SVtsA58 Cell line at 39.5 degrees C (effector-stimulated cAMP profile, lack of expression of brush-border hydrolases and Tamm-Horsfall protein) suggest that it originates from the cortical Collecting Tubule, and probably from principal Cells.