Expression of glycosphingolipids in serum-free primary cultures of mouse kidney cells: male-female differences and androgen sensitivity

1994 ◽  
Vol 137 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Sonja K. Gross ◽  
Timothy A. Lyerla ◽  
James E. Evans ◽  
Robert H. McCluer
1992 ◽  
Vol 70 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Timothy M. Rose ◽  
Sandra Tremblay ◽  
Edward W. Khandjian

The pattern of [35S]methionine-labeled proteins from primary cultures of mouse kidney epithelial cells arrested in G0 phase was analyzed by two-dimensional gel electrophoresis and compared with that observed from cultures of actively proliferating and SV40-transformed mouse kidney cells. A major polypeptide (p65) migrating with a molecular mass of 65 000 daltons and a pI of 5.8 was detected in quiescent cultures of cells which had exhausted their finite division potential. Under the experimental conditions used, these cells had lost sensitivity to growth factors and were irreversibly blocked in G0 phase of the cell cycle. In cultures of actively proliferating mouse kidney cells, the expression of p65 was not observed until just prior to arrest. Moreover, proliferating cultures of immortalized mouse kidney cells that had been reactivated from their quiescent state by infection with SV40 did not express p65. Subcellular localization studies suggest that p65 is associated with the crude nuclear fraction. In addition, p65 is glycosylated and binds the lectin concanavalin A. Pulse–chase experiments demonstrated that p65 was short lived with an estimated half life of 10 min. Thus, p65 appears to be a growth-arrest specific gene product whose expression is repressed during the proliferative state of mitotically active mouse kidney cells.Key words: G0 phase, senescence, proliferation, quiescence, SV40-transformed mouse cells.


2009 ◽  
Vol 2 (6) ◽  
pp. 517-524 ◽  
Author(s):  
Adel B. Korkor ◽  
Richard W. Gray ◽  
Helen L. Henry ◽  
Jack G. Kleinman ◽  
Samuel S. Blumenthal ◽  
...  

1997 ◽  
Vol 273 (3) ◽  
pp. C843-C851 ◽  
Author(s):  
H. A. Franch ◽  
P. V. Curtis ◽  
W. E. Mitch

The combination of epidermal growth factor (EGF) plus transforming growth factor-beta 1 (TGF-beta 1) causes hypertrophy in renal epithelial cells. One mechanism contributing to hypertrophy is that EGF induces activation of the cell cycle and increases protein synthesis, whereas TGF-beta 1 prevents cell division, thereby converting hyperplasia to hypertrophy. To assess whether suppression of proteolysis is another mechanism causing hypertrophy induced by these growth factors, we measured protein degradation in primary cultures of proximal tubule cells and in cultured NRK-52E kidney cells. A concentration of 10(-8) M EGF alone or EGF plus 10(-10) M TGF-beta 1 decreased proteolysis by approximately 30%. TGF-beta 1 alone did not change protein degradation. Using inhibitors, we examined which proteolytic pathway is suppressed. Neither proteasome nor calpain inhibitors prevented the antiproteolytic response to EGF + TGF-beta 1. Inhibitors of lysosomal proteases eliminated the antiproteolytic response to EGF + TGF-beta 1, suggesting that these growth factors act to suppress lysosomal proteolysis. This antiproteolytic response was not caused by impaired EGF receptor signaling, since lysosomal inhibitors did not block EGF-induced protein synthesis. We conclude that suppression of lysosomal proteolysis contributes to growth factor-mediated hypertrophy of cultured kidney cells.


1991 ◽  
Vol 125 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Bertil G. Casslén ◽  
Michael J. K. Harper

Abstract. The aim of the study was to explore the possibility of using human endometrial epithelial cells in serum-free culture as a sensitive assay for hormonal effects on the human endometrium. Glands were isolated following enzymatic digestion of the endometrial tissue and plated on a collagen matrix. The epithelial cells were grown in either medium containing serum or in supplemented serum-free medium. No morphologic difference was found between cells grown in these two media for up to 5 days, using either light or scanning electron microscopy. Secretion of prostaglandin F2α (PGF2α) in response to estradiol was not lower in serum-free medium than in medium containing serum for the first 2 days of culture, whereas secretion declined after prolonged incubation in the serum-free medium. This response to estradiol was clearly dose-dependent, and it was further enhanced by addition of arachidonic acid, the precursor for prostaglandin synthesis, to the medium. Co-culture of endometrial stromal cells did not influence the secretion of PGF2α by epithelial cells. We conclude that the secretion of PGF2α from primary cultures of human endometrial epithelial cells grown on collagen in serum-free medium can be used for a limited period as an assay of estrogenic effects on the human endometrium.


Intervirology ◽  
1976 ◽  
Vol 7 (4-5) ◽  
pp. 201-210 ◽  
Author(s):  
Bertram Flehmig ◽  
Angelika Vallbracht ◽  
Hans-Joachim Gerth

2004 ◽  
Vol 15 (11) ◽  
pp. 5172-5186 ◽  
Author(s):  
Moe R. Mahjoub ◽  
M. Qasim Rasi ◽  
Lynne M. Quarmby

Polycystic kidney disease and related syndromes involve dysregulation of cell proliferation in conjunction with ciliary defects. The relationship between cilia and cell cycle is enigmatic, but it may involve regulation by the NIMA-family of kinases (Neks). We previously showed that the Nek Fa2p is important for ciliary function and cell cycle in Chlamydomonas. We now show that Fa2p localizes to an important regulatory site at the proximal end of cilia in both Chlamydomonas and a mouse kidney cell line. Fa2p also is associated with the proximal end of centrioles. Its localization is dynamic during the cell cycle, following a similar pattern in both cell types. The cell cycle function of Fa2p is kinase independent, whereas its ciliary function is kinase dependent. Mice with mutations in Nek1 or Nek8 have cystic kidneys; therefore, our discovery that a member of this phylogenetic group of Nek proteins is localized to the same sites in Chlamydomonas and kidney epithelial cells suggests that Neks play conserved roles in the coordination of cilia and cell cycle progression.


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