scholarly journals Marker expression, behaviors, and responses vary in different lines of conditionally immortalized cultured podocytes

2011 ◽  
Vol 301 (3) ◽  
pp. F660-F671 ◽  
Author(s):  
Seetharamaiah Chittiprol ◽  
Phylip Chen ◽  
Danica Petrovic-Djergovic ◽  
Tad Eichler ◽  
Richard F. Ransom

The state-of-the-art cultured podocyte is conditionally immortalized by expression of a temperature-sensitive mutant of the SV40 large-T antigen. These cultures proliferate at 33°C and differentiate at 37°C into arborized cells that more closely resemble in vivo podocytes. However, the degree of resemblance remains controversial. In this study, several parameters were measured in podocyte cell lines derived from mouse (JR, KE), human (MS), and rat (HK). In all lines, the quantities of NEPH1 and podocin proteins and NEPH1 and SYNPO mRNAs were comparable to glomeruli, while synaptopodin and nephrin proteins and NPHS1 and NPHS2 mRNAs were <5% of glomerular levels. Expression of Wilms' tumor-1 (WT1) mRNA in mouse lines was comparable to glomeruli, but rat and human lines expressed little WT1. Undifferentiated human and mouse lines had similar proliferation rates that decreased after differentiation, while the rate in rat cells remained constant. The motility of different lines varied as measured by both general motility and wound-healing assays. The toxicity of puromycin aminonucleoside was MS ∼ JR >> KE, and of doxorubicin was JR ∼ KE > MS, while HK cells were almost unaffected. Process formation was largely a result of contractile action after formation of lamellipodia. These findings demonstrate dramatic differences in marker expression, response to toxins, and motility between lines of podocytes from different species and even between similarly-derived mouse lines.

1996 ◽  
Vol 109 (5) ◽  
pp. 899-909 ◽  
Author(s):  
B. Capel ◽  
J.R. Hawkins ◽  
E. Hirst ◽  
D. Kioussis ◽  
R. Lovell-Badge

Cell cultures from the urogenital ridge have been established to facilitate the study of the regulation and downstream interactions of Sry in mammalian sex determination. Cells have been explanted from transgenic mice carrying a temperature sensitive SV40 large T-antigen, and established in ongoing cultures. Analysis of the cells in these cultures at the electron microscope level reveals multiple cell types that compare to the cell types found in vivo during this period of development. Primordial germ cells, that are simultaneously explanted in the course of these experiments, also survive in culture. The explants undergo a morphogenetic organization into branching cord-like structures when cells are trypsinized and plated in extracellular matrix (Matrigel). We analyzed the expression of a number of molecular markers of the fetal gonad during monolayer culture, during in vitro morphogenesis in Matrigel, and in clonal lines derived from the complex explants. This analysis included Sry which is found to be expressed in some cultures from XY urogenital ridges that have been maintained for as long as 8 months.


2010 ◽  
Vol 298 (3) ◽  
pp. F557-F567 ◽  
Author(s):  
Toru Sakairi ◽  
Yoshifusa Abe ◽  
Hiroshi Kajiyama ◽  
Linda D. Bartlett ◽  
Lilian V. Howard ◽  
...  

Evidence suggests that loss of podocytes into urine contributes to development of glomerular diseases; shed podocytes are frequently viable and proliferate in culture conditions. To determine the phenotypic characteristics of viable urinary cells derived from human subjects, we established long-term urinary cell culture from two patients with focal segmental glomerulosclerosis and two healthy volunteers, via transformation with the thermosensitive SV40 large T antigen (U19tsA58) together with human telomerase (hTERT). Characterization of arbitrarily selected two clonal cell lines from each human subject was carried out. mRNA expression for the podocyte markers synaptopodin, nestin, and CD2AP were detected in all eight clones. Podocin mRNA was absent from all eight clones. The expression of nephrin, Wilms' tumor 1 (WT1), and podocalyxin mRNA varied among the clones, which may be due to transformation and/or cloning. These results suggest that podocyte cell lines can be established consistently from human urine. The generation of podocyte cell lines from urine of patients and healthy volunteers is novel and will help to advance studies of podocyte cell biology. Further improvements in the approaches to cell transformation and/or cell culture techniques are needed to allow cultured podocytes to fully reproduce in vivo characteristics.


2010 ◽  
Vol 299 (4) ◽  
pp. F802-F809 ◽  
Author(s):  
Toru Sakairi ◽  
Yoshifusa Abe ◽  
Parmijit S. Jat ◽  
Jeffrey B. Kopp

We transformed mouse podocytes by ectopic expression of cyclin-dependent kinase 4 (CDK4). Compared with podocytes transformed with a thermo-sensitive SV40 large T antigen mutant tsA58U19 (tsT podocytes), podocytes transformed with CDK4 (CDK4 podocytes) exhibited significantly higher expression of nephrin mRNA. Synaptopodin mRNA expression was significantly lower in CDK4 podocytes and in tsT podocytes under growth-permissive conditions (33°C) compared with tsT podocytes under growth-restricted conditions (37°C), which suggests a role for cell cycle arrest in synaptopodin mRNA expression. Confluent CDK4 podocytes showed significantly higher mRNA expression levels for nephrin, synaptopodin, Wilms tumor 1, podocalyxin, and P-cadherin compared with subconfluent cultures. We carried out experiments to clarify roles of various factors in the confluent podocyte cultures; our findings indicate that cell-cell contact promotes expression of five podocyte marker genes studied, that cellular quiescence increases synaptopodin and podocalyxin mRNA expression, and that soluble factors play a role in nephrin mRNA expression. Our findings suggest that CDK4 podocytes are useful tools to study podocyte biology. Furthermore, the role of cell-cell contact in podocyte gene expression may have relevance for podocyte function in vivo.


1999 ◽  
Vol 44 (10) ◽  
pp. 823-834 ◽  
Author(s):  
M.H. Parkar ◽  
L. Kuru ◽  
M. O’Hare ◽  
H.N. Newman ◽  
F. Hughes ◽  
...  

2011 ◽  
Vol 301 (4) ◽  
pp. F784-F792 ◽  
Author(s):  
Xuan Bu ◽  
Yang Zhou ◽  
Hua Zhang ◽  
Wenjing Qiu ◽  
Lu Chen ◽  
...  

Podocyte injury is considered to play important roles in the pathogenesis of human glomerular disease. There is accumulating evidence suggesting that hepatocyte growth factor (HGF) elicits preventive activity for glomerular cells in animal models of chronic renal diseases. In this study, we demonstrated that delivery of a naked plasmid vector encoding the human HGF gene into mice by a hydrodynamic-based in vivo gene transfection approach markedly reduced proteinuria and attenuated podocyte injury in a mouse model induced by puromycin aminonucleoside (PAN) injection. Systemic administration by rapid injection via the tail vein of a naked plasmid containing HGF cDNA driven under a cytomegalovirus promoter (pCMV-HGF) produced a remarkable level of human HGF protein in the circulation. Tissue distribution studies suggested that the kidney expressed a high level of the HGF transgene. Meanwhile, compared with tubules and interstitium, a higher level of exogenous HGF protein was detected in the glomeruli. Administration of pCMV-HGF dramatically abated the urine albumin excretion and podocyte injury in PAN nephropathy in mice. Exogenous expression of HGF produced evidently beneficial effects, leading to restoration of Wilms' tumor-1 (WT1) and α-actinin-4 expression and attenuation of ultrastructural damage of the podocytes. In vitro, HGF not only restored WT1 and α-actinin-4 expression but also inhibited albumin leakage of podocytes incubated with PAN in a Transwell culture chamber. These results suggest that HGF might provide a novel strategy for amelioration of podocyte injury.


1997 ◽  
Vol 6 (3) ◽  
pp. 231-238 ◽  
Author(s):  
M.E. Truckenmiller ◽  
Ora Dillon-Carter ◽  
Carlo Tornatore ◽  
Henrietta Kulaga ◽  
Hidetoshi Takashima ◽  
...  

In vitro growth properties of three CNS-derived cell lines were compared under a variety of culture conditions. The M213-20 and J30a cell lines were each derived from embryonic CNS culture with the temperature-sensitive (ts) allele of SV40 large T antigen, tsA58, while the A7 cell line was immortalized using wild-type SV40 large T antigen. Cells immortalized with tsA58 SV40 large T proliferate at the permissive temperature, 33° C, while growth is expected to be suppressed at the nonpermissive temperature, 39.5°C. Both the M213-20 and J30a cell lines were capable of proliferating at 39.5°C continuously for up to 6 mo. All three cell lines showed no appreciable differences in growth rates related to temperature over a 7-day period in either serum-containing or defined serum-free media. The percentage of cells in S-phase of the cell cycle did not decrease or was elevated at 39.5°C for all three cell lines. After 3 wk at 39.5°C, the three cell lines also showed positive immunostaining using two monoclonal antibodies reacting with different epitopes of SV40 large T antigen. Double strand DNA sequence analyses of a 300 base pair (bp) fragment of the large T gene from each cell line, which included the ts locus, revealed mutations in both the J30a and M213-20 cell lines. The J30a cell line ts mutation had reverted to wild type, and two additional loci with bp substitutions with predicted amino acid changes were also found. While the ts mutation of the M213-20 cells was retained, an additional bp substitution with a predicted amino acid change was found. The A7 cell line sequence was identical to the reference wild-type sequence. These findings suggest that (a) nucleic acid sequences in the temperature-sensitive region of the tsA58 allele of SV40 large T are not necessarily stable, and (b) temperature sensitivity of cell lines immortalized with tsA58 is not necessarily retained.


1996 ◽  
Vol 74 (5) ◽  
pp. 623-632 ◽  
Author(s):  
Margarida O. Krause

This review represents a synthesis of the work of the author and her collaborators through 40 years of research aimed at an understanding of chromatin composition and functional arrangement. It describes the progressive experimental stages, starting with autoradiography and protein analysis and continuing on to a more functional approach testing the template properties of intact nuclei, as well as nuclei depleted of, or reconstituted with, defined fractions extracted from the chromatin of other cell lines or tissues. As new questions were raised at each phase of these studies, the investigation was shifted from chromosomal proteins to the role of a small RNA that coextracted with one protein fraction and whose properties suggested a transcription-activating function. The active RNA was identified as a class in RNA, designated as 7 SK. Its properties suggested a role in the activation of two oncogenes, the SV 40 T-antigen and the mammalian c-myc gene. A detailed analysis of the c-myc gene expression during transformation induction in temperature-sensitive mammalian cells finally culminated in in vivo evidence for a role of 7 SK in c-myc deregulation, using cells transfected with antisense oligonucleotides to block 7 SK activity. This was followed by an investigation of promoter targeting by 7 SK RNP using electrophoretic mobility shift assays with whole or 7 SK-depleted cell extracts. Taken together, these studies indicate that 7 SK RNP participates in transformation-dependent deregulation of the c-myc gene by activation of two c-myc minor promoters. The implications of these findings are discussed.Key words: chromatin structure, histones, nonhistones, 7 SK RNA, the c-myc gene, transcription regulation, SV 40, transformation.


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