Limits...
The PPARδ ligand GW501516 reduces growth but not apoptosis in mouse inner medullary collecting duct cells.

Clark J, Nasrallah R, Hébert RL - PPAR Res (2009)

Bottom Line: The collecting duct (CD) expresses considerable amounts of PPARδ.High doses of GW501516 decreased both DNA and protein synthesis in these cells by 80%, but had no overall effect on cell viability.Although anisomycin treatment resulted in an increase of caspase-3 levels of about 2.59-fold of control, GW501516 did not affect anisomycin-induced changes in active caspase-3 levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Cellular and Molecular Medicine, Kidney Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5.

ABSTRACT
The collecting duct (CD) expresses considerable amounts of PPARδ. While its role is unknown in the CD, in other renal cells it has been shown to regulate both growth and apoptosis. We thus hypothesized that PPARδ reduces apoptotic responses and stimulates cell growth in the mouse CD, and examined the effect of GW501516, a synthetic PPARδ ligand, on these responses in mouse IMCD-K2 cells. High doses of GW501516 decreased both DNA and protein synthesis in these cells by 80%, but had no overall effect on cell viability. Although anisomycin treatment resulted in an increase of caspase-3 levels of about 2.59-fold of control, GW501516 did not affect anisomycin-induced changes in active caspase-3 levels. These results show that a PPARδ ligand inhibits growth but does not affect anisomycin-apoptosis in a mouse IMCD cell line. This could have therapeutic implications for renal diseases associated with increased CD growth responses.

No MeSH data available.


Related in: MedlinePlus

PGE2 increases PPARδ protein expression. Protein was isolated from IMCD-K2cells that had been treated with serum-free media (control, C), 10−5 M indomethacin (Indo, I), or 10−6 M PGE2 in the presence of I (PI) 2, 8, and 24 hours. The proteins were (a) run on an SDS-PAGE gel and Westernblotted using an anti-PPARδ antibody (1 : 500). A representative blot of 24-hourtreatment is shown. The membranes were stripped and β-actin was detected tonormalize samples for (b)densitometric analysis. Expression is presented as fold of control. Values aremeans  ±  S.E.M.; n = 3–6. *P < .05 compared to control; §P < .05 compared to indomethacin.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2651001&req=5

fig3: PGE2 increases PPARδ protein expression. Protein was isolated from IMCD-K2cells that had been treated with serum-free media (control, C), 10−5 M indomethacin (Indo, I), or 10−6 M PGE2 in the presence of I (PI) 2, 8, and 24 hours. The proteins were (a) run on an SDS-PAGE gel and Westernblotted using an anti-PPARδ antibody (1 : 500). A representative blot of 24-hourtreatment is shown. The membranes were stripped and β-actin was detected tonormalize samples for (b)densitometric analysis. Expression is presented as fold of control. Values aremeans ± S.E.M.; n = 3–6. *P < .05 compared to control; §P < .05 compared to indomethacin.

Mentions: Since PGE2 has been known to activate PPARδ to regulate several growth processes [7, 14],it was ascertained thatif PGE2 stimulation could affect PPARδ expression in IMCD-K2 cells. Indomethacin, aCOX inhibitor, was used to inhibit endogenous PG synthesis. As shown in Figures 3(a)and 3(b), treatment with PGE2, in the presence ofindomethacin, for 8 hours resulted in a significant increase, of ∼2-fold, inPPARδ protein expression compared to control orindomethacin alone, as measured by Western Blotting. Stimulation for 24 hours also resulted inincreased PPARδ protein expression, but this increase was notsignificant when compared with indomethacin alone. A representative blot for 24hours is shown in Figure 3(a). However, two-hour stimulation did notalter the protein levels of PPARδ. We also examined the effect of PGE2 on PPARδ mRNA expression by real-time PCR. As shown in Figure 4, PPARδ mRNA remained unchanged with any treatmentgroup or exposure time. Forskolin had no effect on expression either (data notshown) indicating that cAMP does not alter PPARδ protein or RNA expression.


The PPARδ ligand GW501516 reduces growth but not apoptosis in mouse inner medullary collecting duct cells.

Clark J, Nasrallah R, Hébert RL - PPAR Res (2009)

PGE2 increases PPARδ protein expression. Protein was isolated from IMCD-K2cells that had been treated with serum-free media (control, C), 10−5 M indomethacin (Indo, I), or 10−6 M PGE2 in the presence of I (PI) 2, 8, and 24 hours. The proteins were (a) run on an SDS-PAGE gel and Westernblotted using an anti-PPARδ antibody (1 : 500). A representative blot of 24-hourtreatment is shown. The membranes were stripped and β-actin was detected tonormalize samples for (b)densitometric analysis. Expression is presented as fold of control. Values aremeans  ±  S.E.M.; n = 3–6. *P < .05 compared to control; §P < .05 compared to indomethacin.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2651001&req=5

fig3: PGE2 increases PPARδ protein expression. Protein was isolated from IMCD-K2cells that had been treated with serum-free media (control, C), 10−5 M indomethacin (Indo, I), or 10−6 M PGE2 in the presence of I (PI) 2, 8, and 24 hours. The proteins were (a) run on an SDS-PAGE gel and Westernblotted using an anti-PPARδ antibody (1 : 500). A representative blot of 24-hourtreatment is shown. The membranes were stripped and β-actin was detected tonormalize samples for (b)densitometric analysis. Expression is presented as fold of control. Values aremeans ± S.E.M.; n = 3–6. *P < .05 compared to control; §P < .05 compared to indomethacin.
Mentions: Since PGE2 has been known to activate PPARδ to regulate several growth processes [7, 14],it was ascertained thatif PGE2 stimulation could affect PPARδ expression in IMCD-K2 cells. Indomethacin, aCOX inhibitor, was used to inhibit endogenous PG synthesis. As shown in Figures 3(a)and 3(b), treatment with PGE2, in the presence ofindomethacin, for 8 hours resulted in a significant increase, of ∼2-fold, inPPARδ protein expression compared to control orindomethacin alone, as measured by Western Blotting. Stimulation for 24 hours also resulted inincreased PPARδ protein expression, but this increase was notsignificant when compared with indomethacin alone. A representative blot for 24hours is shown in Figure 3(a). However, two-hour stimulation did notalter the protein levels of PPARδ. We also examined the effect of PGE2 on PPARδ mRNA expression by real-time PCR. As shown in Figure 4, PPARδ mRNA remained unchanged with any treatmentgroup or exposure time. Forskolin had no effect on expression either (data notshown) indicating that cAMP does not alter PPARδ protein or RNA expression.

Bottom Line: The collecting duct (CD) expresses considerable amounts of PPARδ.High doses of GW501516 decreased both DNA and protein synthesis in these cells by 80%, but had no overall effect on cell viability.Although anisomycin treatment resulted in an increase of caspase-3 levels of about 2.59-fold of control, GW501516 did not affect anisomycin-induced changes in active caspase-3 levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Cellular and Molecular Medicine, Kidney Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5.

ABSTRACT
The collecting duct (CD) expresses considerable amounts of PPARδ. While its role is unknown in the CD, in other renal cells it has been shown to regulate both growth and apoptosis. We thus hypothesized that PPARδ reduces apoptotic responses and stimulates cell growth in the mouse CD, and examined the effect of GW501516, a synthetic PPARδ ligand, on these responses in mouse IMCD-K2 cells. High doses of GW501516 decreased both DNA and protein synthesis in these cells by 80%, but had no overall effect on cell viability. Although anisomycin treatment resulted in an increase of caspase-3 levels of about 2.59-fold of control, GW501516 did not affect anisomycin-induced changes in active caspase-3 levels. These results show that a PPARδ ligand inhibits growth but does not affect anisomycin-apoptosis in a mouse IMCD cell line. This could have therapeutic implications for renal diseases associated with increased CD growth responses.

No MeSH data available.


Related in: MedlinePlus