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Pioglitazone administration alters ovarian gene expression in aging obese lethal yellow mice.

Brannian JD, Eyster KM, Weber M, Diggins M - Reprod. Biol. Endocrinol. (2008)

Bottom Line: Women with polycystic ovary syndrome (PCOS) are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD), which have been shown to reduce androgen levels and improved ovulatory function.These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM), and actin-related protein 6 homolog (ARP6).TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Obstetrics and Gynecology and Division of Basic Biomedical Sciences Sanford School of Medicine of The University of South Dakota, Sioux Falls and Vermillion, SD, USA. jbrannia@usd.edu

ABSTRACT

Background: Women with polycystic ovary syndrome (PCOS) are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD), which have been shown to reduce androgen levels and improved ovulatory function. Acting via peroxisome proliferator-activated receptor (PPAR) gamma, TZD alter the expression of a large variety of genes. Lethal yellow (LY; C57BL/6J Ay/a) mice, possessing a mutation (Ay) in the agouti gene locus, exhibit progressive obesity, reproductive dysfunction, and altered metabolic regulation similar to women with PCOS. The current study was designed to test the hypothesis that prolonged treatment of aging LY mice with the TZD, pioglitazone, alters the ovarian expression of genes that may impact reproduction.

Methods: Female LY mice received daily oral doses of either 0.01 mg pioglitazone (n = 4) or an equal volume of vehicle (DMSO; n = 4) for 8 weeks. At the end of treatment, ovaries were removed and DNA microarrays were used to analyze differential gene expression.

Results: Twenty-seven genes showed at least a two-fold difference in ovarian expression with pioglitazone treatment. These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM), and actin-related protein 6 homolog (ARP6). For most altered genes, pioglitazone changed levels of expression to those seen in untreated C57BL/6J(a/a) non-mutant lean mice.

Conclusion: TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.

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Related in: MedlinePlus

Relative increase in expression of RELMα by Real Time RT-PCR. Bars represent mean ± SD, in relative gene expression calculated relative to endogenous GAPDH expression. An RNA concentration-response validation curve was carried out to determine the concentration of RNA to add to the RT-PCR reaction. All samples were run in duplicate, n = 3 animals per group.
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Figure 1: Relative increase in expression of RELMα by Real Time RT-PCR. Bars represent mean ± SD, in relative gene expression calculated relative to endogenous GAPDH expression. An RNA concentration-response validation curve was carried out to determine the concentration of RNA to add to the RT-PCR reaction. All samples were run in duplicate, n = 3 animals per group.

Mentions: Expression of RELMα in the ovary has not been previously reported. Therefore microarray results were verified by Real Time RT-PCR. The difference in expression of RELMα by RT-PCR was nearly eight-fold (Figure 1), confirming a significant increase in mRNA levels in pioglitazone-treated mice. Since gonadal fat is a known source of RELMα [21], we sought to confirm that the RELMα expression was within the ovary proper. RELMα protein was detected in mouse ovarian sections from untreated age-matched LY mice by immunocytochemistry, confirming that RELMα was expressed within the ovary rather than in adhering fat tissue. RELMα primarily localized in perivascular cells, which on the basis of morphology and distribution were likely to be macrophages, although this was not confirmed (Figure 2). Western blot analysis of protein extracts of vehicle- and pioglitazone-treated LY mice did not reveal a significant difference in protein expression (Figure 3).


Pioglitazone administration alters ovarian gene expression in aging obese lethal yellow mice.

Brannian JD, Eyster KM, Weber M, Diggins M - Reprod. Biol. Endocrinol. (2008)

Relative increase in expression of RELMα by Real Time RT-PCR. Bars represent mean ± SD, in relative gene expression calculated relative to endogenous GAPDH expression. An RNA concentration-response validation curve was carried out to determine the concentration of RNA to add to the RT-PCR reaction. All samples were run in duplicate, n = 3 animals per group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2279121&req=5

Figure 1: Relative increase in expression of RELMα by Real Time RT-PCR. Bars represent mean ± SD, in relative gene expression calculated relative to endogenous GAPDH expression. An RNA concentration-response validation curve was carried out to determine the concentration of RNA to add to the RT-PCR reaction. All samples were run in duplicate, n = 3 animals per group.
Mentions: Expression of RELMα in the ovary has not been previously reported. Therefore microarray results were verified by Real Time RT-PCR. The difference in expression of RELMα by RT-PCR was nearly eight-fold (Figure 1), confirming a significant increase in mRNA levels in pioglitazone-treated mice. Since gonadal fat is a known source of RELMα [21], we sought to confirm that the RELMα expression was within the ovary proper. RELMα protein was detected in mouse ovarian sections from untreated age-matched LY mice by immunocytochemistry, confirming that RELMα was expressed within the ovary rather than in adhering fat tissue. RELMα primarily localized in perivascular cells, which on the basis of morphology and distribution were likely to be macrophages, although this was not confirmed (Figure 2). Western blot analysis of protein extracts of vehicle- and pioglitazone-treated LY mice did not reveal a significant difference in protein expression (Figure 3).

Bottom Line: Women with polycystic ovary syndrome (PCOS) are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD), which have been shown to reduce androgen levels and improved ovulatory function.These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM), and actin-related protein 6 homolog (ARP6).TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Obstetrics and Gynecology and Division of Basic Biomedical Sciences Sanford School of Medicine of The University of South Dakota, Sioux Falls and Vermillion, SD, USA. jbrannia@usd.edu

ABSTRACT

Background: Women with polycystic ovary syndrome (PCOS) are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD), which have been shown to reduce androgen levels and improved ovulatory function. Acting via peroxisome proliferator-activated receptor (PPAR) gamma, TZD alter the expression of a large variety of genes. Lethal yellow (LY; C57BL/6J Ay/a) mice, possessing a mutation (Ay) in the agouti gene locus, exhibit progressive obesity, reproductive dysfunction, and altered metabolic regulation similar to women with PCOS. The current study was designed to test the hypothesis that prolonged treatment of aging LY mice with the TZD, pioglitazone, alters the ovarian expression of genes that may impact reproduction.

Methods: Female LY mice received daily oral doses of either 0.01 mg pioglitazone (n = 4) or an equal volume of vehicle (DMSO; n = 4) for 8 weeks. At the end of treatment, ovaries were removed and DNA microarrays were used to analyze differential gene expression.

Results: Twenty-seven genes showed at least a two-fold difference in ovarian expression with pioglitazone treatment. These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM), and actin-related protein 6 homolog (ARP6). For most altered genes, pioglitazone changed levels of expression to those seen in untreated C57BL/6J(a/a) non-mutant lean mice.

Conclusion: TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.

Show MeSH
Related in: MedlinePlus