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Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus).

Vrooman LA, Young KA - Reprod. Biol. Endocrinol. (2010)

Bottom Line: MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p<0.05), while all other MMPs and TIMPs tested showed no significant difference in mRNA expression in the estrous cycle.Extent of immunostaining for MMP-14, TIMP-1, and TIMP-2 was significantly more abundant in P, E, and DI than in DII (p<0.05).No significant changes were observed in MMP and TIMP mRNA or extent of protein immunostaining with exposure to 3, 6, 9, or 12 weeks of SD, however protein was present and was localized to follicular and luteal steroidogenic cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Reproductive Biology Group, Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840, USA.

ABSTRACT

Background: Matrix metalloproteinases (MMPs) are implicated as mediators for ovarian remodeling events, and are involved with ovarian recrudescence during seasonal breeding cycles in Siberian hamsters. However, involvement of these proteases as the photoinhibited ovary undergoes atrophy and regression had not been assessed. We hypothesized that 1) MMPs and their tissue inhibitors, the TIMPs would be present and differentially regulated during the normal estrous cycle in Siberian hamsters, and that 2) MMP/TIMP mRNA and protein levels would increase as inhibitory photoperiod induced ovarian degeneration.

Methods: MMP-2, -9, -14 and TIMP-1 and -2 mRNA and protein were examined in the stages of estrous (proestrus [P], estrus [E], diestrus I [DI], and diestrus II [DII]) in Siberian hamsters, as well as after exposure to 3, 6, 9, and 12 weeks of inhibitory short photoperiod (SD).

Results: MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p<0.05), while all other MMPs and TIMPs tested showed no significant difference in mRNA expression in the estrous cycle. Extent of immunostaining for MMP-2 and -9 peaked in P and E then significantly declined in DI and DII (p<0.05). Extent of immunostaining for MMP-14, TIMP-1, and TIMP-2 was significantly more abundant in P, E, and DI than in DII (p<0.05). Localization of the MMPs and TIMPs had subtle differences, but immunostaining was predominant in granulosa and theca cells, with significant differences noted in staining intensity between preantral follicles, antral follicles, corpora lutea, and stroma classifications. No significant changes were observed in MMP and TIMP mRNA or extent of protein immunostaining with exposure to 3, 6, 9, or 12 weeks of SD, however protein was present and was localized to follicular and luteal steroidogenic cells.

Conclusions: Although MMPs appear to be involved in the normal ovarian estrus cycle at the protein level in hamsters, those examined in the present study are unlikely to be key players in the slow atrophy of tissue as seen in Siberian hamster ovarian regression.

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Representative MMP and TIMP protein immunodetection during the estrous cycle in Siberian hamsters. Ovarian immunohistochemical staining (dark red stain on purple/blue hematoxylin background) for all MMPs and TIMPs. (A-D) MMP-2 immunostaining, (E-H) MMP-9 immunostaining, (I-L) MMP-14 immunostaining, (M-P) TIMP-1 immunostaining, and (Q-T) TIMP-2 immunostaining. Insets show negative control immunostaining (no primary antibody present).
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Figure 4: Representative MMP and TIMP protein immunodetection during the estrous cycle in Siberian hamsters. Ovarian immunohistochemical staining (dark red stain on purple/blue hematoxylin background) for all MMPs and TIMPs. (A-D) MMP-2 immunostaining, (E-H) MMP-9 immunostaining, (I-L) MMP-14 immunostaining, (M-P) TIMP-1 immunostaining, and (Q-T) TIMP-2 immunostaining. Insets show negative control immunostaining (no primary antibody present).

Mentions: Primary anti-mouse antibodies for MMPs-2, 9, and 14 and TIMPs-1 and -2 were used on paraffin embedded tissue sections (Figures 3 and 4). No staining was observed in control sections processed without primary antibodies (Figure 4, insets). To confirm specificity in hamster tissue, mouse ovaries were also used, and staining patterns in these positive controls matched what was observed in the hamster ovaries for all antibodies (data not shown). All MMP and TIMP protein expression displayed cytoplasmic staining present at some level in all stages of estrous; staining was diffuse in MMP-2 (Figure 3A), MMP-14 (Figure 3C), and the TIMPs (Figure 3D,E), and tended to concentrate around the nucleus for MMP-9 (Figure 3B). In addition to cytoplasmic immunostaining, membrane staining was also observed in TIMP-2 stained sections (Figure 3F).


Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus).

Vrooman LA, Young KA - Reprod. Biol. Endocrinol. (2010)

Representative MMP and TIMP protein immunodetection during the estrous cycle in Siberian hamsters. Ovarian immunohistochemical staining (dark red stain on purple/blue hematoxylin background) for all MMPs and TIMPs. (A-D) MMP-2 immunostaining, (E-H) MMP-9 immunostaining, (I-L) MMP-14 immunostaining, (M-P) TIMP-1 immunostaining, and (Q-T) TIMP-2 immunostaining. Insets show negative control immunostaining (no primary antibody present).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2913988&req=5

Figure 4: Representative MMP and TIMP protein immunodetection during the estrous cycle in Siberian hamsters. Ovarian immunohistochemical staining (dark red stain on purple/blue hematoxylin background) for all MMPs and TIMPs. (A-D) MMP-2 immunostaining, (E-H) MMP-9 immunostaining, (I-L) MMP-14 immunostaining, (M-P) TIMP-1 immunostaining, and (Q-T) TIMP-2 immunostaining. Insets show negative control immunostaining (no primary antibody present).
Mentions: Primary anti-mouse antibodies for MMPs-2, 9, and 14 and TIMPs-1 and -2 were used on paraffin embedded tissue sections (Figures 3 and 4). No staining was observed in control sections processed without primary antibodies (Figure 4, insets). To confirm specificity in hamster tissue, mouse ovaries were also used, and staining patterns in these positive controls matched what was observed in the hamster ovaries for all antibodies (data not shown). All MMP and TIMP protein expression displayed cytoplasmic staining present at some level in all stages of estrous; staining was diffuse in MMP-2 (Figure 3A), MMP-14 (Figure 3C), and the TIMPs (Figure 3D,E), and tended to concentrate around the nucleus for MMP-9 (Figure 3B). In addition to cytoplasmic immunostaining, membrane staining was also observed in TIMP-2 stained sections (Figure 3F).

Bottom Line: MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p<0.05), while all other MMPs and TIMPs tested showed no significant difference in mRNA expression in the estrous cycle.Extent of immunostaining for MMP-14, TIMP-1, and TIMP-2 was significantly more abundant in P, E, and DI than in DII (p<0.05).No significant changes were observed in MMP and TIMP mRNA or extent of protein immunostaining with exposure to 3, 6, 9, or 12 weeks of SD, however protein was present and was localized to follicular and luteal steroidogenic cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Reproductive Biology Group, Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840, USA.

ABSTRACT

Background: Matrix metalloproteinases (MMPs) are implicated as mediators for ovarian remodeling events, and are involved with ovarian recrudescence during seasonal breeding cycles in Siberian hamsters. However, involvement of these proteases as the photoinhibited ovary undergoes atrophy and regression had not been assessed. We hypothesized that 1) MMPs and their tissue inhibitors, the TIMPs would be present and differentially regulated during the normal estrous cycle in Siberian hamsters, and that 2) MMP/TIMP mRNA and protein levels would increase as inhibitory photoperiod induced ovarian degeneration.

Methods: MMP-2, -9, -14 and TIMP-1 and -2 mRNA and protein were examined in the stages of estrous (proestrus [P], estrus [E], diestrus I [DI], and diestrus II [DII]) in Siberian hamsters, as well as after exposure to 3, 6, 9, and 12 weeks of inhibitory short photoperiod (SD).

Results: MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p<0.05), while all other MMPs and TIMPs tested showed no significant difference in mRNA expression in the estrous cycle. Extent of immunostaining for MMP-2 and -9 peaked in P and E then significantly declined in DI and DII (p<0.05). Extent of immunostaining for MMP-14, TIMP-1, and TIMP-2 was significantly more abundant in P, E, and DI than in DII (p<0.05). Localization of the MMPs and TIMPs had subtle differences, but immunostaining was predominant in granulosa and theca cells, with significant differences noted in staining intensity between preantral follicles, antral follicles, corpora lutea, and stroma classifications. No significant changes were observed in MMP and TIMP mRNA or extent of protein immunostaining with exposure to 3, 6, 9, or 12 weeks of SD, however protein was present and was localized to follicular and luteal steroidogenic cells.

Conclusions: Although MMPs appear to be involved in the normal ovarian estrus cycle at the protein level in hamsters, those examined in the present study are unlikely to be key players in the slow atrophy of tissue as seen in Siberian hamster ovarian regression.

Show MeSH
Related in: MedlinePlus