TY - JOUR
T1 - Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus)
AU - Vrooman, Lisa A.
AU - Young, Kelly A.
N1 - Funding Information:
We thank Jesus Reyes and the Kelley lab for their assistance and use of facilities for radioimmunassay, Dr. Simon Malcomber for use of his embedding machine. We would especially like to thank our CSULB Reproductive Laboratory colleagues, Dr. Asha Shahed and Carling McMichael for their help in tissue collection, Greer McMichael for her expertise in ovarian histology, and Kerri Loke for her assistance in radioimmunoassay. We also thank the anonymous peer reviewers for, among other helpful ideas, suggesting separating immunostain-ing counts by follicular structure. This study was supported by the Beckman Scholars award (LAV), the Howell/CSUPERB Research Fellowship (LAV), NIH SCORE 5-S06GM063119-05 (KAY), and NIH 1SC3GM089611-01(KAY).
PY - 2010/6/25
Y1 - 2010/6/25
N2 - 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.
AB - 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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U2 - 10.1186/1477-7827-8-79
DO - 10.1186/1477-7827-8-79
M3 - Article
C2 - 20579366
AN - SCOPUS:77955385752
SN - 1477-7827
VL - 8
JO - Reproductive Biology and Endocrinology
JF - Reproductive Biology and Endocrinology
M1 - 79
ER -