OBJECTIVE: To determine the expression of matrix metalloproteinase (MMP-26) and tissue inhibitor of MMP (TIMP) in the endometrium of women with normal menstrual cycles compared with users of levonorgestrel implants. DESIGN: Prospective observational study. SETTING: Academic research center. PATIENT(S): Fifty patients with normal menstrual cycles who requested permanent surgical sterilization (tubal ligation) and 35 users of levonorgestrel implants. INTERVENTION(S): Endometrial biopsy. MAIN OUTCOME MEASURE(S): Expression of MMP-26, TIMP-3, and TIMP-4 by immunohistochemistry and semiquantitative analysis of staining intensity by using the H score. RESULT(S): Endometrium from women with a normal menstrual cycle and users of levonorgestrel implants expresses MMP-26, TIMP-3, and TIMP-4. These substances are present in various types of endometrial cells; expression is strongest in surface and glandular epithelial cells, followed by vascular endothelial and endometrial stromal cells. Inflammatory and immune-related cells also stained strongly for MMP-26 and TIMPs. Semiquantitative analysis of the staining intensity of endometrial epithelial and stromal cells indicated that expression of MMP-26, TIMP-3, and TIMP-4 peaks during the early to mid-luteal phase. Expression of MMP-26 is elevated in users of levonorgestrel implants who experienced irregular uterine bleeding. CONCLUSION(S): Endometrial expression of MMP-26 and TIMP-4 is present throughout the menstrual cycle and is elevated during the early to mid-luteal phase in normally cycling women. Further elevations in MMP-26 are seen in users of levonorgestrel implants who experience irregular uterine bleeding. These substances thus seem to play a role in hormonal regulation and endometrial tissue remodeling.
OBJECTIVE: To determine the expression of matrix metalloproteinase (MMP-26) and tissue inhibitor of MMP (TIMP) in the endometrium of women with normal menstrual cycles compared with users of levonorgestrel implants. DESIGN: Prospective observational study. SETTING: Academic research center. PATIENT(S): Fifty patients with normal menstrual cycles who requested permanent surgical sterilization (tubal ligation) and 35 users of levonorgestrel implants. INTERVENTION(S): Endometrial biopsy. MAIN OUTCOME MEASURE(S): Expression of MMP-26, TIMP-3, and TIMP-4 by immunohistochemistry and semiquantitative analysis of staining intensity by using the H score. RESULT(S): Endometrium from women with a normal menstrual cycle and users of levonorgestrel implants expresses MMP-26, TIMP-3, and TIMP-4. These substances are present in various types of endometrial cells; expression is strongest in surface and glandular epithelial cells, followed by vascular endothelial and endometrial stromal cells. Inflammatory and immune-related cells also stained strongly for MMP-26 and TIMPs. Semiquantitative analysis of the staining intensity of endometrial epithelial and stromal cells indicated that expression of MMP-26, TIMP-3, and TIMP-4 peaks during the early to mid-luteal phase. Expression of MMP-26 is elevated in users of levonorgestrel implants who experienced irregular uterine bleeding. CONCLUSION(S): Endometrial expression of MMP-26 and TIMP-4 is present throughout the menstrual cycle and is elevated during the early to mid-luteal phase in normally cycling women. Further elevations in MMP-26 are seen in users of levonorgestrel implants who experience irregular uterine bleeding. These substances thus seem to play a role in hormonal regulation and endometrial tissue remodeling.
Authors: Ilpo Koskivirta; Otto Rahkonen; Mikko Mäyränpää; Sari Pakkanen; Michael Husheem; Annele Sainio; Harri Hakovirta; Jukka Laine; Eero Jokinen; Eero Vuorio; Petri Kovanen; Hannu Järveläinen Journal: Histochem Cell Biol Date: 2006-03-07 Impact factor: 4.304