TY - JOUR
T1 - Rat amnion type IV collagen composition and metabolism
T2 - Implications for membrane breakdown
AU - Lei, Hanqin
AU - Kalluri, Raghuram
AU - Furth, Emma E.
AU - Baker, Andrew H.
AU - Strauss, Jerome F.
PY - 1999
Y1 - 1999
N2 - We report here that rat amnion type IV collagens are composed primarily of α1(IV) and α2(IV) chains. Amnion basement membrane collagens were more sensitive to degradation by collagenases than were adult rat kidney basement membrane collagens, which are enriched in α3(IV), α4(IV), and α6(IV) chains. Amnion type IV collagen content per unit of protein was markedly reduced by Day 21 of pregnancy, the day of delivery. Increased amnion levels of matrix metalloproteinase (MMP)-2 and MMP-9, gelatinases that degrade type IV collagen, were found by Day 21, suggesting that collagen breakdown was responsible, in part, for the decline in amnion type IV collagen. Infection of organ cultures of Day 18 rat amnions with a recombinant adenovirus expressing MMP-9 (AdMMP-9) caused release of collagen fragments detected as hydroxyproline in the culture fluid, amnion cell detachment, and apoptosis. The AdMMP-9-induced apoptosis was prevented by the MMP inhibitor batimastat. These findings suggest that MMPs are implicated in anoikis and apoptotic death of amnion cells, and may be part of a complex program of fetal membrane remodeling that occurs before delivery.
AB - We report here that rat amnion type IV collagens are composed primarily of α1(IV) and α2(IV) chains. Amnion basement membrane collagens were more sensitive to degradation by collagenases than were adult rat kidney basement membrane collagens, which are enriched in α3(IV), α4(IV), and α6(IV) chains. Amnion type IV collagen content per unit of protein was markedly reduced by Day 21 of pregnancy, the day of delivery. Increased amnion levels of matrix metalloproteinase (MMP)-2 and MMP-9, gelatinases that degrade type IV collagen, were found by Day 21, suggesting that collagen breakdown was responsible, in part, for the decline in amnion type IV collagen. Infection of organ cultures of Day 18 rat amnions with a recombinant adenovirus expressing MMP-9 (AdMMP-9) caused release of collagen fragments detected as hydroxyproline in the culture fluid, amnion cell detachment, and apoptosis. The AdMMP-9-induced apoptosis was prevented by the MMP inhibitor batimastat. These findings suggest that MMPs are implicated in anoikis and apoptotic death of amnion cells, and may be part of a complex program of fetal membrane remodeling that occurs before delivery.
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U2 - 10.1095/biolreprod60.1.176
DO - 10.1095/biolreprod60.1.176
M3 - Article
C2 - 9858503
AN - SCOPUS:0032894412
SN - 0006-3363
VL - 60
SP - 176
EP - 182
JO - Biology of reproduction
JF - Biology of reproduction
IS - 1
ER -