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Estrogen protects lenses against cataract induced by transforming growth factor-beta (TGFbeta).

Hales AM, Chamberlain CG, Murphy CR, McAvoy JW - J. Exp. Med. (1997)

Bottom Line: Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFbeta and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance.The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFbeP.It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Histology, and Institute for Biomedical Research (F-13), The University of Sydney, New South Wales, Australia.

ABSTRACT
Cataract, already a major cause of visual impairment and blindness, is likely to become an increasing problem as the world population ages. In a previous study, we showed that transforming growth factor-beta (TGFP) induces rat lenses in culture to develop opacities and other changes that have many features of human subcapsular cataracts. Here we show that estrogen protects against cataract. Lenses from female rats are more resistant to TGFbeta-induced cataract than those from males. Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFbeta and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance. Sex-dependent and estrogen-related differences in susceptibility to cataract formation, consistent with a protective role for estrogen, have been noted in some epidemiological studies. The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFbeP. It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases.

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Influence of ovarian hormones on induction of cataract by TGFβ. Ovariectomized rats received vehicle alone (A), estrogen replacement (B),  or progesterone replacement (C). Lenses were cultured with 0.15 ng/ml TGFβ2 and photographed after 7 d. Lenses from rats that received vehicle alone  or progesterone developed distinct opacities (A and C), whereas lenses from rats that received estrogen remained transparent (B). Bar, 400 μm.
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Figure 2: Influence of ovarian hormones on induction of cataract by TGFβ. Ovariectomized rats received vehicle alone (A), estrogen replacement (B), or progesterone replacement (C). Lenses were cultured with 0.15 ng/ml TGFβ2 and photographed after 7 d. Lenses from rats that received vehicle alone or progesterone developed distinct opacities (A and C), whereas lenses from rats that received estrogen remained transparent (B). Bar, 400 μm.

Mentions: Having established that lenses from female rats showed more resistance to the cataractogenic effects of TGFβ than those from males, ovariectomized rats were used to assess the contribution of ovarian hormones to this phenomenon. Lenses from ovariectomized rats (without hormone replacement) developed opacities when cultured with 0.15 ng/ml TGFβ (Table 2; Fig. 2 A), a concentration shown to have negligible effect on lenses from normal female rats (Table 1; Fig. 1 B). Lenses from ovariectomized rats which received estrogen, however, did not develop opacities under these conditions (Table 2; Fig. 2 B), while the response of lenses from rats treated with progesterone was similar to that of lenses from vehicle-treated rats (Table 2; Fig. 2 C).


Estrogen protects lenses against cataract induced by transforming growth factor-beta (TGFbeta).

Hales AM, Chamberlain CG, Murphy CR, McAvoy JW - J. Exp. Med. (1997)

Influence of ovarian hormones on induction of cataract by TGFβ. Ovariectomized rats received vehicle alone (A), estrogen replacement (B),  or progesterone replacement (C). Lenses were cultured with 0.15 ng/ml TGFβ2 and photographed after 7 d. Lenses from rats that received vehicle alone  or progesterone developed distinct opacities (A and C), whereas lenses from rats that received estrogen remained transparent (B). Bar, 400 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196117&req=5

Figure 2: Influence of ovarian hormones on induction of cataract by TGFβ. Ovariectomized rats received vehicle alone (A), estrogen replacement (B), or progesterone replacement (C). Lenses were cultured with 0.15 ng/ml TGFβ2 and photographed after 7 d. Lenses from rats that received vehicle alone or progesterone developed distinct opacities (A and C), whereas lenses from rats that received estrogen remained transparent (B). Bar, 400 μm.
Mentions: Having established that lenses from female rats showed more resistance to the cataractogenic effects of TGFβ than those from males, ovariectomized rats were used to assess the contribution of ovarian hormones to this phenomenon. Lenses from ovariectomized rats (without hormone replacement) developed opacities when cultured with 0.15 ng/ml TGFβ (Table 2; Fig. 2 A), a concentration shown to have negligible effect on lenses from normal female rats (Table 1; Fig. 1 B). Lenses from ovariectomized rats which received estrogen, however, did not develop opacities under these conditions (Table 2; Fig. 2 B), while the response of lenses from rats treated with progesterone was similar to that of lenses from vehicle-treated rats (Table 2; Fig. 2 C).

Bottom Line: Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFbeta and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance.The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFbeP.It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Histology, and Institute for Biomedical Research (F-13), The University of Sydney, New South Wales, Australia.

ABSTRACT
Cataract, already a major cause of visual impairment and blindness, is likely to become an increasing problem as the world population ages. In a previous study, we showed that transforming growth factor-beta (TGFP) induces rat lenses in culture to develop opacities and other changes that have many features of human subcapsular cataracts. Here we show that estrogen protects against cataract. Lenses from female rats are more resistant to TGFbeta-induced cataract than those from males. Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFbeta and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance. Sex-dependent and estrogen-related differences in susceptibility to cataract formation, consistent with a protective role for estrogen, have been noted in some epidemiological studies. The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFbeP. It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases.

Show MeSH
Related in: MedlinePlus