Antioxidant potential of specific estrogens on lipid peroxidation.

Subbiah, M.T.R.; Kessel, Bruce; Agrawal, Mohit; Rajan, R. Sundara; Abplanalp, William; Rymaszewski, Z

doi:10.1210/jcem.77.4.8408459

Cited by 110 publications

(90 citation statements)

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“…The loss of estrogen seen in ovariectomized mice leads to progressive muscle atrophy (45). Estrogens may help stabilize membranes (115), act as antioxidants (102,103), and thereby protect from muscle damage and inflammation (47,108). However, others have shown estrogens to be negative regulators of muscle mass.…”

Section: Integration Of Signaling Pathways To Modulate Ups Function Imentioning

confidence: 99%

The ubiquitin proteasome system in atrophying skeletal muscle: roles and regulation

Bilodeau

Coyne

Wing

2016

American Journal of Physiology-Cell Physiology

130

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Bilodeau PA, Coyne ES, Wing SS. The ubiquitin proteasome system in atrophying skeletal muscle: roles and regulation. Am J Physiol Cell Physiol 311: C392-C403, 2016. First published August 10, 2016; doi:10.1152/ajpcell.00125.2016.-Muscle atrophy complicates many diseases as well as aging, and its presence predicts both decreased quality of life and survival. Much work has been conducted to define the molecular mechanisms involved in maintaining protein homeostasis in muscle. To date, the ubiquitin proteasome system (UPS) has been shown to play an important role in mediating muscle wasting. In this review, we have collated the enzymes in the UPS whose roles in muscle wasting have been confirmed through loss-of-function studies. We have integrated information on their mechanisms of action to create a model of how they work together to produce muscle atrophy. These enzymes are involved in promoting myofibrillar disassembly and degradation, activation of autophagy, inhibition of myogenesis as well as in modulating the signaling pathways that control these processes. Many anabolic and catabolic signaling pathways are involved in regulating these UPS genes, but none appear to coordinately regulate a large number of these genes. A number of catabolic signaling pathways appear to instead function by inhibition of the insulin/IGF-I/protein kinase B anabolic pathway. This pathway is a critical determinant of muscle mass, since it can suppress key ubiquitin ligases and autophagy, activate protein synthesis, and promote myogenesis through its downstream mediators such as forkhead box O, mammalian target of rapamycin, and GSK3␤, respectively. Although much progress has been made, a more complete inventory of the UPS genes involved in mediating muscle atrophy, their mechanisms of action, and their regulation will be useful for identifying novel therapeutic approaches to this important clinical problem.hormones; muscle atrophy SKELETAL MUSCLE SERVES TWO essential functions, a contractile function for locomotion/maintenance of posture and a metabolic function as the protein reservoir of the body. The myofibers that make up the muscle consist primarily of myofibrillar proteins. The ability of the body to maintain posture or to move arises from the precise organization of myofibrillar proteins into a contractile unit called the sarcomere. The sarcomere consists of thick filaments containing primarily myosin that can slide over thin filaments containing primarily actin. Both types of filaments contain additional regulatory proteins and are linked to the ␣-actinin-containing Z disk, the thin filaments directly so and the thick filaments via titin. Vimentin and desmin are intermediate filaments that serve to anchor sarcomeres properly at the Z disks. These myofibrillar proteins, as well as the sarcoplasmic proteins, also serve as the protein reservoir of the body. Upon fasting, once hepatic glycogen stores are depleted, muscle protein degradation must be activated to provide amino acids to the liver for gluconeogenesis. These amino a...

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Section: Integration Of Signaling Pathways To Modulate Ups Function Imentioning

confidence: 99%

The ubiquitin proteasome system in atrophying skeletal muscle: roles and regulation

Bilodeau

Coyne

Wing

2016

American Journal of Physiology-Cell Physiology

130

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“…Estrogens have been shown to have in vitro antioxidant effects on membrane phospholipid peroxidation (Sugioka et al 1987) and experimental evidence indicates an antioxidant and atheroprotective role (Yagi & Komura 1986, Huber et al 1990, Subbiah et al 1993, Sack et al 1994, Arnal et al 1996. The relationship between sex steroid hormones and the cellular antioxidant enzyme system has also been investigated.…”

Section: Introductionmentioning

confidence: 99%

Effects of estrogens and androgens on erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase activities during the menstrual cycle

Massafra¹,

Gioia²,

Felice³

et al. 2000

Journal of Endocrinology

115

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The effects of physiological changes in estrogens and androgens on the erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase enzyme activities during the menstrual cycle were investigated in healthy eumenorrheic women. Blood samples were taken on alternate days from twelve normally cyclic women (age range: 20 to 27 years; mean age: 24·1 years) from the first day of one menstrual cycle until the first day of the subsequent one. Plasma was analyzed for FSH, LH, estradiol, progesterone, testosterone, free testosterone and androstenedione concentrations. Erythrocyte superoxide dismutase, catalase and glutathione peroxidase activities were evaluated on the same days and cycle length was standardized on the basis of the preovulatory estradiol peak. Significant cyclic phase-related changes were observed in glutathione peroxidase (P<0·05), with higher glutathione peroxidase activity levels from the late follicular to the early luteal phase compared with those found in the early follicular phase (P<0·001 and P<0·002 respectively). A significant positive correlation was observed between mean estradiol and glutathione peroxidase cycle-related variations (r=0·80, P<0·001), whereas no significant cycle phase-dependent changes were seen in superoxide dismutase and catalase. No effect of progesterone and androgens on the erythrocyte antioxidant enzyme system was documented. The findings indicate that physiological ovarian estradiol production during the menstrual cycle may have an important role in regulating erythrocyte glutathione peroxidase activity.

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“…The dihydroequilenin epimers, for example, have been shown to be among the most potent estrogens in CEE for the prevention of low density lipoprotein (LDL) oxidation [31,32]. They were also shown to be more effective than the estradiol epimers in protecting cultured neuronal cells from glutamate toxicity [33,34].…”

Section: Discussionmentioning

confidence: 99%

Molecular characterization of a B-ring unsaturated estrogen: Implications for conjugated equine estrogen components of Premarin

et al. 2008

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Conjugated equine estrogens (CEEs) are routinely used for hormone replacement therapy (HRT), making it important to understand the activities of individual estrogenic components. Although 17β-estradiol (17β-E2), the most potent estrogen in CEE, has been extensively characterized, the actions of nine additional less potent estrogens are not well understood. Structural differences between CEEs and 17β-E2 result in altered interactions with the two estrogen receptors (ERα and ERβ) and different biological activities. To better understand these interactions, we have determined the crystal structure of the CEE analog, 17β-methyl-17α-dihydroequilenin (NCI 122), in complex with the ERα ligand-binding domain and a peptide from the glucocorticoid receptor-interacting protein 1 (GRIP1) coactivator. NCI 122 has chemical properties, including an unsaturated B-ring and 17α-hydroxyl group, which are shared with some of the estrogens found in CEEs. Structural analysis of the NCI 122-ERα LBD-GRIP1 complex, combined with biochemical and cell-based comparisons of CEE components, suggests that factors such as decreased ligand flexibility, decreased ligand hydrophobicity and loss of a hydrogen bond between the 17-hydroxyl group and His524, contribute significantly to the reduced potency of CEEs on ERα.

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Antioxidant potential of specific estrogens on lipid peroxidation.

Cited by 110 publications

References 0 publications

The ubiquitin proteasome system in atrophying skeletal muscle: roles and regulation

The ubiquitin proteasome system in atrophying skeletal muscle: roles and regulation

Effects of estrogens and androgens on erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase activities during the menstrual cycle

Molecular characterization of a B-ring unsaturated estrogen: Implications for conjugated equine estrogen components of Premarin

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