Age-dependent role of steroids in the regulation of growth of the hen follicular wall

Lebedeva, I.; Lebedev, V A; Großmann, Roland; Parvizi, Nahid

doi:10.1186/1477-7827-8-15

Cited by 18 publications

(9 citation statements)

References 39 publications

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“…Furthermore, concentrations of androgens used to stimulate these cells were quite high. Thus, androgenic effects on follicle development may be concentration-and age-dependent, consistent with reports of age-dependent differential effects of hormones and growth factors (46,47). For our studies, we did not use prepubertal animals because prepubertal GC-specific ARKO animals still had normal follicular development (13).…”

Section: Nonspecific) (D-f)supporting

confidence: 79%

Androgens regulate ovarian follicular development by increasing follicle stimulating hormone receptor and microRNA-125b expression

Sen

Prizant

Light

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

252

186

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Although androgen excess is considered detrimental to women's health and fertility, global and ovarian granulosa cell-specific androgen-receptor (AR) knockout mouse models have been used to show that androgen actions through ARs are actually necessary for normal ovarian function and female fertility. Here we describe two AR-mediated pathways in granulosa cells that regulate ovarian follicular development and therefore female fertility. First, we show that androgens attenuate follicular atresia through nuclear and extranuclear signaling pathways by enhancing expression of the microRNA (miR) miR-125b, which in turn suppresses proapoptotic protein expression. Second, we demonstrate that, independent of transcription, androgens enhance follicle-stimulating hormone (FSH) receptor expression, which then augments FSHmediated follicle growth and development. Interestingly, we find that the scaffold molecule paxillin regulates both processes, making it a critical regulator of AR actions in the ovary. Finally, we report that low doses of exogenous androgens enhance gonadotropin-induced ovulation in mice, further demonstrating the critical role that androgens play in follicular development and fertility. These data may explain reported positive effects of androgens on ovulation rates in women with diminished ovarian reserve. Furthermore, this study demonstrates mechanisms that might contribute to the unregulated follicle growth seen in diseases of excess androgens such as polycystic ovary syndrome. O ther than the obligatory role of androgens as estrogen precursors in steroidogenesis (1), little is known about the direct involvement of androgens in the female ovary. For many decades, excess androgens in women have been considered detrimental to women's health, as diseases such as polycystic ovary syndrome (PCOS) are associated with reduced fertility. In the past, these negative effects of androgens on female fertility were thought to occur primarily at the level of the hypothalamus and pituitary (2, 3), although important data across different species (4-7) suggested that androgens could also directly promote follicle growth (8, 9). Attitudes about androgen actions in female fertility changed with the development of global androgenreceptor knockout (ARKO) mice (10-12). The female ARKO mice had considerable reproductive defects, with decreased fertility, defective follicular development, reduced ovulation, and premature ovarian failure. In other words, the phenotype of these ARKO mice suggested that androgen signaling might actually be important for normal female reproductive health. Intriguingly, through the generation of granulosa cell (GC)-specific ARKO mice, we (13) and then others (14) demonstrated that essentially all the observed reproductive phenotypes in the complete AR-null mice are caused by androgen actions in GCs. These results highlighted that, with regard to fertility, androgen signaling in the ovary is at least as important as androgen signaling in the pituitary or hypothalamus. By using this GC-specific ARK...

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Section: Nonspecific) (D-f)supporting

confidence: 79%

Androgens regulate ovarian follicular development by increasing follicle stimulating hormone receptor and microRNA-125b expression

Sen

Prizant

Light

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

252

186

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“…Interestingly, similar to MT2, GnIHR was also found to be expressed in both the thecal and granulosa layers32. It has been reported that E2 secretion and GnIHR expression regulate egg production and quality33343536. GnIHR is mainly expressed in the pituitary.…”

Section: Discussionmentioning

confidence: 87%

Melatonin implantation improved the egg-laying rate and quality in hens past their peak egg-laying age

Yang

Zhu

et al. 2016

Sci Rep

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The egg-laying rates of hens approximately 470 days of age exhibited a positive correlation to blood melatonin levels. The hens with an egg-laying rate <30%, 30~90% and ≥90% had blood melatonin levels of 5.8 ± 2.6, 74.0 ± 32.9 and 445.9 ± 115.3 ng/ml, respectively. When 10 mg of melatonin was implanted into the hens at 300, 360, 470 and 550 days of age, the egg-laying rates increased 4.63 ± 0.46%, 8.38 ± 1.45%, 4.93 ± 0.85% and 7.93 ± 0.91%, respectively, compared to that of the controls. Melatonin implantation in hens at 300–470 days of age was observed to enhance egg production and reduce the rate of appearance of sharpei eggs. Melatonin (10 mg) implanted in hens 360 days of age did not influence the blood levels of progesterone (P4) or the gene expression levels of ovarian follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), oestradiol receptor alpha (ERα), superoxide dismutase 2 (SOD2) or melatonin receptor 1 (MT1). In contrast, melatonin significantly elevated the serum oestradiol-17β (E2) content, down-regulated the gene expression of gonadotropin-inhibitory hormone receptor (GnIHR), and enhanced the expression of melatonin receptor 2 (MT2). This result indicates that the improved egg-laying rate by melatonin was the result of increased serum oestradiol and decreased ovarian GnIHR. These alterations may be mediated by MT2 activation.

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“…The reproductive performance of chicken females is known to deteriorate in accordance with age .The ovaries and particularly the follicles are the primary targets of senescence (Lebedeva et al, 2010). Various factors are associated with the initiation of the gradual decline in egg production in a flock of aging birds, which include the different sizes of yolk follicles as well as the changes in the pattern of yolk accumulation into the follicle and the high rate of atresia in the small follicles in addition to the slight transfers of follicles into rapid growth phase among old hens (Oguike et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Effect of Octacosanol Supplementation on Productive and Physiological Performance of Aged Silver Montazah Strain During Summer Season

werdany

Mohamed²,

Habib³

et al. 2019

Journal of Productivity and Development

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The objective of this study was to evaluate the impact of supplementation levels (0, 8, 16 and 24 mg octacosanol (octa) / kg diet) on productive and physiological performance of aged Silver Montazah strain. A total number of 120 laying hens and 24 cocks of Silver Montazah local strain at 60 weeks of age was utilized in a completely randomized design and randomly assigned into 4 treatment groups (30 hens + 6 cocks in each treatment). Each group was divided into three replicates (10 hens and 2 cocks in each replicates). The 1 st group was fed the basal diet and served as the control group .The 2 nd , 3 rd and 4 th groups were fed the basal diet supplemented with 8, 16, and 24 mg octacosanol /kg diet respectively. The obtained results revealed that egg production percentage, egg mass, feed conversion ratios, concentrations of cholesterol, triglycerides, and LDL cholesterol, ovary weights, number of small yellow follicles (SYFs) and large white follicles (LWFs) were significantly (P≤0.05) improved by supplemented at levels of 16 mg or 24 mg octa /kg diet as compared with the control group. In addition, albumen height and Haugh unit were significantly (P≤0.05) improved than the control group at level of 24 mg octa /kg diet. Yolk diameter, concentrations of total protein, progesterone, estradiol, FSH, and LH, sperm cell concentration as well as sperm motility, dead spermatozoa, sperm abnormality and acrosomal 518 EL-WARDANY damage were significantly improved by increasing levels of octa when compared with the control group. Conclusively, it is clear that, supplementation of 16 mg octacosanol /kg diet is recommended for improving most of productive and reproductive traits, including egg production, some parameters egg quality, of semen quality and reduce serum lipid of laying hens, during summer season, under Inshas, Sharkia Province, Egypt environment conditions.

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Age-dependent role of steroids in the regulation of growth of the hen follicular wall

Cited by 18 publications

References 39 publications

Androgens regulate ovarian follicular development by increasing follicle stimulating hormone receptor and microRNA-125b expression

Androgens regulate ovarian follicular development by increasing follicle stimulating hormone receptor and microRNA-125b expression

Melatonin implantation improved the egg-laying rate and quality in hens past their peak egg-laying age

Effect of Octacosanol Supplementation on Productive and Physiological Performance of Aged Silver Montazah Strain During Summer Season

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