Leptin and Leptin Receptor Expression in the Rat Ovary

Ryan, Natalie K.; Hoek, Kylie H. Van der; Robertson, Sarah A.; Norman, Robert J.

doi:10.1210/en.2003-0584

Cited by 66 publications

(67 citation statements)

References 39 publications

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“…Similar results were found by Ryan et al (2003) who reported a reduction of 80% leptin at 9-h post-hCG administration. In our studies, the expression of hypothalamic leptin receptors was not altered by hCG administration, while the content of these receptors was high in both the pituitary and the ovarian tissue.…”

Section: Discussionsupporting

confidence: 89%

“…However, we firmly believe that these findings will be useful in future investigations, since we have shown for the first time that the expression of leptin receptors along the HPO axis is clearly modified by gonadotropins in a differential manner. In previous studies using this biological model, it has been shown that eCG administration resulted in a gradual increase in plasmatic oestrogens, and that after hCG injection, these levels diminished to basal values a few hours before ovulation occurs (Espey et al 1989, 1991, Ryan et al 2003. These results, together with those obtained in this work, suggest that oestrogens could be exerting a negative feedback on the expression of leptin receptors in the hypothalamic tissue.…”

Section: Ctrlsupporting

confidence: 81%

“…eCG induced an increase in the expression of both the long and short isoforms of leptin receptors in hypothalamus, although this result was only significant with the short forms. Ryan et al (2003) found that plasmatic leptin decreases 70% after eCG administration in immature rats primed with eCG/hCG, and that the basal values were recovered 48-h post-eCG. These results appear to suggest that leptin receptors are sensitive to change in plasmatic leptin concentrations, in order to balance a ligand lack.…”

Section: Discussionmentioning

confidence: 86%

“…These results suggest that the hypothalamus is not responsive to plasmatic leptin changes during hCG treatment. Ryan et al (2003) also reported that mRNA expression of both the short and long forms of the leptin receptor in the immature gonadotropinprimed rat ovary increases after hCG administration, followed by a dramatic reduction 24 h after this treatment. In the present study, we found that the ovarian content of both proteins (ObRb and Ob-Rs) was increased before follicular rupture.…”

Section: Discussionmentioning

confidence: 88%

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Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Yorio¹,

Bilbao²,

Pustovrh³

et al. 2008

Journal of Endocrinology

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To investigate the expression of leptin receptors (Ob-R) in the rat hypothalamus-pituitary-ovarian axis, immature rats were treated with eCG/hCG and Ob-R expression was evaluated by western blot analysis. The Ob-R expression increased 24 h after eCG administration in all the tissues assayed. In the hypothalamus, these levels immediately decreased to those obtained without treatment. In the pituitary, the Ob-R expression continued to be elevated 48 h after eCG administration, whereas the hCG injection did not modify these levels. Similar results were obtained with the ovarian long isoform. To assess the effect of leptin on its receptors, Ob-R was assessed in hypothalamus, pituitary and ovarian explants cultured in the presence or absence of leptin (0 . 3-500 ng/ml). In the hypothalamus, we found a biphasic effect: the Ob-R expression was either reduced or increased at low or high concentrations of leptin respectively. LH-releasing hormone secretion increased at 1 ng/ml. In the pituitary, Ob-R increased at 10 or 30 ng/ml of leptin for the long and short isoforms respectively. Leptin also induced an increase in LH release at 30 ng/ml. In the ovarian culture, the presence of leptin produced an increase in Ob-R expression at different ranges of concentrations and a dosedependent biphasic effect on the progesterone production. In conclusion, all these results clearly suggest that leptin is able to modulate the expression of its own receptors in the reproductive axis in a differential way. Moreover, the positive or negative effect that leptin exerts on the ovulatory process may be dependent on this regulation.

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Section: Discussionsupporting

confidence: 89%

Section: Ctrlsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 88%

See 2 more Smart Citations

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Yorio¹,

Bilbao²,

Pustovrh³

et al. 2008

Journal of Endocrinology

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“…The expression of leptin receptors was observed in human and rat granulosa (GC) and theca cells (Cioffi et al, 1997;Karlsson et al, 1997;Agarwal et al, 1999;Ryan et al, 2003), in luteinized GC and theca cells harvested from prepubertal gilts (in a single in vitro study) and in the porcine corpus luteum (CL) and ovarian stroma (OS; Ruiz-Cortes et al, 2000;Smolinska et al, 2007a). The ovary is also believed to be a site of leptin synthesis.…”

Section: Introductionmentioning

confidence: 99%

Expression of leptin and its receptor genes in the ovarian follicles of cycling and early pregnant pigs

Smolińska

Kamiński

Siawrys

et al. 2013

Animal

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Leptin is a polypeptide hormone produced primarily by adipocytes. It has been implicated in the regulation of satiety and energy homeostasis. Leptin has been suggested to play a role in reproduction based on its involvement in the regulation of the hypothalamic-pituitary-gonadal axis via endocrine, paracrine and/or autocrine pathways. The aim of the present study was to localize the cellular distribution of leptin and the long isoform of leptin receptor (OB-Rb) genes in porcine ovarian antral follicles and to compare the expression levels of leptin and OB-Rb mRNAs in porcine granulosa cells (GC), theca interna (TIC) and theca externa (TEC) cells during the luteal phase of the estrous cycle and in early pregnancy. The expression of leptin and OB-Rb genes was detected in GC, TIC and TEC. Significantly higher levels of leptin gene expression in GC were observed during the mid-and late-luteal phases of the cycle than on days 30 to 32 of pregnancy. On days 14 to 16 of pregnancy, leptin mRNA expression was higher than that on days 14 to 16 of the cycle. The expression of the OB-Rb gene in GC and TEC increased during pregnancy in comparison with the analyzed luteal phases of the cycle. Our results validate the hypothesis that locally produced leptin plays a role in the regulation of porcine reproduction at the ovarian level and exerts a direct effect on porcine follicles. The differences in OB-Rb gene expression in porcine GC and theca cells also suggest that their sensitivity to leptin varies in the ovaries of pregnant and cyclic pigs.

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Computational and artificial neural network based study of functional SNPs of human LEPR protein associated with reproductive function

Muruganandhan

Manian

2019

J of Cellular Biochemistry

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Genetic polymorphisms are mostly associated with inherited diseases, detecting and analyzing the biological significance of functional single‐nucleotide polymorphisms (SNPs) using wet laboratory experiments is an arduous task hence the computational analysis of putative SNPs is essential before conducting a study on a large population. SNP in the leptin receptor (LEPR) could result in the retention of intracellular signalling due to the structural and functional instability of the receptor causing abnormal reproductive function in human. In this first comprehensive computational analysis of LEPR gene mutation, we have identified and analyzed the functional consequence and structural significance of the SNPs in LEPR using recently developed several computational algorithms. Thirteen deleterious mutations such as W13C, S93G, I232R, Q307H, Y354C, E497A, Q571H, R612H, K656N, T690A, T699M V741M, and L760R were identified in the LEPR gene coding region. Backpropagation algorithm has been developed to forestall the deleterious nature of SNP and to validate the outcome of the tested computational tools. From ConSurf prediction three SNPs (Q571H, R612H, and T699M) were highly conserved on LEPR protein and the most deleterious variant R612H had one hydrogen bond abolished and severely reduced protein stability. Molecular docking suggested that the mutant (R612H) LEPR had lowest binding energy than native LEPR with the ligand molecule. Thus the energetically destructive changeover of ARG to HIS in R612H could possibly affect the LEPR protein structural stability and functional constancy due to interruption in the amino acid interactions and could result in reproductive disorders in human and increases the complication in obstetric and pregnancy outcome.

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Leptin and Leptin Receptor Expression in the Rat Ovary

Cited by 66 publications

References 39 publications

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Expression of leptin and its receptor genes in the ovarian follicles of cycling and early pregnant pigs

Computational and artificial neural network based study of functional SNPs of human LEPR protein associated with reproductive function

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