The Differential Regulation of CART Gene Expression in a Pituitary Cell Line and Primary Cell Cultures of Ovine Pars Tuberalis Cells

Barrett, Perry; Morris, Marie; Moar, Kim-Marie; Mercer, Julian G.; Davidson, J. A.; Findlay, P.A.; Adam, Carole; Morgan, Peter J.

doi:10.1046/j.1365-2826.2001.00634.x

Cited by 39 publications

(35 citation statements)

References 24 publications

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“…Until 1995 when Douglass and his co-workers [10] identified CART as a mRNA species whose expression increased acutely after psychomotor stimulant administration. The nucleotide and predicted amino acid sequences of CART from rat [10], human [31], mouse [32], sheep [33] and cattle [34] have been reported previously and were highly homologous among different species. However, the expression of CART mRNA in the porcine ovary has not been reported.…”

Section: Discussionmentioning

confidence: 60%

Study on the relationship between expression patterns of cocaine-and amphetamine regulated transcript and hormones secretion in porcine ovarian follicles

Meng

Jing

et al. 2018

Biol Res

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Background: Cocaine-and amphetamine regulated transcript (CART) is an endogenous neuropeptide, which is widespread in animals, plays a key role in regulation of follicular atresia in cattle and sheep. Among animal ovaries, CART mRNA was firstly found in the cattle ovaries. CART was localized in the antral follicles oocytes, granulosa and cumulus cells by immunohistochemistry and in situ hybridization. Further research found that secretion of E 2 was inhibited in granulosa cells with a certain dose of CART, the effect depends on the stage of cell differentiation, suggesting that CART could play a crucial role in regulating follicle atresia. The objective of this study was to characterize the CART expression model and hormones secretion in vivo and vitro in pig follicle granulosa cells, preliminarily studied whether CART have an effect on granulosa cells proliferation and hormones secretion in multiparous animals such as pigs. Methods:The expression levels of CART mRNA in granulosa cells of different follicles were analyzed using qRT-PCR technology. Immunohistochemistry technology was used to localize CART peptide. Granulosa cells were cultured in medium supplemented with different concentrations of CART and FSH for 168 h using Long-term culture system, and observed using a microscope. The concentration of Estradiol (E 2 ) and progesterone (P) in follicular fluids of different test groups were detected by enzyme linked immunosorbent assay (ELISA). Results:Results showed that expression level of CART mRNA was highest in medium follicles, and significantly higher than that in large and small follicles (P < 0.05). Immunohistochemical results showed that CART were expressed both in granulosa cells and theca cells of large follicles, while CART were detected only in theca cells of medium and small follicles. After the granulosa cells were cultured for 168 h, and found that concentrations of E 2 increase with concentrations of follicle-stimulating hormone (FSH) increase when the CART concentration was 0 μM. And the concentration of FSH reached 25 ng/mL, the concentration of E 2 is greatest. It shows that the production of E 2 needs induction of FSH in granulosa cells of pig ovarian follicles. With the increasing of CART concentrations (0.01, 0.1, 1 μM), E 2 concentration has a declining trend, when the FSH concentrations were 25 and 50 ng/mL in the medium, respectively. Conclusions:These results suggested that CART plays a role to inhibit granulosa cells proliferation and E 2 production, which induced by FSH in porcine ovarian follicular granulosa cells in vitro, but the inhibition effect is not significant. So

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Section: Discussionmentioning

confidence: 60%

Study on the relationship between expression patterns of cocaine-and amphetamine regulated transcript and hormones secretion in porcine ovarian follicles

Meng

Jing

et al. 2018

Biol Res

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“…In the rat, there are complex changes in OB-Rb expression with lactation, with an increase in expression in the supraoptic nucleus, a decrease in expression in the VMH, and no change in the ARC, DMH, or PVN (15). By contrast, fasting or feed restriction increases OB-Rb expression in the ARC and VMH in both rats (9,13) and sheep (29), suggesting that leptin suppresses expression of its receptor in the ARC and VMH. Our data for lactating sheep are consistent with this reciprocal relationship between leptin and OB-Rb expression.…”

Section: Discussionmentioning

confidence: 99%

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Sørensen

Adam²,

Findlay³

et al. 2002

American Journal of Physiology-Regulatory, Integrative and Comp

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Sheep were fed ad libitum and killed at 6 and 18 days of lactation; ad libitum-fed nonlactating sheep were killed as controls. Despite increased food intake, lactating ewes were in negative energy balance. Lactation decreased plasma leptin and adipose tissue leptin mRNA concentrations. OB-Rb gene expression, determined by in situ hybridization, was increased in the hypothalamic arcuate nucleus (ARC) and ventromedial hypothalamic nucleus (VMH) at both stages of lactation. Neuropeptide Y (NPY) was increased by lactation in both the ARC and dorsomedial hypothalamus (DMH), although increased gene expression in the DMH was only apparent at day 18 of lactation. Gene expression was decreased for cocaine-and amphetamine-regulated transcript (CART) in the ARC and VMH and for proopiomelanocortin in ARC during lactation. Agouti-related peptide gene expression was increased in the ARC, and melanocortin receptor expression was unchanged in both the ARC and VMH with lactation. Thus the hypoleptinemia of lactation may activate NPY orexigenic pathways and attenuate anorexigenic melanocortin and CART pathways in the hypothalamus to promote the hyperphagia of lactation. hypothalamic neuropeptides; appetite NUTRIENT REQUIREMENTS ARE markedly increased during lactation to meet the demands for milk production (7,70). In most mammals, these additional requirements are met primarily by increasing food intake (7,20,70), but factors regulating the hyperphagia of lactation are not well understood. In addition, in many species, the increased intake is insufficient to meet the metabolic demands, resulting in a state of negative energy balance during early lactation when body lipid reserves are mobilized (7,69). In some species such as the rat, the degree of negative energy balance is usually slight, with animals mobilizing ϳ1 g fat/day (7). Domestic ruminants, however, usually exhibit a greater degree of negative energy balance during early lactation (7, 11), which can impact on their welfare and productivity (28), yet the regulatory mechanisms have not been elucidated.It is postulated that leptin, a peptide hormone secreted by adipose tissue (75), could play a role in the hyperphagia of lactation. Leptin acts on hypothalamic neuronal systems to regulate energy balance and neuroendocrine function; in particular, a reduction in circulating leptin is a potent signal of negative energy balance, activating compensatory orexigenic pathways in the hypothalamus (3-5, 35, 64). Key targets are neurons in the hypothalamic arcuate nucleus (ARC) expressing the signaling form of the leptin receptor (OB-Rb); these are the orexigenic peptides neuropeptide Y (NPY) and agouti-related peptide (AGRP) and the anorexigenic peptides proopiomelanocortin (POMC, precursor for melanocortins) and cocaine-and amphetamine-regulated transcript (CART) (4,5,31,62,64,72). Adipose leptin gene expression and serum leptin concentrations are reported to be reduced during lactation in the monogastric rat in most (16,36,39,56,65,74), but not all (17,19,61), studies. NPY (18,21,...

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“…Our study examined only the colocalization between pituitary ppCART mRNA and ACTH immunoreactivity. However, the evidence would suggest that CART is localized to more than one anterior pituitary cell population (6,8). Our dual ICC and ISH results suggest that CART is also found in pituitary cell populations that do not express ACTH.…”

Section: Discussionmentioning

confidence: 99%

Regulation of rat pituitary cocaine- and amphetamine-regulated transcript (CART) by CRH and glucocorticoids

Stanley

Murphy²,

Bewick

et al. 2004

American Journal of Physiology-Endocrinology and Metabolism

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Cocaine- and amphetamine-regulated transcript (CART) was originally isolated from rat brain, but CART is also synthesized and stored in the anterior pituitary. The localization of pituitary CART and factors regulating its synthesis are largely unknown. The regulation of pituitary CART synthesis and release in response to CRH and glucocorticoids was examined in vitro and in vivo. CART immunoreactivity (CART-IR) was released from anterior pituitary segments. This release was increased 15-fold in response to corticotropin-releasing hormone (CRH). Intraperitoneal administration of CRH to rats significantly increased plasma CART-IR. Furthermore, CART-IR content and plasma CART-IR were significantly increased in adrenalectomized rats, and anterior pituitary CART mRNA expression, CART-IR content, and plasma CART-IR were significantly decreased in corticosterone-treated rats. Plasma CART-IR showed a pattern of diurnal variation similar to that of ACTH and corticosterone, and plasma CART-IR was positively correlated with corticosterone. CART-IR was detectable in the medium of the corticotroph cell line AtT-20. Dual in situ hybridization for prepro-CART (ppCART) mRNA expression and immunocytochemistry for ACTH showed localization of ppCART mRNA to a subpopulation of ACTH-immunoreactive cells. These findings demonstrate that pituitary CART expression and release are regulated by CRH and the glucocorticoid environment and that pituitary CART is partly localized to corticotrophs.

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The Differential Regulation of CART Gene Expression in a Pituitary Cell Line and Primary Cell Cultures of Ovine Pars Tuberalis Cells

Cited by 39 publications

References 24 publications

Study on the relationship between expression patterns of cocaine-and amphetamine regulated transcript and hormones secretion in porcine ovarian follicles

Study on the relationship between expression patterns of cocaine-and amphetamine regulated transcript and hormones secretion in porcine ovarian follicles

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Regulation of rat pituitary cocaine- and amphetamine-regulated transcript (CART) by CRH and glucocorticoids

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