Gonadotropin-Releasing Hormone Stimulates Annexin 5 Messenger Ribonucleic Acid Expression in the Anterior Pituitary Cells

Kawaminami, Mitsumori; Tsuchiyama, Yoshiyuki; Saito, Shihori; Katayama, Mikio; Kurusu, Shiro; Hashimoto, Itaru

doi:10.1006/bbrc.2002.6573

Cited by 24 publications

(24 citation statements)

References 24 publications

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“…However, it is not known whether the phospholipid binding is physiologically relevant to some particular function. Our findings here, together with our previous results [6][7][8]52], suggest a role for annexin A5 in signal transduction in the gonadotropes. This idea is further supported by the results reported by other groups.…”

Section: Discussionsupporting

confidence: 87%

“…These changes result in the enhancement or suppression of multiple genes [17,18]. We demonstrated that annexin A5 is one of the major genes that are stimulated by GnRH in the gonadotropes [5,7,8]. The expression of annexin A5 mRNA was stimulated by TPA but not by dbcAMP.…”

Section: Discussionmentioning

confidence: 99%

“…The frequency of the GnRH pulses seems to influence the different effects on cell function of the gonadotropes [2][3][4]. Recently, we demonstrated that GnRH stimulates the expression of annexin A5 mRNA in gonadotropes [5][6][7][8]. Because ovariectomy enhanced annexin A5 expression in the gonadotropes and estradiol inhibited it, the expression of pituitary annexin A5 was thought to be physiologically regulated by hypothalamic GnRH [6].…”

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confidence: 99%

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Gonadotropin Releasing Hormone (GnRH) Enhances Annexin A5 mRNA Expression through Mitogen Activated Protein Kinase (MAPK) in L.BETA.T2 Pituitary Gonadotrope Cells

et al. 2008

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Abstract. The mechanism by which GnRH stimulates annexin A5 expression was examined with LβT2 gonadotrope cells. Continuous stimulation with GnRH analog (GnRHa, Des-Gly10 [Pro9]-GnRH ethylamide) transiently elevated LHβ mRNA expression while maintaining annexin A5 mRNA at high levels for 24 h. GnRH antagonist blocked the effect of GnRHa on annexin A5. While 12-O-tetradecanoyl-phorbol-13 acetate, a protein kinase C activator, increased the expression of annexin A5 mRNA, bisindolylmaleimide, an inhibitor of protein kinase C, suppressed GnRHa-stimulated expression of annexin A5 and LHβ mRNA. GnRHa stimulation of LHβ mRNA was inhibited to a greater extent than annexin A5 by a calcium chelator BAPTA/AM. Although a calcium ionophore ionomycin stimulated the expression of both genes, only LHβ was down-regulated. The MAPK kinase inhibitor PD98059 inhibited GnRHa induction of annexin A5 but not LHβ mRNA. EGF stimulated the expression of annexin A5 mRNA but caused only a transient effect on LHβ mRNA expression. These results indicate that GnRH stimulation of signaling pathway for annexin A5 mRNA expression is distinct from that of LHβ mRNA and dependent more on MAPK. GnRH is a hypothalamic neuropeptide that regulates pituitary gonadotropin secretion. GnRH neuron secretes GnRH in a pulsatile fashon at the median eminence of the hypothalamus. Portal blood also shows pulsatile fluctuations of GnRH [1]. The frequency of the GnRH pulses seems to influence the different effects on cell function of the gonadotropes [2][3][4]. Recently, we demonstrated that GnRH stimulates the expression of annexin A5 mRNA in gonadotropes [5][6][7][8]. Because ovariectomy enhanced annexin A5 expression in the gonadotropes and estradiol inhibited it, the expression of pituitary annexin A5 was thought to be physiologically regulated by hypothalamic GnRH [6]. We also demonstrated that annexin A5 participates in GnRH control of gonadotropin secretion. Annexin A5 itself stimulates both LH and FSH release, while an annexin A5 antisense oligonucleotide reduces GnRH stimulation of LH [7]. These findings suggest that intracellular annexin A5 is requisite for GnRH stimulation of gonadotropin secretion.In mammals, the annexin family consists of a group of at least 12 Ca 2+ -dependent phospholipid binding proteins [9,10]. Annexin A1 was first identified as a mediator of the anti-inflammatory activity of glucocorticoids [11]. The identification of other annexins followed, including annexin A5 that was discovered as a protein that inhibits phospholipase A 2 and suppresses blood coagulation [12,13]. These activities are thought to be due to its ability to bind phospholipids, although it is not clear whether these activities are relevant to physiological function. However, as we showed in the gonadotropes, annexin A5 may be at least necessary for an intracellular signaling in some cell types [14][15][16].

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Gonadotropin Releasing Hormone (GnRH) Enhances Annexin A5 mRNA Expression through Mitogen Activated Protein Kinase (MAPK) in L.BETA.T2 Pituitary Gonadotrope Cells

et al. 2008

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“…As GnRH has been demonstrated to stimulate the expression of annexin A5 in pituitary gonadotropes, luteal cells and Leydig cells [11][12][13]24], annexin A5 seems to be a marker protein of GnRH action in the mammary gland. The present results show the specific distribution of annexin A5 in mammary epithelial cells, and suggest that GnRH would act on the epithelial cells at involution.…”

Section: Discussionmentioning

confidence: 99%

Immunohistochemical Localization of Annexin A5 in the Mammary Gland of Rats: Up-Regulation of Expression by Pup Removal

Rieanrakwong

Yonezawa

Kurusu

et al. 2010

The Journal of Veterinary Medical Science

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ABSTRACT. The distribution of annexin A5, a cytosolic protein related to gonadotropin releasing hormone action, was examined in the mammary gland of rats by immunohistochemistry with special reference to changes by lactation. Annexin A5 was observed in the interstitial tissues but not alveolar cells in virgin rats, while mammary epithelial cells became positive for annexin A5 in pregnant rats. The intensity of annexin A5 was decreased in lactating rats and dramatically increased after weaning, especially on the nucleus. When pups were removed from their dam at mid-lactation (day 10), annexin A5 was also increased on day 12. Apoptotic epithelial cells detected by terminal deoxynucleotidyl transferase nick end labeling were simultaneously increased. Annexin A5 mRNA expression of mammary tissues was increased after pup removal. These results are the first to demonstrate the distribution of annexin A5 in the mammary glands of lactating rats, and the enhanced expression in mammary epithelial cells after lactation suggests its involvement in mammary epithelial cell involution.KEY WORDS: annexin A5, mammary gland, mammary involution.

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“…Although the biochemical properties of annexinfamily proteins suggest roles in significant cell functions, the function of these proteins in physiological processes is still obscure [7]. We previously demonstrated that annexin 5 is synthesized in the anterior pituitary gland [8] and later found that it is produced by pituitary gonadotropes under the regulation of gonadotropin releasing hormone (GnRH) [9][10][11][12][13]. As annexin 5 augments gonadotropin secretion in vitro [13] and antisense oligodeoxynucleotide to annexin 5 mRNA retards luteinizing hormone release by GnRH, annexin 5 is thought to mediate at least part of the action of GnRH on pituitary gonadotropes [13].…”

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Annexin 5 Inhibits Thyrotropin Releasing Hormone (TRH) Stimulated Prolactin Release in the Primary Culture of Rat Anterior Pituitary Cells

et al. 2004

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Abstract. Annexin 5, a novel calcium-phospholipid binding protein, is thought to be involved in hormone secretion by the anterior pituitary gland. Gonadotropin releasing hormone stimulates annexin 5 synthesis, which, in turn, enhances gonadotoropin secretion. On the other hand, annexin 5 was shown to inhibit prolactin release in vitro. To understand the nature of the opposing effects of annexin 5 on these two major pituitary hormones, the present study examines the inhibitory effect of annexin 5 on prolactin release in relation to thyrotropin stimulating hormone (TRH) using primary cultures of anterior pituitary cells of adult female rats. While recombinant rat annexin 5 was found to have little effect on basal prolactin release, it significantly inhibited TRH-stimulated prolactin release. Addition of specific anti-annexin 5 serum to the culture increased basal prolactin release in a concentration dependent manner, and no further increase in prolactin release was observed following application of TRH in the presence of anti-annexin 5. The enhanced basal prolactin release induced by anti-annexin 5 was reversed by the simultaneous administration of indomethacin, an inhibitor of cyclooxygenase. These results demonstrate that endogenous pituitary annexin 5 exerts an inhibitory effect on prolactin release and suggest that this is attained by suppression of eicosanoid synthesis in vitro.

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Gonadotropin-Releasing Hormone Stimulates Annexin 5 Messenger Ribonucleic Acid Expression in the Anterior Pituitary Cells

Cited by 24 publications

References 24 publications

Gonadotropin Releasing Hormone (GnRH) Enhances Annexin A5 mRNA Expression through Mitogen Activated Protein Kinase (MAPK) in L.BETA.T2 Pituitary Gonadotrope Cells

Gonadotropin Releasing Hormone (GnRH) Enhances Annexin A5 mRNA Expression through Mitogen Activated Protein Kinase (MAPK) in L.BETA.T2 Pituitary Gonadotrope Cells

Immunohistochemical Localization of Annexin A5 in the Mammary Gland of Rats: Up-Regulation of Expression by Pup Removal

Annexin 5 Inhibits Thyrotropin Releasing Hormone (TRH) Stimulated Prolactin Release in the Primary Culture of Rat Anterior Pituitary Cells

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