scholarly journals SAT-009 SSRI Use in the Peripartum Period Regulates Mammary Gland Parathyroid Hormone Related Protein (PTHrP) by a Serotonylation-Dependent Mechanism

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Celeste Sheftel ◽  
Luma C Sartori ◽  
Laura L Hernandez
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Bone Loss ◽  
G Proteins ◽  
Related Protein ◽  
Serotonin Content ◽  
Parathyroid Hormone Related Protein ◽  
Serotonin Signaling ◽  
Hc11 Cells ◽  
Dependent Mechanism

Abstract During lactation, a woman experiences a considerable amount of bone loss and recent studies suggest bone deficits persist years postpartum. Furthermore, selective serotonin uptake inhibitors (SSRIs), which are often prescribed to women experiencing peripartum depression, have been linked to osteopenia. Serotonin signaling can increase parathyroid hormone related protein (PTHrP), a bone remodeling protein which liberates calcium for the milk. Additionally, fluoxetine (a common SSRI) results in increased mammary gland serotonin content and PTHrP, and treatment during the peripartal period reduced maternal bone mineral density. One proposed mechanism of serotonin action is by its covalent addition to proteins by transglutaminase (TG2), termed serotonylation. We therefore investigated whether the combination of fluoxetine and lactation can exacerbate maternal bone loss and the underlying mechanism. We hypothesized that SSRI-induced serotonin signaling in the lactating mammary gland increases PTHrP through a serotonylation-dependent mechanism. Treatment of mouse mammary epithelial cells (HC11) with fluoxetine significantly upregulates PTHrP gene expression and the concentration of its downstream effector, cAMP, over control (P < 0.0004). Furthermore, treatment of the HC11 cells with fluoxetine in addition to a TG2 inhibitor, monodansylcadaverine, restores PTHrP mRNA expression to levels observed in the control. Small g-proteins have emerged as a common target protein for serotonylation. Currently, our data suggest that the g-proteins, RhoA and Rab4, are potential serotonylation targets in the mammary gland. Together these data suggest that the molecular process of serotonyation in HC11 cells links serotonin signaling to increased PTHrP expression. Future work is directed at using the cre-lox system to genetically ablate serotonylation using a WAPCre/TG2Flox transgenic mouse to determine whether decreasing serotonylation in vivo in the mammary gland during lactation improves maternal bone mass.

scholarly journals Temporally regulated overexpression of parathyroid hormone-related protein in the mammary gland reveals distinct fetal and pubertal phenotypes

2001 ◽  
Vol 171 (3) ◽  
pp. 403-416 ◽  
Author(s):  
ME Dunbar ◽  
P Dann ◽  
CW Brown ◽  
J Van Houton ◽  
B Dreyer ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Transgenic Mice ◽  
Mammary Development ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Epithelial Cell Apoptosis ◽  
Ductal Elongation ◽  
Ductal Branching ◽  
Lobuloalveolar Development

We have previously demonstrated that overexpression of parathyroid hormone-related protein (PTHrP) in the mammary glands of transgenic mice results in defects in ductal elongation and branching during puberty and in lobuloalveolar development during pregnancy. In addition, we have shown that PTHrP is necessary for the formation of the initial ductal tree during embryonic mammary development. In order to examine the effect of varying the timing of PTHrP overexpression on mammary development, we created tetracycline-regulated, K14-tTA/Tet(O)-PTHrP double transgenic mice. In this report, we document that this 'tet-off' system directs transgene expression to the mammary gland and that it is fully repressed in the presence of tetracycline. Using these mice, we demonstrate that transient overexpression of PTHrP before birth causes defects in ductal branching during puberty and that overexpression of PTHrP during puberty decreases the rate of ductal elongation. Furthermore, we demonstrate that if PTHrP overexpression is initiated after ductal morphogenesis is completed, lobuloalveolar development is unaffected. Finally, we demonstrate that the impairment in ductal elongation caused by PTHrP is associated with an increase in the basal rate of epithelial cell apoptosis in terminal end buds and a failure to increase end bud cell proliferation and decrease apoptosis in response to estrogen and progesterone.

Cortisol, parathyroid hormone-related protein and the onset of calcium secretion by the mammary gland of the goat

1997 ◽  
Vol 64 (4) ◽  
pp. 633-636
Author(s):  
GORDON E. THOMPSON ◽  
S. KHAWAR ABBAS ◽  
CARL HOLT ◽  
ANTHONY D. CARE
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Tight Junctions ◽  
Calcium Transport ◽  
Extracellular Fluid ◽  
Secretory Cells ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Calcium Secretion

During lactogenesis in the goat, the onset of secretion of calcium into milk occurs at parturition (Thompson et al. 1995) at approximately the same time as the onset of secretion of parathyroid hormone-related protein (PTHrP) by the mammary gland (Ratcliffe et al. 1992); these events may be unrelated or PTHrP may be involved in calcium transport from blood to milk.Parturition in goats is initiated by fetal secretion of cortisol (Flint et al. 1978) and maternal secretion of cortisol also increases (Paterson & Linzell, 1971). Injecting cortisol locally into the sinus of a mammary gland of the late-pregnant goat when the tight junctions between secretory epithelial cells appear to be ‘loose’, and injectate can reach the basolateral surfaces of secretory cells, stimulates an early tightening of these junctions (Thompson, 1996) as occurs naturally at parturition. This tightening can be produced by an increased concentration of ionized calcium in the extracellular fluid of the gland (Neville & Peaker, 1981).The experiments reported here were undertaken to determine if cortisol injection stimulates the mammary gland to secrete both PTHrP and calcium before parturition.

scholarly journals Cloning of bovine parathyroid hormone-related protein (PTHrP) cDNA and expression of PTHrP mRNA in the bovine mammary gland

1998 ◽  
Vol 20 (2) ◽  
pp. 271-280 ◽  
Author(s):  
SF Wojcik ◽  
FL Schanbacher ◽  
LK McCauley ◽  
H Zhou ◽  
V Kartsogiannis ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Cdna Library ◽  
Bovine Milk ◽  
Bovine Brain ◽  
Molecular Heterogeneity ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Lactating Mammary Gland ◽  
Brain Cdna Library

Parathyroid hormone-related protein (PTHrP) produced by the mammary gland has been postulated to have multiple functions in both the mother and neonate. In humans, alternative 3'-mRNA splicing and endoproteolytic processing result in multiple bioactive PTHrP peptides. Multiple PTHrP peptides also have been reported in bovine milk. To investigate the source of molecular heterogeneity of PTHrP in bovine milk, bovine PTHrP was cloned from a bovine brain cDNA library, sequenced and used to characterize the mammary PTHrP transcript. A 1065 bp clone (bP1) for bovine PTHrP was isolated from a brain cDNA library. The bP1 clone contained the entire coding sequence of PTHrP and 61 and 473 nucleotides of the 5'- and 3'-untranslated regions (UTRs) respectively. The predicted amino acid sequence of bovine PTHrP was 72-92% homologous to the sequences of chicken, rat, mouse, human, and canine PTHrP with the highest sequence divergence present in the C-terminal region of the peptide. The 5'- and 3'-UTRs of bovine brain PTHrP have a high degree of homology to exons 4 and 9 of human PTHrP respectively. PTHrP was expressed as a single 1200 nucleotide mRNA transcript in lactating bovine mammary tissue. RT-PCR using region-specific oligonucleotide primers derived from bP1 demonstrated that PTHrP mRNA transcripts in bovine brain and lactating mammary gland utilize the same 5'- and 3'-UTRs. Expression of PTHrP mRNA was localized to secretory and ductular epithelial cells within the lactating mammary gland, as detected using in situ hybridization. Expression of PTHrP mRNA was demonstrated in the mammary gland during late pregnancy and throughout lactation in cows.

Rescue of the parathyroid hormone-related protein knockout mouse demonstrates that parathyroid hormone-related protein is essential for mammary gland development

Development ◽  
1998 ◽  
Vol 125 (7) ◽  
pp. 1285-1294 ◽  
Author(s):  
J.J. Wysolmerski ◽  
W.M. Philbrick ◽  
M.E. Dunbar ◽  
B. Lanske ◽  
H. Kronenberg ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Branching Morphogenesis ◽  
Mammary Epithelial ◽  
Related Protein ◽  
Transgenic Expression ◽  
Parathyroid Hormone Related Protein ◽  
Pthrp Receptor

Parathyroid hormone-related protein (PTHrP) was originally discovered as a tumor product that causes humoral hypercalcemia of malignancy. PTHrP is now known to be widely expressed in normal tissues and growing evidence suggests that it is an important developmental regulatory molecule. We had previously reported that overexpression of PTHrP in the mammary glands of transgenic mice impaired branching morphogenesis during sexual maturity and early pregnancy. We now demonstrate that PTHrP plays a critical role in the epithelial-mesenchymal communications that guide the initial round of branching morphogenesis that occurs during the embryonic development of the mammary gland. We have rescued the PTHrP-knockout mice from neonatal death by transgenic expression of PTHrP targeted to chondrocytes. These rescued mice are devoid of mammary epithelial ducts. We show that disruption of the PTHrP gene leads to a failure of the initial round of branching growth that is responsible for transforming the mammary bud into the rudimentary mammary duct system. In the absence of PTHrP, the mammary epithelial cells degenerate and disappear. The ability of PTHrP to support embryonic mammary development is a function of amino-terminal PTHrP, acting via the PTH/PTHrP receptor, for ablation of the PTH/PTHrP receptor gene recapitulates the phenotype of PTHrP gene ablation. We have localized PTHrP expression to the embryonic mammary epithelial cells and PTH/PTHrP receptor expression to the mammary mesenchyme using in situ hybridization histochemistry. Finally, we have rescued mammary gland development in PTHrP-null animals by transgenic expression of PTHrP in embryonic mammary epithelial cells. We conclude that PTHrP is a critical epithelial signal received by the mammary mesenchyme and involved in supporting the initiation of branching morphogenesis.

scholarly journals Serotonin induces parathyroid hormone-related protein in goat mammary gland

2018 ◽  
Vol 96 (3) ◽  
pp. 1010-1016 ◽  
Author(s):  
W J Zang ◽  
H Li ◽  
Z F Zhang ◽  
R QuZhen ◽  
Y Z CuoMu ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein

Production of parathyroid hormone-related protein by the rat mammary gland in pregnancy and lactation

1992 ◽  
Vol 263 (6) ◽  
pp. E1077-E1085 ◽  
Author(s):  
M. Rakopoulos ◽  
S. J. Vargas ◽  
M. T. Gillespie ◽  
P. W. Ho ◽  
H. Diefenbach-Jagger ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Parathyroid Hormone ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
Related Protein ◽  
Sprague Dawley ◽  
Parathyroid Hormone Related Protein ◽  
Pregnancy And Lactation ◽  
Rat Mammary Gland ◽  
In Pregnancy

Production of parathyroid hormone-related protein by the rat mammary gland in pregnancy and lactation. Am. J. Physiol. 263 (Endocrinol. Metab. 26): E1077-E1085, 1992.--Production of parathyroid hormone-related protein (PTHrP) by the mammary gland of Sprague-Dawley rats has been examined using immunohistochemistry and in situ hybridization to detect PTHrP and PTHrP mRNA, respectively. PTHrP and PTHrP mRNA could be demonstrated in nests of epithelial cells of the developing mammary gland at day 14 of pregnancy and in the epithelial secretory cells lining the alveoli during the latter stages of pregnancy and during lactation. A specific radioimmunoassay was also used to measure the concentration of PTHrP secreted in the milk throughout lactation. The concentration of PTHrP in milk was relatively low initially but increased during the latter stages of lactation, whereas calcium concentrations remained virtually constant throughout lactation. No correlation was found between the concentrations of calcium and PTHrP in rat milk. These results show that PTHrP is present in rat milk and also in mammary tissue before parturition, and therefore it may assist in the development of the mammary gland during pregnancy.

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