scholarly journals Genomic Priming of the Antisecretory Response to Estrogen in Rat Distal Colon throughout the Estrous Cycle

2009 ◽  
Vol 30 (6) ◽  
pp. 751-751
Author(s):  
Fiona O'Mahony ◽  
Rodrigo Alzamora ◽  
Ho-Lam Chung ◽  
Warren Thomas ◽  
Brian J. Harvey
Keyword(s):  
Estrogen Receptor ◽  
Estrous Cycle ◽  
Intestinal Secretion ◽  
Distal Colon ◽  
Estrogen Receptor Α ◽  
Transcriptional Level ◽  
Colonic Crypt ◽  
Estrogen Regulation ◽  
Antisecretory Effect ◽  
Crypt Cells

ABSTRACT The secretion of Cl− across distal colonic crypt cells provides the driving force for the movement of fluid into the luminal space. 17β-Estradiol (E2) produces a rapid and sustained reduction in secretion in females, which is dependent on the novel protein kinase Cδ (PKCδ) isozyme and PKA isoform I targeting of KCNQ1 channels. This sexual dimorphism in the E2 response is associated with a higher expression level of PKCδ in female compared with the male tissue. The present study revealed the antisecretory response is regulated throughout the female reproductive (estrous) cycle and is primed by genomic regulation of the kinases. E2 (1-10 nm) decreased cAMP-dependent secretion in colonic epithelia during the estrous, metestrous, and diestrous stages. A weak inhibition of secretion was demonstrated in the proestrous stage. The expression levels of PKCδ and PKA fluctuated throughout the estrous cycle and correlated with the potency of the antisecretory effect of E2. The expression of PKCδ and PKA were up-regulated by estrogen at a transcriptional level via a PKCδ-MAPK-cAMP response element-binding protein-regulated pathway indicating a genomic priming of the antisecretory response. PKCδ was activated by the membrane-impermeant E2-BSA, and this response was inhibited by the estrogen receptor antagonist ICI 182,780. The 66-kDa estrogen receptor-α isoform was present at the plasma membrane of female colonic crypt cells with a lower abundance found in male colonic crypts. The study demonstrates estrogen regulation of intestinal secretion both at a rapid and transcriptional level, demonstrating an interdependent relationship between both nongenomic and genomic hormone responses.

scholarly journals Genomic Priming of the Antisecretory Response to Estrogen in Rat Distal Colon throughout the Estrous Cycle

2009 ◽  
Vol 94 (11) ◽  
pp. 4627-4628
Author(s):  
Fiona O'Mahony ◽  
Rodrigo Alzamora ◽  
Ho-Lam Chung ◽  
Warren Thomas ◽  
Brian J. Harvey
Keyword(s):  
Estrogen Receptor ◽  
Estrous Cycle ◽  
Intestinal Secretion ◽  
Distal Colon ◽  
Estrogen Receptor Α ◽  
Transcriptional Level ◽  
Colonic Crypt ◽  
Estrogen Regulation ◽  
Antisecretory Effect ◽  
Crypt Cells

Abstract The secretion of Cl− across distal colonic crypt cells provides the driving force for the movement of fluid into the luminal space. 17β-Estradiol (E2) produces a rapid and sustained reduction in secretion in females, which is dependent on the novel protein kinase Cδ (PKCδ) isozyme and PKA isoform I targeting of KCNQ1 channels. This sexual dimorphism in the E2 response is associated with a higher expression level of PKCδ in female compared with the male tissue. The present study revealed the antisecretory response is regulated throughout the female reproductive (estrous) cycle and is primed by genomic regulation of the kinases. E2 (1–10 nm) decreased cAMP-dependent secretion in colonic epithelia during the estrous, metestrous, and diestrous stages. A weak inhibition of secretion was demonstrated in the proestrous stage. The expression levels of PKCδ and PKA fluctuated throughout the estrous cycle and correlated with the potency of the antisecretory effect of E2. The expression of PKCδ and PKA were up-regulated by estrogen at a transcriptional level via a PKCδ-MAPK-cAMP response element-binding protein-regulated pathway indicating a genomic priming of the antisecretory response. PKCδ was activated by the membrane-impermeant E2-BSA, and this response was inhibited by the estrogen receptor antagonist ICI 182,780. The 66-kDa estrogen receptor-α isoform was present at the plasma membrane of female colonic crypt cells with a lower abundance found in male colonic crypts. The study demonstrates estrogen regulation of intestinal secretion both at a rapid and transcriptional level, demonstrating an interdependent relationship between both nongenomic and genomic hormone responses.

Structure, tissue distribution and estrogen regulation of splice variants of the sea bream estrogen receptor α gene

Gene ◽  
2012 ◽  
Vol 503 (1) ◽  
pp. 18-24 ◽  
Author(s):  
P.I.S. Pinto ◽  
R. Teodósio ◽  
S. Socorro ◽  
D.M. Power ◽  
A.V.M. Canário
Keyword(s):  
Estrogen Receptor ◽  
Tissue Distribution ◽  
Splice Variants ◽  
Estrogen Receptor Α ◽  
Sea Bream ◽  
Estrogen Regulation ◽  
Estrogen Receptor Α Gene

scholarly journals The estrogen receptor α Σ3 mRNA splicing variant is differentially regulated by estrogen and progesterone in the rat uterus

2005 ◽  
Vol 186 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J Varayoud ◽  
J G Ramos ◽  
L Monje ◽  
V Bosquiazzo ◽  
M Muñoz-de-Toro ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Alternative Splicing ◽  
Estrous Cycle ◽  
Low Dose ◽  
Estrogen Receptor Α ◽  
Mrna Splicing ◽  
Female Rats ◽  
Rt Pcr ◽  
Mrna Isoforms ◽  
Rat Uterus

The gene for estrogen receptor α (ERα) has been shown to be under complex hormonal control and its activity can be regulated by mRNA alternative splicing. Here we examined the regulation of ERα transcription and translation in the rat uterus by ovarian steroid hormones. We examined whether expression of ERα mRNA splice isoforms is hormonally regulated in ovariectomized (OVX) and cycling rats. Adult OVX female rats were treated daily with 17-β estradiol (E2) (0.05 μg/rat or 5 μg/rat), progesterone (P4) (1 mg/rat) or a combination of both hormones for 4 days. Animals were killed 24 h after the last injection and uterine horns were removed. In order to determine whether ERα mRNA isoforms are differentially expressed under various physiological conditions, animals were evaluated at proestrus, estrus and diestrus. The ERα protein and mRNA were detected by immunohistochemistry and comparative RT-PCR analysis respectively. The presence of ERα mRNA isoforms was evaluated using a nested RT-PCR assay. In OVX control rats, ERα mRNA and protein levels were high, demonstrating a constitutive expression of the ERα gene in the uterus. When animals received P4 or the high dose of E2, a significant decrease in both ERα mRNA and protein was observed in the uterus. However, when rats were protein was treated with the low dose of E2, only the ERα down-regulated; no changes were observed in ERα mRNA expression. In addition to the full-length ERα mRNA, OVX control rat uteri expressed three shorter transcripts: Σ3, Σ4 and Σ3,4 (lacking exon 3, exon 4, or both 3 and 4 respectively). Surprisingly, when OVX animals were treated with P4, the low dose of E2 or a combination of both steroids, expression of the Σ3 isoform was completely abolished. During the estrous cycle, all ERα mRNA splicing variants were detected at proestrus and estrus. However, in diestrus, significant low levels of the Σ3 isoform were observed. In summary, our results suggest a dose-dependent relationship between E2 concentrations and the level of control in the ERα transcription–translation cascade. Moreover, the alternative splicing of the ERα primary transcript is influenced by the hormonal milieu, suggesting that these events could affect the estrogen responsiveness of the rat uterus during the estrous cycle.

Estrogen regulation of trefoil factor 1 expression by estrogen receptor α and Sp proteins

2005 ◽  
Vol 302 (1) ◽  
pp. 96-107 ◽  
Author(s):  
Jian-Min Sun ◽  
Virginia A. Spencer ◽  
Lin Li ◽  
Hou Yu Chen ◽  
Jenny Yu ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Estrogen Receptor Α ◽  
Trefoil Factor ◽  
Estrogen Regulation ◽  
Trefoil Factor 1

Regulation of intracellular pH in crypt cells from rabbit distal colon

1994 ◽  
Vol 267 (3) ◽  
pp. G409-G415 ◽  
Author(s):  
S. L. Abrahamse ◽  
A. Vis ◽  
R. J. Bindels ◽  
C. H. van Os
Keyword(s):  
Intracellular Ph ◽  
Distal Colon ◽  
Buffering Capacity ◽  
Colonic Crypt ◽  
Bafilomycin A1 ◽  
Acid Load ◽  
Intracellular Buffering Capacity ◽  
Crypt Cells ◽  
Exchange Activity ◽  
In Cells

H+ secretory mechanisms and intrinsic intracellular buffering capacity were studied in crypt cells from rabbit distal colon. To this end crypts of Lieberkuhn were isolated by microdissection, and intracellular pH (pHi) was measured using digital imaging fluorescence microscopy and the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)- 5(6)-carboxyfluorescein. In the absence of HCO(3-)-CO2 and presence of Na+, resting pHi was 7.51 +/- 0.04 (n = 237/23, cells/crypts). However, 6 min after superfusion with a solution containing zero Na+, 1 x 10(5) M Sch-28080 and 5 x 10(-8) M bafilomycin A1, pHi in cells at the bottom of the crypts was significantly reduced, whereas pHi in cells at the top of the crypts remained unchanged. The intrinsic buffering capacity of cells from the middle to the top portion of crypts was significantly higher in the pHi range 7.2-7.6 than of cells at the bottom of the crypt. H+ secretion after an NH(4+)-NH3 pulse amounted to 245 +/- 53 microM/s (n = 73/7) at pHi 7.1 and was largely Na+ dependent and ethylisopropylamiloride sensitive. The Na(+)-independent recovery of pHi after an acid load was insensitive to Sch-28080 and bafilomycin A1. In conclusion, pHi in colonic crypt cells is regulated through Na+/H+ exchange activity in the absence of HCO3-. In addition, intracellular buffering capacity varied with the position along the crypt axis, whereas Na+/H+ exchange activity and pHi did not.

Expression of estrogen receptor α and β genes in the mediobasal hypothalamus, pituitary and ovary during the canine estrous cycle

2003 ◽  
Vol 347 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Shingo Hatoya ◽  
Ryuzo Torii ◽  
Daijiro Kumagai ◽  
Kikuya Sugiura ◽  
Noritoshi Kawate ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Estrous Cycle ◽  
Estrogen Receptor Α ◽  
Mediobasal Hypothalamus
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