Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Oct;15(10):1034-44.
doi: 10.1038/mp.2009.78. Epub 2009 Aug 18.

Effect of ovarian hormones on genes promoting dendritic spines in laser-captured serotonin neurons from macaques

C L Bethea  1 , A P Reddy
Affiliations

Effect of ovarian hormones on genes promoting dendritic spines in laser-captured serotonin neurons from macaques

C L Bethea et al. Mol Psychiatry. 2010 Oct.

Abstract

Dendritic spines are the elementary structural units of neuronal plasticity and the cascades that promote dendritic spine remodeling center on Rho GTPases and downstream effectors of actin dynamics. In a model of hormone replacement therapy, we sought the effect of estradiol (E) and progesterone (P) on gene expression in these cascades in laser-captured serotonin neurons from rhesus macaques with complementary DNA array analysis. Ovariectomized rhesus macaques were treated with either placebo, E or E+P through Silastic implant for 1 month before euthanasia. The midbrain was obtained, sectioned and immunostained for tryptophan hydroxylase (TPH). TPH-positive neurons were laser captured using an Arcturus Laser Dissection Microscope (PixCell II). RNA from laser-captured serotonin neurons (n=2 animals/treatment) was hybridized to Rhesus Affymetrix GeneChips. With E±P treatment, there was a significant change in 744 probe sets (analysis of variance, P<0.05), but 10,493 probe sets exhibited a twofold or greater change. Pivotal changes in pathways leading to dendritic spine proliferation and transformation included twofold or greater increases in expression of the Rho GTPases called CDC42, Rac1 and RhoA. In addition, twofold or greater increases occurred in downstream effectors of actin dynamics, including p21-activated kinase (PAK1), Rho-associated coiled-coil-containing protein kinase (ROCK), PIP5K, IRSp53, Wiskott-Aldrich syndrome protein (WASP), WASP family Verprolin-homologous protein (WAVE), MLC, cofilin, gelsolin, profilin and three subunits of actin-related protein (ARP2/3). Finally, twofold or greater decreases occurred in CRIPAK, LIMK2 and myosin light chain kinase (MLCK). The regulation of RhoA, Rac1, CDC42, ROCK, PIP5k, IRSp53, WASP, WAVE, LIMK2, CRIPAK1, MLCK, ARP2/3 subunit 3, gelsolin, profilin and cofilin was confirmed with nested quantitative reverse transcriptase-PCR on laser-captured RNA (n=3 animals/treatment). The data indicate that ovarian steroids target gene expression of the Rho GTPases and pivotal downstream proteins, that in turn would promote dendritic spine proliferation and stabilization on serotonin neurons of the dorsal raphe nucleus.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Chart illustrating the key Rho GTPases and their downstream effectors for actin and myosin activation leading to dendritic spine protrusion and transformation. RNA extracted from laser captured serotonin neurons was labeled and hybridized to the Rhesus Affymetrix GeneChip (n=2 animals/treatment) and the results were analyzed with GeneSifter. The genes in red increased 2-fold or greater and the genes in blue decreased 2-fold or greater with E or E+P treatment compared to ovariectomized placebo treated controls.
Figure 2
Figure 2
Histograms illustrating changes in gene expression obtained with nested qRT-PCR on RNA extracted from laser captured serotonin neurons (n=3 animals/treatment). The Rho GTPases, RhoA, and Rac1 significantly increased with E alone (ANOVA p<0.0002 and 0.00115, respectively) whereas CDC42 increased with E and E+P (ANOVA p<0.05). Downstream effectors ROCK2 increased with E+P (ANOVA p<0.0047) whereas PIP5K and IRSp53 increased with E alone (ANOVA p<0.05 and #t-test p<0.0114, respectively). The variance in IRSp53 in the E+P treated group was significantly different from the ovx group (+F test p<0.0028). * p<0.05 different from ovx control with Student-Newman-Keuls posthoc pairwise comparison after ANOVA.
Figure 3
Figure 3
Histograms illustrating changes in gene expression obtained with nested qRT-PCR on RNA extracted from laser captured serotonin neurons (n=3 animals/treatment). Intermediaries WAVE and WASP were significantly increased with E treatment, respectively (ANOVA p< 0.0129 and #t-test p<0.0001). The variance in WASP in the E+P treated group was significantly different from the ovx group (+F test p<0.0027). The actin regulatory proteins ARP3 and cofilin significantly increased with E and E+P treatment (ANOVA p<0.0329 and p<0.0093, respectively). However, gelsolin and profilin increases only with E+P (ANOVA p<0.0029 and p<0.0001, respectively). * p<0.05 different from ovx control with Student-Newman-Keuls posthoc pairwise comparison after ANOVA.
Figure 4
Figure 4
Histograms illustrating changes in gene expression obtained with nested qRT-PCR on RNA extracted from laser captured serotonin neurons (n=3 animals/treatment). Downstream of Rac1, MLCK was significantly decreased by E and E+P treatment (ANOVA p<0.0166) whereas LIMK2 was significantly decreased by E+P treatment (#t-test p<0.05; F-test p<0.0001). The endogenous Pak1 inhibitor, CRIPAK, was significantly decreased by E and E+P treatment (ANOVA p<0.0001). * p<0.05 different from ovx control with Student-Newman-Keuls posthoc pairwise comparison after ANOVA.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Manji HK, Quiroz JA, Sporn J, Payne JL, Denicoff K, et al. Enhancing neuronal plasticity and cellular resilience to develop novel, improved therapeutics for difficult-to-treat depression. Biol Psychiatry. 2003 Apr 15;53(8):707–742. - PubMed
    1. Ethell IM, Pasquale EB. Molecular mechanisms of dendritic spine development and remodeling. Prog Neurobiol. 2005 Feb;75(3):161–205. - PubMed
    1. Butler AK, Uryu K, Chesselet MF. A role for N-methyl-D-aspartate receptors in the regulation of synaptogenesis and expression of the polysialylated form of the neural cell adhesion molecule in the developing striatum. Dev Neurosci. 1998;20(2–3):253–262. - PubMed
    1. McKinney RA, Capogna M, Durr R, Gahwiler BH, Thompson SM. Miniature synaptic events maintain dendritic spines via AMPA receptor activation. Nat Neurosci. 1999 Jan;2(1):44–49. - PubMed
    1. Cooke BM, Woolley CS. Gonadal hormone modulation of dendrites in the mammalian CNS. J Neurobiol. 2005 Jul;64(1):34–46. - PubMed

Publication types

MeSH terms