scholarly journals Age- and Sex-Dependent Changes in Androgen Receptor Expression in the Developing Mouse Cortex and Hippocampus

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Houng-Wei Tsai ◽  
Saori Taniguchi ◽  
Jason Samoza ◽  
Aaron Ridder

During the perinatal period, male mice are exposed to higher levels of testosterone (T) than females, which promotes sexual dimorphism in their brain structures and behaviors. In addition to acting via estrogen receptors after being locally converted into estradiol by aromatase, T also acts directly through androgen receptor (AR) in the brain. Therefore, we hypothesized that AR expression in the developing mouse cortex and hippocampus was sexually dimorphic. To test our hypothesis, we measured and determined AR mRNA and protein levels in mouse cortex/hippocampus collected on the day of birth (PN0) and 7 (PN7), 14 (PN14), and 21 (PN21) days after birth. We demonstrated that, as age advanced, AR mRNA levels increased in the cortex/hippocampus of both sexes but showed no sex difference. Two AR proteins, the full-length (110 kDa) and a smaller isoform (70 kDa), were detected in the developing mouse cortex/hippocampus with an age-dependent increase in protein levels of both AR isoforms at PN21 and a transient masculine increase in expression of the full-length AR protein on PN7. Thus, we conclude that the postnatal age and sex differences in AR protein expression in combination with the sex differences in circulating T may cause sexual differentiation of the mouse cortex/hippocampus.

2001 ◽  
Vol 356 (3) ◽  
pp. 883-889 ◽  
Author(s):  
Lorraine GAMBLING ◽  
Ruth DANZEISEN ◽  
Susan GAIR ◽  
Richard G. LEA ◽  
Zehane CHARANIA ◽  
...  

Maternal iron deficiency during pregnancy induces anaemia in the developing fetus; however, the severity tends to be less than in the mother. The mechanism underlying this resistance has not been determined. We have measured placental expression of proteins involved in iron transfer in pregnant rats given diets with decreasing levels of iron and examined the effect of iron deficiency on iron transfer across BeWo cell layers, a model for placental iron transfer. Transferrin receptor expression was increased at both mRNA and protein levels. Similarly, expression of the iron-responsive element (IRE)-regulated form of the divalent metal transporter 1 (DMT1) was also increased. In contrast, the non-IRE regulated isoform showed no change in mRNA levels. Protein levels of DMT1 increased significantly. Iron efflux is thought to be mediated by the metal transporter protein, IREG1/ferroportin1/MTP1, and oxidation of Fe(II) to Fe(III) prior to incorporation into fetal transferrin is carried out by the placental copper oxidase. Expression of IREG1 was not altered by iron deficiency, whereas copper oxidase activity was increased. In BeWo cells made iron deficient by treatment with desferrioxamine (‘deferioxamine’), iron accumulation from iron-transferrin increased, in parallel with increased expression of the transferrin receptor. At the same time, iron efflux also increased, showing a higher flux of iron from the apical to the basolateral side. The data show that expression of placental proteins of iron transport are up-regulated in maternal iron deficiency, resulting in an increased efficiency of iron flux and a consequent minimization of the severity of fetal anaemia.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Hetal Mistry ◽  
Madeline Levy ◽  
Meaghan Roy-O'Reilly ◽  
Louise McCullough

Background and Purpose: Orosomucoid-1 (ORM-1) is an abundant protein with important roles in inflammation and immunosuppression. We utilized RNA sequencing to measure mRNA levels in human ischemic stroke patients, with confirmation by serum ORM-1 protein measurements. A mouse model of ischemic stroke was then used to examine post-stroke changes in ORM-1 within the brain itself. Hypothesis: We tested the hypothesis that ORM-1 levels increase following ischemic stroke, with sex differences in protein dynamics over time. Methods: RNA sequencing was performed on whole blood from ischemic stroke patients (n=23) and controls (n=12), with Benjamini-Hochberg correction for multiple testing. Enzyme-linked immunosorbent assay was performed on serum from ischemic stroke patients (n=28) and controls (n=8), with analysis by T-test. For brain analysis, mice (n=14) were subjected to a 90-minute middle cerebral artery occlusion (MCAO) surgery and sacrificed 6 or 24 hours after stroke. Control mice underwent parallel “sham” surgery without occlusion. Western blotting was used to detect ORM-1 protein levels in whole brain, with analysis by two-way ANOVA. Results: RNA sequencing showed a 2.8-fold increase in human ORM-1 at 24 hours post-stroke (q=.0029), an increase also seen in serum ORM-1 protein levels (p=.011). Western blot analysis of mouse brain revealed that glycosylated (p=0.0003) and naive (p=0.0333) forms of ORM-1 were higher in female mice compared to males 6 hours post-stroke. Interestingly, ORM-1 levels were higher in the brains of stroke mice at 6 hours (p=.0483), while at 24 hours ORM-1 levels in stroke mice were lower than their sham counterparts (p=.0212). In both human and mouse data, no sex differences were seen in ORM-1 levels in the brain or periphery at 24 hours post-stroke. Conclusion: In conclusion, ORM-1 is a sexually dimorphic protein involved in the early (<24 hour) response to ischemic stroke. This research serves as an initial step in determining the mechanism of ORM-1 in the ischemic stroke response and its potential as a future therapeutic target for both sexes.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yanlan Chen ◽  
Wen Huang ◽  
Wenlin Jiang ◽  
Xianghong Wu ◽  
Biao Ye ◽  
...  

HIV-1 transactivator protein (Tat) has been shown to play an important role in HIV-associated neurocognitive disorders. The aim of the present study was to evaluate the relationship between occludin and amyloid-beta (Aβ) transfer receptors in human cerebral microvascular endothelial cells (hCMEC/D3) in the context of HIV-1-related pathology. The protein expressions of occludin, receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP1) in hCMEC/D3 cells were examined using western blotting and immunofluorescent staining. The mRNA levels of occludin, RAGE, and LRP1 were measured using quantitative real-time polymerase chain reaction. HIV-1 Tat at 1 µg/mL and the Rho inhibitor hydroxyfasudil (HF) at 30 µmol/L, with 24 h exposure, had no significant effect on hCMEC/D3 cell viability. Treatment with HIV-1 Tat protein decreased mRNA and protein levels of occludin and LRP1 and upregulated the expression of RAGE; however, these effects were attenuated by HF. These data suggest that the Rho/ROCK signaling pathway is involved in HIV-1 Tat-mediated changes in occludin, RAGE, and LRP1 in hCMEC/D3 cells. HF may have a beneficial influence by protecting the integrity of the blood-brain barrier and the expression of Aβtransfer receptors.


2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 199-199 ◽  
Author(s):  
Daisuke Kajiwara ◽  
Kazuhisa Minamiguchi ◽  
Masanao Seki ◽  
Hiroya Mizutani ◽  
Hiroki Aoyagi ◽  
...  

199 Background: Two new therapies, enzalutamide and abiraterone, directed at the androgen receptor (AR) signaling axis, represent important advances in the management of castration-resistant prostate cancer (CRPC). However, eventually almost all of patients acquire resistance to these drugs by a variety of mechanisms. Ligand independent AR activation such as induction of AR splice variants and AR overexpression are major issues of current CRPC progression. In the present study, we report the biological characterization of TAS3681, which is a new AR antagonist with AR downregulation activity, and propose this concept as a potential new approach for the treatment of CRPC. Methods: For assay of AR transactivation, prostate cancer (PCa) cells were transiently transfected with androgen-responsive reporter gene construct. The transfected cells were treated with growth factor and cytokine in steroid-depleted media, and luciferase activity was measured. To evaluate the effect of TAS3681 on AR and c-Myc protein expression, PCa cells were treated with TAS3681 in steroid-depleted media. AR and c-Myc protein levels were determined by western blot. Real-time PCR was used to analyze the mRNA levels of c-Myc and c-Myc target gene. Chromatin immunoprecipitation was performed to determine the enrichment of AR at the element. Results: TAS3681 dose-dependently reduced AR protein levels in PCa cells. In contrast to enzalutamide, TAS3681 suppressed androgen-independent AR transactivation by growth factor and cytokine. In PCa cells which express full-length AR and splice variant AR-v7, TAS3681 suppressed AR-v7 target gene expression through downregulation of AR-v7. Moreover, TAS3681 reduced expression of c-Myc, critical driver of androgen-independent mechanisms of PCa progression, via AR downregulation activity. In addition, real-time PCR assay showed the transcriptional suppression of c-Myc and its target gene by TAS3681. Conclusions: TAS3681 exhibits suppressive effects on ligand-independent AR activation via AR decreasing activity. These finding suggest that TAS3681 could be a candidate of breakthrough therapy for resistance to current AR pathway target drugs.


PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0177711 ◽  
Author(s):  
Eric R. Schuppe ◽  
Devaleena S. Pradhan ◽  
Kevin Thonkulpitak ◽  
Cathleen Drilling ◽  
Michael Black ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
M. A. Nieuwesteeg ◽  
J. A. Willson ◽  
M. Cepeda ◽  
M. A. Fox ◽  
S. Damjanovski

Extracellular matrix (ECM) remodeling is essential for facilitating developmental processes. ECM remodeling, accomplished by matrix metalloproteinases (MMPs), is regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs). While the TIMP N-terminal domain is involved in inhibition of MMP activity, the C-terminal domain exhibits cell-signaling activity, which is TIMP and cell type dependent. We have previously examined the distinct roles of theXenopus laevisTIMP-2 and -3 C-terminal domains during development and here examined the unique roles of TIMP-1 N- and C-terminal domains in earlyX. laevisembryos. mRNA microinjection was used to overexpress full-length TIMP-1 or its individual N- or C-terminal domains in embryos. Full-length and C-terminal TIMP-1 resulted in increased lethality compared to N-terminal TIMP-1. Overexpression of C-terminal TIMP-1 resulted in significant decreases in mRNA levels of proteolytic genes including TIMP-2, RECK, MMP-2, and MMP-9, corresponding to decreases in MMP-2 and -9 protein levels, as well as decreased MMP-2 and MMP-9 activities. These trends were not observed with the N-terminus. Our research suggests that the individual domains of TIMP-1 are capable of playing distinct roles in regulating the ECM proteolytic network during development and that the unique functions of these domains are moderated in the endogenous full-length TIMP-1 molecule.


2005 ◽  
Vol 289 (5) ◽  
pp. E857-E863 ◽  
Author(s):  
Anastasia Kariagina ◽  
Svetlana Zonis ◽  
Mahta Afkhami ◽  
Dmitry Romanenko ◽  
Vera Chesnokova

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine belonging to the gp130 family. LIF is induced peripherally and within the brain during inflammatory or chronic autoimmune diseases and is a potent stimulator of the hypothalamic-pituitary-adrenal (HPA) axis. Here we investigated the role of LIF in mediating glucocorticoid receptor (GR) expression in the HPA axis. LIF treatment (3 μg/mouse, ip) markedly decreased GR mRNA levels in murine hypothalamus (5-fold, P < 0.01) and pituitary (1.7-fold, P < 0.01) and downregulated GR protein levels. LIF decreased GR expression in murine corticotroph cell line AtT20 within 2 h, and this effect was sustained for 8 h after treatment. LIF-induced GR mRNA reduction was abrogated in AtT20 cells overexpressing dominant-negative mutants of STAT3, indicating that intact JAK-STAT signaling is required to mediate LIF effects on GR expression. Conversely, mice with LIF deficiency exhibited increased GR mRNA levels in the hypothalamus and pituitary (3.5- and 3.5-fold, respectively; P < 0.01 for both) and increased GR protein expression when compared with wild-type littermates. The suppressive effects of dexamethasone on GR were more pronounced in LIF-null animals. These data suggest that LIF maintains the HPA axis activation by decreasing GR expression and raise the possibility that LIF might contribute to the development of central glucocorticoid resistance during inflammation.


2003 ◽  
Vol 284 (1) ◽  
pp. R51-R56 ◽  
Author(s):  
Sharla F. Young ◽  
Jennifer L. Smith ◽  
Jorge P. Figueroa ◽  
James C. Rose

Corticotroph responsiveness to arginine vasopressin (AVP) increases during late gestation in fetal sheep. The mechanism of this increase in AVP responsiveness is currently unknown but could be related to an increase in vasopressin type 1b (V1b) receptor expression in the pituitary during development. To determine if there are ontogenic changes in V1b receptor expression that may help explain the changes in ACTH responses to AVP, we studied pituitaries from three groups of fetal sheep [100, 120, or 140 days gestational age (dGA)]. V1b receptor mRNA and protein significantly decreased by 140 dGA. Peak V1b mRNA levels were detected at 100 dGA, while peak V1b protein levels were detected at 120 dGA. The reduction in V1b receptor expression in late gestation may be due to the naturally occurring peripartum increase in fetal plasma cortisol because cortisol infusion at 122–130 dGA decreased V1b receptor mRNA. Thus there is a marked decrease in the expression of the V1b receptor in the pituitary during fetal development, leaving the role of the V1b receptor in increasing AVP responsiveness uncertain.


2005 ◽  
Vol 289 (2) ◽  
pp. R410-R417 ◽  
Author(s):  
Nancy K. Valego ◽  
Yixin Su ◽  
Luke C. Carey ◽  
Sharla F. Young ◽  
Stephen B. Tatter ◽  
...  

Although it has been recognized for over a decade that hypothalamic-pituitary disconnection (HPD) in fetal sheep prevents the late gestation rise in plasma cortisol concentrations, the underlying mechanisms remain unclear. We hypothesized that reductions in adrenal responsiveness and ACTH receptor (ACTH-R) expression may be mediating factors. HPD or sham surgery was performed at 120 days of gestation, and catheters were placed for blood sampling. At ∼138 days of gestation, fetuses were killed, and adrenals were removed for cell culture and analyses of ACTH-R mRNA and protein. After 48 h, adrenocortical cells were stimulated with ACTH for 2 h, and the medium was collected for cortisol measurement. The same cells were incubated overnight with medium or medium containing ACTH or forskolin (FSK), followed by ACTH stimulation (as above) and cortisol and cellular ACTH-R mRNA analyses. HPD prevented the late gestation increase in plasma cortisol and bioactive ACTH and reduced adrenal ACTH-R mRNA and protein levels by over 35%. HPD cells secreted significantly less cortisol than sham cells (3.2 ± 1.2 vs. 47.3 ± 11.1 ng·ml−1·2 h−1) after the initial ACTH stimulation. Overnight incubation of HPD cells with ACTH or FSK restored cortisol responses to acute stimulation to levels seen in sham cells initially. ACTH-R mRNA levels in cells isolated from HPD fetuses were decreased by over 60%, whereas overnight incubation with ACTH or FSK increased levels by approximately twofold. Our findings indicate that the absence of the cortisol surge in HPD fetuses is a consequence, at least in part, of decreased ACTH-R expression and adrenal responsiveness.


2019 ◽  
Author(s):  
Shayna E. Thomas-Jardin ◽  
Haley Dahl ◽  
Mohammed S. Kanchwala ◽  
Freedom Ha ◽  
Joan Jacob ◽  
...  

ABSTRACTBackgroundThe Androgen Receptor (AR) nuclear transcription factor is a therapeutic target for prostate cancer (PCa). Unfortunately, patients can develop resistance to AR-targeted therapies and progress to lethal disease, underscoring the importance of understanding the molecular mechanisms that underlie treatment resistance. Inflammation is implicated in PCa initiation and progression and we have previously reported that the inflammatory cytokine, interleukin-1 (IL-1), represses AR mRNA levels and activity in AR-positive (AR+) PCa cell lines concomitant with the upregulation of pro-survival biomolecules. Thus, we contend that IL-1 can select for AR-independent, treatment-resistant PCa cells.MethodsTo begin to explore how IL-1 signaling leads to the repression of AR mRNA levels, we performed comprehensive pathway analysis on our RNA sequencing data from IL-1-treated LNCaP PCa cells. Our pathway analysis predicted Nuclear Factor Kappa B (NF-κB) p65 subunit (RELA), a canonical IL-1 signal transducer, to be significantly active and potentially regulate many genes, including AR. We used siRNA to silence the NF-κB family of transcription factor subunits, RELA, RELB, c-REL, NFKB1, or NFKB2, in IL-1-treated LNCaP, C4-2, and C4-2B PCa cell lines. C4-2 and C4-2B cell lines are castration-resistant LNCaP sublines and represent progression towards metastatic PCa disease; and we have previously shown that IL-1 represses AR mRNA levels in C4-2 and C4-2B cells.ResultssiRNA revealed that RELA alone is sufficient to mediate IL-1 repression of AR mRNA and AR activity. Intriguingly, while LNCaP cells are more sensitive to IL-1-mediated repression of AR than C4-2 and C4-2B cells, RELA siRNA led to a more striking de-repression of AR mRNA levels and AR activity in C4-2 and C4-2B cells than in LNCaP cells.ConclusionsThese data indicate that there are RELA-independent mechanisms that regulate IL-1-mediated AR repression in LNCaP cells and suggest that the switch to RELA-dependent IL-1 repression of AR in C4-2 and C4-2B cells reflects changes in epigenetic and transcriptional programs that evolve during PCa disease progression.


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