Glucocorticoids and serotonin alter glucocorticoid receptor mRNA levels in fetal guinea-pig hippocampal neurons, in vitro

2005 ◽  
Vol 17 (7) ◽  
pp. 743 ◽  
Author(s):  
P. Erdeljan ◽  
M. H. Andrews ◽  
J. F. MacDonald ◽  
S. G. Matthews
Keyword(s):  
Guinea Pig ◽  
Glucocorticoid Receptor ◽  
Hpa Axis ◽  
Hippocampal Neurons ◽  
In Situ Hybridisation ◽  
Fetal Life ◽  
Mrna Levels ◽  
Glucocorticoid Receptor Mrna ◽  
Synthetic Glucocorticoids

The hypothalamic–pituitary–adrenal (HPA) axis is susceptible to programming during fetal life. Such programming occurs, at least partially, at the level of the hippocampus. The hippocampus plays a central role in regulation of the HPA axis and release of endogenous glucocorticoids, via mediation of glucocorticoid negative feedback. Fetal exposure to synthetic glucocorticoids can permanently alter glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) levels within the hippocampus, and serotonin is thought to be involved in this process. In the present study, we hypothesised that dexamethasone, cortisol and serotonin exposure would modify GR mRNA expression within fetal guinea-pig hippocampal cultures. Cultures were derived from 40-day-old guinea-pig fetuses, and were exposed to 0, 1, 10 and 100 nm dexamethasone, cortisol or serotonin for 4 days. Expression of GR and MR mRNA was examined by in situ hybridisation followed by high-resolution silver emulsion autoradiography. Four-day exposure to dexamethasone (P < 0.05; 100 nm) or cortisol (P = 0.08; 100 nm) downregulated the expression of GR mRNA within neurons. There was no change in the expression of MR mRNA levels following cortisol treatment. Exposure to serotonin (100 nm) significantly increased GR mRNA levels in hippocampal neurons. We conclude that synthetic and endogenous glucocorticoids, as well as serotonin, can influence GR expression during hippocampal development and in this way may act to permanently programme HPA function.

Spaceflight modulates insulin-like growth factor binding proteins and glucocorticoid receptor in osteoblasts

1998 ◽  
Vol 85 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Yasuhiro Kumei ◽  
Hitoyata Shimokawa ◽  
Hisako Katano ◽  
Hideo Akiyama ◽  
Masahiko Hirano ◽  
...  
Keyword(s):  
Growth Factor ◽  
Glucocorticoid Receptor ◽  
Space Shuttle ◽  
Mrna Levels ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Dihydroxyvitamin D ◽  
Protein Levels ◽  
Glucocorticoid Receptor Mrna ◽  
Cellular Dna

Rat osteoblasts were cultured for 4 or 5 days during a Space Shuttle mission. After 20-h treatment with 1α,25-dihydroxyvitamin D3, conditioned media were harvested and cellular DNA and/or RNA were fixed on board. The insulin-like growth factor binding protein (IGF BP)-3 levels in the media were three- and tenfold higher than in ground controls on the fourth and fifth flight days, as quantitated by Western ligand blotting and radioimmunoassay, respectively. The increased IGF BP-3 protein levels correlated with two- to threefold elevation of IGF BP-3 mRNA levels, obtained by reverse transcription-polymerase chain reaction. The IGF BP-5 mRNA levels in flight cultures were 33–69% lower than in ground controls. The IGF BP-4 mRNA levels in flight cultures were 75% lower than in ground controls on the fifth day but were not different on the fourth day. The glucocorticoid receptor mRNA levels in flight cultures were increased by three- to eightfold on the fourth and fifth days compared with levels in ground controls. These data suggest potential mechanisms underlying spaceflight-induced osteopenia.

Determinants of leptin gene expression in fat depots of lean mice

2002 ◽  
Vol 282 (1) ◽  
pp. R226-R234 ◽  
Author(s):  
Yiying Zhang ◽  
Kai-Ying Guo ◽  
Patricia A. Diaz ◽  
Moonseong Heo ◽  
Rudolph L. Leibel
Keyword(s):  
Gene Expression ◽  
Glucocorticoid Receptor ◽  
Insulin Receptor ◽  
Physiological Role ◽  
Mrna Levels ◽  
Strongly Correlated ◽  
Fat Depots ◽  
Tnf Α ◽  
Adipocyte Volume

The relationship of leptin gene expression to adipocyte volume was investigated in lean 10-wk-old male C57BL/6J mice. mRNA levels for leptin, insulin receptor, glucocorticoid receptor, and tumor necrosis factor (TNF)-α in inguinal, epididymal, and retroperitoneal adipose tissues were quantified and related to adipocyte volume. Leptin mRNA levels were highly correlated with adipocyte volume within each fat depot. Multiple regression analysis of pooled data from the three depots showed that leptin mRNA levels were strongly correlated with adipocyte volumes (β = 0.84, P < 0.001) and, to a smaller degree, with glucocorticoid receptor mRNA levels (β = 0.36, P < 0.001). Depot of origin had no effect ( P > 0.9). Rates of leptin secretion in vitro were strongly correlated with leptin mRNA levels ( r = 0.89, P < 0.001). mRNA levels for TNF-α, insulin receptor, and glucocorticoid receptor showed no significant correlation with adipocyte volume. These results demonstrate that depot-specific differences in leptin gene expression are mainly related to the volumes of the constituent adipocytes. The strong correlation between leptin gene expression and adipocyte volume supports leptin's physiological role as a humoral signal of fat mass.

scholarly journals RTP801/REDD1 contributes to neuroinflammation severity and memory impairments in Alzheimer’s disease

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Leticia Pérez-Sisqués ◽  
Anna Sancho-Balsells ◽  
Júlia Solana-Balaguer ◽  
Genís Campoy-Campos ◽  
Marcel Vives-Isern ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Hippocampal Neurons ◽  
Mrna Levels ◽  
Spine Density ◽  
Memory Impairments ◽  
Protein Levels ◽  
Synaptic Markers ◽  
5Xfad Mice

AbstractRTP801/REDD1 is a stress-regulated protein whose upregulation is necessary and sufficient to trigger neuronal death. Its downregulation in Parkinson’s and Huntington’s disease models ameliorates the pathological phenotypes. In the context of Alzheimer’s disease (AD), the coding gene for RTP801, DDIT4, is responsive to Aβ and modulates its cytotoxicity in vitro. Also, RTP801 mRNA levels are increased in AD patients’ lymphocytes. However, the involvement of RTP801 in the pathophysiology of AD has not been yet tested. Here, we demonstrate that RTP801 levels are increased in postmortem hippocampal samples from AD patients. Interestingly, RTP801 protein levels correlated with both Braak and Thal stages of the disease and with GFAP expression. RTP801 levels are also upregulated in hippocampal synaptosomal fractions obtained from murine 5xFAD and rTg4510 mice models of the disease. A local RTP801 knockdown in the 5xFAD hippocampal neurons with shRNA-containing AAV particles ameliorates cognitive deficits in 7-month-old animals. Upon RTP801 silencing in the 5xFAD mice, no major changes were detected in hippocampal synaptic markers or spine density. Importantly, we found an unanticipated recovery of several gliosis hallmarks and inflammasome key proteins upon neuronal RTP801 downregulation in the 5xFAD mice. Altogether our results suggest that RTP801 could be a potential future target for theranostic studies since it could be a biomarker of neuroinflammation and neurotoxicity severity of the disease and, at the same time, a promising therapeutic target in the treatment of AD.

Effect of acoustic stress on glucocorticoid receptor mRNA in the cochlea of the guinea pig

2003 ◽  
Vol 120 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Tsumoru Terunuma ◽  
Shimako Kawauchi ◽  
Miwako Kajihara ◽  
Satoru Takahashi ◽  
Akira Hara
Keyword(s):  
Guinea Pig ◽  
Glucocorticoid Receptor ◽  
Acoustic Stress ◽  
Receptor Mrna ◽  
Glucocorticoid Receptor Mrna

scholarly journals Absence of Thyroid Hormone Induced Delayed Dendritic Arborization in Mouse Primary Hippocampal Neurons Through Insufficient Expression of Brain-Derived Neurotrophic Factor

2021 ◽  
Vol 12 ◽  
Author(s):  
Hiroyuki Yajima ◽  
Izuki Amano ◽  
Sumiyasu Ishii ◽  
Tetsushi Sadakata ◽  
Wataru Miyazaki ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Neurotrophic Factor ◽  
Hippocampal Neurons ◽  
Brain Derived Neurotrophic Factor ◽  
Mrna Levels ◽  
Protein Levels ◽  
Primary Hippocampal Neurons ◽  
Developmental Impairment

Thyroid hormone (TH) plays important roles in the developing brain. TH deficiency in early life leads to severe developmental impairment in the hippocampus. However, the mechanisms of TH action in the developing hippocampus are still largely unknown. In this study, we generated 3,5,3’-tri-iodo-l-thyronine (T3)-free neuronal supplement, based on the composition of neuronal supplement 21 (NS21), to examine the effect of TH in the developing hippocampus using primary cultured neurons. Effects of TH on neurons were compared between cultures in this T3-free culture medium (-T3 group) and a medium in which T3 was added (+T3 group). Morphometric analysis and RT-qPCR were performed on 7, 10, and 14 days in vitro (DIV). On 10 DIV, a decreased dendrite arborization in -T3 group was observed. Such difference was not observed on 7 and 14 DIV. Brain-derived neurotrophic factor (Bdnf) mRNA levels also decreased significantly in -T3 group on 10 DIV. We then confirmed protein levels of phosphorylated neurotrophic tyrosine kinase type 2 (NTRK2, TRKB), which is a receptor for BDNF, on 10 DIV by immunocytochemistry and Western blot analysis. Phosphorylated NTRK2 levels significantly decreased in -T3 group compared to +T3 group on 10 DIV. Considering the role of BDNF on neurodevelopment, we examined its involvement by adding BDNF on 8 and 9 DIV. Addition of 10 ng/ml BDNF recovered the suppressed dendrite arborization induced by T3 deficiency on 10 DIV. We show that the lack of TH induces a developmental delay in primary hippocampal neurons, likely caused through a decreased Bdnf expression. Thus, BDNF may play a role in TH-regulated dendritogenesis.

Electrophysiological Roles of L-Type Channels in Different Classes of Guinea Pig Sympathetic Neuron

1999 ◽  
Vol 82 (2) ◽  
pp. 818-828 ◽  
Author(s):  
Philip J. Davies ◽  
David R. Ireland ◽  
Juan Martinez-Pinna ◽  
Elspeth M. McLachlan
Keyword(s):  
Guinea Pig ◽  
Action Potential ◽  
Hippocampal Neurons ◽  
Sympathetic Ganglia ◽  
Bk Channels ◽  
Half Width ◽  
Sk Channels ◽  
Single Action ◽  
Ganglion Neurons

The electrophysiological consequences of blocking Ca2+ entry through L-type Ca2+ channels have been examined in phasic ( Ph), tonic ( T), and long-afterhyperpolarizing ( LAH) neurons of intact guinea pig sympathetic ganglia isolated in vitro. Block of Ca2+entry with Co2+ or Cd2+ depolarized T and LAH neurons, reduced action potential (AP) amplitude in Ph and LAHneurons, and increased AP half-width in Ph neurons. The afterhyperpolarization (AHP) and underlying Ca2+-dependent K+ conductances ( gKCa1 and gKCa2) were reduced markedly in all classes. Addition of 10 μM nifedipine increased input resistance in LAHneurons, raised AP threshold in Ph and LAH neurons, and caused a small increase in AP half-width in Ph neurons. AHP amplitude and the amplitude and decay time constant of gKCa1 were reduced by nifedipine in all classes; the slower conductance, gKCa2, which underlies the prolonged AHP in LAH neurons, was reduced by 40%. Surprisingly, AHP half-width was lengthened by nifedipine in a proportion of neurons in all classes; despite this, neuron excitability was increased during a maintained depolarization. Nifedipine’s effects on AHP half-width were not mimicked by 2 mM Cs+ or 2 mM anthracene-9-carboxylic acid, a blocker of Cl− channels, and it did not modify transient outward currents of the A or D types. The effects of 100 μM Ni2+ differed from those of nifedipine. Thus in Ph neurons, Ca2+ entry through L-type channels during a single action potential contributes to activation of K+ conductances involved in both the AP and AHP, whereas in T and LAH neurons, it acts only on gKCa1 and gKCa2. These results differ from the results in rat superior cervical ganglion neurons, in which L-type channels are selectively coupled to BK channels, and in hippocampal neurons, in which L-type channels are selectively coupled to SK channels. We conclude that the sources of Ca2+ for activating the various Ca2+-activated K+conductances are distinct in different types of neuron.

Sign in / Sign up

Export Citation Format

Share Document