slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
The impact of androgens on rat hippocampal synaptoneurosomes Pierre Le Grevès PowerPoint Presentation
Download Presentation
The impact of androgens on rat hippocampal synaptoneurosomes Pierre Le Grevès

Loading in 2 Seconds...

play fullscreen
1 / 16

The impact of androgens on rat hippocampal synaptoneurosomes Pierre Le Grevès - PowerPoint PPT Presentation


  • 112 Views
  • Uploaded on

The impact of androgens on rat hippocampal synaptoneurosomes Pierre Le Grevès Dept. of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, S-171 77 Stockholm Sweden and Dept. of Pharmaceutical Biosciences, Uppsala University, BMC, Box 591, S-751 24 Uppsala, Sweden.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'The impact of androgens on rat hippocampal synaptoneurosomes Pierre Le Grevès' - jalen


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

The impact of androgens on rat hippocampal synaptoneurosomes

Pierre Le Grevès

Dept. of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, S-171 77 Stockholm Sweden and Dept. of Pharmaceutical Biosciences, Uppsala University, BMC, Box 591, S-751 24 Uppsala, Sweden.

slide2

The impact of androgens on rat hippocampal synaptoneurosomes

Androgenic anabolic steroids (AAS) Impact on mood, aggression and anxiety

  • human studies:
    • long-term AAS --> manic states, aggression
    • acute AAS --> reduced anxiety
  • animal studies
    • long-term AAS --> increased aggression
    • acute testosterone --> decrease anxiety-like behaviour
slide3

Androgens

- effects on the brain -

  • cognitive function
    • androgens organizational and activational role in cognitive function
  • synaptic plasticity
    • affect hippocampal spine synapse density in male and female rats
  • hippocampal signaling cascades
    • altered phosphorylation of ERK in cultured primary hippocampal neurons
  • NMDA receptor and ERK -- synaptic plasticity -- cognitive function
slide4

Classical steroid action (slow)

The AR is found in the cytoplasm and consists of a conserved C-terminal ligand binding domain (LBD) and a DNA-binding domain (DBD).

Upon binding of the steroid to the LBD in an allosteric fashion, the receptor undergoes conformational changes leading to a transcriptionally active state.

Rapid steroid action

Extranuclear localized AR have been found

A role in the initiation of signaling pathways has been discussed.

Completely unrelated proteins have been suggested to mediate the rapid actions of steroid hormones.

Membrane bound androgen recognition moieties, coupled to G-proteins, were found to rapidly increase calcium influx in osteoblasts.

G protein-coupled steroid recognition sites situated in the CNS have only been found for estrogens

slide7

Nongenomic (rapid) action of steroids

  • involves rapid changes on cell membrane
  • affect intracellular [Ca2+]
  • neuronal plasticity and neurite outgrowth
  • Potentially mediated through
  • direct action on specific binding sites not related to AR
  • classical AR receptor activating kinases
  • by membrane localised AR - G-protein coupled
  • via changes in membrane fluity - interaction with phospholipids
slide9

Combined pathway and multivariate data analysis on quantitative proteomics data; application on the impact of androgens on the rat hippocampus

Pierre Le Grevès, Uwe Rossbach*, Roman Zubarev

AAS 12 hours

AAS 6 hours

  • Conclusions
  • Key node- and multivariate data analysis show relatively good agreement (high confidences) in the regulation of underlying hit proteins.
  • Some of the most regulated proteins (according to the OPLS-DA model) were not connected to a Key node in the ExPlain software.
  • Functional classification of the most up-regulated Key node scores in the multivariate analysis (S-plots) suggests that AAS stimulates hippocampal G-protein signaling, glycolysis and protein-protein interaction (the adaptor protein clathrin) at six and twelve hours after its administration
  • Functional classification of the most down-regulated Key node scores in the multivariate analysis (S-plots) suggests that AAS inhibits some energy and metabolic processes in the rat hippocampus at both time points.

Background and purpose

We have earlier presented interesting findings on the acute effects of 19-nortestosterone [an anabolic androgenic steroid (AAS)] on synaptic components in the rat hippocampus (1, 2). To further investigate the molecular mechanisms underlying the fast action of AAS we have applied quantitative proteomic involving LC-MS combined with pathway- and multivariate data analysis.

The variable importance in the projection (VIP). VIP positions the overall contribution of the variables (here Key nodes) to the OPLS-DA model. VIP values more than 1.0 (listed here) are considered as statistical significant contribution to the model.

Table 1. Key nodes regulated by AAS at 6 or 12h: The Key nodes are sorted by P-values (with Welch’s correction) calculated from each Key node scores generated in the ExPlain software. Values for confidence (p(corr)[1]), variable importance in the projection (VIP), its standard error (VIP SE) created in the OPLS-DA model and hits list from ExPlain are also shown. Hits are proteins found in Mascot searches based on LC-MS data. These hits underlie Key node scores and, as can be seen in the table, several Key nodes are based on the same protein hit.

AAS 12 hours

AAS 6 hours

S-plot from the OPLS-DA model generated in the SIMCA-P+ software. The plots show contributors (w*c[1]) versus confidence (p(corr)[1]) of the model variables (proteins or Key nodes).

Methods

Tryptic fragments of a protein extract from rat hippocampal synaptoneurosomes were loaded onto fused silica microcapillary columns packed with C18 resin and analyzed in an online fashion, with peptides eluted directly into an Orbitrap mass spectrometer using nano-LC and a nano-ESI source. Data-dependent acquisition methods were employed, with both MS1 (30,000 RP) and MS2 (HCD; 7,500 RP) spectra acquired in the Orbitrap mass analyzer. The .raw files were converted to .mgf format (in-house software) for subsequent database searching using MASCOT. Resulting .dat files were processed using in-house quantitative software employing a label-free method (3, 4). The ExPlain software (Biobase, Germany) was used for upstream Key node score analysis and the Simca software (Umetrics, Sweden) for multivariate data analysis.

References

Rossbach, U.L., Le Greves, M., Nyberg, F., Zhou, Q. & Le Greves, P. (2010). Acute 19-nortestosterone transiently suppresses hippocampal MAPK pathway and the phosphorylation of the NMDA receptor. Mol Cell Endocrinol, 314, 143-9.

Rossbach, U.L., Steensland, P., Nyberg, F. & Le Greves, P. (2007). Nandrolone-induced hippocampal phosphorylation of NMDA receptor subunits and ERKs. Biochem Biophys Res Commun, 357, 1028-33.Marin

Marin-Vicente, C. & Zubarev, R.A. (2009). Search engine for proteomics. G. I. T. Laboratory Journal, 11-12.

Marin-Vicente, C. & Zubarev, R.A. (2010). Search engine for proteomics. G. I. T. Laboratory Journal, 1-2.

Karolinska Institutet Scheeles väg 2 Tel +46-8-52487869

Pierre Le Grevès 171 77 Stockholm E-mail: pierre.le-greves@ki.se

Depatment of Medical Biochemistry and Biophysics, Div of Molecular Biometry

slide10

S-plot from the OPLS-DA The plots show contributors (w*c[1]) versus confidence (p(corr)[1]) of the model variables

slide11

S-plots

Key nodes

Proteins

slide12

S-plots

Key nodes

Proteins

slide13

S-plots

Key nodes

Proteins

slide14

The variable importance in the projection (VIP). VIP positions the overall contribution of the variables (here Key nodes) to the OPLS-DA model. VIP values more than 1.0 (listed here) are considered as statistical significant contribution to the model.

slide15

AAS 12 hours

AAS 6 hours

Table 1. Key nodes regulated by AAS at 6 or 12h: The Key nodes are sorted by P-values (with Welch’s correction) calculated from each Key node scores generated in the ExPlain software. Values for confidence (p(corr)[1]), variable importance in the projection (VIP), its standard error (VIP SE) created in the OPLS-DA model and hits list from ExPlain are also shown. Hits are proteins found in Mascot searches based on LC-MS data. These hits underlie Key node scores and, as can be seen in the table, several Key nodes are based on the same protein hit.

slide16

Conclusions

  • Key node- and multivariate data analysis show relatively good agreement (high confidences) in the regulation of underlying hit proteins.
  • Some of the most regulated proteins (according to the OPLS-DA model) were not connected to a Key node in the ExPlain software.
  • Functional classification of the most up-regulated Key node scores in the multivariate analysis (S-plots) suggests that AAS stimulates hippocampal G-protein signaling, glycolysis and protein-protein interaction (the adaptor protein clathrin) at six and twelve hours after its administration
  • Functional classification of the most down-regulated Key node scores in the multivariate analysis (S-plots) suggests that AAS inhibits some energy and metabolic processes in the rat hippocampus at both time points.