RbAp48 transgenic mice for drug discovery in age-related memory decline
Described is a transgenic mouse with two transgenes, each of which transgene comprises a DNA sequence encoding a dominant negative form of RbAp48 protein, wherein the expression of the dominant negative form of RbAp48 is spatially restricted to the forebrain by a CaM Kinase IIa promoter and wherein the expression of the dominant negative form of RbAp48 is controlled by tetracycline-controlled transcriptional activation. Also provided are methods for evaluating in the transgenic mouse the potential therapeutic effect of an agent for slowing, inhibiting or preventing age-related memory decline in a mammalian subject.
1. A transgenic mouse whose genome comprises:
i) a nucleic acid sequence encoding a dominant negative RbAp48 (RbAp48-DN) protein operably linked to a tetracycline promoter; and
ii) a nucleic acid sequence encoding a tetracycline controlled transactivator (tTA) operably linked to a CaM Kinase IIa promoter, wherein expression of the RbAp48-DN is restricted to the forebrain, and wherein said mouse is capable of having a memory deficit as compared to a wild-type mouse upon administration of tetracycline.
2. The transgenic mouse of claim 1 , wherein said RbAp48-DN lacks the N-terminal 54 amino acids of RbAp48.
3. A method for identifying an agent that slows, inhibits, or prevents a memory deficit, the method comprising:
a) administering tetracycline to the mouse of claim 1 such that expression of RbAp48-DN is induced in the brain and a memory deficit occurs;
b) administering an agent to the mouse of step a);
c) determining the memory of the mouse of step b), wherein increased memory as compared to a transgenic mouse of claim 1 not given the agent indicates the agent slows, inhibits, or prevents a memory deficit.
4. The method of claim 3 , wherein the agent increases RbAp48 expression.
5. The method of claim 3 , wherein the agent is epicatechin.
6. The method of claim 3 , wherein the agent is a histone acetyl transferase.
7. The method of claim 3 , wherein the agent is a histone deactylase (HDAC) inhibitor.
8. The method of claim 7 , wherein the HDAC inhibitor is selected from the group consisting of belinostat, mocetinostat, panobinostat, dacinostat, 4-Dimethylamino-N-(6-hydoxycarbamoylhexyl)-beinzamide, N-(2-aminophenyl)-N′-phenyl-octanediamide, etinostat, tacedinaline, suberoylanilide hydroxamic acid (SAHA), trichostatin A, traproxin B, valproic acid, (E)-3-(2-butyl-1-(2-(diethylamino)ethyl)-1H-benzo[d]imidazol-5-yl)-N-hydroxyacrylamide, romidepsin, givinostat, and sulforaphane.
9. The method of claim 3 , wherein the agent is a phosphodiesterase inhibitor.
10. The method of claim 9 , wherein the phosphodiesterase inhibitor is selected from the group consisting of vinpocetine, erythro-9-(2-hydroxy-3-nonyl)adenine), arofyllin, denbufylline, Drotaverine, etazolate, filaminast, (3R,5R)-5-(3-(cyclopentyloxy)-4-methoxyphenyl)-3-(3-methylbenzyl)piperidin-2-one, ibudilast, irsogladine, mesembrine, roflumilast, rolipram, MEM 1917, MEM 1414.
11. The method of claim 3 , wherein the memory is assessed using novel object recognition.
12. The method of claim 3 , wherein the memory is assessed using the Morris water maze.
13. The method of claim 3 , wherein expression of RbAp48-DN is induced 10 days prior to administering the agent.
14. The method of claim 3 , further comprising determining the cerebral blood volume (cbv) in the dentate gyrus in the mouse of step b), wherein increased cbv as compared to a transgenic mouse of claim 1 not given the agent further indicates the agent slows, inhibits, or prevents a memory deficit.