We aim to set up a novel RNA based therapeutic strategy to screen and identify agents that slow down the spread of scrapies diseases to humans (Crueutzfeld-Jacob syndrome (CJD)) by limiting translation of the endogenous human cellular prion protein (PrPc). Limiting intracellular levels of endogenous PrPc should prevent this endogenous Cu/Zn metaloprotein from being a viable target for protein conversion by infectious PrP (PrPsc) from meat sources (i.e. Scapie from Sheep), and from beef (mad cow disease). Binding of small molecules to the 5'end of the PrPc transcript reduces its translational efficiency. This project is to set up the screening conditions to enable the use of the 5'untranslated region in front of the PrP (variant 2) transcript as a drug target so that we can identify novel and highly selective inhibitors that prevent intracellular prion (PrP) translation. We will use our prior expertise to high throughput screen the Alzheimer's APP 5'UTR, now to screen a chosen MLSCN drug library (HTS) and identify small molecule PrP UTR directed leads to be developed into effective prion translation inhibitors. Neurodegenerative diseases often occur due to the altered expression or aberrant folding of specific proteins, for example amyloid from APP in Alzheimer's disease, Prion protein in CJD and 1-synuclein in Parkinson's disease. However, our strategy is to prevent the translation of their key endogenous gene products in humans. Specificity of leads screened against the human PrP-vt2 5'UTR target will be assured after counter- screens with in-house stably transfected neural cell lines that each express the APP 5'UTR-luciferase and 1-syn 5'UTR-luciferase as key counter targets. This RNA based screening strategy will provide greater specificity to identify useful inhibitors of intracellular prion levels as a therapeutic strategy to offset this terrible neurodegenerative wasting disorder. Protein and DNA based approaches would be predicted to generate more off-target hits.
The data to be accumulated through this R21 molecular libraries screening cooperative mechanism will permit a high throughput transfection based screen of an important RNA target, the 5'untranslated region of the Parkinson's alpha synuclein (ASYN) transcript. This 5'UTR is an attractive therapeutic target for Parkinson's disease (PD), and newly identified ASYN 5'UTR specific leads may be developed by medicinal chemistry potentially to limit neurotoxic ASYN production in dopaminergic neurons. Use of 5'UTR specific MLSCN hits will probe the mechanism of translation of ASYN mRNA relevant to PD. Compounds directed to 5'UTRs of other mRNAs will probe mechanism of translation of the A2-amyloid precursor protein mRNA in Alzheimer's disease (SOD-1 mRNA in ALS, and PrP mRNA in Cruetzsfeld- Jacob Syndrome).
| Gao, Jin; Cahill, Catherine M; Huang, Xudong et al. (2018) S-Adenosyl Methionine and Transmethylation Pathways in Neuropsychiatric Diseases Throughout Life. Neurotherapeutics 15:156-175 |
| Bandyopadhyay, Sanghamitra; Rogers, Jack T (2014) Alzheimer's disease therapeutics targeted to the control of amyloid precursor protein translation: maintenance of brain iron homeostasis. Biochem Pharmacol 88:486-94 |
