Composition and method of using mir-302 precursors as drugs for treating alzheimer's diseases

Abstract

This invention generally relates to a composition and method of using recombinant microRNAs (miRNA) and their hairpin-like precursors (pre-miRNA) as therapeutic drugs for treating Alzheimer's diseases (AD). More specifically, the present invention relates to the use of man-made miRNA miR-302 precursors (pre-miR-302) for AD therapy in humans. These pre-miR-302 molecules can be mass produced in prokaryotes as a form of DNA expression-competent DNA vectors and/or hairpin-like RNAs. As prokaryotic cells do not transcribe or process hairpin-like RNAs, the present invention also teaches a method for expressing pre-miRNAs in prokaryotes, i.e. pro-miRNA, using a novel hairpin-like RNA transcription mechanism newly found in prokaryotes. Additionally, since miR-302 is a well-known embryonic stem cell (ESC)-specific factor in humans, our novel findings of this invention can be further used to advance the designs and development of novel regenerative medicine for treating many other ageing-related degenerative diseases, such as Parkinson's diseases, osteoporosis, diabetes, and cancers.

1 . A method of protecting human brain neurons from Aβ-induced neurotoxicity in Alzheimer's diseases with at least one hairpin-like RNA mimics of microRNA precursor (hairpin-like pre-miRNA mimics), comprising:
 (a) formulating at least one hairpin-like pre-miRNA mimic with glycylglycerin or its chemical derivatives, wherein the at least one hairpin-like pre-miRNA mimic contains SEQ. ID. NO.2; and 
 (b) delivering at least one of the formulated hairpin-like pre-miRNA mimic into at least one neuron. 
 
     
     
         2 . The method as defined in  claim 1 , wherein said hairpin-like pre-miRNA mimics are miR-302 precursors (pre-miR-302) in a structural conformation selected from the group consisting of microRNA (miRNA), small hairpin RNA (shRNA), small interfering RNA (siRNA), their precursors and homologs, and a combination thereof. 
     
     
         3 . The method as defined in  claim 1 , wherein said hairpin-like pre-miRNA mimics consist of SEQ. ID. NO3, SEQ. ID. NO. 4, SEQ. ID. NO. 5, and SEQ. ID. NO.6. 
     
     
         4 . The method as defined in  claim 1 , wherein the expression of said hairpin-like pre-miRNA mimics produces miR-302a, miR-302b, miR-302c and miR-302d in the treated neurons. 
     
     
         5 . The method as defined in  claim 1 , further comprising a step of inducing Akt signaling activation. 
     
     
         6 . The method as defined in  claim 5 , wherein said Akt signaling activation improves insulin resistance in the treated neurons. 
     
     
         7 . The method as defined in  claim 6 , further comprising a step of suppressing p-307 IRS-1 serine phosphorylation, increasing IRS-1 tyrosine phosphorylation, or both. 
     
     
         8 . The method as defined in  claim 5 , wherein said Akt signaling activation further stimulates Nanog expression to increase sensitivity of insulin signaling. 
     
     
         9 . The method as defined in  claim 1 , further comprising a step of inducing Nrf2/HO-1 expression to reduce Aβ-induced intracellular ROS accumulation and apoptosis. 
     
     
         10 . The method as defined in  claim 1 , further comprising a step of inducing CD34-positive adult stem cell expansion.