miRNAs as non-invasive biomarkers for Parkinson's disease

1. A method for diagnosing Parkinson's disease comprising the steps of:

(i) isolating total intracellular RNA from platelets, red blood cells and white blood cells obtained from a whole blood sample taken from a subject,

(ii) determining in said total intracellular RNA an expression profile of a set comprising at least two miRNAs, wherein the at least two miRNAs have a nucleotide sequence according to SEQ ID NO:2 (hsa-miR-1228) and a nucleotide sequence according to SEQ ID NO:4 (hsa-miR-24),

(iii) comparing the expression profile determined in said total intracellular RNA to a reference expression profile of at least two healthy control subjects, and

(iv) detecting a down-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:2 in said total intracellular RNA compared to the reference expression profile and an up-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:4 in said total intracellular RNA compared to the reference expression profile, thereby diagnosing Parkinson's disease in said subject,

wherein the method comprises a further step of:

(v) subjecting said subject identified to be afflicted with Parkinson's disease to medical or surgical intervention directed to Parkinson's disease.

2. The method of claim 1 , wherein the determining of the expression profile includes reverse-transcription of the nucleotide sequence of the at least two miRNAs comprised in the set into cDNA.

3. The method according to claim 1 , wherein the whole blood sample is collected in a whole blood collection tube, preferably it is collected in a PAXgene Blood RNA tube, Tempus Blood RNA tube, EDTA-tube, Na-citrate tube or ACD-tube and optionally contains an additive for stabilizing the RNA-fraction.

4. The method according to claim 1 , wherein the red blood cells, platelets and white blood cells are obtained from the whole blood sample taken from the subject by centrifuging the whole blood sample and removing the supernatant.

5. The method of claim 1 , wherein the determining of an expression profile of a set comprising at least two miRNAs in said total intracellular RNA in step (ii) comprises the steps of:

(a) reverse-transcribing the at least two miRNAs comprised in said total intracellular RNA into non-naturally occurring cDNA;

(b) amplifying the cDNA of step (a); and

(c) quantifying the amplified cDNA, thereby determining the expression profile of said at least two miRNAs.

6. The method of claim 1 , wherein the determining of an expression profile of a set comprising at least two miRNAs in said total intracellular RNA in step (ii) comprises the steps of:

(a) adding a DNA-fragment to the 3′-end of the at least two miRNAs comprised in said total intracellular RNA, thereby forming non-naturally occurring RNA-DNA hybrids;

(b) reverse-transcribing said RNA-DNA hybrids to cDNA; and

(c) quantifying the reverse-transcribed RNA-DNA hybrids, thereby determining the expression profile of said at least two miRNAs.

7. The method of claim 1 , wherein the medical or surgical intervention directed to Parkinson's disease is selected from the group consisting of medication, surgical intervention or lifestyle modification.

8. A method for diagnosing Parkinson's disease comprising the steps of:

(i) determining an expression profile of a set comprising at least two miRNAs representative for Parkinson's disease in a blood cell preparation derived from a whole blood sample from a subject, wherein the at least two miRNAs have a nucleotide sequence according to SEQ ID NO:2 (hsa-miR-1228) and a nucleotide sequence according to SEQ ID NO: 4 (hsa-miR-24),

(ii) comparing the expression profile determined in the blood cell preparation derived from a whole blood sample from the subject to a reference expression profile of at least two healthy control subjects, and

(iii) detecting a down-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:2 in the blood cell preparation derived from a whole blood sample from the subject compared to the reference expression profile and an up-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:4 in the blood cell preparation derived from a whole blood sample from the subject compared to the reference expression profile, and thereby diagnosing Parkinson's disease in said subject,

wherein the method comprises a further step of:

(iv) subjecting said subject identified to be afflicted with Parkinson's disease to medical or surgical intervention directed to Parkinson's disease.

9. A method for diagnosing Parkinson's disease comprising the steps of:

(i) isolating total intracellular RNA from platelets, red blood cells and white blood cells obtained from a whole blood sample taken from a subject,

(ii) determining in said total intracellular RNA an expression profile of a set comprising at least two miRNAs, wherein the at least two miRNAs have a nucleotide sequence according to SEQ ID NO:2 (hsa-miR-1228) and a nucleotide sequence according to SEQ ID NO:4 (hsa-miR-24),

(iii) comparing the expression profile determined in said total intracellular RNA to a reference expression profile of at least two healthy control subjects, and

(iv) detecting a down-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:2 in said total intracellular RNA compared to the reference expression profile and an up-regulation of the miRNA having a nucleotide sequence according to SEQ ID NO:4 in said total intracellular RNA compared to the reference expression profile, and thereby diagnosing Parkinson's disease in said subject,

wherein the determining of an expression profile of a set comprising at least two miRNAs in said total intracellular RNA in step (ii) comprises the steps of:

(a) adding a DNA-fragment to the 3′-end of the at least two miRNAs comprised in said total intracellular RNA, thereby forming non-naturally occurring RNA-DNA hybrids;

(b) reverse-transcribing said RNA-DNA hybrids to cDNA; and

(c) quantifying the reverse-transcribed RNA-DNA hybrids, thereby determining the expression profile of said at least two miRNAs,

wherein the method comprises a further step of:

(v) subjecting said subject identified to be afflicted with Parkinson's disease to medical or surgical intervention directed to Parkinson's disease.

10. The method of claim 1 , wherein the medical intervention is administration of a drug for treatment of Parkinson's disease to said subject.

11. The method of claim 1 , wherein the medical intervention is administration of one or more of a dopaminergic drug, carbidopa-levodopa, a dopamine agonist, a MAO-B inhibitor, a catechol O-methyltransferase (COMT) inhibitor, an anticholinergic, and Amantadine to said subject.

12. The method of claim 8 , wherein the medical intervention is administration of a drug for treatment of Parkinson's disease to said subject.

13. The method of claim 8 , wherein the medical intervention is administration of one or more of a dopaminergic drug, carbidopa-levodopa, a dopamine agonist, a MAO-B inhibitor, a catechol O-methyltransferase (COMT) inhibitor, an anticholinergic, and Amantadine to said subject.

14. The method of claim 9 , wherein the medical intervention is administration of a drug for treatment of Parkinson's disease to said subject.

15. The method of claim 9 , wherein the medical intervention is administration of one or more of a dopaminergic drug, carbidopa-levodopa, a dopamine agonist, a MAO-B inhibitor, a catechol O-methyltransferase (COMT) inhibitor, an anticholinergic, and Amantadine to said subject.