Serum microRNA qPCR profiling and validation indicate upregulation of circulating miR-145-5p and miR-26a-5p in migraineurs.

Background: In recent years, miRNAs found in biological fluids have gained interest as biomarkers of numerous conditions, including migraine. This study aimed to identify differences in the levels of circulating miRNAs in the serum of migraineurs as compared to healthy controls, as well as between patients with different types of migraine and during the ictal and nonictal phases of the condition.

Methods: The screening phase of the study included serum from 13 migraine patients and 13 sex and age matched controls. A panel of 179 miRNAs was analysed using locked nucleic acid SYBR based qPCR. Based on statistical analysis (U Mann-Whitney test) and data from existing literature, nine miRNAs were selected for validation by TaqMan qPCR in an independent cohort of 26 migraineurs and eleven healthy controls. For comparison between the study and control group, U Mann-Whitney test was performed. The differences between patients with chronic and episodic migraine, migraine with and without aura and in ictal and nonictal phases were analysed with Kruskal-Wallis test. The results were corrected for multiple comparisons using Benjamini-Hochberg method. In all analysis p value ≤ 0,05 was considered as significant.

Results: Two miRNAs, miR-145-5p and miR-26a-5p were significantly upregulated in serum of migraineurs compared to healthy controls. MiRNA-19a-3p was downregulated in patients currently experiencing migraine headache compared to those in the interictal period. No differences were found between patients with different migraine types.

Conclusion: The results of our study add to the growing body of evidence for dysregulation of the circulating miRNA profile by migraine. They are further supported by previous reports on differential expression of miR-145-5p, miR-26a-5p and miR-19a-3p in migraineurs. However, more research on larger populations is needed to validate these findings, as well as elucidate the role of circulating miRNAs in the condition. Moreover, to wholly explore the biomarker potential of miRNAs, migraine patients should not only be compared to healthy controls but also to populations with different headache disorders.