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Expression analysis of stress-induced lncRNAs in PBMCs from multiple sclerosis patients (Bachelor thesis)

Παπουτσούδης, Χρήστος/ Papoutsoudis, Christos

Multiple Sclerosis (MS) is the most commonly appeared autoimmune disease of the Central Nervous System (CNS) in the world, accounting around for 2.9 million patients worldwide. The disease is formally known since 1868, when it was recorded for the first time by Jean-Martin Charcot. Its main characteristic is the destruction of the myelin sheath that surrounds and insulates the nerve cells of the CNS, which leads to the manifestation of lesions, characteristic of the disease. Multiple sclerosis’ diagnosis is based on McDonald criteria, and a proper diagnosis must prove the Dissemination In Time and Space of the lesions in CNS, meaning that the lesions must appear at different times and areas of the CNS. For this specific thesis, an expression analysis has taken place for two long non coding RNAs, NORAD and GAS5, which are both expressed during stress. The technique used was Real Time PCR, with absolute and relative quantification via beta-actin. A total of 45 samples from patients with MS and 16 samples from healthy individuals (controls) were examined. These samples were isolated from peripheral blood mononuclear cells (PBMCs). The analysis results initially showed that β-actin, which was used for relative quantification, does not have stable expression in patients with MS and therefore cannot be used as a reference gene for this disease. Specifically, actin expression levels in samples from patients with MS were significantly reduced compared to healthy individuals. Regarding lncRNAs, statistically significant results (p<0.05) showed that healthy individuals (Control) express 2.5 times more NORAD compared to patients with MS. In fact, women with MS express approximately 3 times less NORAD than Controls. This study revealed statistically significant under-expression of NORAD in patients with MS, thus highlighting its value as a potential biomarker. In contrast, GAS5 did not show a statistically significant correlation with MS, which, however, should be further investigated, given its action in cellular stress conditions.