Synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies, and multiple system atrophy (MSA), are a group of neurodegenerative diseases characterized by the oligomerization of α-synuclein protein in neurons or glial cells. Various splicing isoforms of α-synuclein have been described, each with different aggregation properties. The α-synuclein gene (SNCA) has been identified as a highly significant genetic risk locus associated with various synucleinopathies across populations. This study aimed to assess the association of SNCA genetic variants with MSA and the levels of SNCA transcripts in peripheral blood mononuclear cells (PBMCs) from MSA and PD patients.

In this retrospective case–control study, 96 MSA patients, 1086 PD patients, and 485 healthy volunteers were included. PCR followed by restriction endonuclease analysis was used to detect four SNCA single-nucleotide polymorphisms (rs356219, rs3756063, rs11931074, and rs356168) in these individuals. In addition, RT-qPCR was performed to detect the levels of α-synuclein transcripts (SNCA mRNA isoforms -140, -126, and -112) in PBMCs of 24 MSA patients (including parkinsonian (MSA-P) and cerebellar (MSA-C) variants), 31 PD patients, and 32 healthy volunteers.

The frequency of the ‘T’ allele (of rs11931074) was significantly higher in MSA patients than in the healthy controls. The level of SNCA-140 mRNA was significantly decreased in MSA and PD patients compared with the controls, while the level of SNCA-112 mRNA was significantly increased in MSA-P patients than in PD patients and the controls. SNCA-112 mRNA/SNCA-140 mRNA and SNCA-112 mRNA/SNCA-126 mRNA ratios were significantly increased in MSA patients than in the controls.

The SNCA rs11931074 polymorphism is associated with MSA. There is a pronounced alteration in the expression of SNCA transcripts in PBMCs of MSA and PD patients.

The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) family regulates fundamental processes in both innate and adaptive immunity. Aberrant NF-κB activation, whether through canonical or non-canonical signaling pathways, contributes to chronic inflammation, autoimmunity, allergy, and primary immunodeficiency/autoinflammatory syndromes, while also influencing host defense and tissue repair mechanisms. The present review aims to synthesize molecular architecture, upstream triggers, ubiquitin-centered relay systems, and the dynamic regulation of NF-κB activity. The major findings on the NF-κB signaling pathway encompass its dual molecular mechanisms (canonical and non-canonical), its central roles in immune and inflammatory responses, cell survival, and development, as well as its complex regulatory networks. We interpret NF-κB as a master integrator of diverse signals, essential for both acute and long-term physiological processes. Dysregulation of NF-κB underlies many diseases, and while it is a promising therapeutic target, its ubiquitous functions demand precise modulation to avoid adverse effects. In conclusion, the proper function of the NF-κB signaling pathway is essential for maintaining cellular homeostasis and immune defense; its dysregulation is linked to chronic inflammatory diseases, autoimmune disorders, and cancer, which underscores the pathway’s significance as a therapeutic target. Although it elucidates molecular processes and treatment options, experimental validation of emerging therapeutic concepts such as ubiquitin code editing and spatial immunology remains limited.