Association of APOE Serum Levels and APOE ε2, ε3, and ε4 Alleles with Optic Neuritis

Implication of Apolipoprotein E gene variants in pediatric-onset multiple sclerosis: Possible association with disease susceptibility and its clinical characteristics, in a Hellenic cohort

BACKGROUND

Apolipoprotein E (ApoE) plays a major role in lipid homeostasis and myelination in the central nervous system. Although ApoE gene variants have been linked with cognitive impairment in the setting of Multiple sclerosis (MS), no association with disease susceptibility was found, while similar studies in pediatric-onset MS (POMS) are limited.

OBJECTIVE

This study aims to explore the role of ApoE gene variants in the POMS susceptibility of a Hellenic cohort and any association with disease features.

METHODS

112 POMS, fulfilling the revised IPMSSG 2013 criteria, 391 adult-onset MS (AOMS) and 200 healthy controls (HCs), were enrolled. After DNA extraction, ApoE genotyping was performed by a polymerase chain reaction and sequence-specific-oligonucleotide technique.

RESULTS

ApoE2/E3 genotype and ApoE2 allele were found to be significantly more frequent among POMS patients compared to HCs [(20.5% vs 11 %, OR [95 %]: 2.1 (1.1-4.0), p = 0.03)], and [(11% vs 5.3 %, OR [95 %]: 2.3 (1.2-4.1), p = 0.01)], respectively. Additionally, significantly lower frequencies of the ApoE3/E3 genotype and the ApoE3 allele were observed in POMS patients compared to HCs (59.8% vs 79 %, OR [95 %]:0.40 (0.24-0.65), p = 0.0005 and 79% vs 89 % 0.46, OR [95 %]: (0.30-0.73), p = 0.001)], respectively.

CONCLUSIONS

The ApoE2 allele may represent a novel risk factor for POMS development.

Uncovering the Genetics and Physiology behind Optic Neuritis

Optic neuritis (ON) is an inflammatory condition affecting the optic nerve, leading to vision impairment and potential vision loss. This manuscript aims to provide a comprehensive review of the current understanding of ON, including its definition, epidemiology, physiology, genetics, molecular pathways, therapy, ongoing clinical studies, and future perspectives. ON is characterized by inflammation of the optic nerve, often resulting from an autoimmune response. Epidemiological studies have shown a higher incidence in females and an association with certain genetic factors. The physiology of ON involves an immune-mediated attack on the myelin sheath surrounding the optic nerve, leading to demyelination and subsequent impairment of nerve signal transmission. This inflammatory process involves various molecular pathways, including the activation of immune cells and the release of pro-inflammatory cytokines. Genetic factors play a significant role in the susceptibility to ON. Several genes involved in immune regulation and myelin maintenance have been implicated in the disease pathogenesis. Understanding the genetic basis can provide insights into disease mechanisms and potential therapeutic targets. Therapy for ON focuses on reducing inflammation and promoting nerve regeneration. Future perspectives involve personalized medicine approaches based on genetic profiling, regenerative therapies to repair damaged myelin, and the development of neuroprotective strategies. Advancements in understanding molecular pathways, genetics, and diagnostic tools offer new opportunities for targeted therapies and improved patient outcomes in the future.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

Cognitive Impairment in Multiple Sclerosis

Almost three million individuals suffer from multiple sclerosis (MS) throughout the world, a demyelinating disease in the nervous system with increased prevalence over the last five decades, and is now being recognized as one significant etiology of cognitive loss and dementia. Presently, disease modifying therapies can limit the rate of relapse and potentially reduce brain volume loss in patients with MS, but unfortunately cannot prevent disease progression or the onset of cognitive disability. Innovative strategies are therefore required to address areas of inflammation, immune cell activation, and cell survival that involve novel pathways of programmed cell death, mammalian forkhead transcription factors (FoxOs), the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), and associated pathways with the apolipoprotein E (APOE-ε4) gene and severe acute respiratory syndrome coronavirus (SARS-CoV-2). These pathways are intertwined at multiple levels and can involve metabolic oversight with cellular metabolism dependent upon nicotinamide adenine dinucleotide (NAD+). Insight into the mechanisms of these pathways can provide new avenues of discovery for the therapeutic treatment of dementia and loss in cognition that occurs during MS.