Background and Objectives: Over the past few years, there has been a significant shift in focus from developing better diagnostic tools to detecting Alzheimer’s disease (AD) earlier and initiating treatment interventions. This review will explore four main objectives: (a) the role of biomarkers in enhancing the diagnostic accuracy of AD, highlighting the major strides that have been made in recent years; (b) the role of neuropsychological testing in identifying biomarkers of AD, including the relationship between cognitive performance and neuroimaging biomarkers; (c) the amyloid hypothesis and possible molecular mechanisms of AD; and (d) the innovative AD therapeutics and the challenges and limitations of AD research. Materials and Methods: We have searched PubMed and Scopus databases for peer-reviewed research articles published in English (preclinical and clinical studies as well as relevant reviews and meta-analyses) investigating the molecular mechanisms, biomarkers, and treatments of AD. Results: Genome-wide association studies (GWASs) discovered 37 loci associated with AD risk. Core 1 biomarkers (α-amyloid Aβ42, phosphorylated tau, and amyloid PET) detect early AD phases, identifying both symptomatic and asymptomatic individuals, while core 2 biomarkers inform the short-term progression risk in individuals without symptoms. The recurrent failures of Aβ-targeted clinical studies undermine the amyloid cascade hypothesis and the objectives of AD medication development. The molecular mechanisms of AD include the accumulation of amyloid plaques and tau protein, vascular dysfunction, neuroinflammation, oxidative stress, and lipid metabolism dysregulation. Significant advancements in drug delivery technologies, such as focused Low-Ultrasound Stem, T cells, exosomes, nanoparticles, transferin, nicotinic and acetylcholine receptors, and glutathione transporters, are aimed at overcoming the BBB to enhance treatment efficacy for AD. Aducanumab and Lecanemab are IgG1 monoclonal antibodies that retard the progression of AD. BACE inhibitors have been explored as a therapeutic strategy for AD. Gene therapies targeting APOE using the CRISPR/Cas9 genome-editing system are another therapeutic avenue. Conclusions: Classic neurodegenerative biomarkers have emerged as powerful tools for enhancing the diagnostic accuracy of AD. Despite the supporting evidence, the amyloid hypothesis has several unresolved issues. Novel monoclonal antibodies may halt the AD course. Advances in delivery systems across the BBB are promising for the efficacy of AD treatments.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-β plaques, tau hyperphosphorylation, and chronic neuroinflammation. Emerging evidence suggests a crucial role of lipid signaling pathways in AD pathogenesis, particularly those mediated by autotaxin (ATX) and lysophosphatidic acid (LPA). ATX, an enzyme responsible for LPA production, has been implicated in neuroinflammatory processes, blood–brain barrier dysfunction, and neuronal degeneration. LPA signaling, through its interaction with specific G-protein-coupled receptors, influences neuroinflammation, synaptic plasticity, and tau pathology, all of which contribute to AD progression. This review synthesizes recent findings on the ATX/LPA axis in AD, exploring its potential as a biomarker and therapeutic target. Understanding the mechanistic links between ATX, LPA, and AD pathology may open new avenues for disease-modifying strategies.

Migraine is one of the most common neurological disorders and the second most disabling human condition. The molecular mechanisms of migraine have been linked to neuropeptide release, endothelial dysfunction, oxidative stress and inflammatory processes. Acid sphingomyelinase (aSMase) is a secreted enzyme that leads to sphingomyelin degradation to produce ceramide. Its activity has been associated with several molecular processes involved in migraine. Therefore, this cross-sectional study aims to study the potential role of aSMase in patients with episodic and chronic migraine. In this cross-sectional pilot study, serum samples from female healthy controls (n = 23), episodic migraine (EM) patients (n = 31), and chronic migraine (CM) patients (n = 28) were studied. The total serum levels of aSMase were determined by ELISA. In addition, the serum levels of sphingomyelin (SM), dihydro-sphingomyelin (dhSM), ceramide (Cer), and dihydro-ceramide (dhCer) were determined by mass spectrometry as biomarkers involved in the main molecular pathways associated with aSMase. aSMase serum levels were found significantly elevated in both EM (3.62 ± 1.25 ng/mL) and CM (3.07 ± 0.95 ng/mL) compared with controls (1.58 ± 0.72 ng/mL) (p < 0.0001). ROC analysis showed an area under the curve (AUC) of 0.94 (95% CI: 0.89–0.99, p < 0.0001) and 0.90 (95% CI: 0.81–0.99, p < 0.0001) for EM and CM compared to controls, respectively. Regarding other biomarkers associated with aSMase’s pathways, total SM serum levels were significantly decreased in both EM (173,534 ± 39,096 pmol/mL, p < 0.01) and CM (158,459 ± 40,010 pmol/mL, p < 0.0001) compared to the control subjects (219,721 ± 36,950 pmol/mL). Elevated serum levels of aSMase were found in EM and CM patients compared to the control subjects. The decreased SM levels found in both EM and CM indicate that aSMase activity plays a role in migraine. Therefore, aSMase may constitute a new therapeutic target in migraine that should be further investigated.