Lipidomics of Bioactive Lipids in Alzheimer's and Parkinson's Diseases: Where Are We?

Lipids are not only constituents of cellular membranes, but they are also key signaling mediators, thus acting as "bioactive lipids". Among the prominent roles exerted by bioactive lipids are immune regulation, inflammation, and maintenance of homeostasis. Accumulated evidence indicates the existence of a bidirectional relationship between the immune and nervous systems, and lipids can interact particularly with the aggregation and propagation of many pathogenic proteins that are well-renowned hallmarks of several neurodegenerative disorders, including Alzheimer's (AD) and Parkinson's (PD) diseases. In this review, we summarize the current knowledge about the presence and quantification of the main classes of endogenous bioactive lipids, namely glycerophospholipids/sphingolipids, classical eicosanoids, pro-resolving lipid mediators, and endocannabinoids, in AD and PD patients, as well as their most-used animal models, by means of lipidomic analyses, advocating for these lipid mediators as powerful biomarkers of pathology, diagnosis, and progression, as well as predictors of response or activity to different current therapies for these neurodegenerative diseases.

Potent T cell-mediated anti-inflammatory role of the selective CB2 agonist lenabasum in multiple sclerosis.

BACKGROUND: Lenabasum is a synthetic cannabinoid receptor type-2 (CB2) agonist able to exert potent anti-inflammatory effects, but its role on T cells remains unknown. OBJECTIVES: The present study was undertaken to investigate anti-inflammatory mechanisms of lenabasum in T lymphocyte subsets and its in vivo therapeutic efficacy in experimental autoimmune encephalomyelitis (EAE). METHODS: Mononuclear cells from 17 healthy subjects (HS) and 25 relapsing-remitting multiple sclerosis (RRMS) patients were activated in presence or absence of lenabasum and analysed by flow cytometry and qRT-PCR. EAE mice were treated with lenabasum, and clinical score and neuroinflammation were evaluated. RESULTS: Lenabasum significantly reduced TNF-a production from CD4+ T cells and CD8+ T cells in a dose-dependent manner in both HS and RRMS patients. In MS patients, lenabasum also reduced activation marker CD25 and inhibited IL-2 production from both T cell subsets and IFN-γ and IL-17 from committed Th1 and Th17 cells, respectively. These effects were blocked by the pretreatment with selective CB2 inverse agonist SR144528. In vivo treatment of EAE mice with lenabasum significantly ameliorated disease severity, reduced neuroinflammation and demyelination in spinal cord. CONCLUSION: Lenabasum exerts potent T cell-mediated immunomodulatory effects, suggesting CB2 as a promising pharmacological target to counteract neuroinflammation in MS.

Resolution of inflammation is altered in chronic heart failure and entails a dysfunctional responsiveness of T lymphocytes.

Chronic heart failure (CHF) is characterized by an ongoing nonresolving inflammatory status, where T lymphocytes seem critical. It has been recently recognized that transition from acute to chronic inflammation could be caused by defects in resolving inflammation, the resolution of which is mediated by a novel family of ω-3-derived specialized proresolving lipid mediators such as resolvins. We analyzed 27 elderly patients with CHF and 23 healthy age-matched control subjects, and we reported significantly lower levels of D-series resolvin (RvD)1 in plasma of patients with CHF that were associated with a reduced ability of their leukocytes to produce this lipid via its biosynthetic enzyme 15-lipoxygenase and that correlated with gas exchange dysfunction. Furthermore, when pretreating ex vivo peripheral blood mononuclear cells of patients with CHF with RvD1 or RvD2, we found that neither of them was able to modulate the immune response of CD8+ and CD4+ T cells in terms of proinflammatory cytokine production, namely TNF-α, IFN-γ, IL-17, and IL-2. Such impaired T-cell responsiveness in patients with CHF was associated with a significant reduction in mRNA and protein expression of RvD1 receptor GPR32, suggesting a defective signaling in the proresolving pathway. We conclude that patients with CHF show alterations in producing proresolving mediator RvD1 and a failure of adaptive immune cells in responding to the anti-inflammatory actions of RvDs that may contribute to the progression of chronic inflammation. Thus, the proresolution pathway might be a potential candidate to design better treatments for CHF aimed at reducing T cell-mediated chronic inflammation.-Chiurchiù, V., Leuti, A., Saracini, S., Fontana, D., Finamore, P., Giua, R., Padovini, L., Incalzi, R. A., Maccarrone, M. Resolution of inflammation is altered in chronic heart failure and entails a dysfunctional responsiveness of T lymphocytes.