The role of alpha-synuclein in the development of the dopaminergic neurons in the substantia nigra and ventral tegmental area

Neurotoxic effects of aluminum and manganese: From molecular to clinical effects

The existing data demonstrate that aluminum (Al) and manganese (Mn) possess neurotoxic effects upon overexposure due to induction of neuronal oxidative stress and apoptosis, synaptic dysfunction and neurotransmitter metabolism, neuroinflammation, and cytoskeletal pathology. However, systematic evidence regarding contribution of these metals to development of neurological diseases are lacking. Therefore, in this review we provide a summary of the existing data on contribution of Al and Mn exposure to brain diseases and its symptoms. Causal relations were demonstrated for development of parkinsonism upon exposure to high doses of Mn, whereas Al overload is considered the key contributor to dialysis encephalopathy. Certain studies demonstrate that Al and Mn overexposure is associated with neurodegenerative diseases including Alzheimer's and Parkinson's diseases, as well as neurodevelopmental disorders like autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Although laboratory studies demonstrate the potential contribution of Al and Mn to molecular pathogenesis of these diseases, clinical findings supporting the causal role of metals is these pathologies are yet insufficient. Therefore, estimation of the contribution of these metals to neurological disorders is essential for development of more effective early diagnostics and prevention of diseases under exposure to adverse neurological effects of Al and Mn compounds.

A novel function for α-synuclein as a regulator of NCK2 in olfactory bulb: implications for its role in olfaction

To investigate physiological function of α-synuclein is important for understanding its pathophysiological mechanism in synucleinopathies including Parkinson's disease. Employing knockout mice, we found that Snac/α-synuclein deletion induced aberrant projection of olfactory sensory neurons and hyposmia. We identified 9 axon guidance associated differentially expressed proteins using iTRAQ based Liquid Chromatograph Mass Spectrometer. NCK2 is most significantly down-regulated protein among them. We further found that either α-synuclein deletion or NCK2 deficiency induced Eph A4 inactivation. Re-expressing Snac/α-synuclein in its knockout neurons reversed the down-regulation of NCK2, as well as the inactivation of EphA4. Overexpression of Snac/α-synuclein in α-synuclein deleted mice reversed the down-regulation of NCK2 and pEphA4, and improved the olfactory impairment of mice. Correlation analysis showed that there is a significant correlation between the protein level of α-synuclein, NCK2, and pEphA4, respectively. Nonetheless, immunoprecipitation analysis showed that NCK2 was associated with both EphA4 and Rho A, suggesting that NCK2 as a scaffolding protein to modulate Eph A4/Rho A pathway. Moreover, Rho A activity was significantly lower in α-synuclein deficient mice. Thus, α-synuclein regulates olfactory neurons projection through NCK2 dependent EphA4/Rho A pathway. Malfunction of α-synuclein because of deletion may cause aberrant olfactory neurons projection. This extended our knowledge of α-synuclein functions, which may explain why olfaction is usually impaired in some synucleinopathies.

Impacts of Omega-3 Fatty Acids, Natural Elixirs for Neuronal Health, on Brain Development and Functions

Omega-3 fatty acids play a seminal role in maintaining the structural and functional integrity of the nervous system. These specialized molecules function as precursors for many lipid-based biological messengers. Also, studies suggest the role of these fatty acids in regulating healthy sleep cycles, cognitive ability, brain development, etc. Dietary intake of essential poly unsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are foundational to the optimal working of the nervous system. Besides regulating health, these biomolecules have great therapeutic value in treating several diseases, particularly nervous system diseases and disorders. Many recent studies conclusively demonstrated the beneficial effects of Omega-3 fatty acids in treating depression, neuropsychiatric disorders, neurodegenerative disorders, neurochemical disorders, and many other illnesses associated with the nervous system. This chapter summates the multifaceted role of poly unsaturated fatty acids, especially Omega-3 fatty acids (EPA and DHA), in the neuronal health and functioning. The importance of dietary intake of these essential fatty acids, their recommended dosages, bioavailability, the mechanism of their action, and therapeutic values are extensively discussed.

Omega-3 Fatty Acids as Druggable Therapeutics for Neurodegenerative Disorders

Neurodegenerative disorders are commonly associated with a complex pattern of pathophysiological hallmarks, including increased oxidative stress and neuroinflammation, which makes their treatment challenging. Omega-3 Fatty Acids (O3FA) are natural products with reported neuroprotective, anti-inflammatory, and antioxidant effects. These effects have been attributed to their incorporation into neuronal membranes or through the activation of intracellular or recently discovered cell-surface receptors (i.e., Free-Fatty Acid Receptors; FFAR). Molecular docking studies have investigated the roles of O3FA as agonists of FFAR and have led to the development of receptor-specific targeted agonists for therapeutic purposes. Moreover, novel formulation strategies for targeted delivery of O3FA to the brain have supported their development as therapeutics for neurodegenerative disorders. Despite the compelling evidence of the beneficial effects of O3FA for several neuroprotective functions, they are currently only available as unregulated dietary supplements, with only a single FDA-approved prescription product, indicated for triglyceride reduction. This review highlights the relative safety and efficacy of O3FA, their drug-like properties, and their capacity to be formulated in clinically viable drug delivery systems. Interestingly, the presence of cardiac conditions such as hypertriglyceridemia is associated with brain pathophysiological hallmarks of neurodegeneration, such as neuroinflammation, thereby further suggesting potential therapeutic roles of O3FA for neurodegenerative disorders. Taken together, this review article summarizes and integrates the compelling evidence regarding the feasibility of developing O3FA and their synthetic derivatives as potential drugs for neurodegenerative disorders.