Aluminum-induced alterations of purinergic signalling in embryonic neural progenitor cells

The ubiquitous presence of aluminum in the environment leads to a high likelihood of human exposure. Neurotoxicity of the trivalent cationic form of this metal (Al3+) occurs in the central nervous system via accumulation of Al in cells of neural origin, including neural progenitor cells (NPCs). NPCs play a key role in the development and regeneration of the brain throughout life; therefore, this metal may contribute to neuropathological conditions. Here, we evaluated the effects of different Al³⁺ concentrations (0-50 μM) on the purinergic system of NPCs isolated from embryonic telencephalons, cultured as neurospheres. Al³⁺ adhered to the cell surface of neurospheres reducing extracellular ATP release, as well as ATP, ADP, and AMP hydrolysis by NTPDase and 5'-nucleotidase, respectively. In addition, impaired nucleotide release by Al³⁺ reduced P2Y1 and adenosine A2A receptors expression in differentiated neurospheres. These receptors are crucial for NPC proliferation during brain development and self-repair against external stimuli, such as metal exposure. Thus, Al³⁺ represents an environmental agent linked to neurodegeneration through alterations in the ATP-signalling pathway, proving to be a potential mechanism associated with NPC proliferation and brain degeneration.

Regioselective synthesis, biological evaluation, and molecular docking of dihydropyrimidin-4-ols as acetylcholinesterase inhibitors

A new series of 3,6-disubstituted 2-(methylthio)-4-(trifluoromethyl)-3,4-dihydropyrimidin-4-ols displaying methyl, phenyl, aryl, and heteroaryl groups at the 6-position; and methyl, ethyl, allyl, and phenyl groups at the 3-position of the dihydropyrimidine ring, were synthesized and evaluated in vitro for acetylcholinesterase inhibitory activity. Seven compounds showed activity with IC₅₀ values in the lower micromolar range. The compound 4-trifluoromethyl-6-(4-fluorophenyl)-3-methyl-2-methylthio-3,4-dihydropyrimidin-4-ol (6e) had the best inhibitory activity (IC₅₀ 2.2 ± 0.9 μm) and this inhibition was characterized as competitive. The molecular docking study showed that the acetylcholinesterase enzyme accommodates compound 6e in its catalytic site. The enantiomers of compound 6e, present similar interactions: π-π stacking interactions between the aromatic ring of the ligand's 4-fluorophenyl moiety and the aromatic rings of the electron-rich Trp84; and H-bonds between the hydroxyl group of Tyr121 and the hydroxyl moiety from 6e. The antioxidant effect of the dihydropyrimidin-4-ols was also investigated.

Exercise Training positively modulates the Ectonucleotidase Enzymes in Lymphocytes of Metabolic Syndrome Patients

In this study, we investigated the cardiovascular risk factors as well as ectonucleotidase activities in lymphocytes of metabolic syndrome (MetS) patients before and after an exercise intervention. 20 MetS patients, who performed regular concurrent exercise training for 30 weeks, 3 times/week, were studied. Anthropometric, biochemical, inflammatory and hepatic parameters and hydrolysis of adenine nucleotides and nucleoside in lymphocytes were collected from patients before and after 15 and 30 weeks of the exercise intervention as well as from participants of the control group. An increase in the hydrolysis of ATP and ADP, and a decrease in adenosine deamination in lymphocytes of MetS patients before the exercise intervention were observed (P<0.001). However, these alterations were reversed by exercise training after 30 weeks of intervention. Additionally, exercise training reduced the inflammatory and hepatic markers to baseline levels after 30 weeks of exercise. Our results clearly indicated alteration in ectonucleotidase enzymes in lymphocytes in the MetS, whereas regular exercise training had a protective effect on the enzymatic alterations and on inflammatory and hepatic parameters, especially if it is performed regularly and for a long period.