Selenoproteins are a family of special proteins that contain the 21st amino acid, selenocysteine (Sec), in their sequence. Selenoprotein P has 10 Sec residues and modulates selenium homeostasis and redox balance in the brain. Previously, we found that the Sec-devoid His-rich motif of selenoprotein P (Selenop-H) suppressed metal-induced aggregation and neurotoxicities of both Aβ and tau in vitro. To investigate the intervening capacity of Selenop-H on the neuropathology and cognitive deficits of triple transgenic AD (3 × Tg-AD) mice, the Selenop-H gene packaged in rAAV9 was delivered into the hippocampal CA3 regions of mice via stereotaxic injection. Four months later, we demonstrated that Selenop-H (1) improved the spatial learning and memory deficits, (2) alleviated neuron damage and synaptic protein loss, (3) inhibited both tau pathology and amyloid beta protein (Aβ) aggregation, (4) activated both BDNF- and Src-mediated TrkB signaling, and (5) increased MT3 and ZnT3 levels and restored Zn2+ homeostasis in the mice model of AD. The study revealed that Selenop-H is potent in ameliorating AD-related neuropathology and cognitive deficits by modulating TrkB signaling and Zn2+ homeostasis.

There has been an increasing demand for bio vanillin for a variety of applications. Although vanillin production using biotechnological methods based on microbial fermentation has been extensively explored, the use of isolated enzymes for vanillin synthesis has not yet attracted much attention. Lipoxygenase (LOX) is an iron‐containing dioxygenase well known for catalysing the hydroperoxidation of polyunsaturated fatty acids and esters. Its newly discovered ability to catalyse the oxidative cleavage of isoeugenol to vanillin offers a promising solution for synthesizing bio vanillin. In this study, soybean LOX was used as the catalyst for vanillin synthesis. The reaction was optimised by examining the effects of pH, temperature, substrate concentration, and enzyme dosage. By investigating the impact of various additives, including two denaturants, seven chelators, six surfactants, 10 organic solvents, eight deep eutectic solvents, and 13 natural deep eutectic solvents, it was found that denaturants (urea and guanidine) and some chelators (e.g. ethylenediaminetetraacetic acid, EDTA) are effective in improving synthetic yields, by up to 133 and 406%, respectively, relative to the additive‐free reaction system. Two free‐radical catalytic mechanisms were proposed to explain the new activity of the enzyme for vanillin synthesis.

(1) Background: As a natural carbohydrate, sialic acid (SA) is helpful for brain development, cognitive ability, and the nervous system, but there are few reports about the effect of SA on Alzheimer’s disease (AD). (2) Method: The present study evaluated the effect of SA on cognitive ability, neuronal activity, Aβ formation, and tau hyperphosphorylation in a double transgenic AD (2×Tg-AD) mice model. The 2×Tg-AD mice were randomly divided into four groups: the AD control group, 17 mg/kg SA-treated AD group, 84 mg/kg SA-treated AD group, and 420 mg/kg SA-treated AD group. Mice from all four groups were fed to 7 months of age for the behavioral test and to 9 months of age for the pathological factors investigation. (3) Results: In the Morris water maze, the escape latency significantly decreased on the fifth day in the SA-treated groups. The number of rearing and crossing times in the open field test also increased significantly, compared with the control group. SA treatment significantly reduced amyloid β-peptide (Aβ) and nerve fibers and increased the number of Nissl bodies in the brain of AD mice. (4) Conclusions: SA reduced the neuron damage by reducing Aβ and inhibited tau protein hyperphosphorylation, which improved the cognitive ability and mobility of AD mice.