AIM: To study the neuroprotective roles of neuroglobin (NGB) over-expression in the SH-SY5Y cells transfected with pAPPswe.METHODS:The plasmid pEGFP-NGB was successfully constructed and transfected into the SH-SY5Y cells, which were pretreated with pAPPswe.MTT assay was applied to detect the effect of NGB over-expres-sion on the cell survival rates.JC-1 staining was used to detect the level of mitochondrial transmembrane potential.The cell apoptosis was analyzed by flow cytometry.The effects of NGB over-expression on the protein level of p-Akt, Akt and caspase-3/9 were determined by Western blotting.The generation of Aβ42 in the cells was measured by ELISA.RE-SULTS:The cell survival rate was remarkably increased after transfection with NGB compared with control group and emp-ty plasmid group (P<0.05).The over-expression of NGB significantly inhibited the decrease in mitochondrial membrane potential induced by pAPPswe.The over-expression of NGB inhibited the apoptosis of the cells.Furthermore, over-expres-sion of NGB not only inhibited the expression of caspase-3 and caspase-9, but also induced the production of p-Akt, which was prevented by LY294002, an inhibitor of PI3K/Akt.The generation of Aβ42 was inhibited in the cells with the over-ex-pression of NGB.CONCLUSION: Over-expression of NGB significantly inhibits the SH-SY5Y cell injuries induced by pAPPswe and inhibits the expression of caspase-3/9, which is tightly related with cell apoptosis.Furthermore, the neuro-protective roles of NGB may be via activating PI3K/Akt signaling pathway.

AIM:To observe the effects of neuroglobin ( NGB) overexpression on the apoptosis induced by Aβin the brains of double transgenic AD ( APPswe/PS1dE9) mice and to explore its potential mechanisms .METHODS:Twenty-four 13-month-old double transgenic AD mice were randomly divided into 3 groups:intracerebroventricular injection with normal saline (NS) group, intracerebroventricular injection with pcDNA3.1 and NS group, and intracerebroventricular injection with pcDNA3.1 and pNGB group.Immunohistochemistry was used to detect the expression of Aβ1-42 in the brains. TUNEL staining was used for analyzing the apoptosis , and the protein levels of cleaved caspase-3, caspase-9, PI3K, Akt and p-Akt were determined by Western blot .RESULTS: After intracerebroventricular injection with pNGB , the areas of Aβ1-42 in the hippocampus and cortex were decreased compared with NS group and pcDNA 3.1+NS group (P<0.01).The TUNEL-positive staining cells in the pNGB group were less than those in NS group and pcDNA 3.1 group ( P<0.01 ) . NGB overexpression attenuated the protein levels of cleaved caspase-3 and caspase-9 (P<0.01), but induced the produc-tion of PI3K and p-Akt (P<0.01).CONCLUSION:Overexpression of pNGB significantly inhibits the generation of Aβand attenuates the apoptosis induced by Aβ, indicating that NGB overexpression activates PI 3K/Akt pathway and inhibits the production of cleaved caspase-3 and caspase-9, which were tightly related with apoptosis .

Bibenzyls, a kind of important plant polyphenols, have attracted growing attention for their broad and remarkable pharmacological activities. However, due to the low abundance in nature, uncontrollable and environmentally unfriendly chemical synthesis processes, these compounds are not readily accessible. Herein, one high-yield bibenzyl backbone-producing Escherichia coli strain was constructed by using a highly active and substrate-promiscuous bibenzyl synthase identified from Dendrobium officinale in combination with starter and extender biosynthetic enzymes. Three types of efficiently post-modifying modular strains were engineered by employing methyltransferases, prenyltransferase, and glycosyltransferase with high activity and substrate tolerance together with their corresponding donor biosynthetic modules. Structurally different bibenzyl derivatives were tandemly and/or divergently synthesized by co-culture engineering in various combination modes. Especially, a prenylated bibenzyl derivative ( 12) was found to be an antioxidant that exhibited potent neuroprotective activity in the cellular and rat models of ischemia stroke. RNA-seq, quantitative RT-PCR, and Western-blot analysis demonstrated that 12 could up-regulate the expression level of an apoptosis-inducing factor, mitochondria associated 3 (Aifm3), suggesting that Aifm3 might be a new target in ischemic stroke therapy. This study provides a flexible plug-and-play strategy for the easy-to-implement synthesis of structurally diverse bibenzyls through a modular co-culture engineering pipeline for drug discovery.