Effects of berberine on a rat model of chronic stress and depression via gastrointestinal tract pathology and gastrointestinal flora profile assays.

Chronic stress and depression are challenging conditions to treat, owing to their complexity and lack of clinically available and effective therapeutic agents. The aim of the present study was to investigate the mechanism by which berberine acts, by examining alterations to gastrointestinal tract histopathology and flora profile in a rat model, following the induction of stress. Research associating gastrointestinal flora and depression has increased, thus, the present study hypothesized that stress induces depression and changes in the gastrointestinal system.

High yields and soluble expression of superoxide dismutases in Escherichia coli due to the HIV-1 Tat peptide via increases in mRNA transcription.

This study aimed to validate the high yield and soluble expression of proteins carrying the transactivator of transcription (Tat) peptide tag, and further explored the potential mechanism by which the Tat tag increases expression. Escherichia coli superoxide dismutase (SOD) proteins, including SodA, SodB and SodC, were selected for analysis. As expected, the yields and the solubility of Tat-tagged proteins were higher than those of Tat-free proteins, and similar results were observed for the total SOD enzyme activity.

Pichia pastoris Production of Tat-NGB and Its Neuroprotection on Rat Pheochromocytoma Cells.

Neuroglobin (NGB) is a newly discovered neuroprotector and mainly localized in the neurons and retinal cells of the central and peripheral nervous systems in vertebrates, and its prokaryotic expression protein of which fused with HIV-1 virus-encoded Tat peptide exhibited significant antioxidant and anti-hypoxia. However, no study has documented on the anti-hypoxia of yeast expressed Tat-NGB. To address it, the NGB cDNA fragment with and without Tat tag was designed and conjugated to pPIC9K followed by electroporation, and positive colonies were screened.