N-Terminal Acetylation and C-Terminal Amidation of Spirulina platensis-Derived Hexapeptide: Anti-Photoaging Activity and Proteomic Analysis.

Ultraviolet (UV) irradiation is a potent inducer for skin photoaging. This paper investigated the anti-photoaging effects of the acetylated and amidated hexapeptide (AAH), originally identified from Spirulina platensis, in (Ultraviolet B) UVB-irradiated Human immortalized keratinocytes (Hacats) and mice. The results demonstrated that AAH had much lower toxicity on Hacats than the positive matrixyl (81.52% vs. 5.32%). Moreover, AAH reduced MDA content by 49%; increased SOD, CAT, and GSH-Px activities by 103%, 49%, and 116%, respectively; decreased MMP-1 and MMP-3 expressions by 27% and 29%, respectively, compared to UVB-irradiated mice. Employing isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics, 60 differential proteins were identified, and major metabolic pathways were determined. Network analysis indicated that these differential proteins were mapped into an interaction network composed of two core sub-networks. Collectively, AAH is protective against UVB-induced skin photoaging and has potential application in skin care cosmetics.

Mesenchymal stem cells attenuate sepsis-induced liver injury via inhibiting M1 polarization of Kupffer cells.

Sepsis is a leading cause of death in intensive care units that can result in acute hepatic damage. Animal experiments and clinical trials have shown that mesenchymal stem cell (MSC) therapy has some beneficial in several liver diseases. However, the protective effects of MSC therapy on sepsis-induced hepatic damage and associated mechanisms are not completely understood. The aim of the present study was to investigate the effects of MSCs on sepsis-induced liver injury and underlying mechanisms. A rat model of sepsis-induced liver injury was established by cecal ligation and puncture, and serum alanine aminotransferase and aspartate transaminase activities as well as liver histological changes were measured. Inflammatory cytokines, Kupffer cell M1 phenotype markers, and associated signal molecules were also determined in septic rats and in lipopolysaccharide (LPS)-treated Kupffer cells. Our results showed that injection of MSCs attenuated sepsis-induced liver injury. Treatment with MSCs inhibited activation of Kupffer cells towards M1 phenotype, attenuated TNF-α and IL-6 expression, and promoted IL-4 and IL-10 expression in septic rats and LPS-treated Kupffer cells. Furthermore, MSCs also inhibited the nuclear translocation of nuclear factor-kappa B in LPS-challenged Kupffer cells and the liver of septic rats. These results indicated that MSCs attenuated sepsis-induced liver injury through suppressing M1 polarization of Kupffer cells.