Rac1 Promotes Cell Motility by Controlling Cell Mechanics in Human Glioblastoma
Authors: Xu, Jing; Galvanetto, Nicola; Nie, Jihua; Yang, Yili; Torre, Vincent
The failure of existing therapies in treating human glioblastoma (GBM) mostly is due to the ability of GBM to infiltrate into healthy regions of the brain; however, the relationship between cell motility and cell mechanics is not well understood. Here, we used atomic force microscopy (AFM), live-cell imaging, and biochemical tools to study the connection between motility and mechanics in human GBM cells. It was found thatRac1 inactivation by genomic silencing and inhibition with EHT 1864 reduced cell motility, inhibited cell ruffles, and disrupted the dynamics of cytoskeleton organization and cell adhesion. These changes were correlated with abnormal localization of myosin IIa and a rapid suppression of the phosphorylation of Erk1/2. At the same time, AFM measurements of the GBM cells revealed a significant increase in cell elasticity and viscosity following Rac1 inhibition. These results indicate that mechanical properties profoundly affect cell motility and may play an important role in the infiltration of GBM. It is conceivable that the mechanical characters might be used as markers for further surgical and therapeutical interventions.
beta-Lactoglobulin Heptapeptide Reduces Oxidative Stress in Intestinal Epithelial Cells and Angiotensin II-Induced Vasoconstriction on Mouse Mesenteric Arteries by Induction of Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) Translocation
OXIDATIVE MEDICINE AND CELLULAR LONGEVITY
Authors: Pepe, Giacomo; Basilicata, Manuela Giovanna; Carrizzo, Albino; Adesso, Simona; Ostacolo, Carmine; Sala, Marina; Sommella, Eduardo; Ruocco, Marco; Cascioferro, Stella; Ambrosio, Mariateresa; Pisanti, Simona; Di Sarno, Veronica; Bertamino, Alessia; Marzocco, Stefania; Vecchione, Carmine; Campiglia, Pietro
Peptides derived from buffalo dairy products possess multiple healthy properties that cannot be exerted as long as they are encrypted in parent proteins. To evaluate the biological activities of encrypted peptide sequences from buffalo ricotta cheese, we performed a simulated gastrointestinal (GI) digestion. Chemical and pharmacological characterization of the digest led to the identification of a novel peptide endowed with antioxidant and antihypertensive action. The GI digest was fractionated by Semiprep-HPLC, and fractions were tested against reactive oxygen species (ROS) release in an H2O2-treated intestinal epithelial cell line. UHPLC-PDA-MS/MS analysis revealed the presence of an abundant beta-lactoglobulin peptide (BRP2) in the most active fraction. Pharmacological characterization of BRP2 highlighted its antioxidant activity, involving ROS reduction, nuclear factor erythroid 2-related factor 2 (Nrf2) activation, and cytoprotective enzyme expression. The bioavailability of BRP2 was evaluated in intestinal transport studies through a Caco-2 cell monolayer. Equal bidirectional transport and linear permeability indicate that BRP2 was absorbed mainly through passive diffusion. In addition to its local effects, the BRP2 administration on mouse mesenteric arteries was able to reduce the angiotensin II-induced vasoconstriction by the Nrf2 nuclear translocation, the reduction of the active form of Ras-related C3 botulinum toxin substrate 1 (Rac1), and the NADPH oxidase activity. These data further highlight the role of buffalo ricotta cheese-derived peptides against oxidative stress-related diseases and suggest their health-promoting potential.