In situ enzymatic activity of transglutaminase isoforms on brain tissue sections of rodents: A new approach to monitor differences in post-translational protein modifications during neurodegeneration.

Mammalian transglutaminases (TGs) catalyze the irreversible post-translational modifications of proteins, the most prominent of which is the calcium-dependent formation of covalent acyl transfers between the γ-carboxamide group of glutamine and the ε-amino-group of lysine (GGEL-linkage). In the central nervous system, at least four TG isoforms are present and some of them are differentially expressed under pathological conditions in human patients. However, the precise TG-isoform-dependent enzymatic activities in the brain as well as their anatomical distribution are unknown.

Effect of the ATP-binding cassette transporter ABCG2 on pharmacokinetics: experimental findings and clinical implications.

Introduction: The ATP-binding cassette transporter ABCG2 can actively extrude a broad range of endogenous and exogenous substrates across biological membranes. Thereby, ABCG2 limits oral drug bioavailability, mediates hepatobiliary and renal excretion and participates functionally in the blood-brain barrier.

Areas Covered: The paper provides a review of the clinical evidence of the role of ABCG2 in the bioavailability and brain disposition of drugs.

Transporter gene expression in human head and neck squamous cell carcinoma and associated epigenetic regulatory mechanisms.

Expression levels of membrane transporters may affect the disposition, and thereby treatment efficacy, of anticancer drugs in human head and neck squamous cell carcinoma (HNSCC). Herein, we analyzed the gene expression profile of membrane transporters in HNSCC. In addition, we evaluated the mechanisms of transporter regulation in HNSCC and focused on the role of the nuclear pregnane X receptor (or NR1I2) and epigenetic mechanisms.