An artificial CuII complex with intriguing oxygen radical-quenching profile. X-ray structure, cytochrome c assay, and ESR study

An artificial copper complex incorporating a cell-penetrating peptide inhibits nuclear factor-κB (NF-κB) activation

Nuclear factor-κB (NF-κB) is an inducible transcription factor activated by a variety of cytokines, and promotes the transcription of genes involved in cancer, inflammation, autoimmune disease, and viral infection, among others. Because of its involvement in numerous disease processes, considerable research has focused on NF-κB as a potential drug target. We previously reported that cupric ion (Cu(2+)) blocks NF-κB activation. However, Cu(2+) is unsuitable for drug applications. The copper complex of an artificial peptide HPH-Pep (HPH-Pep-Cu(2+)) was a promising alternative, but it did not easily cross the cell membrane. We report the development of a NF-κB inhibiting Cu(2+) complex with improved cell-penetrating activity arising from the coupling of a Tat peptide to HPH-Pep-Cu(2+).

Knockouts of SOD1 and GPX1 exert different impacts on murine islet function and pancreatic integrity

Metabolic subtlety and clinical relevance of different forms of reactive oxygen species in diabetes remain unclear. Using single knockout of Cu,Zn-superoxide dismutase (SOD1(-/-)) or Se-glutathione peroxidase-1 (GPX1(-/-)) and their double-knockout (DKO) mouse models, we determined if elevating endogenously-derived superoxide and hydroperoxide exerted distinct impacts and mechanisms on body glucose homeostasis. Whereas the three knockout groups displayed decreased plasma insulin concentrations and islet β-cells mass, only SOD1(-/-) showed decreased body weight, increased blood glucose, and blocked glucose-stimulated insulin secretion. Null of SOD1 and GPX1 elevated respective islet superoxide and hydroperoxide production, and upregulated p53 phosphorylation. Knockout of SOD1 downregulated the foxhead box A2/pancreatic and duodenal homeobox 1 pathway in a superoxide-dependent fashion at epigenetic, mRNA, and protein levels in islets, but improved insulin signaling in liver and muscle. The SOD1(-/-) mice showed more apparent pancreatitis than the GPX1(-/-) mice that were more susceptible to the cerulein-induced amylase increase. Knockout of SOD1 impaired islet function, pancreas integrity, and body glucose homeostasis more than that of GPX1. Simultaneous ablation of both enzymes did not result in additive or aggravated metabolic outcomes.

Antiviral activities against herpes simplex virus type 1 by HPH derivatives and their structure-activity relationships

The compound named Histidine-pyridine-histidine (HPH) is an oxygen-activating ligand derived from the structure of bleomycin. We synthesized HPH derivatives, namely HPH-1 to -8, and investigated their antiviral activities against herpes simplex virus type 1. HPH-8 showed potent antiviral activity with an EC50 of 15 microM, and relatively high cytotoxicity with a CC50 of 37 microM. In contrast, HPH-4 indicated a weaker antiviral activity with an EC50 of 79 microM, but exhibited a far more less cytotoxicity (CC50 500 microM). Other HPH derivatives showed no effects against antiviral activities and cytotoxicities.

Sensitization of hyperthermic treatment of leukemic cell lines by a synthetic peptide

A compound named HPH-Pep, a peptide constructed from pyridine and histidine units, showed sensitizing effect on the hyperthermic treatment of L-1210, Molt-4, and HL60 cells. The survival rate of these cells was greatly reduced by combined treatment with heating at 44 degrees C and HPH-pep. The treatment of L-1210 and Molt-4 cells with HPH-Pep resulted in a significant breakdown of the survival rate at 44 degrees C. The cell death induced by HPH-Pep under hyperthermic condition seemed to involve iron and peroxide.