Thioredoxin-1 attenuates indomethacin-induced gastric mucosal injury in mice.

Indomethacin is one of non-steroidal anti-inflammatory drugs that are commonly used clinically and often cause gastric mucosal injury as a side effect. Generation of reactive oxygen species (ROS) and activation of apoptotic signaling are involved in the pathogenesis of indomethacin-induced gastric mucosal injury. Thioredoxin-1 (Trx-1) is a small redox-active protein with anti-oxidative activity and redox-regulating functions. The aim of this study was to investigate the protective effect of Trx-1 against indomethacin-induced gastric mucosal injury. Trx-1 transgenic mice displayed less gastric mucosal damage than wild type (WT) C57BL/6 mice after intraperitoneal administration of indomethacin. Administration of recombinant human Trx-1 (rhTrx-1) or transfection of the Trx-1 gene reduced indomethacin-induced cytotoxicity in rat gastric epithelial RGM-1 cells. Pretreatment with rhTrx-1 suppressed indomethacininduced ROS production and downregulation of phosphorylated Akt in RGM-1 cells. Survivin, a member of inhibitors of apoptosis proteins family, was downregulated by indomethacin, which was suppressed in Trx-1 transgenic mice or by administration of rhTrx-1 in RGM-1 cells. Trx-1 inhibits indomethacin-induced apoptotic signaling and gastric ulcer formation, suggesting that it may have a preventive and therapeutic potential against indomethacin-induced gastric injury.

Recombinant human thioredoxin suppresses lipopolysaccharide-induced bronchoalveolar neutrophil infiltration in rat.

Human thioredoxin (TRX) is a multifunctional redox-active protein. We previously reported that the intraperitoneal administration of recombinant human thioredoxin (rhTRX) attenuates inflammatory cytokine- or bleomycin-induced lung injury in mice. In this study, the effect of rhTRX injected intravenously after lipopolysaccharide (LPS) injection was analyzed in rats. Rats were injected with LPS followed by treatment with rhTRX. Although the bolus injection exerted no protective effect, continuous intravenous administration of rhTRX significantly suppressed percentage number of neutrophils in bronchoalveolar lavage fluid. Histological examination also showed that rhTRX decreased neutrophil infiltration in the lung tissues. Administered rhTRX was mainly excreted into the urine and the tissue accumulation of rhTRX in the lung was marginal. LPS-induced oxidative stress in the lung was slight in this model. These results demonstrated that continuous intravenous administration of rhTRX suppresses LPS-induced bronchoalveolar neutrophil infiltration by an anti-chemotactic effect. Administration of rhTRX did not promote the tumor growth nor affect chemosensitivity in the xenotransplantation model, suggesting the safety of rhTRX therapy for cancer patients.

Genetic analysis of Nakano Cataract and its modifier genes in mice.

The Nakano Cataract (NCT) is an autosomal, recessive, single gene mutation in mice leading to an osmotic cataract induced by an endogenous inhibitor of Na, K-ATPase. In this report, we further refined the map position of the mutant locus to a <0.7c M segment between D16Mit5 and D16Mit185 in 1,000 BALB/c-nct/nct x(BALB/c- nct/nctxMSM)F1 backcrossed mice with PCR-based microsatellite analysis. The NCT in the original Nakano mice developed at 3 weeks of age, rapidly formed a pin-head type dense opacity, whereas the cataract in the congenic BALB/c- nct/nct mice developed at 5-6 weeks of age or later, slowly formed a diffuse opacity. A major histological difference was the presence or absence of heavy condensation of the lens nucleus. These two types of cataract were segregated in the backcrossed mice. Linkage analysis of the two subtypes among the backcrossed mice revealed two recessive BALB/c-derived modifier genes on chromosome 3 and 10.