Sex-specific transgenerational effects of preconception exposure to arsenite: metabolic phenotypes of C57BL/6 offspring.

Chronic exposure to inorganic arsenic (iAs) has been linked to diabetes in both humans and mice, but the role of iAs exposure prior to conception and its transgenerational effects are understudied. The present study investigated transgenerational effects of preconception iAs exposure in C57BL/6J mice, focusing on metabolic phenotypes of G1 and G2 offspring. Body composition and diabetes indicators, including fasting blood glucose, fasting plasma insulin, glucose tolerance, and indicators of insulin resistance and beta cell function, were examined in both generations. The results suggest that the preconception iAs exposure in the parental (G0) generation induced diabetic phenotypes in G1 and G2 offspring in a sex-dependent manner. G1 females from iAs-exposed parents developed insulin resistance while no significant effects were found in G1 males. In the G2 generation, insulin resistance was observed only in males from iAs-exposed grandparents and was associated with higher bodyweights and adiposity. Similar trends were observed in G2 females from iAs-exposed grandparents, but these did not reach statistical significance. Thus, preconception iAs exposure altered metabolic phenotype across two generations of mouse offspring. Future research will investigate the molecular mechanisms underlying these transgenerational effects, including epigenomic and transcriptomic profiles of germ cells and tissues from G0, G1 and G2 generations.

Ex vivo exposures to arsenite and its methylated trivalent metabolites alter gene transcription in mouse sperm cells.

We have previously reported that preconception exposure to iAs may contribute to the development of diabetes in mouse offspring by altering gene expressions in paternal sperm. However, the individual contributions of iAs and its methylated metabolites, monomethylated arsenic (MAs) and dimethylated arsenic (DMAs), to changes in the sperm transcriptome could not be determined because all three As species are present in sperm after in vivo iAs exposure. The goal of the present study was to assess As species-specific effects using an ex vivo model. We exposed freshly isolated mouse sperm to either 0.1 or 1 µM arsenite (iAsIII) or the methylated trivalent arsenicals, MAsIII and DMAsIII, and used RNA-sequencing to identify differentially expressed genes, enriched pathways, and associated protein networks. For all arsenicals tested, the exposures to 0.1 µM concentrations had greater effects on gene expression than 1 µM exposures. Transcription factor AP-1 and B cell receptor complexes were the most significantly enriched pathways in sperm exposed to 0.1 µM iAsIII. The Mre11 complex and Antigen processing were top pathways targeted by exposure to 0.1 µM MAsIII and DMAsIII, respectively. While there was no overlap between gene transcripts altered by ex vivo exposures in the present study and those altered by in vivo exposure in our prior work, several pathways were shared, including PI3K-Akt signaling, Focal adhesion, and Extracellular matrix receptor interaction pathways. Notably, the protein networks associated with these pathways included those with known roles in diabetes. This study is the first to assess the As species-specific effects on sperm transcriptome, linking these effects to the diabetogenic effects of iAs exposure.

Protective effect of Bu-zhong-yi-qi decoction, the water extract of Chinese traditional herbal medicine, on 5-fluorouracil-induced renal injury in mice.

BACKGROUND: Drug-induced renal injury is a serious toxic side effect of 5-fluorouracil (5-FU) treatment. Bu-zhong-yi-qi decoction (BZYQD), a water extract of Chinese traditional herbal medicine, is widely used in Asia as an alternative treatment to reduce the side effects of chemotherapy and also improve cancer survival. However, the mechanism is unknown. This study is designed to investigate the protective effect of BZYQD on 5-FU-induced renal injury in mice. METHODS: Mice were divided into four groups: the control, 5-FU, 5-FU + low, and high BZYQD group. Mice in the three latter groups were administered 5-FU (100 mg/kg/day, intraperitoneally) for six days, and in the 5-FU + low and high BZYQD groups were given BZYQD (1 or 2 g raw herb/kg/day, intragastrically) beginning four days before 5-FU and continuing until the termination of the experiment. The right kidney fixed in formalin for histological examination and the left was homogenized to measure the levels of apoptosis-related proteins and activities of oxidative stress-related biomarkers. Blood samples were collected for measuring renal function-related biochemical indices. RESULTS: Renal morphology injury, increased urea nitrogen and creatinine concentration, and decreased SOD, CAT, and GSH-Px were all observed in 5-FU-administrated mice. However, BZYQD almost reversed the morphological injury as well as renal function-related indices and antioxidant enzyme activity. CONCLUSION: These results suggest that BZYQD inhibits 5-FU-induced renal injury, possibly through the reduction of apoptosis and necrosis in renal tubular epithelial cells via the antioxidant mechanism. Henceforth, BZYQD may be a potential antioxidant against drug-induced oxidative stress.