Microarray analysis of the global alterations in the gene expression in the placentas from cigarette-smoking mothers.

The effects of maternal cigarette smoking on the transcriptome of human full-term placentas were investigated by a microarray analysis. QPCR was performed for a selected set of metabolizing genes. Differentially expressed genes were selected by fold change (+/-1.5-fold) and analysis of variance (P<0.05) between the control and smoker groups. The expression of 174 probe sets was affected significantly. Chronic cigarette smoking induced the expression of CYP1A1. A trend toward a decrease in the expression of several steroid hormone-metabolizing enzymes, including CYP19A1, was detected. The expression of phase II enzymes was not altered, and no enriched categories were observed among the regulated genes, except for aryl hydrocarbon receptor (AhR)-CYP1A1. The unaltered expression of phase II enzymes may result in an increase in the levels of active metabolites and elevated oxidative chemical stress in the placenta and the fetus. On the basis of our results, it seems that cigarette smoke acts as a hormone disrupter in the placenta.

Expression of Human Glucose Transporter Type 1 and Rat Hexokinase Type II Complementary DNAs in Rainbow Trout Embryos: Effects on Glucose Metabolism.

: Sugars are utilized poorly in fish mainly because of low rates of transport across plasma membrane and phosphorylation. To evaluate whether it is possible to augment carbohydrate metabolism in fish using heterologous genes, expression of human glucose transporter type 1 (hGLUT1) and rat hexokinase type II (rHKII) complementary DNAs cloned with cytomegalovirus promoter was followed in rainbow trout embryos. Both genes were transcribed. Hexokinase activity, undetectable in control, was found in transformed blastulas. Increased rates of 14C-methylglucose uptake and sensitivity to cytochalasin B indicated the presence of facilitative hexose transport due to hGLUT1 expression. Effect of hGLUT1 on production of 14CO2 from glucose was greater than that of rHKII. Coexpression of the genes did not increase the rate of glucose oxidation compared with expression of hGLUT1 alone.

Expression of rat gene for L-gulono-gamma-lactone oxidase, the key enzyme of L-ascorbic acid biosynthesis, in guinea pig cells and in teleost fish rainbow trout (Oncorhynchus mykiss).

The ability of rainbow trout liver and kidney preparations to produce L-ascorbic acid with an added source of L-gulono-gamma-lactone oxidase (GLO) and the absence of their own GLO activity suggested that the reason for the absence of L-ascorbic acid biosynthesis in fish and in guinea pig, a scurvy-prone mammal, can be similar. Nevertheless, results of rat GLO cDNA expression in guinea pig cells and in rainbow trout proved different. In guinea pig cells, rat GLO was expressed in a functional form. Regardless of recombinant GLO transcripts detected in rainbow trout embryos, alevins and in juvenile fish, neither GLO protein nor GLO activity were found. Furthermore, production of L-ascorbic acid in transgenic rainbow trout was not revealed in feeding tests with vitamin C-free diets or after direct administration of L-gulono-gamma-lactone. These results indicate that conditions required for translation or stability of rat GLO are absent in rainbow trout tissues.