ABSTRACT
In this study, we carried out toxicogenomic analysis using in-house cDNA microarray to ascertain the long-term effects of neonatal exposure to genistein, also known as phytoestrogen, on testicular gene expression in mice. Male ICR mice, 1 day after birth, were exposed for 5 days to genistein (1000 microg/mouse/day) or diethylstilbestrol (DES) (50 microg/mouse/day), used as an example of a potent estrogen, and their testes were used when they were 12 weeks old. Since exposure to DES was been reported to induce morphological changes and alteration of gene expression in reproductive organs, DES was used as a positive control. Genistein-treated mice did not show any histological abnormalities or increased apoptotic cells in testes, but these abnormalities and increases were found in DES-treated mice. On the other hand, mRNA expression analysis using in-house cDNA microarray revealed that 2 down-regulated genes (GeneBank accession No. W49392 and AI430907) were detected in genistein-treated mouse testes. Moreover, real-time PCR analysis revealed that mRNAs of the W49392 gene, estrogen receptor alpha (ERalpha) and androgen receptor (AR), were down-regulated in the testes of both genistein-treated and DES-treated mice. In our present study using toxicogenomic analysis, long-term alteration in testicular mRNA expression, without morphological change in testes, was detected after neonatal treatment with genistein, indicating that the W49392 gene, in addition to ERalpha and AR, might be useful as a biological marker for predicting the effects of neonatal exposure to DES and genistein.
Subject(s)
Gene Expression Profiling , Gene Expression Regulation, Developmental/drug effects , Genistein/toxicity , Growth Inhibitors/toxicity , Testis/drug effects , Animals , Animals, Newborn , Apoptosis/drug effects , Body Weight/drug effects , Diethylstilbestrol/toxicity , Estrogen Receptor alpha , Estrogens, Non-Steroidal/toxicity , In Situ Nick-End Labeling , Male , Mice , Mice, Inbred ICR , Oligonucleotide Array Sequence Analysis , Organ Size/drug effects , RNA, Messenger/metabolism , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Receptors, Estrogen/genetics , Receptors, Estrogen/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Testis/metabolism , Testis/pathologyABSTRACT
In this study, we investigated the effects of neonatal exposure to exogenous estrogen (diethylstilbestrol: DES, 17beta-estradiol: E2) on testicular gene expressions. Male C57BL/6J mice, 1 day after birth, were subcutaneously injected with DES or E2 (3 micrograms/mouse/day) for 5 days, and then they were raised for 8 weeks. In morphological observation of 8-week-old mice testes, spermatozoa were absent from many seminiferous tubules in DES-treated mice testes, but there was no change in E2-treated mice testes. Analysis of in-house cDNA microarray (mouse cDNA 889 genes) revealed that 17 genes were altered in DES-treated mice testes at 8 weeks of age, compared to each control. Real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) analysis of these genes revealed that some genes, which were changed in E2-treated testis, were the same as in DES-treated testis, whereas in other cases there was a difference between DES-treated and E2-treated testis. The present results suggest that each exogenous estrogenic compound has both a common gene expression change pattern and its own testicular gene expression change pattern. Mol. Reprod. Dev. 67: 19-25, 2004.
Subject(s)
Diethylstilbestrol/pharmacology , Estradiol/pharmacology , Estrogens, Non-Steroidal/pharmacology , Gene Expression Profiling , Testis/drug effects , Testis/physiology , Toxicogenetics , Animals , Animals, Newborn , Gene Expression Regulation, Developmental , Male , Mice , Mice, Inbred C57BL , Oligonucleotide Array Sequence Analysis , Spermatozoa/cytology , Spermatozoa/metabolism , Testis/cytologyABSTRACT
We examined the effect of neonatal exposure to diethylstilbestrol (DES) on mouse testicular gene expression, using in-house mouse fetus (day 14.5) cDNA microarrays. Newborn male ICR mice were exposed to DES (50 microg/mouse/day) from neonatal day 1 to 5. Differential expression was detected in 14 genes in 4-week-old (day 28) mouse testes by cDNA microarray analysis; 11 genes (AI035263, AU080565, AU080361, AU080678, AI131681, AU080631, AA986882, AI037066, AA986537, AI156816, and AI596237) were up-regulated and three genes (AI131656, AI118968, and AI117606) were down-regulated in DES-treated mouse testes. Higher expression levels of the former eight genes, out of the up-regulated genes picked-up by the microarray, were also confirmed by reverse transcription and real-time polymerase chain reaction (real-time RT-PCR) analysis. However, the differential expression of other genes could not be confirmed. Real-time RT-PCR analysis also revealed that expression levels of the eight genes were still higher in DES-treated testes at 8 and 12 weeks of age. Our results suggest that cDNA microarray analysis is a useful method by which a large number of gene expressions are simultaneously detected and changes in gene expression are screened. In addition, our results suggest that these genes, whose expressions are changed in the testes of adult mice by fetal or neonatal exposure to exogenous chemicals, might be candidates for predictive biological markers.
