Abstract
Testosterone has been previously shown to induce persistent susceptibility to Plasmodium chabaudi malaria in otherwise resistant female C57BL/6 mice. Here, we investigate as to whether this conversion coincides with permanent changes of hepatic gene expression profiles. Female mice aged 10-12 weeks were treated with testosterone for 3 weeks; then, testosterone treatment was discontinued for 12 weeks before challenging with 10(6) P. chabaudi-infected erythrocytes. Hepatic gene expression was examined after 12 weeks of testosterone withdrawal and after subsequent infection with P. chabaudi at peak parasitemia, using Affymetrix microarrays with 22 690 probe sets representing 14 000 genes. The expression of 54 genes was found to be permanently changed by testosterone, which remained changed during malaria infection. Most genes were involved in liver metabolism: the female-prevalent genes Cyp2b9, Cyp2b13, Cyp3a41, Cyp3a44, Fmo3, Sult2a2, Sult3a1, and BC014805 were repressed, while the male-prevalent genes Cyp2d9, Cyp7b1, Cyp4a10, Ugt2b1, Ugt2b38, Hsd3b5, and Slco1a1 were upregulated. Genes encoding different nuclear receptors were not persistently changed. Moreover, testosterone induced persistent upregulation of genes involved in hepatocellular carcinoma such as Lama3 and Nox4, whereas genes involved in immune response such as Ifn gamma and Igk-C were significantly decreased. Our data provide evidence that testosterone is able to induce specific and robust long-term changes of gene expression profiles in the female mouse liver. In particular, those changes, which presumably indicate masculinized liver metabolism and impaired immune response, may be critical for the testosterone-induced persistent susceptibility of mice to P. chabaudi malaria.