Androgen Boosts Hepatitis B Virus Replication

StephenW

http://www.asm.org/index.php/news-room/tip0212a.html
Androgen Boosts Hepatitis B Virus Replication

Androgen enhances replication of hepatitis B virus (HBV), rendering males more vulnerable than females to this virus, according to research published in the February Journal of Virology.
“Our studies allowed us to understand the gender disparity of HBV carriers, and why this virus tends to cause more severe liver disease in men than in women,” says principal investigator James Ou of the University of Southern California.

The researchers found no difference between levels of virus in prepubescent male and female mice. However, post-puberty, levels in males exceeded those in females, in some cases by more than double, says Ou. Subsequently castrating male mice reduced the viral load, but injecting castrated mice with an androgen agonist resulted in a rising viral load again.

In a third set of experiments, the researchers removed the androgen receptor by genetic knockout, once again abolishing the androgen’s effect on hepatitis B replication. Then they drilled down still further, discovering elements within the HBV genome which are recognized by the host’s activated androgen receptor, which then boosts viral gene expression and replication.

Epidemiologic studies have shown that men are three to seven times more likely than women to become HBV carriers, and male HBV carriers are more likely to develop cancer of the liver (hepatocellular carcinoma) than female carriers.

“Hepatitis B virus is one of the most important human pathogens,” says Ou. “Approximately 350 million people worldwide are chronically infected, and roughly one million die annually.”

HBV can be transmitted sexually, as well as via non-sterile needles, and perinatally. In areas where the virus is endemic, it is frequently transmitted among young children. It is present in blood (including menstrual blood), vaginal secretions, saliva, semen, breast milk, and to a lesser extent in other bodily fluids.  A vaccine is available for HBV.

(Y. Tian, C.f. Kuo, W.-l. Chen, and J.-h.J. Ou, 2012. Enhancement of hepatitis B virus replication by androgen and its receptor in mice. J. Virol. 86:1904-1910.)
Last Updated on Wednesday, 15 February 2012 13:44





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StephenW

雄激素增强B型肝炎病毒复制

雄激素增强B型肝炎病毒（HBV）的复制，使男性比这个病毒的女性更脆弱，据考证在病毒学二月杂志发表。

“我们的研究让我们了解乙肝病毒携带者的性别差异，为什么这种病毒往往会造成更严重的肝男性比女性疾病，说：”南加州大学的首席研究员詹姆斯·欧。

研究人员没有发现病毒水平之间的差异在青春期前的雄性和雌性小鼠。然而，进入青春期后，男性的水平超出一倍以上的女性，在某些情况下，欧说。随后阉割雄性小鼠病毒载量减少，但去势小鼠注射雄激素受体激动剂再次导致病毒载量上升。

在第三组的实验中，研究人员去除雄激素受体基因剔除，再次取消乙肝复制的雄激素的效果。然后，他们钻进一步，确认这是由主机的激活雄激素受体，从而提高了病毒的基因表达和复制的HBV基因组内发现的元素。

流行病学研究表明，男性的3至7倍，比女性更容易成为乙肝病毒携带者，男性乙肝病毒携带者更容易患上癌症肝癌（肝细胞癌）比女性携带者。

“B型肝炎病毒是人类最重要的病原体之一，说：”欧。慢性感染“全球大约有350万人，大约一万，每年死亡。”

HBV可传输性，以及通过未消毒的针头，和围产期。在病毒流行的地方，它经常被传染幼童。它是目前在血液（包括经血），阴道分泌物，唾液，精液，乳汁，并在其他体液程度较轻。乙肝疫苗。