Tuesday morning on the Today show , Charlie Sheen revealed that he is HIV-positive. The 50-year-old actor told Matt Lauer that he was diagnosed four years ago."I’m here to admit that I am in fact HIV-positive and I have to put a stop to this onslaught, this barrage of attacks and of sub-truths and very harmful... stories that [I am] threatening the health of others, which couldn’t be farther from the truth," sheen explained.His appearance on Today arrives one day ahead of an upcoming National Enquirer issue expected to hit stands on November 18 which is purported to contain details about how the actor allegedly hid his HIV status from sexual partners.Sheen says that he has disclosed his status to all former sexual partners, and since the time of his diagnosis has only had sex with two women. The two partners were "warned ahead of time" and monitored by Sheen's own doctor.It's been more than a decade since Sheen was cast as the womanizing uncle character on Two and a Half Men that ultimately made him one of the most highly paid actors on television. Since then, he has personally and professionally unfurled, and was kicked off the show in 2011 after calling its producer a "a contaminated little maggot." Since then, the actor embarked on a comedy tour in 2013, but does not currently appear to have any new projects in progress.Sheen's former Spin City co-star Heather Locklear expressed support for him this morning in a heartfelt Instagram post. "My heart hurts," she wrote. "Prayers for Charlie and his family."