you look so healthy and youthful

Researchers at Stanford University report that they can rejuvenate human cells by reprogramming them back to a youthful state. They hope that the technique will help in the treatment of diseases, such as osteoarthritis and muscle wasting, that are caused by the aging of tissue cells.

A major cause of aging is thought to be the errors that accumulate in the epigenome, the system of proteins that packages the DNA and controls access to its genes. The Stanford team, led by Tapash Jay Sarkar, Dr. Thomas A. Rando and Vittorio Sebastiano, say their method, designed to reverse these errors and walk back the cells to their youthful state, does indeed restore the cells’ vigor and eliminate signs of aging.

In their report, published in Nature Communications, they described their technique as “a significant step toward the goal of reversing cellular aging” and could produce therapies “for aging and aging-related diseases.”

Leonard P. Guarente, an expert on aging at MIT, said the method was “one of the most promising areas of aging research” but that it would take a long time to develop drugs based on RNA, the required chemical.

The Stanford approach utilizes powerful agents known as Yamanaka factors, which reprogram a cell’s epigenome to its time zero, or embryonic state.

Embryonic cells, derived from the fertilized egg, can develop into any of the specialized cell types of the body. Their fate, whether to become a skin or eye or liver cell, is determined by chemical groups, or marks, that are tagged on their epigenome.

In each type of cell, these marks make accessible only the genes that the cell type needs, while locking down all other genes in the DNA. The pattern of marks thus establishes each cell’s identity. As the cell ages, it accumulates errors in the marking system, which degrade the cell’s efficiency at switching on and off the genes needed for its operations.

In 2006, Dr. Shinya Yamanaka, a stem cell researcher at Kyoto University, amazed biologists by showing that a cell’s fate could be reversed with a set of four transcription factors — agents that activate genes — that he had identified. A cell dosed with the Yamanaka factors erases the marks on the epigenome so the cell loses its identity and reverts to the embryonic state. Erroneous marks gathered during aging are also lost in the process, restoring the cell to its state of youth.

Yamanaka shared the 2012 Nobel Prize in medicine for the work.

But the Yamanaka factors are no simple panacea.

Applied to whole mice, the factors made cells lose their functions and primed them for rapid growth, usually cancerous; the mice all died.

In 2016, Juan Carlos Izpisua Belmonte of the Salk Institute for Biological Studies in San Diego found that the two effects of the Yamanaka factors — erasing cell identity and reversing aging — could be separated, with a lower dose securing just age reversal. But he achieved this by genetically engineering mice, a technique not usable in people.

In their paper last week, the Stanford team described a feasible way to deliver Yamanaka factors to cells taken from patients, by dosing cells kept in cultures with small amounts of the factors.

If dosed for a short enough time, the team reported, the cells retained their identity but returned to a youthful state, as judged by several measures of cell vigor.

-- Nicholas Wade, New York Times (printed in star advertiser)

Bill Gates leaving Microsoft board

Microsoft announced on Friday that Bill Gates is leaving the board, effective Friday. Gates is also stepping down from his position on the board of Berkshire Hathaway.

“I have made the decision to step down from both of the public boards on which I serve – Microsoft and Berkshire Hathaway – to dedicate more time to philanthropic priorities including global health and development, education, and my increasing engagement in tackling climate change,” Gates said on LinkedIn. “The leadership at the Berkshire companies and Microsoft has never been stronger, so the time is right to take this step.”

“With respect to Microsoft, stepping down from the board in no way means stepping away from the company,” Gates said. “Microsoft will always be an important part of my life’s work and I will continue to be engaged with Satya and the technical leadership to help shape the vision and achieve the company’s ambitious goals. I feel more optimistic than ever about the progress the company is making and how it can continue to benefit the world.”

Gates co-founded Microsoft in 1975 with Paul Allen, who died in 2018. Gates was CEO until 2000 when Steve Ballmer took over the role. Microsoft’s current CEO, Satya Nadella, took over in 2014. Gates was director of the board at Microsoft until 2014 but began dedicating more of his time to the Bill & Melinda Gates Foundation in 2008.

Gates is among Microsoft’s top shareholders. He owns 1.36% of shares, according to FactSet. The company went public in 1986 and is now one of the most highly valued companies in the world with a market cap of $1.21 trillion.

“It’s been a tremendous honor and privilege to have worked with and learned from Bill over the years,” said Microsoft CEO Satya Nadella.

“Bill founded our company with a belief in the democratizing force of software and a passion to solve society’s most pressing challenges. And Microsoft and the world are better for it. The board has benefited from Bill’s leadership and vision. And Microsoft will continue to benefit from Bill’s ongoing technical passion and advice to drive our products and services forward. I am grateful for Bill’s friendship and look forward to continuing to work alongside him to realize our mission to empower every person and every organization on the planet to achieve more.”