Stress gives cells a ‘second childhood’

What doesn’t kill cells may make them stronger—or considerably more flexible, at least. New findings from Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe and Charles Vacanti at Brigham and Women’s Hospital in the United States suggest that exposing mouse cells to acidic stress can make them regress to an extremely developmentally immature state, transcending even that of embryonic stem (ES) cells (1, 2).

ES cells have the developmental capacity to form any tissue type in the body and this ‘pluripotency’ makes them of great interest to both scientists and clinicians. As these cells must be harvested from early-stage embryos, however, human ES cell research remains a politically and ethically fraught issue. As an alternative, researchers can ‘reprogram’ adult cells into ES cell-like induced pluripotent stem (iPS) cells, which offer the advantage of being genetically matched to their donor—an important consideration for regenerative medicine. However, the generation of iPS cells typically requires the introduction of reprogramming genes, which may affect their function or risk of cancerous transformation.

Obokata and colleagues have now discovered an alternative route to pluripotency, drawing on inspiration from the plant world. “Plants [such as] carrots can produce stem cells from totally differentiated cells when they are exposed to strong external stresses like dissection,” Obokata said in a recent interview with Nature. “I instinctively felt that we may have a similar mechanism to plants.”

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