Molecular Basis of Beta Cell Growth in Pregnancy Revealed

JDRF researchers at Stanford University found that menin, a protein known to suppress tumors, also plays a role in restraining insulin-producing beta cells from multiplying—raising the possibility that a therapy aimed at reducing menin levels could regenerate beta cells in people with type 1 diabetes. The discovery, made in mice by Seung Kim and colleagues, is published in the journal Science. The researchers were interested in menin’s role in gestational diabetes, a temporary form of diabetes that develops in two percent to five percent of women during pregnancy. They created mice that overproduce the hormone, and found that when these mice became pregnant, the islets grew insufficiently and the animals developed diabetes. A separate part of their study showed that the hormone prolactin, which is abundant during pregnancy, reduced menin levels and increased beta cell mass in non-pregnant mice. To expand this research, JDRF is funding a collaboration between Dr. Kim at Stanford University and Dr. Matthew Meyerson at Harvard Medical School, through an Academic Research and Development grant. The aims of the follow-up project are to validate this role for menin in humans and identify peptides that inhibit menin’s actions.