Biology of Pituitary Stem Cells

The pituitary gland is an organ with a low rate of cell turnover. While differentiated hormone-producing cells can re-enter the cell cycle, most of these cells are not dividing. There is some evidence that the pituitary can undergo limited regeneration after tissue injury. However, the regeneration is generally insufficient to meet physiologic demand, such that hormone replacement therapy is still needed. There is great interest in uncovering the mechanisms whereby specific hormone-producing cells are generated and to understand the similarities and differences for each cell type. Our understanding of anterior pituitary stem cells and committed progenitor cells has increased in the last several years. In this review, we update our previous version and outline the recent advances in pituitary stem cell biology. We lay the foundation with some background on pituitary development, cite some of the foundation studies on pituitary progenitors, and discuss pituitary stem cells in relation to the disease states of hypopituitarism and pituitary adenoma. We discuss areas of important, ongoing investigation, and future challenges.