Figure 2.

Signalling by pregnancy hormones prolactin (PrL) and placental lactogen (PL) through the prolactin receptor (PrlR) through the Jak/Stat pathway improves glucose stimulated insulin secretion (GSIS), prevents apoptosis and promotes proliferation and expansion. Hepatocyte growth factor (HGF) signals through AKT and mTOR via cMet to improve β-cell adaptations. Epidermal growth factor (EGF) through epidermal growth factor receptor (EGF-R) and ras/extracellular signal-related kinases (ERK) signalling can mediate proliferation and expansion; the ras/ERK pathway can also be mediated lactogens. Transcription factors (such as Hnf4a, FoxD3, FoxM1) can modulate expression of genes that mediate these adaptations.