Early administration of keratinocyte growth factor improves β-cell regeneration in rat with streptozotocin-induced diabetes

The aim of our study was to investigate the ability of keratinocyte growth factor (KGF; palifermin) in regulating β-cell growth in normal newborn rats and in rats with neonatal diabetes. Wistar rats were injected with streptozotocin (STZ) to induce diabetes on the dayof birth. From days 2 to 6 after birth, animals received a daily s.c. injection of KGF (STZ/KGF group) and at the dose of 3 mg/kg body weight or saline solution (STZ groups). A group of non-diabetic Wistar rats was treated either with saline (Wistar group) or with KGF from days 2 to 6 after birth at the dose of 3 mg/kg body weight (Wistar/KGF group). β-cell mass was measured at day 7 after birth in all groups. β- and ductal cells replication were measured in all groups and apoptosis was assessed in the pancreas of 2-, 4-, and 7-day-old STZ and STZ/KGF rats. The total β-cell mass of the 7-day-old KGF/STZ neonates was significantly increased compared with that of age-matched STZ rats. β-cell replication rate was decreased at day 2 in the STZ/KGF group and was similar in the 4- and 7-day-old rats from STZ and STZ/KGF groups. Duct cell replication was significantly increased in the pancreas of 2- and 4-day-old KGF/STZ neonates when compared with that of age-matched rats from STZ control group. The rate of apoptosis in the neonatal pancreases of STZ and KGF/STZ groups was not significantly different. In non-diabetic Wistar rats, KGF treatment led to a slight but significant increase in duct cell proliferation at day 2 without significant changes in the total β-cell mass in the 7-day-old rats. We provide evidence for a growth-promoting effect of KGF during β-cell regeneration in neonatal diabetic rats. KGF exerts strong mitogenic effect on the pancreatic duct cells, thus expanding the population of precursor cells that subsequently differentiate into insulin-producing β-cells.