Synergistic Effect of Hyperglycemia and p27^kip1 Suppression on Adult Mouse Islet Beta Cell Replication

Table 2

The effect of p27^kip1 silencing on islet glucose-stimulation insulin secretion in vitro. After 24 h of transduction and at 3 and 7 days of culturing, batches of 30 islets per well were sequentially exposed to different concentrations of glucose. Islets were incubated in 100 mg/dL glucose for 60 min. After the medium was collected, the same batch of islets was washed and then stimulated with 360 mg/dL of glucose for 60 min. The net difference of insulin secretion from the glucose stimulation test (GSIS; ng/islet × 60 min) was calculated as the difference of the insulin content between the medium containing 360 mg/dL and medium containing 100 mg/dL glucose. The stimulation index (SI) was considered as the ratio of insulin content of the medium containing 360 mg/dL of glucose over that of the medium containing 100 mg/dL of glucose for the same batch of islets.

	Time	Targeting islet	Non-targeting islet control	P value
GSIS (ng/islet × 60 min)	Day 3	0.17±0.02 (𝑛=6)	0.20±0.02 (𝑛=10)	>0.05
	Day 7	0.24±0.09 (𝑛=6)	0.17±0.02 (𝑛=12)	>0.05
SI	Day 3	2.6±0.3 (𝑛=6)	2.8±0.4 (𝑛=10)	>0.05
	Day 7	2.4±0.3 (𝑛=6)	2.6±0.3 (𝑛=12)	>0.05