Figure 3. LIRKO Serum Induces Selective β Cell Replication In Vivo.

Five to 6-week-old mice were injected intraperitoneally twice daily with 150 µl serum derived from 6-month-old control or LIRKO mice on days 1, 3, and 5. BrdU was injected intraperitoneally (100 mg/kg body weight) on days 2, 4, and 6. Animals were sacrificed 5 hr before the last BrdU injection, and tissues were dissected for immunostaining studies.

(A) Schematic of the experimental design.

(B and C) Representative images and quantification of BrdU+ insulin+ cells: two sections separated by 80 µm were analyzed, and at least 4,000 insulin+ cells were counted for each animal.

(D and E) Representative images and quantification of BrdU+ glucagon+ cells: 400–600 glucagon+ cells were counted in each animal.

(F and G) Representative images and quantification of TUNEL+ insulin+ cells: at least 2,000 insulin+ cells were counted in each animal.

(H) Representative images and quantification of nuclei BrdU+ in indicated tissues: for each animal, 4,000–5,000 cells were counted in sections from liver, kidney, spleen, and lung, and 1,500 cells were counted in sections from visceral (Visc.) and subcutaneous (Sc.) adipose tissue and skeletal muscle.

Data represent mean ± SEM. *p ≤ 0.05 (n = 3 in each group).