Figure 4.

TGFβ1 and TGFBI production by islets and renal parenchyma. (A) TGFβ1 production by isolated islets. WT islets were cultured in F-12K serum-free medium (200 islets/0.2 ml/well in 48-well plates) for the durations indicated. TGFβ1 in supernatants was measured by ELISA of duplicate samples. Means ± SD of TGFβ1 levels are reported. (B) TGFBI production by WT islets upon exogenous TGFβ1 stimulation. WT islets were cultured as described in (A), and TGFBI in supernatants was measured at different time points by ELISA of duplicate samples. In some culture, recombinant mouse TGFβ1 (20 ng/ml) was added at 48 h after the initiation of culture. Means ± SD of TGFBI levels are reported. In (A and B), experiments were performed more than twice, and data from representative experiments are reported. (C and D) TGFβ1 and TGFBI production by renal parenchyma after trauma. The left kidneys of WT mice were sham-operated to mimic islet transplantation procedures, After 48 h, the renal parenchyma near the wound was pared, and its RNA extracted to measure TGFβ 1 (C) and TGFBI (D) mRNA levels by RT–qPCR in duplicate. The results are expressed as ratios of TGFβ1 or TGFBI versus β-actin signals. Unmanipulated right kidneys served as controls, and lines link the ratios of two kidneys (operated versus unmanipulated) from the same mouse. P values (paired Student's t test) are reported.