Forced Lamβ1 expression in podocytes of Lamb2−/− mice prevents nephrotic syndrome. (A) Reduced albuminuria in Lamb2−/−; Neph-B1 mice. SDS/PAGE/Coomassie blue analysis of 1 μL of urine from mice of the following genotypes: lane 3, Lamb2−/−; Neph-B1H; lane 4, Lamb2−/−; lane 5, Lamb2+/−; Neph-B1H (lanes 3–5 were from 3-wk-old mice); lane 7, Lamb2+/−; Neph-B1L; lane 8, Lamb2−/−; Neph-B1L (lanes 7 and 8 were from 10-mo-old mice). Lane 1, markers. Arrow indicates the size of albumin. (B) Graph showing albumin-to-creatinine ratios (g/g) in urine of Lamb2−/−; Neph-B1 and control mice. Lamb2−/−; Neph-B1 mice survived more than 1 y and had greatly reduced albuminuria compared with Lamb2−/− mice, which survive 1 mo with ∼100 g urinary albumin/g creatinine. Note that the low Lamβ1-expressing mice (Neph-B1L) showed heavier albuminuria than the high expressing mice (Neph-B1H).