title: Mesangial cells from transgenic mice with progressive glomerulosclerosis exhibit stable, phenotypic changes including undetectable MMP-9 and increased type IV collagen.
abstract: Mice transgenic for bovine growth hormone (bGH) develop progressive mesangial sclerosis resulting in uremia. Mesangial cells from bGH mice were isolated to determine whether the cells maintained a stable phenotypic change in the synthesis and degradation of extracellular matrix, which contribute to the glomerular lesions in vivo. The bGH mesangial cells were 1.2-fold larger than cells from control mice. They had a 1.7-fold increase in doubling time, a 7-fold decrease in labeling index (p < 0.0001), and a 2.4- and 2-fold decrease in c-myc (p < 0.05) and insulin-like growth factor I gene expression, respectively. Collagen synthesis and degradation were studied by PCR, ELISA, and gelatin zymography. bGH mesangial cell alpha 1 collagen IV mRNA levels were increased 2.3-fold (0.47 +/- 0.25 versus 0.20 +/- 0.09 attomoles/500 cells, p < 0.01) whereas secreted collagen IV and collagen IV in the cell lysates were increased 1.4-fold (25.1 +/- 5 versus 17.2 +/- 4 ng/ml/10(5) cells) and 1.8-fold (30.5 +/- 3 versus 16.7 +/- 3 ng/ml/10(5), p < 0.05), respectively. There were no differences in collagen I mRNA levels or in the protein content of either the media or cell lysates. We were not able to detect metalloproteinase 9 (MMP-9) mRNA expression or MMP-9 protein in bGH mesangial cell medium, whereas both mRNA and protein were present in controls. MMP-2 mRNA and enzyme activity in bGH cells were, however, elevated 1.5-fold (p < 0.05) and 2.1-fold (p = 0.05) over controls. Transforming growth factor beta 1 mRNA in bGH cells was 1.6-fold higher than that of controls (p < 0.05). The data suggest that (a) mesangial lesions may result from stable, genetically induced, phenotypic changes in mesangial cells, and (b) alterations of MMP-9 and collagen IV expression by mesangial cells may contribute to an imbalance between extracellular matrix synthesis and degradation and play a critical role in the genesis of glomerulosclerosis.
authors.affiliation: Renal Cell Biology Section, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Jacot
authors.forename: G E
authors.initials: GE
authors.lastname: Striker
authors.forename: M
authors.initials: M
authors.lastname: Stetler-Stevenson
authors.forename: L J
authors.initials: LJ
authors.lastname: Striker
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D003094:Collagen / Q000032:analysis / Q000096:biosynthesis*; D017364:Collagenases / Q000032:analysis / Q000096:biosynthesis*; D017931:DNA Primers; D018093:Gelatinases / Q000032:analysis / Q000096:biosynthesis; D005920:Glomerular Mesangium / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D005921:Glomerulonephritis / Q000378:metabolism / Q000473:pathology*; D013006:Growth Hormone / Q000096:biosynthesis* / Q000235:genetics; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D008666:Metalloendopeptidases / Q000032:analysis / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D013006:Growth Hormone; D003094:Collagen; D017364:Collagenases; D018093:Gelatinases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9