Focal glomerulosclerosis (FGS) is characterized by the accumulation of mesangial matrix and lack of mesangial cells (MC). We studied the role of glomerular hypertension (GH) in the development of MC hypoplasia.
Methods
We used an in vitro model of GH to study the effect of GH on MC apoptosis. Cultured rat endothelial cells were grown in the intracapillary space and MCs were grown in the extracapillary space. MC proliferation as well as apoptosis was evaluated under simulated normal glomerular pressure (SNGP) as well as simulated glomerular hypertension (SGH). Apoptosis was determined morphologically by DNA fragmentation using Hoechst staining as well as with the use of DNA gel electrophoresis. MCs grown under SNGP and SGH were also evaluated for the expression of genes associated with active cell death. In addition, we evaluated the effect of direct applied pressure on MC apoptosis.
Results
MCs grown under SGH were less elliptical and had a tendency to develop a dome in the center. Direct applied pressure promoted MC apoptosis in a dose and time dependent manner. DNA gel electrophoresis from MCs grown under SGH also showed integer multiples of 180 base pairs (ladder pattern); whereas cells grown under SNGP showed no DNA fragmentation. SGH increased mRNA expression of cathepsin-B (SNGP, 0.31 ± 0.04 vs SGH, 0.57 ± 0.03, P < 0.01, n = 3) and SGP-2 (SNGP, 0.55 ± 0.05 vs SGH, 1.08 ± 0.12, P < 0.01, n = 3) in MCs when compared to cells grown under SNGP.
Conclusions
The present in vitro study suggests that GH has the potential to convert a hypercellular mesangium into a hypocellular one. This effect of GH is associated with expression of genes associated with active cell death.
WheltonPK, KlagMJ.Hypertension as a risk factor for renal disease: review of clinical and epidemiological evidence. Hypertension1989;13: (1 Suppl):1–19.
2.
KlahrS, SchreinerG, IchikawaI.The progression of renal disease. N Engl J Med1988;318:1657–8.
3.
RaijL, ChiouXH, OwensR, WrigleyB.Therapeutic implications of hypertension-induced glomerular injury. Am J Med1985;79:(3C Suppl):37–41.
4.
PettingerWA, LeeHC, ReischJ, MitchellHC.Long term improvement in renal function after short term strict blood pressure control in hypertensive nephrosclerosis. Hypertension1989;13:766–72.
5.
ParvingHH, AndersonAR, SmithUM, SvendsenPA.Early antihypertensive treatment reduces rate of decline in kidney function in diabetic nephropathy. Lancet1983;1:1175–9.
6.
BrazyPC, FitzwilliamJF.Progressive renal disease: role of race and antihypertensive medications. Kidney Int1990;37:1113–9.
7.
BerstromJ, AlvestrandA, BuchtM, GutierrezA.Progression of chronic renal failure in man is retarded with more frequent clinical follow-ups and better blood pressure control. Clin Nephrol1986;25:1–6.
8.
RostandSG, BrownG, KirkKA, RutskyEA, DustanHP.Renal insufficiency in treated hypertension. N Engl J Med1989;320:684–8.
9.
SagarS, GibbonsN, ValderramaE, SinghalPC.Glomerular protease activity modulates the development of focal segmental glomerulosclerosis. Clin Nephrol1995;44:356–61.
10.
RaijL, AzarS, KeaneWF.Role of hypertension in progressive glomerular injury. Hypertension1985;7:398–404.
11.
AzarS, JohnsonMA, ScheinmanJ, BrunoL, TobianL.Regulation of glomerular capillary pressure and filtration rate in young Kyoto hypertensive rats. Clin Sci1979;56:203–9.
12.
NeuringerJR, BrennerBM.Hemodynamic theory of progressive renal disease. A 10-year update in brief review. Am J Kidney Dis1992;22:98–104.
13.
StrikerGE, HeC-J, LiuZH, YanfDCW, ZalpusRK, EspositoC, StrikerLJ.Pathogenesis of nonimmune glomerulosclerosis: studies in animals and potential applications to humans. Lab Invest1995;73:596–605.
14.
BorderWA, NobleNA, YamamotoT, HarperJR, YamaguchiY, PierschbacherMD, RuoslahtiE.Natural inhibitor of transforming growth factor-β protects against scarring in experimental kidney disease. Nature1992;360:361–4.
15.
SugiyamaH, KashiharaN, MakinoH, YamasakiY, OtaZ.Apoptosis in glomerular sclerosis. Kidney Int1996;49:103–11.
16.
DeenWM, MaddoxDA, RobertsonCR, BrennerBM.Dynamics of the glomerular ultrafiltration in the rat. VII. Response to reduced renal mass. Am J Physiol1974; 227:556–62.
17.
HostetterTH, OlsonJL, RennkeHG, VenkatchalamMA, BrennerBM.Hyperfiltration in remnant nephrons: a potentially adverse response to renal ablation. Am J Physiol1981;241:F85–F93.
18.
AndersonS, MeyerTW, RennkeHG, BrennerBM.Control of glomerular hypertension limits glomerular injury in rats with reduced renal mass. J Clin Invest1985;76:612–9.
19.
SinghalPC, ScharschmidtLA, GibbonsN, HaysRM.Contraction and relaxation of cultured mesangial cells on a silicone rubber surface. Kidney Int1986;30:862–73.
20.
SinghalPC, SantiagoA, SatrianoJ, HaysRM, SchlondorffD.Effects of vasoactive agents on uptake of immunoglobulin-G complexes by mesangial cells. Am J Physiol1990;258:F589–96.
21.
SinghalPC, GibbonsN, FrankiN, ReddyK, MattanaJ, WagnerJ.Glomerular hypertension: An in vitro model[abstract]. J Am Soc Nephrol1996;7:1588.
22.
WongP, PineaultJM, LakinsJ, TailleferD, LegerJG, WangC, TenniswoodMP.Genomic organization and expression of the rat TRPM-2 (clusterin) gene, a gene implicated in apoptosis. J Biol Chem1993;268:5021–31.
23.
GuenetteRS, MooibroekM, WongK, WongP, TenniswoodM.Cathepsin B, a cysteine protease implicated in metastatic progression, is also expressed during regression of the rat prostate and mammary glands. Eur J Biochem1994;226:311–21.
24.
ChomczynskiP, SacchiN.Single-step method of RNA isolation by acid guanidine thiocyanate phenol-chloroform extraction. Anal Biochem1987;162:156–9.
25.
MattanaJ, SinghalPC.Applied pressure modulates mesangial cell proliferation and matrix synthesis. Am J Hyper1995;8:1112–20.
26.
SharmaP, ReddyK, FrankiN, SanwalV, SankaranR, AhujaTS, GibbonsN, MattanaJ, SinghalPC.Native and oxidized low density lipoproteins modulate mesangial cell apoptosis. Kidney Int1996;50:1604–11.
27.
LieberthalW, TriacaV, LevineJ.Mechanisms of death induced by cisplatin in proximal tubular epithelial cells: apoptosis vs. necrosis. Am J Physiol1996;270:F700–8.
28.
ThompsonC.B. Apoptosis in the pathogenesis and treatment of disease. Science1995;267:1456–62.
29.
WyllieAH, KerrJFR, CurrieAR.Cell death: The significance of apoptosis. Int Rev Cytol1980;68:251–305.
30.
OberhammerF, WilsonPR, SikorskaM.Apoptotic death in epithelial cells: Cleavage of DNA to 300 and/or 50 kb fragments prior to or in the absence of internucleosomal fragmentation. EMBO J1993;12:3679–84.
31.
FilipskiJ, LeblancJ, YoudaleT, SikorskaM, WalkerPR.Periodicity of DNA folding in higher order chromatin structures. EMBO J1990;9:1319–27.
32.
HarrisonDJ.Cell death in the diseased glomerulus. Histopathology. 1988;12:679–83.
BakerAJ, MooneyA, HughesJ, LombardiD, JohnsonRJ, SavillJ.Mesangial cell apoptosis: The major mechanism for resolution of glomerular hypercellularity in experimental mesangial proliferative nephritis. J Clin Invest1994;94:2105–16.
35.
ShimizuA, KitamuraH, MasudaY, IshizakiM, SugisakiY, YamanakaN.Apoptosis in the repair process of experimental proliferative glomerulonephritis. Kidney Int1995;47:114–21.
36.
SugiyamaH, KashiharaN, MakinoH, YamasakiY, OtaZ.Apoptosis in glomerulosclerosis. Kidney Int1996;49:103–11.
37.
BodiI, AbrahamAA, KimmelPL.Apoptosis in human immunodeficiency virus-associated nephropathy. Am J Kidney Dis1995:26:286–91.
38.
ShahS.Role of reactive oxygen metabolites in experimental glomerular disease. Kidney Int1989;35:1093–106.
39.
DiamondJR. Role of reactive oxygen species in animal models of glomerular disease. Am J Kidney Dis1992;19:292–300.
40.
DiamondJR, BonventreJV, KarnovskyMJ.A role for oxygen free radicals in aminonucleoside nephrosis. Kidney Int1986;29:478–83.
41.
NathKA, CrottAJ, HostetterTH.Oxygen consumption and oxidant stress in surviving nephrons. Am J Physiol1990;258:F1354–62.
42.
RicardoSD, BertramJF, RyanGB.Reactive oxygen species in puromycin aminonucleoside nephrosis: In vitro studies. Kidney Int1994:45:1057–69.
43.
SugiyamaH, KashiharaN, YamasakiY, SekikawaT, OkamotoK, KanaoK, MaeshimaY, MakinoH, OtaZ.Reactive oxygen species induces apoptosis in cultured mesangial cells. [abstract]. J Am Soc Nephrol1994;6:796.
44.
SinghalPC, SharmaP, ReddyK, SanwalV, RawalJ, FrankiN, GibbonsN.Human Immunodeficiency virus-1 gp160 protein modulates mesangial cell proliferation and apoptosis. Nephron1997;76:284–95.
