Long-term prevention of renal insufficiency, excess matrix gene expression, and glomerular mesangial matrix expansion by treatment with monoclonal antitransforming growth factor-beta antibody in db/db diabetic mice - PubMed (original) (raw)

Long-term prevention of renal insufficiency, excess matrix gene expression, and glomerular mesangial matrix expansion by treatment with monoclonal antitransforming growth factor-beta antibody in db/db diabetic mice

F N Ziyadeh et al. Proc Natl Acad Sci U S A. 2000.

Abstract

Emerging evidence suggests that transforming growth factor-beta (TGF-beta) is an important mediator of diabetic nephropathy. We showed previously that short-term treatment with a neutralizing monoclonal anti-TGF-beta antibody (alphaT) in streptozotocin-diabetic mice prevents early changes of renal hypertrophy and increased matrix mRNA. To establish that overactivity of the renal TGF-beta system mediates the functional and structural changes of the more advanced stages of nephropathy, we tested whether chronic administration of alphaT prevents renal insufficiency and glomerulosclerosis in the db/db mouse, a model of type 2 diabetes that develops overt nephropathy. Diabetic db/db mice and nondiabetic db/m littermates were treated intraperitoneally with alphaT or control IgG, 300 microgram three times per week for 8 wk. Treatment with alphaT, but not with IgG, significantly decreased the plasma TGF-beta1 concentration without decreasing the plasma glucose concentration. The IgG-treated db/db mice developed albuminuria, renal insufficiency, and glomerular mesangial matrix expansion associated with increased renal mRNAs encoding alpha1(IV) collagen and fibronectin. On the other hand, treatment with alphaT completely prevented the increase in plasma creatinine concentration, the decrease in urinary creatinine clearance, and the expansion of mesangial matrix in db/db mice. The increase in renal matrix mRNAs was substantially attenuated, but the excretion of urinary albumin factored for creatinine clearance was not significantly affected by alphaT treatment. We conclude that chronic inhibition of the biologic actions of TGF-beta with a neutralizing monoclonal antibody in db/db mice prevents the glomerulosclerosis and renal insufficiency resulting from type 2 diabetes.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Increased glomerular TGF-β1 mRNA in diabetic db/db mice. In situ hybridization of kidney sections: (A) antisense TGF-β1 riboprobe in 16-wk-old control db/m mouse showing minimal hybridization signal; (B) antisense TGF-β1 riboprobe in 16-wk-old diabetic db/db mouse showing increased hybridization signal in the mesangial area; (C) sense TGF-β1 riboprobe used as negative control in diabetic db/db mouse showing absence of hybridization signal; and (D) quantitative analysis of area of TGF-β1 hybridization signal in db/db vs. db/m mice. Twenty glomeruli were studied in each group, and the values presented are the mean ± SE for four mice in each group. *, P < 0.05 vs. db/m.

Figure 2

Figure 2

Up-regulation of renal TGF-β type II receptor in db/db mice. (A) Representative Northern blot showing increased TGF-β type II receptor mRNA in db/db mouse kidney compared with db/m mouse kidney. (B) Summary of densitometric analyses of receptor/mrpL32 mRNA ratios (mean ± SE, n = 5 for each group). The relative ratio in the db/m group is assigned a value of 1. *, P < 0.05 vs. db/m. (C) Representative immunoblot showing increased TGF-β type II receptor protein in db/db mouse kidney compared with db/m mouse kidney.

Figure 3

Figure 3

Kidney matrix gene expression in diabetic mice treated with anti-TGF-β antibody. A representative Northern blot of kidney RNA probed with α1(IV) collagen cDNA (A) and fibronectin cDNA (C) and then with ribosomal mrpL32. Each lane represents RNA from individual mice (db/m or db/db), treated with either IgG or anti-TGF-β antibody (αT). Summary of densitometric analyses of α1(IV) collagen/mrpL32 mRNA ratios (B) and fibronectin/mrpL32 mRNA ratios (D) in the four treatment groups (mean ± SE, n = 8 for each IgG group and n = 9 for each αT group). The relative mRNA ratio in the normal-IgG group is assigned a value of 1. *, P < 0.05 vs. normal-IgG, **, P < 0.05 vs. diabetic-IgG.

Figure 4

Figure 4

Anti-TGF-β antibody therapy significantly prevents mesangial matrix expansion in diabetic mice. Representative photomicrographs of PAS-stained kidney sections from: (A) normal db/m mouse treated with control IgG; (B) normal db/m mouse treated with anti-TGF-β antibody (αT); (C) diabetic db/db mouse treated with control IgG; and (D) diabetic db/db mouse treated with αT. Note the diffusely expanded extracellular mesangial matrix in the diabetic mouse treated with IgG and the marked prevention of this expansion in the diabetic mouse treated with αT. Quantitative measurement of extracellular mesangial matrix expansion (E) is expressed as PAS-positive mesangial material per total glomerular tuft cross-sectional area. An average value was obtained from analyses of 30 glomeruli per mouse. Data are mean ± SE, n = 8 for each IgG group and n = 9 for each αT group. *, P < 0.05 vs. normal-IgG, **, P < 0.05 vs. diabetic-IgG.

Figure 5

Figure 5

Anti-TGF-β antibody therapy normalizes renal function but not albuminuria in diabetic mice. (A) Creatinine clearance in normal db/m and diabetic db/db groups treated with either IgG or anti-TGF-β antibody (αT). Clearance was calculated based on urine volumes and plasma and urine creatinine concentrations. ELISA specific for mouse albumin was used to assess albuminuria in 24-h urine collections, which was standardized per mg creatinine. (B) The increased excretion of albumin in db/db mice treated with IgG (vs. db/m mice) remained persistently elevated in db/db mice treated with αT. Data are mean ± SE, n = 8 for each IgG group and n = 9 for each αT group. *, P < 0.05 vs. normal-IgG or normal-αT, **, P < 0.05 vs. diabetic-IgG.

Comment in

Similar articles

Cited by

References

    1. Ziyadeh F N. Am J Kidney Dis. 1993;22:736–744. - PubMed
    1. Ziyadeh F N. Kidney Int Suppl. 1996;54:S10–S13. - PubMed
    1. Ziyadeh F N. Miner Electrolyte Metab. 1995;21:292–302. - PubMed
    1. Ayo S H, Radnik R A, Glass W F, II, Garoni J A, Rampt E R, Appling D R, Kreisberg J I. Am J Physiol. 1991;260:F185–F191. - PubMed
    1. Danne T, Spiro M J, Spiro R G. Diabetes. 1993;42:170–177. - PubMed

Publication types

MeSH terms

Substances

Grants and funding

LinkOut - more resources