Novel Approach to Specific Growth Factor Inhibition in Vivo

Abstract

Mesangial cell proliferation and matrix accumulation, driven by platelet-derived growth factor (PDGF), contribute to many progressive renal diseases. In a novel approach to antagonize PDGF, we investigated the effects of a nuclease-resistant high-affinity oligonucleotide aptamer in vitro and in vivo. In cultured mesangial cells, the aptamer markedly suppressed PDGF-BB but not epidermal- or fibroblast-growth-factor-2-induced proliferation. In vivo effects of the aptamer were evaluated in a rat mesangioproliferative glomerulonephritis model. Twice-daily intravenous (i.v.) injections from days 3 to 8 after disease induction of 2.2 mg/kg PDGF-B aptamer, coupled to 40-kd polyethylene glycol (PEG), led to 1) a reduction of glomerular mitoses by 64% on day 6 and by 78% on day 9, 2) a reduction of proliferating mesangial cells by 95% on day 9, 3) markedly reduced glomerular expression of endogenous PDGF B-chain, 4) reduced glomerular monocyte/macrophage influx on day 6 after disease induction, and 5) a marked reduction of glomerular extracellular matrix overproduction (as assessed by analysis of fibronectin and type IV collagen) both on the protein and mRNA level. The administration of equivalent amounts of a PEG-coupled aptamer with a scrambled sequence or PEG alone had no beneficial effect on the natural course of the disease. These data show that specific inhibition of growth factors using custom-designed, high-affinity aptamers is feasible and effective.

YB-1 Acts as a Ligand for Notch-3 Receptors and Modulates Receptor Activation

“…Our data show that Notch-3 receptor was detected at the basal membrane of some tubular and collecting duct cells within the inner renal medulla in the adult kidney, whereas no glomerular cells were immunopositive. Subsequent to induction of mesangioproliferative Anti-Thy1.1 nephritis, Notch-3 receptor was detected within the mesangial compartment of glomeruli, and its expression peaked at a time with maximal mesangial cell proliferation rates (29) and, notably, coincided temporally and spatially with increased glomerular YB-1 protein expression.…”

“…Mesangioproliferative Anti-Thy1.1 Nephritis-Mesangioproliferative anti-Thy1.1 nephritis was induced in male Wistar rats as described (29). Renal tissue for light microscopy was fixed in Methacarn at the indicated time points and embedded in paraffin.…”

Bufalin Inhibits Platelet-Derived Growth Factor-BB-Induced Mesangial Cell Proliferation through Mediating Cell Cycle Progression

“…Specific antagonism of PDGF reduces MC proliferation and glomerulosclerosis in experimental mesangial proliferative glomerular disease. [2][3][4][5] Various mitogenic stimuli share the cell cycle as the final common pathway in the proliferative signaling cascade. Modulation of the expression and function of cell cycle regulatory proteins is an important mechanism for cell growth inhibition.…”

Molecular recognition elements - DNA/RNA-aptamers to proteins

“…У животных, получавших раствор аптамера, наблюдали уменьшение моноцит-макрофагового индекса и сверхпродукцию компонентов клубочкового матрикса. Контрольному животному в течение 6 дней вводили олигонуклеотид со случайной последовательностью или просто раствор ПЕГа [63].…”