Modulation of osteoblast activity by serum from diabetic and non-diabetic patients on hemodialysis: A three-dimensional culture study

Background: The aims of our study were to develop a three-dimensional model based on normal human osteoblasts and to determine, with this method, the osteoblastic response to sera of non-diabetic and diabetic patients on hemodialysis for chronic renal failure. Methods: A protocol for culture of osteoblastic cells in three-dimensional meshworks of bovine type I collagen was developed. The effect on cultures of sera from three groups of patients was studied: 1) 12 diabetic patients on hemodialysis [age: 65 ± 5.2 years; sex: 6 men, 6 women; duration of dialysis treatment: 21.25 (6-41) months]; 2) 12 non-diabetic patients on hemodialysis [age: 65.5 ± 5.4 years; sex: 6 men, 6 women; duration of dialysis treatment: 21.35 (6-40) months]; and 3) 12 healthy volunteer donors (age: 64.2 ± 4.9 years; 6 men, 6 women). The three-dimensional cultures obtained were processed in the same way as undecalcified bone biopsies, sectioned and stained. A histomorphometrical study was conducted. Parameters calculated were cell number, volume of newly-formed collagen, volume of newly-formed collagen per cell, mineral volume and mineral volume per cell. Results: Number of osteoblastic cells was significantly higher in non-diabetic than in diabetic and control serum-treated cultures. Newly-formed collagen volume was significantly higher in non-diabetic serum-treated cultures than in controls. Deposited mineral volume was significantly lower in diabetic and non-diabetic serum-treated cultures compared to control serum-treated cultures. Conclusions: The model of three-dimensional culture proposed in the present study is useful in the study of different osteoblast functions including the rate of collagen formation and mineralization.