Alterations in proteins of bone marrow extracellular matrix in undernourished mice

The objective of the present study was to determine the effect of protein m alnutrition on the glycoprotein content of bone marrow extracellular matrix (ECM). Two-month-old male Swiss mice were submitted to protein malnutritio n with a low-protein diet containing 4% casein as compared to 20% casein in the control diet. When the experimental group had attained a 20% loss of t heir original body weight, we extracted the ECM proteins from bone marrow w ith PBS buffer, and analyzed ECM samples by SDS-PAGE (7.5%) and ECL Western blotting. Quantitative differences were observed between control and exper imental groups. Bone marrow ECM from under nourished mice had greater amoun ts of extractable fibronectin (1.6-fold increase) and laminin (4.8-fold inc rease) when compared to the control group. These results suggest an associa tion between fluctuations in the composition of the hematopoietic microenvi ronment and altered hematopoiesis observed in undernourished mice.