Enhancement of albumin expression in bone tissues with healing rat fractures

Abstract

The characterization of 66 kDa protein molecule, a major protein component which is produced from femoral-diaphyseal tissues with fracture healing (Igarashi and Yamaguchi [2002] Int. J. Mol. Med. 9:503-508), was investigated. Weaning rats were killed at 7 and 14 days after femoral fracture. When the femoral-diaphyseal tissues with fracture healing were cultured for 48 h in a serum-free medium, many proteins in the bone tissues were released into the medium. Analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that a protein molecule of approximately 66 kDa was markedly increased in culture medium from bone tissues with fracture healing. N-terminal sequencing of 66 kDa protein indicated that its N-terminus was identical to that of rat albumin. Western blot analysis of medium 66 kDa protein showed expression of albumin. This expression was significantly enhanced by fracture healing. The expression of albumin was seen in the diaphyseal (cortical bone) and metaphyseal (trabecular bone) tissues of rat femur. When the femoral-diaphyseal tissues obtained at 7 days after femoral fracture were cultured in a serum-free medium containing either vehicle, parathyroid hormone (1-34) (10(-7) M), insulin-like growth factor-I (10(-8) M) or zinc acexamate (10(-4) M), medium albumin was significantly increased in the presence of those bone-stimulating factors. The addition of albumin (0.5 or 1.0 mg/ml of medium) caused a significant increase in calcium and deoxyribonucleic acid contents in the femoral-diaphyseal and -metaphyseal tissues obtained from normal rats in vitro. The present study demonstrates that fracture healing induces a remarkable production of albumin which is a major protein component produced from femoral-diaphyseal tissues of rats, and that albumin has an anabolic effect on bone components.

Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin

“…6D). Moreover, "ectopic" albumin expression has been previously described in healing bone (18); skin (19); granulosa cells (20); kidney and pancreas (21); and mammary gland (22). Furthermore, albumin was described to affect The T cells were harvested after 1, 2, or 3 h. Cytoplasmic and nuclear fractions were run on SDS transferred to nitrocellulose and tested with Pen 9 antibody.…”

MC3T3-E1 cell adhesion to hydroxyapatite with adsorbed bone sialoprotein, bone osteopontin, and bovine serum albumin

“…A series of studies by Yamaguchi and colleagues have suggested that albumin is released by osteoblast cells present in fracture healing sites and this excess albumin increases the proliferation state of the surrounding cells. [49][50][51] In one of these studies, Ishida and Yamaguchi showed that supplementing a standard culture medium with varying amounts of BSA led to a significant increase in the number of MC3T3-E1 cells present after 24, 48, and 72 hours of culture in a dose dependent manner. 49 A similar trend was seen in the number of cells present in this study after only 5 total hours of cell culture (2 hours of adhesion and 3 hours of MTT uptake) as shown in Figure 7.…”

Human Microglial Cells Synthesize Albumin in Brain

“…Recently, Yamaguchi et al . [18] provided convincing evidence of albumin synthesis in bone tissues cultured in serum-, albumin-free medium. There has been no specific report about the synthesis of albumin in brain either at the mRNA level or at the protein level.…”