Mineralization and the Expression of Matrix Proteins During In Vivo Bone Development

Abstract

The in vivo expression of fibronectin, type I collagen, and several non-collagenous proteins was correlated with the development of bone in fetal and early neonatal rat calvariae. Fibronectin was the earliest matrix protein expressed in calvariae, with a peak expression in fetal 16- and 17-day (d) bones. Fibronectin expression coincided with the condensation of preosteoblasts prior to calcification and decreased once bone mineralization commenced. The expression of type I collagen, osteonectin, bone sialoprotein, and alkaline phosphatase mRNAs was found at 17 d. The increase in type I collagen mRNA levels was correlated with a 3.5-fold increase in calcium deposition at 19-20 d. Bone sialoprotein and alkaline phosphatase peaked on fetal 21 d while osteonectin remained at a low level and was localized to the osteoblast layer and the osteocyte lacunae. Osteopontin mRNA levels increased rapidly in neonatal calvariae. After birth, osteonectin and fibronectin were mainly associated with blood vessels. Thus, fibronectin is one of the earliest matrix proteins expressed in calvariae and is rapidly followed by type I collagen, bone sialoprotein, and alkaline phosphatase. Osteocalcin, osteonectin, and osteopontin mRNAs have similar patterns of expression in the developing fetal calvaria, and their synthesis coincided with mineralization.

Therapeutic touch affects DNA synthesis and mineralization of human osteoblasts in culture

“…Because bone formation occurs by the sequential synthesis and secretion of extracellular matrix proteins to form osteoid which subsequently mineralizes, 26 Northern blot analyses of message levels for the bone matrix proteins; alkaline phosphatase (AP), bone sialoprotein (BSP), and Type I collagen, were performed in three separate experiments. At 2 weeks of TT treatment on HOB cultures, BSP, AP, and Type I collagen message levels increased 44, 81, and 39%, respectively, compared to untreated cells (Fig.…”

“…[27][28][29][30] All living organisms reveal a dynamic biomagnetic field that is indicative of both natural biological changes and abnormal biological states. 26 Several studies reveal large pulsed biomagnetic fields emanating from the hands of practitioners in a variety of modalities including TT, Qi-gong, yoga, meditation, and martial arts. [27][28][29]31 A shift in energy emission by practitioners performing Therapeutic Touch was measured in a superconducting quantum interference device (SQUID) magnetometer, and biomagnetic fields have been recorded at a frequency from 8 to 10 Hz from practitioners' hands.…”

Inactivation of anoctamin-6/Tmem16f, a regulator of phosphatidylserine scrambling in osteoblasts, leads to decreased mineral deposition in skeletal tissues

“…To further characterize the defect in mineralization, we compared the mineralized region of the periosteum demarcated by von Kossa staining to the region of cells expressing Ibsp, which precedes mineralization. (45) On parallel sections of the radius, we measured the distance from the joint to the onset of Ibsp expression and von Kossa-stained mineral deposition, respectively. We found that Ibsp expression is induced at a similar distance from the joint in wild-type and Ano6 À/À mutant embryos (Fig.…”

Functions of Transforming Growth Factor-β Family Type I Receptors and Smad Proteins in the Hypertrophic Maturation and Osteoblastic Differentiation of Chondrocytes

“…During bone formation, osteoblast differentiation is marked by the sequential activation of many genes encoding characteristic bone matrix proteins like alkaline phosphatase, type I collagen, bone sialoprotein, osteopontin, and osteocalcin (43). Osteocalcin is exclusively synthesized by mature osteoblasts (44) and therefore represents a bone-specific marker.…”