Circ_CUX1/miR-130b-5p/p300 axis for parathyroid hormone-stimulation of Runx2 activity in rat osteoblasts: A combined bioinformatic and experimental approach.

Parathyroid hormone (PTH) regulates the expression of bone remodeling genes by enhancing the activity of Runx2 in osteoblasts. p300, a histone acetyltransferase, acetylated Runx2 to activate the expression of its target genes. PTH stimulated the expression of p300 in rat osteoblastic cells.

Exosomes in bone remodeling and breast cancer bone metastasis.

Exosomes are endosome-derived microvesicles that carry cell-specific biological cargo, such as proteins, lipids, and noncoding RNAs (ncRNAs). They play a key role in bone remodeling by enabling the maintenance of a balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Recent evidence indicates that exosomes disrupt bone remodeling that occurs during breast cancer (BC) progression.

Role of p300, a histone acetyltransferase enzyme, in osteoblast differentiation.

Bone is a dynamic and tough connective tissue that undergoes constant remodeling throughout life. Bone-forming osteoblasts respond to various hormones, cytokines, and growth factors, and synthesize extracellular matrix components. Runx2 (Runt-related transcription factor 2), a bone transcription factor, is essential for ossification by stimulating the expression of osteoblast differentiation marker genes, including type I collagen, alkaline phosphatase, and osteocalcin.