AbstractProenkephalin encodes a group of small peptides with opiate‐like activity, the endogenous opioids, known to function as neurohormones, neuromodulators, and neurotransmitters. Recently, we have demonstrated that in addition to its abundance in fetal brain tissue, proenkephalin is highly expressed in nondifferentiated mesodermal cells of developing fetuses. We identified the skeletal tissues, bone, and cartilage as major sites of proenkephalin expression. To examine the possibility that proenkephalin is involved in bone development we have studied the expression of this gene in bone‐derived cells, its modulation by bone active hormones, and the effects of enkephalin‐derived peptides on osteoblastic phenotype. Our studies revealed that osteoblastic cells synthesize high levels of proenkephalin mRNA which are translated, and the derived peptides are secreted. Reciprocal interrelationships between osteoblast maturation and proenkephalin expression were established. These results together with our observations demonstrating inhibitory effects of proenkephalin‐derived peptides on osteoblastic alkaline phosphatase activity, strongly support the notion that proenkephalin is involved
📖 افتح في inklap 🔗 DOI 📮 اطلب بحثاً