J Korean Assoc Oral Maxillofac Surg.  1997 Nov;23(4):581-596.

CHANGES OF CYCLINS, CYCLIN DEPENDENT KINASES, CYCLIN DEPENDENT KINASE INHIBITORS DURING GLOSSAL DEVELOPMENT IN THE RATS

• Kim HH
• Lee SC

Abstract

The molecular mechanisms that regulate glossal muscle cell cycle and terminal differentiation remain largely unknown. To determine which cyclins, cyclin dependent kinases (CDKs), cyclin dependent kinase inhibitors (CKIs) are important for glossal cell proliferation, we have examined expression of cyclins CDKs, CKIs during normal glossal muscle development in the rat. All cyclins, CDKs, and KIP/CIP family of CKIs were highly expressed during fetal glossal muscle development, then they decreased at different rates after birth. While the mRNAs of cyclin Dl, D3, E , A, and B decreased gradually in glossal muscle during all stages of development, the protein levels of these cyclins decreased differently in tongue during pre- and postnatal development. While the functionally active formed of cyclin Dl, cyclin D3 and E proteins were observed until 7 days after birth, cyclin A and B proteins were decreased more slowly. While the CDK4, CDK6, CDK2, cdc2, and proliferating cell nuclear antigen (PCNA) proteins were higllly present during fetal glossal muscle development and gradually decreased during postnatal development. Particularly, cdc2 levels decreased markedly after birth. Immunohistochemical data for PCNA was consistent with Western blotting data for PCNA temporally and spatially. The mRNA and protein levels of p21, p27, and p57 were high, then their levels changed differently during glossal development. While the mRNA levels of p21 and p57 decreased gradually, the mRNA level of p27 did not change during glossal development. While the protein levels of p21 and p57 in tongue decreased markedly after birth, the protein levels of p27 increased slightly after birth, then decreased at adulthood. These findings suggest that the all cyclins and CDKs observed are involved in glossal muscle cell cycle, and reduction of cyclins and CDKs and induction of p21 are associated with the withdrawal of glossal muscle cell cycle after birth.

MeSH Terms

Animals
Blotting, Western
Cell Proliferation
Cyclin A
Cyclin D3
Cyclin-Dependent Kinases*
Cyclins*
Humans
Muscle Cells
Muscle Development
Parturition
Phosphotransferases*
Proliferating Cell Nuclear Antigen
Rats*
RNA, Messenger
Tongue
Cyclin A
Cyclin D3
Cyclin-Dependent Kinases
Cyclins
Phosphotransferases
Proliferating Cell Nuclear Antigen
RNA, Messenger