Biomaterial Database

The mechanism of inhibition of 3T3-L1 preadipocyte differentiation by prostaglandin F2alpha. 1996

C W Miller, and D A Casimir, and J M Ntambi

Department of Biochemistry, The University of Wisconsin-Madison, 53706, USA.

We have shown previously that treatment of 3T3-L1 preadipocytes with prostaglandin F2alpha (PGF2alpha) and fluprostenol, a prostanoid FP2 receptor (FP receptor) agonist, inhibited adipocyte differentiation. In this study, we demonstrate that the inhibition by PGF2alpha is controlled by concentrations of PGF2alpha rather than regulation of FP receptor levels or binding. Membranes prepared from either 3T3-L1 preadipocytes or adipocytes exhibited specific binding for PGF2alpha, suggesting that FP receptors are present throughout differentiation. Endogenous PGF2alpha production in 3T3-L1s was lower in differentiating cells compared with uninduced preadipocytes, providing further evidence that regulation occurs at the level of ligand concentration. Stimulation of the FP receptor causes a transient intracellular calcium increase, an activation of a calcium/calmodulin-dependent protein kinase (CaMK), and an increase in DNA synthesis, associated with the inhibition of differentiation. Calcium mobilizing agents, A23187 and thapsigargin, mimic the FP receptor-induced inhibition of differentiation, suggesting a role for calcium. KN-62, a CaMK inhibitor, reversed the inhibition of differentiation when added to differentiating cells with fluprostenol, suggesting a critical role for a CaMK in the inhibition. The activation of CaMK was responsible for an increase in DNA content and thymidine incorporation. The increase in DNA synthesis occurs without a concomitant increase in cell proliferation. Early differentiation markers remain intact with PGF2alpha treatment, defining the interference with normal postconfluent mitosis as the time period of differentiation that is affected by PGF2alpha. These results implicate the modulation of PGF2alpha levels in the inhibition of 3T3-L1 adipocyte differentiation through an FP receptor-mediated increase in intracellular calcium and associated increase in DNA synthesis.

UI	MeSH Term	Description	Entries
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D011453	Prostaglandins	A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.	Prostaglandin,Prostanoid,Prostanoids
D011461	Prostaglandins F, Synthetic	Analogs or derivatives of prostaglandins F that do not occur naturally in the body. They do not include the product of the chemical synthesis of hormonal PGF.	PGF Synthetic,Prostaglandin F Analogs,Prostaglandin F Analogues,Synthetic Prostaglandins F,Analogs, Prostaglandin F,Analogues, Prostaglandin F,Synthetic, PGF
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013234	Stem Cells	Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.	Colony-Forming Units,Mother Cells,Progenitor Cells,Colony-Forming Unit,Cell, Mother,Cell, Progenitor,Cell, Stem,Cells, Mother,Cells, Progenitor,Cells, Stem,Colony Forming Unit,Colony Forming Units,Mother Cell,Progenitor Cell,Stem Cell