Biomaterial Database

The role of MAPKs in adipocyte differentiation and obesity. 2005

F Bost, and M Aouadi, and L Caron, and B Binétruy

Inserm U568, Université de Nice Sophia-Antipolis, Faculté de Médecine, Avenue de Valombrose, 06107 Nice cedex, France. bost@unice.fr

The ERK, p38 and JNK mitogen activated protein kinases (MAPKs) are intracellular signalling pathways that play a pivotal role in many essential cellular processes such as proliferation and differentiation. MAPKs are activated by a large variety of stimuli and one of their major functions is to connect cell surface receptors to transcription factors in the nucleus, which consequently triggers long-term cellular responses. This review focuses on their in vitro and in vivo roles in adipocyte differentiation and obesity. Hyperplasia of adipose tissue is a critical event for the development of obesity. Several studies have analysed the role of MAPKs in vitro in adipocyte differentiation of preadipocyte established cell lines. In the case of ERK, although the first data appeared contradictory, a consensus scenario arises: ERK would be necessary to initiate the preadipocyte into the differentiation process and, thereafter, this signal transduction pathway needs to be shut-off to proceed with adipocyte maturation. The limitation of these cellular models is that only terminal adipocyte differentiation can be analysed, eluding the early proliferative steps of adipogenesis. New insights are now emerging by investigations conducted either in vitro with the use of embryonic stem (ES) cells or in vivo with mice where these genes are invalidated. These studies not only confirm and/or precise the various functions of MAPKs in adipogenesis but, importantly, reveal unsuspected roles, for example JNK in obesity or ERK in adipogenesis of ES cells, and, for a given pathway, assign specific functions to each isoform. It appears now that a fine tuning of the MAPKs regulates both normal and pathological adipogenesis. The precise understanding of the cascade of these molecular events and the way to regulate them will be certainly crucial in order to efficiently fight obesity.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D009765	Obesity	A status with BODY WEIGHT that is grossly above the recommended standards, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
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
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
D017667	Adipocytes	Cells in the body that store FATS, usually in the form of TRIGLYCERIDES. WHITE ADIPOCYTES are the predominant type and found mostly in the abdominal cavity and subcutaneous tissue. BROWN ADIPOCYTES are thermogenic cells that can be found in newborns of some species and hibernating mammals.	Fat Cells,Lipocytes,Adipocyte,Cell, Fat,Cells, Fat,Fat Cell,Lipocyte
D048031	JNK Mitogen-Activated Protein Kinases	A subgroup of mitogen-activated protein kinases that activate TRANSCRIPTION FACTOR AP-1 via the phosphorylation of C-JUN PROTEINS. They are components of intracellular signaling pathways that regulate CELL PROLIFERATION; APOPTOSIS; and CELL DIFFERENTIATION.	jun N-Terminal Kinase,c-jun Amino-Terminal Kinase,c-jun N-Terminal Kinase,jun-NH2-Terminal Kinase,jun-NH2-Terminal Kinases,Amino-Terminal Kinase, c-jun,JNK Mitogen Activated Protein Kinases,Kinase, jun N-Terminal,N-Terminal Kinase, c-jun,N-Terminal Kinase, jun,c jun Amino Terminal Kinase,c jun N Terminal Kinase,jun N Terminal Kinase,jun NH2 Terminal Kinase,jun NH2 Terminal Kinases
D048049	Extracellular Signal-Regulated MAP Kinases	A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.	ERK MAP Kinase,ERK MAP Kinases,Extracellular Signal-Regulated Kinase,Extracellular Signal-Regulated Kinases,Extracellular Signal-Regulated MAP Kinase,MAP Kinases, Extracellular Signal-Regulated,Extracellular Signal Regulated Kinase,Extracellular Signal Regulated Kinases,Extracellular Signal Regulated MAP Kinase,Extracellular Signal Regulated MAP Kinases,Kinase, ERK MAP,Kinase, Extracellular Signal-Regulated,Kinases, Extracellular Signal-Regulated,MAP Kinase, ERK,MAP Kinases, Extracellular Signal Regulated,Signal-Regulated Kinase, Extracellular
D048051	p38 Mitogen-Activated Protein Kinases	A mitogen-activated protein kinase subfamily that regulates a variety of cellular processes including CELL GROWTH PROCESSES; CELL DIFFERENTIATION; APOPTOSIS; and cellular responses to INFLAMMATION. The P38 MAP kinases are regulated by CYTOKINE RECEPTORS and can be activated in response to bacterial pathogens.	Mitogen-Activated Protein Kinase p38,p38 Mitogen-Activated Protein Kinase,p38 MAP Kinase,p38 MAPK,p38 Protein Kinase,p38 SAPK,MAP Kinase, p38,MAPK, p38,Mitogen Activated Protein Kinase p38,Protein Kinase, p38,p38 Mitogen Activated Protein Kinase,p38 Mitogen Activated Protein Kinases
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D018345	Mice, Knockout	Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.	Knockout Mice,Mice, Knock-out,Mouse, Knockout,Knock-out Mice,Knockout Mouse,Mice, Knock out