Biomaterial Database

Osteopontin regulates α-smooth muscle actin and calponin in vascular smooth muscle cells. 2012

Hong Gao, and Marlene C Steffen, and Kenneth S Ramos

Department of Biochemistry and Molecular Biology, University of Louisville, KY 40292, USA.

vSMCs (vascular smooth muscle cells) lose differentiation markers and gain uncontrolled proliferative activity during the early stages of atherosclerosis. Previous studies have shown that OPN (osteopontin) mRNA and protein levels increase significantly on induction of proliferative activity by allylamine (an atherogenic amine) and that this response can be inhibited by OPN antibodies. We have investigated the role of OPN in vSMC differentiation. Primary cultures of aortic mouse vSMCs were transfected with an OPN expression plasmid and several vSMC differentiation markers including α-SM actin (α-smooth muscle actin), SM22-α, tropomyosin and calponin were monitored in this cellular model. α-SM actin and calponin protein levels were significantly decreased by OPN overexpression. Down-regulation of α-SM actin and calponin was also observed on extracellular treatment of mouse vSMCs with recombinant OPN. In addition, calponin mRNA was significantly decreased under serum-restricted conditions when OPN mRNA was dramatically increased, while α-SM actin mRNA remained unchanged. These data indicate that OPN down-regulates α-SM actin and calponin expression through an extracellular signalling pathway. Functional connectivity between OPN and vSMC differentiation markers has been established. Since vSMCs lose differentiation features during early atherosclerosis, a mechanistic basis for OPN functions as a critical regulator of proliferative cardiovascular disease has been presented.

UI	MeSH Term	Description	Entries
D008810	Mice, Inbred C57BL	One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases.	Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D008840	Microfilament Proteins	Monomeric subunits of primarily globular ACTIN and found in the cytoplasmic matrix of almost all cells. They are often associated with microtubules and may play a role in cytoskeletal function and/or mediate movement of the cell or the organelles within the cell.	Actin Binding Protein,Actin-Binding Protein,Actin-Binding Proteins,Microfilament Protein,Actin Binding Proteins,Binding Protein, Actin,Protein, Actin Binding,Protein, Actin-Binding,Protein, Microfilament,Proteins, Actin-Binding,Proteins, Microfilament
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D002135	Calcium-Binding Proteins	Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.	Calcium Binding Protein,Calcium-Binding Protein,Calcium Binding Proteins,Binding Protein, Calcium,Binding Proteins, Calcium,Protein, Calcium Binding,Protein, Calcium-Binding
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D000096985	Calponins	A family of actin binding proteins mostly in smooth muscle. Calponins include most abundant alpha-calponin (h1 or basic); beta-calponin; neutral calponin (h2 calponin); acidic calponin, SM22, and transgelin. Calponin family members have N-terminal single Calponin Homology (CH) domain and multiple C-terminus 23-amino acids long calponin-like repeats called CLICK-23. Calponins participate in modulation of smooth muscle contraction by binding to ACTINS (F- and G-Actins), CALMODULIN and TROPOMYSIN.	Calponin,Calponin Family Proteins
D000199	Actins	Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.	F-Actin,G-Actin,Actin,Isoactin,N-Actin,alpha-Actin,alpha-Isoactin,beta-Actin,gamma-Actin,F Actin,G Actin,N Actin,alpha Actin,alpha Isoactin,beta Actin,gamma Actin
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
D014162	Transfection	The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.	Transfections