Document Detail


Over-expression of alpha-actinin with a GFP fusion protein is sufficient to increase whole-cell stiffness in human osteoblasts.
MedLine Citation:
PMID:  18636329     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Osteoblasts respond to shear stress by simultaneously increasing their whole-cell stiffness and up-regulating the cytoskeletal crosslinking protein alpha-actinin. The stiffness of reconstituted cytoskeletal networks increases following the addition of alpha-actinin, but the effect of alpha-actinin on whole-cell mechanical behavior has not been investigated. The hypothesis of this study was that increasing alpha-actinin in the cytoskeleton would be sufficient to increase whole-cell stiffness. hFOB osteoblasts were transfected with a plasmid for GFP-tagged alpha-actinin, resulting in a 150% increase in the amount of alpha-actinin. The GFP-alpha-actinin fusion protein co-fractionated with the cytoskeleton and co-localized to the same regions of the cytoskeleton as endogenous alpha-actinin. Whole-cell mechanical behavior was measured by atomic force microscopy using a 25 mum diameter microsphere as an indenter. The whole-cell stiffness of cells over-expressing GFP-alpha-actinin was 60% higher than cells expressing only endogenous alpha-actinin (p < 0.002), which was within the range of mechanical behavior observed in osteoblastic cells exposed to 1 and 2 Pa of fluid shear. These results indicate that the up-regulation of alpha-actinin synthesis in osteoblasts is sufficient to alter the whole-cell mechanical behavior and highlights the potential role of alpha-actinin to reinforce cells against mechanical loads.
Authors:
Wesley M Jackson; Michael J Jaasma; Andrew D Baik; Tony M Keaveny
Related Documents :
21187919 - Magnetic fe₃o₄ nanoparticles and chemotherapy agents interact synergistically to in...
17316959 - Comparison of apex and bottom secretion efficiency at chromaffin cells as measured by a...
11719559 - Abc transporters required for endocytosis and endosomal ph regulation in dictyostelium.
15619289 - Rd114-pseudotyped retroviral vectors kill cancer cells by syncytium formation and enhan...
6722889 - The fusion of oocytes of the starfish aphelasterias japonica. iii. reconstruction of oo...
9786949 - Identification of kel1p, a kelch domain-containing protein involved in cell fusion and ...
24061119 - Effects of microcystins, cyanobacterial toxins, on mammalian cells and organs.
7962039 - Role of h-ras in the malignant progression of rat tracheal epithelial cells.
1851869 - Host range specificity of polyomavirus ec mutants in mouse embryonal carcinoma and embr...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-07-18
Journal Detail:
Title:  Annals of biomedical engineering     Volume:  36     ISSN:  1573-9686     ISO Abbreviation:  Ann Biomed Eng     Publication Date:  2008 Oct 
Date Detail:
Created Date:  2008-09-10     Completed Date:  2008-10-09     Revised Date:  2013-05-30    
Medline Journal Info:
Nlm Unique ID:  0361512     Medline TA:  Ann Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1605-14     Citation Subset:  IM    
Affiliation:
Department of Mechanical Engineering, Orthopaedic Biomechanics Laboratory, University of California, 6175 Etcheverry Hall, Mailstop 1740, Berkeley, CA 94720-1740, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Actinin / biosynthesis*,  genetics
Cells, Cultured
Cytoskeleton / physiology*,  ultrastructure
Elasticity
Gene Expression
Green Fluorescent Proteins / biosynthesis*,  genetics
Humans
Microscopy, Atomic Force
Osteoblasts / physiology*,  ultrastructure
Plasmids
Recombinant Fusion Proteins / biosynthesis*,  genetics
Shear Strength
Stress, Mechanical
Transfection
Up-Regulation
Chemical
Reg. No./Substance:
0/Recombinant Fusion Proteins; 11003-00-2/Actinin; 147336-22-9/Green Fluorescent Proteins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The epidemiology of obesity and gastrointestinal and other diseases: an overview.
Next Document:  Craniopharyngioma surgery.