Document Detail


Single-cell analysis of insulin-regulated fatty acid uptake in adipocytes.
MedLine Citation:
PMID:  20570821     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Increased body fat correlates with the enlargement of average fat cell size and reduced adipose tissue insulin sensitivity. It is currently unclear whether adipocytes, as they accumulate more triglycerides and grow in size, gradually become less insulin sensitive or whether obesity-related factors independently cause both the enlargement of adipocyte size and reduced adipose tissue insulin sensitivity. In the first instance, large and small adipocytes in the same tissue would exhibit differences in insulin sensitivity, whereas, in the second instance, adipocyte size per se would not necessarily correlate with insulin response. To analyze the effect of adipocyte size on insulin sensitivity, we employed a new single-cell imaging assay that resolves fatty acid uptake and insulin response in single adipocytes in subcutaneous adipose tissue explants. Here, we report that subcutaneous adipocytes are heterogeneous in size and intrinsic insulin sensitivity. Whereas smaller adipocytes respond to insulin by increasing lipid uptake, adipocytes with cell diameters larger than 80-100 microm are insulin resistant. We propose that, when cell size approaches a critical boundary, adipocytes lose insulin-dependent fatty acid transport. This negative feedback mechanism may protect adipocytes from lipid overload and restrict further expansion of adipose tissue, which leads to obesity and metabolic complications.
Authors:
Oleg Varlamov; Romel Somwar; Anda Cornea; Paul Kievit; Kevin L Grove; Charles T Roberts
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-06-22
Journal Detail:
Title:  American journal of physiology. Endocrinology and metabolism     Volume:  299     ISSN:  1522-1555     ISO Abbreviation:  Am. J. Physiol. Endocrinol. Metab.     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-08-26     Completed Date:  2010-10-06     Revised Date:  2011-09-13    
Medline Journal Info:
Nlm Unique ID:  100901226     Medline TA:  Am J Physiol Endocrinol Metab     Country:  United States    
Other Details:
Languages:  eng     Pagination:  E486-96     Citation Subset:  IM    
Affiliation:
Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, 97006, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adipocytes / cytology,  metabolism*
Animals
Biological Transport
Blood Glucose / metabolism
Boron Compounds / chemistry
Cohort Studies
Fatty Acids / metabolism*
Female
Image Processing, Computer-Assisted
Insulin / blood,  metabolism
Insulin Resistance / physiology*
Macaca mulatta
Microscopy, Confocal
Subcutaneous Fat / cytology,  metabolism*
Grant Support
ID/Acronym/Agency:
1-RO1-DK-79194/DK/NIDDK NIH HHS; P51 RR-00163/RR/NCRR NIH HHS; S10-RR-024585/RR/NCRR NIH HHS; //Canadian Institutes of Health Research
Chemical
Reg. No./Substance:
0/4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-dodecanoic acid; 0/Blood Glucose; 0/Boron Compounds; 0/Fatty Acids; 11061-68-0/Insulin
Comments/Corrections

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


Previous Document:  Diagnostic accuracy of the RBANS in mild cognitive impairment: limitations on assessing milder impai...
Next Document:  Insulin sensitive obesity.