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Impaired Tethering and Fusion of GLUT4 Vesicles in Insulin-Resistant Human Adipose Cells

Lizunov, Vladimir A. ; Lee, Jo-Ping ; Skarulis, Monica C. ; Zimmerberg, Joshua ; Cushman, Samuel W. and Stenkula, Karin LU (2013) In Diabetes 62(9). p.3114-3119
Abstract
Systemic glucose homeostasis is profoundly influenced by adipose cell function. Here we investigated GLUT4 dynamics in living adipose cells from human subjects with varying BMI and insulin sensitivity index (S-i) values. Cells were transfected with hemagglutinin (HA)-GLUT4-green fluorescent protein (GFP)/mCherry (red fluorescence), and were imaged live using total internal reflection fluorescence and confocal microscopy. HA-GLUT4-GFP redistribution to the plasma membrane (PM) was quantified by surface-exposed HA epitope. In the basal state, GLUT4 storage vesicle (GSV) trafficking to and fusion with the PM were invariant with donor subject S-i, as was total cell-surface GLUT4. In cells from insulin-sensitive subjects, insulin augmented GSV... (More)
Systemic glucose homeostasis is profoundly influenced by adipose cell function. Here we investigated GLUT4 dynamics in living adipose cells from human subjects with varying BMI and insulin sensitivity index (S-i) values. Cells were transfected with hemagglutinin (HA)-GLUT4-green fluorescent protein (GFP)/mCherry (red fluorescence), and were imaged live using total internal reflection fluorescence and confocal microscopy. HA-GLUT4-GFP redistribution to the plasma membrane (PM) was quantified by surface-exposed HA epitope. In the basal state, GLUT4 storage vesicle (GSV) trafficking to and fusion with the PM were invariant with donor subject S-i, as was total cell-surface GLUT4. In cells from insulin-sensitive subjects, insulin augmented GSV tethering and fusion approximately threefold, resulting in a corresponding increase in total PM GLUT4. However, with decreasing S-i, these effects diminished progressively. All insulin-induced effects on GLUT4 redistribution and trafficking correlated strongly with S-i and only weakly with BMI. Thus, while basal GLUT4 dynamics and total cell-surface GLUT4 are intact in human adipose cells, independent of donor S-i, cells from insulin-resistant donors show markedly impaired GSV tethering and fusion responses to insulin, even after overnight culture. This altered insulin responsiveness is consistent with the hypothesis that adipose cellular dysfunction is a primary contributor to systemic metabolic dysfunction. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Diabetes
volume
62
issue
9
pages
3114 - 3119
publisher
American Diabetes Association Inc.
external identifiers
  • wos:000323421000018
  • scopus:84887363321
  • pmid:23801575
ISSN
1939-327X
DOI
10.2337/db12-1741
language
English
LU publication?
yes
id
07475eec-0bf4-4be2-9acb-c330e8752e83 (old id 4025596)
date added to LUP
2016-04-01 13:28:17
date last changed
2020-05-06 02:57:25
@article{07475eec-0bf4-4be2-9acb-c330e8752e83,
  abstract     = {Systemic glucose homeostasis is profoundly influenced by adipose cell function. Here we investigated GLUT4 dynamics in living adipose cells from human subjects with varying BMI and insulin sensitivity index (S-i) values. Cells were transfected with hemagglutinin (HA)-GLUT4-green fluorescent protein (GFP)/mCherry (red fluorescence), and were imaged live using total internal reflection fluorescence and confocal microscopy. HA-GLUT4-GFP redistribution to the plasma membrane (PM) was quantified by surface-exposed HA epitope. In the basal state, GLUT4 storage vesicle (GSV) trafficking to and fusion with the PM were invariant with donor subject S-i, as was total cell-surface GLUT4. In cells from insulin-sensitive subjects, insulin augmented GSV tethering and fusion approximately threefold, resulting in a corresponding increase in total PM GLUT4. However, with decreasing S-i, these effects diminished progressively. All insulin-induced effects on GLUT4 redistribution and trafficking correlated strongly with S-i and only weakly with BMI. Thus, while basal GLUT4 dynamics and total cell-surface GLUT4 are intact in human adipose cells, independent of donor S-i, cells from insulin-resistant donors show markedly impaired GSV tethering and fusion responses to insulin, even after overnight culture. This altered insulin responsiveness is consistent with the hypothesis that adipose cellular dysfunction is a primary contributor to systemic metabolic dysfunction.},
  author       = {Lizunov, Vladimir A. and Lee, Jo-Ping and Skarulis, Monica C. and Zimmerberg, Joshua and Cushman, Samuel W. and Stenkula, Karin},
  issn         = {1939-327X},
  language     = {eng},
  number       = {9},
  pages        = {3114--3119},
  publisher    = {American Diabetes Association Inc.},
  series       = {Diabetes},
  title        = {Impaired Tethering and Fusion of GLUT4 Vesicles in Insulin-Resistant Human Adipose Cells},
  url          = {http://dx.doi.org/10.2337/db12-1741},
  doi          = {10.2337/db12-1741},
  volume       = {62},
  year         = {2013},
}