Increased Intracellular Triglyceride in C2C12 Muscle Cells Transfected with Human Lipoprotein Lipase

Poirier, Paul; Marcell, Tere; Huey, Patricia Uelmen; Schlaepfer, Isabel R.; Owens, Geoffrey C.; Jensen, Dalan R.; Eckel, Robert H.

doi:10.1006/bbrc.2000.2528

Cited by 10 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our laboratory previously reported the generation of an in vitro model of LPL overexpression in C2C12 muscle cells (13). C2C12 cells stably transfected with human LPL cDNA (C2C12-LPL) showed a significant 2-fold increase in Munc18c mRNA when compared with the C2C12-control cells ( Fig.…”

Section: C2c12 Cells Transfected With Lpl Overexpress Munc18c and Shomentioning

confidence: 97%

See 1 more Smart Citation

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Schlaepfer

Pulawa

Ferreira

et al. 2003

Journal of Lipid Research

View full text Add to dashboard Cite

Section: C2c12 Cells Transfected With Lpl Overexpress Munc18c and Shomentioning

confidence: 97%

“…C2C12 cells, stably transfected with human LPL (C2C12-LPL) and C2C12-control cells were plated and expanded (13). Cells used for protein and RNA extraction were harvested and stored at Ϫ 80 Њ C.…”

Section: Cell Culturementioning

confidence: 99%

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Schlaepfer

Pulawa

Ferreira

et al. 2003

Journal of Lipid Research

View full text Add to dashboard Cite

“…Details concerning the transfection and selection of C 2C12 myoblast lines have been published previously (33). The following studies utilized these C 2C12 myoblasts stably transfected with a retroviral vector containing human LPL cDNA (C 2/LPL) and control myoblasts transfected with a fusion gene of ␤-galactosidase and neomycin phosphotransferase.…”

Section: Methodsmentioning

confidence: 99%

“…We have previously described C 2 C 12 myocytes stably transfected with human LPL to examine metabolic consequences of cellular LPL overexpression (33). These cells accumulate TG during proliferation and have the potential for acutely increased delivery of TGFA when exposed to TG-rich particles.…”

mentioning

confidence: 99%

Fatty acids increase glucose uptake and metabolism in C₂C₁₂myoblasts stably transfected with human lipoprotein lipase

Capell

Schlaepfer

Wolfe³

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

Capell WH, Schlaepfer IR, Wolfe P, Watson PA, Bessesen DH, Pagliassotti MJ, Eckel RH. Fatty acids increase glucose uptake and metabolism in C2C12 myoblasts stably transfected with human lipoprotein lipase. Am J Physiol Endocrinol Metab 299: E576 -E583, 2010. First published July 13, 2010; doi:10.1152/ajpendo.00618.2009.-Cellular effects of FFA might differ from those of lipoprotein triglyceride (TG)-derived fatty acids (TGFA). The aim of the current study was to examine the relationship between lipoprotein lipase (LPL) expression, TGFA, or FFA availability and glucose metabolism in the absence of insulin in C 2C12 myoblasts. Control myoblasts or myoblasts stably transfected with human lipoprotein lipase (C2/LPL; 15-fold greater LPL activity) were incubated for 12 h in fetal bovine serum-free medium in the absence or presence of Intralipid-20. Intracellular retention of labeled medium glucose was assessed in a subset of experiments. In the presence of Intralipid, medium glucose disappearance was increased in C2/LPL cells but not in control cells. In both cell types, glucose label retention in cellular TG was increased in the presence of Intralipid; incubation with albumin-bound oleate produced similar results. In the presence of Intralipid, the LPL hydrolytic inhibitor tetrahydrolipstatin blocked excess glucose retention in cellular TG but did not significantly decrease glucose disappearance in C2/LPL cells. Changes in glucose transport or hexokinase II did not explain the altered glucose disappearance in C2/LPL cells. Our results suggest that LPL overexpression in these cells leads to chronic metabolic adaptations that alter glucose uptake and retention. in vitro; intracellular lipid; Akt; AMP-activated protein kinase; glucose transporter FATTY ACIDS AND GLUCOSE CAN COMPETE as oxidative fuels within muscle [for review, see Randle (37)]. Additionally, increased triglyceride (TG) content has been associated with insulin resistance in various insulin-sensitive tissues (21,24,29,31,41,43), and accumulation of lipid species within cells might directly affect cell insulin signaling (42). Therefore, examining cellular interactions between lipid and glucose may be valuable in understanding cell metabolism and the pathogenesis of insulin resistance.Studies of the cellular effects of lipids typically focus on free fatty acids (FFA) and have only rarely examined lipoprotein TG-derived fatty acids (TGFA). Circulating within lipoproteins, TGFA have the potential for unique cellular interactions that are distinct from FFA. Specifically, TGFA enter skeletal muscle cells and adipocytes following hydrolytic release, requiring the hydrolytic enzyme lipoprotein lipase (LPL) (14). Additionally, the binding of lipoproteins to LPL at the endothelial surface allows lipoproteins to interact with cell receptors and promotes whole particle uptake (6,13,28,38). Most studies to date utilizing TG emulsions have coinfused heparin, which releases LPL from its endothelial-bound position and disrupts these potential bridging functions. Because ...

show abstract

“…Stably transfected C2C12 myoblasts overexpressing human LPL (13) were plated and expanded to confluence on 12-well plates.…”

Section: Cell Culturementioning

confidence: 99%

Reduction of plasma triglycerides in apolipoprotein C-II transgenic mice overexpressing lipoprotein lipase in muscle

Pulawa

Jensen

Coates³

et al. 2007

Journal of Lipid Research

View full text Add to dashboard Cite

LPL and its specific physiological activator, apolipoprotein C-II (apoC-II), regulate the hydrolysis of triglycerides (TGs) from circulating TG-rich lipoproteins. Previously, we developed a skeletal muscle-specific LPL transgenic mouse that had lower plasma TG levels. ApoC-II transgenic mice develop hypertriglyceridemia attributed to delayed clearance. To investigate whether overexpression of LPL could correct this apoC-II-induced hypertriglyceridemia, mice with overexpression of human apoC-II (CII) were cross-bred with mice with two levels of muscle-specific human LPL overexpression (LPL-L or LPL-H). Plasma TG levels were 319 6 39 mg/dl in CII mice and 39 6 5 mg/dl in wildtype mice. Compared with CII mice, apoC-II transgenic mice with the higher level of LPL overexpression (CIILPL-H) had a 50% reduction in plasma TG levels (P 5 0.013). Heart LPL activity was reduced by z30% in mice with the human apoC-II transgene, which accompanied a more modest 10% decrease in total LPL protein. Overexpression of human LPL in skeletal muscle resulted in dose-dependent reduction of plasma TGs in apoC-II transgenic mice. Along with plasma apoC-II concentrations, heart and skeletal muscle LPL activities were predictors of plasma TGs. These data suggest that mice with the human apoC-II transgene may have alterations in the expression/activity of endogenous LPL in the heart. Furthermore, the decrease of LPL activity in the heart, along with the inhibitory effects of excess apoC-II, may contribute to the hypertriglyceridemia observed in apoC-II transgenic mice. As the rate-limiting enzyme in the hydrolysis of triglycerides (TGs) from circulating TG-rich lipoproteins, LPL is a key enzyme in lipid metabolism. Found in most tissues, LPL is most abundant in adipose tissue, heart, and skeletal muscle. Anchored to the endothelium by heparan proteoglycans within the capillary beds of these tissues, active lipase hydrolyzes the TG core of lipoproteins into FFAs, monoglycerides, and remnant lipoproteins. The lipoprotein-derived FFAs are then available for uptake and use by extrahepatic tissues for either storage or oxidation. Observations from experimental alterations in LPL activity levels and localization underscore LPL's role as a "gatekeeper" for partitioning lipoprotein-derived FFAs between tissues. Perturbations in normal LPL activity levels and distribution in mice have resulted in changes in body composition and lipid and glucose metabolism (1-5).Apolipoprotein C-II (apoC-II) is the specific physiological activator necessary for LPL activity; therefore, it plays a central role in the metabolism of plasma TG. Patients with defects in apoC-II present with high circulating levels of TGs comparable to those seen with LPL deficiency (6-9). However, high concentrations of free apoC-II protein have been shown to inhibit LPL activity in vitro (10). Overexpressing human apoC-II in mice resulted in hypertriglyceridemia attributed to the delayed clearance of VLDL TGs, and human apoC-II levels were highly correlated with plasma TGs (11...

show abstract

Increased Intracellular Triglyceride in C2C12 Muscle Cells Transfected with Human Lipoprotein Lipase

Cited by 10 publications

References 15 publications

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Fatty acids increase glucose uptake and metabolism in C₂C₁₂myoblasts stably transfected with human lipoprotein lipase

Reduction of plasma triglycerides in apolipoprotein C-II transgenic mice overexpressing lipoprotein lipase in muscle

Contact Info

Product

Resources

About

Increased Intracellular Triglyceride in C2C12 Muscle Cells Transfected with Human Lipoprotein Lipase

Cited by 10 publications

References 15 publications

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Fatty acids increase glucose uptake and metabolism in C2C12myoblasts stably transfected with human lipoprotein lipase

Reduction of plasma triglycerides in apolipoprotein C-II transgenic mice overexpressing lipoprotein lipase in muscle

Contact Info

Product

Resources

About

Fatty acids increase glucose uptake and metabolism in C₂C₁₂myoblasts stably transfected with human lipoprotein lipase