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. 2009 Dec 4;284(49):33833-40.
doi: 10.1074/jbc.M109.024869. Epub 2009 Oct 8.

Lysophosphatidylcholine activates adipocyte glucose uptake and lowers blood glucose levels in murine models of diabetes

Kyungmoo Yea  1 , Jaeyoon Kim, Jong Hyuk Yoon, Taewan Kwon, Jong Hyun Kim, Byoung Dae Lee, Hae-Jeong Lee, Seung Jae Lee, Jong-In Kim, Taehoon G Lee, Moon-Chang Baek, Ho Seon Park, Kyong Soo Park, Motoi Ohba, Pann-Ghill Suh, Sung Ho Ryu
Affiliations

Lysophosphatidylcholine activates adipocyte glucose uptake and lowers blood glucose levels in murine models of diabetes

Kyungmoo Yea et al. J Biol Chem. .

Abstract

Glucose homeostasis is maintained by the orchestration of peripheral glucose utilization and hepatic glucose production, mainly by insulin. In this study, we found by utilizing a combined parallel chromatography mass profiling approach that lysophosphatidylcholine (LPC) regulates glucose levels. LPC was found to stimulate glucose uptake in 3T3-L1 adipocytes dose- and time-dependently, and this activity was found to be sensitive to variations in acyl chain lengths and to polar head group types in LPC. Treatment with LPC resulted in a significant increase in the level of GLUT4 at the plasma membranes of 3T3-L1 adipocytes. Moreover, LPC did not affect IRS-1 and AKT2 phosphorylations, and LPC-induced glucose uptake was not influenced by pretreatment with the PI 3-kinase inhibitor LY294002. However, glucose uptake stimulation by LPC was abrogated both by rottlerin (a protein kinase Cdelta inhibitor) and by the adenoviral expression of dominant negative protein kinase Cdelta. In line with its determined cellular functions, LPC was found to lower blood glucose levels in normal mice. Furthermore, LPC improved blood glucose levels in mouse models of type 1 and 2 diabetes. These results suggest that an understanding of the mode of action of LPC may provide a new perspective of glucose homeostasis.

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Figures

FIGURE 1.
FIGURE 1.
The isolation of glucose uptake-stimulating molecules from serum. a, schematic representation of the strategy used to identify the serum factor responsible for stimulating glucose uptake in 3T3-L1 adipocytes. b, C18 reverse phase HPLC (Vydac 218TP1022, 22 × 250 mm) serum elution profile. The relative glucose uptakes are expressed as ratios of uptake increases caused by treatments versus that cause by vehicle alone in 3T3-L1 adipocytes. Small amounts of active fractions were tested to determine whether stimulating activity was reduced by trypsin digestion. The trypsin-resistant fraction (fraction D) was selected and trypsinized prior to a second HPLC purification. c, C4 reverse phase HPLC (Vydac 214TP5215, 2.1 × 150 mm) elution profile of fraction D. d, cation exchange HPLC (Amersham Biosciences Mini-S HR 5/5, 4.6 × 50 mm) elution profile of fraction D.
FIGURE 2.
FIGURE 2.
Mass spectrometry of the glucose uptake-stimulating molecule. a, ESI-TOF MS analysis. Mass spectra of the active fractions of Fig. 1c (top panel) and Fig. 1d (middle panel), and of standard palmitoyl (16:0) LPC (bottom panel). b, mass fragmentation pattern analysis. The MS/MS spectra of the m/z 495.33 mass fragment in the mass spectra shown in a. c, the structure of LPC and the cleavage pattern of its fragmentation.
FIGURE 3.
FIGURE 3.
Effects of LPC on glucose uptake by 3T3-L1 adipocytes. a, 3T3-L1 adipocytes grown in six-well plates were equilibrated in glucose-free Krebs-Ringer buffer for 1 h and then incubated with LPC (0–30 μm) or insulin (10 nm) for 10 min. [14C]2-Deoxy-d-glucose uptake was then measured for 10 min, as described under “Experimental Procedures.” b, 3T3-L1 adipocytes were incubated with 20 μm LPC for 0–20 min. c and d, glucose uptake by 3T3-L1 adipocytes incubated in the absence (control, Con) or the presence of equimolar concentrations (20 μm) of lauroyl LPC (12:0 LPC), myristoyl LPC (14:0 LPC), palmitoyl LPC (16:0 LPC), stearoyl LPC (18:0 LPC), oleoyl LPC (18:1 LPC), arachidoyl LPC (20:0 LPC), palmitoyl LPE (16:0 LPE), palmitoyl LPI (16:0 LPI), or palmitoyl LPG (16:0 LPG) for 10 min. The values are the means ± S.E. of three independent experiments performed in triplicate. *, p < 0.05 versus basal values.
FIGURE 4.
FIGURE 4.
Effect of LPC on the translocations of GLUT4 in 3T3-L1 adipocytes. a, effect of LPC on the translocations of GLUT4 from low density microsomes (LDM) to the PM in 3T3-L1 adipocytes. 3T3-L1 adipocytes were stimulated for 10 min with 20 μm LPC or 100 nm insulin (INS). NT, not treated. The levels of the α1 subunit of Na+/K+-ATPase were used for control purposes. b, relative increases are depicted. The values shown are the means ± S.E. of three independent experiments performed in triplicate.*, p < 0.05 versus basal values.
FIGURE 5.
FIGURE 5.
PI 3-kinase-independent and PKCδ-dependent glucose uptake stimulation by LPC. a, phosphorylations of IRS-1 and AKT2. 3T3-L1 adipocytes were incubated for 30 min with/without LY294002 and then treated with vehicle, 20 μm LPC, or 10 nm insulin (INS) for 10 min. Total cell lysates were analyzed by immunoblotting using the indicated antibodies. β-Actin was used as a protein loading control (Con). The immunoblots shown are representative of three experiments. NT, not treated. b and c, effects of PI 3-kinase or PKC inhibitors on LPC-stimulated glucose uptake. 3T3-L1 adipocytes were treated with or without LY294002, Gö6976, or rottlerin for 30 min before being treated with 20 μm LPC. Glucose uptakes were then measured for 10 min as described under “Experimental Procedures.” d, the effects of wild-type PKCδ and DN-PKCδ overexpression on LPC-stimulated glucose uptake. 3T3-L1 adipocytes expressing wild-type PKCδ, DN-PKCδ, or DN-PKCζ were incubated with vehicle or 20 μm LPC for 10 min. Glucose uptakes were then assayed as indicated. An adenovirus containing the LacZ gene (LacZAdV) was used as a control. The values shown are the means ± S.E. of three independent experiments performed in triplicate. *, p < 0.05.
FIGURE 6.
FIGURE 6.
Blood glucose lowering effect of LPC in normal ICR mice. a and b, acute glucose reduction by LPC in ICR mice. 8-week-old male mice were intravenously injected with phosphate-buffered saline, insulin, or various LPCs. Blood glucose levels were monitored for 0–120 min after injections. c, serum insulin levels in 8-week-old male mice after a single intravenous injection of saline, glucose, or LPC. d, the effect of Ki16425 (an LPA receptor inhibitor) on the blood glucose reduction by LPC. 8-week-old male ICR mice were pretreated with Ki16425 (10 μmol/kg) for 30 min and then intravenously administered saline, LPC, or LPA. All of the animals had free access to water and were cared for in accordance with the guidelines issued by our institution. The data shown are the means ± S.D. (n = 5–6). *, p < 0.05 versus vehicle. NT, not treated.
FIGURE 7.
FIGURE 7.
The in vivo effect of LPC blood glucose levels in murine models of type 1 and 2 diabetes. a, the acute glucose lowering effect of LPC in the STZ-induced insulin-deficient ICR male mouse model. b, the acute glucose lowering effect of LPC in obese C57BLKSJ-db/db mice. All of the animals had free access to water. The animals were cared for in accordance with our institution's guidelines. The data shown are the means ± S.D. (n = 5–6). *, p < 0.05 versus vehicle. NT, not treated.
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References

    1. Saltiel A. R., Kahn C. R. (2001) Nature 414, 799–806 - PubMed
    1. Chiasson J. L., Rabasa-Lhoret R. (2004) Diabetes 53, (Suppl. 3) S34–S38 - PubMed
    1. Moller D. E. (2001) Nature 414, 821–827 - PubMed
    1. Hespel P., Vergauwen L., Vandenberghe K., Richter E. A. (1996) Diabetes 45, (Suppl. 1) S99–S104 - PubMed
    1. Elmendorf J. S. (2002) J. Membr. Biol. 190, 167–174 - PubMed

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