FAT/CD36 expression is not ablated in spontaneously hypertensive rats - PubMed (original) (raw)

FAT/CD36 expression is not ablated in spontaneously hypertensive rats

Arend Bonen et al. J Lipid Res. 2009 Apr.

Abstract

There is doubt whether spontaneously hypertensive rats (SHR; North American strain) are null for fatty acid translocase (FAT/CD36). Therefore, we examined whether FAT/CD36 is expressed in heart, muscle, liver and adipose tissue in SHR. Insulin resistance was present in SHR skeletal muscle. We confirmed that SHR expressed aberrant FAT mRNAs in key metabolic tissues; namely, the major 2.9 kb transcript was not expressed, but 3.8 and 5.4 kb transcripts were present. Despite this, FAT/CD36 protein was expressed in all tissues, although there were tissue-specific reductions in FAT/CD36 protein expression and plasmalemmal content, ranging from 26-85%. Fatty acid transport was reduced in adipose tissue (-50%) and was increased in liver (+47%). Normal rates of fatty acid transport occurred in heart and muscle, possibly due to compensatory upregulation of plasmalemmal fatty acid binding protein (FABPpm) in red (+123%) and white muscle (+110%). In conclusion, SHRs (North American strain) are not a natural FAT/CD36 null model, the North American strain of SHR express FAT/CD36, albeit at reduced levels.

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Figures

Fig. 1.

Fig. 1.

Basal (A) and insulin stimulated glucose transport (B) in hindlimb perfused muscles in WKY and spontaneously hypertensive rats (SHR). Hindlimb perfusion was performed using controlled flow rates and radiolabeled 3-O-methylglucose with (20 mU/ml) or without insulin (basal) as described in the Methods. Data are mean ± SEM, N = 4 for each treatment * P < 0.05, SHR vs. WKY ** P < 0.05, white muscle vs. red muscle.

Fig. 2.

Fig. 2.

FAT mRNA blot in heart (H), red (R) and white (W) muscle, adipose tissue (A), and liver (L) of WKY and SHR (A) and the quantification of 2.9 kb (B), 3.8 kb (C), and 5.4 kb (D) FAT transcripts in WKY and SHR. Data were quantified by determining the density of each blot, which was normalized for loading using 28S RNA. Data are mean ± SEM, N = 3–4 for each tissue examined in each group of animals SHR. ND, not detected.

Fig. 3.

Fig. 3.

Protein expression of fatty acid translocase (FAT/CD36) in heart, red and white skeletal muscle, adipose tissue, and liver in WKY and SHR. Data are mean ± SEM, N = 5–8 for each tissue examined in each group of animals. R, red muscle; W, white muscle; H, heart; A, adipose tissue; L, liver FAT/CD36 was detected at 88 kDa. Data were quantified by determining the density of each blot and normalized using Ponceau staining. Ponceau stains are shown below Western blot for FAT/CD36 * P < 0.05, SHR vs. WKY. Inset: FAT/CD36 protein expression in tissue homogenates using a commercially available antibody.

Fig. 4.

Fig. 4.

Plasma membrane FAT/CD36 in heart, red and white skeletal muscle, adipose tissue, and liver in WKY and SHR. Data are mean ± SEM, N = 4–8 for each tissue examined in each group of animals. R, Red muscle; W, white muscle; H, heart; A, adipose tissue; L, liver FAT/CD36 was detected at 88 kDa. Data were quantified by determining the density of each blot and normalized using Ponceau staining. Ponceau stains are shown below Western blot for FAT/CD36 * P < 0.05, SHR vs. WKY. Inset: plasma membrane FAT/CD36 protein using a commercially available antibody.

Fig. 5.

Fig. 5.

Rate of palmitate transport into giant vesicles prepared from heart, red and white skeletal muscle, liver, and adipose tissue in WKY and SHR. Data are mean ± SEM, N = 6–8 for each tissue examined in each group of animals * P < 0.05, SHR vs. WKY.

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References

    1. Bonen A., A. Chabowski, J. J. F. P. Luiken, and J. F. C. Glatz. 2007. Is membrane transport of FFA mediated by lipid, protein, or both? Mechanisms and regulation of protein-mediated cellular fatty acid uptake: molecular, biochemical, and physiological evidence. Physiology (Bethesda). 22 15–29. - PubMed
    1. Kampf J. P., and A. M. Kleinfeld. 2007. Is membrane transport of FFA mediated by lipid, protein, or both? An unknown protein mediates free fatty acid transport across the adipocyte plasma membrane. Physiology (Bethesda). 22 7–14. - PubMed
    1. Kampf J. P., A. M. Kleinfeld, A. Bonen, A. Chabowski, J. J. F. P. Luiken, and J. F. C. Glatz. 2007. Is membrane transport of FFA mediated by lipid, protein, or both?: Points of agreement. Physiology (Bethesda). 22 29. - PubMed
    1. Stahl A. 2004. A current review of fatty acid transport proteins (SLC27). Pflugers Arch. 447 722–727. - PubMed
    1. Febbraio M., N. A. Abumrad, D. P. Hajjar, K. Sharma, W. Cheng, S. Frieda, A. Pearce, and R. L. Silverstein. 1999. A null mutation in murine CD36 reveals an important role in fatty acid and lipoprotein metabolism. J. Biol. Chem. 274 19055–19062. - PubMed

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