Skip to main content
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1998 Mar 15;101(6):1468–1477.

Dual mechanisms for the low plasma levels of truncated apolipoprotein B proteins in familial hypobetalipoproteinemia. Analysis of a new mouse model with a nonsense mutation in the Apob gene.

E Kim 1, C M Cham 1, M M Véniant 1, P Ambroziak 1, S G Young 1
PMCID: PMC508703  PMID: 9502790

Abstract

Familial hypobetalipoproteinemia (FHbeta), a syndrome characterized by low plasma cholesterol levels, is caused by mutations in the apo-B gene that interfere with the synthesis of apo-B100. FHbeta mutations frequently lead to the synthesis of a truncated form of apo-B, which typically is present in plasma at < 5% of the levels of apo-B100. Although many FHbeta mutations have been characterized, the basic mechanisms causing the low plasma levels of truncated apo-B variants have not been defined. We used gene targeting to create a mutant allele that exclusively yields a truncated apo-B, apo-B83. In mice heterozygous for the Apob83 allele, plasma levels and the size and density distribution of apo-B83-containing lipoproteins were strikingly similar to those observed in humans with FHbeta and an apo-B83 mutation. Analysis of mice carrying the Apob83 mutation revealed two mechanisms for the low plasma levels of apo-B83. First, Apob83 mRNA levels and apo-B83 secretion were reduced 76 and 72%, respectively. Second, apo-B83 was removed rapidly from the plasma, compared with apo-B100. This mouse model provides a new level of understanding of FHbeta and adds new insights into apo-B metabolism.

Full Text

The Full Text of this article is available as a PDF (449.6 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baserga S. J., Benz E. J., Jr Beta-globin nonsense mutation: deficient accumulation of mRNA occurs despite normal cytoplasmic stability. Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2935–2939. doi: 10.1073/pnas.89.7.2935. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Baserga S. J., Benz E. J., Jr Nonsense mutations in the human beta-globin gene affect mRNA metabolism. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2056–2060. doi: 10.1073/pnas.85.7.2056. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Borén J., Rustaeus S., Olofsson S. O. Studies on the assembly of apolipoprotein B-100- and B-48-containing very low density lipoproteins in McA-RH7777 cells. J Biol Chem. 1994 Oct 14;269(41):25879–25888. [PubMed] [Google Scholar]
  4. CHENG D. W., CHANG L. F., BAIRNSON T. A. Gross observations on developing abnormal embryos induced by maternal vitamin E deficiency. Anat Rec. 1957 Oct;129(2):167–185. doi: 10.1002/ar.1091290204. [DOI] [PubMed] [Google Scholar]
  5. Farese R. V., Jr, Cases S., Ruland S. L., Kayden H. J., Wong J. S., Young S. G., Hamilton R. L. A novel function for apolipoprotein B: lipoprotein synthesis in the yolk sac is critical for maternal-fetal lipid transport in mice. J Lipid Res. 1996 Feb;37(2):347–360. [PubMed] [Google Scholar]
  6. Farese R. V., Jr, Garg A., Pierotti V. R., Vega G. L., Young S. G. A truncated species of apolipoprotein B, B-83, associated with hypobetalipoproteinemia. J Lipid Res. 1992 Apr;33(4):569–577. [PubMed] [Google Scholar]
  7. Farese R. V., Jr, Ruland S. L., Flynn L. M., Stokowski R. P., Young S. G. Knockout of the mouse apolipoprotein B gene results in embryonic lethality in homozygotes and protection against diet-induced hypercholesterolemia in heterozygotes. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1774–1778. doi: 10.1073/pnas.92.5.1774. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Farese R. V., Jr, Véniant M. M., Cham C. M., Flynn L. M., Pierotti V., Loring J. F., Traber M., Ruland S., Stokowski R. S., Huszar D. Phenotypic analysis of mice expressing exclusively apolipoprotein B48 or apolipoprotein B100. Proc Natl Acad Sci U S A. 1996 Jun 25;93(13):6393–6398. doi: 10.1073/pnas.93.13.6393. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Grundy S. M., Vega G. L. What is meant by overproduction of apo B-containing lipoproteins? Adv Exp Med Biol. 1991;285:213–222. doi: 10.1007/978-1-4684-5904-3_26. [DOI] [PubMed] [Google Scholar]
  10. Homanics G. E., Maeda N., Traber M. G., Kayden H. J., Dehart D. B., Sulik K. K. Exencephaly and hydrocephaly in mice with targeted modification of the apolipoprotein B (Apob) gene. Teratology. 1995 Jan;51(1):1–10. doi: 10.1002/tera.1420510102. [DOI] [PubMed] [Google Scholar]
  11. Homanics G. E., Smith T. J., Zhang S. H., Lee D., Young S. G., Maeda N. Targeted modification of the apolipoprotein B gene results in hypobetalipoproteinemia and developmental abnormalities in mice. Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2389–2393. doi: 10.1073/pnas.90.6.2389. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Huang L. S., Voyiaziakis E., Markenson D. F., Sokol K. A., Hayek T., Breslow J. L. apo B gene knockout in mice results in embryonic lethality in homozygotes and neural tube defects, male infertility, and reduced HDL cholesterol ester and apo A-I transport rates in heterozygotes. J Clin Invest. 1995 Nov;96(5):2152–2161. doi: 10.1172/JCI118269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ishibashi S., Brown M. S., Goldstein J. L., Gerard R. D., Hammer R. E., Herz J. Hypercholesterolemia in low density lipoprotein receptor knockout mice and its reversal by adenovirus-mediated gene delivery. J Clin Invest. 1993 Aug;92(2):883–893. doi: 10.1172/JCI116663. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kessler O., Chasin L. A. Effects of nonsense mutations on nuclear and cytoplasmic adenine phosphoribosyltransferase RNA. Mol Cell Biol. 1996 Aug;16(8):4426–4435. doi: 10.1128/mcb.16.8.4426. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Krul E. S., Kinoshita M., Talmud P., Humphries S. E., Turner S., Goldberg A. C., Cook K., Boerwinkle E., Schonfeld G. Two distinct truncated apolipoprotein B species in a kindred with hypobetalipoproteinemia. Arteriosclerosis. 1989 Nov-Dec;9(6):856–868. doi: 10.1161/01.atv.9.6.856. [DOI] [PubMed] [Google Scholar]
  16. Krul E. S., Parhofer K. G., Barrett P. H., Wagner R. D., Schonfeld G. ApoB-75, a truncation of apolipoprotein B associated with familial hypobetalipoproteinemia: genetic and kinetic studies. J Lipid Res. 1992 Jul;33(7):1037–1050. [PubMed] [Google Scholar]
  17. Krul E. S., Tikkanen M. J., Cole T. G., Davie J. M., Schonfeld G. Roles of apolipoproteins B and E in the cellular binding of very low density lipoproteins. J Clin Invest. 1985 Feb;75(2):361–369. doi: 10.1172/JCI111708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Li X., Catalina F., Grundy S. M., Patel S. Method to measure apolipoprotein B-48 and B-100 secretion rates in an individual mouse: evidence for a very rapid turnover of VLDL and preferential removal of B-48- relative to B-100-containing lipoproteins. J Lipid Res. 1996 Jan;37(1):210–220. [PubMed] [Google Scholar]
  19. Linton M. F., Farese R. V., Jr, Chiesa G., Grass D. S., Chin P., Hammer R. E., Hobbs H. H., Young S. G. Transgenic mice expressing high plasma concentrations of human apolipoprotein B100 and lipoprotein(a). J Clin Invest. 1993 Dec;92(6):3029–3037. doi: 10.1172/JCI116927. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Linton M. F., Farese R. V., Jr, Young S. G. Familial hypobetalipoproteinemia. J Lipid Res. 1993 Apr;34(4):521–541. [PubMed] [Google Scholar]
  21. Maquat L. E. When cells stop making sense: effects of nonsense codons on RNA metabolism in vertebrate cells. RNA. 1995 Jul;1(5):453–465. [PMC free article] [PubMed] [Google Scholar]
  22. Marcel Y. L., Hogue M., Theolis R., Jr, Milne R. W. Mapping of antigenic determinants of human apolipoprotein B using monoclonal antibodies against low density lipoproteins. J Biol Chem. 1982 Nov 25;257(22):13165–13168. [PubMed] [Google Scholar]
  23. McCormick S. P., Linton M. F., Hobbs H. H., Taylor S., Curtiss L. K., Young S. G. Expression of human apolipoprotein B90 in transgenic mice. Demonstration that apolipoprotein B90 lacks the structural requirements to form lipoprotein. J Biol Chem. 1994 Sep 30;269(39):24284–24289. [PubMed] [Google Scholar]
  24. McCormick S. P., Ng J. K., Taylor S., Flynn L. M., Hammer R. E., Young S. G. Mutagenesis of the human apolipoprotein B gene in a yeast artificial chromosome reveals the site of attachment for apolipoprotein(a). Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10147–10151. doi: 10.1073/pnas.92.22.10147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. McCormick S. P., Ng J. K., Véniant M., Borén J., Pierotti V., Flynn L. M., Grass D. S., ConnollyA, Young S. G. Transgenic mice that overexpress mouse apolipoprotein B. Evidence that the DNA sequences controlling intestinal expression of the apolipoprotein B gene are distant from the structural gene. J Biol Chem. 1996 May 17;271(20):11963–11970. doi: 10.1074/jbc.271.20.11963. [DOI] [PubMed] [Google Scholar]
  26. Nielsen L. B., McCormick S. P., Pierotti V., Tam C., Gunn M. D., Shizuya H., Young S. G. Human apolipoprotein B transgenic mice generated with 207- and 145-kilobase pair bacterial artificial chromosomes. Evidence that a distant 5'-element confers appropriate transgene expression in the intestine. J Biol Chem. 1997 Nov 21;272(47):29752–29758. doi: 10.1074/jbc.272.47.29752. [DOI] [PubMed] [Google Scholar]
  27. Parhofer K. G., Barrett P. H., Aguilar-Salinas C. A., Schonfeld G. Positive linear correlation between the length of truncated apolipoprotein B and its secretion rate: in vivo studies in human apoB-89, apoB-75, apoB-54.8, and apoB-31 heterozygotes. J Lipid Res. 1996 Apr;37(4):844–852. [PubMed] [Google Scholar]
  28. Parhofer K. G., Barrett P. H., Bier D. M., Schonfeld G. Lipoproteins containing the truncated apolipoprotein, Apo B-89, are cleared from human plasma more rapidly than Apo B-100-containing lipoproteins in vivo. J Clin Invest. 1992 Jun;89(6):1931–1937. doi: 10.1172/JCI115799. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Parhofer K. G., Daugherty A., Kinoshita M., Schonfeld G. Enhanced clearance from plasma of low density lipoproteins containing a truncated apolipoprotein, apoB-89. J Lipid Res. 1990 Nov;31(11):2001–2007. [PubMed] [Google Scholar]
  30. Parhofer K. G., Hugh P., Barrett R., Bier D. M., Schonfeld G. Determination of kinetic parameters of apolipoprotein B metabolism using amino acids labeled with stable isotopes. J Lipid Res. 1991 Aug;32(8):1311–1323. [PubMed] [Google Scholar]
  31. Pease R. J., Milne R. W., Jessup W. K., Law A., Provost P., Fruchart J. C., Dean R. T., Marcel Y. L., Scott J. Use of bacterial expression cloning to localize the epitopes for a series of monoclonal antibodies against apolipoprotein B100. J Biol Chem. 1990 Jan 5;265(1):553–568. [PubMed] [Google Scholar]
  32. Piedrahita J. A., Zhang S. H., Hagaman J. R., Oliver P. M., Maeda N. Generation of mice carrying a mutant apolipoprotein E gene inactivated by gene targeting in embryonic stem cells. Proc Natl Acad Sci U S A. 1992 May 15;89(10):4471–4475. doi: 10.1073/pnas.89.10.4471. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Purcell-Huynh D. A., Farese R. V., Jr, Johnson D. F., Flynn L. M., Pierotti V., Newland D. L., Linton M. F., Sanan D. A., Young S. G. Transgenic mice expressing high levels of human apolipoprotein B develop severe atherosclerotic lesions in response to a high-fat diet. J Clin Invest. 1995 May;95(5):2246–2257. doi: 10.1172/JCI117915. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Seglen P. O. Preparation of rat liver cells. II. Effects of ions and chelators on tissue dispersion. Exp Cell Res. 1973 Jan;76(1):25–30. doi: 10.1016/0014-4827(73)90414-x. [DOI] [PubMed] [Google Scholar]
  35. Srivastava N., Noto D., Averna M., Pulai J., Srivastava R. A., Cole T. G., Latour M. A., Patterson B. W., Schonfeld G. A new apolipoprotein B truncation (apo B-43.7) in familial hypobetalipoproteinemia: genetic and metabolic studies. Metabolism. 1996 Oct;45(10):1296–1304. doi: 10.1016/s0026-0495(96)90251-6. [DOI] [PubMed] [Google Scholar]
  36. Verma K., Wei King D. Disorders of the developing nervous system of vitamin E-deficient rats. Acta Anat (Basel) 1967;67(4):623–635. doi: 10.1159/000143009. [DOI] [PubMed] [Google Scholar]
  37. Véniant M. M., Pierotti V., Newland D., Cham C. M., Sanan D. A., Walzem R. L., Young S. G. Susceptibility to atherosclerosis in mice expressing exclusively apolipoprotein B48 or apolipoprotein B100. J Clin Invest. 1997 Jul 1;100(1):180–188. doi: 10.1172/JCI119511. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Young S. G., Hubl S. T., Smith R. S., Snyder S. M., Terdiman J. F. Familial hypobetalipoproteinemia caused by a mutation in the apolipoprotein B gene that results in a truncated species of apolipoprotein B (B-31). A unique mutation that helps to define the portion of the apolipoprotein B molecule required for the formation of buoyant, triglyceride-rich lipoproteins. J Clin Invest. 1990 Mar;85(3):933–942. doi: 10.1172/JCI114522. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Zhang S. H., Reddick R. L., Piedrahita J. A., Maeda N. Spontaneous hypercholesterolemia and arterial lesions in mice lacking apolipoprotein E. Science. 1992 Oct 16;258(5081):468–471. doi: 10.1126/science.1411543. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES