Abstract
Dextran sulfate (DS) was previously shown to inhibit phagosome-lysosome (P-L) fusion whereas dextran (D) of equivalent size was ineffective. The uptake and interiorization of DS were examined with a tritiated product over the course of 4 d in culture. The exposure of macrophages to 20 micrograms/ml of 3H-DS led to linear uptake for 4 d, at which time fusion was inhibited. Macrophage interiorization of 3H-DS was greatly increased by forming insoluble complexes with either serum lipoproteins or purified human low density lipoproteins (LDL). Under these conditions fusion was inhibited within 4 h. The uptake of large quantities of acetylated LDL in the absence of DS was not associated with the inhibition of fusion. Lipoproteins therefore served as the DS carriers and were not themselves inhibitory. The intralysosomal pH of control and D-treated macrophages was 4.76 (+/-0.06) and 4.68 (+/- 0.02), respectively. Storage of DS was associated with a decreased pH to 4.36 (+/-0.14). Increasing the intralysosomal pH with either NH4Cl or chloroquine failed to modify inhibited P-L fusion. Hydrogen ion concentration was therefore not an important factor in DS inhibition. Secondary lysosomes were isolated from D- and DS-loaded cells and exhibited excellent latency. These lysosomes were exposed to the membrane probes, alpha- and Beta-parinaric acid, and compared in fluorescence polarization measurements. The results with the Beta isomer consistently indicated that the membranes of DS lysosomes were more rigid than the D samples. It is suggested that high intralysosomal concentrations of DS interact directly with either lipid and/or polypeptide moieties of the luminal face of the membrane, thereby decreasing its fluidity and fusibility.
Full Text
The Full Text of this article is available as a PDF (946.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Basu S. K., Brown M. S., Ho Y. K., Goldstein J. L. Degradation of low density lipoprotein . dextran sulfate complexes associated with deposition of cholesteryl esters in mouse macrophages. J Biol Chem. 1979 Aug 10;254(15):7141–7146. [PubMed] [Google Scholar]
- Basu S. K., Goldstein J. L., Anderson G. W., Brown M. S. Degradation of cationized low density lipoprotein and regulation of cholesterol metabolism in homozygous familial hypercholesterolemia fibroblasts. Proc Natl Acad Sci U S A. 1976 Sep;73(9):3178–3182. doi: 10.1073/pnas.73.9.3178. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CHEN R. F., BOWMAN R. L. FLUORESCENCE POLARIZATION: MEASUREMENT WITH ULTRAVIOLET-POLARIZING FILTERS IN A SPECTROPHOTOFLUOROMETER. Science. 1965 Feb 12;147(3659):729–732. doi: 10.1126/science.147.3659.729. [DOI] [PubMed] [Google Scholar]
- CORNWELL D. G., KRUGER F. A. Molecular complexes in the isolation and characterization of plasma lipoproteins. J Lipid Res. 1961 Apr;2:110–134. [PubMed] [Google Scholar]
- Cohn Z. A., Parks E. The regulation of pinocytosis in mouse macrophages. II. Factors inducing vesicle formation. J Exp Med. 1967 Feb 1;125(2):213–232. doi: 10.1084/jem.125.2.213. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fraley R. T., Jameson D. M., Kaplan S. The use of the fluorescent probe alpha-parinaric acid to determine the physical state of the intracytoplasmic membranes of the photosynthetic bacterium, Rhodopseudomonas sphaeroides. Biochim Biophys Acta. 1978 Jul 20;511(1):52–60. doi: 10.1016/0005-2736(78)90064-0. [DOI] [PubMed] [Google Scholar]
- Geisow M. J., D'Arcy Hart P., Young M. R. Temporal changes of lysosome and phagosome pH during phagolysosome formation in macrophages: studies by fluorescence spectroscopy. J Cell Biol. 1981 Jun;89(3):645–652. doi: 10.1083/jcb.89.3.645. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldstein J. L., Ho Y. K., Basu S. K., Brown M. S. Binding site on macrophages that mediates uptake and degradation of acetylated low density lipoprotein, producing massive cholesterol deposition. Proc Natl Acad Sci U S A. 1979 Jan;76(1):333–337. doi: 10.1073/pnas.76.1.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iverius P. H. The interaction between human plasma lipoproteins and connective tissue glycosaminoglycans. J Biol Chem. 1972 Apr 25;247(8):2607–2613. [PubMed] [Google Scholar]
- Jermyn M. A. Increasing the sensitivity of the anthrone method for carbohydrate. Anal Biochem. 1975 Sep;68(1):332–335. doi: 10.1016/0003-2697(75)90713-7. [DOI] [PubMed] [Google Scholar]
- Kim Y. C., Nishida T. Nature of interaction of dextran sulfate with lecithin dispersions and lysolecithin micelles. J Biol Chem. 1977 Feb 25;252(4):1243–1249. [PubMed] [Google Scholar]
- Mahoney E. M., Hamill A. L., Scott W. A., Cohn Z. A. Response of endocytosis to altered fatty acyl composition of macrophage phospholipids. Proc Natl Acad Sci U S A. 1977 Nov;74(11):4895–4899. doi: 10.1073/pnas.74.11.4895. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nathan C. F., Root R. K. Hydrogen peroxide release from mouse peritoneal macrophages: dependence on sequential activation and triggering. J Exp Med. 1977 Dec 1;146(6):1648–1662. doi: 10.1084/jem.146.6.1648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nishida T., Cogan U. Nature of the interaction of dextran sulfate with low density lipoproteins of plasma. J Biol Chem. 1970 Sep 25;245(18):4689–4697. [PubMed] [Google Scholar]
- Ohkuma S., Poole B. Fluorescence probe measurement of the intralysosomal pH in living cells and the perturbation of pH by various agents. Proc Natl Acad Sci U S A. 1978 Jul;75(7):3327–3331. doi: 10.1073/pnas.75.7.3327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rudel L. L., Lee J. A., Morris M. D., Felts J. M. Characterization of plasma lipoproteins separated and purified by agarose-column chromatography. Biochem J. 1974 Apr;139(1):89–95. doi: 10.1042/bj1390089. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider D. L. ATP-dependent acidification of intact and disrupted lysosomes. Evidence for an ATP-driven proton pump. J Biol Chem. 1981 Apr 25;256(8):3858–3864. [PubMed] [Google Scholar]
- Sklar L. A., Hudson B. S., Petersen M., Diamond J. Conjugated polyene fatty acids on fluorescent probes: spectroscopic characterization. Biochemistry. 1977 Mar 8;16(5):813–819. doi: 10.1021/bi00624a001. [DOI] [PubMed] [Google Scholar]
- Sklar L. A., Hudson B. S., Simoni R. D. Conjugated polyene fatty acids as fluorescent probes: synthetic phospholipid membrane studies. Biochemistry. 1977 Mar 8;16(5):819–828. doi: 10.1021/bi00624a002. [DOI] [PubMed] [Google Scholar]
- Sklar L. A., Miljanich G. P., Dratz E. A. Phospholipid lateral phase separation and the partition of cis-parinaric acid and trans-parinaric acid among aqueous, solid lipid, and fluid lipid phases. Biochemistry. 1979 May 1;18(9):1707–1716. doi: 10.1021/bi00576a012. [DOI] [PubMed] [Google Scholar]
- Steinman R. M., Brodie S. E., Cohn Z. A. Membrane flow during pinocytosis. A stereologic analysis. J Cell Biol. 1976 Mar;68(3):665–687. doi: 10.1083/jcb.68.3.665. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TOURTELLOTTE C. D., DZIEWIATKOWSKI D. D. A DISORDER OF ENDOCHONDRAL OSSIFICATION INDUCED BY DEXTRAN SULPHATE. J Bone Joint Surg Am. 1965 Sep;47:1185–1202. [PubMed] [Google Scholar]
- Terho T. T., Hartiala K. Method for determination of the sulfate content of glycosaminoglycans. Anal Biochem. 1971 Jun;41(2):471–476. doi: 10.1016/0003-2697(71)90167-9. [DOI] [PubMed] [Google Scholar]