scholarly journals Tilorone-induced lysosomal storage of glycosaminoglycans in cultured corneal fibroblasts: biochemical and physicochemical investigations

1995 ◽  
Vol 312 (1) ◽  
pp. 215-222 ◽  
Author(s):  
J Fischer

Tilorone (2,7-bis[2-(diethylamino)ethoxy]-fluoren-9-one) and several other bis-basic compounds are known to induce lysosomal glycosaminoglycan (GAG) storage. The responsible pathomechanism has not been elucidated yet. The assumption of an unspecific disturbance of lysosomal proenzyme targeting due to elevation of endosomal pH is opposed by the hypothesis of formation of a complex between tilorone and GAGs within the lysosomes, which renders GAGs indigestible to glycosidases. In cultures of bovine corneal fibroblasts the amounts of intracellular GAGs [dermatan sulphate (DS), heparan sulphate (HS) and chondroitin sulphate (CS)] were quantified. The fibroblasts were exposed to tilorone (5 microM), which was found to be readily taken up by the cells and to be accumulated within acidic compartments to finally achieve millimolar concentrations. Under these conditions the GAG storage is predominantly due to the accumulation of DS; however, the DS secretion into the culture medium was not affected. The HS accumulation was much less pronounced, accounting only for 3% of total GAG storage. Ammonium chloride (10 mM), which is known to diminish lysosomal enzyme activity by interfering with the mannose 6-phosphate receptor-mediated transport, prevents both HS and DS breakdown. By means of NMR spectroscopy it was shown that tilorone itself tends to display a concentration-dependent aggregation which was enhanced in the presence of GAGs. The diethylamino groups of tilorone interact physicochemically with DS, and to a smaller extent with HS, but not with chondroitin 4-sulphate. Thus, the strength of the interaction between tilorone and the different GAGs in vitro correlates with the potency of tilorone to inhibit the breakdown of the individual GAGs in cultured bovine fibroblasts. The results support the hypothesis of a specific interaction between tilorone and particular GAGs, rendering these resistant to enzymic degradation.

Zygote ◽  
2007 ◽  
Vol 15 (3) ◽  
pp. 225-232 ◽  
Author(s):  
A.-S. Bergqvist ◽  
J. Ballester ◽  
A. Johannisson ◽  
N. Lundeheim ◽  
H. Rodríguez-Martínez

SummaryGlycosaminoglycans (GAGs) are present in the oviduct in which the major part of sperm capacitation occurs. In this study we have tested how capacitation of frozen-thawed bull spermatozoa is effected by exposure to different GAGs detectable or possibly present in oviductal fluid; i.e. heparin, hyaluronan, heparan sulphate, dermatan sulphate and chondroitin sulphate. Following exposure of different duration, the spermatozoa were stained with either Chlortetracycline (CTC) or merocyanine-540 and evaluated with epifluorescent light microscopy or flow cytometry, respectively. Heparin elicited a significant increase in the number of alive, capacitated spermatozoa, either expressed as higher merocyanine-540 fluorescence (p < 0.0001) or as B-pattern (p = 0.0021) in the CTC assay, during 4 h of incubation. When comparing the different GAG treatments one by one to the negative control in the flow cytometric study, only heparin and dermatan sulphate were significant (p < 0.0001) higher than the control at 0–30 min of incubation. Duration of incubation did not affect the proportion of capacitated spermatozoa when measured as merocyanine-540 fluorescence or CTC B-pattern, but the length of the incubation did affect the number of dead (Yo-PRO 1 positive) spermatozoa (p < 0.0001). Exposure to zona pellucida proteins significantly increased the proportion of acrosome reacted spermatozoa (p = 0.016). Both heparin and dermatan sulphate induce capacitation of frozen-thawed bull spermatozoa in vitro.


2006 ◽  
Vol 393 (3) ◽  
pp. 767-777 ◽  
Author(s):  
Peng Guo ◽  
Liqiang Zhang ◽  
Hongjie Zhang ◽  
Yanming Feng ◽  
Guozhong Jing

RRF (ribosome recycling factor) consists of two domains, and in concert with EF-G (elongation factor-G), triggers dissociation of the post-termination ribosomal complex. However, the function of the individual domains of RRF remains unclear. To clarify this, two RRF chimaeras, EcoDI/TteDII and TteDI/EcoDII, were created by domain swaps between the proteins from Escherichia coli and Thermoanaerobacter tengcongensis. The ribosome recycling activity of the RRF chimaeras was compared with their wild-type RRFs by using in vivo and in vitro activity assays. Like wild-type TteRRF (T. tengcongensis RRF), the EcoDI/TteDII chimaera is non-functional in E. coli, but both wild-type TteRRF, and EcoDI/TteDII can be activated by coexpression of T. tengcongensis EF-G in E. coli. By contrast, like wild-type E. coli RRF (EcoRRF), TteDI/EcoDII is fully functional in E. coli. These findings suggest that domain II of RRF plays a crucial role in the concerted action of RRF and EF-G for the post-termination complex disassembly, and the specific interaction between RRF and EF-G on ribosomes mainly depends on the interaction between domain II of RRF and EF-G. This study provides direct genetic and biochemical evidence for the function of the individual domains of RRF.


1979 ◽  
Vol 42 (1) ◽  
pp. 27-30 ◽  
Author(s):  
MELANIE R. MAAS ◽  
FREDERICK J. POST ◽  
D. K. SALUNKHE

The influence of sodium salts of the macronutrients nitrate, phosphate, sulfate, and chloride; and the micronutrients iron, calcium, copper, cobalt, nickel, and manganese on growth of Phytophthora infestans and synthesis of glycoalkaloids by the fungus was investigated. Maximum growth levels were demonstrated when 0.04% phosphate, 0.04% chloride, or 2–5 mg of iron/liter were employed in the culture medium. Results indicate that upon substitution of the individual sodium salts of the macronutrients for the potassium and magnesium salts or addition of sodium chloride to the basal medium, the concentration of glycoalkaloids synthesized by the fungus decreased significantly. Regression analysis showed that the concentration of phosphate in the medium had the most influence on the amount of glycoalkaloids produced by P. infestans. Increasing the phosphate concentration in the medium resulted in increasing amounts of glycoalkaloids being produced by the fungus. As the mass of mycelium increased in media containing different amounts of phosphate, the quantity of glycoalkaloids synthesized by the fungus decreased.


1987 ◽  
Vol 241 (2) ◽  
pp. 591-601 ◽  
Author(s):  
M Sobue ◽  
H Habuchi ◽  
K Ito ◽  
H Yonekura ◽  
K Oguri ◽  
...  

A series of aryl and alkyl O-beta-D-xylosides and their analogues with S, NH or CH2 in the glycosidic linkage were prepared and examined for their ability to act as artificial chain initiators of chondroitin (dermatan) sulphate synthesis in embryonic chick cartilage, foetal rat skin and 6-week-old-rat aorta under conditions where normal protein-core synthesis was inhibited by cycloheximide. For all these tissues in culture, phenyl O-beta-D-xyloside and phenyl beta-D-thioxyloside were clearly more effective than the corresponding N-xyloside and homo-C-xyloside. Introduction of a carboxy group to the para position of their aglycone yielded derivatives with far lower initiator activity. In a concentration range lower than 0.1 mM, the effectiveness of alkyl beta-D-thioxyloside was greatly influenced by the carbon number (n) of the alkyl group and was at a maximum at n = 7 or 8 for the cartilage, at n = 5 for the skin and at n = 4 for the aorta. In the beta-xyloside-treated cartilages, the average length of newly formed chondroitin sulphate chains reflected the chain-initiator activity of added xyloside, i.e. the higher the initiator activity, the shorter the average chain length. In the skin and aorta, none of the drugs could relieve the inhibition of heparan sulphate synthesis caused by cycloheximide. Fertilized hens' eggs were each injected on day 9 with 9.2 mumol of beta-xyloside and the skeletal systems of embryos were examined a week later. The embryos treated with beta-xylosides of relatively high initiator activity showed a 30-40% decrease in the overall growth rate of skeletons, whereas those treated with beta-xylosides of low initiator activity showed little or no decrease in the growth rate. The results are consistent with the notion that the observed change in skeletal morphology results mainly, if not completely, from beta-xyloside-induced synthesis of core-protein-free chondroitin sulphate, and further suggest that a procedure employing a series of beta-xyloside homologues with various initiator activities will furnish an easily applied criterion on which to test the specificity of xyloside action on biological processes.


1965 ◽  
Vol 97 (2) ◽  
pp. 432-439
Author(s):  
NL Noble ◽  
RJ Boucek

1. The incorporation of sulphate into the trichloroacetic acid-precipitable fraction of 9-day chick-embryo corium, incubated in Krebs-Ringer phosphate buffer, pH7, is dependent on the sulphate concentration of the medium. Uptake of sulphate is linear with time for 3.5-4hr. and is maximal at 37.5 degrees in the presence of air or oxygen. d-Glucose stimulates the incorporation of sulphate but l-glutamine has no effect. 2. Incorporation of sulphate by the chick corium is enzymic and apparently involves the synthesis of active sulphate (adenosine 3‣-phosphate 5‣-sulphatophosphate) and the transfer of sulphate from adenosine 3‣-phosphate 5‣-sulphatophosphate to acceptor glycosaminoglycuronoglycan. This proposal on the nature of the process is suggested by the similarity between the energy of activation calculated for sulphate-incorporation in the chick-corium preparation and the energy requirement reported for sulphate-activation with purified yeast enzymes. 3. The 9-day chick-embryo corium is composed principally of fibroblasts; there are no histologically demonstrable mast cells. The young fibroblast is apparently responsible for the incorporation of sulphate into glycosaminoglycuronoglycans tentatively identified as chondroitin sulphate(s), heparan sulphate and heparin-like material.


1984 ◽  
Vol 217 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Y Ohhashi ◽  
F Hasumi ◽  
Y Mori

Glycosaminoglycans synthesized in polymorphonuclear (PMN) leucocytes isolated from blood (peripheral PMN leucocytes) and in those induced intraperitoneally by the injection of caseinate (peritoneal PMN leucocytes) were compared. Both peripheral and peritoneal PMN leucocytes were incubated in medium containing [35S]sulphate and [3H]glucosamine. Each sample obtained after incubation was separated into cell, cell-surface and medium fractions by trypsin digestion and centrifugation. The glycosaminoglycans secreted from peripheral and peritoneal PMN leucocytes were decreased in size by alkali treatment, indicating that they existed in the form of proteoglycans. Descending paper chromatography of the unsaturated disaccharides obtained by the digestion of glycosaminoglycans with chondroitinase AC and chondroitinase ABC identified the labelled glycosaminoglycans of both the cell and the medium fractions in peripheral PMN leucocytes as 55-58% chondroitin 4-sulphate, 16-19% chondroitin 6-sulphate, 16-19% dermatan sulphate and 6-8% heparan sulphate. Oversulphated chondroitin sulphate and oversulphated dermatan sulphate were found only in the medium fraction. In peritoneal PMN leucocytes there is a difference in the composition of glycosaminoglycans between the cell and the medium fractions; the cell fraction was composed of 60% chondroitin 4-sulphate, 5.5% chondroitin 6-sulphate, 16.8% dermatan sulphate and 13.9% heparan sulphate, whereas the medium fraction consisted of 24.5% chondroitin 4-sulphate, 28.2% chondroitin 6-sulphate, 33.7% dermatan sulphate and 10% heparan sulphate. Oversulphated chondroitin sulphate and oversulphated dermatan sulphate were found in the cell, cell-surface and medium fractions. On the basis of enzymic assays with chondro-4-sulphatase and chondro-6-sulphatase, the positions of sulphation in the disulphated disaccharides were identified as 4- and 6-positions of N-acetylgalactosamine. Most of the 35S-labelled glycosaminoglycans synthesized in peripheral PMN leucocytes were retained within cells, whereas those in peritoneal PMN leucocytes were secreted into the culture medium. Moreover, the amount of glycosaminoglycans in peritoneal PMN leucocytes was significantly less than that in peripheral PMN leucocytes. Assay of lysosomal enzymes showed that these activities in peritoneal PMN leucocytes were 2-fold higher than those in peripheral PMN leucocytes.


2021 ◽  
Vol 5 (2) ◽  
pp. 26-30
Author(s):  
Affandi Omar ◽  
Dyg Pertiwi Abg Kamaludin ◽  
Salina Abdul Rahman ◽  
Rosnani Mohamed ◽  
Fatimah Diana Amin Nordin ◽  
...  

Background: Mucopolysaccharidoses type II (MPS II) is an X-linked lysosomal storage disease (LSD). It is due to mutation in IDS gene encoding iduronate-2-sulphatase (IDS) involved in the catabolism of dermatan sulphate and heparan sulphate. Currently, the treatments for MPS II patients are enzyme replacement therapy (ERT) and bone marrow transplantation (BMT). However, ERT is not effectively reducing the central nervous system manifestation and finding the suitable donor maybe quite challenging in BMT. Over the past decades, pharmacological chaperone has been an alternative approach for management of MPS II patient. Here, we described the in vitro profiling of small molecules in group of chondroitin/dermatan (CD) sulphate disaccharide, heparin oligosaccharides, unsaturated heparin disaccharides and 6-O-desulphated heparin oligosaccharide, using recombinant human iduronate-2-sulphatase (rhIDS). Twenty-one small molecule compounds with several concentrations were each screened by inhibition and thermal stability assays. Results: Our study revealed that condroitin dermatan trisulphate (CD3S), heparin tetrasaccharide (H4Sac), heparin octasaccharide (H8Sac) and heparin octadecasaccharide (H18Sac) showed high inhibition constant, Ki and low inhibition concentration, IC50 in comparison to others. In the thermal stability study, only rhIDS incubated with CD3S was found to preserve enzyme activity (20%) after incubated at 67oC. Conclusion: Overall, our experiments discovered that CD3S was able to bind, inhibit and chaperone rhIDS. These features suggest a potential pharmacological chaperone for MPS II.


1988 ◽  
Vol 251 (2) ◽  
pp. 411-418 ◽  
Author(s):  
L A Beavan ◽  
M Davies ◽  
R M Mason

Newly synthesized rat glomerular [35S]proteoglycans were labelled in vivo after injecting Na2[35S]SO4 intraperitoneally. At the end of the labelling period (7 h) the kidneys were perfused in situ with 0.01% (w/v) cetylpyridinium chloride. This fixed proteoglycans in the tissue and increased their recovery 2-3-fold during subsequent isolation of glomeruli from the renal cortex. The glomeruli were fractionated by a modified osmotic lysis and detergent extraction procedure [Meezan, Brendel, Hjelle & Carlson (1978) in The Biology and Chemistry of Basement Membranes (Kefalides, N.A., ed.), Academic Press, New York; Kanwar & Farquhar (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 4493-4497] to obtain a basement membrane preparation. The proteoglycans released at each stage of the procedure were characterized using DEAE-Sephacel ion-exchange chromatography, chondroitinase ABC and HNO2 digestion and Sepharose CL-4B gel-permeation chromatography. About 85% of the [35S]proteoglycans synthesized were of the heparan sulphate variety, the remainder being chondroitin sulphate proteoglycans. Three sizes of heparan sulphate proteoglycans were identified. The largest (HS1, Kav. 0.47) accounts for 44% of the total extractable heparan sulphates. About one third of HS1 were extracted from the glomerular basement-membrane fraction with 8 M-urea and 4 M-guanidine hydrochloride but the remainder were released from the glomerulus during preparation of the fraction. The two smaller molecules (HS2, Kav. 0.56 and HS3, Kav. 0.68) accounted for 27% and 28% of the extractable heparan sulphate respectively and were not associated with the basement membrane fraction. HS1, HS2 and HS3 were also isolated from non-fixed glomeruli labelled in vivo but with much lower recovery. In glomeruli labelled in vitro, heparan sulphate accounted for only 35% of the proteoglycans, the remainder being of the chondroitin sulphate type. Proteoglycans similar to HS1, HS2 and HS3 were present in glomeruli labelled in vitro but, in addition, a large, highly charged heparan sulphate (HS1a) was extracted from the glomerular basement-membrane fraction of these glomeruli. It accounted for 6% of the total heparan sulphate.


1985 ◽  
Vol 228 (2) ◽  
pp. 443-450 ◽  
Author(s):  
G Venn ◽  
R M Mason

The absence of keratan sulphate synthesis from skeletal tissues of young and mature mice and rats has been confirmed by (1) analysis of specific enzyme degradation products of newly synthesized glycosaminoglycans, and (2) immunohistochemistry and radioimmunoassay using a monoclonal antibody directed against keratan sulphate. Approx. 98% of the [35S]glycosaminoglycans synthesized in vivo by mouse and rat costal cartilage, and all of those of lumbar disc, are chondroitin sulphate. The remainder in costal cartilage were identified as heparan sulphate in mature rats. In contrast, [35S]glycosaminoglycans synthesized by cornea of both species comprised both chondroitin sulphate and keratan sulphate. In mice keratan sulphate accounted for 12-25% and in rats 40-50% of the total [35S]glycosaminoglycans, depending on the age of the animal. Experiments in vitro with organ culture of cartilage and cornea confirm these results. Absence of keratan sulphate from mouse costal cartilage and lumbar disc D1-proteoglycans was corroborated by inhibition radioimmunoassay with the monoclonal antibody MZ15 and by lack of staining for keratan sulphate in indirect immunofluorescence studies using the same antibody.


1991 ◽  
Vol 275 (2) ◽  
pp. 515-520 ◽  
Author(s):  
M Norman ◽  
G Ekman ◽  
U Ulmsten ◽  
K Barchan ◽  
A Malmström

Profound changes occur in the cervix during pregnancy. In particular, the connective tissue is remodelled. To elucidate the mechanisms behind this process, the metabolism of cervical connective tissue was studied using tissue cultures. Cervical biopsies from non-pregnant and pregnant women were incubated with [35S]sulphate. The proteoglycans of the tissue specimens were purified by ion-exchange and gel chromatography and characterized by SDS/PAGE and by enzymic degradation. In the non-pregnant cervix, the incorporation of [35S]sulphate into the proteoglycans was linear for 48 h. During the first 6 h of incubation the accumulation of chiefly one small labelled proteoglycan (apparent Mr 110,000) substituted with dermatan sulphate was recorded. This is in accordance with the known proteoglycan composition of non-pregnant cervical tissue. In addition, small amounts of two larger radioactive dermatan/chondroitin sulphate proteoglycans (apparent Mr values 220,000 and greater than 500,000) were recorded. After longer periods of incubation the proportion of heparan sulphate proteoglycans increased considerably. The pregnant tissue showed a clearly different composition of labelled proteoglycans. An increased accumulation of the two larger dermatan/chondroitin sulphate proteoglycans was seen in addition to the dominant small dermatan sulphate proteoglycan of the non-pregnant cervix. The rate of accumulation of these two proteoglycans was about 3 times higher in the pregnant tissue, whereas that of the small dermatan sulphate proteoglycan was only increased 2-fold. The fact that the concentration of proteoglycans in the pregnant cervix is approximately one-half of that in the non-pregnant cervix indicates that the turnover of proteoglycans in pregnant cervical tissue is significantly increased. The major effect of this profound change of metabolism was a 50% decrease in proteoglycan content and a 2-fold increased proportion of a dermatan sulphate proteoglycan with an apparent Mr of 220,000.


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