Glycosaminoglycan polysaccharides are components of animal extracellular matrices and regulate cell functions based on their various sulfation and epimerization pattern structures. The present study ...aimed to find glycosaminoglycan structures to promote neural differentiation. We investigated the effect of exogenous glycosaminoglycans with well-defined structures on the all-trans-retinoic acid-induced neural differentiation of P19 embryonal carcinoma cells, which is an ideal model culture system for studying neural differentiation. We found that chondroitin sulfate E and heparin, but not any other glycosaminoglycans, upregulated the expressions of neural specific markers but not a grail specific marker. Chondroitin sulfate E was suggested to function during spheroid formation, however, equimolar concentration of its oligosaccharide did not show promotive effect on the neural differentiation. Another finding was that hyaluronan oligosaccharide mixture markedly downregulated the expressions of a myelin specific marker. These findings suggested that the specific sulfation pattern and/or chain length of exogenous added glycosaminoglycan is important to regulate neural differentiation and myelination.
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•Chondroitin sulfate E and heparin promoted neural differentiation in P19 cells.•Chondroitin sulfate E worked during spheroid formation.•Chondroitin sulfate E oligosaccharide did not promote neural differentiation.•Hyaluronan oligosaccharide downregulated the expression of myelin basic protein.•Neural differentiation was regulated by specific structure of glycosaminoglycan.
Specific inhibitors of hyaluronan (HA) biosynthesis can be valuable therapeutic agents to prevent cancer invasion and metastasis. We have found previously that 4-methylumbelliferone (MU) inhibits HA ...synthesis in human skin fibroblasts and in group C Streptococcus. In this paper, the inhibition mechanism in mammalian cells was investigated using rat 3Y1 fibroblasts stably expressing HA synthase (HAS) 2. Exposure of the transfectants to the inhibitor resulted in significant reduction of HA biosynthesis and matrix formation. The evaluation of HAS transcripts and analysis of cell-free HA synthesis demonstrated the post-transcriptional suppression of HAS activity by MU. Most interesting, the post-transcriptional suppression of HAS activity was also observed using p-nitrophenol, a well known substrate for UDP-glucuronyltransferases (UGT). We investigated whether the inhibition was exerted by the glucuronidation of MU using both high pressure liquid chromatography and TLC analyses. The production of MU-glucuronic acid (GlcUA) was consistent with the inhibition of HA synthesis in HAS transfectants. MU-GlcUA was also detected at a similar level in control cells, suggesting that the glucuronidation was mediated by an endogenous UGT. Elevated levels of UGT significantly enhanced the inhibitory effects of MU. In contrast, the inhibition by MU was diminished to the control level when an excess of UDP-GlcUA was added to the cell-free HA synthesis system. We propose a novel mechanism for the MU-mediated inhibition of HA synthesis involving the glucuronidation of MU by endogenous UGT resulting in a depletion of UDP-GlcUA.
4-Methylumbelliferone (MU) inhibits the cell surface hyaluronan (HA) formation, and that such inhibition results in suppression of adhesion and locomotion of cultured melanoma cells. Here, we examine ...the effect of MU on melanoma cell metastasis in vivo. MU-treated melanoma cells showed both decreased cell surface HA formation and suppression of liver metastasis after injection into the mice. Oral administration of MU to mice decreased tissue HA content. These HA knock-down mice displayed suppressed liver metastasis. Thus, both cell surface HA of melanoma cells and recipient liver HA can promote liver metastasis, indicating that MU has potential as an anti-metastatic agent.
► Divalent metal cation binds to chondroitin sulfate with different efficiencies. ► Chondroitin sulfate metal salts as donors regulate hyaluronidase transglycosylation. ► Barium enhances the ...transglycosylation of hyaluronidase. ► Zinc inhibits the transglycosylation of hyaluronidase. ► Strong inhibitory effect of zinc is recovered by addition of EDTA.
Glycosaminoglycans were prepared as salts of different divalent cations and tested as donors in bovine testicular hyaluronidase catalyzed transglycosylation reactions. All of the metal cations examined had similar binding efficiency of divalent cations to hyaluronan. However, cations bound with different efficiencies to chondroitin sulfate species and the differences were marked in the case of chondroitin 6-sulfate; the numbers of cations bound per disaccharide unit were estimated to be 0.075 for Mn, 1.231 for Ba, 0.144 for Zn, and 0.395 for Cu. While barium salt of chondroitin sulfates enhanced transglycosylation, the zinc salt of chondroitin sulfates inhibited transglycosylation. Therefore, by selecting the proper divalent cation salt of chondroitin sulfates as a donor in the transglycosylation reaction it is possible to improve the yields of the products.
Highly purified proteoglycan (PG) extracted from the nasal cartilage of salmon heads was applied to the ex vivo expansion of hematopoietic progenitor cells prepared from human umbilical cord blood in ...serum-free cultures supplemented with the combination of early-acting cytokines, thrombopoietin (TPO), interleukin-3 (IL-3) and stem cell factor (SCF). PG showed no promoting effects on the cell proliferation rate; however, they promoted the generation of progenitor cells for granulocyte-macrophages, erythrocytes and/or megakaryocytes in culture with TPO alone or SCF plus TPO. However, no promoting effect was observed in a combination of IL-3 plus SCF, which showed the highest cell proliferation rate. PG failed to promote the generation of mixed colony-forming units (i.e. the relatively immature cells in hematopoiesis). These results suggest that PG acts on the relatively mature stem/progenitor cells, and may function as a regulatory factor in the differentiation pathway of hematopoiesis.
The structure of 4-methylumbelliferone (MU) consists of coumarin with 4-methyl group and 7-hydroxy group. MU inhibits HA synthesis and pericellular HA matrix formation. In this study, we used 10 MU ...derivatives which have hydroxy groups and methyl groups at various positions of coumarin to investigate a more effective HA inhibitor than MU. First, human pancreatic cancer cell (KP1-NL) growth assay was analyzed by Alamar Blue to determine the non-toxic concentration of MU derivatives, and the inhibitory effect on HA synthesis in the cell cultures was analyzed by HA measuring kit. Next, cell surfaces of cancer cells were analyzed by particle-exclusion assay. In conclusion, both hydroxy and methyl groups are necessary for HA inhibition by MU, and two hydroxy groups inhibited HA synthesis more strongly than MU.
Hyaluronan controls keratinocyte proliferation and regeneration. We examined effect of UV on the expression of hyaluronan synthases (HASs) and hyaluronidases in cultured normal human newborn foreskin ...epidermal keratinocytes, NHEK(F). HAS3 mRNA was expressed predominantly and HAS2 mRNA expressed in lesser amounts and both were up-regulated after a single irradiation with moderate UVB but hyaluronidases was unchanged. Increased accumulation of hyaluronan in the culture medium mirrored the UVB-induced increase in the mRNA levels of HAS3 and HAS2. Unexpectedly, hyaluronan derived from UVB-irradiated and non-irradiated cells had identical size distribution. Increased expression of KGF and IL-1β was detected just prior to the increase of HAS3 and HAS2 mRNAs after UVB irradiation. Antibody-neutralization study revealed that KGF and/or IL-1β were at least involved in the up-regulation of HAS3 and HAS2 expressions. UVB-irradiated cells may enhance hyaluronan production to maintain homeostasis through up-regulation of
HAS3 and
HAS2 genes via cytokine response mechanism.
Hyaluronan (HA) is a ubiquitous, major component of the pericellular matrix and is necessary for various physiological processes. It plays a very important role in biological barriers. We previously ...reported that 4-methylumbelliferone (MU) inhibits HA synthesis and pericellular HA matrix formation in cultured human skin fibroblasts, Streptococcus equi FM100, and B16F10 melanoma cells. We hypothesized that MU-mediated inhibition of HA synthesis and pericellular HA matrix formation would increase the efficacy of anticancer drugs. We have already demonstrated in vitro, using a sandwich binding protein assay and a particle exclusion assay, that MU inhibits HA synthesis and formation of the pericellular HA matrix, respectively, in human KP1-NL pancreatic cancer cells. AlamarBlue assay revealed that the anticancer effect of gemcitabine in KP1-NL cells was increased by pretreatment with MU. In vivo simultaneous administration of MU and gemcitabine to tumor-bearing mice with severe combined immunodeficiency disease (SCID) decreased the size of the primary and metastatic tumors more than did gemcitabine alone. These data strongly suggest that a combination of MU and gemcitabine is effective against human pancreatic cancer cells. MU may have potential as a chemosensitizer and may provide us with a new anticancer strategy.
Infection with Plasmodium falciparum during pregnancy results in the adherence of infected red blood cells (IRBCs) in placenta, causing pregnancy-associated malaria with severe health complications ...in mothers and fetuses. The chondroitin 4-sulfate (C4S) chains of very low sulfated chondroitin sulfate proteoglycans (CSPGs) in placenta mediate the IRBC adherence. While it is known that partially sulfated but not fully sulfated C4S effectively binds IRBCs, structural interactions involved remain unclear and are incompletely understood. In this study, structurally defined C4S oligosaccharides of varying sulfate contents and sizes were evaluated for their ability to inhibit the binding of IRBCs from different P. falciparum strains to CSPG purified from placenta. The results clearly show that, with all parasite strains studied, dodecasaccharide is the minimal chain length required for the efficient adherence of IRBCs to CSPG and two 4-sulfated disaccharides within this minimal structural motif are sufficient for maximal binding. Together, these data demonstrate for the first time that the C4S structural requirement for IRBC adherence is parasite strain-independent. We also show that the carboxyl group on nonreducing end glucuronic acid in dodecasaccharide motif is important for IRBC binding. Thus, in oligosaccharides containing terminal 4,5-unsaturated glucuronic acid, the nonreducing end disaccharide moiety does not interact with IRBCs due to the altered spatial orientation of carboxyl group. In such C4S oligosaccharides, 14-mer but not 12-mer constitutes the minimal motif for inhibition of IRBC binding to placental CSPG. These data have important implications for the development and evaluation of therapeutics and vaccine for placental malaria.
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