Chondroitin 4-O-sulfotransferase-1 regulates the chain length of chondroitin sulfate in co-operation with chondroitin N-acetylgalactosaminyltransferase-2

2011 ◽  
Vol 434 (2) ◽  
pp. 321-331 ◽  
Author(s):  
Tomomi Izumikawa ◽  
Yuka Okuura ◽  
Toshiyasu Koike ◽  
Naoki Sakoda ◽  
Hiroshi Kitagawa
Keyword(s):  
Enzyme Activity ◽  
Chondroitin Sulfate ◽  
Chain Length ◽  
Critical Role ◽  
Enzymatic Activities ◽  
Cell Mutant ◽  
Expression Levels ◽  
L Cells ◽  
L Cell ◽  
Mutant Cells

Previously, we demonstrated that sog9 cells, a murine L cell mutant, are deficient in the expression of C4ST (chondroitin 4-O-sulfotransferase)-1 and that they synthesize fewer and shorter CS (chondroitin sulfate) chains. These results suggested that C4ST-1 regulates not only 4-O-sulfation of CS, but also the length and amount of CS chains; however, the mechanism remains unclear. In the present study, we have demonstrated that C4ST-1 regulates the chain length and amount of CS in co-operation with ChGn-2 (chondroitin N-acetylgalactosaminyltransferase 2). Overexpression of ChGn-2 increased the length and amount of CS chains in L cells, but not in sog9 mutant cells. Knockdown of ChGn-2 resulted in a decrease in the amount of CS in L cells in a manner proportional to ChGn-2 expression levels, whereas the introduction of mutated C4ST-1 or ChGn-2 lacking enzyme activity failed to increase the amount of CS. Furthermore, the non-reducing terminal 4-O-sulfation of N-acetylgalactosamine residues facilitated the elongation of CS chains by chondroitin polymerase consisting of chondroitin synthase-1 and chondroitin-polymerizing factor. Overall, these results suggest that the chain length of CS is regulated by C4ST-1 and ChGn-2 and that the enzymatic activities of these proteins play a critical role in CS elongation.

Analysis of CD44 interactions with hyaluronan in murine L cell fibroblasts deficient in glycosaminoglycan synthesis: a role for chondroitin sulfate

1998 ◽  
Vol 111 (7) ◽  
pp. 1021-1029
Author(s):  
L.E. Esford ◽  
A. Maiti ◽  
S.A. Bader ◽  
F. Tufaro ◽  
P. Johnson
Keyword(s):  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Sodium Chlorate ◽  
Post Translational Modification ◽  
Binding Ability ◽  
Glycosaminoglycan Synthesis ◽  
L Cells ◽  
L Cell ◽  
Oligosaccharide Processing ◽  
Hyaluronan Binding

CD44 is a widely expressed cell adhesion molecule that binds the extracellular matrix component, hyaluronan, in a tightly regulated manner. Previous studies have shown that the CD44-hyaluronan interaction is affected by changes in the glycosylation state of CD44. In this study, we take advantage of several well-characterized murine L cell mutants defective in heparan sulfate synthesis (gro2C cells), heparan sulfate and chondroitin sulfate synthesis (sog9 cells), and glycosaminoglycan and oligosaccharide processing (sog8 cells) to assess the effects of these defects on the hyaluronan binding ability of CD44. In parental L cells and gro2C cells, CD44 was induced to bind hyaluronan after addition of the activating, anti-CD44 monoclonal antibody, IRAWB 14. By contrast, no inducible binding was observed in sog9 cells. Treatment of L cells with sodium chlorate, an inhibitor of sulfation, also abolished inducible hyaluronan binding. However, inducible and some constitutive hyaluronan binding was observed in sog8 cells. This indicates that sulfation and, in particular, the addition of chondroitin sulfate are required for inducible hyaluronan binding by CD44 in L cells. However, in the absence of fully processed oligosaccharides, chondroitin sulfate is not essential for hyaluronan binding, indicating that the effect of chondroitin sulfate is dependent upon the glycosylation state of the cell. Thus, in addition to glycosylation, chondroitin sulfate biosynthesis is an important post-translational modification that can affect the hyaluronan binding ability of CD44.

scholarly journals Sarcalumenin is essential for maintaining cardiac function during endurance exercise training

2009 ◽  
Vol 297 (2) ◽  
pp. H576-H582 ◽  
Author(s):  
Qibin Jiao ◽  
Yunzhe Bai ◽  
Toru Akaike ◽  
Hiroshi Takeshima ◽  
Yoshihiro Ishikawa ◽  
...  
Keyword(s):  
Exercise Training ◽  
Cardiac Function ◽  
Endurance Exercise ◽  
Maximal Exercise ◽  
Storage System ◽  
Critical Role ◽  
Pressure Overload ◽  
Sodium Calcium Exchanger ◽  
Expression Levels ◽  
Echocardiographic Examination

Sarcalumenin (SAR), a Ca2+-binding protein located in the longitudinal sarcoplasmic reticulum (SR), regulates Ca2+ reuptake into the SR by interacting with cardiac sarco(endo)plasmic reticulum Ca2+-ATPase 2a (SERCA2a). We have previously demonstrated that SAR deficiency induced progressive heart failure in response to pressure overload, despite mild cardiac dysfunction in sham-operated SAR knockout (SARKO) mice ( 26 ). Since responses to physiological stresses often differ from those to pathological stresses, we examined the effects of endurance exercise on cardiac function in SARKO mice. Wild-type (WT) and SARKO mice were subjected to endurance treadmill exercise training (∼65% of maximal exercise ability for 60 min/day) for 12 wk. After exercise training, maximal exercise ability was significantly increased by 5% in WT mice ( n = 6), whereas it was significantly decreased by 37% in SARKO mice ( n = 5). Cardiac function assessed by echocardiographic examination was significantly decreased in accordance with upregulation of biomarkers of cardiac stress in SARKO mice after training. After training, expression levels of SERCA2a protein were significantly downregulated by 30% in SARKO hearts, whereas they were significantly upregulated by 59% in WT hearts. Consequently, SERCA2 activity was significantly decreased in SARKO hearts after training. Furthermore, the expression levels of other Ca2+-handling proteins, including phospholamban, ryanodine receptor 2, calsequestrin 2, and sodium/calcium exchanger 1, were significantly decreased in SARKO hearts after training. These results indicate that SAR plays a critical role in maintaining cardiac function under physiological stresses, such as endurance exercise, by regulating Ca2+ transport activity into the SR. SAR may be a primary target for exercise-related adaptation of the Ca2+ storage system in the SR to preserve cardiac function.

scholarly journals ATM loss leads to synthetic lethality in BRCA1 BRCT mutant mice associated with exacerbated defects in homology-directed repair

2017 ◽  
Vol 114 (29) ◽  
pp. 7665-7670 ◽  
Author(s):  
Chun-Chin Chen ◽  
Elizabeth M. Kass ◽  
Wei-Feng Yen ◽  
Thomas Ludwig ◽  
Mary Ellen Moynahan ◽  
...  
Keyword(s):  
Synthetic Lethality ◽  
Critical Role ◽  
Nonhomologous End Joining ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Atm Kinase ◽  
Strand Breaks ◽  
Homology Directed Repair ◽  
Dna Damage Signaling ◽  
Mutant Cells

BRCA1 is essential for homology-directed repair (HDR) of DNA double-strand breaks in part through antagonism of the nonhomologous end-joining factor 53BP1. The ATM kinase is involved in various aspects of DNA damage signaling and repair, but how ATM participates in HDR and genetically interacts with BRCA1 in this process is unclear. To investigate this question, we used the Brca1S1598F mouse model carrying a mutation in the BRCA1 C-terminal domain of BRCA1. Whereas ATM loss leads to a mild HDR defect in adult somatic cells, we find that ATM inhibition leads to severely reduced HDR in Brca1S1598F cells. Consistent with a critical role for ATM in HDR in this background, loss of ATM leads to synthetic lethality of Brca1S1598F mice. Whereas both ATM and BRCA1 promote end resection, which can be regulated by 53BP1, 53bp1 deletion does not rescue the HDR defects of Atm mutant cells, in contrast to Brca1 mutant cells. These results demonstrate that ATM has a role in HDR independent of the BRCA1–53BP1 antagonism and that its HDR function can become critical in certain contexts.

Migrating Progenitor Cells Derived From Injured Cartilage Surface Respond to Damage-Associated Molecular Patterns

Cartilage ◽  
2021 ◽  
pp. 194760352110495
Author(s):  
Lei Ding ◽  
Cheng Zhou ◽  
Hongjun Zheng ◽  
Quanming Wang ◽  
Haiyan Song ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Progenitor Cells ◽  
Quantitative Polymerase Chain Reaction ◽  
Critical Role ◽  
Cartilage Degeneration ◽  
Expression Levels ◽  
Chondrogenic Progenitor Cells ◽  
The Difference ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Objective: To delineate the response of migrating chondrogenic progenitor cells (CPCs) that arose from the surface of mechanically injured articular cartilage to proinflammatory damage-associated-molecular-patterns (DAMPs). Design: Bovine CPCs and non-CPC chondrocytes isolated from either impacted or scratched articular cartilage were studied. Those 2 types of cells were treated with mitochondrial DAMPs (MTDs; 10 nM fMLF and 10 µg/mL CpG DNA), or 10 nM HMGB1, or 10 ng/mL IL-1b for 24 hours. At the end of experiments, conditioned media and cell lysates were collected for analysis of expression levels of matrix metalloproteinases (MMPs), chemokines, and cytokines that are associated with cartilage degeneration with Western blotting and quantitative polymerase chain reaction. The difference of expression levels was compared by Welch’s t-test. Results: Our data indicated that HMGB1 and MTDs remarkably upregulated pro-MMP-13 expression in CPCs. Compared with non-CPCs, CPCs expressed significantly more baseline mRNAs of MMP-13, CXCL12, and IL-6. MTDs greatly increased the expression of MMP-13 and IL-6 in CPCs by over 100-fold ( P < 0.001). MTDs also significantly increased IL-8 expression in CPCs to a similar extent ( P < 0.001). However, when IL-1b was present, CPCs expressed less MMP-3 and active MMP-13 proteins as well as less CCL2 and IL-6 than did non-CPCs. Conclusions: We concluded that CPCs were more sensitive than non-CPCs in response to DAMPs, especially MTDs. The proinflammatory nature of CPCs implied their critical role in the early phase of posttraumatic osteoarthritis development.

Generation and Maintenance of Immune Interferon-Producing Cells Induced by Allogeneic Stimulation in Mice

1980 ◽  
Vol 29 (2) ◽  
pp. 383-389
Author(s):  
Yasuhiko Ito ◽  
Hiizu Aoki ◽  
Yoshinobu Kimura ◽  
Michiko Takano ◽  
Koichiro Maeno ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Culture Fluid ◽  
Suppressive Effect ◽  
Interferon Production ◽  
Spleen Cells ◽  
Immune Interferon ◽  
L Cells ◽  
L Cell ◽  
Interferon Activity ◽  
Allogeneic Stimulation

When spleen cells derived from C57BL/6 mice immunized with L cells 7 days previously were cocultured with antigenic cells, immune interferon appeared in the culture fluid. We analyzed the tissue distribution of the immune interferon-producing cells (IIPC) which appeared in various lymphoid organs after allogeneic stimulation. Although fluid from cocultures of L-cell-sensitized thymocytes and L-cells could not detect interferon activity consistently, small numbers of IIPC could be detected by using the enumeration method of IIPC. The generation, maintenance, and nature of IIPC emerging in the spleen were different depending on how the host mice were immunized. Multiple antigenic stimulations were more effective and induced longer-lasting immune interferon production than a single stimulation. IIPC induced by a single stimulation appeared to be sensitive to cortisone, vinblastine, and cyclophosphamide and were relatively short lived. In contrast, IIPC induced by multiple stimulations seemed to be partially resistant to these drugs and long lived. When mice were immunized with intact L-cells, carrageenan, a known antimacrophage agent, had no effect on immune interferon production. However, when mice were immunized with solubilized L-cell antigen, this drug displayed a suppressive effect on immune interferon production.

scholarly journals Chondroitin Sulfate N-Acetylgalactosaminyltransferase-1 Plays a Critical Role in Chondroitin Sulfate Synthesis in Cartilage

2007 ◽  
Vol 282 (6) ◽  
pp. 4152-4161 ◽  
Author(s):  
Kenichiro Sakai ◽  
Koji Kimata ◽  
Takashi Sato ◽  
Masanori Gotoh ◽  
Hisashi Narimatsu ◽  
...  
Keyword(s):  
Chondroitin Sulfate ◽  
Critical Role

scholarly journals Use of immobilized lactoperoxidase to label L cell proteins involved in adhesion to polystyrene.

1980 ◽  
Vol 85 (2) ◽  
pp. 402-413 ◽  
Author(s):  
N W Chin ◽  
K W Lanks
Keyword(s):  
Molecular Weight ◽  
Tissue Culture ◽  
Broad Spectrum ◽  
Peptide Mapping ◽  
Limited Proteolysis ◽  
Functional Association ◽  
One Dimensional ◽  
L Cells ◽  
L Cell ◽  
10 Nm Filaments

Proteins involved in the attachment of murine L cells to polystyrene have been identified by a technique designed to iodinate only those macromolecules coming into closet apposition to the substratum. Whereas soluble lactoperoxidase (LPO) catalyzes the radioiodination of a broad spectrum of polypeptides, the same enzyme immobilized on polystyrene tissue culture flasks discriminately labels 55,000 and 42,000 mol wt polypeptides that adhere tightly to the substratum after the cells are removed. One-dimensional peptide mapping following limited proteolysis showed that the labeled 55,000 mol wt polypeptide is similar to a component of comparable molecular weight present in the detergent-extracted cytoskeleton. The functional association of two cytoskeletal structures, presumably 10-nm filaments and actin, is discussed, and alternative explanations for their susceptibility to iodination by immobilized LPO are presented.

scholarly journals Gestational methyl donor deficiency alters key proteins involved in neurosteroidogenesis in the olfactory bulbs of newborn female rats and is associated with impaired olfactory performance

2013 ◽  
Vol 111 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
Sarah El Hajj Chehadeh ◽  
Grégory Pourié ◽  
Nicolas Martin ◽  
Jean-Marc Alberto ◽  
Jean-Luc Daval ◽  
...  
Keyword(s):  
Growth Retardation ◽  
Critical Role ◽  
Regulatory Protein ◽  
Olfactory Discrimination ◽  
Female Rats ◽  
Dependent Manner ◽  
Olfactory Bulbs ◽  
Control Female ◽  
Expression Levels ◽  
Methyl Donor

Gestational methyl donor deficiency (MDD) leads to growth retardation as well as to cognitive and motor disorders in 21-d-old rat pups. These disorders are related to impaired neurogenesis in the cerebral neurogenic areas. Olfactory bulbs (OB), the main target of neuronal progenitors originating from the subventricular zone, play a critical role during the postnatal period by allowing the pups to identify maternal odour. We hypothesised that growth retardation could result from impaired suckling due to impaired olfactory discrimination through imbalanced apoptosis/neurogenesis in the OB. Since neurosteroidogenesis modulates neurogenesis in OB, in the present study, we investigated whether altered neurosteroidogenesis could explain some these effects. Pups born to dams fed a normal diet (n 24) and a MDD diet (n 27) were subjected to olfactory tests during the lactation and weaning periods (n 24 and 20, respectively). We studied the markers of apoptosis/neurogenesis and the expression levels of the key neurosteroidogenic enzyme aromatase, the cholesterol-transfer protein StAR (steroidogenic acute regulatory protein) and the ERα oestrogen receptor and the content of oestradiol in OB. The 21-d-old MDD female pups displayed lower body weight and impaired olfactory discrimination when compared with the control pups. MDD led to greater homocysteine accumulation and more pronounced apoptosis, along with impaired cell proliferation in the OB of female pups. The expression levels of aromatase, StAR and ERα as well as the content of oestradiol were lower in the OB of the MDD female pups than in those of the control female pups. In conclusion, gestational MDD may alter olfactory discrimination performances by affecting neurogenesis, apoptosis and neurosteroidogenesis in OB in a sex-dependent manner. It may be involved in growth retardation through impaired suckling.

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