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Glycosaminoglycan analogs as a novel anti-inflammatory strategy.

Severin IC, Soares A, Hantson J, Teixeira M, Sachs D, Valognes D, Scheer A, Schwarz MK, Wells TN, Proudfoot AE, Shaw J - Front Immunol (2012)

Bottom Line: In vitro, these molecules prevented chemokine-GAG binding and chemokine receptor activation without disrupting coagulation.However, in vivo, these compounds caused variable results in a murine peritoneal recruitment assay, with a general increase of cell recruitment.In more disease specific models, such as antigen-induced arthritis and delayed-type hypersensitivity, an overall decrease in inflammation was noted, suggesting that the primary anti-inflammatory effect may also involve factors beyond the chemokine system.

View Article: PubMed Central - PubMed

Affiliation: Merck Serono Geneva Research Centre Geneva, Switzerland.

ABSTRACT
Heparin, a glycosaminoglycan (GAG), has both anti-inflammatory and anti-coagulant properties. The clinical use of heparin against inflammation, however, has been limited by concerns about increased bleeding. While the anti-coagulant activity of heparin is well understood, its anti-inflammatory properties are less so. Heparin is known to bind to certain cytokines, including chemokines, small proteins which mediate inflammation through their control of leukocyte migration and activation. Molecules which can interrupt the chemokine-GAG interaction without inhibiting coagulation could therefore, represent a new class of anti-inflammatory agents. In the present study, two approaches were undertaken, both focusing on the heparin-chemokine relationship. In the first, a structure based strategy was used: after an initial screening of potential small molecule binders using protein NMR on a target chemokine, binding molecules were optimized through structure-based design. In the second approach, commercially available short oligosaccharides were polysulfated. In vitro, these molecules prevented chemokine-GAG binding and chemokine receptor activation without disrupting coagulation. However, in vivo, these compounds caused variable results in a murine peritoneal recruitment assay, with a general increase of cell recruitment. In more disease specific models, such as antigen-induced arthritis and delayed-type hypersensitivity, an overall decrease in inflammation was noted, suggesting that the primary anti-inflammatory effect may also involve factors beyond the chemokine system.

No MeSH data available.


Related in: MedlinePlus

Crystallographic structure of CCL5 (A) with Molecules 1 and 2 bound. The contents of the asymmetric unit are displayed, showing the distance between the two molecules binding to the protein. (B) binding site of Molecules 1 and 2. The binding pocket for Molecule 2 is the same as in panel 2A, but Molecule 1, and its associated binding pocket are from a symmetry-related dimer. The distance between the two molecules in thus only 10 Å, compared to over 30 Å in panel 2A.
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Figure 2: Crystallographic structure of CCL5 (A) with Molecules 1 and 2 bound. The contents of the asymmetric unit are displayed, showing the distance between the two molecules binding to the protein. (B) binding site of Molecules 1 and 2. The binding pocket for Molecule 2 is the same as in panel 2A, but Molecule 1, and its associated binding pocket are from a symmetry-related dimer. The distance between the two molecules in thus only 10 Å, compared to over 30 Å in panel 2A.

Mentions: The structure of Molecule 1 complexed to CCL5 was obtained at a resolution of 1.8 Å (see Figure 2A). The complex crystallized in the same crystal form as the wild-type protein, with two monomers (called monomer A and B) in the asymmetric unit. With the exception of the extreme N- and C-termini, the protein structure is essentially the same as that of the wild-type protein. However, the analysis of the structure revealed that the two copies of Molecule 1 in the structure were not identical, and that one of the two molecules was actually a minor contaminant (<0.5%) of the original batch of Molecule 1. Molecule 1 was found in close proximity to a surface loop composed of residues Ser31A-Gly32A-Lys33 (hereafter called the 30s pocket; see Figure 2A). The sulfonate group of Molecule 1 forms two hydrogen bonds with the main chain nitrogen of Gly32A (3.0 Å and 3.3 Å), while the carboxylate group of Molecule 1 forms a hydrogen bond with the Lys33A sidechain (2.8 Å). The hydroxyl group of Molecule 1 forms a hydrogen bond with a crystallographic symmetry-related monomer of CCL5 to the main chain carbonyl group of Pro18A (3.2 Å). Molecule 2 (see Figure 1A) is the minor contaminant identified in the crystal structure, and binds to a pocket on monomer A composed of residues Thr43A to Arg47A (hereafter called the 40s pocket; see Figure 2B). The sulfonate group of Molecule 2 forms a hydrogen bond with Thr43A (2.5 Å), and a relatively weak one with Arg47A side chain (3.5 Å). The hydroxyl group of Molecule 2 forms a hydrogen bond with Thr43A (3.1 Å). While in the same asymmetric unit, Molecules 1 and 2 are fairly distant from one another (~25 Å), they are relatively close when a crystallographic symmetry-related molecule of CCL5 is included (~10 Å). It is this proximity that suggested that the linking of Molecules 1 and 2 might engender a molecule with much higher potency than either of the individual molecules, since they may be acting as two-independent GAG monomers. Consequently, attempts were made to optimize Molecules 1 and 2 for their respective pockets, and subsequently to link them.


Glycosaminoglycan analogs as a novel anti-inflammatory strategy.

Severin IC, Soares A, Hantson J, Teixeira M, Sachs D, Valognes D, Scheer A, Schwarz MK, Wells TN, Proudfoot AE, Shaw J - Front Immunol (2012)

Crystallographic structure of CCL5 (A) with Molecules 1 and 2 bound. The contents of the asymmetric unit are displayed, showing the distance between the two molecules binding to the protein. (B) binding site of Molecules 1 and 2. The binding pocket for Molecule 2 is the same as in panel 2A, but Molecule 1, and its associated binding pocket are from a symmetry-related dimer. The distance between the two molecules in thus only 10 Å, compared to over 30 Å in panel 2A.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472544&req=5

Figure 2: Crystallographic structure of CCL5 (A) with Molecules 1 and 2 bound. The contents of the asymmetric unit are displayed, showing the distance between the two molecules binding to the protein. (B) binding site of Molecules 1 and 2. The binding pocket for Molecule 2 is the same as in panel 2A, but Molecule 1, and its associated binding pocket are from a symmetry-related dimer. The distance between the two molecules in thus only 10 Å, compared to over 30 Å in panel 2A.
Mentions: The structure of Molecule 1 complexed to CCL5 was obtained at a resolution of 1.8 Å (see Figure 2A). The complex crystallized in the same crystal form as the wild-type protein, with two monomers (called monomer A and B) in the asymmetric unit. With the exception of the extreme N- and C-termini, the protein structure is essentially the same as that of the wild-type protein. However, the analysis of the structure revealed that the two copies of Molecule 1 in the structure were not identical, and that one of the two molecules was actually a minor contaminant (<0.5%) of the original batch of Molecule 1. Molecule 1 was found in close proximity to a surface loop composed of residues Ser31A-Gly32A-Lys33 (hereafter called the 30s pocket; see Figure 2A). The sulfonate group of Molecule 1 forms two hydrogen bonds with the main chain nitrogen of Gly32A (3.0 Å and 3.3 Å), while the carboxylate group of Molecule 1 forms a hydrogen bond with the Lys33A sidechain (2.8 Å). The hydroxyl group of Molecule 1 forms a hydrogen bond with a crystallographic symmetry-related monomer of CCL5 to the main chain carbonyl group of Pro18A (3.2 Å). Molecule 2 (see Figure 1A) is the minor contaminant identified in the crystal structure, and binds to a pocket on monomer A composed of residues Thr43A to Arg47A (hereafter called the 40s pocket; see Figure 2B). The sulfonate group of Molecule 2 forms a hydrogen bond with Thr43A (2.5 Å), and a relatively weak one with Arg47A side chain (3.5 Å). The hydroxyl group of Molecule 2 forms a hydrogen bond with Thr43A (3.1 Å). While in the same asymmetric unit, Molecules 1 and 2 are fairly distant from one another (~25 Å), they are relatively close when a crystallographic symmetry-related molecule of CCL5 is included (~10 Å). It is this proximity that suggested that the linking of Molecules 1 and 2 might engender a molecule with much higher potency than either of the individual molecules, since they may be acting as two-independent GAG monomers. Consequently, attempts were made to optimize Molecules 1 and 2 for their respective pockets, and subsequently to link them.

Bottom Line: In vitro, these molecules prevented chemokine-GAG binding and chemokine receptor activation without disrupting coagulation.However, in vivo, these compounds caused variable results in a murine peritoneal recruitment assay, with a general increase of cell recruitment.In more disease specific models, such as antigen-induced arthritis and delayed-type hypersensitivity, an overall decrease in inflammation was noted, suggesting that the primary anti-inflammatory effect may also involve factors beyond the chemokine system.

View Article: PubMed Central - PubMed

Affiliation: Merck Serono Geneva Research Centre Geneva, Switzerland.

ABSTRACT
Heparin, a glycosaminoglycan (GAG), has both anti-inflammatory and anti-coagulant properties. The clinical use of heparin against inflammation, however, has been limited by concerns about increased bleeding. While the anti-coagulant activity of heparin is well understood, its anti-inflammatory properties are less so. Heparin is known to bind to certain cytokines, including chemokines, small proteins which mediate inflammation through their control of leukocyte migration and activation. Molecules which can interrupt the chemokine-GAG interaction without inhibiting coagulation could therefore, represent a new class of anti-inflammatory agents. In the present study, two approaches were undertaken, both focusing on the heparin-chemokine relationship. In the first, a structure based strategy was used: after an initial screening of potential small molecule binders using protein NMR on a target chemokine, binding molecules were optimized through structure-based design. In the second approach, commercially available short oligosaccharides were polysulfated. In vitro, these molecules prevented chemokine-GAG binding and chemokine receptor activation without disrupting coagulation. However, in vivo, these compounds caused variable results in a murine peritoneal recruitment assay, with a general increase of cell recruitment. In more disease specific models, such as antigen-induced arthritis and delayed-type hypersensitivity, an overall decrease in inflammation was noted, suggesting that the primary anti-inflammatory effect may also involve factors beyond the chemokine system.

No MeSH data available.


Related in: MedlinePlus