heparitin-sulfate and Endotoxemia

Sepsis is a lethal syndrome manifested by an unregulated, overwhelming inflammation from the host in response to infection. Here, we exploit the use of a synthetic heparan sulfate octadecasaccharide (18-mer) to protect against sepsis. The 18-mer not only inhibits the pro-inflammatory activity of extracellular histone H3 and high mobility group box 1 (HMGB1), but also elicits the anti-inflammatory effect from apolipoprotein A-I (ApoA-I). We demonstrate that the 18-mer protects against sepsis-related injury and improves survival in cecal ligation and puncture mice and reduces inflammation in an endotoxemia mouse model. The 18-mer neutralizes the cytotoxic histone-3 (H3) through direct interaction with the protein. Furthermore, the 18-mer enlists the actions of ApoA-I to dissociate the complex of HMGB1 and lipopolysaccharide, a toxic complex contributing to cell death and tissue damage in sepsis. Our study provides strong evidence that the 18-mer mitigates inflammatory damage in sepsis by targeting numerous mediators, setting it apart from other potential therapies with a single target.

Topics: Animals; Apolipoprotein A-I; Disease Models, Animal; Endotoxemia; Heparitin Sulfate; HMGB1 Protein; Lipopolysaccharides; Mice; Sepsis

Sepsis, a systemic inflammatory response to infection, commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity. We postulated that sepsis-associated ALI is initiated by degradation of the pulmonary endothelial glycocalyx, leading to neutrophil adherence and inflammation. Using intravital microscopy, we found that endotoxemia in mice rapidly induced pulmonary microvascular glycocalyx degradation via tumor necrosis factor-α (TNF-α)-dependent mechanisms. Glycocalyx degradation involved the specific loss of heparan sulfate and coincided with activation of endothelial heparanase, a TNF-α-responsive, heparan sulfate-specific glucuronidase. Glycocalyx degradation increased the availability of endothelial surface adhesion molecules to circulating microspheres and contributed to neutrophil adhesion. Heparanase inhibition prevented endotoxemia-associated glycocalyx loss and neutrophil adhesion and, accordingly, attenuated sepsis-induced ALI and mortality in mice. These findings are potentially relevant to human disease, as sepsis-associated respiratory failure in humans was associated with higher plasma heparan sulfate degradation activity; moreover, heparanase content was higher in human lung biopsies showing diffuse alveolar damage than in normal human lung tissue.

Topics: Acute Lung Injury; Adoptive Transfer; Animals; Cell Adhesion; Disease Models, Animal; Endothelium; Endotoxemia; Enzyme Activation; Gene Expression Regulation; Glucuronidase; Glycocalyx; Heparitin Sulfate; Humans; Intercellular Adhesion Molecule-1; Intestinal Perforation; Lipopolysaccharides; Lung; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Pulmonary Alveoli; Receptors, Tumor Necrosis Factor, Type I; Respiratory Insufficiency; Tumor Necrosis Factor-alpha; Ventilator-Induced Lung Injury

Increased vascular permeability is a characteristic feature of sepsis which, in the past, has been ascribed exclusively to a malfunction of endothelial cells. However, recently it has become evident that the endothelial glycocalyx is of considerable importance concerning various aspects of vascular physiology, e.g. the vascular barrier and inflammation. Heparan sulfate, one of its essential components is characteristically traceable in blood, in case the endothelial glycocalyx is damaged or destroyed.. In 15 pigs we investigated whether the administration of endotoxin from gram-negative bacteria (Escherichia coli) results in increased serum levels of heparan sulfate, signalizing a shedding of the glycocalyx. In addition, markers of inflammation (white blood cell count, platelet count, tumour necrosis factor-α and interleukin-6) were evaluated over an observation period of 6 hours.. Serum heparan sulfate concentrations significantly increased over time in the endotoxin group and were significantly elevated in comparison to the control group 6 hours after administration of endotoxin (p<0.001). In the endotoxin group all markers of inflammation significantly changed during the time course.. The administration of bacterial endotoxin induced a significant rise in degradation products of the endothelial glycocalyx.

Topics: Animals; Endothelium, Vascular; Endotoxemia; Endotoxins; Glycocalyx; Heparitin Sulfate; Swine

Anticoagulant therapy attracts much attention for the treatment of severe sepsis since recent studies have revealed that some anticoagulants have the ability to regulate the inflammatory response. The purpose of this study was to examine whether danaparoid sodium (DA) is effective for the treatment of organ dysfunction in sepsis.. Sixty-four Wistar rats were intravenously injected with 5.0 mg/kg of lipopolysaccharide (LPS) and then divided into two groups: the DA group and the control group (n = 32 each). The DA group was injected intravenously with 400 U/kg of DA immediately after LPS injection, whereas the control group received saline. Blood samples were drawn at 1, 6, 12, and 24 hours after LPS injection, and organ damage markers and coagulation markers were measured. In the other series, 10 rats treated with LPS were divided into DA and control groups (n = 5 each). Blood samples were collected at 1, 3, and 6 hours after LPS injection and served for the cytokine measurements.. The elevation of the organ damage markers, such as alanine aminotransferase and lactate dehydrogenase, was significantly suppressed in the DA group. Coagulation markers, such as AT activity and fibrinogen levels, were maintained better in the DA group at 6 hours. The elevation of proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1, and IL-6 was significantly suppressed in the DA group. On the other hand, there was no significant difference in anti-inflammatory cytokines such as IL-4 and IL-10.. DA preserves the organ dysfunction in LPS-challenged rats. Although the mechanism is not fully elucidated, not only the improvement of coagulation disorder but also the regulation of circulating levels of proinflammatory cytokines may play a role in the mechanism.

Topics: Animals; Chondroitin Sulfates; Cytokines; Dermatan Sulfate; Endotoxemia; Heparitin Sulfate; Inflammation Mediators; Lipopolysaccharides; Multiple Organ Failure; Rats; Rats, Wistar