A fully human anti-BMP6 antibody reduces the need for erythropoietin in rodent models of the anemia of chronic disease.

Recombinant erythropoietin (EPO) and iron substitution are a standard of care for treatment of anemias associated with chronic inflammation, including anemia of chronic kidney disease. A black box warning for EPO therapy and concerns about negative side effects related to high-dose iron supplementation as well as the significant proportion of patients becoming EPO resistant over time explains the medical need to define novel strategies to ameliorate anemia of chronic disease (ACD). As hepcidin is central to the iron-restrictive phenotype in ACD, therapeutic approaches targeting hepcidin were recently developed. We herein report the therapeutic effects of a fully human anti-BMP6 antibody (KY1070) either as monotherapy or in combination with Darbepoetin alfa on iron metabolism and anemia resolution in 2 different, well-established, and clinically relevant rodent models of ACD. In addition to counteracting hepcidin-driven iron limitation for erythropoiesis, we found that the combination of KY1070 and recombinant human EPO improved the erythroid response compared with either monotherapy in a qualitative and quantitative manner. Consequently, the combination of KY1070 and Darbepoetin alfa resulted in an EPO-sparing effect. Moreover, we found that suppression of hepcidin via KY1070 modulates ferroportin expression on erythroid precursor cells, thereby lowering potentially toxic-free intracellular iron levels and by accelerating erythroid output as reflected by increased maturation of erythrocyte progenitors. In summary, we conclude that treatment of ACD, as a highly complex disease, becomes more effective by a multifactorial therapeutic approach upon mobilization of endogenous iron deposits and stimulation of erythropoiesis.

Inhibition of arthritis in the Lewis rat by apolipoprotein A-I and reconstituted high-density lipoproteins.

OBJECTIVE: This study questions whether high-density lipoproteins (HDLs) and apolipoprotein A-I inhibit joint inflammation in streptococcal cell wall peptidoglycan-polysaccharide (PG-PS)-induced arthritis in female Lewis rats. APPROACH AND RESULTS: Administration of PG-PS to female Lewis rats caused acute joint inflammation after 4 days, followed by remission by day 8. The animals subsequently developed chronic joint inflammation that persisted until euthanasia at day 21. Treatment with apolipoprotein A-I 24 hours before and 24 hours after PG-PS administration reduced the acute and chronic joint inflammation. Treatment with apolipoprotein A-I at days 7, 9, and 11 after PG-PS administration reduced the chronic joint inflammation. Treatment with apolipoprotein A-I or reconstituted HDLs consisting of apolipoprotein A-I complexed with phosphatidylcholine 24 hours before and at days 1, 7, 9, and 11 after PG-PS administration reduced acute and chronic joint inflammation. Treatment with apolipoprotein A-I also reduced the inflammatory white blood cell count, synovial fluid proinflammatory cytokine levels, synovial tissue macrophage accumulation, as well as toll-like receptor 2, and inflammatory cytokine expression. At the molecular level, preincubation of human monocyte-derived macrophages with apolipoprotein A-I or reconstituted HDLs before PG-PS stimulation inhibited the PG-PS-induced increase in toll-like receptor 2 and myeloid differentiation primary response gene (88) mRNA levels, nuclear factor-κB activation, and proinflammatory cytokine production. The effects of apolipoprotein A-I and reconstituted HDLs were abolished by transfecting the human monocyte-derived macrophages with ATP-binding cassette transporter A1 or G1 siRNA. CONCLUSIONS: Apolipoprotein A-I and reconstituted HDLs attenuate PG-PS-induced arthritis in the rat. Studies in human monocyte-derived macrophages indicate that this benefit may be because of the inhibition of toll-like receptor 2 expression and decreased nuclear factor-κB activation in macrophages.

Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

Genotoxicity studies of PolyGlycopleX (PGX): a novel dietary fiber.

PolyGlycopleX (PGX), a novel dietary fiber, produces no mutagenic effects in bacterial tester strains Salmonella typhimurium TA 98, TA 100, TA 1535, and TA 1537 and Escherichia coli WP2 uvrA at concentrations of 0.316, 1.00, 3.16, 10.0, 31.6, and 100 microg/plate. No biologically relevant increases in revertant colonies of any of the 5 strains are observed at any concentration; however, a reduction at 100 microg/plate in TA 1537 is noted. PGX, analyzed for polychromatic erythrocyte micronuclei induction in mice following a single 1x, 0.5x, and 0.2x maximum tolerable dose intraperitoneal treatment, produces no biologically relevant increase in any dose group. Males at 1x maximum tolerable dose show a reduction of micronuclei-containing cells. High-dose animals show signs of systemic toxicity, including a reduction of spontaneous activity, rough fur, palpebral closure, prone position, and constricted abdomen. These genotoxicity studies show PGX to be nonmutagenic in both the Ames bacterial reverse mutation assay and the mammalian erythrocyte micronucleus test.

Dietary glycine prevents peptidoglycan polysaccharide-induced reactive arthritis in the rat: role for glycine-gated chloride channel.

Peptidoglycan polysaccharide (PG-PS) is a primary structural component of bacterial cell walls and causes rheumatoid-like arthritis in rats. Recently, glycine has been shown to be a potential immunomodulator; therefore, the purpose of this study was to determine if glycine would be protective in a PG-PS model of arthritis in vivo. In rats injected with PG-PS intra-articularly, ankle swelling increased 21% in 24 to 48 h and recovered in about 2 weeks. Three days prior to reactivation with PG-PS given intravenously (i.v.), rats were divided into two groups and fed a glycine-containing or nitrogen-balanced control diet. After i.v. PG-PS treatment joint swelling increased 2.1 +/- 0.3 mm in controls but only 1.0 +/- 0.2 mm in rats fed glycine. Infiltration of inflammatory cells, edema, and synovial hyperplasia in the joint were significantly attenuated by dietary glycine. Tumor necrosis factor alpha (TNF-alpha) mRNA was detected in ankle homogenates from rats fed the control diet but not in ankles from rats fed glycine. Moreover, intracellular calcium was increased significantly in splenic macrophages treated with PG-PS; however, glycine blunted the increase about 50%. The inhibitory effect of glycine was reversed by low concentrations of strychnine or chloride-free buffer, and it increased radiolabeled chloride influx nearly fourfold, an effect also inhibited by strychnine. In isolated splenic macrophages, glycine blunted translocation of the p65 subunit of NF-kappaB into the nucleus, superoxide generation, and TNF-alpha production caused by PG-PS. Further, mRNA for the beta subunit of the glycine receptor was detected in splenic macrophages. This work supports the hypothesis that glycine prevents reactive arthritis by blunting cytokine release from macrophages by increasing chloride influx via a glycine-gated chloride channel.

Role of endogenous enteric organisms in the reactivation of arthritis.

Reactive arthritis is an acute form of arthritis apparently caused by a combination of bacterial infection and genetic influences. Recent experiments using an animal model suggest that certain bacterial cell wall polymers originating from endogenous enteric bacteria may be responsible for the condition.

Capsular type-specific polysaccharide partially inhibits group B Streptococcus-induced pulmonary hypertension.

Capsular type-specific polysaccharide is thought to be an important pathogenetic factor in Group B streptococcus (GBS) sepsis. To determine the effects of capsular type-specific polysaccharide on GBS-induced hemodynamic responses, anesthetized infant piglets were infused for 3 h with three related GBS Type lb strains that express different amounts of capsular type-specific polysaccharide. A larger capsule strain and a smaller capsule strain were isolated from an infected infant and its mother, respectively. A capsule-deficient mutant was then made from the larger capsule strain by transposon insertion mutagenesis. The smaller capsule strain and capsule-deficient mutant caused similar elevations in mean pulmonary artery pressure and pulmonary vascular resistance index and reductions in cardiac index. The larger capsule strain caused moderate pulmonary hypertension, but this response was smaller than for the other two GBS strains. Further comparisons in responses between the large capsule strain and its capsule-deficient mutant were then performed using unanesthetized piglets. The mutant caused significantly greater pulmonary hypertension and arterial plasma thromboxane B2 levels than the large capsule strain. The pulmonary hypertension induced by both strains was reversed by dazmegrel, a thromboxane A2 synthase inhibitor. These results suggest that (1) capsular type-specific polysaccharide is not an essential component in the generation of acute hemodynamic responses; (2) expression of large amounts of capsular type-specific polysaccharide on the organism surface partially inhibits GBS-induced pulmonary hypertension; and (3) the inhibition of the pulmonary responses is due to reduced thromboxane A2 release.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential events in the pathogenesis of streptococcal cell wall-induced arthritis and their modulation by bis(5-amidino-2-benzimidazolyl)methane (BABIM).

This report builds on the authors' earlier discovery of bis(5-amidino-2-benzimidazolyl)methane (BABIM) as a strong suppressive agent for streptococcal cell wall fragment-induced arthritis in the Lewis rat. As a synthetic inhibitor of trypsinlike proteases, BABIM opens up a new route to the control of inflammatory joint disease. To gain a deeper insight into the function of the compound, the authors have now studied its influence on the sequential development of the joint changes and the associated lesions in spleen and liver. Bis(5-amidino-2-benzimidazolyl)methane is shown to block acute synovitis, to retard and reduce granuloma formation in spleen and liver, to decrease neutrophilic leukocytosis, and to diminish hemopoietic hyperplasia in the bone, and thus also to mitigate the distinctive osteoclastic and chondroclastic events. The compound does not interfere with the splenic immune response, the temporary rise in hepatocytic mitotic activity, or the organ deposition of streptococcal cell walls.

Biologic properties of bacterial lipopolysaccharides treated with chromium chloride.

Addition of small amounts of chromium chloride to a saline suspension of Salmonella typhosa lipopolysaccharide (LPD; Difco) caused a marked reduction in several of the biologic activities of this substance including toxicity, B-cell mitogenicity, plasma colony-stimulating activity (CSA), radioprotective effect, and induction of the dermal Shwartzman reaction. Nevertheless, LPS treated with chromium chloride was found to be at least as effective as untreated LPS in enhancing resistance of B6CBF1 mice to the lethal effects of Klebsiella pneumoniae infection.

Characterization of an endotoxic lipopolysaccharide from Coxiella burnetii.

Phase I Coxiella burnetii antigen isolated by phenol extraction from purified suspensions of C. burnetii in phase I is a complex lipopolysaccharide (LPS) molecule containing substances typical of the bacterial LPS. Some endotoxic properties of this C. burnetii LPS, namely pyrogenicity and skin epinephrine reaction in rabbits, hypothermia in white rats, lethal effect on chicken embryos or on actinomycin-D-treated mice are similar to those of LPS isolated from other Gram-negative bacteria.

Studies on lipopolysaccharides isolated from strains of Neisseria gonorrhoeae.

Lipopolysaccharides, extracted by phenol-water from five strains fo Neisseria gonorrhoeae, were purified by treatment with ribonuclease followed by multiple washes. These preparations were fatal to mice when administered in submicrogram amounts with actinomycin D, the LD50 values varying from 4 to 16 mug/kg. Analyses showed that all preparations contained glucose, galactose, glucosamine, heptose, 2-keto-3-deoxyoctonic acid and phosphate. All the lipopolysaccharides contained the same fatty acids, namely beta-OH-10:0, beta-OH-12:0, beta-OH-14:0, 12:0, 14:0,16:0, 16:1, 18:0 and 18:1. We were unable to detect significant differences between the lipopolysaccharides of virulent and avirulent gonococci or between penicillin-sensitive and resistant strains. Gonococcal lipopolysaccharides appeared to lack O-antigen side chains.