Rescue with an anti-inflammatory peptide of chickens infected H5N1 avian flu

Chickens suffering from avian flu caused by H5N1 influenza virus are destined to die within 2 days due to a systemic inflammatory response. Since HVJ infection (1,2) and influenza virus infection (3,4) cause infected cells to activate homologous serum complement, the systemic inflammatory response elicited could be attributed to the unlimited generation of C5a anaphylatoxin of the complement system, which is a causative peptide of serious inflammation. In monkeys inoculated with a lethal dose of LPS (4 mg/kg body weight), inhibition of C5a by an inhibitory peptide termed AcPepA (5) rescued these animals from serious septic shock which would have resulted in death within a day (6). Therefore, we tested whether AcPepA could also have a beneficial effect on chickens with bird flu. On another front, enhanced production of endothelin-1 (ET-1) and the activation of mast cells (MCs) have been implicated in granulocyte sequestration (7). An endothelin receptor derived antisense homology box peptide (8) designated ETR-P1/fl was shown to antagonize endothelin A receptor (ET-A receptor) (9) and reduce such inflammatory responses as endotoxin-shock (10) and hemorrhagic shock (11), thereby suppressing histamine release in the circulation (12). Thus, we also administered ETR-P1/fl to bird flu chickens expecting suppression of a systemic inflammatory response

Estrogen receptor alpha and beta differentially mediate C5aR agonist evoked Ca2+-influx in neurons through L-type voltage-gated Ca2+ channels

Complement C5a is associated primarily with inflammation. The widespread expression of its receptors, C5aR and C5L2 in neuronal cells, however, suggests additional regulatory roles for C5a in the CNS. C5aR agonist (PL37-MAP) evokes Ca2+-influx in GT1-7 neuronal cell line and the Ca2+-influx is regulated by estradiol. In the present study, we examined further the mechanism of Ca2+-influx and the contribution of the two estrogen receptor (ER) isotypes, ERα and ERβ, to estrogenic modulation of intracellular Ca2+-content. GT1-7 neurons were treated with isotype selective ER agonists for 24 h then C5aR agonist evoked Ca2+-responses were measured by Ca2+-imaging. Transcriptional changes were followed by real-time PCR. We found that not only estradiol (100 pM), but the ERα selective agonist PPT (100 pM) enhanced the PL37-MAP-evoked Ca2+-influx (E2: 215%, PPT: 175%, compared to the PL37-MAP-evoked Ca2+-influx). In contrast, the ERβ selective agonist DPN (100 pM) significantly reduced the Ca2+-influx (32%). Attenuated Ca2+-response (25%) was observed in Ca-free environment and depletion of the Ca2+-pool by CPA eliminated the remaining elevation in the Ca2+-content, demonstrating that the majority of Ca2+ originated from the extracellular compartment. L-type voltage-gated Ca2+-channel (L-VGCC) blocker nifedipine abolished the Ca2+-influx, while R-type Ca2+-channel blocker SNX-482 had no effect, exemplifying the predominant role of L-VGCC in this process. Acute pre-treatments (8 min) with ER agonists did not affect the evoked Ca2+-influx, revealing that the observed effects of estrogens were genomic. Therefore, we checked estrogenic regulation of C5a receptors and L-VGCC subunits. ER agonists increased C5aR mRNA expression, whereas they differentially regulated C5L2. Estradiol decreased transcription of Cav1.3 L-VGCC subunit. Based on these results we propose that estradiol may differentially modulate C5a-induced Ca2+-influx via L-VGCCs in neurons depending on the expression of the two ER isotypes

CD59 protects rat kidney from complement mediated injury in collaboration with Crry

CD59 protects rat kidney from complement mediated injury in collaboration with Crry.BackgroundAs previously reported, the membrane-bound complement regulator at the C3 level (Crry/p65) is important in maintaining normal integrity of the kidney in rats. However, the role of a complement regulator at the C8/9 level (CD59) is not clear, especially when activation of complement occurs at the C3 level. The aim of this work was to elucidate the in vivo role of CD59 under C3 activating conditions.MethodsTwo monoclonal antibodies, 5I2 and 6D1, were used to suppress the function of Crry and CD59, respectively. In order to activate alternative the pathway of complement, the left kidney was perfused with 5I2 and/or 6D1 and was recirculated.ResultsIn the kidneys perfused with 5I2 alone, deposition of C3 and membrane attack complex (MAC) was observed in the peritubular capillaries, vasa recta, and tubular basement membranes. Cast formation, tubular dilation and degeneration, and cellular infiltration were observed at days 1 and 4, and they recovered by day 7. Further suppression of CD59 by 6D1 significantly enhanced the deposition of MAC and worsened the already exacerbated tubulointerstitial injury. These effects of 6D1 were dose dependent. Perfusion with 6D1 alone did not induce histologic damage or MAC deposition in the tubulointerstitium.ConclusionsIn rats, CD59 maintains normal integrity of the kidney in collaboration with Crry in rats against complement-mediated damage in vivo

Complement C5a inhibition improves late hemodynamic and inflammatory changes in a rat model of nonocclusive mesenteric ischemia

BACKGROUND: Nonocclusive mesenteric ischemia (NOMI) can evolve in a variety of low-flow states. Although the mechanisms leading to NOMI-related intestinal necrosis are largely unknown, circumstantial evidence suggests that excessive vasoconstriction and complement activation both play important roles in this process. Because targeting of the circulatory malfunction of the splanchnic area could be of therapeutic relevance, we set out to investigate the long-term effects of treatment with a complement C5a antagonist in a rat model of partial aortic occlusion (PAO)-induced transient mesenteric hypoperfusion. METHODS: The mean arterial pressure of the splanchnic area was kept between 30 and 40 mm Hg by 60 minutes of PAO in anesthetized male Sprague-Dawley rats. C5a inhibitor acetyl-peptide-A (AcPepA; 4 mg kg-1 intravenously) or vehicle administration was initiated at the 45th minute of PAO. After 24 hours, the animals were reanesthetized to record the macrohemodynamics and ileal microcirculation, and plasma and tissue samples were taken for determination of high-mobility group box protein-1 (HMGB-1), endothelin-1, tumor necrosis factor (TNF)-alpha levels, and small intestinal leukocyte infiltration. Epithelial structural changes were visualized by in vivo confocal laser scanning endomicroscopy. RESULTS: At 24 hours after PAO, mean arterial pressure, heart rate, and cardiac output were significantly greater, the intestinal intramural microcirculation was significantly impaired, and plasma HMGB-1, endothelin-1, TNF-alpha levels, the degree of epithelial damage and leukocyte infiltration was increased. The AcPepA treatment moderated the hemodynamic and microcirculatory changes, and decreased inflammatory activation and histologic signs of mucosal damage. CONCLUSION: C5a inhibition ameliorated the potentially harmful local mesenteric hypoperfusion and global long-term inflammatory consequences of PAO. This approach is of promise for use in NOMI-associated situations

Guideline for Hereditary Angioedema (HAE) 2010 by the Japanese Association for Complement Research - Secondary Publication

ABSTRACTThis guideline was provided by the Japanese Association for Complement Research targeting clinicians for making an accurate diagnosis of hereditary angioedema (HAE), and for prompt treatment of the HAE patient in Japan. This is a 2010 year version and will be updated according to any pertinent medical advancements