Controlling the complement system in inflammation

Brain edema formation and therapy after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) accounts for about 10% of all strokes in the United States of America causing a high degree of disability and mortality. There is initial (primary) brain injury due to the mechanical disruption caused by the hematoma. There is then secondary injury, triggered by the initial injury but also the release of various clot-derived factors (e.g., thrombin and hemoglobin). ICH alters brain fluid homeostasis. Apart from the initial hematoma mass, ICH causes blood-brain barrier disruption and parenchymal cell swelling, which result in brain edema and intracranial hypertension affecting patient prognosis. Reducing brain edema is a critical part of post-ICH care. However, there are limited effective treatment methods for reducing perihematomal cerebral edema and intracranial pressure in ICH. This review discusses the mechanisms underlying perihematomal brain edema formation, the effects of sex and age, as well as how edema is resolved. It examines progress in pharmacotherapy, particularly focusing on drugs which have been or are currently being investigated in clinical trials.

Single-cell atlas of murine adrenal glands reveals immune-adrenal crosstalk during systemic <i>Candida albicans</i> infection

Fungal sepsis remains a major health threat with high mortality, where the adrenal gland stress response has been rarely reported. <i>Candida albicans</i> (<i>C.albicans</i>) is the most common opportunistic fungal pathogen of life-threatening disseminated candidiasis and fungal sepsis. In the present study, we performed single-cell RNA sequencing (scRNA-Seq) using the 10x Genomics platform to analyze the changes in murine adrenal transcriptome following systemic <i>C.albicans</i> infection. A total of 16 021 cells were categorized into 18 transcriptionally distinct clusters, representing adrenocortical cells, endothelial cells, various immune cells, mesenchymal cells, smooth muscle cells, adrenal capsule, chromaffin cells, neurons and glials. As the main cell component in the adrenal gland responsible for steroidogenesis, the adrenocortical cells dramatically diminished and were further grouped into 10 subclusters, which differently distributed in the infected and uninfected samples. Pseudo-time analysis revealed transitions of the adrenocortical cells from the initial normal states to active or dysfunctional states following systemic <i>C.albicans</i> infection <i>via</i> two trajectory paths. Endothelial cells in the highly vascularized organ of adrenal gland further proliferated following infection, with the upregulation of genes positively regulating angiogenesis and downregulation of protective genes of endothelial cells. Immune cells were also excessively infiltrated in adrenal glands of <i>C.albicans</i>-infected mice. Macrophages dominated the immune microenvironments in murine adrenal glands both before and after <i>C.albicans</i> infection, mediating the crosstalk among the steroid-producing cells, endothelial cells and immune cells within the adrenal gland. NLR family, pyrin domain containing 3 (NLRP3, encoded by <i>Nlrp3</i>) and complement receptor 3 (CR3, encoded by <i>Itgam</i>) were found to be significantly upregulated on the adrenal macrophages upon systemic <i>C.albicans</i> infection and might play critical roles in mediating the myeloid response. Meanwhile, the number and strength of the interactions between the infiltrating immune cells and adrenal resident cells were unveiled by cell-cell communication analysis to be dramatically increased after systemic <i>C.albicans</i> infection, indicating that the immune-adrenal crosstalk might contribute to the compromised functions of adrenal cells. Overall, our comprehensive picture of the murine adrenal gland microenvironment in systemic <i>C.albicans</i> infection provides deeper insights into the immune-adrenal cell communications during fungal sepsis.

Preparation, Characterization and Anti-Complementary Activity of Three Novel Polysaccharides from Cordyceps militaris

This investigation focuses on the three novel polysaccharides from Cordyceps militaris and then discusses their characterization and anti-complementary activity. The three polysaccharides from C. militaris (CMP-1, CMP-2 and CMP-3) were prepared using a DEAE-52 cellulose column. The HPLC, HPGPC, FT-IR and Congo red analyses were used to characterize their monosaccharides, molecular weight and stereo conformation, which demonstrated that the three polysaccharides were homogenous polysaccharides with different molecular weights and were composed of at least ten monosaccharides with different molar ratios, and all had a triple-helix conformation. The evaluation of anti-complementary activity demonstrated that the three polysaccharides significantly inhibited complement activation through the classical pathway and alternative pathway. Preliminary mechanism studies indicated that CMP-1, CMP-2 and CMP-3 acted with C2, C5, C9, factor B, factor B, and P components in the overactivation cascade of the complement system. The analysis of the Pearson correlation and network confirmed that the ribose, glucuronic acid and galacturonic acid composition were negatively correlated with the anti-complementary activity of polysaccharides. These results suggested that the three novel polysaccharides are potential candidates for anti-complementary drugs.

Isolation and Structural Characterization of Two Polysaccharides from Dracocephalum moldavica and Their Anti-Complementary Activity

The two novel polysaccharides, DMP-1 and DMP-2, with molecular weights of 4.1553×10⁵  kDa and 1.9764×10⁵  kDa, respectively, were isolated from Dracocephalum moldavica. The structural characterization indicated that DMP-1 and DMP-2 shared a similar backbone consisting of →5)-Araf-(1→, Manp-(1→, Glcp-(1→, →2)-Manp-(1→, →6)-Glcp-(1→ and →3,6)-Galp-(1→ with a different molar ratios and triple-helix structures with α- and β-type glycosidic bonds. The anti-complementary activity evaluation showed that DMP-1 and DMP-2 had strong complement inhibition through the classical pathway (CP), alternative pathway (AP) and lectin pathway (LP). Mechanistic studies indicated that DMP-1 can block the activation cascade of the complement system by targeting C2, C3, C5, C9, Factor B and Factor P, and that DMP-2 inhibited complement activation by blocking C2, C3, C4, C5, C9 and Factor B.

Association of Blood Group Antigen CD59 with Disease

In 2014, the membrane-bound protein CD59 became a blood group antigen. CD59 has been known for decades as an inhibitor of the complement system, located on erythrocytes and on many other cell types. In paroxysmal nocturnal haemoglobinuria (PNH), a stem cell clone with acquired deficiency to express GPI-anchored molecules, including the complement inhibitor CD59, causes severe and life-threatening disease. The lack of CD59, which is the only membrane-bound inhibitor of the membrane attack complex, contributes a major part of the intravascular haemolysis observed in PNH patients. This crucial effect of CD59 in PNH disease prompted studies to investigate its role in other diseases. In this review, the role of CD59 in inflammation, rheumatic disease, and age-related macular degeneration is investigated. Further, the pivotal role of CD59 in PNH and congenital CD59 deficiency is reviewed.

The role of complement in brain injury following intracerebral hemorrhage: A review

Intracerebral hemorrhage (ICH) is a significant cause of death and disability and current treatment is limited to supportive measures to reduce brain edema and secondary hematoma expansion. Current evidence suggests that the complement cascade is activated early after hemorrhage and contributes to brain edema/injury in multiple ways. The aim of this review is to summarize the most recent literature about the role of the complement cascade after ICH. Primary literature demonstrating complement mediated brain edema and neurologic injury through the membrane attack complex (MAC) as well as C3a and C5a are reviewed. Further, attenuation of brain edema and improved functional outcomes are demonstrated after inhibition of specific components of the complement cascade. Conversely, complement also plays a significant role in neurologic recovery after ICH and in other neurologic disorders. We conclude that the role of complement after ICH is complex. Understanding the role of complement after ICH is essential and may elucidate possible interventions to reduce brain edema and injury.

Association between serum ficolin-1 level and disease progression in primary biliary cholangitis

Pattern recognition molecules (PRMs) in the complement system contribute to homeostasis as mediators of complement activation. The contribution of PRMs to primary biliary cholangitis (PBC) is unknown. In the current study, we aimed to assess the association between PRMs and the clinical findings of PBC. A total of 122 PBC patients and 20 healthy controls were enrolled. We measured four different PRMs (mannose-binding lectin [MBL], ficolin-1, ficolin-2 and ficolin-3) using stored sera, and retrospectively analyzed the associations between PRMs and laboratory findings, histological findings, and the development of cirrhosis-related conditions. Ficolin-1 levels were significantly higher in the PBC patients than in the healthy controls (152 ng/mL vs 102 ng/mL, P = 0.034), but no significant differences were observed regarding MBL, ficolin-2, and ficolin-3 levels. Ficolin-1 was significantly correlated with alkaline phosphatase (ALP). Low ficolin-1 levels were significantly associated with the development of cirrhosis-related conditions independent for histological stage and ALP levels (hazard ratio: 0.933; 95% confidence interval: 0.875-0.994; P = 0.032). Patients with low levels of ficolin-1 (< 77 ng/mL) had a significantly increased rate of developing cirrhosis-related conditions. Low ficolin-1 levels were associated with disease progression independent of histological stage and ALP levels in patients with PBC.

Ficolin-1 gene (FCN1) -144 C/A polymorphism is associated with adverse outcome of severe pneumonia in the under-five Egyptian children: A multicenter study

BACKGROUND

Pneumonia is the foremost cause of child death worldwide. M-ficolin is encoded by the FCN1 gene and represents a novel link between innate and adaptive immunity.

OBJECTIVES

To investigate the FCN1 -144 C/A (rs10117466) polymorphism as a potential marker for pneumonia severity and adverse outcome namely complications or mortality in the under-five Egyptian children.

METHODS

This was a prospective multicenter study that included 620 children hospitalized with World Health Organization-defined severe pneumonia and 620 matched healthy control children. Polymorphism rs10117466 of the FCN1 gene promoter was analyzed by PCR-SSP, while serum M-ficolin levels were assessed by ELISA.

RESULTS

The FCN1 A/A genotype and A allele at the -144 position were more frequently observed in patients compared to the control children (43.4% vs 27.6%; odds ratio [OR]: 1.62; [95% confidence interval {CI}: 1.18-2.2]; for the A/A genotype) and (60.8% vs 52.5%; OR: 1.4; [95% CI: 1.19-1.65]; for the A allele); P < .01. The FCN1 -144 A/A homozygous patients had significantly higher serum M-ficolin concentrations (mean: 1844 ± 396 ng/mL) compared with those carrying the C/C or C/A genotype (mean: 857 ± 278 and 1073 ± 323 ng/mL, respectively; P = .002). FCN1 -144 A/A genotype was an independent risk factor for adverse outcomes in children with severe pneumonia (adjusted OR = 4.85, [95% CI: 2.96-10.25]; P = .01).

CONCLUSION

The FCN1 A/A genotype at the -144 position was associated with high M-ficolin serum levels and possibly contributes to enhanced inflammatory response resulting in the adverse outcome of pneumonia in the under-five Egyptian children.

A natural bioactive feed additive alters expression of genes involved in inflammation in whole blood of healthy Angus heifers

A greater demand for food animal production without antibiotics has created the common practice of feeding food animals dietary immunomodulatory feed additives (IFA) throughout their life cycle. However, little is known about the impact of IFA on cytokine and chemokine signaling in non-stressed, non-pathogen-challenged food animals during the early feeding period. We evaluated the expression of 82 genes related to cytokine and chemokine signaling in the whole blood of growing Angus heifers to determine the effect of IFA supplementation on cytokine and chemokine signaling during the first 28 d of feeding. One gene (CCL1) was significantly up-regulated and 14 genes (17%) were significantly down-regulated by IFA feeding during the entire early feeding period including 5 of 21 (24%) evaluated chemokine and IL receptors (CCR1, CCR2, IL1R1, IL10RA, IL10RB). These data when taken together suggest providing an IFA in the diet of growing beef cattle during the early feeding period may suppress the inflammatory response through cytokine–cytokine receptor signaling.

Expression Signatures of Cisplatin- and Trametinib-Treated Early-Stage Medaka Melanomas

Small aquarium fish models provide useful systems not only for a better understanding of the molecular basis of many human diseases, but also for first-line screening to identify new drug candidates. For testing new chemical substances, current strategies mostly rely on easy to perform and efficient embryonic screens. Cancer, however, is a disease that develops mainly during juvenile and adult stage. Long-term treatment and the challenge to monitor changes in tumor phenotype make testing of large chemical libraries in juvenile and adult animals cost prohibitive. We hypothesized that changes in the gene expression profile should occur early during anti-tumor treatment, and the disease-associated transcriptional change should provide a reliable readout that can be utilized to evaluate drug-induced effects. For the current study, we used a previously established medaka melanoma model. As proof of principle, we showed that exposure of melanoma developing fish to the drugs cisplatin or trametinib, known cancer therapies, for a period of seven days is sufficient to detect treatment-induced changes in gene expression. By examining whole body transcriptome responses we provide a novel route toward gene panels that recapitulate anti-tumor outcomes thus allowing a screening of thousands of drugs using a whole-body vertebrate model. Our results suggest that using disease-associated transcriptional change to screen therapeutic molecules in small fish model is viable and may be applied to pre-clinical research and development stages in new drug discovery.

Structural characterization and anticomplement activity of an acidic polysaccharide containing 3-O-methyl galactose from Juniperus tibetica

A water-soluble acidic polysaccharide containing 3-O-methyl galactose, named YB-PS4, was isolated from the twigs and leaves of Juniperus tibetica Kom. Its structure was characterized by monosaccharide composition analysis, methylation, and NMR spectroscopy. It was concluded that YB-PS4 had a backbone composed of→2,4)-α-Rhap-(1→, →3,5)-α-Araf-(1→, →2,4)-α-Galp-(1 → and →4)-α-GalpA-(1→, with branches of →2)-α-Rhap-(1→,→3)-α-Araf-(1 → and →2)-3-O-Me-α-Galp-(1→. The possible repetitive units were speculated and further analyzed by oligosaccharide analysis. YB-PS4 showed inhibitory effects on complement activation through the classical pathway (CH₅₀ = 94.23 ± 8.90 μg/mL) and alternative pathway (AP₅₀ = 194.76 ± 9.20 μg/mL). Preliminary mechanism study indicated that it interacted with C1q, C2, C3, C4 and C5. These studies pointed a way to understand the active constituents of J. tibetica and provided scientific bases for YB-PS4 as a complement inhibitor.

Display of the Albumin-Binding Domain in the Envelope Improves Lentiviral Vector Bioavailability

Vesicular stomatitis virus G glycoprotein (VSVg) is extensively used for retroviral and lentiviral vector (LV) pseudotyping. However, VSVg pseudotyped vectors are serum inactivated, blocking the in vivo gene delivery. Several strategies have been employed to prevent complement inactivation, including chemical and genetic envelope modifications. This study employed the streptococcal albumin-binding domain (ABD) to generate a construct to express ABD as a glycosylphosphatidylinositol-anchored protein. LV particles bearing ABD are able to bind bovine and human serum albumin in vitro. Neither the lentiviral vector production titer nor the in vitro transduction was affected by the ABD display. The study demonstrated that ABD-bearing LVs are protected from human complement inactivation. More importantly, intravenous administration demonstrated that the presence of ABD significantly reduces lentivector sequestration in liver and bone-marrow cells. Therefore, the use of ABD represents an improvement for in vivo gene therapy applications. The results strongly point to ABD display as a universal strategy to increase the in vivo efficacy of different viral vectors.

Iridoids from Pedicularis verticillata and Their Anti-Complementary Activity

Three new iridoids named as pediverticilatasin A - C (1 - 3, resp.), together with five known iridoids (4 - 8, resp.) were isolated from the whole plants of Pedicularis verticillata. The structures of three new compounds were identified as (1S,7R)-1-ethoxy-1,5,6,7-tetrahydro-7-hydroxy-7-methylcyclopenta[c]pyran-4(3H)-one (1), (1S,4aS,7R,7aS)-1-ethoxy-1,4a,5,6,7,7a-hexahydro-7-hydroxy-7-methylcyclopenta[c]pyran-4-carboxylic acid (2), (1S,4aS,7R,7aS)-1-ethoxy-1,4a,5,6,7,7a-hexahydro-7-hydroxy-7-methylcyclopenta[c]pyran-4-carbaldehyde (3). Their structures were elucidated on the basis of spectroscopic methods and compared with the NMR spectra data in the literature. All compounds were evaluated for their anti-complementary activity on the classical pathway of the complement system in vitro. Among which, compounds 1, 3, and 6 exhibited anti-complementary effects with CH₅₀ values ranging from 0.43 to 1.72 mm, which are plausible candidates for developing potent anti-complementary agents.

Structure characterization of two novel polysaccharides isolated from the spikes of Prunella vulgaris and their anticomplement activities

ETHNOPHARMACOLOGICAL RELEVANCE

The spikes of Prunella vulgaris have long been used as a traditional Chinese medicine to treat various inflammation-related diseases. The aim of this study was to isolate and characterize homogenous polysaccharides from this herb and to evaluate their anticomplement activity.

MATERIALS AND METHODS

Anticomplement activity-guided fractionation of the hot water extract of P. vulgaris was performed by DEAE-cellulose and size-exclusion chromatography, yielding two homogeneous polysaccharides PW-PS1 and PW-PS2. The homogeneity, molecular weight, monosaccharide composition and linkage of the two polysaccharides were determined in addition to other chemical characterizations. The anticomplement activity of the polysaccharides was evaluated and expressed as 50% hemolytic inhibition concentration through the classical pathway (CH₅₀ value) and alternative pathway (AP₅₀ value). The preliminary mechanism for the complement activation cascade was also assessed.

RESULTS

PW-PS1 and PW-PS2 were both branched acidic polysaccharides. PW-PS1 was composed of Ara, Xyl, and 4-methoxy-Glc A in a ratio of 1.0: 2.6: 0.8. The main linkages of the sugar residues of PW-PS1 included terminal β-d-Xylp, 1,4-linked β-d-Xylp, 1,3-linked α-d-Arap, 1,3,5-linked α-d-Arap, and terminal 4-methoxy-α-d-Glcp A. PW-PS2 was composed of Rha, Ara, Xyl, Gal, and Gal A in a ratio of 0.6: 1.0: 1.3: 1.8: 3.4. The main linkages between the sugar residues of PW-PS2 included terminal Araf, 1,4-linked β-d-Xylp, 1,3-linked α-d-Rhap, terminal α-d-Galp, and 1,4,6-linked α-d-Galp. PW-PS1 and PW-PS2 inhibited complement activation through both the classical and alternative pathways with CH₅₀ values of 0.28 and 0.13mg/mL, respectively, and AP₅₀ values of 0.40 and 0.35mg/mL, respectively. Preliminary mechanism studies using complement component-depleted sera showed that PW-PS1 acted on the C1q, C3, and C9 components and that PW-PS2 acted on the C1q, C2, C3, C5, and C9 components.

CONCLUSION

Our study suggested that PW-PS1 and PW-PS2 could be valuable for the treatment of diseases associated with the excessive activation of the complement system.

Flavonol glycosides and other phenolic compounds from Viola tianshanica and their anti-complement activities

CONTEXT

Viola tianshanica Maxim. (Violaceae) is a perennial herb distributed in Central Asia, especially in the Xinjiang Uygur Autonomous Region (XUAR) of China. Preliminary study showed that the ethanol extract of the herb exhibited the anti-complement activity against the classical pathway, but the active components responsible for this capacity remain unknown and are yet to be studied.

OBJECTIVE

The objective of this study was the isolation and identification of the anti-complement constituents of V. tianshanica.

MATERIALS AND METHODS

The ethyl acetate and n-butanol fractions from the ethanol extract of V. tianshanica were purified. The structures of the isolates were identified by spectroscopic methods, and comparing their spectral data with those reported in the literature. All the isolates (0.02-2.50 mg/mL) were evaluated for their anti-complement activity against the classical and alternative pathways.

RESULTS

Twenty-one phenolic compounds including 15 flavonol O-glycosides (1-15), one flavone 6,8-di-C-glycoside (16), one flavone aglycone (17), and four phenolic acid derivatives (18-21) were isolated and identified. Bioassay showed that 11 compounds inhibited the classical pathway and the alternative pathway with CH50 and AP50 values of 0.113-1.210 mM and 0.120-1.579 mM, respectively. Preliminary mechanistic study using complement-depleted sera demonstrated that 1 acted on C1q, C2, C4, and C9 components, 16 on C1q, C4, and C5, and 21 on C1q, C3, C4, and C9.

CONCLUSION

All isolated compounds except 1 and 10 were reported for the first time from V. tianshanica. Compound 16 is the first flavone C-glycoside isolated from the herb. Flavonol O-glycosides and phenolic acids contributed the anti-complement activity of the herb.

Shell Cleavable Dendritic Polyglycerol Sulfates Show High Anti-Inflammatory Properties by Inhibiting L-Selectin Binding and Complement Activation

A new class of fully synthetic shell cleavable multivalent polysulfates is prepared by introducing degradable linkers into a stable biocompatible dendritic polyglycerol scaffold and subsequent sulfation. The sulfated polymers show different degradation profiles, low anticoagulant and high anti-inflammatory properties, are able to efficiently bind to L-selectin and inhibit the complement activation at very low concentrations in vitro.

Properdin Contributes to Allergic Airway Inflammation through Local C3a Generation

Complement is implicated in asthma pathogenesis, but its mechanism of action in this disease remains incompletely understood. In this study, we investigated the role of properdin (P), a positive alternative pathway complement regulator, in allergen-induced airway inflammation. Allergen challenge stimulated P release into the airways of asthmatic patients, and P levels positively correlated with proinflammatory cytokines in human bronchoalveolar lavage (BAL). High levels of P were also detected in the BAL of OVA-sensitized and challenged but not naive mice. Compared with wild-type (WT) mice, P-deficient (P(-/-)) mice had markedly reduced total and eosinophil cell counts in BAL and significantly attenuated airway hyperresponsiveness to methacholine. Ab blocking of P at both sensitization and challenge phases or at challenge phase alone, but not at sensitization phase alone, reduced airway inflammation. Conversely, intranasal reconstitution of P to P(-/-) mice at the challenge phase restored airway inflammation to wild-type levels. Notably, C3a levels in the BAL of OVA-challenged P(-/-) mice were significantly lower than in wild-type mice, and intranasal coadministration of an anti-C3a mAb with P to P(-/-) mice prevented restoration of airway inflammation. These results show that P plays a key role in allergen-induced airway inflammation and represents a potential therapeutic target for human asthma.

Effects of Tityus serrulatus scorpion venom on thromboelastogram in rats

Thromboelastometry was used to evaluate blood coagulation in anesthetized rats after intravenous administration of Tityus serrulatus scorpion venom (Tx). Tracheostomy followed by catheterization of the left jugular vein and right carotid artery were performed for Tx or Ringer's lactate solution injection and blood sample harvesting, respectively. Blood samples were obtained at the beginning of the experiments (baseline) and at two, five, 15, 30, and 60 min after intoxication. The following coagulation parameters were analyzed: CT (Clotting Time), CFT (Clotting Formation Time), Alpha Angle (α), MCF (Maximum Clot Firmness) and TPI (Thrombodynamic Potential Index). Toxin-induced hypercoagulability was demonstrated at the 15 and 60 min. We hypothesize Tx-induced hypercoagulability and enhanced clot formation could be explained by catecholamine release, systemic inflammatory response, and complement system activation, at least in the first hour after envenomation. Further studies are needed to determine the molecular mechanism of Tx-induced coagulopathy.

Effects of Chinese medicine shen-fu injection on the expression of inflammatory cytokines and complements during post-resuscitation immune dysfunction in a porcine model

OBJECTIVE

To investigate the action of Shen-Fu Injection (SFI) in regulating the expression of the serum complements and inflammatory cytokines synthesized and released in response to the stress of global ischemia accompanying cardiac arrest (CA) and resuscitation.

METHODS

Thirty pigs were randomly divided into the sham (n=6) and 3 returns of spontaneous circulation (ROSC) groups (n=24). After 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs of the ROSC groups were randomized into three groups (n=8 per group), which received central venous injection of SFI (SFI group), epinephrine (EP group), or saline (SA group). Hemodynamic status and blood samples were obtained at 0, 0.5, 1, 2, 4, 6, 12, and 24 h after ROSC.

RESULTS

Serum concentrations of specific activation markers of the complement system C3, C4 and C5b-9 were increased during cardiopulmonary resuscitation through 24 h after ROSC. There were intense changes of various pro-inflammatory cytokines and anti-inflammatory cytokines as early as 0.5 h after CA. Compared with the EP and SA groups, SFI treatment reduced the proinflammatory cytokines levels of interleukin (IL)-6, IL-8 and tumor necrosis factor α (TNF-α, P<0.05), and increased the anti-inflammatory cytokine levels of IL-4 and IL-10 (P<0.05). Further, SFI treatment decreased the values of C3, C4 and C5b-9 compared with the EP and SA groups.

CONCLUSIONS

SFI, derived from the ancient Chinese medicine, has significant effects in attenuating post-resuscitation immune dysfunction by modulating the expression of complements and cytokines levels. The current study provided an experimental basis for the clinical application of a potential pharmacologic target for post resuscitation immune dysfunction.

Anticomplement monoterpenoid glucosides from the root bark of Paeonia suffruticosa

Six new (1-6) and 19 known monoterpenoid glucosides were isolated from the root bark of Paeonia suffruticosa. The monoterpenoid glucosides 1, 2, 7, 10-19, and 22 exhibited anticomplement effects with CH50 and AP50 values ranging from 0.14 to 2.67 mM and 0.25 to 3.67 mM, respectively. In a mechanistic study, suffrupaeoniflorin A (1) interacted with C1q, C3, C5, and C9, while galloylpaeoniflorin (12) and galloyloxypaeoniflorin (19) acted on C1q, C3, and C5 components in the complement activation cascade.

Two New Compounds and Anti-complementary Constituents from Amomum tsao-ko

Two new compounds, (2 R,3 R,4 R)–3′,5′-dimethoxy-3,4,7,4′-tetrahydroxy-flavan (1) and 2-(4-hydroxy-3-methoxybenzoyl)-4-methoxy-benzaldehyde (2), together with 35 known phenolic compounds were obtained from the fruits of Amomum tsao-ko. Structures of the new compounds were elucidated on the basis of spectroscopic means, including 2D NMR, and high-resolution MS analysis. The isolated compounds were tested in vitro for their complement-inhibitory properties against the classical pathway (CP) and alternative pathway (AP). The results showed that 14 compounds exhibited anti-complementary activities against the CP and AP with CH50 values of 0.42 - 4.43 mM and AP50 values of 0.53 −1.51 mM. Preliminary mechanism studies showed that 1,7-bis(4-hydroxyphenyl)–4( E)-hepten-3-one (8) blocked C1q, C2, C3, C4, C5 and C9 components of the complement system, and hydroquinone (15) acted on C1q, C2, C3, C5 and C9 components.

Homogalacturonans from preinfused green tea: structural characterization and anticomplementary activity of their sulfated derivatives

Two homogeneous water-soluble polysaccharides (TPSR4-2B and TPSR4-2C) were obtained from preinfused green tea. Their average molecular weights were estimated to be 41 kDa and 28 kDa, respectively. A combination of composition, methylation, and configuration analysis, as well as NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1-4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and 28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester. Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid-pyridine ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C demonstrated a stronger inhibitory effect on the complement activation through the classic pathway, compared to that of heparin. Preliminary mechanism studies by using complement component depleted-sera indicated that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r, C1s, C2, C5, and C9 but not with C3 and C4. The relationship between DS and the anticomplementary activity of sulfated derivatives of homogalacturonans showed that low sulfated derivatives of homogalacturonans also exhibited potent anticomplementary effect, which might greatly reduce the side effects related to heparin and oversulfated chondroitin sulfate, such as anticoagulant activity and allergic-type reaction. These results suggested that sulfated derivatives of homogalacturonans might be promising drug candidates for therapeutic complement inhibition.

Osteoarthritis year 2012 in review: biology

This review focuses on recent findings in pathobiology of osteoarthritis (OA). The progress in this field will be illustrated based on three questions; 1. What factors maintain or alter the articular chondrocyte phenotype? 2. What is the role of inflammation in OA? 3. Is there a role for aging-related genes in OA? Recent findings make it more and more obvious that OA is not a single tissue disease, but that development and progression of OA is the resulted of an integrated complex of local and systemic factors that contribute to the pathobiology of this widespread disease.

Variation in FCN1 affects biosynthesis of ficolin-1 and is associated with outcome of systemic inflammation

Ficolin-1 is a recognition molecule of the lectin complement pathway. The ficolin-1 gene FCN1 is polymorphic, but the functional and clinical consequences are unknown.The concentration of ficolin-1 in plasma and FCN1 polymorphisms in positions -1981 (rs2989727), -791 (rs28909068), -542 (rs10120023), -271 (rs28909976), -144 (rs10117466) and +7918 (rs1071583) were determined in 100 healthy individuals. FCN1 expression by isolated monocytes and granulocytes and ficolin-1 levels in monocyte culture supernatants were assessed in 21 FCN1-genotyped individuals. FCN1 polymorphisms were determined in a cohort of 251 patients with systemic inflammation. High ficolin-1 plasma levels were significantly associated with the minor alleles in position -542 and -144. These alleles were also significantly associated with high FCN1 mRNA expression. The level of ficolin-1 in culture supernatants was significantly higher in individuals homozygous for the minor alleles at positions -542 and -144. Homozygosity for these alleles was significantly associated with fatal outcome in patients with systemic inflammation. None of the other investigated polymorphisms were associated with FCN1 and ficolin-1 expression, concentration or disease outcome. Functional polymorphic sites in the promoter region of FCN1 regulate both the expression and synthesis of ficolin-1 and are associated with outcome in severe inflammation.

Pathways of Complement Activation Following Intestinal Ischemia-Reperfusion in Macaque

Complement activation is a key component in the inflammation cascade. In the present study, intestinal ischemia-reperfusion (IIR) was introduced to macaques, and the pathways of complement activation in the multiple organ dysfunction syndrome (MODS) following IIR were investigated, which may provide evidence on the mechanisms underlying the endogenous protection in systemic inflammatory response. IIR was performed by clamping superior mesenteric artery and releasing clamp in 5 macaques. Immunization rate nephelometry and CH50 total complement detection were employed to measure the serum concentration of C3, C4, C-reactive protein (CRP) and total complements. Immunocytochemistry was carried out to detect the contents of IL-1 and NF-κB in polymorphonuclear cells (PMN). Flow cytometry was done to measure the apoptosis rate of PMN. At 24 h after IIR, the amount of total complement (106.6±18.07 U/mL) was reduced to 62.1±9.52 U/mL (p<0.05). In addition, the C3 was reduced by 30% (p<0.05) but C4 remained unchanged after IIR (0.1342±0.07 vs 0.1420±0.06, P>0.05). The apoptosis rate (15.4%±1.14%) of PMN was markedly reduced (3.5%±0.53%) following IIR (p<0.05) accompanied by increased contents of IL-1 and NF-κB. Moreover, CRP was also significantly elevated after IIR (4.33±1.13 mg/L vs 17.73±0.86 mg/L; p<0.01). Following IIR, complements are activated through the alternative pathway. Complement activation fragments can inhibit the apoptosis of PMN and elevate the expressions of acute phase inflammatory proteins including CRP and IL-1, which promotes the inflammation cascade and facilitates the occurrence of MODS.

Anticomplementary activity of oleanane-type triterpenes from the roots of Aceriphyllum rossii

To gain a better understanding of the anticomplement activity of triterpenoids, the complement activity of five unusual oleanane-type triterpenoids, bearing a carboxyl group at the C-29 position, were estimated against the classical pathway of a complementary system. The five triterpenoids were obtained from the roots of Aceriphyllum rossii (Saxifragaceae), and were determined to be aceriphyllic acids B-E (1-4) and K (5). Of the isolated compounds, compounds 1, 2 and 5 showed anticomplement activities, with IC(50) values of 328.4, 77.5 and 348.6 μM, respectively, whereas, compounds 3 and 4 were inactive. This showed that a carboxyl group at the C-23 position and an α-configuration of a hydroxyl group at the C-3 position in the olean-29-carboxylic acid triterpenoids seemed to play an important role in the anticomplement activity of human serum against erythrocytes.

A New Unusual Δ11(12)-Oleane Triterpene and Anti-Complementary Triterpenes from Prunella Vulgaris Spikes

Anti-complementary activity-guided fractionation of the ethanolic extract of Prunella vulgaris spikes led to the isolation of a new, unusual Δ11(12) triterpene, 3β,13β-dihydroxyolic-11-ene-28-oic acid (1), along with thirteen known triterpenes (2-14). The structure of the new compound was established by 1D and 2D NMR spectroscopic analysis. All the isolates were evaluated for their anti-complementary activity against the classical pathway (CP) and alternative pathway (AP). Eight triterpenes (1-8) showed anti-complementary activity against CP and AP, with CH50 and AP50 values of 0.15-0.37 mg/mL, and 0.29-0.53 mg/mL, respectively. Mechanism study using complement-depleted sera showed that oleanolic acid (2) acted selectively on C1q, C5, and C9 components, while 2α-hydroxy oleanolic acid (3) interacted with C1q, C3, C5 and C9, and 2α,3α-dihydroxyolic-12-ene-28-oic acid (4) blocked C1q, C2, C3, C5 and C9.

Preparation of pseudotyped lentiviral vectors resistant to inactivation by serum complement

A major obstacle to in vivo delivery of lentivirus or other retroviral vectors is their lability in the presence of serum. In vivo, these viral particles are rapidly destroyed by nonspecific complement-mediated degradation mechanisms. The eventual effective use of retroviral vectors for in vivo gene delivery would be greatly facilitated by the development of methods to protect the viral particles from such degradation. This protocol describes methods for the production of complement-stabilized lentiviral vectors either by pseudotyping the viral particles with a fusion envelope protein containing the complement-regulatory protein CD55 (decay accelerating factor, DAF) or by coassembly with the native DAF protein. An in vitro serum inactivation assay is also described.

Novel adenovirus vectors 'capsid-displaying' a human complement inhibitor

Adenovirus (Ad) vectors are currently the most commonly utilized gene transfer vectors in humans worldwide. Unfortunately, upon contact with the circulatory system, Ads induce several, innate, complement-dependent toxicities that limit the full potential for Ad-based gene transfer applications. Therefore, we have constructed several novel Ad5-based vectors, 'capsid-displaying' as fiber or pIX fusion proteins, a complement-regulatory peptide (COMPinh). These novel Ads dramatically minimize Ad-dependent activation of the human and non-human primate complement systems, as determined by several assays. In summary, our work has shown that a novel COMPinh-displaying Ad5 has the potential for broadening the safe use of Ad vectors in future human applications.

beta-Arrestins modulate Adenovirus-vector-induced innate immune responses: differential regulation by beta-arrestin-1 and beta-arrestin-2

Adenovirus (Ad)-based vectors have been utilized in human gene transfer clinical trials since 1993. Unfortunately, innate immune responses directed against the Ad capsid and/or its genetic cargo can significantly limit the usage of Ad vectors. Previous studies have demonstrated that several signaling pathways are triggered by Ads, inclusive of TLR-dependent pathways. The G-protein-coupled receptor adaptors beta-arrestin-1 (beta-Arr1) and beta-arrestin-2 (beta-Arr2) are known to have pivotal roles in regulating TLR4 triggered signaling and inflammatory responses. In this study, we examined the role of beta-arrestins in Ad5-vector-induced inflammatory responses. Our studies reveal that both beta-arrestins are capable of modulating Ad5-vector-induced inflammatory responses in vivo and in vitro. Importantly, our studies divulge another level of complexity to these responses, as our results demonstrate beta-Arr1 to be a positive regulator, and beta-Arr2 a negative regulator of Ad5 induced innate immune responses. These data may allow gene therapy biologists to more accurately study the mechanisms underlying Ad5-vector-induced immune responses, and may also direct future efforts to modulate these mechanisms to improve the safety and/or efficacy of this important gene transfer vector.

Complement and renal transplantation: from donor to recipient

Long-term kidney graft survival is affected by different variables including donor condition, ischemia-reperfusion injury, and graft rejection during the transplantation process. The complement system is an important mediator of renal ischemia-reperfusion injury and in rejecting allografts. However, donor complement C3 seems to be crucial in renal transplantation-related injury as renal injury is attenuated in C3 deficient kidney grafts. Interestingly, before ischemia-reperfusion induced C3 expression, C3 is already induced in donors suffering from brain death. Therefore, strategies targeting complement activation in the brain-dead donor may increase graft viability and transplant outcome.

Isolation and characterization of an anti-complementary protein-bound polysaccharide from the stem barks of Eucommia ulmoides

EWDS-1, a homogeneous protein-bound polysaccharide, was isolated as an anti-complementary agent from the stem barks of Eucommia ulmoides. EWDS-1 was identified as a branched proteoglycan with average molecular weight about 2,000,000 Da, composed of Gal, Glc and Ara in the ratio of 2.1:1.0:0.9, along with trace of Rha, Xyl, Man, as well as 3.95% of protein. The linkages of the residues of EWDS-1 were deduced by methylation analysis and NMR technique. Bioassay showed that EWDS-1 inhibited complement activation on both the classic and alternative pathways with CH(50) and AP(50) values of 203+/-20 microg/ml and 45+/-8 microg/ml, respectively. Preliminary mechanism studies by using complement component depleted-sera indicated that EWDS-1 inhibits activation of complement system by interacting with C1q, C1r, C1s, C2, C3, C4, C5 and C9. The results suggested that EWDS-1 could be of promising benefits in treatment of the complement associated diseases.

Early detection of memory deficits and memory improvement with vaccinia virus complement control protein in an Alzheimer's disease model

Vaccinia virus complement control protein (VCP) inhibits both the classical and alternate complement pathways. In diseases such as traumatic brain injury (TBI) and Alzheimer's disease (AD), pathological inflammation is caused by amongst several factors, prolonged or inappropriate activation of the complement system and is a significant cause of neurodegeneration. This study investigates for the first time the use of a cheeseboard maze to evaluate cognitive deficits and the effect of VCP on memory processes in 2- and 3-month-old mice that express mutant amyloid precursor protein (APPswe) and mutant presenilin 1 (Ps1dE9) that correspond to a form of early onset AD. A four-phase training schedule was carried out on the cheeseboard maze before intracranial injections of 5 microl of VCP (1.7 microg/microl) or 5 microl saline. Two weeks later the effect of VCP on memory was evaluated. A statistically significant decrease in goal latency in VCP-treated mice than saline-treated transgenic mice in both the first probe and reverse tasks was observed. Similarly, after a second intracranial VCP or saline injection performed 2 months later, the 6.5- and 7.5-month aged VCP-injected mice performed significantly better in goal latency in both second probe and reverse tasks than saline-treated mice. These data also demonstrated that the use of a dry maze is a sensitive technique for distinguishing cognitive measures between non-transgenic and APPswe/PS1De9 transgenic mice at a much earlier stage.

Serum mannan-binding lectin levels in patients with celiac disease: an analysis of clinical and autoimmune features

Mannan-binding lectin (MBL) is the central protein in the activation of complement through the lectin pathway. MBL plasma concentration is genetically determined and varies significantly among individuals. Recent findings suggest that MBL is associated with the pathogenesis of celiac disease (CD). In this study, MBL and C-reactive protein (CRP) levels were determined in 101 celiac patients and 120 controls, with the aim to associate with the presence of gluten in the diet, disease severity, and the presence of concomitant autoimmune diseases. MBL concentration was determined by ELISA and CRP by nephelometry, using a high-sensitivity method. EmA-IgA and other autoantibodies were tested by indirect immunofluorescence. Although a significant increase in MBL levels was observed in male patients compared to female (P = 0.024), the absence of any other association suggests that circulating MBL and CRP concentrations are not associated with clinical and autoimmune CD features in Brazilian patients.

New evaluation therapies for sepsis

This article presents an analysis of the literature of the last 2 years on the treatment of sepsis and septic shock. It appears that most of the antimediator therapies applied in phase II or III clinical trials yielded disappointing results. But, many other therapeutic approaches are proposed or are ongoing, and many papers report critical analysis of the reasons for the lack of success of past clinical trials.