scholarly journals Antimicrobial Peptide Arenicin-1 Derivative Ar-1-(C/A) as Complement System Modulator

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 631
Author(s):  
Ilia A. Krenev ◽  
Ekaterina S. Umnyakova ◽  
Igor E. Eliseev ◽  
Yaroslav A. Dubrovskii ◽  
Nikolay P. Gorbunov ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Cancer Cells ◽  
Disulfide Bond ◽  
Complement System ◽  
Targeted Therapeutics ◽  
Arenicola Marina ◽  
Functional Activities ◽  
Complement Proteins ◽  
Natural Forms ◽  
Therapeutics Development

Antimicrobial peptides (AMPs) are not only cytotoxic towards host pathogens or cancer cells but also are able to act as immunomodulators. It was shown that some human and non-human AMPs can interact with complement proteins and thereby modulate complement activity. Thus, AMPs could be considered as the base for complement-targeted therapeutics development. Arenicins from the sea polychaete Arenicola marina, the classical example of peptides with a β-hairpin structure stabilized by a disulfide bond, were shown earlier to be among the most prospective regulators. Here, we investigate the link between arenicins’ structure and their antimicrobial, hemolytic and complement-modulating activities using the derivative Ar-1-(C/A) without a disulfide bond. Despite the absence of this bond, the peptide retains all important functional activities and also appears less hemolytic in comparison with the natural forms. These findings could help to investigate new complement drugs for regulation using arenicin derivatives.

scholarly journals Modulation of Human Complement System by Antimicrobial Peptide Arenicin-1 from Arenicola marina

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 480 ◽  
Author(s):  
Ekaterina Umnyakova ◽  
Nikolay Gorbunov ◽  
Alexander Zhakhov ◽  
Ilia Krenev ◽  
Tatiana Ovchinnikova ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Complement System ◽  
Complement Activation ◽  
Marine Invertebrates ◽  
Cytotoxic Agents ◽  
Arenicola Marina ◽  
Low Concentrations ◽  
Marine Polychaete ◽  
Hypothetical Mechanism

Antimicrobial peptides from marine invertebrates are known not only to act like cytotoxic agents, but they also can display some additional activities in mammalian organisms. In particular, these peptides can modulate the complement system as was described for tachyplesin, a peptide from the horseshoe crab. In this work, we investigated the influence on complement activation of the antimicrobial peptide arenicin-1 from the marine polychaete Arenicola marina. To study effects of arenicin on complement activation in human blood serum, we used hemolytic assays of two types, with antibody sensitized sheep erythrocytes and rabbit erythrocytes. Complement activation was also assessed, by the level of C3a production that was measured by ELISA. We found that the effect of arenicin depends on its concentration. At relatively low concentrations the peptide stimulates complement activation and lysis of target erythrocytes, whereas at higher concentrations arenicin acts as a complement inhibitor. A hypothetical mechanism of peptide action is proposed, suggesting its interaction with two complement proteins, C1q and C3. The results lead to the possibility of the development of new approaches for therapy of diseases connected with complement dysregulation, using peptide regulators derived from natural antimicrobial peptides of invertebrates.

Targeting Membrane Receptors of Ovarian Cancer Cells for Therapy

2019 ◽  
Vol 19 (6) ◽  
pp. 449-467
Author(s):  
Zhiquan Liang ◽  
Ziwen Lu ◽  
Yafei Zhang ◽  
Dongsheng Shang ◽  
Ruyan Li ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Receptor Binding ◽  
Cytoreductive Surgery ◽  
Therapeutic Strategies ◽  
Membrane Receptors ◽  
Ovarian Cancer Cells ◽  
Advanced Stage ◽  
Targeted Therapeutics ◽  
Cellular Processes

Ovarian cancer is a leading cause of death worldwide from gynecological malignancies, mainly because there are few early symptoms and the disease is generally diagnosed at an advanced stage. In addition, despite the effectiveness of cytoreductive surgery for ovarian cancer and the high response rates to chemotherapy, survival has improved little over the last 20 years. The management of patients with ovarian cancer also remains similar despite studies showing striking differences and heterogeneity among different subtypes. It is therefore clear that novel targeted therapeutics are urgently needed to improve clinical outcomes for ovarian cancer. To that end, several membrane receptors associated with pivotal cellular processes and often aberrantly overexpressed in ovarian cancer cells have emerged as potential targets for receptor-mediated therapeutic strategies including specific agents and multifunctional delivery systems based on ligand-receptor binding. This review focuses on the profiles and potentials of such strategies proposed for ovarian cancer treatment and imaging.

Serine proteases of the complement system

2000 ◽  
Vol 28 (5) ◽  
pp. 545-550 ◽  
Author(s):  
R. B. Sim ◽  
A. Laich
Keyword(s):  
Complement System ◽  
Serine Proteases ◽  
Enzymic Activity ◽  
Host Cells ◽  
Complement Protein ◽  
Factor B ◽  
Complement Proteins ◽  
Protein Protein Interaction ◽  
The Complement System ◽  
Natural Inhibitors

The complement system in blood plasma is a major mediator of innate immune defence. The function of complement is to recognize, then opsonize or lyse, particulate materials, including bacteria, yeasts and other microrganisms, host cell debris and altered host cells. Recognition occurs by binding of complement proteins to charge or saccharide arrays. After recognition, a series of serine proteases is activated, culminating in the assembly of complex unstable proteases called C3/C5 convertases. These activate the complement protein C3, which acts as an opsonin. The complement serine proteases include the closely related Clr, Cls, MASPs 1–3 (80–90 kDa), C2 and Factor B (100 kDa), Factor D (25 kDa) and Factor 1 (85 kDa). Each of these has unusually restricted specificity and low enzymic activity. The C1r, C1s and MASP group occur as proenzymes. When activated, they are regulated, like many plasma serine proteases, by a serpin, C1-inhibitor. C2 and Factor B, however, have complex multiple regulation by a group of complement proteins called the Regulation of Complement Activation (or RCA) proteins, whereas Factors I and D appear to have no natural inhibitors. Advances in structure determination and protein-protein interaction properties are leading to a more detailed understanding of the complement-system proteases, and are indicating possible new routes for potential therapeutic control of complement.

scholarly journals Complement proteins C7 and CFH control the stemness of liver cancer cells via LSF-1

2016 ◽  
Vol 372 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Hyang Sook Seol ◽  
Sang Eun Lee ◽  
Joon Seon Song ◽  
Je-Keun Rhee ◽  
Shree Ram Singh ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Cancer Cells ◽  
Complement Proteins ◽  
Liver Cancer Cells

Inhibitory effects of Bombyx mori antimicrobial peptide cecropins on esophageal cancer cells

2020 ◽  
Vol 887 ◽  
pp. 173434
Author(s):  
Ping Xu ◽  
Dingding Lv ◽  
Xihui Wang ◽  
Yongsheng Wang ◽  
Chengxiang Hou ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Antimicrobial Peptide ◽  
Cancer Cells ◽  
Bombyx Mori ◽  
Inhibitory Effects ◽  
Esophageal Cancer Cells

scholarly journals Mcl-1 Degradation Is Required for Targeted Therapeutics to Eradicate Colon Cancer Cells

2017 ◽  
Vol 77 (9) ◽  
pp. 2512-2521 ◽  
Author(s):  
Jingshan Tong ◽  
Peng Wang ◽  
Shuai Tan ◽  
Dongshi Chen ◽  
Zaneta Nikolovska-Coleska ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Targeted Therapeutics ◽  
Colon Cancer Cells

scholarly journals Viral-derived complement inhibitors: current status and potential role in immunomodulation

2016 ◽  
Vol 242 (4) ◽  
pp. 397-410 ◽  
Author(s):  
Hadi Abou-El-Hassan ◽  
Hassan Zaraket
Keyword(s):  
Complement System ◽  
Defense Mechanisms ◽  
Inflammatory Diseases ◽  
Immune Defense ◽  
Current Status ◽  
Viral Origin ◽  
Complement Proteins ◽  
Complement Inhibitors ◽  
Autoimmune And Inflammatory Diseases ◽  
The Complement System

The complement system is one of the body’s major innate immune defense mechanisms in vertebrates. Its function is to detect foreign bodies and promote their elimination through opsonisation or lysis. Complement proteins play an important role in the immunopathogenesis of several disorders. However, excessive complement activation does not confer more protection but instead leads to several autoimmune and inflammatory diseases. With inappropriate activation of the complement system, activated complement proteins and glycoproteins may damage both healthy and diseased tissues. Development of complement inhibitors represents an effective approach in controlling dysregulated complement activity and reducing disease severity, yet few studies have investigated the nature and role of novel complement inhibitory proteins of viral origin. Viral complement inhibitors have important implications in understanding the importance of complement inhibition and their role as a promising novel therapeutic approach in diseases caused by dysregulated complement function. In this review, we discuss the role and importance of complement inhibitors derived from several viruses in the scope of human inflammatory and autoimmune diseases.

scholarly journals Semi-Quantitative Multiplex Profiling of the Complement System Identifies Associations of Complement Proteins with Genetic Variants and Metabolites in Age-Related Macular Degeneration

2021 ◽  
Vol 11 (12) ◽  
pp. 1256
Author(s):  
I. Erkin Acar ◽  
Esther Willems ◽  
Eveline Kersten ◽  
Jenneke Keizer-Garritsen ◽  
Else Kragt ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Genetic Variants ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Complement Protein ◽  
Complement Proteins ◽  
New Associations ◽  
Age Related ◽  
The Complement System

Age-related macular degeneration (AMD) is a major cause of vision loss among the elderly in the Western world. The complement system has been identified as one of the main AMD disease pathways. We performed a comprehensive expression analysis of 32 complement proteins in plasma samples of 255 AMD patients and 221 control individuals using mass spectrometry-based semi-quantitative multiplex profiling. We detected significant associations of complement protein levels with age, sex and body-mass index (BMI), and potential associations of C-reactive protein, factor H related-2 (FHR-2) and collectin-11 with AMD. In addition, we confirmed previously described associations and identified new associations of AMD variants with complement levels. New associations include increased C4 levels for rs181705462 at the C2/CFB locus, decreased vitronectin (VTN) levels for rs11080055 at the TMEM97/VTN locus and decreased factor I levels for rs10033900 at the CFI locus. Finally, we detected significant associations between AMD-associated metabolites and complement proteins in plasma. The most significant complement-metabolite associations included increased high density lipoprotein (HDL) subparticle levels with decreased C3, factor H (FH) and VTN levels. The results of our study indicate that demographic factors, genetic variants and circulating metabolites are associated with complement protein components. We suggest that these factors should be considered to design personalized treatment approaches and to increase the success of clinical trials targeting the complement system.

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