Earthworm protease in anti-thrombosis and anti-fibrosis

Development of a Methodology Based on Optical Interferometry for Measuring Fibrinolytic Activity

Fibrinolytic activity assay is particularly important for the detection, diagnosis, and treatment of cardiovascular disease and the development of fibrinolytic drugs. A novel efficacious strategy for real-time and label-free dynamic detection of fibrinolytic activity based on ordered porous layer interferometry (OPLI) was developed. Fibrin or a mixture of fibrin and plasminogen (Plg) was loaded into the highly ordered silica colloidal crystal (SCC) film scaffold to construct a fibrinolytic response interference layer to measure fibrinolytic activity with different mechanisms of action. Fibrinolytic enzyme-triggered fibrinolysis led to the migration of interference fringes in the interferogram, which could be represented by optical thickness changes (ΔOT) tracked in real time by the OPLI system. The morphology and optical property of the fibrinolytic response interference layer were characterized, and the Plg content in the fibrinolytic response interference layer and experimental parameters of the system were optimized. The method showed adequate sensitivity for the fibrinolytic activity of lumbrokinase and streptokinase, with wide linear ranges of 12-6000 and 10-2000 U/mL, respectively. Compared with the traditional fibrin plate method, it has a lower detection limit and higher linearity. The whole kinetic process of fibrinolysis by these two fibrinolytic drug models was recorded in real time, and the Michaelis constant and apparent kinetic parameters were calculated. Importantly, some other blood proteins were less interfering with this system, and it showed reliability in fibrin activity detection in real whole blood samples. This study established a better and more targeted research method of in vitro fibrinolysis and provided dynamic monitoring data for the analysis of fibrinolytic activity of whole blood.

Pharmacological effects of bioactive agents in earthworm extract: A comprehensive review

This review compiles information from the literature on the chemical composition, pharmacological effects, and molecular mechanisms of earthworm extract (EE) and suggests possibilities for clinical translation of EE. We also consider future trends and concerns in this domain. We summarize the bioactive components of EE, including G-90, lysenin, lumbrokinase, antimicrobial peptides, earthworm serine protease (ESP), and polyphenols, and detail the antitumor, antithrombotic, antiviral, antibacterial, anti-inflammatory, analgesic, antioxidant, wound-healing, antifibrotic, and hypoglycemic activities and mechanisms of action of EE based on existing in vitro and in vivo studies. We further propose the potential of EE for clinical translation in anticancer and lipid-modifying therapies, and its promise as source of a novel agent for wound healing and resistance to antibiotic tolerance. The earthworm enzyme lumbrokinase embodies highly effective anticoagulant and thrombolytic properties and has the advantage of not causing bleeding phenomena due to hyperfibrinolysis. Its antifibrotic properties can reduce the excessive accumulation of extracellular matrix. The glycolipoprotein extract G-90 can effectively scavenge reactive oxygen groups and protect cellular tissues from oxidative damage. Earthworms have evolved a well-developed defense mechanism to fight against microbial infections, and the bioactive agents in EE have shown good antibacterial, fungal, and viral properties in in vitro and in vivo experiments and can alleviate inflammatory responses caused by infections, effectively reducing pain. Recent studies have also highlighted the role of EE in lowering blood glucose. EE shows high medicinal value and is expected to be a source of many bioactive compounds.

Purification and identification of thrombolytic peptides from enzymatic hydrolysate of Pheretima vulgaris

Pheretima vulgaris has been prescribed for the treatment of cardiovascular diseases in China for several hundred years in the form of dried powder in the clinic. However, the peptides with the potential antithrombotic activity of this source have never been reported. The total active proteins from Pheretima vulgaris were hydrolyzed by eight different commercial proteases and the alcalase hydrolysate showed the strongest thrombolytic activity. Four original thrombolytic peptides were isolated and characterized using bioactivity-directed fractionation of the active hydrolysate. The amino acid sequences were identified as HEPLPEP (m/z 818.40076), EYPLPEP (m/z 844.39648), LGEPSVP (m/z 698.39648), and LLAPP (m/z 510.28043) by nanoLC-ESI-Orbitrap mass spectrometry with PEAKS software. HEPLPEP and EYPLPEP, containing the common -PLPEP residue, showed superior thrombolytic activity in plasmin assay and fibrinogen-thrombin time assay. This research confirmed that Pheretima vulgaris was a potential source of active peptides with thrombolytic activities and provided novel candidates for the thrombolytic agents. PRACTICAL APPLICATIONS: Thrombosis has become the leading cause of mortality as it was the common underlying pathology of cardiovascular diseases, such as ischemic heart disease, and stroke. The demand for thrombolytics has increased gradually as the incidence trends of thrombosis-related diseases raise with the aging of the population. Four novel thrombolytic peptides were characterized from Pheretima vulgaris proteins hydrolysates, among which HEPLPEP and EYPLPEP could prevent the formation of thrombus and degrade existing thrombus in vitro. These peptides are promising to be meritorious templates for developing thrombolytic agents. The structure-function relationship of peptides resulting from the presence of specific residues in these sequences may contribute to extending the knowledge about their thrombolytic activity, which may be useful in designing novel thrombolytic agents. The present research based on a bioactivity-directed isolation strategy could also be applied to other animal-derived traditional Chinese medicines with proteins or peptides as their function basis.

A Strategy for Rapid Discovery of Marker Peptides Associated with Fibrinolytic Efficacy of Pheretima aspergillum Based on Bioinformatics Combined with Parallel Reaction Monitoring

Quality control of animal-derived traditional Chinese medicines has improved dramatically as proteomics research advanced in the past few decades. However, it remains challenging to identify quality attributes with routine proteomics approaches since protein with fibrinolytic activity is rarely reported in pheretima, a typical animal-derived traditional medicine. A novel strategy based on bioinformatics combined with parallel reaction monitoring (PRM) was developed here to rapidly discover the marker peptides associated with a fibrinolytic effect. Potential marker peptides were found by lumbrokinase sequences’ alignment and in silico digestion. The fibrinogen zymography was used to visually identify fibrinolytic proteins in pheretima. As a result, it was found that the fibrinolytic activity varied among different portions of pheretima. Fibrinolytic proteins were distributed regionally in the anterior and anterior-mid portion and there was no significant fibrinogenolytic activity observed in the mid-posterior and posterior portion. Finally, PRM experiments were deployed to validate and quantify selected marker peptides and a total of 11 peptides were identified as marker peptides, which could be potentially used in quality control of pheretima. This strategy provides a robust workflow to benefit the quality control of other animal-derived traditional medicines.

Natural inhibitors from earthworms for the crystallization of calcium oxalate monohydrate

Two proteins are proposed as CaOx nucleation and crystal growth regulators. The site-specific adsorption of inhibitors is confirmed from both macroscopic and microscopic perspectives.

Bioevaluation of Pheretima vulgaris Antithrombotic Extract, PvQ, and Isolation, Identification of Six Novel PvQ-Derived Fibrinolytic Proteases

Thrombosis is a disease that seriously endangers human health, with a high rate of mortality and disability. However, current treatments with thrombolytic drugs (such as recombinant tissue-plasminogen activator) and the oral anticoagulants (such as dabigatran and rivaroxaban) are reported to have a tendency of major or life-threatening bleeding, such as intracranial hemorrhage or massive gastrointestinal bleed with non-specific antidotes. In contrast, lumbrokinase is very specific to fibrin as a substrate and does not cause excessive bleeding. It can dissolve the fibrin by itself or convert plasminogen to plasmin by inducing endogenous t-PA activity to dissolve fibrin clots. Therefore, searching for potentially new therapeutic molecules from earthworms is significant. In this study, we first collected a strong fibrinolytic extract (PvQ) from the total protein of the Pheretima vulgaris with AKTA pure protein purification systems; its fibrinolytic bioactivity was verified by the fibrin plate assay and zebrafish thrombotic model of vascular damage. Furthermore, according to the cell culture model of human umbilical vein endothelial cells (HUVECs), the PvQ was proven to exhibit the ability to promote the secretion of tissue-type plasminogen activator (t-PA), which further illustrated that it has an indirect thrombolytic effect. Subsequently, extensive chromatographic techniques were applied to reveal the material basis of the extract. Fortunately, six novel earthworm fibrinolytic enzymes were obtained from the PvQ, and the primary sequences of those functional proteins were determined by LC-MS/MStranscriptome cross-identification and the Edman degradation assay. The secondary structures of these six fibrinolytic enzymes were determined by circular dichroism spectroscopy and the three-dimensional structures of these proteases were predicted by MODELLER 9.23 based on multi-template modelling. In addition, those six genes encoding blood clot-dissolving proteins were cloned from P. vulgaris by RT-PCR amplification, which further determined the accuracy of proteins primary sequences identifications and laid the foundation for subsequent heterologous expression.

Development of a sensitive indirect competitive enzyme-linked immunosorbent assay for high-throughput detection and risk assessment of aflatoxin B1 in animal-derived medicines

Animal-derived medicine is an important part of traditional Chinese medicine (TCM). Studies have shown that many animal-derived medicinal products are susceptible to contaminate of aflatoxins, nevertheless, the rapid detection for animal-derived medicine is prone to be ignored. Here we developed a sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) for rapid screening of aflatoxin B₁ (AFB₁) in ground beetle, cockroach, silkworm and earthworm. The sensitivity of the icELISA method was significantly enhanced. The IC₅₀ for the four animal-derived medicinal samples ranged from 0.092 to 0.135 ng mL^-1; the limit of detection (LOD) was 0.008-0.020 ng mL^-1. To obtain high accuracy, the extraction solution and time were evaluated. By using this method, a total of 138 samples were investigated, and the detection rates of AFB₁ in ground beetle and earthworm samples were 26.6% and 16.7%, respectively. The result was validated by liquid chromatography combined with tandem mass spectrometry, and an excellent correlation was observed between the two datasets, with a R² value of 0.999. Our results indicate that the proposed method can be used for the rapid detection of AFB₁ in animal-derived medicine. Furthermore, the quantitative risk assessment was conducted for ground beetle and earthworm based on the results, demonstrating that the intake of AFB₁ in ground beetle had a slight threat to the risk of cancer.

A novel fibrinolytic enzymes from the Korean traditional fermented food-Jotgal: Purification and characterization

The fibrinolytic activity in Korean traditional fermented food, Jotgal (pickled fish) was identified. Though the fibrinolytic activity could vary in different kinds of Jotgal, this activity seems to be produced by microorganisms during the natural fermentation stage. From Gonjaengijot (pickled opossum shrimp), two novel fibrinolytic enzymes named by JP-I and JP-II, have been purified by ethanol precipitation, Bio-GEL P-100 gel filtration, and DEAE-cellulose ion-exchange chromatography. Compared to the crude enzyme extract, the specific activity of the JP-I and JP-II increased 258, 85-fold with the recovery of 22.1, 8.5%, respectively. The molecular weights of both enzymes were estimated as 36 kDa on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal condition for fibrinolytic activity of JP-I was at 50°C and pH 8.1, while that of JP-II was at 45°C and 9.9. Both enzymes were stable at a broad range of pH (5.0 to 10.5) and have metalloprotease nature. From these results, it concludes that these enzymes could be a novel potent thrombolytic agent. PRACTICAL APPLICATIONS: The fibrinolytic enzyme is one of the clinical agents for cardiovascular diseases which is the leading cause of morbidity and mortality worldwide with 17 million deaths every year. A variety of fibrinolytic enzymes are found and characterized from various sources such as plants, animals, and microorganisms, and new sources for fibrinolytic enzymes continue to be explored. Jotgal, widely used in Korean people's diet, is a traditional Korean seafood prepared from many different types of fishes, fish eggs, fish intestines, and shellfishes. Through an amount of research, some of fibrinolytic enzymes were found and purified from Jotgal, however, no studies have been done on fibrinolytic enzyme from opossum shrimp. In this study, the purification, enzymatic characteristics, and fibrinolytic activity of the proteases, originated from Korean traditional fermented food, Jotgal were reported. These enzymes could be novel potent thrombolytic agent.