Anti-thrombosis Repertoire of Blood-feeding Horsefly Salivary Glands

Abstract

Blood-feeding arthropods rely heavily on the pharmacological properties of their saliva to get a blood meal and suppress immune reactions of hosts. Little information is available on antihemostatic substances in horsefly salivary glands although their saliva has been thought to contain wide range of physiologically active molecules. In traditional Eastern medicine, horseflies are used as antithrombosis material for hundreds of years. By proteomics coupling transcriptome analysis with pharmacological testing, several families of proteins or peptides, which exert mainly on anti-thrombosis functions, were identified and characterized from 60,000 pairs of salivary glands of the horsefly Tabanus yao Macquart (Diptera, Tabanidae). They are: (I) ten fibrin(ogen)olytic enzymes, which hydrolyze specially alpha chain of fibrin(ogen) and are the first family of fibrin(ogen)olytic enzymes purified and characterized from arthropods; (II) another fibrin(ogen)olytic enzyme, which hydrolyzes both alpha and beta chain of fibrin(ogen); (III) ten Arg-Gly-Asp-motif containing proteins acting as platelet aggregation inhibitors; (IV) five thrombin inhibitor peptides; (V) three vasodilator peptides; (VI) one apyrase acting as platelet aggregation inhibitor; (VII) one peroxidase with both platelet aggregation inhibitory and vasodilator activities. The first three families are belonging to antigen five proteins, which show obvious similarity with insect allergens. They are the first members of the antigen 5 family found in salivary glands of blood sucking arthropods to have anti-thromobosis function. The current results imply a possible evolution from allergens of blood-sucking insects to anti-thrombosis agents. The extreme diversity of horsefly anti-thrombosis components also reveals the anti-

Ayadualin, a novel RGD peptide with dual antihemostatic activities from the sand fly Lutzomyia ayacuchensis, a vector of Andean-type cutaneous leishmaniasis

“…Disintegrins present their RGD sequences to integrins by forming a characteristic disulfide bond-stabilized loop, the formation of which is essential for their activity, and competitively interfere with the binding between fibrinogen and integrins resulting in inhibition of platelet aggregation [27][28][29]. In insects, this family of proteins has been found solely in the salivary glands of the horsefly Tabanus yao [29,30]. On the other hand, a short RGD-containing peptide was identified from Lu.…”

“…Platelet aggregation was measured by using a microplate method as described previously [33]. Briefly, 100 μl of PRP was mixed with 30 After incubation for 1 hr at 37˚C, the wells were washed three times with PBS-T, and a mouse anti-human CD41 (GPIIb) monoclonal antibody (Exbio, Praha, Czech Republic) was added. Following 1 hr-incubation at 37˚C and three washes, the wells were further incubated with horseradish peroxidase (HRP)-conjugated goat anti-mouse IgG (BD Biosciences, San Diego, CA) for 1 hr at 37˚C.…”

The Salivary Gland Transcriptome of the Eastern Tree Hole Mosquito,Ochlerotatus triseriatus

“…gambiae that were found to be overexpressed in bacterial-challenged mosquitoes, such as the protein gi 46095203 (Shi and Paskewitz 2004). The serine proteases cannot be easily functionally characterized, as they may play an endogenous role as activators of immunity, such as prophenoloxidase activators, or in specific roles in blood feeding, such as plasminogen activator or fibrinogenases, as was found for salivary proteases of tabanids (Xu et al 2008, Ma et al 2009). The DNase enzyme from O. triseriatus has a clear signal peptide indicative of secretion.…”

Ecosystem Services Provided by the Little Things That Run the World

“…The anticoagulants and other components in the salivary glands of blood-sucking insects, for example in horseflies, have been used for hundreds of years as anti-thrombosis treatments in Eastern Medicine [86].…”