A novel expression profile of the Loxosceles intermedia spider venomous gland revealed by transcriptome analysis

Abstract

Spiders of the Loxosceles genus are cosmopolitan, and their venom components possess remarkable biological properties associated with their ability to act upon different molecules and receptors. Accidents with Loxosceles intermedia specimens are recognized as a public health problem in the south of Brazil. To describe the transcriptional profile of the L. intermedia venom gland, we generated a wide cDNA library, and its transcripts were functionally and structurally analyzed. After initial analyses, 1843 expressed sequence tags (ESTs) produced readable sequences that were grouped into 538 clusters, 281 of which were singletons. 985 reads (53% of total ESTs) matched to known proteins. Similarity searches showed that toxin-encoding transcripts account for 43% of the total library and comprise a great number of ESTs. The most frequent toxins were from the LiTx family, which are known for their insecticidal activity. Both phospholipase D and astacin-like metalloproteases toxins account for approximately 9% of total transcripts. Toxins components such as serine proteases, hyaluronidases and venom allergens were also found but with minor representation. Almost 10% of the ESTs encode for proteins involved in cellular processes. These data provide an important overview of the L. intermedia venom gland expression scenario and revealed significant differences from profiles of other spiders from the Loxosceles genus. Furthermore, our results also confirm that this venom constitutes an amazing source of novel compounds with potential agrochemical, industrial and pharmacological applications.

Characterization of Brown spider (Loxosceles intermedia) hemolymph: Cellular and biochemical analyses

“…Phospholipases-D, metalloproteases, hyaluronidases, and insecticidal peptides, among others, have already been described and characterized as components of Loxosceles venoms, whose effects are due to the synergistic effect of the several toxins. Transcriptome analysis has also been performed, showing the percentages of each toxin in the total mRNA of the venom gland (Gremski et al, 2010;Fernandes-Pedrosa et al, 2008). Concerning proteomic approaches, there are 3 studies on the venom of Loxosceles spiders (Machado et al, 2005;dos Santos et al, 2009;Zobel-Thropp et al, 2014).…”

Pattern of inflammatory response to Loxosceles intermedia venom in distinct mouse strains: A key element to understand skin lesions and dermonecrosis by poisoning

“…We would have expected a more linear response, but the sphingomyelinase D activity observed only in the highest concentration (100ug/mL) can be explained by the use of venom pool of different spiders Loxosceles intermedia diluted in physiological saline, being this concentration related to the total protein, it is not possible to affirm the exact concentration of the enzyme sphingomyelinase in relation to protein concentration tested. The transcriptomic analysis of whole venom of L. intermedia showed that 20.2% of transcripts coding for toxins belonged to sphingomyelinase D (Gremski et al, 2010), thus it can be said that for lower total protein concentrations tested in this work, 10 and 30 ug/mL, corresponding respectively approximately 2 and 6 ug/mL of sphingomyelinase D, not being the activity at these concentrations detected accurately.…”

Helminthes and insects: maladies or therapies

“…Furthermore, it has been found that, when the level of HA decreases under conditions in which hyaluronidase activity increases, the moisture and tension of the skin are reduced, and histamine is released from mast cells (Barla et al 2009), so, the future recognition and characterization of hyaluronidase inhibitors will be relevant to the development of contraceptives, anti-tumor, antimicrobial, anti-venom, anti-wrinkle, anti-aging agents, and allergy and inflammation suppressors (da Silveira et al 2007; Barla et al 2009). From this context, it is obvious that Loxosceles recombinant hyaluronidases are associated with numerous potential applications (Gremski et al 2010). TCTP protein has been identified in Loxosceles intermedia venom gland, and it has been proposed as a potential cancer biomarker (Slaby et al 2009) as TCTP protein levels are upregulated in cancer cells and in human tumors ) and downregulated in biological models of tumor reversion (Tuynder et al 2004).…”