Tarantulas and Their Venomous Relatives

Poecilotheria metallica/ Zoological Survey of India

Jazlyn Mooney & Ann Stevenson

Introduction

• We chose to study tarantula venom due to its broad spectrum of potential pharmaceutical uses.

• During our research we noticed that many large venomous spiders are commonly mistaken as tarantulas, thus creating an unnatural fear of tarantulas within the human population.

Introduction

• What is venom?

• True Tarantulas- The difference between Old World & New World - Potential uses and mechanism- Case Studies

• Venom of Spiders Commonly Mistaken as Tarantulas

- Potential uses and mechanisms

Introduction

• Envenomation

• Antivenin

• Newly Discovered Species

• Summary

• Conclusion

What is venom?

Poisonous fluid secreted by animals and insects by typically injected into prey or

aggressors by biting or stinging.

TRUE TARANTULAS

New

World

Old World

Categorization

True Tarantulas are categorized as either New World or Old World based solely on their geographic location.

Briesemeister Projection

Tarantulas

Tarantulas

Out with the Old in with the New• New World Tarantulas appear to have a mild

temperament, thus seemingly they are more “tolerable” of humans. It is thought that the behavior may be due to an extra defense. Theses spiders have the ability to flick urticating hairs off of their bodies, while Old World Tarantulas can only envenomate presumed predators (tarantulaguyuk, 2011).

– Urticating hairs of a tarantula will cause varying levels of discomfort which include: burning, stinging, and itchiness. During molting periods tarantulas may incorporate these hairs on the webs as an additional deterrent to potential predators (tarantulaguyuk, 2011).

Grammostola spatulata

http://aboutmonca.blog.cz/galerie/sklipkani/obrazek/6023307

Grammostola spatulata

• Geographic Location: Northern Chile and Argentina (animal-world.com)– G. spatulata is the brown variety of the Chilean Rose Hair– New World Tarantula

• Lifespan of females is about 20 years and males live about 6 years (animal-world.com)

• Typically very docile so they are commonly sold as low maintenance pets

• Venom is nontoxic for humans (Dobson 2001)

GsMTx4• Isolated from G. spatulata with a specificity

for particular mechanosensitive ion channels (MSC). MSCs are ubiquitious non-specific tissues.

• Target: Stretch activated MSCs

• Potential Treatment: for cardiac arrhythmia, muscular dystrophy and glioma

GsMTx4 Mechanism

• The peptide binds to boundary lipids surrounding the channel and alters the voltage gated channel (Gottlieb et al. 2004)

– Boundary lipids are bent toward the channel

• Appears to be selective for Stretch Activated Channels (Escoubas and Lachlan 2004)

GsMTx4 Mechanism

GsMTx4 alters the plasma membrane by bending the areas around the stretch activated voltage gated channels.

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Poecilotheria regalis

http://www.mmo-champion.com

www.Beechhold, Henry

Poecilotheria regalis

• pronounced pee-suh-luh-THI-ree-uh (Beechhold, 2000)

• P. regalis is known as the Indian Ornamental– New World tarantula

• It is primarily arboreal (bighairyspiders.com)

• There haven’t been a lot of studies done on the venom of P. regalis– We decided to look up a couple of cases involving P. regalis

envenomation to see if we could come up with any ideas about the potential type of venom it carries.

P. regalis venom• Case 1

– "If you recall I mentioned that I was bitten by a 4 inch regalis last week and reported no particular problems other than a sore finger, of which the discomfort is slowly disappearing. I have now noticed one or 4 other things. Now whether they are related to this bite I simply don't know, only those who have been bitten before maybe able to comment. 2 nights ago approximately 24 hours after the bite my right calf muscle seized for approx. 5 minutes. I put this down to a simple muscle cramp. (Had them before but not for a few years). At approx. 6am in the morning I had another in the same leg. Now this got me thinking if it was related to the T bite. That day I seemed very tired, exhausted and wanted to sleep, but I plodded on. The next day, still tired I finished work at 12pm dozed on the sofa and at around 3pm I got the same cramp, only this time in my left calf, later that day a muscle in my lower jaw temporarily seized during a yawn.” (www.bighairyspiders.com)

P. regalis venom• Case 2– “In 2000, a middle-aged man was bitten on his finger by an

Indian Ornamental Tarantula (Poecilotheria regalis Poecilotheriinae) whose body was 4 cm long. He developed local swelling and erythema of the hand, and severe local pain. At follow up, 8 days later, these symptoms had resolved but he still had a tight feeling and cramps in the bitten hand and vague generalized ‘flu-like’ myalgias (muscle pain). “ (Ahmed et al. 2009)

• Case 3– A man bitten by Poecilotheria regalis “experienced violent pain

that radiated up the bitten arm into the axillary lymph nodes and persisted for 20 min.” (Ahmed et al. 2009)

P. regalis venom• Case 4

– Personal Blog with video here is the link if you want to check it out: http://www.arachnoboards.com/ab/showthread.php?140875Poecilotheriaregalis&s=2ebd7a5f14e6425f0d51a377fef376b1

“10:45pm - Initial bite:Felt like a hot penny nail going through the skin. The actual bite felt hot - no little prick of pain, just heat. I immediately took 4 Benedryl [sic]. My hand turned red in a matter of seconds and I could actually feel the 'heat' going up my arm.11:20pm:Sweating profusely, cramps going all the way up my arm to my shoulder. Pain very bad!12:20am:Jaw started to hurt as well - other cramping continued. Pain about an 8 on a scale of 1-10. Left to go to the ER to have my vitals checked. Heart rate was up but otherwise I was fine, except for the cramping and pain. I was also nauseous by this point. Due to a 4 hour wait at the ER, I left at this point.12:40am:Joints in my arms and legs started hurting really bad…shortness of breath continued. Benedryl [sic] really kicking in now - very tired and dizzy. Walking was difficult due to being so dizzy, tired, and having severe cramping.” (arachnoboards.com)

Venom HypothesisWe believe that this venom is likely a neurotoxin based on the localized pain and the muscle cramps experienced by victims in all four cases. There were additional cases of envenomation that we read about, and muscle cramps continue to be one of the major symptoms. Muscle cramps may indicate that the venom has some effect on potassium channels.

VENOMOUS SPIDERS COMMONLY MISTAKEN FOR TARANTULAS

Phoneutria nigriventer

courtesy of João P. Burini

courtesy of João P. Burini

Phoneutria nigriventer• “Phoneutria” translates to Murderess in Greek (Brazilian

Wandering Spider)

• Found throughout South America and Costa Rica (Brazilian Wandering Spider)

• Commonly known as the Brazilian Wandering Spider or Banana Spider – This spider often hides in bunches of bananas during the day

• Can deliver potentially fatal doses of venom to humans– LD50 = 200 µg/kg (Ori and Ikeda 1998)

PnTx2-6 Neurotoxin

• Isolated from P. nigriventer

• Target: calcium channels

• Potential Treatment: erectile dysfunction (ED) (Nunes, 2010)

PnTx2-6 Mechanism for ED

• Pntx2-6 indirectly induces activity in calcium channels which increases the level of nitric oxide (NO).

• NO boosts circulation in the penis by helping the walls of the blood vessels to relax in cavernosal of rats (Nunes, 2010).

PnTx3-6• PnTx3-6 was isolated from P. nigriventer – potential safer alternative to morphine (addictive opiate)

and zinconotide which causes headache, nausea, confusion, vomiting, etc. (De Souza 2011).

• Target: Ca2+ ion gated channels

• Potential treatment for allodynic, long-term, and pre or postoperative pain – Authors observed no neurological, cardiac, or

immunological side effects in any rats or mice. The withdrawal symptoms were also less severe when using PnTx3-6 (De Souza 2011).

PnTx3-6 Mechanism• Molecular binding site is still unknown (Vieira

et al. 2005)

• Completely or incompletly blocks the external pore of the calcium channels

• Complete blockage of N-type calcium channel suggests that the toxin binds tightly to the external mouth of the channel and physically occludes the pore (Vieira et al. 2005).

Macrothele raveni

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Macrothele raveni

• Commonly known as the Chinese Funnel Web

• The body length of this hairy spider is only 2-3cm (Zeng, et al 2003)

• The LD50 = 0.772 mg/kg of raventoxin-I in mice (Zeng, et al 2003)

Macrothele raveni

• Venom isolated from M. raveni selectively suppresses the growth of cancerous cells via apoptosis

• Target: caspase 3 and caspase 8 pathways

• Potential Treatment: myelogenous leukemia (Liu et al., 2012)

M. raveni venom• Venom activates

caspase 3 an apoptosis-related peptidase that interacts with caspase 8.

– Caspase 3 plays a central role in the execution-phase of cell apoptosis via the extrinsic signaling pathway. (Clark and Tyler, 2009)

Clarke and Tyler, 2009

M. raveni venom• In the extrinsic pathway,

death ligands bind and activate their cognate receptors (Fas). (Clarke and Tyler, 2009)

• The toxin induces apoptosis in myelogenous leukemia K562 cell line without affecting other cells (Liu et al., 2012)

Clarke and Tyler, 2009

Atrax robustus

Tirin/Ianmacm

http://www.arachnoboards.com/

Atrax robustus• A. robustus is a venomous

funnel web spider centrally located in Sydney, Australia

• One of the only spider species with confirmed deaths

-Most appear to be caused by males (inchem.org)

• The Sydney Funnel Web Spider injects venom every time it strikes

- This venom is known as Robustoxin (inchem.org)

- LD50 = 0.16 mg/kg (Sheumack et al. 1984)

http://www.micropest.com/

Robustoxin

• Robustoxin affects the cardiovascular system, central nervous system and peripheral nervous system

– Robustoxin alone causes a typical syndrome of envenomation in primates and man of whole male Atrax robustus venom. (Sheumack et al. 1984)

– On the autonomic system the venom causes both inhibition of neurally mediated release of transmitters (eg noradrenaline, acetylcholine) and an increase in spontaneous transmitter release. A similar action on the skeletal muscle neuromuscular junction has been postulated (inchem.org)

Envenomation

Envenomation

• The bite causes intense pain and redness

• Symptoms of envenomation can be seen within the first ten minutes. – Symptoms include: muscle spasms, salivation or

lachrymation, piloerection (goose bumps), tachycardia, shortness of breath, disorientation, and confusion (inchem.org)

– Hypertension, hypotension, pulmonary edema, and raised intracranial pressure can also occur in severe envenomation (inchem.org)

Venom Optimization Hypothesis

The “venom optimization hypothesis” postulates that due to the high metabolic costs of venom regeneration, venom dosage is behaviorally controlled and used as economically as possible. (Morgenstern & King, 2012)

Morgenstern and King, 2012

Antivenin

http://www.venompatrol.org

Focus

We focused specifically on antivenin for the Sydney Funnel Web Spider (A. robustus), because it has the most confirmed fatalities out of all venomous spiders. Antivenin isolated from the Sydney Funnel Web Spider has also been used to treat envenomation from another genera of funnel web known as Hadronyche.

Background• This map gives the location of

two genera of the Australian Funnel Web Spiders (Atrax and Hadronyche).

• An antivenin from A. robustus known as FWS AV went into use beginning in 1980 (Graudins, et al. 2002).

• Physicians began to treat bites from Hadronyche genera with FWS AV and noticed that symptoms of envenomation were alleviated in their patients (Graudins, et al. 2002).

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Researchers confirmed that FWS AV can be used to treat envenomation from both A. robustus and several species of Hadronyche spiders (H. versuta, H. infensa, H. cerberea, and H. Formidabilis).

The Research

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Antivenin Conclusion

• The ability to use the same antivenin across multiple species of animals is known as polyvalence.

• The polyvalence of FWS AV is likely due to venom homologies across these two genera of Funnel Web Spiders.– Researchers believe it may be linked to

atracotoxins, which are shared by both genera. (Graudins et al., 2002.)

Newly Discovered Species

Poecilotheria rajaei

Ranil Nanayakkara / British Tarantula Society

Poecilotheria rajaei

• pronounced pee-suh-luh-THI-ree-uh (Beechhold, 2000)

• Discovered and identified April 2013 in Sri Lanka

• Size of the human face

• Usually found in trees, however with habitat shrinking found in old abandoned buildings (Drake, 2013)

• Not toxic to humans (Drake, 2013)

Summary• Tarantulas and their close relatives both

produce venom that affect many systems of the body. Their venom seems to be highly specialized, and targets only particular ion channels.

• Venom is constructed of numerous compounds whose functions and consequences vary based on environment.

Conclusion

• We realize that although we had a unnatural fear for tarantulas and their sister taxa in the beginning , we now respect them for the potential medical benefits they can provide for us.

– Maybe that’s worth the creepiness of these wonderful arachnids?

• Tarantula venom has novel compounds that come with both positive and negative consequences. Learning about these compounds may help to develop new pharmaceuticals and new antivenins for spider bites.

References• Ahmed, N., et al. 2009. “Symptom in search of a toxin: muscle spasms following

bites by Old World tarantula spiders (Lampropelma nigerrimum,Pterinochilus murinus, Poecilotheria regalis) with review” Oxford University Press. Vol. 102 pp 851–857.

• Beechhold, Henry F. "A Key to the Pronunciation and Meaning of Scientific Names of Popular Species Part I: Pronunciation." A Key to the Pronunciation and

Meaning of Scientific Names of Popular Species Part I: Pronunciation.” The American Tarantula Society, 2000. Web. 16 Apr. 2013. <http://atshq.org/articles/beechwp1.html>.

• "Brazilian Wandering Spider." Brazilian Wandering Spider. Turkcebilgi, 2010. Web. 15 Apr. 2013. <http://english.turkcebilgi.com/Brazilian wandering spider>.

• Clarke, P. and Tyler, K.L. 2009. “Apoptosis in animal models of virus- induced disease” Nature Review Microbiology. Vol. 7 pp. 144-155

• C., Rob. "P. Regalis Bite Report Thread: Poecilotheria Regalis." Web Blog post. Arachnoboards RSS. vBulletin, Nov. 2007. Web. 17 Apr. 2013. <http://www.arachnoboards.com/ab/showthread.php?140875 Poecilotheria-regalis>.

References• De Souza, A.H., et al., 2011. “Antiallodynic effect and side effects of Phα1β,

a neurotoxin from the spider Phoneutria nigriventer: Comparison with conotoxin MVIIA and morphine.” Toxicon Vol. 58 pp 626-633.

• Dobson, Roger, 2001. “Spider venom may prevent atrial fibrillation” Western Journal of Medicine Vol. 3 pp 164.

• Drake, N., 2013 "New Giant Tarantula Discovered in Sri Lanka | Wired.com." Wired Science. 2 Apr. 2013. Web. Date accessed 5 Apr. 2013.

• Escoubas, Pierre, and Lachlan, Rash. 2004. "Tarantulas: eight-legged pharmacists and combinatorial chemists." Toxicon Vol. 43 pp. 555 – 574.

• Gottlieb, Philip A. et al. 2004. “Mechanosensitive Ion Channels as Drug Targets” CNS & Neurological Disorders Vol. 3, pp 61-72.

• Graudins, A., et al., 2002. “Cross-reactivity of Sydney funnel-web spider antivenom: neutralization of the in vitro toxicity of other

Australian funnel-web (Atrax and Hadronyche) spider venoms” Toxicon Vol. 40 pp 259–266.

References • Gurley, Russ, and Brough, Clarice. "Rose-haired Tarantula." Animal World.

Animal World, 2012. Web. 15 Apr. 2013. <http://animal-world.com/encyclo/reptiles/spiders/rosehairtarantula.php>.

• Liu, Z., et al., 2012. “The venom of the spider Macrothele raveni induces apoptosis in the myelogenous leukemia K562 cell line.” Leukemia Research. Vol. 36, No. 8, pp 1063-1066.

• Nunes, K.P, et al. 2010, “Nitric Oxide-Induced Vasorelaxation in Response to PnTx2-6 Toxin from Phoneutria nigriventer Spider in Rat Cavernosal Tissue” The Journal of Sexual Medicine Volume 7 Issue 12 pp 3879-3888.

• Ori, Masahisa and Ikeda, Hiroyoshi, 1998. "Spider Venoms and Spider Toxins". Jounal of Toxicology.Toxin reviews 17 (3): 405-426.

• Sheumack DD, Baldo BA, Carroll PR, Hampson F, Howden ME, Skorulis A, 1984. "A comparative study of properties and toxic constituents of funnel web spider (Atrax) venoms". Comparative biochemistry and physiology Vol. 78 pp. 55-68.

References• Schumm, Thomas. "Tarantula Bites!" Web log post. Phong's Tarantulas!

N.p., 2013. Web. 17 Apr.2013. <http://www.bighairyspiders.com/bites.shtml>.

• Tarantulaguyuk. "New World and Old World tarantula's." HubPages. August 7, 2011 Web. Date accessed April 13 2013.

• Vieira, Luciene B., et al. 2005. “Inhibition of High Voltage-Activated Calcium Channels by Spider Toxin PnTx3-6” The Journal of Pharmacology and Experimental Therapeutics Vol. 314, No. 3, pp 1370-1377.

• White, Julian "Atrax Robustus." (PIM 049). International Programme on Chemical Safety, n.d. Web. 16 Apr. 2013. <http://www.inchem.org/documents/pims/animal/atrax.htm>

• Zeng. X., et al 2003 "Purification and characterization of raventoxin-I and raventoxin-III, two neurotoxic peptides from the venom of the spider Macrothele raveni" Toxicon 41 651-656