The peptide Phα1β, from spider venom, acts as a TRPA1 channel antagonist with antinociceptive effects in mice

Abstract

BACKGROUND AND PURPOSEPeptides from venomous animals have long been important for understanding pain mechanisms and for the discovery of pain treatments. Here, we hypothesized that Phα1β, a peptide from the venom of the armed spider Phoneutria nigriventer, produces analgesia by blocking the TRPA1 channel. EXPERIMENTAL APPROACHCultured rat dorsal root ganglion (DRG) neurons, human fetal lung fibroblasts (IMR90) or HEK293 cells expressing the human TRPA1 (hTRPA1-HEK293), human TRPV1 (hTRPV1-HEK293) or human TRPV4 channels (hTRPV4-HEK293), were used for calcium imaging and electrophysiology. Nociceptive responses induced by TRPA1, TRPV1 or TRPV4 agonists or by bortezomib were investigated in mice. KEY RESULTSPhα1β selectively inhibited calcium responses and currents evoked by the TRPA1 agonist, allyl isothiocyanate (AITC), on hTRPA1-HEK293, IMR90 fibroblasts and DRG neurons. Phα1β did not affect calcium responses evoked by selective TRPV1 (capsaicin) or TRPV4 (GSK 1016790A) agonists on the various cell types. Intrathecal (i.t.) and intraplantar (i.pl.) administration of low doses of Phα1β (up to 300 pmol per paw) attenuated acute nociception and mechanical and cold hyperalgesia evoked by AITC (i.t. or i.pl.), without affecting responses produced by capsaicin or hypotonic solution. Notably, Phα1β abated the TRPA1-dependent neuropathic pain-like responses induced by bortezomib. In vitro and in vivo inhibition of TRPA1 by Phα1β was reproduced by a recombinant form of the peptide, CTK 01512-2. CONCLUSIONS AND IMPLICATIONSPhα1β and CTK 01512-2 selectively target TRPA1, but not other TRP channels. This specific action underlines the potential of Phα1β and CTK 01512-2 for pain treatment.Abbreviations AITC, allyl isothiocyanate; BTZ, bortezomib; CIPN, chemotherapy-induced peripheral neuropathy; DRG, dorsal root ganglia; i.pl., intraplantar; IMR90, human fetal lung fibroblasts; PWT, paw withdrawal threshold; VGCCs, voltage-gated calcium channels

Targeting nociceptive transient receptor potential channels to treat chronic pain: current state of the field

“…TRPA1 null mice have substantially attenuated cold allodynia evoked by oxaliplatin, cisplatin and bortezomib (Nassini et al, ; Trevisan et al, ). These findings have been reproduced by pharmacological inhibition with HC‐030031 (Nassini et al, ; Trevisan et al, ), a peptide blocker of TRPA1 channels (Tonello et al, ), or the more advanced TRPA1 channel antagonist, HC‐068559 (Moran et al, ). Although studies have suggested that oxaliplatin and cisplatin cause cold hypersensitivity in part by up‐regulating expression of TRPA1 channels in sensory neurons (Ta et al, ; Yamamoto et al, ), increased sensitivity of the TRPA1 channel may also play a role.…”

“…A wide variety of reports testing both pharmacological agents and gene deletions have suggested that TRPA1 channels play a critical role in mechanical hypersensitivity after chemotherapy‐induced peripheral neuropathy. These include oxaliplatin (Nassini et al, ; Materazzi et al, ; Zhou et al, ), bortezomib (Trevisan et al, ; Tonello et al, ) and paclitaxel (Materazzi et al, ; Moran et al ., 2011a). Given the similarities in mechanisms between chemotherapy‐induced peripheral neuropathy and painful diabetic neuropathy, it is not surprising that there has also been significant data implicating TRPA1 channels in painful diabetic neuropathy.…”

Evaluation of DNA damage in spinal cord and mutagenic effect of a Phα1β recombinant toxin with analgesic properties from the Phoneutria nigriventer spider

“…In fact, these toxins have different antinociceptive effects when compared with ω‐CTx‐MVIIA, which have been explained due to diverse actions on N‐type VGCC or due to inhibition on other VGCC such as R‐type, P/Q‐type and L‐type . In addition, Phα1β and CTK 01512‐2 have shown antagonism on TRPA1 channels, besides acting on VGCC, which may increase not only their antinociceptive effects, but also their adverse reaction . Otherwise, ω‐CTx‐MVIIA is a selective and reversible blocker of the N‐type VGCC, preventing calcium influx .…”

“…The antinociceptive activities of Phα1β were reached at doses at which no side effects have been shown . Moreover, Phα1β toxin is a selective TRPA1 receptor antagonist and, therefore, may produce effective antinociception with reduced doses …”

Resolvin D3 controls mouse and human nociceptive functions and preclinical progression of psoriasis

“…The time spent licking, flinching, and biting the injected hindpaw was recorded for 5 min. 19 Chemical itch tests: The pruritogens chloroquine (100 g; Sigma), histamine (100 g; Sigma), and serotonin (4 g; Sigma) were dissolved in 0.9% sterile saline and injected intradermally in the cheek in a volume of 20 l. The behavior of each animal was video-recorded over the following 30 min, and the number of hindpaw scratch bouts was counted.…”