Araldi D, Ferrari L, Levine J (2016) Gi-protein-coupled 5-HT1B/D receptor agonist sumatriptan induces type I hyperalgesic priming. Pain 157:1773-1782. doi: 10.1097/j.pain.0000000000000581

Summary: The present study explored the possibility that, like MOR and A1-adenosine receptor agonists, triptans would also induce type II hyperalgesic priming. In addition, they explored the 5-HT receptor subtypes at which triptans act (5-HT1B, 5-HT1D and 5-HT7) to induce priming. They report that while sumatriptan, a prototypical 5-HT1B/D receptor agonist induces hyperalgesic priming, this priming meets the criteria for type I rather than type II priming. Isolectin B4 (IB4)-saporin (Cat. #IT-10), was diluted in saline, and a dose of 3.2 μg, in a volume of 20 μL was administered intrathecally to rats. The neurotoxin [Sar9,Met(O2) 11]-substance P-saporin (SSP-Saporin, Cat. #IT-11) was diluted in saline, and a dose of 100 ng, in a volume of 20 μL was administered intrathecally. In a model of pain chronification, sumatriptan induces both mechanical hyperalgesia at the site of injection and type I hyperalgesic priming, in nociceptors innervating the cutaneous injection site.

Related Products: IB4-SAP (Cat. #IT-10), SSP-SAP (Cat. #IT-11)

La J, Feng B, Kaji K, Schwartz E, Gebhart G (2016) Roles of isolectin B4-binding afferents in colorectal mechanical nociception. Pain 157:348-354. doi: 10.1097/j.pain.0000000000000380

Summary: Primary afferent neurons are often classified as peptidergic or non-peptidergic. One characteristic of the non-peptidergic neurons is that they bind isolectin-B4. In the spinal cord these neurons terminate mainly in inner lamina II. Non-peptidergic neurons in the spinal cord have been found to be involved in various aspects of pain response. In this work the authors examined the role of non-peptidergic neurons in the viscerosensory system. Rats received 1.5 μg of intrathecal recombinant IB4-SAP (Cat. #IT-10) between the L5 and L6 vertebrae. Saporin (Cat. #PR-01) was used as a control. While IHC demonstrated that a majority of viscerosensory L6 colon DRG neurons are IB4+, they do not play a significant role in colorectal mechano-nociception.

Related Products: IB4-SAP (Cat. #IT-10), Saporin (Cat. #PR-01)

Sakurai T, Kamiyoshi A, Kawate H, Mori C, Watanabe S, Tanaka M, Uetake R, Sato M, Shindo T (2016) A non-inheritable maternal Cas9-based multiple-gene editing system in mice. Sci Rep 6:20011. doi: 10.1038/srep20011

Summary: In this work, the authors generated transgenic mice with systemic Cas9 overexpression (Cas9 mice) in order to simplify the procedure of generating genetically modified animals using the CRISPR/Cas9 system – only guide RNAs (gRNAs) would need to be administered to induce mutations at target loci. To test Cas9 mice for genome editing in vitro, the authors transiently transfected primary fibroblasts from Cas9 mice with Ggta1 gRNA (Ggta1 is responsible for synthesizing the cell-surface α-Gal epitope). They treated the fibroblasts with rIB4-SAP (Cat. #IT-10) and found that it killed Ggta1 +/+ and KO/+ cells, while biallelic Ggta1 KO cells survived as they did not synthesize the α-Gal epitope. This indicated that primary cells from the Cas9 transgenic mice have CRISPR/Cas9 genome editing capability with the administration of gRNA alone. The success of their experiments indicate that this method could potentially be used to generate other genetically modified animals.

Related Products: IB4-SAP (Cat. #IT-10)

Kras J, Weisshaar C, Pall P, Winkelstein B (2015) Pain from intra-articular NGF or joint injury in the rat requires contributions from peptidergic joint afferents. Neurosci Lett 604:193-198. doi: 10.1016/j.neulet.2015.07.043

Summary: Both peptidergic and non-peptidergic neurons innervate the facet joint, which is the source of pain in a majority of neck trauma. In this work the authors examined these subpopulations of neurons to determine the contribution of each in facet joint pain. 100 ng of SSP-SAP (Cat. #IT-11) was injected into bilateral C6/C7 facet joints of rats. Alternatively, rats received 5 μg of rIB4-SAP (Cat. #IT-10) via the same method. Saporin (Cat. #PR-01) was used as control. SSP-SAP, but not rIB4-SAP was able to prevent NGF-induced mechanical and thermal hypersensitivity. SSP-SAP administration also prevented behavioral hypersensitivity and NGF upregulation in the dorsal root ganglion after facet joint distraction. The data indicate that interference with peptidergic signaling within the facet joint may be a treatment for pain originating in that location.

Related Products: SSP-SAP (Cat. #IT-11), IB4-SAP (Cat. #IT-10), Saporin (Cat. #PR-01)

Araldi D, Ferrari L, Levine J (2015) Repeated mu-opioid exposure induces a novel form of the hyperalgesic priming model for transition to chronic pain. J Neurosci 35:12502-12517. doi: 10.1523/JNEUROSCI.1673-15.2015

Summary: Repeated administration of mu-opioid receptor agonists can lead to persistent mechanical hyperalgesia. One current hypothesis is that a form of hyperalgesic priming is triggered by the repeated activation of these receptors. Classic hyperalgesic priming is associated with signaling via protein kinase Cε (PKε), which is mediated by isolectin-B4+ (IB4) nociceptors. In this work the authors eliminated the IB4+ nociceptors with a 3.2 μg intrathecal injection of recombinant IB4-SAP (Cat. #IT-10). The authors found that hyperalgesic priming induced through the use of DAMGO was dependent on protein kinase A activation rather than activation of PKε. This work demonstrates a novel model for hyperalgesic priming transitioning to chronic pain.

Related Products: IB4-SAP (Cat. #IT-10)

Saeed A, Pawlowski S, Ribeiro-da-Silva A (2015) Limited changes in spinal lamina I dorsal horn neurons following the cytotoxic ablation of non-peptidergic C-fibers. Mol Pain 11:54. doi: 10.1186/s12990-015-0060-z

Summary: For the most part nociceptive information is moved from the periphery to the spinal cord through small diameter primary afferents. One subclass of these afferents is further divided into peptidergic and non-peptidergic populations. The authors examined the role of the non-peptidergic afferents in normal nociception and pain, especially the aspect that in rat neuropathic and inflammatory pain models there is novel expression of neurokinin-1 receptors in some neurons normally devoid of this protein. Rats received 4.8-μg injections of rIB4-SAP (Cat. #IT-10) into the left sciatic nerve, over three injection sites. While the number of non-peptidergic neurons was significantly reduced, de novo expression of the neurokinin-1 receptor was not increased in lamina I pyramidal projection neurons.

Related Products: IB4-SAP (Cat. #IT-10)

Oyamaguchi A, Abe T, Sugiyo S, Niwa H, Takemura M (2016) Selective elimination of isolectin B4-binding trigeminal neurons enhanced formalin-induced nocifensive behavior in the upper lip of rats and c-Fos expression in the trigeminal subnucleus caudalis. Neurosci Res 103:40-47. doi: 10.1016/j.neures.2015.07.007

Summary: In adult rats non-peptidergic neurons and peptidergic neurons innervate different areas and layers of the lamina. It is thought that these two neuronal populations play different roles in nociceptive processing, but the specific function of each group is not well understood. In order to investigate peptidergic and non-peptidergic neurons in orofacial pain processing the authors injected the cisterna magna of rats with 2.9 μg of rIB4-SAP (Cat. #IT-10). Blank-SAP (Cat. #IT-21) was used as a control. The lesioned animals displayed more frequent face-rubbing responses on the administration of formalin, indicating that IB4-binding neurons in the trigeminal nerve play an anti-nociceptive role in response to this type of pain.

Related Products: IB4-SAP (Cat. #IT-10), Blank-SAP (Cat. #IT-21)

Ono K, Ye Y, Viet C, Dang D, Schmidt B (2015) TRPV1 expression level in isolectin B₄-positive neurons contributes to mouse strain difference in cutaneous thermal nociceptive sensitivity. J Neurophysiol 113:3345-3355. doi: 10.1152/jn.00973.2014

Summary: In order to determine whether IB4-positive trigeminal sensory neurons affect pain sensitivity, the authors administered 2 μg of rIB4-SAP (Cat. #IT-10) to the right infraorbital foramen. Saporin (Cat. #PR-01) was used as a control.

Related Products: IB4-SAP (Cat. #IT-10), Saporin (Cat. #PR-01)

Sato M, Watanabe S (2015) Featured Article: Drug-free selection of stable transfectants using targeted toxin technology and a vector expressing cell-surface carbohydrate-digesting enzyme. Targeting Trends 16(2)

Related Products: IB4-SAP (Cat. #IT-10)

Read the featured article in Targeting Trends.

See Also:

• Sato M et al. A combination of targeted toxin technology and the piggyBac-mediated gene transfer system enables efficient isolation of stable transfectants in nonhuman mammalian cells. Biotechnol J 10:143-153, 2015.

Devesa I, Ferrándiz-Huertas C, Mathivanan S, Wolf C, Luján R, Changeux J, Ferrer-Montiel A (2014) αCGRP is essential for algesic exocytotic mobilization of TRPV1 channels in peptidergic nociceptors. Proc Natl Acad Sci U S A 111:18345-18350. doi: 10.1073/pnas.1420252111

Summary: The sensitization of transient receptor potential vanilloid 1 (TRPV1) can lead to the development and maintenance of chronic pathological pain conditions. In this work the authors determined that TRPV1 receptors use membrane insertion mechanisms in order to potentiate neuronal excitability. In order to specifically link this activity to peptidergic neurons the authors treated rat primary dorsal root ganglion cultures with 10 mM rIB4-SAP (Cat. #IT-10) to deplete the non-peptidergic neurons.

Related Products: IB4-SAP (Cat. #IT-10)