targeted-toxins

Pittenger CJ (2015) Modeling Tourette syndrome pathophysiology through targeted manipulation of striatal interneurons. Neuroscience 2015 Abstracts 6.07. Society for Neuroscience, Chicago IL.

Summary: Postmortem studies of Tourette syndrome patients has revealed a reduction in the number of specific striatal interneurons. The authors explored the hypothesis that this neuronal deficit is enough to produce the symptoms of Tourette syndrome in mice. Animals received 90-ng injections of Anti-ChAT-SAP (Cat. #IT-42) into the striatum. Rabbit IgG-SAP (Cat. #IT-35) was used as a control. The data suggest that loss of the striatal interneurons is enough to produce some, but not all, of the symptoms caused by Tourette syndrome.

Related Products: Anti-ChAT-SAP (Cat. #IT-42), Rabbit IgG-SAP (Cat. #IT-35)

See Also:

• Xu M et al. Targeted ablation of cholinergic interneurons in the dorsolateral striatum produces behavioral manifestations of Tourette syndrome. Proc Natl Acad Sci U S A 112:893-898, 2015.

Q: I’m trying to find out if enough Anti-DBH-SAP will be retrogradely transported and taken up by non targeted sympathetic neurons by bulk fluid-phase endocytosis. Does saporin become degraded after it kills the neuron or does it enter the extracellular matrix?

A: It is very unlikely that a targeted toxin such as Anti-DBH-SAP is freed from the targeted neuron in a meaningful condition. There has never been a reported identification of a targeted toxin, functionally or not, after it has eliminated its targeted neuron. Current evidence indicates that effective suicide transport agents undergo endocytosis at nerve terminals followed by retrograde axonal transport of the endocytic vesicles containing the toxin. Experiments using vincristine have shown that the retrograde axonal transport of suicide transport toxins utilizes the fast transport system (microtubules). However, it is not known what determines whether or not a specific toxin-ligand undergoes axonal transport after internalization.

Related Products: Anti-DBH-SAP (Cat. #IT-03)

Aoki S, Wickens JR (2015) Featured Article: A specific immunotoxin elucidates a causal role of striatal cholinergic system in behavioral flexibility. Targeting Trends 16(4)

Related Products: Anti-ChAT-SAP (Cat. #IT-42)

Read the featured article in Targeting Trends.

See Also:

• Aoki S et al. Role of Striatal Cholinergic Interneurons in Set-Shifting in the Rat. J Neurosci 35:9424-9431, 2015.

Aicher S, Hermes S, Hegarty D (2015) Denervation of the lacrimal gland leads to corneal hypoalgesia in a novel rat model of aqueous dry eye disease. Invest Ophthalmol Vis Sci 56:6981-6989. doi: 10.1167/iovs.15-17497

Summary: One result of functional disruption of the tear gland is dry eye disease (DED), which represents a group of disorders rather than a singular one. DED manifests itself in altered responses to noxious corneal stimulation, but many of these patients do not actually have dry eyes or tear gland dysfunction. In order to investigate what circuits are involved in DED the authors created two models, one of which used the ablation of p75 receptor-expressing neurons innervating the extraorbital lacrimal gland. Rats received 2.5 μg of 192-IgG-SAP (Cat. #IT-01) directly into the left extraorbital lacrimal gland. Tear production in the lesioned animals was normal, and responses to noxious cold stimuli were impaired. This accompanied by unchanged fiber density indicates that the nociceptive signaling was affected on a molecular level.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Devoto P, Flore G, Saba P, Frau R, Gessa G (2015) Selective inhibition of dopamine-beta-hydroxylase enhances dopamine release from noradrenergic terminals in the medial prefrontal cortex. Brain Behav 5:e00393. doi: 10.1002/brb3.393

Summary: Dopamine-beta-hydroxylase (DBH) is a neuronal enzyme that is a potential target for the treatment of cocaine abuse, alcohol dependence, and eating disorders. Here the authors administered 5 μg of icv Anti-DBH-SAP (Cat. #IT-03) to rats, and assessed the effect of the dopaminergic lesion on levels of extracellular dopamine. Mouse IgG-SAP (Cat. #IT-18) and saporin (Cat. #PR-01) were used as controls. Extracellular levels of dopamine were significantly increased in both lesioned animals and those treated with the DBH inhibitor nepicastat. Clonadine could reverse the nepicastat effect, but not the effect of Anti-DBH-SAP treatement. The data demonstrate a mechanism for the synergistic effect of cocaine on nepicastat-induced dopamine release.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Mouse IgG-SAP (Cat. #IT-18), Saporin (Cat. #PR-01)

Cao Q, Lu J, Li Q, Wang C, Wang X, Lee V, Wang C, Nguyen H, Zheng G, Zhao Y, Alexander S, Wang Y, Harris D (2016) CD103+ dendritic cells elicit CD8+ t cell responses to accelerate kidney injury in adriamycin nephropathy. J Am Soc Nephrol 27:1344-1360. doi: 10.1681/ASN.2015030229

Summary: Although it is known that dendritic cells (DCs) are involved in chronic kidney disease, it is not well understood how they either resolve or aggravate the condition. CD103+ dendritic cells in particular, are known to maintain tolerance through interaction with regulatory T cells, as well as protect against infection through interactions with CD8+ T cells. In this work the authors depleted CD103+ DCs by administering 1 mg/kg of anti-CD103-SAP (Cat. #IT-50) to the intraperitoneal space of mice subject to adriamycin nephropathy. Rat IgG-SAP (Cat. #IT-17) was used as a control. Elimination of the CD103+ DCs attenuated the kidney injury, indicating that in murine chronic kidney disease CD103+ DCs are pathogenic rather than therapeutic.

Related Products: Anti-CD103-SAP (Cat. #IT-50), Rat IgG-SAP (Cat. #IT-17)

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)

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)

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)

Apps R, Strata P (2015) Neuronal circuits for fear and anxiety – the missing link. Nat Rev Neurosci 16(10):642. doi: 10.1038/nrn4028 PMID: 26333516

Objective: To study the active role of the cerebellar network in conditioned and unconditioned fear by quantifying the connection of cerebellar cortical areas to emotional driven responses.

Summary: The article seeks to quantify the connection of cerebellar cortical areas like the prefrontal cortex to emotional driven responses, like the freezing associated with fearful stimuli. CTB-SAP lesioned rats, causing localized cell death in the fear associated regions of the brain being studied, are compared to sham-lesioned rats and the length of freezing time as a response to a negatively-percevied auditory tone and cat-odor.

Usage: Rats received microinjections of the neurotoxin CTB–Saporin into the vermal lobule VIII which resulted in a localized lesion of cerebellar cortical connections.

Related Products: CTB-SAP (Cat. #IT-14)