targeted-toxins

Li A, Wang Q, Elsarelli M, Brown R, Ritter S (2015) Hindbrain catecholamine neurons activate orexin neurons during systemic glucoprivation in male rats. Endocrinology 156:2807-2820. doi: 10.1210/en.2015-1138

Summary: Norepinephrine and epinephrine-secreting catecholamine neurons are strong stimulators of food intake. The authors investigated the interaction between these catecholamine neurons and orexin neurons in the perifornical lateral hypothalamus (PeFLH), which are known to be involved with the stimulation of food intake, increased arousal, and behavioral activation. Rats received 82-ng injections of Anti-DBH-SAP (Cat. #IT-03) into the PeFLH terminal field in order to lesion catecholamine neurons. Saporin (Cat. #PR-01) was used as a control. Assessment of food intake in response to 2-deoxy-D-glucose, as well as selective catecholamine activation, indicated that orexin neuron activation may be involved in glucoprivic appetite responses.

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

Navratilova E, Xie J, Meske D, Qu C, Morimura K, Okun A, Arakawa N, Ossipov M, Fields H, Porreca F (2015) Endogenous opioid activity in the anterior cingulate cortex is required for relief of pain. J Neurosci 35:7264-7271. doi: 10.1523/JNEUROSCI.3862-14.2015

Summary: There are a number of neuronal circuits involved in the processing of pain, including those that control somatosensory, affective, and cognitive aspects of pain perception. Opioid signaling in the anterior cingulate cortex (ACC) plays a part in pain modulation – this area has also been implicated in the encoding of pain aversiveness. In order to examine the neuronal mechanisms of pain relief and the following reward, the authors of this paper administered 48 ng of Dermorphin-SAP (Cat. #IT-12) into the rostral ACC of rats. Saporin (Cat. #PR-01) was used as a control. The results illuminate the opioid pathway during pain treatment, and the dependence of nucleus accumbens dopaminergic transmission on upstream ACC opioid circuits during pain processing.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Saporin (Cat. #PR-01)

Nichols N, Vinit S, Bauernschmidt L, Mitchell G (2015) Respiratory function after selective respiratory motor neuron death from intrapleural CTB-saporin injections. Exp Neurol 267:18-29. doi: 10.1016/j.expneurol.2014.11.011

Summary: Amyotrophic lateral sclerosis (ALS) ultimately causes death from ventilator failure. Genetic models of ALS suffer from high variability of the rate, timing, and extent of respiratory motor neuron death. The authors created a novel model of induced respiratory motor neuron death using CTB-SAP (Cat. #IT-14). Rats received 25 μg or 50 μg intrapleural injections of CTB-SAP; Saporin (Cat. #PR-01) was used as a control. After 7 days, motor neuron survival approximated what is seen in end-stage ALS rats, while there was minimal cell death in other brainstem or spinal cord regions. CTB-SAP also caused microglial activation, decreased breathing during chemoreceptor stimulation, and diminished phrenic motor output in anesthetized rats – all hallmarks of ALS.

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

Gulino R, Parenti R, Gulisano M (2015) Novel mechanisms of spinal cord plasticity in a mouse model of motoneuron disease. Biomed Res Int 2015:654637. doi: 10.1155/2015/654637

Summary: Here the authors investigate spinal plasticity mechanisms involving a number of different proteins, including BDNF, Shh, Notch-1, Numb, and Noggin. The model used is a mouse motoneuron depletion strategy, where the animals receive 3 μg of CTB-SAP (Cat. #IT-14) into each of the medial and lateral gastrocnemius muscles. The results indicate that TDP-43, a nuclear DNA/RNA binding protein, may be an important regulator of synaptic plasticity.

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

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)

Q: I ordered a targeted toxin. Will it come in powder form? How do I re-dissolve it?

A: Our Saporin conjugate products are all provided in sterile PBS solution within a concentration range of 0.5 – 3 mg/ml. Saporin is an extremely safe ‘toxin’ to handle in standard laboratory environments when in solution for several reasons. Solutions in general are easier to corral and keep contained than powders and consequently are less likely to accidentally end up on an individual’s skin, tongue, or in one’s eyes. As a lyophilized product, Saporin would also be present at an extremely high concentration such that there is cause for concern should it contact the body of the user in any way. Lastly, our Saporin conjugates have historically required dilution prior to use for both in vitro and in vivo procedures. As such, it is much easier to ensure the amount of material you, as a customer, are receiving and the subsequent dilution is accurately adjusted to your desired concentration when providing these products already in solution. If upon receiving a Saporin conjugate you believe the product to be lyophilized or in a powder form, please contact us immediately, prior to opening the vial.

Related Products: Targeted Toxins

Wu Y, Song S, Liu H, Xing D, Wang X, Fei Y, Li G, Zhang C, Li Y, Zhang L (2015) Role of adrenomedullin in the cerebrospinal fluid-contacting nucleus in the modulation of immobilization stress. Neuropeptides 51:43-54. doi: 10.1016/j.npep.2015.03.007

Summary: The CSF-contacting nucleus (CSF-CN) is a brain structure containing neurons that can bidirectionally transmit signals between the brain parenchyma and the CSF. In order to better understand what regulatory peptides modulate this organ, the authors eliminated the CSF-CN of rats with a 500-ng icv injection of CTB-SAP (Cat. #IT-14). Saporin (Cat. #PR-01) was used as a control. The elimination of the CSF-CN worsened the response to chronic immobilization stress; with other data this information suggests that the CSF-CN uses adrenomedullin as a stress-related peptide.

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

Q: I’m interested in your anti-DBH-saporin toxin for lesioning central catecholaminergic neurons. I see from the product description that the antibody used is a mouse monoclonal – designed to specifically target rat DBH. My interest is to produce targeted lesions in mouse transgenic. Will this product still work specifically? Thanks.

A: Unfortunately, we do not have really good data to support the use of our Anti-DBH-SAP (Cat. #IT-03) in mice. There is significant homology between mouse and rat DBH, however the actual antigen for both the mouse monoclonal we use in the immunotoxin and an alternate unpurified rabbit polyclonal, is native bovine DBH enzyme. For further background information there are two references where our product was used in mice. The references are listed below.

An early sympathetic nervous system influence exacerbates collagen-induced arthritis via CD4+ / CD25+ cells.[1] The sympathetic nervous system can play conflicting roles in collagen-induced arthritis (CIA). CD4+CD25+ T cells can play an immunoregulatory effect in this system depending on the expression of the FoxP3 transcription factor. Mice received 5-µg intraperitoneal injections of anti-DBH-SAP to induce an early sympathectomy. The results indicate that the sympathetic nervous system increases disease severity in CIA by stimulating some of the proinflammatory aspects of CD4+CD25+ T cells.

An opposing time-dependent immune-modulating effect of the sympathetic nervous system conferred by altering the cytokine profile in the local lymph nodes and spleen of mice with type II collagen-induced arthritis.[2] In this work the authors examined the role of the sympathetic nervous system (SNS) in late stages of chronic arthritis. 5 µg intraperitoneal injections of anti-DBH-SAP in mice were used to confirm that previous 6-OHDA injections caused a sympathectomy. The results demonstrate that the SNS supports inflammation during the asymptomatic phase of arthritis, but inhibits inflammation during the chronic symptomatic phase.

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

References

1. Harle P et al. An early sympathetic nervous system influence exacerbates collagen-induced arthritis via CD4+CD25+ cells. Arthritis Rheum 58:2347-2355, 2008.
2. Harle P et al. An opposing time-dependent immune-modulating effect of the sympathetic nervous system conferred by altering the cytokine profile in the local lymph nodes and spleen of mice with type II collagen-induced arthritis. Arthritis Rheum 52:1305-1313, 2005.

Peters C, Hayashida K, Suto T, Houle T, Aschenbrenner C, Martin T, Eisenach J (2015) Individual differences in acute pain-induced endogenous analgesia predict time to resolution of postoperative pain in the rat. Anesthesiology 122:895-907. doi: 10.1097/ALN.0000000000000593

Summary: The authors investigated the relationship between preoperative Conditioned Pain Modulation (CPM) and the time course of recovery from surgery. CPM was evaluated using forepaw capsaicin injections into rats. During the study, lesioned rats received 5-μg intrathecal injections of anti-DBH-SAP (Cat. #IT-03), followed 14 days later by a partial L5 spinal nerve ligation surgery. Mouse-IgG-SAP (Cat. #IT-18) was used as a control. CPM was partially blocked in the lesioned animals, suggesting descending noradrenergic signaling is important in the time course of recovery from surgery.

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

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.