targeted-toxins

Koshy Cherian A, Kucinski A, Wu R, deJong IEM, Sarter M (2019) Co-treatment with rivastigmine and idalopirdine reduces the propensity for falls in a rat model of falls in Parkinson’s disease. Psychopharmacology 236:1701–1715. doi: 10.1007/s00213-018-5150-y

Objective: The authors used a longer and more taxing rotating beam apparatus to determine the potential therapeutic efficacy of idalopirdine when combined with rivastigmine.

Summary: The results extend the prediction that the combined treatment with idalopirdine and an AChE inhibitor improves complex movement control and reduces propensity for falls in patients with movement disorders.

Usage: Basal forebrain cholinergic neurons situated in the nucleus basalis and substantia innominata were targeted with 192-IgG-SAP in aCSF infused bilaterally (200 ng/μL; 0.8 μL/hemisphere).

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

Gao ZR, Chen WZ, Liu MZ, Chen XJ, Wan L, Zhang XY, Yuan L, Lin JK, Wang M, Zhou L, Xu XH, Sun YG (2019) Tac1-expressing neurons in the periaqueductal gray facilitate the itch-scratching cycle via descending regulation. Neuron 101(1):45-59.e9. doi: 10.1016/j.neuron.2018.11.010

Objective: To determine the neural mechanism promoting the itch-scratching cycle.

Summary: Ablation of Tac1+ but not SST+ neurons decreases itch-induced scratching behavior. l/vlPAG Tac1+ neurons Induce Scratching Behavior via a Descending Pathway.

Usage: To ablate the spinal GRPR+ neurons, mice were intrathecally injected with Bombesin-SAP or Control Blank-SAP (400 ng/5 mL).

Related Products: Bombesin-SAP (Cat. #IT-40), Blank-SAP (Cat. #IT-21)

Saika F, Kiguchi N, Matsuzaki S, Kobayashi D, Kishioka S (2019) Inflammatory macrophages in the sciatic nerves facilitate neuropathic pain associated with type 2 diabetes mellitus. J Pharmacol Exp Ther 368(3):535-544. doi: 10.1124/jpet.118.252668

Objective: To determine whether inflammatory macrophages contribute to neuropathic pain associated with type 2 diabetes-mellitus (T2DM).

Summary: Inhibitory agents for macrophage-driven neuroinflammation could be potential candidates for novel pharmacotherapy against intractable neuropathic pain.

Usage: Injections of Mac-1-SAP or unconjugated Saporin (10 μl) were administered 3 times every 2 days. Perineural administration of Mac-1-SAP improved high-fat diet (HFD)-induced mechanical allodynia and the accumulation of F4/80+ macrophages and the upregulation of inflammatory mediators in the SCN after HFD-feeding.

Related Products: Mac-1-SAP mouse/human (Cat. #IT-06), Saporin (Cat. #PR-01)

Xiong L, Liu Y, Zhou M, Wang G, Quan D, Shen C, Shuai W, Kong B, Huang C, Huang H (2018) Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction. Europace 20(12):2036-2044. doi: 10.1093/europace/euy090

Objective: To evaluate the cardiac electrophysiologic effects of targeted ablation of cardiac sympathetic neurons (TACSN) in a canine model of chronic myocardial infarction (MI).

Summary: Targeted ablation of cardiac sympathetic neuron attenuates sympathetic remodelling and improves ventricular electrical remodelling in the chronic phase of MI. These data suggest that TACSN may be a novel approach to treating ventricular arrhythmias.

Usage: 20 μl of CTB-SAP (1.2 mg/ml) was mixed with 4 μl of 3% Evans blue dye to make it visible (CTB-SAP is colorless), ensuring localization within the ganglia. The CTB-SAP/ Evan blue dye solution was slowly and intermittently injected into the left stellate ganglia using a glass micropipette.

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

Ostrin LA, Strang CE, Chang K, Jnawali A, Hung L-F, Arumugam B, Frishman LJ, Smith EL, Gamlin PD (2018) Immunotoxin-induced ablation of the intrinsically photosensitive retinal ganglion cells in rhesus monkeys. Front Neurol 9:1000. doi: 10.3389/fneur.2018.01000

Objective: To develop and validate a targeted ipRGC immunotoxin to ultimately examine the role of ipRGCs in macaque monkeys.

Summary: Findings demonstrated that Melanopsin-SAP was specific for ipRGCs, and induced a graded reduction in the PLR (pupillary light reflex), as well as in ipRGC-driven pupil response with concentration.

Usage: Solutions of 0.316, 1, 3.16, 10, and 50 μg delivered intravitreally.

Related Products: Melanopsin-SAP (Cat. #IT-44)

Qiu M, Li J, Tan L, Zhang M, Zhou G, Zeng T, Li A (2018) Targeted ablation of distal cerebrospinal fluid-contacting nucleus alleviates renal fibrosis in chronic kidney disease. Front Physiol 9:1640. doi: 10.3389/fphys.2018.01640

Objective: To test the hypothesis that distal cerebrospinal fluid-contacting nucleus (dCSF-CNs) might affect the renin-angiotensin system (RAS) in kidney injury progression.

Summary: Less CTB-labeled neurons were found in dCSF-CNs of CTB-SAP-treated rats. Meanwhile, CTB-SAP downregulated AGT, Ang II, AT1R, NOX2, catalase, MCP-1, IL-6, fibronectin, and collagen I, and upregulated ACE2 and Mas receptor. Targeted dCSF-CNs ablation could alleviate renal inflammation and fibrosis in chronic kidney injury.

Usage: CTB-SAP (500 ng) into the lateral ventricles over a 3-min period.

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

Seel S, Eacott M, Langston R, Easton A (2018) Cholinergic input to the hippocampus is not required for a model of episodic memory in the rat, even with multiple consecutive events. Behav Brain Res 354:48-54. doi: 10.1016/j.bbr.2017.06.001

Summary: The authors use 192-IgG-SAP (Cat. #IT-01) to examine episodic memory. Continual trials versions of an episodic memory task are unimpaired by cholinergic lesions of the medial septum. In contrast continual trial versions of a location-context (where-which) task are impaired in the same animals. The results replicate the effects of lesions on one-trial a day versions of the same tasks. Increasing the amount of interference between trials by increasing the overlap of features in consecutive events has no effect on the behavioural outcome of these lesions. The result is interpreted in light of models of acetylcholine function centered around pattern separation.

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

Ueda H, Neyama H, Nagai J, Matsushita Y, Tsukahara T, Tsukahara R (2018) Involvement of lysophosphatidic acid-induced astrocyte activation underlying the maintenance of partial sciatic nerve injury-induced neuropathic pain. Pain 159:2170-2178. doi: 10.1097/j.pain.0000000000001316

Related Products: Mac-1-SAP mouse/human (Cat. #IT-06)

Cammarata C, DeRosa ED, Anderson AK (2018) Lifespan and cholinergic changes in cognitive flexibility in rats. Neuroscience 2018 Abstracts 512.05 / GGG8. Society for Neuroscience, San Diego, CA.

Summary: The ability to update one’s mental schemas in order respond flexibly and adaptably – i.e. cognitive flexibility – is crucial to navigating a dynamic environment. Proactive interference (PI) is a phenomenon wherein prior memory impedes the formation of new memories for similar information, biasing behavior toward no-longer-relevant schemas. Thus, overcoming PI is an important aspect of cognitive flexibility. PI is exacerbated during aging, and in turn contributes to age-related deficits in cognitive flexibility. In young animals and young adult humans, resolution of PI has been found to rely on neuromodulatory activity via Acetylcholine (ACh), and ACh levels are known to decline in aging, however it has yet to be demonstrated whether these age-related changes in ACh directly contribute to age-related increase in PI. Here, we first compared PI resolution in middle-aged (13 months, n = 8) and old (23 months, n= 11) male Long Evans rats, finding that old animals were more inefficient in resolving PI when compared to the middle-aged animals. Furthermore we performed cholinergic deafferentation, with the immunotoxin 192-IgG saporin (SAP; 0.2 µl of 0.3 µg/µl dissolved in sterile phosphate buffered sale in each of four locations targeting bilateral anterior and posterior basal forebrain), in our older rats (N= 5 SAP and N=6 Sham) which had no effect on the floor performance of older rats. This suggests that the inability to resolve PI seen in the aged rats may be due to already-depleted levels of ACh. We are currently collecting local field potential data in the prelimbic and posterior parietal cortices in behaving older and younger rats and will combine this with central administration of muscarinic cholinergic pharmacology to continue to examine age-related changes in the cortical dynamics that support cognitive flexibility. Based on prior findings in our laboratory examining similar attentional flexibility, we predict the young animals will demonstrate increased beta band LFP activity in the posterior parietal cortex, and potentially increased beta coherence between prefrontal and posterior parietal cortices, related to successful resolution of PI. We expect such activity to be mitigated by cholinergic antagonists and in the older animals.

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

Daripelli S, Bhayrapuneni G, Tirumalesetty C, Benade V, Subramanian R, Petlu S, Praveena N, Jayarajan P, Shinde A, Badange R, Bhatta V, Nirogi R (2018) SUVN-G3031, H3 receptor inverse agonist produces wake promoting activity in rats with hypocretin-2-saporin lesions of the lateral hypothalamus. Neuroscience 2018 Abstracts 679.23 / VV4. Society for Neuroscience, San Diego, CA.

Summary: Numerous studies have demonstrated that brain histamine plays a crucial role in maintenance of wakefulness, attention, learning and other cognitive processes. SUVN-G3031, a potent H3 receptor inverse agonist is being developed for the treatment of narcolepsy and other sleep related disorders. SUVN-G3031 is one of the lead molecules with hKi of 8.7 nM and has more than 100 fold selectivity against the related GPCRs. SUVN-G3031 exhibited desired pharmacokinetic properties and brain penetration. SUVN-G3031 blocked R-α-methylhistamine induced water intake and increased tele-methylhistamine levels in brain and cerebrospinal fluid. A single oral administration of SUVN-G3031 produced significant increase in acetylcholine, histamine, dopamine and norepinephrine levels in the cortex. SUVN-G3031 produced wake promoting activity in male Wistar rats. In the present study, effects of SUVN-G3031 on sleep/ wake profile were evaluated in rats with lateral hypothalamic lesion using neurotoxin hypocretin-2-saporin. Narcoleptic-like sleep behavior was observed in rats injected with hypocretin-2-saporin in lateral hypothalamus. SUVN-G3031 produced significant increase in wakefulness with concomitant decrease in rapid eye movement (REM) sleep in these animals. These results are in agreement with electroencephalography (EEG) studies carried out in healthy male Wistar rats. Results from the current study and the neurotransmitter modulations produced by SUVN-G3031 provide a strong basis for the potential of SUVN-G3031 in treatment of sleep related disorders. First in human, Phase 1 studies for SUVN-G3031 are completed underUS IND and SUVN-G3031 has shown desirable pharmacokinetic profile with safety and tolerability in healthy human volunteers. Phase 2 study for narcolepsy is currently being planned.

Related Products: Orexin-B-SAP (Cat. #IT-20)