targeted-toxins

Bogen O, Araldi D, Sucher A, Kober K, Ohara PT, Levine JD (2024) Isolectin B4 (IB4)-conjugated streptavidin for the selective knockdown of proteins in IB4-positive (+) nociceptors. Mol Pain 17448069241230419. doi: 10.1177/17448069241230419 PMID: 38246917

Objective: To address the need for selective transfection methods, the authors covalently linked isolectin B4 (IB4) to streptavidin and analyzed whether it could be used to study protein function in IB4(+)-nociceptors

Summary: Rats treated intrathecally with IB4-conjugated streptavidin complexed with biotinylated antisense oligonucleotides for protein kinase C epsilon (PKCε) mRNA werefound to have: (a) less PKCε in dorsal root ganglia (DRG), (b) reduced PKCε expression in IB4(+) but not IB4(–) DRG neurons, and (c) fewer transcripts of the PKCε gene in the DRG. This knockdown in PKCε expression in IB4(+) DRG neurons is sufficient to reverse hyperalgesic priming, a rodent model of chronic pain that is dependent on PKCε in IB4(+)- nociceptors.

Usage: For each intrathecal injection 2.3μL IB4-streptavidin (30 pmol of conjugate with 120 pmol of biotin binding sites), 1.2μL biotinylated ODN (c = 100 pmol/μl) and 16.5μL PBS were mixed (injection volume = 20μL),

Related Products: Streptavidin-ZAP (Cat. #IT-27), IB4-SAP (Cat. #IT-10)

Masmudi-Martín M, López-Aranda MF, Navarro-Lobato I, Khan ZU (2024) A role of frontal association cortex in long-term object recognition memory of objects with complex features in rats. Eur J Neurosci 59(7):1743-1752. doi: 10.1111/ejn.16243 PMID: 38238909

Objective: Provide evidence that the frontal association cortex and not the Perirhinal cortex is essential for object recognition memory (ORM) of objects with complex features.

Summary: The Perirhinal cortex is a brain area that has been seen as being crucial for ORM. However, the authors challenge that thought by using an ORM enhancer named RGS14414. Used as a tool, expression of it in rat brain frontal association cortex induced the formation of long-term complex ORM whereas the expression of the enhancer in Perirhinal cortex didn’t illicit the same effect. The authors also showed that expression of the enhancer in Perirhinal cortex instead caused formation of ORM of objects with only simple features. Furthermore, the selective elimination of frontal association cortex neurons via OX7-SAP (IT-02) completely removed the formation of complex ORM.

Usage: OX7-SAP (IT-02) was injected into the frontal association cortex of rats at a dose of 0.2 ug in 1 ul.

Related Products: OX7-SAP (Cat. #IT-02)

Maiarù M, Leese C, Silva-Hucha S, Fontana-Giusti S, Tait L, Tamagnini F, Davletov B, Hunt SP (2024) Substance P-botulinum mediates long-term silencing of pain pathways that can be re-instated with a second injection of the construct in mice. J Pain 25(6):104466. doi: 10.1016/j.jpain.2024.01.331 PMID: 38218509

Summary: The authors discuss how Substance P-Botulinum is used to try to replicate the permanent results achieved with Substance P-Saporin (SP-SAP, SSP-SAP).

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

See Also:

• Mantyh PW et al. Inhibition of hyperalgesia by ablation of lamina I spinal neurons expressing the substance P receptor. Science 278:275-279, 1997.
• Nichols ML et al. Transmission of chronic nociception by spinal neurons expressing the substance P receptor. Science 286:1558-1561, 1999.
• Brown DC et al. Intrathecal substance p-saporin in the dog: efficacy in bone cancer pain. Anesthesiology 119(5):1178-1185, 2013.
• Wiley RG et al. Anti-nociceptive effects of selectively destroying substance P receptor-expressing dorsal horn neurons using [Sar(9),Met(O(2))(11)]-substance P-saporin: Behavioral and anatomical analyses. Neuroscience 146:1333-1345, 2007.
• Vierck CJ et al. Comparison of operant escape and innate reflex responses to nociceptive skin temperatures produced by heat and cold stimulation of rats. Behav Neurosci. 2004;118(3):627-35.

Ivanova D, O’Byrne KT (2024) New methods to investigate the GnRH pulse generator. J Mol Endocrinol 72(2):e230079. doi: 10.1530/JME-23-0079 PMID: 38085702

Objective: To review the latest methodologies and insights into the GnRH pulse generator and its role in regulating reproductive hormone secretion.

Summary: The paper discusses recent advancements in understanding the GnRH pulse generator and its role in reproductive hormone secretion. It highlights the involvement of kisspeptin/neurokinin B/dynorphin (KNDy) neurons and the use of advanced techniques like genetic mouse models, electrophysiology, optogenetics, and calcium imaging. These findings enhance our comprehension of the KNDy network’s oscillatory behavior and its regulation by gonadal steroids, which is crucial for developing better infertility treatments.

Related Products: NKB-SAP (Cat. #IT-63)

See Also:

• Helena C et al. KNDy neurons modulate the magnitude of the steroid-induced luteinizing hormone surges in ovariectomized rats. Endocrinology 156:4200-4213, 2015.

McDougle M, de Araujo A, Singh A, Yang M, Braga I, Paille V, Mendez-Hernandez R, Vergara M, Woodie LN, Gour A, Sharma A, Urs N, Warren B, de Lartigue G (2024) Separate gut-brain circuits for fat and sugar reinforcement combine to promote overeating. Cell Metab 36:1-15. doi: 10.1016/j.cmet.2023.12.014 PMID: 38242133

Objective: To investigate the separate gut-brain circuits for sugar and fat reinforcement and their combined effect on overeating.

Summary: This study reveals that intestinal fats and sugars are sensed by distinct vagal populations, each engaging separate central reward circuits to cause dopamine release and reinforcement. Combining fat and sugar triggers both circuits, leading to increased dopamine efflux and promoting overeating, highlighting a subconscious drive to consume obesogenic diets.

Usage: 0.5 µl of CCK-SAP (IT-31) or Blank-SAP as a negative control (IT-21) were injected bilaterally into the nodose ganglion for selective vagal deafferentation of the upper GI tract of mice.

Related Products: CCK-SAP (Cat. #IT-31), Blank-SAP (Cat. #IT-21)

Malley KM, Ruiz AD, Darrow MJ, Danaphongse TT, Shiers S, Ahmad FN, Mota Beltran C, Stanislav BT, Rennaker II RL, Kilgard MP, Hays SA (2023) Neural mechanisms responsible for vagus nerve stimulation-dependent enhancement of somatosensory recovery. SSRN doi: 10.2139/ssrn.4662058

Objective: Optimizing and identifying mechanism of curative action in Vagus Nerve Stimulation therapy on a model of somatosensory deficiency.

Summary: Vagus Nerve Stimulation (VNS) offers promise as a means to treat impairments in somatosensory function after a nerve injury. In a model of chronic sensory loss, VNS of moderate intensity was found to be the most therapeutic. VNS treatment mechanisms were found through models of cholinergic deficits created by 192-IgG-SAP.

Usage: Lesions to the nucleus basalis of rats were made with 192-IgG-SAP [IT-01] (0.375 mg/mL in saline).

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

de Paula FS (2023) Immunomodulatory impact of memory T lymphocyties in periodontitis. Univ Minnesota Thesis.

Objective: This thesis paper sought to determine whether local reactivation of oral tissue resident memory cells (TRM) of a defined antigen specificity could exacerbate ligature-induced periodontal (LIP), a model for periodontal disease in mice.

Summary: Reactivation of oral TRM aggravated alveolar bone loss and amplified gingival and cervical lymph node (cLN) inflammation. Furthermore, oral TRM reactivation enhanced transcriptional changes in pro-inflammatory and periodontitis-related genes. Therapeutic depletion of CD103-expressing oral TRM in advanced of LIP mitigated alveolar bone loss and associated gingiva and cLN inflammation. The study provides evidence that local reactivation of oral TRM can potentiate periodontitis.

Usage: Anti-CD103-SAP (IT-50) was administered in mice via i.p. injection (7 ug in PBS).

Related Products: Anti-CD103-SAP (Cat. #IT-50)

Loftén A, Adermark L, Ericson M, Söderpalm B (2023) Regulation of ethanol-mediated dopamine elevation by glycine receptors located on cholinergic interneurons in the nucleus accumbens. Addict Biol 28(12):e13349. doi: 10.1111/adb.13349 PMID: 38017639

Objective: The aim of this study was to explore the role of glycine receptors (GlyRs) on cholinergic interneurons (CIN) in sustaining extracellular dopamine levels and in ethanol-induced dopamine release.

Summary: Alcohol use disorder is one of the major psychiatric disorders worldwide. Ethanol reward is one of the many factors contributing to the disorder. The rewarding and reinforcing properties of ethanol have been linked to activation of the mesolimbic dopamine system, an effect that involves glycine receptors (GlyRs) in the nucleus accumbens. The study suggests that CIN are not important for GlyR-mediated regulation of basal dopamine output, but that CIN ablation blunts the ethanol-induced dopamine release by reducing the release of GlyR agonists.

Usage: CIN were ablated by Anti-ChAT-SAP administered locally in the nucleus accumbens of male Wistar rats. Rabbit-IgG-SAP was used as a control. Microinfusion was performed unilaterally into the nAc at a concentration of 0.5 ug/ul at 0.05 ul/min for 10 min for a total of 0.5 ul.

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

Takanami K, Kuroiwa M, Ishikawa R, Imai Y, Oishi A, Hashino M, Shimoda Y, Sakamoto H, Koide T (2023) Function of gastrin-releasing peptide receptors in ocular itch transmission in the mouse trigeminal sensory system. Front Mol Neurosci 16:1280024. doi: 10.3389/fnmol.2023.1280024 PMID: 38098939

Objective: To investigate the role of gastrin-releasing peptide (GRP) and GRP receptor (GRPR) in itch transmission in the spinal somatosensory system, and to determine whether the GRP system is involved in itch neurotransmission of the eyes in the trigeminal sensory system

Summary: Administering itch mediators like histamine (His) and chloroquine (CQ) caused high levels of eye scratching in a concentration-dependent manner, with significant gender differences observed for His. Histological studies showed that His and CQ significantly activated GRPR-expressing neurons in a specific brain region of transgenic mice. Blocking these neurons with a GRPR antagonist or eliminating them reduced CQ-induced scratching. Injecting a GRPR agonist without an itch stimulus led to excessive facial scratching, indicating the central role of GRPR neurons in mediating itch responses.

Usage: 500 ng Blank-SAP (IT-21) or 500 ng Bombesin-SAP (IT-40) were intracisternally administered (5-uL volume) 2 weeks prior to behavioral experiments.

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

Konturek-Ciesla A (2023) Aging hematopoiesis: Functional insights and prospects for rejuvenation. Lund University Thesis.

Objective: To examine the function of hematopoietic stem cells (HSCs), the source of all mature blood cells, during adulthood and upon aging.

Summary: A gradual decrease in HSCs multi-lineage differentiation capacity, with the most significant reduction in their lymphoid output. The decreased lymphopoiesis could be attributed to the lymphoid progenitor subset, MPP Ly-I, revealing defects in the HSCs transition to these cells. Hematopoietic rejuvenation techniques studied through HSCs and their aging processes.

Usage: Anti-CD45-SAP (IT-91) was delivered to ex vivo HSCs cells.

Related Products: Anti-CD45.2-SAP (Cat. #IT-91)