saporin

Wu B, Zhao TV, Jin K, Hu Z, Abdel MP, Warrington KJ, Goronzy JJ, Weyand CM (2021) Mitochondrial aspartate regulates TNF biogenesis and autoimmune tissue inflammation. Nat Immunol 22(12):1551-1562. doi: 10.1038/s41590-021-01065-2

Objective: To identify a deficiency of mitochondrial aspartate production as a key abnormality in autoimmune T cells.

Summary: Shortage of mitochondrial aspartate disrupted the regeneration of the metabolic cofactor nicotinamide adenine dinucleotide (NAD), causing ADP-deribosylation of the endoplasmic reticulum (ER) sensor GRP78/BiP. Transfer of intact mitochondria into T cells as well as supplementation of exogenous aspartate rescued the mitochondria-instructed expansion of ER membranes and suppressed TNF release and rheumatoid tissue inflammation.

Usage: Immunofluorescence (Permeabilization by 0.5% Saporin)

Related Products: Saporin (Cat. #PR-01)

Illath K, Kar S, Gupta P, Shinde A, Wankhar S, Tseng FG, Lim KT, Nagai M, Santra TS (2022) Microfluidic nanomaterials: From synthesis to biomedical applications. Biomaterials 280:121247. doi: 10.1016/j.biomaterials.2021.121247

Objective: To evaluate the current state of the controlled synthesis of nanomaterials using microfluidic devices.

Summary: In summary, inherent features of microfluidics enabled the controlled synthesis of biopolymer and silica nanomaterials that can easily encapsulate drugs.

Usage: Saporin was loaded quickly with nanogel of various sizes and observed that saporin loaded protein releasing depended on the density of cross-linking.

Related Products: Saporin (Cat. #PR-01)

Shramm PA, Ancheta LR, Bouajram R, Lappi DA (2021) A brief history of saporin and its contributions to neuroscience. Neuroscience 2021 Abstracts J002.11. Society for Neuroscience, Virtual.

Summary: When investigating the origins of targeted toxins (a drug, therapy, or scientific tool directed to a unique extracellular target), an appropriate place to begin is with the Nobel Prize-winning work of Paul Ehrlich and his concept of the “magic bullet.” Over 100 years later, the use of targeted toxins to perform molecular neurosurgery has become a vital practice that allows researchers to observe changes in organisms after eliminating a neuronal population. A prime example of this practice is the specific targeting of cholinergic neurons in the basal forebrain to mimic Alzheimer’s disease (AD). The research tool designed for this purpose is 192-IgG-Saporin, an antibody conjugated to the ribosome-inactivating protein (RIP) Saporin. Researchers have used this targeted toxin for over 30 years. A 2019 publication by Verkhratsky et al. reviews AD models and states this is the only lesion model that specifically targets cholinergic neurons. In 1983, during a quest to find the optimal payload for a targeted toxin, Fiorenzo Stirpe and colleagues discovered Saporin, a plant protein isolated from the common soapwort plant Saponaria officinalis. Unlike ricin and abrin, Saporin does not have a binding chain and cannot enter a cell on its own. Scientists have devised new ways to use Saporin to advance their research and drug development activities. Just a few examples include: 1. A novel suicide gene therapy approach that uses a vector encoding a double-stranded DNA aptamer to deliver the gene encoding Saporin, 2. Delivery of Saporin encapsulated in a nanotechnology system for development of cancer treatments, 3. A deeper understanding of the difference between pain and itch and the relevant pathways, and 4. Development of a stable epilepsy animal model that is used for screening specific treatments that will lead to micro-methods to eliminate the disease. This review will focus on Saporin as the payload delivered to cells. Targeted toxins (typically targeted by an antibody or peptide chemically linked or genetically fused) provide robust tools for neuroscience where ablation of specific neuronal populations is used to study behavior and function. Saporin is an ideal molecule because of its extreme resistance to high temperatures and denaturation, retention of catalytic activity after conjugation, and lack of a binding chain to allow entrance to the cytoplasm of cells on its own. As a result, it is one of the most studied RIPs used for its vigorousness, potency, safety, and ease of use in the laboratory. The information presented will shed light on the history of Saporin, current applications, and what the future holds for this protein in the neuroscience field.

Related Products: Saporin (Cat. #PR-01)

View the complete poster.

Chen X, Liu H, Li A, Ji S, Fei H (2021) Hydrophobicity-tuned anion responsiveness underlies endosomolytic cargo delivery mediated by amphipathic vehicle peptides. J Biol Chem 297(6):101364. doi: 10.1016/j.jbc.2021.101364

Objective: The study focuses on hydrophobicity and a structure-function strategy to evolve a template peptide for endosomolytic cargo delivery.

Summary: The peptide LP6 could dramatically promote cargo cell entry and facilitate cytosolic delivery of biomacromolecules such as saporin.

Usage: HeLa cells were treated with saporin (10, 20, 50μg/ml) in the absence (–) or presence (+) of LP6 (20μM) to confirm the cytosolic delivery ability of LP6.

Related Products: Saporin (Cat. #PR-01)

Lodhi MS, Khan MT, Bukhari SMH, Sabir SH, Samra ZQ, Butt H, Akram MS (2021) Probing transferrin receptor overexpression in gastric cancer mice models. ACS Omega 6(44):29893-29904. doi: 10.1021/acsomega.1c04382

Objective: To investigate the role of the transferrin receptor, a glycoprotein receptor that is expressed many-folds on rapidly growing cells due to the greater demand of iron, in gastric cancer.

Summary: A mouse model of gastric cancer has the potential to be used in the future to study the therapeutic effects of cancer medicines, and overexpression of transferrin receptors could be identified through the designed probe to be used as diagnostics.

Related Products: MonoBiotin-ZAP (Cat. #BT-ZAP)

See Also:

• Daniels TR et al. Conjugation of an anti transferrin receptor IgG3-avidin fusion protein with biotinylated saporin results in significant enhancement of its cytotoxicity against malignant hematopoietic cells. Mol Cancer Ther 6:2995-3008, 2007.

Borkowski LF, Smith CL, Keilholz AN, Nichols NL (2021) Divergent receptor utilization is necessary for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections. J Neurophysiol 126(3):709-722. doi: 10.1152/jn.00236.2021

Objective: The authors tested the hypothesis that phrenic long-term facilitation (pLTF) following treatment with CTB-SAP is: 1) adenosine 2A (A2A) receptor-dependent at 7d; and 2) serotonin (5-HT) receptor-dependent at 28d.

Summary: This study furthers understanding of the contribution of differential receptor activation to pLTF and its implications for breathing following respiratory motor neuron death.

Usage: Male rats received bilateral, intrapleural injections of CTB-SAP or Saporin Control (25 μg).

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

Dai M, Nakamura S, Takahashi C, Sato M, Munetomo A, Magata F, Uenoyama Y, Tsukamura H, Matsuda F (2021) Reduction of arcuate kappa-opioid receptor-expressing cells increased luteinizing hormone pulse frequency in female rats. Endocr J 68(8):933-941. doi: 10.1507/endocrj.EJ20-0832

Summary: The number of Kiss1-expressing cells in the ARC was not affected by ARC Dyno-SAP treatment. Dynorphin-Kappa opioid receptor (KOR) signaling within the ARC seems to mediate the suppression of the frequency of pulsatile GnRH/LH release, and neurons in the hypothalamic arcuate nucleus (ARC) non-KNDy KOR neurons may be involved in the mechanism modulating GnRH/LH pulse generation.

Usage: Female rats were stereotaxically injected with Dyno-SAP (20 ng/200 nL) or unconjugated Saporin (18.6 ng/200 nL) as a control, bilaterally into the anterior and posterior ARC (total of 4 injection sites).

Related Products: Dyno-SAP (Dynorphin-SAP) (Cat. #IT-68), Saporin (Cat. #PR-01)

Marques SM, Naves LM, Silva TME, Cavalcante KVN, Alves JM, Ferreira-Neto ML, de Castro CH, Freiria-Oliveira AH, Fajemiroye JO, Gomes RM, Colombari E, Xavier CH, Pedrino GR (2021) Medullary noradrenergic neurons mediate hemodynamic responses to osmotic and volume challenges. Front Physiol 12:649535. doi: 10.3389/fphys.2021.649535

Summary: The study sought to determine the role of noradrenergic neurons in hypertonic saline infusion (HSI)-induced hemodynamic recovery. Findings show that together the A1 and A2 neurons are essential to HSI-induced cardiovascular recovery in hypovolemia.

Usage: Medullary catecholaminergic neurons were lesioned by nanoinjection of Anti-DBH-SAP (0.105 ng·nl−1) into A1, A2, or both (LES A1; LES A2; or LES A1+A2, respectively). Sham rats received nanoinjections of unconjugated saporin in the same regions.

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

Liu Y, Forsythe P (2021) Vagotomy and insights into the microbiota-gut-brain axis. Neurosci Res 168:20-27. doi: 10.1016/j.neures.2021.04.001

Objective: To review the use of vagotomy as a tool to explore the role of the vagus nerve in gut to brain signaling.

Summary: This review article is a summary of the knowledge gained from vagotomy, a surgical procedure that involves removing part of the vagus nerve. The article discusses using CCK-SAP to specifically ablate afferent vagal nerves in the gastrointestinal tract.

Usage: The article references a study by Diepenbroek et al. that used CCK-SAP in the following dosages: In vitro: each well was treated with a different dose of saporin conjugates (0, 2.4, 24, or 240 ng) for 24 h. In vivo: An equal volume (rat: 1 µl; mouse: 0.5 µl) of CCK-SAP (250 ng/µl) or Saporin (250 ng/µl) was injected at two sites rostral and caudal to the laryngeal nerve branch.

Related Products: CCK-SAP (Cat. #IT-31), Saporin (Cat. #PR-01)

See Also:

• Diepenbroek C et al. Validation and characterization of a novel method for selective vagal deafferentation of the gut. Am J Physiol Gastrointest Liver Physiol 313:G342-G352, 2017.

Andriessen AS, Donnelly CR, Ji RR (2021) Reciprocal interactions between osteoclasts and nociceptive sensory neurons in bone cancer pain. Pain Rep 6(1):e867. doi: 10.1097/PR9.0000000000000867

Summary: Current pharmacotherapies available for bone cancer pain are insufficient to provide safe and efficacious pain relief. The authors discuss the mechanisms used by cancer cells within the bone tumor microenvironment (TME) to drive bone cancer pain.

Usage: Microglial ablation using Mac-1-SAP (15 μg in 8.8 μl i.t.) and Saporin control (Cat. #PR-01, 8.8 μg in 8.8 μl), is sufficient to attenuate nerve injury-induced pain in male, but not female mice.

See: Sorge R et al. Different immune cells mediate mechanical pain hypersensitivity in male and female mice. Nat Neurosci 18:1081-1083, 2015.

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