Optimization of the rat digit abduction score (DAS) assay: Evaluation of botulinum neurotoxin activity in the gastrocnemius lateralis, peronei, and extensor digitorum longus

Cornet, Sylvie; Périer, Cindy; Kalinichev, Mikhail

doi:10.1016/j.toxcx.2020.100029

Cited by 6 publications

(17 citation statements)

References 24 publications

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“…Previously, the efficacy of different BoNT preparations was demonstrated in the DAS assay in mice 10 , 27 and in rats. 4 , 5 , 10 , 28 The DAS assay presents several advantages as it measures (1) the effect of locally administered BoNT on adaptive/functional use of the hind paw (digit abduction), (2) BoNT potency (ED 50 ), (3) kinetics of BoNT, and (4) tolerability. To our knowledge, the present study is the first direct comparison of a recombinant BoNT to its natural analog using the DAS assay.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, as we demonstrated previously in rats, injection into the peroneus muscle complex has a more pronounced effect than in the triceps surae. 5 Moreover, in rats, the role of muscles adjacent to peroneus, such as the extensor digitorum longus, cannot be excluded as a result of the potential diffusion. 5 Mice were also less sensitive to onabotulinumtoxinA (onaBoNT/A) compared with rats in a previous DAS assay.…”

Section: Discussionmentioning

confidence: 99%

“…The rat DAS assay was performed as described previously. 5 The hindlimb digit abduction reflex was induced by grasping the animal lightly around the torso and lifting it swiftly into the air or by lifting it with the nose pointing downward. The digit abduction response of each rat was scored on a 5‐point scale, from normal reflex (DAS 0) to full inhibition of the digit abduction reflex (DAS 4).…”

Section: Methodsmentioning

confidence: 99%

“…injection of BoNT into the hindleg. 1 , 2 , 5 The dose–effect relationship between the amount of injected BoNT and its local paralytic effect allows for the determination of BoNT potency, onset, and duration of action. Second, we aimed to further characterize the functional activity of rBoNT/A1 by evaluating its effects on the contractile and electrical properties of injected muscle and its morphology using the in situ muscle force assay.…”

Section: Introductionmentioning

confidence: 99%

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Recombinant botulinum neurotoxin serotype A1 in vivo characterization

Périer

Martin

Cornet

et al. 2021

Pharmacology Res & Perspec

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Clinically used botulinum neurotoxins (BoNTs) are natural products of Clostridium botulinum. A novel, recombinant BoNT type A1 (rBoNT/A1; IPN10260) has been synthesized using the native amino acid sequence expressed in Escherichia coli and has previously been characterized in vitro and ex vivo. Here, we aimed to characterize rBoNT/A1 in vivo and evaluate its effects on skeletal muscle. The properties of rBoNT/A1 following single, intramuscular administration were evaluated in the mouse and rat digit abduction score (DAS) assays and compared with those of natural BoNT/A1 (nBoNT/A1). rBoNT/A1‐injected tibialis anterior was assessed in the in situ muscle force test in rats. rBoNT/A1‐injected gastrocnemius lateralis (GL) muscle was assessed in the compound muscle action potential (CMAP) test in rats. The rBoNT/A1‐injected GL muscle was evaluated for muscle weight, volume, myofiber composition and immunohistochemical detection of cleaved SNAP25 (c‐SNAP25). Results showed that rBoNT/A1 and nBoNT/A1 were equipotent and had similar onset and duration of action in both mouse and rat DAS assays. rBoNT/A1 caused a dose‐dependent inhibition of muscle force and a rapid long‐lasting reduction in CMAP amplitude that lasted for at least 30 days. Dose‐dependent reductions in GL weight and volume and increases in myofiber atrophy were accompanied by immunohistochemical detection of c‐SNAP25. Overall, rBoNT/A1 and nBoNT/A1 exhibited similar properties following intramuscular administration. rBoNT/A1 inhibited motoneurons neurotransmitter release, which was robust, long‐lasting, and accompanied by cleavage of SNAP25. rBoNT/A1 is a useful tool molecule for comparison with current natural and future modified recombinant neurotoxins products.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Recombinant botulinum neurotoxin serotype A1 in vivo characterization

Périer

Martin

Cornet

et al. 2021

Pharmacology Res & Perspec

Self Cite

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“…In order to overcome these limitations, efforts have been made to develop alternative solutions. For example, the nonlethal mouse Digit Abduction Score (DAS), recently adapted to rats, has been developed to detect and identify BoNTs serotype after intramuscular injection into lower limb skeletal muscle [ 100 , 101 ]. Nonetheless, these assays still require large numbers of animals and lack precision and reproducibility due to subjective read-out characterized by the retraction of the limb.…”

Section: Bont Detection Assaysmentioning

confidence: 99%

Emerging Opportunities in Human Pluripotent Stem-Cells Based Assays to Explore the Diversity of Botulinum Neurotoxins as Future Therapeutics

Lamotte

Perrier

Martinat

et al. 2021

IJMS

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Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and are responsible for botulism, a fatal disorder of the nervous system mostly induced by food poisoning. Despite being one of the most potent families of poisonous substances, BoNTs are used for both aesthetic and therapeutic indications from cosmetic reduction of wrinkles to treatment of movement disorders. The increasing understanding of the biology of BoNTs and the availability of distinct toxin serotypes and subtypes offer the prospect of expanding the range of indications for these toxins. Engineering of BoNTs is considered to provide a new avenue for improving safety and clinical benefit from these neurotoxins. Robust, high-throughput, and cost-effective assays for BoNTs activity, yet highly relevant to the human physiology, have become indispensable for a successful translation of engineered BoNTs to the clinic. This review presents an emerging family of cell-based assays that take advantage of newly developed human pluripotent stem cells and neuronal function analyses technologies.

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