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Bannister, T. D.

Publications and source records attributed to Bannister, T. D..

3 recordsLinked to original sources

Pharmacological rescue of mitochondrial dysfunction, neurite degeneration, and premature death of ALS and AD iPSC-derived neurons

Mitochondrial (MT) dysfunction is a key driver of ALS pathology. Without a healthy MT system, motor neurons (MN) function at sub-optimal levels and die. In addition, other effects of ALS, like axon/dendrite degeneration, may occur from a pathophysiological cascade spurred by MT dysfunction. A phenotypic screen identified Dipyridamole (DPM), an FDA-approved and safe drug, as having extraordinary effects on ALS patient induced pluripotent stem cell (iPSC)-derived MNs. The drug prevented MT fragmentation, loss of MT content, impaired MT bioenergetics, axon/dendrite degeneration, and premature MN death, extending neuronal survival by more than fivefold. Importantly, its efficacy extended across iPSC-derived neurons representing two different familial forms of ALS (C9orf72, TDP43) and Alzheimers disease (PSEN1), implying broad neuroprotection across ALS forms and other neurodegenerative diseases. DPM increased MT respiration and pyruvate uptake in a mechanism requiring the Mitochondrial Pyruvate Carrier (MPC), mechanistically explaining its biological activities. Thus, DPM is a promising drug to repurpose or refine for treating neurodegenerative diseases or other diseases that would benefit by augmenting pyruvate uptake into MT. TeaserDipyridamole, an FDA-approved drug, restores mitochondrial function and protects neurons in ALS and Alzheimers disease.

neuroscience↗

Hyperactivity in mice induced by opioid agonists with partial intrinsic efficacy and biased agonism; alone and in combination with morphine

Opioid analgesics like morphine and fentanyl induce mu-opioid receptor (MOR)-mediated hyperactivity in mice. Here we show that morphine, fentanyl, SR-17018, and oliceridine have submaximal intrinsic efficacy in the mouse striatum using 35S-GTP{gamma}S binding assays. While all of the agonists act as partial agonists for stimulating G protein coupling in striatum, morphine, fentanyl and oliceridine are fully efficacious in stimulating locomotor activity; meanwhile, the noncompetitive biased agonists, SR-17018 and SR-15099 produce submaximal hyperactivity. Moreover, the combination of SR-17018 and morphine attenuates hyperactivity while antinociceptive efficacy is increased. The combination of oliceridine with morphine increases hyperactivity which is maintained over time. These findings provide evidence that noncompetitive agonists at MOR can be used to suppress morphine-induced hyperactivity while enhancing antinociceptive efficacy; moreover, they demonstrate that intrinsic efficacy measured at the receptor level is not directly proportional to drug efficacy in the locomotor activity assay.

pharmacology and toxicology↗

Comparison of morphine, oxycodone and the biased MOR agonist SR-17018 for tolerance and efficacy in mouse models of pain.

The mu opioid receptor-selective agonist, SR-17018, preferentially activates GTP{gamma}S binding over {beta}arrestin2 recruitment in cellular assays. In mice, SR-17018 stimulates GTP{gamma}S binding in brainstem and produces antinociception with potencies similar to morphine. However, it produces much less respiratory suppression and mice do not develop antinociceptive tolerance in the hot plate assay upon repeated dosing. Herein we evaluate the effects of acute and repeated dosing of SR-17018, oxycodone and morphine in additional models of pain-related behaviors. In the mouse warm water tail immersion assay, an assessment of spinal reflex to thermal nociception, repeated administration of SR-17018 produces tolerance as does morphine and oxycodone. SR-17018 retains efficacy in a formalin-induced inflammatory pain model upon repeated dosing, while oxycodone does not. In a chemotherapeutic-induced neuropathy pain model SR-17018 is more potent and efficacious than morphine or oxycodone, moreover, this efficacy is retained upon repeated dosing of SR-17018. These findings demonstrate that, with the exception of the tail flick test, SR-17018 retains efficacy upon chronic treatment across several pain models.

pharmacology and toxicology↗