Muscarinic acetylcholine type 1 receptor antagonism activates TRPM3 to augment mitochondrial function and drive axonal repair in adult sensory neurons

Sanjana Chauhan; Darrell R Smith; Shiva Shariati-Ievari; Abhay Srivastava; Sanjiv Dhingra; Michel Aliani; Paul Fernyhough

doi:10.1016/j.molmet.2024.102083

Muscarinic acetylcholine type 1 receptor antagonism activates TRPM3 to augment mitochondrial function and drive axonal repair in adult sensory neurons

Mol Metab. 2024 Dec 16:92:102083. doi: 10.1016/j.molmet.2024.102083. Online ahead of print.

Authors

Sanjana Chauhan¹, Darrell R Smith², Shiva Shariati-Ievari³, Abhay Srivastava⁴, Sanjiv Dhingra⁴, Michel Aliani³, Paul Fernyhough⁵

Affiliations

¹ Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Canada; Department of Pharmacology and Therapeutics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.
² Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Canada.
³ Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Canada; Department of Food and Human Nutritional Sciences, Faculty of Agricultural and Food Sciences, University of Manitoba, Winnipeg, Canada.
⁴ Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Canada; Department of Physiology and Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.
⁵ Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Canada; Department of Pharmacology and Therapeutics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada. Electronic address: pfernyhough@sbrc.ca.

PMID: 39694091
DOI: 10.1016/j.molmet.2024.102083

Abstract

Objective: Antagonism of the muscarinic acetylcholine type 1 receptor (M₁R) promotes sensory axon repair and is protective in peripheral neuropathy, however, the mechanism remains elusive. We investigated the role of the heat-sensing transient receptor potential melastatin-3 (TRPM3) cation channel in M₁R antagonism-mediated nerve regeneration and explored the potential of TRPM3 activation to facilitate axonal plasticity.

Methods: Dorsal root ganglion (DRG) neurons from adult control or diabetic rats were cultured and treated with TRPM3 agonists (CIM0216, pregnenolone sulfate) and M₁R antagonists pirenzepine (PZ) or muscarinic toxin 7 (MT7). Ca²⁺ transients, mitochondrial respiration, AMP-activated protein kinase (AMPK) expression, and mitochondrial inner membrane potential were analyzed. The effect of M₁R activation or blockade on TRPM3 activity mediated by phosphatidylinositol 4,5-bisphosphate (PIP₂) was studied. Metabolic profiling of DRG neurons and human neuroblastoma SH-SY5Y cells was conducted.

Results: M₁R antagonism induced by PZ or MT7 increased Ca²⁺ influx in DRG neurons and was inhibited by TRPM3 antagonists or in the absence of extracellular Ca²⁺. TRPM3 agonists elevated Ca²⁺ levels, augmented mitochondrial respiration, AMPK activation and neurite outgrowth. M₁R antagonism stimulated TRPM3 channel activity through inhibition of PIP₂ hydrolysis to activate Ca²⁺/calmodulin-dependent protein kinase kinase β (CaMKKβ)/AMPK, leading to augmented mitochondrial function and neuronal metabolism. DRG neurons with AAV-mediated shRNA knockdown of TRPM3 exhibited suppressed antimuscarinic drug-induced neurite outgrowth. TRPM3 agonists increased glycolysis and TCA cycle metabolites, indicating enhanced metabolism in DRG neurons and SH-SY5Y cells.

Conclusions: Activation of the TRPM3/CaMKKβ/AMPK pathway promoted collateral sprouting of sensory axons, positioning TRPM3 as a promising therapeutic target for peripheral neuropathy.

Keywords: Axonal regeneration; Bioenergetics; Diabetic neuropathy; GPCR; Metabolomics; Mitochondria; Neuronal metabolism.