The human-specific nicotinic receptor subunit CHRFAM7A reduces α7 receptor function in human induced pluripotent stem cells-derived and transgenic mouse neurons

Eur J Neurosci. 2024 Sep;60(5):4893-4906. doi: 10.1111/ejn.16474. Epub 2024 Jul 28.

Abstract

We investigated the impact of the human-specific gene CHRFAM7A on the function of α7 nicotinic acetylcholine receptors (α7 nAChRs) in two different types of neurons: human-induced pluripotent stem cell (hiPSC)-derived cortical neurons, and superior cervical ganglion (SCG) neurons, taken from transgenic mice expressing CHRFAM7A. dupα7, the gene product of CHRFAM7A, which lacks a major part of the extracellular N-terminal ligand-binding domain, co-assembles with α7, the gene product of CHRNA7. We assessed the receptor function in hiPSC-derived cortical and SCG neurons with Fura-2 calcium imaging and three different α7-specific ligands: PNU282987, choline, and 4BP-TQS. Given the short-lived open state of α7 receptors, we combined the two orthosteric agonists PNU282987 and choline with the type-2 positive allosteric modulator (PAM II) PNU120596. In line with different cellular models used previously, we demonstrate that CHRFAM7A has a major impact on nicotinic α7 nAChRs by reducing calcium transients in response to all three agonists.

Keywords: CHRFAM7A; CHRNA7; calcium; hiPSC; nicotinic receptor; superior cervical ganglion.

MeSH terms

  • Animals
  • Benzamides / pharmacology
  • Bridged Bicyclo Compounds / pharmacology
  • Calcium / metabolism
  • Cerebral Cortex / cytology
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / metabolism
  • Choline / metabolism
  • Choline / pharmacology
  • Humans
  • Induced Pluripotent Stem Cells* / drug effects
  • Induced Pluripotent Stem Cells* / metabolism
  • Isoxazoles
  • Mice
  • Mice, Transgenic*
  • Neurons* / drug effects
  • Neurons* / metabolism
  • Nicotinic Agonists / pharmacology
  • Phenylurea Compounds
  • Superior Cervical Ganglion / cytology
  • Superior Cervical Ganglion / metabolism
  • alpha7 Nicotinic Acetylcholine Receptor* / genetics
  • alpha7 Nicotinic Acetylcholine Receptor* / metabolism

Substances

  • alpha7 Nicotinic Acetylcholine Receptor
  • Chrna7 protein, human
  • Choline
  • PNU-282987
  • Bridged Bicyclo Compounds
  • Nicotinic Agonists
  • Benzamides
  • 1-(5-chloro-2,4-dimethoxyphenyl)-3-(5-methylisoxazol-3-yl)urea
  • Calcium
  • Isoxazoles
  • Phenylurea Compounds