A clickable neurosteroid photolabel reveals selective Golgi compartmentalization with preferential impact on proximal inhibition.
Anesthetic, GABA-active neurosteroids potently augment GABAA receptor function, leading to important behavioral consequences. Neurosteroids and their synthetic analogues are also models for a wide variety of cell-permeant neuroactive compounds. Cell permeation and compartmentalization raise the possibility that these compounds' actions are influenced by their cellular partitioning, but these contributions are not typically considered experimentally or therapeutically. To examine the interplay between cellular accumulation and pharmacodynamics of neurosteroids, we synthesized a novel chemical biology analogue (bio-active, clickable photolabel) of GABA-active neurosteroids. We discovered that the analogue selectively photo-labels neuronal Golgi in rat hippocampal neurons. The active analogue's selective distribution was distinct from endogenous cholesterol and not completely shared by some non-GABA active, neurosteroid-like analogues. On the other hand, the distribution was not enantioselective and did not require energy, in contrast to other recent precedents from the literature. We demonstrate that the soma-selective accumulation can act as a sink or source for steroid actions at plasma-membrane GABA receptors, altering steady-state and time course of effects at somatic GABAA receptors relative to dendritic receptors. Our results suggest a novel mechanism for compartment-selective drug actions at plasma-membrane receptors.
Departments of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Xiaoping
X
Jiang
Departments of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Hong-Jin
HJ
Shu
Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Kathiresan
K
Krishnan
Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Mingxing
M
Qian
Departments of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Amanda A
AA
Taylor
Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Anesthesiology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Taylor Family Institute for Innovative Psychiatry Research, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Douglas F
DF
Covey
Departments of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Taylor Family Institute for Innovative Psychiatry Research, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.
Charles F
CF
Zorumski
Departments of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Taylor Family Institute for Innovative Psychiatry Research, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA. Electronic address: menneris@wustl.edu.
Steven
S
Mennerick
D016475:3T3 Cells; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D051379:Mice; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism* / Q000494:pharmacology; D019920:Photoaffinity Labels / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D014982:Xenopus laevis
D018377:Neurotransmitter Agents; D019920:Photoaffinity Labels
Anesthetic; Anxiolytic; GABA(A) receptor; Golgi; Inhibition; Synaptic