PMID- 23454521
OWN - NLM
STAT- MEDLINE
DCOM- 20131105
LR  - 20130422
IS  - 1879-0712 (Electronic)
IS  - 0014-2999 (Linking)
VI  - 705
IP  - 1-3
DP  - 2013 Apr 5
TI  - Design and functional evaluation of an optically active mu-opioid receptor.
PG  - 42-8
LID - S0014-2999(13)00119-2 [pii]
LID - 10.1016/j.ejphar.2013.01.065 [doi]
AB  - The use of opioids, which achieve therapeutic analgesia through activation of 
      mu-opioid receptors, are limited in the management of chronic pain by adverse 
      effects including tolerance and addiction. Optogenetics is an emerging approach 
      of designing molecular targets that can produce cell-specific receptor-mediated 
      analgesia with minimal side effects. Here we report the design and functional 
      characterization of a chimeric mu-opioid receptor that could be photoactivated to 
      trigger intracellular signaling. A prototype optoactive mu-opioid receptor 
      (optoMOR) was designed by replacing the intracellular domains from rhodopsin with 
      those of the native mu-opioid receptor and was transiently expressed in human 
      embryonic kidney (HEK293) cells. Expression and distribution of the protein were 
      confirmed by immunocytochemistry. The signal-transduction mechanisms induced by 
      photoactivation of the optoMOR were evaluated and compared with the native 
      mu-opioid receptor stimulation by an agonist, D-Ala(2), N-MePhe(4), 
      Gly-ol-enkephalin (DAMGO). Cells were depolarized by extracellular potassium and 
      the depolarization-induced calcium (Ca(2+)) influx was quantified by using Fura-2 
      imaging. The forskolin-stimulated adenylate cyclase/cAMP cascade was evaluated by 
      ELISA or western blotting of brain-derived neurotrophic factor (BDNF) and the 
      phosphorylation of cAMP response element binding protein (CREB). The optoMOR 
      protein distribution was observed intracellularly and on the plasma membrane 
      similar to the native mu-opioid receptor in HEK293 cells. Photoactivation of 
      optoMOR decreased the Ca(2+) influx and inhibited the forskolin-induced cAMP 
      generation, activation of CREB, and BDNF levels in optoMOR-expressing cells 
      similar to the activation of native mu-opioid receptor by DAMGO. Thus the current 
      study has accomplished the design of a prototype optoMOR and characterized the 
      cellular signaling mechanisms activated by light stimulation of this receptor.
CI  - Published by Elsevier B.V.
FAU - Barish, Philip A
AU  - Barish PA
AD  - Department of Biomedical Engineering, University of Florida, Gainesville, Florida 
      32607, USA.
FAU - Xu, Ying
AU  - Xu Y
FAU - Li, Jianxin
AU  - Li J
FAU - Sun, Jiao
AU  - Sun J
FAU - Jarajapu, Yagna P R
AU  - Jarajapu YP
FAU - Ogle, William O
AU  - Ogle WO
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130227
PL  - Netherlands
TA  - Eur J Pharmacol
JT  - European journal of pharmacology
JID - 1254354
RN  - 0 (Analgesics, Opioid)
RN  - 0 (Brain-Derived Neurotrophic Factor)
RN  - 0 (CREB1 protein, human)
RN  - 0 (Cyclic AMP Response Element-Binding Protein)
RN  - 0 (Receptors, Opioid, mu)
RN  - 100929-53-1 (Enkephalin, Ala(2)-MePhe(4)-Gly(5)-)
RN  - 9009-81-8 (Rhodopsin)
SB  - IM
MH  - Analgesics, Opioid/pharmacology
MH  - Brain-Derived Neurotrophic Factor/metabolism
MH  - Cyclic AMP Response Element-Binding Protein/metabolism
MH  - Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
MH  - HEK293 Cells
MH  - Humans
MH  - Optogenetics
MH  - Photic Stimulation
MH  - Receptors, Opioid, mu/agonists/*genetics/metabolism
MH  - Rhodopsin/genetics
EDAT- 2013/03/05 06:00
MHDA- 2013/11/06 06:00
CRDT- 2013/03/05 06:00
PHST- 2012/07/03 00:00 [received]
PHST- 2013/01/23 00:00 [revised]
PHST- 2013/01/31 00:00 [accepted]
PHST- 2013/03/05 06:00 [entrez]
PHST- 2013/03/05 06:00 [pubmed]
PHST- 2013/11/06 06:00 [medline]
AID - S0014-2999(13)00119-2 [pii]
AID - 10.1016/j.ejphar.2013.01.065 [doi]
PST - ppublish
SO  - Eur J Pharmacol. 2013 Apr 5;705(1-3):42-8. doi: 10.1016/j.ejphar.2013.01.065. 
      Epub 2013 Feb 27.