TY - JOUR
T1 - The volume-regulated anion channel (LRRC8) in nodose neurons is sensitive to acidic pH
AU - Wang, Runping
AU - Lu, Yongjun
AU - Gunasekar, Susheel
AU - Zhang, Yanhui
AU - Benson, Christopher J.
AU - Chapleau, Mark W.
AU - Sah, Rajan
AU - Abboud, François M.
N1 - Funding Information:
We thank Arlinda LaRose and Angela M. Hester for assistance with word processing and manuscript preparation; Shawn Roach for help in editing the Figures; Carol A. Whiteis and Michael Cicha for assistance in isolating and culturing nodose neurons; Kristina W. Thiel for assistance with manuscript preparation; Fred S. Lamb for consultation; Michael J. Welsh for the use of laboratory facilities and for consultation; Huiyu Gong for helping with the immunostaining; and Thomas O. Moninger for help with pH imaging. We also thank the University of Iowa DNA Facility, Central Microscopy Research Facility, and Office of Animal Resources for support. The work was supported by Program Project grant HL014388-42 from the NIH (FMA, MWC, and CJB), NIDDK, 1RO1DK106009 (RS), Department of Veterans Affairs VA Merit Award 1 BX001414 (MWC), and VA Merit Award BX000776 (CJB), as well as the NHLBI T32 Iowa Cardiovascular Interdisciplinary Research Fellowship HL007121 (RW), the American Heart Association Fellow-to-Faculty award (RS), American Cancer Society Pilot Grant (RS), and Roy J. Carver Trust (RS).
Funding Information:
The work was supported by Program Project grant HL014388-42 from the NIH (FMA, MWC, and CJB), NIDDK, 1RO1DK106009 (RS), Department of Veterans Affairs VA Merit Award 1 BX001414 (MWC), and VA Merit Award BX000776 (CJB), as well as the NHLBI T32 Iowa Cardiovascular Interdisciplinary Research Fellowship HL007121 (RW), the American Heart Association Fellow-to-Faculty award (RS), American Cancer Society Pilot Grant (RS), and Roy J. Carver Trust (RS).
Publisher Copyright:
© 2017 American Society for Clinical Investigation. All rights reserved.
PY - 2017/3/9
Y1 - 2017/3/9
N2 - The leucine rich repeat containing protein 8A (LRRC8A), or SWELL1, is an essential component of the volume-regulated anion channel (VRAC) that is activated by cell swelling and ionic strength. We report here for the first time to our knowledge its expression in a primary cell culture of nodose ganglia neurons and its localization in the soma, neurites, and neuronal membrane. We show that this neuronal VRAC/SWELL1 senses low external pH (pHo) in addition to hypoosmolarity. A robust sustained chloride current is seen in 77% of isolated nodose neurons following brief exposures to extracellular acid pH. Its activation involves proton efflux, intracellular alkalinity, and an increase in NOX-derived H2O2. The molecular identity of both the hypoosmolarity-induced and acid pHo–conditioned VRAC as LRRC8A (SWELL1) was confirmed by Cre-flox–mediated KO, shRNA-mediated knockdown, and CRISPR/Cas9-mediated LRRC8A deletion in HEK cells and in primary nodose neuronal cultures. Activation of VRAC by low pHo reduces neuronal injury during simulated ischemia and N-methyl-D-aspartate–induced (NMDA-induced) apoptosis. These results identify the VRAC (LRRC8A) as a dual sensor of hypoosmolarity and low pHo in vagal afferent neurons and define the mechanisms of its activation and its neuroprotective potential.
AB - The leucine rich repeat containing protein 8A (LRRC8A), or SWELL1, is an essential component of the volume-regulated anion channel (VRAC) that is activated by cell swelling and ionic strength. We report here for the first time to our knowledge its expression in a primary cell culture of nodose ganglia neurons and its localization in the soma, neurites, and neuronal membrane. We show that this neuronal VRAC/SWELL1 senses low external pH (pHo) in addition to hypoosmolarity. A robust sustained chloride current is seen in 77% of isolated nodose neurons following brief exposures to extracellular acid pH. Its activation involves proton efflux, intracellular alkalinity, and an increase in NOX-derived H2O2. The molecular identity of both the hypoosmolarity-induced and acid pHo–conditioned VRAC as LRRC8A (SWELL1) was confirmed by Cre-flox–mediated KO, shRNA-mediated knockdown, and CRISPR/Cas9-mediated LRRC8A deletion in HEK cells and in primary nodose neuronal cultures. Activation of VRAC by low pHo reduces neuronal injury during simulated ischemia and N-methyl-D-aspartate–induced (NMDA-induced) apoptosis. These results identify the VRAC (LRRC8A) as a dual sensor of hypoosmolarity and low pHo in vagal afferent neurons and define the mechanisms of its activation and its neuroprotective potential.
UR - http://www.scopus.com/inward/record.url?scp=85033208941&partnerID=8YFLogxK
U2 - 10.1172/jci.insight.90632
DO - 10.1172/jci.insight.90632
M3 - Article
AN - SCOPUS:85033208941
SN - 2379-3708
VL - 2
JO - JCI insight
JF - JCI insight
IS - 5
M1 - e90632
ER -