Format

Send to

Choose Destination
Biochem Biophys Res Commun. 2014 Feb 28;445(1):225-9. doi: 10.1016/j.bbrc.2014.01.185. Epub 2014 Feb 6.

Endogenous and exogenous hydrogen sulfide facilitates T-type calcium channel currents in Cav3.2-expressing HEK293 cells.

Author information

1
Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, Higashi-Osaka 577-8502, Japan.
2
Department of Life Science, Kinki University School of Science and Engineering, Higashi-Osaka 577-8502, Japan.
3
Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan.
4
Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, Higashi-Osaka 577-8502, Japan. Electronic address: kawabata@phar.kindai.ac.jp.

Abstract

Hydrogen sulfide (H2S), a gasotransmitter, is formed from l-cysteine by multiple enzymes including cystathionine-γ-lyase (CSE). We have shown that an H2S donor, NaHS, causes hyperalgesia in rodents, an effect inhibited by knockdown of Cav3.2 T-type Ca(2+) channels (T-channels), and that NaHS facilitates T-channel-dependent currents (T-currents) in NG108-15 cells that naturally express Cav3.2. In the present study, we asked if endogenous and exogenous H2S participates in regulation of the channel functions in Cav3.2-transfected HEK293 (Cav3.2-HEK293) cells. dl-Propargylglycine (PPG), a CSE inhibitor, significantly decreased T-currents in Cav3.2-HEK293 cells, but not in NG108-15 cells. NaHS at 1.5mM did not affect T-currents in Cav3.2-HEK293 cells, but enhanced T-currents in NG108-15 cells. In the presence of PPG, NaHS at 1.5mM, but not 0.1-0.3mM, increased T-currents in Cav3.2-HEK293 cells. Similarly, Na2S, another H2S donor, at 0.1-0.3mM significantly increased T-currents in the presence, but not absence, of PPG in Cav3.2-HEK293 cells. Expression of CSE was detected at protein and mRNA levels in HEK293 cells. Intraplantar administration of Na2S, like NaHS, caused mechanical hyperalgesia, an effect blocked by NNC 55-0396, a T-channel inhibitor. The in vivo potency of Na2S was higher than NaHS. These results suggest that the function of Cav3.2 T-channels is tonically enhanced by endogenous H2S synthesized by CSE in Cav3.2-HEK293 cells, and that exogenous H2S is capable of enhancing Cav3.2 function when endogenous H2S production by CSE is inhibited. In addition, Na2S is considered a more potent H2S donor than NaHS in vitro as well as in vivo.

KEYWORDS:

Ca(v)3.2; Cystathionine-γ-lyase; HEK293 cells; Hydrogen sulfide; T-type calcium channel

PMID:
24508802
DOI:
10.1016/j.bbrc.2014.01.185
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center