Effects of glucosamine on Ca2+ signaling and K+ channel currents in T lymphocytes.
- Author:
Eun Young SUH
1
;
Bo PANG
;
Sung Joon KIM
;
Woo Kyung KIM
Author Information
1. Department of Physiology, Seoul National University College of Medicine, Seoul, Korea.
- Publication Type:Original Article
- Keywords:
Glucosamine;
Calcium;
T cell;
Ion channel
- MeSH:
Calcium;
Fluorometry;
Functional Food;
Fura-2;
Glucosamine;
HEK293 Cells;
Ion Channels;
Lymphocytes;
T-Lymphocytes
- From:Korean Journal of Medicine
2010;79(5):536-542
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND/AIMS: Glucosamine is widely taken as a functional food, and some studies reported its anti-inflammatory effects. K+ channels and intracellular signal play important roles in the activation of immune cells such as T lymphocytes. Therefore we aimed to examine the effects of glucosamine on the cell physiological parameters. METHODS: In Jurkat-T lymphocytes, intracellular [Ca2+] ([Ca2+]i) was measured using fura-2 fluorimetry, and voltage-gated K+ current (I(Kv)) was measured using whole-cell clamp technique. Ca2+-activated K+ current (I(Kca)) was measured in HEK293 cells over expressing SK4 using inside-out patch clamp technique. RESULTS: An acute application of glucosamine (0.5 mM) affected neither the increase in [Ca2+]i induced by CD3 stimulation (anti-CD3 Ab, 5 microgram/mL) nor the I(Kv) in Jurkat-T cells. A chronic stimulation of with anti-CD3 Ab (5 microgram/mL, 24~36 hr) largely increased the amplitude of IKv. However, the combined treatment with glucosamine (0.1 mM) did not block the increase of I(Kv). The I(KCa) in SK4-overexpressing cells was slightly decreased by glucosamine (0.5 mM). CONCLUSIONS: While glucosamine had a minor inhibitory effect on SK4 K+ channels, the anti-inflammatory effects of glucosamine could not be explained by the effects on the Ca2+ signaling in T lymphocytes.
