Effects of electroacupuncture on interleukin -2 , interferon -gamma and extracellular-regulated protein kinase signaling pathways in the splenic T cells of traumatized rats

Abstract

Objective To investigate effect of electroacupuncture (EA) on interleukin-2 (IL -2)and interferon-gamma(IFN-γ)protein and mRNA expression,as well as extracellular- regulated protein kinase1/2 (ERK1/2) signaling pathway,and evaluate the signaling regulatory mechanism of EA effect. Methods Thirty-two male Sprague-Dawley (SD) rats were divided randomly into four groups (Control,EA,Trauma,and T+EA group,n=8).Rats were anesthetized,and aseptically incised longitudinally to a length of 6 cm along the dorsal median line and 5 cm along the abdominal median line,and the abdominal viscera were exposed for 3 min.EA was applied at bilateral Zusanli and Lanwei acupoints.At postoperative day 3,splenic T cells were isolated using the nylon column method.IL-2 and interferon-gamma(IFN-γ) protein and mRNA expressions were assayed by ELISA and reverse transcriptionpolymerase chain reaction (RT-PCR),respectively.We examine the activity of ERK1/2 using Western-blot,and the DNA binding activity of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) using Trans-AM ELISA-based kits. Results IL-2 and IFN-γ protein expression in splenic T cells of rats in Trauma group were markedly decreased 3 days after operation than Control group (37.4±2.0)vs (76.1±3.7) ng/L, (30.6±1.3) vs (49.9±2.6) ng/L,P＜0.01),IL-2 and IFN-γ mRNA expression in Trauma group were also decreased (P＜0.01).This was accompanied with a significant depression in the activity of ERK1/2,NF-κB and AP-1 (P＜0.01,Trauma group vs Control group).IL-2 and IFN-γ production in T+EA group were significantly increased compared with Trauma group (58.3±1.1) vs (37.4±2.0) ng/L, (39.2±1.5) vs (30.6±1.3) ng/L,P＜0.01),and IL-2 and IFN-γ mRNA expression,ERK1/2activation as well as NF-κB and AP-1 DNA binding activity were also increased (P＜0.01).Compared with Control group,the protein and mRNA expressions of IL-2 and IFN-γ,and the activity of ERK1/2,NF-κB and AP-1 in splenic T cells of T+EA group are not different.Conclusions EA may ameliorate impaired immune function following surgical trauma by regulating IL-2,IFN -γ protein and mRNA expression in splenic T cells and at least in part,involves the signaling pathways of ERK1/2 as well as NF-κB and AP-1. Key words: Electroacupuncture; Surgical trauma; Interleukin-2; Interferon-gamma; Extracellular- regulated protein kinase