New Modes of GPCR Signalling

The Kv1.3 Channel Blocker Scorpion Polypeptide has an Therapeutic
effect on EAE Rats with a Molecule Mechanism
Zhi Li1#, Wanhong Liu1#, Song Han2, Liang Li1, Yuanteng Fan1, Zhihao Wang1, Bo
Yang1, Wu Yingliang2*, Xiaohua He1* and Wenxin Li2
1School of Medicine, Wuhan University, Wuhan 430071, China
2College of Life sciences, Wuhan University, Wuhan 430072, China
# Equal contribution to this work
Objective: Experimental autoimmune encephalomyelitis(EAE), an ideal model of
human multiple sclerosis(MS), is a kind of autoimmune disease in central nervous
system .We are to investigate the efficacy of the Kv1.3 channel blocker scorpion
polypeptide on the inhibition of T cell proliferation in vitro and the therapy of EAE rats
in vivo .Furthermore, to study the T cell activation signaling transduction pathways
which are associated with the Kv1.3 channel.Method: Female inbred Sprague
Dawley(SD) rats with age of 8-10weeks were immunized by their own cerebral and
spinal cord homogenate in Freund's complete adjuvant with subcutaneous injection of
0.06g/100g antigen. The administration of polypeptide was 100ug/kg .i.p. for 14days,
rats were observed for 16days and the clinical score of EAE were recorded. The lesion
tissues were Hematoxylin -Eosin(H.E.) stained to observe the inflammatory infiltration
under the microscope. By transmission electron microscopy (TEM),the structure of
loose myelin and the axonal damage of neurons were observed. The cytokine levels of
IL-2,IFN-γ,TNF-α from the rats serum were detected by the ELISA assay. In vitro T
cells proliferation assay, spleen cells from EAE rats were cultured in a 96-well plates
and activated by antigen, treated with different doses of drugs, cells were cultured for
72h and were added with [ 3 H]-thymidine for 18h before being harvested , the cpm
values(the [ 3 H]-thymidine incorporation )were measured by the liquid
scintillation .Result: From the H.E. sections , the polypeptide can efficiently attenuate
the inflammatory infiltration into the central nervous system. From the ultra structure of
the tissues, the myelin and axon from polypeptide treatment group were basically
normal.IL-2 and TNF-α of EAE group were significantly higher than the control
(* P