Research For Correlation Tau Protein With Nerve Axonal Injury In Experimental Autoimmune Encephalomyelitis

Objective:Study the phosphorylation and non phosphorylation of two different forms of tau protein dynamic changes of different periods and significance in axon experimental autoimmune encephalomyelitis(EAE).Methods:72 mice which weight only 18 g ~ 20 g, age 8 ~ 10 weeks of C57 BL / 6 female mice what bought from Beijing tong lihua experimental animal were randomly divided into 6groups, each group having 12. Mice immuning in 14, 25, 50 days which defined as acute phase mice, paralysis phase mice, remission phase mice, 6 groups will divide into the acute phase of EAE group, EAE paralysis period and EAE remission group, the control stage of acute paralysis group, the control group, the comparison remission group in turn. In immuning 14, 25, 50 days, 12 mice were randomly divided into two groups, each group having six. Each mice need one hundred micrograms of MOG35-55, calculating how many MOG will be needed,diluting 3 mg/ml MOG mixed with CFA in volume, adding a certain amount of mycobacterium tuberculosis which stimulate immunity. Liquid mix into the needle syringe suctioning repeatedly until the mixture sample change turbidity. Multi-point spine of EAE mice inject emulsion which have only 0.3 ml, and abdomen inject 500 ng pertussis toxin as immune enhancer in 0 days and 2 days. Control group given saline mixture injection as control.Nerve function score was measured by five points scoring criteria, from the date of the immune until death.Brain tissue was fixed and embedded.Tissue inflammation changes observed by HE staining and observed tau protein content ofdifferent periods axon by immunohistochemical, measuring GSK3 concentration with ELISA method in serum in mice.Results:1.International general five points scoring method in mice, mice gradually develop any of the following, which the tail is weak, loss of appetite fur, burnish declining,appearing aggravating double hind leg muscle tension reducing and cerebellum impairing gait instability, which not influence the daily movement; performance for the hind limbs weakness in mice is aggravating, which affect daily movement; passive cannot recover after turn over, which can move after stimulation; mice is shown as two hind legs completely paralyzed; forelimbs appear weakened muscle strength; mice do not move,which cannot finish eating, but no is death in mice. Weakness ease in immune remission limbs. Nerve function score decline after reaching high marks.2 Control brain tissue do not see obvious abnormity in acute period, paralysis period having visible axon atrophy in remission period. Inflammatory cells can be seen infiltrating through the blood vessels in EAE brain tissue of acute group. Paralysis period appear white matter structure is loose and organization is empty, except infiltration of numerous inflammatory cells. Infiltration of inflammatory cells decreased in remission period, but the leaving axon atrophy.3.Positive axon was characterized by swelling, deep dyeing. Longitudinal section show spindle section shape, transverse section dotted, counting segmental shape axon section and number. Number of phosphorylated tau protein expression were 4.09±1.09,5.82±1.32, 7.55±1.62 in positive number control stage of acute group, the paralysis of acute group, the remission of acute group axon; number of phosphorylated Tau protein express 28.40 ±2.60, 48.40±3.81, 29.42±1.07 in acute phase of EAE group, paralysis of EAE group, remission of EAE group; EAE paralysis period is higher than the acute phase of EAE group(P < 0.01), higher than the EAE group(P < 0.01).4 Contrasting serum GSK3 of each set six mice, EAE group was higher than the control group, difference has statistical significance(P < 0.01), the EAE group paralysis stage was higher than acutestage and remission(P < 0.01).5 There is a linear correlation between serum GSK3 in paralysis phase and remission phase of EAE mice and phosphorylated tau protein.Conclusions:The phosphorylated tau protein was associated with nerve function score in mice. The phosphorylated tau protein was associated with axonal injury. The level of serum GSK3 can indirectly reflect the axonal injury in mice.