Study On The Expression Of FcRL3 Gene In Neuromyelitis Optica And Multiple Sclerosis

ObjectiveIn our previous study, we found that gene variances of Fc receptor-like 3(FcRL3) are associated with neuromyelitis optica(NMO) and multiple sclerosis(MS) in the Han Chinese population. The aim of this part is to further validated the biological functions of positive associated SNP loci in Fc RL3 with NMO and MS, especially with the the diverse phases in NMO and MS patients and to explore the role of Fc RL3 in the pathogenesis of NMO and MS. Meanwhile we constructed a Jurkat cell model expressing Fc RL3 in vitro to observe the effect of methylprednisolone on the level of Fc RL3 transcription in the acute phase of NMO and MS, preliminarily exploring the possible pathogenesis of Fc RL3 in NMO and MS.Methods1. FcRL3 mRNA levels of peripheral blood morphonuclear cells(PBMC) collected from 62 MS cases and 98 NMO cases in the different stages including the period of peak and relief and 77 controls were measured by real-time quantitative PCR. Besides, the reaction of before、during and after treatment were analyzed. 2. Fc RL3 m RNA levels in Jurkat cells in different drug-using phase were measured by real-time quantitative PCR. The impact of methylprednisolone on the Fc RL3 gene transcription and its protein levels in Jurkat cells was tested by western blotting and flow cytometer.Results1. PBMC from controls expressd higher levels of Fc RL3 m RNA than patients, no matter NMO or MS. Meanwhile, in peak phase of NMO cases, PBMC expressed higher levels of Fc RL3 m RNA than that in relief phase. 2. PBMC from MS CC homozygotes expressd higher levels of Fc RL3 m RNA than TT homozygotes and CT heterozygotes(CC vs CT: p=0.014, CC vs TT: p=0.005). The genotype effect on Fc RL3 m RNA levels was also significiant in NMO cases(CC vs CT: p=0.038). However, there was no significant difference in controls. As to the same genotype, there was significant difference in the expression of Fc RL3 between MS and controls(CT: p=0.009; TT: p=0.001). Moreover, PBMC from controls expressd higher levels of Fc RL3 m RNA than NMO cases(CT: p=0.004; TT: p=0.000). 3. In the NMO group, we observed that PBMC expressed different levels of Fc RL3 m RNA at different period(before- during- after treatment) in the same patient. That is: The expression of Fc RL3 was inhibited after methylprednisolone treatment while increased in relief phase. 4. There is significant statistical difference among the NMO patients with different duration(peak phase – relief phase). Fc RL3 m RNA expression in relief phase was higher(p = 0.045); However, in the MS group, this phenomenon could not be found(p = 0.297). 5. Jurkat cells were verified expressing high levels of Fc RL3 protein. We observed that Jurkat cells expressed different levels of Fc RL3 protein when intervened with different dosages of methylprednisolone. Jurkat cells would be inhibited but not dead with 0.25 mg methylprednisolone intervention, therefore 0.25 mg was the most proper concentration. 6. The levels of Fc RL3 m RNA was inhibited after being intervened with 0.25 mg methylprednisolone but increased after a certain period of time. The same trend was observed in the protein and cell levels as well.Conclusion:1. The genetic Fc RL3 is associated with NMO and MS in Han Chinese population. 2. SNP rs7528684 influences the expression of Fc RL3 m RNA and protein in PBMC. PBMC from patients in the relief phase express higher levels of Fc RL3 m RNA than controls, suggesting a protective response which needs to be further studied. 3. Fc RL3 expression in Jurkat cells showed a relation of dose-time effect with the intervention of methylprednisolone, suggesting that Fc RL3 gene plays a role in immunoregulation and intracellular signaling pathways.ObjectiveNeuromyelitis optica(NMO) and multiple sclerosis(MS) are autoimmune demyelinating diseases of the central nervous system. The discovery of NMO immunoglobulin G(NMO-Ig G) antibody has improved the clinical definition of NMO. Autophagy is involved in innate and adaptive immune responses to modulate B cell and T cell survival. Perturbations in the autophagy passway which could in turn modulate the onset and outcome in a number of inflammatory or autoimmune diseases. Recently, the autophagy-related genes(ATGs) have been proved to be associated with several autoimmune and inflammation diseases. Increased T cell expression of ATG5 may be correlated with the pathogenesis of inflammatory demyelination in MS. However, the association of ATG5 variants with MS and NMO patients has not been well studied.MethodsSingle nucleotide polymorphisms were genotyped by matrix-assisted laser desorption or ionization time of flight mass spectrometry(MALDI-TOF MS) in 144 anti-aquaporin 4 antibody-negative conventional MS patients, 109 NMO patients including thirty-five anti-aquaporin 4 antibody-positive NMO patients and 288 controls from southeastern China. And then we analyzed the relationship between SNPs of ATG5 gene with patients.ResultsIn the cohort of NMO patients we observed that the CC genotype of rs548234 increased susceptibility to NMO(p = 0.016), while the allele T of rs548234(p=0.003)and the allele A of rs6937876(p=0.009) acted as protective factors for NMO-Ig G positive NMO patients. However, no association was found between ATG5 variants and MS patients.Conclusion:These results indicated that ATG5 variants are associated with NMO but not MS patients, which may provide a clue for further clarifying the autoimmune mechanisms of autophagy-related pathogenesis in NMO.