Study On MRNA Expression Of Neurogranin Gene In Peripheral Blood Mononuclear Cells From SLE Patients

Part1Objective: To clone and identify Neurogranin gene and its alternative splicing variantsin peripheral blood mononuclear cells from SLE patients.Methods: Specific primers were designed to amplify the coding region of humanNeurogranin gene and then the fragments from PCR were ligated into PMD18-T vector.After transformation, positive clones were identified by colony PCR and sequencing.Results: Three alternative splicing variants of Neurogranin gene have been cloned fromPBMCs isolated from SLE patients, and two of which were not been reported yet.Conclusion: Two new variants exist in the PBMCs of SLE patients, and the function ofwhich remains to be further researched. Part2Objective: To investigate the expression level of Neurogranin and its alternative splicingvariant in the PBMCs from patients with SLE and to analyze the relationship between theexpression level and disease activity level as well as the downstream signalmolecules-CaMKIV. To further clarify the role of Ng in the pathogenesis of SLE.Methods: The expression level of Ng and CaMKIV in PBMCs from SLE patients(n=45)and healthy controls(n=24) was detected by fluoresent real-time quantitative PCR.TheSPSS17.0software was used for statistical analysis.Results:1.The expression level of Ng mRNA in SLE patients was significantly increasedthan healthy controls (P <0.01). Compared with the control and inactive SLE groups，the expression of Ng in the active SLE group was up-regulated, and there was no significantdifference in the expression levels of Ng between the inactive SLE and the control groups(P>0.05).2. No statistical difference was found between SLE patients and healthy controls at themRNAexpression level of Ng-IN.3. The expression level of Ng mRNA in PBMCs of SLE patients was positivelycorrelated with SLE disease activity index(SLEDAI)(r=0.666,P<0.01)4. The expression level of Ng mRNA was positively correlated with the expressionlevel of CaMKIV mRNAin PBMCs of SLE patients (r=0.460, P<0.01)Conclusion: The over-expression of Ng mRNA in SLE patients and the positive correlationbetween Ng mRNA expression and SLEDAI revealed that ectopic expression of Ng genemay be related with the occurrence and development of SLE. In addition，the Ng expressionwas positively correlated with CaMKIV, suggesting that Ng may participate in thepathogenesis of SLE through mediating Ca2+signal transduction and regulating thefunction of downstream CaMKIV.