BACKGROUND: Central nervous system (CNS) myelin is made up of 70% lipids and 30% proteins with human brain myelin basic protein (hMBP) constituting 1/3 of the proteins. MBP is a family of proteinswith four isoforms only in human brain. OBJECTIVE: To investigate the expression of MBP and its immunological function. DESIGN: Single sample study. SETTING: Department of Biochemistry and Molecule Biology, Huaxi College of Priclinical Medicine and Forensic Medicine, Sichuan University. MATERIALS: This experiment was conducted at Department of Bio chemistry and Molecule Biology, Huaxi College of Priclinical Medicine and Forensic Medicine, Sichuan University from August 2003 to March 2004. Relative molecular weight was 215000 hMBP cDNA clone pGEMP,prokaryotic expression recombinant vector pGEX-5T, T4 DNA Ligase,calf intestine alkaline phosphates, X-gal, IPTG, 123 Ladder (BRL), nitrocellu lose ,4-chloro-1-Naphthol;MBP and Anti- MBP ELISA kit. INTERVENTIONS: ①hBMP gene cDNA clone segment was digested with EcoR1 and BamH1; ②Construction and transformation of the recombinant expression vector p5TMP; ③ The growth and induced expression of the recombinant expression vector transformed bacteria; ④ Preparation of the antibody of recombinant hMBP. MAIN OUTCOME MEASURES: ① Detection and identification of the expressed protein product; ② Detection and identification of hMBP anti body. RESULTS: ① Screening and identification of recombinant MBP: The 4 999 bp pGEX-5T DNA and 557 bp MBP inserted fragment were obtained, indicating that the white colonies contained recombinant expression plasmid of exogenous DNA; ② A dense band disappeared from the control plasmid while a new special polypeptide band with apparent molecular weight 42 000 was detected in recombinant cell lysate; ③After 5 subcutaneous injections, antibody was obtained at 1:16 titer. The specificity of the antibody to MBP was confirmed.CONCLUSION: Compared with the original expression vector, the new constructed expression vector containing 215 000 MBP exons Ⅰ-Ⅶ coding sequence was not only without the coding area defects of 34 bp in 5' sequence but also expressed more highly in prokaryote obviously. In addition, the recombinant MBP antibody prepared successfully.

Objective To evaluate the copy number variation of FCGR3B gene in Henan Han systemic lupus erythematosus (SLE) patients and healthy controls,and explore the association between FCGR3B gene copy number variants (CNVs) and lupus nephritis (LN) susceptibility in Henan Han population.Methods FCGR3B CNVs was investigated in 142 SLE patients with nephritis,187 SLE patients without nephritis and 328 healthy controls.A modified methodology based on competitive PCR named Multiplex AccuCopyTM Kit was used to detect FCGR3B copy number.Clinical and laboratory data were collected retrospectively from the medical record.Logistic regression analysis was used to determine the association of FCGR3B copy number variants with LN susceptibility.Rank correlation was used to determine the correlations between FCGE3B copy number variants and clinical phenotypes of LN.Results No significant difference was detected in the copy number variations of FCGR3B in different groups.Low copy number of FCGR3B was more commonly seen in patients with nephritis (P=0.042),and was a risk factor for LN (OR=2.059; 95％ CI:1.081-3.921; P=0.028).However,high copy number (＞ 2) had no effect on SLE patients without nephritis(OR=1.152; 95％CI:0.711-1.866; P=0.565) and LN patients (OR=0.838; 95％ CI:0.529-1.329; P=0.454).There were no associations between FCGR3B copy number variants and clinical phenotypes and immunologic characteristics of LN.Conclusion The low copy number of FCGR3B is a risk factor for LN in Henan Han population.

Objective To investigate the expression of miRNA-31 in peripheral blood mononuclear cells (PBMCs) of rheumatoid arthritis (RA) patients,and the relationship between miRNA-31 and disease activity of RA.Methods After obtaining the informed consent,peripheral blood samples of 56 RA patients,12 systemic lupus erythematosus (SLE) patients,6 Sj(o)gren's syndrome (SS) patients and 30 healthy controls were collected from the Department of Rheumatology,Peking University Third Hospital.RNA was extracted from the PBMCs which were separated by Ficoll-Paque PLUS.The expression of miRNA-31 in the PBMCs of RA patients,SLE patients,SS patients and healthy controls was detected by real-time Polymerase Chain Reaction (PCR).Furthermore,according to the RA disease activity score (DAS28),RA patients were divided into high,moderate and low disease activity groups and remission group,and miRNA-31 expression was compared between different groups.Data were analyzed using t test or Mann-Whitney U test.Results The expression of miRNA-31 in PBMCs of RA patients was 7.25 times (P=0.003 8) higher when compared with that of the control group.To be specific,the expression of miRNA-31 was 10.63 times in PBMCs of high activity RA group (P=0.01) and 8.95 times in moderate activity RA group (P=0.000 3) when compared with that of the control group,and there was no significant difference between low activity,remission groups and control groups in terms of miRNA-31 expression.Furthermore,the expression of miRNA-31 in PBMCs of SLE patients was not significantly different from the control and miRNA-31 expression in PBMCs of SS patients was 1.64 times (P=0.02) higher than that of the RA patients,but the average level of miRNA-31 was much less than that of RA patients.The increased miRNA-31 may serve as a diagnostic marker for disease activity of RA.

Objective To investigate the expression level of oxidized low density lipoprotein (ox-LDL) and its scavenger receptor scavenger receptor that binds phosphatidylserine and oxidized lipoprotein (SRPSOX) in patients with rheumatoid arthritis (RA),and to explore the relationship between ox-LDL and disease activity.Methods The serum ox-LDL in RA patients and healthy control group were detected by enzymelinked immunosorbent assay (ELISA),as well as the fluidox-LDL in RA,osteoarthritis (OA) and inflammatory arthritis (IA).The expression of SR-PSOX in mixed cells of RA and IApatients was detected by western blot.The expression of serum ox-LDL between RA groupand the control group was analyzed by t-test and non-parametric test.The correlation of serum ox-LDL expression levels in RA patients with C-reactive protein (CRP),erythrocyte sedimentation rate (ESR) and other inflammatory factors and disease activitywas analyzed by Pearson linear regression.Results The expression of ox-LDL in the serum of RA patients was significantly higher than that of normal control group [(3 076±131) mU/ml,(2 334±84) mU/ml,t=4.242,P＜0.01].The expression of ox-LDL in synovial fluid of RA patients was significantly higher than that of the OA group [(4 963±354) mU/ml],(3 956±347) mU/ml,t=2.372,P＜0.05).The expression of SR-PSOX in synovial fluid mixed cells of RA patients was higher than that of the IA group [(4.92±0.18) vs (0.24±0.04),t=33.53,P＜0.01].The expression of ox-LDL in serum of RA patients was negatively correlated with ESR,CRP and overall disease activity DAS28 (r=-9.42,P=0.009;r=-0.35,P=0.029 7;r=0.42,P=0.008 4).The expression of ox-LDL in the serum of RA patients with moderate disease activity was significantly higher than those patients with high disease activity [(3 302±138) mU/ml vs (2 464±228) mU/ml,t=3.335,P＜0.01],however,those with low disease activity and disease remission had higher serum ox-LDL expression but without statistical significant differences.After treated with anti-rheumatic drugs (DMARDs),serum ox-LDL of RA patients had a trend of slight increasing butwithout sign-ificant difference.The ox-LDL/LDL-C or ox-LDL/HDL-C was negatively not correlated with disease activity score in 28 (DAS28),ESR,CRP.Conclusion In RA patients,the expression of ox-LDL in the serum and synovial fluid is high and the SR-PSOX expressionin synovial fluid is also high.The serum ox-LDL levels are negatively correlated with ESR,CRP and DAS28,which are related to disease activity of RA.These findings suggest that the ox-LDL and the receptor SR-PSOX may play a role in RA pathogenesis,but needs further study.

Objective:To investigate the effects of oxidized low density lipoprotein (Ox-LDL) on cell proliferation and mRNA expression of inflammatory factors in fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA).Methods:Tissue culture was used to isolate and 4-6 generation cultured RA-FLS cells were used for subsequent experiments. RA-FLS were stimulated for 24 hours with different con-centr-ations of human Ox-LDL, then the MTS cell proliferation and toxicity test kit were used to detect the prolifer-ation of RA-FLS. Real time-polymerase chain reaction (RT-PCR) was used to test the expression of inflamm- atory factors like interleukin (IL)-6, transforming growth factor (TGF)-β, IL-8, tumor necrosis factor (TNF)-α and receptors like CD36 and scavenger receptor binds phosphatidylsed neoxidized lipoprotein (SR-PSOX) inRA-FLS. T test and F test were used in this study. Results:Ox-LDL (10, 25, 50 μg/ml) could obviously promote the proliferation of RA-FLS, and theabsorbance values (490 nm) were (1.04±0.15), (1.05±0.14), and (1.00±0.10), respectively, all higher than the control group (0.81±0.04) and the difference was statistically significant ( F=4.737, P<0.01). In addition, 50 μg/ml and 100 μg/ml Ox-LDL also promoted the expression of IL-6 mRNA ( F=14.709, P<0.01) and inhi-bited the expression of TGF-β mRNA ( F=299.074, P<0.01), but there was no obvious effect on the expression of IL-8 and TNF-α. Ox-LDL stimulation could obviously promote the expression of SR-PSOX receptor on RA-FLS ( F=68.636, P<0.01) and inhibit the expression of CD36( F=18.085, P<0.01). After the transfection of siRNA, SR-PSOX mRNA level was significantly inhibited and the mRNA expression of IL-6 was significantly decreased after Ox-LDL stimulation of RA-FLS ( t=3.875, P<0.01), while TGF-β mRNA expres-sion was not significantly changed( t=-0.193, P>0.05). Conclusion:Ox-LDL may play a role in promoting the activation of RA-FLS proliferation and the expression of IL-6 mRNA by increasing the SR-PSOX receptor of RA-FLS, suggesting that Ox-LDL is involved in the synovial inflammation of RA.

Objective:To explore the clinical and imaging characteristics of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) caused by mitochondrial DNA 14453G>A (m.14453G>A) mutation.Methods:A case of MELAS caused by m.14453G>A mutation in the First Affiliated Hospital of Harbin Medical University on October 12, 2021 was reported. At the same time, the reported cases of MELAS and Leigh syndrome (LS) caused by the m.14453G>A mutation were reviewed. This enabled a comprehensive summarization, analysis, and comparison of these cases.Results:The patient was a female. She has suffered from the disease since 13-year old with seizures, accompanied by the disturbance of mood and the loss of memory. Brain magnetic resonance imaging findings consisted of lesions in frontal, parietal, occipital, temporal lobe and cerebellar. The patient was initially considered with autoimmune encephalitis and posterior reversible encephalopathy syndrome. Since direct sequencing of the complete mitochondrial genome from blood of the patient revealed m.14453G>A mutation in ND6 gene, and the mutation rate was 17.0%, the patient eventually diagnosed with MELAS based on clinical manifestations, imaging examinations, and genetic testing results. Using "m.14453G>A" as the search term, the relevant literature in China and abroad was retrieved and those with complete clinical data were identified. A total of 11 cases of m.14453G>A mutation including this case were reported, of whom 5 patients were diagnosed as MELAS, and 6 patients were diagnosed as LS. Among the 11 patients, those being adolescent or adult and with lesions in the cortex and subcortical white matter were probably be MELAS; those being infant or young child and with lesions in basal ganglia, thalamus and brainstem could be LS. Conclusions:Mitochondrial disease caused by m.14453G>A gene mutation shows a great heterogeneity, which can cause MELAS and LS. The clinical phenotype of the m.14453G>A mutation may be related to the age of onset and lesion′ s location.