[Role of the CCL28-CCR10 pathway in monocyte migration in rheumatoid arthritis].

OBJECTIVE: To examine the expression of chemokine receptor CCR10 on monocytes/macrophages in the joints of patients with rheumatoid arthritis (RA), and to investigate the role of chemokine CCL28 and its receptor CCR10 in the migration of RA monocytes and its mechanism. METHODS: The expression of CCR10 in synovial tissues from 8 RA patients, 4 osteoarthritis (OA) patients, and 4 normal controls was analyzed by immunohistochemistry, and cell staining was scored on a 0-5 scales. Flow cytometry was used to measure the percentage of CCR10 positive cells in CD14+ monocytes from peripheral blood of 26 RA patients and 20 healthy controls, as well as from synovial fluid of 15 RA patients. The chemotactic migration of monocytes from RA patients and healthy controls in response to CCL28 was evaluated using an in vitro Transwell system. Western blotting was conducted to assess phosphorylation of the extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) pathways in RA monocytes upon CCL28 treatment. RESULTS: CCR10 was predominantly expressed in RA synovial lining cells and sublining macrophages, endothelial cells, and lymphocytes. CCR10 expression was significantly increased on lining cells and sublining macrophages in RA synovial tissue compared with OA and normal synovial tissue (both P < 0.01). The patients with RA had markedly elevated expression of CCR10 on peripheral blood CD14+ monocytes compared with the healthy controls [(15.6±3.0)% vs. (7.7±3.8)%, P < 0.01]. CCR10 expression on synovial fluid monocytes from the RA patients was (32.0±15.0)%, which was significantly higher than that on RA peripheral blood monocytes (P < 0.01). In vitro, CCL28 caused significant migration of CD14+ monocytes from peripheral blood of the RA patients and the healthy controls at concentrations ranging from 10-100 µg/L (all P < 0.01). The presence of neutralizing antibody to CCR10 greatly suppressed CCL28-driven chemotaxis of RA monocytes (P < 0.01). Stimulation of RA monocytes with CCL28 induced a remarkable increase in phosphorylation of ERK and Akt (both P < 0.05). ERK inhibitor (U0126) and phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002) strongly reduced the migration of RA monocytes in response to CCL28 (both P < 0.01). CONCLUSION: RA patients had increased CCR10 expression on peripheral blood, synovial fluid, and synovial tissue monocytes/macrophages. CCL28 ligation to CCR10 promoted RA monocyte migration through activation of the ERK and PI3K/Akt signaling pathways. The CCL28-CCR10 pathway could participate in monocyte recruitment into RA joints, thereby contributing to synovial inflammation and bone destruction.

[Diagnostic performances of salivary gland ultrasonography for Sjögren's syndrome].

OBJECTIVE: To evaluate the diagnostic performances of salivary gland ultrasonography(SGUS)in Sjögren's syndrome(SS). METHODS: A total of 246 patients with dry mouth and/or eyes who were treated in the outpatient department and inpatient department of Rheumatology and Immunology Department of the Ninth People's Hospital, Shanghai Jiaotong University School of Medicine from December 2019 to January 2022 were collected. All patients received SGUS examination and scored by 2019 outcome measures in rheumatology clinical trial (OMERACT)ultrasonic scoring system.Their general information, unstimulated saliva flow rate(USFR), Schirmer test and serological test results were recorded. In the study, 193 cases had lip gland biopsy. The 2016 American College of Rheumatology(ACR)/ European League Against Rheumatism(EULAR)classification criteria were adopted as the diagnostic standard of SS. χ2 test was used to compare the difference of salivary gland ultrasonic scores between the two groups. The receiver operating characteristic(ROC) curve was used to evaluate the accuracy of SGUS in diagnosing SS, and the disease characteristics of SGUS positive group and negative group in the SS patients were compared. RESULTS: A total of 175 patients were SS group according to the ACR/EULAR classification, and the remaining 71 patients were non-SS group.There was no significant difference in age [(54.2±11.8) years vs. (53.4±14.9) years, P=0.705] and female (94.4% vs.93.1%, P=1.000) between SS and non-pSS groups. A total of 109 patients were SGUS positive (≥ 2 points), of whom 104 patients met the SS diagnosis and 5 patients did not meet the SS diagnosis. The positive rate of SGUS in SS group was significantly higher than that in non-SS group (59.4% vs. 7.0%, P < 0.001). The accuracy of 2019 OMERACT ultrasonic scoring system to predict ACR/EULAR classification was good, with an area under the curve of 0.762 (95%CI 0.701-0.823). The absolute agreement between the SGUS outcome and ACR-EULAR classification was 69.1%(170/246), with a sensiti-vity of 59.4%(104/175), specificity of 93%(66/71), positive predictive value of 95.4%(104/109) and negative predictive value of 48.2% (66/137). A total of 81 patients were positive SGUS combined with anti-SSA antibody, 100% (81/81) fulfilled the ACR-EULAR criteria, 85 patients were negative SGUS and anti SSA antibody, and 60 patients(70.6%, 60/85) did not fulfil the ACR-EULAR criteria. SGUS positive group had higher antinuclear antibody(ANA) positive rate(83.1% vs. 98.1%, P < 0.001) in the patients with SS. CONCLUSION: The OMERACT ultrasonic scoring system has high diagnostic value in SS. The combination of SGUS and anti-SSA antibody can improve the diagnostic value.

[Recommendations of diagnosis and treatment of primary Sjögren's syndrome in China].

Sjögren's syndrome is a chronic systemic autoimmune disease characterized by lymphocyte proliferation and progressive exocrine gland damage. In China, standardized diagnosis and treatment for Sjögren's syndrome lags behind other common rheumatic diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Based on the evidence and guidelines from China and other countries, Chinese Sjögren's Syndrome Collaborative Research Group together with stomatologist and ophthalmologist developed Standardization of diagnosis and treatment of primary Sjögren's syndrome. The purposes are: (1) to standardize the detection and interpretation of key indicators for the diagnosis of Sjögren's syndrome, including serum anti SSA antibody and labial gland pathology; (2) to suggest using widely accepted disease activity index in evaluation of the disease; (3) to standardize rational management for Sjögren's syndrome patients with topical and systemic diseases.

In vitro hepatic differentiation of mesenchymal stem cells from human fetal bone marrow.

We examined whether human fetal mesenchymal stem cells (FMSCs) derived from fetal bone marrow were able to differentiate into functional hepatocyte-like cells in vitro. The surface phenotype of FMSCs was characterized by flow cytometry. To induce hepatic differentiation of FMSCs, we added hepatocyte growth factor, basic fibroblast growth factor and oncostatin M into the cell culture medium. After 21 days of hepatocyte induction, FMSCs expressed the hepatocyte-specific markers, alpha-fetoprotein and cytokeratin 18, as demonstrated by immunofluorescence staining. Differentiated FMSCs also demonstrated in vitro functions characteristic of liver cells, including albumin production, urea secretion and glycogen storage. In conclusion, fetal bone marrow-derived FMSCs are able to differentiate into functional hepatocytelike cells and may serve as a source of cells for liver disease therapy.

Inhibition of 6A8 alpha-mannosidase gene expression resulted in telomere length shortening in nasopharyngeal carcinoma cell CNE-2L2.

Telomere length shortening was observed in the nasopharyngeal carcinoma cell CNE-2L2 when 6A8 alpha-mannosidase expression was inhibited by antisense 6A8 DNA. Transduction with mock or an irrelevant DNA did not affect the telomere length in the carcinoma cells. Telomerase activity and mRNA transcription of TRF 1 and 2 were not changed in the cells treated with antisense 6A8. The Con A binding test showed an enhancement on the proteins isolated from the cells treated with antisense 6A8, but not on those from mock- or irrelevant DNA-treated cells. The data imply an association between glycosylation modification with telomere shortening in antisense 6A8-treated cells.

Modification of glycosylation reduces microvilli on rat liver epithelial cells.

Effect of glycosylation modification on the shape of microvillus was investigated on rat liver epithelial cell line WB-F344. Since rat ER alpha-mannosidase has 89% identity to human 6A8 alpha-mannosidase, we used an antisense 6A8 cDNA fragment to inhibit expression in WB-F344 cells. Cells were transfected with antisense 6A8, the relevant sense fragment or the mock plasmid. Genomic PCR for neo(R) demonstrated integration of the transfected gene into host DNA. Enzymatic activity assay on p -nitro-phenyl-alpha-D-mannopyranoside showed suppression of ER alpha-mannosidase expression in the cells transfected with antisense 6A8. Concanavalin A binding to these cells was enhanced, indicating a modification in glycosylation. Number reduction and blunting of microvillus on these cells was observed. Transduction with the sense fragment or the mock had no effect. Cells with suppressed ER alpha-mannosidase expression grew slower in culture. Our results indicate an obvious effect of glycosylation modification on microvilli, which might be related with malfunctioning of cells.

Long-term expression of a transferred gene in Epstein-Barr virus transformed human B cells.

Delivering a gene into the Epstein-Barr virus (EBV)-transformed B cells is useful in studying effects of the gene on B-cell functions. However, although people have been able to efficiently transfer genes into and get them expressed in B-lympho blastoid cells for a time probably long enough to kill the cells using vectors harbouring oriP, the expression time of the delivered gene is not long enough in order to study the gene function in B cells. To solve this problem, we constructed an adeno-associated virus (AAV) plasmid pAGX(+) based on plasmids pSub201 and pRc/CMV. We developed and packaged recombinant AAV (rAAV) expression vectors containing an antisense or a sense DNA fragment of 6A8 cDNA encoding a human alpha-mannosidase, or an antisense fragment of 5D4 cDNA encoding a human cell membrane protein, or EYFP DNA. EBV-transformed B cell SKW6 and 3D5 were transduced with those rAAV or the mock. Transduction with the rAAV-EYFP showed an infection frequency of 64 +/- 3.5% and 58 +/- 6.2% for SKW6 and 3D5 cell, respectively. Genomic polymerase chain reaction (PCR) for neoR gene indicated an integration of the transferred gene into the host DNA. After being cultured and propagated for over 12 months, the cells were detected for the expression of the transferred gene. The RT-PCR, enzymatic assay and Con A binding test demonstrated an inhibition of 6A8 alpha-mannosidase in both SKW6 and 3D5 cells transduced with the antisense 6A8 DNA. Immunofluorescence staining with monoclonal antibodies (MoAb) 5D4 showed a reduction of the 5D4 protein expression on both the cells transduced with the antisense 5D4 DNA. The DNA fragmentation assay showed a resistance of the cells with 6A8 alpha-mannosidase inhibition to apoptosis induction by anti-Fas antibody. The data indicate that the AAV vector pAGX(+) can efficiently introduce genes into EBV-transformed B cells and the delivered gene can be expressed in the cells for more than 12 months which may be long enough for the study of gene functions in B cells.

[6A8 alpha-mannosidase catalyzes p-nitrophenyl-alpha-D-mannopyranoside].

OBJECTIVE: To confirm the alpha-mannosidase nature of the protein encoded by 6A8 cDNA. METHODS: 1) To construct a full-length 6A8 cDNA based on the three cloned DNA fragments by means of gene recombinant technique; 2) To insert the 6A8 cDNA into eukaryotic expression vector pCDI; 3) To transfect the recombinant pCDI-6A8 into COS-7 cells; 4) To characterize the nature of the protein encoded by 6A8 cDNA by means of enzymic activity assay and Western blotting assay. RESULTS: The constructed 6A8 cDNA was the right cDNA in sequence. The enzymetic activity of the homogenate of COS-7 cells transfected with pCDI-6A8 was 3-4 times higher than that of the cells transfected with the mock or the wild cells. The enzymetic reaction could not be inhibited by swainsonine. Western blot showed a band of 120,000 recognized by mAb 6A8. The band in the cells transfected with pCDI-6A8 cDNA was much darker than that in the cells transfected with the mock or in the wild cells. CONCLUSION: The protein encoded by 6A8 cDNA is a kind of alpha-mannosidase, which belongs to type II alpha-mannosidase.

Cloning, expression and characterization of a cDNA (6A8) encoding a novel human alpha-mannosidase.

A 3300-bp cDNA (6A8) has been isolated from a human tonsil cell lambdagt11 cDNA library (GenBank accession number: AF044414). The 6A8 gene is localized on human chromosome 13q31-32. Its cDNA has an open reading frame from position 57 bp to 3243 bp, encoding a 1062 amino-acid polypeptide. The sequence of the polypeptide has 89% identity to rat liver ER alpha-mannosidase. Homogenates of COS-7 cells transfected with 6A8 cDNA showed an enhanced enzymatic activity with p-nitro-phenyl-alpha-D-mannopyranoside, which was not inhibited by swainsonine. These data suggest that 6A8 alpha-mannosidase belongs to the class II alpha-mannosidase. Western blot analysis showed a band for 6A8 cDNA encoded protein of approximately 120 kDa. Northern blot analysis revealed two 6A8 mRNA transcripts with different tissue distribution. Enhanced concanavalin A (ConA) binding to CNE-2L2 cells transfected with a reverse 6A8 DNA was observed, indicating that the 6A8 protein is an important cellular alpha-mannosidase.