Association between SLCO1A2 genetic variation and methotrexate toxicity in human rheumatoid arthritis treatment.

Methotrexate (MTX), one of the important disease-modifying anti-rheumatic drugs, is the first-line drug for rheumatoid arthritis (RA) treatment. However, its adverse drug effects (ADEs) often lead to the abortion of MTX therapy. Human organic anion-transporting polypeptide 1A2 (OATP1A2, also referred as OATP-A or OATP1) encoded by SLCO1A2 gene is an important isoform of the solute carrier transporter (SLC) family. It is known to participate in the cellular uptake of MTX. In our previous study, we identified four OATP1A2 natural variants (E184K, D185N, T259P, and D288N) with impaired MTX uptake activity. This study aimed to evaluate the association of the SLCO1A2 genetic variations encoding these OATP1A2 variants and MTX-related toxicity in RA patients. A total of 60 RA patients were genotyped for these four polymorphisms (G550A, G553A, A775C, and G862A). The association between SLCO1A2 genetic variations and MTX toxicity was analyzed by binary logistic regression analysis. Single nucleotide polymorphisms (SNPs) analysis revealed that A775C and G862A SNPs were not detected in RA patients enrolled in this study, and the presence of 550AA genotype was associated with a high risk of MTX ADEs. Haplotype analysis revealed that H3 (H3 = AG) showed a high risk of MTX ADEs. Furthermore, there was a significant association of 550AA genotype and impaired MTX disposition, which might be the cause of the increased incidence of MTX ADEs in RA patients. Therefore, genetic variations in SLCO1A2 gene are risk factors for MTX toxicity and its information contributes to the prediction of MTX-related toxicity in RA treatment.

Preptin promotes proliferation and osteogenesis of MC3T3-E1 cells by upregulating ß-catenin expression.

Preptin, an oligopeptide secreted by pancreatic ß-cell, plays a significant role in glycometabolism and bone metabolism. Preptin strengthens proliferation and differentiation of osteoblasts, but the mechanism is unclear. Here, we explored the role of the Wnt/ß-catenin signaling pathway which is well known to affect bone development and remodelling in the function of preptin. We found that preptin promoted the cell proliferative activity and osteoblastic differentiation in osteoblast-like MC3T3-E1 cells in a dose-independent manner, as evidenced by elevation in osteogenic genes, alkaline phosphatase activity and alizarin red staining in a dose-independent manner. Additionally, our findings demonstrated that the ß-catenin expression level and runt-related transcription factor 2, which is the key downstream target of this pathway, were increased. The Wnt/ß-catenin signalling pathway antagonist DKK1 abrogated the proliferative effect and differentiation function of preptin in MC3T3-E1 cells. These data indicated that preptin may be a potential therapeutic target for the treatment of osteoporosis and that osteogenic impact of preptin in MC3T3-E1 cells might be mediated by the Wnt/ß-catenin signalling pathway. © 2019 IUBMB Life, 9999(9999):1-9, 2019.

The ubiquitin ligase Peli1 inhibits ICOS and thereby Tfh-mediated immunity.

T follicular helper (Tfh) cells are crucial for regulating autoimmune inflammation and protective immunity against viral infection. However, the molecular mechanism controlling Tfh cell differentiation is poorly understood. Here, through two mixed bone marrow chimeric experiments, we identified Peli1, a T cell-enriched E3 ubiquitin ligase, as an intrinsic regulator that inhibits Tfh cell differentiation. Peli1 deficiency significantly promoted c-Rel-mediated inducible T-cell costimulator (ICOS) expression, and PELI1 mRNA expression was negatively associated with ICOS expression on human CD4+ T cells. Mechanistically, increased ICOS expression on Peli1-KO CD4+ T cells enhanced the activation of PI3K-AKT signaling and thus suppressed the expression of Klf2, a transcription factor that inhibits Tfh differentiation. Therefore, reconstitution of Klf2 abolished the differences in Tfh differentiation and germinal center reaction between WT and Peli1-KO cells. As a consequence, Peli1-deficient CD4+ T cells promoted lupus-like autoimmunity but protected against H1N1 influenza virus infection in mouse models. Collectively, our findings established Peli1 as a critical negative regulator of Tfh differentiation and indicated that targeting Peli1 may have beneficial therapeutic effects in Tfh-related autoimmunity or infectious diseases.

Epidemiology of Takayasu arteritis in Shanghai: A hospital-based study and systematic review.

BACKGROUND: Takayasu arteritis (TAK) is a rare large vessel vasculitis, and epidemiological data on TAK are lacking in China. Thus, we designed this study to estimate the TAK prevalence and incidence in residential Shanghai, China. METHODS: Data on diagnosed TAK cases aged over 16 years were retrieved from 22 tertiary hospitals in Shanghai through hospital electronic medical record systems between January 1, 2015 and December 31, 2017 to estimate the prevalence and incidence. A systematic literature review based on searches in PubMed, Ovid-Medline, Excerpta Medica Database (EMBASE), Web of Science, and China National Knowledge Infrastructure (CNKI) was performed to summarize TAK distribution across the world. RESULTS: In total 102 TAK patients, with 64% female, were identified. The point prevalence (2015-2017) was 7.01 (95% CI 5.65-8.37) cases per million, and the mean annual incidence was 2.33 (1.97-3.21) cases per million. The average age of TAK patients was 44 ± 16 years, with the highest prevalence (11.59 [9.23-19.50] cases per million) and incidence (3.55 [0.72 3.74] cases per million) in the 16 to 34 years population. Seventeen reports were included in the system review, showing that the epidemiology of TAK varied greatly across the world. The incidence and prevalence were both relatively higher in Asian countries, with the prevalence ranging 3.3-40 cases per million and annual incidence ranging 0.34-2.4 cases per million. CONCLUSIONS: The prevalence and incidence of TAK in Shanghai was at moderate to high levels among the previous reports. The disease burden varied globally among racial populations.

Phenotypic and functional alterations of pDCs in lupus-prone mice.

Plasmacytoid dendritic cells (pDCs) were considered to be the major IFNα source in systemic lupus erythematosus (SLE) but their phenotype and function in different disease status have not been well studied. To study the function and phenotype of pDCs in lupus-prone mice we used 7 strains of lupus-prone mice including NZB/W F1, NZB, NZW, NZM2410, B6.NZM(Sle1/2/3), MRL/lpr and BXSB/Mp mice and C57BL/6 as control mice. Increased spleen pDC numbers were found in most lupus mice compared to C57BL/6 mice. The IFNα-producing ability of BM pDCs was similar between lupus and C57BL/6 mice, whereas pDCs from the spleens of NZB/W F1 and NZB mice produced more IFNα than pDCs from the spleens of C57BL/6 mice. Furthermore, spleen pDCs from MRL-lpr and NZM2410 mice showed increased responses to Tlr7 and Tlr9, respectively. As the disease progressed, IFN signature were evaluated in both BM and spleen pDC from lupus prone mice and the number of BM pDCs and their ability to produce IFNα gradually decreased in lupus-prone mice. In conclusion, pDC are activated alone with disease development and its phenotype and function differ among lupus-prone strains, and these differences may contribute to the development of lupus in these mice.

In Vivo Therapeutic Success of MicroRNA-155 Antagomir in a Mouse Model of Lupus Alveolar Hemorrhage.

OBJECTIVE: Diffuse alveolar hemorrhage (DAH) is a rare but life-threatening complication of systemic lupus erythematosus (SLE). Pristane-treated B6 mice develop severe DAH within 2 weeks of treatment. MicroRNA-155 (miR-155) is a pleiotropic microRNA that plays a crucial role in the regulation of immune responses. Recent studies have revealed a pathogenic role of miR-155 in various autoimmune disorders. The purpose of this study was to examine the role of miR-155 in the development of DAH in pristane-induced lupus using miR-155-knockout (miR-155(-/-)) mice and miR-155 antagomir to silence miR-155. METHODS: DAH was induced by an intraperitoneal injection of 0.5 ml of pristane. MicroRNA-155 antagomir was administered intravenously to silence miR-155 expression. Lung tissues were collected for RNA extraction and were embedded in paraffin for sectioning. Gene expression profiling data were analyzed using Ingenuity Pathway Analysis. Real-time quantitative polymerase chain reaction analysis was used for single-gene validation. Luciferase reporter assay and argonaute 2 immunoprecipitation were performed for target validation. RESULTS: MicroRNA-155 expression was significantly increased during the development of DAH. Disease progression was reduced in miR-155(-/-) mice as well as by in vivo silencing of miR-155 using a miR-155 antagomir. MicroRNA-155 silencing dampened pristane-induced ectopic activation of multiple inflammatory pathways and reduced the expression of proinflammatory cytokines. Several negative regulators of NF-κB signaling were inhibited by pristane and were reactivated in miR-155(-/-) mice. In particular, the antiinflammatory factor peroxisome proliferator-activated receptor α was identified as a direct target of miR-155. CONCLUSION: MicroRNA-155 promotes pristane-induced lung inflammation. It contributes to ectopic activation of NF-κB signaling pathways by targeting multiple negative regulators. MicroRNA-155 antagomir may be a promising therapeutic strategy for treating acute lung inflammation in lupus.