Effect of miR-124a on collagen-induced arthritis in mice and the underlying mechanisms / 中南大学学报(医学版)

OBJECTIVES@#Rheumatoid arthritis (RA) is a chronic autoimmune disease. MicroRNA has been shown to play an important role in RA. MicroRNA-124a (miR-124a) has anti-proliferative and anti-inflammatory effects in RA fibroblast synovial cells. This study aims to explore the effects of miR-124a overexpression on arthritis in collagen-induced arthritis (CIA) mice and the underlying mechanisms.@*METHODS@#Bovine type II collagen and complete Ferris adjuvant were used to induce CIA model from DBA/1 mice. Twenty-eight days after initial immunization (D28), CIA mice were randomly divided into a model group, a miR-124a treatment group, and a negative control (NC) group. Physiological saline, miR-124a agomir, and miR-124a agomir NC were injected into the skin at the tail root of mice every 3 days for 4 times, respectively. The degree of joint swelling and arthritis index of mice were recorded accordingly. Sixty-three days after initial immunization (D63), the mice were sacrificed to obtain the synovial tissue of ankle joint. HE staining was used to observe the proliferation of synovial cell, infiltration of inflammatory cell, pannus, and bone erosion of synovial tissues; TUNEL staining was used to detect cell apoptosis; qRT-PCR was used to detect the mRNA expression of miR-124a, phosphatidylinositol-3-kinase catalytic subunit alpha (PIK3CA) and its downstream genes Bcl-2 and Bax. Immunohistochemistry was used to detect the protein expression of PIK3CA, Bcl-2, and Bax protein in synovial tissues of each group.@*RESULTS@#Different degrees of swelling presented in the paws of DBA/1 mice at D28, which indicated the CIA model was constructed successfully. Forty-eight days after initial immunization (D48), the paws of mice in the miR-124a treatment group were only slightly red and swollen, while the paws of mice in the model group and the NC group were obviously red and swollen. The arthritis index of mice in the miR-124a treatment group were decreased significantly compared to the NC group at D51, D53, D59, and D62 (51, 53, 59, 62 days after initial immunization) (all P<0.05). Sixty-three days after initial immunization (D63), HE staining indicated that the scores of synovial cell proliferation, inflammatory cell infiltration, synovial pannus, and bone erosion were significantly reduced in the miR-124a treatment group (P<0.05 or P<0.01), while cell apoptosis was increased in the miR-124a treatment group compared with the model group and NC group (P<0.01 or P<0.001). Besides, the expression of miR-124a and Bax in the synovial tissue in miR-124a treatment group was significantly higher than those in the model group and NC group (P<0.01 or P<0.001), while the expressions of PIK3CA and Bcl-2 were decreased (P<0.05 or P<0.01 or P<0.001), and the ratio of Bcl-2 to Bax was significantly decreased (P<0.01 or P<0.001).@*CONCLUSIONS@#Overexpression of miR-124a can reduce arthritis in CIA mice bacause it could promote synovial cell apoptosis and inhibit synovial cell proliferation via targeting PIK3CA and regulating its downstream pathways.

Biological connotation of four traditional Chinese medicine syndromes of rheumatoid arthritis based on "disease-syndrome-symptom" association network / 中国中药杂志

The present study explored the biological connotation of traditional Chinese medicine(TCM) syndromes of rheumatoid arthritis(RA) from the "disease-syndrome-symptom" association network. RA patients with four TCM syndromes(dampness-heat obstruction, phlegm-stasis obstruction, Qi-blood deficiency, and liver and kidney deficiency), three for each type, were assigned as the RA TCM syndrome group, and three healthy volunteers as the normal control group. The differential gene sets of four syndromes were screened out through transcriptome expression profiling and bioinformatics mining. The relevant gene sets of syndrome-related clinical symptoms were collected from TCMIP v2.0(http://www.tcmip.cn/). The "disease-syndrome-symptom" association networks of four RA syndromes were established by using the intersection genes of syndrome-related differential genes and symptom-related genes, and the key network target genes of each syndrome were screened out and the corresponding biological functions were mined through topological feature calculation and enrichment analysis. The genes associated with clinical symptoms such as vasculitis, joint pain, and fever in the damp-heat obstruction syndrome ranked the top, and the key network target genes of this syndrome were most significantly enriched in the pathways related to material and energy metabolism and thermal reaction biological processes. The clinical symptom-related genes of the phlegm-stasis obstruction syndrome were most significantly enriched in the pathways related to "immunity-inflammation", nervous system regulation, and sensory response. The clinical symptoms such as hypoglycemia, hypotension, weight loss, palpitation, and arrhythmia in Qi-blood deficiency syndrome were predominant, and its key network target genes were most significantly enriched in the pathways related to the nervous system and "immunity-inflammation" response. The abnormal symptoms in the liver and kidney in the liver and kidney deficiency syndrome were commonly seen, and its key network target genes were most significantly enriched in the "immunity-inflammation" regulatory pathways, and liver and kidney development and metabolic response. In conclusion, the differences and connections of the biological basis between different TCM syndromes of RA are in line with the theoretical interpretation of TCM on the etiology and pathogenesis of RA. This study summarized the objective essence of syndromes to a certain extent from the "disease-syndrome-symptom" association network and is expected to provide a theoretical basis for the discovery of serum biomarkers of RA syndromes.

Association between matrix metalloproteinase-1 (MMP-1) protein level and the risk of rheumatoid arthritis and osteoarthritis: a meta-analysis

Recent publications have investigated the potential role of the protein level of matrix metalloproteinase-1 (MMP-1) in the susceptibility to rheumatoid arthritis (RA) and osteoarthritis (OA). However, no unanimous conclusion was obtained. Therefore, we carried out a meta-analysis to explore the association between MMP-1 expression and these two clinical disorders. After database searching and screening, we enrolled a total of eighteen articles for the pooled analysis. We observed a significant association between RA cases and controls in the whole population [SMD (standard mean difference)=1.01, P=0.017]. There were similar positive results in the subgroup analysis of "population-based control" (SMD=1.50, P=0.032) and "synovial fluid" (SMD=1.32, P=0.049). In addition, we observed an increased risk in OA cases, compared with controls, in the overall analysis (SMD=0.47, P=0.004) and subsequent subgroup analysis of "knee OA" (SMD=0.86, P<0.001), "Asian/China" (SMD=0.76, P=0.003), "cartilage-Asian/China" (SMD=1.21, P<0.001), and "synovial fluid-Asian/China" (SMD=0.73, P=0.004). In summary, a high protein level of MMP-1 in synovial fluid may be associated with the susceptibility to RA, and the high MMP-1 level in the cartilage tissue or synovial fluid may be related to the pathogenesis of knee OA in the Chinese population. This should be confirmed by larger sample sizes.

Therapeutic mechanism of Psammosilene tunicoides extract on rheumatoid arthritis based on NLRP3 inflammasome / 中国中药杂志

In this study, we investigated the mechanism of crude extract of Psammosilene tunicoides(CEPT) in the treatment of rheumatoid arthritis(RA) based on the Nod-like receptor protein 3(NLRP3) inflammasome. The collagen-induced arthritis(CIA) mouse model was established. On day 32 after the primary immunization, according to the arthritis score, the mice were randomly divided into model group, positive control(methotrexate) group, low-and high-dose CEPT groups, and normal group, with 10 mice in each group. According to the administration dose of each group, the mice were continuously administered for 21 days. Every four days during the administration, the paw edema degree, arthritis score, and spleen index of the mice were measured; histopathological examination was performed for the ankles of the mice; the contents of IL-1β and IL-18 in the serum were determined; the protein expression levels of NLRP3, caspase-1, and apoptosis-associated speck-like protein containing a CARD(ASC), as well as the mRNA expression levels of NLRP3 and caspase-1 in the ankle joints of the mice were detected. The results showed that compared with those in the model group, the mice in the positive control group and CEPT groups had significantly decreased the contents of IL-1β and IL-18 in the serum and spleen index(P<0.01), significantly lowered arthritis score and degree of paw edema(P<0.01), alleviated arthritic infiltration of the knee, and down-regulated protein and mRNA levels of NLRP3, ASC, and caspase-1 in the ankle joint(P<0.01). These results suggest that P. tunicoides may reduce the paw edema and arthritis score and alleviate the inflammatory response in CIA mice by inhibiting the expression of NLRP3. This study provides a basis for the study of immune regulation of P. tunicoides in RA.

Screening and analysis for autophagy / 中南大学学报(医学版)

OBJECTIVES@#Long non-coding RNA (lncRNA) has become a key epigenetic regulator that regulates gene expression and affects a variety of biological processes. LncRNA plays an important role in the occurrence and development of rheumatoid arthritis (RA). The study on lncRNA in peripheral blood cells of RA patients has been reported. However, there is no study on autophagy regulation by lncRNA in RA patients. This study aims to provide a new direction for the diagnosis and treatment of RA via screening the changes of lncRNAs in RA fibroblast-like synoviocytes (RA-FLSs) before and after autophagy and finding the key lncRNAs targeting RA-FLSs autophagy.@*METHODS@#Synovial tissues of 6 RA patients after knee and hip joint surgery were obtained, and RA-FLSs were cultured to the 5th generation for further experiments (tissue culture method). After treatment with mTOR inhibitor PP242, the expression of LC3-II was detected by Western blotting. Total RNAs of 3 cases of RA-FLSs before and after treatment with mTOR inhibitor PP242 were extracted by TRIzol and screened by Agilent Human ceRNA Microarray 2019 (4×180 K, design ID: 086188) chip. The lncRNAs with significantly changed expression levels were selected (difference multiple≥2.0, @*RESULTS@#RA-FLSs were successfully isolated and cultured from the synovial tissues of the patient's knee or hip joint. After 6 RA-FLSs were treated with PP242, the expression level of autophagy marker protein LC3-II was increased (@*CONCLUSIONS@#Differentially expressed lncRNAs in RA-FLSs have been identified with microarray analysis. In RA, differential expression of lncRNAs is involved in the autophagy of RA-FLSs. The underlying mechanisms based on bioinformatics analysis include regulating the secretion of cytokines, such as IL-6, TGF-β, TNF-α and IL-17, participating in the immune cell differentiation, such as Th17, Th1, Th2 cells and osteoclasts, as well as regulating the autophagy pathway, MAPK, FoxO, and other signaling pathways. It has been verified that the expression of ENST0000584721.1 is up-regulated and ENST0000615939.1 is down-regulated after autophagy of RA FLSs, which provides a good experimental basis for further study on the mechanism of lncRNA in RA-FLSs autophagy.

Inokosterone Is A Potential Drug Target of Estrogen Receptor 1 in Rheumatoid Arthritis Patients: Analysis from Active Ingredient of Cyathula Officinalis / 中国结合医学杂志

OBJECTIVE@#To elucidate the active compounds and the molecular mechanism of Cyathula Officinalis as a drug treatment for rheumatoid arthritis (RA).@*METHODS@#The target genes of active ingredients from Cyathula Officinalis were obtained from bioinformatics analysis tool for the molecular mechanism of traditional Chinese medicine. The protein-protein interaction between the target genes were analyzed using STRING and Genemania. The transcriptome of RA patients compared to healthy people (GSE121894) were analyzed using R program package Limma. The relative expression of the target genes was obtained from the RNA-seq datasets. The molecular docking analyses were processed based on the molecular model of estrogen receptor 1 (ESR1) binding with estradiol (PDB ID:1A52). The binding details were analyzed by SYBYL.@*RESULTS@#Inokosterone, ecdysterone, and cyaterone were the 3 active ingredients from Cyathula Officinalis that bind to target genes. Of all the significantly changed genes from RA patients, ESR1, ADORA1, and ANXA1 were significantly increased in mRNA samples of RA patients.@*CONCLUSION@#ESR1, the transcription factor that binds inokosterone in the molecular binding analysis, is the target protein of Cyathula Officinalis.

Xinfeng Capsules promotes apoptosis of synovial fibroblasts and attenuates inflammation in rheumatoid arthritis by regulating lncRNA MAPKAPK5-AS1 / 中国中药杂志

To explore the regulatory effects of Xinfeng Capsules(XFC) on the apoptosis of synovial fibroblasts(FLS) and inflammation in rheumatoid arthritis(RA) via lncRNA MAPKAPK5-AS1(MK5-AS1). Thirty healthy people and 30 patients with RA due to spleen deficiency and dampness exuberance were collected for extracting the peripheral blood mononuclear cells(PBMCs) before and after XFC treatment, which were used to observe the correlation between MK5-AS1 and clinical indicators as well as MK5-AS1 expression before and after XFC treatment. Following the establishment of RA-FLS cell line and the preparation of XFC-containing serum, MK5-AS1-overexpression plasmid was constructed and transfected into RA-FLS for investigating the efficacy of XFC-containing serum in regulating inflammation and apoptosis of RA-FLS via MK5-AS1. The expression of MK5-AS1 in PBMCs of patients with RA due to spleen deficiency and dampness exuberance was decreased(P<0.001). The ROC curve analysis revealed the AUC of 83.9%. Correlation analysis showed that MK5-AS1 was negatively correlated with ESR, CRP, RF, CCP, and spleen deficiency and dampness exuberance syndrome score. The expression of MK5-AS1 increased significantly after XFC treatment(P<0.001). As demonstrated by association analysis, XFC decreased MK5-AS1, ESR, CRP, RF, and spleen deficiency and dampness exuberance syndrome score, with the degree of support all greater than 83%, confidence greater than 80%, and lift greater than 1. The results of RT-qPCR showed that the MK5-AS1 RNA expression significantly decreased after TNF-α stimulation(P<0.01), which, however, increased significantly after the intervention with XFC-containing serum(P<0.05). Such expression rose again after the transfection of pcDNA3.1-MK5-AS1(P<0.01). ELISA results showed that TNF-α stimulation elevated the expression of pro-inflammatory factor IL-17 but lowered the expression of anti-inflammatory factor IL-4(P<0.01). After intervention with XFC-containing serum, the expression of IL-17 decreased while that of IL-4 increased(P<0.01). The transfection of pcDNA3.1-MK5-AS1 contributed to the reduction in IL-17 expression but the elevation in IL-4 expression(P<0.01). The immunofluorescence(IF) findings demonstrated that the expression of pro-apoptotic protein Bax was down-regulated, whereas that of the anti-apoptotic protein Bcl-2 was up-regulated after TNF-α stimulation(P<0.01). After the intervention with XFC-containing serum, the Bax expression was increased, while Bcl-2 expression was decreased(P<0.01), which were remarkably collaborated by the transfection of pcDNA3.1-MK5-AS1(P<0.05). The expression of MK5-AS1 is significantly decreased in both RA-PBMCs and RA-FLS, implying that XFC inhibits inflammatory reaction and promotes the apoptosis in RA by regulating the expression of MK5-AS1.

Mechanism of Huangqi Guizhi Wuwu Decoction in treatment of rheumatoid arthritis based on UPLC-LTQ-Orbitrap-MS, network pharmacology, and cell experiment / 中国中药杂志

In this study, ultra-high performance liquid chromatography-linear ion trap/electrostatic field orbit trap combined-type mass spectrometry(UPLC-LTQ-Orbitrap-MS) was used to analyze the main active components of Huangqi Guizhi Wuwu Decoction(HQGZ). A total of 50 active components were identified from HQGZ and 108 potential targets of the components related to the treatment of rheumatoid arthritis were retrieved based on network pharmacology, including 87 key targets, followed by Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the targets. The result indicated that HQGZ may exert therapeutic effects mainly through the sphingolipid signaling pathway, tumor necrosis factor(TNF) signaling pathway, as well as the positive regulation of ribonucleic acid(RNA) polymerase Ⅱ promoter transcription, inflammatory response and other biological processes. At the same time, cell experiment was performed to verify the key proteins in the TNF signaling pathway. The results demonstrated that HQGZ significantly reduced the expression of caspase-3(CASP3), TNF, relaxed(RELA) protein, and IkappaB kinase beta(IKBKB) in fibroblast-like synoviocytes induced by TNF-α. The results of UPLC-LTQ-Orbitrap-MS, network pharmacology and cell experiment showed that the active components in HQGZ may inhibit inflammatory response and regulate immune function and cell apoptosis by modulating key proteins in TNF signaling pathway to treat rheumatoid arthritis.

Mechanism of Olibanum-Myrrha in treatment of rheumatoid arthritis based on network pharmacology and molecular docking / 中国中药杂志

In this paper, network pharmacology method and molecular docking technique were used to investigate the target genes of Olibanum and Myrrha compatibility and the possible mechanism of action in the treatment of rheumatoid arthritis(RA). Our team obtained the main active components of Olibanum-Myrrha based on literatures study, relevant traditional Chinese medicine systematic pharmacological databases and literature retrieval, and made target prediction of the active components through SwissTargetPrediction database. At the same time, RA-related targets were collected through DrugBank, GeneCards and Therapeutic Target Database(TDD) databases; and VENNY 2.1 was use to collect intersection targets to map common targets of drug and disease of Venn diagram online. The team used STRING database to construct PPI protein interaction network diagram, and screen out core targets according to the size of the interaction, and Cytoscape 3.6.0 software was used to construct network models of "traditional Chinese medicine-component-target" "traditional Chinese medicine-component-target-disease" and core target interaction network model. The intersection target was analyzed by using DAVID 6.8 online database for GO function analysis and KEGG pathway enrichment analysis, and Pathon was used to visualization. AutoDock Vina and Pymol were used to connect the core active components with the core targets. Sixteen active components of Olibanum-Myrrha pairs were found and collected in the laboratory, and 320 relevant potential targets, 468 RA-related targets and 62 intersection targets were obtained through the Venn diagram. It mainly acted on multiple targets, such as IL6, TNF, IL1 B and MAPK1, involving TNF signaling pathway and Toll-like receptor signaling pathway in RA treatment. Finally, in this study, possible targets and signaling pathways of Olibanum-Myrrha compatibility therapy for RA were discussed, and molecular docking between core targets and core active components was conducted, which could provide scientific basis for the study on the mechanism of Olibanum-Myrrha compatibility.

Effect of Xinfeng Capsules-containing serum on TNF-α-induced apoptosis and inflammation of fibroblast-like synoviocytes in rheumatoid arthritis / 中国中药杂志

The aim of this paper was to observe the effect of Xinfeng Capsules(XFC)-containing serum on the apoptosis and inflammation of fibroblast-like synoviocytes(FLS) in rheumatoid arthritis(RA) induced by tumor necrosis factor-α(TNF-α), so as to investigate the mechanism of XFC in the treatment of RA. RA-FLS immortalized cell line was established, and XFC drug-containing serum was prepared. CCK-8, ELISA, RT-qPCR, immunofluorescence and TUNEL were used to observe the effect of XFC-containing serum on RA-FLS apoptosis and inflammatory indexes. CCK-8 results showed that the optimal concentration and time of TNF-α on RA-FLS were 10 ng·mL~(-1) and 48 h, respectively; and the optimal concentration and time of XFC on RA-FLS were 6.48 mg·g~(-1) and 72 h, respectively. The results of ELISA showed that compared with RA-FLS group, the expressions of TNF-α, IL-1β, IL-6, IL-8 in TNF-α+RA-FLS group were significantly increased, while the expressions of IL-4 and IL-10 were significantly decreased(P<0.01); after intervention with XFC-containing serum, the expressions of TNF-α, IL-1β, IL-6, IL-8 were significantly decreased, whereas the expressions of IL-4 and IL-10 were significantly increased(P<0.01). The results of RT-qPCR showed that compared with RA-FLS group, the mRNA expressions of Fas, FasL, caspase-3, caspase-8, Bax, Bcl-X1 in TNF-α+RA-FLS group were significantly decreased, while the mRNA expression of Bcl-2 was significantly increased(P<0.001); after intervention with XFC-containing serum, the mRNA expressions of Fas, FasL, caspase-3, caspase-8, Bax, Bcl-X1 were significantly increased, whereas the mRNA expression of Bcl-2 was significantly decreased(P<0.01). The results of immunofluorescence showed that compared with RA-FLS group, the protein expressions of caspase-3 and Bax in TNF-α+RA-FLS group was significantly lower than those in RA-FLS group(P<0.05); after intervention with XFC-containing serum, the protein expressions of caspase-3 and Bax were significantly increased, whereas the protein expression of Bcl-2 was significantly decreased(P<0.05). TUNEL results showed that compared with RA-FLS group, the apoptosis of TNF-α+RA-FLS group was decreased(P<0.05); after intervention with XFC-containing serum, the apoptosis was significantly increased(P<0.05). One of the mechanisms of XFC in the treatment of RA is to promote the apoptosis of RA-FLS and inhibit its inflammatory reaction.

Effect of swertiamarin, gentiopicrin and sweroside on cell apoptosis and expression of Bcl-2 in rheumatoid arthritis fibroblast-like synoviocytes / 中国中药杂志

The aim of this paper was to discuss the effect of swertiamarin, gentiopicrin and sweroside on rheumatoid arthritis fibroblast-like synoviocytes(RA-FLSs) and B-cell lymphoma-2(Bcl-2) and their mechanisms. ZINC database and RCSB PDB database were retrieved for 3 D chemical structures of swertiamarin, gentiopicrin and sweroside and 3 D target protein structures. AutoDock Mgltools 1.5.6, AutoDockVina 1.1.2 and pyMOL 2.2.0 were applied for molecular docking to analyze the relationship between Bcl-2(1 GJH) target protein and important ingredients. The cell apoptosis of RA-FLSs was tested by Annexin V-FITC. The Bcl-2 protein expression of RA-FLSs treated with different ingredients was tested by Western blot. The Bcl-2 mRNA expression of RA-FLSs treated with different ingredients was tested by RT-PCR. Swertiamarin, gentiopicrin and sweroside were docked well with Bcl-2(1 GJH). The binding energy of swertiamarin was-6.9 kcal·mol~(-1), the binding energy of gentiopicrin was-6.7 kcal·mol~(-1) and the binding energy of sweroside was-6.4 kcal·mol~(-1). Compared with the blank group, the Bcl-2 protein expression of each group were reduced, while that of the gentiopicrin group was the highest(P<0.01). Compared with the blank group, the Bcl-2 mRNA expression of each groups were reduced. Gentiopicrin can reduce the Bcl-2 protein expression and the Bcl-2 mRNA expression, so as to promote the RA-FLSs apoptosis.

Methylation status and expression of TWEAK gene promoter region in peripheral blood of patients with rheumatoid arthritis / 北京大学学报(医学版)

OBJECTIVE@#To explore the relationship between tumor necrosis factor like weak inducer of apoptosis (TWEAK) gene and the pathogenesis of rheumatoid arthritis (RA) by detecting the DNA methylation level, mRNA expression level and serum protein concentration of TWEAK gene in peripheral blood.@*METHODS@#The MassARRAY method was used to detect the DNA methylation level of the TWEAK gene in the peripheral blood of 112 RA patients and 86 matched healthy volunteers. The real-time quantitative polymerase chain reaction method was used to detect the mRNA expression level of the TWEAK gene in the peripheral blood of the subjects. The enzyme-linked immunosorbent assay method was used to detect the serum TWEAK protein concentration of the subjects. The TWEAK gene DNA methylation level, mRNA expression level and serum protein concentration between the RA group and the healthy control group were compared, and the relationship between it and the degree of disease activity analyzed.@*RESULTS@#The overall DNA methylation level of TWEAK gene and the DNA methylation levels of CpG_11, CpG_17.18.19.20, CpG_40.41.42 site in the RA group were higher than those in the healthy control group (P=0.002, P=0.01, P=0.006, P=0.002, respectively). The DNA methylation level of CpG_55.56 site in the high disease activity group was higher than that in the medium and low disease activity group (P=0.041). The expression level of TWEAK gene mRNA in the peripheral blood of the RA group was lower than that of the healthy control group (P=0.023). The expression level of TWEAK gene mRNA in the high disease activity group was lower than that in the medium and low disease activity group (P=0.035). The serum TWEAK protein concentration of the RA group was not significantly different from that of the healthy control group (P=0.508), but it was positively correlated with the mRNA expression level (r=0.482, P < 0.001).@*CONCLUSION@#The TWEAK gene is closely related to the onset and progression of RA, and its hypermethylation state may be one of the epigenetic mechanisms regulating its low mRNA expression, and it can be used as one of the important indicators for clinical monitoring and evaluation of RA.

Susceptibilidad genética y enfermedad autoinmune reumática: Revisión narrativa / Genetic susceptibility and autoimmune rheumatic disease: Narrative review

La autoinmunidad es la consecuencia de la pérdida de control y regulación de la respuesta inmune. Se re-porta que ocurre entre 5 y 9% de patologías a nivel mundial. A las enfermedades con esta anomalía se les denomina autoinmunes y se clasifican de acuerdo con el órgano o sistema afectado. Las reumáticas involucran al tejido conectivo y las articulaciones. Los factores asociados a su aparición incluyen: edad, género, medioam-biente y genéticos. La susceptibilidad genética indica la presencia de uno o varios genes asociados al desarrollo de determinada enfermedad, cuya expresión podría ser el producto de la migración, selección, recombinación y adaptación de genes entre las poblaciones, lo que explica la variación fenotípica y la expresión clínica resultan-te. Los estudios de asociación del genoma completo (GWAS por sus siglas en inglés) han permitido identificar múltiples genes involucrados con enfermedades reumáticas, destacan el lupus eritematoso sistémico y artritis reumatoide, asociadas con más de 60 alelos, y otras como la espondilitis anquilosante, en donde la asociación ha sido primordialmente con un gen y sus polimorfismos. Esta revisión tiene como objetivo informar el estado de la susceptibilidad determinada genéticamente para estas enfermedades y el impacto que tiene sobre la expresión clínica. Se realizó una búsqueda en PubMed y la base de datos de la biblioteca Cochrane, se incluyeron artículos relacionados con las palabras clave propuestas desde el 2000. La revisión identifica genes y la asociación con estas enfermedades, expone la diversidad existente y justifica continuar la búsqueda de genes en todas las poblaciones.

Autoimmunity is the consequence of the loss of control and regulation of the immune response. It is reported that between 5 and 9% of pathologies occur worldwide. Diseases with this abnormality are called autoimmune and are classified according to the organ or system affected. Rheumatic diseases involve connective tissue and joints. Factors associated with its appearance include age, gender, environment, and genetics. Genetic suscepti-bility indicates the presence of one or more genes associated with the development of a certain disease, whose expression could be the product of migration, selection, recombination and adaptation of genes between popu-lations, which explains the phenotypic variation and the resulting clinical expression. Genome wide association studies (GWAS) have allowed the identification of multiple genes involved with rheumatic diseases, including systemic lupus erythematosus and rheumatoid arthritis, associated with more than 60 alleles, and others such as ankylosing spondylitis, where the association has been primarily with a gene and its polymorphisms. This review aims to report the status of genetically determined susceptibility to these diseases and the impact it has on clinical expression. A search was carried out in PubMed and the Cochrane library database, articles related to the proposed keywords from the year 2000 were included. The review identifies genes and the association with these diseases, exposes the existing diversity and justifies continuing the search for genes in all populations.

Association of kir2dl2 gene with anti-cyclic citrullinated protein antibodies for serodiagnosis in rheumatoid arthritis

Rheumatoid arthritis is a clinical autoimmune syndrome that causes joint damage. The positive or negative anti-cyclic citrullinated protein (CCP) antibodies serodiagnosis differentiates two subsets of the disease, each with different genetic background. Previous studies have identified associations between KIR genes and rheumatoid arthritis but not with anti-CCP serodiagnosis. Therefore, we investigated the proportion of patients seropositive and seronegative to anti-CCP and its possible association with KIR (killer cell immunoglobulin-like receptor) genes. We included 100 patients with rheumatoid arthritis from western Mexico, who were determined for anti-CCP serodiagnosis by ELISA, and 16 KIR genes were genotyped by PCR-SSP. The proportion of seropositive anti-CCP patients was 83%, and they presented a higher frequency of KIR2DL2 genes than the seronegative group (73.6% vs. 46.2%, p = 0.044) which, in turn, presented a higher KIR2DL2-/ KIR2DL3+ genotype frequency than the first ones (46.2% vs. 17.2%, p = 0.043). These results suggest different KIR genetic backgrounds for each subset of the disease according to anti-CCP serodiagnosis.

La artritis reumatoide es un síndrome clínico autoinmune que causa daño en las articulaciones. El serodiagnóstico positivo o negativo para anticuerpos proteicos anti-cíclicos citrulinados (CCP) diferencia dos subconjuntos de la enfermedad, cada uno con diferente fondo genético. Estudios previos han identificado asociaciones entre los genes killer cell immunoglobulin- like receptor (KIR) y la artritis reumatoide, pero no con el serodiagnóstico de anti-CCP. Por lo tanto, investigamos la proporción de seropositividad y seronegatividad anti-CCP y su posible asociación con genes KIR. Se incluyeron 100 pacientes con artritis reumatoide del occidente de México, a quienes se les determinó su serodiagnóstico anti-CCP por ELISA y también se les realizó genotipificación de 16 genes KIR por PCR-SSP. La proporción de pacientes seropositivos anti-CCP fue del 83% y presentaron una mayor frecuencia génica KIR2DL2 que el grupo seronegativo (73.6% vs. 46.2%, p = 0.044), estos últimos presentaron mayor frecuencia genotípica KIR2DL2-/KIR2DL3+ que los primeros (46.2% vs. 17.2%, p = 0.043). Los resultados sugieren diferente fondo genético KIR para cada subconjunto de la enfermedad, de acuerdo con el serodiagnóstico anti-CCP.

Association between tumor necrosis factor polymorphisms and rheumatoid arthritis as well as systemic lupus erythematosus: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) plays an important role in autoimmune diseases. Previous studies have investigated the association of TNF-α-238G/A (rs361525) and -308G/A (rs1800629) polymorphisms with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, no agreed conclusion had been made. Therefore, this meta-analysis was conducted to assess the associations of TNF-α-238G/A and -308G/A polymorphisms with RA and SLE risk. A systematic search was conducted in commonly used databases. Meta-analysis was performed by STATA12.0. A total of 43 studies were included. In the overall population, the TNF-α-238A allele was observed to be a protective factor for RA (A vs G: OR=0.75, 95%CI=0.57-0.99, P=0.040) and the TNF-α-308A allele was found to be a risk factor for SLE (A vs G: OR=1.78, 95%CI=1.45-2.19, P<0.001). However, no evidence of association was found between TNF-α-238 G/A polymorphism and SLE nor between -308G/A and RA. In the subgroup analysis, TNF-α-308A allele played a pathogenic role for RA in Latin Americans (A vs G: OR=1.46, 95%CI=1.15-1.84, P=0.002) and for SLE in Latin Americans (A vs G: OR=2.12, 95%CI=1.32-3.41, P=0.002) and Europeans (A vs G: OR=2.03, 95%CI=1.56-2.63, P<0.001), while it played a protective role for RA in Asians (A vs G: OR=0.54, 95%CI=0.32-0.90, P=0.017). No significant association was found between TNF-α-308G/A and SLE susceptibility in Africans and Asians. This meta-analysis demonstrated that TNF-α-238A was associated with decreased risk of RA rather than SLE, while -308G/A polymorphism was associated with SLE rather than RA. Stratification analysis indicated that different ethnicities would have different risk alleles.

Association study of AFF1 rs340630 polymorphism with genetic susceptibility to rheumatoid arthritis in Chinese population

This study was performed to examine whether the AF4/FMR2 family, member 1 (AFF1) rs340630 polymorphism is involved in the genetic background of rheumatoid arthritis (RA) in a Chinese population. Two different study groups of RA patients and controls (328 RA patients and 449 healthy controls in the first study group; 232 RA patients and 313 controls in the second study group) were included in our study. Overall, there was no significant difference in either genotype (P=0.71 and 0.64 in the first and second study group, respectively) nor allele (in the first study group: A vs G, P=0.65, OR=1.05, 95%CI=0.85-1.29; in the second study group: G vs A, P=0.47, OR=1.10, 95%CI=0.86-1.40) frequencies of AFF1 rs340630 polymorphism between RA patients and controls. Our study represents the first report assessing the association of AFF1 rs340630 polymorphism with RA risk. No significant evidence was found for the dominant or recessive models. Further case-control studies with larger sample sizes and fine-mapping studies are needed to clarify the role of AFF1 in the genetic basis of RA.

The rs878081 polymorphism of AIRE gene increases the risk of rheumatoid arthritis in a Chinese Han population: a case-control study

The autoimmune regulator (AIRE), a transcriptional regulator expressed in medullary thymic epithelial cells, plays an important role in thymocyte education and negative selection. Several citations studying the association between the rs878081 exon polymorphism of the AIRE gene and the risk of rheumatoid arthritis (RA) in different populations have yielded conflicting findings. Thus, this case-control study involving 300 RA cases and 300 controls was aimed to identify whether such association existed in a Chinese Han population from East China. The rs878081 polymorphism of the AIRE gene was genotyped. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using the chi-squared test, genetic model analysis, and stratification analysis. Genetic model analysis showed significant correlations between the TT genotype and the risk of RA (OR: 1.89, 95%CI: 1.03-3.47 in TT vs CC; OR: 1.84, 95%CI: 1.02-3.31 in TT vs CC+TC). Stratification analyses of sex, age, smoking, and alcoholism suggested that the rs878081 polymorphism of the AIRE gene increased RA risk among non-smokers. In conclusion, rs878081 polymorphism of AIRE gene increases the risk of RA in a Chinese Han population.

Genética de la artritis reumatoide en Chile / Genetics of rheumatoid arthritis in Chile

La artritis reumatoide (AR) es una enfermedad sistémica crónica y autoinmune, que afecta principalmente a las articulaciones sinoviales. Al igual que ocurre con muchas enfermedades autoinmunes, la etiología de la AR es multifactorial y desconocida. La susceptibilidad genética es evidente en AR, situando su heredabilidad en aproxima-damente el 60%. La importancia del conocimiento de los factores genéticos asociados con la AR se sitúa en la contribución a la comprensión de los mecanismos patogénicos de la enfermedad, así como a su aplicación clínica que nos acerque a un tratamiento más personalizado de los pacientes por medio de marcadores de riesgo, diagnóstico y/o pronóstico. En este artículo se revisan los factores genéticos de la AR, y se hace una aproximación a la situación en poblaciones latinoamericanas en general, y chile-na en particular.

Rheumatoid arthritis (RA) is an autoimmune inflammatory rheumatic disease that affects many tissues and organs, mainly synovial joints. Like many autoimmune dis-eases, the etiology of RA is multifactorial and unknown. Genetic susceptibility is evi-dent in RA, with its heritability around the 60%.The relevance of the knowledge of the genetic factors associated with RA relies on its contribution to the understanding of the pathological mechanisms of the disease, and the clinical applicability. This better understanding let us develop a more personalized treatment through genetic markers for risk, diagnostic and prognostic. In this paper, genetic factors of RA are reviewed and a general view of the Latin American populations, and particularly Chilean, is made.

Meta-analysis of the association between PADI4 -92C/G polymorphism and rheumatoid arthritis in the Chinese population

Many studies have evaluated the correlation between peptidylarginine deiminase 4 (PADI4) -92C/G polymorphism and rheumatoid arthritis (RA), but the results remain inconclusive. Therefore, we performed a meta-analysis in the Chinese population to provide comprehensive data on the association between PADI4 -92C/G polymorphism and RA. Eligible studies published before May 2016 were identified in PubMed and Chinese databases. The strengths of these associations were assessed by pooled odds ratios (OR) and 95% confidence interval (CI). Eight studies documenting a total of 1351 RA cases and 1585 controls were included in this meta-analysis. In the overall analysis, a significant association between the PADI4 -92C/G polymorphism and RA was found in the Chinese population (G vs C: OR=1.32, 95%CI=1.02-1.71; GG+CG vs CC: OR=1.75, 95%CI=1.20-2.53). The subgroup analyses stratified by geographic area(s) and source of controls revealed significant results in South China, in hospital-based studies and population-based studies. In summary, this meta-analysis suggested that PADI4 -92C/G polymorphism may be associated with the RA incidence in the Chinese population, especially for South China. Further studies conducted on other ethnic groups are required for definite conclusions.

Association of PTPN22 rs2476601 polymorphism with rheumatoid arthritis and celiac disease in Khuzestan Province, Southwestern Iran

Background: Single-nucleotide polymorphism [SNP] rs2476601 within protein tyrosine phosphatase non-receptor type 22 gene [PTPN22] has been shown to be a risk factor for different autoimmune diseases. This study explored the association of 1858 C/T SNP with rheumatoid arthritis [RA] and celiac disease [CD] in a region covering southwest of Iran

Methods: Totally, 52 patients with CD, 120 patients with RA, and 120 healthy subjects were selected. The samples were genotyped for the rs2476601 in PTPN22 gene using the tetra-amplification refractory mutation system polymerase chain reaction

Results: The frequency of +1858T risk allele was significantly increased in both RA [P=0.021, OR=2.56, 95%CI=1.19-5.47] and CD [P=0.002, OR=3.87, 95%CI=1.68-8.95] patients, as compared to the control group. However, no association was found between the +1858C/T PTPN22 gene SNP and the anticyclic citrullinated peptide and rheumatoid factor positivity in RA patients

Conclusions: PTPN22 gene could play a crucial role in people's susceptibility to certain autoimmune diseases