Stability of housekeeping genes in inflamed joints of spontaneous and collagen-induced arthritis in DBA/1 mice.

BACKGROUND: DBA/1 mice arthritis models have contributed to our understanding of human rheumatoid arthritis (RA) and spondyloarthritis (SpA) pathogenesis, as well as the exploration of therapeutic targets for treatment. Quantitative polymerase chain reaction (qPCR) is an indispensable tool in molecular research, which requires reference gene validation to obtain consistent and reliable results. OBJECTIVE: To determine the stability of candidate reference genes for qPCR in the joint of collagen-induced arthritis (CIA) and spontaneous arthritis (SpAD) DBA/1 mice. METHODS: The expression of eleven commonly used reference genes (ACTB, B2M, EF1a, GAPDH, HMBS, HPRT, PPIB, RPL13A, SDHA, TBP, and YWHAZ) was assessed by qPCR and the data were compared using delta-Ct methods and the geNorm, NormFinder, and RefFinder software packages. Genes identified as stable in each model were used for the quantification of inflammatory cytokines RESULTS: The gene stabilities differed between the two arthritis models in the DBA/1 mice. EF1a and RPL13A were the best reference genes for SpAD, while RPL13A and TBP were the best for the CIA. These genes allowed the data normalization for the quantification of the inflammatory cytokines in both models; these results showed an increase in the expression of IL-1B, IL-12B, IL-17A, and IL-6 in the inflamed joints. The use of different primer sequences for the same reference gene resulted in different relative quantification values. CONCLUSION: This study demonstrates that commonly used reference genes may not be suitable for arthritic tissues from DBA/1 mice, and strengthening the principle that meticulous validation of reference genes is essential before each experiment to obtain valid and reproducible qPCR data for analysis or interpretation.

Alteraciones temporomandibulares y odontológicas en pacientes con artritis reumatoide / Temporomandibular and odontological abnormalities in patients with rheumatoid arthritis

OBJETIVO: Caracterizar las afecciones orofaciales en pacientes con artritis reumatoide (AR) y compararlas con las presentes en pacientes sin la enfermedad de la ciudad de Chihuahua, Chihuahua, México. MÉTODOS: El estudio incluyó a 30 pacientes con diagnóstico de AR y 30 pacientes consecutivos en una consulta de odontología. A través de una revisión clínica odontológica, se compararon entre los grupos variables relacionadas con: 1) trastornos clínicos y radiográficos de la articulación temporomandibular, 2) análisis biomecánico craneocervical, 3) estado de la dentición y necesidades de tratamiento, 4) estado periodontal, 5) estado de higiene oral y 6) dolor facial. Además se determinó la asociación entre las variables estudiadas a través de pruebas de correlación. RESULTADOS: Los pacientes con AR tuvieron una mayor prevalencia de alteraciones en la articulación temporomandibular, tanto clínicas (100 vs. 60%; p < 0,001) como radiográficas incluyendo erosiones (50 vs. 16; p = 0,010), en comparación con la población de referencia. Además los pacientes con AR tuvieron mayor cantidad de pérdidas dentales (6,9±5,7 vs. 3±2; p = 0,001), caries (13,4±5,4 vs. 4,9±6,5; p = 0,001), periodontitis (1,3±0,9 vs. 0,8±0,8; p = 0,015), higiene oral deficiente (43,3 vs. 13,3%; p = 0,005) y más dolor facial (66,7 vs. 20%; p < 0,001). El análisis de cefalometría de Rocabado mostró diferencias en el ángulo craneocervical y triángulo hioideo entre AR y controles. Se obtuvieron correlaciones significativas entre las alteraciones orales y las temporomandibulares. CONCLUSIONES: Los pacientes con AR mostraron un mayor deterioro orofacial, lo que refleja la importancia de atención multidisciplinaria incluyendo la evaluación odontológica periódica

OBJECTIVE: To characterize the orofacial abnormalities in patients with rheumatoid arthritis (RA) and compare them with those in a reference population. METHODS: The study included 30 RA patients and 30 consecutive patients in an odontology clinic in whom RA was ruled out. Patients underwent a clinical dental examination which included: 1) clinical and radiographic abnormalities of the temporomandibular joint; 2) biomechanical craniocervical analysis; 3) state of dentition and treatment needs; 4) periodontal status; 5) oral hygiene status; and 6) facial pain, which was compared among study groups. In addition, the association between the variables studied was determined through correlation tests. RESULTS: Patients with RA showed a higher prevalence of temporomandibular abnormalities, both clinical (100.0% vs. 60.0%, P<.001) and radiographic, including erosions (50.0% vs. 16.0%, P=.010), compared with individuals in the control group. Likewise, patients with RA had a greater number of missing teeth (6.9±5.7 vs. 3.0±2.0, P=.001), more caries (13.4±5.4 vs. 4.9±6.5, P=.001), periodontitis (1.3±0.9 vs. 0.8±0.8, P=.015), poorer oral hygiene (43.3% vs. 13.3%, P=.005) and greater facial pain (66.7% vs. 20.0%, P <.001). The cephalometric analysis of Rocabado showed differences in the craniocervical angle and hyoid triangle between RA and controls. Significant correlations were obtained between oral and temporomandibular abnormalities. CONCLUSIONS: Patients with RA showed a greater orofacial deterioration, which reflects the importance of multidisciplinary care, including periodic dental examination

Oral health and orofacial function in patients with rheumatoid arthritis.

The aim of the study was to describe the oral health and orofacial function of Mexican patients with rheumatoid arthritis (RA) and their association with clinical and radiological aspects of the disease. Patients with RA received a complete odontological exam, which also included a clinical and radiographic assessment of the temporomandibular joint (TMJ). The rheumatologic assessment included detailed profiling of the disease and serological and radiographic parameters. The study included 62 RA patients; the median (min-max) age was 51 (18-72) years old and 8.5 (1-39) years of disease duration. The 63.6% of the patients had DAS28 ≥ 3.2, and a median (min-max) of Sharp/van der Heijde score (SvdHS) of 41 (0-214). 98.3% of the patients presented caries, which were severe in 53.3% of the cases. The 73.8% of the patients were missing teeth due to caries, with a median (min-max) of 4 (0-32) teeth missing per patient. Oral hygiene was classified as bad in 49.1% of patients and only 15.3% of them had a healthy periodontium. The TMJ function was abnormal in 98.4% of the patients and 62.9% of them presented moderate or severe TMJ disorder (TMD). The radiographic damage of the TMJ correlated positively with the SvdHS. No correlations were found between disease activity or structural progression and orofacial variables, including periodontitis. There are severe oral and orofacial health problems in RA patients despite having medical attention for their disease. Multidisciplinary management remains an area of opportunity for both the medical specialists and the health system in our country.

Temporomandibular and Odontological Abnormalities in Patients with Rheumatoid Arthritis. / Alteraciones temporomandibulares y odontológicas en pacientes con artritis reumatoide.

OBJECTIVE: To characterize the orofacial abnormalities in patients with rheumatoid arthritis (RA) and compare them with those in a reference population. METHODS: The study included 30 RA patients and 30 consecutive patients in an odontology clinic in whom RA was ruled out. Patients underwent a clinical dental examination which included: 1) clinical and radiographic abnormalities of the temporomandibular joint; 2) biomechanical craniocervical analysis; 3) state of dentition and treatment needs; 4) periodontal status; 5) oral hygiene status; and 6) facial pain, which was compared among study groups. In addition, the association between the variables studied was determined through correlation tests. RESULTS: Patients with RA showed a higher prevalence of temporomandibular abnormalities, both clinical (100.0% vs. 60.0%, P<.001) and radiographic, including erosions (50.0% vs. 16.0%, P=.010), compared with individuals in the control group. Likewise, patients with RA had a greater number of missing teeth (6.9±5.7 vs. 3.0±2.0, P=.001), more caries (13.4±5.4 vs. 4.9±6.5, P=.001), periodontitis (1.3±0.9 vs. 0.8±0.8, P=.015), poorer oral hygiene (43.3% vs. 13.3%, P=.005) and greater facial pain (66.7% vs. 20.0%, P <.001). The cephalometric analysis of Rocabado showed differences in the craniocervical angle and hyoid triangle between RA and controls. Significant correlations were obtained between oral and temporomandibular abnormalities. CONCLUSIONS: Patients with RA showed a greater orofacial deterioration, which reflects the importance of multidisciplinary care, including periodic dental examination.

Exercise Exacerbates the Transcriptional Profile of Hypoxia, Oxidative Stress and Inflammation in Rats with Adjuvant-Induced Arthritis.

Physical exercise (PE) is recommended for Rheumatoid Arthritis (RA), but the molecular and biological mechanisms that impact the inflammatory process and joint destruction in RA remain unknown. The objective of this study was to evaluate the effect of PE on the histological and transcriptional changes in the joints of adjuvant-induced arthritis (AIA) rat model. AIA rats were subjected to PE on a treadmill for eight weeks. The joints were subjected to histological and microarray analysis. The differentially expressed genes (DEGs) by PE in the arthritic rats were obtained from the microarray. The bioinformatic analysis allowed the association of these genes in biological processes and signaling pathways. PE induced the differential expression of 719 genes. The DEGs were significantly associated with pathogenic mechanisms in RA, including HIF-1, VEGF, PI3-Akt, and Jak-STAT signaling pathways, as well as response to oxidative stress and inflammatory response. At a histological level, PE exacerbated joint inflammatory infiltrate and tissue destruction. The PE exacerbated the stressed joint environment aggravating the inflammatory process, the hypoxia, and the oxidative stress, conditions described as detrimental in the RA joints. Research on the effect of PE on the pathogenesis process of RA is still necessary for animal models and human.

DNA Damage and Deficiencies in the Mechanisms of Its Repair: Implications in the Pathogenesis of Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a perplexing and potentially severe disease, the pathogenesis of which is yet to be understood. SLE is considered to be a multifactorial disease, in which genetic factors, immune dysregulation, and environmental factors, such as ultraviolet radiation, are involved. Recently, the description of novel genes conferring susceptibility to develop SLE even in their own (monogenic lupus) has raised the interest in DNA dynamics since many of these genes are linked to DNA repair. Damage to DNA induces an inflammatory response and eventually triggers an immune response, including those targeting self-antigens. We review the evidence that indicates that patients with SLE present higher levels of DNA damage than normal subjects do and that several proteins involved in the preservation of the genomic stability show polymorphisms, some of which increase the risk for SLE development. Also, the experience from animal models reinforces the connection between DNA damage and defective repair in the development of SLE-like disease including characteristic features such as anti-DNA antibodies and nephritis. Defining the role of DNA damage response in SLE pathogenesis might be strategic in the quest for novel therapies.

Hypoxia and its implications in rheumatoid arthritis.

Alterations in tissue oxygen pressure contribute to a number of diseases, including rheumatoid arthritis (RA). Low partial pressure of oxygen, a condition known as hypoxia, is a relevant feature in RA since it is involved in angiogenesis, inflammation, apoptosis, cartilage degradation, energy metabolism, and oxidative damage. Therefore, alterations in hypoxia-related signaling pathways are considered potential mechanisms of disease pathogenesis. The objective of this review is to highlight and update our current knowledge of the role of hypoxia in the pathogenesis of RA. We describe the experimental evidence that RA synovial tissue exists in a hypoxic state, as well as the origin and involvement of synovial hypoxia in different aspects of the pathogenic process.

Oxidative Stress Relevance in the Pathogenesis of the Rheumatoid Arthritis: A Systematic Review.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease whose pathogenic mechanisms remain to be elucidated. The oxidative stress and antioxidants play an important role in the disease process of RA. The study of oxidants and antioxidants biomarkers in RA patients could improve our understanding of disease pathogenesis; likely determining the oxidative stress levels in these patients could prove helpful in assessing disease activity and might also have prognostic implications. To date, the usefulness of oxidative stress biomarkers in RA patients is unclear and the evidence supporting them is heterogeneous. In order to resume and update the information in the status of oxidants and antioxidants and their connection as biomarkers in RA, we performed a systematic literature search in the PubMed database, including clinical trials published in the last five years using the word combination "rheumatoid arthritis oxidative stress". In conclusion, this review supports the fact that the oxidative stress is an active process in RA pathogenesis interrelated to other better known pathogenic elements. However, some controversial results preclude a definite conclusion.

Rheumatic Diseases in Chihuahua, México: A COPCORD Survey.

BACKGROUND: Rheumatic diseases (RDs) represent a global problem for health care systems and patients. Community Oriented Program for Control of Rheumatic Diseases (COPCORD) is a low-cost screening tool for detecting musculoskeletal (MSK) pain and RDs. OBJECTIVE: The aim of this study was to examine the pattern of MSK pain and RDs in clinic population in Chihuahua City, Mexico. METHODS: A cross-sectional study was conducted in 7 primary health clinics using the COPCORD methodology in subjects older than 18 years. People with MSK pain not induced by trauma (positive cases) were evaluated by primary care physicians and rheumatologists. RESULTS: The study included 1006 individuals with a mean age of 46.0 (SD, 15.8) years; 751 (74.7%) were women. Musculoskeletal pain in the previous 7 days was reported by 571 individuals (56.75%; 95% confidence interval [CI], 53.8%-60.1%), and 356 cases (35.4%; 95% CI, 32.5%-38.4%) were COPCORD positive. The mean pain intensity in visual analog scale was 6.62 (SD, 2.4). The most common painful joint was the knee (54.7%; 95% CI, 51.1%-59.0%). Two hundred eighty subjects with MSK pain (49.0%) previously sought medical attention, and 375 (65.7%) were under treatment. Functional impairment was reported by 69.8% of the COPCORD-positive subjects. The prevalence of RDs was 21.4% (95% CI, 18.9%-23.8%). The most prevalent disease was osteoarthritis (10.3%; 95% CI, 8.6%-12.4%), followed by regional pain syndromes (5.5%; 95% CI, 4.1%-7.0%), rheumatoid arthritis (1.4%; 95% CI, 0.8%-2.2%), and mechanical low-back pain (1.4%; 95% CI, 0.7%-2.2%). CONCLUSIONS: Musculoskeletal pain is an important problem that affects our community. The data provided in this study will be presented to the local authorities to help in the development of prevention strategies.

Molecular mechanisms of bone formation in spondyloarthritis.

Spondyloarthritis comprise a group of inflammatory rheumatic diseases characterized by its association to HLA-B27 and the presence of arthritis and enthesitis. The pathogenesis involves both an inflammatory process and new bone formation, which eventually lead to ankylosis of the spine. To date, the intrinsic mechanisms of the pathogenic process have not been fully elucidated, and our progress is remarkable in the identification of therapeutic targets to achieve the control of the inflammatory process, yet our ability to inhibit the excessive bone formation is still insufficient. The study of new bone formation in spondyloarthritis has been mostly conducted in animal models of the disease and only few experiments have been done using human biopsies. The deregulation and overexpression of molecules involved in the osteogenesis process have been observed in bone cells, mesenchymal cells, and fibroblasts. The signaling associated to the excessive bone formation is congruent with those involved in the physiological processes of bone remodeling. Bone morphogenetic proteins and Wnt pathways have been found deregulated in this disease; however, the cause for uncontrolled stimulation remains unknown. Mechanical stress appears to play an important role in the pathological osteogenesis process; nevertheless, the association of other important factors, such as the presence of HLA-B27 and environmental factors, remains uncertain. The present review summarizes the experimental findings that describe the signaling pathways involved in the new bone formation process in spondyloarthritis in animal models and in human biopsies. The role of mechanical stress as the trigger of these pathways is also reviewed.