Positive transcriptional response on inflammation and joint remodelling influenced by physical exercise in proteoglycan-induced arthritis: An animal study.

AIMS: To assess the effect of physical exercise (PE) on the histological and transcriptional characteristics of proteoglycan-induced arthritis (PGIA) in BALB/c mice. METHODS: Following PGIA, mice were subjected to treadmill PE for ten weeks. The tarsal joints were used for histological and genetic analysis through microarray technology. The genes differentially expressed by PE in the arthritic mice were obtained from the microarray experiments. Bioinformatic analysis in the DAVID, STRING, and Cytoscape bioinformatic resources allowed the association of these genes in biological processes and signalling pathways. RESULTS: Arthritic mice improved their physical fitness by 42.5% after PE intervention; it induced the differential expression of 2,554 genes. The bioinformatic analysis showed that the downregulated genes (n = 1,371) were significantly associated with cellular processes that mediate the inflammation, including Janus kinase-signal transducer and activator of transcription proteins (JAK-STAT), Notch, and cytokine receptor interaction signalling pathways. Moreover, the protein interaction network showed that the downregulated inflammatory mediators interleukin (IL) 4, IL5, IL2 receptor alpha (IL2rα), IL2 receptor beta (IL2rß), chemokine ligand (CXCL) 9, and CXCL12 were interacting in several pathways associated with the pathogenesis of arthritis. The upregulated genes (n = 1,183) were associated with processes involved in the remodelling of the extracellular matrix and bone mineralization, as well as with the processes of aerobic metabolism. At the histological level, PE attenuated joint inflammatory infiltrate and cartilage erosion. CONCLUSION: Physical exercise influences parameters intimately linked to inflammatory arthropathies. Research on the effect of PE on the pathogenesis process of arthritis is still necessary for animal and human models.Cite this article: Bone Joint Res. 2020;9(1):36-48.

Prevalence of rheumatic diseases in Raramuri people in Chihuahua, Mexico: a community-based study.

This study aimed to determine the prevalence of musculoskeletal (MSK) pain and rheumatic diseases in the Raramuri population (also known as Tarahumaras) who are an indigenous group in the northern state of Chihuahua in Mexico. We used the Community-Oriented Program for Control of Rheumatic Diseases (COPCORD) methodology. An analytical cross-sectional study was conducted including indigenous Raramuri aged ≥18 years from communities settled in Chihuahua City. Subjects with positive MSK pain were evaluated by primary care physicians and rheumatologists. Demographic and occupational factors such as gender and job type associated with rheumatic disease were investigated. A total of 380 indigenous Raramuri (mean age 33.6 ± 13.1 years; 37.9 % male) were interviewed. Seventy-six individuals (20 %) reported MSK pain in the last 7 days. Pain intensity was reported as "severe" and "the most severe" in 30 % of the cases. Fifty-six individuals (14.7 %) reported pain in the past and 86 (22.6 %) had either past or current pain. The prevalence of rheumatic diseases was 10.5 %. Diagnosed diseases were osteoarthritis (6.6 %), low back pain (1.6 %), spondyloarthritis (0.8 %), rheumatoid arthritis (0.5 %), non-specific arthritis (0.5 %), rheumatic regional pain syndromes (0.3 %), and fibromyalgia (0.3 %). Rheumatic disease was associated with the following variables: age (odds ratio (OR) 1.04, 95 % confidence interval (CI) 1.02-1.08; p = 0.006), family history of rheumatic symptoms (OR 6.9; 95 % CI 2.6-18.7; p < 0.001), and Health Assessment Questionnaire-Disability Index (OR 28.9; 95 % CI 2.8-289.7; p < 0.001). A high prevalence of non-traumatic MSK pain suggests the need for a rheumatic disease prevention program in the Raramuri people in Chihuahua, Mexico.

Bone lineage proteins in the entheses of the midfoot in patients with spondyloarthritis.

OBJECTIVE: Patients with juvenile-onset spondyloarthritis (SpA) may develop ankylosis of the midfoot resembling the spinal changes seen in patients with ankylosing spondylitis (AS). The study of the histopathology of the feet of patients with tarsitis could help us understand the pathogenesis of bone formation in affected structures in the SpA. The objective of our study was to describe the histopathologic characteristics of the midfoot in patients with tarsitis associated with SpA. METHODS: We obtained synovial sheaths, entheses, and bone samples from 20 patients with SpA with midfoot pain/tenderness and swelling. Tissue samples underwent H&E staining; immunohistochemistry for CD3, CD4, CD8, CD68, and CD20 cell identification; and immunofluorescence for bone lineage proteins, including osteocalcin, osteopontin, parathyroid hormone-related protein, bone sialoprotein, and alkaline phosphatase. RESULTS: Slight edema and hyalinization were found in some tendon sheaths, and few inflammatory cells were detected in the entheses. In bones, we found some changes suggesting osteoproliferation, including endochondral and intramembranous ossification, but no inflammatory cells. In entheses showing bone proliferation, we detected osteocalcin and osteopontin in cells with a fibroblast-mesenchymal phenotype, suggesting the induction of entheseal cells toward an osteoblast phenotype. CONCLUSION: Osteoproliferation and abnormal expression of bone lineage proteins, but no inflammatory infiltration, characterize midfoot involvement in patients with SpA. In this sense, tarsitis (or ankylosing tarsitis) resembles the involvement of the spine in patients with AS. Ossification may be in part explained by the differentiation of mesenchymal entheseal cells toward the osteoblastic lineage.

Assessment of different decalcifying protocols on Osteopontin and Osteocalcin immunostaining in whole bone specimens of arthritis rat model by confocal immunofluorescence.

Confocal immunofluorescence is a valuable technique for the detection of relevant molecules in the pathogenesis of arthritis in rat models; however, it requires efficient processing of tissues including bone decalcification. The decalcification process must ensure the complete removal of calcium and also a proper preservation of cellular structures and, specially, the antigenicity of the tissue to allow the immunodetection of the molecules of interest. In the present study, we evaluated the effect of four different decalcifying solutions: the Morse´s solution, 10% EDTA (pH 7.4), 7% HCl/2% EDTA and 5% Nitric acid, as well as four different treatments of the tissues (including microwave irradiation) in the processes of decalcification for large pieces of adult rat bones (hind paw, fore paw, knee and column). We assessed the time of decalcification, the easiness of slicing, the morphological preservation and finally, the antigenicity of two different bone proteins (Osteopontin (OPN) and Osteocalcin (OC)) measured by its immunofluorescence intensity under controlled confocal microscopy conditions. Our results showed that the specimen size and the presence of skin are critical factors for the rate of decalcification, and no significant benefit was found if microwave irradiation is applied to the tissue. The comprehensive statistical analysis showed that the optimal solution for the detection of OPN and OC by confocal immunofluorescence is the 5% Nitric Acid, and followed by 10% EDTA (pH 7.4), Ana Morse solution and 7% HCl/2% EDTA.

Treatment of multicentric reticulohistiocytosis with tocilizumab.

Multicentric reticulohistiocytosis (MRH) is a rare multisystem, granulomatous debilitating disease. It affects the skin with a nodular diffuse dermatitis and the joints with a severe, potentially deforming, and handicapping arthritis. No standardized therapy exists, it is a disease with heterogeneous severity, and therefore, a diversity of therapeutic responses has been published.Current experience with anti-tumor necrosis factor agents in disease-modifying antirheumatic drug-refractory MRH cases is encouraging, and other agents such as bisphosphonates have proven effective as well. Histological analysis of the granulomatous inflammatory lesions have shown the presence of cytokines including tumor necrosis factor α, interleukin 1, and interleukin 6; the presence of the latter makes tocilizumab a plausible alternative.In this article, we report a 35-year-old woman with MRH refractory to a combined scheme of prednisone and methotrexate, both at high doses, and who received tocilizumab achieving remission on both cutaneous and articular symptoms. Our patient markedly improved by the second infusion (8 mg/kg monthly), and after 9 infusions, she remained asymptomatic; no toxicity was detected. Tocilizumab could be an alternative for disease-modifying antirheumatic drug-refractory MRH.

Lactoferrin: structure, function and applications.

Lactoferrin (LF) is an 80 kDa iron-binding glycoprotein of the transferrin family that is expressed in most biological fluids and is a major component of the mammalian innate immune system. Its protective effects range from direct antimicrobial activities against a large panel of microorganisms, including bacteria, viruses, fungi and parasites, to anti-inflammatory and anticancer activities. These extensive activities are made possible by mechanisms of action utilising not only the capacity of LF to bind iron but also interactions of LF with molecular and cellular components of both host and pathogens. This review summarises the putative antimicrobial mechanisms, clinical applications and heterologous expression models for LF.