Patients with ankylosing spondylitis present a distinct CD8 T cell subset with osteogenic and cytotoxic potential.

OBJECTIVES Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease affecting mainly the axial skeleton. Peripheral involvement (arthritis, enthesitis and dactylitis) and extra-musculoskeletal manifestations, including uveitis, psoriasis and bowel inflammation, occur in a relevant proportion of patients. AS is responsible for chronic and severe back pain caused by local inflammation that can lead to osteoproliferation and ultimately spinal fusion. The association of AS with the human leucocyte antigen-B27 gene, together with elevated levels of chemokines, CCL17 and CCL22, in the sera of patients with AS, led us to study the role of CCR4+ T cells in the disease pathogenesis. METHODS CD8+CCR4+ T cells isolated from the blood of patients with AS (n=76) or healthy donors were analysed by multiparameter flow cytometry, and gene expression was evaluated by RNA sequencing. Patients with AS were stratified according to the therapeutic regimen and current disease score. RESULTS CD8+CCR4+ T cells display a distinct effector phenotype and upregulate the inflammatory chemokine receptors CCR1, CCR5, CX3CR1 and L-selectin CD62L, indicating an altered migration ability. CD8+CCR4+ T cells expressing CX3CR1 present an enhanced cytotoxic profile, expressing both perforin and granzyme B. RNA-sequencing pathway analysis revealed that CD8+CCR4+ T cells from patients with active disease significantly upregulate genes promoting osteogenesis, a core process in AS pathogenesis. CONCLUSIONS Our results shed light on a new molecular mechanism by which T cells may selectively migrate to inflammatory loci, promote new bone formation and contribute to the pathological ossification process observed in AS

Patients with ankylosing spondylitis present a distinct CD8 T cell subset with osteogenic and cytotoxic potential

OBJECTIVES Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease affecting mainly the axial skeleton. Peripheral involvement (arthritis, enthesitis and dactylitis) and extra-musculoskeletal manifestations, including uveitis, psoriasis and bowel inflammation, occur in a relevant proportion of patients. AS is responsible for chronic and severe back pain caused by local inflammation that can lead to osteoproliferation and ultimately spinal fusion. The association of AS with the human leucocyte antigen-B27 gene, together with elevated levels of chemokines, CCL17 and CCL22, in the sera of patients with AS, led us to study the role of CCR4$^{+}$ T cells in the disease pathogenesis. METHODS CD8$^{+}$CCR4$^{+}$ T cells isolated from the blood of patients with AS (n=76) or healthy donors were analysed by multiparameter flow cytometry, and gene expression was evaluated by RNA sequencing. Patients with AS were stratified according to the therapeutic regimen and current disease score. RESULTS CD8$^{+}$CCR4$^{+}$ T cells display a distinct effector phenotype and upregulate the inflammatory chemokine receptors CCR1, CCR5, CX3CR1 and L-selectin CD62L, indicating an altered migration ability. CD8$^{+}$CCR4$^{+}$ T cells expressing CX3CR1 present an enhanced cytotoxic profile, expressing both perforin and granzyme B. RNA-sequencing pathway analysis revealed that CD8$^{+}$CCR4$^{+}$ T cells from patients with active disease significantly upregulate genes promoting osteogenesis, a core process in AS pathogenesis. CONCLUSIONS Our results shed light on a new molecular mechanism by which T cells may selectively migrate to inflammatory loci, promote new bone formation and contribute to the pathological ossification process observed in AS

The role of CD8+CCR4+ T-cells in axial spondyloarthritis

Axial spondyloarthritis (AxSpA) is an inflammatory disease affecting the axial skeleton. The infiltrate of T-cells in the structural lesions has been found to contribute to bone remodeling, but consensus relating the functional contribution of different T-cell subsets to pathogenesis has not been reached yet. Aim of the project was to characterize circulating T-cells and their homing markers from axSpA patients in order to identify cellular populations that could migrate to inflamed tissues and be implicated in axSpA. We found an altered proportion of circulating naïve and memory T-cells in axSpA patients, and a skew in favor of CD8+ T-cells expressing the chemokine receptor CCR4. Since CCL17 and CCL22, the two ligands for CCR4, are found to be elevated in the sera of axSpA patients, we investigated in details the role of CD8+CCR4+ T cells in axSpA. Our data showed that circulating CD8+CCR4+ T-cells display an effector memory phenotype and express homing markers for tissues that are target of the disease. Noteworthy, CD8+CCR4+ T cells from axSpA patients were activated, expressed markers of proliferation and acquired a cytotoxic phenotype, as demonstrated by the increased production of granzyme and perforin. CD8+CCR4+ T cells from axSpA patients upregulate the transcription of genes involved in bone mineralization and downregulate genes involved in osteoclast differentiation, indicating their possible involvement in bone remodeling. Furthermore, CD8+CCR4+ T cells stimulated with PMA and ionomycin were able to produce and release TNF and IL-8, two cytokines involved in osteoclastogenesis, indicating that CD8+CCR4+ T-cells after stimulation would be able to promote osteoclasts differentiation and neutrophils recruitment. Taken together our data suggest that CD8+CCR4+ T cells might exert a pathogenic role in axSpA, by releasing mediators of tissue damage, bone remodeling and recruitment of other pro inflammatory cells

From osteoarthritic synovium to synovial-derived cells characterization: synovial macrophages are key effector cells

The aim of the study was to characterize synovial cells from OA synovium with low-grade and moderate-grade synovitis and to define the role of synovial macrophages in cell culture

New wearable system for step-counting telemonitoring and telerehabilitation based on the Codivilla spring

During stroke rehabilitation at home, the most used equipment is the Codivilla spring for both bilateral and one-side stroke damage. A novel Codivilla spring prosthesis has been electronically sensorized in order to allow new functionalities pertinent to telerehabilitation, such as the step counting and biofeedback mapping of gait-phases. The principal elements of the electronics are a couple of force-sensing resistors affixed in the plantar area of the prosthesis, and a wearable unit with a microprocessor-based on Microchip technology (Microchip Technology, Inc., Chandler, AZ) for data processing and a telemetric system based on Aurel technology (Aurel, Modigliana, Italy) for data tansfer. While ambulating, the foot-sensing resistors detect the pressure of the foot-tip and heel. The microprocessor provides step-counting on the basis of an algorithm. The microprocessor also drives two vibrotactile actuators (one at the foot-tip and the other at the heel). These actuators are fixed at the level of the belt directly in contact with the skin and give biofeedback mapping of the gait-phases to the patient wearing the prosthesis, who can then walk without looking at his or her feet. The sensorized prosthesis was tested on six subjects undergoing stroke rehabilitation at level 2 of the Tinetti test. These subjects performed five repetitions of 100 steps with three different instructions (fast, slow, and normal). The mean error was lower than 0.6%. A test conducted by means of Cosmed devices (Cosmed USA, Chicago, IL) also showed that the biofeedback function provided by means of the actuators diminished the energy expenditure by 0.7% in mean value. The next phase will be the optimization of the equipment for long-term medical application in a patient's home

Emerging Players at the Intersection of Chondrocyte Loss of Maturational Arrest, Oxidative Stress, Senescence and Low-Grade Inflammation in Osteoarthritis

The prevalence of Osteoarthritis (OA) is increasing because of the progressive aging and unhealthy lifestyle. These risk factors trigger OA by removing constraints that keep the tightly regulated low turnover of the extracellular matrix (ECM) of articular cartilage, the correct chondrocyte phenotype, and the functionality of major homeostatic mechanisms, such as mitophagy, that allows for the clearance of dysfunctional mitochondria, preventing increased production of reactive oxygen species, oxidative stress, and senescence. After OA onset, the presence of ECM degradation products is perceived as a “danger” signal by the chondrocytes and the synovial macrophages that release alarmins with autocrine/paracrine effects on the same cells. Alarmins trigger innate immunity in the joint, with important systemic crosstalks that explain the beneficial effects of dietary interventions and improved lifestyle. Alarmins also boost low-grade inflammation: the release of inflammatory molecules and chemokines sustained by continuous triggering of NF-κB within an altered cellular setting that allows its higher transcriptional activity. Chemokines exert pleiotropic functions in OA, including the recruitment of inflammatory cells and the induction of ECM remodeling. Some chemokines have been successfully targeted to attenuate structural damage or pain in OA animal models. This represents a promising strategy for the future management of human OA

MicroRNAs and Autophagy: Fine Players in the Control of Chondrocyte Homeostatic Activities in Osteoarthritis

Osteoarthritis (OA) is a debilitating degenerative disease of the articular cartilage with a multifactorial etiology. Aging, the main risk factor for OA development, is associated with a systemic oxidative and inflammatory phenotype. Autophagy is a central housekeeping system that plays an antiaging role by supporting the clearance of senescence-associated alterations of macromolecules and organelles. Autophagy deficiency has been related to OA pathogenesis because of the accumulation of cellular defects in chondrocytes. Microribonucleic acids (microRNAs or miRs) are a well-established class of posttranscriptional modulators belonging to the family of noncoding RNAs that have been identified as key players in the regulation of cellular processes, such as autophagy, by targeting their own cognate mRNAs. Here, we present a state-of-the-art literature review on the role of miRs and autophagy in the scenario of OA pathogenesis. In addition, a comprehensive survey has been performed on the functional connections of the miR network and the autophagy pathway in OA by using "microRNA," "autophagy," and "osteoarthritis" as key words. Discussion of available evidence sheds light on some aspects that need further investigation in order to reach a more comprehensive view of the potential of this topic in OA