Involvement of Mitochondrial Dysfunction in the Inflammatory Response in Human Mesothelial Cells from Peritoneal Dialysis Effluent.

Recent studies have related mitochondrial impairment with peritoneal membrane damage during peritoneal dialysis (PD) therapy. Here, we assessed the involvement of mitochondrial dysfunction in the inflammatory response in human mesothelial cells, a hallmark in the pathogenesis of PD-related peritoneal membrane damage. Our ex vivo studies showed that IL-1β causes a drop in the mitochondrial membrane potential in cells from peritoneal effluent.

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis.

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress.

Mitochondrial Dysfunction Plays a Relevant Role in Pathophysiology of Peritoneal Membrane Damage Induced by Peritoneal Dialysis.

Preservation of the peritoneal membrane is an essential determinant of the long-term outcome of peritoneal dialysis (PD). Epithelial-to-mesenchymal transition (EMT) plays a central role in the pathogenesis of PD-related peritoneal membrane injury. We hypothesized that mitochondria may be implicated in the mechanisms that initiate and sustain peritoneal membrane damage in this setting.

Autophagy Activation by Resveratrol Reduces Severity of Experimental Rheumatoid Arthritis.

Scope: Previous work reported that dietary supplementation with resveratrol lowers synovial hyperplasia, inflammatory and oxidative damage in an antigen-induced arthritis (AIA) model. Here, it is investigated whether resveratrol can regulate the abnormal synovial proliferation by inducing autophagy and controlling the associated inflammatory response.

Methods And Results: Animals treated with resveratrol 8 weeks before AIA induction show the highest significant signal for microtubule-associated protein 1 light chain 3 by confocal microscopy.

Role of mitochondrial dysfunction on rheumatic diseases.

Rheumatic and musculoskeletal diseases are a heterogeneous group of disorders affecting joint tissues and in some cases even organs, some of them being among the most common diseases worldwide. Mitochondria are the organelles considered as powerhouse of cells providing energy to the organism mainly through oxidative phosphorylation. However, mitochondria are also involved in crucial pathways responsible for maintaining cell physiology, such as the activation of metabolic and survival signaling, and innate and adaptive immune response.

The mitochondrial inhibitor oligomycin induces an inflammatory response in the rat knee joint.

Background: Recent findings support a connection between mitochondrial dysfunction and activation of inflammatory pathways in articular cells. This study investigates in vivo in an acute model whether intra-articular administration of oligomycin, an inhibitor of mitochondrial function, induces an oxidative and inflammatory response in rat knee joints.

Methods: Oligomycin was injected into the rat left knee joint on days 0, 2, and 5 before joint tissues were obtained on day 6.

Resveratrol lowers synovial hyperplasia, inflammatory markers and oxidative damage in an acute antigen-induced arthritis model.

Objective: The present study aimed to determine the protective effects of dietary supplementation with resveratrol (RSV) in an acute antigen-induced arthritis (AIA) model.

Methods: Rats were randomly divided into three groups: control, AIA and RSV-treated AIA group. RSV (12.

A pathogenetic role for endothelin-1 in peritoneal dialysis-associated fibrosis.

In patients undergoing peritoneal dialysis (PD), chronic exposure to nonphysiologic PD fluids elicits low-grade peritoneal inflammation, leading to fibrosis and angiogenesis. Phenotype conversion of mesothelial cells into myofibroblasts, the so-called mesothelial-to-mesenchymal transition (MMT), significantly contributes to the peritoneal dysfunction related to PD. A number of factors have been described to induce MMT in vitro and in vivo, of which TGF-β1 is probably the most important.

Mitochondrial dysfunction promotes and aggravates the inflammatory response in normal human synoviocytes.

Objectives: In RA, synoviocytes cause increased oxidative stress, leading to mitochondrial alterations that may participate in the pathogenesis of RA. Here we investigated whether mitochondrial dysfunction induces inflammatory responses in cultured normal human synoviocytes, a hallmark of RA.

Methods: Mitochondrial dysfunction was induced with the inhibitor oligomycin.

Mitochondrial dysfunction and the inflammatory response.

Inflammation has been linked to multiple degenerative and acute diseases as well as the aging process. Moreover, mitochondrial alterations play a central role in these processes. Mitochondria have an important role in pro-inflammatory signaling; similarly, pro-inflammatory mediators may also alter mitochondrial function.

Mitochondrial dysfunction increases inflammatory responsiveness to cytokines in normal human chondrocytes.

Objective: Alterations in mitochondria play a key role in the pathogenesis of osteoarthritis (OA). The role of inflammation in the progression of OA has also acquired important new dimensions. This study was undertaken to evaluate the potential role of mitochondrial dysfunction in increasing the inflammatory response of normal human chondrocytes to cytokines.

Effect of nitric oxide on mitochondrial activity of human synovial cells.

Background: Nitric oxide (NO) is a messenger implicated in the destruction and inflammation of joint tissues. Cartilage and synovial membrane from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) have high levels of NO. NO is known to modulate various cellular pathways and, thus, inhibit the activity of the mitochondrial respiratory chain (MRC) of chondrocytes and induce the generation of reactive oxygen species (ROS) and cell death in multiple cell types.

Clinical significance of high levels of soluble tumour necrosis factor-α receptor-2 produced by alternative splicing in rheumatoid arthritis: a longitudinal prospective cohort study.

Objectives: We investigated whether serum levels of an alternatively spliced soluble (s)TNF receptor-2 (DS-TNFR2) affected the clinical response to anti-TNF-α therapy, classical DMARDs or radiological evidence of disease progression in patients with RA.

Methods: We included 116 patients with RA. Cohort 1: 52 DMARD-naïve early RA patients [mean (s.

Proteomic analysis by two-dimensional electrophoresis to identify the normal human chondrocyte proteome stimulated by tumor necrosis factor alpha and interleukin-1beta.

Objective: To determine the intracellular proteome of normal human chondrocytes stimulated with interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha) and to ascertain differences in the protein expression patterns of these 2 cytokines.

Methods: Normal human knee cartilage chondrocytes were incubated for 48 hours without stimulation or stimulated with IL-1beta (5 ng/ml) or with TNFalpha (10 ng/ml). For each culture condition, protein extracts from 4 normal subjects were pooled and resolved using 2-dimensional electrophoresis.

Mitochondrial dysfunction activates cyclooxygenase 2 expression in cultured normal human chondrocytes.

Objective: Mitochondrial alterations play a key role in the pathogenesis of osteoarthritis (OA). This study evaluated a potential role of mitochondrial respiratory chain (MRC) dysfunction in the inflammatory response of normal human chondrocytes.

Methods: Commonly used inhibitors of the MRC were utilized to induce mitochondrial dysfunction in normal human chondrocytes.

Proteomic analysis of human osteoarthritic chondrocytes reveals protein changes in stress and glycolysis.

Osteoarthritis (OA) is characterized by cartilage degradation. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. The aim of this study was to analyze, by a proteomic approach, the changes that are characteristic of OA chondrocytes, and to identify new OA-related proteins.

[Evidence of inflammatory mechanisms in osteoarthritis].

Classically, osteoarthritis (OA) is not considered an inflammatory arthropathy, because of the presence of a small number of neutrophils in the synovial fluid and the absence of systemic manifestations of inflammation. Besides, the characteristics of articular cartilage (avascular, alymphatic and aneural) do disable to fulfill with the classical signs of inflammation (redness, swelling, heat, pain). However, thanks to development of molecular and cellular biology, there are multiple studies which shown that different proinflammatory mediators, such as the cytokines IL-1β and TNFα, could be important in the development of this disease.

Decreased metalloproteinase production as a response to mechanical pressure in human cartilage: a mechanism for homeostatic regulation.

Articular cartilage is optimised for bearing mechanical loads. Chondrocytes are the only cells present in mature cartilage and are responsible for the synthesis and integrity of the extracellular matrix. Appropriate joint loads stimulate chondrocytes to maintain healthy cartilage with a concrete protein composition according to loading demands.

Mitochondrial dysfunction in osteoarthritis.

In osteoarthritis (OA) a time or age dependent process leads to aberrant cartilage structure which is characterized by reduced number of chondrocytes, loss of existing cartilage extracellular matrix, the production of matrix with abnormal composition and pathologic matrix calcification. Because chondrocyte matrix synthesis and mineralization are modulated by the balance between ATP generation and consumption, the mechanism by which chondrocytes generate energy have been a topic of interest. The analysis of mitochondrial respiratory chain (MRC) activity in OA chondrocytes shows a significant decrease in complexes II and III compared to normal chondrocytes.

Proteomic characterization of human normal articular chondrocytes: a novel tool for the study of osteoarthritis and other rheumatic diseases.

Articular cartilage is composed of cells and an extracellular matrix. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. There is currently a great lack of knowledge about the chondrocyte proteome.

Pig chondrocyte xenoimplants for human chondral defect repair: an in vitro model.

The objective of this study was to evaluate the use of cultured porcine chondrocyte xenotransplantation for the repair of human chondral defects. Two-millimeter-diameter defects were drilled into explants of femoral cartilage from healthy adult donors. No cells were implanted in the chondral defects of the control group, while pig chondrocytes from normal femoral cartilage were deposited into the treated chondral defects.

Xeno-implantation of pig chondrocytes into rabbit to treat localized articular cartilage defects: an animal model.

Articular cartilage has only a limited ability to regenerate. The transplantation of autologous chondrocytes is currently used to treat focal defects in human articular cartilage, although use of organs, tissues, or cells from different species is being investigated as an alternative treatment. The object of this study was to use xeno-transplantation of cultured pig chondrocytes for the repair of rabbit chondral defects, and to analyze the significance of tissue rejection in this animal model.

Mitochondrial respiratory activity is altered in osteoarthritic human articular chondrocytes.

Objective: Osteoarthritis (OA) is a degenerative rheumatic disease that is associated with extracellular matrix degradation and chondrocyte apoptosis in the articular cartilage. The role of mitochondria in degenerative diseases is widely recognized. We undertook this study to evaluate mitochondrial function in normal and OA chondrocytes and to examine age-related changes in mitochondria.